Separators for electrochemical cells

Abstract

This invention pertains to separators for electrochemical cells which comprise a microporous pseudo-boehmite layer; electrolyte elements comprising such separators; electrical current producing cells comprising such separators; and methods of making such separators, electrolyte elements and cells.

1 . A separator for an electric current producing cell, wherein said separator comprises a microporous layer comprising pseudo-boehmite and a binder.  
     
     
         2 . The separator of  claim 1 , wherein said binder is present in an amount of 3 to 200% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         3 . The separator of  claim 1 , wherein said binder is present in an amount of 5 to 70% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         4 . The separator of  claim 1 , wherein said binder is an organic binder.  
     
     
         5 . The separator of  claim 1 , wherein said binder is selected from the consisting of: 
 polyvinyl alcohols, polyethylene oxides, alkylated polyethylene oxides, polyvinyl pyrrolidones, polyvinyl butyrals, cellulosics, polymers comprising quaternary ammonium groups, polyacrylamides and non-hydrolyzed derivatives and partially hydrolyzed derivatives, polyvinyl ethers, polyethyleneimines, polyurethanes, epoxies, melamine formaldehydes, urea formaldehydes; copolymers thereof, copolymers of maleic anhydride and derivatives and esters thereof; gelatin; starch; and mixtures of the foregoing binders.    
     
     
         6 . The separator of  claim 1 , wherein said binder is an inorganic binder.  
     
     
         7 . The separator of  claim 1 , wherein said binder is selected from the group consisting of: 
 colloidal silicas, colloidal non-hydrated aluminum oxides, colloidal tin oxides, colloidal titanium oxides, colloidal zirconium oxides, and colloidal zinc oxides.    
     
     
         8 . The separator of  claim 1 , wherein said binder further comprises one or more additives selected from the group consisting of: 
 pigments, crosslinking agents, catalysts for non-radiation curing, sensitizers for radiation curing, plasticizers, surfactants, and dispersants.    
     
     
         9 . The separator of  claim 1 , wherein pores of said microporous layer are impregnated with a composition comprising a polymer.  
     
     
         10 . The separator of  claim 9 , wherein said polymer is ionically conductive.  
     
     
         11 . The separator of  claim 9 , wherein said composition further comprises a crosslinking agent.  
     
     
         12 . The separator of  claim 1 , wherein said microporous layer has a thickness of from 1 micron to 50 microns.  
     
     
         13 . The separator of  claim 1 , wherein said microporous layer has a thickness of from 1 micron to 25 microns.  
     
     
         14 . The separator of  claim 1 , wherein said microporous layer has a thickness of from 2 microns to 15 microns.  
     
     
         15 . An electrolyte element for an electric current producing cell, wherein said electrolyte element comprises: 
 (a) a separator comprising a microporous layer comprising pseudo-boehmite and a binder; and,    (b) an organic electrolyte contained within pores of said microporous layer.    
     
     
         16 . The electrolyte element of  claim 15 , wherein said binder is present in an amount of 3 to 200% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         17 . The electrolyte element of  claim 15 , wherein said binder is present in an amount of 5 to 70% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         18 . The electrolyte element of  claim 15 , wherein said binder is an organic binder.  
     
     
         19 . The electrolyte element of  claim 15 , wherein said binder is selected from the group consisting of: 
 polyvinyl alcohols, polyethylene oxides, alkylated polyethylene oxides, polyvinyl pyrrolidones, polyvinyl butyrals, cellulosics, polymers comprising quaternary ammonium groups, polyacrylamides and non-hydrolyzed derivatives and partially hydrolyzed derivatives, polyvinyl ethers, polyethyleneimines, polyurethanes, epoxies, melamine formaldehydes, urea formaldehydes; copolymers thereof; copolymers of maleic anhydride and derivatives and esters thereof; gelatin; starch; and mixtures of the foregoing binders.    
     
     
         20 . The electrolyte element of  claim 15 , wherein said binder is an inorganic binder.  
     
