In-situ synchrotron X-ray radiography on high temperature polymer electrolyte fuel cells

In contrast to classical low temperature polymer electrolyte fuel cells (LT-PEFCs), the membrane conductivity in high temperature polymer electrolyte fuel cells (HT-PEFCs) (operating temperature similar to 160 degrees C) is based on proton transport within phosphorus-oxygen acids at different levels of hydration, orthophosphoric acid (H(3)PO(4)) being the simplest example. We present for the first time in-situ synchrotron X-ray radiography measurements applied to a HT-PEFC to gain insight into the local composition of the membrane electrode assembly (MEA) under dynamic operating conditions. Transmission changes during the radiographic measurements exhibit a clear influence of the formation of product water on the membrane composition. (C) 2010 Elsevier B.V. All rights reserved.