Electrode-electrolyte composite powders for a fuel cell and method for the preparation thereof

A method for preparing electrode-electrolyte composite particles, which comprises,

• (1) dissolving a starting material of an electrode raw material in a solvent to obtain an electrode solution, wherein the electrode raw material is selected from the group consisting of lanthanum raw material, strontium raw material, manganese raw material, nickel raw material, and combinations thereof, and adding thereto one material selected from an amino acid, citric acid and a polymer resin, together with a powder form of an electrolyte material which does not dissolve in the electrode solution to obtain an electrode-electrolyte mixture, the solvent comprising water and nitric acid;
• (2) ball-milling the electrode-electrolyte mixture;
• (3) subjecting the ball-milled mixture to self-combustion or heat treatment, to form composite particles in crystalline form;
• and
• (4) calcining the composite particles to form the electrode-electrolyte composite particles, wherein the electrode-electrolyte composite particles comprise La1-xSrxMnO3wherein 0.05≦x≦0.85.