Pre‐Oxidating and Pre‐Carbonizing to Regulate the Composition and Structure of Coal Tar Pitch: The Fabrication of Porous Carbon for Supercapacitor Applications

Abstract

The capacitive properties of supercapacitors highly rely on the reasonable design of high‐performance electrode materials. Herein, a synergetic strategy of pre‐oxidation and pre‐carbonization is proposed to prepare coal tar pitch (CTP) based porous carbon. The formation mechanism of porous carbon is revealed. Pre‐oxidation increases the heteroatom content and promotes the decomposition of polycyclic aromatic hydrocarbons into small molecules, which is more conducive to improving the subsequent activation and enhancing the microporous specific surface area. Also, the autoclave pre‐carbonization promotes the polymerization of the precursors and increases the carbon yield. Benefiting from the synergistic effect of pre‐oxidation and pre‐carbonation, the obtained carbon exhibits a superior specific capacitance of 365 F g−1. Meanwhile, ZnCl2 is used as a hydrogen‐bonding acceptor to synthesize ZnCl2‐EG/PVA deep eutectic solvent (DES) gel, and it is applicable to acidic, neutral, and alkaline electrolytes. The capacitor assembled with the prepared porous carbon and DES gel electrolyte achieves a high energy density of 41.3 Wh kg−1 and works well in unconventional temperatures (−40–75 °C). This work confirms the effect of pre‐oxidation and pre‐carbonization on the fabrication of CTP‐based carbon material and expects to prepare porous carbon using other pre‐oxidation/carbonization agents.

Tailoring the Optical Properties of Coal Pitch-Derived Carbon Dots by Graphitization Controlling

“…Therefore, developing clean utilization technologies of coal pitch is important in response to global demand for green use of fossil fuels . By virtue of the carbon-rich feature, upgrading the traditional carbonaceous materials (coal, tar, and pitch) into carbon-based products is a promising strategy to realize their clean and high-value utilization. − Carbon dots (CDs), a member of the “carbon family,” have unique physicochemical characteristics and much more interesting attributes, including quantum confinement effects, tunable optical performances, abundant surface states, excellent charge transfer capability, and the ability to integrate with diverse nanomaterials, which enable them a wide range of applications. − Therefore, converting coal pitch to CDs is a potentially valuable strategy to realize their new applications. − …”

Heteroatom doping-induced formation of closed pores for high-performance sodium storage hard carbon anodes

“…S4, ESI†). 22 Energy dispersive X-ray spectroscopy (EDS) shows that elements C, O, N, and S are uniformly distributed in CDRTF (Fig. 1e).…”

“…The increase in the spacing between carbon layers with the effect of heteroatom doping also plays a contributory role in the increase in capacity. 22…”