Nanocarbon materials for lithium-ion battery anodes: Review

Carbon allotropes are widely used as anodes and conductive additives for lithium-ion batteries (LIBs) owing to their large surface area, high electrical conductivity, and stability. By far, as only graphite has been commercialized, with limited capacity and stability, it is important to explore other carbon allotropes as anodes. Our review provides a comprehensive study of theoretical insights and electrochemical comparison of various carbon allotropes, mostly as anodes in LIBs. The theoretical insights mainly express the interaction of Li-ions with each carbon allotrope and guide about Li-ion diffusivity and adsorption that varies with geometry, edges, doping, vacancies, etc. Electrochemical battery performance discusses the structural limits of each carbon structure and emphasizes adopting methods such as doping, hybridization, and derivatization to improve LIB anode performance. To the above framework of theoretical and electrochemical investigation of carbon allotropes, a third layer of recyclability is purposely included to offer sustainable approaches in selecting the most appropriate carbon allotrope as anode for LIBs. The recycling process of each carbon with the most relevant purification method is highlighted, encouraging the use of greener and more sustainable approaches. In the landscape of carbon-based anode materials, this review directs through theoretical, experimental, and sustainable aspects to optimize carbon allotropes as potential LIB anodes. • Theoretical and experimental insights on carbon allotropes for LIB anodes. • Impact of geometry, edges, doping, and vacancies on Li-ion adsorption and diffusion. • Enhancements in capacity and stability via doping, hybridization, and derivatization. • Sustainable recycling approaches for carbon anodes with efficient purification routes. • Guidelines for selecting the best carbon allotrope towards greener LIB anodes.