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.”
AM our review.pdf 继2011年初在Nanoscale(2011, 3 ,45)杂志上发表了关于单相（单组份）金属氧化物一维纳米结构阵列在锂离子电池电极应用方面的综述后，最近我们课题组在Advanced Materials发表了基于金属氧化物的复合（多组分）有序纳米结构阵列/薄膜用于电化学能量存储器件（锂电、超级电容器）的综述论文“Recent Advances in Metal Oxide-based Electrode Architecture Design for Electrochemical Energy Storage”。文章主要总结了近几年我们小组及国际上其他课题组在这方面的一些进展。设计到的电极材料范围相对较小，但我们从电子的运输、离子扩散以及组分界面协同等方面重点强调了有序复合电极结构的设计，对此方向上的主要研究进展都进行了客观详细的总结和评述。望各位同行、朋友多多批评指教。
“赝能隙”和超导状态之间的关系 高温铜氧化物超导体一个长久未解之谜是“赝能隙”（pseudogap）的存在。所谓“赝能隙”，是指一个与超导状态的特征能隙相似、但也在非超导状态中出现的能隙。Kohsaka等人对与超导现象和“赝能隙”状态相关的电子激发进行了详细研究，发现了两个非常不同的行为类型： 一个类型为在动量空间的状态，它们相应于对超导现象负责的、预期存在的离位电子对；另一个类型为局限于真实空间的一些异常状态，它们相应于“赝能隙”。这两种激发类型之间的关系，为“赝能隙”和超导状态之间仍然神秘的关系提供了一个新视角，强化了与绝缘母化合物性能的概念联系（在绝缘母化合物中，真实空间的电子局域化是它们行为的关键）。 How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+ δ Y. Kohsaka 1 , 2 , C. Taylor 1 , P. Wahl 1 , A. Schmidt 1 , Jhinhwan Lee 1 , K. Fujita 1 , 3 , J. W. Alldredge 1 , 4 , K. McElroy 4 , Jinho Lee 1 , 5 , 6 , H. Eisaki 7 , S. Uchida 3 , D.-H. Lee 8 J. C. Davis 1 , 6 LASSP, Department of Physics, Cornell University, Ithaca, New York 14853, USA RIKEN, Wako, Saitama 351-0198, Japan Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan Department of Physics, University of Colorado, Boulder, Colorado 80309, USA School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK CMPMS Department, Brookhaven National Laboratory, Upton, New York 11973, USA Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan Department of Physics, University of California, Berkeley, California 94720, USA Correspondence to: J. C. Davis 1 , 6 Correspondence and requests for materials should be addressed to J.C.D. (Email: jcdavis@ccmr.cornell.edu ). Top of page Abstract The antiferromagnetic ground state of copper oxide Mott insulators is achieved by localizing an electron at each copper atom in real space ( r -space). Removing a small fraction of these electrons (hole doping) transforms this system into a superconducting fluid of delocalized Cooper pairs in momentum space ( k -space). During this transformation, two distinctive classes of electronic excitations appear. At high energies, the mysterious ‘pseudogap’ excitations are found, whereas, at lower energies, Bogoliubov quasi-particles—the excitations resulting from the breaking of Cooper pairs—should exist. To explore this transformation, and to identify the two excitation types, we have imaged the electronic structure of Bi2Sr2CaCu2O8+ δ in r -space and k -space simultaneously. We find that although the low-energy excitations are indeed Bogoliubov quasi-particles, they occupy only a restricted region of k -space that shrinks rapidly with diminishing hole density. Concomitantly, spectral weight is transferred to higher energy r -space states that lack the characteristics of excitations from delocalized Cooper pairs. Instead, these states break translational and rotational symmetries locally at the atomic scale in an energy-independent way. We demonstrate that these unusual r -space excitations are, in fact, the pseudogap states. Thus, as the Mott insulating state is approached by decreasing the hole density, the delocalized Cooper pairs vanish from k -space, to be replaced by locally translational- and rotational-symmetry-breaking pseudogap states in r -space. LASSP, Department of Physics, Cornell University, Ithaca, New York 14853, USA RIKEN, Wako, Saitama 351-0198, Japan Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan Department of Physics, University of Colorado, Boulder, Colorado 80309, USA School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK CMPMS Department, Brookhaven National Laboratory, Upton, New York 11973, USA Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan Department of Physics, University of California, Berkeley, California 94720, USA
