Room temperature lamination of Li-on polymer

Abstract

According to an exemplary embodiment a polyvinylidene diflouride homopolymer and solvent, such as acetone, are mixed together to form a solution. The solution is coated on a porous electrode. The coated electrode is immersed in a bath, such as denatured Ethanol, thereby creating a porous membrane on the electrode. The membrane coated electrode is then dried. After drying membrane coated electrode is placed opposite another porous electrode with the membrane positioned substantially between the first and second electrodes. The membrane is compressed between the electrodes dry bonding the membrane with the other electrode thereby forming a good physical bound. Alternatively the membrane may be formed on both electrodes and the membranes are then compressed between the electrodes thereby dry bonding the first and second electrodes together. In yet another embodiment the membrane may be formed separately then compressed between the electrodes thereby dry bonding the membrane with the two electrodes.

What is claimed is:  
     
         1 . A method of manufacturing an electrolytic cell comprising the steps of: 
 placing a porous membrane between a first electrode and second electrode;    compressing the membrane between the electrodes thereby dry bonding the membrane to the electrodes.    
     
     
         2 . The method of    claim 1    wherein said step of compressing further comprises calendering said membrane and first electrode with said second electrode.  
     
     
         3 . The method of    claim 1   , wherein the first electrode has a porosity substantially between 25-40% and said second electrode as a porosity substantially between 25 to 40%.  
     
     
         4 . The method of    claim 1   , wherein said step of compressing further comprises compressing said membrane at least 20%.  
     
     
         5 . The method of    claim 1   , wherein said membrane initially has a porosity of at least 50%.  
     
     
         6 . The method of    claim 5   , wherein said membrane is formed of a polyvinylidene diflouride homopolymer.  
     
     
         7 . The method of    claim 1   , wherein said dry bond has an adhesion force greater than 10 N/cm 2 .  
     
     
         8 . The method of    claim 1    further comprising the steps of: 
 mixing a polyvinylidene diflouride homopolymer and solvent to form a solution;  
 coating said solution on said first electrode;  
 coating said solution on said second electrode;  
 immersing said first and second coated electrodes in a liquid filled bath thereby creating a porous membrane on said first and second electrodes;  
 drying the first and second coated electrodes;  
 placing the first electrode opposite said second electrode with the respective membranes positioned substantially between said first and second electrodes;  
 compressing the membranes between the first and second electrodes thereby dry bonding said first and second electrodes together.  
 
     
     
         9 . The method of    claim 8    wherein said step of compressing further comprises compressing said membrane at least 25%.  
     
     
         10 . The method of    claim 8   , wherein said step of creating said porous membranes on said first and second electrodes further comprises creating said membranes having a porosity of at least 60%.  
     
     
         11 . The method of    claim 10   , wherein said step of creating said porous membranes on said first and second electrodes further comprises creating said membrane on said first electrode having a thickness of 50 μm to 120 μm and said membrane on said second electrode having a thickness of 25 μm to 100 μm.  
     
     
         12 . An electrolytic cell made according to the method of    claim 11   .  
     
     
         13 . A method of manufacturing an electrolytic cell comprising the steps of: 
 providing a first electrode coated with a porous membrane;    placing said membrane and first electrode opposite a second electrode with said membrane positioned substantially between said first and second electrodes; and    compressing the membrane between the electrodes thereby dry bonding the membrane with said second electrode.    
     
     
         14 . The method of    claim 13   , further comprising the steps of: 
 mixing a polyvinylidene diflouride homopolymer and solvent to form a solution; coating said solution on said first electrode;    immersing said first electrode in a liquid filled bath thereby creating said porous membrane on said first electrode; and    drying said membrane and first electrode before compressing said membrane and first electrode with said second electrode.    
     
     
         15 . The method of    claim 13   , wherein in said first electrode is a negative electrode and said second electrode is a positive electrode.  
     
     
         16 . The method of    claim 13   , wherein said first electrode is a positive electrode and said second electrode is a negative electrode.  
     
     
         17 . The method of    claim 13   , wherein the first electrode has a porosity of at least 30% and said second electrode as a porosity of at least 25%.  
     
     
         18 . The method of    claim 13   , wherein said step of compressing further comprises calendering said membrane and first electrode with said second electrode.  
     
     
         19 . The method of    claim 15   , wherein said step of compressing further comprises compressing said membrane at least 20%.  
     
     
         20 . The method of    claim 13   , wherein said step of creating a membrane further comprises creating a membrane initially having a porosity substantially of at least 50%.  
     
     
         21 . The method of    claim 20   , wherein said step of creating a membrane further comprises creating a membrane having a thickness at least 50 μm.  
     
     
         22 . The method of    claim 13   , wherein said dry bond has an adhesion force greater than 10 N/cm 2 .  
     
     
         23 . An electrolytic cell made according to the method of    claim 13   .  
     
     
         24 . A method of manufacturing an electrolytic cell comprising the steps of: 
 placing a first porous membrane between a first electrode and second electrode;    placing a second porous membrane between said second electrode and a third electrode;    compressing said first membrane and said second membrane between said first and s second electrodes and said second and third electrodes, respectively, thereby dry bonding said first membrane and said second membrane to said first and second electrodes and said second and third electrodes, respectively.    
     
     
         25 . The method of    claim 24   , wherein said first and third electrodes are positive and said second electrode is negative.  
     
     
         26 . The method of    claim 24   , wherein said first and third electrodes are negative and said second electrode is positive.  
     
     
         27 . The method of    claim 24   , wherein said dry bond has an adhesion force greater than 10 N/CM 2 .  
     
     
         28 . An electrolytic cell made according to the method of    claim 24   .  
     
     
         29 . A method of manufacturing a lithium secondary cell including a microporous polyvinylidene diflouride homopolymer (PVdF) membrane comprising the steps of: 
 providing a lithium based electrode;    placing the PVdF membrane on said electrode; and    compressing said electrode and membrane, wherein said electrode and the PVdF membrane are dry bonded with an adhesion force of at least 10 N/cm 2 .    
     
     
         30 . The method of    claim 29   , wherein the step of compression compresses said membrane to at least 70 percent of its original thickness.  
     
     
         31 . A Lithium ion cell manufactured according to the method of    claim 31   .  
     
     
         32 . A method of manufacturing a lithium secondary cell including a microporous polyvinylidene diflouride homopolymer (PVDF) membrane comprising the steps of: 
 providing a lithium based electrode;    coating said electrode with a first PVDF membrane;    placing a second PVDF membrane on first PVdF membrane; and    compressing said electrode coated PVdF membrane and said second PVDF membrane, wherein said electrode coated PVDF membrane and said second PVdF membrane are dry bonded with an adhesion force of at least 10 N/cm 2 .    
     
     
         33 . The method according to    claim 32   , wherein said step of compressing compresses said first and second membranes to at least 70 percent of their original thickness.  
     
     
         34 . A Lithium ion cell manufactured according to the method of    claim 32   .