Electrolyte system
An electrolyte system having a conductive salt dispersed in a solvent mixture, the solvent mixture having an organic nitrile solvent and a co-solvent. The concentration of the conductive salt in the electrolyte system is 1.25 molar to 3.0 molar.
1. An electrolytic cell comprising:
two electrodes;
wherein at least one of the electrodes comprises activated carbon;
wherein the activated carbon electrode comprises:
pores having a size of ≦1 nm, which provide a combined pore volume of ≧0.3 cm 3 /g;
pores having a size of from >1 nm to ≦2 nm, which provide a combined pore volume of ≧0.05 cm 3 /g; and
<0.15 cm 3 /g combined pore volume of any pores having a size of >2 nm;
an electrolyte system comprising:
a conductive salt selected from the consisting of quaternary ammonium salts, cyclic aromatic imidazolium salts, and asymmetric ammonium salts dispersed in a solvent mixture,
wherein a concentration of the conductive salt in the electrolyte system is from about 1.25 molar to about 3.0 molar; and
the solvent mixture comprises an acetonitrile and a co-solvent.
2. An electrolytic cell of claim 1 , wherein the electrolytic cell is an electric double layer capacitor.
3. An electrolytic cell of claim 1 wherein the concentration of the conductive salt in the electrolyte system is about 1.5 molar.
4. An electrolytic cell of claim 1 , wherein the co-solvent is an organic ester.
5. An electrolytic cell of claim 1 , wherein the co-solvent is selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl-methyl carbonate, and butylene carbonate.
6. An electrolytic cell of claim 1 , wherein an amount of the co-solvent in the solvent mixture is from about 1 to about 75% by weight.
7. An electrolytic cell of claim 1 having a conductivity greater than 45 mS/cm at ambient temperature.