论文部分内容阅读
采用溶胶-凝胶法制备出电化学性能优异的xLiFePO_4·yLi_3V_2(PO_4)_3/C复合正极材料。研究了复合比例对材料的组成、微观结构和电化学性能的影响。结果表明,当LiFePO_4和Li_3V_2(PO_4)_3的摩尔比为7:1,所得复合材料的颗粒尺寸在40~80nm之间,颗粒表面均匀地覆盖了一层无定形碳。在0.1C倍率下的首次放电容量为129.7mAh/g,充放电效率为96.0%;在1C、2C和5C倍率下,该材料的首次放电容量分别为104.6,89.3,71.6mAh/g,30次循环后的容量保持率为99.9%、95.1%和98.6%,表现出了良好的电化学稳定性。
The xLiFePO_4 · yLi_3V_2 (PO_4) _3 / C composite cathode material with excellent electrochemical performance was prepared by sol-gel method. The effect of composite ratio on the composition, microstructure and electrochemical properties of the materials was investigated. The results show that when the molar ratio of LiFePO 4 and Li 3 V 2 (PO 4) 3 is 7: 1, the particle size of the obtained composite is between 40 and 80 nm, and the surface of the particles is uniformly covered with a layer of amorphous carbon. The first discharge capacity at the rate of 0.1C was 129.7mAh / g and the charge-discharge efficiency was 96.0%. The first discharge capacity of the material at the rates of 1C, 2C and 5C were 104.6, 89.3, 71.6mAh / g, The capacity retention after cycling was 99.9%, 95.1% and 98.6%, showing good electrochemical stability.