纳米Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4)正极材料的合成及电化学性能  

Synthesis and electrochemical performance of nano Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4) cathode material

作　　者：李虹 李豫云 刘红雷 向明武 苏长伟[1,2,3] 刘晓芳 郭俊明[1,2] 李力[4] LI Hong;LI Yu-yun;LIU Hong-lei;XIANG Ming-wu;SU Chang-wei;LIU Xiao-fang;GUO Jun-ming;LI Li(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;Yunnan Gold Mining Group Precious Metals Testing Co.LTD,Kunming 650215,Yunnan,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工程研究中心,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 [4]云南黄金矿业集团贵金属检测有限公司,云南昆明650215

出　　处：《云南大学学报（自然科学版）》2022年第1期116-125,共10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项目青年项目(202001AU070008)。

摘　　要：采用液相无焰燃烧法在500℃反应1 h,然后在600℃二次焙烧3、6、9 h和12 h制备了尖晶石型Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4)正极材料.结果表明,不同二次焙烧时间制备的Li-Ni复合共掺材料没有改变LiMn_(2)O_(4)的尖晶石结构,随着焙烧时间的增加,颗粒尺寸增大,结晶性提高.二次焙烧时间为9 h的Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4)样品的颗粒尺寸约为70~100 nm,具有优异的电化学性能,在1 C(1 C=148 mA·h·g^(-1))倍率,初始放电比容量为94.8 mA·h·g^(-1),400次循环后展现出72.15%的容量保持率;在5 C下初始放电比容量可达到89.7 mA·h·g^(-1),800次循环后,仍能维持70.79%的容量保持率.并且具有较小的电荷转移电阻和较低的表观活化能.Li-Ni复合掺杂能够有效抑制Jahn-Teller效应和缓解Mn的溶解,稳定晶体结构,提高循环稳定性和倍率性能.Spinel Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4) cathode material was synthesized via a flameless combustion method at 500℃for 1 h followed by calcination at 600℃for 3,6,9 and 12 h,respectively.Results show that Li-Ni codoping material prepared at different secondary calcination time did not change the spinel structure of LiMn_(2)O_(4).With the increased calcination time,the particle size was increased and the crystallinity was enhanced.At the secondary calcination time of 9 h,the obtained Li_(1.05)Ni_(0.05)Mn_(1.90)O_(4) cathode material shows the particle size of 70-100 nm,and exhibits an excellent electrochemical performance with the first-discharge specific capacity of94.8 mA·h·g^(-1) and the capacity retention rate of 72.15%after 400 cycles at 1 C(1 C=148 mA·h·g^(-1)).Moreover,an initial discharge capacity of 89.7 mA·h·g^(-1) with a capacity retention rate of 70.79%can be obtained after 800 cycles at 5 C.The optimized electrode has a low charge transfer resistance and apparent activation energy.The Li-Ni co-doping inhibits the Jahn-Teller effect effectively and alleviates Mn dissolution,hence,stabilizing the crystal structure and enhancing the rate capability and cycle performance.

关 键 词：尖晶石型LiMn_(2)O_(4) Li-Ni共掺 无焰燃烧法 焙烧时间 Jahn-Teller效应 Mn的溶解 纳米 正极材料 

分 类 号：TM912[电气工程—电力电子与电力传动]