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采用化学共沉淀法制备球形前驱体Ni _0.7 Co _0.15 Mn _0.15 (OH) ₂, 将其与LiOH ?  H₂O充分混合后高温烧结制备出锂离子电池正极材料球形LiNi _0.7 Co _0.15 Mn _0.15 O ₂, 用X射线衍射(XRD)、扫描电镜(SEM)、热重--差热分析(TG/DSC)以及恒电流充放电测试对样品进行表征, 研究了烧结温度对产物的形貌和电化学性能的影响。结果表明, 在750℃合成的LiNi _0.7 Co _0.15 Mn _0.15 O ₂物相单一无杂相, 具有标准的α--NaFeO₂晶型, 为层状嵌锂复合氧化物。SEM测试显示, 产物为球形且球形度较好, 颗粒粒度均一, 分布较窄, 平均粒径在10 μm左右。在3.0--4.3 V、0.2C充放电条件下, 25℃其初始放电容量高达185.2 mA ? h/g, 30轮循环后容量保持率达到98.32%。可见球形LiNi _0.7 Co _0.15 Mn _0.15 O ₂显示了较高的首轮放电容量以及良好的循环性能, 表现出较好的电化学性能。

Spherical LiNi _0.7 Co _0.15 Mn _0.15 O ₂ powder was synthesized by firing LiOH·H₂O and the spherical Ni _0.7 Co _0.15 Mn _0.15 (OH)₂ prepared by co-precipitation method. The obtained powder was characterized by X-ray diffraction (XRD), Scanning electronic microscope (SEM), Thermogravimetric/Differential scanning calorimeter (TG/DSC) and constant current charge-discharge cycling. The results show that the optimal preparation condition of the layered LiNi _0.7 Co _0.15 Mn _0.15 O₂  was 750 under oxygen flowing. The XRD pattern of the sample prepared under the above condition can be identified by a typical structure of hexagonal α-NaFeO₂ type. The SEM micrograph of LiNi _0.7 Co _0.15 Mn _0.15 O₂ shows that the particle size is about 10 μm with narrow grain size. Electrochemical measurements show that it delivered an initial discharge capacity of 185.2 mA·h/g with the voltage range 3–4.3V at the 0.2C rate and initial capacity retention of 98.32% after 30 cycles.