LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的低温性能及动力学分析  

Low temperature performances and kinetic analysis on LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2

作　　者：李光胤[1,2] 黄震雷[1] 张占军[2] 周恒辉[1] 

机构地区：[1]北京大学化学与分子工程学院,北京100871 [2]中国科学院大学化学与化学工程学院,北京100049

出　　处：《中国科学：化学》2014年第7期1167-1174,共8页SCIENTIA SINICA Chimica

基　　金：科技部中国-新加坡国际合作项目(2012DFG52130);北大先行科技产业有限公司资助

摘　　要：通过高温烧结制备了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2,并用XRD、SEM和恒流充放电对材料的结构、形貌和低温电性能进行了表征,通过线性极化、GITT和EIS等手段研究分析了低温下LiNi1/3Co1/3Mn1/3O2性能变差的原因.结果表明,-20℃时,LiNi1/3Co1/3Mn1/3O2材料的0.1、0.2、1和5 C倍率放电比容量依次为25℃时同倍率下放电比容量的83.2%、68.4%、57.2%和34.1%,放电中值电压比25℃时依次降低了0.049、0.125、0.364和0.531 V.低温充放电过程表现出明显的极化现象,其中最显著的极化来自锂离子穿过活性物质/电解液界面过程以及电荷转移过程,而非锂离子在电极材料内部的扩散过程.LiNi1/3Co1/3Mn1/3O2 was prepared by high temperature sintering. The structure, morphology and low temperature performances were characterized by XRD, SEM and charge/discharge test. The reasons of capacity fade at low temperature were analyzed by linear polarization, GITT, and EIS. The results show that, compared with 25 ℃, the capacity of LiNi1/3Co1/3Mn1/3O2 at -20 ℃ delivers 83.2%, 68.4%, 57.2% and 34.1% at 0.1, 0.2, 1 and 5 C, respectively. The discharge mid-voltage reduces 0.049, 0.125, 0.364 and 0.531 V, respectively. It should be noticed that the significant polarization at low temperature charge/discharge process is mainly arised from the process of lithium ions traversing electrode/electrolyte interface and charge transfer, rather than lithium ions diffusion process in electrode material.

关 键 词：锂离子电池 低温性能 恒电流间歇滴定法 

分 类 号：TM912[电气工程—电力电子与电力传动]