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.