多孔球形Li_2MnSiO_4/C正极材料的制备及电化学性能  

Preparation and electrochemical performance of porous spherical Li_2MnSiO_4/C cathode material

作　　者：汪燕鸣[1] 王广健[1] 丁素芳[1] 

机构地区：[1]淮北师范大学化学与材料科学学院,安徽淮北235000

出　　处：《功能材料》2012年第7期924-926,931,共4页Journal of Functional Materials

基　　金：安徽省2012年高等学校优秀青年人才基金资助项目(2012SQRL226ZD);安徽省科技厅自然科学基金面上资助项目(11040606M42);2011年淮北师范大学青年科研资助项目(201132)

摘　　要：采用湿法球磨-喷雾干燥法制备了多孔球形锂离子电池Li2MnSiO4/C复合正极材料。X射线衍射(XRD)表明合成的Li2MnSiO4具有正交结构,属于Pmn21空间群。扫描电镜(SEM)和透射电镜(TEM)显示粉体复合材料为直径10μm左右的球形团簇,由100nm左右的颗粒堆积而成,颗粒表面包覆1层大约3nm的碳层。电化学测试表明,在0.05和0.5C倍率下,Li2MnSiO4/C样品的首次放电容量分别为153和110mAh/g,50次循环后容量分别保持80%和66%。Porous spherical Li2MnSiO4/C composite was prepared via a wet ball milling-spray drying method and exploited as cathode material for lithium ion batteries.X-ray diffraction（XRD） pattern of the sample conformed the formation of orthorhombic Li2MnSiO4 with Pmn21 space group.The scanning electron microscopy（SEM） and transmission electron microscopy（TEM） showed that the aggregated spherical particles in diameter of 10μm which were composed of large numbers of nanoparticles with size of 100nm.The Li2MnSiO4 nanoparticles were covered with a carbon layer of 3nm thick.The electrochemical test reveale that the initial discharge capacities of Li2MnSiO4/C were 153 and 110mAh/g at 0.05 and 0.5C rate,with the capacity retention of 80% and 66% after 50 cycles,respectively.

关 键 词：锂离子电池 硅酸锰锂 多孔球形 正极材料 

分 类 号：TM912.9[电气工程—电力电子与电力传动]