First-principles theory of doping in layered oxide electrode materials

Abstract

Doping lithium-ion battery electrode materials LiMO${}_2$ (M = Co, Ni, Mn) with impurities has been shown to be an effective way to optimize their electrochemical properties. Here, we report a detailed first-principles study of layered oxides LiCoO${}_2$, LiNiO${}_2$, and LiMnO${}_2$ lightly doped with transition-metal (Fe, Co, Ni, Mn) and non-transition-metal (Mg, Al) impurities using hybrid-density-functional defect calculations. We find that the lattice site preference is dependent on both the dopant's charge and spin states, which are coupled strongly to the local lattice environment and can be affected by the presence of co-dopant(s), and the relative abundance of the host compound's constituting elements in the synthesis environment. On the basis of the structure and energetics of the impurities and their complexes with intrinsic point defects, we determine all possible low-energy impurity-related defect complexes, thus providing defect models for further analyses of the materials. From a materials modeling perspective, these lightly doped compounds also serve as model systems for understanding the more complex, mixed-metal, LiMO${}_2$-based battery cathode materials.

10 pages, 8 figures

References in corpus (5)

• Defect chemistry in layered transition-metal oxides from screened hybrid density functional calculations
• Defect physics, delithiation mechanism, and electronic and ionic conduction in layered lithium manganese oxide cathode materials
• Successes and failures of Hubbard-corrected density functional theory: The case of Mg doped LiCoO${}_2$
• Polaron formation, native defects, and electronic conduction in metal tungstates
• Effect of magnesium doping on the orbital and magnetic order in LiNiO2

Cited by in corpus (1)

• Doping Li-rich cathode material Li${}_2$MnO${}_3$: Interplay between lattice site preference, electronic structure, and delithiation mechanism