锂离子电池正极材料LiFePO_4的合成及电化学性能

Synthesis and Electrochemical Performance of Cathode Material LiFePO_4 for Lithium-Ion Battery

采用固相合成法在不同温度制度下合成掺杂碳的LiFePO4正极材料,计算出各样品的结构参数并对各样品进行电化学测试·结构参数的计算结果表明:合成温度升高,样品的结晶程度更好,结构更紧凑,更趋稳定·电化学测试结果说明:700℃合成的产物具有良好的电化学性能,在0 1C倍率下放电,其室温初始放电容量为140 4mAh/g,循环10次后容量衰减较小·此条件合成的LiFePO4放电容量与目前工业化生产的LiCoO2相当,具有良好的应用前景·

The olivine LiFePO_4 was studied as cathode material for lithium-ion battery. Carbon-doped LiFePO_4 was synthesized through solid-state reaction at different temperatures, of which the structural parameters of samples were calculated and electrochemical tests were performed for samples. The calculated results showed that with the elevated synthesizing temperature, the samples show higher crystallinity and more compact and stable structure. The testing results showed that the samples synthesized at 700℃ have good electrochemical performance. The initial specific capacity discharged at 0.1C rate and room temperature is 140.4 mAh/g, with very little capacity fading after 10 cycles. The discharge capacity of LiFePO_4 synthesized in such a way is equivalent to that of the present commercial LiCoO_2 as cathode material. It has a promising future in application.