Reasonable　design　of　robust　bifunctional　oxygen　catalysts　from　an　electronic　structure　perspective　is　intriguing　and　challenging　for　the　development　of　high　active　rechargeable　zinc-air　batteries　(ZABs).　In　this　study,　the　favorable　regulation　of　the　electronic　structure　of　the　cobalt　oxide　nanoclusters　was　firstly　predicted　by　density　functional　theory　(DFT)　simulation,　and　then　experimentally　verified　by　confining　sub-nanometer　CoOx　clusters　(0.86　nm)　into　the　small　pore　of　ZIF-8　derived　N-doped　nanomaterials　(PNC)　using　a　microporous　MOFs　confinement　strategy.　The　confined　effect　of　the　MOF　micropores　not　only　enhanced　the　stability　of　the　sub-nanometer　cobalt　oxide　clusters,　but　also　make　it　coupled　with　CoNx　to　further　regulate　the　electronic　structure　of　the　former,　synergistic　resulting　in　enhanced　ORR/OER　actives.　As　a　result,　the　optimized　0.05CoOx@PNC　catalyst　demonstrates　outstanding　bifunctional　oxygen　performance　with　a　smaller　potential　gap　of　0.67　V.　Moreover,　the　rechargeable　Zn-air　batteries　integrated　0.05CoOx@PNC　air　cathode　displays　encouraging　performance　with　a　peak　power　density　of　157.1　mW　cm−2,　a　specific　capacity　of　887　mAh　gZn−1at　10　mA　cm−2　and　long-term　cyclability　for　over　200　h,　significantly　outperforming　the　benchmark　electrode　couple　consisted　of　Pt/C/RuO2.　DFT　calculation　further　revealed　that　reducing　particle　size　and　coupling　with　CoN　could　effectively　regulate　the　charge　distribution　of　CoOx　nanoclusters　and　downshift　the　D-band　center　of　Co　adsorption　sites　in　CoOx　nanoclusters,　which　reduced　the　reaction　barrier　of　intermediate　O2*　and　OH*　and　ORR/OER　overpotential,　thus　accelerating　the　overall　ORR/OER　kinetic　process.　This　work　offers　a　novel　reference　for　the　construction　of　a　robust　sub-nanometer　cluster　catalysts　in　the　field　of　ZABs.　©　2021