Three‐Dimensional Porous Spongy Ti3C2Tx MXene/Polyvinyl Alcohol/Agar Gel Electrolyte with High Ionic Conductivity Enables Highly Reversible Zinc‐Ion Batteries

Abstract

Gel electrolyte is one of the key components of flexible energy storage devices. The construction of a three‐dimensional (3D) porous gel electrolyte with high ionic conductivity is a very effective strategy to improve the performance of zinc‐ion batteries (ZIBs). Herein, porous polyvinyl alcohol‐Agar‐sodium dodecyl sulfate‐MXene‐dimethyl sulfoxide (DMSO) (denoted as PVA‐Agar‐SDS‐MXene‐DMSO (PASMD)) gel electrolyte with double network is prepared through one‐pot method by adding two‐dimensional (2D) MXene to improve its ionic conductivity and DMSO to increase its low‐temperature resistance. Meanwhile, the as‐prepared PASMD gel electrolyte with a high ionic conductivity of 50.63 mS cm−1 realizes the gradient induction and redistribution of Zn2+, which drives oriented Zn (002) plane deposition of Zn2+ and then achieves uniform Zn deposition and dendrite‐free anode. The specific capacity of the assembled flexible Zn//PASMD//β‐MnO2 battery can reach 205 mAh g−1 at 0.2 A g−1. It also exhibits good performance both at room temperature and −20 °C with stable cyclic stability for more than 1000 h. After 1000 cycles at 1 A g−1, the assembled flexible battery stabilizes at 67 mAh g−1. This work provides an alternative pathway for the development of high‐performance gel electrolytes with low‐temperature resistance and high‐ionic conductivity for flexible ZIBs.