Li(Ni0.4Co0.2Mn0.4)O2包覆Al2O3对隔膜形貌及结构的影响

摘要

以Al2O3包覆前后的Li(Ni0.4Co0.2Mn0.4)O2为正极活性物质,中间相炭微球(MCMB)为负极活性物质,与聚丙烯(PP)-聚乙烯(PE)-PP三层隔膜组装成18650型锂离子电池,在循环不同次数后,用SEM观察隔膜形貌,XRD分析其精细结构.在电池的循环过程中,隔膜出现微孔闭合及微观结构改变；包覆抑制了隔膜中微孔的闭合,同时提高了结构稳定性.%18650 type Li-ion battery was assembled with PP-PE-PP three-layer separator using Li(Ni0.4Co0.2Mno0.4)O2 before and after AI2O3 coating as cathode active material, MCMB as anode active material. The morphology of the separator was observed by SEM and the fine structure was tested by XRD after different cycle number. The partial holes of separators were closed during cycle process and the fine structure was changed.The coating suppressed the closing of holes of separators,at the same time,improved the structure stability.