Carbon Structure and Raman Spectroscopy

It is now well-known that Raman spectroscopy is being used for tracking the structural form of carbons used in industrial applications. The structure of graphite, microcrystalline graphite, and the nanotubes and buckeyballs are well understood and described by rigorous physical methods. However, many of the carbon materials used in large commercial applications are not as well characterized. Depending on the substrates from which they are made, they can be graphitic, graphitizable, or non-graphitizable. For instance, the preferred carbon for use in the anodes of Li+ batteries is termed hard carbon, and its properties depend on the selection of starting materials and processing conditions. In this column, we will describe what is known about the structures of these materials and how Raman spectroscopy can characterize them. If you follow my columns, you will realize that this is not the first column that I have written on the Raman spectra of carbons. In this case, the ultimate goal is to provide our readers enough information for them develop correlations between the Raman spectral characteristics and performance of the materials.