The demand for energy-efficient, decentralized and environmentally friendly power production is expected to grow in the coming years. Solid oxide fuel cells (SOFC) have received much attention due to their wide range of applications. Cells with different designs (planar and tubular) and supports (electrolyte-, anode- or metal- supported) have been developed and intensively tested in terms of performance, degradation rate and lifetime. Still, technical improvement and especially the cost reduction are crucial factors to make SOFC attractive for the market.

In the framework of a public funded project, a novel SOFC-concept is evaluated that has advantages in terms of costs and lifetime. The cell is mechanically supported by an inert porous silicate layer on the air side and was designed to enable a one-step co-sintering process of the entire cell at temperatures between 1100 °C and 1300 °C (Fig.1). In this contribution, we present the current status of the cell performance in this novel SOFC concept. First investigations carried on co-sintered button cells showed very promising results, namely high OCV values and a power density up to 300 mW/cm² at 750 °C in pure hydrogen.

However, the impedance analysis of the cells points out that a further cathode optimization would be beneficial for the overall cell performance in the novel layout. An additional electrochemical and microstructural analysis of symmetrical cells with a LSM-YSZ cathode sintered on a silicate support showed that cathode properties [1], in particular the oxygen reduction reaction, are strongly influenced by the presence of the silicate during co-sintering, due to evaporation of transition metals from the substrate.