Enhancing lithium storage by reticulated RGO as a buffer layer in silicon‑carbon composites

Abstract

To improve the capacity and extend the lifespan of lithium-ion batteries, silicon‑carbon composite anode materials have been extensively researched in recent years. This work presented a method of using reticulated reduced graphene oxide (RGO) as a buffer layer for silicon‑carbon anode materials. It involved initially loading reticulated graphene oxide (GO) onto the surface of silicon nanoparticles with a SiOx shell (Si@SiOx) to obtain a hierarchical structured Si@SiOx@GO nanoparticles, and then embedding them into the interior of core-shell nanofibers using coaxial electrospinning technology. After carbonization, the fabricated core-shell nanofibers formed a layered porous carbon framework (Si@SiOx@RGO-X/HPCNFs), where GO was reduced to RGO. During the charging and discharging cycles, RGO provided mechanical strength and flexible buffering for the volume expansion of silicon-based nanoparticles. Furthermore, the formation of Si-O-C covalent bonds established a strong and efficient contact/adhesion between silicon oxide and graphene, mitigating potential detachment issues even under high-rate cycling. Consequently, the Si@SiOx@RGO-2/HPCNFs anode exhibited a significant reversible capacity (1041.6 mAh g−1) after 100 cycles at 100 mA g−1, along with excellent high-rate performance and long-term cycling stability.