Calixarene-Functionalized Porous Carbon Aerogels for Polysulfide Capture: Cathodes for High Performance Lithium-Sulfur Batteries.

Abstract

A cage-type composite was successfully prepared by attaching p-sulfonatocalix[4]arene to a porous activated carbon aerogel (ACA). The resulting composite showed a high specific surface area of 1620.7 m2 g-1 and a high sulfur loading of 2.5 mg cm-2 . The calixarene is uniformly dispersed on the carbon spheres and efficiently captures polysulfides by interaction with the sulfonate groups. Meanwhile, the cross-linked porous structure of the composite restricts the migration of polysulfides. The cathode delivers an outstanding electrochemical performance with an initial capacity of 1304.7 mAh g-1 at 0.2 C. Furthermore, it displays excellent long-term cycling stability, maintaining 884.7 mAh g-1 after 300 cycles at 0.5 C. Density functional theory (DFT) adsorption calculations support the strong interaction between the calixarenes and polysulfides and reveal the capture mechanism.