锂离子电池正极材料Li[Li0.20Ni0.128CO0.136Mn0.536]O2的研制

采用共沉淀法得到前驱体M(OH)2(M=Ni、Co、Mn)后与氢氧化锂(LiOH·H2O)进行高温固相反应得到锂离子电池正极材料Li[Li0.20Ni0.128Co0.136Mn0.536]O2,并对该材料进行Al2O3包覆.通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和电化学测试手段对产物的结构、形貌以及电化学性能进行研究.XRD结果表明合成的材料具有典型的α-NaFeO2层状结构,包覆后结构没有变化.SEM照片显示前驱体以及包覆前后颗粒粒径均在10μm左右.在0.1 C下,材料的首次放电比容量达到210.2 mAh/g,循环80次后降为153.4 mAh/g.Al2O3包覆后,同样条件下首次放电比容量为220.5 mAh/g,80次循环后比容量保持在211.5 mAh/g,说明包覆后材料的循环寿命得到了显著提高.

Li[Li0.20Ni0.128Co0.136Mn0.536]O2 cathode material for lithium-ion batteries

The layered Li[Li0.20Ni0.128Co0.136Mn0.536]O2 power was synthesized by reacting precursor M(OH)2(M=Ni,Co,Mn) prepared by co-precipitation with LiOH·H2O through high temperature solid-state method.The surface of cathode material was coated with Al2O3.The XRD,SEM and electrochemical measurements were used to characterize the structure,morphology and electrochemical performance of the product.The XRD results show that the as-prepared Li[Li0.20Ni0.128Co0.136Mn0.536]O2 has a-NaFeO2 layered structure.Al2O3 coating does not cause structure change.The SEM images show that the particles after coating have similar shape and size to the precursor.At 0.1 C rate,the discharge specific capacity is 210.2 mAh/g at the first cycle and in the 80th cycle,it is 153.4 mAh/g.After Al2O3 coating,the discharge specific capacity reaches 220.5 mAh/g and remains 211.5 mAh/g after 80 cycles.It shows that Al2O3 coating improves the cycling performance significantly.