Hydrogen related technologies have gained importance in the latest period due to the hydrogen role in the energy transition process from fossil to sustainable sources. Solid oxide cells (SOCs) represent one of the most promising technologies. Its basic unit comprises of an electrolyte, an anode and a cathode. Due to the high operation temperature (~ 800 °C) it does not need Pt-metals catalysts and features higher efficiency than lower temperature cells. However, the high operation temperature poses high requirements on the materials properties. Despite a significant material development, the electrolyte is still responsible for majority of ohmic losses in the system.