Numerical comparison between conventional and interdigitated flow fields in Proton Exchange Membrane Fuel Cells (PEMFCs)

The recent trend towards the decarbonization of the energy system has renewed the scientific community's interest in fuel cells. These devices have the potential to eliminate, or greatly reduce, the production of greenhouse gases. Polymeric Electrolyte Membrane Fuel Cells (PEMFC) are among the most promising technologies in this regard, being suited for various applications in stationary power plants, vehicles, and portable power devices. The critical issues in PEMFC are the limitation of oxygen transport through the air cathode and water management at high current density operation, which could be largely limited by modifying the design of the reactant supplier channels. In this paper, a three- dimensional CFD approach is used to compare straight and interdigitated flow fields, focusing on the increased current density and improved water management in the diffusion and catalyst layers for the interdigitated design. The simulation results show that the fluid is forced to flow through the porous layers, promoting a convection-type transport, leading to better water removal from the porous layers as well as to increased transport rates of reactants/products to/from the catalyst layers. This leads to reduced concentration overpotentials, and it shows the potential of simulation-driven design for high energy density PEMFC systems.