Boosting the “Solid–Liquid–Solid” Conversion Reaction via Bifunctional Carbonate-Based Electrolyte for Ultra-long-life Potassium–Sulfur Batteries

作     者：Shufen Ye Nan Yao Dr. Xiang Chen Mingze Ma Lifeng Wang Zhihao Chen Dr. Yu Yao Prof. Qiang Zhang Prof. Yan Yu 

作者机构：Hefei National Research Center for Physical Sciences at the Microscale Department of Materials Science and Engineering iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) CAS Key Laboratory of Materials for Energy Conversion University of Science and Technology of China Hefei Anhui 230026 China Contribution: Writing - original draft (lead) Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical Engineering Tsinghua University Beijing 100084 China Contribution: Data curation (lead) Contribution: Software (lead) Contribution: Formal analysis (equal) Contribution: ​Investigation (equal) Contribution: Writing - review & editing (lead) Contribution: Supervision (lead) National Synchrotron Radiation Laboratory Hefei Anhui 230026 China Contribution: Conceptualization (lead) 

出 版 物：《Angewandte Chemie》 

年 卷 期：2023年第135卷第44期

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 

主　　题：Carbonate Solvent Concentration Electrolytes Electrode–Electrolyte Interphase Potassium Sulfur Batteries Solid–Liquid–Solid Phase Conversion 

摘      要：Potassium–sulfur (K−S) batteries have attracted wide attention owing to their high theoretical energy density and low cost. However, the intractable shuttle effect of K polysulfides results in poor cyclability of K−S batteries, which severely limits their practical application. Herein, a bifunctional concentrated electrolyte (3 mol L −1 potassium bis(trifluoromethanesulfonyl)imide in ethylene carbonate (EC)) with high ionic conductivity and low viscosity is developed to regulate the dissolution behavior of polysulfides and induce uniform K deposition. The organic groups in the cathode electrolyte interphase layer derived from EC can effectively block the polysulfide shuttle and realize a “solid–liquid–solid reaction mechanism. The KF-riched solid-electrolyte interphase inhibits K dendrite growth during cycling. As a result, the achieved K−S batteries display a high reversible capacity of 654 mAh g −1 at 0.5 A g −1 after 800 cycles and a long lifespan over 2000 cycles at 1 A g −1 .