1. 沸石-模板纳米碳材料用于能源存储与转化 纳米碳材料代表了物理、化学和材料科学领域最热门的话题之一。通过沸石-模板制备纳米碳材料已经发展了20多年。近年来,以沸石为模板的纳米碳的新颖结构和性能不断得到开发,并在能源存储和转化领域也逐渐兴起。在此, 澳门大学汤子康教授 联合 深圳大学张晗教授 、 东北师范大学郎中玲博士 等人,总结了以沸石为模板的纳米碳在先进合成技术、新兴性质和新颖应用中的最新进展:i)由于沸石的多样性,相应纳米碳的结构众多;ii)通过各种合成技术手段,可以获得沸石-模板纳米碳的新特性,例如多级孔隙率、异质原子掺杂和纳米颗粒负载能力;iii)沸石-模板纳米碳的应用也从传统的气体/蒸气吸附技术发展到了先进的能源存储技术,包括锂离子电池、Li-S电池、燃料电池、金属-O 2 电池等。最后,作者展望了沸石-模板纳米碳材料的未来发展趋势及方向。 原文链接: https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202001335 2. 碱金属硫化物作为安全、高容量金属-硫电池的正极 可充电碱金属-硫(M-S)电池因其具有高能量密度和低成本而被公认为是最有前景的下一代储能技术之一。然而,金属多硫化物在有机液体电解质中的溶解以及与金属负极有关的安全性问题极大地阻碍了M-S电池的发展。碱金属硫化物(M 2 S x )作为正极材料,可与各种安全的非碱金属负极配对,例如硅和锡。因此,结合使用的M 2 S x 正极-基M–S电池可以实现高容量和安全性,从而提供了更为可行的电池技术以供实际应用。在这篇综述中, 澳大利亚伍伦贡大学刘华坤/Yun‐\Xiao Wang团队 系统总结了开发M 2 S x 正极-基M–S电池的最新进展,包括M 2 S x 正极的活化方法、M2Sx正极的优化以及电解质和负极材料的改进。此外,还指出了M 2 S x 正极-基M–S电池的未来研究方向。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202001764 3. 可逆交联聚合物粘结剂实现高性能锂-硫电池 由于电池的广泛使用对环境存在一定负面影响,所以电池的可持续性需要纳入电池的系统研究中。在本文中, 美国劳伦斯伯克利国家实验室Liu Gao课题组 通过羧基-氨基离子相互作用使聚丙烯酸和聚乙烯亚胺交联,合成了一种可溶性离子交联聚合物(DICP),并将其作为锂-硫电池的粘结剂。这种相互作用受pH所控制。因此,交联的粘结剂(聚合物)网络可在碱性条件下轻松解离,从而提供了一种简便的策略——通过方便的洗涤方法即可回收有价值的组分。使用回收碳-硫复合材料所制备的硫正极可提供与新鲜电极相当的容量。此外,诸如原位X-射线吸收光谱、原位UV-可见光谱、X-射线光电子能谱和密度泛函理论计算的电池性能和表征,证实了DICP是一种比其商用产品更为有效抑制多硫化物在电解质中溶解的粘结剂。通过将可逆交联聚合物粘结剂用于回收的Li-S电池,其电化学性能得到显著改善,该研究阐明了大规模储能系统的可持续发展。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202003605 4. 核-双壳结构实现高倍率钠存储 具有可控化学成分的核-多壳结构因其较优的电化学性能而备受关注。在此, 中国石油大学(华东)孙道峰/康文裴团队 采用金属-有机框架(MOF)-on-MOF的自模板化策略,制备了具有核-双壳结构的秋葵-状双金属硫化物(Fe 7 S 8 /C@ZnS/N-C@C),其中Fe 7 S 8 /C分布在核中,而ZnS嵌入其中一层。通过层层组装法制备了MOF-on-MOF前驱体,其中具有MIL-53内核、ZIF-8外壳和间苯二酚-甲醛(RF)层(MIL-53@ZIF-8@RF)。用硫粉煅烧后,所得结构具有多级碳基质、丰富的内界面和分层的活性物质分布。结果,它提供了快速的钠离子反应动力学、出色的赝电容贡献、良好的抗体积变化能力以及逐步的钠化/脱钠反应机理。作为钠离子电池的负极材料,Fe 7 S 8 /C@ZnS/N-C@C的电化学性能优于Fe 7 S 8 /C@ZnS/N-C、Fe 7 S 8 /C或ZnS/N‐\C。在5.0 A g -1 电流密度下循环1万次后,能够展现出364.7 mAhg -1 高且稳定的容量,并且容量衰减率仅为0.00135%。这种MOF-on-MOF自模板化策略可能提供一种方法,以可控合成具有一定组分的核-多壳结构用于能源存储与转化。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.201907641 5. 核壳结构转化反应机理及其储钾性能 各种金属硫属化物材料已被探究作为K离子电池(KIBs)的新型负极材料。在本工作中, 韩国高丽大学Yun Chan Kang课题组 探索了K离子与碲化铁之间的电化学反应。在初始放电和充电之后,使用原位和非原位方法进行了详细分析,包括X-射线衍射(XRD)、X-射线光电子能谱(XPS)、透射电子显微镜(TEM)和循环伏安法(CV)。从FeTe 2 与K离子反应的第二次循环起,可逆的反应机理为2Fe + K 5 Te 3 + K 2 Te↔2FeTe 1.1 + 1.8Te + 7K + + 7e ‐\ 。通过简单的渗透和进一步碲化过程合成了能够容纳碲化铁纳米晶(FeTe 2 -C)的中空碳纳米球,以补偿在钾化和脱钾过程中纳米晶大的体积变化。一次循环后形成的杂化FeTe1.1和准金属Te的协同作用产生了出色的电化学性能,并且具有均匀分布纳米晶的核-壳结构嵌入了碳壳中。FeTe 2 - C电极表现出出色的长循环性能(在0.5 A g -1 电流密度下,500次循环后的容量为171 mA hg -1 )和优异的倍率性能(126 mA hg -1 ),甚至当电流密度为10 A g -1 时,亦是如此。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/smtd.202000556 (本期作者:毛毛的维)
1.聚阴离子磷酸钒钠用于下一代钠离子电池 以Na 3 V 2 (PO 4 ) 3 形式的聚阴离子-型磷酸钒钠(Na)显示出高的容量、良好的倍率性能和出色的循环性能。该配方中三个Na离子中的两个可以在3.4 V vs Na+/Na电压的情况下以V 3+ / 4+ 的氧化进行脱嵌。在可逆过程中,两个Na离子发生嵌入,导致放电容量为117.6 mAh g -1 。并且,可以发生进一步的嵌入,但在1.4 V vs Na + /Na的低电压下,伴随着V 3+ / 2+ 的还原,从而产生60 mAh g -1 的容量。由于其出色的电化学性能,自20世纪90年代发现以来,它就引起了很多关注。要开发真正可用的聚阴离子-型磷酸钒盐,必须更好地了解其晶体结构、钠离子传输和电子结构。因此, 湖北第二师范学院吴田课题组 和 新加坡国立大学吕力(Li Lu)课题组 合作,在本篇综述中重点讨论了聚阴离子-型磷酸钒盐Na 3 V 2 (PO 4 ) 3 的晶体结构和电子结构内部,从而为实现高效电化学存储提供有关见解。最后,作者对这一研究领域进行了展望。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202001289 2.二维金属-有机聚合物实现高效钠存储 南开大学陈军/李福军课题组 通过d-π杂化策略,合成了一种金属-有机聚合物:Ni配位的四氨基-苯并醌(Ni-TABQ),其聚合物链通过氢键链接,形成了坚固的二维(2D)层状结构。它沿着聚合物链和氢键的方向提供了电子传导和Na + 扩散的途径。以共轭苯甲酰羰基和亚胺作为Na + 嵌入和脱出的氧化还原中心,Ni-TABQ在100 mA g -1 时可提供约469.5 mAh g -1 的高容量,在8 A g -1 时可提供345.4 mAh g -1 的高容量。高的容量可维持100次循环,其库仑效率几乎达到100%。出色的电化学性能归因于这种由坚固Ni-N和氢键实现的独特2D电子传导和Na+扩散途径。这项研究将为分子设计和电化学应用提供启发。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202008726 3.超快剥离黑磷,实现高效锂存储 寡层黑磷(BP)是一类新兴的2D(能源)材料。然而,其可控的制备仍然具有挑战性。在此, 香港理工大学Lawrence Yoon Suk Lee/Shu Ping Lau团队 提出了一种高效的制备路线,可在低沸点溶剂中使用脉冲激光来大规模生产寡层BP纳米片。通过改变激光辐照时间、能量和溶剂类型,可精确控制纳米片的层数和横向尺寸。通过等离子体猝灭机理和原位产生蒸汽泡减弱的层间相互作用,进一步理解了过程。对BP纳米片的出色控制可以研究形貌对锂离子电池性能的影响。低的层数有利于电荷传输和Li + 离子扩散,而高的深宽比不仅可以改善电荷传输,而且可以增加Li + 离子的扩散路径。这项研究提供了关于使用激光量身定制薄2D材料的见解,也为形貌-电化学能源转换和存储的关系提供了见解。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.201903490 4.纳米ZnCo2O4/多孔rGO实现高效锂存储 最近,二元ZnCo 2 O 4 由于其高理论容量和良好的环境友好性,在锂离子电池(LIBs)方面引起了极大的关注。然而,较低的电导率和循环过程中严重的体积效应/颗粒团聚阻碍了它们的广泛应用。为了解决这些问题, 济南大学原长洲/曹丙强课题组 设计了一种快速的激光-辐照方法,以有效合成具有丰富氧空位的纳米ZnCo 2 O 4 /多孔还原氧化石墨烯(rGO)混合物作为LIBs的负极。具有丰富氧空位的纳米维度ZnCo 2 O 4 和柔性rGO之间的协同作用可确保丰富的活性位点、快速的电子/离子传输和坚固的结构稳定性,并抑制纳米级ZnCo 2 O 4 的团聚,从而有利于实现出色的电化学锂存储性能。结果表明是,最佳的L-ZCO@rGO-30负极在0.05 A g -1 时表现出约1053 mAh g -1 的大可逆容量,还展现出了优异的循环稳定性(在1.0 A g -1 下循环250次,容量约746 mAh g -1 )和卓越的倍率性能(在3.2 A g -1 时,约为686 mAh g -1 )。进一步的动力学分析证实,电容-控制过程主导了该负极的电化学反应。更重要的是,这种合理设计有望将其扩展为智能制造其他具有丰富氧空位的金属氧化物/多孔rGO混合物,以达到先进的LIBs,甚至更高水平。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/smll.202001526 5.COF衍生的碳纳米片用于高效钾存储 先前对钾离子电池(PIBs)的研究表明,极具前景的碳负极材料应在不同的长度尺度上具有精心设计的功能,包括原子尺度上均匀的异质原子掺杂、亚纳米尺度上适当的碳分布以及纳米到宏观尺度上的多级孔隙。然而,构造具有所有特征的碳材料仍然存在巨大挑战。在此, 上 海大学王勇课题组 和 东华大学李小鹏课题组 合作,报道了一种新颖的策略:通过客体掺杂和高温共价-有机框架(COF)-客体相互作用,将有序COF转变为具有多层次结构的碳纳米片。所制备的碳材料具有氮和磷的均匀共掺杂、宽约0.4 nm的碳层间距,以及丰富的微孔/介孔/大孔。所组装好的PIB负极在100 mA g -1 时可提供404 mAh g -1 的高可逆钾存储容量,并且还展现出了出色的长循环稳定性,在1000 mA g -1 下循环2000次能够保持179 mAh g -1 的容量,使其成为PIBs性能最佳的碳负极。这项工作证明了COF-客体化学在碳结构多级设计中的强大魅力。 原文链接: https://onlinelibrary.wiley.com/doi/abs/10.1002/smtd.202000159 (本期作者:毛毛的维)
作者:姜红 刘治科 刘生忠 Low Temperature Fabrication for High Performance FlexibleCsPbI2Br Perovskite Solar Cells Shengzhong (Frank) Liu, Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced EnergyTechnology, School of Materials Science and Engineering, ShaanxiNormal University, Xi’an, Dalian National Laboratory for CleanEnergy, iChEM, Dalian Institute of Chemical Physics,Chinese Academy of Sciences, Dalian Zhike Liu, Key Laboratory of Applied Surface and Colloid ChemistryMinistry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced EnergyTechnology, School of Materials Science and Engineering, ShaanxiNormal University 较传统的有机无机杂化钙钛矿,以CsPbX3为基的无机钙钛矿材料,例如CsPbI2Br,由于其优异的光照和热稳定性,近年来受到了人们的广泛关注。然而,高质量的CsPbI2Br钙钛矿薄膜通常需要在较高的温度(250 ℃)下获得,高温条件限制了柔性无机钙钛矿器件的发展。因此,研究一种可以在低温条件下获得高质量CsPbI2Br钙钛矿薄膜的方法对于制备高效柔性无机钙钛矿器件至关重要。 日前,陕西师范大学的刘治科教授、刘生忠教授报道了低温制备高性能柔性无机CsPbI2Br钙钛矿太阳电池的最新成果,文章发表在Wiley期刊 Advanced Science。采用PbI2(DMSO)和PbBr2(DMSO)络合物代替PbI2和PbBr2作为前驱体,低温制备了高效无机CsPbI2Br钙钛矿太阳电池。 图1. 通过传统过程和DMSO处理两种途径合成无机钙钛矿的反应坐标图。Ea,Ea1,Ea2是反应需要克服的能量势垒。 采用纯CsI, PbI2和PbBr2制备无机CsPbI2Br钙钛矿材料需要克服一个较高的能量势垒(Ea),因此需要较高的制备温度。而采用易斯碱基的前驱体可以将无机钙钛矿材料的制备过程分为两个阶段:PbI2(路易斯碱)X的形成和钙钛矿的形成。这样就可以通过克服两个较低的能量势垒合成CsPbI2Br钙钛矿,从而降低了无机钙钛矿材料的制备温度。同时,通过引入路易斯碱络合物PbI2(DMSO)和PbBr2(DMSO),也可以延缓CsPbI2Br钙钛矿薄膜的结晶过程,从而在低温条件下制备出高质量的CsPbI2Br钙钛矿薄膜和高效率的CsPbI2Br硬质和柔性电池。 图2. 基于DMSO络合物制备的无机钙钛矿薄膜的XRD图谱及太阳电池结构和性能图。 通过XRD测试发现PbI2(DMSO)和PbBr2(DMSO)前驱体可以降低CsPbI2Br钙钛矿的制备温度,提高钙钛矿薄膜的结晶质量。最终在低温(120oC)下,获得效率为13.54%的硬质CsPbI2Br钙钛矿太阳电池。 图3. 柔性基底钙钛矿薄膜表征 通过SEM表征发现PbI2(DMSO)和PbBr2(DMSO)前驱体可以提高CsPbI2Br钙钛矿薄膜在柔性衬底上的致密度,降低其粗糙度,该结果有助于提高CsPbI2Br钙钛矿薄膜的空气稳定性。 图4.柔性基底CsPbI2Br太阳电池性能 由于引入PbI2(DMSO)和PbBr2(DMSO)前驱体降低了钙钛矿薄膜的制备温度,研究人员在低温下(130oC)制备了高效柔性CsPbI2Br钙钛矿太阳电池,器件效率达到11.73%,为目前报道的柔性无机钙钛矿电池的最高效率。稳定输出效率也可稳定在11.70。 图5.柔性基底CsPbI2Br电池稳定性 通过无机钙钛矿薄膜稳定性测试,研究人员发现基于PbI2(DMSO)和PbBr2(DMSO)前驱体低温制备的无机CsPbI2Br钙钛矿薄膜比传统方法制备的薄膜表现出较好的湿度稳定性。同时,将传统器件和基于DMSO络合物的器件放在空气中老化,经过5个小时,传统电池效率衰减超过40%;而经过700个小时,基于DMSO络合物的器件仍能保持其初始效率的70%。结果表明使用PbI2(DMSO)和PbBr2(DMSO)前驱体可以显著提高CsPbI2Br钙钛矿电池的稳定性。 总之,作者通过使用PbI2(DMSO)和PbBr2(DMSO)前驱体降低了无机钙钛矿薄膜的制备温度和合成速率,获得了高质量的CsPbI2Br 薄膜和高效无机CsPbI2Br钙钛矿电池。该方法对于制备其它体系的无机钙钛矿(CsPbI3、CsPbBr3)电池具有很好的借鉴作用。 通讯作者/课题组介绍 陕西师范大学刘生忠教授和刘治科教授领导的团队最近在钙钛矿器件方面取得了系列国际领先的研究成果,包括:2018年将前驱体工程应用于全无机CsPbI2Br钙钛矿太阳电池,获得了效率高达14.78%的无机钙钛矿电池 (Adv. Funct. Mater. 2018, 1803269); 2018年低温溶液法制备了二维TiS2材料,并将其作为电子传输层应用于平面钙钛矿太阳电池(J. Mater. Chem. A, 2018, 6, 9132-9138); 在平面型钙钛矿电池和柔性钙钛矿电池方面,先后几次报道了领域最高效率 (Nat. Commun. 2018, 9, 3239; Adv. Mater. 2016, 28, 5206-5213; Energy Environ. Sci. 2015, 8, 3208-3214)。最近,该课题组发展了优质的Nb2O5电子传输层的低温沉积工艺,制备的柔性钙钛矿电池效率达到18.40% (Adv. Mater. 2018, 30, 1801418)。这些成果均达到了同类研究的国际先进水平。 \0 \0 姜红 刘治科 \0 \0 刘生忠 期刊介绍 Advanced Science is an interdisciplinary premium open access journal covering fundamental and applied research in materials science, physics and chemistry, medical and life sciences, as well as engineering. In 2018, the Impact Factor has increased by almost 40% to a value of 12.441 (2018 Journal Citation Reports). Advanced Science publishes cutting-edge research, selected through a strict and fair reviewing process and presented using highest quality production standards to create a premium open access journal. Top science enjoying maximum accessibility is the aim of this vibrant and innovative research publication platform. 点击访问期刊主页,浏览更多相关信息: https://onlinelibrary.wiley.com/journal/21983844 点击阅读文章: https://onlinelibrary.wiley.com/doi/full/10.1002/advs.201801117
杂原子掺杂是一种提高碳材料钠储存性能的有前途的方法。尤其,氮原子是研究最多的掺杂剂,它可以在六元碳晶格引入更多的缺陷点位。近年来,除了氮,硫元素的掺杂也引起了越来越多的关注。由于硫有一对孤对电子,容易极化,提高碳材料的化学活性。不仅如此,最近的理论计算证明:氮、硫元素的共掺杂可以带来协同效应由于电荷密度和自旋密度的重新分配。然而,目前为止,合成杂原子掺杂碳材料的方法依然非常有挑战性,亟待开发出简单的新方法。 近日, 中国科学技术大学余彦教授 课题组在国际著名期刊 Small 上发表题为“ A Flexible Sulfur‐Enriched Nitrogen Doped Multichannel Hollow Carbon Nanofibers Film for High Performance Sodium Storage ”的文章。在这项工作中, 通过静电纺丝技术和热处理升华硫制备富硫N掺杂多通道中空碳纳米纤维(表示为S-NCNF)膜作为柔性钠离子电池(NIB)的负极材料 。S-NCNF薄膜具有优异的电化学性能,特别是具有高倍率容量(电流密度为10 A g -1 时为132 mA h g -1 )和显著的长循环稳定性(2 A g -1 电流密度下经过2000次循环后可逆比容量为187 mA h g -1 )。材料具有丰富的缺陷和较大的的层间距,这种独特的3D结构改善了钠储存性能。密度泛函理论计算表明掺杂硫的含氮碳纳米纤维不仅可以促进钠的吸附,而且有利于电子的转移。因此,该方法是设计具有其他杂原子掺杂的自支撑碳基薄膜的提供一种新思路。 论文链接: https://doi.org/10.1002/smll.201802218 作者简介: 余彦教授 中国科学技术大学材料科学与工程系教授,博士生导师。2006年获得中国科学技术大学博士学位,2011年,入选中组部首批青年千人。先后在美国(Florida International University)和德国马普固体研究所(Max Planck Institute for Solid State Research)从事科学研究工作。 主要研究方向为高性能锂离子电池、钠离子电池、锂硫电池等关键电极材料的设计、合成及储能机制。目前在J. Am. Chem. Soc., Angew. Chem. Int. Ed., Adv. Mater., Nano Lett., Energy Environ. Sci.,等国际著名期刊上发表论文100余篇,其中有10余篇入选ESI高引频论文。 更多 链接地址: http://www.espun.cn/news/detail-322.html \0 文章来源: 易丝帮 \0
