Surface engineering of nanoporous substrate for solid oxide fuel cells with atomic layer-deposited electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Solid oxide fuel cells (SOFCs) are promising clean energy devices.
• Atomic layer deposition (ALD) enables precise thin-film fabrication for SOFC electrolytes.
• Anodic aluminum oxide (AAO) provides a robust support structure for thin-film electrolytes.

Purpose of the Study:

• To investigate the impact of bottom electrode catalyst (BEC) thickness on the electrochemical performance of ALD-electrolyte SOFCs.
• To understand the relationship between BEC morphology, mass transport, and power density.
• To optimize BEC design for enhanced SOFC efficiency.

Main Methods:

• Fabrication of SOFCs with ALD-thin film electrolytes on AAO supports.
• Electrochemical characterization of cells with varying BEC thicknesses (0.5x and 4x AAO pore size).
• Analysis of power density and impedance spectra at elevated temperatures (500 °C).

Main Results:

• Cells with thicker BECs (4x AAO pore size) exhibited significantly higher peak power density.
• A ≈11-fold increase in peak power density was observed for the thicker BEC cell compared to the thinner one at 500 °C.
• Thicker BECs facilitate enhanced active mass transport, crucial for improved performance.

Conclusions:

• BEC thickness is a critical parameter for optimizing SOFC performance.
• Optimized BECs with improved mass transport are essential for high-power-density SOFCs.
• ALD-electrolyte SOFCs on AAO supports show great potential, especially with tailored electrode designs.