尖晶石LiNi0.5Mn1.5O4中掺杂Fe的作用机理

Affecting Mechanism of Doping Fe in Spinel LiNi0.5Mn1.5O4

摘要:

利用湿化学法结合固相反应法制备了尖晶石LiNi0.5Mn1.5O4和掺杂Fe的LiNi0.45Fe0.1Mn1.45O4材料, 从晶体结构、表面形貌、充放电曲线特点、倍率性能等方面比较了掺杂Fe以后对材料的影响, 并结合热重实验, 通过测试失重量, 进而分析了材料中的氧缺陷含量, 推导出掺杂Fe的作用机理: 尖晶石LiNi0.5Mn1.5O4材料中掺杂Fe元素, 能够使材料晶体中保持一定的氧缺陷, 从而使得材料含有一定量的Mn3 , 提高了材料充放电倍率性能.

Abstract:

Spinel LiNi0.5Mn1.5O4 and Fe-doped compound LiNi0.45Fe0.1Mn1.45O4 were synthesized by a wet chemical method combining a solid state reaction process. The comparison from the aspects of crystal structure, surface morphology, charge-discharge characteristics and rate capability of spinel LiNi0.5Mn1.5O4 and LiNi0.45Fe0.1Mn1.45O4 was made. The mechanism of doped Fe was deduced based on the measured oxygen deficiency amount from the TGA experiment. The doped Fe can maintain some oxygen deficiency which makes spinel LiNi0.5Mn1.5O4 contain some Mn3 , improving the rate capability.