Activated carbon with exceptionally high surface area and tailored nanoporosity obtained from natural anthracite and its use in supercapacitors

We have developed high performance supercapacitor electrodes while demonstrating that using one-step simple industry friendly activation technique, precise control over pore size distribution can be obtained from natural resource. Irrespective of the same staring material, natural anthracite, the obtained samples exhibited two distinctly different pore size distributions exploiting the size differences of the activating agents, which are potassium (KOH) and sodium (NaOH) ions respectively. This precise control over pore sizes enabled us to obtain an unprecedented observation of 136% enhancement of energy density while there is no loss of power density was observed. This unique observation is a result of almost no loss in ion diffusion properties within the electrodes, irrespective of the change of electrolyte to more viscous ionic liquid (Ethyl-Methyl Imidazolium Tetrafluoroborate) from a less viscous aqueous and organic based electrolytes. This size-selective activation enabled us tailoring a highly desirable pore size distribution, a combination of bigger micropores and smaller mesopores. This not only provided very high specific surface area of 2934.60 m2/g with a total pore volume of 1.33 cm3/g, and highest capacitance (198.15 F/g) in aqueous electrolyte, it has also resulted in very high energy density of 82.93 Wh/kg and high power density of ~3487 W/kg.