Polyvinylchloride-derived N, S co-doped carbon as an efficient sulfur host for high-performance Li–S batteries - Carbon4Energy

The intrinsic polysulfide shuttle in lithium-sulfur (Li-S) batteries have significantly limited their practical applications. Conductive carbon materials with heteroatom doping and rich porosity are the most common tactics for the effective prevention of polysulfide shuttle but usually obtained with high costs and tedious procedures. Herein, we managed to obtain highly porous N, S-codoped carbon materials through treating inexpensive PVC (a type of widely applicable plastic) with KOH. The as-resulted NS-C was revealed to be highly efficient hosts for sulfur, achieving large reversible capacities of 1205 mAh g-1 and 836 mAh g-1 at 0.1 C and 1.0 C, respectively. More importantly, a high capacitance retention of ~66% was achieved after 500 cycles at 1.0 C. The significantly enhanced cycling performance was mainly ascribed to both hierarchically porous structure and heavy N, S co-dopants, which respectively provided physical blocks and chemical traps for the efficient immobilization of intermediate lithium polysulfides. Combining the facile route for converting PVC plastics into value-added carbon materials with its high performance for hosting sulfur, we may safely envision a big step for the practical implantation of Li-S battery.