Positive electrode films for alkali metal polymer batteries and method for making same

Abstract

A process for extruding a thin positive electrode sheet having at least 40%/wt of solid content for a lithium polymer battery through a single or twin screw extruder is disclosed as well as a positive electrode sheet produced therefrom. A mixture of active cathodic intercalation material, lithium salt and electronic conductive material is mixed with a polymer of the polyether family in a ratio of at least 40% of total weight into the mixing chamber of an extrusion machine and extruded through a classical sheet die into a thin cathode sheet or film onto a substrate in sheet form.

What is claimed is:  
     
         1 . A method for combining electrode components comprising: 
 an active material,    an ionically-conductive polymer,    an electrolyte salt,    and no added solvent,    the method comprising processing the electrode components using a single screw extruder.    
     
     
         2 . The method of  claim 1  wherein the combined electrode components include a total of less than 0.8 percent by weight solvent.  
     
     
         3 . The method of  claim 1  wherein the combined electrode components include a total of less than 0.1 percent by weight solvent.  
     
     
         4 . The method of  claim 1  wherein comprises active material selected from the group consisting of oxides of vanadium, its lithiated versions, and mixtures thereof.  
     
     
         5 . The method of  claim 1  wherein the electrode components comprise at least 40%/wt of said active material.  
     
     
         6 . The method of  claim 1  wherein the electrode components comprise at least 50%/wt of said active material.  
     
     
         7 . The method of  claim 1  wherein the electrode components comprise at least 60%/wt of said active material.  
     
     
         8 . The method of  claim 1  wherein the electrode components comprise from about 57-67 weight percent active material.  
     
     
         9 . The method of  claim 1  wherein the electrode components further comprise electrically-conductive material comprising carbon black, graphite, or a combination thereof.  
     
     
         10 . The method of  claim 9  wherein the electrically-conductive material comprises a mixture of carbon and graphite in a ratio of carbon/graphite ranging from about 0.5:1 to 2:1.  
     
     
         11 . The method of  claim 1  wherein the ionically-conductive polymer is selected from the group consisting of: polymers or copolymers of ethylene oxide, and cyclic ether oxides.  
     
     
         12 . The method of  claim 11  wherein the ionically-conductive polymer comprises a polyethylene oxide.  
     
     
         13 . The method of  claim 1  wherein the electrolyte salt comprises a lithium salt.  
     
     
         14 . The method of  claim 13  wherein the lithium salt is TFSI bis(trifluoromethanesulfonyl)imide salt.  
     
     
         15 . A method for combining electrode components comprising: 
 an active material,    an ionically-conductive polymer,    an electrolyte salt,    wherein the method comprises processing the electrode components using a single screw extruder and    wherein the electrode components are processed in a molten state.    
     
     
         16  A method of producing a battery cathode, the method comprising: 
 processing a mixture of ingredients comprising greater than about 50 weight percent active material, from about 1 to about 10 weight percent electrically-conductive material comprising carbon black, graphite, or a combination thereof, from about 10 to about 40 weight percent polymer comprising ionically-conductive polyethylene oxide polymer, from about 4 to about 10 weight percent lithium salt, wherein the mixture includes a total of less than about 0.8 percent by weight solvent, the method comprising using a single or twin screw extruder and processing the mixture in a molten state.  
 
     
     
         17 . A method for combining electrode components comprising: 
 an active material,    an ionically-conductive polymer,    an electrolyte salt,    and no added solvent,    the method comprising processing the electrode components using a twin screw extruder.    
     
     
         18 . The method of  claim 17  wherein the combined electrode components include a total of less than 0.8 percent by weight solvent.  
     
     
         19 . The method of  claim 17  wherein the combined electrode components include a total of less than 0.1 percent by weight solvent.  
     
     
         20 . The method of  claim 17  wherein comprises active material selected from the group consisting of oxides of vanadium, its lithiated versions, and mixtures thereof.  
     
