Identification of ferrimagnetic orbitals preventing spinel degradation by charge ordering in LixMn2O4

Article

关键词: ELECTRONIC-STRUCTURE;    COMPTON-PROFILE;    X-RAY;    MAGNETIC-PROPERTIES;    SCATTERING;    LIMN2O4;    TRANSITION;    INSIGHTS;    LITHIUM;   

DOI  :  10.1103/PhysRevB.100.205104

来源: SCIE

【 摘 要 】

Spinel LixMn2O4 is a key cathode material that is used extensively in commercial Li-ion batteries. A challenge with this material has been that the capacity of the battery fades with cycling, an effect that can be traced to the presence of an antiferromagnetic insulator phase in the fully lithiated LiMn2O4 (LMO) and the associated charge disproportionation that drives distortions of the MnO6 octahedra. Here, by combining x-ray magnetic Compton scattering experiments with parallel first-principles computations, we show that the antiferromagnetic phase of LMO is surrounded by a robust ferrimagnetic metallic phase, which becomes stable when even a small amount of Li is removed from or added to the charge-ordered LMO. In this surprising ferrimagnetic state, charge-ordering and octahedral distortions are found to be strongly suppressed. We identify the nature of the ferrimagnetic orbitals involved through theoretical and experimental analyses of the magnetic Compton scattering spectra.

【 授权许可】

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