Li intercalation into multilayer graphene with controlled defect densities

We studied the influence of defect density in multilayer graphene sheets on the intercalation of Li ions by means of x-ray photoelectron spectroscopy. The multilayer graphene was prepared by chemical vapor deposition on Ni substrates. The deposition of Li at room temperature results in immediate intercalation, while additional annealing at 300 °C partially removes Li from the sample surface. We found that varying the defect density over several orders of magnitude does not influence the intercalation process. We propose that the edges of the graphene flakes are the dominant sites that facilitate Li intercalation in multilayer graphene.