Influence of Y^(3+) doping on structure and electrochemical performance of layered Li_(1.05)V_3O_8  

作　　者：刘丽英 田彦文 翟玉春 徐茶清 

机构地区：[1]School of Materials and Metallurgy,Northeastern University

出　　处：《中国有色金属学会会刊：英文版》2007年第1期110-115,共6页Transactions of Nonferrous Metals Society of China

基　　金：Project(2003224005)supported by the Liaoning Science and Technology Fund,China

摘　　要：LiOH.H2O,V2O5 and Y(NO3)3 were used as raw materials to synthesize the precursors containing Li,V and Y by liquid-state reaction,then the cathode materials Li1.05YxV3-xO8(x=0,0.002 5,0.005,0.01,0.02,0.1,0.2)for lithium-ion battery were obtained by calcining the precursors.The influence of Y3 +doping on structure,conductivity and electrochemical performance of Li1.05V3O8 were investigated by using XRD,cyclic voltammograms,AC impedance,etc.The results show that Li1.05YxV3-xO8 with different doping amounts have well-developed crystal structure of layered Li1.05V3O8 and lengthened interlayer distance of(100) crystal plane.Y3 + can insert into crystal lattice completely when the doping amount is small and the impurity phase of YVO4 is found when x≥0.1.There is no change in the process of Li+insertion-deinsertion with Y 3+doping.The conductivity is clearly improved due to small amount of Y 3+ doping and it tends to increase first and then decrease with increasing doping amount.The initial discharge capacity and plateau potential are both enhanced with proper amount of Y3 +doping.When x is 0.005,the first specific discharge capacity reaches 288.9 mA.h/g,4.60%larger than that of undoped sample(276.2 mA.h/g).When x≤0.1,the average discharge plateau potentials are enhanced by about 0.15 V,which makes for higher energy density.LiOH.H2O, V2O5 and Y（NO3）3 were used as raw materials to synthesize the precursors containing Li, V and Y by liquid-state reaction, then the cathode materials Li1.05YxV3-xO8 （x=0, 0.002 5, 0.005, 0.01, 0.02, 0.1, 0.2） for lithium-ion battery were obtained by calcining the precursors. The influence of y^3＋ doping on structure, conductivity and electrochemical performance of Li1.05V3O8 were investigated by using XRD, cyclic voltammograms, AC impedance, etc. The results show that Li1.05YxV3-xO8 with different doping amounts have well-developed crystal structure of layered Li1.05V3O8 and lengthened interlayer distance of （100） crystal plane, y^3＋ can insert into crystal lattice completely when the doping amount is small and the impurity phase of YVO4 is found when x≥0.1. There is no change in the process of Li^＋ insertion-deinsertion with y^3＋ doping. The conductivity is clearly improved due to small amount of y^3＋ doping and it tends to increase first and then decrease with increasing doping amount. The initial discharge capacity and plateau potential are both enhanced with proper amount of y^3＋ doping. When x is 0.005, the first specific discharge capacity reaches 288.9 mA·h/g, 4.60 % larger than that of undoped sample （276.2 mA·h/g）. When x≤0.1, the average discharge plateau potentials are enhanced by about 0.15 V, which makes for higher energy density.

关 键 词：锂电池 阴极 导电性 循环伏安图 电化学 

分 类 号：TG115[金属学及工艺—物理冶金]