Abstract

INTRODUCTION Solid oxide fuel cells are one of the fastest developing energy converters. The advancement introduced by research community provides steady state progress is stability and performance of the fuel cells. Significant influence on the cell’s performance and stability is related to cell design. The simplest design just consists of an anode, a solid electrolyte and a cathode. However, in order to improve the properties, the structure is nowadays modified and additional functional layers and introduced. The most commonly today’s cells are fabricated using the Ni-cerment anode, yttria stabilized zirconia (YSZ) electrolyte and perovskite cathode. It is well known that at high temperatures the YSZ reacts with the perovskite cathode forming the SrZrO3 and La2Zr2O7 phases [1,2]. These phases create a high resistance interlayers what decreases the cell performance. To avoid it a diffusion barrier in the form of thin film need to be created. This film separates cathode from electrolyte preventing the diffusion of strontium and lanthanum ions. The most common barrier is made of gadolinia doped ceria (CGO). It is chemically stable with good transport properties and its thermal expansion coefficient is compatible with YSZ and the most of commonly used cathodes. Many different methods are used to produce such a layer. The quality of the layer may differ depending on the method used [3,4]. In this paper a cost effective spray pyrolysis method was used for CGO fabrication. The influence of the CGO layer thickness and quality of obtained film on efficiency of diffusion barrier was investigated.

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