Synthesis of NiCo2S4-based nanostructured electrodes supported on nickel foams with superior electrochemical performance

NiCo₂S₄-based nanostructured films have been grown directly onto nickel foams by a facile two-step method, involving the growth of NiCo-precursor and subsequent conversion into NiCo₂S₄ via a sulfidation process, with the aid of sodium dodecyl surfactant (SDS). This synthesis method enables the fabrication of binder- and conductive additive-free electrodes for supercapacitors. The influence of the surfactant on the crystal structure, morphology, and electrochemical performance of the electrodes has been investigated. The NiCo₂S₄-SDS films exhibit a complex cellular and hierarchical porous structure, which are different from NiCo₂S₄-pure films with nanotube arrays structure. Moreover, the electrochemical tests show that the NiCo₂S₄-SDS nanostructured electrode exhibits an ultrahigh specific capacitance of 2519 F g⁻¹ at 0.5 A g⁻¹, which doubles that of the NiCo₂S₄-pure nanotube arrays electrode. In addition, the NiCo₂S₄-SDS electrode exhibits excellent cycling stability with 90.7 % capacitance retention at 10 A g⁻¹ after 8000 cycles. In view of the low cost and superior electrochemical performance, the NiCo₂S₄-SDS electrodes are promising electrode materials for high-performance supercapacitors.