Solvation structure and dynamics of Li and LiO_(2)and their transformation in non-aqueous organic electrolyte solvents from first-principles simulations  

利用第一性原理模拟研究Li和LiO_(2)的溶剂化结构和动力学及其在非水有机电解质溶剂中的转化

作　　者：Behnaz Rahmani Didar a Axel Groß Behnaz Rahmani Didar;Axel Groß(乌尔姆大学理论化学研究所,德国乌尔姆;乌尔姆赫尔姆霍兹研究所电化学储能,德国乌尔姆)

机构地区：[1]Institute of Theoretical Chemistry,Ulm University,Albert-Einstein-Allee 11,D-89081 Ulm,Germany [2]Helmholtz Institute Ulm(HIU)Electrochemical Energy Storage,Helmholtzstrasse 11 D-89081 Ulm,Germany

出　　处：《Chinese Journal of Catalysis》2022年第11期2850-2857,共8页催化学报（英文）

基　　金：supported by the German Research Foundation (DFG) through contract GR 1503/38-1。

摘　　要：Density functional theory calculations together with ab initio molecular dynamics(AIMD)simulations have been used to study the solvation,diffusion and transformation of Li^(+)and LiO_(2)upon O_(2)reduction in three organic electrolytes.These processes are critical for the performance of Li-air batteries.Apart from studying the structure of the solvation shells in detail,AIMD simulations have been used to derive the diffusivity and together with the Blue Moon ensemble approach to explore LiO_(2)formation from Li^(+)and O_(2)−and the subsequent disproportionation of 2LiO_(2)into Li_(2)O_(2)+O_(2).By comparing the results of the simulations to gas phase calculations,the impact of electrolytes on these reactions is assessed which turns out to be more pronounced for the ionic species involved in these reactions.利用密度泛函理论计算和从头算分子动力学(AIMD)模拟研究了三种有机电解质中Li^(+)和LiO_(2)在O_(2)还原时的溶剂化、扩散和转化.这些过程对锂空气电池的性能至关重要.除详细研究溶剂化壳层结构外,还利用AIMD模拟推导了扩散率,并与Blue-Moon系综方法一起探索Li^(+)和O_(2)-形成LiO_(2)以及2LiO_(2)歧化为Li_(2)O_(2)+O_(2).通过对比模拟结果和气相计算结果,研究电解质对这些反应的影响,结果表明,对于参与这些反应的离子物种,电解质的影响更为显著.

关 键 词：Li-air batteries Li oxide Oxygen reduction Density functional theory Ab initio molecular dynamics SOLVATION DIFFUSIVITY DISPROPORTIONATION 

分 类 号：TM911.41[电气工程—电力电子与电力传动] O641.1[理学—物理化学] O646[理学—化学]