JPH08222227A - Non-woven cloth for porous metal base material - Google Patents

Abstract

PURPOSE: To increase tensile strength and porosity of a non-woven cloth. CONSTITUTION: Plating is applied to a non-woven cloth 1 to form a porous metal structure to be is used for a battery electrode substrate. The number of non-woven cloth fibers 2 is 30 pieces/mm<2> through 130 pieces/mm<2> . One type of fibers selected out of two-denier through five-denier size of fibers, mixed fibers in a range of two-denier through five-denier or one-denier fiber and at least three-denier mixed fibers are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-woven fabric for a material of a metal porous body which is a substrate for a battery electrode. By doing so, a porous metal body is obtained, and the pores of the porous metal body are filled with an active material to be used as a battery electrode plate.

[0002]

2. Description of the Related Art In order to form a porous metal body for a battery electrode substrate from a non-woven fabric of this kind, the non-woven fabric is first subjected to a conductive treatment, and then a required metal is plated, followed by soot removal and sintering. The non-woven fabric is burnt off to form a porous body made of metal. In the above-described series of steps, the conductive, plating, soot removal, and sintering are sequentially performed while the nonwoven fabric sheet unwound from the roll is continuously pulled and conveyed. Since the nonwoven fabric is continuously pulled and conveyed as described above, the nonwoven fabric needs a required tension, and
Higher tension is required to increase the line speed. Further, since the step of filling the formed metal porous body with the active material is also performed while continuously pulling the metal porous body, the metal porous body itself formed from the nonwoven fabric also needs a required tension.

Further, in the metal porous body used as the battery electrode substrate, the active material filled in the pores has conventionally not been conductive, so that the pore diameter is reduced and the contact area with the active material is large. Has been said to be preferable. Therefore, when a non-woven fabric is used as a material for a metal porous body, it is preferable to narrow the gap between the fibers. Therefore, by using fine fibers having a wire diameter of 1 to 2 denier, the number of fibers is increased and the porosity is decreased. Without this, the gap between the fibers, that is, the pore diameter was reduced.

Further, the metallic porous body formed from the non-woven fabric is
For the reason that the filling amount of the active material can be increased and the filling work is facilitated, the plate thickness is 1 mm.
The thickness is required to be as thick as ~ 5 mm. Therefore, the thickness of the nonwoven fabric, which is the material of the porous metal body, must be large. Therefore, conventionally, a non-woven fabric prepared by a method in which fibers made of polyester fiber or the like are fixed by a binder made of an epoxy resin and a thickness of the resin is taken out when dried by utilizing the characteristics of the epoxy resin is most widely used.

[0005]

As described above, in the conventional nonwoven fabric, since the fiber diameter is reduced and the number of fibers is increased, the gaps between the fibers are small and the fibers are dense. At times, it is difficult for metal to enter the inside of the nonwoven fabric, and the difference in plating thickness between the inner layer portion of the formed metal porous body and the outer layer portions on both front and back surfaces becomes large, and delamination is likely to occur. Further, if the metal adhesion amount per area is constant, and the number of fibers increases, the metal adhesion amount per fiber decreases,
The tension of the formed metal porous body tended to be weak as a whole.

[0006] Specifically, the 1 denier polyester fibers 45 g / m ² was adhered with an epoxy resin binder 30 g / m ^2, in total weight 75 g / m ^2, the nonwoven fabric to create a thickness at 3 mm, its tension It was 1.4 kgf / 20 mm. This non-woven fabric is subjected to a conductive treatment, metal plating, desolvated and sintered, and has a metal weight of 420 g / m ² and a tension of 1.8 kgf.
/ 20 mm to 2.5 kgf / 20 mm. On the other hand, recently, in order to increase productivity in the active material filling process,
The line speed must be increased, and the tension of the metal porous body is required to be 3 to 4 kgf / 20 mm, and the above nonwoven fabric has a problem of insufficient tension.

Further, if the gaps between the fibers are made dense, the treatment liquid such as the plating liquid is likely to be contained, and the treatment liquid is often taken out. In particular, when an epoxy resin is used as the resin binder, the thickness does not recover, so that it is difficult to squeeze the processing liquid, and there is a problem that a large amount of waste is generated in the processing liquid.

In response to the above-mentioned problems, recently, a conductive inorganic substance such as a cobalt compound is coated on the surface of the active material (nickel hydroxide) filling the pores of the metal porous body to make the active material conductive. The technology to have it has been developed, and it has become possible to apply electricity to the active material that is not in contact with the porous metal body. As a result, the porous metal body does not need to have a small pore size or a small gap between fibers, and has a structure capable of increasing the filling amount of the active material.

