Application of step potential electrochemical spectroscopy in pouch cell prototype capacitors

Abstract

Herein we demonstrate the application of the step potential electrochemical spectroscopy (SPECS) technique to evaluate the electrochemical behaviour of large prototype capacitor devices for the first time. SPECS is generally applied for deconvoluting different charge storage mechanisms such as capacitive and diffusional processes. This study showed the effectiveness of SPECS technique to characterise the electrochemical performance of prototype pouch cell and to obtain invaluable information, including instability of the cell such as leakage current, degradation of the electrochemical cell, and a shortage of electrolyte species at highest potentials. This study also showed that the behaviour of capacitive and diffusional processes throughout different sweep rates is the same regardless of cell footprint and capacitance.