Entanglement Added to Cross-Linked Chains Enables Tough Gelatin-Based Hydrogel for Zn Metal Batteries.

Currently, it is still challenging to develop a hydrogel electrolyte matrix that can successfully achieve a harmonious combination of mechanical strength, ionic conductivity, and interfacial adaptability. Herein, a multi-networked hydrogel electrolyte with a high entanglement effect based on gelatin/oxidized dextran/methacrylic anhydride, denoted as ODGelMA is constructed. Attribute to the Schiff base network formulation of ─RC═N─, oxidized dextran integrated gelatin chains induce a dense hydrophilic conformation group. Furthermore, addition of methacrylic anhydride through a grafting process, the entangled hydrogel achieves impressive mechanical features (6.8 MPa tensile strength) and high ionic conductivity (3.68 mS cm at 20 °C). The ODGelMA electrolyte regulates the zinc electrode by circumventing dendrite growth, and showcases an adaptable framework reservoir to accelerate the Zn desolvation process. Benefiting from the entanglement effect, the Zn anode achieves an outstanding average Coulombic efficiency (CE) of 99.8% over 500 cycles and cycling stability of 900 h at 5 mA cm and 2.5 mAh cm. The Zn||I full cell yields an ultra-long cycling stability of 10 000 cycles with a capacity retention of 92.4% at 5 C. Furthermore, a 60 mAh single-layer pouch cell maintains a stable work of 350 cycles.