南京工业大学青年教师邵宗平教授，博士生张春明及合作者在国家杰出青年基金 (No.51025209) ，国家科技部 973 项目 (No.2007CB209704) 和教育部新世纪优秀人才计划的支持下在以甲烷为燃料采用进行气电共生的研究方面取得重要进展。 甲烷是天然气、煤层气和生物沼气的主要组成成分，是一种重要的能源物质和化工原料， 作者创新性地采用单室固体氧化物燃料电池结合高性能甲烷转化催化剂于同一气室中，成功实现了电能和合成气的高效共生，并实现零尾气排放。该 研究成果日前刊登于化学领域国际权威期刊德国《应用化学》上 ( Angew. Chem. Int.Ed. 2011, 50, 1792-1797) ， 并被以内插图形式报道。其研究成果受到评审人的高度评价： “This is an excellent and truly exciting paper. The results are extremely interesting and would enhance the position of SOFCs as the preferred co-generation technology for practical applications...”,“This is an outstanding manuscript on the conversion of methane with oxygen to syngas and electricity…” ， 两位评审人都将该研究工作的重要性选为 “Very Important” , 该论文被 德国《应用化学》选为 VIP 论文。 邵宗平 教授（ 2010 年国家杰出青年基金获得者）， 2005 年加入我校以来一直从事新能源材料与技术的研究，这是继其发表在国际膜科学杂志上的两篇论文相继被评为 2007 年和 2008 年度全国百篇最具影响国际学术论文以来，研究成果再次受到国内外同行的承认。 VIP paper.pdf
High-capacity, high-rate Li-ion battery for HEV or EVs; mixed oxide cathode and Sn-C anode 作者： Mike Millikin The new battery features high energy content and high rate capability. Images of anode material (left) and cathode (right). Click to enlarge. Researchers from the University of Rome Sapienza (Italy) and Hanyang University (S. Korea) are developing a new advanced lithium-ion battery featuring a high capacity Sn-C nanostructured anode and a high rate, high-voltage Li O4 spinel cathode. The new chemistry offers excellent performances in terms of cycling life, i.e., around 100 high rate cycles; of rate capability, operating at 5C and still keeping more than 85% of the initial capacity; and of energy density, expected to be of the order of 170 Wh kg-1. These combined features make the battery a very promising energy storage for powering low- or zero-emission HEV or EV vehicles, the team report in a paper published in the Journal of the American Chemical Society . Enhancements in energy density necessarily require the passage from the present lithium ion technology to novel, advanced chemistries based on high performance electrode materials. Good examples are lithium metal alloy anodes and spinel cathodes. It is expected that advancements in lithium ion battery technology can be achieved by combining these high performance electrode materials in a complete cell configuration. In a previous paper we described a novel design battery formed by combining a high capacity nanostructured tin-carbon (Sn-C) anode with a high voltage LiNi0.5Mn1.5O4 spinel cathode. The excellent performance in terms of cycle life and rate capability confirmed the validity of the concept, thus encouraging us to extend the approach for obtaining other, advanced lithium ion battery chemistries. In this work we disclose an important example based on a Sn-C anode having an optimized morphology with a high rate, new Li O4 cathode. —Hassoun et al. Anode . While Lithium metal alloys (Li-M, M = Sn, Si, Sb, etc.) are very appealing as anode materials due to their higher specific capacity, the authors noted, the large volume expansion-contraction experienced during their electrochemical process in lithium cells has prevented their commercial use. The researchers had earlier shown that the volume stress issue can be addressed by developing suitable electrode morphologies, such as M-C nanocomposites. The anode in their current work is basically similar to one they previously reported, although considerably upgraded in terms of surface morphology and rate capability. In particular, the issue of large irreversible capacity that affected the original material was addressed by a suitable surface treatment. The Sn-C electrode was also upgraded in