Ionic Decoupling in PEM Water Electrolyzers and Cost-Effective Cell Components

Abstract

Potential profiles through the PEM water electrolyzer anode compartment have been found to be highly dependent on feedwater resistivity (see Figure 1). Typical type II industrial feedwater leads to a considerable drop in local potential from the anode catalyst layer (> 1.5 V vs. RHE) to the bipolar plate (1.0 V vs. RHE). At such a potential, cost-effective materials like stainless steel and carbon are stable [1] which expands their use case from PEM fuel cells to PEM water electrolyzers. Moreover, the potential profiles suggest substituting most of the PTL by more cost-effective materials than titanium, e.g., stainless steel [1].[1] H. Becker et al. Assessing potential profiles in water electrolysers to minimize titanium use, Energ. Environmental Sci . 2022, 15, 2508-2518. Figure 1