JPH10144321A - Manufacture of metallic porous body and battery using metallic porous body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method by which a pseudo metallic porous body to be made by fixing many fibrous metals vertically on a metal base material plate can be produced at high productivity and low cost while producing high quality products. SOLUTION: Metal resin composite fiber of short fiber type containing metal powder for a range of 30-85 weight % is produced by melt spinning method. This metal resin composite fiber 20 is spread or flocked on the metal base material plate 28. Adhesive is painted on the metal base material plate 28 before and after the process of spreading or flocking the metal resin composite fiber 20. While dissolving and removing the resin in the metal resin composite fiber 20 by baking the metal powder in the metal resin composite fiber 20 is combined each other by baking to make fiber type metal 70, and it is combined together on the metal base material plate 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a secondary battery such as a nickel-metal hydride storage battery, a nickel cadmium battery and a lithium ion secondary battery, and more particularly to a battery such as an electric vehicle or a power tool which requires a large current. The present invention relates to a method for producing a porous metal body that can be suitably used as a core material of an electrode plate, and a battery using the porous metal body as a core material for an electrode plate.

[0002]

2. Description of the Related Art Porous metal bodies are widely used in mechanical parts and various other industrial fields, and have been produced by various methods. In the past, there has been a manufacturing method in which a metal powder is formed and sintered by a raw material powder filling sintering method or a powder compression sintering method. In recent years, electroless plating is performed on the skeleton surface of a three-dimensional mesh-shaped sponge-like foam such as urethane. Generally, a manufacturing method in which a metal is adhered by a plating method such as electrolytic plating or vapor phase plating, and a manufacturing method in which a foam is immersed in a slurry in which metal powder is dispersed are generally adopted. Further, a method of forming a felt-like nonwoven fabric in which fibrous metals are irregularly entangled (see JP-A-56-88266) and a method of sintering and rolling a stainless steel thin wire assembly (Japanese Patent Laid-Open No. 4-165006) Publications are being considered.

In general, an electrode plate of a battery has a structure in which the above porous metal body is used as a core material and the porous metal body is filled with a positive or negative active material. As the metal porous body for the core material of the electrode plate in a battery in which a chemical reaction occurs, among various kinds as described above, a metal foamed porous body having a three-dimensional network structure has been generally adopted in recent years. ing. This metal foam porous body is obtained by electroplating a sponge-like foam body. For example, as a core material for an electrode plate in a secondary battery such as a nickel cadmium battery or a nickel metal hydride battery, as shown in FIG. A metal foam porous body 1 which is a sponge-like metal in which many holes 3 are formed by nickel 2 is used. Since the metal foam has a spongy three-dimensional network structure, the porous metal body 1 has a maximum porosity of 98% and a pore diameter of about 50 to 500 μm.

The porous metal foam 1 is disclosed in Japanese Patent Publication No. Sho 57-3
It is manufactured by a manufacturing method as described in JP-A-9317. That is, a sponge-like foam such as a polyurethane sheet having a three-dimensional mesh shape is impregnated with a conductive paint such as carbon, or after imparting conductivity by means such as electroless plating, the foaming is performed. A metal is attached to the skeleton surface of the body by a plating method, and the metal is heated to bake and remove only the sponge-like foam, thereby obtaining a metal foam porous body 1.

[0005]

However, in the battery using the above-mentioned metal foamed porous body 1 as a core material for an electrode plate, the amount of the active material which becomes a slurry having a relatively high viscosity per unit volume is reduced. When the size of the hole 3 in FIG. 10 is increased to increase the size, the active material filled in the center of the hole 3 that does not directly contact the mesh-shaped nickel 2 is not used for charge and discharge. And the discharge characteristics per unit volume of the battery cannot be improved. vice versa,
If the porosity is increased while reducing the size of the holes 3, it is difficult to fill the holes 3 with the active material, so that the filling amount is reduced, and the nickel 2 is thinned to increase the electric resistance, and a sufficient current is supplied. Stops flowing. Therefore, a battery using an electrode plate having the porous metal body 1 as a core material can be used for applications requiring a large current, such as an electric vehicle, a power tool or an electric lawn mower. Can not.

