Enhancement of capacitance retention of ZnCo2S4@Metal organic framework composite electrodes by hydrothermal process

Abstract

Metal organic framework-derived materials are promising electrodes for electrochemical supercapacitors due to their surface area, porosity, and excellent redox behaviors. In the present study the fabrication of ZnCo2S4 and ZnCo2S4@ZIF-67 composites synthesized by solid-state grinding and hydrothermal processing for supercapacitor utilization. Studies using XRD, XPS, FTIR, BET, FE-SEM, and HR-TEM are employed to validate the morphological, surface, and structural characteristics. Highly conductive ZnCo2S4 nanostructured materials are intercalated with MOF surfaces to enhance electron transport. The high number of active sites involved in the rapid electrochemical phase fluctuation using 1 M KOH electrolyte may be the cause of this. ZnCo2S4 and ZnCo2S4@ZIF-67 composites are used to create the working electrode, while a 1 M KOH electrolyte is used for the supercapacitor. By employing a three-electrode design, the created composite electrodes improve cyclic retention with specific capacitances of 245 and 447.14F/g at 1 A/g, respectively. Two electrode configurations are used to build ZnCo2S4@ZIF-67/1M KOH/SSC, which produced results of 151.42F/g at 1 A/g, 85.2 % capacitance retention at 7 A g−1 of 7000 cycles, and 18.93 Wh kg−1 energy density at 642.85 W kg−1 power density. Thus, the fabricated composite electrodes may find application in electrochemical symmetric supercapacitor via two electrode configuration systems. © 2024 Elsevier B.V.