作为锂硫电池中的一类特殊的正极材料,热解聚丙烯腈/硫(或称:硫化聚丙烯腈,缩写为:pPAN/S)和某些微孔碳/S复合材料可以完全规避多硫离子溶解的问题,能够在商业化的碳酸酯电解液中获得优异的循环稳定性。但是,在pPAN/S或微孔碳/S复合材料中,S的含量通常很难超过50wt%,且容量利用率不高,导致该复合材料的总体能量密度不高,限制了其实际应用。 近日, 新加坡南洋理工大学楼雄文教授 课题组报道了 一种热解聚丙烯腈/二硫化硒(pPAN/SeS2)复合材料,其活性物质含量高达63wt%,作为电池的正极材料展现了优异的储锂和储钠性能 。研究者指出:活性物质含量的提升有两方面原因,首先,Se元素的摩尔质量是S的约2.5倍,因此,Se的引入能显著提高复合材料中活性物质的质量百分比;其次,相对于粉末状的PAN,在多通道pPAN的微孔、介孔尺度的孔道结构中能储存部分具有电化学活性的SeS2,进一步提升复合材料中活性物质的比例。 形貌结构: 在热处理过程中,PS受热分解,形成了连续贯通的孔道结构,同时PAN与SeS2发生脱氢反应,Se-S链状分子与PAN的高分子骨架形成化学键,得到pPAN/SeS2复合材料。与pPAN/S和pPAN/Se相比,pPAN/SeS2结合了二者各自的优点。pPAN/SeS2的电化学活性更多地类似于pPAN/Se;同时,得益于在理论比容量和电导率上的优势,pPAN/SeS2的放电比容量又远高于二者。 电化学性能: 在0.5 A g -1 的电流密度下,pPAN/SeS2复合正极的储锂比容量高于1000mAh g -1 ,其库伦效率约为100%。同时,pPAN/SeS2展现了优异的倍率性能和长循环稳定性,在4 A g -1 的电流密度下,循环2000次后还保持较高的容量。 研究者又将pPAN/SeS2用于室温Na-SeS2电池的正极材料,显示出了优异的反应活性。在室温0.1 A g -1 的电流密度下,pPAN/SeS2第二次放电比容量高达944 mA h g -1 ,其循环和倍率性能明显优于pPAN/S。 通过对100次循环后的Li-SeS2电池进行拆解分析,发现pPAN/SeS2具有很好的电化学稳定性,在循环过程中完全没有Se或S的溶解问题,电极片和电极材料都保持了很好的稳定性。 该研究制备pPAN/SeS2的方法较简单,同时,pPAN/SeS2展示出了优异的储锂和储钠性能,既具有较高的容量,又具有较好的循环稳定性。值得指出的是,虽然该工作中Se:S的比例在1:2时获得了很好的容量与倍率的平衡,但是,基于材料成本、电池性能、应用领域等综合因素考虑,正极材料中的Se/S比例仍然有很多优化提升的空间。 图1. pPAN/SeS2的形貌和结构 图2. 对pPAN/SeS2和一些对比样品的表征 图3. pPAN/SeS2和pPAN/S,pPAN/Se的电化学性能对比 图4. Li-SeS2电池的性能 图5. 室温Na-SeS2电池的性能 图6. 对循环后的pPAN/SeS2进行的相关表征 \0链接地址: http://www.espun.cn/news/detail-291.html \0 文章来源: 易丝帮
研究的热点,包括静电纺丝理论中经典的Taylor锥与喷射理论、纳米纤维的弯曲非稳定性理论,同时归纳了针对纺丝流体大部分为非牛顿流体的性质,静电纺丝中高聚物流体非稳定性理论的研究过程和进展。 The research topic aims at the classical Taylor cone and jet theory in electrospinning theory and the bending instability theory of nanofibers. At the same time, they summarize the properties of mostly non-Newtonian fluids for spinning fluids, and conclude research process and development of the instability of polymer fluids in electrospinning. 静电纺丝的工艺参数主要包括纺丝液的浓度、纺丝电压、接收距离和纺丝液供应速率。对于静电纺丝工艺参数的研究主要涉及工艺参数对产品的纤维直径、孔隙率、强度等性能指标的影响。通过可以总结出纤维直大量的不同聚合物的实验结果。 The electrospinning parameters mainly include the concentration of the spinning solution, the spinning voltage, the receiving distance and the spinning solution supply rate. The study of electrospinning parameters mainly involves the influence of process parameters on the product's fiber diameter, porosity, strength and other performance indicators. By these data, the experimental results of a large number of different polymers with straight fibers can be summarized. 与纤径的变化大体上与纺丝电压呈反向变化趋势,维液浓度呈正向变化趋势。在纤维直径影响因素的研究中,宋叶萍等人通过响应面法的Box-Behnken设计(BBD)建立了纤维直径预测模型,简化了实验过程,并通过模型优化了纺丝工艺。 The change of the fiber diameter and the change of the spinning voltage are in the opposite directions, and the dimensional concentration of the liquid shows a positive change. In the study of influencing factors of fiber diameter, Song Yeping et al. established the fiber diameter prediction model by the Box-Behnken design (BBD) of the response surface method, which simplifies the experimental process and optimizes the spinning process through the model. 目前实验室用的静电纺设备主要有单纺型和同轴型两类,其中前者数量居多,因为它只有一个喷丝头,设备组装容易。而同轴型设备主要制备皮芯型结构的纳米纤维,需要不同孔径的喷丝装置同同时对液体供应装置也有特殊要求,所以轴组合。 At present, lab electrospinning equipment mainly consists of single spinning type and coaxial type. Among them, the number of the former is mostly because it only has one spinneret and the equipment is easy to assemble; while the coaxial device mainly prepares a core-structured nanofiber, which requires different diameters of the spinning device and also has special requirements for the liquid supply device, so the assembly is more difficult. —————————— 文章来源:http://www.qingzitech.net/application-of-electrospinning-technology-in-li-ion-battery
四家中国企业进入前十名,比亚迪排第三 May 5th, 2015 by James Ayre Republish Reprint Those interested in tracking the state of the electric vehicle (EV) battery manufacturing market will likely be interested in taking a look at the chart and table below — which provide a fair amount of data on the market as pertaining to consumer electric car batteries (not pertaining to “heavy duty” vehicles such as buses, or to energy storage systems). And a big thanks to José Pontes for the numbers. Battery Manufacturer 1st Quarter 2015 (MWh) 2014 (MWh) % of 1Q 2015 % of 2014 Panasonic 888 2726 45% 41% AESC 361 1620 18% 24% BYD 196 461 10% 7% Mitsubishi/GS Yuasa 135 451 7% 7% LG Chem 114 886 6% 13% Samsung 105 314 5% 5% Wanxiang 62 0 3% 0% Beijing Pride Power (BPP) 47 121 2% 2% Tianneng 38 77 2% 1% SB LiMotive 37 0 2% 0% Total 1983 6656 100% 100% As you can see, Panasonic continues to dominate the market — with Tesla’s strong showing being a major factor. The company supplies Volkswagen as well, though, it should be remembered — giving it some growth potential beyond the Tesla association. The joint venture between Nissan Motors and NEC, AESC, is continuing on its long dive (down nearly 20% of top 10 market share in just 3 years). Considering that Nissan will be sourcing batteries from LG Chem in the future, this dive is set to continue. BYD is continuing to do well — and it should be noted here that these figures don’t even factor in the company’s electric buses or its energy storage solutions (which are considerable). BYD’s market share is especially thanks to the top-selling Qin EV , but also its many other market offerings. The rest of the list (again, coming to us via the EV Sales blog ) is about what you’d expect — a slow loss of top 10 market share mostly, with the exception of LG Chem and Samsung, which are providing the batteries for the Chevy Volt and some of BMW’s electric offerings, respectively. Some of the small companies further down the list have managed to gain some market share as well, though. Wanxiang managed to climb to number 7 (up from number 11 in 2014) with a top 10 market share increase of 2% thanks to the success of the Zotye E20, etc.
SAE International Publishes New standard, SAE J2601, to Establish Worldwide Basis for H2 Fueling of Fuel Cell Electric Vehicles WARRENDALE, Pa., July 24, 2014 - SAE International published the J2601 standard, “ Fueling Protocols for Light Duty Gaseous Hydrogen Surface Vehicles ”, the light duty hydrogen fueling protocol which will serve as the baseline for fueling the first generation hydrogen Fuel Cell Electric Vehicle (FCEVs) with hydrogen. This standard will be used worldwide for hydrogen fueling stations. “SAE J2601 enables a safe and quick hydrogen fueling experience for FCEVs,” according to Jesse Schneider, lead of the SAE J2601 and J2799 standards. He added: “SAE J2601 enables hydrogen stations to have a fueling time within 3-5 minutes. In addition, with a consistently high end state of charge resulting in, this standard fuels FCHEVs with resulting range of 300+ miles. With the current –state of the art –- FCEV 60% efficiency, the hydrogen fuel transfer is equivalent to 100-200 kWh electrical energy (depending on tank size). Therefore, SAE J2601 establishes FCEVs as the only zero emission vehicle technology to meet the same customer fueling and range expectations as conventional vehicles today.” The standard J2601 fueling protocol uses a look-up table approach and an average pressure ramp rate which has been verified over the last 13 years. The SAE J2601 Standard fueling tables use a simple control where the dispenser fuels until the target pressure based on initial start conditions, giving a consistent hydrogen fueling. This protocol, termed the “J2601 standard fueling”, method has been validated from the laboratory with test tanks to the field with automaker hydrogen storage under extreme conditions on three continents with test tanks and vehicles. The data confirming this hydrogen fueling methodology -from automakers and hydrogen fuel providers- has been documented in the 2014 SAE World Congress Technical Paper (2014-01-1833). J2601 standardizes hydrogen fueling for both 35MPa and 70MPa pressure classes. Obtaining extended driving ranges in FCEVs with hydrogen fueling is accomplished by compressing hydrogen to 70MPa (or H70). The speed of hydrogen fueling is directly related to the amount of cooling that the dispenser allows, to offset the heat of compression. Therefore, a H70-T40 fueling dispenser enables this fast-fueling by providing hydrogen fuel at -40C to the fuel cell vehicle. SAE J2601 has a number of updates from the previous Technical Information Report including “top-off” and “fall-back fueling” along with numerous improvements for robust operation at of the hydrogen dispenser. SAE International is a global association committed to being the ultimate knowledge source for the engineering profession. By un iting more than 145,000 engineers and technical experts, we drive knowledge and expertise across a broad spectrum of industries. We act on two priorities: encouraging a lifetime of learning for mobility engineering professionals and setting the standards for industry engineering. We strive for a better world through the work of our philanthropic SAE Foundation, including programs like A World in Motion and the Collegiate Design Series™. - www.sae.org - http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleasesPAGE=showReleaseRELEASE_ID=2620
前几天发一篇 危险的高空锂电池 , 危险原因就是锂电池不能耐高温. 最近在Angewandte Chemie International Edition看到一篇相关报道,他的阻燃型锂盐用于燃料电池,热稳定温度可以达到200度,锂电池正在向高温高稳定性迈进! 另外 在Advanced Materials 一个利用Sn 4 P 3 阳极材料的钠离子电池也挺有意思,可逆电容量可达718 mA h g −1. Phosphoryl-Rich Flame-Retardant Ions (FRIONs): Towards Safer Lithium-Ion Batteries † http://onlinelibrary.wiley.com/doi/10.1002/anie.201310867/abstract Abstract The functionalized catecholate, tetraethyl (2,3-dihydroxy-1,4-phenylene)bis(phosphonate) (H 2 -DPC), has been used to prepare a series of lithium salts Li , Li , Li , and Li . The phosphoryl-rich character of these anions was designed to impart flame-retardant properties for their use as potential flame-retardant ions (FRIONs), additives, or replacements for other lithium salts for safer lithium-ion batteries. The new materials were fully characterized, and the single-crystal structures of Li and Li have been determined. Thermogravimetric analysis of the four lithium salts show that they are thermally stable up to around 200 °C. Pyrolysis combustion flow calorimetry reveals that these salts produce high char yields upon combustion. Tin Phosphide as a Promising Anode Material for Na-Ion Batteries http://onlinelibrary.wiley.com/doi/10.1002/adma.201305638/abstract Sn 4 P 3 is introduced for the first time as an anode material for Na-ion batteries. Sn 4 P 3 delivers a high reversible capacity of 718 mA h g −1 , and shows very stable cycle performance with negligible capacity fading over 100 cycles, which is attributed to the confinement effect of Sn nanocrystallites in the amorphous phosphorus matrix during cycling.
