Heterogeneous Cell Ageing in Polymer Electrolyte Fuel Cell Stacks
Polymer electrolyte fuel cell stacks, in the commonly used bipolar arrangement, consist of multiple stacked single cells in a filter-press-type arrangement. The bipolar arrangement connects the cells in series electrically and in parallel for the reactant and coolant flows; therefore, all cells have to carry the same current but they can receive different reactant mass flows. The reactant and the coolant supply may be different owing to statistically varying percolation resistances of the fluids and owing to the position of the cells in the stack. Therefore, the commonly made assumption that individual cells perform equally is valid neither for normal operation nor for the degradation of individual cells. Differences between cells can be of systematic or stochastic nature and translate into differences in the degradation rate under operation or start/stop conditions. The four main cases are discussed.
KeywordsFuel Cell Cell Voltage Proton Exchange Membrane Fuel Cell Membrane Electrode Assembly Current Density Distribution
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- Blair, J.D., and Dircks, K. (1992) Method and apparatus for monitoring fuel cell performance, US Patent 5,170,124Google Scholar
- Freunberger, S.A., SchneIDer, I.A., Sui, P.-C., Wokaun, A., Djilali, N., and Büchi, F.N. (2007) Cell Interaction Phenomena in Polymer Electrolyte Fuel Cell Stacks, J. Electrochem. Soc., submittedGoogle Scholar
- Lacy, R.A. (2001) Measuring cell voltages of a fuel cell stack, US Patent 6,313,750Google Scholar
- Pekula, N., Heller, K., Chuang, P.A., Turhan, A., Mench, M.M., Brenizer, J.S., and Unlu, K. (2005) Study of water distribution and transport in a polymer electrolyte fuel cell using neutron imaging, Nucl. Instrum. Methods Phys. Res. Sect. A: Accelerators Spectrometers Detectors Associated Equipment, 542, 134–141CrossRefGoogle Scholar
- Reiser, C. (2004) Battery-boosted, rapID startup of frozen fuel cell United States Patent 6,777,115Google Scholar