Seminal Literature

Discovery And Commercialization Of The Graphite Anode Yazami and Touzain first demonstrated the electrochemical intercalation of lithium into graphite with a polymer electrolyte in 1983 1. Since then, graphite has become the preferred anode in lithium-ion batteries.

FUNDAMENTALS 2

Graphite is an allotrope of carbon with sp hybridization where graphene sheets are linked together through relatively weak Van der Waals forces 1. Li intercalates into graphite (inserts itself between graphene layers) in stages. In the final stage, a stoichiometry of LiC6 is reached, corresponding to a theoretical specific capacity of 372 mAh g–1 2.

CHALLENGES

RECENT DEVELOPMENTS

Limited rate capability in the lithiation process (charging) can result in lithium plating on the graphite surface, leading to short circuits 2. First cycle irreversible capacity loss due to electrolyte reduction and formation of solid electrolyte interphase SEI. Graphite is unable to be recycled via traditional pyrometallurgy or hydrometallurgy 2.

Natural vs. synthetic graphite: while synthetic graphite is often more expensive than natural graphite, it benefits from higher purity, better thermal stability, and independence from natural resources 2. Embedding silicon/silicon oxide for increased energy densities. Silicon has a theoretical energy density of 3578 mAh g1 2.

OCV of graphite || Li system Source: 1 Yazami, R., and Ph Touzain. "A reversible graphite-lithium negative electrode for electrochemical generators." Journal of Power Sources 9.3 1983 365371. 2 Asenbauer, Jakob, et al. "The success story of graphite as a lithium-ion anode material–fundamentals, remaining challenges, and recent developments including silicon (oxide) composites." Sustainable Energy & Fuels 4.11 2020 53875416.

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