Research Progress of Silicon/Carbon Anodes in Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have garnered attention because of their high energy density and lightweight properties. However, LIBs typically use graphite for the anode material, which shows a relatively low specific capacity that can hardly meet the growing energy storage demands. Compared with traditional graphite anodes, silicon anodes have already been proven to possess higher specific capacities. Additionally, silicon is abundant and relatively inexpensive. Nonetheless, silicon anodes undergo significant volume expansion during the charge-discharge process, generating mechanical stress that can lead to potential cracking and capacity loss. Moreover, they exhibit relatively low initial coulombic efficiency, causing a considerable amount of lithium to be irreversibly consumed during the initial cycles. To address these issues, various nanotechnology-based strategies have been developed, including silicon/carbon (Si/C) composite anodes and the development of other nanostructured materials. These approaches aim to optimize interface structure, particle structure, and composite structure design to enhance battery performance and durability. This paper provides a comprehensive review of the application of nanotechnology in silicon anodes, focusing on the advancements in silicon/carbon composites and their effects on mitigating volume expansion, improving initial coulombic efficiency, and maintaining capacity retention. Additionally, it analyzes the impact of different nanostructure designs on battery performance.