An Ultrafast Charge-Driven Topological Intercalation Prelithiation Strategy for Carbon-Silicon Composite Anodes.

Abstract

Prelithiation emerges as an effective technique to enhance the initial Coulombic efficiency (ICE) and cycling stability of silicon oxide based carbon composite (C/SiO_x) anodes, yet traditional approaches remain plagued by sluggish kinetics, cumbersome procedures, safety hazards, and inadequate precision. Here, a facile topological intercalation prelithiation method capable of forming a robust and homogeneous solid electrolyte interface (SEI) network on porous C/SiO_x nanofiber anodes in merely 30 s is reported. Through constructing three charge-driven topology models derived from flexible SiO_x/porous carbon nanofiber (SiO_x/PCNF) films, the mechanism of this fast Li⁺-intercalation process is unraveled. Abundant surface defects on SiO_x/PCNF enhance lithium salt adsorption and dissociation, while the active solvated Li⁺-ions can quickly intercalate into SiO_x/PCNF along an orientation pathway, realizing a high ICE of 99.44%. This topological prelithiation forges a 3D inorganic-rich SEI architecture that dualizes functionality: It curtails electrolyte degradation while alleviating volume fluctuation and mechanical stress, while enabling precision Li⁺-ion replenishment. This topochemical paradigm not only achieves ICE reinforcement and cycling resilience (1000 stable cycles), but also slashes prelithiation duration by orders of magnitude.