Analysis of low-loading electrodes for PEM water electrolyzers

Proton exchange membrane water electrolysis (PEMWE) technology is one of the cleanest methods of producing green hydrogen. The widespread adoption of this technology by industries is hindered by the operating and investment costs associated with the use of precious metal catalysts, such as iridium (for the anode side) and platinum (for the cathode side). Moreover, comparing data across the proton exchange membrane water electrolyzer (PEMWE) research community is challenging due to variations in materials used, cell assembly, and testing conditions. In the first study, different sources of performance variation are addressed, and a key finding highlights the importance of temperature in determining reaction kinetics and overall cell performance. Using different cell hardware with identical materials resulted in a maximum deviation of 50 mV. Furthermore, choosing the right testing equipment is a crucial factor, as inaccuracies in collected data can mislead the research at the cost of time, effort, and expense. Potentiostat is the right test equipment for electrochemical systems, enabling accurate measurements and reliable testing. The compression ratio, which is often not reported, has a significant influence on cell performance. An optimal compression ratio is needed to achieve good performance, as over- or under-compression leads to elevated high frequency resistance (HFR). A need to standardize the materials used and cell hardware is demonstrated, as the discrepancy in cell performance arises from these two sources. Other challenges to commercialization of PEMWE include catalyst instability, membrane degradation, poor microstructure of the anode catalyst layer (ACL), reduced active area utilization, and mass transport limitations, especially at high current densities. In the other study, we explore the use of pore formers to create desired microstructures for PEMWE anodes. Low-loading anodes with modified porosities were fabricated using commercial catalysts and carbon-based pore formers. The pore former added catalyst-coated membranes (CCMs) were manufactured inhouse, enabling precise control over the porosity of the catalyst layer. The results highlight that we can achieve slightly higher mass current density with the addition of vulcan carbon. Furthermore, the obtained data indicate that the pore former can indeed improve active area utilization.