• Hollenkamp, Anthony
• Huynh, Thuy

Abstract

Through the interpretation of porosity and intrusion data, and correlation to the electrochemical response in a non-aqueous electrolyte, this study has confirmed that not only are carbon blacks very effective in improving the electrical connectivity of a carbon electrode coating, but they also significantly modify the porosity of the electrode coating and thereby also influence ionic diffusion.Carbon blacks are more effective conductive fillers than graphites in EDLC electrodes.The highly branched structure of carbon blacks allows multiple electrical contact points which results in a lower electrode electronic resistance.The presence of carbon black can decrease inter-particle porosity (both volume and size) and introduce additional porosity that is characteristic of the type of carbon employed. It is observed that electrode coatings prepared from a carbon slurry have a highly macroporous structure and that electrolyte accessibility to individual activated carbon particles is unlikely to be the limiting factor to accessing capacitance.Electrochemical testing has confirmed the strong relationship between bulk electrode resistance and the accessibility of capacitance at different rates.

Topics

• impedance spectroscopy
• Carbon
• void
• porosity