Fig. 8

GCD curves of (a) NiO, (b) Mn₃O₄, and (c) NiO–Mn₃O₄ nanocomposite in various current density, (d) comparative GCD curve of three electrodes in current density 1 A g⁻¹, (e) cycling stability of electrodes, (f) Nyquist plots of the electrodes (The inset shows the equivalent circuit and a close-up view of the high-frequency region).