Nanoporous silver cathode surface treated by atomic layer deposition of CeOx for low-temperature solid oxide fuel cells

Abstract

We evaluated the performance of solid oxide fuel cells (SOFCs) with a 50 nm thin silver (Ag) cathode surface treated with cerium oxide (CeOx) by atomic layer deposition (ALD). The performances of bare and ALD-treated Ag cathodes were evaluated on gadolinia-doped ceria (GDC) electrolyte supporting cells with a platinum (Pt) anode over 300 degrees C- 450 degrees C. Our work confirms that ALD CeOx treatment enhances cathodic performance and thermal stability of the Ag cathode. The performance difference between cells using a Ag cathode optimally treated with an ALD CeOx surface and a reference Pt cathode is about 50% at 450 degrees C in terms of fuel cell power output in our experiment. The bare Ag cathode completely agglomerated into islands during fuel cell operation at 450 degrees C, while the ALD CeOx treatment effectively protects the porosity of the cathode. We also discuss the long-term stability of ALD CeOx-treated Ag cathodes related to the microstructure of the layers.