A solid-oxide fuel cell that operates at 500 degreesC (instead of 600 degreesC and higher), with lower material cost and better long-term stability, is presented. Its key piece is a cathode made of a silver/copper-doped bismuth vanadate (Ag-BI-CUVOX) composite, which reduces oxygen at lower temperatures and diminishes the resistance between the cathode and the electrolyte. The Figure shows an SEM cross section of the described cell.