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 g-1 [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): 365-371. [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): 5387-5416.

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