Figure 12.

FESEM images of flower-like NiCo₂O₄ (a and b) and hierarchical mesoporous structured NiCo₂O₄ (c and d); electrochemical performance of hierarchical mesoporous NiCo₂O₄ electrodes. (e) CV curves at scan rates of 1.0, 2.0, 5.0 and 10.0 mV·s⁻¹, respectively; (f) GCD curves at various current densities; (g) Effects of current density on its specific capacitance; (h) Cycling performance over 1000 cycles at a current density of 6.0 A·g⁻¹. The inset shows the GCD curve at a current density of 6.0 A·g⁻¹ [72].