F-掺杂LiMn_2O_4的结构及高温性能

Structure and electrochemical performance of high temperature for F-doped LiMn_2O_4

采用溶胶-凝胶法合成了掺杂F-的LiMn2O4。通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)对掺杂F-的LiMn2O4材料的组成、结构、微观形貌等进行了分析与表征,用恒电流充放电测试了不同F-掺杂量的LiMn2O4在高温(55℃)下的电化学性能。XRD结果表明:在一定的掺杂范围内,所合成的材料具有良好的晶型,且为尖晶石立方结构。电化学测试结果表明: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,但降低了其在高温下的储存性能。

Spinel LiMn2O4 doped F- was synthesized by sol-gel method. Its component, structure and microscopic shape were studied by XRD and SEM, The electrochemical performance of high temperature for the LiMn2O4 doped by different amounts of F- was tested by constant current charge-discharge. Results of XRD show that the crystallinity of the synthesized material is very well and the structure is pure spinel phase. The electrochemical test shows that it improves the capacity of the material, enhances the stability and improves the cycle performance of high temperature but it decreases the stored performance of high temperature with F-doping.