5V锂离子电池正极材料LiNi0.5Mn1.5O4的合成与Li^＋在材料中的扩散性能  

Preparation of LiNi_(0.5)Mn_(1.5)O_4 as 5 V Cathode Materials for Lithium Ion Battery and Diffusion Performance of Li^+ in the Materials

作　　者：卢华权[1] 吴锋[1] 苏岳锋[1] 李宁[1] 陈实[1] 包丽颖[1] 

机构地区：[1]北京理工大学化工与环境学院,国家高技术绿色材料发展中心,北京100081

出　　处：《高等学校化学学报》2011年第4期946-951,共6页Chemical Journal of Chinese Universities

基　　金：国家“九七三”计划项目(批准号:2009CB220100)资助

摘　　要：采用草酸盐共沉淀法合成了5 V正极材料LiNi0.5Mn1.5O4,研究了不同温度下合成材料的结构形貌与电化学性能之间的关系.结果表明,在900℃下合成样品的电化学性能最好,首次放电容量达到133.0mA.h/g,经30周循环后,容量仍然保持在132.2 mA.h/g,容量保持率高达99.4%.采用恒电位间歇滴定法(PITT)和电化学阻抗谱法(EIS)测定了锂离子在LiNi0.5 Mn1.5 O4材料中的扩散系数.结果表明,在LiNi0.5Mn1.5O4材料放电过程中,在不同的电位下,锂离子扩散系数在10-10～10-11 cm2/s范围内变化.5 V cathode material LiNi0.5M1.5O4 was synthesized via an oxalate co-precipitation method,and the relationship between the structure,morphology and the electrochemical performance of the material was investigated.The results show that the sample synthesized at 900 ℃ has the best electrochemical performance.Its initial discharge capacity reaches 133.0 mA·h/g,and after cycled for 30 times,still maintains at 132.2 mA·h/g（capacity retention 99.4%）.The chemical diffusion coefficient of Li＋ ion in LiNi0.5M1.5O4 cathode material was measured by potentiostatic intermittent titration technique（PITT） and electrochemical impedance spectroscopy（EIS）.The chemical diffusion coefficient of Li＋ ion ranges in 10-10—10-11 cm2/s.

关 键 词：锂离子电池 正极材料 草酸盐共沉淀 LINI0.5MN1.5O4 扩散系数 

分 类 号：O646.21[理学—物理化学]