Electrode, solid oxide cell including the same, and method of preparing solid oxide cell

A solid oxide cell comprising:

• an air electrode;
• a fuel electrode;
• and a solid electrolyte layer disposed between the air electrode and the fuel electrode,
• wherein at least one of the air electrode or the fuel electrode comprises a composite conductor,
• wherein the composite conductor comprises:
• a first mixed conductor containing a first metal oxide having a perovskite structure, and
• a second mixed conductor containing a second metal oxide having a perovskite structure,
• wherein ionic conductivity of the first mixed conductor is greater than ionic conductivity of the second mixed conductor, and
• electronic conductivity of the second mixed conductor is greater than electronic conductivity of the first mixed conductor.

A method of preparing a solid oxide cell, the method comprising:

• providing a composition comprising a first metal oxide having a perovskite structure, and a second metal oxide having a perovskite structure;
• applying the composition to a surface of a first stack including a fuel electrode and a solid electrolyte layer, the surface with the applied composition adjacent to the solid electrolyte layer to provide a second stack;
• and
• heat-treating the second stack to provide the solid oxide cell, the solid oxide cell comprising an air electrode including a composite conductor, wherein the composite conductor comprises:
• a first mixed conductor comprising the first metal oxide;
• and a second mixed conductor comprising the second metal oxide,
• wherein ionic conductivity of the first mixed conductor is greater than ionic conductivity of the second mixed conductor, and
• electronic conductivity of the second mixed conductor is greater than electronic conductivity of the first mixed conductor.