Scientists work to develop ceramic conductors for Li-ion batteries Published on July 31st, 2013 | Edited by: Jim Destefani Making the lithium-ion batteries that power everything from hybrid and all-electric vehicles to cell phones and other mobile electronic devices safer, longer lasting, and less expensive is a key goal for researchers in the field. Conventional Li-ion batteries use a liquid conducting medium to allow current to flow between the battery’s anode and cathode. Scientists at Michigan State University (E. Lansing) are among several groups working to change that by developing solid conductors with current-conducting capability the same as or better than that of liquid conductors. “We’re working to create the next generation of batteries for electric vehicles,” says researcher Jeff Sakamoto. “If you want to eliminate ‘range anxiety’ and sticker shock, you must have a battery that stores a lot more energy—four or five times more—and cost about a fourth or fifth of what lithium-ion batteries cost today.” According to Sakamoto, assistant professor of chemical engineering and materials science, a class of ceramics called superionic conductors is among the most promising candidate solid conductor materials. “The goal is to move away from liquid cells and toward solid-state batteries that are safer, cheaper to manufacture, less sensitive to degradation at higher temperatures, and more durable,” Sakamoto says in this news release . Ions move throughs superionic conductors just as efficiently as through liquid electrolyte—at ~1 mS/cm at room temperature, according to Sakamoto. “In a typical superionic conductor, a stable ceramic oxide or sulfide primary lattice provides a ‘skeleton framework’ that allows a highly mobile sublattice of cations, in this case lithium ions, to move freely,” he explains in an email. The MSU team is studying ceramic oxide superionic conductors with the garnet mineral structure and nominal composition of Li 7 La 3 Zr 2 O 12 . Sakamoto says he has been working with this material, along with Jeff Wolfenstine of the Army Research Lab in Adelphi, Md., for about four years. Rapid induction hot pressing technique developed at MSU results in test membranes of ~98% theoretical density to enable fundamental studies. Credit: G.L. Kohuth/MSU. “I am excited about this material because it has a unique combination of superionic conductivity and stability against lithium,” Sakamoto says. “The latter opens the electrochemical stability window to enable metallic lithium or other advanced anode materials.” The MSU group has synthesized the material in powder form through solid state reactions and a sol–gel alkoxide method, and now is using a “simple, cheap, scaleable water-based technique,” Sakamoto says. (The large photo above shows Travis Thompson, a doctoral student in materials science and engineering, preparing to synthesize the material. Credit: G.L. Kohuth/MSU.) “Once we obtain the powders, we fabricate and densify membranes through a rapid induction hot pressing technique that we developed,” he continues. “Although it may not be scaleable, RIHP does produce membranes in close to the ideal form (~98% theoretical density) to enable fundamental studies.” Sakamoto says the garnet material was first reported by a German research group several years ago, and that researchers at Toyota, BASF, Bosch, NGK, Samsung, and other companies are also working with the material. “My group has investigated new areas such as synthesis, stability, and device integration,” he says. “I am optimistic that this material has the potential to enable numerous new energy storage technologies such as solid-state, redox-flow, lithium-sulfur, and lithium-oxygen energy storage technology.”
锂-空气电池 目前的发展方向是使这种电池能适用于电动汽车 空气催化剂:金和铂的合金纳米微粒(深色的区域)位于炭黑色基底上(浅色图案);这些材料共同提高了锂-空气电池的效率。 来源: Yi-Chun Lu 该催化剂由金和铂的合金纳米微粒组成;在测试中,它能将充电能量的77%作为电能释放出来。研究人员说,这比之前公布的70%左右的记录还要高。6月第2周,《美国化学会志》(Journal of the American Chemical Society)在线发表了这项研究,该研究提出了一种制造锂-空气电池催化剂的新方法,它甚至能达到比商用电池所需的85%~90%更高的效率。 锂-空气电池通过锂和空气中的氧反应来产生电能,由于其具有储存能量高的潜力而受到关注。与相同重量的如今使用的锂离子电池相比,锂-空气电池可以实际存储多达3倍的能量,比如,可以延长电动汽车的行驶距离。 但锂-空气电池样品也存在一些问题。除了非常的低效之外,它们通常只能持续几十个充电和放电周期。它们也不活跃,只能缓慢地释放能量,并容易被二氧化碳和水污染。作为其中一个电极的金属锂非常活跃,具有危险性,并最终形成会导致短路的树状晶体。 为了提高电池的效率,这项新的催化剂研究由材料科学工程和机械工程教授杨绍红(Yang Shao-Horn)领导,与机械工程和生物工程教授金柏莉•哈迈德-斯契费尔利(Kimberly Hamad-Schifferli)合作,设法解决其中最重要的问题。该催化剂有助于延长电池寿命。 当锂-空气电池放电时,金属锂与氧气起反应生成氧化锂并释放电子。当充电时,氧气被释放,金属锂被还原。新的催化剂促进了这些反应,由此减少了电池充放电时能量的损失。催化剂里的金原子可以促进锂和氧的结合;而铂原子则有助于还原反应,释放氧。 在某些方面,研究结果有悖于之前的假设。铂是已知的能促进燃料电池中氢氧结合的最好的催化剂之一,是最早试用于锂-空气电池用来催化锂和氧的材料之一。但是实验表明,铂的表现并不好,所以它被放弃了。 麻省理工学院的研究人员发现,铂在锂-空气电池中是有用的,但只是在逆向反应——充电过程中从氧化锂中释放氧——中有用。杨绍红说:“大家都知道铂在电池放电时不活跃,但我们发现,铂在充电反应中是最好的催化剂之一。” 杨绍红表示,另一方面,由于金的惰性,它通常被认为是一种不良的催化剂。事实上,麻省理工学院的研究人员是第一次使用金控制实验,来测量使用不良催化剂的反应。令他们吃惊的是,他们发现,金在催化锂和氧的结合时表现出色——比铂好很多(在杨绍红的研究小组发现这点之前的几个月,丰田公司的研究者就已经演示了这一成果,并注册了专利)。此外,研究人员发现,这两种催化剂在纳米微粒状态下结合时效率更高。杨绍红说:“它们在一起工作时会相互促进。” 除了提高效率,促进这些反应还有望增加锂-空气电池可充电的次数——通过减少会阻塞电池的氧化锂。当麻省理工学院的研究人员继续研发锂-空气电池时,他们将探讨这种可能性;他们会更细致地研究金铂催化剂,以了解它们是如何工作的;并通过对不同材料的组合来研发新的催化剂。 麻省理工学院的研究人员正努力通过使用少量的铂和金来降低催化剂的成本。一种方法是,在较便宜的材料制成的纳米微粒表层涂上薄薄的一层贵重的金属。法国庇卡底大学(Universite de Picardie Jules Verne)教授让•马里•塔拉斯孔(Jean-Marie Tarascon)表示,其他研究人员已经证实,廉价的氧化锰催化剂对锂-空气电池有效。他说目前这些材料已被证明比杨绍红的催化剂更有效率。
Super-powered battery breakthrough claimed by US team By Leo Kelion Technology reporter http://www.bbc.co.uk/news/technology-22191650 Researchers claim their technology could shrink the size of batteries by 10 times while offering the same power A new type of battery has been developed that, its creators say, could revolutionise the way we power consumer electronics and vehicles. The University of Illinois team says its use of 3D-electrodes allows it to build microbatteries that are many times smaller than commercially available options, or the same size and many times more powerful. It adds they can be recharged 1,000 times faster than competing tech. However, safety issues still remain. Details of the research are published in the journal Nature Communications . Battery breakthrough The researchers said their innovation should help address the issue that while smart phones and other gadgets have benefited from miniaturised electronics, battery advances have failed to pace. Batteries work by having two components - called electrodes - where chemical reactions occur. In simple terms, the anode is the electrode which releases electrons as a result of a chemical reaction. The cathode is the electrodeon the other side of the battery to which the electrons want to flow and be absorbed - but a third element, the electrolyte, blocks them from travelling directly. When the battery is plugged into a device the electrons can flow through its circuits making the journey from one electrode to the other. The scientists'breakthrough involved finding a new way to integrate the anode andcathode at the microscale. The battery electrodes have small intertwined fingers that reach into each other, project leader Prof William King told the BBC. That does a couple of things. It allows us to make the battery have a very high surface area eventhough the overall battery volume is extremely small. And it gets the two halves of the battery very close together so the ions and electrons do not have far to flow. Because we're reduced the flowing distance of the ions and electrons we can get the energy out much faster. Across-section of the battery reveals the 3D-design of the research project'sanodes and cathodes Repeatable technique The battery cells were fabricated by adapting a process developed by another team at the university which is designed to make it faster to recharge the batteries than lithium ion(Li-on) and nickel metal hydride (NiMH) equivalents. It involves creating a lattice made out of tiny polystyrene spheres and then filling the space in and around the structure with metal. The spheres are then dissolved to leave a 3D-metal scaffold onto which a nickel-tin alloy is added to form the anode, and a mineral called manganese oxyhydroxide to form the cathode. Finally the glass surface onto which the apparatus was attached was immersed into a liquid heated to 300C(572F). Today we're making small numbers of these things in a boutique fabrication process, but while that's reliable and we can repeat it we need to be able to make large numbers of these things over large areas, said Prof King. But in principle our technology is scaleable all the way up to electronics and vehicles. You could replace your car battery with one of our batteries and it would be 10 times smaller, or 10 times more powerful. With that in mind you could jump start a car with the battery in your cell phone. Safety fear Other battery experts welcomed the teams’ efforts but said it could prove hard to bring the technology to market. The challenge is to makea microbattery array that is robust enough and that does not have a single short circuit in the whole array via a process that can be scaled up cheaply, said Prof Clare Grey from the University of Cambridge's chemistry department. University of Oxford's Prof Peter Edwards - an expert in inorganic chemistry and energy - also expressed doubts. This is a very exciting development which demonstrates that high power densities are achievable by such innovations, he said. The challenges are:scaling this up to manufacturing levels; developing a simpler fabrication route; and addressing safety issues. I'd want to know if these microbatteries would be more prone to the self-combustion issues that plagued lithium-cobalt oxide batteries which we've seen become an issue of concern with Boeing's Dreamliner jets. Prof King acknowledged that safety was an issue due to the fact the current electrolyte was a combustible liquid. He said that in the test equipment only a microscopic amount of the liquid was used, making the risk ofan explosion negligible - but if it were scaled up to large sizes the danger could become significant. However, he added that he soon planned to switch to a safer polymer-based electrolyte to address the issue. Prof King added that he hoped to have the technology ready to be trialled as a power source for electronic equipment before the end of the year. The University of Illinois at Urbana-Champaign team is one of several groups attempting to overhaul the way we power gadgets. Researchers in Texas are working on a kind of battery that can be spray-painted onto any surface while engineers at the University of Bedfordshire are exploring the idea of using radio waves as an energy source. Prof William King hopes to use themicrobattery to power electronic equipment before the end of the year
http://www.ncbi.nlm.nih.gov/pubmed/19739146 Small. 2009 Oct;5(20):2236-42. doi: 10.1002/smll.200900382. Nanostructured silicon anodes for lithium ion rechargeable batteries. Teki R , Datta MK , Krishnan R , Parker TC , Lu TM , Kumta PN , Koratkar N . Source Department of Chemical Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. Abstract Rechargeable lithium ion batteries are integral to today's information-rich, mobile society. Currently they are one of the most popular types of battery used in portable electronics because of their high energy density and flexible design. Despite their increasing use at the present time, there is great continued commercial interest in developing new and improved electrode materials for lithium ion batteries that would lead to dramatically higher energy capacity and longer cycle life. Silicon is one of the most promising anode materials because it has the highest known theoretical charge capacity and is the second most abundant element on earth. However, silicon anodes have limited applications because of the huge volume change associated with the insertion and extraction of lithium. This causes cracking and pulverization of the anode, which leads to a loss of electrical contact and eventual fading of capacity. Nanostructured silicon anodes, as compared to the previously tested silicon film anodes, can help overcome the above issues. As arrays of silicon nanowires or nanorods, which help accommodate the volume changes, or as nanoscale compliant layers, which increase the stress resilience of silicon films, nanoengineered silicon anodes show potential to enable a new generation of lithium ion batteries with significantly higher reversible charge capacity and longer cycle life.
现在动力型锂电池已经成为最近几年的新亮点,但是鱼龙混杂,虚假广告漫天飞,笔者为动力电池行业的,想就此提供一些判断依据,来供大家参考,欢迎讨论,扔砖头,但不要漫骂.本人在苏州星恒电源有限公司就职,专业动力锂电池制造,笔者亲自测试过国内14家同行电池国外5家电池,包含你们听说过的和没有听说过的品牌,偏驳之处还请各位不吝赐教.请各位本着讨论的心态参与 由于小容量锂电池已经相当成熟了,所以本贴不再进行讨论.本贴所有言论限制在6Ah以上容量锂电池. 在电池技术最发达的日本声称自己能做6Ah以上动力锂电池的厂家没有超过5家,而在中国居然有20家以上的企业声称自己能做动力型锂电池,我不能说中国的企业完全不如日本,但在锂电池这一块,日本企业的普遍技术水平的确在中国之上(先声明,敝人从来抵制日货,但决不盲目的自大,一个产业的发展,一个国家的发展需要科学的态度和认真的精神),保护电路的重要性毋庸讳言,但锂电芯本身的安全是锂电池组安全的最后一道底线,没有这样一个底线保证,在保护板故障,或者短路,撞车等异常状况时,出安全事故的概率就会异常的高 笔者认为判断一个公司宣传的是否属实,看他的动力锂电池是否过关,可以主要从以下几个方面判断: 1 看有没有权威的第三方认证机构的安全认证证书,此类证书国内就有一些号称可以做动力锂电的企业是拿不出来的,还有一些企业会拿出MOTO,NOKIA等在小容量电池方面的一堆证书给客户看,但各位一定要明白你不是打算用他的小容量手机电池能,你要用动力型电池,如果简单把容量扩大就能做动力型,那动力型锂电早就漫天飞了.所以你要看他在动力型电池方面的证书,这种证书就基本上没有企业可以拿得出来,因为我公司过UL认证已经两年了,在6Ah以上的锂电池里,我们还是全球唯一一家拿到UL证书的,另外还有独立认证试验室extra energy的认证证书.当然不排除日本有个别企业做得也很好,但他们在锂电池方面看不起UL,使用自己本国标准,日本在锂电方面的标准比UL高,目前国内没有企业在动力锂电池方面通过此标准,我们正在做. 2 看使用什么样的正极材料,目前在可充电锂电池里,使用量最多的材料大概有以下几种:钴酸锂,锰酸锂,镍钴锰酸锂,磷酸铁锂,衡量正极材料安全性主要考验: A 容不容易在充电时形成枝晶,实际上就是锂在分子材料中占的原子数量比,越容易形成就越不安全,在这个指标上,钴酸锂和镍钴锰酸锂比较差. B 氧化-还原温度,钴酸锂和镍钴锰酸锂大概150度,锰酸锂300度,磷酸铁锂400度,此指标衡量的是发生燃烧的温度,因此可以衡量磷酸铁锂最安全,锰酸锂次之,其余两种较差 3 安全测试的指标(不带保护板测试) UL的标准是:过充,满电直接短路,满电挤压,满电撞击,满电150度高温.各个锂电生产企业一般都有产品的这几项测试的数据,因为这几个试验是UL和国标的要求.拿到数据并亲自验证数据真实性后做对比,就可以看得出来到底哪家的安全性更好. A 过充一般企业(包括小电芯)可以做到1C5V,2C5V,国内有企业可以做到2C6V,UL的标准是3C10V不爆炸不起火,目前只有我们一家可以做到 B 短路UL标准是100毫欧电阻短路,不爆炸不起火,这个指标在小电芯领域已经是普遍的标准了,但动力型电池个别厂家还是不能做到,大多数厂家都能做到 C 满电各方向挤压不爆炸不起火,UL挤压标准是13KN,其他认证标准有所不同,国内含我们也只有3家企业能过(我亲自测试过国内14家同行电池,恕不能署名,会招来漫骂) D 满电撞击,UL标准是9.1公斤钢棒撞击,国内有些声称做动力电池的企业不能过 E 满电高温UL标准是150度10分钟,不爆炸不起火,国内声称自己做动力锂电池的企业在此项测试上无法通过 F 过充针刺是我企业的标准,满电后将直径8毫米的钢钉直接钉穿电池,并将钢钉留在电池里,直到电放光位置,不爆炸不起火,国内更是没有一家企业的6Ah以上电芯可以通过此项测试 另外我们企业标准的各项试验除不爆炸不起火要求外,另外要求外壳温度不超过150度(高温试验除外) 4 是什么样的结构,传统的圆柱形电芯是卷绕式结构,因为在高温时隔膜面积会收缩,卷绕结构会造成大面积的正负极直接短路,具有很大的安全隐患,方型的层叠结构在设计时隔膜面积直接预留10%~20%,在发生高温萎缩时仍能保证良好的隔断性能. 5 动力电池生产线的产能,电池生产厂在对自己的电池没有完全的自信的时候是不会大规模扩大产能的,能做出一块好电池,并不能等于能批量做出好电池.在参观工厂的时候不要看他大规模的手机电池生产线,要看专门的动力电池生产线,实际上两种生产线是基本上不兼容的,专业的动力电池生产线跟手机电池线有很大的区别,如果没有专业的生产线,说明企业本身对自己电池没有信心,或者说还没有解决大批量生产的不良问题.除我们之外,国内能月产几万只合格动力锂电芯的厂家一家都没有,你可以向他们订购1000组10串电池,看看要多久能交得出,我们目前要交1000组电池10天的周期就够了,生产组装只要三天,因为要算上做四次容量测试检验的时间,所以要10天. 6 通过此企业在自己动力电池主攻市场上的客户反应来判断 其余的技术方法和市场还有很多,就不再多说了,各位自有高招,我公司目前主攻电动自行车市场,其他行业市场工作也将逐渐展开.电动自行车虽然简单,但是对电池的要求相当苛刻,每天都要充放,工作电流又大,风里来雨里去,颠簸流离,决不是数码电池工作条件可比,4月17日上海国际电动车展会,一共有近30家参展商展出锂电车,只有两家不是用我们的,但这两家在展会后就转而使用我们的了,并在展会期间就到工厂参观,并亲自操作安全试验. 苏州星恒电源有限公司是联想集团和中科院合作兴建专业动力锂电池生产企业,拥有完全自主知识产权,承担国家863锂电池相关课题,国家863混合动力汽车用锂电池供应商,与同济大学,德国大众汽车公司,上海大众,上汽集团合作开发的“超越2号”“超越3号”混合动力汽车每天都在测试,已经合作运行3年多的时间了,预计将在08到10年实现商业化运营. 公司目前主要产品可以2C放电的10Ah,30Ah电池,和7.5Ah和15Ah可以200A充电300A放电的高功率电池,目前产能电芯4000只/天,7月份一万只每天,自从05年9月解决批量良品率问题后开始大规模出货,到现在累计出货一万两千组,目前每月出货5000组,出货量还在增加,国内及国外各有一半左右,长三角做高档车和出口车的电动车厂都是我们客户,各位可以在网上搜寻这些公司电话直接咨询,目前在苏州每个大商场都可以买到使用我们电池的电动车,在上海,杭州,北京也有不少地方卖,特别是长三角的城市,留心点都可以买到,北京的朋友留心5月份,我们一口气在北京投放了6000辆车,并且和车厂联合大规模宣传,还有免费送车的抽奖,不要错过呀,目前大概有60款使用我们电池的电动车在市场上销售和使用. 比如有一款使用36V10Ah的轻便型锂电车,全铝合金车架,整车带电池20公斤,可折叠后提到楼上,装在汽车后备厢里,没有电当自行车骑,带变速,减震,骑行很舒服,续行里程35~40公里,助力模式可以达到60~70公里,市场售价2800~3000元 有兴趣联系我yangjie@xingheng.com.cn小灵通0512-68172907,公司网站http://www.xingheng.com.cn欢迎咨询,交流,并欢迎拿同行电芯到我公司亲自操作对比安全试验.