In addition, the above-mentioned metal foamed porous body is expensive due to the use of a plating method in its manufacturing process, in addition to the cost of related equipment and waste liquid treatment, and the large power consumption. Further, it is difficult to control the plating conditions, so that the plating rate cannot be increased, and the productivity cannot be improved. For this reason, the metal foam porous body 1 is expensive, and the number of electrode plates used increases, so that a low-cost electrode plate is an essential condition. Can not be used at all from the surface.

Therefore, the applicant of the present application has proposed a quasi-porous metal porous body which can further increase the utilization of an active material when used as a core material for an electrode plate of a battery and can extract a large current. (Japanese Patent Application No. 8-73528).
This porous metal body is formed by arranging a large number of fibrous metals such as nickel fibers on a metal base plate serving as a main current collector in an arrangement perpendicular to the metal base plate. Are combined by sintering. When this porous metal is used as a core material for an electrode plate of a battery, the porous metal is shaped like a sword, so that many active materials can be smoothly filled, and most of the active material is collected. Since it comes into contact with the fibrous metal functioning as an electric body, the utilization of the active material is significantly higher than that of the metal foamed porous body. Therefore,
A battery using the metal porous body as a core material for an electrode plate,
It is suitable for applications requiring a large current, such as for electric vehicles.

However, the above-mentioned problem that remains in the porous metal body is that it is difficult to produce fibrous metal as a constituent element with high productivity. In particular, a thin metal having a diameter of 200 μm or less can be uniformly produced at a high yield. Attempts to manufacture into a complicated shape would increase the cost at present. Therefore, there is a long-awaited need for a manufacturing method capable of obtaining a high-quality metal porous body while mass-producing the above-described porous metal body at low cost.

Therefore, the present invention provides a metal porous body having a pseudo-porous structure in which a large number of fibrous metals are stood or fixed three-dimensionally on a metal base plate, with high productivity and low cost. It is an object of the present invention to provide a method for manufacturing a porous metal body which can be manufactured by using the method described above, and a battery using the porous metal body.

[0010]

Means for Solving the Problems To achieve the above object, a method for producing a porous metal body according to the first invention of the present application comprises bonding a large number of fibrous metals to one or both sides of a metal base plate. A method of producing a pseudo-porous metal porous body by spinning a short fibrous metal-resin composite fiber containing metal powder in a range of 30 to 85% by weight,
A step of arranging the metal resin composite fibers in a forest or three-dimensionally on a metal base plate and temporarily fixing the same, and baking to decompose and remove the resin in the metal resin composite fibers, Bonding the metal powders to each other to form a fibrous metal and, simultaneously, bonding the fibrous metal to the metal base plate.

According to the first aspect of the present invention, since the metal-resin composite fiber is manufactured by the spinning method, the number of steps is relatively small, and it can be manufactured at low cost by using an inexpensive facility such as an extruder. In addition, since the metal-resin composite fiber can be manufactured by using the metal-resin kneaded material containing the metal powder in the range of 30 to 85% by weight, even if it is extruded at a high speed by the binder action of the resin, it is not cut, and Also, there is no breakage when arranging or three-dimensionally arranging them on the metal base plate and temporarily fixing them. Further, since the metal powder is contained in an amount of 30% by weight or more, the fibrous metal formed after firing does not have insufficient strength. Therefore, a high quality product can be obtained by producing a pseudo porous metal porous body formed by bonding a large number of fibrous metals on a metal base plate at high productivity and at low cost.

In order to achieve the above object, a method of manufacturing a porous metal body according to a second invention of the present application is directed to a pseudo porous metal formed by bonding a large number of fibrous metals to one or both surfaces of a metal base plate. A method for producing a porous body, comprising:
A step of producing, by a spinning method, a short fibrous double-structured composite fiber in which a metal-resin composite fiber containing 95% by weight is covered with a resin skin layer; A step of arranging or three-dimensionally arranging and temporarily fixing the resin, and baking to decompose and remove the resin in the double-structure composite fiber, and bonding the metal powder in the double-structure composite fiber to each other to form a fibrous material. Forming the metal and bonding the fibrous metal to the metal base plate at the same time as forming the metal.

