Supercapacitive performance of a PEDOT⊃metal–porphyrin framework composite in a concentrated aqueous LiClO4 electrolyte

Abstract

Lanthanide-based metal–porphyrin framework-poly(3,4-ethylenedioxythiophene) (Ln-MPF-PEDOT) materials are largely underexplored for use in supercapacitor applications in concentrated aqueous electrolytes. In this study, we report the successful synthesis of a new three-dimensional neodymium–porphyrin MOF (Nd-MPF), followed by the in situ oxidative polymerization of PEDOT within its porous channels. The Nd-MPF exhibits excellent structural stability, retaining its crystallinity and framework integrity throughout the polymerization process. Symmetric PEDOT⊃Nd-MPF electrodes demonstrate a wide electrochemical stability window of 1.6 V in concentrated aqueous LiClO₄ electrolyte and deliver a high specific capacitance of 166 mF cm⁻². The energy and power densities of the PEDOT⊃Nd-MPF electrode are as high as 29 µWh cm⁻² and 13 mW cm⁻², respectively. Finally, our material retains over 75% of its capacitance after 10 000 continuous galvanostatic charge–discharge cycles, highlighting the potential of PEDOT⊃Nd-MPF as a high-performance supercapacitor electrode material.