Clad structure and battery terminal component

Abstract

To provide a clad structure and battery terminal component that easily ensure bonding strength between aluminum and copper materials without requiring a diffusion reaction suppression layer composed of Ni, and which offers long-term reliability even for battery applications such as in automobiles.SOLUTION: A clad structure has a first shaft portion including a first shaft outer surface extending downward and a first shaft bottom surface at the downwardly extending end, and a flange portion having a flange top surface and a flange bottom surface extending radially from the upper end of the first shaft portion and perpendicular to the first shaft portion. A clad structure has a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, and a second surface made of a copper material extends from the flange outer surface to the flange lower surface. An aluminum material containing 99 mass% or more of Al is present between the aluminum alloy material and the copper material. A battery terminal component uses the clad structure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a clad structure and a battery terminal part, and more particularly to a clad structure and a battery terminal part suitable for a negative electrode terminal electrically connected to the negative electrode side of a lithium ion secondary battery or the like. [Background technology]

[0002] Conventionally, a technique has been known in which a diffusion reaction suppression layer made of Ni (hereinafter referred to as "Ni layer") is provided in an aluminum-copper clad material to suppress excessive diffusion reactions that occur between the aluminum material and the copper material due to heating. For example, Patent Document 1 discloses an aluminum-copper clad material in which an aluminum material and a copper material are pressure-welded with a thin Ni layer provided between them. Patent Document 1 also discloses that the clad material after pressure welding is subjected to diffusion annealing in order to increase the bonding strength between the aluminum layer, Ni layer, and copper layer.

[0003] Furthermore, a technology for forming a battery terminal component using the aluminum-copper clad material having the above-described Ni layer as a raw material is known. For example, Patent Document 2 discloses a cross-sectional structure (see FIG. 10 of the third embodiment) of a battery terminal component having a flange portion and a shaft portion, a T-shaped cross section along the shaft portion, and a Ni layer between an aluminum layer and a copper layer. Patent Document 2 also discloses that the effects of the Ni layer include preventing the formation of brittle Al-Cu intermetallic compounds between the aluminum layer and the copper layer and preventing corrosion (galvanic corrosion) caused by direct contact between the aluminum layer and the copper layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-156995 [Patent Document 2] Patent No. 6581440 Summary of the Invention [Problem to be solved by the invention]

[0005] However, aluminum-copper clad materials with a Ni layer and battery terminal components formed using such materials carry the risk of impairing various properties (e.g., electrical conductivity, thermal conductivity, ductility, and formability) due to the presence of the Ni layer compared to structures without the Ni layer. For example, the electrical conductivity (specific electrical resistivity) of Ni is approximately 2.5 times that of Al. The specific electrical resistivity of Al is approximately 1.6 times that of Cu. The thermal conductivity (thermal conductivity) of Ni is approximately 2.6 times that of Al. The thermal conductivity of Al is approximately 0.6 times that of Cu. Therefore, structures with a Ni layer may not achieve the desired electrical conductivity or thermal conductivity. Furthermore, Ni is slightly harder than Cu, less ductile than Cu or Al, and highly adhesive. Therefore, structures with a Ni layer may experience problems such as burrs and work hardening during the formation of battery terminal components.

[0006] One object of the present invention is to provide a clad structure and a battery terminal component that can easily ensure the bonding strength between an aluminum material and a copper material without having a diffusion reaction suppression layer made of Ni, and that can be expected to have long-term reliability even when used in batteries for automobiles, etc. [Means for solving the problem]

[0007] The clad structure of the present invention comprises a first axial portion having a first axial outer surface extending downward and a first axial undersurface at an end extending downward; and a flange portion having a flange upper surface and a flange undersurface extending radially from an upper end of the first axial portion perpendicular to the first axial portion, and a flange outer surface at an end extending radially of the flange upper surface and the flange undersurface, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, and a second surface made of copper material extends from the flange outer surface to the flange undersurface, the first axial outer surface, and the first axial undersurface, and an aluminum material containing 99% or more by mass of Al is present between the aluminum alloy material and the copper material.

