Beyond the Limitation: Advancing Calcium Metal Batteries Through Electrolyte Salt Engineering

Calcium‐based batteries have attracted considerable attention as an important battery system in the post‐lithium era, owing to their low cost, resource abundance, and the potential for high energy density derived from the multivalent nature of calcium ions. Nevertheless, the development of calcium‐based batteries has been hindered by the scarcity of ideal electrolytes. The compatibility between the metal anode and the electrolyte is of paramount importance. This paper outlines the history of electrolytes for reversible Ca plating/stripping. Requirement of high‐performance electrolyte salts is thereafter summarized. Furthermore, potential solutions to current challenges and future research opportunities have been discussed in depth. We hope that this paper will catalyze advancements in electrolyte development so as to accelerate the construction of highly reversible, high‐performance calcium battery systems.