Core-Shell Structure of a Polypyrrole-Coated Phosphorus/Carbon Nanotube Anode for High-Performance Lithium-Ion Batteries

Black phosphorus is regarded as a promising anode material due to its high theoretical specific capacity and fast-charging safety compared with the commercial graphite-based anode materials. However, the practical application of a black phosphorus anode is constrained by the large volumetric variation, unstable electrode/electrolyte interface, and shuttle effect of soluble phosphorus intermediates. Herein, we fabricated a phosphorus/carbon nanotube@polypyrrole (BP/CNT@PPy) composite via a simple high-energy ball-milling (HEBM) and liquid polymerization method. When it was used as the anode material for lithium-ion batteries, the elastic and conductive PPy coating layer played an important role in buffering volume expansion, improving electrical conductivity, and maintaining the integrity of active materials. Thus, the BP/CNT@PPy electrode exhibits excellent cyclic stability. This work provides a favorable strategy to design a high-performance phosphorus anode for lithium-ion batteries.