According to the second aspect of the invention, the same effect as in the first aspect of the invention can be achieved, and the metal resin composite fiber containing the metal powder in the range of 40 to 95% by weight is covered with the resin skin layer. Because the heavy structure composite fiber is formed by the spinning method,
As for the metal-resin composite fiber in the center of the double-structure composite fiber, the deterioration of the mechanical properties of the fiber itself is reinforced by the resin skin layer, and the kneaded material with a high content of metal powder as described above is extruded at high speed from a molding machine. It does not cut even if it is wound at high speed while being extruded and pulled. Therefore, the productivity and the yield of the double-structure composite fiber can be remarkably improved. Moreover, it is possible to prevent the fibrous metal from adhering to each other by the resin skin layer.

[0014] The first, the second invention, the metal-resin composite fiber, or a dual structure composite fiber, metal component basis weight is distributed at a rate of 100g / m ² ~1000g / m ² on a metal substrate sheet Is preferred.

Accordingly, when used as a core material for an electrode plate of a battery, a space for filling the active material between the fibrous metals can be sufficiently ensured, and the battery having a sufficient charge / discharge capacity can be provided. Can be obtained.

In the first and second aspects of the present invention, it is preferable that the metal-resin composite fiber or the double-structure composite fiber is spun so that the fiber diameter becomes 10 to 300 μm.

[0017] Accordingly, by having a fiber diameter of 10 µm or more, sufficient strength can be maintained even after sintering, and since the fiber diameter is 300 µm or less, it can be used as a core material for battery electrodes. When used, a space that can sufficiently fill the active material can be secured between the fibrous metals.

Further, in the first and second aspects of the present invention, the metal-resin composite fiber or the double-structure composite fiber may be used in an amount of 0.5 to 5
It is preferable to cut to a length of mm.

If it is less than 0.5 mm, a sufficient space cannot be ensured, and if it is more than 5 mm, the active material cannot be filled to the root of the fibrous metal at the time of filling.

[0020] This makes the composition suitable for use as a core material for an electrode of a battery.

In order to achieve the above object, a battery according to a third invention of the present application uses a porous metal body manufactured by the manufacturing method of the first invention or the second invention as a core material and interposes between each fibrous metal. An electrode plate is formed by filling an active material.

In this battery, the active material is smoothly filled between the fibrous metals to provide a sufficient filling amount, and the fibrous metals are arranged at extremely small intervals in a forest or three-dimensionally. As a result, most of the active material comes into contact with the fibrous metal, resulting in an extremely high utilization rate of the active material. Further, since the current flows through the metal base plate as the main current collector, the electric resistance is extremely small. Therefore, a large current can be obtained.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a first half process chart for manufacturing a metal-resin composite fiber in a method for manufacturing a porous metal body according to one embodiment of the present invention. In the figure, in the kneading tank 4, for example, the average particle size is 3.0 μm.
m, a metal powder 7 such as a nickel powder and a polymer resin 8 such as a polyvinyl butyral resin are mixed and accommodated, and if necessary, a solvent is mixed as a solvent, and the mixture is sufficiently stirred by a stirring blade 9. I do. In addition to the illustration, a kneading machine such as a well-known three-roll mill or kneader can be used for this kneading.

The metal powder 7 is preferably nickel powder in the case of producing a metal porous body to be used as a core material for an electrode plate of a battery, but is not particularly limited to nickel powder. Any metal can be used as long as it can be sintered according to the conditions. Further, the metal powder 7 is not limited to a pure metal. Even if a metal oxide or hydroxide is used, there is no problem because the metal powder 7 is reduced at a later stage of the manufacturing process.

The mixture of the metal powder 7 and the polymer resin 8 is put into a hopper 11 of an extruder 10, and further kneaded by a screw 13 rotated in a direction indicated by an arrow by a motor 12. 1
It is transported in the direction toward 7. The kneaded material is in a molten state when being transferred by the screw 13, is extruded in a thread form from the nozzle portion 17, is further formed into a metal resin composite fiber 20 having a required shape through a spinneret 18, and is wound up. It is wound up while being pulled by the roll 19.

