JP6251938B2 - Porous metal and method for producing the same, electrode plate and battery - Google Patents

Description

  The present invention relates to a metal porous body, a method for producing the same, an electrode plate using the metal porous body, and a battery, and more specifically, a metal porous body having locally different thicknesses of skeleton parts constituting the metal porous body, and The present invention relates to a manufacturing method, an electrode plate, and a battery.

  Conventionally, it has been proposed to use a metal porous body as an electrode material for a battery (see, for example, JP 2000-357519 A and JP 2013-62129 A). In Japanese Patent Laid-Open No. 2000-357519, a battery electrode in a form in which two metal porous bodies having different numbers of cells are stacked is used, and when the battery electrode is wound in a spiral shape, the metal porous body having a large number of cells is placed outside. It is disclosed that the electrode is prevented from being broken. In JP2013-62129A, a porous metal body whose skeleton thickness (thickness) is gradually reduced from one main surface to the other main surface is used as an electrode for a battery. It is disclosed that when the coil is wound in a spiral shape, processing is performed with the side having a small thickness (thickness) as the outer peripheral side, thereby improving workability and preventing breakage of the skeleton on the outer peripheral side.

JP 2000-357519 A JP2013-62129A

  However, in order to form the electrode disclosed in JP 2000-357519 A, a urethane sponge sheet having a different number of cells is bonded to form a two-layer urethane sponge sheet, and the urethane sponge sheet is plated. It is necessary to carry out a complicated process. Furthermore, it is difficult to control the thickness of the formed plating layer due to variations in the number of cells in the urethane sponge sheet.

  Moreover, since the electrode disclosed by Unexamined-Japanese-Patent No. 2013-62129 is manufactured by the special process of slicing the metal porous body after plating, manufacturing cost is high. In addition, the skeleton of the porous metal body may be damaged in the slicing step. Furthermore, since the thickness of the skeleton on the one surface of the metal porous body is the smallest, there is a possibility that damage will occur on the one surface by contacting with other equipment when processing the metal porous body. There is also.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to easily perform processes such as a bending process, a press process, and a compression process, and to be attributed to the process. An object of the present invention is to provide a low-cost metal porous body that can suppress the occurrence of breakage such as cracks and edge breaks, a manufacturing method thereof, and an electrode plate and a battery using the metal porous body.

  The porous metal body according to the present invention is a porous metal body having a first main surface and a second main surface located on the opposite side of the first main surface and having a three-dimensional network structure. Positioned between the skeleton thickness t1 of the three-dimensional network structure on the first main surface, the skeleton thickness t2 of the three-dimensional network structure on the second main surface, and the first main surface and the second main surface The skeleton thickness t3 of the three-dimensional network structure at the internal position satisfies the relationship of t1> t2> t3 and t2 / t1 ≦ 0.8.

  Moreover, the manufacturing method of the metal porous body which concerns on this invention includes the 1st main surface and the 2nd main surface located in the opposite side to the said 1st main surface, The base which has a three-dimensional network structure A step of preparing a porous body. Furthermore, the manufacturing method of the metal porous body includes a step of forming a metal plating layer from the first main surface side on the surface of the base porous body by a plating method, and a second main surface on the surface of the base porous body by a plating method. Forming a metal plating layer from the side. The amount of current in the step of forming the metal plating layer from the first main surface side is larger than the amount of current in the step of forming the metal plating layer from the second main surface side.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to process easily, such as a bending process, the metal porous body which can suppress generation | occurrence | production of the damage resulting from the said process can be obtained.

It is a partial cross section schematic diagram of the metal porous body concerning the embodiment of the present invention. It is an expansion schematic diagram of the metal porous body shown in FIG. It is a cross-sectional schematic diagram of the skeleton of the three-dimensional network structure in the region III of FIG. It is a cross-sectional schematic diagram of the frame | skeleton of the three-dimensional network structure in the area | region IV of FIG. It is a cross-sectional schematic diagram of the frame | skeleton of the three-dimensional network structure in the area | region V of FIG. It is a schematic diagram for demonstrating thickness distribution of the frame | skeleton of the metal porous body shown in FIG. It is a schematic diagram of the battery which concerns on embodiment of this invention. 1 is a schematic diagram of a fuel cell according to an embodiment of the present invention. It is a schematic diagram for demonstrating the structure of the single cell of the fuel cell shown in FIG. It is a flowchart for demonstrating the manufacturing method of the metal porous body shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the metal porous body shown in FIG.

