锰酸锂掺杂Fe和Co的性质的第一性原理计算  

First-principles calculations for properties of lithium manganate doped with transition metals Fe and Co

作　　者：陆远 王继芬[1] 谢华清[1] LU Yuan;WANG Ji-Fen;XIE Hua-Qing(School of Resources and Environmental Engineering,Shanghai Polytechnic University,Shanghai 201209,China)

机构地区：[1]上海第二工业大学资源与环境工程学院,上海201209

出　　处：《原子与分子物理学报》2023年第1期158-163,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(51776116);国家自然科学基金重大项目(51590902)。

摘　　要：文章基于密度泛函理论的第一性原理计算,研究了LiMn_(2)O_(4)电池材料在掺杂Fe和Co离子时的电子结构和电化学性能.发现Fe\\Co取代Mn^(3+)在热力学上是会更加稳定,提升电化学性能.掺杂Fe后,LiMn_(2)O_(4)电池材料晶格参数减小(约0.3%);掺杂Co后,LiMn_(2)O_(4)电池材料晶格参数减小(约0.5%).这两种掺杂方式让与之相邻的Mn^(3+)被氧化成Mn^(4+),从而降低了Jahn-Teller畸变情况产生可能性.对于掺Fe尖晶石型锰酸锂(Li_(8)Mn_(15)FeO_(32)),Mn环境中的Li离子会更容易被提取,第一次放电电压从原来的3.7 V增加至4.623 V;对于掺Co尖晶石型锰酸锂(Li_(8)Mn_(15)CoO_(32)),第一次放电电压从原来的3.7 V增加至4.101 V.研究为锂电池电容量研究提供理论数据的参考.Based on first-principles calculations of density functional theory,the electronic structure and electrochemical properties of LiMn_(2)O_(4)battery materials doped with Fe and Co ions were investigated.It is found that Fe\\Co instead of Mn^(3+)is more stable in thermodynamics and improves electrochemical performance.When LiMn_(2)O_(4)doped with Fe and Co,the lattice parameters will decrease about 0.3%and 0.5%,respectively.These two doping modes allow the adjacent Mn^(3+)to be oxidized to Mn^(4+),thus reducing the possibility of Jahn-Teller distortion.For Fe-doped spinel lithium manganate(Li_(8)Mn_(15)FeO_(32)),Li ions in Mn environment can be extracted more easily,and the first discharge voltage increases from 3.7 V to 4.623 V.For Co doped spinel lithium manganate(Li_(8)Mn_(15)CoO_(32)),the first discharge voltage is increased from 3.7 V to 4.101 V.This study provides theoretical data reference for the study of lithium battery capacity and solves the problem of low discharge voltage existing in LiMn_(2)O_(4) battery materials.

关 键 词：LiMn_(2)O_(4)尖晶石氧化物 第一性原理计算 JAHN-TELLER效应 Fe/Co掺杂 电压 

分 类 号：TM912[电气工程—电力电子与电力传动]