• Systematic investigation of LiMO₂ (M = Co, Ni, Fe, Mn) cathodes within a unified computational framework using GGA, LDA, and their +U-corrected variants. • Verification that Hubbard-U corrections significantly improve lattice parameters, band gap predictions, voltage profiles, and mechanical stability relative to conventional DFT. • Accurate reproduction of experimental trends for LiCoO₂ and LiNiO₂, while providing new theoretical benchmarks for metastable cobalt-free LiFeO₂ and LiMnO₂. • Identifies mechanical instability—not electrochemical limitation—as the key obstacle for Fe- and Mn-based layered cathodes, guiding rational stabilization strategies for sustainable cobalt-free materials. . The development of cobalt-free, high-performance cathode materials for lithium-ion batteries requires a fundamental understanding of how transition-metal chemistry governs structural, electronic, and electrochemical behavior. This comprehensive computational study investigates LiMO₂ (M = Co, Ni, Fe, Mn) cathodes within a unified comparative framework, enabling direct evaluation of cation-dependent trends across the series. While LiCoO₂ and LiNiO₂ are well-established layered cathodes, Fe- and Mn-based alternatives remain less explored despite their relevance for sustainable battery chemistries. Our calculations reproduce key experimental trends in lattice parameters, band gaps, and voltage profiles for LiCoO₂ and LiNiO₂, while providing novel theoretical benchmarks for LiFeO₂ and LiMnO₂ treated as metastable layered R3̅m reference structures. Mechanical stability analysis shows that LiCoO₂ and LiNiO₂ satisfy the Born stability criteria, whereas LiFeO₂ and LiMnO₂ exhibit pronounced mechanical instability, consistent with their experimentally observed preference for non-layered polymorphs. The predicted full-delithiation voltages follow the trend: LiCoO₂ (4.62 V) > LiFeO₂ (4.20 V) > LiMnO₂ (4.17 V) > LiNiO₂ (4.11 V), reflecting intrinsic differences in transition-metal redox energetics within an equivalent crystallographic framework. Although thermodynamically unfavorable, the metastable layered Fe- and Mn-based phases serve as theoretical reference systems that illustrate how lattice symmetry and electron correlation influence electrochemical descriptors. These results establish a consistent theoretical framework for interpreting structure–property relationships in layered LiMO₂ cathodes and for informing future studies of cobalt-reduced and cobalt-free materials. .
Nazarihan et al. (Sun,) studied this question.