Raman Spectroscopy of an Aged Low Temperature Polymer Electrolyte Fuel Cell Membrane
Journal article, 2011
The cost and durability of the membrane electrode assembly (MEA) are today limiting factors for large-scale commercialisation of the polymer electrolyte membrane fuel cell (PEMFC). The MEA durability in a real working fuel cell (FC) is closely linked to specific operating conditions such as temperature, gas humidity, load dynamics, etc. This often results in both chemical and mechanical degradation of the ion-conducting membrane and subsequent operation failure of the FC. In this study, Raman spectroscopy is used to identify and distinguish between two different degradation processes for a 1,500 h in situ aged FC membrane. The primary process is due to the loss of proton conducting sulphonic acid end groups over the entire membrane. The secondary process is a degradation of the fluorinated backbone concentrated to the cathode interface; making possible the collapse of carbon into the resulting voids of the membrane. Using spatially resolved Raman spectroscopy we can unambiguously observe both the localisation and the state of the carbon inside the membrane; being similar/identical to the microporous layer (MPL).
Polymer Electrolyte Fuel Cell