A guiding principle to prepare active carbon with high electric double layer capacitance

摘要

The largest capacitance per volume of 35F/ml was obtained in electric double layer capacitor with spherical carbon of optical anisotropy activated with NaOH. The activation conditions with NaOH as well as pre-calcination conditions must be optimized with the particular carbon of spherical shape. The guideline to obtain the largest capacitance is discussed in terms of optical anisotropy, shape, and density of precursor carbons as well as moderate activation. The selective introduction of right size pores with graphitic wall is a key to achieve the highest density of electrolyte adsorption in the polar solvent.