Realizing Sub-5 nm Red Phosphorus Dispersion in a SiO_x/C Matrix for Enhanced Lithium Storage

With high capacity and suitable working plateau, silicon oxide (SiO_x) has become a promising lithium-ion battery (LIB) anode material. However, bare SiO_x usually suffers from sluggish electron transport and unsatisfactory cyclability. Composting SiO_x with a second phase has become an efficient strategy to tackle the current drawbacks. Herein, a P/SiO_x/C ternary composite, featuring sub-5 nm red phosphorus (P) clusters uniformly dispersed in a dense SiO_x/C matrix has been constructed through an "inside-out" synthesis strategy. The nanosizing of bulk red P sealed in an organosilica matrix is realized by the high-temperature treatment-driven sublimation/diffusion. With the red P amount of ∼7.53 wt %, the P/SiO_x/C ternary composite provides a stable discharge capacity of ∼950 mAh g^-1 and also manifests a decent rate capability (510 mAh g^-1 at 5 A g^-1). This study affords a ternary compositing strategy for designing SiO_x-based anode materials with desirable electrochemical performance for the next-generation LIBs.