[Description of Embodiment of Present Invention]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  (1) As shown in FIGS. 1 to 6, the porous metal body according to the embodiment of the present invention includes a first main surface 11 and a second main surface 11 located on the opposite side of the first main surface 11. A porous metal body 10 having a main surface 12 and having a three-dimensional network structure. The thickness t1 of the skeleton 13a of the three-dimensional network structure on the first main surface 11, the thickness t2 of the skeleton 13b of the three-dimensional network structure on the second main surface 12, and the first main surface 11 and the second main surface The thickness t3 of the skeleton 13c having the three-dimensional network structure at the internal position located between 12 and 12 satisfies the relationship of t1> t2> t3 and t2 / t1 ≦ 0.8. The value t2 / t1 is preferably 0.7 or less, and more preferably 0.6 or less.

  In this way, the thickness t2 of the skeleton 13b is sufficiently thin on the second main surface 12 side, and the thickness t3 of the skeleton 13c is further reduced at the internal position (region IV in FIG. 1). In the case where the metal porous body 10 is bent with the second main surface 12 side outside, the occurrence of breakage such as cracks in the second main surface 12 can be suppressed. Furthermore, when pressing or compressing is performed, it is possible to prevent the occurrence of breakage or the like at the end. For example, when the metal porous body is used as an electrode material, the separator and the metal as the electrode material are used. Even if it contacts with a porous body, possibility that the said separator will be damaged can be reduced. Further, since the thickness t2 of the skeleton 13b on the second main surface 12 is larger than the thickness t3 of the skeleton 13c on the internal position, the thickness of the skeleton 13b on the second main surface 12 is the thickness of the skeleton 13c on the internal position. The strength of the second main surface 12 can be made higher than when the thickness is equal to the thickness t3 (for example, when the thickness of the skeleton on the second main surface 12 is the thinnest). Therefore, it is possible to suppress the occurrence of breakage in the porous metal body 10 due to the contact of the second main surface 12 with another instrument or the like.

  Further, since the metal porous body 10 can be formed from one base porous body as described later without using a complicated process such as joining two urethane sponge sheets or slicing the metal porous body, the manufacturing cost is reduced. It is possible to obtain the metal porous body 10 in which the increase in the thickness is suppressed.

  (2) In the metal porous body 10, the thickness t2 of the skeleton 13b of the three-dimensional network structure on the second main surface 12 and the thickness t3 of the skeleton of the skeleton 13c of the three-dimensional network structure at the internal position are t3 / It is preferable to satisfy the relationship of t2 ≧ 0.5.

  Here, as a result of structural analysis evaluating the deformation behavior and strength of the metal porous body 10 during compression, the inventors of the present application have found that the skeleton at the internal position in the thickness direction of the metal porous body 10 It has been found that when the cross-sectional area is insufficient, the strength of the metal porous body 10 is reduced. Therefore, by defining the skeleton thickness t3 of the skeleton 13c of the three-dimensional network structure at the internal position as described above, the skeleton breakage of the skeleton 13c of the three-dimensional network structure at the internal position in the thickness direction of the porous metal body 10 is defined. Make the area large enough. As a result, the strength reduction of the metal porous body 10 during processing such as rolling can be suppressed.

  Note that the thickness t1 of the skeleton 13a having the three-dimensional network structure on the first main surface 11 is the measured value obtained by measuring the thickness of the exposed skeleton 13a at any five locations on the first main surface. Say the average value. Further, the thickness t2 of the skeleton 13b of the three-dimensional network structure on the second main surface 12 is the measured value obtained by measuring the thickness of the skeleton 13b exposed at any five points on the second main surface. Say the average value. Furthermore, the thickness t3 of the skeleton 13c having the three-dimensional network structure at the internal position is a depth from the first main surface 11 to the second main surface 12 in a cross section obtained by cutting the metal porous body 10 in the thickness direction. The thickness of the skeleton 13c exposed to the cross section is measured at five predetermined positions (depths) in the direction, and the average value of the measured values is referred to.

