Interpenetrating\nComposite Hydrogel Electrolyte with\nOrganic/Inorganic Polar Groups for Stable Zinc Metal Anode

Hydrogel electrolytes have been widely explored in flexible\nzinc\nbatteries owing to their considerable mechanical strain and water-retaining\nproperties. However, it is difficult to balance the contradiction\nbetween the ionic conductivity and the mechanical strength due to\nthe deterioration of structural stability with the addition of electrolyte\nsalts. To address this, we designed a coassembling organic–inorganic\nhydrogel (P–P/M) based on poly­(vinyl alcohol)-polyacrylamide\n(P–P) interpenetrating matrix decorated with Zn-based montmorillonite\n(Zn-MMT). The Zn-MMT with overall negative potential can attract and\nregulate the transport of Zn<sup>2+</sup>, while the Brønsted/Lewis\nacid sites with positive polarizations offer anchoring sites for anions,\nwhich increases the cation transference number and reduces byproduct\nformation. Moreover, the formation of hydrogen bonds in the hydrogel\ncan weaken the contact between free water molecules and the zinc cations,\nwhich effectively suppresses the corrosion of zinc foil. Consequently,\nthe Zn//Zn cell with P–P/M electrolyte delivers a long cycle\nlife of 2400 h at 0.5 mA cm<sup>–2</sup>. The good mechanical\nproperties of the P–P/M hydrogel boost its application in flexible\npouch cells even under bending and cutting conditions. This study\nprovides an effective approach to designing organic–inorganic\nhydrogel electrolytes for long-life flexible zinc batteries.