Analytical solution for the voltage distribution in one-dimensional porous electrode subjected to cyclic voltammetric (CV) conditions

An analytical solution for the voltage distribution in one-dimensional porous electrode subjected to cyclic voltammetric (CV) conditions was developed by considering the resistivity of both electrode and electrolyte. Voltage distribution inside the electrode as a function of dimensionless distance was generated at different electrode phase resistances. The analytical solution of voltage distribution for cyclic voltammetric conditions was employed in deriving the charging currents. Capacitance studies were conducted on carbons derived from catechol-formaldehyde gels prepared at pH conditions of 3, 6, and 7.5 in 30 wt.% H₂SO₄ electrolyte using CV and constant current charge/discharge studies. Charging currents derived from voltage distribution were fitted with experimental anodic part of CV curves and equivalent series resistance (ESR) was generated. Thus, generated ESR values were compared with that obtained using constant current charge-discharge curves. The model fitted resistance values matched closely with resistance values obtained from galvanostatic constant current charge-discharge method.