原位还原固相法合成LiFePO_4/(C+Cu)及性能研究

Preparation of LiFePO_4/(C+Cu) material by in-situ reduction solid state reaction and its electrochemical performance

以CuO为铜源,葡萄糖为碳源采用原位还原固相法合成LiFePO_4/(C+Cu)材料。采用XRD、SEM、EDS、LAND电池测试系统及电化学工作站等对材料的晶体结构、形貌和电化学性能进行测试,重点分析了材料的低温特性。结果表明:添加10%的葡萄糖合成的LiFePO_4/(C+Cu)展示出较好的电化学性能,尤其是低温性能。25℃,0.1C下首次放电比容量高达151.1 m Ah/g,-20℃时0.1C首次放电比容量107.6 mAh/g,为25℃相应倍率放电比容量的71.2%。

Cu-C co-coated on the surface of LiFePO4（LiFePO4/（C＋Cu）） cathode materials were prepared through in-situ solid state reduction reaction. The optimized additive amount of carbon was determined by electrochemical test of series content-dependent samples. Crystalline structure, morphology and electrochemical performance of the samples were characterized by X-ray diffraction, SEM, EDS, charge-discharge tests and AC impedance techniques.Low-temperature performances of the synthesized material were discussed. Results show that the LiFePO4/（C＋Cu）cathode material shows improved electrochemical performance especially at low temperature with 10% glucose additive. At 25 ℃ and 0.1C, specific capacity of the Cu-C co-coated sample reaches 151.1 mAh/g. At-20℃, the discharge capacity of Cu-coated materials is 107.6 mAh/g at 0.1C, which reaches about 71.2% of that at room temperature.