Solvent-Dominated or Salt-Controlled? Mechanistic Insights and Design Principles for Water-in-Salt and Deep Eutectic Solvent Electrolytes in Aqueous Energy Storage

IF 8.9 2区化学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Chemical record Pub Date : 2026-09-22 Epub Date: 2026-06-23 DOI:10.1002/tcr.70189

Balaraman Vedhanarayanan, Jagadesh Nagaraj, Tsung-Wu Lin, Hsin-Hui Shen, K. C. Seetha Lakshmi

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引用次数: 0

Abstract

Aqueous energy storage technologies are gaining renewed attention due to their safety, low cost, and environmental compatibility. Highly concentrated electrolytes, including water-in-salt (WIS) and deep eutectic solvent (DES) systems, significantly expand the electrochemical stability window (ESW) of water, enabling higher operating voltages. However, reported improvements often conflate thermodynamic, kinetic, and interfacial effects. This review presents a mechanistic analysis of ESW expansion by distinguishing bulk solvation behavior from interfacial chemistry, ion transport limitations, and solid–electrolyte interphase formation. WIS electrolytes are predominantly salt-controlled, whereas DES systems are solvent-dominated through hydrogen-bond networks. This framework clarifies their distinct transport and stability characteristics. The review further evaluates common experimental methodologies for ESW, conductivity, and interfacial analysis. By integrating literature trends, practical performance limits are defined, and standardized evaluation protocols are proposed. Finally, actionable design principles and an experimental checklist are provided to improve reproducibility and guide the rational development of advanced aqueous energy storage systems.

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溶剂主导还是盐控制？盐中水和深共晶溶剂电解质在水储能中的机理和设计原则。

水性储能技术因其安全、低成本和环境兼容性而重新受到关注。高浓度的电解质，包括盐中水（WIS）和深共晶溶剂（DES）体系，显著扩大了水的电化学稳定窗口（ESW），实现了更高的工作电压。然而，报道的改进通常将热力学、动力学和界面效应混为一谈。本文综述了通过区分界面化学、离子传输限制和固体-电解质界面相形成的体溶剂化行为来分析ESW膨胀的机理。WIS电解质主要由盐控制，而DES系统则通过氢键网络以溶剂为主。这个框架阐明了它们独特的运输和稳定性特征。本文进一步评估了常用的ESW、电导率和界面分析实验方法。通过整合文献趋势，定义了实际性能极限，并提出了标准化的评价方案。最后，提出了可操作的设计原则和实验清单，以提高可重复性，指导先进的水储能系统的合理开发。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Chemical record 化学-化学综合

CiteScore

11.00

自引率

3.00%

发文量

188

审稿时长

>12 weeks

期刊介绍： The Chemical Record (TCR) is a "highlights" journal publishing timely and critical overviews of new developments at the cutting edge of chemistry of interest to a wide audience of chemists (2013 journal impact factor: 5.577). The scope of published reviews includes all areas related to physical chemistry, analytical chemistry, inorganic chemistry, organic chemistry, polymer chemistry, materials chemistry, bioorganic chemistry, biochemistry, biotechnology and medicinal chemistry as well as interdisciplinary fields. TCR provides carefully selected highlight papers by leading researchers that introduce the author''s own experimental and theoretical results in a framework designed to establish perspectives with earlier and contemporary work and provide a critical review of the present state of the subject. The articles are intended to present concise evaluations of current trends in chemistry research to help chemists gain useful insights into fields outside their specialization and provide experts with summaries of recent key developments.