Apparatus and method of preparing electrochemical cells

A method of preparing an electrochemical cell comprising an anode, a cathode, and a polymeric layer positioned between the anode and cathode which comprises the steps of:

• (a) forming an anode composition comprising a carbon material, a first polymer, and a first plasticizer;
• (b) forming a cathode composition comprising a cathode active material, a second polymer, and a second plasticizer;
• (c) forming a polymeric matrix comprising a third polymer and a third plasticizer that is positioned between the anode composition and cathode composition;
• (d) removing said first, second, and third plasticizers by extraction with a supercritical fluid to form an electrochemical cell precursor by a process comprising the steps of:
• (i) providing an apparatus that comprises:
• a sealable chamber defining a compartment adapted to receive an article containing a plasticizer;
• means for circulating a supercritical fluid into said compartment that comes into contact with said article;
• and
• means for separating supercritical fluid and plasticizer from a mixture of supercritical fluid and plasticizer;
• (ii) placing said anode composition, cathode composition, and polymeric matrix into said compartment and contacting the same with a supercritical fluid, wherein said supercritical fluid during said contacting is maintained under conditions of temperature and pressure such that said supercritical fluid takes up at least a portion of said plasticizers;
• (iii) removing said supercritical fluid loaded with said portion of plasticizer taken up during said contacting;
• and
• (d) inserting an electrolyte solution comprising an electrolyte solvent and salt into the electrochemical precursor.