尖晶石型LiCr_(0.2)Mn_(1.8)O_4的合成与电化学性能

Synthesis and Electrochemical Characteristic of Spinel LiCr_(0.2)Mn_(1.8)O_4

将LiOH,MnCO3和Cr2(CO3)3按n(Li)∶n(Cr)∶n(Mn)=1.02∶0.2∶1.8分别称量,置于研钵中混合并用二次蒸馏水分散研磨,800℃焙烧,用悬浮固相反应合成了尖晶石LiCrxMn2-xO4(x=0.2)化合物。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、差热分析(DTA)、X射线能谱(EDS)和傅里叶红外光谱(FTIR)对合成物质的结构作了表征,并用循环伏安和恒电流循环技术对合成产物的电化学性能进行了考察。结果表明,LiCr0.2Mn1.8O4的颗粒主要为六角立方的尖晶石型,单个颗粒尺寸在1μm左右;39次循环后的充/放电比容量为101/99 mA.h.g-1,充/放电效率分别保持在98%和96%。

The spinel phase of LiCr Mn2xO4 （x = 0,0, 2） was synthesized via suspended solid reaction of LiOH, MnCO3 and Cr2 （ CO3 ） 3 prepared by dispersing stoichiometric amount of Li, Cr and Mn salts in the proportion of n（Li） ：n（Cr） ：n（Mn） = 1.02：0. 2：1.8. The mixture was added to distilled water and rubbed repeatability, desiccated and calcined at 800℃. The material was characterized with XRD, SEM, FTIR, TGA and EDS, and the electrochemical properties were investigated using cyclic voltammetry and charge-discharge cycling techniques. The results show that the LiCrxMn2 x O4 is spinel phase of hexagonal cube, size of single grain about 1 μm; the charge and discharge capacities of the LiCr0.2Mn1.8O4 are still 101/99 mA·h·g^-1 and the efficiencies of charge and discharge keep to 98% and 96% respectively after 39 cycles.