锂离子电池正极材料LiFePO_4的合成与性能研究

Synthesis and Electrochemical Characteristics of Li-ion Battery Cathode Material LiFePO_4

以Li2CO3,FeSO4.7H2O、(NH4)2HPO4和Na2EDTA为原料,采用水热法合成了锂离子电池正极材料LiFePO4,研究了原料混合液pH值对产物形貌和电化学性能的影响。结果表明,在pH=8下合成的样品属于橄榄石结构,0.1C、3.0～4.3 V条件下充放电的首次放电比容量为141 mAh.g-1,第20次循环的比容量为138 mAh.g-1。

LiFePO4 was synthesized by hydrothermal reaction using Li2CO3,FeSO4·7H2O and（NH4）2HPO4 as starting materials.The effects of pH value on the particle morphology and electrochemical performance were investigated.The results show that the sample synthesized at pH=8 has a single ordered olivine structure under charge-discharge at 0.1C and voltage range of 3.0～4.3 V,the initial specific discharge capacity is 141 mAh·g-1,and the specific capacity at 20 th cycle is 138 mAh·g-1.