Morphology-dependent metal-organic frameworks via solvent and Co ion effect for high performance battery-supercapacitor hybrid device

Abstract

MOFs have been widely recognized in battery-supercapacitor hybrid devices. Here, the electrochemical performance of Ni MOF as a battery-type material was primarily improved by morphological engineering based on solvent and Co ions. Varying the solvent type, solvent ratio, and Ni/Co ratio, NiCo(1:0.5)MOF HO showed the largest specific capacitance of 1225.56 F g (specific capacity of 551.50 C g) at 0.5 A g, owing to its largest specific surface and good redox activity caused by the difference in the solvent solubility, solvent polarity and coordination ability of metal ions. Furthermore, a solid-state battery-supercapacitor hybrid device was assembled, serving NiCo(1:0.5)MOF HO and active carbon material obtained from bamboo as the positive and negative electrodes, separately. At a power density of 750.00 W kg, this device emerged with a large energy density of 108.96 Wh kg. After 5000 cycles, it can maintain 89.09 % of the initial value. Notably, this device could furnish energy for the LED emitting, reflecting a giant application potential.