A soft approach towards composite porous carbon/conducting polymer supercapacitors: layer-by-layer integration of pyrolyzed ZIF-8 MOF and PANI-PSS supramolecular complexes

Abstract

Amid the global energy crisis, the search for safe, sustainable, and high-performance energy storage is urgent. Supercapacitors—renowned for their exceptional power density and cycling stability—offer a compelling path forward, especially when engineered with eco-friendly materials and neutral-pH aqueous electrolytes. In this work, we present a simple yet powerful layer-by-layer (LbL) strategy to fabricate supercapacitor electrodes by integrating porous carbon from pyrolyzed ZIF-8 (PCZIF-8) with a polyaniline–polystyrene sulfonate (PANI-PSS) complex. The resulting films were probed via cyclic voltammetry and electrochemical quartz crystal microbalance (eQCM) to unravel their charge-storage dynamics, while galvanostatic cycling tested their long-term resilience. The composite film exhibits specific capacitances of 225 F g−1 in 0.1 M HCl and 160 F g−1 in 0.1 M KCl for 1 A g−1 charge–discharge galvanostatic curves. The specific capacitance increased by more than 1000% when a porous carbon was used instead of a non-porous one. The inclusion of PCZIF-8 delivered a substantial performance leap under mild, environmentally benign conditions—all using low-cost, readily synthesized components. This synergy between conductive polymers and porous carbons from MOFs opens a sustainable and scalable route to next-generation energy storage.