Multi-Sine EIS for Early Detection of PEMFC Failure Modes

Abstract

Electrochemical impedance spectroscopy (EIS) is a powerful technique that can be used to detect small changes in electrochemical systems and subsequently identify the source of the change. While promising, analysis is often non-intuitive and time-consuming, where collection times of a single EIS spectrum can reach several minutes. To circumvent the long collection times associated with traditional EIS measurements, a multi-sine EIS technique was proposed in which the simultaneous application of many frequencies can reduce the acquisition time to less than a minute. This shortened acquisition time opens the possibility to use multi-sine EIS as a real-time diagnostic tool for monitoring the state-of-health of commercial fuel cell systems. In this work, a single-cell proton exchange membrane fuel cell (PEMFC) was characterised using multi-sine EIS, by establishing steady-state impedance response under baseline conditions before systematically changing operating conditions and monitoring the dynamic changes of the impedance response. Our initial results demonstrate that full multi-sine EIS spectra, encompassing a frequency range from 50 kHz to 0.5 Hz, can be collected and analysed using simple equivalent circuit models in 50 s. It is shown that this timeframe is sufficiently short to capture the dynamic response of the fuel cell in response to changing operating conditions, thereby validating the use of multi-sine EIS as a diagnostic technique for in-situ monitoring and fault detection during fuel cell operation.

Early Warning for the Electrolyzer: Monitoring CO2 Reduction via In‐Line Electrochemical Impedance Spectroscopy

“…To avoid the typical delay associated with gathering EIS spectra (> 15 min), this approach employs a multi-sine EIS wherein multiple frequencies are applied to the cell simultaneously. [35,36] The faster measurement times of multisine EIS make real time monitoring possible. This rapid data acquisition allows a higher frequency of data collection and system monitoring throughout the experiment and has been previously applied to PEM (proton exchange membrane) fuel cells using electronic loads -which is not feasible for the electrolyzer-based application case or for systems operating at the industrial power level.…”

“…This rapid data acquisition allows a higher frequency of data collection and system monitoring throughout the experiment and has been previously applied to PEM (proton exchange membrane) fuel cells using electronic loads -which is not feasible for the electrolyzer-based application case or for systems operating at the industrial power level. [35,36] In this study, we employ multi-sine EIS to monitor an MEA CO 2 RR electrolyzer throughout its operation. We simulate and characterise assembly, gradual, and immediate failure modes typical of these systems.…”

“…In‐line EIS collects data in real‐time, enabling instantaneous, non‐invasive diagnostics and performance management. To avoid the typical delay associated with gathering EIS spectra (>15 min), this approach employs a multi‐sine EIS wherein multiple frequencies are applied to the cell simultaneously [35,36] . The faster measurement times of multi‐sine EIS make real time monitoring possible.…”

“…The faster measurement times of multi‐sine EIS make real time monitoring possible. This rapid data acquisition allows a higher frequency of data collection and system monitoring throughout the experiment and has been previously applied to PEM (proton exchange membrane) fuel cells using electronic loads ‐ which is not feasible for the electrolyzer‐based application case or for systems operating at the industrial power level [35,36] …”