Photometric Method to Determine Membrane Degradation in Polymer Electrolyte Fuel Cells

Abstract

A new method for measuring membrane degradation in polymer electrolyte fuel cells (PEFCs) is proposed. The method is based on the detection of fluoride ions in effluent water from the cathode- and anode outlet of the PEFC using photometry (PM). The fluoride emission rate (FER) is an indicator of the membrane’s state of health (SoH) and can be used to measure the chemical membrane degradation. Commercial catalyst-coated membranes (CCMs) have been tested at 80 °C and 90 °C at 30% relative humidity (RH) to investigate the reliability of the developed method for fuel cell effluent samples. To verify the measurement, a mean-difference plot was created by measuring the same data with a fluorine selective electrode. The average difference was at ±0.13 nmol h−1 cm−2, which indicates good agreement between the two methods. These new findings imply that PM is a promising method for quick and simple assessment of membrane degradation in PEM technology.

Analysis of PEM Water Electrolyzer Failure Due to Induced Hydrogen Crossover in Catalyst-Coated PFSA Membranes

“…For the calculation of the FER ( h −1 ·cm −2 ); the fluoride concentration in the water sample, c F (mg·L −1 ); the molar mass of fluoride, M F (g·mol −1 ); the volume of the exhaust water, V water (L); the active cell area, A cell , (cm 2 ); and the sampling time, n sampling (hours) need to be considered [ 27 ]. In Figure 7 , the FER during the ASTs from the two cells tested at 60 °C and 80 °C and the cumulative FER at BoT and EoT are displayed.…”

“…The fluoride emission from the membrane was monitored with a photometric method, as recently described by our group [ 27 ]. Therefore, 100 µL of Zr(IV)-SPADNS2 (Merck, Darmstadt, Germany) was added to 900 µL of each sample.…”