Ni/Co bimetallic flower-like metal-organic frameworks with enhanced performance for high-power energy storage applications

Metal-organic frameworks (MOFs) are promising materials for supercapacitors due to their surface area and tunable pore size. Pristine monometallic MOFs suffer from low conductivity. In this work, bimetallic Ni-rich/Co-MOFs were synthesized via a one-step solvothermal method. Various Ni2+ and Co2+ stoichiometric ratios were considered and their impact on MOF structure and electrochemical performance was evaluated. It was found that Co2+ substitution in the initial Ni-MOF structure enhanced the electrochemical properties, providing a specific capacitance of 1303 F g-1 (145 mAh g-1) at 1 A g-1, almost double than the monometallic Ni-MOF. An optimum stoichiometric ratio of (2)Ni:(1)Co was obtained.