本人写的一个针对硫化铅量子点太阳能电池的最新综述,对2011-2012年间量子点太阳能电池的研究做了一些总结,欢迎感兴趣的朋友下载讨论: Recent development in colloidal quantum dots photovoltaics Frontiers of Optoelectronics 2012, DOI 10.1007/s12200-012-0285-7. Li Peng , Jiang Tang*, Mingqiang Zhu 摘要:The increasing demanding for sustainable and green energy supply spurred the surging research on high- ef fi ciency, low-cost photovoltaics. Colloidal quantum dot solar cell (CQDSC) is a new type of photovoltaic device using lead chalcogenide quantum dot film as the absorber materials. It not only has the potential to break the 33 % Shockley-Queisser efficiency limit for single junction solar cell, but also possesses the low-temperature, high-throughput solution processing. Since its first report in 2005, CQDSCs experienced rapid progress achieving acertified 7% efficiency in 2012, an averaged 1% efficiency gain per year. In this paper, we reviewed the research progress reported in the last two years. We started with background introduction and motivation for CQDSC research. We then briefly introduced the evolution history of CQDSC development as well as multiple exciton generation effect. We further focused on the latest efforts in improving the light absorption and carrier collection efficiency, including the bulk-heterojunction structure, quantum funnel concept, band alignment optimization and quantum dot passivation. Afterwards, we discussed the tandem solar cell and device stability, and concluded this article with a perspective. Hopefully, this review paper covers the major achievement in this field in year 2011 –2012 and provides readers with a concise and clear understanding of recent CQDSC development.
之前氧化锌微米花球准固态电池的续篇,组里面的兄弟把效率从4.2提升到6.2%,目前该类型电池的最高效率。。。有木有希望到9%,让我们拭目以待。。。 ----------------------------------------------------------------------- Optimizing nanosheet-based ZnO hierarchical structure through ultrasonic-assisted precipitation for remarkable photovoltaic enhancement in quasi-solid dye-sensitized solar cells Yantao Shi , Chao Zhu , Lin Wang , Wei Li , Chun Cheng , Kin Ming Ho , Kwok Kwong Fung and Ning Wang J. Mater. Chem., 2012,22, 13097-13103 DOI: 10.1039/C2JM31106B Received 22 Feb 2012, Accepted 09 May 2012 First published on the web 09 May 2012 http://pubs.rsc.org/en/Content/ArticleLanding/2012/JM/c2jm31106b For ZnO hierarchical structures composed of interlaced nanosheets, it has been proved that they are more favorable for electron transportation in the photoanodes of ZnO-based dye-sensitized solar cells (DSCs). Here, we introduce ultrasonic-assisted precipitation for fabricating novel nanosheet-based ZnO hierarchical flowers (HFs) in aqueous solution. With the powerful ultrasound irradiation, these nanosheets on the HFs are not only interlaced and monocrystalline, but also axially oriented, porous and ultrathin. Furthermore, broad channels enclosed by adjacent nanosheets can deeply extend into the inner parts of the HFs. Structural improvements reveal that the specific area of the novel HFs as well as their performances on light-capturing and electron transport have been largely improved compared with those prepared through direct precipitation. Remarkably, when assembled into quasi-solid DSCs, ZnO HF photoanodes show a high conversion efficiency up to 6.19% (under AM 1.5, 100 mW cm ㈢ illumination), the highest record of quasi-solid ZnO-based DSCs up to now.
http://news.xinhuanet.com/it/2009-12/11/content_12628766.htm 您的位置: 新华网主页 - 新华数码 比涂鸦还简单 科学家造新电池超锂电池10倍 2009年12月11日 09:21:32 来源: 综合 在各种电子设备深入人民群众生产生活的今天,能源的瓶颈显得越来越明显。性能越强,能耗越大,这几乎已经成为定理。看看各种号称轻薄的笔记本扩展电池的重量,看看iPhone 3GS的续航时间,电池早已不堪重负。 所谓科技以人为本,电池技术既是各种便携电子产品的瓶颈,也成为了科学家们研究的重点。最近美国斯坦福大学的科学家们就展示了自己在这个领域的最新研究成果:经过纳米科技强化后,一张纸也能变成超级电池——将特殊的银碳纳米墨水涂在一张纸上,这张纸就是一块电池。是的,就这么简单。 斯坦福大学的科学家表示,这种神奇变化全依赖于银碳纳米墨水。银碳纳米墨水混合了三种物质:单壁碳纳米管、镀银纳米线薄膜和普通墨水。其中,前两者用于形成“蓄电池”的两极,而墨水的功用是将前两者固定在纸上。 利用这种墨水制作出来的纸电池最大的特点就是拥有超高的效率,几乎可以达到锂电池的10倍,而且不依赖特殊纸张,普通纸就能和墨水配合。另外,这种纳米结构的电池也非常耐用,其寿命可以轻易达到40,000次的充放电循环,至少比锂电池高出了一个数量级。 由于同时具备了低成本、轻薄、高寿命等多个特点,其应用前景难以想象。实验室的工作人员崔义(Yi Cui)介绍说:“现在确实需要一个低成本、高性能的能量储存方式。” 纸电池研究人员–崔义 (Yi Cui),这位以及后面出现的演示人员都是华人科学家。 纸电池的制作步骤之一:将混合了单壁碳纳米管和镀银纳米线薄膜的墨水涂在纸上 博士后胡兵 (Bing Hu)在演示纸电池的制作步骤之一 今年9月份,世界领先的高性能电池制造商晶澳太阳能(JA Solar)也宣布了类似的技术,将采用Innovalight硅墨水技术商业化新一代太阳能电池产品。(来源:爱活网 http://pugetsound.sites.acs.org/apps/photos/photo?photoid=110082438 2010 Pauling Symposium from M Diblee Yi Cui at the symposium Back to Album Photo 1 of 23 Previous | Next http://www.lbl.gov/Publications/Currents/Archive/Oct-01-2004.html October 1st, 2004 Berkeley Lab Scientist Wins E.O. Lawrence Award Moore Foundation Boosts Supernova Research Autumn Moon Festival Celebrates Asian Traditions Ready, Set � Runaround XXVII Next Friday ‘Dream Beams’ Achieved with Laser Wakefield Acceleration Meet Lab Director Chu at All Hands Reception What Lies Beneath in Buried Nanolayer Interfaces New Insights into Hydrated Electrons Berkeley Lab Scientists Gain New incite on Photosynthesis Bound for DC, Schroeder Follows Long Tradition of Service in Nation’s Capital Flea Market People, AWARDS HONORS Berkeley Lab Scientist Wins E.O. Lawrence Award By Lynn Yarris Richard Saykally, a professor of chemistry with UC Berkeley who joined Berkeley Lab’s Chemical Sciences Division (CSD) a year ago, has been named one of seven new winners of the E.O. Lawrence Award by Secretary of Energy Spencer Abraham. Saykally won the award in the chemistry category for his groundbreaking developments in the field of spectroscopy. “We are all enriched by the contributions these researchers have made, ranging from engines with no moving parts to better ways to see the stars,” Secretary Abraham said in announcing the 2004 Lawrence Awards, which were named for Berkeley Lab’s founder, Ernest Orlando Lawrence, the Nobel Prize-winning inventor of the cyclotron. The awards, the highest given by the DOE, recognize outstanding scientific contributions in atomic energy. “The Lawrence awards, and the research for which they are given, show that DOE could easily be called the Department of Science and Energy,” Secretary Abraham said. Each winner of this year’s Lawrence Award will receive a gold medal, a citation, and $50,000. The awards will be presented at a ceremony in Washington, D.C. on Nov. 8. Saykally, a professor on campus for 25 years, is Berkeley Lab’s 26th recipient of a Lawrence Award. His award citation reads: “For the invention of velocity modulation spectroscopy of molecular ions; for the development of far-infrared vibration-rotation spectroscopy of radicals, clusters and carbon chains; for the elucidation of the structure and potential energy surfaces for water clusters; and for the development and application of cavity ring-down spectroscopy techniques.” The Lawrence Awards were established by Dwight D. Eisenhower in 1959. Recipients are chosen by independent panels from thousands of nominations by international scientists and research organizations. The awards are intended to encourage the careers of scientists who show exceptional promise. The other 2004 Lawrence Award winners were Nathaniel Fisch of Princeton University and the Princeton Plasma Physics Laboratory; Bette Korber, Fred Mortensen and Gregory W. Swift of Los Alamos National Laboratory; Claire Max of UC Santa Cruz and Lawrence Livermore National Laboratory; and Ivan Schuller of UC San Diego. Saykally has spent much of his professional career finding unique new ways to explore important physical phenomena we know little about. Richard Saykally is the 26th Berkeley Lab scientist to win an E.O. Lawrence Award, the highest DOE science honor. Take, for example, his invention of velocity modulation spectroscopy to study molecular ions — enigmatic and elusive molecules with a net electrical charge. Molecular ions play critical roles in many areas of chemistry and physics, including the creation of plasmas (ionized gases), such as those found in lightning and the Northern Lights, and the formation of molecules in space and the upper atmosphere. Using standard spectroscopy techniques to study molecular ions is difficult because their light absorption properties are overlapped and drowned out by the stronger light absorption of electrically neutral molecules. Saykally solved this problem through the use of an alternating electric discharge that caused molecular ions to move towards the negative electrodes while neutral molecules remained unaffected. This enabled him to easily distinguish the molecular ions in his spectroscopic studies. Said CSD Director Dan Neumark, “Rich Saykally is one of the world’s leading spectroscopists. He has invented several new experimental techniques and has developed novel conceptual frameworks for understanding the high-resolution spectra of weakly bound species, such as ammonia and water clusters, which cannot be treated by the standard tools of spectroscopy.” Born in Rhinelander, Wis., in 1947, Saykally earned his B.S. at the University of Wisconsin at Eau Claire in 1970 and his Ph.D. at the University of Wisconsin at Madison in 1977. Prior to coming to Berkeley in 1979, he was a National Research Council Postdoctoral Fellow at the National Institutes for Science and Technology at Boulder, Colo. He currently holds the Class of 1932 Distinguished Professor Chair at Berkeley and is the co-author of more than 300 scientific publications. Among the 35-and-counting scientific honors Saykally has received are the National Science Foundation’s Presidential Young Investigator Award, the E. R. Lippincott Medal for Spectroscopy, the Centenary Medal of the United Kingdom’s Royal Society of Chem-istry, and the Irving Langmuir Award in Chemical Physics. He is a member of the National Academy of Sciences, a Fellow of the Royal Society of Chemistry, the American Physical Society, the Optical Society of America, the American Academy of Arts and Sciences, and the Amer-ican Association for the Advance-ment of Science. Saykally was also recognized as an outstanding educator when he won the UC Berkeley Distinguished Teach-ing Award in 1992. In his career, he has mentored nearly 50 Ph.D. students as well as a large number of postdoctorals and undergraduates, and has been actively involved in national secondary school education projects. Upon learning he had won the Lawrence Award, Saykally said, “It is a real honor to follow the many great Berkeley scientists who have been recognized by this award, and it is a fitting tribute to the accomplishments that my brilliant students and postdoctorals have managed through their hard work and creativity.” Moore Foundation Boosts Supernova Research by Paul Preuss The Nearby Supernova Factory will compile a catalog of the light curves, spectra, and other features of hundreds of nearby Type Ia supernovae. The federal government has lately paid less attention to the history and fate of the universe than to returning to the moon. Thus a recent $2.38-million grant from the Gordon and Betty Moore Foundation supporting the work of the Nearby Supernova Factory (SNfactory) is particularly welcome. Its purpose is to further dark energy research through the study of Type Ia supernovae. “We are delighted with the wisdom and foresight shown by the Moore Foundation in supporting cutting-edge research in the physical sciences,” says Saul Perlmutter. He and Michael Levi, both of the Physics Division, are principal investigators for the grant, made to UC Berkeley’s Space Sciences Laboratory. They note that “there was no natural home for this research in the shrinking federal physical research portfolio.” Because Type Ia supernovae are very bright and remarkably similar in their brightness, they make the best cosmological “standard candles.” In 1998 Perlmutter and his colleagues used them to conclude that the universe is flying apart at an accelerating rate, propelled by mysterious dark energy. “Good as Type Ia supernovae are as standard candles, there is a residual uncertainty of a few percent in brightness measurements, and thus distance measurements,” says Levi, an uncertainty which must be reduced for futher studies of dark energy. The way to reduce uncertainty is to learn more about the physics of nearby supernovae. Physics Division astronomer Greg Aldering, who leads the international SNfactory, says, “We designed the SNfactory to discover hundreds of nearby Type Ia supernovae while they are still brightening — and close enough to measure with great precision.” The Gordon and Betty Moore Foundation was established by Intel cofounder Gordon Moore (best known for “Moore’s Law” predicting the doubling of computer chip capacity every two years) and by his wife Betty. The Foundation supports environmental conservation, science, and higher education. Autumn Moon Festival Celebrates Asian Traditions Take one full moon, add 1,000 years of tradition, and you’ll get the Autumn Moon Festival, an occasion celebrated by nearly 90 Berkeley Lab employees and their families last Thursday thanks to the Asian Club. The festival is a popular celebration of abundance and togetherness dating back to China’s Song Dynasty, more than 1,000 years ago. The event traditionally occurs on the fifteenth day of the eighth lunar month, when the moon is at its fullest and brightest — an ideal time to celebrate the summer harvest and the lore of mythical moon goddess Chang O. “The Autumn Moon Festival has many themes, but the main one is, it traditionally emphasizes the importance of family and community unity,” said Paul Gee, who was anointed “king” of the event. “We want the Lab to be more aware of Asian culture, and we also want to reflect the diversity of the people who work here.” A king needs a queen, so Laura Luo was anointed “queen,” and the two presented Lab Director Steven Chu with a moon cake. Attendees also enjoyed Chinese moon cake while listening to Larry Li Guo’s version of “Chang’er the Beauty and Houyi the Archer,” a 1,000-year-old myth about their love for each other, the moon, and moon cakes. Last week’s occasion marked the first time the Asian Club celebrated this tradition. Ready, Set � Runaround XXVII Next Friday By Monica Friedlander Twenty-seven years ago, Bruce Heppler pedaled his unique wheeled contraption amid the throng of runners and walkers in the Lab's first Runaround. Whoever said you can’t improve on a good thing must have had the Berkeley Lab Runaround in mind. Now in its 27th year, the event has the same look and feel as the very first time that hundreds of walkers, runners, and riders of various vehicles huffed and puffed their way up and down the Lab’s slopes back in 1978. When participants take off next Friday, Oct. 8., they will walk, run or bike roughly the same course, partake in the same sense of competitiveness and goofiness, and will be greeted at the cafeteria, as always, with food, music, as well as the highly treasured Runaround t-shirts. Even the funky prize categories that first Runaround organizer Harvey Levy called “the categories of absurdity” will be awarded as always — everything from best legs to best costumes. The race begins at the Firehouse at noon and ends at the cafeteria parking lot. The course is 1.86 miles (3 kilometers) long, with some steep elevation changes. All employees and retirees healthy enough to take on the challenge are encouraged to participate. To add to the whimsical atmosphere, individual and group costumes are highly recommended. Needless to say, the light-hearted spirit will not deter the competitiveness of the elite runners, who have their eyes set on crossing the finish line first. The timers are ready for them. To make sure that all participants in the Runaround have a good time and stay healthy before, during and after the event, organizers and members of the Lab’s Health Services have the following suggestions: Before the Runaround: Check with your doctor to make sure you have no medical problems that may preclude you from taking part. Prepare by walking or running three to four times a week to increase strength and endurance. Eat a meal composed of protein and carbohydrates two to three hours prior to each workout. Drink fluids two to three hours before each workout and bring water to drink during your walk or run. Wear comfortable shoes and clothes that do not restrict your stride or rub against your skin. Apply sunscreen to your face, ears, neck, arms, and legs. During the Runaround: Prepare your body by doing stretching exercises. Carry water to drink. Apply sunscreen to sun exposed areas. After the Runaround: Stop by the Health Services table at the finish line if you experience any medical problems. Pick up your t-shirt. Partake in the refreshments, entertainment, and camaraderie of the Lab’s most popular event of the year. For more information on the Runaround, a course map, and past results, see the Runaround website at http://cfi.lbl.gov/~derenzo/ runaround/ . ‘Dream Beams’ Achieved with Laser Wakefield Acceleration by Paul Preuss Members of the L'OASIS group (left to right) are Wim Leemans, Cameron “Dream beam,” announces the cover of this week’s Nature, and the beam in question, pictured in sinuous waves of blue and black, was created right here at Berkeley Lab — a major technological advance achieved by the L’OASIS group led by Wim Leemans in the Center for Beam Physics of the Accelerator and Fusion Research Division. (L’OASIS stands for Laser Optics and Accelerator Systems Integrated Studies.) For a quarter of a century physicists