Hierarchical porous carbon from waste tire pyrolysis carbon black via in-situ SiO2 templating for high-performance supercapacitors

Abstract

Realizing high-value recycling of pyrolysis carbon black (CBp) is essential to promoting the sustainable development of the waste tire pyrolysis industry. However, the high-end applications of CBp are restricted by its high ash content, small specific surface area and poor electrical conductivity. Herein, waste tire-derived CBp were successfully converted to hierarchical porous activated carbon (ACBp1) for high-performance supercapacitors by one-step acid purification coupled with in-situ SiO₂ template activation. This method not only greatly reduces the ash content by avoiding use of environmentally-hazardous hydrofluoric acid, but also is beneficial to forming a rich interconnected pore structure to increase the ion and electron migration rate. ACBp1 achieves a specific capacitance of 246 F g⁻¹ at current density of 1 A g⁻¹, while maintaining 95 % of initial capacitance after 100,000 charge-discharge cycles at 100 A g⁻¹. The ACBp1-based zinc ion hybrid supercapacitor demonstrates a high specific capacity of 66 mAh g⁻¹ at 0.5 A g⁻¹. This study provides a new idea to improve the utilization efficiency of CBp and offers a new way to further develop cheap and sustainable energy storage materials.