Method of making films and laminated cell structures
AssigneeDelphi Technologies, Inc.
InventorMarc W. Rogers
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Abstract
In the method of the invention, plasticizer is extracted from a polymeric film electrode, electrolyte or laminated film structure thereof, by contacting the film, with an extraction solvent mixture comprising a polar co-solvent, and carbon dioxide which is in a solvent fluidic state, at a temperature greater than or equal to 31.degree. C. and less than 35.degree. C. The pressure of extraction is sufficient to maintain the fluidic state at the temperature range stated. The co-solvent is present in an amount up to about 10% by weight of the extraction solvent mixture. The co-solvent is characterized by having a liquid state at the temperature and pressure of extraction.
Claims23
In a method for forming a solid film comprising a polymer and plasticizer and then removing the plasticizer from said film, the improvement comprising:
- extracting said plasticizer from said film by contacting said film with an extraction solvent mixture comprising carbon dioxide and an organic polar co-solvent, said carbon dioxide, CO.sub.2, being in a solvent fluidic state at a temperature greater than or equal to 31.degree. C. and less than 35.degree. C., and at a pressure to maintain said fluidic state at said temperature, with said co-solvent present in an amount up to about 10 percent by weight of said extraction solvent mixture, and said co-solvent characterized by having a liquid state at said temperature and pressure.
In a method of making a laminated structure comprising:
- forming a first electrode comprising a first polymer, a first plasticizer and a first active material;
- forming a second electrode comprising a second polymer, a second plasticizer and a second active material;
- forming a separator membrane comprising a third polymer and a third plasticizer;
- bonding said electrodes and said separator membrane to form a unitary battery structure;
- extracting at least a portion of said plasticizer from said structure;
- the improvement comprising:
- contacting said structure with an extraction solvent mixture comprising carbon dioxide and alcohol, said carbon dioxide being in a solvent fluidic state at a temperature greater than or equal to 31.degree. C. and less than 35.degree. C., and at a pressure to maintain said fluidic state at said temperature, with said alcohol present in an amount up to about 10 percent by weight of said extraction solvent mixture.
Dependencies are inferred from the claim text.