The　BaCo0.4Fe0.4Zr0.1Y0.1O3-delta　(BCFZY)　perovskite　oxide　is　a　highly　promising　cathode　material　for　solid　oxide　fuel　cells　(SOFCs),　mainly　due　to　its　exceptional　three-phase　conductivity　at　the　elevated　temperatures　and　remarkable　oxygen　reduction　reaction　(ORR)　activity.　Nevertheless,　its　limited　electronic　and　ionic　conductivities　at　relatively　lower　temperatures　poses　a　significant　challenge　for　its　low-temperature　applications.　To　address　this　issue,　the　Cu　doping　in　the　B-site　of　BCFZY　is　proposed.　It　is　observed　that　Cu　doping　significantly　enhances　both　the　electronic　conductivity　and　oxygen　exchange　kinetics,　leading　to　a　notable　reduction　in　polarization　resistance　and　a　substantial　improvement　in　ORR　catalytic　activity.　Specifically,　the　Ni-YSZ　anodesupported　single　cell　equipped　with　BCFZYCu(4)　as　the　cathode　exhibits　a　remarkable　power　density　of　1.30　W　cm(-2)　at　700　degrees　C,　which　surpasses　that　of　the　single　cell　with　BCFZY　cathode　by　51.16　%.　An　in-depth　mechanism　study　has　revealed　that　the　enhanced　performance　is　closely　linked　to　the　increased　orbitals　hybridization　induced　by　Cu　doping.　This　not　only　enlarges　the　covalency　of　the　Co-O/Cu-O　bonds　but　also　shifts　the　metal　3d　and　O2p　band　center　closer　to　the　Fermi　level,　which　significantly　facilitates　the　oxygen　adsorption,　dissociation,　and　oxygen　ion　exchange　processes　of　the　BCFZYCu(4)　cathode.