(Invited) Factors Affecting Electrochemical Capacitor Performance

Abstract

Electrochemical capacitors are an emerging technology suited for high power pulse applications. The performance of these devices is dependent on their composite materials, including the electroactive materials, conductive additives and electrolyte, as well as the electrode substrates and separators, as well as cell engineering, which includes factors such as anode-to-cathode ratio and the amount of conductor added to each electrode. The combination of each of these factors leads to the overall performance of the device. Many electrochemical methods have been used to explore the behaviour of electrochemical capacitors, with techniques such as cyclic voltammetry and galvanostatic charge-discharge cycling providing information on material performance. Other methods such as electrochemical impedance spectroscopy and potential floating measurements have also been used to provide performance, conductivity and stability information. We have also contributed to the development of electrochemical methods with the application of step potential electrochemical spectroscopy (SPECS) to a variety of electrochemical capacitor systems. Here we will present a range of outcomes arising from the application of SPECS to explore the effects of electrolyte, charge storage mechanism, and conductivity on elctrochemical capacitor performance.