Electronegativity‐Driven Frontier Orbital Engineering in B‐Ti Diatomic Synergy Enables Selective Li ₂ C ₂ O ₄ Conversion in Li‐CO ₂ Batteries

ABSTRACT As a promising alternative to sluggish Li 2 CO 3 ‐based Li‐CO 2 electrochemistry, Li 2 C 2 O 4 offers a favorable 2e − discharge pathway, yet its selective formation and reversible decomposition remain debated. Herein, we propose a nonmetal‐metal synergistic catalyst—B‐Ti coregulated layered transition metal boride Ti 18 B 18 O 9 /graphene (B‐Ti/TiBOG)—to enable efficient CO 2 ‐to‐Li 2 C 2 O 4 conversion via frontier orbital engineering (FOE). Density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations reveal that the low electronegativity of B (O > N > C > B) induces asymmetric Ti coordination, driving strong B 2p and Ti 3d orbital hybridization near the Fermi level, and better structural stability, outperforming C/N/O‐Ti analogs. Interestingly, this unique FO alignment activates CO 2 by populating its antibonding orbitals through a bidirectional “acceptance‐feedback” mechanism to enhance CO 2 adsorption (from −0.19 to −1.05 eV). The B‐Ti synergy selectively stabilizes Li 2 C 2 O 4 nucleation while kinetically suppressing its conversion to Li 2 CO 3 (barrier > 0.68 eV). Consequently, the hybrid B‐Ti/TiBOG catalyst achieves exceptional bifunctionality, yielding a minimal total overpotential (0.75 V) for CO 2 ‐to‐Li 2 C 2 O 4 cycling—maintained in the tetraethylene glycol dimethyl ether (TEGDME) solvent environments. This work highlights electronegativity‐driven FOE in B‐Ti diatomic synergy as key for rechargeable Li‐CO 2 batteries.