制备方法对Li1.2Ni0.17Co0.07Mn0.56O2富锂正极材料电化学性能的影响

采用喷雾干燥法、共沉淀法、固相法3种方法制备化学计量式为Li1.2Ni0.17Co0.07Mn0.56O2的锂离子电池富锂正极材料。电化学测试表明，喷雾干燥法制备的材料电化学性能最好，0.1 C充放电首圈脱锂和嵌锂容量分别为283.9 mA/(h?g)和231.7 mA/(h?g)。与共沉淀法和固相法相比较，喷雾干燥法制备的材料1 C倍率充放电时表现出良好的循环稳定性，50次循环后容量没有衰减，仍为153.4 mA/(h?g)，共沉淀法和固相法制备的材料50次循环放电容量分别为133.5 mA/(h?g)和123.6 mA/(h?g)。ICP分析结果指出，喷雾干燥法制备的电极材料元素比例最符合初始的Li1.2Ni0.17Co0.07Mn0.56O2设计配比。而且喷雾干燥法制备的材料颗粒更为细小均匀，有利于提高材料的电化学性能。

Study on the electrochemical performance of Li_(1.2)Ni_(0.17)Co_(0.07)Mn_(0.56)O_2 synthesized by different methods

Lithium rich Li1.2Ni0.17Co0.07Mn0.56O2 cathode materials for lithium ion batteries were synthesized by three different methods：a spray-drying method, a co-precipitation method and a solid-state reaction method. Electrochemical tests show that the sample prepared by the spray-drying method presents the best cycling performance with discharge capacity of 153.4 mA?h?g－1 at 1 C rate. No degradation was observed after 50 cycles. While the samples prepared by the co-precipitation method and the solid-state reaction method delivered the capacity of 133.5 mA?h?g－1 and 123.6 mA?h? g－1, respectively, after 50 cycles under 1 C rate charge-discharge. The results of ICP measurements indicate that only the composition of the sample prepared by the spray-drying method can exactly consist with the formula Li1.2Ni0.17Co0.07Mn0.56O2. Furthermore, FSEM observation shows that the sample by spray-drying method has smaller particle size with even particle size distribution, which would benefit its electrochemical performance.