PEALD YSZ-based bilayer electrolyte for thin film-solid oxide fuel cells

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Solid oxide fuel cells (SOFCs) require efficient electrolytes for high performance.
• Yttria-stabilized zirconia (YSZ) is a promising electrolyte material for SOFCs.
• Thin film electrolytes offer advantages in SOFC design and operation.

Purpose of the Study:

• To investigate the electrochemical performance of YSZ thin film electrolytes deposited by plasma enhanced atomic layer deposition (PEALD).
• To compare the performance of PEALD YSZ electrolytes with sputtered YSZ electrolytes in thin film SOFCs.
• To identify the factors contributing to performance differences.

Main Methods:

• Fabrication of bi-layered thin film YSZ electrolytes using PEALD on nanoporous anodic aluminum oxide substrates.
• Fabrication of thin film SOFCs utilizing PEALD YSZ electrolytes.
• Electrochemical performance testing of SOFCs, including open circuit voltage (OCV) and power density measurements.
• Comparison with SOFCs employing sputtered YSZ electrolytes.

Main Results:

• The SOFC with PEALD YSZ electrolyte achieved a higher open circuit voltage (OCV) of 1.0 V and a peak power density of 182 mW cm(-2) at 450 °C.
• The SOFC with sputtered YSZ electrolyte showed a lower OCV of 0.88 V and a peak power density of 70 mW cm(-2).
• The superior performance of the PEALD YSZ electrolyte is attributed to reduced ohmic and activation losses and improved gas and electrical current tightness.

Conclusions:

• PEALD is an effective technique for depositing high-performance YSZ thin film electrolytes for SOFCs.
• PEALD YSZ electrolytes enable enhanced electrochemical performance in thin film SOFCs compared to sputtered electrolytes.
• The improved performance is linked to enhanced electrolyte properties, including reduced losses and better sealing.