[0008] The cladding structure according to the present invention includes the first axial portion (the first axial portion having a first axial outer surface extending downward and a first axial lower surface at an end extending downward), the flange portion (the flange portion having a flange upper surface and a flange lower surface extending in a radial direction perpendicular to the first axial portion from an upper end of the first axial portion, and a flange outer surface at an end extending in the radial direction of the flange upper surface and the flange lower surface), and a first leg inner surface and a first leg outer surface extending downward from an outer edge of the first leg bottom surface, with the first axial lower surface serving as a first leg bottom surface. and a first leg portion having a first leg bottom surface at an end extending downward from the first leg inner surface and the first leg outer surface, and a first recess defined by the first leg bottom surface and the first leg inner surface, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, and a second surface made of a copper material extends from the flange outer surface to the flange bottom surface, the first shaft outer surface, the first leg outer surface, the first leg bottom surface, the first leg inner surface, and the first leg bottom surface.

[0009] The cladding structure according to the present invention comprises the first axial portion (the first axial portion having a first axial outer surface extending downward and a first axial lower surface at the end extending downward), the flange portion (the flange portion having a flange upper surface and a flange lower surface extending in a radial direction perpendicular to the first axial portion from the upper end of the first axial portion, and flange outer surfaces at the ends extending in the radial direction of the flange upper surface and the flange lower surface), a second axial outer surface extending upward, and an upper and a second shaft portion having a second shaft upper surface at an end extending toward the flange, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, and the second shaft upper surface, and a second surface made of a copper material extends from the flange outer surface to the flange lower surface, the first shaft outer surface, the first leg outer surface, the first leg lower surface, the first leg inner surface, and the first leg bottom surface.

[0010] The cladding structure according to the present invention comprises the first axial portion (the first axial portion having a first axial outer surface extending downward and a first axial lower surface at the end extending downward), the flange portion (the flange portion having a flange upper surface and a flange lower surface extending in a radial direction perpendicular to the upper end of the first axial portion from the upper end of the first axial portion, and a flange outer surface at the end extending in the radial direction of the flange upper surface and the flange lower surface), the second axial portion (the second axial portion having a second axial outer surface extending upward and a second axial upper surface at the end extending upward), and a first leg bottom surface having a central portion of the first axial lower surface as a first leg bottom surface and a second leg bottom surface extending downward from an outer edge of the first leg bottom surface. and a first recess defined by the first leg bottom surface and the first leg inner surface, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, and the second shaft upper surface, and a second surface made of a copper material extends from the flange outer surface to the flange lower surface, the first shaft outer surface, the first leg outer surface, the first leg lower surface, the first leg inner surface, and the first leg bottom surface.

[0011] The cladding structure according to the present invention comprises the first axial portion (the first axial portion having a first axial outer surface extending downward and a first axial lower surface at the end extending downward), the flange portion (the flange portion having a flange upper surface and a flange lower surface extending in a radial direction perpendicular to the first axial portion from the upper end of the first axial portion, and a flange outer surface at the end extending in the radial direction of the flange upper surface and the flange lower surface), the second axial portion (the second axial portion having a second axial outer surface extending upward and a second axial upper surface at the end extending upward), and a second leg bottom surface extending upward from the outer edge of the second leg bottom surface, with a central portion of the second axial upper surface as a second leg bottom surface. and a second leg portion including a second leg inner surface and a second leg outer surface extending from the flange outer surface to the flange upper surface, the second leg outer surface, the second leg outer surface, the second leg upper surface, the second leg inner surface, and the second leg bottom surface, and a second recess defined by the second leg bottom surface and the second leg inner surface, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second outer-axis surface, the second leg outer surface, the second leg upper surface, the second leg inner surface, and the second leg bottom surface, and a second surface made of a copper material extends from the flange outer surface to the flange lower surface, the first outer-axis surface, and the first leg bottom surface.

[0012] The cladding structure according to the present invention includes the first axial portion (the first axial portion having a first axial outer surface extending downward and a first axial lower surface at an end extending downward), the flange portion (the flange portion having a flange upper surface and a flange lower surface extending in a radial direction perpendicular to the first axial portion from an upper end of the first axial portion, and a flange outer surface at an end extending in the radial direction of the flange upper surface and the flange lower surface), the second axial portion (the second axial portion having a second axial outer surface extending upward and a second axial upper surface at an end extending upward), the first leg portion (the first leg portion having a central portion of the first axial lower surface as a first leg bottom surface, a first leg inner surface and a first leg outer surface extending downward from an outer edge of the first leg bottom surface, and a first leg lower surface at an end extending downward from the first leg inner surface and the first leg outer surface), and the first recess portion (the first leg bottom surface and the first leg outer surface a second leg portion including a second leg inner surface (a first recess defined by the leg inner surface), a second leg inner surface and a second leg outer surface extending upward from the outer edge of the second leg bottom surface, with a central portion of the second shaft upper surface as the second leg bottom surface, and a second leg upper surface at an end extending upward from the second leg inner surface and the second leg outer surface; and a second recess defined by the second leg bottom surface and the second leg inner surface, wherein a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, the second leg outer surface, the second leg upper surface, the second leg inner surface, and the second leg bottom surface, and a second surface made of copper material extends from the flange outer surface to the flange lower surface, the first shaft outer surface, the first leg outer surface, the first leg outer surface, the first leg lower surface, the first leg inner surface, and the first leg bottom surface.

