Electric Double Layer Capacitors Based on Polyacrylonitrile-derived Porous Carbon Beads: Effects of particle size and composite

Abstract

Two sizes of polyacrylonitrile beads were prepared as precursors of carbon beads by varying the reaction solvent ratio of N,N-dimethylformamide to methanol for dispersion polymerization reaction. The spherical structure of the carbon beads were maintained after carbonization and activation. Charge-discharge tests and AC-impedance analyses revealed that the electric resistance between the particles is low without conducting supplements. In addition, an appropriate pore size brought by the KOH activation of smaller carbon beads lead to a better capacitor performance at high current conditions.