Hierarchical mesoporous Mn2O3/NiO/Co3O4 nanocubes derived from Prussian blue analogues for high performance asymmetric supercapacitors†

Abstract

In this paper, hierarchical Mn₂O₃/NiO/Co₃O₄ (denoted as MNC) composite nanocubes composed of small nanoparticles were obtained by calcinating a Prussian blue analogue (PBA) nanocube precursor. The effects of heating temperature and phase composition on the electrochemical performance were systematically studied. The results showed that the MNC-400 electrode reached a high capacity of 264.8 F g⁻¹ at 1 A g⁻¹ with a good capacitance retention of 82.1% (5000 cycles). The asymmetric supercapacitor (ASC) constructed with the MNC-400 electrode and activated carbon (AC) can provide a high energy density of 33.8 W h kg⁻¹ at a power density of 780.0 W kg⁻¹ and an excellent cycling stability of 86.4% after 5000 cycles.