High-yield and nitrogen self-doped hierarchical porous carbon from polyurethane foam for high-performance supercapacitors

Confronted with the environmental pollution and energy crisis issues, upcycling of waste plastics for energy storage applications has attracted broad interest. Polyurethane (PUR) is a potential candidate for the preparation of N-doped carbon materials. However, its low carbon yield limits the utilization of PUR waste. In this study, PUR foam was converted into N-doped hierarchical porous carbon (NHPC) through an autogenic atmosphere pyrolysis (AAP)-KOH activation approach. An ultra-high carbon yield of 55.0% was achieved through AAP, which is more than 17 times the carbon yield of conventional pyrolysis of PUR. AAP converted 83.2% of C and 61.0% of N in PUR into derived carbon material. The high conversion rate and self-doping effect can increase the environmental and economic benefits of this approach. KOH activation significantly increased the specific surface area of carbon materials to 2057 m(2) g(-1) and incorporated hierarchical porous structure and O-containing functional groups to the carbon materials. The obtained NHPCs were applied to improve the performance of supercapacitors. The electrochemical measurement revealed that NHPCs exhibited a high specific capacitance of 342 F g(-1) (133 F cm-3) at 0.5 A g(-1), low resistance, and outstanding cycling stability. The energy density and power density of the supercapacitor were improved to 11.3 W h kg(- 1) and 250 W kg(-1), respectively. This research developed a possible solution to plastic pollution and energy shortage.

Automated summary

Polyurethane (PUR) waste can be converted into N-doped hierarchical porous carbon (NHPC) with high carbon yield through autogenic atmosphere pyrolysis (AAP)-KOH activation. The NHPCs have been applied to improve the performance of supercapacitors, showing high specific capacitance, low resistance, and outstanding cycling stability.