Symmetry-broken Mn-Co3O4/RuO2 heterointerfaces enable catalytic shunting and self-adaptive oxygen electrocatalysis in Li-O2 batteries

Mn doping creates symmetry-broken Co δ+ -O-Ru δ− heterointerfaces. • Polarized Ru and Co sites enable catalytic shunting of ORR and OER. • Reversible metal-oxygen bond adaptation accelerates Li 2 O 2 conversion. • The catalyst delivers an ultralow discharge-charge overpotential of 0.37 V. • Li-O 2 cells reach 34,738 mAh g −1 and cycle stably for 208 cycles. Aprotic Li-O 2 batteries require efficient bifunctional oxygen electrocatalysis, yet ORR and OER impose conflicting demands on oxygen-intermediate adsorption and product desorption. Herein, we construct a symmetry-broken Mn-doped Co 3 O 4 /RuO 2 heterointerface on carbon cloth to couple catalytic shunting with self-adaptive interfacial bonding. Mn incorporation reinforces Co-O-Ru coupling and generates asymmetric Co δ⁺ -O-Ru δ⁻ units, as verified by XPS, XAS, and theoretical calculations. The resulting interfacial polarization spatially divides the oxygen-redox pathway: electron-enriched Ru sites preferentially promote O₂ adsorption/activation for ORR, whereas electron-deficient Co sites facilitate Li₂O₂ decomposition/desorption for OER. Meanwhile, in situ Raman spectroscopy and theoretical bond-length analysis reveal reversible metal-oxygen bond elongation/contraction during discharge/charge, enabling temporal adaptation of interfacial bonding to evolving intermediates. This spatial shunting and temporal self-adaptation synergistically mitigate the adsorption-desorption conflict, improve Li 2 O 2 reversibility, and maintain efficient charge-transfer pathways. Consequently, the Mn-Co 3 O 4 /RuO 2 cathode achieves a low overpotential of 0.37 V, a high discharge capacity of 34,781 mAh g −1 , and stable cycling for 208 cycles. This study provides a shunt-adaptive heterointerface strategy for multistep oxygen electrocatalysis. Download: Download high-res image (275KB) Download: Download full-size image