One-Pot Hydrothermal-Derived NiS2-CoMo2S4 with Vertically Aligned Nanorods as a Binder-Free Electrode for Coin-Cell-Type Hybrid Supercapacitor

Transition bimetallic sulfides are exploited as high-capacity electrode materials in energy storage devices owing to their abundant electroactive sites and relatively high electrical conductivity compared with metal oxides. Here, an in situ conversion of metal ions into NiS2-CoMo2S4 vertically aligned nanorod arrays on nickel foam (NS-CMS NRAs@NF) using a one-step hydrothermal technique to address the dead-mass limitation and multi-step preparation methods is reported. An in situ-converted NS-CMS NRAs obtained for 12 h of reaction time (NS-CMS NRAs-12 h@NF) delivers a superior areal capacity of 780 mu Ah cm(-2) to the other NS-CMS electrodes synthesized for 6 h (543.1 mu Ah cm(-2)) and 18 h (636.7 mu Ah cm(-2)) at 7 mA cm(-2). A coin-cell-type hybrid supercapacitor (HSC) is also fabricated to unveil the practical adaptability of NS-CMS NRAs-12 h@NF electrode. Utilizing its structural and active material intriguing features, assembled coin-cell-type HSC achieves a high areal capacitance of 246.2 mF cm(-2 )(5 mA cm(-2)) along with maximum areal energy density (147 mu Wh cm(-2)) and power density (21.3 mW cm(-2)), respectively. Furthermore, the capability of coin-cell-type HSC in real-time applications is also inspected. This work promotes in situ deposition strategy to fabricate metal sulfide-based nanostructures for high-performance electrochemical capacitors.

Automated summary

By converting metal ions using a one-step hydrothermal technique, vertically aligned nanorod arrays of nickel sulfide-cobalt molybdenum sulfide on nickel foam were synthesized, showing high capacitance in energy storage applications. The coin-cell-type hybrid supercapacitor with the NS-CMS NRAs-12 h@NF electrode achieved a high areal capacitance, energy density, and power density, demonstrating the potential of in situ deposition strategy for high-performance electrochemical capacitors.