F^-掺杂LiMn_2O_4的合成及电化学性能

Synthesis and electrochemical performance of LiMn_2O_4 doped with F^-

采用溶胶-凝胶法合成掺杂F-的LiMn2O4。通过XRD、SEM对掺杂F-的LiMn2O4材料的组成、结构、微观形貌等进行分析与表征,测试不同F-掺杂量的LiMn2O4在常温(20℃)、高温(55℃)下的电化学性能。结果表明:所合成的材料具有良好的尖晶石立方结构,无杂相;F-的掺杂提高了材料的比容量,增强了材料的稳定性,改善了其在高温下的循环性能。当F-的掺入量x由0增加到0.1时,材料的比容量由119.7 mA.h/g增加到124.9 mA.h/g,高温下充放电30个循环后容量保持率由79.4%增加到84.4%。

Spinel LiMn2O4 doped with F was synthesized by solgel method. Its component, structure and morphology were studied by XRD and SEM. The electrochemical performance of the LiMn2O4 doped with F^- was tested by constant current charge-discharge measurement at 20℃ and 55℃. The results show that the synthesized material is pure spinel phase. The electrochemical Li intercalation capacity of the synthesized cathode materials is improved, and the stability and cycle ability are enhanced at 55℃ due to the F-doping. As the amount off increases from 0 to 0.1, the capacity of the materials increases from 119.7 mA·h/g to 124.9 mA·h/g, and the rate of capacity retention after 30 cycles at 55 ℃ increases from 79.4% to 84.4%.