have been trying to push charged particles to high energies with devices called laser wakefield accelerators, which offer the possibility of compact, high-energy machines for probing the subatomic world, studying new materials and new technologies, and medical applications. In theory, particles accelerated by the electric fields of laser-driven waves of plasma could reach, in just a few score meters, the high energies attained by miles-long machines that use conventional radio-frequency acceleration. But while researchers have generated electric fields in plasmas a thousand to ten thousand times greater than in conventional accelerators, these large fields exist only over the short distance the laser pulse remains intense. Typically that’s only a few hundred micrometers (millionths of a meter) for a tightly focused pulse, and the energies of the accelerated particles are so widespread that fewer than one percent have enough punch for scientific applications. Channeling better beams Their research makes the cover of the September 30, 2004 issue of Nature. Now, using a technique called “plasma-channel guiding,” the L’OASIS group has accelerated bunches of electrons numbering several billion electrons each, all within a few percent of the same high energy of more than 80 million electron volts. “Laser wakefield acceleration works on the principle that by sending a laser pulse through a gas to create a plasma — separating negatively charged electrons from positively charged ions in the gas — some of the free electrons will be carried along in the wake of the plasma wave created by the laser,” Leemans explains. “Imagine that the plasma is the ocean, and the laser pulse is a ship moving through it. The electrons are surfers riding the wave created by the ship’s wake.” Unfortunately, simply punching a laser pulse through a plume of gas makes for a very short trip. “The acceleration distance is limited to what’s called the Rayleigh length — the length over which the laser remains focused,” says Leemans. “For optimum acceleration, you have to keep the wake going for many Rayleigh lengths, until just before the electrons start to get ahead of the wave and lose energy” — a distance otherwise known as the dephasing length. To achieve this, Leemans, working with graduate student Cameron Geddes and other colleagues, employed “the plasma analogue of an optical fiber.” The L’OASIS laser first sends an igniter pulse through the gas, to form a sort of “wire” of plasma. A second, heater pulse enters from the side and heats the plasma wire; as the channel expands, it becomes denser at the edges and less dense at the center. Five hundred trillionths of a second later, an intense driver pulse, with peak power approaching 10 trillion watts, plows through the plasma capillary. “There’s a close analogy between the plasma channel and an actual optical fiber of the kind used to send data,” Leemans says. In the simplest optical fibers, “the glass in the center has a higher index of refraction — meaning that light moves through it more slowly — and the surrounding glass walls have a lower index of refraction.” Thus the wavefront of the light stays flat as it moves through the fiber. The same is true of the plasma channel, because the plasma is denser at the edges than in the center. “Plasma actually has a lower index of refraction than vacuum, so the wavefront moving through the center of the channel moves slower than at the edges. This flattens the otherwise spherical laser wavefront and extends the distance over which the laser stays intense.” How is it that the electrons in the bunch are accelerated to nearly the same energy? To analyze their successful experiments, the group collaborated with the Tech-X Corporation of Boulder, Colorado, using the company’s VORPAL plasma simulation code to model their results on supercomputers at NERSC. The most critical factor, they found, lies in matching the long acceleration path to the dephasing length. The channeling technique not only opens the way to compact accelerators with multiple stages, says Leemans, but it “has already suggested novel sources of radiation” including coherent infrared and terahertz radiation and efficient generation of x-ray pulses measured in quadrillionths of a second. “High-quality electron beams from a laser wakefield accelerator using plasma-channel guiding,” by Cameron Geddes, Csaba Toth, Jeroen van Tilborg, Eric Esarey, Carl Schroeder, David Bruhwiler, Chet Nieter, John Cary, and Wim Leemans, appears in the September 30, 2004 issue of Nature . Meet Lab Director Chu at All Hands Reception Berkeley Lab employees who have not yet had a chance to meet new Laboratory Director Steven Chu in person will get the opportunity next Tuesday. From 3 to 4:30 p.m., he will appear at a welcome “all hands” reception in the cafeteria main dining room. After brief remarks, Director Chu will be available to answer questions and greet attendees. Light refreshments will be provided What Lies Beneath in Buried Nanolayer Interfaces By Lynn Yarris When incident waves of x-rays from the ALS interfere with x-ray waves reflected from a sample that’s grown on top of a nano-scale multilayer mirror, a vertical standing wave is formed that can be used to identify and study various properties of each atom in the sample. Nanotechnology is superficial, the joke goes, meaning that when objects become so tiny, everything takes place on their surfaces. However, the nanosized components of future computers and memory storage devices will actually consist of multiple overlying layers of materials. This means scientists need a way to selectively study the interfaces buried below surfaces. Researchers at the Advanced Light Source (ALS) have developed just such a technique. Charles Fadley, a physicist affiliated with Berkeley Lab’s Materials Sciences Division and a professor of physics with the University of California at Davis, led this research effort. His principal collaborators on the project have been See-Hun Yang, now at the IBM Almaden Research Center, and Simon Mun, now an ALS staff scientist. “We’ve developed a new way of selectively looking below the surface in nanolayers of materials using soft x-ray standing waves,” says Fadley. “This permits us for the first time to apply all of the principal ALS spectroscopies in a much more depth-sensitive way that directly yields chemical state and magnetic information near the buried interface between two materials.” Layered nanostructures will play an especially critical role in the development of the next generation of magnetic read-heads for high-density data storage, and for the much-anticipated magnetic random-access memory chips or MRAMs. Using spintronics — the spin of electrons rather than their charge — to store data, MRAM promises “instant-on” computers that can store more information and access it faster, while consuming far less power than today’s machines. To reach these goals, however, scientists and engineers need a way to “see” what’s going on at the interfaces where different layers of materials meet. Furthermore, they need to do this without damaging the materials, a requirement that demands extreme delicacy because each layer is only a few atoms thick. “The most powerful method for studying these interfaces has been scanning transmission electron microscopy, but it can’t be considered nondestructive,” says Fadley. “Using standing waves of soft x-rays, we can nondestructively analyze buried interfaces for atomic composition, and for chemical, magnetic, and electronic structures.” Charles Fadley (front), working with See-Hun Yang (left) and Bongjin Simon Mun, are using a standing wave spectroscopy technique and the circularly polarized light of ALS Beamline 4.0.2 (shown here) to study buried interfaces in nanolayers of materials that will be critical to future electronic devices and magnetic storage media. A standing wave is a vibrational pattern that’s created when two waves of identical frequency interfere with one another while traveling in opposite directions through the same medium. In this case, x-ray waves from the ALS strike a sample grown on top of a nanoscale multilayer mirror, which was designed by researchers at Berkeley Lab’s Center for X-Ray Optics to create especially strong reflected waves. When incident ALS x-ray waves interfere with waves reflected from the sample, specific points along the interfering waves appear to be standing still, even though they are vibrating up and down. The interactions between these standing waves and the inner “core” electrons of an atom can be used to identify that atom and study its various properties. Since Fadley and his research group wanted to investigate the thickness-dependence of the phenomena they were studying, they needed to make their standing wave probe depth-sensitive. They accomplished this by growing their samples in the shape of a wedge, and scanning a beam of x-rays across the surface at an angle that created a vertical standing wave. “The intensity maximum of our standing waves, which generates most of the signal we measure, occurs at a particular depth below the surface,” says Fadley. “This gives us the depth-sensitivity and the high resolution we need to map the changes in chemical and magnetic behavior that take place at, and around, an interface.” The beams used to create the standing-wave probe are circularly polarized soft x-rays generated at ALS Beamline 4.0.2. A beam of light is circularly polarized when its electric-field component rotates either clockwise or counterclockwise around the direction in which the beam is traveling. The absorption of circularly polarized light by a magnetic material at an interface reveals much about the magnetic moments of the atoms at that interface. This makes Beamline 4.0.2, which is powered by one of the ALS’s premier undulator magnets, ideal for studying the types of buried interfaces that will be found in future data storage devices. “With soft x-ray standing waves we can, for the first time, look at multilayered nanostructures using a tour de force of all the relevant spectroscopy techniques, including photoelectron, x-ray emission and x-ray absorption spectroscopies,” says Fadley. Fadley and his colleagues have already used their standing wave technique to gain new insight into the mechanisms behind the phenomenon known as giant magneto-resistance, or GMR — a 20 to 50 percent boost in electrical conductivity that occurs when a magnetic field is applied to interfaces between magnetic and nonmagnetic metals. GMR nanostructures can be found in virtually all of today’s computer disc read heads, and a detailed understanding of the buried interfaces in these devices is critical to their performance. “We applied the standing wave technique to an iron/chrome interface and were able to determine the width of the interface, as well as a detailed profile of the magnetic field running through it,” Fadley says. “We observed that chrome, which normally is nonmagnetic, was being magnetized by iron just below the interface, but in a direction opposite to the field of the iron.” Fadley says that the standing wave spectroscopy technique he and his group have developed should also prove useful for future studies of ultrathin films, liquid layers, molecular clusters and environmentally-related surface chemistry. Combined with an x-ray microscope, it could also be used to do spectroscopy in three dimensions New Insights into Hydrated Electrons Understanding May Lead to Clues into Biological Processes that Can Cause Disease By Dan Krotz Chemical Sciences Division Director Daniel Neumark Sometimes, it pays to think small. By observing how a single electron behaves amid a cluster of water molecules, a team of scientists has gained a better understanding of a fundamental process that drives a myriad of biological and chemical phenomena, such as the formation of reactive molecules in the body that can cause disease. The researchers, led by Chemical Sciences Division Director Daniel Neumark, used an extremely fast imaging technique to observe an excited electron, surrounded by several dozen water molecules, relax back to its original energy state. This journey occurred much more quickly than one theory predicts, lending credence to an opposing theory and helping to solve a longstanding puzzle in the world of hydrated electrons. Neumark conducted the study with scientists from UC Berkeley and Israel’s Tel Aviv University. Their research is published in the September 16, 2004 edition of the online Science Express. As their name implies, hydrated electrons are electrons that are dissolved in water. They occupy an elliptical void formed by six water molecules, and they’ve intrigued scientists since their discovery in 1962. The simple fact that they exist is interesting, as is their little understood role in many biological and chemical processes. Although it is too early to tell how Neumark’s work will elucidate the behavior of hydrated electrons in the real world, such as how they conspire to form free radicals (highly reactive molecules that can damage tissue and contribute to diseases such as cancer, rheumatoid arthritis, and heart disease), it will help shape future research. Leading up to this study, scientists had been divided as to how hydrated electrons react after they’ve been excited. One theory holds that electrons convert back to their original energy state in about 50 femtoseconds, or 50 millionths of a billionth of a second. The other theory contends this conversion takes much longer, about 500 femtoseconds. To help settle the case, Neumark’s team observed a single electron in a tiny cluster of between 25 and 50 water molecules. Such clusters give scientists an extremely close look at the electron’s dynamics. For example, they can determine whether water molecules are simply rearranging themselves around an electron in an excited or a ground state, or whether these dynamics indicate the actual transition of the electron between these states. The team created an electronic excitation by zapping the cluster with a femtosecond laser pulse. They then used time-resolved photoelectron imaging to take snapshots of the electron as it relaxed back to its ground state. The dynamics and rate of this conversion, when extrapolated to how hydrated electrons behave in bulk, suggest that hydrated electrons relax back to their unexcited state in about 50 femtoseconds — a finding that tips the scales in favor of this theory. “Resolving which of these two models is correct is a key step. We’ve used time-resolved studies of finite clusters to resolve an issue of fundamental importance, namely the dynamics of an excited hydrated electron,” says Neumark. “More generally, this work represents a fairly unique example of how studies of clusters can elucidate bulk phenomena. Berkeley Lab Scientists Gain New incite on Photosynthesis By Lynn Yarris Seeking to unlock the secrets of photosynthesis are, left to right, Alán Aspuru-Guzik, Graham Fleming, Romelia Salomón-Ferrer, Brian Austin, Harsha Vaswani, William Lester, and Ricardo Oliva. Solar power remains the ultimate Olympic gold medal dream of a clean, efficient and sustainable source of energy. The problem has been that in order to replace fossil fuels, we need to get a lot more proficient at harvesting sunlight and converting it into energy. Nature has solved this problem through photosynthesis. All we have to do is emulate it. But first, we need a much better understanding of how photosynthesis works at the molecular and electronic levels. “After working on the problem for about 3 billion years, nature has achieved an energy transfer efficiency of approximately 97 percent,” says Graham Fleming, director of Berkeley Lab’s Physical Biosciences Division and an internationally acclaimed leader in spectroscopic studies of photosynthetic processes. “If we can get a complete understanding as to how this is done, creating artificial versions of photosynthesis should be possible.” Towards this end, Fleming has teamed his capabilities in ultrafast spectroscopic experiments with the computational expertise of Chemical Sciences Division theoretical chemist William Lester, Jr. Their collaboration received one of three inaugural INCITE Awards (Innovative and Novel Computational Impact on Theory and Experiment) from the U.S. Department of Energy’s Office of Science. The INCITE program is aimed at advancing a select number of computationally intensive scientific projects with high-impact potential by providing a substantial amount of time on the supercomputers at NERSC. “The theory behind energy transfer in photosynthesis is more than 50 years old, but it has never been fully tested,” Fleming says. “Some aspects of this theory are beyond current experimental testing capabilities, but can be simulated at NERSC.” Says Lester, “Before we had computational capabilities such as those at NERSC, it was not possible to model the energy and electron transfer processes we want to study. NERSC can provide us with the computers and software support that will enable us to run codes that will give us the information we need and could not otherwise obtain.” Life on Earth is dependent upon the photosynthetic reactions that green plants and cyanobacteria use to convert energy from sunlight into chemical energy. Among other things, these reactions are