Li/Ti摩尔比对Li_(4)Ti_(5)O_(12)负极材料组成、结构和电化学性能的影响  

Effects of Li/Ti Molar Ratio on Composition,Structure and Electrochemical Properties of Li_(4)Ti_(5)O_(12) Anode Material

作　　者：潘冰冰 胡朴 赵周桥 窦林涛 邹义琪 张占辉[1] PAN Bingbing;HU Pu;ZHAO Zhouqiao;DOU Lintao;ZOU Yiqi;ZHANG Zhanhui(School of Materials Science and Engineering,Wuhan Institute of Technology,Wuhan 430205,China)

机构地区：[1]武汉工程大学材料科学与工程学院,湖北武汉430205

出　　处：《武汉工程大学学报》2021年第3期283-287,共5页Journal of Wuhan Institute of Technology

基　　金：武汉工程大学第十一届研究生教育创新基金(CX2019081)。

摘　　要：采用高温固相法制备不同锂钛摩尔比条件下的样品,探究锂钛摩尔比对钛酸锂的组成、结构和电化学性能的影响。通过X-射线衍射仪和扫描电子显微镜测定材料的组成、结构和形貌。结果表明:锂钛摩尔比在0.78~0.82之间可得到纯相的Li_(4)Ti_(5)O_(12);低锂钛摩尔比(0.74、0.76)存在TiO2杂相,其晶胞参数要高于Li_(4)Ti_(5)O_(12);然而高锂钛摩尔比(0.84~0.88)会产生Li2TiO3杂相。不同锂钛摩尔比(0.78~0.84)制备的样品形貌接近无明显差异,晶粒尺寸在1~6μm之间。电学性能结果表明:锂钛摩尔比在0.78~0.84之间时,适量提高锂含量有助于提升材料的比容量,过量提高会使材料的循环稳定性和倍率性能变差。锂钛摩尔比为0.82得到的Li_(4)Ti_(5)O_(12)比容量[198(mA·h)/g,0.5C]、循环性能和倍率性能最优。High temperature solid-state approach was used to prepare Li_(4)Ti_(5)O_(12) anode material.Influence of Li/Ti molar ratio on composition,structure and electrochemical performance was then investigated.The composition and morphology of the obtained material were determined by X-ray diffraction and scanning electron microscopy.The results showed that pure Li_(4)Ti_(5)O_(12) can be obtained when the Li/Ti molar ratios are in the range of 0.78-0.82.TiO2 impurity phase exists in the samples with low Li/Ti molar ratios(0.74,0.76),whose lattice parameters are higher than that of Li_(4)Ti_(5)O_(12).However,high Li/Ti molar ratios(0.84-0.88)lead to Li2 TiO3 impurities.The morphologies of the samples with different Li/Ti molar ratios in the range of0.78-0.84 are similar.The particle sizes of the sample are in the range of 1-6μm.The electrochemical performance results indicated that when the Li/Ti molar ratios are in the range of 0.78-0.84,an appropriate amount of lithium content improves the specific capacity of the material,while an excessive amount of lithium content makes the cycling stability and multiplier performance of the material worse.Li_(4)Ti_(5)O_(12) with Li/Ti molar ratio of 0.82 displays the best specific capacity[198(mA·h)/g,0.5 C],cycling stability and rate capability.

关 键 词：锂离子电池 钛酸锂 锂钛摩尔比 电化学性能 

分 类 号：O646[理学—物理化学]