Boosting capacitive performance of electrode material by facile incorporation of phthalic acid ligand-based bimetallic MOF for supercapacitors

The bimetallic approach can offer a synergistic effect and energy-efficient metal-organic frameworks (MOFs) based electrode materials for electrochemical applications. The interconnected frameworks convert themselves into a two-dimensional conducting stacked structure with the favorable entity of metal ions bonded to metal-ligand covalence. This network prioritizes charge transport within the plane, minimizing the importance of out-plane transport. To achieve this, we propose a straightforward and efficient method for integrating Ni2+ and Co2+ metal ions with 1, 2-benzene dicarboxylic acid (phthalic acid) ligands. By employing this strategy, we can fabricate a bimetallic metal-organic framework electrode using a simple aromatic ligand, thus avoiding the complex synthesis typically associated with MOFs. This specially designed MOF electrode material enhances the electrochemical activities of the selected ligands. The presence of redox-active centers and conductive structure provides excellent behavior of the material with a high performance of 1755 Fg−1 (754.82 Cg−1) at 2 Ag−1. Also, the fabricated asymmetric device delivers (58.25 Whkg−1 energy density and 1299.90 Wkg−1 power density) with only a 9 % reduction in capacitance over 22 K cycles. The strategic design of a bimetallic Ni-Co-based metal-organic framework with bidentate ligand offers the potential to increase the electrochemical activities relative to single metallic MOFs.