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

## TL;DR

Researchers developed and validated a 1 kW non-PGM AEM electrolyzer stack with large electrodes, demonstrating stable performance and energy efficiency.

## Contribution

The study presents a scalable non-PGM AEMWE stack design validated at a large scale with in-situ DRT analysis.

## Key findings

- A 1 kW, 500 cm2 non-PGM AEMWE stack achieved stable operation at 1.0 A cm–2 with 53.2 kWh kgH2–1 efficiency.
- Five cells in the stack showed uniform performance confirmed by statistical analysis.
- DRT analysis on large-scale stacks provided kinetic insights comparable to lab-scale electrodes.

## Abstract

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 kgH2

–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.