Effect of precursor characteristics on properties and supercapacitor performances of porous carbon

Various carbon sources have been employed to prepare porous carbon; yet, the influence of intrinsic characteristics in precursors on the physicochemical properties and performance of porous carbon products remains insufficiently explored. Herein, precursors prepared by selective treatments yielded porous carbons with unique structures and chemical properties. Significant differences in pore distribution, internal microstructure, and oxygen species were observed, leading to marked variations in electrochemical performance in symmetrical supercapacitors. TX-J-PC, derived from a precursor containing Fe, Ca, and Mg, delivers an exceptionally high micropore proportion of 72.1%, the highest specific capacitance of 179.64 F/g at 0.1 A/g, and an energy density of 40.99 Wh/kg at 327.89 W/kg. In contrast, TX-S-PC, prepared from the precursor containing Al and Si, shows the largest surface area of 3101 m²/g, a high capacitance retention of 85.92% after 10000 cycles, and a capacity retention of 82.31% at 10 A/g. TX-PC, directly produced from pristine anthracite, exhibits faster charge transfer, improved mass transfer kinetics, and an energy density of 24.66 Wh/kg at 5.01 kW/kg. The structure-function relationship demonstrated that the disorder degree of aromatic layers instead of pore structure could improve supercapacitor performance. Moreover, group C-O-C is conducive to achieving high-specific capacitance, while abundant C=O sites contribute to better rate performance and extended service life of supercapacitors. This study provides deep insights into the structure-performance relationship in supercapacitors and offers a novel perspective on the large-scale regulation of porous carbon properties.