碳包覆对LiFePO4/C正极材料性能的影响

Effect of carbon coating on performance of LiFePO4/C cathode material

以葡萄糖为碳源,采用共沉淀法合成了LiFePO4/C一次颗粒,再经过喷雾干燥法使得一次颗粒堆积成二次颗粒。对样品进行了结构表征、形貌观察和电化学性能测试。结果表明当Fe和C6H12O6的摩尔比为1∶0.2时,其锂离子扩散速率为8.789×10^-12cm^2/s,在0.1C下首次放电比容量为140.8mAh/g,库仑效率为98.2%,经过50次循环后,样品的比容量仍然高达106.1mAh/g,容量保持率为87.7%,具有良好的循环性能及容量保持率。

LiFePO4/C primary particles were prepared by co-precipitation with glucose as carbon source. The primary particles were then stacked into secondary particles by spray dry method. The structure, morphology and electrochemical properties of the samples were characterized. The results show that when the molar ratio of Fe and C6H12O6 is 1∶0.2, the diffusion rate of lithium ion is 8.789×10^-12 cm^2/s, the initial discharge specific capacity is 140.8 mAh/g at 0.1 C, and the coulomb efficiency is 98.2%. After 50 cycles, the specific capacity of the sample is still 106.1 mAh/g and the capacity retention is 87.7%. It has good cycle performance and capacity retention.