Moderately Solvated Co‐Solvent Electrolyte for −60°C to 100°C Wide‐Temperature Zinc Metal Batteries

ABSTRACT Wide operational temperature ranges for energy storage systems are in urgent demand for electric vehicles, aerospace technology, and military and grid‐scale utilization. Recently, Zn metal batteries based on co‐solvent electrolyte show great promise for extreme temperature applications. However, their performance is still remarkably limited by sluggish cationic dehydration kinetics at low temperatures and poor cycling stability at elevated temperatures. Here, we present a moderately solvated co‐solvent electrolyte design based on the alcohol ether co‐solvents. Theoretical calculations and experimental analyses reveal that the ethylene glycol methyl ether co‐solvent significantly suppresses solvated water reactivity by strengthening hydrogen bonding through its strongly solvated ether group, while its strongly solvated hydroxyl group facilitates cationic dehydration kinetics. Consequently, Zn||PANI batteries based on this electrolyte demonstrate stable operation across −60°C–100°C. This wide operating range of 160°C surpasses all of the temperature ranges reported to date. The battery delivers a high capacity of 70.1 mAh g − 1 at −40°C under a high rate of 5 A g − 1 . Ultralong cyclability has been achieved over 14 000 (capcacity retention:82%) and 3300 cycles at room temperature and 70°C, respectively. This work provides new insights on moderate solvation chemistry to enable long‐life metal batteries operating across a −60°C–100°C.