Controllable preparation and capacitance performance of bimetal Co/Ni-MOF

In this paper, bimetal Co/Ni organic framework material (Co/Ni-MOF) is prepared by one-step solvothermal method. By adjusting the concentration of the inserted metal Ni, the electrochemical performance of bimetal MOF is controlled. As cobalt to nickel ratio is 1:2, its largest specific capacitance value is 2608 F g−1 at 1 A g−1 and it remains 88% after 5000 charging-discharging cycles. As well as its ion transfer time is the shortest among those of the other bimetal MOF. After assembled into supercapacitors with biochar, it delivers an energy density of 47.3 Wh kg−1 at 780 W kg−1 and 85% of its initial specific capacitance is obtained after 5000 cycles. These results confirm its potential application as electrode material of supercapacitor devices.