Recovering the electrochemical window by forming a localized solvation nanostructure in ionic liquids with trace water

• 作者: Jianing Meng Meng Ye Yue Wang Yinglun Sun Xu Zhang Kaiyuan Shi Xingbin Yan
• 来源期刊: 中国科学：化学（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: ARTICLES
• 页码范围: 96-105
• 页数: 10页
• 语种: 英文

摘要

Motivated by the fascinating merits of wide electrochemical stability window (ESW) and nonflammability,ionic liquids (ILs)have been utilized as advanced electrolytes in various emerging electrochemical energy storage technologies.However,ILs are hygroscopic to the water in the air and the presence of trace water will narrow the ESW of ILs.In this article,we report that a localized solvation nanostructure (LSNS) is formed in ILs,which plays an important role in fully recovering the originally decreased ESW of[EMIM][TFSI]IL owing to the trace water.Such LSNS is consisted ofLi+ ions with water molecules as the center,TFSI-anions as the secondary periphery and EMIM+ cations as the outermost layer after adding the proper amount of LiTFSI.This nanostructure can restrain the possibility of trace water to approach the electrode/electrolyte interfaces and adverse redox reactions,thereby recovering the ESW.Moreover,the effectiveness of this strategy in different kinds ofILs to fully recover ESW decreasing is verified.This article comes up with a feasible method to eliminate the trace water caused ESW drop for IL-based electrolytes and provides a new insight for understanding the molecular-level interaction between different ions in ILs with water molecules.