利用碳热还原法成功制备了碳包覆Li3V2(PO4)3正极材料.X射线衍射研究表明材料具有纯相单斜结构.高分辨透射电子显微镜观察到材料表面存在5～ 10 nm的包覆碳层.碳包覆Li3V2(PO4)3材料在3.0～4.3V电压区间内可提供120 mA· h/g(C/4倍率)、115mA·h/g(1C倍率)和110mA·h/g(2C倍率)的可逆容量,并且在循环300次后容量保持率超过97％,显示出良好的应用前景.该材料在充放电循环初期经历了不可逆容量损失.高分辨透射电子显微镜研究表明,该不可逆容量损失来源于材料表面生成的固体电解质中间相(SEI膜),红外光谱分析表明,SEI膜的成份主要包括ROCO2Li和RCO2Li等有机物,以及Li2CO3、LixPFy和LixPOyFz等无机物.表面SEI膜经历初期电化学循环后趋于稳定,从而保证碳包覆Li3V2(PO4)3正极材料优良的电化学性能.
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