     
         21 . The method of  claim 17  wherein the electrode components comprise at least 40%/wt of said active material.  
     
     
         22 . The method of  claim 17  wherein the electrode components comprise at least 50%/wt of said active material.  
     
     
         23 . The method of  claim 17  wherein the electrode components comprise at least 60%/wt of said active material.  
     
     
         24 . The method of  claim 17  wherein the electrode components comprise from about 57-67 weight percent active material.  
     
     
         25 . The method of  claim 17  wherein the electrode components further comprise electrically-conductive material comprising carbon black, graphite, or a combination thereof.  
     
     
         26 . The method of  claim 25  wherein the electrically-conductive material comprises a mixture of carbon and graphite in a ratio of carbon/graphite ranging from about 0.5:1 to 2:1.  
     
     
         27 . The method of  claim 17  wherein the ionically-conductive polymer is selected from the group consisting of: 
 polymers or copolymers of ethylene oxide, and cyclic ether oxides.  
 
     
     
         28 . The method of  claim 27  wherein the ionically-conductive polymer comprises a polyethylene oxide.  
     
     
         29 . The method of  claim 17  wherein the electrolyte salt comprises a lithium salt.  
     
     
         30 . The method of  claim 29  wherein the lithium salt is TFSI bis(trifluoromethanesulfonyl)imide salt.  
     
     
         31 . A method for combining electrode components comprising: 
 an active material,    an ionically-conductive polymer,    an electrolyte salt,    and no added solvent,    the method comprising processing the electrode components using a reciprocating single screw extruder.    
     
     
         32 . The method of  claim 31  wherein each electrode component contains essentially no solvent.  
     
     
         33 . The method of  claim 31  wherein each electrode component is a dry material that contains no solvent.  
     
     
         34 . The method of  claim 31  wherein the combined electrode components include essentially no solvent.  
     
     
         35 . The method of  claim 31  wherein the combined electrode components include a total of less than 0.5 percent by weight solvent.  
     
     
         36 . The method of  claim 31  wherein the active material comprises a metal oxide.  
     
     
         37 . The method of  claim 31  wherein the active material comprises a metal oxide selected from the group consisting of oxides of vanadium, manganese, cobalt, nickel, chromium, aluminum, tungsten, molybdenum, titanium, their lithiated versions, and mixtures thereof.  
     
     
         38 . The method of  claim 31  where the active material comprises a vanadium oxide.  
     
     
         39 . The method of  claim 31  wherein the electrode components comprise from about 50-86 weight percent active material.  
     
     
         40 . The method of  claim 31  wherein the electrode components comprise from about 60-68 weight percent active material.  
     
     
         41 . The method of  claim 31  wherein the components further comprise electrically-conductive material comprising carbon black, graphite, or a combination thereof  
     
     
         42 . The method of  claim 31  wherein the ionically-conductive polymer comprises a derivative of monomers comprising an oxygen-containing monomer or a nitrogen-containing monomer.  
     
     
         43 . The method of  claim 31  wherein the ionically-conductive polymer comprises a polyalkylene oxide polymer or copolymer.  
     
     
         44 . The method of  claim 31  wherein the electrolyte salt comprises a fluorinated lithium salt.  
     
     
         45 . The method of  claim 31  wherein the electrolyte salt is chosen from the group consisting of lithium hexafluoroarsenate, lithium perchlorate, lithium hexafluorophosphate, lithium trifluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium tris(trifluoromethanesulfonyl)methide, and mixtures thereof.  
     
     
         46 . The method of  claim 31  wherein the electrode components comprise: 
 greater than about 50 weight percent active material, from about 1 to about 10 weight percent electrically-conductive material comprising carbon black, graphite, or a combination thereof,  
 from about 10 to about 40 weight percent ionically-conductive polymer,  
 from about 3 to about 15 weight percent lithium salt, and less than about 0.5 weight percent solvent.  
 
