Tuning　the　d-orbital　electronic　configuration　of　active　sites　to　achieve　well-optimized　adsorption　strength　of　oxygen-containing　intermediates　toward　reversible　oxygen　electrocatalysis　is　desirable　for　efficient　rechargeable　Zn-Air　batteries　but　extremely　challenging.　Herein,　this　work　proposes　to　construct　a　Co@Co3O4　core–shell　structure　to　regulate　the　d-orbital　electronic　configuration　of　Co3O4　for　the　enhanced　bifunctional　oxygen　electrocatalysis.　Theoretical　calculations　first　evidence　that　electron　donation　from　Co　core　to　Co3O4　shell　could　downshift　the　d-band　center　and　simultaneously　weak　spin　state　of　Co3O4,　result　in　the　well-optimized　adsorption　strength　of　oxygen-containing　intermediates　on　Co3O4,　thus　contributing　a　favor　way　for　oxygen　reduction/evolution reaction　(ORR/OER)　bifunctional　catalysis.　As　a　proof-of-concept,　the　Co@Co3O4　embedded　in　Co,　N　co-doped　porous　carbon　derived　from　thickness　controlled　2D　metal-organic-framework　is　designed　to　realize　the　structure　of　computational　prediction　and　further　improve　the　performance.　The　optimized　15Co@Co3O4/PNC　catalyst　exhibits　the　superior　bifunctional　oxygen　electrocatalytic　activity　with　a　small　potential　gap　of　0.69 V　and　a　peak　power　density　of　158.5 mW　cm−2　in　ZABs.　Moreover,　DFT　calculations　shows　that　the　more　oxygen　vacancies　on　Co3O4　contribute　too　strong　adsorption　of　oxygen　intermediates　which　limit　the　bifunctional　electrocatalysis,　while　electron　donation　in　the　core–shell　structure　can　alleviate　the　negative　effect　and　maintain　superior　bifunctional　overpotential.　©　2023　Wiley-VCH　GmbH.