The spinneret 18 is for molding the kneaded material into a metal resin composite fiber 20 having a circular cross section and a predetermined fiber diameter, and produces a porous metal body used as a core material for an electrode plate of a battery. In this case, the fiber diameter can be set in the range of 10 to 300 μm, preferably 30 to 200 μm.
Set to m. When the thickness is set to 30 μm or less, the strength after mounting on a metal base plate to be described later and firing is weak, so that the state perpendicular to the metal base plate cannot be maintained and the active material is filled. It is difficult to become a porous metal body having a sufficient space for it. On the other hand, if it is set to 200 μm or more, the fiber diameter is too large, and it is not possible to secure a sufficient space for filling the active material. Also, the above kneaded material,
The content of the metal powder 7 is set to 30 to 85% by weight.
This is because if it is set to 30% by weight or less, the strength after mounting on a metal base plate and firing is insufficient, while 85% by weight
When the above setting is made, when the kneaded material is spun by the extruder 10, cutting cannot be performed with the winding tension of the winding roll 19 and cutting occurs to reduce the yield, or the rotation speed of the screw 13 is reduced. This is because productivity cannot be improved because it cannot be increased.

FIG. 2 is a process diagram showing the first half of the production of the porous metal body, including the second half of the production of the metal-resin composite fiber. In the figure, the metal-resin composite fiber 20 wound on the above-mentioned winding roll 19 is fed to a sizing feeder 21.
, And are intermittently transported by being drawn out by a predetermined size, cut by the cutter device 22 into a short fiber having a predetermined length, further unraveled by the unraveling machine 23, and then temporarily stored in the storage box 24. . The length of the short fibrous metal-resin composite fiber 20 is set to about 0.5 mm to 5 mm, whereby a metal porous body suitable as a core material for an electrode plate of a battery can be obtained. Note that the step of FIG. 1 and the step of cutting the metal-resin composite fiber 20 in FIG. 2 may be configured as a continuous step.

Subsequently, the metal-resin composite fiber 20 having a predetermined length in the storage box 24 is forcibly sent out from the storage box 24 and put into the hopper 27 for spraying. Below the hopper 27, a metal base plate 28 is continuously transferred horizontally at a constant speed by a transfer mechanism (not shown) and a pair of guide rollers 29. The metal resin composite fibers 20 are sprayed on the metal base plate 28 from the spraying hopper 27 by a predetermined amount, and the metal resin composite fibers 20 are arranged on the metal base plate 28 in a substantially uniform distribution. The amount of the metal resin composite fiber 20 sprayed from the spraying hopper 27 is 100 to 1000, which is the metal component weight per unit area of the porous metal body formed through the reduction step described below.
g / m ² is set. In particular, when manufacturing a porous metal body used as a core material for an electrode plate of a battery, it is desirable to set the basis weight of the metal component to a ratio of 150 to 600 g / m ² . This is because if it is set to 150 g / m ² or less, a sufficient charge / discharge capacity cannot be obtained, while if it is set to 600 g / m ² or more, the space between the fibrous metals 70 described below is insufficient. The active material cannot be sufficiently filled, and a sufficient charge / discharge capacity cannot be obtained.

As the metal base plate 28, a thin band-shaped metal flat plate having a large number of fine holes formed by a perforation process, a thin material made of a non-woven fabric having air permeability without a perforation process is used. A strip-shaped metal flat plate, a thin strip-shaped metal flat plate that is not perforated, or a metal foil can be used. Further, the metal base plate 28 may be either magnetic or non-magnetic. However, when used as a core material of a battery electrode plate, the metal base plate 28 has a conductivity because it performs a current collecting action. is necessary. In particular, when used as a core material for an electrode plate of a secondary battery having a large discharge characteristic such as a nickel-metal hydride battery or a nickel cadmium battery, due to a chemical reaction,
It is preferable to use nickel as the metal base plate 28 and the metal powder 7.

The metal-resin composite fibers 20 uniformly distributed on the metal base plate 28 move with the transfer of the metal base plate 28.
It enters into the orienting magnet unit 30 arranged above and below the transfer path of the metal base plate 28. The two-oriented magnet portion 30 is opposed to the plurality of magnets 30a so as to form a pair with each other.
8, the metal base plate 28
A uniform orientation magnetic field is generated within a certain distance along the transfer path. Accordingly, the metal-resin composite fibers 20 on the metal base plate 28 receive a magnetic field perpendicular to the metal base plate 28 and are oriented and aligned perpendicular to the metal base plate 28.

