Analysis of cold start in polymer electrolyte fuel cells

To enhance cold start capability and survivability of polymer electrolyte fuel cells ( PEFCs ) at subzero temperatures, a fundamental understanding of the principles involved is required. In this work an analytical model is presented to describe heat balance, ice formation in the catalyst layer, water transport characteristics throughout a fuel cell at very low temperatures, and the ensuing voltage behavior during PEFC cold start. The model is used to elucidate cold start behaviors of a PEFC from - 10 and - 20 degrees C and to identify key parameters controlling PEFC cold start, such as the initial membrane water content prior to startup and thermal mass of bipolar plates. (c) 2006 The Electrochemical Society.