Self-assembled ultrathick MoS2 conductive hydrogel membrane via ionic gelation for superior capacitive energy storage

Abstract

Conductive hydrogel membranes with nanofluids channels represent one of the most promising capacitive electrodes due to their rapid kinetics of ion transport. The construction of these unique structures always requires new self-assembly behaviors with different building blocks, intriguing phenomena of colloidal chemistry. In this work, by delicately balancing the electrostatic repulsions between 2D inorganic nanosheets and the electrostatic adsorption with cations, we develop a general strategy to fabricate stable free-standing 1T molybdenum disulphide (MoS₂) hydrogel membranes with abundant fluidic channels. Given the interpenetrating ionic transport network, the MoS₂ hydrogel membranes exhibit a high-level capacitive performance 1.34 F/cm² at an ultrahigh mass loading of 11.2 mg/cm². Furthermore, the interlayer spacing of MoS₂ in the hydrogel membranes can be controlled with ångström-scale precision using different cations, which can promote further fundamental studies and potential applications of the transition-metal dichalcogenides hydrogel membranes.