The present invention has been made in view of the above-mentioned problems. The gap between fibers can be increased without lowering the tension, and the metal can be surely attached to the inner layer side during plating, and the active material can be obtained. It is an object of the present invention to provide a non-woven fabric that can be filled with a large amount.

[0010]

In order to achieve the above object, the present invention provides a porous metal body by plating a non-woven fabric according to claim 1 as a raw material of the porous metal body to be a battery electrode substrate. And the number of fibers of the non-woven fabric is 30 /
Provided is a non-woven fabric for a material of a metal porous body, which is set to be not less than mm ^{2 and not} more than 130 pieces / mm ² .

The above-mentioned non-woven fabric may be one prepared by fixing fibers with a resin binder, or one prepared by heat-bonding and fixing fibers without using a resin binder,
Further, it can be applied to those prepared by any conventionally provided method, such as those prepared by crimping fibers by a water jet method or the like. In addition, the fiber is a short fiber of about 50 mm to 60 mm, and it is 1 at 60 mm or more.
It may be a continuous fiber having a length of about 00 mm or less.

The number of the above fibers is calculated by the following formula. [Fiber weight / (specific gravity × plate thickness × length × width)] / cross-sectional area of one fiber = number of fibers / mm ² For example, fiber weight 45 g / m ² , specific gravity 1.38, product plate thickness 1.39 mm, Fiber diameter 2d (2denier 14.3μ)
m), [45g / m ² /(1.38g/cm ³ × 1.39mm × 1m × 1m)] / (14.3
μm / 2) ² × 3.14 = 146 lines / mm ² Specifically, as shown in FIG. 6, from the cross-sectional photograph of the width direction W, the length direction L, and the plane S of the nonwoven fabric in three directions, per unit area The number of fibers is counted, and the number of fibers in three directions is summed to obtain the above 30 fibers / mm ² ~
The range is 130 lines / mm ² .

Further, in the present invention, the fiber may be one kind of fiber having a fiber diameter selected from 2 denier to 5 denier, a fiber mixed in the range of 2 denier to 5 denier, or 1 denier. The non-woven fabric according to claim 1, wherein the fiber is a fiber mixed with at least 3 denier or more.

That is, conventionally, a thin fiber of 1 denier was mainly used, but in the present invention, a relatively thick fiber of 2 denier, 3 denier, 4 denier, or 5 denier is used. There are the following modes. Only one of 2 denier, 3 denier, 4 denier and 5 denier fibers; 2 denier + 3 denier, 3 denier + 4 denier,
3 denier + 5 denier, 4 denier + 5 denier, or 2 denier + 3 denier + 4 denier + 5 denier combinations; 1 denier + 3 denier + 5 denier, 1 denier +
2 denier + 3 denier, 2 denier + 4 denier, etc. Except for only 1 denier and 2 denier combinations, 1 denier is combined with at least 3 denier fibers. If the fiber diameter is in the range of 2 denier to 5 denier, various fiber diameters such as 2.5 denier, 3.7 denier and 4.8 denier are also preferably used.

Further, in claim 3, the fiber amount is 45
g / m ² on any one of to 20 g / Claim m is set to ² in the range 1 or claim 2 provides a nonwoven fabric according. Furthermore, claim 4 provides the nonwoven fabric according to any one of claims 1 to 3, wherein the fibers are fixed with a urethane resin binder.

Further, according to a fifth aspect of the present invention, a non-woven fabric having fibers fixed with a resin binder is plated, and then desolvated and sintered to form a metal porous body, and a material for the metal porous body to be a battery electrode substrate. The number of fibers in the non-woven fabric is 30
Number of fibers / mm ² or more, 130 fibers / mm ² or less, fiber amount of 45
Set ^{g / m 2 ~20g / m 2} , and one type of fibers fiber diameter as the fiber is selected from among 5 denier from 2 denier, fiber were mixed in a range of 5 denier from 2 denier or, 1 A non-woven fabric for a porous metal material is provided, which comprises using fibers obtained by mixing at least 3 denier fibers with denier fibers and using an elastic urethane resin binder as the resin binder. .

Further, in the sixth aspect, the nonwoven fabric according to any one of the first to fifth aspects is provided in which polyester fibers are used as the fibers.

