Design a novel mixed-ligand Ni-MOF/MWCNT nanocomposite to enhance the electrochemical performance of supercapacitors

Abstract

Metal-organic frameworks (MOFs) have garnered considerable interest for supercapacitors as electrode materials. Although MOFs possess large pore sizes and high specific surface areas, most MOFs face major challenges due to their inferior stability and low electronic conductivity. In this study, we synthesized Ni-MOF/MWCNT nanocomposite using a mixed-ligand approach through hydrothermal method to provide more redox reaction sites, facilitate ion diffusion, increase the stability, and electronic conductivity of the electrode. Benzoic acid (BA) has partially replaced Benzene-1,3,5-tricarboxylic acid (BTC). BTC has been used to shape Ni-MOF nanosheets into flower-like microspheres, which can reduce the electron/ion diffusion path. The introduction of BA and combination of MWCNT and Ni-MOF result in high electric conductivity. Furthermore, the combination of two organic ligands, and the synergistic effect of MWCNTs and Ni-based MOFs lead to excellent electrochemical performance. The prepared Ni-MOF/MWCNT nanocomposite shows an outstanding capacitance of 900 F g⁻¹ at 0.5 A g⁻¹ and excellent cycling stability with 82 % capacity etention over 1000 cycles. This study presents an innovative strategy for enhancing energy storage performance.