responsible for the production of all of our planet’s oxygen. In high school biology, students learn that nature uses chlorophyll, the family of green pigment molecules, as a light absorber and energy-transfer agent, but the chemistry behind this process is extremely complicated. What’s more, photosynthetic chemistry takes place on a femtosecond timescale (a femtosecond being one millionth of a billionth of a second). “According to the first law of photosynthetic economics, a photon saved is a photon earned,” Fleming says. “Nature has designed one of the most exquisitely effective systems for harvesting light, with the reactions happening too fast for any light to be wasted as heat. Current synthetic light-harvesting devices, however, aren’t following nature’s model.” Fleming has been using femtosecond spectroscopy techniques to shed scientific light on nature’s light-harvesting and energy-transferring secrets. Photosynthesis in plants starts with a light harvesting system, which consists of two protein complexes, Photo-system I and Photosystem II. Each complex features light-absorbing antennae made up of members from two families of pigment molecules, chlorophylls and caroten-oids. These pigment antennae are able to capture photons of sunlight over a wide spectral and spatial cross-section. Using a computational method called a quantum Monte Carlo (QMC) simulation and the IBM SP computer at NERSC, Berkeley Lab scientists are calculating optimal electronic pathways for photosynthetic energy transfer. These are the largest electronic and molecular calculations ever performed for a biological molecule using a QMC code The chlorophyll and carotenoid molecules gain extra “excitation” energy from the captured photons that is immediately funneled from one neighboring molecule to the next, until it arrives at another molecular complex, which serves as a reaction center for converting energy from solar to chemical. This transferal of excitation energy involves several hundred molecules and hundreds of individual steps along different electronic pathways, yet still transpires within 30 picoseconds for Photosystem I and 200 picoseconds for Photosystem II. By human standards of time, that’s instantaneous. “If we can follow the steps in transferring energy from donor to acceptor molecules, we might be able to design new and much more effective strategies for synthetic light harvesters,” Fleming says. Because the extra energy being transferred from one molecule to the next changes the way each molecule absorbs and emits light, the flow of energy can be spectroscopically followed. However, to do this, Fleming and his experimental research team need to know what spectroscopic signals they should be looking for. This is where the INCITE grant will help. Working with NERSC staff members — most prominently, David Skinner — and using NERSC’s IBM SP computer, Lester has developed and is running a quantum Monte Carlo computer code to predict the optimal electronic pathways for photosynthetic energy transfer. A “quantum Monte Carlo” is a statistical model for studying strongly correlated systems such as electrons. Says Lester, “Most people have long thought of computational chemistry as only being able to tackle simple systems reliably, but we’ve come a long way with improved implementation of our algorithms in recent years.” With the INCITE grant, which will provide them with a million processor hours, Fleming and Lester are studying the electronic structures behind a defense mechanism within the photosynthetic system that protects plants from absorbing more solar energy than they can immediately utilize, and, as a result, suffering from oxidation damage. The focus will be on the carotenoids in Photosystem II, which appear to be the controlling elements behind this photoprotective mechanism. “The photosynthetic light-harvesting system is so sensitive to changing light conditions, it will even respond to the passing of clouds overhead,” says Fleming. “It is one of nature’s supreme examples of nanoscale engineering.” Other researchers working with Fleming and Lester on this project include Alán Aspuru-Guzik, Romelia Salomón-Ferrer, Brian Austin, Harsha Vaswani and Ricardo Oliva. Bound for DC, Schroeder Follows Long Tradition of Service in Nation’s Capital By Ron Kolb Lee Schroeder, pictured in his Lab office, prepares for his extended stay in Washington. The official acronym to describe nuclear scientist Lee Schroeder’s newest assignment is IPA: Inter-agency Personnel Agreement. But it might as well be SWS: Scientist With Suitcase. After all, this is Schroeder’s third dispatch to Washington D.C., and in each case, he and his wife Beverly pack their bags and settle in for an extended stay in the nation’s capital. But he’s happy to do it, on behalf of his profession and his colleagues. “I see this as an enabling position — enabling the community to carry out the most important nuclear science,” he says. “This” is the IPA that began in August in the Department of Energy’s Nuclear Physics program office under Associate Director Dennis Kovar. For at least the next year, Schroeder will work out of the Germantown (MD) office, dealing with priorities in research and associated funding, reviewing projects and agreements, and interacting with the Nuclear Science Advisory Committee (NSAC) on the implementation of the current five-year plan and the development of the next one. “No matter what the outcome of the election, there will be budget issues,” he says. “One of the big questions facing nuclear science is, will RIA (Rare Isotope Accelerator, pronounced REE-uh) go forward? It presently has CDO (the mission needs statement) and is poised to move forward. It’s a near-billion-dollar project and among the highest priorities of the DOE Office of Science for the construction of new facilities.” RIA will be the world’s most powerful research facility dedicated to producing and exploring new rare isotopes that are not found naturally on earth. The beams in RIA will be 10 to 100 times more powerful than those available today. It will allow physicists to explore the structure and forces that make up the nucleus of atoms, learn how chemical elements that made up the world were created, and play a role in developing new nuclear medicines and techniques. He also notes that nuclear science will play an important role in the global future, especially in areas like energy production. With the fossil fuel production curve going down, societies will be faced with alternative energy choices, one of which is the very controversial nuclear energy question. “In the U.S. especially, we will have to confront this question,” Schroeder predicts, “even though it’s highly politicized. We know we can produce it (nuclear energy), but can we handle the waste, and how do we as a society deal with safety? We must confront these questions in an unemotional way. Drawing on experience The DOE and other federal programs request interagency personnel exchanges like Schroeder’s to take advantage of the experience and the knowledge gleaned from years of successful research on the front lines. Berkeley Lab physicist Moishe Pripstein just returned from a two-year IPA assignment working as program manager for the U.S. effort at the Large Hadron Collider (LHC), due to go on line at CERN in Switzerland in mid-2007. Both the DOE and the National Science Foundation are involved, as well as close to 800 researchers and engineers across the country. Pripstein described his experience in Germantown as “answering and sending a lot of e-mail, talking on the phone a lot, organizing reviews, and walking the halls of DOE and poking my nose in where I probably shouldn’t.” Modesty prevents him from acknowledging his success connecting the physics practitioners in the field with the agencies in Washington, a bridging role with which he is most comfortable. He says such communication is critical as program priorities are reassessed. Moishe Pripstein just returned from his IPA assignment in Washington. Arriving at the Lab full-time in 1965 with a doctorate from UC Berkeley in hand, Pripstein has been involved for five decades in some of the most significant physics experiments to develop here, including the ill-fated Superconducting Super Collider and the BaBar b-factory at SLAC, for which he was head of the Berkeley Lab group. After BaBar was running smoothly for several years, Pripstein says he sought the LHC coordinating role. “To be frank, I had been very fortunate here (at Berkeley Lab) to get well supported for my research and my ideas,” he recalls. “I felt I should give something back.” Committed for one year, he ended up staying for two. Pripstein emphasized how significant Schroeder’s role will be. “It’s especially important now, because with the budget difficulties facing us in the future, it will be important to reassess priorities in the field. The agency, and the field, are at a critical juncture,” he says. National Energy Research Scientific Computer Center scientist Craig Tull also departed this fall as a detailee in the high-energy physics office of DOE, coordinating computing systems planning for the LHC and other program projects. Schroeder’s first long-distance experience was in 1987-1989, when he was detailed to DOE Nuclear Physics as a manager of the $70 million Heavy Ion Program. His expertise was coveted because of his work on the start-up team for Berkeley Lab’s heavy ion program in the 1970s, and his subsequent service as both scientific coordinator and scientific director of the old Bevalac. Again in 1992, he was called to Washington to be assistant director for physical science and engineering in the White House Office of Science and Technology Policy (OSTP). In the administration of George Bush Sr., he had a huge portfolio that included responsibilities with DOE, NASA and the National Science Foundation, among others. With an administration change, he returned to Berkeley and, from 1995 to 2002, he directed the Nuclear Science Division. “I’ve been a scientific bureaucrat for a long time,” he laughs, noting that can be a good thing when responding to the inevitable frustrations of process, priority-setting, and red tape. “You have to respond to it,” he says. “You can’t short-circuit it.” Schroeder has seen it all — or most of it — in his 33 years as researcher and manager since arriving at Berkeley Lab in 1971. And DOE’s Kovar hopes to take advantage of all three decades in the coming year. 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Cui Among Top Young Innovators Berkeley Lab guest Yi Cui, who works in the Materials Sciences lab of Paul Alivisatos, was named to be one “100 young innovators of nanotech” by Technology Review, a publication of the Massachusetts Institute of Technology. Many of this year’s TR100 honorees, the article says, “are turning to nanotechnology to gain an unprecedented level of precision, control, and flexibility in creating new materials and devices. In Memoriam: Ming Xie (1959-2004) An expert in the theory of free-electron lasers and staff scientist in AFRD, Ming Xie passed away in China on Aug. 23 after a year-long battle with cancer. Born in Beijing in 1959, Ming earned his B.S. in physics from Wuhan University in 1982. He came to the US for his graduate education and obtained his M.S. (1984) and Ph.D. (1989) degrees from Stanford University. Following his graduation, he joined Berkeley Lab as a postdoc and was promoted to staff scientist shortly thereafter. He also held the position of guest professor at Beijing University since 1998. Ming’s lifelong interest was the theory of free-electron lasers, for which he gained wide recognition. This work led him to contribute to other areas, such as laser acceleration theory and its connection with electromagnetic radiation, gamma-gamma interactions, physics of the interaction point of future high-energy colliders, and charged-particle cooling for muon colliders. He authored or co-authored some 70 papers and contributed to the design reports on three new accelerators. He is survived by his wife, a 16-year-old son, a sister, and his parents. His colleagues at the Center for Beam Physics are planning a memorial service
电子香烟的安全性问题一直备受关注,不仅仅是与普通烟草香烟相比较的安全性问题,而且也包括是否会在使用过程中产生爆炸等其他安全性问题。美国就有人因为使用电子香烟的电池发生爆炸,导致嘴受伤。根据官方人士对爆炸原因的审查结果,认为是电池不合格。这种电子香烟很有可能是一种山寨产品,对于电池爆炸的原因解释如下:其一是电池产品不合格,另一个可能的原因是电子香烟的 IC 卡上没有过放电保护程序;一旦用户继续吸电子香烟 , 电池过量放电 , 反过来又会引起电池过热而引发爆炸。一般正规生产厂家生产的电子香烟,特别是持有电子香烟专利技术的生产厂家,会对其产品配备一个高质量的电池 , 投放市场之前,在所有情况下都被仔细地检查和进行过测试,而且在电子香烟的 IC 卡上,有电池过充电保护程序和过放电保护程序,可以防止爆炸事故的发生。更多信息请浏览: Ecigy Company. Why the Copycat’s Products Have the Health and Safety Problem s.
同一起跑线上的两块电池 鲍海飞 2012-8-30 我的第一部手机一直陪伴着我大约 6 年了!就是那种很土很土的小平板,上面是小小的屏幕,下面是小小的字母数码按键。同事们一直劝我赶快扔掉换个新的,但是毕竟用惯了,总也舍不得,而且其性能还算可以,发个短信对方也能收到,打个电话也没有什么耽搁,况且我也没有太多业务,也就一直没有换新的手机,直到今天还在使用。 手机从商店买来的时候就配了两块电池。头两年的时候,我经常交替地使用这两块电池,一个在用的时候,另一块就及时充满电,当一块用光了,就换另一块,就这样一直交替地使用。可是有一段时间,我懒得把电池从手机里面拔出来,就直接给手机充电了,而把另一块电池就放到了抽屉里。大约过了半年的光景,我想起了那块闲置的电池。当我再给那块电池充电的时候,那块闲置的电池早已经罢工了,根本就充不进去电了!没办法,我只能继续使用原来那块电池。按说,一般估计电池的使用寿命也就三年,结果,奇迹发生了!我这唯一的一块电池居然今天还在使用,而那块闲置的电池却永久地放在抽屉里了。 两个由同种材料构成的、在同一个流水线上加工出来的电池,处在在同一个起跑线上的两块电池居然有着两种截然不同的命运,是天生固有的吗?还是有一个就理所当然地天长地久,而另一个却过早地寿终正寝成了短命鬼吗?当然不是。只是由于个人的疏忽,一个一直在使用,而另一个却被束之高阁。结果,被使用的电池依旧生机盎然,一直在勤勤恳恳地工作;而被束之高阁的电池虽然没有锈迹斑斑、形状依旧,但却只能无奈地退出了历史舞台!多么大的反差! 由电池想到了现状,曾经有多少时候,我们谈人才、谈理想、说环境、讲体制、论成长,看了这个案例总有让人说不出的滋味。一块电池,尚且如此,由于闲置,就自生自灭了,又何况人呢? 有时候,在恶劣的环境下,我们要善于应对,如果被束之高阁,成为摆设也许真的就没有用了!这个时候,你还能怀疑达尔文先生的进化论吗?这个时候,你不怀疑庄子的‘无用乃大用’的理论吗?尽管每一种理论都有其时代、环境和历史的背景。 曾经,有这样一句广告词:‘不要让孩子输在起跑线上!’其含义可能远不止于此,它还有第二层含义、第三层含义、甚至更多。有的孩子赢在了起跑线上,但是由于各种原因,如父母的过于‘揠苗助长’,只能导致‘伤仲永’了。而那些没有赢在起跑线上的孩子,其命运就更难说了。若得到‘用’,即使是所谓的‘寒门’也依然能够创造辉煌;反之,若得不到‘用’,即使是‘豪门’也将一事无成。 写到这里,我想起了莎士比亚说过的一句名言: To be, or not to be 。它究竟隐藏着什么更深刻的含义,莫非和我这电池理论一样,它里面也隐含着其存在的价值和意义? 或许,你应该欣喜,自己‘被人’或者‘被自己’使用着,你在不断地被‘充电’又‘放电’,完成生命的一次又一次灿烂。当我们得不到‘用’的时候,我们就应该要及时给自己充电,你就自己‘折腾’自己,要不断的自我知识更新、思维更新、观念更新,这样才能够保持生命和存在的常新和长新。
为了完成基金内容,最近一直在做非水性电解液电镀金属薄膜。但这个领域相比目前热的又红又紫的能源材料来讲,自然逊色颇多。于是想到了将电沉积薄膜与锂离子电池负极材料结合起来,虽然这方面的研究也是铺天盖地了,但这项研究所采用的电沉积工艺还是区别于传统的,所以获得的Sn基薄膜的形貌和结构也有所不同,这样就有了研究的必要性。于是,在胆碱基离子液体中进行了电沉积Sn薄膜的工艺研究,结构表征发现薄膜具有多孔不连续结构,并且薄膜表面自然氧化成SnO2,而与集流体接触的Sn发生了合金化,原位生成了Cu6Sn5,这种原位合金化作用可以进一步增强活性材料与集流体的结合强度,降低电池内阻。相关报道请参与最新刊登在j power source上的文章。Thanks for your attention! Non-aqueous electrodeposition of porous tin-based film as an anode for lithium-ion battery Journal of Power Sources,214 (2012) 200-207 http://www.sciencedirect.com/science/article/pii/S0378775312008191?v=s5
今天一天都在CCS-RSC论坛待着……全是关于电池的,包括聚合物太阳能电池、染料敏化太阳能电池、燃料电池、锂电池等等,报告时间从早上九点到下午五点半(中午12点到14点午饭时间)。 上午:墨尔本大学Andrew B. Holmes教授(聚合物太阳能电池),诺丁汉大学Elizabeth Gibson博士(聚合物太阳能电池),中国科学院化学所王朝晖研究员(染料敏化太阳能电池),厦门大学郑南峰教授(燃料电池),报告时间均为40分钟。 下午:中国科学院长春应用化学研究所王鹏研究员(染料敏化太阳能电池),40分钟;北京理工大学曲良体教授(石墨烯量子点),华南理工大学吴宏滨教授(聚合物太阳能电池),中国科学院化学所李永舫研究员(聚合物太阳能电池),20分钟;帝国理工学院Martyn A. McLachlan博士(杂化太阳能电池结构),中国科学院化学所郭玉国研究员(锂电池),40分钟。 以上按照演讲先后顺序排列。全部都是用英语讲,摧残,身心疲惫…
美国纽约大学、纽约州立大学石溪分校和英国剑桥大学的研究人员开发出基于核磁共振成像(MRI)方法的锂电池内部检测技术,可为电池内部运作提供诊断服务,提高电池性能和安全性。相关研究成果发表在《自然—材料学》上。 锂电池充电时,锂纤维会附着在锂电池内部的碳电极上,会导致电池短路、过热着火,甚至爆炸。研究人员可利用该方法扫描分析锂电池内部的化学成分,消除隐患。。 核磁共振成像技术属于非侵入性技术,可以提供电池内部的微观结构,可视化电极表面上的微小变化。电解质和电极表面都可以使用这种可视化技术,提供了全面了解电池性能的变化进程。研究人员将进一步研究高清晰成像、成像时间更短的技术和方法,最终使电池更轻、更安全、更灵活。 该方法还可用于研究材料表面的不规则行为和裂缝,还可评估其他电化学设备,如燃料电池。该研究得到了美国能源部和美国国家科学基金会的资助。 7 Li MRI of Li batteries reveals location of microstructural lithium There is an ever-increasing need for advanced batteries for portable electronics, to power electric vehicles and to facilitate the distribution and storage of energy derived from renewable energy sources The increasing demands on batteries and other electrochemical devices have spurred research into the development of new electrode materials that could lead to better performance and lower cost (increased capacity, stability and cycle life, and safety). These developments have, in turn, given rise to a vigorous search for the development of robust and reliable diagnostic tools to monitor and analyse battery performance, where possible,in situ. Yet, a proven, convenient and non-invasive technology, with an ability to image in three dimensions the chemical changes that occur inside a full battery as it cycles, has yet to emerge. Here we demonstrate techniques based on magnetic resonance imaging, which enable a completely non-invasive visualization and characterization of the changes that occur on battery electrodes and in the electrolyte. The current application focuses on lithium-metal batteries and the observation of electrode microstructure build-up as a result of charging. The methods developed here will be highly valuable in the quest for enhanced battery performance and in the evaluation of other electrochemical devices. http://www.nature.com/nmat/journal/v11/n4/full/nmat3246.html#affil-auth
MIT科技评论“2016十大突破性技术”出炉 现在看只有两三项靠谱,但也非突破性 It is serious science, all things need to face up to time. 云适配获千万美金B轮融资,将开发移动端企业安全浏览器,- 就是 后来的“红芯浏览器”,牛皮吹大了! 襄樊市委副书记、市政协主席万桃元向记者介绍,襄樊高新青山电动车公司公司董事长曹青山经过20 多年的研究,在纯电动汽车电池和动力总成(电池、电机、电控)方面上取得了重大突破。其三项核心技术为磷酸铁钒锂离子电池、双定子磁悬复合转子直流电机、控制和能量回收系统。公司改装的电动车取得了三个五的好成绩:汽车可行驶里程50万公里,单次充电续驶里程500公里,经济时速下吨百公里能耗 5 度。技术位居世界领先水平。 现在湖北省委、省政府和襄樊市委、市政府对高新青山电动车事业予以高度重视及大力支持。首期扶持3000万项目启动资金。 今天看CCTV 10 魔力发明秀介绍 磷酸铁钒锂离子电池,很吃惊!节目中有一位北京理工大学教授简单点评:在国内整体水平此发明是不错的。却没有细说,在国际上相比又如何呢?实用性呢?如成本呢。总感觉他话中有话? 网上有人说他是骗子 “若真是可行,比亚迪的工程师可以集体bye-bye!” 要知道AIP潜艇蓄电池是当前常规潜艇的研究难点,西门子采用燃料电池,瑞典采用Striling 斯特林发动机。不解?硫酸铁钒锂离子电池真有如何神奇么?还是另一个水变油的传奇呢?请高手指点!