  (3) In the metal porous body 10, the internal position (region V) is located in a region closer to the second main surface 12 than an intermediate point between the first main surface 11 and the second main surface 12. May be. In this case, bending of the metal porous body 10 with the second main surface 12 side outside can be performed more easily while suppressing the occurrence of cracks and the like.

  (4) In the metal porous body 10, the thickness of the skeleton 13 gradually decreases from the first main surface 11 toward the internal position, while the skeleton 13 extends from the internal position toward the second main surface 12. The thickness may be gradually increased. In this case, since the rigidity of the skeleton gradually changes in the thickness direction of the metal porous body 10, the metal porous body can be bent more smoothly.

  (5) In the metal porous body 10, the material constituting the metal porous body 10 may include an alloy containing nickel. In this case, the metal porous body 10 can be applied as an electrode (positive electrode plate 21) of the battery 20.

  (6) The electrode plate (positive electrode plate 21) according to the embodiment of the present invention includes the metal porous body 10 and an active material filled in the metal porous body 10. In this way, an electrode plate that can be easily bent while suppressing the occurrence of cracks and the like can be obtained.

  (7) The battery 20 according to the embodiment of the present invention is a battery 20 including a positive electrode and a negative electrode, and uses the electrode plate (positive electrode plate 21) as at least one of a positive electrode and a negative electrode. In this way, it is possible to obtain a highly reliable battery in which the probability of occurrence of breakage in the electrode plate is reduced. From another point of view, the battery 20 includes a battery can and the electrode plate (positive electrode plate 21) disposed inside the battery can. The electrode plate may be bent so that the second main surface faces outward. In this way, it is possible to obtain a highly reliable battery 20 in which the occurrence of breakage in the electrode plate is suppressed by using the electrode plate that can be bent while suppressing the occurrence of cracks and the like. it can.

  The battery according to the embodiment of the present invention may be a fuel cell 40 including a hydrogen electrode 46 and an oxygen electrode 47. The fuel cell 40 includes the metal porous body 10 in at least one of the hydrogen electrode 46 and the oxygen electrode 47. More specifically, the hydrogen electrode 46 includes a catalyst layer 43 a and a gas diffusion layer 44 a, and the gas diffusion layer 44 a may include the metal porous body 10. The oxygen electrode 47 may include a catalyst layer 43 b and a gas diffusion layer 44 b, and the gas diffusion layer 44 b may include the metal porous body 10. Also in this case, it is possible to suppress the occurrence of breakage such as breakage at the end of the gas diffusion layer in the press processing or compression processing for forming the gas diffusion layer of the hydrogen electrode 46 or the oxygen electrode 47. For this reason, it is possible to reduce the possibility that the damaged portion comes into contact with another constituent material of the fuel cell 40 and the other constituent material is damaged.

  (8) The method for manufacturing the metal porous body 10 according to the embodiment of the present invention includes a first main surface and a second main surface located on the opposite side of the first main surface, and is three-dimensional. A step (S10) of preparing a base porous body having a network structure is provided. Furthermore, the manufacturing method of the metal porous body includes a step (S30) of forming a metal plating layer from the first main surface side on the surface of the base porous body by a plating method, and a second method on the surface of the base porous body by a plating method. Forming a metal plating layer from the main surface side (S40). The amount of current in the step of forming the metal plating layer from the first main surface side is larger than the amount of current in the step of forming the metal plating layer from the second main surface side. In this way, the thickness of the metal plating layer formed from the first main surface side (that is, the thickness t1 of the skeleton 13a constituting the three-dimensional network structure of the metal porous body) is relatively set to the second main surface side. It can be made thicker than the thickness of the metal plating layer. Furthermore, since the metal plating layer is formed by plating, the thickness of the metal plating layer to be formed gradually increases from the first main surface or the second main surface of the base porous body toward the inside of the base porous body. The metal plating layer can be formed so as to be thin. As a result, the metal porous body 10 according to the embodiment of the present invention can be easily manufactured.

