The　BaCo0.4Fe0.4Zr0.1Y0.1O3-δ　(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　anode-supported　single　cell　equipped　with　BCFZYCu4　as　the　cathode　exhibits　a　remarkable　power　density　of　1.30　W　cm−2　at　700　℃,　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　O　2p　band　center　closer　to　the　Fermi　level,　which　significantly　facilitates　the　oxygen　adsorption,　dissociation,　and　oxygen　ion　exchange　processes　of　the　BCFZYCu4　cathode.　©　2025　Elsevier　B.V.