Double layer high power capacitor comprising a liquid organic electrolyte

Ideally polarizable supercapacitor consisting of a positive electrode and its current collector, of a negative electrode and its current collector, said electrodes comprising a carbon material, of a separator and of a nonaqueous liquid electrolyte impregnating said separator and said electrodes, characterized in that the nonaqueous liquid electrolyte is an organic solution of a sodium or potassium salt or an alkaline-earth metal salt, by itself or as a mixture in a solvent comprising one or more amides;

• and
• the solution is based on an aprotic polar solvent comprising an amide of formula:
• in which:
• R1 is a hydrogen atom or a C1 to C3 alkyl radical,
• R2, R3, which are identical or different, are the hydrogen atom or a methyl, ethyl or propyl radical.