<i>Operando</i> Measurement of Layer Breathing Modes in Lithiated Graphite

Despite their ubiquitous usage and increasing societal dependence on Li-ion batteries, there remains a lack of detailed empirical evidence Li intercalation/deintercalation into graphite even though this process dictates the performance, longevity, safety system. Here, we report direct detection dissociation specific crystallographic phases in lithiated graphite, which form through stepwise staging process. Using operando measurements, LiC18, LiC12, LiC6 are observed via distinct low-frequency Raman features, result displacement lattice by induced local strain. Density functional theory calculations confirm nature Raman-active vibrational modes, to layer breathing modes (LBMs) graphite. The new findings indicate graphene-like characteristics under deep charged condition due imposed strain inserted Li. Moreover, our approach also provides simple experimental tool measure structure full intercalation conditions.