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

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中文摘要：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(NiBr2DME)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NiBr2DME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,NiBr2DME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 NiBr2DME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 mgcm-2、液硫比为5μLmg-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.

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

外文摘要：Lithium-sulfur(Li-S)batteries with high theo-retical 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 in-terfacial instability of Li anodes have seriously hindered the practical application of Li-S batteries.Optimizing the elec-trolyte 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(NiBr2DME),as an electrolyte additive,which serves as the dual function of regulating LiPSs redox and synchronously stabilizing Li anodes.We reveal that NiBr2DME can interact with LiPSs via Ni-S and Li-Br bonds,and accelerate the mutual transformation of LiPSs,thus re-ducing the accumulation of LiPSs in the electrolyte.In addi-tion,NiBr2DME can form a stable LiBr-containing interfacial layer on the Li metal surface,and promote the uniform elec-trodeposition of Li+ions,and inhibit the formation of Li dendrites.Thus,Li-S batteries with a concentration of 0.5 mmol L-1 NiBr2DME 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 5 μL 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.

外文关键词：

Li-S batterieselectrolyte additivenickel bromide dimethoxyethaneregulating LiPSs redoxstabilizing Li anode

作者：

孟怡轩、张梅芳、王有亮、刘琛、张泽、吁霁、蔡建信、杨震宇

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作者单位：

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

关键词：

Li-S batteries electrolyte additive nickel bromide dimethoxyethane regulating LiPSs redox stabilizing Li anode

基金：

Jiangxi Province Leading Talent Project for Academic and Technical Leaders in Major DisciplinesNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNatural Science Foundation of Jiangxi ProvinceNatural Science Foundation of Jiangxi ProvinceElite Scientists Sponsorship Program by Jiangxi Association for Science and Technology

项目编号：

20213BCJ2202422269013222630092186300620224ACB21300120212BBE530512023QT07

出版年：

2024

DOI：

10.1007/s40843-024-2969-3

中国科学:材料科学(英文)

CSTPCD

ISSN：

年,卷(期)：2024.67(9)