LiNi0.6Co0.1+xMn0.3-xO2（x=0,0.1）正极材料的合成与电化学性能研究

Synthesis and electrochemical properties of LiNi0.6Co0.1+xMn0.3-xO2（x=0,0.1） cathode material for Li-ion batteries

采用高温固相法在相同条件下合成了LiNi0.6Co0.1Mn0.3O2与LiNi0.6Co0.2Mn0.2O2正极材料,利用XRD、SEM表征了材料的结构与形貌,通过恒电流充放电测试、循环伏安(CV)和交流阻抗(EIS)研究了其电化学性能。结果表明,室温条件下以0.2 C倍率在3.0~4.3 V电压范围内,LiNi0.6Co0.1Mn0.3O2的首次放电比容量为171.8 mAh/g,1 C循环100次后容量保持率为78.5%;LiNi0.6Co0.2Mn0.2O2的首次放电比容量为174.6 mAh/g,1 C循环100次后容量保持率为83.0%。CV与EIS测试表明,相比LiNi0.6Co0.2Mn0.2O2,LiNi0.6Co0.1Mn0.3O2材料有更大的极化与电荷转移阻抗。

The ternary materials of LiNi0.6Co0.1Mn0.3 O2 and LiNi0.6Co0.2Mn0.2 O2 were synthesized by high temperature state method, and the structure and morphology of the materials were characterized by XRD and SEM. The electrochemical properties were investigated by galvanostatic charge-discharge test, cyclic voltammetry(CV) and electrochemical impedance(EIS). The results show that the LiNi0.6Co0.1Mn0.3 O2 achieves an initial discharge specific capacity of 171.8 mAh/g at 3.0-4.3 V with 0.2 C rate, and the capacity retention is 78.5% after 100 cycles at 1 C rate. The LiNi0.6Co0.2Mn0.2 O2 achieves an initial discharge specific capacity of 174.6 mAh/g, and the capacity retention is 83.0% after 100 cycles at 1 C rate. The CV and EIS tests show that the LiNi0.6Co0.1Mn0.3 O2 has greater polarization and electron transfer impedance than LiNi0.6Co0.2Mn0.2 O2.