中文摘要：

采用高能球磨辅助固相法制备碳包覆并掺杂Mn的LiFePO4正极材料LiFe1-xMnxPO4（x=0.04、0.05、0.06和0.07）。通过X线衍射光谱仪（XRD）、场发射扫描电子显微镜（FESEM）、比表面积（BET）及恒流充放电等测试手段考察Mn的掺杂量及碳的包覆量对LiFePO4的结构、形貌及电化学性能的影响,最终确定优化条件。结果表明：Mn掺杂量x=0.06及碳的前驱体（蔗糖）添加量为LiFe0.94Mn0.06PO4质量的2.5%（碳最终质量分数为1.26%）时,所获得的碳包覆和Mn掺杂的LiFePO4正极材料的电化学性能最优异,其0.1C倍率的放电比容量为165.1 mA·h/g,10C倍率的放电比容量仍达92.4 mA·h/g,50次循环后容量保持率分别为96.7%及89.2%。

英文摘要：

Olivine LiFePO4 cathode materials co-modified with carbon coating and Mn2＋ doping were synthesized by a high energy ball milling-promoted solid-state reaction.The effects of manganese and carbon contents on the structure,morphology and electrochemical performances of LiFePO4 were characterized by X-ray diffraction（XRD）,filed-emission scanning electron microscope（FESEM）,Brunauer-Emmett-Teller（BET） nitrogen sorption method,and galvano charge-discharge analysis.The results showed that the optimal manganese and carbon contents were x=0.06 and 1.26%.The discharge capacities of LiFe0.94Mn0.06PO4/1.26%C reached 165.1 and 92.4 mA·h/g at 0.1C and 10C rates,and the corresponding capacity retention rates were 96.7% and 89.2% after 50 cycles.