The uniform distribution of the current and temperature under the normal operating conditions of the polymer electrolyte membrane water electrolyzer (PEMWE) cell is important to ensure its high efficiency and durability. In this work, a segmented sensor plate S++ is inserted between the flow field plate and current distributor plate at the cathode side of a single PEMWE cell to measure the local current and temperature distribution under different water flow configurations of the anode and cathode side and various current loads of PEMWE. The active area of the single PEMWE cell is 50 cm². One hundred segments in the segmented sensor plate provide high resolution in the current and temperature distribution measurement. The current and temperature distribution are measured under co-flow and counter-flow of water recirculation between anode and cathode and under different current loads from 10A to 70A. Besides, the polarization curve and electrometrical impedance spectrum are measured under different water flow configurations.

Initial results reveal that when operated with co-flow of water re-circulation in anode and cathode, the cell shows better performance. With co-flow configuration, the charge transfer for hydrogen evolution and oxygen evolution reaction is larger compared with counter-flow configuration. The current shows similar distribution pattern under different water flow configuration and different current loads. However, uniformity in current distribution becomes better with lower current. The temperature distribution is not significantly influenced by the current load, while the counter-flow of water re-circulation results in more uniform temperature distribution.