Cathode|Electrolyte Interface Engineering by a Hydrogel Polymer Electrolyte for a 3D Porous High‐Voltage Cathode Material in a Quasi‐Solid‐State Zinc Metal Battery by In Situ Polymerization

Abstract

AbstractThis work highlights the development of a superior cathode|electrolyte interface for the quasi solid‐state rechargeable zinc metal battery (QSS‐RZMB) by a novel hydrogel polymer electrolyte using an ultraviolet (UV) light‐assisted in situ polymerization strategy. By integrating the cathode with a thin layer of the hydrogel polymer electrolyte, this technique produces an integrated interface that ensures quick Zn2+ ion conduction. The coexistence of nanowires for direct electron routes and the enhanced electrolyte ion infiltration and diffusion by the 3D porous flower structure with a wide open surface of the Zn‐MnO electrode complements the interface formation during the in situ polymerization process. The QSS‐RZMB configured with an integrated cathode (i‐Zn‐MnO) and the hydrogel polymer electrolyte (PHPZ‐30) as the separator yields a comparable specific energy density of 214.14 Wh kg−1 with that of its liquid counterpart (240.38 Wh kg−1, 0.5 M Zn(CF3SO3)2 aqueous electrolyte). Other noteworthy features of the presented QSS‐RZMB system include its superior cycle life of over 1000 charge‐discharge cycles and 85% capacity retention with 99% coulombic efficiency at the current density of 1.0 A g−1, compared to only 60% capacity retention over 500 charge‐discharge cycles displayed by the liquid‐state system under the same operating conditions.