Silicon-doped graphene nanoflakes with tunable structure: Flexible pyrolytic synthesis and application for lithium-ion batteries

Incorporation of heteroatoms into graphene layers is a powerful way of tuning their surface and structure. We developed for the first time a tunable approach for the synthesis of Si-doped jellyfish-like graphene nanoflakes (Si-GNFs) via template pyrolysis. The synthesis parameters were shown to affect the doping level, silicon bonding type, heteroatom localization in Si-GNFs, and the defectiveness of the synthesized material. The silicon incorporation into GNF layers creates acidic and basic Lewis sites as it was tested in the butanol-2 conversion over SiGNF. Doping of GNFs with Si significantly boosted the specific capacity of GNF-based electrode of the lithium-ion battery up to 600 mAh*g(- 1). The capacity enhancement was ascribed to the redistribution of the electron density due to the difference in electronegativity between C and Si, corrugation of the graphene layers by heteroatoms, and reduction of silicon species. The synthesis conditions were shown to strongly affect the capacity and cycle stability of the electrode.

Automated summary

The study developed a tunable approach for the synthesis of Si-doped jellyfish-like graphene nanoflakes. The doping of GNFs with Si significantly boosted the specific capacity of the lithium-ion battery electrode, and synthesis conditions strongly affected the electrode performance.