Concentrated mixed cation acetate "water-in-salt" solutions as green and low-cost high voltage electrolytes for aqueous batteries

Maria R. Lukatskaya, Jeremy I. Feldblyum, David G. Mackanic, Franziska Lissel, Dominik L. Michels, Yi Cui, Zhenan Bao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

308 Scopus citations


Electrolyte solutions are a key component of energy storage devices that significantly impact capacity, safety, and cost. Recent developments in "water-in-salt" (WIS) aqueous electrolyte research have enabled the demonstration of aqueous Li-ion batteries that operate with capacities and cyclabilities comparable with those of commercial non-aqueous Li-ion batteries. Critically, the use of aqueous electrolyte mitigates safety risks associated with non-aqueous electrolytes. However, the high cost and potential toxicity of imide-based WIS electrolytes limit their practical deployment. In this report, we disclose the efficacy of inexpensive, non-toxic mixed cation electrolyte systems for Li-ion batteries that otherwise provide the same benefits as current WIS electrolytes: extended electrochemical stability window and compatibility with traditional intercalation Li-ion battery electrode materials. We take advantage of the high solubility of potassium acetate to achieve the WIS condition in a eutectic mixture of lithium and potassium acetate with water-to-cation ratio as low as 1.3. Our work suggests an important direction for the practical realization of safe, low-cost, and high-performance aqueous Li-ion batteries.

Original languageEnglish (US)
Pages (from-to)2876-2883
Number of pages8
JournalEnergy and Environmental Science
Issue number10
StatePublished - Oct 2018

Bibliographical note

Publisher Copyright:
© 2018 The Royal Society of Chemistry.

ASJC Scopus subject areas

  • Environmental Chemistry
  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Pollution


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