Waste cotton cloth derived flexible current collector with optimized electrical properties for high performance lithium-sulfur batteries

Lithium-sulfur batteries (LSB) have gained enormous attention owing to its high theoretical energy density and capacity. However, poor utilization of sulfur and sluggish reaction kinetics leads to unsatisfactory performance of these batteries. Herein, we tune the electrical properties of a carbon cloth derived from waste cotton by suitably selecting the carbonization temperature and utilize it as a current collector in LSB. The fibrous architecture with enhanced electrical conductivity provides efficient channels for electron transport leading to better activation of sulfur. As a result, LSB delivers a high initial discharge capacity of 1171 mA h g(-1) at 0.1C rate. Further, LSB cell with addition of a second layer as upper collector between cathode and separator exhibits a high initial capacity of 592 mA h g(-1) at an even faster rate of 1C and retains 81.2% of the initial capacity after 500 cycles with a low capacity fade of 0.033% per cycle. Even with a higher loading of 3.05 mg cm(-2), the LSB maintains a capacity of 423 mA h g(-1) at 0.2C after 200 cycles with 98% Coulombic efficiency. Moreover, the flexible current collector opens possibilities for development of flexible and wearable energy storage devices. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

By tuning the electrical properties of a carbon cloth and using it as a current collector, the performance of lithium-sulfur batteries can be improved, leading to higher discharge capacity and cycling stability. The addition of a second layer as upper collector further enhances the initial capacity and cycling stability of the batteries. Moreover, the use of a flexible current collector opens up possibilities for the development of flexible and wearable energy storage devices.