研究发现，氧参与是描述传统层状氧化物中电荷补偿的关键因素。通过高分辨率OK边共振弹性X射线散射（RIXS）映射，揭示了镍丰富LiNi0.8Co0.2yAlyO2电池正极材料的共同电荷补偿模式，涉及过渡金属红ox和氧共价作用。RIXS映射显示，在完全脱锂时出现尖锐特征，这与碱金属富集系统中的晶格氧电荷补偿相关。该特征随荷电状态的变化反映了氧参与下O2p态的耗尽。
摘要：
Oxygen participation, arising from increased transition metal-oxygen covalency during delithiation, is considered essential for the description of charge compensation in conventional layered oxides. The advent of high-resolution mapping of the O K-edge resonant inelastic X-ray scattering (RIXS) provides an opportunity to revisit the onset and extent of oxygen participation. Combining RIXS with an array of structural and electronic probes for the family of Ni-rich LiNi 0.8 Co 0.2y Al y O 2 cathodes, we identify common charge compensation regimes that are assigned to formal transition metal redox (o4.25 V) and oxygen participation through covalency (44.25 V). From O K-edge RIXS maps, we find the emergence of a sharp RIXS feature in these systems when approaching full delithia-tion, which has previously been associated with lattice oxidized oxygen in alkali-rich systems. The lack of transition metal redox signatures and strong covalency at these high degrees of delithia-tion suggest this RIXS feature is similarly attributed to lattice oxygen charge compensation as in the alkali-rich systems. The RIXS feature's evolution with state of charge in conventional layered oxides is evidence that this feature reflects the depopulation of occupied O 2p states associated with oxygen participation.
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