三元动力锂离子电池不同温度循环失效分析

Analysis of cycling performance failure of ternary power lithium ion cell at different temperature

对不同温度条件下循环后石墨/镍钴锰酸锂(LiNi0.6Co0.2Mn0.2O2)43 Ah动力锂离子电池进行分析,研究温度对循环性能的影响.通过小倍率恢复和电化学交流阻抗(EIS)分析极化对容量衰减的影响.通过扫描电镜(SEM)、X射线衍射仪(XRD)、扣电、原子吸收、容量微分(dQ/dV)对拆解后材料进行表征.循环并没有破坏正、负极材料整体结构,但导致比容量损失;隔膜在循环过程中出现局部闭孔;高温循环对正极造成的影响更大.

43 Ah graphite/LiNi0.6Co0.2Mn0.2O2 power lithium ion cells after cycling under different temperature conditions were analyzed to study the effect of temperature on the cycling performance.Small ratio recovery and EIS were used to analyze the effect of polarization on capacity fade.SEM,XRD,coin cell,atomic absorption and dQ/dV were used to characterize the material after disassembling.The whole structure of cathode and anode material was not destroyed after cycle,but the specific capacity was lost;the separator was shut down partly during the cycling process;high temperature cycle had more effect on cathode.