La^(3+)掺杂尖晶石LiMn_2O_4的第一性原理研究  

First-principle study on La-doped spinel LiMn_2O_4

作　　者：黄美红[1] 梁兴华[1] 曾帅波 王玉江[2] 陈海燕[3] 

机构地区：[1]广西科技大学,柳州545006 [2]广西大学,南宁530005 [3]广东工业大学,广州510006

出　　处：《化工新型材料》2017年第11期198-200,204,共4页New Chemical Materials

基　　金：广西汽车零部件与整车技术重点实验室自主研究课题(15-A-03-01;2015KFZD02);广西科技大学研究生教育创新计划项目(GKYC201617)

摘　　要：采用第一性原理,研究了La^(3+)掺杂尖晶石LiMn_2O_4的电子态密度、原子布局、电荷密度等。结果表明,La^(3+)掺杂后体系结构稳定,带隙降低、费米附近能带数增加,费米能由-1.50eV增加到-0.86eV,平均电压提高,充放电速率提高;总态密度中O、Mn、La提供的能量高,其形成的化学键强度大,空间构架稳固,晶体塌陷的几率低;形成能为负值,La—O、Mn—O键长较短,共价性强,键稳定不易断裂,循环稳定性提高;LiLa_(0.125)Mn_(1.875)O_4理论容量比LiMn_2O_4高。The electron density of states,atomic population and electric charge density of La-doped spinel LiMn2O4 were investigated by first-principles theory.The results showed that the structure of La-doped spinel LiMn2O4 was stable,the band gap decreased and the number of bands near the Fermi energy increased.The Fermi energy was increased from -1.50 eV to-0.86 eV,the average voltage and the charge-discharge rate were increased simultaneously.O,Mn and La provided high energy for the total density of states and form strong chemical bonds,indicated that the space frame was stable and the probability of crystal collapse was low.The formation energy of LiLa（0.125）Mn（1.875）O4 was negative and La—O,Mn—O bond was short,thus the covalent was strong and the bond was stable,therefore the cycle stability was improved.The theoretical capacity of LiLa（0.125）Mn（1.875）O4 was higher than LiMn2O4.

关 键 词：第一性原理 掺杂 尖晶石LIMN2O4 电荷密度 

分 类 号：O614.111[理学—无机化学]