Tailored Properties of Carbon for Supercapacitors by Blending Lignin and Cellulose to Mimic Biomass as Carbonaceous Precursor

Graphical Cellulose and lignin blend as carbonaceous precursor paves a feasible way to break through the restriction by intrinsic proportion of cellulose and lignin in natural biomass, allowing for tailoring and optimizing composition, structure and porosity of resultant activated carbon (AC) materials to promote power density, energy density and rate performance of supercapacitors. KOH-activated carbon materials prepared from biomass-derived carbon source, cellulose and lignin, were compared. Mixtures of different ratios of cellulose and lignin were used to partially mimic biomass as carbon source. This allows tailoring and optimizing of the KOH activated carbon materials by getting rid of the restriction of the intrinsic proportion of cellulose and lignin in specific biomass. The results indicate that cellulose use results in a more porous structure, whereas lignin use leads to more partially activated graphite structure. The activated carbon material (CL1) prepared from blend of cellulose with lignin in mass ratio of 1 : 1 exhibits a high specific surface area of 2000.39 m 2 g −1 , and in TEABF 4 /ACN (tetraethylammonium tetrafluoroborate dissolved in acetonitrile) electrolyte it showed a maximum specific capacitance of 136.10 F g −1 , a maximum energy density of 18.11 Wh kg −1 , and a capacitance retention of 85.04 % under current density as high as 15 A g −1 .