Solid polymer electrolyte composite membrane comprising porous ceramic support

Abstract

A solid polymer electrolyte composite membrane and method of manufacturing the same. The composite membrane comprises a porous ceramic support having a top surface and a bottom surface. The porous ceramic support may be formed by laser micromachining a ceramic sheet or may be formed by electrochemically oxidizing a sheet of the base metal. A solid polymer electrolyte fills the pores of the ceramic support and preferably also covers the top and bottom surfaces of the support. Application of the solid polymer electrolyte to the porous support may take place by applying a dispersion to the support followed by a drying off of the solvent, by hot extrusion of the solid polymer electrolyte (or by hot extrusion of a precursor of the solid polymer electrolyte followed by in-situ conversion of the precursor to the solid polymer electrolyte) or by in-situ polymerization of a corresponding monomer of the solid polymer electrolyte.

1 . A solid polymer electrolyte composite membrane, said solid polymer electrolyte composite membrane comprising:
 (a) a ceramic support, said ceramic support having opposing top and bottom surfaces and a plurality of pores extending from said top surface to said bottom surface, wherein at least some of said pores are positioned in a peripheral portion of the ceramic support and at least some of said pores are positioned in a non-peripheral portion of the ceramic support and wherein said pores are positioned in a greater concentration in said non-peripheral portion than in said peripheral portion; and   (b) a first solid polymer electrolyte at least partially filling at least some of said pores.   
     
     
         2 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein each of said plurality of pores extends in a straight line perpendicularly from said top surface to said bottom surface. 
     
     
         3 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said plurality of pores are arranged in a non-random pattern. 
     
     
         4 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein at least some of said pores are arranged in a honeycomb pattern. 
     
     
         5 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said pores are cylindrical in shape. 
     
     
         6 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said pores have a diameter of about 0.01 to 200 microns. 
     
     
         7 . The solid polymer electrolyte composite membrane as claimed in  claim 6  wherein said pores have a diameter of about 1 to 200 microns. 
     
     
         8 . The solid polymer electrolyte composite membrane as claimed in  claim 6  wherein said pores have a diameter of about 0.01 to 100 microns. 
     
     
         9 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said pores constitute about 20% to 95% of said ceramic support. 
     
     
         10 . The solid polymer electrolyte composite membrane as claimed in  claim 9  wherein said pores constitute about 40% to 70% of said ceramic support. 
     
     
         11 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said ceramic support comprises a material selected from the group consisting of silica, quartz, glass, boron carbonate, silicon carbide, alumina, titania, silica tungstate, sintered valve metal oxides and non-conductive diamond or diamond-like coatings. 
     
     
         12 . The solid polymer electrolyte composite membrane as claimed in  claim 11  wherein said ceramic support comprises a ceramic selected from the group consisting of silica, alumina and silicon carbide. 
     
     
         13 . The solid polymer electrolyte composite membrane as claimed in  claim 12  wherein said ceramic support is made of alumina. 
     
     
         14 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said ceramic support has a thickness of about 1 to 50 microns. 
     
     
         15 . The solid polymer electrolyte composite membrane as claimed in  claim 14  wherein said ceramic support has a thickness of about 7.5 to 15 microns. 
     
     
         16 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said first solid polymer electrolyte is selected from the group consisting of polymer compositions that contain metal salts, polymeric gels that contain electrolyte and ion exchange resins. 
     
     
         17 . The solid polymer electrolyte composite membrane as claimed in  claim 16  wherein said first solid polymer electrolyte is an ion exchange resin. 
     
     
         18 . The solid polymer electrolyte composite membrane as claimed in  claim 17  wherein said first solid polymer electrolyte is perfluorosulfonic acid (PFSA) polymer. 
     
     
         19 . The solid polymer electrolyte composite membrane as claimed in  claim 18  wherein said PFSA polymer has an equivalent weight of about 200 to 2000. 
     
     
         20 . The solid polymer electrolyte composite membrane as claimed in  claim 19  wherein said PFSA polymer has an equivalent weight of about 500 to 1200. 
     
     
         21 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein all of said pores are completely filled with said first solid polymer electrolyte and wherein said top and bottom surfaces of said ceramic support are covered with said first solid polymer electrolyte. 
     
     
         22 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said solid polymer electrolyte composite membrane has a thickness of about 5 to 300 microns. 
     
     
         23 . The solid polymer electrolyte composite membrane as claimed in  claim 22  wherein said solid polymer electrolyte composite membrane has a thickness of about 7.5 to 200 microns. 
     
     
         24 . The solid polymer electrolyte composite membrane as claimed in  claim 1  wherein said solid polymer electrolyte composite membrane has an ionic conductivity of 0.001 S/cm to 0.7 S/cm at room temperature with a relative humidity of 100%. 
     
     
         25 . A method of preparing a solid polymer electrolyte composite membrane, said method comprising the steps of:
 (a) providing a ceramic support, said ceramic support having a top surface and a bottom surface;   (b) lasing at least one pore in said ceramic support, said at least one pore extending transversely from said top surface to said bottom surface; and   (c) filling at least one of said at least one pore with a first solid polymer electrolyte.   
     
     
         26 . The method as claimed in  claim 25  wherein said step of providing a ceramic support comprises providing a metal sheet and electrochemically oxidizing said metal sheet. 
     
     
         27 . A method of preparing a perfluorosulfonic acid polymer, said method comprising the steps of:
 (a) providing a sulfonyl fluoride precursor of said perfluorosulfonic acid polymer; and   (b) adding a weak base to said sulfonyl fluoride precursor to convert said sulfonyl fluoride precursor to said perfluorosulfonic acid polymer.