Microprobe study of the effect of Li intercalation on the structure of graphite

The structural stability of graphite electrodes in Li-ion cells, which were cycled at room temperature and 60 °C was investigated. We observed gradual structural degradation of the graphite, which was most pronounced on the electrode surface but also extended into the bulk of the electrode. Graphite particles close to the Cu current collector remained almost unchanged, whereas those close to the electrode/electrolyte interface suffered significant structural damage. Structural degradation of the graphite led to an increased anode surface reactivity vs. the electrolyte. A thick layer of inorganic products from side reactions was observed on the disordered carbon areas of the anode.