(684f) Activated Carbon and Its Modified Materials From Ddgs' Bio-Char for Supercapacitors

Activated Carbon and its modified Materials from DDGS’ Bio-char for Supercapacitors

Super-capacitor is an important electrical energy storage device for promoting widespread application of electrical automobiles, brake energy recovery systems as well as enhancing energy efficient of instruments requiring peak power source, include elevator, crane and locomotives. Pursuing advances in super-capacitors technology is also critical to satisfy needs for developing the future energy storage systems to promote using sustainable wind or solar electricity in rural areas as well as improve application of electrical automobiles. Ultimately, to achieve highly stable reversible electrical energy storage capacity and high power density in supercapacitors, carbon materials to fabricate electrodes, should possess a hierarchical mesoporous structure with high surface, high conductivity, suitable pore size distribution and long-term cycle stability. Until now, the most hopeful research for increasing energy and power density of supercapacitors focused on innovative carbon materials The hierarchical carbon, with high specific surface area (2959 m² g⁻¹) and high pore volume (1.65 cm³ g⁻¹) was prepared from sustainable feedstock - biochar, which was a waste from a thermochemical process optimized for bio-oil production, using KOH catalytic activation. The hierarchical carbon after HNO₃ treatment, as electrode materials, showed improved specific capacitance 260 F g⁻¹ in 6 mol L⁻¹ KOH at a current density of 0.6A g⁻¹, while the specific capacitance of carbon without oxidation exhibits relative high (200 F g⁻¹) at a higher current density (0.5A g⁻¹) in 6 mol L⁻¹ KOH and it can also shows 150 F g⁻¹ in the typical organic solution of 1 mol L^-1 tetraethylammonium tetrafluoroborate in acetonitrile after 1000 cycles. More importantly, the capacitive performances of the hierarchical carbons are much better than general bio-inspired activated carbons, ordered mesoporous carbons and commercial graphene, thus highlighting the success of preparing high performance supercapacitor electrode material from biochar and potential for improving economic viability of thermochemical biofuel processes by converting biochar to a high value added carbon materials.