Patent ID: 6273921
Filing Date: 2001-08-14
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
A method of making a battery comprising:forming one or more cells containing plasticizer;securing said one or more cells in an airtight leak-free extraction chamber, said chamber in fluid communication with a fluid delivery system;contacting the cells with a compressed or dense phase gas consisting essentially of carbon dioxide, said carbon dioxide at a pressure and temperature equal to, above, or below the critical pressure and/or critical temperature of carbon dioxide;extracting the cell(s) maintained at a temperature above the critical temperature of carbon dioxide by sequentially flowing compressed or dense phase carbon dioxide extraction solvent and then changing the phase of the carbon dioxide between the supercritical state and the liquid state by varying the pressure of the carbon dioxide in a series of alternating steps between two pressures at or above the critical pressure of carbon dioxide, maintaining said pressure at the completion of each step for a period of time sufficient to remove the plasticizer and/or one or more contaminants, said maintaining contact between said carbon dioxide and said one or more cells for said period of time at each step;changing the phase of the carbon dioxide without attempting to minimize or modulate any change in the temperature of the fluid during the phase change;varying the temperature of the carbon dioxide by causing a rapid and significant change in pressure of the fluid by either expansion to produce cooling or compression to produce heating of the fluid;contacting said one or more cells with an electrolyte;applying 15-20 pounds per square inch of static carbon dioxide pressure to said extraction chamber;applying and then releasing a static pressure plug of 20-100 pounds per square inch of carbon dioxide pressure to the extraction chamber to remove an excess of said electrolyte; andapplying 15-20 pounds per square inch of static carbon dioxide pressure to said extraction chamber.