Spectroscopic Investigation of Ion Transport Mechanisms in Polyacrylonitrile Based Electrolytes

聚合物电解质是新一代锂离子电池所需要的重要材料．本文从分析聚丙烯腈（ＰＡＮ）－增塑剂－ＬｉＣｌＯ４体系中各组份间的相互作用出发，用Ｒａｍａｎ光谱，红外（ＩＲ）光谱，Ｘ射线光电子能谱（ＸＰＳ）及核磁共振（ＮＭＲ）等谱学方法研究了聚合物电解质中各组份之间的相互关系和Ｌｉ＋离子在聚合物电解质中的输运机理．发现Ｌｉ＋离子既可与增塑剂分子中含有孤对电子的原子发生作用而形成缔合物，也可与ＰＡＮ中Ｃ≡Ｎ基团上的Ｎ原子发生作用形成缔合物．增塑剂分子通过Ｃ＝Ｏ或Ｓ＝Ｏ基团与ＰＡＮ的Ｃ≡Ｎ基团以偶极子的形式相互排斥．在与Ｌｉ＋离子相互作用形成缔合物时，聚合物分子与增塑剂分子间存在激烈的竞争．在凝胶态中的运动是聚合物电解质Ｌｉ＋离子的主要运动形式．提出了Ｌｉ＋离子在ＰＡＮ为基的聚合物电解质中的一种可能传导机制．强调了增塑剂在聚合物电解质中的重要作用．Raman, IR, X-ray photoelectron (XPS), and NMR spectra of components in polyacrylonitrilebased electrolytes have been studied. It is found that there are strong interactions among the components though different systems show different interaction characteristics. A concept of competition is proposed between the polymer matrix and the plasticizer on associating with the Li~+ ions. By analyzing the important functions of the plasticizer, a possible mechanism of the ions transport in the polymer electrolyte is suggested.作者联系地址：中国科学院物理研究所固态离子学实验室Author's Address: Lab. for Solid State Ion., Inst. of Phy., Chinese Academy of Sciences, Beijing 10008

Nano-Sn/Hard Carbon Composite as Anode Material for Lithium Ion Batteries

利用金属铁和钴纳米颗粒的催化活化作用,制备了多孔硬碳球.应用聚焦离子束切割技术,观察到扩孔后的硬碳球中充满彼此连通的发达中孔.在此多孔硬碳球中填入纳米锡(Sn)颗粒,对复合材料的电化学性能进行了测试.The tin(Sn) nano particles were embedded into the mesopores of hard carbon spherules(HCS) to form a composite anode material for lithium ion batteries.The structure of the obtained composite was characterized by X-ray diffraction(XRD) while its electrochemical performances were evaluated with galvanostatic cycling.It is found that the embedding Sn nanoparticles into porous HCS not only result in a composite material with high lithium storage capacity and capacity retention,but also increase the initial coulombic efficiency of the composite.Based on the infrared spectroscopic analysis,the enhanced initial coulombic efficiency is attributed to the inductive decomposition of the ROCO2Li species in the solid electrolyte interphase(SEI) layer by the tin nano particles in the composite.作者联系地址：中国科学院物理研究所固态离子实验室;Author's Address: Laboratory for Solid State Ionics,Institute of Physics,Chinese Academy ofSciences,Beijing 100190,Chin

Polypyrrole-Transition Metal-Oxygen Coordination Complexes as High Performance Lithium Storage Material

目前锂离子电池电极材料主要使用无机材料. 近年来有机物电极材料虽有报道，但这些材料大都比容量低、倍率性能差. 本文介绍一类新型有机金属配合物聚吡咯-过渡金属-氧储锂材料的合成、结构及电化学性能. 结合扩展X-射线吸收精细结构谱分析和密度泛函理论计算，发现这类材料呈现多层结构特征，层内稳定的过渡金属-吡咯N的配位作用及循环过程中层间过渡金属-氧键的可逆断裂和结合使该类材料具有很高的储锂容量和循环稳定性，且聚吡咯导电网络使得该材料具有良好的倍率性能. 这类新材料将有望成为锂离子电池的高比容量负极材料.作者联系地址：1. Key Laboratory for Renewable Energy, Chinese Academy of Sciences；Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condense Matter Physics；Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; 2. Société civile Synchrotron SOLEIL L'Orme des Merisiers, Saint-Aubin-BP 48, 91192 GIF-sur-YVETTE CEDEX, France通讯作者E-mail：[email protected]；[email protected]

重离子辐照制备电池用微孔膜及其阻抗性质；Preparation of Microporous Membranes by Swift Heavy Ion Irradiation and Impedance Characterization

利用离子辐照结合径迹蚀刻方法制备聚丙烯(PP)微孔膜.用加速器产生的单核能为11.4MeV·u-1(总能量2245.8MeV)的197Au离子束辐照PP膜,剂量为1×108ions·cm-2.辐照后PP膜沿离子路径产生损伤区域,用硫酸与重铬酸钾的混合液进行蚀刻(5-30min),制备出孔径为380-1610nm的聚丙烯微孔膜.对膜的表面和断面形貌进行表征,微孔膜的孔径大小及空间分布均匀,孔道上下贯通,形状近似为圆柱形.给出了微孔膜的孔隙率理论公式.将制备的聚丙烯微孔膜用作锂离子电池隔膜,用电化学阻抗谱(EIS)测定浸满电解液的微孔膜的离子电导率,并与商用隔膜进行比较.分析表明辐照剂量和孔径大小均会影响膜的孔隙率和离子电导率,选择合适的辐照剂量和蚀刻时间,可以制备出孔隙率和离子电导率符合应用标准的聚丙烯微孔膜

Applications of Raman Spectroscopy Technique in Lithium Ion Batteries

综述拉曼光谱(Raman spectroscopy)在锂离子电池碳负极材料、尖晶石LiMn2O4和LiFePO4正极材料、聚合物和室温熔盐电解质以及电极/电解质界面膜研究中的应用,分析了非原位拉曼测试手段与原位拉曼测试手段的优缺点,展望了这一领域目前有待解决的问题和可能应用的新技术.The Raman spectroscopy has been widely used in the study of lithium ion batteries.In this short review,we gave some examples of the applications of Raman spectroscopy in the study of electrode materials including carbonaceous materials,spinel LiMxMn2-x O4,LiFePO4,as well as polymer electrolytes,room temperaturemolten salt electrolytes and the solid-electrolyte interphase layers.The advantages and disadvantages of the ex-situ and in-situ Raman spectrum techniques are discussed.Using new Raman techniques to investigate Li-ion batteries are suggested.作者联系地址：中国科学院物理研究所;Author's Address: Institute of Physics,Chinese Academy of Sciences,Beijing 100190,Chin