摘要
采用高温固相法合成了Li_4Ti_5O_(12)和Li_4Ti_(4.95)Ce_(0.05)O_(12)负极材料,采用X射线粉末衍射(XRD)、扫描电镜(SEM)、循环伏安(CV)和充放电测试等手段研究样品的结构和电化学性能。XRD图谱表明铈掺杂并没有改变样品的晶体结构;循环伏安曲线表明Li_4Ti_(4.95)Ce_(0.05)O_(12)样品具有更好的可逆性,铈的掺杂有利于锂离子的可逆脱嵌;微分电容曲线表明Li_4Ti_(4.95)Ce_(0.05)O_(12)的充放电的峰电位值差比Li_4Ti_5O_(12)小,说明前者具有更小的电化学极化;充放电测试表明,5 C倍率充放电时,Li_4Ti_(4.95)Ce_(0.05)O_(12)和Li_4Ti_5O_(12)的可逆放电容量分别为120 m A·h/g和80 m A·h/g左右,说明铈的掺杂提高了Li_4Ti_5O_(12)材料的倍率容量和循环性能。
Li4Ti5O12and Li4Ti4.95Ce0.05O12 anode materials were prepared by high temperature solidstate method. The structure and electrochemical performance of the materials were investigated by X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,cyclic voltammetry（ CV）,charge-discharge tests. XRD patterns indicate that cerium doping does not change the crystal structure of the sample.Cyclic voltammetry curves indicate that Li4Ti4.95Ce0.05O12 has better reversibility than that of pristine Li4Ti5O12,and the cerium doping is in favour of the intercalation and de-intercalation of lithium ion. The differential capacity versus voltage plots show that Li4Ti4.95Ce0.05O12 has a smaller charge-discharge peak difference than that of pristine Li4Ti5O12, indicating that the former has lower electrochemical polarization. Charge-discharge tests exhibit that the reversible discharge capacity of Li4Ti4.95Ce0.05O12 and Li4Ti5O12are about 120 m A · h / g and 80 m A · h / g at 5C charge-discharge rates,indicating that the cerium doping improves the rate capacity and cycling performance of Li4Ti5O12 material.
出处
《有色金属工程》
CAS
CSCD
北大核心
2016年第5期9-13,共5页
Nonferrous Metals Engineering
基金
安徽工业大学研究生创新研究基金(2015020)
安徽工业大学优秀创新团队项目(TD201202)
安徽省大学生创新创业训练计划项目(201510360172)
