3D interconnected networks of a ternary hierarchical carbon nanofiber/MnO2/Ni(OH)2 architecture as integrated electrodes for all-solid-state supercapacitors

Abstract

We demonstrate the design and fabrication of hierarchical Ni(OH)₂ nanosheets vertically grown on a porous carbon nanofiber/MnO₂ composite (CF/MnO₂) to form three dimensional interconnected networks via a facile hydrothermal process for supercapacitor applications. The obtained CF/MnO₂/Ni(OH)₂ electrode exhibits high specific capacitance (2079 F g⁻¹ at 0.5 A g⁻¹ in 6 M KOH aqueous solution), rendering its promising application as a potential electrode for supercapacitors. In order to increase the energy density, an asymmetric supercapacitor (ASC) has been successfully fabricated using CF/MnO₂/Ni(OH)₂ as the positive electrode and CFs as the negative electrode. The as-fabricated all-solid-state ASC device achieves a maximum energy density of 67.6 W h kg⁻¹, highly comparable with the previously reported Ni(OH)₂-based ASCs. The present hierarchical CF/MnO₂/Ni(OH)₂ ternary hybrid brings new opportunities to design and develop high-performance electrode materials for next-generation supercapacitors in flexible electronics.