Red Phosphorus-Embedded Cross-Link-Structural Carbon Films as Flexible Anodes for Highly Reversible Li-Ion Storage

Red phosphorus (P) is considered to be one of the most attractive anodic materials for lithium-ion batteries (LIBs) due to its high theoretical capacity of 2596 mAh g^-1. However, intrinsic characteristics such as the poor electronic conductivity and large volume expansion at lithiation impede the development of red P. Here, we design a new strategy to embed red P particles into a cross-link-structural carbon film (P-C film), in order to improve the electronic conductivity and accommodate the volume expansion. The red P/carbon film is synthesized via vapor phase polymerization (VPP) followed by the pyrolysis process, working as a flexible binder-free anode for LIBs. High cycle stability and good rate capability are achieved by the P-C film anode. With 21% P content in the film, it displays a capacity of 903 mAh g^-1 after 640 cycles at a current density of 100 mA g^-1 and a capacity of 460 mAh g^-1 after 1000 cycles at 2.0 A g^-1. Additionally, the Coulombic efficiency reaches almost 100% for each cycle. The superior properties of the P-C films together with their facile fabrication make this material attractive for further flexible and high energy density LIB applications.