Chemical vapor deposition-assisted activation for tailoring mesoporous carbon from polar components of coal tar pitch for zinc-ion hybrid capacitors

The high mesoporosity and excellent conductivity of porous carbon (PC) enhance the energy and power densities of zinc-ion hybrid capacitors (ZIHCs). However, conventional methods for forming mesopores often undermine the structural integrity and conductivity of PC. The work develops an chemical vapor deposition (CVD)-assisted KOH activation to fabricate mesoporous PCs from the polar components extracted from coal tar pitch using a deep eutectic solvent. The integrated strategy employs KOH not only for pore formation but also as a “structure-directing substrate” to ensure the establishment of the mesopores and conductive network of the PC. The polar-component-derived porous carbon (PCR) exhibits a specific surface area (3149.6 m 2 g −1 ) and a mesopore ratio of 79.4%, enabling numerous storage sites and fast transfer kinetics for Zn 2+ . The ZIHC assembled by PCR delivers a high capacity of 240.9 mAh g −1 , an impressive power density of 16.1 kW kg −1 , and a remarkable energy density of 200.27 Wh kg −1 . Furthermore, the ZIHC demonstrates an excellent cycling stability, retaining 90.6% of initial capacitance after 16,000 cycles. The strategy of simultaneously elevating conductivity and mesopore ratio offers a promising route for high-performance carbon cathodes towards next-generation wearable electronics. This research unveils an innovative approach utilizing deep eutectic solvents and chemical vapor deposition coupled with chemical activation to transform coal tar pitch into high-performance mesoporous carbon for zinc-ion hybrid capacitors. The findings significantly enhance energy density and stability, offering promising advancements for future energy storage solutions. • Highly active component is extracted from coal tar pitch using deep eutectic solvent. • Mesoporous carbon is prepared via chemical vapor deposition coupled with activation. • The mesoporous carbon shows high specific surface area and excellent electrical conductivity. • As-assembled zinc-ion hybrid supercapacitors deliver a high energy-power density.