Solid Oxide Fuel Cells with Magnetron Sputtered Single-Layer SDC and Multilayer SDC/YSZ/SDC Electrolytes.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Samarium-doped ceria (SDC) offers higher ionic conductivity than yttria-stabilized zirconia (YSZ) for intermediate-temperature solid oxide fuel cells (IT-SOFCs).
• Optimizing electrolyte structure is crucial for improving SOFC performance and efficiency.

Purpose of the Study:

• To compare the performance of anode-supported SOFCs using single-layer SDC and multilayer SDC/YSZ/SDC thin-film electrolytes.
• To investigate the effect of YSZ blocking layer thickness on SOFC performance.
• To determine the optimal electrolyte configuration for enhanced IT-SOFC operation.

Main Methods:

• Fabrication of single-layer SDC and multilayer SDC/YSZ/SDC electrolytes via magnetron sputtering.
• Characterization of electrolyte structure using X-ray diffraction and scanning electron microscopy.
• Performance evaluation through current-voltage measurements and impedance spectroscopy at 500-800 °C.

Main Results:

• Single-layer SDC electrolytes achieved 0.8 V open circuit voltage and 651 mW/cm² power density at 650 °C.
• Multilayer SDC/YSZ/SDC electrolytes with a 1 µm YSZ blocking layer improved open circuit voltage to 1.1 V.
• The optimized 3/1/1 µm SDC/YSZ/SDC electrolyte demonstrated maximum power densities of 2263 mW/cm² at 800 °C and 1132 mW/cm² at 650 °C.

Conclusions:

• Multilayer SDC/YSZ/SDC electrolytes significantly enhance IT-SOFC performance compared to single-layer SDC.
• A 1 µm YSZ blocking layer is optimal for maximizing power density in the multilayer structure.
• SDC-based electrolytes, particularly multilayer configurations, show great promise for efficient IT-SOFC applications.