Controlled synthesis of NiCo₂S₄ nanostructures on nickel foams for high-performance supercapacitors

A rational synthesis strategy is developed to fabricate hierarchical NiCo₂S₄ nanostructures with controllable mass loadings on Ni foams. The three-dimensional nanoarchitecture ensures good mechanical and electrical connections to increase the ion diffusion and charge transport rate as well as the robust stiffness of the electrode. When used as electrodes for supercapacitors, the novel electrode exhibits outstanding energy storage performance. The specific capacitance is closely associated with the mass loading of the NiCo₂S₄ nanostructures, which manifest 1739 F g^-1 at 1 A g^-1 along with a maximum areal capacitance of 4.0 F cm^-2, high-rate retention of 85.2% at 30 A g^-1 and good cycling stability at an optimal mass loading of 2.3 mg cm^-2. The electrochemical results demonstrate that our NiCo₂S₄ nanostructures are promising electrode materials for high-performance supercapacitor applications.