溶液蒸干法合成LiFePO_4及性能研究

Preparation of LiFePO_4 by solution evaporating method and its performance research

探讨了一种液相法合成LiFePO4正极材料的新工艺,称为溶液蒸干法。通过XRD、SEM等测试方法对前驱体的组成、结构和形貌进行了表征,通过LiFePO4合成过程的分析,推断了过程的反应机理;此外,通过添加PEG合成了LiFePO4/C复合正极材料,并对其进行了结构和电化学性能表征。结果表明:合成的样品虽然存在极微量的杂质,但是主晶相为LiFePO4,0.1C倍率下首次放电比容量为156.5mAh/g,循环40次,平均每次的放电比容量损失率仅为0.16%。

A novel method for preparing LiFePO4 was discussed and it can be called solution evaporating method. The component, structure and morphology of the precursor was characterized by XRD and SEM. A reasonable conclusion of the mechanism was deduced by analysis of the process. The structure and electrochemical properties of LiFePO4/C synthesized with PEG as carbon source were studied. The results showed that the major phase was LiFePO4 although a little impurity was included. The initial discharge capacity of the sample was 156.5mAh/g at 0.1C and the average attenuation was 0. 16% after 40 cycles.