摘要
以氢氧化锂、乙酸锰和草酸为原料,固相反应12h合成富锂尖晶石Li4Mn5O12,用XRD,SEM和电化学性能测试等方法表征材料结构和性能.结果显示,分350℃和500℃温度二段焙烧合成的Li4Mn5O12材料结晶度大,晶型完整,样品为块状颗粒,分布均匀,粒度范围在1～5μm之间.电化学性能最优,首次放电容量为151mA·h·g^-1.充放电后材料进一步XRD分析发现,充放电循环使Li4Mn5O12结构发生变化,循环多次后,材料中已发现少量尖晶石LiMn2O4存在.
The lithium-rich Li4Mn5O12 compound is synthesized by the solid-state reaction for 12h with LiOH·H2O, Mn（CH3COO）2 and H2C2O4 as raw materials. And the material structure and property are characterized by X- ray diffraction（XRD）, scanning electron micrograph （SEM） and electrochemical measurements. The results indicate that the Li4Mn5O12 prepared by a two-step calcination procedure at 350℃ and 500℃ is well-order crystal, high crystallinity and even grain size with chop-shape particles sized from 1- 5μm, presents advanced electrochemical performance, and its initial discharge capacity reaches to 151 mAh·g^-1. It is found by XRD of the material cycled for many times that the structure of the material is transformed by the charge-discharge cycle, and there are a few of LiMn2O4 in the material after cycling many times.
出处
《有色金属》
CSCD
北大核心
2007年第3期25-29,共5页
Nonferrous Metals
基金
国家863计划资助项目(2003AA32X010)
湖南省教育厅资助项目(04c161)