[0013] The cladding structure according to the present invention may be configured such that the outer flange surface of the flange portion has a boundary between the first surface continuing from the upper flange surface and the second surface continuing from the lower flange surface.

[0014] The clad structure having the above-mentioned configuration is suitable for use as a battery terminal part.

[0015] The battery terminal component according to the present invention can be constructed using a clad structure having any of the above-described configurations.

[0016] The battery terminal part of the present invention may be configured such that the outer flange surface of the flange portion has a boundary portion between the first surface continuing from the upper flange surface and the second surface continuing from the lower flange surface. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a clad structure and a battery terminal component that can easily ensure the bonding strength between an aluminum material and a copper material without having a diffusion reaction suppression layer made of Ni, and that can be expected to have long-term reliability even when used in batteries for automobiles, etc. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an example (Configuration Example A) of an embodiment of a cladding structure according to the present invention. [Figure 2] FIG. 2 is a diagram showing an example (Configuration Example B) of an embodiment of a cladding structure according to the present invention. [Figure 3] FIG. 1 is a diagram showing an example (Configuration Example C) of an embodiment of a cladding structure according to the present invention. [Figure 4] FIG. 1 is a diagram showing an example (configuration example D) of an embodiment of a cladding structure according to the present invention. [Figure 5] FIG. 1 is a diagram showing an example (Configuration Example E) of an embodiment of a cladding structure according to the present invention. [Figure 6] FIG. 1 is a diagram showing an example (Configuration Example F) of an embodiment of a cladding structure according to the present invention. [Figure 7] FIG. 1 is a flow chart showing an example of a manufacturing process (manufacturing method) of a cladding structure according to the present invention. [Figure 8] FIG. 10 is a diagram showing an example of a clad piece prepared in a material preparation step. [Figure 9] FIG. 3 is a diagram showing an example of a first molded body molded in a first molding step. [Figure 10] FIG. 4 is a diagram showing an example of a second molded body molded in a second molding step. [Figure 11] FIG. 10 is a diagram showing an example of a third molded body molded in a third molding step. [Figure 12] FIG. 1 is a diagram showing an example of a negative electrode side terminal connection structure in which a clad structure is used as a battery terminal component to electrically connect a negative electrode side component of one battery to a connection component connected to another battery. [Figure 13] FIG. 1 is a diagram showing an example of a negative electrode side terminal connection structure in which a clad structure is used as a battery terminal component to electrically connect a negative electrode side component of one battery to a connection component connected to another battery. DETAILED DESCRIPTION OF THE INVENTION

[0019] The clad structure according to the present invention will be described with reference to the drawings as appropriate, giving configuration examples A to F that are considered to be preferred embodiments. Note that the clad structure according to the present invention is not limited to configuration examples A to F. The clad structure according to the present invention is particularly suitable for battery components that require weight reduction while maintaining electrical properties, such as a terminal component (battery terminal component 1) for electrically connecting a negative electrode component of a battery to a connecting component (bus bar) between the battery. Configuration examples A to F will be described below in this order.

[0020] <Configuration example A> 1 shows a clad structure 1A (battery terminal component 1A) as configuration example A. The clad structure 1A (battery terminal component 1A) is a molded body obtained by plastically deforming a clad plate according to the region.

[0021] As shown in FIG. 1, the cladding structure 1A (battery terminal component 1A) has a first shaft portion 10 including a first shaft outer surface 10a extending downward (toward the Z2 side) and a first shaft lower surface 10b at the end extending downward (toward the Z2 side). The cladding structure 1A (battery terminal component 1A) also has a flange portion 11 including a flange upper surface 11a and a flange lower surface 11b extending in a radial direction (X direction) perpendicular to the first shaft portion 10 from the upper (Z1 side) end of the first shaft portion 10, and a flange outer surface 11c at the end extending in the radial direction (X direction) of the flange upper surface 11a and the flange lower surface 11b. The shapes of the first shaft portion 10 and the flange portion 11 as viewed from the Z direction are not particularly limited and may be, for example, a round shape such as a circle or an ellipse, or a polygonal shape such as a square or a hexagon.

