Breaking Consecutive Hydrogen‐Bond Network Toward High‐Rate Hydrous Organic Zinc Batteries

Abstract

AbstractZinc batteries hold great potential for stationary energy storage but suffer from severe dendrite growth, corrosion, and hydrogen evolution troubles in aqueous electrolytes. Despite the impressive efficacy of non‐flammable hydrous organic electrolytes in addressing these problems, the insufficient ionic conductivity hinders the rate capability and practicability of hydrous organic Zn batteries. Here, methanol is proposed as a co‐solvent for ethylene glycol (EG)‐based hydrous organic electrolytes, where its methyl terminal group can interrupt the continuous intermolecular hydrogen bond network among EG. The new hydrous organic electrolyte exhibits a doubled ionic conductivity without sacrificing the exceptional nonflammability. As a result, the Zn anode exhibits a long‐term cycling stability over 4000 h at 0.5 mA cm−2, a high Coulombic efficiency of 99.5%, high‐rate capability up to 20 mA cm‒2, and impressive low‐temperature tolerance of ‒60 °C. The Zn||V2O5 pouch cell with the electrolyte is capable of operating under extreme operation conditions involving needling, package breakage, and even exposure to fire. This work paves an avenue toward electrolyte design for high‐rate practical Zn batteries and beyond.