MIT researchers have found a way to improve the energy density of a type of battery known as lithium-air (or lithium-oxygen) batteries, producing a device that could potentially pack several times more energy per pound than the lithium-ion batteries that now dominate the market for rechargeable devices in everything from cellphones to cars. The work is a continuation of a project that last year demonstrated improved efficiency in lithium-air batteries through the use of noble-metal-based catalysts. In principle, lithium-air batteries have the potential to pack even more punch for a given weight than lithium-ion batteries because they replace one of the heavy solid electrodes with a porous carbon electrode that stores energy by capturing oxygen from air flowing through the system, combining it with lithium ions to form lithium oxides. The new work takes this advantage one step further, creating carbon-fiber-based electrodes that are substantially more porous than other carbon electrodes, and can therefore more efficiently store the solid oxidized lithium that fills the pores as the battery discharges. "We grow vertically aligned arrays of carbon nanofibers using a chemical vapor deposition process. These carpet-like arrays provide a highly conductive, low-density scaffold for energy storage," explains Robert Mitchell, a graduate student in MIT's Department of Materials Science and Engineering (DMSE) and co-author of a paper describing the new findings in the journal Energy and Environmental Science . During discharge, lithium-peroxide particles grow on the carbon fibers, adds co-author Betar Gallant, a graduate student in MIT's Department of Mechanical Engineering. In designing an ideal electrode material, she says, it's important to "minimize the amount of carbon, which adds unwanted weight to the battery, and maximize the space available for lithium peroxide," the active compound that forms during the discharging of lithium-air batteries. "We were able to create a novel carpet-like material — composed of more than 90 percent void space — that can be filled by the reactive material during battery operation," says Yang Shao-Horn, the Gail E. Kendall Professor of Mechanical Engineering and Materials Science and Engineering and senior author of the paper. The other senior author of the paper is Carl Thompson, the Stavros Salapatas Professor of Materials Science and Engineering and interim head of DMSE. In earlier lithium-air battery research that Shao-Horn and her students reported last year, they demonstrated that carbon particles could be used to make efficient electrodes for lithium-air batteries. In that work, the carbon structures were more complex but only had about 70 percent void space. The gravimetric energy stored by these electrodes — the amount of power they can store for a given weight — "is among the highest values reported to date, which shows that tuning the carbon structure is a promising route for increasing the energy density of lithium-air batteries," Gallant says. The result is an electrode that can store four times as much energy for its weight as present lithium-ion battery electrodes. In the paper published last year, the team had estimated the kinds of improvement in gravimetric efficiency that might be achieved with lithium-air batteries; this new work "realizes this gravimetric gain," Shao-Horn says. Further work is still needed to translate these basic laboratory advances into a practical commercial product, she cautions. Because the electrodes take the form of orderly "carpets" of carbon fibers — unlike the randomly arranged carbon particles in other electrodes — it is relatively easy to use a scanning electron microscope to observe the behavior of the electrodes at intermediate states of charge. The researchers say this ability to observe the process, an advantage that they had not anticipated, is a critical step toward further improving battery performance. For example, it could help explain why existing systems degrade after many charge-discharge cycles. Ji-Guang Zhang, a laboratory fellow in battery technology at the Pacific Northwest National Laboratory, says this is "original and high-quality work." He adds that this research "demonstrates a very unique approach to preparing high-capacity electrodes for lithium-air batteries." http://web.mit.edu/newsoffice/2011/better-battery-storage-0725.html
Single nanowires provide unique tool for nanoscale battery diagnosis ( Nanowerk Spotlight ) Traditionally, battery materials have usually been studied with bulk quantities in a complex environment with both active electrode components and many other supporting materials such as polymer binders and conductive additives. Although nanomaterials have been found to be able to improve battery performance, the complexity has made it hard to tell clearly about their advantages. Moreover, it is difficult to know whether fast capacity fading is due to the intrinsic nature of the transport property changes of active nanomaterials or an extrinsic reason from their interactions with the supporting materials, if all of them are studied together. The goal to understand the intrinsic reason of active material capacity fading has motivated a group of researchers to design single nanowire electrochemical devices as an extremely simplified model system to push the fundamental limits of the nanowire materials for energy storage applications. The result is a powerful and effective diagnostic tool for property degradation of lithium ion based energy storage devices. In the September 10, 2010 online edition of Nano Letters ( Single Nanowire Electrochemical Devices ), they report a study of vanadium oxide based cathode and silicon based anode at the single nanowire level and demonstrated that a single nanowire electrode can work as a versatile platform to study the correlation between material structure changes, transport property, and electrochemical property. In our work, the electrical transport property evolution of the single nanowire under charging/discharging test has been reported for the first time, Liqiang Mai tells Nanowerk. By designing single nanowire electrode devices, our findings show that conductivity of the nanowire electrode decreased reversibly for vanadium oxide nanowire by shallow discharge/charge or irreversibly for vanadium oxide nanowire by deep discharge/charge, or silicon nanowire during the electrochemical reaction, which limits the cycle life of the devices. Schematic diagram of a single nanowire electrode device design. A single vanadium oxide nanowire or silicon nanowire is the work electrode, and HOPG or LiCoO 2 nanofilm is the counter electrode. The electrolyte is the PEO-LiClO 4 -PC-EC polymer. (Reprinted with permission from American Chemical Society) This first all-solid-state single nanowire electrochemical device, designed by Mai, a professor at the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing at Wuhan University of Technology (WUT), and advanced research scholar at the Lieber Research Group at Harvard University, together with Yajie Dong, a graduate student of the same Harvard group, and their collaborators from the WUT-Harvard Joint Nano Key Lab, is a unique and versatile platform for in situ probing the intrinsic mechanism for electrode capacity fading, which is one of the biggest challenges in Li ion based energy storage devices. The insight gained from our study could help understand why the capacities of lithium ion batteries fade during their life time and provide scientific basis for designing, diagnosing and optimizing high performance lithium ion based energy storage devices says Dong. Restraining the conductivity decrease of battery electrode materials is a key issue for improving the performance of lithium ion batteries. The team has reported on their work on using chemical prelithiation to improve cycling performance of nanostructured electrode materials in a previous publication ( Improved cycling stability of nanostructured electrode materials enabled by prelithiation ). The electrode device in this research was configured with one vanadium oxide nanowire with a length of 10-45 m and a diameter of 20-100 nm as cathode, and one flake of highly ordered pyrolytic graphite as anode. Dong explains that during battery charge or discharge, Li + ions move out or into the cathode materials, oxidizing or reducing it to different states. This process was usually studied ex situ after disassembling the battery. So far, only in situ XRD or NMR could provide some indirect hint on materials structure changes during the battery test. Our single nanowire battery design provides a unique advantage to study this in situ without disturbing the battery components. In addition, such a single nanowire electrochemical device could also find applications in providing the potential power needs of nanodevices in future self-powered nanosystems. Designed as a nanoscale electrical energy storage device, it could be combined with nanowire-based solar cells, nanogenerators, etc for powering nanodevices in the fields of nanoelectronics, optoelectronics or biosensing. Mai notes that the research and development of lithium ion based energy storage devices has been focused in two directions. On one hand, in the areas of electric vehicles and other large grid scale energy storage devices, these batteries are becoming bigger and bigger. On the other hand, in the areas of microelectronics or even self-powered nanosystems, they are becoming smaller and smaller. In either direction, when the size scales start to diverge from traditional batteries by orders of magnitude, the old battery design won't be efficient enough to achieve high energy, power density and long cycle life with satisfactory safety features. Novel efficient design based on deep understanding of battery behaviors, such as the intrinsic reasons of energy storage device performance degradation studied in our work, will be important for tomorrow's energy storage devices Mai concludes. By Michael Berger. Copyright 2010 Nanowerk http://www.nanowerk.com/spotlight/spotid=18211.php
密苏里大学出了一个简报,该校的Kwon J. W.教授在物理应用快报上报道了最新的关于微型核电池的结果,这种新型的二次电池概念在能源领域研究比较少,但是由于能量密度比一般锂电池高几个数量级,所以在某些特殊环境下应用很有希望,如纳米卫星。核电池的提法比较吓人,但并不是我们通常所想的发生核裂变的链式反应输出能量,而是利用被辐射后的高能同位素衰变时逐步释放出的能量。Kwon在这个新工作中主要贡献在于利用金属硒作为能量接受体,避免了固体半导体材料在高能辐射下因为晶格发生畸变而失效。具体的工作原理是同位素硫35释放出高能beta射线激发半导体硒中处于价带的电子,造成电荷分离,半导体硒和金属电极形成肖特基势垒促进了电子和空穴的分离,当外电路加上载荷时,电子就会经由外加载荷奔向空穴结婚,灯亮了。Kwon目前得到的能量转换效率仅有1.2%,功率在nW级。 这种利用核辐射来制备电池是不是为核废料处理提供了一种能源回收的策略? MU Researchers Create Smaller and More Efficient Nuclear Battery Mizzou scientist develops a powerful nuclear battery that uses a liquid semiconductor Oct. 07, 2009 Story Contact(s) : Kelsey Jackson, JacksonKN@missouri.edu , (573) 882-8353 COLUMBIA, Mo. Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri researchers are developing a nuclear energy source that is smaller, lighter and more efficient. To provide enough power, we need certain methods with high energy density, said Jae Kwon, assistant professor of electrical and computer engineering at MU. The radioisotope battery can provide power density that is six orders of magnitude higher than chemical batteries. Kwon and his research team have been working on building a small nuclear battery, currently the size and thickness of a penny, intended to power various micro/nanoelectromechanical systems (M/NEMS). Although nuclear batteries can pose concerns, Kwon said they are safe. People hear the word nuclear and think of something very dangerous, he said. However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems. His innovation is not only in the batterys size, but also in its semiconductor. Kwons battery uses a liquid semiconductor rather than a solid semiconductor. The critical part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor, Kwon said. By using a liquid semiconductor, we believe we can minimize that problem. Kwon has been collaborating with J. David Robertson, chemistry professor and associate director of the MU Research Reactor , and is working to build and test the battery at the facility. In the future, they hope to increase the batterys power, shrink its size and try with various other materials. Kwon said that the battery could be thinner than the thickness of human hair. Theyve also applied for a provisional patent. Kwons research has been published in the Journal of Applied Physics Letters and Journal of Radioanalytical and Nuclear Chemistry . In addition, last June, he received an outstanding paper award for his research on nuclear batteries at the IEEE International Conference on Solid-State Sensors, Actuators and Microsystems in Denver (Transducers 2009). (谁找到第二篇文章和我说一声)
The timelineTimeline A timeline is a graphical representation of a chronological sequence of events, also referred to as a chronology. It can also mean a schedule of activities, such as a timetable.... of solar cellSolar cell A solar cell or photovoltaic cell is a device that converts sunlight directly into electricity by the photovoltaic effect. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the source is unspecified.... s begins in the 1800s when it is observed that the presence of sunlight is capable of generating usable electrical energy. Solar cells have gone on to be used in many applications. They have historically been used in situations where electrical power from the grid is unavailable. The last world record achieved in solar cell efficiency appears in bold. arex Corp.(Enron/Amoco)v.Arco Solar, Inc.Ddel, 805 Fsupp 252 Fed Digest. Discussion Ask a question about 'Timeline of solar cells'Start a new discussion about 'Timeline of solar cells'Answer questions from other usersFull Discussion Forum Encyclopedia The timelineTimeline A timeline is a graphical representation of a chronological sequence of events, also referred to as a chronology. It can also mean a schedule of activities, such as a timetable.... of solar cellSolar cell A solar cell or photovoltaic cell is a device that converts sunlight directly into electricity by the photovoltaic effect. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the source is unspecified.... s begins in the 1800s when it is observed that the presence of sunlight is capable of generating usable electrical energy. Solar cells have gone on to be used in many applications. They have historically been used in situations where electrical power from the grid is unavailable. The last world record achieved in solar cell efficiency appears in bold. Timeline 1800s 1839 - Alexandre Edmond BecquerelA. E. Becquerel Alexandre-Edmond Becquerel was a France physicist who studied the solar spectrum, magnetism, electricity, and optics. He is known for his work in luminescence and phosphorescence.... observes the photoelectric effectPhotoelectric effect The photoelectric effect is a phenomenon in which electrons are emitted from matter after the absorption of energy from electromagnetic wave such as x-rays or visible light.... via an electrode in a conductive solution exposed to light. 1873 - Willoughby SmithWilloughby Smith Willoughby Smith was an English electrical engineer who discovered the photoconductivity of the element selenium. This discovery led to the invention of photoelectric cells, including those used in the earliest television systems.... finds that seleniumSelenium Selenium is a chemical element with the atomic number 34, represented by the chemical symbol Se, an atomic mass of 78.96. It is a nonmetal, chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature.... is photoconductive. 1877 - W.G. Adams and R.E. Day observed the photovoltaic effect in solid seleniumSelenium Selenium is a chemical element with the atomic number 34, represented by the chemical symbol Se, an atomic mass of 78.96. It is a nonmetal, chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature.... , and published a paper on the selenium cell. 'The action of light on selenium,' in Proceedings of the Royal Society, A25, 113. 1883 - Charles FrittsCharles Fritts Charles Fritts was an American inventor credited with creating the first working solar cell in 1884.Fritts coated the semiconductor material selenium with an extremely thin layer of gold.... develops a solar cell using selenium on a thin layer of gold to form a device giving less than 1% efficiency. 1887 - Heinrich Hertz investigates ultraviolet light photoconductivity. 1887 - James Moser reports dye sensitised photoelectrochemical cell. 1888 - Edward WestonEdward Weston (chemist) Edward Weston was an English chemist noted for his achievements in electroplating and his development of the electrochemical cell, named the Weston cell, for the voltage standard.... receives patent US389124, Solar cell, and US389125, Solar cell. 1894 - Melvin Severy receives patent US527377, Solar cell, and US527379, Solar cell. 1897 - Harry Reagan receives patent US588177, Solar cell.. 1900-1929 1901 - Nikola TeslaNikola Tesla Nikola Tesla was an inventor and a mechanical engineer and electrical engineer. Tesla was born in the village of Smiljan near the town of Gospic, in Croatia .... receives the patent US685957, Apparatus for the Utilization of Radiant Energy, and US685958, Method of Utilizing of Radiant Energy. 1902 - Philipp von Lenard observes the variation in electron energy with light frequency. 1904 - Albert EinsteinAlbert Einstein Albert Einstein was a Germany-born theoretical physics. He is best known for his theory of relativity and specifically mass?energy equivalence, expressed by the equation E = mc2.... publishes a paper on the photoelectric effect. Wilhelm Hallwachs makes a semiconductor-junction solar cell (copperCopper Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity.... and copper oxideCopper oxide Copper oxide can refer to*Copper oxide , a red powder;*Copper oxide , a black powder.... ). 1913 - William CoblentzWilliam Coblentz William Weber Coblentz was an United States physicist notable for his contributions to infrared radiometry and spectroscopy.... receives US1077219, Solar cell. 1914 - Sven Ason Berglund patents methods of increasing the capacity of photosensitive cells. 1916 - Robert MillikanRobert Millikan Robert Andrews Millikan was an United States experimental physics, and Nobel Prize for Physics in physics for his measurement of the charge on the electron and for his work on the photoelectric effect.... conducts experiments and proves the photoelectric effect. 1918 - Jan CzochralskiJan Czochralski Jan Czochralski was a Poland chemistry who invented the Czochralski process, which is used to grow single crystals and is used in the production of semiconductor wafers.... , a Polish scientist, produces a method to grow single crystals of metal. Decades later, the method is adapted to produce single-crystal silicon. 