Exploring the practical applications of silicon anodes: a review of silicon-based composites for lithium-ion batteries

The increasing demand for high energy density batteries has spurred the development of the next generation of lithium-ion batteries. Silicon (Si) materials have great potential as anode materials in such batteries owing to their ultra-high theoretical specific capacities, natural abundance, and environmental friendliness. However, the large volume expansion and poor conductivity of Si can deteriorate the anode structure, thereby limiting electrochemical performance and inhibiting commercial application. The optimised combination of Si materials and high-performance graphite may yield synergistic effects arising from the high theoretical capacity of Si and the ultra-high stability of graphite, and thus broaden the practical applications of Si-based anode materials. In this review, we summarise recent developments in the synthesis of silicon-carbon (Si/C) composites, and the design and modification of the composite structural layers. Additionally, the key problems, challenges, and prospects in the commercialization of Si/C composites are systematically analyzed.