Enhanced cycle stability of aprotic Li-O_(2) batteries based on a self-defensed redox mediator  

作　　者：Guiru Sun Yan Wang Daming Yang Zexu Zhang Wei Lu Ming Feng 

机构地区：[1]Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education,Jilin Normal University,Changchun 130103,China [2]College of Information Technology,Jilin Engineering Research Center of Optoelectronic Materials and Devices,Jilin Normal University,Siping 136000,China

出　　处：《Chinese Chemical Letters》2024年第3期449-452,共4页中国化学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21978110 and 52171210);the Jilin Province Science and Technology Department Program(Nos.YDZJ202101ZYTS047,20220201130GX and 20200201187JC);the Science and Technology Project of Jilin Provincial Education Department(No.JJKH20210444KJ)。

摘　　要：LiBr as a promising redox mediator(RM)has been applied in Li-O_(2)batteries to improve oxygen evolution reaction kinetics and reduce overpotentials.However,the redox shuttle of Br_(3)^-can induce the unexpected reactions and thus cause the degradation of LiBr and the corrosion of Li anode,resulting in the poor cyclability and the low round-trip efficiency.Herein,MgBr_(2)is firstly employed with dual functions for Li-O_(2)batteries,which can serve as a RM and a SEI film-forming agent.The Br^(–)is beneficial to facilitating the decomposition of Li_(2)O_(2)and thus decreasing the overpotential.Additionally,a uniform SEI film containing Mg and MgO generates on Li anode surface by the in-situ spontaneous reactions of Mg^(2+)and Li anode in an O_(2)environment,which can suppress the redox shuttle of Br_(3)^-and improve the interface stability of Li anode and electrolyte.Benefiting from these advantages,the cycle life of Li-O_(2)battery with MgBr_(2)electrolyte is significantly extended.

关 键 词：MgBr_(2) Redox mediator Redox shuttle Li anode SEI film 

分 类 号：TQ131.11[化学工程—无机化工] TM911.41[电气工程—电力电子与电力传动]