Laser-ablated red phosphorus on carbon nanotube film for accelerating polysulfide conversion toward high-performance and flexible lithium–sulfur batteries

Abstract

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 (RPEN)-coated carbon nanotube (CNT) film (RPEN@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 RPEN of uniform morphology, which are deposited on the CNT film by a direct spinning method. The RPEN@CF interlayer provides pathways for effective Li+ and electron transfer and strong chemical interaction with LiPSs. The S/RPEN@CF electrode shows a superior specific capacity of 782.3 mAh g−1 (3 C-rate) and good cycling performances (769.5 mAh g−1 after 500 cycles at 1 C-rate). Density functional theory calculations reveal that the morphology and dispersibility of RPEN are crucial in enhancing Li+ and electron transfer kinetics and effective trap of LiPSs. This work demonstrates the possibility of using the RPEN@CF interlayer for the enhanced electrochemical performances of Li–S batteries and other flexible energy storage devices.