Performance limits and stability horizons in next-generation anion exchange membrane water electrolysis for hydrogen production

In this paper, we reviewed the performance boundaries and operational stability horizons governing next-generation AEMWE platforms. This review study indicates that standard state-of-the-art AEMWE configurations achieve industrially relevant cell voltages of 1.7–1.9 V at 1.0 A cm⁻², with optimized systems reaching current densities up to ~2.0–2.7 A cm⁻² at ~1.8 V as reported in literatures. Membrane hydroxide conductivity typically spans 50–100 mS cm⁻¹ at 60–80 °C with water uptake levels between 20 wt.% and 80 wt.%. While hydrogen Faradaic efficiencies consistently exceed 95–99% under steady-state, transient operating conditions can drop this metric to 90–95% due to gas crossover. Operational stability remains the primary commercialization bottleneck; reported cell degradation rates vary significantly from 10 μV h⁻¹ to >1000 μV h⁻¹ under continuous testing, driven by quaternary ammonium functional group decay, backbone cleavage via nucleophilic attack, catalyst dissolution, support corrosion, and electrode delamination. Addressing these constraints through advanced hydrocarbon membrane chemistries, tailored ionomer cross-linking, optimized porous transport layers, and standardized AST protocols is essential to meet the Clean Hydrogen Partnership target of degradation rates below 0.5% per 1000 hours at current densities above 1.5 A cm⁻².