Scalable fabrication of silicon/activated carbon composite anodes with superior capacity for Lithium-ion batteries

Silicon is one of the most attractive anode materials for lithium-ion batteries due to its exceptionally high theoretical capacity (∼3579 mAh g⁻¹). However, its practical implementation is severely restricted by extensive volume changes during lithiation/delithiation, leading to mechanical degradation and rapid capacity fading. To overcome these limitations, silicon/activated carbon (Si/AC) composites containing 10, 20, and 30 wt% Si were synthesized via a scalable ball milling approach. Among them, the Si10/AC composite exhibited optimal structural integrity, high specific surface area, and favorable ion diffusion properties. It delivered a high initial capacity of 1634 mAh g⁻¹ and retained 935 mAh g⁻¹ after 400 cycles at C/10, with a stable Coulombic efficiency of ∼95 %. These results underscore the effectiveness of the carbon matrix in mitigating silicon's volume expansion, enhancing conductivity, and maintaining electrode stability. The Si10/AC architecture offers a promising pathway for the development of high-performance, durable silicon-based anodes for next-generation lithium-ion batteries.