Highly Entangled Hydrogel Enables Stable Zinc Metal Batteries via Interfacial Confinement Effect

Hydrogel electrolytes are expected to be useful for stable zinc metal batteries; however, it is extremely challenging to develop a hydrogel electrolyte that balances mechanical properties, ionic conductivity, and interface stability. Herein, we report a highly entangled hydrogel electrolyte that achieves pronounced mechanical properties (446 kPa tensile strength) and high ionic conductivity (3.93 mS cm–1) by optimizing the dense reversible conformation of hydrophilic chains. Moreover, due to the interfacial confinement effect, the highly entangled hydrogel electrolyte enables a dynamically stabilized anode with a non-dendritic planar morphology. Thus, the zinc anode with this electrolyte system exhibits a long-term cycle stability of 6000 h at 0.5 mA cm–2 and over 220 h at an impressive depth-of-discharge of 68.4%. This work provides an important concept for realizing practical high-performance wearable zinc–manganese batteries.