Three-dimensional electrochemical simulation of proton exchange membrane fuel cell with distributed resistance modeling method

In this study, a new modeling method is developed for analyzing the obstructive effects against the reactant gas because of the deformation of the gas diffusion layer (GDL), which is the interaction between the serpent flow field of the anode side and the straight channels with tapered structures of the cathode side due to the compression after the assembly of the proton exchange membrane fuel cell (PEMFC) stack. This method is based on the stochastic reconstruction technology to obtain the GDL porous material, and then the permeabilities of the reconstructed material through-plane can be predicted by normal computational fluid dynamics method. Coupling with the 3-dimensional GDL mechanical deformation model based on finite-element analysis, the profile for describing the distribution of the nonuniform permeabilities in GDL is produced, which particularly focuses on the regions under the ridges between anode and cathode bipolar plates. This distributed resistance map can be used as valuable inputs of physical properties to the electrochemical simulation. Hence, the details of the mass transportation between the gas flow channels and catalyst layer can be captured and analyzed. The simulation results show the deformation of the GDL has significant effects on the gas flow mass transportation and thereby the electrochemical performance. Meanwhile, with the new modeling method, the simulation results are getting more closer to the measurements in all operating current densities. Compared with the conventional method, the accuracy of the simulation is increased. Additionally, it can be observed that the generated water is taking main effect as obstacles to the reactant gas in the higher operating current density, which is playing a more leading role than the resistance of the porous media itself.