Mn^(2+)掺杂对V_2O_5纳米材料结构与电化学性能的影响  

Effect of Mn^(2+) Doping on Structure and Electrochemical Properties of V_2O_5 as the Rechargeable Electrode Material

作　　者：李兆龙[1] 孙华君[1] 徐杰[1] 张晓艳[1] 黄胜男[1] 朱泉峣[1] 陈文[1] Galina S.Zakharova 

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070 [2]俄罗斯科学院乌拉尔分院固态化学研究所

出　　处：《无机材料学报》2013年第11期1200-1206,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(51072152;50872101);国家自然科学基金国际合作项目(中-俄51011120252);科技部国际合作项目(2013DFR50710);湖北省自然科学基金重点项目(2010CDA015);武汉市科学技术计划项目(201051730550);中央高校基本科研业务费专项基金(125201010)~~

摘　　要：以V2O5粉末、H2O2和Mn(CH3COO)2·4H2O为原料,采用水热法制备了纳米结构的锂离子电池阴极材料Mnx V2O5。运用X射线衍射(XRD)、X射线光电子能谱分析(XPS)和扫描电镜(SEM)测试对制备的材料进行结构和形貌表征,并利用充放电测试和交流阻抗测试研究了样品的电化学性能。结果表明:随着锰掺杂量的增加,V2O5的正交晶型层状结构未发生改变,其层间距逐渐扩大,形貌由纳米短棒状向纳米带簇状变化。电化学测试表明:Mn2+掺杂提高了V2O5的电化学性能,其首次充放电效率由70.8%提高到90%以上;Mn0.01V2O5经过90次充放电循环后,其容量仍为192.2 mAh/g。Mn2+掺杂对V2O5电极材料的离子电导率有影响,Mn0.02V2O5离子电导率由未掺杂时的6.27×10-4S/cm提高到1.58×10-3S/cm。MnxV2O5 （x=0~0.06） was prepared by hydrothermal method with H2O2 and V2O5 as precursors and Mn2＋ added directly in the sol preparation process. Structures and morphologies of the materials were characterized by X-ray diffraction （XRD）, X-ray Photoelectron Spectroscope （XPS） and scanning electron microscope （SEM）. The results indicate that the V2O5 is well crystallized as an orthorhombic structure without any detectable impurity phase with the doping of Mn2＋. The doping Mn2＋ is situated between anionic sheets of VO6 chain in the V2O5 and the morphology of V2O5 changes from nanorods to nanobelts cluster. The electrochemical behavior of the MnxV2O5 acted as cathode materials is studied by charge-discharge test and electrochemical impedance spectra （EIS） test through a three electrode system. The results indicate that the efficiency of the first charge-discharge of the material enhances to 90% with the Mn2＋ doping. The discharge capacity of the Mn0.01V2O5 is up to 192.2 mAh/g after 90 charge-discharge cycles at 0.2C rate. The doping Mn2＋ performs efficiently in ionic conductivity of V2O5 electrode material, and the ionic conductivity of Mn0.02V2O5 is enhanced from 6.27×10-4 S/cm to 1.58×10-3 S/cm.

关 键 词：MnxV2O5 电极材料 离子掺杂 电化学性能 

分 类 号：O657[理学—分析化学]