High-Pressure Characteristics of a Low-Ir-Loading PEM Water Electrolysis MEA

The market share of green hydrogen produced by water electrolysis is rising and the first commercial applications of larger electrolysis systems (>10 MW) are being commissioned. The high iridium use of proton exchange membrane water electrolysis technology can hinder large scale application and requires next-generation low-iridium membrane-electrode assemblies (MEA). It is key that these materials show good durability under industrial conditions, of which high pressure (≥ 3MPa) is a key parameter. For that reason, we have evaluated the performance and durability characteristics of Toshiba’s low-iridium MEA (0.15 mg/cm2 iridium) under high pressure and pressure cycling conditions. These characteristics were negatively influenced by PTL deformation upon pressurization. The negative effects could be successfully mitigated via either the use of thicker PTLs or optimal flow field designs. This study shows that high pressure induced deformation of the PTL is a key factor for degradation and how this can successfully be addressed for the low-iridium Toshiba MEA.