高性能Li-Ni双掺杂尖晶石型Li_(1.05)Ni_(0.02)Mn_(1.93)O_(4)正极材料的制备  

Facile preparation of high-performance Li-Ni dual-doping spinel Li_(1.05)Ni_(0.02)Mn_(1.93)O_(4) cathode material

作　　者：李豫云 李虹 向明武 郭俊明[1,2] 刘晓芳[1,2] 白玮[1,2] LI Yu-yun;LI Hong;XIANG Ming-wu;GUO Jun-ming;LIU Xiao-fang;BAI Wei(National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials,Yunnan Minzu University,Kunming 650500,China;Yunnan Provincial Higher Educational Key Laboratory of Green-chemical Materials,Yunnan Minzu University,Kunming 650500,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

出　　处：《现代化工》2022年第6期94-100,共7页Modern Chemical Industry

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、600℃二次焙烧不同时间制备锂、镍共掺杂尖晶石型Li_(1.05)Ni_(0.02)Mn_(1.93)O_(4)正极材料。焙烧不同时间制备的样品均呈现出LiMn_(2)O_(4)的尖晶石晶体结构且均为单相,没有任何杂质相出现。延长焙烧时间有利于晶粒发育,提高合成材料的结晶性。二次焙烧9 h合成的正极材料具有良好的循环稳定性和倍率性能,在1 C倍率的首次放电容量为102.1 mA·h/g,500次循环后具有69.15%的容量保持率;在5 C释放出91.9 mA·h/g容量;10 C循环1000次的容量保持率为76.35%。具有较好的循环可逆性、较小的电荷转移阻抗和较低的表观活化能。适量的锂、镍共掺杂可有效提高LiMn_(2)O_(4)的结构稳定性、抑制Jahn-Teller效应和缓解锰的溶解,使其具有更高的电化学性能。Li-Ni co-doped Li_(1.05)Ni_(0.02)Mn_(1.93)O_(4) cathode materials are synthesized via a liquid phase flameless combustion method at 500℃for 1 h,followed by calcination at 600℃for various lengths of time.All the as-prepared samples correspond to the spinel crystal structure of LiMn_(2)O_(4) with a single-phase,without any impurity phase.With longer calcination time,the particle size is increased and the crystallinity is enhanced.The sample synthesized for 9 h of calcination has an excellent cycle stability and rate performance,delivers an initial discharge capacity of 102.1 mAh·g^(-1)and maintains a capacity retention of 69.15%after 500 cycles at 1 C.The initial discharge capacity is 91.9 mAh·g^(-1)at 5 C,and the capacity retention is 76.35%at 10 C after 1000 cycles.The optimized electrode has a good cycling reversibility,a small charge transfer impedance and a low apparent activation energy.Appropriate Li,Ni ions dual-doping can effectively improve the structural stability of spinel LiMn_(2)O_(4),inhibit the Jahn-Teller effect and relieve the dissolution of Mn,hence improving electrochemical performance.

关 键 词：无焰燃烧 Li-Ni双掺杂 焙烧时间 正极材料 LiMn_(2)O_(4) 

分 类 号：TM912[电气工程—电力电子与电力传动]