Nanoarchitectonics of metal-organic frameworks on nickel‑cobalt hydroxides hollow prisms for supercapacitors

Metal-organic frameworks (MOFs) are of interest because of their high specific surface area and multifunctional structure. MOFs prepared by nanoarchitectonics approaches have demonstrated excellent performance in supercapacitors. This study reports the synthesis of uniformly sized NiCo hydroxide prisms by precipitation, followed by the synthesis of NiCo-hydroxide@Ni-MOF hollow prisms at room temperature (25 °C), which are assembled by vertically aligned Ni-MOF nanosheets. The hollow structure inhibited the agglomeration of Ni-MOF nanosheets and exposed more active sites, which accelerated electrolyte ion diffusion. The obtained sample (NiCo-hydroxide@Ni-MOF) exhibited good electrochemical properties, with a specific capacitance of 1610 F g−1 at 1 A g−1. The asymmetric supercapacitor (ASC) fabricated using the NiCo-hydroxide@Ni-MOF hollow prisms as a cathode had an energy density of 49.4 W h kg−1 at a power density of 825 W kg−1. The ASC exhibited a cycling stability of 84 % after 5000 cycles. This study provides a facile synthetic method for hollow structure assembled with MOF nanosheets for application in supercapacitors. •Room-temperature synthesis of NiCo-hydroxide@Ni-MOF hollow prisms.•NiCo-hydroxide@Ni-MOF had good electrochemical properties (1610 F g−1 at 1 A g−1).•NiCo-hydroxide@Ni-MOF-based asymmetric supercapacitor (ASC) is a suitable cathode.•ASC had an energy density of 49.4 Wh kg−1 at a power density of 825 W kg−1.•ASC exhibited a cycling stability of 84 % after 5000 cycles.