Abstract
This work is based on the development and optimization of electrolytes for proton conducting ceramic fuel cells (PCFC), operating at 600 °C temperature range. The first part of this PhD consists in developing systems based on a composite electrolyte (proton conductors (BZY)-alkali carbonates or sulphates) which have the advantage of operating at lower temperatures (400-500°C). The study was dedicated to the development, characterization and understanding of the conduction mechanisms in this type of composite. Promising results have been obtained compared to monophasic classical electrolytes.The second part is focused on the improvement of the sintering properties of the wall known BCZY electrolyte by using nano-powders and single or double sintering aids associating two transition metals (ZnO-Li2O) or one transition metal and one alkali carbonates. The significant decrease of the sintering temperature allows to consider the development of innovativemetal supported devices.