Solubility Challenges in Battery Electrolytes

Chemical Reviews, vol. 125, pp. 11216–11259

Abstract

This review provides a foundational understanding of solubility to support researchers in navigating challenges in battery electrolyte development. We survey recent strategies aimed at controlling, and typically maximizing, solubility in electrochemical systems, with a focus on redox flow and metal-ion batteries. The review begins with an accessible overview of solubility concepts, methods for accurately determining solubility for battery-relevant materials, and solubility prediction. We then discuss how solubility can be tuned by modifying the electrolyte solution structure or by tailoring the molecular structure of the active material itself, and we examine emerging strategies to decouple electrolyte capacity from solubility in flow batteries. In the context of metal and metal-ion batteries, we highlight the role of solvation structures in concentrated electrolytes and their influence on both bulk and interfacial properties. Finally, trade-offs associated with high-concentration formulations, such as increased viscosity and reduced ionic conductivity, are considered in light of their impact on practical deployment. We conclude with a forward-looking perspective on solubility as a central design parameter in battery electrolyte research.

Authors 8

1. David Reber corresponding

   Swiss Federal Laboratories for Materials Science and Technology

   Affiliation as printed

   Empa, Swiss Federal Laboratories for Materials Science and Technology

2. Zhiyu Wang

   National University of Singapore

   Affiliation as printed

   Department of Materials Science and Engineering

   National University of Singapore

   Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore

3. Kiana Amini

   University of British Columbia

   Affiliation as printed

   Department of Materials Engineering

   University of British Columbia

   Department of Materials Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada

4. Yan Jing

   National University of Singapore

   Affiliation as printed

   Department of Materials Science and Engineering

   National University of Singapore

   Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore

5. Julia Lorenzetti

   École Polytechnique Fédérale de Lausanne · Swiss Federal Laboratories for Materials Science and Technology

   Affiliation as printed

   Empa, Swiss Federal Laboratories for Materials Science and Technology

   Institute of Materials

   École Polytechnique Fédérale de Lausanne

6. Kang Xu
   Affiliation as printed

   SES AI Corp

   SES AI Corp., Woburn, Massachusetts 01801, United States

7. Abhishek Khetan Aachen Fuel Science Center

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

   The Fuel Science Center

   The Fuel Science Center, RWTH Aachen University, 52062 Aachen, Germany

8. Qing Wang

   National University of Singapore

   Affiliation as printed

   Department of Materials Science and Engineering

   National University of Singapore

   Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore