A new approach for the improved interpretation of capacitance measurements for materials utilised in energy storage

Abstract

A simple galvanostatic circuit methodology is reported allowing the capacitance of an electrochemical electrolytic capacitor to be accurately measured, without recourse to expensive instrumentation. The method avoids problems found in current electrochemical impedance spectroscopy analysis, which give rise to profiles that may result in false or inaccurate derivation of the electrolytic capacitance. The advantages of this approach are that the circuit is easy and cheap to fabricate. The system is linear, regardless of the texture of the electrode and the type of electrolyte, and the measurement is direct so that no presumable equivalent circuit model is required. Such work is highly important for those developing new materials in energy storage, as it allows the reliable measurement of capacitance to be achieved without the need for expensive or complex instrumentation. This paper also highlights that users are more informed through checking capacitances using a variety of techniques, though such a circuit could in theory eliminate the need for affirmation of values utilising other electrochemical methods/techniques.