Abstract: Novel organic electrolytes comprising tetrafluoroborates and hexafluorophosphates of doubly charged cations of N,N-dialkyl-1,4-diazabicyclo[2.2.2]octanediium (DADACO) are disclosed, which have general formula (2), where R is the alkyl C1-C4, and Y31 is a BF4− or PF6− anion. The invention also comprises a process for the preparation of said electrolytes comprising at least one compound of formula (2) and the use of compounds of formula (2) dissolved in an aprotic polar solvent or a mixture of such solvents as an electrolyte for an electrochemical double layer capacitor.