An organometallic salt as the electrolyte additive to regulate lithium polysulfide redox and stabilize lithium anodes for robust lithium-sulfur batteries  

一种调节锂多硫化物氧化还原性和锂负极稳定性的金属有机盐电解质添加剂

作　　者：Yixuan Meng Meifang Zhang Youliang Wang Chen Liu Ze Zhang Ji Yu Jianxin Cai Zhenyu Yang 孟怡轩;张梅芳;王有亮;刘琛;张泽;吁霁;蔡建信;杨震宇(Key Laboratory of Jiangxi Province for Environment and Energy Catalysis,School of Chemistry and Chemical Engineering,Nanchang University,Nanchang,330031,China;Institute of Carbon Neutral New Energy Research,Yuzhang Normal University,Nanchang,330031,China;School of Biological and Chemical Engineering,Zhejiang University of Science and Technology,Hangzhou,310023,China)

机构地区：[1]Key Laboratory of Jiangxi Province for Environment and Energy Catalysis,School of Chemistry and Chemical Engineering,Nanchang University,Nanchang,330031,China [2]Institute of Carbon Neutral New Energy Research,Yuzhang Normal University,Nanchang,330031,China [3]School of Biological and Chemical Engineering,Zhejiang University of Science and Technology,Hangzhou,310023,China

出　　处：《Science China Materials》2024年第9期2880-2888,共9页中国科学（材料科学）（英文版）

基　　金：supported by the Jiangxi Province Leading Talent Project for Academic and Technical Leaders in Major Disciplines(20213BCJ22024);National Natural Science Foundation of China(22269013,22263009 and 21863006);Natural Science Foundation of Jiangxi Province(20224ACB213001 and 20212BBE53051);Elite Scientists Sponsorship Program by Jiangxi Association for Science and Technology(2023QT07)。

摘　　要：Lithium-sulfur(Li-S)batteries with high theoretical specific energy are considered to be one of the highly promising next-generation energy storage systems.However,the shuttle effect of lithium polysulfides(LiPSs)and the interfacial instability of Li anodes have seriously hindered the practical application of Li-S batteries.Optimizing the electrolyte composition with additives can significantly improve the battery performance and has attracted great attention.Herein,we propose an organometallic salt,i.e.,nickel bromide dimethoxyethane(NiBr_(2)DME),as an electrolyte additive,which serves as the dual function of regulating LiPSs redox and synchronously stabilizing Li anodes.We reveal that NiBr_(2)DME can interact with LiPSs via Ni-S and Li-Br bonds,and accelerate the mutual transformation of LiPSs,thus reducing the accumulation of LiPSs in the electrolyte.In addition,NiBr_(2)DME can form a stable LiBr-containing interfacial layer on the Li metal surface,and promote the uniform electrodeposition of Li^(+)ions,and inhibit the formation of Li dendrites.Thus,Li-S batteries with a concentration of 0.5 mmol L^(-1)NiBr_(2)DME show an initial capacity of 919.8 mAh g^(-1)at 0.2 C,and a high capacity retention of 89.3%after 100 cycles.Even at the 4 C rate,a high discharge capacity of 602.9 mAh g^(-1)is achieved.Surprisingly,the good cycling performance is maintained under poor electrolyte conditions with sulfur loading of 4.8 mg cm^(-2)and electrlyte/sulfur ratio of 5µL mg^(-1).This work provides a positive solution to achieve the suppression of shuttle effect,the regulation of LiPSs redox and the stabilization of Li anodes.锂硫电池具有较高的理论比能,被认为是极具发展前景的下一代储能系统之一.然而,多硫化锂的穿梭效应和锂阳极的界面不稳定性严重阻碍了锂硫电池的实际应用.利用添加剂优化电解液的组成可以显著提高电池的性能.本工作中,我们提出了一种有机金属盐,即溴化镍-二甲氧基乙烷(NiBr_(2)DME)作为电解质添加剂,它具有调节LiPSs氧化还原和稳定锂阳极的双重功能.我们发现NiBr_(2)DME可以通过Ni-S和Li-Br键与LiPSs相互作用,加速了LiPSs的相互转化,从而减少了LiPSs在电解质中的积累.此外,NiBr_(2)DME能在锂金属表面形成稳定的含LiBr界面层,促进锂离子的均匀电沉积,抑制锂枝晶的形成.使用浓度为0.5 mmol L^(-1)NiBr_(2)DME的Li-S电池在0.2 C下的初始容量为919.8 mAh g^(-1),循环100次后容量保持率高达89.3%.即使在4 C的速率下,也可以实现602.9 mAh g^(-1)的高放电容量.在含硫量为4.8 mg cm^(-2)、液硫比为5μL mg-1的较差电解质条件下,电池仍能保持良好的循环性能.本研究为实现抑制穿梭效应、调控LiPSs氧化还原和稳定锂阳极提供了积极的解决方案.

关 键 词：Li-S batteries electrolyte additive nickel bromide dimethoxyethane regulating LiPSs redox stabilizing Li anode 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ138.13[化学工程—无机化工]