     
     
         47 . The method of  claim 46  wherein the active material comprises a metal oxide selected from the group consisting of oxides of vanadium, manganese, cobalt, nickel, chromium, aluminum, tungsten, molybdenum, titanium, their lithiated versions and mixtures thereof.  
     
     
         48 . The method of  claim 46  where the ionically-conductive polymer comprises a derivative of monomers comprising an oxygen-containing monomer or a nitrogen-containing monomer.  
     
     
         49 . The method of  claim 46  wherein the ionically-conductive polymer comprises a polyalkylenoxide polymer or copolymer.  
     
     
         50 . The method of  claim 46  wherein the lithium salt is chosen from the group consisting of lithium hexafluoroarsenate, lithium perchlorate, lithium hexafluorophosphate, lithium trifluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, lithium tris(trifluoromethanesulfonyl)methide, and mixtures thereof.  
     
     
         51 . The method of  claim 31  wherein the extruder comprises 
 multiple feed inlets and a downstream extruding end, and wherein  
 the ionic salt feeds into the extruder at a first feed position,  
 the ionically-conductive polymer, the active material, and the electrically-conductive material each feed into the extruder at one or more feed positions downstream from the ionic salt feed position.  
 
     
     
         52 . The method of  claim 51  wherein the ionically-conductive polymer feeds into the extruder as a solid containing no solvent.  
     
     
         53 . The method of  claim 51  wherein the ionically-conductive polymer feeds into the extruder as a melt.  
     
     
         54 . The method of  claim 51  wherein the ionically-conductive polymer feeds into the extruder at a second position downstream from the first feed position, and a mixture comprising active material and electrically-conductive material is fed at a third feed position downstream from the second feed position.  
     
     
         55 . The method of  claim 51  wherein ionically-conductive polymer, active material, and electrically-conductive material are combined and fed into the extruder as a single mixture at a second feed position.  
     
     
         56 . The method of  claim 51  wherein a mixture comprising active material, electrically-conductive material, and ionically-conductive polymer is fed at a second feed position, and a mixture comprising active material and electrically-conductive material is fed at a third feed position downstream from the second feed position.  
     
     
         57 . A method for combining electrode components comprising: 
 an active material,    an ionically-conductive polymer,    an electrolyte salt,    wherein the method comprises processing the electrode components using a reciprocating single screw extruder and    wherein an ionically-conductive polymer salt complex material is processed in a molten state.    
     
     
         58 . A method of producing a battery cathode, the method comprising processing a mixture of ingredients comprising: 
 greater than about 50 weight percent active material, from about 1 to about 10 weight percent electrically-conductive material comprising carbon black, graphite, or a combination thereof,    from about 10 to about 40 weight percent polymer comprising ionically-conductive polyalkylenoxide polymer,    from about 3 to about 15 weight percent fluorinated lithium salt, wherein the mixture includes a total of less than about 0.5 percent by weight solvent, the method comprising using a reciprocating extruder and processing an ionically-conductive polymer salt complex in a molten state.    
     
     
         59 . The method of  claim 58  further comprising depositing an extrudate of the electrode components onto a substrate.  
     
     
         60 . The method of  claim 59  wherein the substrate is chosen from the group consisting of a liner, a current collector, a separator, or an electrolyte.  
     
     
         61 . The method of  claim 58  wherein the ingredients include at least about 50 weight percent active ingredient.  
     
     
         62 . The method of  claim 58  wherein the ingredients include 
 at least about 60 weight percent lithiated vanadium oxide.  
 
     
     
         63 . A method for combining electrode components comprising: 
 ionically-conductive polymer, electrolyte salt,    the method comprising processing electrolyte components using a reciprocating single screw extruder,    wherein ionically-conductive polymer is fed to the extruder downstream from electrolyte salt.    
     
     
         64 . The method of  claim 63  wherein the ionically-conductive polymer feeds into the extruder as a melt.  
     
     
         65 . The method of  claim 63  wherein the electrode components contain no added solvent.  
     
     
         66 . The method of  claim 63  wherein the components further comprise active material.