微波诱导液相无焰燃烧法制备LiMn_(1.925)Cu_(0.075)O_(4)正极材料及电化学性能  

Preparation and electrochemical performance of LiMn_(1.925)Cu_(0.075)O_(4)cathode material by microwave induced solution flameless combustion method

作　　者：刘海洋 陈锐芳 苏长伟 郭俊明[1,2] 白玮[1,2] 向明武 LIU Hai-yang;CHEN Rui-fang;SU Chang-wei;GUO Jun-ming;BAI Wei;XIANG Ming-wu(National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials,Yunnan Minzu University,Kunming 650500,Yunnan,China;Key Laboratory of Green-Chemistry Materials in University of Yunnan Province,Yunnan Minzu University,Kunming 650500,Yunnan,China;College of Materials and Chemical Engineering,Hunan Institute of Engineering,Xiangtan 411104,Hunan,China)

机构地区：[1]云南民族大学生物基材料绿色制备技术国家地方联合中心,云南昆明650500 [2]云南民族大学云南省高校绿色化学材料重点实验室,云南昆明650500 [3]湖南工程学院材料与化工学院,湖南湘潭411104

出　　处：《云南大学学报（自然科学版）》2022年第6期1233-1240,共8页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(51972282,U1602273);云南省基础研究计划青年项目(202001AU070008).

摘　　要：采用微波诱导液相无焰燃烧法快速制备LiMn_(1.925)Cu_(0.075)O_(4)正极材料.通过X射线衍射分析(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)测试手段表明,Cu掺杂未改变尖晶石LiMn_(2)O_(4)的晶体结构;随着焙烧时间的延长,颗粒尺寸逐渐增大,晶界逐步清晰;Cu^(2+)进入LiMn_(2)O_(4)晶格中.电化学测试表明,二次焙烧8 h的LiMn_(1.925)Cu_(0.075)O_(4)正极材料表现出优异的电化学性能.在1 C倍率下,首次放电比容量为110.9 mA·h·g^(−1),循环400次后容量保持率63.9%;在5 C和10 C高倍率下可实现1000次循环,首次放电比容量分别为108.9、94.8 mA·h·g^(−1),保持率分别为61.3%、68.1%.Cu掺杂有效抑制Mn的溶解和Jahn-Teller效应,提高材料的结构稳定性与电化学性能.LiMn_(1.925)Cu_(0.075)O_(4)cathode material was prepared by microwave induced solution flameless combustion method.The X-ray diffraction(XRD),the scanning electron microscopy(SEM),the X-ray photoelectron spectroscopy(XPS)test showed that the crystal structure of LiMn_(2)O_(4)was not changed with the doping of Cu;the roasting time prolonging,the particule size increases gradually,and the grain boundary becomed clear,Cu^(2+)was successfully doped into LiMn_(2)O_(4).The electrochemical tests showed that the cathode material of LiMn_(1.925)Cu_(0.075)O_(4)exhibits an outstanding electrochemical performance at the second calcination time of 8 h.It delivered first discharge specific capacity of 110.9 mA·h·g^(−1)and a capacity retention rate of 63.9%after 400 cycles at 1 C;at high current rate of 5 C and 10 C,a long life of 1000 cycles could be achieved,and it showed the first-discharge specific capacity of 108.9,94.8 mA·h·g^(−1)and a retention rate of 61.3%,68.1%,respectively.The Cu doping could restrain effectively the Jahn-Teller effect and alleviate Mn dissolution,and hence improved the electrochemical performance and structural stability of the material.

关 键 词：锂离子电池 微波 LiMn_(2)O_(4) CU掺杂 液相无焰燃烧法 正极材料 

分 类 号：TM912[电气工程—电力电子与电力传动]