Sponge-like NiCo2S4 nanosheets supported on nickel foam as high-performance electrode materials for asymmetric supercapacitors

Abstract

Herein, binder-free sponge-like NiCo₂S₄ nanosheets supported on Ni foam with ultra-high mass loading were synthesized via a facile one-step hydrothermal route. The unique 3D sponge-like network structure of the obtained NiCo₂S₄ nanosheets is feasible for the fast transport of ions and electrons. The NiCo₂S₄ nanosheet-based electrode could achieve a high area capacity of 11.97 F cm⁻² at 15 mA cm⁻², demonstrating its superior electrochemical performance. Besides, the corresponding asymmetric supercapacitor possesses a maximum area energy density of 0.47 mW h cm⁻² at a power density of 6.59 mW cm⁻² and a great cycle life with 80.1% capacitance retention even after 5000 cycles. The outstanding performances confirm that the obtained sponge-like NiCo₂S₄ nanosheets grown on Ni foam can be a prospective candidate for electrochemical energy storage.