Heterointerface-Enabled Anti-Reverse-Current Electrodes for Alkaline Water Electrolyzers at 1000 mA cm^-2

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Alkaline water electrolysis (AWE) is crucial for green hydrogen production.
• Fluctuating renewable energy sources cause reverse current (RC) effects, damaging AWE electrodes.
• Electrode durability is a major bottleneck for industrial-scale AWE.

Purpose of the Study:

• To engineer robust AWE electrodes resistant to electrochemical reconstruction and mechanical fatigue.
• To improve electrode stability and efficiency under demanding operational conditions.
• To address the challenge of reverse current effects in AWE.

Main Methods:

• Gradient interlayer engineering using Ni(112̅)/Ni₃S₂(1̅20) heterointerfaces.
• Electrochemical characterization to assess catalytic activity and stability.
• Cross-sectional characterization and theoretical calculations for mechanistic studies.

Main Results:

• Achieved high catalytic activity (1.79 V @1000 mA cm^-2), meeting U.S. DOE 2026 targets.
• Demonstrated excellent operational stability (>1500 h at 1000 mA cm^-2 in 30 wt % KOH at 80 °C).
• Exhibited exceptional RC resistance over 3600 accelerated startup/shutdown cycles.

Conclusions:

• The developed gradient interlayer strategy significantly enhances AWE electrode durability.
• Interface engineering, specifically interface crystallography, is a viable design paradigm for robust electrodes.
• This approach overcomes the stability-activity dilemma for industrially relevant electrolyzers.