Multilayered YSZ/GZO films with greatly enhanced ionic conduction for low temperature solid oxide fuel cells

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Ionics

Background:

• Ionic conductivity in solid oxide fuel cells (SOFCs) is crucial for efficiency.
• Heterostructured electrolytes offer potential for improved performance.
• Controlling strain in thin films is key to optimizing ionic transport.

Purpose of the Study:

• To investigate the effect of strain confinement on ionic conductivity in multilayered electrolytes.
• To develop a strategy for enhancing ionic conduction through controlled lattice mismatch and layer thickness.
• To demonstrate a novel approach for creating advanced electrolytes for low-temperature SOFCs.

Main Methods:

• Epitaxial growth of multilayered 8 mol%Y(2)O(3) stabilized ZrO(2) (YSZ) and Gd(2)Zr(2)O(7) (GZO) films using pulsed laser deposition (PLD).
• Manipulation of lattice mismatch and layer thickness to achieve coherent, dislocation-free interfaces.
• Characterization of ionic conductivity in strained heterostructures.

Main Results:

• Achieved nearly ideal tensile strain (3%) confined within individual YSZ layers.
• Demonstrated a two-order-of-magnitude increase in oxide-ion conductivity compared to bulk YSZ.
• Obtained high ionic conductivity (0.01 S cm(-1) at 475 °C), outperforming existing electrolytes.

Conclusions:

• Strain confinement in heterostructured films is a viable strategy for enhancing ionic conductivity.
• This approach enables the development of advanced electrolytes for miniaturized solid-state ionic devices operating below 500 °C.
• Optimized ionic conduction through controlled strain offers a promising pathway for next-generation energy devices.