     
         21 . The electrolyte element of  claim 15 , wherein said binder is selected from the group consisting of: 
 colloidal silicas, colloidal non-hydrated aluminum oxides, colloidal tin oxides, colloidal titanium oxides, colloidal zirconium oxides, and colloidal zinc oxides.    
     
     
         22 . The electrolyte element of  claim 15 , wherein said binder further comprises one or more additives selected from the group consisting of: 
 pigments, crosslinking agents, catalysts for non-radiation curing, sensitizers for radiation curing, plasticizers, surfactants, and dispersants.    
     
     
         23 . The electrolyte element of  claim 15 , wherein said organic electrolyte comprises one or more materials selected from the group consisting of: 
 liquid electrolytes, gel polymer electrolytes, and solid polymer electrolytes.    
     
     
         24 . The electrolyte element of  claim 15 , wherein said microporous layer has a thickness of from 2 microns to 15 microns.  
     
     
         25 . A method of making a separator for an electric current producing cell, said separator comprising a microporous layer comprising pseudo-boehmite and a binder, wherein said method comprises the steps of: 
 (a) coating onto a substrate a liquid mixture comprising a boehmite sol, a binder, and a liquid medium; and,    (b) drying the coating formed in step (a) to yield said microporous layer.    
     
     
         26 . The method of  claim 25 , wherein said liquid medium comprises water.  
     
     
         27 . The method of  claim 25 , wherein said liquid medium comprises one or more organic solvents.  
     
     
         28 . The method of  claim 25 , wherein said liquid medium comprises one or more protic organic solvents selected from the group consisting of: 
 alcohols and glycols.    
     
     
         29 . The method of  claim 25 , wherein said liquid medium comprises one or more protic organic solvents selected from the group consisting of: 
 methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, ethylene glycol, and propylene glycol.    
     
     
         30 . The method of  claim 25 , wherein said liquid medium comprises ethanol.  
     
     
         31 . The method of  claim 25 , wherein said liquid medium comprises water and one or more organic solvents.  
     
     
         32 . The method of  claim 25 , wherein said binder is present in an amount of3 to 200% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         33 . The method of  claim 25 , wherein said binder is present in an amount of 5 to 70% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         34 . The method of  claim 25 , wherein said binder is an organic binder.  
     
     
         35 . The method of  claim 25 , wherein said binder is selected from the group consisting of: 
 polyvinyl alcohols, polyethylene oxides, alkylated polyethylene oxides, polyvinyl pyrrolidones, polyvinyl butyrals, cellulosics, polymers comprising quaternary ammonium groups, polyacrylamides and non-hydrolyzed derivatives and partially hydrolyzed derivatives, polyvinyl ethers, polyethyleneimines, polyurethanes, epoxies, melamine formaldehydes, urea formaldehydes; copolymers thereof; copolymers of maleic anhydride and derivatives and esters thereof; gelatin; starch; and mixtures of the foregoing binders.    
     
     
         36 . The method of  claim 25 , wherein said binder is an inorganic binder.  
     
     
         37 . The method of  claim 25 , wherein said binder is selected from the group consisting of: 
 colloidal silicas, colloidal non-hydrated aluminum oxides, colloidal tin oxides, colloidal titanium oxides, colloidal zirconium oxides, and colloidal zinc oxides.    
     
     
         38 . The method of  claim 25 , wherein said binder further comprises one or more additives selected from the group consisting of: 
 pigments, crosslinking agents, catalysts for non-radiation curing, sensitizers for radiation curing, plasticizers, surfactants, and dispersants.    
     
     
         39 . The method of  claim 25 , wherein pores of said microporous layer are impregnated with a composition comprising a polymer.  
     
     
         40 . The method of  claim 39 , wherein said polymer is ionically conductive.  
     
     
         41 . The method of  claim 39 , wherein said composition further comprises a crosslinking agent.  
     
     
         42 . The method of  claim 25 , wherein said microporous layer has a thickness of from 1 micron to 50 microns.  
     
     
         43 . The method of  claim 25 , wherein said microporous layer has a thickness of from 1 micron to 25 microns.  
     
