Micro-Spatial Hydrothermal Preparation of Nitrogen-doped Carbon/NiCo₂S₄ Electrode Material for Supercapacitors

Reasonable combination of carbon and pseudocapacitive material in a composite electrode can produce a high-performance supercapacitor. However, the nano-structured pseudocapacitive materials tend to assemble randomly into microscale bulky forms during the preparation of composite electrode materials, which suffer from a low specific surface area and a mechanically weak structure, resulting in poor electrochemical performance. In this article, a nitrogen-doped carbon/NiCo₂S₄ electrode material was prepared by micro-spatial hydrothermal reaction in the multicellular microstructure of auricularia. The micro-space-multicellular microstructure of auricularia can provide a huge and efficient nucleation center of NiCo₂S₄ nanomaterials during the hydrothermal reaction. The morphology of nitrogen-doped carbon/NiCo₂S₄ electrode material can be effectively controlled by changing the amount of metal ions. The stacked NiCo₂S₄ nanoparticles of the NC/NiCo₂S₄-6 electrode material exhibit a network-like structure to a certain extent. The maximum mass specific capacitance of the NC/NiCo₂S₄-6 electrode material is about 1131 F g⁻¹ at a current density of 0.25 A g⁻¹. There is 81.5% retention of its initial capacitance after 10,000 cycles.