Fullerene Assisted Modification of Zeolitic Imidazolate Framework-8 for Electrochemical Energy Storage

The growing demand for high-performance energy storage systems necessitates the development of advanced electrode materials with superior capacitance, stability, and conductivity. However, conventional metal-organic frameworks (MOFs) like zeolitic imidazolate framework-8 (ZIF-8) suffer from poor electrical conductivity and structural instability, limiting their practical applications. To address this challenge, a series of electrode was developed through modification of ZIF-8 with varying concentrations (%, w/w) of fullerene (C60) ranging 2 to 12 in sulfone polymer as binder. ZIF-8 and C60 were characterized and identified via Fourier transformed infrared spectra and powder X-ray diffraction techniques. Electrodes were exemplified through diversified field emission electron microscopy (FESEM), electrical and electrochemical methods. Electrodes exhibiting the highest electrical conductivity was identified and explored further for electrochemical applications. Cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and DC polarization of electrodes have been investigated in KOH (1.0M) with reference to Ag/AgCl. The CV curves reveal a specific capacitance (Cs) of 494 F/g at 1 mV/s for C60 (10%) modified ZIF-8 electrode in the potential span of –1.4 to –0.3 V. Over 1000 cycles, these electrodes show 97% retention in specific capacitance, demonstrating excellent cyclic stability. EIS measurements with potentiodynamic polarization show high electrochemical stability with corrosion rate of 0.04 mm/yr and high inhibition efficiency of 94.61. Morphological analysis confirmed that incorporating C60 into the ZIF-8 electrode significantly reduces its tendency for delamination. These results highlight the significant potential of fullerene-assisted ZIF-8 modification in enhancing the electrical conductivity, specific capacitance, and long-term stability of electrode materials. The study underscores the viability of this nanocomposite for next-generation electrochemical energy storage systems, particularly in sustainable energy applications.