Visualization of the Oxygen Partial Pressure on the Gas-Diffusion-Layer Surface under the Single-Serpentine Flow Channel and the Ribs in a Polymer Electrolyte Membrane Fuel Cell during the Power Generation

摘要

The reaction distribution inside a polymer electrolyte fuel cell (PEFC) is important for the cell performance and durability, and needs to be elucidated. Visualization of the oxygen partial pressure(ρ(O_2)) was conducted at the surface of a gas diffusion layer (GDL) under the single-serpentine flow channel and the ribs inside a see-through cell during the operation. A luminescent porphyrin dye was used to visualize ρ(O_2)at the temperature of 80℃ and the relative humidity of 53%. The oxygen utilization (U0_2) was changed from 0% to 80% by changing the current density, ρ(O_2) under the ribs was lower than that under the flow channel, and the difference in ρ(0_2) became larger with increasing Uo_2. A small difference in configuration of an MEA in the cell was found to influence the ρ(0_2) pattern. This technique is expected to be used as a powerful tool for the cell and MEA designs.