[0018]

In the non-woven fabric according to claim 1, the number of fibers is 3
Since it is set to 0 fibers / mm ² or more and 130 fibers / mm ² or less, it is possible to make the fiber gap larger than before. The fiber density of the conventional non-woven fabric was 145 fibers / mm ² or more. When the gap between the fibers is increased as described above, the plating liquid can surely flow into the inner layer portion of the non-woven fabric during the plating, the metal can be attached to the surface of the fiber of the inner layer portion, and the front and back outer layer portion and the inner layer portion of the non-woven fabric can be adhered. The amount of adhered metal can be made uniform. In addition, when the same amount of metal as in the case of a large number of conventional fibers is deposited during plating, the amount of metal deposited on one fiber can be increased, and as a result, the tension of the porous metal body can be increased. . Furthermore, when the active material is easy to fill the voids with large gaps and the conductive active material (the surface of the active material is coated with a conductive material such as a cobalt compound), the flow of electricity is prevented. Well, there is no problem caused by increasing the gap.

[0019] As described in claim 2, the number of fibers reduces conventionally, when the 30 lines / mm ² to 130 DEG present / mm ^2, instead of 1 denier fibers conventionally used, or, It is preferred to use relatively thick fibers of 2 to 5 denier in combination with 1 denier of fiber. That is, the decrease in strength due to the decrease in the number of fibers is compensated by using thick fibers, and conversely,
As described above, the strength and the tension can be improved by increasing the metal deposition amount per fiber.

As described in claim 3, the fiber amount is 45 g.
/ M ^{2 to 20} g / m ^{2 When} a non-woven fabric made of the fiber amount is used as a raw material to form a metal porous body, a metal adhesion amount and pores are suitable for battery electrode substrates. Can be formed.

When the fibers are fixed with a urethane resin binder as described in claim 4, the urethane resin has elasticity and is restored to its original thickness even when compressed by passing through a roll and drawing. It is not necessary to keep the initial thickness large. Therefore, the number of fiber intersections can be increased to increase the strength and tension.

As described in claim 5, the number of fibers is 30
Fibers / mm ² or more and 130 fibers / mm ² or less, and as the fibers, a relatively thick fiber having a fiber diameter of 2 denier to 5 denier is used, and the fiber amount is 45 g /
Even if it is set to m ² to ²⁰ g / m ² , the thickness of the non-woven fabric is reduced due to the decrease in the number of fibers, but it is described above that the elastic urethane resin binder is used as the resin binder. As described above, since the thickness is recovered by the elasticity, it is not necessary to set the initial thickness of the nonwoven fabric to a large value, and the final product (porous metal body) having a required thickness can be obtained.

Furthermore, as described in claim 6, when polyester fiber is used as the fiber, the adhesion with the urethane resin binder is good, so that the intersection of the fibers is firmly fixed and the strength and the tension are excellent. A non-woven fabric can be obtained.

[0024]

Embodiments of the present invention will be described below. Figure 1
1 shows a non-woven fabric 1 according to an embodiment of the present invention. The non-woven fabric 1 is formed by fixing fibers 2 made of polyester fibers with a urethane resin binder 3. As a method for producing the non-woven fabric 1 composed of the fibers 2 and the urethane resin binder 3, various conventionally known production methods can be adopted. If the fibers are polyester fibers and the resin binder is the urethane resin binder, the non-woven fabric can be produced by any of the production methods. May be created. In this embodiment, short fibers of about 50 mm to 60 mm are used as the above fibers.

The thickness W of the non-woven fabric 1 is 1.8 mm, and the required thickness of the metal porous body as the final product is 1.5 mm.
In contrast, the thickness is increased by 20%. The nonwoven fabric 1 has a number of short fibers 2 per area of 30 / mm ^{2 to} 13
0 present / mm ^2, is set in a range of 45g / m ² ~20g / m ² fiber weight. As shown in FIG. 4 (A), by reducing the number of short fibers 2 as described above, the gap S surrounded by the short fibers 2 of the non-woven fabric 1 becomes smaller than that of the conventional one shown in FIG. 4 (B). It is larger than the gap S ′ surrounded by the fibers in the case of 145 fibers / mm ² .

The short fiber 2 has a large fiber diameter of 2 denier (14.3 μmφ) to 5 denier (22.6 μm).
φ) selected from one type of fiber.
It should be noted that a plurality of types of fibers in the range of 2 denier to 5 denier may be combined, and further, 1 denier fiber may be combined with at least 3 denier fiber or more.

