Synthesis of Coal Tar‐Based Hypercrosslinked Polymers via Friedel‐Crafts Alkylation: An Efficient Way to Access Carbon Electrode Material for Supercapacitors

Coal tar (CT) has potential applications as a carbon material precursor due to its malleability and high carbon content. However, the low carbonization rate of CT is a major constraint to its development. In this work, a microporous carbon material (CF 2 CT) is synthesized from CT via the Friedel–Crafts alkylation reaction, which results in a significant increase in the carbonization yield (68%). In the absence of an activator, the CF 2 CT showed specific surface areas (766 m 2 g −1 ) and micropore volumes (0.32 cm 3 g −1 ), with pore diameters mainly centered on 0.5–0.8 nm. The CF 2 CT exhibited an excellent gravimetric capacitance of 342 F g −1 under 1 A g −1 in a three‐electrode system, while its capacitance remained approximately 98% over 10 000 cycles under 10 A g −1 . The symmetrical supercapacitors fabricated with CF 2 CT showed a 7.8 Wh kg −1 energy density and a 250 W kg −1 power density, with capacitance remaining up to 100% at 10 A g −1 after undergoing 10 000 cycles. This study proposes an idea for the preparation of high‐yield carbon precursors from coal tar while also offering a promising HCP‐derived carbon material for supercapacitor electrodes.