A pipe 32 connected to an adhesive container 31 is inserted between the two-oriented magnet sections 30, and a spray nozzle 33 at the tip of the pipe 32 is arranged toward the upper surface of the metal base plate 28. ing. From this spray nozzle 33,
The adhesive 34 contained in the adhesive container 31 is sprayed on the metal base plate 28 after the metal-resin composite fibers 20 have been vertically oriented and aligned, and the metal-resin composite fibers 20 The adhesive layer is temporarily fixed in an oriented / aligned state. As the adhesive 34, a polyvinyl acetate resin, an acrylic resin, a butyral resin, a phenol resin, or the like can be used. If the same type of metal powder as the metal base plate 28 and the metal powder 7 is mixed with the adhesive 34 and used, the metal base plate 28 and the fibrous metal 70 can be more firmly integrated in a reduction step described later. Can,
A more desirable porous metal body can be obtained.

FIG. 3 is a process chart of the latter half of the process for producing a porous metal body according to the above embodiment. In this latter half step, a porous metal body in which many fibrous metals 70 are integrated with the metal base plate 28 is obtained. In the dry oxidation step, drying is performed at a predetermined temperature in a dry oxidation furnace 37 under an air atmosphere.

Finally, in the reduction step, the temperature is raised to 1000 ° C. in a reducing atmosphere of a reducing gas, for example, 5% of hydrogen gas and 95% of nitrogen gas, and firing is performed. By this baking, the oxidized nickel is reduced by hydrogen to nickel and simultaneously binds to each other to form a fibrous metal 70, and the fibrous metal 70 and the metal base plate 28 are firmly bonded and integrated, As shown in FIG. 4, a sword-shaped porous metal body 39 having a high porosity is completed. The porous metal body 39 shown in FIG.
8 shows a state where a large number of fibrous metals 70 are fixed on both surfaces.

The porous metal body 40 shown in FIG. 5 is oriented and oriented by the orienting magnet unit 30 in each step of the above embodiment.
In the aligning step, the orientation magnet portion 30 is obtained by disposing the orientation magnet portion 30 on only one side of the metal base plate 28. Are fixed on the metal base plate 28 in a three-dimensionally entangled state. Even the metal porous body 40 having such a shape can be sufficiently used as a core material for an electrode plate of a battery. In this case, since only one of the oriented magnet portions 30 is disposed, the manufacturing cost is reduced. There is an advantage that can be reduced.

FIG. 6 is a process diagram showing a first half of a process for producing a double-structured composite fiber in a method for producing a porous metal body according to another embodiment of the present invention. The first process is the same as that shown in FIG. Metal-resin composite fiber 20 by extruder 10A
And the second extrusion molding machine 10B are juxtaposed. The hopper 11 of the second extruder 10B has a polymer resin pellet 4 such as polyethylene terephthalate.
1 is housed.

However, the nozzle 17 of the second extruder 10B has a larger diameter than the nozzle 17 of the first extruder 10A. The string-like resin 42 extruded from the second extruder 10B is used as the metal-resin composite fiber 2 from the first extruder 10A.
It is sent to the double-structure spinneret 43 together with 0. The double-structured spinneret 43 covers the periphery of the metal-resin composite fiber 20 with a resin 42 such as polyethylene terephthalate and sends it out. The double-structure composite fiber 44 sent out from the double-structure spinneret 43 is taken up by the take-up roller 19.
When the double-structured composite fiber 44 wound by the winding roller 19 is cut into a predetermined size by the same cutting step as in FIG. 1, as shown in the perspective view schematically shown in FIG. The short fiber-like double structure composite fiber 44 in which the periphery of the composite structure is covered with the resin skin layer 47 is obtained.

The metal-resin composite fiber 20 of this embodiment is manufactured by mixing the metal powder 7 so as to contain the metal powder 7 in the range of 60 to 95% by weight. That is, even if the content of the metal powder 7 is increased as described above, the double-structure composite fiber 44
Since the deterioration of the mechanical properties of the fiber itself is reinforced by the resin skin layer 47, the metal-resin composite fiber 20 is drawn out from the first extruder 10A at a high speed, and is wound at a high speed while being pulled by the winding roll 19. Even if it is not cut.

