Sulfhydryl-functionalized COF-based electrolyte strengthens chemical affinity toward polysulfides in quasi-solid-state Li-S batteries  

作　　者：Linnan Bi Jie Xiao Yaochen Song Tianrui Sun Mingkai Luo Yi Wang Peng Dong Yingjie Zhang Yao Yao Jiaxuan Liao Sizhe Wang Shulei Chou 

机构地区：[1]Yangtze Delta Region Institute(Quzhou),University of Electronic Science and Technology of China,Quzhou,China [2]National and Local Joint Engineering Research Center of Lithium-ion Batteries and Materials Preparation Technology,Key Laboratory of Advanced Battery Materials of Yunnan Province,Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming,China [3]Institute for Carbon Neutralization,College of Chemistry and Materials Engineering,Wenzhou University,Wenzhou,China [4]School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu,China [5]School of Materials Science and Engineering,Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials,Shaanxi University of Science&Technology,Xi'an,China

出　　处：《Carbon Energy》2024年第9期221-234,共14页碳能源（英文）

基　　金：This research was supported by the National Natural Science Foundation of China(52202104);the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(LZY23B030002);the China Postdoctoral Science Foundation(2021T140433,2020M683408);the Quzhou Science and Technology Bureau Project(2022D015,2023D023);the International Cooperation Projects of Sichuan Provincial Department of Science and Technology(2021YFH0126);the Fundamental Research Funds for the Central Universities(ZYGX2020ZB016);the Key Research and Development Program of Yunnan Province China(202103AA080019);Yunnan Major Scientific and Technological Projects(202202AG050003).

摘　　要：For lithium-sulfur batteries(Li-S batteries),a high-content electrolyte typically can exacerbate the shuttle effect,while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion efficiency,so achieving an appropriate electrolyte-to-sulfur ratio(E/S ratio)is essential for improving the battery cycling efficiency.A quasi-solid electrolyte(COF-SH@PVDF-HFP)with strong adsorption and high catalytic conversion was constructed for in situ covalent organic framework(COF)growth on highly polarized polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)fibers.COF-SH@PVDF-HFP enables efficient Li-ion conductivity with low-content liquid electrolyte and effectively suppresses the shuttle effect.The results based on in situ Fourier-transform infrared,in situ Raman,UV–Vis,X-ray photoelectron,and density functional theory calculations confirmed the high catalytic conversion of COF-SH layer containing sulfhydryl and imine groups for the lithium polysulfides.Lithium plating/stripping tests based on Li/COF-SH@PVDF-HFP/Li show excellent lithium compatibility(5 mAh cm^(-2) for 1400 h).The assembled Li-S battery exhibits excellent rate(2 C 688.7 mAh g^(-1))and cycle performance(at 2 C of 568.8 mAh g^(-1) with a capacity retention of 77.3%after 800 cycles).This is the first report to improve the cycling stability of quasi-solid-state Li-S batteries by reducing both the E/S ratio and the designing strategy of sulfhydryl-functionalized COF for quasi-solid electro-lytes.This process opens up the possibility of the high performance of solid-state Li-S batteries.

关 键 词：lithium-sulfur batteries low electrolyte-to-sulfur ratio polysulfide shuttle PVDF-HFP/COF 

分 类 号：TM912[电气工程—电力电子与电力传动]