Local strain switches CO₂ reduction to a 3.13 V Li₂C₂O₄ pathway for Li-CO₂ batteries

The practical application of Li–CO₂ batteries is hindered by sluggish reaction kinetics and the formation of insulating Li₂CO₃, which severely compromise their energy efficiency and cycling stability. This work transcends conventional catalytic paradigms by harnessing synergistic lattice-mediated electronic perturbations—specifically, a periodic surface superlattice that engenders localized compressive strain—to reconFig. the near-Fermi-level d-band electronic landscape of catalytically active transition metal sites. This strain-induced d-band reconstruction, characterized by a downward Fermi level shift concomitant with an upward d-band center migration, fundamentally amplifies Cu–O orbital hybridization and thermodynamically stabilizes a low-bandgap Li₂C₂O₄ metastable discharge manifold. Consequently, the resulting Li–CO₂ cell achieves an exceptional discharge voltage plateau of 3.13 V (overpotential of merely 0.42 V), uninterrupted operation exceeding 1300 hours at 20 μA cm⁻², and an energy retention ratio of 88%. Comprehensive in situ spectro-electrochemical and ab initio theoretical validations unequivocally ascribe this performance enhancement to the strain-modulated d-band control and the resultant non-conventional Li₂C₂O₄ reaction pathway, thereby establishing a previously unexplored catalyst design logic for advanced metal–gas battery systems.