Factors influencing the performance and durability of polymer electrolyte membrane water electrolyzer: A review

Hydrogen is the best energy vector for renewable and intermittent power sources. Electrolysis coupled with renewable energy resources is the most promising for the production of green hydrogen among the current hydrogen production methods. The polymer electrolyte membrane water electrolyzer (PEMWE) is the frontrunner of electrolyzer technology because of its ability to operate at high current densities and compact design, thereby enabling high-pressure operation. This review summarizes the static parameters (stack assembly and design aspects) and dynamic parameters (operating parameters and gas bubble removal) affecting PEMWE's performance, as well as static parameters (stack design) and dynamic parameters (operating parameters) affecting durability. For PEMWE, stack design plays an important role in the electrolyzer performance and durability, such as the fabrication of the bipolar plate and the material selection of the stack components. Recently, novel stack designs have shown promising performance and durability enhancements by lowering the ohmic and mass losses, enabling constant clamping pressure inside the stack, and eliminating the degradation of the BPP plates by using 3D-printed plastic plates, which also greatly lower the cost of the stack. Operating parameters, including temperature, pressure, and water flow rate, can be regulated during operation. However, temperature and pressure have a more significant impact on PEMWE's performance and durability than water flow rate. Research on magnetic fields, ultrasonic power, pulsed power, and pressure swings has shown promising results in increasing gas removal rate to enhance PEMWE's performance by addressing intrinsic mass transport limitations. However, their application to large PEMWE systems has not been extensively tested. Further studies are needed to elucidate their mechanism and potential in PEMWE applications.