<p>The first-principles calculation and design of LiCoO₂ are studied based on the electronic structure calculation of density functional theory (DFT), including a series of LiCo_0.75M_0.25O₂ (M: Fe, Mn, Cr, Ti, Mo, and W) by doping. The electron structure variation, i.e., the partial density of states (PDOS), of the doping and of Li⁺ de-intercalation (loss of 0.25 Li⁺) are discussed, and the influence of electrochemical performance is analyzed. The results show that: (1) the electronic structure of LiCoO₂ cathode doped with Fe, Mn, Cr, Ti, Mo, and W (LiCo_0.75M_0.25O₂) enhances Co–O skeleton bond of LiCoO₂, leading to an improved cycle life. (2) The Co–O skeleton bond of LiCoO₂ (including doping system) will maintain an intact structure during the Li⁺ de-intercalation but weakened during Li⁺ intercalation. (3) Based on the calculation and analysis of first-principles, especially the calculation and analysis of the <i>t</i>_2g, <i>e</i>_g, and O²⁻ <i>p</i> bands of electrochemically active Co^3+/4+, it is possible to design the composition and electronic structure of doped LiCoO₂ system and gain the doped LiCoO₂ lithium-ion cathode material with the best electrochemical performance. Therefore, the relevant research methods and results shed a light on doping other cathodes for lithium-ion batteries.</p> Graphical abstract <p></p>