In situ growth MoS₂/NiS composites on Ni foam as electrode materials for supercapacitors

A binder-free MoS₂/NiS composite was in-situ grown on Ni foam using electrochemical deposition and successive ionic layer adsorption and reaction (SILAR) method. Studies were then conducted on the effects of the deposition cycles on the electrochemical performance. Use of Ni foam as a substrate during the preparative process reduced the opportunity for NiS and MoS₂ aggregation at the interface. Also constructing a binder-free electrode can make the ion transfer faster, thus improving the electrochemical performance. In a three-electrode system, the MoS₂/NiS composites delivered an areal specific capacitance of 721.43 mF/cm² at a current density of 1 mA/cm². The capacitance retention of MoS₂/NiS composites was up to 91.3% after 1000 cycles, displaying good stability. Moreover, aqueous symmetric supercapacitor system based on MoS₂/NiS composites was also tested, and it displayed areal specific capacitance of 216 mF/cm² with a maximum energy density of 30 µWh/cm² and a maximum power density of 3500 µW/cm² at 3 mA/cm². These results demonstrate that MoS₂/NiS electrodes have broad application prospects as energy storage electrode materials.