Scalable nanostructured membranes for solid-oxide fuel cells.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Solid-state ionic devices, including oxide fuel cells, require high operating temperatures (>800°C), limiting their practical application.
• Thin-film electrolytes reduce ohmic resistance for lower-temperature operation, but large-area membranes (<100 nm) face mechanical instability challenges.
• Scaling up thin-film solid-oxide fuel cells (SOFCs) is hindered by the susceptibility of large-area, thin membranes to mechanical failure.

Discussion:

• Metallic grids provide mechanical support to nanoscale yttria-stabilized zirconia (YSZ) membranes, enabling large-area fabrication (millimetre to centimetre scale).
• This approach overcomes the mechanical fragility of thin (<100 nm) membranes, crucial for device scalability.
• The integration of supported membranes with nanostructured cathodes facilitates efficient electrochemical reactions.

Key Insights:

• Demonstrated thermomechanically stable, large-area nanoscale YSZ membranes with integrated metallic support grids.
• Developed a thin-film solid-oxide fuel cell achieving a power density of 155 mW cm⁻² at 510°C.
• Achieved a total power output exceeding 20 mW from a single fuel-cell chip.

Outlook:

• The developed large-area membranes are suitable for scalable thin-film solid-oxide fuel cells.
• Potential applications extend to other electrochemical energy technologies, including gas separation, hydrogen production, and permeation membranes.
• This advancement paves the way for more efficient and cost-effective electrochemical energy devices operating at reduced temperatures.