LMO和NMC混合正极锂离子电池失效分析

Failure analysis of lithium-ion battery with LMO+NMC blended positive electrode

以活性材料锰酸锂(LMO)和镍钴锰酸锂(NMC)为正极,石墨为负极制成锂离子电池,并对电池进行循环寿命测试。采用X射线衍射(XRD)、扫描电镜(SEM)和电感耦合等离子体发射光谱(ICP-OES)等方法研究电池循环容量的衰减情况。结果表明:随着循环次数增加,极片脱落,掉粉,混合正极材料LMO中Mn溶出,NMC中Ni和Co溶解。混合正极材料的这些变化可能是造成电池循环容量衰减的主要原因。针对上述原因对混合正极的质量控制提出了建议。

Lithium-ion batteries were made of LMO and NMC cathode and graphite anode.Cycling life was tested.The cause of battery capacity loss was studied by means of XRD,SEM and ICP-OES.The results shown that with the increase of cycling,the pole piece had dropped and peeled.Mn in LMO had dissoluted.Ni and Co in NMC had also dissoluted.These changes of blended positive electrode may be the main cause of capacity loss during cycling test.The quality control suggestions of the blended positive electrode were proposed according to above reasons.