Impregnation of sulfur into a 2D pyrene-based covalent organic framework for high-rate lithium–sulfur batteries. Issue 35 (24th August 2018)

• Record Type: Journal Article
• Authors: Meng, Yi; Lin, Guiqing; Ding, Huimin; Liao, Huaping; Wang, Cheng
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 35(2018)
• Page Start: 17186
• Page End: 17191
• Publication Date: 2018-08-24
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta05508d
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : By loading 70 wt% sulfur into a pyrene-based COF (Py-COF), we constructed Li–S batteries with high-rate capacity and long-term stability. Abstract : Two-dimensional covalent organic frameworks (2D COFs) have recently attracted increasing attention in energy storage devices. Herein, by loading 70 wt% sulfur into a pyrene-based 2D COF (Py-COF), we succeeded in the construction of lithium–sulfur (Li–S) batteries with high-rate capacity and long-term stability. The Py-COF/S cathode can deliver a reversible capacity of 481.2 mA h g −1 for up to 550 cycles at 5.0C (1C = 1680 mA g −1 ), which is 73.8% of the initial capacity with a decay rate of 0.048% per cycle. This is a benchmark among all reported COF-based Li–S batteries, and more impressively, even beyond the performances of some porous carbon-based sulfur host electrodes. Specifically, by using commercially available porous carbon BP2000 as the sulfur host under the same conditions, the thus-prepared electrode can only exhibit a reversible capacity of 265 mA h g −1 after 220 cycles at 5.0C, much lower than that of the Py-COF/S electrode. According to cyclic voltammetry analysis, this high performance could be attributed to the fast lithium ion transport in the pores of Py-COF, especially at a high rate. These results clearly demonstrate that it is reasonable to design a 2D COF sulfur host for high performance Li–S batteries.