Localised Electrochemical Impedance Measurement Using an Innovative Reference Electrode Array
Here we report the first localised EIS measurements in a single cell PEMFC using an innovative reference electrode array developed at NPL. By making contact directly with the electrode of interest using a Nafion tube salt bridge inserted through the end plates of the cell, the NPL reference electrode gives an iR-free, localised potential measurement, with the advantage that commercial MEAs can be tested directly with minimal modification to cell hardware. An array of reference electrodes is used to measure the spatial variation in impedance across the active area of the cell under a range of operating conditions, before and after accelerated aging of a commercial MEA. The advantages and disadvantages of this technique and the implications for modelling and optimisation of fuel cell design are discussed.