Hybrid ZnCo₂S₄/Polyindole Electrode for Advanced Supercapacitor: DFT and Raman Mapping-Based Mechanistic Study of...

Energy demand and sustainable development goals are key terms around which materials for future technology are being designed. Here, a core-shell type zinc cobalt sulfide/polyindole (ZCS@PI) composite in a honeycomb structure has been engineered through a two-step electrodeposition process, enhancing charge transfer for fabricating a prototype quasi-solid supercapacitor capable of powering electronic appliances. The ZCS@PI electrode could achieve a specific capacitance of 4700 Fg^-1, with 96% of the charge storage attributed to diffusion-controlled processes. Its high capacitance is attributed to the presence of more electroactive sites, as confirmed by molecular electrostatic potential plots for ZCS and PI. Ex situ Raman spectroelectrochemistry was used to establish the charging/discharging mechanism. Thus, the fabricated prototype device maintained its full energy capacity, exhibiting high capacitance, energy, and power densities, and retained 82% capacitance after 3000 cycles. The device could power LEDs and DC motors, making the design worth on-field use.