Electrochemical impedance spectroscopy (EIS) is a testing and monitoring technique for
electrochemical systems. For batteries, EIS is used as a diagnostic tool to measure performance
and degradation. Parameters relating to charge-transfer kinetics, mass transport, and
thermodynamics can be obtained from the impedance response over a range of frequencies. My
research aims to further this technique by looking at joint time-frequency analysis of an
impedance-like response about a non-steady periodic condition, e.g. when a battery is charging.
By choosing optimum frequencies, we would be able to explore specific electrochemical
processes of interest. This will be coupled with reformulated impedance models of batteries to
estimate parameters quickly. Ideally, this can be done real-time to provide information about the
degradation of a battery as it is being used. This can have applications for understanding battery
usage patterns and then providing optimal strategies for targets such as extending battery life or
reducing charging time.
Advisor: Venkat Subramanian – Chemical Engineering