Fig. 5. (a) CV curves of Fe–Fe_1−xO based T-CMSC and F-CMSC at 100 mV s⁻¹, (b and c) CV curves of Fe–Fe_1−xO based (b) T-CMSC and (c) F-CMSC, respectively, and (d) corresponding areal capacitance of Fe–Fe_1−xO based T-CMSC and F-CMSC (applied scanning rates: 5–200 mV s⁻¹).