Eutectic materials with tunable compositions, low melting points, and enhanced ionic conductivities are ideal for energy storage and conversion. This review covers ionic liquids, molten salts, deep eutectic solvents, alloys, and organic cocrystals, highlighting phase diagram control, component ratios, and thermal stability. Applications in batteries, supercapacitors, and thermal management are discussed and future directions are proposed.

Eutectic materials are versatile for energy storage and conversion due to their tunable composition, depressed melting temperatures, and enhanced ionic conductivity. This review surveys recent developments in eutectic materials, including ionic liquids, molten salts, deep eutectic solvents, alloy materials, and organic cocrystals. The fundamental parameters that dictate eutectic performance, including phase diagram control, component ratios, and thermal stability are analyzed, and its advantages in various aspects of application are summarized. This review concludes with some outlooks for developing energy storage using eutectic materials.