The non-woven fabric 1 is formed as a metal porous body in the process schematically shown in FIG. That is, the nonwoven fabric 1 wound on the roll 5 is continuously unwound and sequentially conveyed by the roll 6, and first, the conductive treatment is performed by the conductive treatment device 7. Then, the non-woven fabric 1 is conveyed to the plating device 8 and the plating liquid is flown to the non-woven fabric 1 to deposit metal on the gap between the outer layer portion and the inner layer portion on both front and back surfaces of the non-woven fabric 1. After the plating is adhered, the plating treatment liquid is squeezed out by the squeeze roll 10 through the water washing device 9. Then, after drying through a drying device 11, it is heated at a required temperature for a required time through a soot / annealing device 12 to burn away the polyester resin short fibers 2 and the urethane resin binder 3, and then a temper rolling device 13 The metal porous body 15 shown in FIG. 3 is formed so as to achieve smoothness and a required plate thickness. The metal porous body 15 has a structure in which pores 16 in both the front and back outer layers and the inner layer are surrounded by a metal skeleton 17. The hole 16
In a later step, is filled with an active material (not shown) to form a battery electrode plate.

[0028]

[Experimental Example] As shown in Table 1, non-woven fabrics (C to I) according to the above-mentioned examples and non-woven fabrics (A and B) of comparative examples were prepared. The short fibers of the non-woven fabric are the same as those of Examples C to I and Comparative Example A,
Polyester fiber is used for both B and Comparative Examples A and B are both 2
Only denier fibers are used. C and D in the embodiment are 2
Using denier fiber, E is 3 denier fiber, F is 4
Denier fibers, G is 5 denier fibers, H is a mixture of 2 denier and 3 denier, and I is 4 denier, 3 denier, 4 denier, and 5 denier short fibers. Further, Comparative Example A uses an epoxy resin as a resin binder, and Comparative Example B uses a urethane resin binder. In both cases, the number of fibers is 145 fibers / mm ^2.
And is outside the scope of the present invention. In Examples C to I, a urethane resin binder was used as a resin binder, and the number of fibers was set to 97 fibers / mm ^{2 to} 59 fibers / mm ² within the range of the present invention. Fiber weights are Comparative Examples A, B and Examples C-
Both I is set in the range of ^{45g / m 2 ~20g / m 2} . Further, the amount of the resin binder is as large as 40% in the case of the epoxy resin of Comparative Example A with respect to the fiber weight, but is 30% in the case of using the urethane resins of Comparative Example B to Examples C to I. The range is 35%. The thickness of the non-woven fabric was 3 mm when the epoxy resin binder of Comparative Example A was used, and 1.8 mm when the urethane resin binders of Comparative Example B and Example were used.

[0029]

【table】

With respect to the non-woven fabrics of Comparative Examples A and B and the non-woven fabrics of Examples C to I shown in Table 1, as shown in Table 2,
Metal adhesion amount 420g / m ² , 300g / m ² , 250g /
Metal plating (nickel plating) was performed at m ² , and the metal was removed and sintered to form a porous metal body having a thickness of 1.5 mm shown in FIG. The tension and porosity of the porous metal bodies of Comparative Examples A and B and Examples C to I were measured.

[0031]

[Table 2]

As shown in Table 2, in the case where the epoxy resin binder of Comparative Example A was used, the tension was lower than that in the case where the urethane resin binder was used, regardless of the amount of metal adhesion. It was This is because when an epoxy resin binder is used, the thickness must be 3 mm, and therefore the number of short fiber intersections is small and the adhesion between short fiber polyester fibers and epoxy resin is poor. . In addition, since the number of fibers is as large as 145 fibers / mm ² , the metal adhesion amount per fiber is reduced. Further, since the number of fibers is large, the porosity is smaller than that of the examples of the present invention. Therefore, the filling amount of the active material is reduced as compared with the embodiment of the present invention.

In Comparative Example B, a urethane resin binder was used, but when the number of fibers was 145 fibers / mm ² , the thickness was thin, so there were many short fiber intersections, and as a result, Comparative Example A Tension is stronger than. However, since the number of fibers is large and the metal adhesion amount per fiber is small, the tension is weaker than in Examples C to I. Further, since the amount of fibers is large, the porosity is smaller than that of the examples of the present invention.

