不同溶剂中电化学合成LiFePO4/C及性能

Electrochemical synthesis of LiFePO_4/C using different solvent and its performance

以无水乙醇、纯水为溶剂,蔗糖为碳源,采用电化学法合成LiFePO4/C锂离子电池复合正极材料。通过X射线衍射(XRD)、扫描电镜(SEM)及充放电性能测试等方法对其晶体结构、微观形貌和电化学性能进行分析研究。结果表明:LiFePO4/C具有单一的橄榄石型晶体结构。其中在无水乙醇溶剂中合成的LiFePO4/C复合正极材料粒径细小且分布均匀,具有最好的电化学性能,在0.2 C的放电倍率下,首次放电比容量达到142.3 mA h/g,充放电循环30次后放电比容量仍保持在141.2 mA h/g。

The LiFePO4/C composite cathode materials was synthesized by electrochemical method using ethanol,water as solvent and sucrose as carbon source. The crystalline structure, morphology and electrochemical performance were investigated by X-ray diffraction, scanning electromicroscope, and charge- discharge measurements. The results showed that LiFePO4/C was simple pure phase olivine-type crystal structure. It is noted that the LiFePO4/C composite cathode materials have small, uniform particle sizes, and thus excellent electrochemical performance with the first discharge specific capacity of 142.3 mAh/g at 0.2 C. After 30 times cycling, the discharge specific capacity wasl41.2 mA h/g.