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 beta-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 similar to 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 m(2) g(-1)) and more optimal mesoporous size (similar to 8-15 nm) as compared to the corresponding value of 72.9 m(2) g(-1) and microporous size of the bare 3D-FL-NiH. The presence of rGO and 3D-FL of the beta-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.