Tween 80-assisted synthesis of high conductivity silicon‑carbon composites as anode materials for high-performance lithium-ion batteries

Abstract

High-theoretical-capacity silicon anodes are critically hindered by huge volume expansion and poor conductivity. Silicon‑carbon composites can effectively enhance the electrode lifetime, but their preparation often suffers from particle aggregation issues. Here, the eco-friendly Tween 80 dispersant is introduced for the first time to assist in synthesizing Si/EG-C-TW80 submicron composites. The resulting Si/EG-C-TW80 exhibits well-dispersed and uniformly coated particles, effectively mitigating electrode expansion and maintaining structural stability. Meanwhile, the increased proportion of graphene-type carbon in the carbon layer effectively improves its conductivity. Batteries with the Si/EG-C-TW80 electrode demonstrate an excellent reversible capacity (1985.8 mAh g⁻¹ at 0.2 A g⁻¹) and high rate capability (933 mAh g⁻¹ at 4 A g⁻¹), in addition, deliver a high specific capacity of 566 mAh g⁻¹ after 500 cycles at 4 A g⁻¹. Furthermore, the LFP||Si/EG-C-TW80 full cell shows superior specific discharge capacities of 140 mAh g⁻¹. This easily scalable and environmentally friendly synthesis method offers great promise for the widespread application of silicon in energy storage systems.