1920s - Solar water-heating systems, utilizing flat collectors (or flat-plate collectors), relied upon in homes and apartment buildings in FloridaFlorida Florida is a U.S. state located in the Southeastern United States of the United States, bordering Alabama to the northwest and Georgia to the northeast.... and southern CaliforniaCalifornia California is a U.S. state on the West Coast of the United States of the United States, along the Pacific Ocean. It is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and to the south the Mexico state of Baja California.... . 1930-1959 1932 - Audobert and Stora discover the photovoltaic effect in Cadmium selenideCadmium selenide Cadmium selenide is a solid, binary compound of cadmium and selenium. Common names for this compound are cadmium selenide, cadmium selenide, and cadmoselite .... (CdSe), a photovoltaic material still used today. 1946 - Russell OhlRussell Ohl Russell Ohl was an American engineer who is generally recognized for patenting the modern solar cell . Ohl was a notable semiconductor researcher prior to the invention of the transistor.... receives patent US2402662, Light sensitive device. 1948 - Gordon TealGordon K. Teal Gordon Kidd Teal invented a method of applying the Czochralski method to produce extremely pure germanium single crystals used in making greatly improved transistors.... and John Little adapt the Czochralski method of crystal growth to produce single-crystalline germanium and, later, silicon. 1950s - Bell LabsBell Labs Bell Laboratories is the research organization of Alcatel-Lucent and previously of the American Telephone Telegraph Company .Bell Laboratories has had its headquarters at Berkeley Heights, New Jersey, and it has research and development facilities throughout the world.... produce solar cells for space activities. 1953 - Gerald Pearson begins research into lithiumLithium Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft alkali metal with a silver-white color. Under standard conditions for temperature and pressure, it is the lightest metal and the least dense solid element.... -siliconSilicon Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. The atomic mass is 28.0855.... photovoltaic cells. 1954 - Bell LabsBell Labs Bell Laboratories is the research organization of Alcatel-Lucent and previously of the American Telephone Telegraph Company .Bell Laboratories has had its headquarters at Berkeley Heights, New Jersey, and it has research and development facilities throughout the world.... announces the invention of the first modern silicon solar cell. Shortly afterwards, they are shown at the National Academy of Science Meeting. These cells have about 6% efficiency. The New York Times forecasts that solar cells will eventually lead to a source of limitless energy of the sun. 1955 - Western ElectricWestern Electric Western Electric Company was an United States electrical engineering company, the manufacturing arm of American Telephone Telegraph from 1881 to 1995.... licences commercial solar cell technologies. Hoffman Electronics-Semiconductor Division creates a 2% efficient commercial solar cell for $25/cell or $1,785/Watt. 1957 - ATT assignors (Gerald L. Pearson, Daryl M. Chapin, and Calvin S. Fuller) receive patent US2780765, Solar Energy Converting Apparatus. They refer to it as the solar batteryBattery (electricity) In electronics, a battery or voltaic cell is a combination of one or more electrochemical cell Galvanic cells which store chemical energy that can be converted into electric potential energy, creating electricity.... . Hoffman Electronics creates an 8% efficient solar cell. 1958 - T. Mandelkorn, U.S. Signal Corps Laboratories, creates n-on-p silicon solar cells, which are more resistant to radiation damage and are better suited for space. Hoffman Electronics creates 9% efficient solar cells. Vanguard I, the first solar powered satellite, was launched with a 0.1W, 100 cm² solar panel. 1959 - Hoffman Electronics creates a 10% efficient commercial solar cell, and introduces the use of a grid contact, reducing the cell's resistance. 1960-1979 1960 - Hoffman Electronics creates a 14% efficient solar cell. 1961 - Solar Energy in the Developing World conference is held by the United NationsUnited Nations The United Nations is an international organization whose stated aims are to facilitate cooperation in international law, international security, economic development, Social change, human rights and achieving world peace.... . 1962 - The TelstarTelstar Telstar was the first active communications satellite, and the first satellite designed to transmit telephone and high-speed data communications.... communications satellite is powered by solar cells. 1963 - Sharp CorporationSharp Corporation is a Japanese electronics manufacturer, founded in 1912.It takes its name from one of its founder's first inventions, the Ever-Sharp mechanical pencil, which was invented by Tokuji Hayakawa in 1915.... produces a viable photovoltaic module of silicon solar cells. 1964 - Farrington DanielsFarrington Daniels Farrington Daniels , an American physical chemist, is considered one of the pioneers of the modern direct use of solar energy.... ' landmark book, Direct Use of the Sun's Energy, published by Yale University PressYale University Press Yale University Press is a book publisher 1908 in literature by George Parmly Day. It became an official Academic department of Yale University 1961 in literature, but remains financially and operationally autonomous.... . 1967 - Soyuz 1Soyuz 1 Soyuz 1 was part of the Soviet Union's space program and was launched into orbit on April 23, 1967, carrying a single astronaut, Colonel Vladimir Mikhaylovich Komarov, who was killed when the spacecraft crashed during its return to Earth.... is the first manned spacecraft to be powered by solar cells 1967 - Akira FujishimaAkira Fujishima is a Japanese chemist, professor emeritus, University of Tokyo.He is known for his significant contributions in discovery and research of photocatalytic and superhydrophilic properties of titanium dioxide.... discovers the Honda-Fujishima effect which is used for hydrolysisHydrolysis Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions.... in the photoelectrochemical cellPhotoelectrochemical cell Photoelectrochemical cells or PECs are solar cells which generate electrical energy from light, including visible light. Each cell consists of a semiconducting photoanode and a metal cathode immersed in an electrolyte.... . 1970 - First highly effective GaAsGaas Gaas is a Communes of France in the Landes Departments of France in Aquitaine in southwestern France.... heterostructure solar cells are created by Zhores Alferov and his team in the USSR. 1971 - Salyut 1Salyut 1 Salyut 1 was the first space station of any kind, and the first Soviet space station. It was launched on April 19, 1971. Its first crew launched in Soyuz 10 but was unable to board it due to a failure in the docking mechanism; its second crew launched in Soyuz 11 and remained on board for 23 productive days.... is powered by solar cells. 1973 - SkylabSkylab Skylab was the first space station the United States launched into orbit, and the second space station ever visited by a human crew. The 100 ton space station was in Earth's orbit from 1973 to 1979, and it was visited by crews three times in 1973 and 1974.... is powered by solar cells. 1974 - Florida Solar Energy CenterFlorida Solar Energy Center The Florida Solar Energy Center is the largest and most active state-supported renewable energy and energy efficiency research, training, testing and certification institute in the United States.... begins . 1974 - J. BaldwinJ. Baldwin James Tennant Baldwin is an American industrial designer and writer. Baldwin was a student of Buckminster Fuller; Baldwin's work has been inspired by Fuller's principles and has popularized and interpreted Fuller's ideas and achievements.... , at Integrated Living Systems, co-develops the world's first building (in New Mexico) heated and otherwise powered by solar and wind powerWind power Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2008, worldwide nameplate capacity of wind-powered generators was 120.8 gigawatts.... exclusively. 1976 - David Carlson and Christopher Wronski of RCA Laboratories create first amorphous silicon PV cells, which have an efficiency of 1.1%. 1977 - The Solar Energy Research InstituteNational Renewable Energy Laboratory The National Renewable Energy Laboratory , located in Golden, Colorado, as part of the U.S. Department of Energy, is the United States' primary laboratory for renewable energy and energy efficiency research and development.... is established at Golden, ColoradoGolden, Colorado The historic City of Golden is a Colorado municipalities#Home_Rule_Municipality that is the county seat of Jefferson County, Colorado, Colorado, United States.... . 1977 - President Jimmy CarterJimmy Carter James Earl Jimmy Carter, Jr. served as the List of Presidents of the United States President of the United States from 1977 to 1981 and was the recipient of the 2002 Nobel Peace Prize.... installs solar panelPhotovoltaic module In the field of photovoltaics, a photovoltaic module or photovoltaic panel is a packaged interconnected assembly of photovoltaic cells, also known as solar cells.... s on the White HouseWhite House The White House is the official residence and principal workplace of the President of the United States. Located at 1600 Pennsylvania Avenue in Washington, D.C., it was built between 1792 and 1800 of white-painted Aquia sandstone in the late Georgian architecture and has been the executive residence of every U.S.... and promotes incentives for solar energy systems. 1977 - The world production of photovoltaic cells exceeded 500 kW Late 1970s: the Energy Crisis1979 energy crisis The 1979 oil crisis in the United States occurred in the wake of the Iranian Revolution. Amid massive protests, the Shah of Iran, Mohammad Reza Pahlavi, fled his country in early 1979, allowing Ayatollah Khomeini to gain control.... ; groundswell of public interest in solar energy use: photovoltaic and active and passive solar, including in architecture and off-grid buildings and home sites. 1980-1999 1980 - The Institute of Energy Conversion at University of Delaware develops the first thin-film solar cell exceeding 10% efficiency using Cu2S/CdS technology. 1982 - Spherical solar cell was developed. 1983 - Worldwide photovoltaic production exceeds 21.3 megawatts, and sales exceed $250 million. 1984 - 30,000 SF Building-Integrated Photovoltaic Roof completed for the Intercultural Center of Georgetown University. At the time of the 20th Anniversary Journey by Horseback for Peace and Photovoltais in 2004 it was still generating an average of one MWh daily as it has for twenty years in the dense urban environment of Washington, DC. 1984 - Amoco Oil pulled factory loan to takeover of Solarex Corporation factory in Frederick, Maryland. 1985 - 20% efficient silicon cells are created by the Centre for Photovoltaic Engineering at the University of New South WalesUniversity of New South Wales The University of New South Wales, also known as UNSW or colloquially as New South, is a university situated in Kensington, New South Wales, a suburb in Sydney, New South Wales, Australia.... . 1986 - 'Solar-Voltaic DomeTM' patented by Lt. Colonel Richard T. Headrick of Irvine, CA as an efficient architectural configuration for building-integrated photovoltaics ; Hesperia, CA field array. 1988-1991 AMOCO/Enron used Solarex patents to sue ARCO Solar out of the business of a-Si, see Solarex Corp.(Enron/Amoco)v.Arco Solar, Inc.Ddel, 805 Fsupp 252 Fed Digest. ) 1989 - Reflective solar concentrators are first used with solar cells. 1990 - The Cathedral of MagdeburgCathedral of Magdeburg The Evangelical Church in Germany Cathedral of Magdeburg , officially called the Cathedral of Saints Catherine and Maurice , is one of the oldest Gothic architecture cathedrals in Germany.... installs solar cells on the roof, marking the first installation on a church in East Germany. 1991 - Efficient Photoelectrochemical cells are developed; the Dye-sensitized solar cell is invented. 1991 - PresidentPresident President is a title held by many leaders of organizations, company, trade unions, university, and country. Etymology, a president is one who Wiktionary:Preside, who sits in leadership .... George H. W. BushGeorge H. W. Bush George Herbert Walker Bush served as the List of Presidents of the United States President of the United States from 1989 to 1993. Bush held a variety of political positions prior to his presidency, including Vice President of the United States in the administration of Ronald Reagan and Director of Central Intelligence under Gerald R.... directs the U.S. Department of Energy to establish the National Renewable Energy LaboratoryNational Renewable Energy Laboratory The National Renewable Energy Laboratory , located in Golden, Colorado, as part of the U.S. Department of Energy, is the United States' primary laboratory for renewable energy and energy efficiency research and development.... (transferring the existing Solar Energy Research Institute). 1992 - University of South Florida fabricates a 15.89-percent efficient thin-film cell 1993 - The National Renewable Energy LaboratoryNational Renewable Energy Laboratory The National Renewable Energy Laboratory , located in Golden, Colorado, as part of the U.S. Department of Energy, is the United States' primary laboratory for renewable energy and energy efficiency research and development.... 's Solar Energy Research Facility is established. 1994 - NREL develops a GaInP/GaAs two-terminal concentrator cell (180 suns) which becomes the first solar cell to exceed 30% conversion efficiency. 1996 - The National Center for Photovoltaics is established. Graetzel, cole Polytechnique Fdrale de Lausannecole polytechnique fdrale de Lausanne The ?cole Polytechnique F?d?rale de Lausanne is one of the two Swiss Federal Institutes of Technology and is located in Lausanne, Switzerland.... , LausanneLausanne Lausanne is a city in Romandy, the French language-speaking part of Switzerland, situated on the shores of Lake Geneva , and facing ?vian-les-Bains and with the Jura mountains to its north-west.... , Switzerland achieves 11% efficient energy conversion with dye-sensitized cells that use a photoelectrochemical effect. 1998 - August and September University of New South Wales made premiere offering of on-line 'Advanced Photovoltaics Short Course' 1998 - Historic Joint Agency Rulemaking into the Role of the Utility Distribution Company in Distributed Generation before the California Public Utilities Commission 98-12-015 and 99-10-025; California Energy Commission 99-DIST-GEN(1) and 99-DIST-GEN(2); California Oversight Board 99-1-A-DG 1999 - Total worldwide installed photovoltaic power reached 1000 megawatts. 2000 2002 President George W. Bush installed a 9 kW 'building-integrated photovoltaics' panel on the roof of a grounds maintenance building at the White House for the National Parks Service. Also installed were two solar water heating systems. 2004 March California Governor Arnold Schwarzenegger proposed Solar Roofs Initiative for one million solar roofs in California by 2017. June 1 Kansas Governor Kathleen Sebelius issued a mandate for 1,000 MWp renewable electricity in Kansas by 2015 per Executive Order 04-05 2006 Polysilicon use in photovoltaicsPhotovoltaics Photovoltaics is the field of technology and research related to the application of solar cells for energy by converting sunlight directly into electricity.... exceeds all other polysilicon use for the first time. January 12 California Public Utilities Commission approved the California Solar Initiative (CSI), a comprehensive $2.8 billion program that provides incentives toward solar development over 11 years. December 5 New World Record Achieved in Solar Cell Technology - New Solar Cell Breaks the 40 Percent Efficient Sunlight-to-Electricity Barrier. 2007 Investors begin offering free installation in return for a long term Power Purchase AgreementPower Purchase Agreement A Power Purchase Agreement is a legal contract between an electricity generator and a host site owner or lessor. The host site owner or lessor purchases energy or capacity from the PPA Provider .... (PPA). April 23 Start of construction of Nellis Solar Power PlantNellis Solar Power Plant The Nellis Solar Power Plant is the largest solar photovoltaic system in North America, and is located within Nellis Air Force Base in Clark County, Nevada, Nevada, on the northeast side of Las Vegas, Nevada.... , a 15 MW PPA installation. 5 MW began operation on October 12, and the final third was completed in December. May The Vatican announced that in order to conserve Earth's resources they would be installing solar panels on some buildings, in a comprehensive energy project that will pay for itself in a few years. June 18 GoogleGoogle Google Inc. is an United States public company, earning revenue from AdWords related to its Google search, Gmail, Google Maps, Google Apps, Orkut, and YouTube services as well as selling advertising-free versions of the Google Search Appliance.... solar panel project begins operation . July 30 University of Delaware claims to achieve new world record in Solar Cell Technology without independent confirmation - 42.8% efficiency. December 18 NanosolarNanosolar Nanosolar is a developer of solar power technology. Based in San Jose, California, CA, Nanosolar has developed and commercialized a low-cost printed electronics solar cell manufacturing process.... ships the first commercial printed CIGSCopper indium gallium selenide Copper indium selenide redirects here.Copper indium gallium selenide is a I-III-VI compound semiconductor material composed of copper, indium, gallium, and selenium.... , claiming that they will eventually ship for less than $1/WattWATT WATT is a radio station broadcasting a News radio-Talk radio-Sports radio format. Licensed to Cadillac, Michigan, it first began broadcasting in 1945.... . However, the company does not publicly disclose the technical specifications or current selling price of the modules. 2008 August 13. New World Record Achieved in Solar Cell Efficiency: Scientists at the U.S. Department of Energy's National Renewable Energy LaboratoryNational Renewable Energy Laboratory The National Renewable Energy Laboratory , located in Golden, Colorado, as part of the U.S. Department of Energy, is the United States' primary laboratory for renewable energy and energy efficiency research and development.... (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity. The inverted metamorphic triple-junction solar cellMultijunction photovoltaic cell Multijunction photovoltaic cells are a sub-class of solar cell or photovoltaic cell developed for higher efficiency. These multijunction cells consist of multiple thin films produced using molecular beam epitaxy and / or Metalorganic vapour phase epitaxy.... was designed, fabricated and independently measured at NREL. http://www.absoluteastronomy.com/topics/Timeline_of_solar_cells http://www1.eere.energy.gov/solar/solar_time_1900.html http://knol.google.com/k/william-pentland/solar-energy/1g0rrsoesmjko/2?version=113 #