Initiator and Crosslinker-Free Zwitterionic Gel Electrolytes via Room-Temperature in Situ Self-Polymerization for Stable Zinc Metal Batteries

Gel polymer electrolytes (GPEs) are promising for aqueous zinc-ion batteries (AZIBs), with in situ GPEs offering improved interfacial contact. However, conventional in situ GPEs require initiators and crosslinkers, which can cause Zn corrosion and ion-trapping effects. Here, we report a zwitterionic in situ GPE that self-polymerization at room temperature without initiators or crosslinkers, enabling uniform Zn plating/stripping. The symmetric cell exhibits remarkable stability, sustaining over 4,000 hours at 0.5 mAh cm⁻² and 0.5 mA cm⁻². A Zn|Zn 0.25 V 2 O 5 full cell further confirms excellent electrochemical performance without side reactions, demonstrating the potential of this system for next-generation AZIBs.