[0022] In the clad structure 1A (battery terminal component 1A), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a. This surface region of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 1, this first surface occupies most of the surface of the aluminum layer 20. Furthermore, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, and the first shaft lower surface 11b. This surface region of the copper material (copper layer 21) is referred to as the second surface. As shown in FIG. 1, this second surface occupies the entire surface of the copper layer 21. Furthermore, an aluminum material containing 99 mass % or more of Al is present between the aluminum alloy material (aluminum alloy layer 20b) and the copper material (copper layer 21). The surface region of the pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1A (battery terminal component 1A).

[0023] As described above, the first shank portion 10 has a first outer shank surface 10a extending downward (toward the Z2 side) and a first lower shank surface 10b at its end extending downward (toward the Z2 side). The first shank portion 10 has a convex portion (inner shank convex portion 10c) made of an aluminum layer 20 that extends from the upper side (Z1 side) to the lower side (Z2 side). The inner shank convex portion 10c has an aluminum alloy layer 20b in its upper side (Z1 side) region and a pure aluminum layer 20a in its lower side (Z2 side) region. The region from the lower side (Z2 side) of the inner shank convex portion 10c to the first lower shank surface 10b and the first outer shank surface 10a is made of a copper layer 21. Therefore, the pure aluminum layer 20a is sandwiched between the aluminum alloy layer 20b on the upper side (Z1 side) and the copper layer 21 on the lower side (Z2 side).

[0024] The aluminum alloy layer 20b, pure aluminum layer 20a, and copper layer 21 that make up the first shaft portion 10 are pressure-welded in this order in the thickness direction (Z direction), and are thermally diffusion bonded at the pressure-welded interface (see FIG. 8), after which they are plastically deformed accordingly. Note that when the original shape of the first shaft portion 10 (see FIG. 9) is obtained into the target shape through rough forming and finish forming, the original copper layer 21 of the first shaft portion 10 is significantly plastically deformed.

[0025] The first outer shaft surface 10a and the first undershaft surface 10b of the first shaft portion 10 are included in the surface constituting the surface region made of copper, and can be made of substantially the same copper material (copper layer 21) as the negative electrode side component 2 (see FIGS. 12 and 13) made of copper. Therefore, because the undershaft surface 11b of the flange portion 11 is made of substantially the same copper material as the negative electrode side component 2, even when a terminal connection structure is adopted in which the undershaft surface 11b and the negative electrode side component 2 come into contact (such as a case in which the seal 4 shown in FIG. 13 is not used), an increase in electrical resistance at the contact interface between them is suppressed, and good conductivity can be ensured between the flange portion 11 and the connection component 3.

[0026] As described above, the flange portion 11 has a flange upper surface 11a and a flange lower surface 11b that extend from the upper (Z1 side) end of the first shaft portion 10 in a radial direction (X direction) perpendicular to the first shaft portion 10. The flange portion 11 further has flange outer surfaces 11c at the ends of the flange upper surface 11a and the flange lower surface 11b that extend in the radial direction (X direction). The flange portion 11 is composed of an aluminum layer 20 on the upper side (Z1 side) and a copper layer 21 on the lower side (Z2 side). The aluminum layer 20 that constitutes the flange portion 11 is composed of an aluminum alloy layer 20b on the upper side (Z1 side) and a pure aluminum layer 20a on the lower side (Z2 side). Therefore, the flange upper surface 11a is the surface of the aluminum alloy layer 20b, and the flange lower surface 11b is the surface of the copper layer 21. A pure aluminum layer 20a exists between the flange upper surface 11a and the flange lower surface 11b. At the flange outer surface 11c, the surface of the aluminum alloy layer 20b continues from the flange upper surface 11a, and the surface of the copper layer 21 continues from the flange lower surface 11b. The pure aluminum layer 20a exists between the aluminum alloy layer 20b continuing from the flange upper surface 11a and the copper layer 21 continuing from the flange lower surface 11b. Therefore, at the flange outer surface 11c, there are boundaries between the aluminum alloy layer 20b and the pure aluminum layer 20a, and between the pure aluminum layer 20a and the copper layer 21.

