Carbons for supercapacitors obtained by one-step pressure induced oxidation at low temperature

Highly microporous carbons are produced by one-step high pressure oxidation of non-porous chars at low temperature (200 °C), using hydrogen peroxide as active di-oxygen source and a further desorption step to eliminate the surface groups and unblock the pores. By adapting the pressure and reaction time, the pore size of carbon can be targeted to the dimension of the ions of the standard organic electrolyte used in electrical double-layer capacitors (TEABF4 in acetonitrile). The main mechanism associated with the low burn-off values seems to be a drilling of the nanopores existing initially in the chars.