  (9) In the method for producing a metal porous body, in the step of forming the metal plating layer from the first main surface side, the base porous body is brought into contact with the cylindrical electrode 34 from the second main surface side. A metal plating layer may be formed. In this case, the thickness of the metal plating layer formed from the first main surface side can be efficiently increased by the plating method using the cylindrical electrode 34.

  In the method for producing a porous metal body, after the step (S40) of forming the metal plating layer from the second main surface side, the thickness t1 of the skeleton of the three-dimensional network structure on the first main surface; The skeleton thickness t2 of the three-dimensional network structure on the second main surface and the skeleton thickness t3 of the three-dimensional network structure at the internal position located between the first main surface and the second main surface are t1. The relationship of> t2> t3 and t2 / t1 ≦ 0.8 may be satisfied. In this case, the metal porous body according to the present embodiment described above can be reliably obtained.

[Details of the embodiment of the present invention]
With reference to FIGS. 1-5, the metal porous body 10 which concerns on this embodiment is demonstrated.

  The metal porous body 10 has a plate-like or sheet-like appearance, and includes a first main surface 11 and a second main surface 12 located on the opposite side of the first main surface 11. As shown in FIG. 2, the metal porous body 10 has a skeleton 13 constituting a three-dimensional network structure. A large number of holes defined by the three-dimensional network structure are formed so as to continue from the surface of the metal porous body 10 to the inside thereof.

  The thickness of the skeleton 13 of the metal porous body 10 has a distribution in the depth direction from the first main surface 11 to the second main surface 12. Specifically, in the region III in the vicinity of the first main surface 11 in the metal porous body 10 of FIG. 1, the skeleton 13a has a relatively thick thickness t1, as shown in FIG. In the region IV in the vicinity of the second main surface 12 of the metal porous body 10, the skeleton 13b has a thickness t2 that is relatively thinner than the thickness t1 described above, as shown in FIG. Further, in the region V closer to the second main surface 12 than the central portion in the thickness direction of the metal porous body 10, the skeleton 13c has a thickness t3 that is relatively thinner than the above-described thickness t2 as shown in FIG. doing.

  As shown in FIG. 6, the metal porous body 10 has a distribution with respect to the thickness of the skeleton 13 from the first main surface 11 side toward the second main surface 12 side. Here, the upper schematic view of FIG. 6 shows a cross section of the porous metal body 10. The horizontal axis in the lower graph of FIG. 6 shows the position in the direction (thickness direction) from the first main surface 11 to the second main surface 12 of the metal porous body 10. The vertical axis of the lower graph indicates the thickness of the skeleton 13.

  As can be seen from FIG. 6, in the metal porous body 10, the thickness t1 of the skeleton 13a in the vicinity of the first main surface 11 is the thickest, and then the position D1 in the depth direction from the first main surface 11 (region V1) ), The thickness of the skeleton 13c is the smallest thickness t3, and the thickness of the skeleton gradually increases toward the second main surface 12 thereafter. The ratio of the thickness t2 of the skeleton 13b in the second main surface 12 to the thickness t1 of the skeleton 13a in the first main surface 11 is 0.8 or less. The ratio of the thickness t3 of the skeleton 13c at the internal position to the thickness t2 of the skeleton 13b on the second main surface 12 is 0.5 or more. In addition, the position D1 in the thickness direction where the thickness of the skeleton 13 is the smallest is located closer to the second main surface 12 than the center of the metal porous body 10 in the thickness direction.

  As described above, by providing the thickness of the skeleton 13 in the thickness direction of the porous metal body 10, for example, when the porous metal body 10 is bent with the first main surface 11 inside, the skeleton 13 is deformed more greatly. Since the thickness of the skeleton 13 on the second main surface 12 side that is the side is relatively thin, the second main surface 12 side of the metal porous body 10 can easily follow even larger deformations. it can. For this reason, generation | occurrence | production of the problem that a crack and damage generate | occur | produce in the metal porous body 10 can be suppressed.

