Review—Energy Storage through Graphite Intercalation Compounds

Research and development with regards to battery technologies have been evolving at a profitably good rate with an impressive amount of progress being made at different levels. Graphite has been continuously preferred as the anode material for lithium-ion batteries since its commercialization in 1991. The interlayer spacing of about 3.35 Å promotes the intercalation of guest ions, thereby resulting in what is called graphite intercalation compounds (GICs). Through such intercalation mechanisms, graphite can contribute to electrochemical charge transfer owing to its ionic and electronic conduction properties. The intercalation of alkali metal ions into graphite is considered the epitome of ion intercalation with regards to layered materials. Putting together various inferences made through the years, this review aims at establishing a foundational understanding of GICs and their applications in energy storage devices. A brief overview of graphite intercalation chemistry has been provided and discussions on the advancements in various GICs ranging from binary-GICs to ternary-GICs have been elaborated. Towards the end, this paper provides a comprehension of the specific strategies that might improve the performance of a GIC, following which the challenges and the future of GIC-based research have also been highlighted.