Plastic waste residue-derived boron and nitrogen co-doped porous hybrid carbon for a modified separator of a lithium sulfur battery

Abstract

The continuous consumption of plastic has caused plastic waste accumulation and negative impacts on the environment. In response to this issue, plastic waste recycling through a pyrolysis process to produce liquid oils has been proposed. However, the pyrolysis process involves discarded or incinerated residue and effective utilization of the pyrolytic residue is required accordingly. This work introduces a hybrid carbon material that has not only high porosity but also polar sites, such as metal oxides and multi-hetero-atom (boron and nitrogen) doping sites. This material was synthesized from pyrolytic residue through a top-down process, unlike the conventional bottom-up synthesis process employed for hybrid carbon. The resultant material is used as a functional layer of a modified separator, and it can effectively suppress the shuttle effect with excellent lithium polysulfide trapping ability and positively contribute to redox reaction kinetics of lithium sulfur batteries. As a result, a resultant cell with the pyrolytic residue derived modified separator exhibited outstanding cyclic stability and electrochemical performance: the capacity decay per cycle was only 0.057% even after 500 cycles at a current density of 1 C. This work will provide a useful reference to suggest a promising approach for effective utilization of the pyrolytic plastic waste residue.