Nanostructured Cathodes for Solid Oxide Fuel Cells by a Solution Spray-Coating Process

作者：Zhang Lei; Zhu Liangzhu; Virkar Anil V^*

来源：Journal of the Electrochemical Society, 2016, 163(13): F1358-F1365.

DOI：10.1149/2.0541613jes

Composite nano-cathodes containing Sr-doped LaMnO3 (LSM) and Gd2O3-doped CeO2 (GDC) were deposited on yttria-stabilized zirconia (YSZ) discs and YSZ/NiO + YSZ bi-layer discs using an aqueous solution. The samples were heated over a range of temperatures from 700 degrees C to 1200 degrees C to form LSM + GDC porous films. The crystallite size was estimated using X-ray diffraction (XRD) Scherrer formula. The crystallite size was in the similar to 3 nm to similar to 80 nm range. Polarization resistance was measured by electrochemical impedance spectroscopy (EIS) from 400 degrees C to 700 degrees C. Nano-cathodes of similar to 70 nm thickness fired at 700 degrees C exhibited polarization resistance of similar to 0.23 Omega cm(2) at 700 degrees C. By contrast, LSM + YSZ cathodes made by a conventional process exhibited polarization resistance of similar to 2 Omega cm(2). Fuel cell tests were conducted at 700 degrees C on cells with nano-cathodes and conventional LSM + YSZ cathode. The maximum power density was similar to 0.51 Wcm(-2) with nano-cathodes. By contrast, the corresponding power density with conventional LSM + YSZ cathodes was similar to 0.11 Wcm(-2). The present work shows that very thin cathode functional layers can be deposited on sintered YSZ/NiO + YSZ bi-layer discs by using an aqueous solution. This approach in principle could be extended to large area cells.

• 出版日期2016