Numerical Investigation on the Electrolyte (PBI/H3PO4) Management of a HT-PEM Fuel Cell

M. J. Hampe, S. Lang, H. Löhn, and T. Zeeden
Technische Universität Darmstadt
Fachgebiet Thermische Verfahrenstechnik
Darmstadt, Germany

PEM fuel cells based on Polybenzimidazole doped with phosphoric acid show many benefits in comparison to conventional perfluorinated sulfocationic membrane materials, but they suffer from a degradation partially caused by the loss of electrolyte. The first step to tackle this degradation problem is to understand the electrolyte management in high temperature PEMFCs.

COMSOL 4.1 was used to model and solve a numerical 2D-simulation which shows the behavior of the electrolyte in the membrane. The model results in a system of 7 coupled application modes consisting of 15 dependent variables with 35.961 degrees of freedom. The simulation results give better understanding of the performance of HT-PEMFCs in accordance with the behavior of the acidic electrolyte in good agreement with experimental results.