Examples C and D are short fibers, and Comparative Examples A and
Although only 2 denier fibers similar to B are used, the number of fibers is reduced to 97 and 64, so the metal adhesion amount per fiber increases, and as a result, urethane resin binder is used. The tension is stronger than that of Comparative Example B. In addition, since the amount of fibers is reduced, the porosity is naturally increased.

In Examples E, F, and G, 3 denier, 4 denier, and 5 denier with gradually increasing thickness of short fibers were used, and the number of fibers was reduced according to the diameter of the fiber. In all of the examples, the tension is stronger than that of the comparative examples A and B, and when the amount of deposited metal is 420 g / m ² , the tension is almost twice that of the comparative example A. Further, although the fiber thickness is large, the porosity is larger than in Comparative Examples A and B because the number of fibers is reduced.

Example H is a combination of 1/2 of two kinds of short fibers of 2 denier and 3 denier, and I is 4 kinds of short fibers of 2 denier, 3 denier, 4 denier and 5 denier in 25% each. It is a combination. These Examples H and I also have higher tension and higher porosity than Comparative Examples A and B.

[0037] For example, a comparative example B in which the number of fibers 145 present / mm ^2, compared to Example D was a 64 / mm ^2, the short fibers in Comparative Example B is a 45 g / m ^2, Example D
Was reduced to 20 g / m ² and, due to this reduction, the metal deposition amount per fiber was 7.9 μm in Comparative Example B and 13.8 μm in Example D when the metal deposition amount was the same. As a result, the tension of the porous metal was 3.0 kgf / 20 mm.
From 4.0kgf / 20mm. In addition, the porosity increased from 92.8% to 94.9% due to the decrease in the fiber amount.

As described above, by reducing the number of fibers, the metal deposition amount per fiber can be increased and the tension of the porous metal body can be set to 3 to 4 kgf / 20 mm. 420 g / m ² → 300 g / m ² → 25
It can be reduced to 0 g / m ² . For example, Comparative Example A
When the amount of metal deposited is 300 g / m ² , the tension of the porous metal is 1.5 kgf / 20 mm, which is insufficient, but in Examples C to I, the amount of metal deposited is 300 g / m ² and the tension is 2.5 k.
It was gf / 20mm to 2.9kgf / 20mm. Metal adhesion amount is 2
At 50 g / m ² , the tensions of Comparative Examples A and B are 1.3 to 1.
Although it is insufficient at 7 kgf / 20 mm, in Examples C to I, the tension was 2.0 kgf / 20 mm or more, and sufficient tension could be obtained. Further, the porosity could be increased by about 1.4% by reducing the metal weight from 420 g / m ² to 250 g / m ² .

The present inventor conducted a number of experiments in which the number of fibers was changed in addition to the above experimental example. The relationship between the number of fibers of the non-woven fabric and the tension of the metal porous body formed from the non-woven fabric was found to be:
It was as shown in FIG. That is, the amount of metal deposited is 250 g
/ M ² to obtain the required tension of 1.8 kgf / 20 mm,
It was found that it is necessary to set the number of fibers to 135 fibers / mm ² or less. If the number of fibers is less than 30 / mm ^{2, the} amount of metal deposited per fiber becomes too large and the surface area of the metal decreases, and the contact area with the active material decreases too much, resulting in a battery electrode plate. The result is that the performance of is deteriorated. Therefore, the number of fibers is preferably 135 fibers / mm ² or less and 30 fibers / mm ² or more.

Further, if a thick fiber having a denier of 6 denier or more is used as the fiber, after the fiber is burnt out by soot removal and annealing, the fiber portion becomes a large cavity, and the portion where the active material cannot be filled increases. In other words, the porosity that can be filled with the active material is lowered. For a metal porous body that is a substrate for battery electrodes, it is preferable that the porosity is large and the amount of the active material filled per area is large. Therefore, fibers in the range of 2 denier to 5 denier are preferably used. Moreover, when the amount of fibers is the same, the number of fibers becomes too small, and it becomes difficult to obtain a uniform nonwoven fabric with less unevenness.

[0041]

As is apparent from the above description, the present invention has the effects listed below. In the non-woven fabric according to claim 1, the number of fibers is 30 fibers / mm ² or more, 130 fibers / mm ²
Since the amount is less than that in the conventional case, if the weight of the deposited metal is the same, the amount of deposited metal per fiber can be increased and the tension can be increased. Furthermore, since the number of fibers is small, the gap between the fibers becomes large, and the plating solution can surely flow into the inner layer of the nonwoven fabric, and the metal can be attached to the surface of the fibers in the inner layer, and the front and back outer layers and the inner layer of the nonwoven fabric can be adhered. The amount of adhered metal can be made uniform. In addition, the porosity can be increased, the filling amount of the active material can be increased, and the life of the battery electrode plate can be lengthened.

