Above and beyond the Lab ScaleCreating a kW-Sized AEM Electrolyzer Validated by In-Situ Distribution of Relaxation...

Most reported anion exchange membrane water electrolyzers (AEMWEs) are currently limited to the usual 1-10 cm² electrodes in single-cell AEMWEs; however, accelerating its technology readiness level necessitates an explosive increment in unit sizes. We report the design, characterization, and validation of a 1 kW, 500 cm² (5 × 100 cm²) non-PGM AEMWE stack. Complete with corrosion protection, internal heating, and a control system, the patented stack design operated stably at 1.0 A cm^-2 with an energy efficiency of 53.2 kWh kg_H2 ^-1. Moreover, to confirm cell-to-cell uniformity, a comprehensive statistical analysis was carried out to reveal five uniformly performing cells. Impedance analysis complemented by distribution of relaxation times (DRT) analysis revealed kinetic insights similar to those traditionally obtained for lab-scale electrodes, proving both non-PGM electrode scalability and efficacy, and the utility of DRT analysis on large-scale AEMWE stacks.