Measurement of Current Density Distribution in Technical PE Fuel Cells

摘要

The distribution of the current density in PE fuel cells with a larger active area is not uniform due to several reasons. The parameters affecting the local performance of a given sector in the cell vary with operating conditions. Partial pressure of the gases, temperature distribution and water content of the membrane are not uniform over the active area. As a result the current generation is not uniform either and some parts of the cell produce more current to compensate for the poor performance of other sectors. Analyzing the I/U curves of a cell at given operation conditions does not give much information about the local distribution of the current density in the cell. Measuring of the local distribution of the current density in the active area of a PE fuel cell therefore is a useful tool for understanding the effects caused by the variation of the different operating parameters. For this purpose a semi-segmented cell was newly developed, allowing local current density measurements while conserving the fluid dynamic properties for the reactant gases as well as the electrical and thermal conductivity.