<p>The efficiency of lithium-carbon dioxide (Li–CO₂) batteries is limited by the sluggish generation/decomposition kinetics of the discharge products (i.e., Li₂CO₃ and carbon) despite the use of state-of-the-art noble metal (NM) catalysts. Li₂C₂O₄ has emerged as a promising alternative product; however, the thermodynamic instability of Li₂C₂O₄ causes it to generally appear as an intermediate in Li₂CO₃ pathways rather than a product during discharge. Here, using comprehensive first-principles calculations, we report tailoring the discharge products of Li–CO₂ batteries to Li₂C₂O₄ via single-atom alloy (SAA) engineering, in which NM-doped copper SAAs (NM₁Cu) are constructed for demonstration. Certain NM₁Cu catalysts display a free-atom-like narrow d-band state and unique charge distribution over the solute NM₁ atom and the surrounding matrix Cu atoms. Such an optimized electronic structure is substantial in Ru₁Cu and Ir₁Cu, which is conducive to the co-activation and coupling of CO₂. The lithiation of *CO₂ intermediate that breaks the charge symmetry of the central C species can further reduce the kinetic barriers of the C–C coupling. These advantages promote Li₂C₂O₄ generation on Ru₁Cu and Ir₁Cu while suppress its subsequent disproportionation. Specifically, they exhibit low theoretical overpotentials and enable facile delithiation under normal charging voltages. This work proposes a universal principle of manipulating electronic structures to achieve Li₂C₂O₄ product, which provides practical guidance for the development of Li–CO₂ batteries.</p>