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.