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.