钴含量对锂离子电池正极材料LiNi0.5-xCo2xMn0.5-XO2的性能影响

采用共沉淀-喷雾法合成出层状LiNi0.5-xCo2xMn0.5-xO2(x=0,0.075,0.15)正极材料,研究了不同掺钴量对材料的结构和电化学性能的影响,并用XRD、SEM及电性能测试考察了所得材料的结构、形貌与电化学性能;XRD分析表明,LiNi0.5-xCo2xMn0.5-xO2具有α-NaFeO2层状结构,Co3+的掺入可促进层状结构的生成,有效减少阳离子混排。电性能测试结果显示,LiNi0.5-xCo2xMn0.5-xO2随着掺钴量的增大,放电容量提高,循环性能变好;样品LiNi0.35Co0.3Mn0.35O2表现出最好的电化学性能,其首次放电效率充放电效率达90%,首次放电容量为172.8 mAh/g,40次循环容量无明显衰减。

Effect of Co Content on Performance of Anode Material for Lithium Ion Battery

The precipitated spray prilling method was used to prepare the layered LiNi0.5-xCo2xMn0.5-xO2（X = 0,0. 075,0.15 ） anode material for lithium ion batteries analysis, XRD, SEM and electrochemical tests were used to characterize the structure, appearance and electrochemical performances of the aimed material. The results of XRD show that all LiNi0.5-xCo2xMn0.5-xO2are pure phase materials with layered α -NaFeO2 structure,and the Co3＋ content can boost layered structure to be produced and effectively restrain the cation - mixing. The electrochemical tests indicate that the discharge capacities of LiNi0.5-xCo2xMn0.5-xO2 increase and the cycle performances become better with the content of Co increasing. The sampleLiNi0.5-xCo2xMn0.5-xO2 has the best electrochemical properties, which has an initial charge capacity of 172.8 mAh/g and an initial efficiency of 90%. After 40 cycles, this sample preserves 100% of the initial discharge capacity, showing perfect cyclic stability.