Rapid and Local EIS on a Segmented Fuel Cell: A New Method for Spatial and Temporal Resolution

A new method for acquiring sub-second electrochemical impedance spectroscopy (EIS) on a segmented proton exchange membrane fuel cell (PEMFC) is applied. High temporally and spatially resolved characterization is obtained through frequency range optimization and imposition of multiple frequencies within one measurement task when characterizing all segments simultaneously. Furthermore, acquisition and postprocessing steps, were decoupled. Spatial and temporal evolution of the transmission line model's (TLM) parameters are characterized such as membrane resistance R-mem as function of operational parameters. The temporal evolution of local and differences to global values are monitored. The transient behavior of re-humidification and stoichiometry variation on membrane resistance are elucidated. Insights in local and global changes and their frequency dependency of membrane resistances addressed to provide a generic guidance for segmented EIS characterization. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.