Superior energy storage performance of MOF/PANI nanocomposites: toward sustainable supercapacitors

Abstract

The urgent demand for sustainable energy storage has driven the development of devices that combine high energy density with excellent power delivery. Supercapacitors, regarded as hybrid energy storage systems with characteristics of both batteries and capacitors, have emerged as attractive candidates for next-generation applications. The key challenge is to design electrode materials that exhibit high capacity, energy density, and durability. In this study, we report a metal–organic framework/polyaniline (MOF/PANI) nanocomposite electrode, engineered to overcome the poor conductivity of MOFs while leveraging their high surface area and porosity. The incorporation of conductive PANI enhances charge transport and structural integrity, enabling superior electrochemical performance. The MOF/PANI electrode achieves a specific capacity of 525.68 C g⁻¹ at 2 A g⁻¹, with 95.3% capacity retention after 4000 cycles. An asymmetric supercapacitor device fabricated from the nanocomposite delivers a specific capacity of 401.44 C g⁻¹ at 0.5 A g⁻¹ current density, along with an energy density of 72.48 Wh kg⁻¹ at a power density of 1299.99 W kg⁻¹. Notably, the device maintains 96% capacity retention over 50k cycles, reflecting outstanding durability. These results highlight the MOF/PANI nanocomposite as a high-performance electrode material, demonstrating significant potential for sustainable supercapacitor applications that bridge the gap between batteries and supercapacitors.