Figure 6

(a) Cyclic performance of Co3O4 (0.5–2.5 V at a current density of 62.5 mA/g), Co3O4/RGO (0.5–2.7 V at a current density of 156 mA/g), Co3O4/h-BN (0.5–2.2 V at a current density of 62.5 mA/g) and Co3O4/RGO/h-BN (0.5–2.7 V at a current density of 208 mA/g) for the 1st, 20th, 40th, 60th, 80th and 100th cycle. (b) Cyclic voltammetric curve and (c,d) EIS spectra of Co3O4, Co3O4/RGO, Co3O4/h-BN and Co3O4/RGO/h-BN performed after 100 charge/discharge cycles.