Molten salt electrochemistry for next-generation batteries.

Inorganic molten salts - composed of freely moving ions at high temperature - have emerged as a new family of electrolytes for batteries owing to their low flammability, high thermal stability and low materials cost. Inorganic molten salt electrolytes surpass their aqueous and organic counterparts by enabling electrochemistry with wider ranges of operating temperatures. Such electrolytes offer abundant charge carriers and unique ionic solvation structures that enhance reaction kinetics, offering superior rate and cycling stabilities. In this Review, we explore molten salt electrochemistry, starting from a fundamental electrochemistry perspective, ending with the batteries and their charge storage mechanisms enabled by molten salt electrolytes. In particular, we discuss the impact of solid-state ion-selective membranes, and also share our perspectives on the future development of advanced molten salt batteries in the frame of materials and electrochemistry innovations.