Hierarchical Two-Dimensional Layered Nickel Disulfide (NiS2)@PEDOT:PSS Nanocomposites as Battery-Type Electrodes for Battery-Type Supercapacitors with High Energy Density

Abstract

Battery-type hybrid supercapacitors (HSCs) (otherwise known as supercapatteries) are novel electrochemical energy storage devices bridge the gap between rechargeable batteries and traditional SCs. Herein, we report the synthesis of layered two-dimensional (2D) nickel disulfide (NiS2) nanosheets (NSNs) modified with poly(3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS) and their successful implementation in battery-type SCs. Initially, a layered 2D NSN is synthesized via a microwave-assisted hydrothermal method and further used as a template to coat PEDOT:PSS in order to prepare NiS2@PEDOT:PSS nanocomposite electrodes by a facile drop-casting method. This is the first-time report on the synthesis of a hierarchical NiS2@PEDOT:PSS nanocomposite electrode for battery-type HSC applications. An asymmetric battery-type HSC fabricated with NSN@PEDOT:PSS nanocomposite as positrode and activated carbon as negatrode delivers a maximum energy density of 52.1 Wh/kg at a current density of 1.6 A/g with a corresponding power density of 2500 W/kg.