Here, we developed a new approach to synthesize NiCo₂S₄ thin films for supercapacitor application using the successive ionic layer adsorption and reaction (SILAR) method on Ni mesh with different molar ratios of Ni and Co precursors. The five different NiCo₂S₄ electrodes affect the electrochemical performance of the supercapacitor. The NiCo₂S₄ thin films demonstrate superior supercapacitance performance with a significantly higher specific capacitance of 1427 F g⁻¹ at a scan rate of 20 mV s⁻¹. These results indicate that ternary NiCo₂S₄ thin films are more effective electrodes compared to binary metal oxides and metal sulfides.

Supercapacitors have garnered substantial interest owing to their capacity to deliver power effectively for short-term applications. However, current supercapacitors suffer from limited stability and low-capacity storage. Metal-organic frameworks (MOFs) have emerged as a promising solution due to their high surface area and abundant active redox sites. MOF-based electrodes combined with aqueous based electrolytes have shown potential to enhance supercapacitor performance. While there is limited literature on MIL-101(Fe) MOF-based electrodes, a comparative study was conducted to investigate the supercapacitor performance of MIL-101(Fe) electrodes synthesized using hydrothermal and microwave-assisted processes. Processing parameters, such as the method used, alter the microstructure, morphology, and uniformity of supramolecular chemistry, impacting electrochemical characteristics. This study aimed to determine the active redox reactions, chemical stability, surface area, adsorption characteristics, and electrochemical characteristics of the electrodes. The electrodes from hydrothermal synthesis [MF(ht)] exhibited excellent electrochemical activity in comparison to the microwave-assisted [MF(m)] electrodes in the three-electrode configuration. At a high current density of 7 A/g, the MF(ht) electrode displayed a remarkable specific capacitance of 775.6 F/g and a good cyclic stability (82% @ 10 A/g) after 5000 galvanostatic charge–discharge cycles. At a current density of 1 A/g, the two-electrode configuration of MF(ht) yielded a high energy density of 74.7 Wh/kg at a power density of 2160 W/kg and a decent cyclic stability after 5000 cycles. The results suggest that the MF(ht) electrodes possess remarkable electrochemical properties that make them a promising candidate for advanced applications in energy storage.