Designing MOF-based carbon and conductive polymer hybrids for high-performance asymmetric supercapacitors

Abstract

Advanced materials with specific conductivity and porosity are essential for high-efficiency energy storage systems. Metal–organic frameworks (MOFs) possess a high surface area and tunable porosity architectures, making them ideal for this application. Integrating MOFs with suitable conductive agents improves their electrical conductivity, creating more channels for rapid charge transfer and overall performance. In this work, we report the development of a ternary composite electrode material composed of zeolitic imidazolate framework (ZIF-67), carbon nanotubes (CNTs), and polyaniline (PAni), synthesized via a simple and scalable combination of stirring and sonication. The resulting ZIF-67/CNT/PAni composite electrode delivered a high specific capacitance of 678 F g⁻¹ at a current density of 1 A g⁻¹, along with outstanding cycling stability, retaining 86% of its initial capacitance after 5000 charge–discharge cycles. Furthermore, an asymmetric supercapacitor (ASC) device assembled using this composite as the positive electrode operated efficiently within a voltage window of 0–1.5 V, achieving a specific capacitance of 109 F g⁻¹ at 1 A g⁻¹. The device exhibited a maximum energy density of 34 Wh kg⁻¹ at a power density of 750 W kg⁻¹, maintaining 88% of its capacitance after 10 000 cycles. These results underscore the synergistic effect of the composite constituents and demonstrate the potential of ZIF-67/CNT/PAni as a high-performance electrode material for next-generation energy storage systems.