Fabrication of ultra-high energy and power asymmetric supercapacitors based on hybrid 2D MoS2/graphene oxide composite electrodes: a binder-free approach

Abstract

Two-dimensional (2D) atomically thick materials, graphene oxide (GO) and layered molybdenum disulfide (MoS₂) nanosheets have been potentially investigated as novel energy storage materials due to their unique physicochemical properties. The present manuscript describes a facile binder-free approach to fabricate large-scale hybrid 2D MoS₂/GO nanosheet-based electrodes using the electrophoretic deposition (EPD) method on a conducting substrate (nickel foam) for supercapacitor device applications. Structural and morphological analysis reveals uniform decoration of the electrophoretically assembled 2D MoS₂/GO nanosheets over the entire substrate surface. The electrochemical supercapacitive measurements of the MoS₂/GO hybrid electrode show a high specific capacitance of ∼613 F g⁻¹ at a low scan rate. Moreover, the MoS₂/GO//GO electrode-based asymmetric supercapacitor device reveals ultra-high energy (23 W h kg⁻¹) and power (17 kW kg⁻¹) density. The superior electrochemical properties of the 2D MoS₂ synergist with high surface area offered by conducting GO and mutually MoS₂/GO improves the electrochemical capacitive performance with charge transport and storage. The direct hybrid electrode fabrication by the EPD method (a binder approach) eliminates the drawbacks offered by resistive binders in conventional electrodes. The present experimental findings can evoke scalable binder-free synthesis of MoS₂/GO hybrid electrodes with enhanced supercapacitive performance in energy storage devices.