Intercalated reduced graphene oxide and its content effect on the supercapacitance performance of the three dimensional flower-like β-Ni(OH)2 architecture

Abstract

Anchoring of three dimensional (3D) metal oxides with a controlled morphology on a reduced graphene sheet (rGO) is a promising and challenging route towards the development of highly efficient electrode materials for supercapacitor applications. Herein, we have designed an interconnected 3D flower-like β-Ni(OH)₂@rGO (3D-FL-NiH@rGO) architecture and studied the effect of rGO on the morphology as well as supercapacitive performance of 3D-FL-NiH in detail. By varying the experimental parameters, the optimized 3D-FL-NiH@rGO composite achieved the highest capacitance of ∼1710 F g⁻¹ at a current load of 2 A g⁻¹ and also exhibited outstanding cycling performance as compared to the bare 3D-FL-NiH. Further investigation revealed that the improved capacitance of 3D-FL-NiH@rGO is due to the unique 3D and flower like architecture of 3D-FL-NiH which provides a high surface area (124.21 m² g⁻¹) and more optimal mesoporous size (∼8–15 nm) as compared to the corresponding value of 72.9 m² g⁻¹ and microporous size of the bare 3D-FL-NiH. The presence of rGO and 3D-FL of the β-NiH provided strain relaxation during the charge–discharge procedures, which enhanced the electrical conductivity of the electrode and hence improved the cycling performance of 3D-FL-NiH@rGO.