GO Regulated Hydrogel Electrolytes with Superior Conducing and Antiswelling Ability for Flexible Supercapacitors

Abstract

Hydrogels, with excellent flexibility, leakage-free, and high safety, are considered as desired electrolytes to build flexible quasisolid-state supercapacitors. Sodium polyacrylate acid (PANa) hydrogel possesses high water retention capacity and ionic conductivity, but its uncontrollable swelling hinders its practical applications. Herein, a novel strategy is proposed to fabricate flexible hybridized electrolyte, where the PANa hydrogel is restricted inside the interlayer spacing of GO membranes. The high-speed spin-treatment regularized GO membrane possesses uniform interlayer channels, where the hydrogel precursor can be infiltrated and in situ polymerized inside the interlayer spacing. Furthermore, the interaction between the PANa polymer chain and GO flakes can prevent structural deformation and uncontrollable swelling of the lamellar membrane. Therefore, the PANa-GO electrolytes exhibit excellent mechanical properties (24.36 MPa), high ionic conductivity (61.03 mS cm −1 ), and outstanding antiswelling ability. Moreover, the supercapacitor device assembled by the PANa-GO-15 electrolyte and MnO 2 electrodes exhibits a high specific capacitance of 123.1 F g −1 at 0.5 A g −1 and good rate ability. Even under bending or low-temperature conditions, the flexible device can still maintain its energy storage ability. This novel structural regularization and confinement approach may offer a new option for designing robust, antiswelling, and high ionic conductivity flexible electrolytes.