  The metal porous body 10 described above can be used as a positive electrode plate 21 of a battery 20, for example, as shown in FIG. That is, as shown in FIG. 7, the battery 20 using the metal porous body according to the present embodiment includes a positive electrode plate 21, a separator 22, and a negative electrode plate 23 that are disposed inside a battery can as a casing. Prepare mainly. The positive electrode plate 21, the separator 22 and the negative electrode plate 23 are disposed inside the casing in a stacked state. The laminated body of positive electrode plate 21, separator 22 and negative electrode plate 23 is held in a wound state (for example, the laminated body is wound in a spiral shape as viewed from the positive electrode side of battery 20 in FIG. 7). . The positive electrode plate 21 includes the metal porous body 10 according to the present embodiment and an active material filled in the metal porous body 10.

  Thus, in the battery 20 having a structure in which the positive electrode plate 21 and the like are held in a wound state, the bent positive electrode plate 21 includes the metal porous body 10 of the above embodiment as a constituent material. For this reason, it is possible to easily deform (bend) the positive electrode plate 21 while suppressing the occurrence of cracks and the like. In addition, the metal porous body which concerns on this embodiment is applicable also to the electrode of the shape different from the electrode processed as mentioned above. For example, the porous metal body according to the present embodiment may be applied to stacked type electrodes such as a secondary battery and a fuel cell. Specifically, the metal porous body 10 described above may be applied to a fuel cell as shown in FIGS.

  8 and 9, the fuel cell 40 using the porous metal body 10 according to this embodiment has a stack structure in which a plurality of single cells 41 are stacked. For example, a solid polymer fuel cell It is. As shown in FIG. 9, the single cell 41 includes an ion exchange membrane 42, catalyst layers 43 a and 43 b, gas diffusion layers 44 a and 44 b, and a separator 45. The ion exchange membrane 42 is a solid polymer membrane containing an aqueous electrolyte solution, for example. A catalyst layer 43 a is formed on the first main surface of the ion exchange membrane 42. In the catalyst layer 43a, a gas diffusion layer 44a is disposed on the side opposite to the side where the ion exchange membrane 42 is located. A catalyst layer 43b is formed on the second main surface of the ion exchange membrane 42 opposite to the first main surface. A gas diffusion layer 44b is disposed on the side opposite to the side where the ion exchange membrane 42 is located in the catalyst layer 43b. The catalyst layer 43 a and the gas diffusion layer 44 a constitute the hydrogen electrode 46, and the catalyst layer 43 b and the gas diffusion layer 44 b constitute the oxygen electrode 47. A structure in which the gas diffusion layer 44a, the catalyst layer 43a, the ion exchange membrane 42, the catalyst layer 43b, and the gas diffusion layer 44b are stacked and fixed is referred to as a membrane / electrode assembly (MEA). A set of separators 45 is arranged so as to sandwich this MEA.

  The gas diffusion layers 44a and 44b serve as current collectors as well as providing a place for battery reaction. Therefore, moderate porosity and mechanical strength are required, and the metal porous body 10 according to the present embodiment can be applied.

Referring to FIG. 9, in the single cell 41, when hydrogen gas is introduced into the hydrogen electrode 46 and oxygen gas is introduced into the oxygen electrode 47, a reaction of H ₂ → 2H ⁺ + 2e ⁻ occurs at the hydrogen electrode 46. The reaction 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O occurs. Protons (H ⁺ ) generated at the hydrogen electrode 46 diffuse through the ion exchange membrane 42 and move to the oxygen electrode 47 side as shown in FIG. Then, water (H 2 _O) is generated in the oxygen electrode 47 and the protons and oxygen are reacted.

  As described above, even when the metal porous body 10 according to the present embodiment is applied to an electrode (for example, the hydrogen electrode 46 or the oxygen electrode 47) of the fuel cell 40 or the like, in the press working or compression working for forming the electrode, Since the occurrence of damage such as breakage at the extreme portion can be suppressed, the electrode contacts with other constituent materials of the battery (for example, the separator, the catalyst layers 43a and 43b, the ion exchange membrane 42, etc.), and the other constituent materials are damaged. Such a possibility can be reduced.

  Next, the manufacturing method of the metal porous body shown in FIGS. 1-5 is demonstrated with reference to FIG. 10 and FIG.

  In the manufacturing method of the metal porous body 10 shown in FIGS. 1-5, as shown in FIG. 10, a base porous body preparation process (S10) is first implemented.

