Commercial anodes with different state of charge are investigated by X-ray diffraction technique using Rietveld method for data collected with standard laboratory equipment. It is shown that full profile refinement gives good approximation for quantitative description of the charge/discharge process and may be used for estimation of real state of charge (SoC). Careful analysis of the diffraction profile with Rietveld method allows us to quantitatively distinguish the contribution of different Li _x C ₆ phases and estimate the real SoC.

In situ⁷Li and ex situ⁶Li nuclear magnetic resonance (NMR) spectroscopy is applied to monitor lithium mobility in a LiNiO₂ cathode during Li-ion (de)intercalation. In situ X-ray absorption spectroscopy and galvanostatic intermittent titration are also used to capture changes during the Li-ion deintercalation process. A considerable line broadening was first found by ⁷Li NMR spectroscopy. The Jahn–Teller distortion hinders the Li diffusion, thus broadening the NMR signal. The observed NMR shifts are compared to Li/vacancy ordering patterns described earlier by Arroyo y de Dompablo et al. Coupled motions of electrons and Li ions are also discovered by both in situ⁷Li and ex situ⁶Li NMR spectroscopy for the first time. They result in local Li environments with an enhanced number of Ni³⁺ neighbors at highly charged states. This opens a new perspective for understanding the highly delithiated structure.