Lawrence Berkeley National Laboratory
Ice Crystallization During Cold-Start of a Proton-Exchange-Membrane Fuel Cell
- Author(s): Dursch, TJ
- Liu, JF
- Trigub, GJ
- Radke, CJ
- Weber, AZ
- et al.
Published Web Locationhttps://doi.org/10.1149/05801.0897ecst
Under subfreezing conditions, ice forms in the gas-diffusion (GDL) and catalyst layers (CL) of proton-exchange-membrane fuel cells (PEMFCs), drastically reducing cell performance. Although a number of strategies exist to prevent ice formation, there is little fundamental understanding of ice-crystallization mechanisms and kinetics within PEMFC components. We incorporate recently developed ice-crystallization kinetic expressions (1-3) within the CL and GDL of a simplified 1-D transient PEMFC cold-start model. To investigate the importance of ice-crystallization kinetics, we compare liquid-water and ice saturations, and cell-failure time predicted using our kinetic rate expression relative to that predicted using a thermodynamic-based approach. We identify conditions under which ice-crystallization kinetics is critical and elucidate the impact of freezing kinetics on low-temperature PEMFC operation. © The Electrochemical Society.