Electrochemical device and process for manufacturing same

Abstract

A plurality of polarizable electrodes, a laminate of a collector layer, a polarizable electrode layer of a porous sheet, and a carbon-based conductive material interposed therebetween, are disposed in a row arrangement, interposing separators between the polarizable electrodes, and an electrolyte is packed between said polarizable electrodes and said separators; the carbon-based conductive material penetrating into the voids in the polarizable electrode layers. A process is provided whereby the polarizable electrode is manufactured by applying a conductive material solution to the collector and/or polarizable electrode sheet surface, superposing the two, and then evaporating out the dispersion medium of the conductive material solution.

What is claimed is:  
     
         1 . In an electrochemical device having an electrode layer having pores and a thickness, and a collector layer, the improvement comprising an adhesive for attaching said electrode layer to said collector layer, said adhesive comprising electrically conductive carbon and a binder, wherein a portion of said adhesive is disposed within the pores of the electrode layer to a depth of about 0.15% to 30% of the thickness of the electrode layer.  
     
     
         2 . An electrochemical device as defined in  claim 1  wherein said portion of said adhesive disposed within the pores of the electrode layer extends to a depth of about 0.25% to about 15% of the thickness of the electrode layer.  
     
     
         3 . An electrochemical device as defined in  claim 1  wherein said electrically conductive material is graphite or carbon black.  
     
     
         4 . An electrochemical device as defined in  claim 1  wherein said electrically conductive material has an average particle size of about 0.5 microns to about 50 microns.  
     
     
         5 . An electrochemical device as defined in  claim 1  wherein said binder consists of at least one material selected from the group consisting of thermoplastic resins, cellulose derivatives, and water glass.  
     
     
         6 . An electrochemical device as defined in  claim 1  wherein said electrically conductive carbon is present in an amount of about 20% to about 30% and said binder is present in an amount by weight of from about 4% to about 20%.  
     
     
         7 . An electrochemical device as defined in  claim 1  wherein said electrically conductive carbon and said binder are present in a relative amount by weight of about 5:1 to about 1:1, electrically conductive carbon to binder.  
     
     
         8 . An electrochemical device as defined in  claim 6  further comprising a dispersion medium present in an amount by weight of about 45% to about 75%.  
     
     
         9 . An electrochemical device as defined in  claim 8  further comprising an additive.  
     
     
         10 . An electrochemical device as defined in  claim 9  wherein said electrically conductive adhesive is natural graphite present in an amount by weight of about 30%, said binder is carboxymethyl cellulose sodium salt present in an amount by weight of about 8%, said dispersion medium is water present in an amount by weight of about 60%, and said additive is ammonia present in an amount by weight of about 2%, said adhesive being disposed in the pores of the electrode layer to a depth of about 0.25% to about 15% of the thickness of the electrode layer.  
     
     
         11 . An electrochemical device as defined in  claim 5  wherein said binder is waterglass.  
     
     
         12 . An electrochemical device as defined in  claim 11  for use in a lithium thionyl chloride battery.