Abstract
A novel activation method involving hydrothermal carbonization (HTC) and a pressure-induced low temperature oxidation has been demonstrated for cellulose derived HTC char by using hydrogen peroxide as an active di-oxygen source. The optimized porosity versus gravimetric capacitance results from cellulose derived HTC char synthesized at 220 oC. Almost homogeneous and small particle size micro-ellipse/sphere, relatively high surface area and narrow pore size distributions lead to a high bulk density, i.e. 0.73 g cm-3, of coating type electrodes, which is much denser than those manufactured from steam activated carbons for supercapacitor industry, i.e., 0.52 g cm-3. The resulting carbon prepared herein achieves a relatively high volumetric capacitance in an organic electrolyte-based supercapacitor reaching a competitive value of industrial system with the features of environment friendly, cost-effective as well as high yield, and less energy consumption.