MoS_(2)尖晶石包覆富锂锰基正极材料的电化学性能  

Electrochemical properties of spinel MoS_(2) coated lithium-rich manganese-based cathode materials

作　　者：周德清 蔡艺嘉 张子芩 周丽萍 胡思江 黄有国 王红强 李庆余 ZHOU Deqing;CAI Yijia;ZHANG Ziqin;ZHOU Liping;HU Sijiang;HUANG Youguo;WANG Hongqiang;LI Qingyu(AnHui EIKTO Battery Company Limited,Xuancheng 242000,Anhui,China;Guangxi Key Laboratory of Low Carbon Energy Materials,School of Chemistry and Pharmaceutical Sciences,Guangxi Normal University,Guilin 541000,Guangxi,China)

机构地区：[1]安徽益佳通电池有限公司,安徽宣城242000 [2]广西师范大学化学与药学学院广西低碳能源材料重点实验室,广西桂林541000

出　　处：《储能科学与技术》2025年第3期1087-1096,共10页Energy Storage Science and Technology

基　　金：广西自然科学基金杰出青年基金项目(2024GXNSFFA010003)。

摘　　要：富锂锰基层状氧化物比容量较高,是发展高能量密度锂离子电池的理想正极材料。然而,在充放电过程中,富锂锰基正极材料存在过渡金属离子迁移和晶格中氧的不可逆反应等问题,导致电极材料低的首次库仑效率、严重的电压衰减和较差的循环稳定性,这些缺点制约了其产业化应用。针对这些问题,采用表面包覆的方法对材料进行改性,在Li_(1.2)Ni_(0.167)Co_(0.167)Mn_(0.666)O_(2)(LLO)材料表面包覆MoS_(2),同时引发了次表面结构的转变。结果表明,MoS_(2)(MS)包覆层能防止材料本体直接暴露在电解液中,有效抑制了界面副反应。三维结构的尖晶石相提高了Li+的扩散速率。在0.1C倍率下,改性材料的首次库仑效率均大于88%。与未改性材料相比,质量分数1%的MoS_(2)包覆量样品LLO@MS1在1.0C倍率下的循环稳定性得到显著提升。在5.0C和10.0C下的放电比容量分别达到160.0 mAh/g和129.0 mAh/g,表明该改性策略提升了材料的综合电化学性能。Li-rich manganese layered oxides exhibit high specific capacity and serve as an optimal cathode material for high-energy-density lithium batteries.However,during charging and discharging,the Li-rich manganese layered oxides cathode materials experience transition metal migration and irreversible oxygen reactions within the lattice.This results in low coulombic efficiency during the first cycle,severe voltage degradation,and poor cycling stability,collectively constraining industrial application.To address these issues,this paper employs surface coating to modify the materials.A MoS_(2) coating was applied to the surface of the Li_(1.2)Ni_(0.167)Co_(0.167)Mn_(0.666)O_(2)(LLO)material,inducing a transformation in the subsurface structure.The findings demonstrate that the MoS_(2) coating layer shields the material from direct exposure to the electrolyte and effectively inhibits interfacial side reactions.The threedimensional structure of the spinel phase facilitates lithium-ion diffusion.The modified materials exhibit initial coulombic efficiencies exceeding 88% at a current density of 0.1C.The cycling stability of LLO@MS1(mass fraction 1%MS_(2) coating)was markedly enhanced relative to that of the unmodified materials when subjected to a current density of 1.0C.The specific discharge capacities reached 160.0 mAh/g and 129.0 mAh/g at 5.0C and 10.0C,respectively,indicating that the modification strategy enhanced overall electrochemical performance.

关 键 词：锂离子电池 富锂锰基 包覆改性 尖晶石相 次表面结构 

分 类 号：TM911[电气工程—电力电子与电力传动]