Electrochemical behaviors of graphene decorated sulfurized polyurethane foam-based ultra-microporous carbon

Abstract

Polyurethane foam is a typical commercial polymer with a large production quantity and its waste needs to be recycled. This work reports a facile method to prepare ultra-microporous carbon from the polyurethane foam (PUF) waste and use it as a reservoir to impregnate sulfur for Li-S batteries. The raw PUF was carbonized and then activated with KOH. By controlling the activation temperatures, four carbon materials (PUFC-T) with different textures and N-doping levels were obtained. PUFC-800 shows the highest BET surface area, microporous volume, and quaternary N and pyridine N-oxide species. The electrochemical test results showed that higher microporous volume is beneficial to increase the uniform distribution of sulfur, as a result, the cycle stability and rate capacity is improved significantly. A large reversible capacity of 542 mAh g-1 can be retained at a large current of 0.5 C after 200 cycles with high sulfur loading of 70%.