Al/Mg共掺杂Li_(2)MnO_(3)电化学性质的第一性原理计算  

First-principles calculation of electrochemical properties of Al/Mg co-doped Li_(2)MnO_(3)

作　　者：曾智泉 张时维 王建川[1] ZENG Zhiquan;ZHANG Shiwei;WANG Jianchuan(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;College of Energy and Electrical Engineering,Qinghai University,Xining 810016,China)

机构地区：[1]中南大学粉末冶金重点实验室,长沙410083 [2]青海大学能源与电子工程院,西宁810016

出　　处：《粉末冶金材料科学与工程》2024年第3期162-171,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(52171025);中德合作研究小组项目(GZ1528)。

摘　　要：双离子掺杂是改善富锂锰基正极材料Li_(2)MnO_(3)电化学性能及循环稳定性的有效方法,然而掺杂离子间微妙的相互作用对Li_(2)MnO_(3)性能的影响机制还不清晰。本研究通过第一性原理计算分别研究Mg单掺杂和Mg/Al共掺杂Li_(2)MnO_(3)的晶格结构、电子结构、O稳定性以及Li扩散动力学。结果表明:相对于Mg单掺杂,Mg/Al共掺杂能引起明显的晶格畸变,提高局域O的电化学活性,但同时会牺牲一定的O稳定性。此外,Mg/Al共掺杂还可以促进局域Li的层内扩散。本研究突出对比了Mg/Al共掺杂和Mg单掺杂对Li_(2)MnO_(3)电化学性能影响的差异,为优化富锂锰基正极材料设计提供理论依据。Dual-ion doping is an effective method to improve the electrochemical properties and cycle stability of Li_(2)MnO_(3),a lithium-rich manganese-based cathode material.However,the influencing mechanism of the subtle interaction between doped ions on the performance of Li_(2)MnO_(3) is still unclear.This study investigated the lattice structure,electronic structure,O stability,and Li diffusion dynamics of Mg single doped and Mg/Al co-doped Li_(2)MnO_(3) through first-principles calculation.The results show that compared with Mg single doping case,Mg/Al co-doping can cause significant lattice distortion,enhance the electrochemical activity of local O,but also sacrifice some O stability,and promote the intralayer diffusion of local Li.This study highlights the differences in the effects of Mg/Al co-doping and Mg single doping on the electrochemical properties of Li_(2)MnO_(3),providing a theoretical basis for optimizing the design of lithium-rich manganese-based cathode materials.

关 键 词：富锂正极材料 掺杂 电化学性质 第一性原理计算 锂离子电池 

分 类 号：TB3[一般工业技术—材料科学与工程]