固相燃烧法快速合成尖晶石型LiMn_(2)O_(4)正极材料及电化学性能  

Rapid synthesis and electrochemical property of spinel LiMn_(2)O_(4) cathode material by solid-phase combustion

作　　者：陶扬 刘晓芳[1,2] 郭俊明[1,2] 向明武 白红丽[1,2] Tao Yang;Liu Xiaofang;Guo Junming;Xiang Mingwu;Bai Hongli(National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials,Yunnan Minzu University,Kunming 650500;Key Laboratory of Green-chemical Materials in University of Yunnan Province,Yunnan Minzu University,Kunming 650500)

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,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,昆明650500

出　　处：《化工新型材料》2022年第5期170-175,共6页New Chemical Materials

基　　金：国家自然科学基金(U1602273和51972282)。

摘　　要：采用固相燃烧法在400℃、500℃、600℃和650℃一次燃烧反应1h,再在650℃焙烧6h,快速制备了LiMn_(2)O_(4)正极材料。采用X射线衍射、扫描电镜、透射电镜、X射线光电子能谱等手段对样品进行表征。结果表明:随着燃烧反应温度的升高,材料的结晶性和颗粒逐渐增大,均属于亚微米尺寸,600℃是LiMn_(2)O_(4)材料颗粒快速生长的关键温度。电化学测试表明,放电比容量和倍率性能随着燃烧温度的升高呈逐渐降低的趋势,其中燃烧温度为400℃合成的LiMn_(2)O_(4)样品(LMO-400)具有最优的倍率性能和循环寿命。在1C和5C,首次放电比容量分别为111mAh/g和90.5mAh/g,循环1000次后容量保持率分为62.1%和67.5%。EIS和CV测试结果表明,LMO-400具有较小的电荷转移电阻150Ω、较小的表观活化能22.22kJ/mol以及较大的锂离子扩散系数1.35×10^(-15)cm^(2)/s。不同的燃烧反应温度对尖晶石型LiMn_(2)O_(4)颗粒尺寸、结晶性等有显著的影响,导致其电化学性能有显著差异,亚微米尺寸的颗粒具有较好的电化学性能。The LiMn_(2)O_(4) cathode material was rapidly prepared by a solid-phase combustion method at 400℃,500℃,600℃and 650℃for 1h,and calcined at 650℃for 6h.The as-prepared samples were characterized by XRD,SEM,TEM,XPS,etc.The results shown that with the increase of combustion reaction temperature,the crystallinity and particles of the material gradually increased,all belonging to the submicron size,and 600℃was the key temperature for the rapid growth of LiMn_(2)O_(4) material particles.The electrochemical test shown that the specific discharge capacity and the rate performance gradually decreased with the increase of combustion temperature.Among them,the LiMn_(2)O_(4) sample(LMO-400)synthesized at the combustion temperature of 400℃possessed the optimal rate performance and cycle life.At 1C and 5C,the initial specific capacity was 111mAh/g and 90.5mAh/g,respectively.After 1000 cycles,the capacity retentions were 62.1%and 67.5%.EIS and CV test results shown that the LMO-400 with the smaller charge transfer resistance of 150Ω,the smaller the apparent activation energy of 22.22kJ/mol and larger lithium ion diffusion coefficient of 1.35×10^(-15)cm^(2)/s.Different combustion reaction temperatures exhibited significant effects on the size and crystallinity of spinel LiMn_(2)O_(4)particles,resulting in significant differences in their electrochemical properties.Submicron particles presented better electrochemical properties.

关 键 词：燃烧反应温度 固相燃烧法 LiMn_(2)O_(4) 正极材料 颗粒尺寸 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]