Ni改性LiFe1-xNixPO4的结构与电化学性能

利用半固相碳热还原法制备了橄榄石型LiFe1-xNixPO4（x=0，0.02，0.05，0．08）锂离子电池正极材料．并用XRD、充放电测试、循环伏安、电化学阻抗测试等研究了其结构和电化学性能．实验结果表明：所制备材料均具有单一的橄榄石结构，其中材料LiFe0.95Ni0.05，PO4的电化学性能最佳．在0．2C和2．4～4．0V条件下恒流充放电，首次放电比容量可达139．35mAh·g^-1，30次循环后放电比容量仍保持在133．98mAh·g^-1以上，保持率为96．15％．循环伏安和电化学阻抗测试表明材料具有良好的充放电可逆性和较小的阻抗。

The structure and performance of LiFe1-XNiXPO4 prepared by carbothermal reduction method

Olivine LiFe1-x NixPO4 （x = 0,0.02,0.05,0.08 ） cathode materials were synthesized by carbothermal reduction method. The powder＇s structure and electrochemical properties were measured by XRD, charge-discharge at constant current, cyclic voltammetry and AC impedance methods. The results showed that the cathode materials LiFe1-xNixPO4（ X = 0 ,0. 02 ,0. 05 ,0. 08 ） had single olivine structure, among which the material LiFe0.95 Ni0.05PO4 exhibited the best electrochemical performance. The first discharge specific capacity was 139.35mAh·g^-1; after 30 cycles, the discharge specific capacity was above 133.98mAh·g^-1 and the capacity retention was above 96.15%. Electrochemical impedance and cyclic voltammogram showed that the sample had lower impedance and good cycle reversibility.