Synthesis of Hierarchical Porous Carbon from Bio-Oil for Supercapacitor Application

The realm of high-performance supercapacitor electrodes grapples with the inherent limitations of biomass-derived carbons: an inadequate count of ion adsorption locales and sluggish ion mobility. Attaining scalability in the synthesis of hierarchical porous carbon (HPC) with precisely defined pore architectures remains an enduring challenge. This review showcases the successful synthesis of HPC from bio-oil on a large scale, accomplished through a MgO template-assisted self-assembly polymerization, followed by sequential pyrolysis and KOH activation strategies. The optimized carbon (HPC1.5-4) achieves a potent specific surface area of 2069 m2 g–1 and a pore volume of 1.30 cm3 g–1 with hierarchical micro-, meso-, and macropores, thus providing ample ion adsorption sites and ion diffusion pathways. Three-electrode supercapacitor fabricated by HPC1.5-4 presents a high specific capacitance of 296 F g–1 at 1 A g–1, outstanding rate capability, and satisfactory cyclic durability. Furthermore, the symmetric supercapacitor in the Na2SO4 electrolyte harvests a high energy density of 18.9 Wh kg–1 at 469.4 W kg–1.