     
         44 . The method of  claim 25 , wherein said microporous layer has a thickness of from 2 microns to 15 microns.  
     
     
         45 . The method of  claim 25 , wherein at least one outermost surface of said substrate comprises a cathode layer and said liquid mixture is coated onto said cathode layer.  
     
     
         46 . The method of  claim 45 , further comprising, subsequent to step (b), the steps of: 
 (c) contacting a surface of said microporous layer with a solution comprising heat- or radiation-curable monomers or oligomers, thereby causing infusion of said monomers or said oligomers into pores of said microporous layer; and,    (d) curing said monomers or said oligomers with an energy source selected from the group consisting of: heat, ultraviolet light, visible light, infrared radiation, and electron beam radiation; thereby forming a polymer.    
     
     
         47 . The method of  claim 46 , wherein said polymer formed in step (d) is an ionic conductive polymer.  
     
     
         48 . The method of  claim 25 , wherein at least one outermost surface of said substrate comprises a release layer and said liquid mixture is coated onto said release layer.  
     
     
         49 . The method of  claim 48 , further comprising, subsequent to step (b), the step of: 
 (c) delaminating said microporous layer from said substrate.    
     
     
         50 . The method of  claim 48 , further comprising, subsequent to step (b), the steps of: 
 (c) contacting a surface of said microporous layer with a solution comprising heat- or radiation-curable monomers or oligomers, thereby causing infusion of said monomers or said oligomers into pores of said microporous layer; and,    (d) curing said monomers or said oligomers with an energy source selected from the group consisting of: heat, ultraviolet light, visible light, infrared radiation, and electron beam radiation; thereby forming a polymer.    
     
     
         51 . The method of  claim 50 , wherein said polymer formed in step (d) is an ionic conductive polymer.  
     
     
         52 . The method of  claim 50 , further comprising, subsequent to step (d), the step of: 
 (e) delaminating said microporous layer from said substrate.    
     
     
         53 . The method of  claim 48 , further comprising, subsequent to step (b), the steps of: 
 (c) contacting a surface of said microporous layer with a coating solution comprising a solid material and a liquid medium; and,    (d) drying the coating formed in step (c) to yield a coating layer comprising said solid material.    
     
     
         54 . The method of  claim 53 , further comprising, subsequent to step (d), the step of: 
 (e) delaminating said microporous layer from said substrate.    
     
     
         55 . The method of  claim 53 , wherein said coating layer formed in step (d) is a cathode layer.  
     
     
         56 . The method of  claim 55 , further comprising, subsequent to step (d), the step of: 
 (e) delaminating said microporous layer from said substrate.    
     
     
         57 . A method of making an electrolyte element for an electric current producing cell, said electrolyte element comprising a microporous layer comprising pseudo-boehmite and a binder, wherein said method comprises the steps of: 
 (a) coating onto a substrate a liquid mixture comprising a boehmite sol, a binder, and a liquid medium;    (b) drying the coating formed in step (a) to yield said microporous layer; and,    (c) contacting a surface of said microporous layer with an organic electrolyte, thereby causing infusion of said electrolyte into pores of said microporous layer.    
     
     
         58 . The method of  claim 57 , wherein said liquid medium comprises water.  
     
     
         59 . The method of  claim 57 , wherein said liquid medium comprises one or more organic solvents.  
     
     
         60 . The method of  claim 57 , wherein said liquid medium comprises one or more protic solvents selected from the group consisting of: alcohols and glycols.  
     
     
         61 . The method of  claim 57 , wherein said liquid medium comprises water and one or more organic solvents.  
     
     
         62 . The method of  claim 57 , wherein said binder is present in an amount of 3 to 200% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         63 . The method of  claim 57 , wherein said binder is present in an amount of 5 to 70% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         64 . The method of  claim 57 , wherein said binder is an organic binder.  
     
