Ultrahigh Rate Capability and Lifespan MnCo2O4/Ni-MOF Electrode for High Performance Battery-Type Supercapacitor

Graphical Nanoflower structural MnCo 2 O 4 /Ni-MOF composite prepared by in situ growth of Ni-MOF on the surface of MnCo 2 O 4 nanorods derived from Co/Mn-MOF at 600 °C has a high cycling stability and outstanding rate performance as supercapacitor electrode material. MnCo 2 O 4 is derived from a Co/Mn bimetallic metal-organic framework (MOF). Then Ni-MOF is directly grown on the surface of the obtained MnCo 2 O 4 to form a nano-flower structure with small balls. A large surface area, abundant active sites of MnCo 2 O 4 and porosity of Ni-MOF allow the prepared MnCo 2 O 4 /Ni-MOF composite material to deliver an excellent electrochemical performance. At the same time, an appropriate thermal treatment temperature of the MnCo 2 O 4 precursor is also very important for controlling the morphology of the obtained MnCo 2 O 4 and electrochemical performances of the resulted composite material including electric conductivity, specific capacitance and rate performance. The prepared MnCo 2 O 4 -600/Ni-MOF shows an ultrahigh rate performance (when the current density increases from 1 to 10 A g −1 , the capacitance retention rate is as high as 93.41 %) and good cycle stability (the assembled asymmetric supercapacitor advice delivers a capacitance retention rate of 94.74 % after 20 000 charge and discharge cycles) as well as a relatively high specific capacitance. These excellent electrochemical properties indicate that MnCo 2 O 4 /Ni-MOF has a good application prospect in the market.