Zhou N, Wang Y, Cui H. Quasi-dynamic study of electrochemical properties of O3-high-Ni ternary single-crystal cathode materials with mirror symmetry: a first-principles study.
NANOSCALE 2023;
15:18383-18394. [PMID:
37933454 DOI:
10.1039/d3nr04586b]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
A total of 16 O3-type high-Ni ternary crystal structures with mirror symmetry were constructed based on the relative locations of Ni, Co, and Mn in order to design high operating voltage and high-capacity cathode materials for lithium-ion batteries. Transition states, powder X-ray diffraction (XRD) patterns, intercalation potentials, and (spin) electronic structures are computed and simulated based on first-principles calculations. The results show that the Li ion diffusion energy barrier, in the structure of the lowest energy counterpart a'aa', is only 0.9 eV. When charged to 75% state of charge (SOC), the Li layer spacing reaches a maximum under electrostatic attraction and Coulomb repulsion forces. The operating voltage and theoretical capacity are up to 4.79 V and 275 mA h g-1, respectively. High-spin Ni2+ participates in the reduction reaction as the main substance and is eventually oxidized to low-spin Ni4+. Intermediate-spin Co3+ also participates in the reduction reaction and is oxidized to low-spin Co4+, with charge compensation provided by O atoms. Mn does not participate in the redox reaction. This study is expected to enrich the library of high-nickel ternary cathode materials and provides a certain reference for the design of (ultra)high-nickel ternary cathode materials with excellent electrochemical properties.
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