ECoS project aims to develop a sustainable technology for green hydrogen production and recycling of carbon dioxide by revolutionizing solid oxide electrolysis with a new class of robust cells with enhanced performance and multi-functional capacity. ECoS objectives are the development of new Solid Oxide Electrolysis Cells (SOEC) electrode materials and single cells and a detailed study of the mechanism of the SOEC fuel electrode degradation processes under H₂O electrolysis and H₂O-CO₂ co-electrolysis conditions. The project aims to provide step change improvements in SOEC technology in terms of performance, endurance, robustness, and production cost. This will be accomplished by using perovskite structure electrocatalysts both for the cathode (fuel: H₂O, CO₂) and anode (O₂) electrode. Developments and optimizations of electrodes and cells will be achieved by applying both conventional and advanced techniques. Conventional approaches entail screen printing and tape casting techniques, while advanced, yet scalable techniques refer to Flame Spray Pyrolysis, which offer the advantage of controlling composition, thickness and porosity of materials and layers that comprise the cell building blocks: electrodes, electrolyte, protective layers and current collectors. Effective application of these techniques can lead to layers of tailored features, allowing also the minimization of successive deposition and heating steps and thus contributing to cost effective cell production process. Regarding the most demanding challenge in SOEC technology, which is the stable efficient cathode electrodes, Ni-metal free ceramic electrocatalysts of perovskite structure will be synthesized and studied. ECoS goes substantially beyond the state of the art by introducing highly ambitious and novel ideas and by combining different research disciplines, including: Materials Science, Surface Science, Electrochemistry, Heterogeneous Catalysis, Engineering and cell/stacks fabrication techniques.