Patent ID: 8236448

Claim:
A fabrication method of 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, said fabrication method comprising the steps of: fusion-bonding the fibers at a cross point by heat treatment, applying a coating of nickel to the fibers subjected to said heat treatment, and compressing said electrode substrate, said core formed of polypropylene and said coating formed of polyethylene, said heat treatment being carried out under conditions of 5 seconds to 3 minutes at 95° C. to 140° C. such that, at the fibers subjected to said heat treatment, 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, wherein said electrode substrate for a battery has a pore size of 20 to 50 μm, a ratio of a mass of polypropylene to a mass of polyethylene in said fiber is 2/8 to 7/3, said electrode substrate satisfies an equation of 1.09 < [ ∑ i = 1 10 ⁢ ( Ac / A ) ] / 10 [ ∑ j = 1 10 ⁢ ( Bc / B ) ] / 10 < 2.0 , where ⁢ ⁢ [ ∑ i = 1 10 ⁢ ( Ac / A ) ] / 10 [ ∑ j = 1 10 ⁢ ( Bc / B ) ] / 10 represents a degree of fusion-bonding, and a thickness of the compressed electrode substrate is 350 μm to 500 μm.