[0027] The aluminum alloy layer 20b, the pure aluminum layer 20a, and the copper layer 21 that make up the flange portion 11 are pressure-welded to each other in the thickness direction (Z direction) in this order, and are thermally diffusion bonded at the pressure-welded interface (see Figure 8), and then are plastically deformed accordingly.

[0028] The flange upper surface 11a of the flange portion 11 is included in the surface that constitutes the surface region made of aluminum alloy material, and can be made of approximately the same aluminum alloy material (aluminum alloy layer 20b) as the connection part 3 (see FIGS. 12 and 13) made of pure aluminum or aluminum alloy material. Therefore, even when a terminal connection structure (see FIGS. 12 and 13) is adopted in which the flange upper surface 11a of the flange portion 11 is in contact with the connection part 3, an increase in electrical resistance at the contact interface between them is suppressed, and good conductivity can be ensured between the flange 11 and the connection part 3.

[0029] Furthermore, the flange undersurface 11b of the flange 11 is included in the surface that constitutes the surface region made of copper, and can be made of substantially the same copper material (copper layer 21) as the negative electrode side component 2 (see FIGS. 12 and 13) made of copper. Therefore, even when a terminal connection structure is adopted in which the flange undersurface 11b and the negative electrode side component 2 come into contact with each other (such as when the seal 4 shown in FIG. 13 is not used), the flange undersurface 11b of the flange 11 is made of substantially the same copper material as the negative electrode side component 2, and therefore an increase in electrical resistance at the contact interface between them is suppressed, and good conductivity can be ensured between the flange 11 and the connection component 3.

[0030] As shown in Fig. 1, the first shaft portion 10 and the flange portion 11 do not have holes that penetrate in the Z direction. Because the first shaft portion 10 and the flange portion 11 do not have through holes in the Z direction, even if the electrolyte leaks from inside the battery (Z2 side) to the negative electrode side terminal connection portion (Z1 side), the electrolyte can be blocked by the clad structure 1A (battery electronic component 1A). This prevents the electrolyte from leaking out of the battery through the negative electrode side terminal connection portion.

[0031] In the clad structure 1A (battery terminal component 1A) shown in Fig. 1, the aluminum alloy layer 20b, the pure aluminum layer 20a, and the copper layer 21 have substantially laminar diffusion regions (hereinafter referred to as "diffusion layers") formed by a thermal diffusion reaction at the pressure-welded interfaces in the thickness direction (Z direction) between the layers. The average thickness of the diffusion layers between the layers is significantly smaller than that of the other three layers. For example, the diffusion layer formed between the pure aluminum layer 20a and the copper layer 21 is thought to have an average thickness of approximately 0.5 µm to 10 µm.

[0032] Within the diffusion layer between the pure aluminum layer 20a and the copper layer 21, an extremely thin, discontinuous oxide film made of aluminum oxide exists along the bonding interface between the diffusion layer and the pure aluminum layer 20a and the bonding interface between the diffusion layer and the copper layer 21. This discontinuous oxide film is believed to originate from a natural oxide film formed on the surface of the pure aluminum plate that constitutes the pure aluminum layer 20a. Even if the oxide film on the surface of the pure aluminum plate is removed by polishing or the like, it immediately regenerates upon exposure to the air. Therefore, a continuous oxide film exists on the surface of the pure aluminum plate immediately before pressure welding (clad rolling).

[0033] During pressure welding (clad rolling), the oxide film on the surface of the pure aluminum sheet is broken up and dispersed, becoming discontinuous, due to the large plastic deformation of the pure aluminum sheet. Immediately after pressure welding (clad rolling), the surface of the pure aluminum sheet (layer) is not exposed to the air, so the broken up and dispersed oxide film remains. During diffusion annealing, Al-Cu intermetallic compounds are formed near the pressure-welded interface between the pure aluminum layer and the copper layer through a thermal diffusion reaction. These Al-Cu intermetallic compounds are thought to be fine and randomly oriented. The random growth of these fine intermetallic compounds further breaks up and disperses the discontinuous oxide film. As a result, many gaps form in the oxide film, increasing the opportunities for direct contact between the pure aluminum and copper. This facilitates the formation of Al-Cu intermetallic compounds, leading to the proper formation of the intermetallic compound layer (diffusion layer), and ultimately to the achievement of optimal diffusion bonding strength between the pure aluminum layer and the copper layer.

