An Efficient Electron-Blocking Interlayer Induced by Metal Ion Diffusion for SOFC Based on Y-Doped Ceria Electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Internal electronic leakage in ceria-based electrolytes hinders solid oxide fuel cell (SOFC) performance.
• Developing effective electron-blocking layers is crucial for enhancing SOFC efficiency.

Purpose of the Study:

• To fabricate and evaluate a novel electron-blocking layer for ceria-based electrolytes.
• To improve the power density and open-circuit voltage of anode-supported SOFCs.

Main Methods:

• In situ fabrication of a doped BaCe_0.8Y_0.2O_3-δ (BCY) electron-blocking layer at the anode-electrolyte interface.
• Characterization of Y_0.2Ce_0.8O_1.9 (YDC20) electrolyte-based SOFCs with and without the BCY interlayer.
• Performance testing at 650 °C, including power density and open-circuit voltage measurements.
• Microstructural and compositional analysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Main Results:

• The YDC20 electrolyte-based SOFC with the BCY interlayer achieved a peak power density of 814 mW/cm² and an open-circuit voltage of 1.0 V at 650 °C.
• Performance significantly surpassed cells with Gd_0.1Ce_0.9O_1.95 (GDC10) electrolyte (453 mW/cm²) and a BCY|YDC20 bilayered electrolyte (419 mW/cm²).
• The electron-blocking interlayer demonstrated high oxygen ionic conductivity, contributing to the performance enhancement.

Conclusions:

• The in situ fabricated BCY electron-blocking layer effectively suppresses electronic leakage in ceria-based electrolytes.
• The optimized BCY interlayer significantly improves the performance of YDC20-based SOFCs.
• This approach offers a promising strategy for developing high-performance solid oxide fuel cells.