Next, a process of manufacturing the porous metal body 39 using the double structure composite fiber 44 will be described. As shown in FIG. 8, the adhesive 34 accommodated in the adhesive container 31 is sprayed by the spray nozzle 33 on the metal base plate 28 which is continuously transferred, and the adhesive layer 48 is formed in advance. On the other hand, the double structure composite fibers 44 are implanted on the metal base plate 28 by electrostatic flocking. That is, the double-structure composite fiber 44 is stored in a storage container 49 having a bottom surface formed of a metal wire mesh 50, and although not shown, a metal substrate is placed between the metal wire mesh 50 and the metal base plate 28. A high voltage is applied from the power supply unit using the material plate 28 as a ground electrode. Thereby, the double-structure composite fiber 44 in the storage container 49 is positively charged via the metal wire mesh 50, and when falling through the mesh of the metal wire mesh 50, the metal base 44 serving as the ground electrode It is sucked by the material plate 28, flies while maintaining the vertical direction with respect to the metal base plate 28, pierces the adhesive layer 48 on the surface of the metal base plate 28, and is implanted, and is held in the implanted state by the adhesive layer 48. You. The double-structure composite fiber 44 may be sprayed on the metal base plate 28 as shown in FIG.

Next, as described above, the double-structure composite fibers 44 implanted on the metal base plate 28 enter the orienting magnet unit 30 with the transfer of the metal base plate 28. The double-structured composite fiber 44 that has not been implanted vertically to the metal base plate 28 in the flocking process receives a magnetic field in a direction perpendicular to the metal base plate 28 and is oriented vertically to the metal base plate 28. . As a result, all the double-structure composite fibers 44 stand vertically on the metal base plate 28.

Subsequently, the resin in the resin skin layer 47 and the polymer resin 8 in the metal-resin composite fiber 20 are decomposed and removed by passing through the drying oxidation furnace 37 and the reduction furnace 38 shown in FIG. The fibrous metals 70 are accurately aligned at substantially equal intervals corresponding to the thickness of the resin skin layer 47, and do not become entangled with each other. Thereby, a very high-quality porous metal body can be obtained.

In the manufacturing method of each of the above embodiments, the metal resin composite fiber 20 or the double structure composite fiber 44 is manufactured with high productivity and yield, and the metal base composite fiber is continuously transferred at a constant speed. Since it is vertically oriented and fixed on the material plate 28, it can be mass-produced with extremely high productivity. Moreover, since no plating method or the like is used, it can be easily manufactured with simple and low-cost equipment.

FIG. 9 shows a battery 51 composed of an electrode plate using the porous metal bodies 39 and 40 obtained by the above-described manufacturing method as a core material. In manufacturing the battery 51, the active material is filled between the fibrous metals 70 of the porous metal bodies 39 and 40, and the surface thereof is rolled by a rolling roller or the like. The separator is interposed between the electrode plate 53 and the negative electrode plate 53 and spirally wound, and is housed in the battery case 57. This battery 51
Is that the active material is smoothly filled between the sword-shaped fibrous metals 70 to provide a sufficient filling amount, and since the spacing between the fibrous metals 70 is small as described above, most of the active material is made of fibers. Since the metal base plate 28 contacts the metal plate 70 and collects electricity, the electric resistance is extremely low.
As a result, the utilization rate of the active material becomes extremely high, and a large current can be taken out.

[0043]

EXAMPLE A polymer resin 8 composed of polyvinyl butyral resin and a metal powder 7 composed of nickel fine powder having an average particle diameter of 3 μm were kneaded, and the kneaded product was extruded by an extrusion molding machine 10 to obtain a nickel content by a melt spinning method. Was obtained 80% by weight. This metal-resin composite fiber 20 was formed into a short fiber having a fiber diameter of 100 μm and a fiber length of 2 mm, and a porous metal body 39 was manufactured using the short fiber. As the metal base plate 28, a nickel-plated steel plate having a thickness of 50 μm was used. The metal-resin composite fiber 20 is evenly spread from a hopper 27 on a metal base plate 28 moving at a constant speed, and is orientated in a vertical direction by an orienting magnet unit 30, and an adhesive made of a polyvinyl alcohol liquid in the orienting magnet unit 30. 34 was sprayed to temporarily fix the metal-resin composite fiber 20 in an oriented state, and then passed through a drying oxidation furnace 37. Similarly,
The metal-resin composite fibers 20 were also fixed on the opposite surface of the metal base plate 28. Finally, it is fired at a temperature of 500 ° C., and is further reduced and sintered in a reducing atmosphere of 5% of hydrogen gas and 95% of nitrogen gas to obtain a pseudo porous metal having a basis weight of 350 g / m ^2. Body 39 was obtained. The porosity was 90%. This is referred to as a first porous metal body.

