Controlled preparation of Ni(OH)2/NiS nanosheet heterostructure as hybrid supercapacitor electrodes for high electrochemical performance

As a battery-type electrode material, Ni(OH)2 has been widely concerned for its ultra-high theoretical specific capacity, however, its poor conductivity and lack of effective active sites hinder its application. It is a great challenge to develop Ni(OH)2 based supercapacitors. It is critical to improve the electrical conductivity and effective active sites to make full use of the energy storage of Ni(OH)2-based materials. Therefore, Ni(OH)2/NiS composites are designed and prepared by controllable low temperature chemical deposition and ion exchange method. Ni(OH)2 nanosheets with various morphology are controllably prepared by low temperature chemical deposition, and then Ni(OH)2/NiS composites are controllably prepared on Ni(OH)2 substrate by ion exchange. Due to the doping of NiS into Ni(OH)2 nanosheets, the conductive network structure is formed, which makes the composite exhibit excellent electrochemical properties, such as high specific capacity, large specific surface area and good electrical conductivity. The as-fabricated Ni(OH)2/NiS indicates an outstanding specific capacity of 240.5 mAh g−1 at 1 A g−1. This paper detailed studies the practical application of hybrid supercapacitors, which may inspire future researchers to design Ni(OH)2-based materials with desired applications.