Synthesis and characterization of CoMn2O4 spinel onto flexible stainless-steel mesh for supercapacitor application

CoMn2O4 spinel was synthesized on stainless steel mesh through a hydrothermal process, controlling the reaction time (6 h, 12 h, 18 h, and 24 h). Characterization techniques included XRD, ATR-FTIR, XPS, and SEM-EDS. The 24-h reaction time led to CoMn2O4 spinel with the desired structure, stoichiometry, and good crystallinity. The sample exhibited a tetragonal structure, with Co–O and Mn–O vibrational bands, and manganese (Mn3+) and cobalt (Co2+) metal oxides on the surface. It had a sheet-like shape with an average particle size of 1.92 ± 0.28 μm. Electrochemical tests showed high CV-specific capacitance of 1014.15 F g−1 at 1 mV s−1 and 764.84 F g−1 at 5 mV s−1, aligned with GCD-specific capacitance at 5 A g−1 (724.61 F g−1) and a charge-transfer resistance of 7.71 Ω. The synthesized electrode holds promise for practical energy storage devices, namely for supercapacitor applications.