  Here, the base porous body in the present embodiment includes a first main surface and a second main surface located on the opposite side of the first main surface, and has a three-dimensional network structure. For example, a porous body (resin porous body) made of a resin can be used. As the resin porous body, a resin foam, a nonwoven fabric, a felt, a woven fabric, or the like is used, but these may be used in combination as necessary. Further, the material of the base porous body is not particularly limited, but a material that can be removed by incineration after plating a metal as described later is preferable. Also, in handling the base porous body, a sheet-like material is preferably a flexible material because it breaks when the rigidity is high. In the present embodiment, it is preferable to use a resin foam as the resin porous body. As the resin foam, any known or commercially available resin may be used as long as it is porous. Examples thereof include urethane foam and foamed styrene. Among these, urethane foam is preferable from the viewpoint of particularly high porosity. The thickness, porosity, and average pore diameter of the foamed resin are not limited, and can be appropriately set according to the application.

  Next, a conductive treatment process (S20) is performed. Here, the method of conducting treatment is not particularly limited as long as the conductive coating layer can be provided on the surface of the base porous body. Examples of the material forming the conductive coating layer include metals such as nickel, titanium, and stainless steel, amorphous carbon such as carbon black, and carbon powder such as graphite. Among these, carbon powder is particularly preferable, and carbon black is more preferable.

  As specific examples of the conductive treatment, for example, when nickel is used, electroless plating treatment, sputtering treatment, and the like are preferably exemplified. In addition, when a material such as titanium, stainless steel or the like, carbon black, graphite or the like is used, a treatment obtained by applying a mixture obtained by adding a binder to the fine powder of these materials to the surface of the base porous body is preferable. . As an electroless plating treatment using nickel, for example, a base porous body such as a foamed resin may be immersed in a known electroless nickel plating bath such as a nickel sulfate aqueous solution containing sodium hypophosphite as a reducing agent. . If necessary, the base porous body such as a foamed resin may be immersed in an activation liquid containing a trace amount of palladium ions (for example, a cleaning liquid manufactured by Kanigen Co., Ltd.) or the like before immersion in the plating bath.

  As a sputtering process using nickel, for example, after attaching a porous base to a substrate holder, ionization is performed by applying a DC voltage between the holder and the target (nickel) while introducing an inert gas. The nickel particles blown off may be deposited on the surface of the base porous body by colliding the inert gas with nickel.

The conductive coating layer may be formed continuously on the surface of the base porous body. The basis weight of the conductive coating layer is not limited and is usually about 5 to 15 g / m ² , preferably about 7 to 10 g / m ² .

  Next, the first plating step (S30) is performed. In this step (S30), a metal plating layer (for example, a nickel layer or an alloy layer containing nickel) is formed on the surface of the base porous body from the first main surface side by plating.

  Next, a second plating step (S40) is performed. In this step (S40), a metal plating layer is formed on the surface of the base porous body from the second main surface side by a plating method. The amount of current in the step (S30) is larger than the amount of current in the step (S40) for forming the metal plating layer from the second main surface side.

  In the step (S30) and step (S40) described above, a conventionally well-known plating method can be used, but an electroplating process is preferably used. The electroplating process may be performed according to a conventional method. For example, in the case of nickel plating, a known or commercially available plating bath can be used, and examples thereof include a watt bath, a chloride bath, a sulfamic acid bath, and the like. A base porous body having a conductive coating layer formed on the surface by electroless plating or sputtering is immersed in a plating bath, and the base porous body is connected to the cathode and the counter electrode plate of the plated metal is connected to the anode to generate direct current or pulsed intermittent current. By applying electricity, an electroplating coating can be further formed on the conductive coating layer. The basis weight (attachment amount) of the conductive coating layer and the plating layer is not particularly limited.

The plating layer may be formed on the conductive coating layer to such an extent that the conductive coating layer is not exposed. The basis weight of the plating layer is not limited and is usually about 150 to 500 g / m ² , preferably about 200 to 450 g / m ² . The total amount of the basis weights of the conductive coating layer and the plating layer described above is preferably 200 g / m ² or more and 500 g / m ² or less. If the total amount is below this range, the strength of the metal porous body may be reduced. Further, if the total amount exceeds this range, it is disadvantageous in terms of cost.

  The first plating step (S30) and the second plating step (S40) described above can be performed using, for example, an apparatus as shown in FIG.

