2024/03/04 by Cem Komurcuoglu, Komurcuoglu, Cem, Alan C. West +3
Engineering · Materials Science · #Advancements in Battery Materials #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Microwave Dielectric Ceramics Synthesis #Transition Metal Oxide Nanomaterials
paper · pdf · doi:10.48550/arxiv.2403.02520
openalex publication_date 2024/03/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The phase transition layered Li0.5NiO2 to spinel Li(NiO2)2 is a potential degradation pathway in LiNiO2-based lithium-ion battery cathodes. We investigated the mechanism of this phase transformation from first principles. Consistent with experimental observations reported in the literature, our results indicate a high energy barrier for the transformation due to high defect-formation energies, a complex charge-transfer mechanism, and electronic frustration. Our results suggest that partially inverse spinel phases are unlikely to form for Li0.5NiO2, a qualitative difference from the chemically similar Li0.5MnO2, in which the transformation occurs at room temperature. We show that Ni and Li atoms migrate concertedly towards their respective spinel sites for the layered-to-spinel transformation to occur. We investigated the charge ordering in layered phases along the LiNiO2-NiO2 composition line, finding a pronounced impact of the symmetry and space group on the layered-to-spinel transition in Li0.5NiO2. Finally, we evaluated the relative stability of different spinel space groups, finding that previously reported experimental observations are consistent with a temperature-averaged structure rather than the 0 Kelvin ground-state structure of Li(NiO2)2 spinel.