Research progress on carbon coating of silicon anode in high-performance lithium-ion batteries

In recent years, the escalating energy demand has promoted the development of rechargeable lithium batteries (LIBs). Silicon anode has attracted much attention by virtue of its extremely high theoretical capacity, relatively low Li-insertion voltage and availability of silicon resources. Nevertheless, the violent volume expansion and fragile solid electrolyte interface (SEI) film hinder the commercial application of Si-based anodes. To solve the above issues, Si materials are combined with various carbonaceous materials, which enhances structural stability and optimizes interface characteristics. In this review, different carbon materials such as amorphous carbon and graphite as three-dimensional (3D) protective coatings for Si anodes to buffer mechanical strain and isolate electrolyte are presented. The novel preparation methods for integrating silicon particles with various carbon materials are outlined. However, carbon materials as protective layer still have some disadvantages, thus necessitating further modification of protective carbon coatings. Recent developments in the modification of protective carbon shells are focused on and the potential substitute for the 3D carbon coating of Si anodes is suggested. This review may help researchers understand the comprehensive information regarding Si/C composite anodes and promote their success in the related fields.