Year: 2008
Type: article
Abstract: This paper investigates the effects of gas crossover. Specifically, mathematical simulations are conducted to elucidate the fundamental changes in fuel-cell operation as permeation of the various gases through the membrane increases. Two cases are explored, with the first one examining uniform increases in the set of gas-permeation coefficients, and the second one the existence of regions of high gas crossover (i.e., membrane pinholes). For the first case, operation at 120 C is studied and a maximum limit for the hydrogen permeation coefficient of 1 x 10{sup -10} mol/bar-cm-s for a 25 {micro}m membrane is determined. For the second case, it is shown that negative current densities and temperature spikes can arise due to mixed-potential and direct-combustion effects where there are large enough pinholes, thereby impacting performance and water and thermal management.
DOI: 10.1149/1.2898130
Author: Adam Z. Weber
Institution: Lawrence Berkeley National Laboratory
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: U.S. Department of Energy
Awards: G1286236842, G3083819904, G969889393
OpenAlex ID: W1991670283