Tailored Mesoporous Carbons for High-Stability Supercapacitors with Optimized Ion Transport

Abstract

Mesoporous carbons with hierarchical porous architectures were synthesized via the carbonization of resorcinol-formaldehyde resins using mesoporous silica templates of varying pore sizes as templates. The resulting carbon materials were extensively characterized to correlate their physicochemical properties with their electrochemical behavior as electrode materials for supercapacitors. Electrochemical performance was evaluated in both aqueous and organic electrolytes using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a three-electrode configuration. In addition, cycling stability using GDC was studied in two electrode cells, showing extremely high capacitance retention, especially in aqueous solution (99% after 20000 galvanostatic charge-discharge cycles). The results demonstrated that, although a high specific surface area contributes positively to charge storage, capacitance is strongly governed by the accessibility of electroactive sites, which in turn is influenced by pore size distribution, connectivity, and electrolyte ion dimensions. The synthesized mesoporous carbons show promise as electrode materials for supercapacitors, particularly for pseudocapacitive applications due to their relatively slow charge-discharge characteristics and high stability. This work underscores the critical role of mesostructure tuning in optimizing ion transport and charge storage dynamics, highlighting the potential of templated mesoporous carbons for high-performance electrochemical energy storage systems.