Polymer resin 8 composed of polyvinyl butyral resin and nickel fine powder (metal powder) having an average particle size of 3 μm
7 was coated with a resin skin layer 47 of polyethylene terephthalate to obtain a double-structure composite fiber 44. The double-structure composite fiber 44 was made into a short fiber having a fiber diameter of 100 μm and a fiber length of 2 mm, and a porous metal body was manufactured using the double-structure composite fiber 44 by the same process as described above. This is referred to as a second porous metal body.

The effect when the electrode plate of the nickel-metal hydride storage battery is formed by using each of the above porous metal bodies as an electrode core will be described. The above first and second porous metal bodies are used as electrode cores, respectively, and nickel hydroxide 9 is added to these cores.
After filling with an active material of 0% by weight and 10% by weight of cobalt oxide, it was dried and further rolled to obtain a positive electrode plate 52 having a thickness of 1 mm and an area of 38 mm × 80 mm. The negative electrode plate 53 has Mn-Ni-Mn-AI-C as a hydrogen storage alloy.
An o-based alloy was made into a paste using styrene butadiene rubber as a binder, applied to a perforated steel sheet, and rolled.

These two electrode plates 52 and 53 are spirally wound with a nylon separator 54 interposed therebetween, accommodated in a battery case 57, and injected with an alkaline electrolyte obtained by dissolving potassium hydroxide in water. It sealed and produced the nickel hydride storage battery. These batteries are referred to as first and second batteries.

For comparison, a third battery using the metal foamed porous body 1 shown in FIG. 10 as a positive electrode plate was manufactured. These batteries were charged under predetermined charging conditions, and the results of a constant current discharge test are shown in (Table 1). In this (Table 1), the discharge time of the third battery was set to 100%, and the first battery using the first and second porous metal bodies of the present invention was used.
And the discharge time of the second battery is shown relatively.

[0048] As is clear from the results shown in Table 1, it was found that the battery comprising the electrode plate using the porous metal body of the present invention as a core material has a remarkable effect particularly in applications where a large current is used.

[0049]

As described above, according to the method for manufacturing a porous metal body of the first invention of the present application, since the metal-resin composite fiber is manufactured by the spinning method, it can be manufactured at low cost with inexpensive equipment.
Moreover, since a fibrous metal can be manufactured using a kneaded material with a resin containing metal powder in the range of 30 to 85% by weight, the resin does not break even when extruded at high speed due to the binder action of the resin. In addition, there is no possibility of breakage when arranging or three-dimensionally arranging and temporarily fixing them on the metal base plate. Further, since the metal powder is contained in an amount of 30% by weight or more, the fibrous metal formed after firing does not have insufficient strength. Therefore, a high quality product can be obtained by manufacturing a pseudo porous metal body having a large number of fibrous metals bonded on a metal base plate at high productivity and at low cost.

According to the method for producing a porous metal body of the second invention of the present application, the content of the metal powder in the metal-resin composite fiber in the double-structure composite fiber is increased to 40 to 95% by weight. From the above, while being preferable in the case of forming a porous metal body, the metal resin composite fiber, as described above, since the deterioration of the mechanical properties of the fiber itself is reinforced by the resin skin layer, the content of the metal powder as described above Even if the kneaded material having a large amount is extruded at a high speed from an extruder and wound up at a high speed while being pulled, it is not cut, so that productivity and yield can be remarkably improved. Moreover, the fibrous metal can be prevented from adhering to each other by the resin skin layer.

