Investigation of output performance and temperature distribution uniformity of PEMFC based on Pt loading gradient design.

Temperature distribution uniformity within the cathode catalyst layer (CCL) and power density are two crucial parameters to characterize the durability and output performance of proton exchange membrane fuel cells (PEMFCs), which are affected by the Pt distribution within the CCL. Therefore, the temperature distribution uniformity within the CCL and the output performance at different operating voltages for a PEMFC with various Pt loading gradient distributions along the in-plane (IP) direction are investigated in this paper. Moreover, a two-dimensional, two-phase, non-isothermal model is developed, and the concepts of high power density range (HPDR) and temperature uniformity index (TUI) are defined in this study. The results indicate that gradient Pt distribution has the opposite effect on output performance and temperature distribution uniformity at low and medium operating voltages; the improvement of one indicator means the deterioration of another. Besides, the optimal output performance is obtained with the uniform Pt distribution at high operating voltages, while the ideal temperature distribution uniformity is achieved by loading more Pt under the channel. Consequently, the output performance and temperature distribution uniformity must be traded off to obtain optimal comprehensive performance of PEMFC at different operating voltages when designing the Pt loading gradient distribution. • Non-uniform Pt loading under the channel and the rib is investigated. • The temperature distribution uniformity is influenced by the operating voltage. • Gradient Pt distribution has advantages at low and medium operating voltages. • Improving temperature distribution uniformity conflicts with output performance. [ABSTRACT FROM AUTHOR]