Anomalous Increase in Carbon Capacitance at Pore Sizes Less Than 1 Nanometer

Abstract

Carbon supercapacitors, which are energy storage devices that use ion adsorption on the surface of highly porous materials to store charge, have numerous advantages over other power-source technologies, but could realize further gains if their electrodes were properly optimized. Studying the effect of the pore size on capacitance could potentially improve performance by maximizing the electrode surface area accessible to electrolyte ions, but until recently, no studies had addressed the lower size limit of accessible pores. Using carbide-derived carbon, we generated pores with average sizes from 0.6 to 2.25 nanometer and studied double-layer capacitance in an organic electrolyte. The results challenge the long-held axiom that pores smaller than the size of solvated electrolyte ions are incapable of contributing to charge storage.

Keywords

Affiliated Institutions

• Centre National de la Recherche Scientifique FR
• Université Toulouse III - Paul Sabatier FR
• Drexel University US
• Centre Interuniversitaire de Recherche et d’Ingénierie des Matériaux FR

Related Publications