Hierarchically structured nanofelt-like β-NiOOH grown on nickel foam as electrode for high performance pseudocapacitor

In present work, nanofiber-composed felt-like β-NiOOH was successfully synthesized on nickel foam via hydrothermal method. The obtained hierarchical nanostructure guarantees the full contact of material with electrolyte and the intimate connection between material and current collector. For the application in pseudocapacitors, these characteristics ensure the excellent electrochemical performance of electrode material. Firstly, it provides high specific capacitance within the whole range of scan rate (2585–802 F g⁻¹ between 5 and 100 mV s⁻¹) and current density (2404–1240 F g⁻¹ between 1.5 and 30 A g⁻¹). Secondly, it greatly promotes the cycle stability of material by withstanding the strain/stress during redox reactions through its unique nanostructure. After 4000 charge–discharge cycles, the material remains 86 % of initial capacitance. These results suggest that the material is a highly promising candidate for application in supercapacitor.