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

Abstract

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.