Nanoscale full-field (FF) transmission X-ray microscopy (TXM) and ensemble-averaged soft X-ray absorption spectroscopy (soft XAS) were used to investigate state-of-charge (SOC) heterogeneities in electrochemically charged or discharged and chemically oxidized samples of LiNi_0.6Mn_0.2Co_0.2O₂ cathode materials. We observed considerable and similar non-uniformities in terms of Ni oxidation states (and, by proxy, lithium distributions) for all the samples in the bulk. Therefore, the chemically delithiated samples are similar to the electrochemically charged samples in terms of mesoscale charge heterogeneity in large polycrystalline particle ensembles. However, the gradient oxidation states of transition metals on the surface, which is partly responsible for the electrode degradation mechanism known as surface reconstruction, is much less apparent in chemically delithiated samples.

纳米级全场（FF）透射X射线显微镜（TXM）和集合平均软X射线吸收光谱（Soft XAS）用于研究电化学充电或放电以及化学氧化中的荷电状态（SOC）异质性LiNi _0.6 Mn _0.2 Co _0.2 O _2的样品正极材料。我们观察到大块中所有样品的Ni氧化态（以及代理的锂分布）存在相当大且相似的不均匀性。因此，就大型多晶粒子集合体的中尺度电荷异质性而言，化学去锂化的样品与电化学带电的样品相似。但是，在表面化学过渡样品中，过渡金属在表面上的梯度氧化态（这部分负责电极降解机理，称为表面重构）在表面上的梯度氧化态要小得多。