Weakly solvating electrolyte enabling solvent-free co-intercalation for stable potassium-ion storage in graphite  

作　　者：Chaojie Cheng Wencong Feng Feiyue Wang Jingke Ren Deyang Guan Wei Chen Jean-Jacques Gaumet Kai Fu Xiaobin Liao Wen Luo 

机构地区：[1]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China [2]School of Materials Science and Engineering,Xinjiang University,Urumqi 830017,China [3]Laboratoire de Chimie et Physique:Approche Multi-échelles,des Milieux Complexes(LCP-A2MC),Institut Jean Barriol,Universitéde Lorraine,Metz 57070,France

出　　处：《Nano Research》2025年第3期234-242,共9页纳米研究(英文版)

基　　金：financial support from the National Key Research and Development Program of China(No.2022YFB2404300);the National Natural Science Foundation of China(Nos.22409153 and 52101269).

摘　　要：Ether electrolytes for potassium-ion batteries exhibit a broader electrochemical window and greater applicability,yet most of them are high-concentration electrolytes with elevated cost.In this study,we propose the use of a weakly solvating cyclic ether electrolyte with tetrahydropyran(THP)as the solvent.This approach induces the formation of a thin and dense inorganic-rich solid electrolyte interphase(SEI)film,which is accompanied by a decrease in the activation energy of electrode interfacial reactions due to the weak ligand binding of THP with K^(+).Density functional theory(DFT)simulations also corroborate the hypothesis that K^(+)has a lower binding energy with THP.During potassium storage process,the phenomenon of solvent co-intercalation of graphite does not occur,which greatly reduces the destruction of the graphite structure and enables a superior electrochemical performance and enhanced cycling stability at a lower concentration(2 M).At a current density of 0.2 C(55.8 mA·g^(-1)),the battery can be stably cycled for 800 cycles(approximately 8 months)with a specific capacity of 171.8 mAh·g^(-1).This study provides a new ether-based electrolyte for potassium ion batteries and effectively reduces the electrolyte cost,which is expected to inspire further development of energy storage batteries.

关 键 词：weakly solvating electrolyte co-intercalation GRAPHITE potassium ion batteries 

分 类 号：TM912[电气工程—电力电子与电力传动]