Surface Modification of Carbon Electrode for Electric Double Layer Capacitor

In this research, spatio-temporal profiles of positive and negative charges in an electric double layer capacitor (EDLC) which consists of activated carbon, treated by plasma discharges were measured. The plasma type was a high frequency glow discharge and the sample of activated carbon is set in the center of glow discharge. Optimal conditions for plasma surface treatment of activated carbon was examined from 0 to 60 min at 150 degrees C in nitrogen gas. As a result, nitrogen atom was doped onto the surface layer of the activated carbon. In addition, electron spectroscopy for chemical analysis (ESCA) spectra of nitrogen in the activated carbon was examined. By etching the surface layer of carbon electrode exposed to the plasma, the doped nitrogen atom penetrated about 3 nm of the surface layer of carbon electrode after 60 min of plasma surface treatment.