【摘要】 以LiOH、V2O5和Cr(NO3)3·9H2O为原料,制备出锂离子电池正极材料Li1．05CrxV3-xO8(x=0,0．005,0．01, 0．02,0．04,0．1),研究了Cr3+掺杂对Li1．05V3O8材料的结构、电导率和电化学性能的影响．结果表明:Li1.05CrxV3-xO8具有良好的层状晶体结构,Cr3+掺杂使(100)晶面的层间距增大;少量掺杂Cr3+不改变锂离子嵌入／脱出过程,随着掺杂量的增加,锂离子脱出过程由一步转化为两步;随着Cr3+掺杂量的增加,电导率呈现先增大而后又减小的趋势,可能是缺陷理论和静电吸引力共同作用的结果;当掺杂量x=0．005时,首次放电比容量达到296．5 mAh·g-1,比未掺杂Cr3+时提高了7．35％,平均放电电压提高了约0．1 V．更多还原

【Abstract】 The lithium-ion battery cathode material Li1.05CrxV3-xO8 (x=0, 0.005, 0.01, 0.02, 0.04, 0.1) were obtained by calcining the precursors and the influence of Cr3+ doping on structure, conductivity and electrochemical performance of Li1.05V3O8 were investigated. The results showed that Li1.05CrxV3-xO8 with different doping amount have well-developed crystal structures of layered Li1.05V3O8 and lengthened interlayer distance of (100) crystal plane. A small doped amount has no influence on the Li+ insertion-deinsertion process, but with increasing amount of Cr3+ doping, the one-step process of Li+ deinsertion transforms to the two-step one. Conductivity is improved due to small amount of Cr3+ doping and it tends to increase first then decrease with increasing doping amount as a result of coaction of defect theory and electrostatic attraction. The initial discharge capacity with Cr3+ doping at x=0.005 reaches 296.5 mAh·g-1, which is 7.35% larger than that of pure material, and average discharge voltage is increased about 0.1 V.更多还原