  FIG. 11 schematically shows the configuration of an apparatus for continuously performing a metal plating process on a band-shaped resin when a band-shaped resin porous body (hereinafter also referred to as a band-shaped resin) is used as the base porous body. FIG. 11 shows a configuration in which a band-shaped resin 32 whose surface is made conductive is sent from left to right in FIG. The first plating tank 31 a includes a cylindrical electrode 34 (cylindrical cathode), an anode 35 (cylindrical anode) provided on the inner wall of the container, and a plating bath 33. By passing the strip-shaped resin 32 through the plating bath 33 along the cylindrical electrode 34, a plating layer is formed on the surface of the strip-shaped resin 32. The plating layer is formed from the side of the first main surface of the strip-shaped resin 32 (the main surface facing the anode 35 inside the plating bath 33). For this reason, the thickness of the plating layer (that is, the thickness of the skeleton 13) gradually decreases from the first main surface side toward the inside of the strip-shaped resin 32. That is, the said process (S30) is implemented in the 1st plating tank 31a.

  The second plating tank 31b is a tank for further plating from one side or both sides, and is configured to be repeatedly plated in a plurality of tanks. Plating is carried out by passing the belt-like resin 32 whose surface is made conductive through a plating bath 38 while sequentially feeding it by an electrode roller 36 which also serves as a feeding roller and an out-of-vessel feeding cathode. In the plurality of tanks, there are anodes 37 provided on both surfaces of the strip-shaped resin 32 via the plating bath 38. By energizing both of the pair of anodes 37 facing both surfaces of the strip-shaped resin 32, the strip-shaped resin 32 Plating layers can be formed on both sides. Further, the thickness of the plating layer formed on the strip-shaped resin 32 by energizing only one of the pair of anodes 37 or changing the amount of current flow between the pair of anodes 37 in the thickness direction of the strip-shaped resin 32. Distribution can be formed. For example, the plating layer can be formed from the upper surface side (second main surface side) of the strip-shaped resin 32 by energizing only the anode 37 facing the upper surface of the strip-shaped resin 32 in the plating bath 38 of FIG. Further, the amount of current in the plating step in the first plating tank 31a described above is larger than the amount of current in the plating step in the second plating tank 31b. That is, the said process (S40) is implemented in the 2nd plating tank 31b. In this way, the distribution of the thickness of the plating layer (the thickness of the skeleton 13) as shown in FIG. 6 can be easily formed.

  Next, a post-processing step (S50) is performed. Specifically, a base porous body such as a resin porous body is removed. In this step (S50), for example, after the above-described electroplating, the porous resin body is decomposed in advance by heat treatment in an oxidizing atmosphere such as air at a temperature of about 600 ° C. to 800 ° C., preferably 600 ° C. to 700 ° C. Remove.

  Thereafter, a heat treatment is performed at a temperature of 1000 ° C. in a reducing atmosphere at a temperature of 750 ° C. or higher, preferably a high temperature, which is disadvantageous in terms of cost and durability of the furnace body material of the reducing furnace. As the reducing atmosphere gas, hydrogen gas, a mixed gas of hydrogen and carbon dioxide, or an inert gas, or a combination thereof can be used as necessary. Preferably, redox efficiency is good by always adding hydrogen gas to the reducing atmosphere gas. In this way, the metal porous body 10 shown in FIG. 1 can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly advantageously applied to porous metal bodies used for battery electrodes.

DESCRIPTION OF SYMBOLS 10 Metal porous body 11 1st main surface 12 2nd main surface 13, 13a-13c Skeleton 20 Battery 21 Positive electrode plate 22, 45 Separator 23 Negative electrode plate 31a 1st plating tank 31b 2nd plating tank 32 Strip-like resin 33, 38 Plating bath 34 Cylindrical electrodes 35 and 37 Anode 36 Electrode roller 40 Fuel cell 41 Single cell 42 Ion exchange membranes 43a and 43b Catalyst layers 44a and 44b Gas diffusion layer 46 Hydrogen electrode 47 Oxygen electrode

Claims (9)

