MgO-MgAl₂O₄-Supported Flat-Tubular Segmented-In-Series SOFCs Featuring Ultra-High Conductivity Interlayer for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• High-performance solid oxide fuel cells (SOFCs) require advanced interlayers for improved conductivity and interfacial compatibility.
• Ceramic-supported SOFCs, particularly flat-tubular segmented-in-series designs, face challenges with interlayer stability and diffusion.

Purpose of the Study:

• To develop a highly conductive and compatible interlayer for MgO-MgAl₂O₄ (MMA)-supported SOFCs.
• To enhance the performance and long-term stability of inert ceramic-supported SOFCs.

Main Methods:

• Fabrication of a 70 vol % NiO-30 vol % MgAl₂O₄ interlayer using a cosintering process.
• Characterization of interlayer conductivity, interfacial compatibility, and diffusion suppression.
• Testing of single-cell and 16-cell flat-tubular segmented-in-series SOFC performance at 850 °C.

Main Results:

• The NiO-MgAl₂O₄ interlayer effectively suppressed MgO diffusion from the MMA substrate to 25 μm.
• Interlayer conductivity exceeded 3400 S cm^-1 at operational temperatures.
• A single cell achieved an open circuit voltage (OCV) of 1.07 V and a power density of 760 mW cm^-2, with excellent stability.
• A 16-cell FT-SIS-SOFC stack demonstrated an OCV of 17 V and a maximum output power of 15 W at 850 °C.

Conclusions:

• The developed NiO-MgAl₂O₄ interlayer is highly conductive and compatible, significantly improving SOFC performance.
• This interlayer technology is critical for advancing inert ceramic-supported FT-SIS-SOFCs.
• The results demonstrate a viable pathway for high-performance, stable solid oxide fuel cell systems.