The Influence of Transient Variations on the Durability of PEM Fuel Cells

Recently, a number of studies have shown that the ionic conductivity of a membrane electrode assembly (MEA) strongly depends on the water retention ability of the proton exchange membrane in the fuel cell. This suggests that water management in the cell is important in achieving high PEMFC performance. Therefore, membrane dehydration, water flooding, and cell durability have become major challenges in PEMFC applications. In this study, we investigated the effect of the transient phenomenon on PEMFC performance using an electrode with an area of 25 cm². Parameters, including the cell temperature, stoichiometry of the fuel/oxidant, relative humidity of the reactive gas, were used for analyzing the performance of PEMFCs, along with fluid field imaging technologies. The results indicated that the ionic conductivity of the proton exchange membrane has a positive effect on PEMFC performance. PEMFC voltage will cause a sudden change in the current density overshoot phenomenon. This is because the decline in oxygen concentration and the oxygen concentration itself are also affected by the water concentration. This study revealed the relationship between the transient phenomenon and the performance of PEMFCs.