A Self-Crystallized Nanofibrous Ni-GDC Anode by Magnetron Sputtering for Low-Temperature Solid Oxide Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• The optimal composition of nickel-gadolinium-doped ceria (Ni-GDC) anodes in solid oxide fuel cells (SOFCs) is application-dependent.
• Co-sputtering allows ratio control but faces challenges due to significant differences in sputtering yields between Ni and GDC targets.

Purpose of the Study:

• To overcome sputtering yield disparities for fabricating Ni-GDC anodes with a wide range of compositions.
• To determine the optimal Ni-GDC ratio for thin-film SOFCs and maximize performance in anodized aluminum oxide (AAO)-supported SOFCs.

Main Methods:

• Utilized a Gd-Ce metal alloy instead of GDC to match sputtering rates with Ni.
• Deposited thin films via sputtering, followed by oxidation to form crystalline GDC under SOFC operating conditions.
• Employed X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) for material characterization.

Main Results:

• Successfully fabricated Ni-GDC films with a wide compositional range by using a Gd-Ce alloy.
• Confirmed the transformation of the Gd-Ce alloy into crystallized GDC under SOFC operational environments.
• Achieved a peak performance of 638 mW/cm² at 500 °C in AAO-supported SOFCs with optimized Ni-GDC thickness.

Conclusions:

• The Gd-Ce alloy approach effectively addresses the sputtering yield mismatch for Ni-GDC anode fabrication.
• The optimized Ni-GDC anode composition and thickness are critical for maximizing the performance of thin-film SOFCs.
• This method enables the development of high-performance SOFCs for various energy applications.