A porous metal body having a first main surface and a second main surface located on the opposite side of the first main surface, and having a three-dimensional network structure,
The skeleton thickness t1 of the three-dimensional network structure on the first main surface, the skeleton thickness t2 of the three-dimensional network structure on the second main surface, the first main surface and the second main surface the thickness t3 of the skeleton of the three-dimensional network structure in the inner position located between the, t1>t2> satisfy the relationship of t3 and t2 / t1 ≦ 0.8,
A thickness t2 of the skeleton of the three-dimensional network structure on the second main surface and a thickness t3 of the skeleton of the three-dimensional network structure on the internal position satisfy a relationship of t3 / t2 ≧ 0.5 Porous body. A porous metal body having a first main surface and a second main surface located on the opposite side of the first main surface, and having a three-dimensional network structure,
The skeleton thickness t1 of the three-dimensional network structure on the first main surface, the skeleton thickness t2 of the three-dimensional network structure on the second main surface, the first main surface and the second main surface Satisfying the relationship of t1>t2> t3 and t2 / t1 ≦ 0.8, with the thickness t3 of the skeleton of the three-dimensional network structure at the internal position located between
The internal position is a porous metal body located in a region closer to the second main surface than an intermediate point between the first main surface and the second main surface. The thickness of the skeleton gradually decreases from the first main surface toward the internal position, while the thickness of the skeleton gradually increases from the internal position toward the second main surface. Claim | item 1 or the metal porous body of Claim 2 . The material which comprises the said metal porous body is a metal porous body of any one of Claims 1-3 containing the alloy containing nickel. The metal porous body according to any one of claims 1 to 4 ,
An electrode plate comprising an active material filled in the metal porous body. A battery comprising a positive electrode and a negative electrode,
A battery using the electrode plate according to claim 5 for at least one of the positive electrode and the negative electrode. A method for producing a porous metal body having a three-dimensional network structure,
Providing a base porous body having a three-dimensional network structure including a first main surface and a second main surface located on the opposite side of the first main surface;
Forming a metal plating layer on the surface of the base porous body from the first main surface side by a plating method;
And a step of forming a metal plating layer on the surface of the base porous body from the second main surface side by a plating method,
The amount of current in the step of forming the metal plating layer from the first main surface side is larger than the amount of current in the step of forming the metal plating layer from the second main surface side ,
The skeleton thickness t1 of the three-dimensional network structure of the metal porous body on the first main surface, the skeleton thickness t2 of the three-dimensional network structure of the metal porous body on the second main surface, and the first main surface The thickness t3 of the skeleton of the three-dimensional network structure of the porous metal body at the internal position located between the surface and the second main surface is such that t1>t2> t3 and t2 / t1 ≦ 0.8. Satisfied,
The thickness t2 of the skeleton of the three-dimensional network structure of the metal porous body on the second main surface and the thickness t3 of the skeleton of the three-dimensional network structure of the metal porous body on the internal position are t3 / t2 ≧ 0. 5. A method for producing a porous metal body that satisfies the relationship of 5 . A method for producing a porous metal body having a three-dimensional network structure,
Providing a base porous body having a three-dimensional network structure including a first main surface and a second main surface located on the opposite side of the first main surface;
Forming a metal plating layer on the surface of the base porous body from the first main surface side by a plating method;
And a step of forming a metal plating layer on the surface of the base porous body from the second main surface side by a plating method,
The amount of current in the step of forming the metal plating layer from the first main surface side is larger than the amount of current in the step of forming the metal plating layer from the second main surface side,
The skeleton thickness t1 of the three-dimensional network structure of the metal porous body on the first main surface, the skeleton thickness t2 of the three-dimensional network structure of the metal porous body on the second main surface, and the first main surface The thickness t3 of the skeleton of the three-dimensional network structure of the porous metal body at the internal position located between the surface and the second main surface is such that t1>t2> t3 and t2 / t1 ≦ 0.8. Satisfied,
The said internal position is a manufacturing method of a metal porous body located in the area | region near the said 2nd main surface from the intermediate point between the said 1st main surface and the said 2nd main surface . The step of forming the metal plating layer from the first main surface side forms the metal plating layer in a state where the porous base is brought into contact with a cylindrical electrode from the second main surface side. The manufacturing method of the metal porous body of Claim 7 or Claim 8 .

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