LiZr_(2)(PO_(4))_(3)包覆对高镍三元正极材料结构及电化学性能的影响  

Effect of LiZr_(2)(PO_(4))_(3) Coating on the Structure and Electrochemical Properties of High Nickel Ternary Cathode Materials

作　　者：刘琳琳 刘杰 陈前林[1] 罗诗键 李翠芹[1] LIU Linlin;LIU Jie;CHEN Qianlin;LUO Shijian;LI Cuiqin(College of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China)

机构地区：[1]贵州大学化学与化工学院,贵阳550025

出　　处：《人工晶体学报》2022年第4期695-703,共9页Journal of Synthetic Crystals

基　　金：大学生创新创业训练计划项目(贵大(国)创字2020(032));贵州省高层次人才培养计划-“百”层次人才(黔科合平台人才[2016]5658)。

摘　　要：高镍三元正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)具有优异的放电能力。但其存在锂镍混排严重、结构稳定性差导致的容量衰减快等问题。为解决这些问题,本论文首先合成NCM811三元正极材料,再利用湿法涂覆的方法将磷酸锆锂LiZr_(2)(PO_(4))_(3)(LZPO)包覆在NCM811三元正极材料的表面,形成LZPO@NCM811三元正极改性材料,并对改性前后的NCM811三元正极材料结构和电化学性能进行研究。研究结果表明,在NCM811表面包覆1%LZPO得到样品的结构最稳定,材料的电化学性能最好:在0.1 C倍率下,首圈放电容量为210.16 mAh/g,远高于未改性NCM811材料(201.01 mAh/g);在循环200圈后,材料的容量保持率为79.4%,优于未改性的NCM811材料(容量保持率为60.0%)。The nickel-rich ternary cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has excellent discharge capacity,which is the favorite to succeed as the next new cathode materials for lithium-ion batteries.However,it has problems such as serious Li^(+)/Ni2^(+) mixed discharge,and rapid capacity fading caused by poor structural stability.In order to solve these problems,accelerate the application process of ternary cathode materials in new energy vehicle.LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)ternary cathode material coated with LiZr_(2)(PO_(4))_(3)(LZPO)was obtained by wet coating method,and the structure and electrochemical performance of LZPO coating on NCM811 ternary cathode material were studied in this paper.The results show that the NCM811 coated with 1%LZPO possess the most stable structure,and the best electrochemical performance.The first cycle discharge capacity at 0.1 C rate is 210.16 mAh/g,which is much higher than that of the pristine NCM811 material(201.01 mAh/g);the capacity retention rate after 200 cycles is 79.4%,which is better than that of pristine NCM811(60.0%).

关 键 词：锂离子电池 NCM811 三元正极材料 磷酸锆锂 包覆改性 RIETVELD结构精修 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131[化学工程—无机化工]