【作者】 熊利芝； 何则强； 黄可龙； 吴显明； 陈上；

【Author】 XIONG Li-zhi~(1,2) HE Ze-qiang~(1,2) HUANG Ke-long~2 WU Xian-ming~1 CHEN Shang~1 (1.College of Chemistry and Chemical Engineering,Jishou University,Jishou 416000,China;2.College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China)

【机构】 吉首大学化学化工学院； 中南大学化学化工学院；

【摘要】 采用固相反应法制备了 LiFe_0．7Mn_0．3O₄-C 复合材料．用 X 射线衍射、扫描电镜和电化学测试对符合材料的结构、形貌和电化学性能进行了研究．结果表明,LiFe_0．7Mn_0．3O₄-C 具有单一的橄榄石结构．碳的加入影响了 LiFe_0．7Mn_0．3O₄的表面形貌．LiFe_0．7Mn_0．3O₄-C 复合材料的颗粒大小在100～200nm 之间,碳均匀地包覆在 LiFe_0．7Mn_0．3O₄ 颗粒的表面．与 LiFe_0．7Mn_0．3O₄相比,LiFe_0．7Mn_0．3O₄-C 复合材料具有更高的可逆比容量、更好的循环性能：0．1C 放电时 LiFe_0．7Mn_0．3O₄-C 复合材料的可逆容量达到141mAh/g,60次循环后平均每次循环的容量损失只有0．19%,而相同条件下60次循环后 LiFe_0．7Mn_0．3O₄平均每次循环的容量损失为0．53%,表明碳的加入有效地改善了 LiFe_0．7Mn_0．3O₄的电化学性能．更多还原

【Abstract】 LiFe_0.7Mn_0.3O₄-C composite was synthesized at 650℃ by solid-state reaction.Structure,surface morphology and electrochemical properties of LiFe_0.7Mn_0.3O₄-C composite were characterized by X-ray diffraction,scanning electron microscopy,and electrochemical measurement,respectively.Results show that LiFe_0.7Mn_0.3O₄-C composite shares a single olivine structure.The morphologies of primary particles are greatly affected by the addition of carbon.The LiFe_0.7Mn_0.3PO₄-C composite has a small particle size of 100-200nm and carbon is coated on the surface of LiFe_0.7Mn_0.3PO₄ uniformly.Compared with LiFe_0.7Mn_0.3O₄,LiFe_0.7Mn_0.3O₄-C composite demonstrates high reversible capacity and perfect cycling performance:the reversible capacity of about 141 mAh/g at a current rate of 0.1C and the capacity loss per cycle is only 0.19% after cycling 60 times,while that of LiFe_0.7Mn_0.3PO₄ is 0.53%, suggesting the electrochemical performance of LiFe_0.7Mn_0.33PO₄ is improved effectively by addition of carbon.更多还原