A self-sacrificing strategy to fabricate a fluorine-modified integrated silicon/carbon anode for high-performance lithium-ion batteries

Abstract

Structural instability due to huge volume changes of silicon during charging and discharging limits its commercial applications. In this work, we prepare a novel fluorine-modified integrated silicon/carbon anode (denoted as F-SC), consisting of yolk–shell particles and hierarchical porous carbon sheets, via a simple one-step self-sacrificing strategy. This integrated structure requires no acid or base etching, making it more efficient and environmentally friendly than other template strategies. Detailed analysis of various characterization studies reveals that the well-designed structure can build a satisfactory expansion space for silicon, enhance lithium-ion reaction kinetics, offer stable interfacial contacts, and establish a three-dimensional conductive network. As a lithium-ion battery (LIB) anode, the prepared composite demonstrates a high initial coulombic efficiency (ICE) of 83.3%, a distinguished reversible capacity of 1013 mA h g⁻¹ at 1 A g⁻¹ after 400 cycles with an average Coulomb efficiency of 99.4% and a superior rate ability of 987 mA h g⁻¹ at an ultrahigh rate of 5 A g⁻¹. The reaction kinetics verify the synergy of solid-state diffusion and surface-controlled reactions. The current research can provide powerful ideas for the rapid commercialization of advanced silicon-based materials.