以H3PO4、FeSO4·7H2O和LiOH·H2O为原料，石墨烯为碳源，采用水热合成法制备锂离子电池正极材料LiFePO4，考察水热反应温度和后期的焙烧温度等工艺条件对合成产物结构、形貌及电化学性能的影响。结果表明，水热反应温度和焙烧温度对合成的LiFePO4形貌结构与电化学性能均有显著的影响，石墨烯的掺入可明显改善材料的电化学性能。当水热温度为150℃、焙烧温度为700℃、石墨烯的掺入量为3%(质量分数)时，制备的样品具有相对较好的电化学性能，0.1C倍率下首次放电比容量为134.0 mA·h/g，经过20次循环后的比容量为131.3 mA·h/g，容量衰减率仅为2.02%。
LiFePO4 cathode material was synthesized using H3PO4, FeSO4·7H2O and LiOH·H2O as raw materials and graphene as carbon source. The effects of hydrothermal temperature and calcination temperature on the structure, micro-morphology and electrochemical performance of the as-synthesized specimens were investigated. The results show that both of hydrothermal temperature and calcination temperature are crucial parameters for the microstructure and electrochemical property of hydrothermal LiFePO4, the incorporation of graphene can significantly improve the electrochemical properties of the material. At the hydrothermal temperature of 150 ℃, the calcination temperature of 700 ℃ and the addition of graphene of about 3% (mass fraction), the as-obtained sample shows good electrochemical performance with initial specific discharge capacity of 134.0 mA·h/g at 0.1C, after 20 cycles, the specific capacity is 131.3 mA·h/g, and the decay rate is only about 2.02%.
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