Method of making a high performance ultracapacitor
AssigneeMaxwell Energy Products, Inc.
InventorsC. Joseph Farahmandi, John M. Dispennette
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Abstract
A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.
Claims56
A method of making a double layer capacitor comprising the steps of:
- impregnating an activated carbon fiber preform with an evenly distributed and continuous path of aluminum, thereby forming an aluminum impregnated carbon fiber preform;
- bonding a current collector plate on a surface of said aluminum impregnated carbon fiber preform;
- aligning a pair of aluminum impregnated carbon fiber preforms having been bonded to a respective current collector plate together, wherein said pair of aluminum impregnated carbon fiber preforms have non-bonded surfaces facing one another;
- placing an ionically conductive separator between said facing surfaces of said pair of aluminum impregnated carbon fiber preforms;
- and
- saturating said pair of aluminum impregnated carbon fiber preforms and said ionically conductive separator with an electrolyte solution.
A method of forming a diffusion bond between an aluminum foil current collector plate and an aluminum/carbon composite electrode comprising the steps of:
- reducing any aluminum oxide layers from said aluminum foil current collector plate;
- and
- pressing said aluminum/carbon composite electrode against said aluminum foil current collector plate at a bonding temperature well below a melting point of aluminum in an inert atmosphere such that aluminum atoms fill voids at an interface of said aluminum/carbon composite electrode and aluminum foil current collector plate to adhere said aluminum foil to said carbon electrode while preventing formation of aluminum carbide at said interface.
A method of making a double layer capacitor comprising the steps of:
- impregnating a pair of activated carbon fiber preforms with aluminum;
- pressing a pair of current collector plates each onto a respective surface of respective ones of said pair of activated carbon fiber preforms;
- aligning the pair of activated carbon fiber preforms together wherein said respective ones of said pair of activated carbon fiber preforms have respective non-bonded surfaces facing one another;
- placing an ionically conductive separator between said non-bonded surfaces of said respective ones of said pair of activated carbon fiber preforms;
- and
- saturating said pair of activated carbon fiber preforms and the ionically conductive separator with an electrolyte solution.
A method of making a double layer capacitor comprising the steps of:
- forming the double layer capacitor, wherein the double layer capacitor has an electrode capacitance of greater than 30 farads/cm.sup.3 and a cell resistivity of less than 15 ohm-cm comprising:
- impregnating a pair of activated carbon fiber preforms with aluminum;
- pressing a pair of current collector plates each onto a respective surface of respective ones of said pair of activated carbon fiber preforms;
- aligning the pair of activated carbon fiber preforms together wherein said respective ones of said pair of activated carbon fiber preforms have respective non-bonded surfaces facing one another;
- placing an ionically conductive separator between said non-bonded surfaces of said respective ones of said pair of activated carbon fiber preforms;
- and
- saturating said pair of activated carbon fiber preforms and the ionically conductive separator with an electrolyte solution.
Dependencies are inferred from the claim text.