Recent advances and design strategies of eutectic electrolytes for lithium metal batteries

Abstract

Lithium metal batteries are regarded as the optimal choice for high-energy-density energy storage due to their superior theoretical capacity and low electrochemical potential. Nevertheless, the instability of conventional electrolytes and the complexity of forming a robust solid electrolyte interface (SEI) on lithium metal anodes have hindered the practical development of this technology. Eutectic electrolytes, as a novel class of electrolytes that exhibit environmental friendliness, safety, cost-effectiveness, and electrochemical stability, demonstrate significant potential in advancing lithium metal battery technology. Despite this promise, systematic reviews focusing specifically on the application of eutectic electrolytes in lithium metal batteries remain limited. In this review, we provide a comprehensive summary of the applications of eutectic electrolytes in both liquid and solid forms, with particular attention to the solvation structures of liquid electrolytes and interfacial challenges of solid electrolytes. Furthermore, we analyze the key challenges associated with eutectic electrolytes, summarize current strategies to address these challenges, and provide an outlook. This review is anticipated to offer valuable insights and guidance for the further advancement of deep eutectic electrolytes in lithium metal batteries.