Air-electrode active material and electrochemical device having the same

2:

• The air electrode active material of claim 1, wherein Ln is Pr, Ce, or La.

3:

• The air electrode active material of claim 2, wherein Ln is Pr.

4:

• The air electrode active material of claim 2, δ is 0.6 to 1.

5:

• The air electrode active material of claim 1, wherein Mis Mo, Nb, W, Ta, or V.

6:

• The air electrode active material of claim 5, wherein Mis Mo.

7:

• The air electrode active material of claim 1, wherein x is 0.1 to 0.3.

8:

• The air electrode active material of claim 1, wherein the air electrode active material has a triple-layer perovskite structure and has a single phase of a tetragonal structure.

9:

• The air electrode active material of claim 1, wherein the space group of the air electrode active material is P/4mmm.

10:

• The air electrode active material of claim 1, wherein the air electrode active material exhibits an Oads/Olat ratio of 4 to 5, which is a ratio of the oxygen adsorption (Oads) peak to the lattice oxygen (Olat) peak, in Ols X-ray photoelectron spectroscopy (XPS) analysis.

11:

• Electrochemical device comprising:
• a fuel electrode, an air electrode, and an electrolyte layer disposed therebetween,
• wherein the air electrode contains the air electrode active material according to claim 1.

12:

• The electrochemical device of claim 11, wherein the electrolyte layer is a proton-conducting electrolyte layer.

13:

• The electrochemical device of claim 11, wherein the air electrode does not include an additional proton ion conductor or electron conductor.

14:

• The electrochemical device of claim 11, wherein the electrochemical device is a Protonic Ceramic Fuel Cell (PCFC), a Protonic Ceramic Electrolyzer Cell (PCEC), or a Reversible Protonic Ceramic Cell (RPCC).