Organic solvent-assisted pore structure modulation in porous carbons for superior energy storage performance in supercapacitors

The pore structure is a significant feature of porous carbons that accounts for their excellent performance in supercapacitors; however, the literature on pore modulation and cleansing is scarce. Here, a novel approach based on organic solvent-assisted pore modulation is reported to tune the pore hierarchy and local carbon-layer arrangement in porous carbons derived from waste biomass. The strategy involves adsorbing n-heptane into porous carbon at room temperature, thereby facilitating realignment of the carbon layers, improving pore hierarchy, and generating short-range graphitic domains. The solvent-assisted pore modulation, together with the high surface area and graphitization, led to a significant increase of 39.4% in specific capacitance, C sp (354 F g -1 /0.5 A g -1 ) as compared to bare porous carbon (254 F g -1 /0.5 A g -1 ). High energy and power densities of 6 Wh kg -1 /10 A g -1 and 13,500 W kg -1 /10 A g -1 , along with a C sp of 105.22 F g -1 /0.5 A g -1 , are achieved for a two-electrode supercapacitor. Density functional theory (DFT) calculations provided insights into an improved pore structure and solvent-induced modulation of the electronic structure, enhancing ion transport and charge storage. This straightforward and promising organic solvent-assisted pore-modulation strategy provides a new route to tailoring pore architecture and short-range graphitic ordering in porous carbons without high-temperature graphitization or chemical functionalization, thereby creating a potentially new line of research in these materials for advanced electrochemical energy-storage applications.