Laser-Ablated Red Phosphorus on Carbon Nanotube Film for Accelerating Polysulfide Conversion toward High-Performance and Flexible Lithium-Sulfur Batteries.

The use of a conducting interlayer between separator and cathode is one of the most promising methods to trap lithium polysulfides (LiPSs) for enhancing the performance of lithium-sulfur (Li-S) batteries. Red phosphorus nanoparticles (RP )-coated carbon nanotube (CNT) film (RP @CF) is reported herein as a novel interlayer for Li-S batteries, which shows strong chemisorption of LiPSs, good flexibility, and excellent electric conductivity. A pulsed laser ablation method is engaged for the ultrafast production of RP of uniform morphology, which are deposited on the CNT film by a direct spinning method. The RP @CF interlayer provides pathways for effective Li and electron transfer and strong chemical interaction with LiPSs. The S/RP @CF electrode shows a superior specific capacity of 782.3 mAh g (3 C-rate) and good cycling performances (769.5 mAh g after 500 cycles at 1 C-rate). Density functional theory calculations reveal that the morphology and dispersibility of RP are crucial in enhancing Li and electron transfer kinetics and effective trap of LiPSs. This work demonstrates the possibility of using the RP @CF interlayer for the enhanced electrochemical performances of Li-S batteries and other flexible energy storage devices.