Facile synthesis of elemental sulfur-mediated fluorine-containing covalent triazine frameworks and their performance in lithium–sulfur batteries

Abstract

Covalent triazine frameworks (CTFs) are considered as ideal potential cathode composites for anchoring lithium sulfide compounds. In this paper, five fluorine-containing CTF materials (FN-CTFs) were successfully prepared by modulating the molar ratio of the feeding monomers TFTN and DCB. During the experiment, the optimal content of sulfur was determined to be 71.92% (mass fraction) by adjusting the sulfur content. The initial discharge capacity of the composite electrode at a rate of 0.5C is 959.5 mA h g⁻¹, and after 200 charge–discharge cycles, the residual rate of discharge capacity is 71.32%, and the discharge capacity is 684.3 mA h g⁻¹. Sulfur utilization, cycling stability and multiplier performance of the SFN-CTF composite cathodes are all superior to those of sulfur cathodes.