Mg2+掺杂锰酸锂的第一性原理研究  

First-principles study on Mg-doped LiMn2O4

作　　者：王云婷[1] 梁兴华[1,3] 吴秋满 梁伦 王玉江 蓝凌霄[1] WANG Yun-Ting;LIANG Xing-Hua;WU Qiu-Man;LIANG Lun;WANG Yu-Jiang;LAN Ling-Xiao(Guangxi Key Laboratory of Automobile Components and Vehicle Technology,Guangxi University of Science&technology,Liuzhou 545006,China;Guangxi University,Nanning 530005,China;Guangdong Institute of New Materials,Guangzhou 510650,China)

机构地区：[1]广西科技大学广西汽车零部件与整车技术重点实验室,柳州545006 [2]广西大学,南宁530005 [3]广东省新材料研究所,广州510650

出　　处：《原子与分子物理学报》2019年第6期1019-1024,共6页Journal of Atomic and Molecular Physics

基　　金：广东省科学院实施创新驱动发展能力建设专项资金(2017GDAS CX-0202);广西汽车零部件与整车技术重点实验室自主研究课题(2017GKLACVTZZ04);广西科技大学研究生教育创新计划项目(YCSW2018202)

摘　　要：利用基于密度泛函理论的第一性原理平面波超软赝势法对Mg^2+掺杂锰酸锂的晶格常数与能带结构、态密度、键布居进行计算和分析,计算结果表明:掺杂Mg^2+后将会促使Mn、O原子的电荷重新分布且其相互作用加强,能带带隙减小,费米能级附近的带数增加,费米能由-1.29 eV增加到-1.02 eV,Mn、O、Mg在总态密度中贡献比较大,锂离子贡献比较小且峰型尖锐局域化严重,提高了Li^+的扩散效率,Mn—O键变短,共价性增强,形成的共价键较稳定,其相互作用形成的骨架较稳定不易坍塌.从而提高了材料的循环充放电性能和电池使用寿命.By means of the first-principles plane wave supersoft pseudopotential method based on density functional theory,the lattice constant and band structure,density of states and bond population of Mg^2+doped lithium manganate were calculated and analyzed.The calculation results show that after doping Mg^2+,the charges of Mn and O atoms will be redistributed and the interaction between them.The band gap will be reduced but the number of bands near the Fermi level will increase,and the Fermi energy will increase from-1.29 eV to-1.02 eV.The O and Mn atoms contributes a lot in the total density of states,the contribution of lithium ions is relatively small and the peak type is sharp and localized,which increases the diffusion efficiency of Li^+,the Mn-O bond becomes shorter,the covalence is enhanced,and the covalent formation is formed.The bond is relatively stable,and the skeleton formed by the interaction is relatively stable and is not easy to collapse,thereby improving the cycle charge and discharge performance of the material and the battery life.

关 键 词：第一性原理 锂离子电池 尖晶石LIMN2O4 能带结构 

分 类 号：O65[理学—分析化学]