Turn the dust into glory: Hierarchical porous carbon cubes derived from waste tire pyrolysis oil exhibits high capability in symmetric capacitors.

Abstract

Fabricating suitable porous carbon materials that are simultaneously applied in various electrochemical energy storage (EES) systems including supercapacitors (SCs) and lithium-ion capacitors (LICs) has an important significance in meeting the increasing demands in high energy density, high power density along with ultra-long life. Herein, cubic hierarchical porous carbon (CHPC) with abundant micro-mesoporous structures and moderate S, N co-doped atoms has been rationally designed by using MgO cubes as the templates and waste tire pyrolysis oil (WTPO) as carbon source and dopant. Attributed to the unique microstructures, the CHPC materials have been successfully utilized in different EES systems. In the aqueous electrolyte system, the assembled CHPC-2//CHPC-2 with 2 mg cm^-2 delivered high specific capacitance of 199.0 at 1 A/g, along with 98.5 % capacity retention rate for 20,000 cycles at 6 A/g. Even at high mass loading of 12 mg cm^-2, CHPC-12//CHPC-12 still can deliver high gravimetric and areal capacitances of 187.0 F g^-1 and 2.24 F cm^-2 at 10 A/g, showing an excellent high-loading performance. Even under extreme conditions of -40 and 60 °C, the assembled SCs still can deliver an ultrahigh capacity retention rate of 97.9 % and 100 % at 10 A/g for 2000 and 8000 cycles, respectively. In addition, the symmetric CHPC//CHPC LICs also have been assembled and displayed a maximal energy density of 133.5 Wh Kg^-1 at 1178.2 W Kg^-1. This work provides new insight into the high-value utilization of WTPO for prepared porous carbon with excellent electrochemical performance in various EES systems.