For the 1D model, the outer cell fa

For the 1D model, the outer cell faces of cathode and anode GDL are coupled in the solver – see double arrow in Fig. 3. The bipolar plates (BP) and cooling channels are not modeled, i.e. heat and electron transport in the BPs are neglected, resulting in constant temperatures and electric potentials at the channel wall and interface GDL/BP. Welding spots between bipolarplates are modeled via regions with a distribution of lower electric contact resistances at the interface GDL/BP–see Fig. 3 and Table 3. Fluid and material properties are listed in the Tables 1 and 2, respectively. The nominal boundary conditions are listed in Table 3. Theboundaries not mentioned in the table are walls with zero gradient conditions.