Nonaqueous electrolyte for electrical storage devices

Patent · Tue Oct 12 04:00:00 EDT 1999

OSTI ID:20013952

McEwen, A B; Yair, E E

Improved nonaqueous electrolytes for application in electrical storage devices such as electrochemical capacitors or batteries are disclosed. The electrolytes of the invention contain salts consisting of alkyl substituted, cyclic delocalized aromatic cations, and their perfluoro derivatives, and certain polyatomic anions having a van der Waals volume less than or equal to 100 {angstrom}{sup 3}, preferably inorganic perfluoride anions and most preferably PF{sub 6}{sup {minus}}, the salts being dissolved in organic liquids, and preferably alkyl carbonate solvents, or liquid sulfur dioxide or combinations thereof, at a concentration of greater than 0.5M and preferably greater than 1.0M. Exemplary electrolytes comprise 1-ethyl-3-methylimidazolium hexafluorophosphate dissolved in a cyclic or acylic alkyl carbonate, or methyl formate, or a combination thereof. These improved electrolytes have useful characteristics such as higher conductivity, higher concentration, higher energy storage capabilities, and higher power characteristics compared to prior art electrolytes. Stacked capacitor cells using electrolytes of the invention permit high energy, high voltage storage.

• Sponsoring Organization: US Department of Energy; US Department of Defense
• DOE Contract Number: FG02-96ER82149
• OSTI ID: 20013952
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
36 MATERIALS SCIENCE
CAPACITIVE ENERGY STORAGE EQUIPMENT
CHEMICAL COMPOSITION
ELECTRIC BATTERIES
ELECTRICAL PROPERTIES
ELECTROLYTES
NONAQUEOUS SOLVENTS