Lithium Intercalation into Mechanically Milled Natural Graphite: Electrochemical and Kinetic Characterization

The electrochemical lithium intercalation into natural graphite milled in various atmospheres was investigated. The atmosphere in which the natural graphite was milled has a strong influence on its final morphology and microstructure. These physical properties in turn have a pronounced effect on the electrochemical lithium intercalation process. The lithium storage capacity increases with the amount of disorder present, but it is also associated with a more pronounced discharge and charge potential hysteresis. Although a milled sample with a larger specific surface area is more susceptible to first cycle irreversible reactions, it has a smaller charge-transfer resistance. The chemical diffusion coefficient of intercalated lithium decreases when a large amount of disorder has been introduced into the sample by the mechanical milling process.