尖晶石LiMn_2O_4表面包覆氧化钴的研究  

Study on the Spinel LiMn_2O_4 Coating with Cobalt Oxide

作　　者：万伟华[1] 唐仁英 唐有根[1] 卢周广[1] 

机构地区：[1]中南大学,湖南长沙410083 [2]湖南稀土金属材料研究院,湖南长沙410014

出　　处：《湖南有色金属》2006年第6期32-34,61,共4页Hunan Nonferrous Metals

摘　　要：采用高温固相法合成尖晶石LiMn2O4,并以化学沉积方式对其进行包覆氧化钴的表面处理。通过X射线衍射(XRD)、扫描电镜(SEM)等技术对表面处理前后的LiMn2O4进行表征,分析了表面处理后LiMn2O4物理特性的变化,并结合电化学性能测试,研究了表面处理及其工艺和条件对LiMn2O4电化学容量与循环性能的影响。结果表明,表面处理后LiMn2O4循环性能显著提高。随氧化物含量的增加,循环性能提高,容量降低。未经表面包覆的LiMn2O4首次充放电容量为108.13mAh/g,50次循环充放电后容量衰减26.3%。500℃加热处理的表面包覆0.5%、2%氧化钴的LiMn2O4首次循环放电容量各为118.38 mAh/g1、15 mAh/g,经过50次充放电循环后,容量分别降低8%、7%。The spinel LiMn2O4 synthesized by the method of solid-state reaction was modified by the chemical deposition process with Cobalt Oxide. The pristine and surface-modified LiMn2O4 were characterized with X-ray diffraction（XRD） and scanning electron microscope （ SEM ） . Effects of the surface-modification and preparation conditions on the electrochemical capacity and the rate capability were studied. The results showed that the cycling life was clearly improved with the increase of Cobalt. The initial capacity of unmodified LiMn2O4 was 108.13 mAh/g and the capacity fade was 26.3% after 50 charge/discharge cycles. On the contrary,spinel LiMn2O4 modified at 500 ℃ with 0.5% ,2% Cobalt Oxide showed the initial capacity of 118.38 mAh/g and 115 mAh/g respectively. After 50 charge/discharge cycles, the capacity each decreased by the extent of 8% and 7%.

关 键 词：LIMN2O4 蓄电池 氧化钴 表面处理 电化学性能 

分 类 号：TG14[一般工业技术—材料科学与工程]