Thermodynamic-Kinetic Coupling of Water Structure Enables Wide-Temperature Zinc Batteries.

Aqueous zinc-ion batteries (AZIBs) offer a path to safe and sustainable energy storage, yet their practicality is hindered by subzero failure, parasitic hydrogen evolution, and interfacial degradation. A key challenge is that preserving water mobility at low temperatures can inadvertently promote parasitic hydrogen evolution under ambient conditions. Here, we design a hydrogel electrolyte that combines a wide operating-temperature window with enhanced interfacial stability through coupled thermodynamic-kinetic regulation of the electrolyte environment. By disrupting the tetrahedral hydrogen-bond network and diversifying local coordination environments, the hydrogel enhances configurational disorder and suppresses water crystallization. Simultaneously, restricted molecular dynamics retard ice nucleation and parasitic hydrogen evolution. This hydrogen-bond architecture further promotes rapid and uniform Zn deposition by regulating the thermodynamics and kineticsof interfacial Zn2+ transfer. Consequently, AZIBs achieve exceptional stability: over 8000 h in symmetric cells, 15 000 cycles in full cells, and high reversibility down to -30°C. This work establishes thermodynamic-kinetic coupling as a promising strategy for designing high-performance aqueous batteries under extreme conditions.