September 28, 2026
Does Nickel Mesh Actually Dissolve in an AEM Electrolyzer?
The short answer: In a properly configured AEM water electrolyzer, the nickel mesh itself does not dissolve.
This is not marketing language. It comes from a study by the Italian National Research Council (CNR-ITAE), which used Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) to analyze the anode compartment after 160 hours of continuous operation.
The result: nickel leaching was “undetectable.”
What the Study Actually Tested
The researchers assembled a flow-field-free AEM single cell using nickel felt as the porous transport layer, with wire-sintered nickel as the interlayer. The operating conditions were realistic:
- Current density: 0.5 A/cm²
- Electrolyte: 1 M KOH
- Temperature: 50°C
- Duration: 160 hours
The degradation rate was 0.18 mV/h—extremely low for an alkaline system.
After the test, they did something critical: they used ICP-OES to measure what actually dissolved into the anolyte. The instrument has detection limits in the parts-per-billion range. If nickel were corroding, it would have shown up.
It did not.
The Real Culprit: Iron, Not Nickel
What ICP-OES did detect was iron dissolution—but from the NiFeOx oxygen evolution catalyst, not from the nickel mesh or interlayer.
This distinction matters enormously for nickel mesh suppliers. The nickel substrate was stable. The catalyst coating, which contains iron as an active component, showed moderate iron loss. That is a catalyst formulation issue, not a substrate corrosion issue.
The study also compared different interlayer materials. Wire-sintered stainless steel and Inconel 600 both degraded over time, with increased resistance attributed to oxidative passivation in the anode compartment.
Wire-sintered nickel did not.
Why This Makes Physical Sense
Nickel’s corrosion resistance in alkaline media is well-established. Unlike in acidic PEM electrolyzers, where even stainless steel requires protective coatings, nickel in KOH operates in a regime where the metal forms a stable, conductive oxyhydroxide surface layer rather than dissolving.
The CNR-ITAE results align with this: the 0.18 mV/h degradation rate over 160 hours, combined with undetectable nickel leaching, confirms that the nickel component is not the limiting factor for durability.
What This Means for Your Selection
If you are evaluating nickel mesh for an AEM or alkaline electrolyzer, the concern should not be “will the nickel dissolve?” The chemistry says it will not, and the ICP data confirms it.
The real variables are:
Configuration matters. The 450 µm nickel felt maintained performance under 10–20 bar external pressure, while a thinner 250 µm felt deteriorated at high current density (>1.5 A/cm²). The nickel interlayer worked well because it was paired with an appropriate PTL.
Interlayer choice matters. Not all nickel products are equal. Wire-sintered nickel outperformed stainless steel and Inconel in long-term stability. If you substitute a cheaper metal, you introduce a corrosion risk that nickel does not have.
The catalyst is a separate variable. Iron loss from NiFeOx is a catalyst design consideration. It does not reflect on the nickel mesh or felt substrate.
The Bottom Line
Back to the original question: does nickel mesh dissolve in an AEM electrolyzer?
CNR-ITAE answered it with ICP-OES. After 160 hours of continuous operation, nickel leaching was below the detection limit. What did dissolve was iron from the catalyst—not the nickel mesh itself. Stainless steel and Inconel interlayers showed passivation-driven degradation; wire-sintered nickel did not.
These data point to a clear conclusion: in the right configuration, nickel mesh is not the durability bottleneck.
