Abstract New oxygen-deficient double perovskites, Ba2FeCoO6-δ, was prepared using facile wet chemical route. The synthesized material was characterized by powder X-ray diffraction, which indicates formation of cubic phase of Ba2FeCoO6-δ with Pm 3 ¯ m symmetry. The electrode of Ba2FeCoO6-δ material was investigated with the help of electrochemical analysis technique in 2 M KOH electrolyte solution. Its behavior shows excellent electrochemical performance, i.e., a maximum specific capacitance 820.0 F g−1 at a current density of 3 A g−1. Further, the proposed Ba2FeCoO6-δ electrode provided two key parameters values, i.e., energy density as 23.06 Wh kg−1 and power density as 677.92 W kg−1 at a current density of 3 A g−1.