Study of the water electrolyzer with proton exchange membrane performance based on Ti current collectors charged with hydrogen

Abstract

This work investigates the influence of hydrogen accumulation in titanium current collectors on the operating characteristics of a water electrolyzer. The investigated dependence is complex and considers the influence of both hydrogen concentration and formed titanium hydride on the characteristics of the water electrolyzer. Additionally, it takes into account the deformation of collectors and the state of their surface, which changes depending on the method of hydrogen charging from the gas phase. As the hydrogen concentration in cathode current collectors increases up to 50.2 at. %, there is a tendency for the performance of the electrolysis cell to decrease. However, the total overvoltage of the cell does not increase by more than 5 %. The transport losses of the cell are primarily affected by the hydrogen content in the current collectors. The change in morphology and structure of grains in the near-surface layer is associated with the formation of the titanium hydride phase and the cracking of samples. The maximum increase in overvoltage for transport losses under the studied conditions was approximately 37.5 %. This effect must be considered when scaling and developing large hydrogen generation systems.