Step Potential Electrochemical Spectroscopy (SPECS) As a Means of Examining the Behaviour of Electrochemical Systems

Abstract

Electrochemical energy storage and conversion devices play a substantial and growing role in society. The study of these systems has likewise continued to grow with significant efforst ongoing globally to develope new and improved materials and systems for consumer use. The basis of a significant proportion of this effort are fundamental material characteristics, as evaluated using a suite of physico-chemical and electrochemical characterization methods. Electrochemically, characterization of such systems is typically based on techniques such as cyclic voltammetry and galvanostatic charge and discharge which provide a solid foundation for material and device performance evaluation. Of course the application of these methods to controlled electrodes allows for the initial characterization of electrochemical behaviour. Electrochemical impedance spectroscopy also plays a role in material and system characterization, albeit under very specific conditions. Here we report on the application of an intermittent discharge and charge methodology, step potential electrochemical spectroscopy (SPECS), in particular its application to separating charge storage mechanisms in electrochemical systems, as well as its combination with additional electrodes and electrochemical techniques to elucidate behaviour.