A Dilatometric Study of Lithium Intercalation into Powder-Type Graphite Electrodes

The thickness change of porous multiparticle graphite electrodes upon first electrochemical lithium intercalation and extraction was investigated by means of electrochemical dilatometry. For all investigated graphites, expansion starts well above 0.5 V vs and thus, before any unsolvated Li intercalation compounds are formed. This finding can be explained by solvent co intercalation during the first charge prior to SEI formation, as described by the Besenhard model. At potentials vs , i.e., in the region of unsolvated intercalation, the dilatation curves reveal the same major staging features that are seen in the corresponding potential profiles.