In the non-woven fabric according to the second aspect, while the number of fibers is reduced, while 2 denier to 5 denier having a larger fiber diameter than before is used, the decrease in strength due to the decrease in the number of fibers is caused by the use of thick fibers. Can be compensated by

In the non-woven fabric of claim 3, since the number of fibers is reduced, the fiber weight is 45 g / m ^{2 to} 20 g /
Until m ^2, preferably, it is reduced to ^{30g / m 2 ~20 g / m} 2. As a result, if the amount of metal deposited per fiber is the same as when the number of fibers is large, the total metal weight can be reduced, and the cost can be reduced.

Since the non-woven fabric of claim 4 uses a urethane resin binder having elasticity as a binder,
Even when compressed by squeezing during roll passing, conductive treatment and water washing treatment, the original thickness can be restored, and it is not necessary to make the initial thickness of the nonwoven fabric twice as thick as the final product. It should be thickened by about%. Therefore, it is possible to increase the intersections of the fibers and increase the tension of the nonwoven fabric and the porous metal body formed from the nonwoven fabric.

In the non-woven fabric of claim 5, the number of fibers is reduced, and as the reduced fibers, relatively thick fibers having a fiber diameter of 2 to 5 denier are used, and a flexible urethane resin binder is used. Since it is used, even if both the metal weight and the fiber weight are reduced, it is possible to form a metal porous body having a required tension and a large porosity, which is suitable as a battery electrode substrate.
By reducing both the metal weight and the fiber weight, a significant cost reduction can be achieved.

Furthermore, in the non-woven fabric of claim 6, since polyester fibers are used as the fibers, the adhesion with the urethane resin binder is good, and therefore the intersections of the fibers are firmly fixed and the strength and tension are excellent. The prepared nonwoven fabric can be obtained. Moreover, since the polyester fiber is inexpensive, the cost of the non-woven fabric can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a nonwoven fabric according to an example of the present invention.

FIG. 2 is a schematic view of a process of forming a porous metal body from the nonwoven fabric.

FIG. 3 is a cross-sectional view of the formed metal porous body.

FIG. 4A is a schematic cross-sectional view of a non-woven fabric of an example,
(B) is a schematic sectional view of a conventional nonwoven fabric.

FIG. 5 is a diagram showing the relationship between the number of fibers and the tension of a porous metal body.

FIG. 6 is a drawing for explaining how to count the number of fibers.

[Explanation of symbols]

 1 Nonwoven fabric 2 Fiber 3 Urethane resin binder 15 Metal porous body

Claims (6)

[Claims] 1. A non-woven fabric is plated to form a metal porous body, which is used as a material for a metal porous body to serve as a battery electrode substrate, wherein the number of fibers of the non-woven fabric is 30 fibers / mm ² or more, 130 fibers / mm ² or more. Nonwoven fabric for metallic porous material set to mm ² or less. 2. The fiber, which is one kind of fiber having a fiber diameter selected from 2 denier to 5 denier, and mixed in the range of 2 denier to 5 denier, or
The non-woven fabric according to claim 1, wherein a fiber obtained by mixing at least 3 denier fibers with 1 denier fiber is used. 3. The fiber amount is 45 g / m ^{2 to} 20 g / m ^2.
Either claim 1 or claim 2 with the range of
Nonwoven fabric according to item. 4. The non-woven fabric according to claim 1, wherein the fibers are fixed with a urethane resin binder. 5. A non-woven fabric is plated to form a metal porous body, which is used as a material for a metal porous body to be a battery electrode substrate, wherein the number of fibers of the non-woven fabric is 30 fibers / mm ² or more, 130 fibers / mm ² or more. mm ² or less, the amount of fibers is set to ^{45g / m 2 ~20g / m 2} , and one type of fibers fiber diameter as the fiber is selected from among 5 denier from 2 denier, the range of 2 denier 5 deniers Of the metal porous body characterized by using the fiber mixed with 1. or the fiber having 1 denier fiber mixed with at least 3 denier fiber or more, and using the elastic urethane resin binder as the resin binder. Non-woven fabric for materials. 6. The nonwoven fabric according to claim 1, wherein a polyester fiber is used as the fiber.