Local Temperature Estimation in PEM Fuel Cell

This study provides insights into the determination of local degradation of low-temperature polymer electrolyte membrane (PEM) fuel cells caused by locally elevated temperatures inside the membrane electrode assembly (MEA). The operating temperature of a fuel cell is usually taken to be the temperature measured at some distance from the electrodes, often in the end plates. However, the electrochemical reaction takes place at so-called triple-phase boundary in the catalyst layer (CL) which is the most proper place for temperature measurements. In practice, insertion of even the smallest thermocouples in the CL or even at the interface between the CL and the gas diffusion layer would change the flow distribution patterns and, therefore, the current density distribution and the temperature distribution. Here, the segmented S++ measurement sensor plate was used to investigate the current distribution in an 11 × 11 array and temperature distribution in a 6 × 6 array at three different operating points (10 A, 20 A and 30 A) at partially and fully humidified conditions for the same MEA composition. The obtained current and temperature data were used as boundary conditions for developing a simple three-dimensional computational fluid dynamics (CFD) model, in order to estimate the maximum temperature inside the CL generated within a fuel cell.