甘氨酸仿生催化锂硫电池界面反应的原位拉曼光谱研究

In Situ Raman Study on Interfacial Reaction of Lithium-Sulfur Battery Catalyzed by Gly

多硫化锂的穿梭效应限制了锂硫电池的商业化。引入高效的催化剂来加快硫转化反应动力学是抑制穿梭效应的有效方法。利用仿生思想,将酶的核心单元“氨基酸”作为催化剂引入锂硫电池正极以解决穿梭效应问题。研究发现,引入氨基酸后,电池展现了优异的电化学性能,表明其促进了对多硫化锂的高效催化转化。在此基础上,利用原位拉曼表征技术,在电池工作状态下,对电极表面的硫转化反应进行实时捕捉,从分子水平上揭示了氨基酸仿生催化剂调控锂硫界面硫转化反应的机理,为未来设计高效的硫转化催化材料和发展高性能的锂硫电池提供现实可行的指导方案。

The shuttle effect of lithium polysulfides(LiPSs)limits the commercialization of lithium-sulfur(Li—S)batteries.The introduction of efficient catalysts to accelerate the sulfur conversion kinetics is an effective way to restrain the shuttle effect.In this paper,inspired by the biomimetic idea,amino acid as the core unit of the enzyme was introduced into the cathode of Li—S battery to solve the shuttle effect problem.It was found that the battery with amino acid showed excellent electrochemical performance,indicating that it promoted the catalytic conversion of LiPSs efficiently.On this basis,using in situ Raman characterization technique,the sulfur conversion reaction on the electrode surface was captured in real time under the working condition of the battery,and the mechanism of amino acid biomimetic catalyst in regulating the sulfur conversion reaction at Li—S interface was revealed at the molecular level.This work provides a realistic and feasible guidance for the design of efficient sulfur conversion catalytic materials and the development of high-performance Li—S batteries in future.