Figure 5

(a) CV curves for the optimized NiCo₂S₄ composite thin films for various Ni and Co ratios (NCS:25) at scan rate from 20 to 100 mV s⁻¹ with a 5 M KOH electrolyte, (b) Specific capacitance of NCS:30, NCS:25, and NCS:20 composite thin films, (c) Charge-discharge curves for NCS:30, NCS:25, and NCS:20 at 10 mA cm⁻² current density in 5 M KOH with −0.4 to 0.6 V potential window, (d) Specific capacitance for NCS:40, NCS:30, NCS:25, NCS:20 and NCS:10 electrodes, (e) Charge-discharge curves for NCS:25 at 1–10 mA cm⁻² current densities in a 5 M KOH electrolyte, (f) specific capacitance of NCS:25 electrode at various current densities from 1–10 mA cm⁻².