Fabrication of the porous MnCo2O4 nanorod arrays on Ni foam as an advanced electrode for asymmetric supercapacitors

Abstract In this work, the porous MnCo2O4 nanorod arrays on three-dimensional Ni foam (PMCN@NF) as electrode material have been fabricated through a mild co-precipitating reaction at room temperature followed by a subsequent thermal treatment. The PMCN@NF electrode material have been characterized by XRD, SEM, TEM, EDS-mapping, BET and XPS technologies. The capacitive performances of the PMCN@NF electrode have been investigated by CV, GCD and EIS. This porous structure possesses an average diameter of ∼6.7 nm. BET interface area is measured to be 105.6 m2 g−1 for this PMCN@NF electrode. This PMCN@NF electrode exhibits the good capacitance of 845.6 F g−1 (tested condition: 1 ampere per gram, 1 A g−1). After 2000 cycles test, it shows a 90.2% retention for specific capacitance of the first test. The MnCo2O4//rGO asymmetric supercapacitor with the stable opening voltage of 1.6 V delivers a maximum energy density of 53.7 Wh kg−1 (when the power density is 1600 W kg−1). When this power density up to 8000 W kg−1, it still achieves an energy density of 31.6 Wh kg−1. The cyclic stability of this device after 5000 cycles can achieve an initial capacitance retention of 82.0%. These results indicate that the porous MnCo2O4 nanorod arrays electrode material is a promising functional material for advanced energy conversion and storage equipment.