锂离子电池高镍LiNi_(0.8)Mn_(0.2)O_(2)正极材料的微波合成及其Co、Al共改性  

Microwave-assisted Synthesis and Co,Al Co-modification of Ni-rich LiNi_(0.8)Mn_(0.2)O_(2) Materials for Li-ion Battery Electrode

作　　者：付宇坤 曾敏[1] 饶先发[1] 钟盛文[1] 张慧娟[2] 姚文俐[1] FU Yukun;ZENG Min;RAO Xianfa;ZHONG Shengwen;ZHANG Huijuan;YAO Wenli(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;School of Materials Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200240,China)

机构地区：[1]江西理工大学材料冶金化学学部,赣州341000 [2]上海理工大学材料科学与工程学院,上海200240

出　　处：《无机材料学报》2021年第7期718-724,I0004-I0006,共10页Journal of Inorganic Materials

基　　金：江西省自然科学基金(20192BAB206021);江西省教育厅(GJJ190423,GJJ200850);赣市财教字([2019]60);国家自然科学基金(51874151)。

摘　　要：高镍正极材料由于较高的比容量和性价比而受到关注,但在循环过程中稳定性较差且安全性能不佳,限制了其更广泛的应用。本研究结合微波辅助共沉淀与高温固相法制备高镍正极LiNi_(0.8)Mn_(0.2)O_(2)二元材料,再掺入不同比例的Co、Al对材料进行改性研究。结果表明,改性后的材料性能明显改善,特别是Li Ni_(0.8)Mn0.1Co_(0.08)Al_(0.02)O_(2)在2.75~4.35 V、1C下循环100次后容量保持率达到91.39%,在5C下放电比容量仍有160.03 mAh·g^(-1),并且掺杂后的材料具有较高的热稳定性,安全性得到提升。其优异的循环保持率归因于Co、Al较好地抑制了循环过程中H2→H3相变的不可逆性对材料结构稳定性的破坏,以及较弱的电极反应极化,使电荷转移电阻降低。Due to high specific capacity and cost performance,high-nickel cathode materials have received much attention.However,its further application is hindered by poor stability and safety performance during cycling.In this work,Ni-rich Li Ni_(0.8)Mn_(0.2)O_(2) materials were prepared through microwave-assisted co-precipitation followed by high-temperature solid-phase method,which can be further modified by doping different proportions of Co and Al.As a result,Li Ni_(0.8)Mn0.1Co_(0.08)Al_(0.02)O_(2)(NMCA-2)exhibits the best electrochemical performance,whose capacity retention rate reaches 91.39%after 100 cycles at 1C in the voltage range between 2.75 and 4.35 V,and still owns a specific discharge capacity of 160.03 mAh·g^(-1) at 5C.Its excellent cyclic retention rate can be attributed to the restrained irreversibility of H2→H3 phase transition during cycling with Co and Al doping,and the lower reaction polarization which contributed to the decline of charge transfer resistance,resulting in good cycle and rate performance of thematerial.Furthermore,high thermal stability of NMCA-2 improves the safety of the material.

关 键 词：LiNi_(0.8)Mn_(0.2)O_(2) Co、Al共改性 微波辅助共沉淀 循环性能 倍率性能 

分 类 号：TQ174[化学工程—陶瓷工业]