Characterization and Comparison of Self-Made and Commercial Catalyst Coated Membranes in a Segmented PEM Fuel Cell - Performance and Limitations Analysis

The local conditions within a PEM fuel cell exhibit variations across the active area due to pressure gradients, changes in gas composition caused by electrochemical reactions, and resulting temperature gradients primarily due to reaction and ohmic heat. By utilizing a segmented "Along-the-channel" cell (ATC), the effects of these heterogeneous conditions can be identified through measurements of current density and impedance distribution. In this study, catalyst coated membranes (CCMs) were produced using screen-printing technology on decal foil and then transferred to a commercial Gore membrane (type M775.15) via hot-pressing and finally framed. The CCMs, with an active area of 2x25cm2, were characterized in a segmented ATC with 25 segments by using an electrochemical multi-channel analyzer comprising of 25 potentiostats, each integrated with a built-in FRA. The self-made CCMs were characterized under different operating conditions (pressure, relative humidity, temperature) and compared to a commercial Gore CCM (A510.1/M775.15/C586.4). Freudenberg GDLs of type H12CX483 were used in all experiments. We can confidently state that the in-house CCM delivers comparable performance, whereas our CCMs showed a slightly increased mass transport at very low cell voltage but better performance in the activation region. To gain a deeper insight into the limitations of the different cell layers, a validated 3D-CFD model (AVL FireM) was utilized and is discussed in this work.