Synthesis of 3D-interconnected hierarchical porous carbon from heavy fraction of bio-oil using crayfish shell as the biological template for high-performance supercapacitors

The practical application of raw biomass in high-performance supercapacitors is mainly hindered by virtue of their relatively rare efficient storage sites and low diffusion kinetics. Herein, hierarchical porous carbons (HPCs) are synthesized from heavy fraction of bio-oil (HB) based on a hard-template method accompanied by different NaOH activation temperatures. Thanks to the favorable 3D-interconnected hierarchical porous structure, ultrahigh specific surface area (3095 m2 g−1), large total pore volume (1.66 cm3 g−1), as well as reasonable content of oxygen atoms (7.83 at. %), CSB-800 delivers a prominent gravimetric specific capacitance of 351 F g−1 (0.5 A g−1), which is considerably superior or at least comparable than previously reported for other biomass-based materials. In addition, the assembled CSB-800//CSB-800 symmetric supercapacitors can reach a superior energy density of 20 W h kg−1 at a power density of 350 W kg−1 (0.5 A g−1). The route proposed for preparing HB-based HPCs broadens a new horizon in exploring large-scale synthesis of electrode materials from industrial by-product and kitchen waste. [Display omitted] •Green synthesis of hierarchical porous carbons (HPCs) from heavy fraction of bio-oil (HB).•Unique porous carbon obtained using crayfish shell (CS) as biological template.•The oxygen doped HPCs possess a high gravimetric specific capacitance of 351 F g−1 at 0.5 A g−1.•The assembled symmetric supercapacitors delivered an excellent energy density of 20 W h kg−1 at 350 W kg−1.