Battery electrode substrate, and electrode employing the same

Abstract

An electrode substrate for a battery has nickel applied as a coat on the surface of a base constituted of crossing of a plurality of fibers including a core formed of synthetic resin and a coating of synthetic resin having a softening temperature lower than the softening temperature of the synthetic resin forming the core. The electrode substrate has the fibers of the base fusion-bonded at a cross point by heat treatment. The ratio of the coating occupying a II-II cross section of the fiber cross point is larger than the ratio of the coating occupying a fiber cross section (III-III cross section) at a site other than at the cross point.

1 . An electrode substrate for a battery, having nickel applied as a coating on a surface of a base constituted of crossing of a plurality of fibers including a core formed of synthetic resin and a coating formed of synthetic resin having a softening temperature lower than the softening temperature of the synthetic resin forming the core, wherein 
 the fibers are fusion-bonded at a cross point by heat treatment, and    an average value of a ratio of a coating occupying a cross section (a) at n cross points of fibers selected arbitrarily and an average value of a ratio of a coating occupying a cross section (b) of m fibers at a site other than at the cross points selected arbitrarily satisfy an equation of:                [       ∑     i   =   1     n     ⁢           ⁢     (     Ac   /   A     )       ]     /   n     >       [       ∑     j   =   1     m     ⁢           ⁢     (     Bc   /   B     )       ]     /   m             where n, m: natural number to obtain the average value of the ratio of the coating occupying the cross section, n≧3, m≧3,    i, j: natural number, i≧1, j≧1,    A: cross sectional area of cross section (a) at cross point,    Ac: cross sectional area of coating at cross section (a),    B: cross sectional area of cross section (b) of fiber other than at cross points,    Bc: cross sectional area of coating at cross section (b), and    the cross section (a) at the cross point is the cross section bisecting a larger angle of angles at a cross point defined by fibers.    
     
     
         2 . The electrode substrate for a battery according to  claim 1 , wherein said electrode substrate for a battery has a pore size of 20 to 50 μm.  
     
     
         3 . The electrode substrate for a battery according to  claim 1 , wherein said fiber has the core formed of polypropylene and the coating formed of polyethylene.  
     
     
         4 . The electrode substrate for a battery according to  claim 3 , wherein a ratio of mass of polypropylene to mass of polyethylene in said fiber is not more than 7/3.  
     
     
         5 . The electrode substrate for a battery according to  claim 1 , wherein an amount of said nickel is 150 g/m 2  to 300 g/m 2 .  
     
     
         6 . An electrode for a battery, wherein the electrode substrate for a battery defined in  claim 1  carries an active material mixture containing nickel hydroxide.  
     
     
         7 . An alkaline battery employing the electrode for a battery defined in  claim 6.