非阻塞I/O
密度泛函理论
离子
化学
氧化还原
氧气
材料科学
结晶学
无机化学
计算化学
催化作用
生物化学
有机化学
作者
Annalena R. Genreith‐Schriever,Hrishit Banerjee,Ashok S. Menon,Euan N. Bassey,Louis F. J. Piper,Clare P. Grey,Andrew J. Morris
出处
期刊:Joule
[Elsevier]
日期:2023-07-01
卷期号:7 (7): 1623-1640
被引量:45
标识
DOI:10.1016/j.joule.2023.06.017
摘要
Ni-rich lithium-ion cathode materials achieve both high voltages and capacities but are prone to structural instabilities and oxygen loss. The origin of the instability lies in the pronounced oxidation of O during delithiation: for LiNiO2, NiO2, and the rock salt NiO, density functional theory and dynamical mean-field theory calculations based on maximally localized Wannier functions yield a Ni charge state of ca. +2, with O varying between −2 (NiO), −1.5 (LiNiO2), and −1 (NiO2). Calculated X-ray spectroscopy Ni K and O K-edge spectra agree well with experimental spectra. Using ab initio molecular dynamics simulations, we observe loss of oxygen from the (012) surface of delithiated LiNiO2, two surface O⋅− radicals combining to form a peroxide ion, and the peroxide ion being oxidized to form O2, leaving behind two O vacancies and two O2− ions. Preferential release of 1O2 is dictated via the singlet ground state of the peroxide ion and spin conservation.
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