Hydrogel Electrolytes for Temperature Robust Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for next-generation energy storage devices due to their cost-effectiveness, enhanced safety, and environmental friendliness. However, conventional liquid electrolytes frequently encounter challenges in wide-temperature applications, such as narrow electrochemical stability windows and interfacial instability between electrodes and electrolytes. In recent years, hydrogel electrolytes (HEs) serving as quasi-solid-state electrolytes (QEs) have been developed for AZIBs to offer a unique blend of the benefits associated with both liquid and solid-state electrolytes. This review begins by systematically outlining the challenges encountered by HEs when subjected to extreme temperature conditions, including electrolyte freezing/evaporation and dendrite growth. Subsequently, a comprehensive analysis of the recent modification strategies that have been proposed to expand the operational temperature range of HEs is conducted. In the end, multidimensional perspectives are provided for future development of wide-temperature hydrogel electrolytes (WTHEs). It is anticipated that this review will expedite the adoption of WTHEs in AZIBs and make a meaningful contribution to the advancement of highly safe energy storage systems.