terms of rate capability, they said. Improvement in the morphology allowed the electrode to operate under high current rates. Cathode . The performance of lithium manganese spinel cathode materials is strongly influenced by the particle size and by the presence of doping metals, they noted. While reduction in the particle size significantly improves the kinetics of the electrochemical lithium insertion/extraction reactions, it also increases reactivity for the electrolyte decomposition. In this work we have addressed this contradictory issue by doping LiMn2O4 spinel with Ni and Co and, at the same time, by preparing the resulting Li O4 cathode with particles at micrometric size (in order to avoid electrolyte decomposition) and using a metal ratio that is expected to provide high working voltage and high rate capability. —Hassoun et al. Full battery. The authors combined the anode and cathode materials in a complete lithium ion battery using an ethylene carbonate:ethyl methyl carbonate, EC: EMC, lithium hexafluorophosphate (LiPF6) electrolyte. Testing showed that the practical working voltage of the battery ranges between 3.9 V and 4.7 V while the specific capacity, related to the cathode mass, is of the order of 125 mAh g-1. In addition, the battery can cycle at 1C with a very stable capacity delivery. Taking an average voltage of 4.2 V, a top specific energy density value of 500 Wh kg-1 is obtained. Assuming a 1/3 reduction factor associated with the weight of the electrolyte, current collector, and aluminum case in a pouch configuration, we obtain a 170 Wh kg-1 value that still exceeds that offered by conventional lithium ion batteries chemistry. Hassoun et al. Resources Jusef Hassoun, Ki-Soo Lee, Yang-Kook Sun, Bruno Scrosati (2011) An Advanced Lithium Ion Battery Based on High Performance Electrode Materials. Journal of the American Chemical Society doi: 10.1021/ja110522x
New Mn-rich high-capacity mixed oxide cathode material for Li-ion batteries 作者： Mike Millikin Researchers in South Korea report the synthesis of high capacity Mn-rich mixed oxide cathode materials for Li-ion batteries. A paper on their work was published in the January issue of the Journal of Nanoscience and Nanotechnology ; the team had presented a poster on their material at the 3rd International Conference on Advanced Lithium Batteries for Automobile Application ( ABAA-3 ) held at Hanyang University in Seoul, Korea in September 2010. Novel cathode active materials, Li O2 (x = 0.09, 0.11) composed of rod-like primary particles, but aggregated spherical shape in appearance, were synthesized. The newly Mn-rich cathode active materials were then adopted as cathodes to show the benefits for Li-ion rechargeable batteries. The results show that to use proper nano-scaled particles as a cathode and to make homogeneous particle sizes have great improvements on electrochemical performances, probably ascribed to enhancement of charge transfer kinetics and lower cell impedance at high voltage region (~4.6 V). Resources Vediappan, Kumaran; Park, Suk-Jun; Kim, Hyun-Soo; Lee, Chang Woo (2011) Preliminary Studies of Mn-Rich Li O2(x = 0.09, 0.11) as Cathode Active Materials for Lithium Rechargeable Batteries. Journal of Nanoscience and Nanotechnology , Volume 11, Number 1, pp. 865-870(6) doi: 10.1166/jnn.2011.3244 Development of high capacity and environmentally benign layered Li O2 (x=0.09, 0.11) cathode active materials for lithium rechargeable batteries. Kumaran Vediappan (Kyung Hee University), Suk-Jun Park (Ecopro), Hyun-Soo Kim (Korea Electrotechnology Research Institute), Chang Woo Lee (Kyung Hee University) Poster P10, ABAA-3
标签: 氧化物
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