Numerical investigation of stresses distribution in a multi-channel PEMFC fuel cell under clamping pressure

As PEMFC technology becomes progressively mature for large-scale commercialization, research and innovation in the mechanical field becomes important. To meet the different requirements in terms of durability and reliability, the mechanical strains must be taken into account when designing the multi-cells PEMFC. A three-dimensional finite element model of a PEMFC has been developed to analyze the behavior of the deformations and corresponding stresses of fuel cell component. The effect of clamping force on the cell performances has been investigated. We show, through the obtained results, the importance of the clamping force on the intrusion of the GDL and the stress generated in the cell components: when the clamping pressure was increased from 0.2 MPa to 0.8 MPa, the GDL intrusion increase from 0.01 mm to 0,038 mm. The results also showed that the strain is important at the ends and decreases when moving towards the middle of the multi-cell PEMFC fuel cell. Finally, the increase in the number of channels affects the distribution of the stresses and the value of the intrusion noticed on the external channel and that of the central channel becomes more important. Consequently, a good management of the clamping force is indispensable to avoid obstruction of fuels and to keep a sufficient seal between the channels.