Covalent Associates, Inc.

Alan B McEwen

David A Evans

Jay L Goldman

Ein-Eli Yair

Thomas J Blakley

Cyclic delocalized cations joined together by spacer groups, with anions of equal number to cations to maintain charge neutrality, are disclosed. These spacer groups may be organic or inorganic in origin and may vary in length. The spacer groups may be saturated, containing single bonds, or may be unsaturated, containing double and triple bonds. With appropriate design these materials can have melting and glass transition temperatures below, around, and above room temperature. The lyophobic character of these materials may be adjusted, providing unique properties. These materials are well suited for use as electrolytes, lubricants, solvents for extractions and for running reactions, biphase catalysis media, media for electroluminescent devices.

Cyclic delocalized cations connected by spacer groups

An electrochemical capacitor is disclosed that features two, separated, high surface area carbon cloth electrodes sandwiched between two current collectors fabricated of a conductive polymer having a flow temperature greater than 130.degree. C., the perimeter of the electrochemical capacitor being sealed with a high temperature gasket to form a single cell device. The gasket material is a thermoplastic stable at temperatures greater than 100.degree. C., preferably a polyester or a polyurethane, and having a reflow temperature above 130.degree. C. but below the softening temperature of the current collector material. The capacitor packaging has good mechanical integrity over a wide temperature range, contributes little to the device equivalent series resistance (ESR), and is stable at high potentials. In addition, the packaging is designed to be easily manufacturable by assembly line methods. The individual cells can be stacked in parallel or series configuration to reach the desired device voltage and capacitance.

Nonaqueous electrical storage device

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 .ANG..sup.3, preferably inorganic perfluoride anions and most preferably PF.sub.6.sup.-, 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 therof. 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.

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Melrose, MA, United States of America

Alan B McEwen