Fig. 7. Understanding the physicochemical properties of lithium-rich layered oxide materials via atomistic calculations.

a Calculated free energy diagrams of the structural evolution on LNMO. The ligands LiO₆, MnO₆, and NiO₆ are represented by green, blue, and gray octahedrons, respectively. The free energy values were calculated based on the total supercell. b The energy difference between the octahedral sites (Li_oct) and tetrahedral sites (Li_tet) in LNMO, CD-LNMO-1, and CD-LNMO. c The reduced Bader charges of oxygen ions under different conditions of the fully delithiated CD-LNMO. The insets show the calculated ELF (isovalues of 0.7) of the oxygen ions in each condition. The Li, TM, and O ions are represented by green, blue and red balls, respectively. d Schematic illustration of the localized conditions and corresponding electronic structure evolution upon cycling. The Li, TM, and O ions are shown as green, purple, and red balls, respectively, and the vacancies are represented as hollow dash cycles. The redox of Mn³⁺/Mn⁴⁺ and Ni²⁺/Ni⁴⁺ are expressed by blue and gray bands, respectively, and lone pair O 2p orbitals and paired O 2p orbitals are marked by lO_2p (red bands) and O_2p (orange bands), respectively. The Fermi level, E_F, is shown as a dashed line.