Plasticized electrode for an alkaline battery

Abstract

An electrode including a conductive metal support and a paste including an electrochemically-active material and a binder. The binder includes a compound of silane type, and a polymer having at least one acrylic monomer, and representing at least approximately 0.15% of the weight of said paste. The use of this binder improves the calendar or cycle life of the battery at a temperature greater than or equal to 25° C., preferably at a temperature greater than or equal to 40° C.

1 . Electrode comprising a conductive metal support and a paste comprising an electrochemically-active material and a binder; this binder comprising: 
 a) a compound of silane type, and    b) a polymer comprising at least one acrylic monomer, and representing at least approximately 0.15% of the weight of said paste.    
   
   
       2 . Electrode according to  claim 1 , in which the polymer represents at least approximately 0.3%, preferably at least approximately 0.45% of the weight of said paste.  
   
   
       3 . Electrode according to  claim 1 , in which the conductive support is two-dimensional.  
   
   
       4 . Electrode according to  claim 1 , in which the compound of silane type has the formula: X p —Si (R) 4-p  in which: 
 X is chosen from the group comprising an alkyl, substituted or not by a halogen, an alkenyl, an aryl, an alkylaryl, an arylalkyl, an alkenylaryl, an arylalkenyl, an epoxy, an amine, a styrylamine, a methacrylate.    R is chosen from the group comprising H, a halogen, a hydroxy, alkoxy, acyloxy group, a cyclic alkyl, an aryl or —NR 2  in which R is H or an alkyl.    p is 1, 2 or 3.    
   
   
       5 . Electrode according to  claim 1 , in which the compound of silane type is glycidyloxypropyltrimethoxy-silane.  
   
   
       6 . Electrode according to one  claim 1 , in which the polymer is chosen from styrene acrylate, poly(meth)acrylate, hydrolyzed styrene-maleic anhydride.  
   
   
       7 . Electrode according to  claim 1 , in which the mass proportions of the polymer and the compound of silane type vary between 95%/5% and 50%/50%.  
   
   
       8 . Electrode according to  claim 1 , in which the mass proportion of the binder is comprised between 0.16 and 3% of the weight of the paste.  
   
   
       9 . Electrode according to  claim 1 , also comprising fibres.  
   
   
       10 . Electrode according to  claim 9 , in which the fibres are polypropylene fibres.  
   
   
       11 . Electrode according to  claim 9 , in which the quantity of fibres added is less than 1.5% of the weight of the paste.  
   
   
       12 . Electrode according to  claim 1 , in which the electrochemically-active material is a compound based on nickel hydroxide.  
   
   
       13 . Electrode according to  claim 1 , in which the electrochemically-active material is a hydrogen-fixing alloy.  
   
   
       14 . Electrode according to  claim 1 , in which the electrochemically-active material is a compound based on cadmium.  
   
   
       15 . Alkaline electrolyte battery comprising an electrode, including a conductive metal support and a paste comprising an electrochemically-active material and a binder; the binder comprising: 
 a) a compound of silane type, and    b) a polymer comprising at least one acrylic monomer, and representing at least approximately 0.15% of the weight of said paste.    
   
   
       16 . Use of a composition comprising: 
 a) a compound of silane type, and    b) a polymer comprising at least one acrylic monomer in the production of a battery electrode, in order to improve the calendar or cycle life of the battery at a temperature greater than or equal to 25° C.