以过渡金属乙酸盐和氢氧化锂为原料,应用共沉淀或流变相预处理高温烧结法优化并制备出L iN i0.4Co0.2Mn0.4O2正极材料.X射线衍射技术(XRD)及R ietveld结构精修、扫描电子显微技术(SEM)、综合热分析(TG-DSC)表征结果和电化学测试结果表明,该材料具有单一层状结构,颗粒大小均匀,热稳定性好,首次放电比容量高达208.7 mA.h/g(2.0~4.6 V,0.1 C),电化学性能优异.非原位(ex situ)XRD测定结果表明,材料充至高电位下发生的不可逆相变造成了材料的循环容量衰减.Cathode material of LiNi_(0.4)Co_(0.2)Mn_(0.4)O_(2) was prepared by mixed hydroxide or rheological reaction method at 850 ℃ within 15 h.The materials were characterized by XRD with Rietveld refinement,SEM,TG-DSC and electrochemical tests.The results showed that it has R-3m layered structure,with a high capacity and good thermal property.It delivered a specific capacity as high as 208.7 mA·h/g(2.0—4.6 V,0.1 C).Phase change of Li_(x)Ni_(0.4)Co_(0.2)Mn_(0.4)O_(2)(0<x<1) in charge-discharge process will affect the cyclic stability of the materials,especially in the first 10 circles.国家自然科学基金(批准号:20473068,29985310)资
