Low temperature double-layer capacitors using asymmetric and spiro-type quaternary ammonium salts

A method of producing a double-layer capacitor, comprising:

• disposing a first porous electrode for conducting a charge and a second porous electrode for conducting an opposing charge in a case;
• preparing an electrolyte solution comprising a quaternary ammonium salt including at least one of triethylmethylammonium tetrafluoroborate (TEMATFB) and spiro-(1,1′)-bipyrrolidium tetrafluoroborate (SBPBF4) dissolved into at least a base solvent and a second solvent for reducing a melting point of the base solvent;
• disposing a separator between the first porous electrode and the second porous electrode, the separator allowing for conduction of ions while electrically insulating the first porous electrode and the second porous electrode;
• and
• soaking the first electrode and the second electrode with the electrolyte solution in the case to enable formation of an electrical double-layer at interfaces of both the first porous electrode and the second porous electrode with the electrolyte solution and thereby exhibit a dielectric interaction between charged surfaces of the first porous electrode and the second porous electrode and the ions of the electrolyte solution.

An apparatus, comprising:

• a first porous electrode means for conducting a charge;
• a second porous electrode means for conducting an opposing charge;
• an electrolyte solution means for soaking the first electrode means and the second electrode means to enable formation of an electrical double-layer at interfaces of both the first porous electrode means and the second porous electrode means with the electrolyte solution means and thereby exhibit a dielectric interaction between charged surfaces of the first porous electrode means and the second porous electrode means and ions of the electrolyte solution means;
• and
• a separator means disposed between the first porous electrode means and the second porous electrode means, the separator means for allowing conduction of the ions while electrically insulating the first porous electrode means and the second porous electrode means;
• wherein the electrolyte solution means comprises a quaternary ammonium salt including at least one of triethylmethylammonium tetrafluoroborate (TEMATFB) and spiro-(1,1′)-bipyrrolidium tetrafluoroborate (SBPBF4) dissolved into at least a base solvent and a second solvent means for reducing a melting point of the base solvent.