Evaluation of the State of Charge of Battery Electrodes with AC Impedance Techniques.

摘要

The main objective of this project was to study the correlations between the state of charge (SOC) of battery electrodes and the frequency dispersion of their impedance. Zinc and silver electrodes were investigated in smooth and porous configurations, under conditions similar to conventional battery applications. The emphasis was on the evolution of random morphologies of a composite dielectric as function of the SOC and the ability of impedance measurements to quantify these changes. We seek theoretical and experimental tools that will help quantify the random morphologies and correlate them with the interfacial chemistry and wish to determine whether phase transitions in transport properties take place during the charge/discharge cycles and how best they can be categorized to provide predictive power for the transport properties in these systems. Keywords: Electrochemical energy storage; Electrical equipment; State of charge; Battery electrodes; Alternating current impedance techniques; Zinc electrodes; Silver electrodes; Organic polymers. (jg)