Improve Lithium-Ion Battery Performance: Amorphous Carbon, Graphene, and Carbon Nanotube-Modified Silicon Anodes

Abstract

With ultra-high theoretical capacity, silicon is seemed as a potential anode for the next generation lithium-ion batteries. Its extremely huge volume expansion (~300%) of Si anode upon lithiation-delithiation processes, however, causes particle pulverization and unstable SEI, hinders its practical application. To solve these drawbacks, related Si-C composite strategies have been proposed by researchers. This review systematically covers typical three types of carbon materials (including amorphous carbon, graphene, and CNTs) that can be employed to modify nanosilicon anodes. Amorphous C has a uniform coating, and economical preparation, which improves stability but it is not sufficiently conductive. Graphene provides high conductivity and mechanical strength, but it is featured by high cost and aggregation. CNTs can be used as a conductive and flexible networks to enhance the cycle life, however, they are difficult to disperse and interfaced. Each carbon population also exhibits unique merits and limitations in improving the mechanical strength, conductivity, and chargeability of silicon anodes. Further work is desired for investigating hybrid carbon structures, tunning interfacial bonding, and scalable, green synthesis. These developments will promote the commercialization of high-energy-density silicon−carbon anodes for advanced Li-ion batteries.