硅烷偶联剂表面改性LiMn2O4的结构及电化学性能  

Surface treatment on structure and property of LiMn2O4 by silane coupling agent

作　　者：王孙发 冯艳艳 张晓鹏 冯兰兰 袁振洛 范广新[1,3,4] 刘宝忠 Wang Sunfa;Feng Yanyan;Zhang Xiaopeng;Feng Lanlan;Yuan Zhenluo;Fan Guangxin;Liu Baozhong(School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000;College of Chemistry and Chemical Engineering,Henan Polytechnic University,Jiaozuo 454000;Jiaozuo Banlv Nano Materials Engineering Co.,Ltd.,Jiaozuo 454000;International Joint Research Laboratory for High-Performance Light Metallic Materials and Numerical Simulations,Henan Polytechnic University,Jiaozuo 454000)

机构地区：[1]河南理工大学材料科学与工程学院,焦作454000 [2]河南理工大学化学化工学院,焦作454000 [3]焦作伴侣纳米材料工程有限公司,焦作454000 [4]河南省高性能轻金属材料及数值模拟国际联合实验室,焦作454000

出　　处：《化工新型材料》2020年第12期124-128,共5页New Chemical Materials

基　　金：国家自然科学基金(51871090、U1804135和51671080);河南省高校科技创新团队(16IRTSTHN005)。

摘　　要：硅烷偶联剂经高温分解对锂离子电池阴极材料LiMn2O4表面改性,对材料的形貌、结构及综合电化学性能进行表征。结果表明:经硅烷偶联剂处理后,SiO2均匀地包覆在材料表面,不影响LiMn2O4的晶体结构和形貌,但明显地改善了材料的电化学性能。其中SiO2包覆质量为1%时,LiMn2O4的综合电化学性能最佳:经100次充放电循环后,LiMn2O4的放电比容量和容量保持率由包覆前的93.88mAh/g和88.03%分别提高到包覆后的112.05mAh/g和94.54%。这归因于包覆层可抑制电解液与电极材料之间发生的副反应,减小固体电解质界面(SEI)膜阻抗(Rf),从而提高材料的结构稳定性和Li+在迁入/脱迁过程中的扩散能力。Particle surface of LiMn2O4 cathode material for lithium ion battery was modified by a pyrolysis of silane coupling agent.The morphology,structure and comprehensive electrochemical properties of the materials were characterized systematically.The results shown that the SiO2 obtained from silane coupling agent was coated on the surface of the material.The coating did not affect the crystal structure and morphology,but the electrochemical properties of LiMn2O4 were improved significantly.The optimum comprehensive performance of the cathode can be obtained at SiO2 coating amount of 1wt%.The initial discharge specific capacity and capacity retention(after 100 charge-discharge cycles)of LiMn2O4 can be increased from 93.88mAh/g and 88.03%to 112.05mAh/g and 94.54%respectively after coating.The reason for this was that the coating layer can inhibit the side reactions between electrolyte and electrode material,which reduced SEI film impedance(Rf),stabilized the structure of the materials and resulted in the improvement the diffusion ability of Li+during the insertion/deinsertion process.

关 键 词：阴极材料 锰酸锂 硅烷偶联剂 包覆改性 电化学性能 

分 类 号：TQ152[化学工程—电化学工业]