Fabrication of a coaxial bilayer bottlebrush-like phosphorus‑carbon composite with enhanced lithium storage performance

Phosphorus is a promising anode material for high-rate lithium ion batteries (LIBs) due to its superior theoretical specific capacity (2596 mAh g−1) and suitable lithiation potential. However, the phosphorus nanoparticles usually have poor electrical conductivity and undergo volume expansion during lithiation. Herein, a coaxial bilayer bottlebrush-like carbon@fibrous‑phosphorus@carbon-nanotube (C@FP@CNT) composite is synthesized by a chemical vapor transport method and in situ carbonization for fibrous phosphorus deposition and surface carbon deposition, respectively. The phosphorus mass loading of C@FP@CNT is as high as 71 %, and all the FP nanorods adhere tightly to the conductive CNTs and surface coating composed of amorphous carbon. FP promotes the carbonization of polyimide (PI) and improves the electrical conductivity of the PI-originated carbon coating. Owing to the unique bilayer coaxial nanostructure, the C@FP@CNT anode shows high capacities of 1852.9 and 1108.1 mAh g−1 at 0.1 and 4.0 A g−1, a capacity of 1451.4 mAh g−1 at 0.2 A g−1 even after 300 cycles, as well as a capacity retention rate of 84.4 %. Meanwhile, the full cells comprising C@FP@CNT anode and LiCoO2 cathode also displays a highly stable cycling performance and a high specific energy density. The results reveal a viable strategy to prepare high-performance alloy-type anodes for LIBs.