Temperature Effects in Polymer Electrolyte Membrane Fuel Cells

Abstract The behavior of proton exchange membrane fuel cells (PEMFCs) strongly depends on the operational temperatures. In mobile applications, for instance in fuel cell electric vehicles, PEMFC stacks are often subjected to temperatures as low as −20 °C, especially during cold start periods, and to temperatures up to 120 °C during regular operation. Therefore, it is important to understand the impact of temperature on the performance and degradation of hydrogen fuel cells to ensure a stable system operation. To get a comprehensive understanding of the temperature effects in PEMFCs, this manuscript addresses and summarizes in‐ situ and ex‐ situ investigations of fuel cells operated at different temperatures. Initially, different measurement techniques for thermal monitoring are presented. Afterwards, the temperature effects related to the degradation and performance of main membrane electrode assembly components, namely gas diffusion layers, proton exchange membranes and catalyst layers, are analyzed.