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.