NCA锂离子蓄电池长期储存温度影响分析

Failure analysis of NCA lithium-ion cell for long storage

以NCA/C 体系18650单体电池为实验样品,研究了三元材料NCA 在100%荷电态不同温度下长期储存的性能衰退情况,并对电池开展了DPA 分析,通过X 射线衍射(XRD)、扫描电子显微镜(SEM)、交流阻抗等分析手段对电池长期储存性能衰退的机理进行了探讨。结果显示,长期储存下蓄电池容量下降、内阻增加,且性能衰退情况受温度影响最大,DPA 分析结果揭示负极是电池长期储存过程中性能衰退的关键影响部件,其在长期储存过程中存在Cu集流体腐蚀,电极电阻率增加是其失效的机理。

Performance of 18650 NCA/C lithium-ion cells was studied for long storage at 100% SOC and various temperature. And then cell possible degradation was discussed by DPA analysis including XRD,EIS and electrode resistivity test .The long storage tests show that the cell’s capacity decayed and impedance increased when stored for a long time. And furthermore the degradation of cells was effected by temperature mostly. DPA analysis show that Cu collector oxidation and resistivity increasing of negative electrode may the cause of cell performance decay.