     
         65 . The method of  claim 57 , wherein said binder is selected from the group consisting of: 
 polyvinyl alcohols, polyethylene oxides, alkylated polyethylene oxides, polyvinyl pyrrolidones, polyvinyl butyrals, cellulosics, polymers comprising quaternary ammonium groups, polyacrylamides and non-hydrolyzed derivatives and partially hydrolyzed derivatives, polyvinyl ethers, polyethyleneimines, polyurethanes, epoxies, melamine formaldehydes, urea formaldehydes; copolymers thereof; copolymers of maleic anhydride and derivatives and esters thereof; gelatin; starch; and mixtures of the foregoing binders.    
     
     
         66 . The method of  claim 57 , wherein said binder is an inorganic binder.  
     
     
         67 . The method of  claim 57 , wherein said binder is selected from the group consisting of: 
 colloidal silicas, colloidal non-hydrated aluminum oxides, colloidal tin oxides, colloidal titanium oxides, colloidal zirconium oxides, and colloidal zinc oxides.    
     
     
         68 . The method of  claim 57 , wherein said binder further comprises one or more additives selected from the group consisting of: 
 pigments, crosslinking agents, catalysts for non-radiation curing, sensitizers for radiation curing, plasticizers, surfactants, and dispersants.    
     
     
         69 . The method of  claim 57 , wherein said organic electrolyte comprises one or more materials selected from the group consisting of: 
 liquid electrolytes, gel polymer electrolytes, and solid polymer electrolytes.    
     
     
         70 . The method of  claim 57 , wherein said organic electrolyte comprises heat- or radiation-curable monomers or oligomers.  
     
     
         71 . The method of  claim 70 , further comprising, subsequent to step (c), the step of: 
 (d) curing said monomers or said oligomers with an energy source selected from the group consisting of: heat, ultraviolet light, visible light, infrared radiation, and electron beam radiation.    
     
     
         72 . The method of  claim 57 , wherein at least one outermost surface of said substrate comprises a cathode layer and said liquid mixture is coated onto said cathode layer.  
     
     
         73 . The method of  claim 72 , further comprising, subsequent to step (b) and prior to step (c), the steps of: 
 (i) contacting a surface of said microporous layer with a solution comprising heat- or radiation-curable monomers or oligomers, thereby causing infusion of said monomers or said oligomers into pores of said microporous layer; and,    (ii) curing said monomers or said oligomers with an energy source selected from the group consisting of: heat, ultraviolet light, visible light, infrared radiation, and electron beam radiation; thereby forming a polymer.    
     
     
         74 . The method of  claim 72 , further comprising, subsequent to step (b) and prior to step (c), the steps of: 
 (i) contacting a surface of said microporous layer with a coating solution comprising a solid material and a liquid medium; and,    (ii) drying the coating formed in step (i) to yield a coating layer comprising said solid material.    
     
     
         75 . An electric current producing cell comprising a cathode, an anode, and an electrolyte element interposed between said cathode and said anode, wherein said electrolyte element comprises: 
 (a) a separator comprising a microporous layer, which microporous layer comprises pseudo-boehmite and a binder; and,    (b) an organic electrolyte contained within pores of said microporous layer.    
     
     
         76 . The cell of  claim 75 , wherein said binder is present in an amount of 3 to 200% of the weight of pseudo-boehmite in said microporous layer.  
     
     
         77 . The cell of  claim 75 , wherein said binder is an organic binder.  
     
     
         78 . The cell of  claim 75 , wherein said binder is an inorganic binder.  
     
     
         79 . The cell of  claim 75 , wherein said cell is a secondary electric current producing cell.  
     
     
         80 . The cell of  claim 75 , wherein said cell is a primary electric current producing cell.  
     
     
         81 . The cell of  claim 75 , wherein said anode comprises one or more anode-active materials selected from the group consisting of: 
 lithium metal, lithium-aluminum alloys, lithium-tin alloys, lithium-intercalated carbons, and lithium-intercalated graphites.    
     
     
         82 . The cell of  claim 75 , wherein said cathode comprises one or more cathode active materials selected from the group consisting of: 
 transition metal chalcogenides, conductive polymers, and sulfur-containing materials.    
     
