Ultrahigh Rate Capability and Lifespan MnCo2 O4 /Ni-MOF Electrode for High Performance Battery-Type Supercapacitor.

MnCo2 O4 is derived from a Co/Mn bimetallic metal-organic framework (MOF). Then Ni-MOF is directly grown on the surface of the obtained MnCo2 O4 to form a nano-flower structure with small balls. A large surface area, abundant active sites of MnCo2 O4 and porosity of Ni-MOF allow the prepared MnCo2 O4 /Ni-MOF composite material to deliver an excellent electrochemical performance. At the same time, an appropriate thermal treatment temperature of the MnCo2 O4 precursor is also very important for controlling the morphology of the obtained MnCo2 O4 and electrochemical performances of the resulted composite material including electric conductivity, specific capacitance and rate performance. The prepared MnCo2 O4 -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 MnCo2 O4 /Ni-MOF has a good application prospect in the market.