Zeolite-Templated Carbons as Supercapacitors: The Fundamental Role of Structural and Textural Properties

Abstract

Zeolite-templated carbons (ZTCs) with controlled properties (particle size, porous network, and structural organization) were used as model materials to understand their performance in supercapacitors. At low current rates (0.1 A g^–1), the capacitance in 1 M H₂SO₄ electrolyte is governed by the specific surface area and increases with the S_BET up to ∼2300 m² g^–1 and then decreases for higher S_BET. At a high current density (10 A g^–1), the capacitance retention is affected by several ZTC properties. Higher mesoporous volume and lower C/O and C/H ratios (high O-groups and edge defect sites) lead to the capacitance retention enhancement. Among the long-range ordered ZTCs (FAU, EMT, and beta), beta ZTC shows the highest capacitance retention owing to its highest mesopore volume, which favors electrolyte diffusion. Moreover, the structural organization of ZTC proved to play an important role on the capacitance retention as well. Therefore, disordered materials (FAU-ZTC-anthracene) show higher capacitance (∼140 F g^–1 at 0.1 A g^–1), capacitance retention (67% at 10 A g ^–1), and long-term cycling (87% after 10000 cycles) than ordered materials (FAU-ZTC-ethylene). Overall, this work highlights the importance not only of the specific surface area but also of the pore architecture and organization, particle size, and chemical structure.