Carbonate-superstructured solid fuel cells with hydrocarbon fuels.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Solid oxide fuel cells (SOFCs) require dense electrolytes to prevent gas mixing and ensure high open-circuit voltage (OCV).
• Traditional SOFC electrolytes need sintering, a process that can be energy-intensive and limit design flexibility.

Purpose of the Study:

• To introduce a new type of fuel cell, the carbonate-superstructured solid fuel cell (CSSFC).
• To demonstrate the potential of in situ generated superstructured carbonate as a novel electrolyte material for enhanced fuel cell performance.

Main Methods:

• Fabrication of a CSSFC utilizing a porous samarium-doped ceria layer.
• In situ generation of a superstructured carbonate within the porous layer to form the functional electrolyte.
• Electrochemical characterization including ionic conductivity and OCV measurements using methane fuel.

Main Results:

• Achieved ultrahigh ionic conductivity of 0.17 S⋅cm^-1 at 550°C.
• Demonstrated unprecedented high OCVs of 1.051 V at 500°C and 1.041 V at 550°C with methane.
• Exhibited a peak power density of 215 mW⋅cm^-2 with dry methane fuel at 550°C, surpassing existing electrolyte-supported SOFCs.

Conclusions:

• The CSSFC offers a new paradigm for solid fuel cell development, moving beyond traditional dense electrolyte requirements.
• In situ carbonate superstructuring provides a highly conductive electrolyte, enabling superior performance metrics.
• This approach presents a promising pathway for efficient and advanced solid fuel cell technologies.