Synthesis of Coal Tar‐Based Hypercrosslinked Polymers via Friedel‐Crafts Alkylation: An Efficient Way to Access Carbon Electrode Material for Supercapacitors
Zhichao Ren, Yanchun Pei, Xueyan Wu, Yan Lv, Rui Xue, Jixi Guo, Xiaogang Zhang
Abstract
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.