<p>LiCoO₂ is widely used as cathode material for Li-ion batteries, owing to its easy synthesis and attractive volumetric energy density. However, the instability of the structure under high voltage limits the charge/discharge voltage below 4.2&#xa0;V, thus delivering half of the theoretical capacity, which constrains the further expansion of applications. Elemental doping is often used as an effective strategy to improve material properties. Therefore, Sb-doped LiCoO₂ is systematically studied based on first principles calculations in this work. The substitution formation energy calculation shows that the incorporation of Sb into LiCoO₂ cathode is thermodynamically favored. The incorporation of Sb expands the unit cell and elongates the Li-O bond, which is conducive to the improvement of rate performance. Electronic structure analysis shows that Sb doping increases the electronic states near the Fermi energy level and enhances the electronic conductivity of the cathode. In addition, the findings show that Sb doping helps to enhance the discharge voltage and cycle stability of LiCoO₂ cathode, where LiCo_0.917Sb_0.083O₂ has better cycle stability. This study provides a theoretical basis for the design of high-performance LiCoO₂ cathodes.</p> Graphical Abstract <p></p>