Ground-state search and modification effects of lanthanide substitution in LiNiO2: a first-principles study

• • LNO+Ce achieves the highest Li/Ni disordering formation energy and oxygen vacancy formation energy among Ln (La–Gd) dopants, with a c/a ratio near 4.99 (comparable to LiCoO2), directly translating to suppressed cation mixing and reduced lattice oxygen loss—critical for extending cycle life in high-nickel cathodes. • • The 4f electron magnetic moment of Ln ions serves as a distinctive marker for converged states; by incorporating this parameter into cutoff-energy convergence plots, the ground-state search reduces computational resource consumption by an order of magnitude compared to exhaustive sampling, enabling routine DFT studies of Ln-doped systems. • • Ln doping generally increases oxygen vacancy formation energy at all three oxygen sites, with the enhancement effect becoming more pronounced as the distance to the Ln site decreases; this spatial gradient informs dopant placement strategies to maximize oxygen retention under high-voltage cycling. • • The workflow provides Uf values for Ln ions in VASP, resolving the convergence instability that previously rendered LNO+Ln simulations impractical; this standardization allows reproducible calculation of formation energies and electronic structures for La–Gd substitutions, accelerating screening of lanthanide dopants for layered cathodes.