焙烧温度对锂离子电池正极材料Li_2MnSiO_4/C电化学性能的影响(英文)  

Calcination Temperature Effects on the Electrochemical Performance of Li_2MnSiO_4/C Cathode Material for Lithium Ion Batteries

作　　者：魏怡[1] 王利娟[1] 闫继[1] 沙鸥[1] 唐致远[1] 马莉 

机构地区：[1]天津大学化工学院,天津300072 [2]东莞迈科科技有限公司,广东东莞523800

出　　处：《物理化学学报》2011年第11期2587-2592,共6页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation ofChina(20973124)~~

摘　　要：采用液相法合成了Li_2MnSiO_4/C复合正极材料,并研究了不同焙烧温度对材料的结构、形貌和电化学性能的影响.利用热重(TG)分析了材料前驱体的热行为,确定了合成Li_2MnSiO_4/C复合正极材料的焙烧温度范围为600-800℃.X射线衍射(XRD)测试结果表明,不同温度下合成的样品材料均具有正交结构,且空间群为Pmn2_1,同时利用扫描电子显微镜(SEM)对所得样品材料的微观形貌及颗粒大小进行了表征.将所得Li_2MnSiO_4/C复合正极材料组装成扣式电池,并在不同的电流密度下进行充放电测试,结果表明:700℃合成的样品材料电化学性能最佳,具有较高的库仑效率及很好的循环稳定性.As a new potential cathode material for lithium ion batteries,Li_2MnSiO_4/C was synthesized by a solution method.The thermal behavior of the precursor for Li_2MnSiO_4/C was measured by thermogravimetric （TG） analysis and the range of calcination temperatures from 600 to 800℃was determined.X-ray powder diffraction（XRD） patterns indicated that all the Li_2MnSiO_4/C samples crystallized in an orthorhombic structure with space group Pmn2_1.The morphology and particle size of the samples were also characterized by scanning electron microscopy（SEM）.The effects of calcination temperature on the electrochemical performance of Li_2MnSiO_4/C were studied using galvanostatic charge-discharge measurements at various current densities.The results showed that the sample prepared at 700℃exhibited a much higher coulombic efficiency and better cyclic performance than the other samples.

关 键 词：锂离子电池 正极材料 Li_2MnSiO_4 液相法 焙烧温度 

分 类 号：O646[理学—物理化学] TM912.9[理学—化学]