According to the battery of the third invention of the present application, the active material is smoothly filled between the respective fibrous metals in the porous metal body to have a sufficient filling amount, and the interval between the respective fibrous metals is as described above. Since it is so small, most of the active material comes into contact with the fibrous metal and the metal base plate performs a current collecting action, so that the electric resistance becomes extremely small. Therefore, the utilization rate of the active material becomes extremely high, and a large current can be obtained.

[Brief description of the drawings]

FIG. 1 is a process chart showing steps of a method for manufacturing a porous metal body according to an embodiment of the present invention.

FIG. 2 is a process chart showing the steps of the method for manufacturing a porous metal body of the embodiment.

FIG. 3 is a process chart of a manufacturing method in the embodiment.

FIG. 4 is a side view showing the porous metal body manufactured according to the embodiment.

FIG. 5 is a side view showing a porous metal body manufactured by a manufacturing method in which some steps of the embodiment are changed.

FIG. 6 is a process chart showing steps of a method for manufacturing a porous metal body according to another embodiment of the present invention.

FIG. 7 is a perspective view schematically showing a double structure conjugate fiber obtained by the same process.

FIG. 8 is a process chart showing steps of a method for manufacturing a porous metal body according to the embodiment.

FIG. 9 is a partially exploded perspective view showing a battery using a porous metal body manufactured by the manufacturing method of the present invention.

FIG. 10 is a schematic partial cross-sectional view of a conventional porous metal foam.

[Explanation of symbols]

 7 Metal powder 8 Resin 10, 10A, 10B Extruder 20 Metal-resin composite fiber 28 Metal base plate 34 Adhesive 37 Dry oxidation furnace 38 Reduction furnace 39, 40 Metal porous body 41 Polymer resin pellet 44 Double structure composite fiber 47 resin skin layer 51 battery 52 positive electrode plate 70 fibrous metal

Claims (9)

[Claims] 1. A method for producing a quasi-porous metal porous body in which a large number of fibrous metals are bonded to one or both surfaces of a metal base plate, wherein the metal powder is contained in an amount of 30 to 85% by weight. Producing a short fibrous metal-resin composite fiber containing by a spinning method, arranging the metal-resin composite fiber in a forest or three-dimensionally on a metal base plate and temporarily fixing the same, Decomposing and removing the resin in the metal-resin composite fiber, binding the metal powder in the metal-resin composite fiber to each other to form a fibrous metal, and simultaneously bonding the fibrous metal to a metal base plate. A method for producing a porous metal body, comprising: 2. The method according to claim 1, wherein the metal-resin composite fibers are temporarily fixed on the metal base plate by distributing the metal components at a weight ratio of 100 to 1000 g / m ² in a stand or three-dimensional manner. The method for producing a porous metal body according to the above. 3. The metal resin composite fiber having a fiber diameter of 10
The method for producing a porous metal body according to claim 1, wherein the porous metal body is obtained by extrusion molding to have a shape of about 300 μm. 4. The method for producing a porous metal body according to claim 1, wherein the metal resin composite fiber is cut into a length of 0.5 to 5 mm. 5. A method for producing a quasi-porous metal porous body in which a large number of fibrous metals are bonded to one or both surfaces of a metal base plate, wherein the metal powder is contained in an amount of 40 to 95% by weight. A step of producing, by a spinning method, a short-fiber-like double-structured composite fiber in which the contained metal-resin composite fiber is covered with a resin skin layer; and forming the double-structured composite fiber on a metal base plate in a forest or three-dimensionally. Arranging and temporarily fixing, and baking to decompose and remove the resin in the double-structured conjugate fiber, and bond the metal powder in the double-structured conjugate fiber to each other to form a fibrous metal. Bonding the fibrous metal to the metal base plate. 6. The double-structure composite fiber is temporarily fixed on a metal base plate by distributing the metal component in a weight ratio of 100 to 1000 g / m ² in a stand or three-dimensional manner. 3. The method for producing a porous metal body according to item 2. 7. The double-structure composite fiber having a fiber diameter of 10
The method for producing a porous metal body according to claim 5, which is obtained by extrusion molding to have a shape of about 300 μm. 8. The method for producing a porous metal body according to claim 5, wherein the double structure conjugate fiber is cut into a length of 0.5 to 5 mm. 9. A battery comprising a porous metal body produced by the production method according to claim 1 as a core material, and an active material filled between fibrous metals to form an electrode plate. .