Toward High-Performance Lithium–Sulfur Batteries: Upcycling of LDPE Plastic into Sulfonated Carbon Scaffold via Microwave-Promoted Sulfonation

Lithium–sulfur batteries were intensively explored during the last few decades as next-generation batteries owing to their high energy density (2600 Wh kg–1) and effective cost benefit. However, systemic challenges, mainly associated with polysulfide shuttling effect and low Coulombic efficiency, plague the practical utilization of sulfur cathode electrodes in the battery market. To address the aforementioned issues, many approaches have been investigated by tailoring the surface characteristics and porosities of carbon scaffold. In this study, we first present an effective strategy of preparing porous sulfonated carbon (PSC) from low-density polyethylene (LDPE) plastic via microwave-promoted sulfonation. Microwave process not only boosts the sulfonation reaction of LDPE but also induces huge amounts of pores within the sulfonated LDPE plastic. When a PSC layer was utilized as an interlayer in lithium–sulfur batteries, the sulfur cathode delivered an improved capacity of 776 mAh g–1 at 0.5C and an excelle...