Probing the degradation of carbon black electrodes in the presence of chloride by electrochemical impedance spectroscopy

The influence of the presence of chloride ions (Cl−) on the electrochemical stability of a porous carbon black electrode was examined. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), we have observed that the durability of this porous carbon layer, similar to those used in fuel cells and supercapacitors, is altered in the presence of chloride. The presence of as little as 1 mM chloride leads to a substantial reduction in electrode capacitance and an increase in the total resistance of the porous layer, which will impact performance in electrochemical energy applications. The effect is more pronounced at higher chloride concentrations.