Facile synthesis of mesoporous NiO nanoflakes on graphene foam and its electrochemical properties for supercapacitor application

Many NiO platelets were formed on Ni foam after hydrothermal process, while flower-like NiO with many small mesoporous nanoflakes was obtained on the surface of graphene foam. Electrochemical results showed that the NiO/graphene composites exhibited very high specific capacitance 1062 F g⁻¹ at 1 A g⁻¹ and excellent cycling stability (90.6% capacitance retention after 5000 cycles at 1 A g⁻¹). The promising NiO/graphene composites exhibited higher supercapacitor performance than NiO platelets on Ni foam. The excellent supercapacitor performance of the former should be attributed to the 3D graphene conductive network and the mesoporous NiO nanoflakes which promoted efficient charge transport and electrolyte diffusion.