Sodium 5-sulfosalicylate-assisted hydrothermal synthesis of a self-supported Co3S4-Ni3S2@nickel foam electrode for all-solid-state asymmetric supercapacitors

Rational design and construction of self-supporting electrodes with high energy exporting densities promise a future of wearable and portable devices. Herein, we demonstrate that, for the first time, a one-pot hydrothermal method for the in-site growth of Co3S4 -Ni3S2 on nickel foam (NF) with the assistance of a chelating agent sodium 5-sulfosalicylate (SSS) (labeled as CS4-Ni3S2@F-SSS) for high-performance super capacitors. Served directly as a self-supporting supercapacitor electrode, CS4-Ni3S2@F-SSS owns a specific capacitance of up to 2825.5 mF cm-2 at a corresponding 2 mA cm(-2) current density and a commendable rate capability of 82% conducted within a current density domain of 2 - 40 mA cm(-2) accompanied by good cyclability. More strikingly, the assembled tow-electrode (CS4-Ni3S2@F-SSS vs. active carbon (AC)@NF) all solid-state asymmetric supercapacitor (ASC) is capable of reaching an energy density of 40.9 Wh kg(-1) at a high power density of 1566.4 W kg(-1) with excellent durability (92.8% retention after 2000 charge-discharge cycles at 8 mA cm(-2)), which are amongst the top of analogous ASCs in peer reports. Additionally, the possible factors that are accountable for the extraordinary supercapacitive performance of CS4-Ni3S2@F-SSS are discussed and analyzed. (C) 2021 Elsevier B.V. All rights reserved.