     
         83 . The cell of  claim 75 , wherein said cathode comprises a sulfur-containing materials.  
     
     
         84 . The cell of  claim 83 , wherein said sulfur-containing material comprises elemental sulfur.  
     
     
         85 . The cell of  claim 83 , wherein said sulfur-containing material comprises a sulfur-containing polymer comprising a covalent polysulfide moiety of the formula, —S m —, wherein m is an integer equal to or greater than 3.  
     
     
         86 . The cell of  claim 83 , wherein said sulfur-containing material comprises a sulfur-containing polymer comprising a covalent polysulfide moiety of the formula, —S m —, wherein m is an integer equal to or greater than 8.  
     
     
         87 . The cell of  claim 85 , wherein said sulfur-containing polymer has a polymer backbone chain comprising conjugated segments.  
     
     
         88 . The cell of  claim 85 , wherein said sulfur-containing polymer has a polymer backbone chain and said polysulfide moiety, —S m —, is covalently bonded by one or both of its terminal sulfur atoms on a side group to said polymer backbone chain.  
     
     
         89 . The cell of  claim 85 , wherein said sulfur-containing polymer has a polymer backbone chain and said polysulfide moiety, —S m —, is incorporated into said polymer backbone chain by covalent bonding of terminal sulfur atoms of said polysulfide moiety.  
     
     
         90 . The cell of  claim 85 , wherein said sulfur-containing polymer comprises greater than 75 weight percent of sulfur.  
     
     
         91 . The cell of  claim 83 , wherein said sulfur-containing material comprises a sulfur-containing polymer comprising an ionic polysulfide moiety selected from the group consisting of; 
 ionic —S m   −  moieties and ionic S m   2−  moieties; wherein m is an integer equal to or greater than 3.    
     
     
         92 . The cell of  claim 83 , wherein said sulfur-containing material comprises a sulfur-containing polymer comprising an ionic polysulfide moiety selected from the group consisting of: 
 ionic —S m   −  moieties and ionic S m   2−  moieties; wherein m is an integer equal to or greater than 8.    
     
     
         93 . The cell of  claim 91 , wherein [the polymer backbone chain of] said sulfur-containing polymer has a polymer backbone chain comprising conjugated segments.  
     
     
         94 . The cell of  claim 91 , wherein said sulfur-containing polymer has a polymer backbone chain and said polysulfide moiety, —S m —, is covalently bonded by one or both of its terminal sulfur atoms on a side group to said [the] polymer backbone chain [of said sulfur-containing polymer].  
     
     
         95 . The cell of  claim 91 , wherein said sulfur-containing polymer comprises greater than 75 weight percent of sulfur.  
     
     
         96 . The cell of  claim 75 , wherein said organic electrolyte comprises one or more materials selected from the group consisting of: 
 liquid electrolytes, gel polymer electrolytes, and solid polymer electrolytes.    
     
     
         97 . The cell of  claim 75 , wherein said organic electrolyte comprises a liquid electrolyte.  
     
     
         98 . The cell of  claim 75 , wherein said organic electrolyte comprises a gel polymer electrolyte.  
     
     
         99 . The cell of  claim 75 , wherein said organic electrolyte comprises a solid polymer electrolyte.  
     
     
         100 . A method of forming an electric current producing cell, said method comprising the steps of: 
 (a) providing an anode;    (b) providing a cathode; and,    (c) interposing an electrolyte element according to  claim 15  between said anode and said cathode.    
     
     
         101 . The method of claim  100 , wherein the organic electrolyte of said electrolyte element comprises one or more materials selected from the group consisting of: 
 liquid electrolytes, gel polymer electrolytes, and solid polymer electrolytes.    
     
     
         102 . The method of claim  100 , further comprising, subsequent to step (c), the step of: 
 (d) imbibing a solution comprising one or more ionic electrolyte salts and one or more electrolyte solvents into said electrolyte element.    
     
     
         103 . The method of claim  101 , wherein said organic electrolyte after step (c) and prior to step (d) does not comprise an ionic electrolyte salt.