[0034] In the clad structure 1A (battery terminal component 1A), the aluminum layer 20 is composed of a pure aluminum layer 20a and an aluminum alloy layer 20b. The aluminum layer 20 composed of the pure aluminum layer 20a and the aluminum alloy layer 20b has a simple structure in which the pure aluminum layer 20a and the aluminum alloy layer 20b are made of a homogeneous Al-based metallic material, making it easily practical. Because the pure aluminum layer 20a and the aluminum alloy layer 20b are made of a homogeneous Al-based metallic material, a homogeneous, approximately laminar diffusion region (diffusion layer) is formed between the pure aluminum layer 20a and the aluminum alloy layer 20b by the thermal diffusion reaction (self-diffusion) of Al. This homogeneous diffusion layer ensures adequate bonding strength between the pure aluminum layer 20a and the aluminum alloy layer 20b. Furthermore, if the pure aluminum layer 20a is substantially free of alloying elements or impurity elements, the thermal diffusion reaction between Al and Cu occurs appropriately between the pure aluminum layer 20a and the copper layer 21, as described above. Therefore, an intermetallic compound layer (diffusion layer) made of an Al-Cu based intermetallic compound is properly formed between the pure aluminum layer 20a and the copper layer 21. Therefore, by employing the aluminum layer 20 made of the pure aluminum layer 20a and the aluminum alloy layer 20b, a clad structure (battery terminal component) without a nickel layer can be properly formed.

[0035] Furthermore, by configuring the aluminum layer 20 from the pure aluminum layer 20a and the aluminum alloy layer 20b, the properties of the pure aluminum layer 20a (electrical conductivity, thermal conductivity, formability, workability, weldability, etc.) can be efficiently utilized. At the same time, the properties of the aluminum alloy layer 20b (mechanical properties such as tensile strength, yield strength, and hardness, ductility, formability, workability, weldability, etc.) can be efficiently utilized. Furthermore, compared to a layer structure consisting of a nickel layer and a pure aluminum layer or a layer structure consisting of a nickel layer and an aluminum alloy layer, the specific electrical resistance of the clad material is reduced (improved electrical conductivity), the thermal conductivity is increased (improved thermal conductivity), and the formability and workability are improved due to the difference in material properties between nickel and aluminum.

[0036] In the clad structure 1A (battery terminal component 1A) shown in FIG. 1 , the pure aluminum layer 20a is made of an aluminum material containing 99% or more by mass of Al. Aluminum materials containing 99% or more by mass are made of aluminum alloys with a composition that belongs to non-heat-treatable aluminum alloys, such as the JIS A1000 series, but this composition is generally classified as pure aluminum. Pure aluminum has better malleability than pure nickel and is suitable for rolling and press processing, which cause plastic deformation by compressive force. Therefore, a pure aluminum sheet made of pure aluminum can be easily pressure-bonded to both a copper sheet and an aluminum alloy sheet by clad rolling. Furthermore, pure aluminum has a lower hardness and work-hardening coefficient (n value) than aluminum alloys and pure copper. Therefore, a pure aluminum sheet made of pure aluminum experiences a relatively small degree of work hardening during pressure welding (clad rolling), allowing it to be smoothly spread between the aluminum alloy sheet and the copper sheet. As a result, the pure aluminum layer 20a can be easily pressure-bonded to both the aluminum alloy layer 20b and the copper layer 21.

[0037] The pure aluminum material suitable for the pure aluminum layer 20a is preferably made of JIS A1000 series or pure aluminum with a composition similar thereto, taking into consideration mechanical properties such as tensile strength, yield strength, elongation, and hardness, as well as electrical conductivity, thermal conductivity, ductility, formability, workability, and weldability. For example, A1050, A1070, A1080, A1085, A1100, and A1200 may be used, which have good electrical conductivity, thermal conductivity, formability, workability, and weldability.

[0038] In the clad structure 1A (battery terminal component 1A) shown in FIG. 1, the aluminum alloy layer 20b is made of an aluminum alloy. Compared to pure aluminum, aluminum alloys have excellent mechanical properties, particularly tensile strength, yield strength, and hardness. These unique properties of aluminum alloys can be utilized by forming the aluminum alloy layer 20b from an aluminum alloy. Furthermore, by forming the clad structure 1A (battery terminal component 1A) so that the aluminum alloy layer 20b using an aluminum alloy with desired properties is dominant, it is possible to impart the desired properties attributable to the aluminum alloy to the clad structure 1A (battery terminal component 1A). For example, by using aluminum alloys such as A3003 and A5052 (described below), it is possible to form a clad structure 1A (battery terminal component 1A) including an aluminum alloy layer 20b with excellent mechanical properties, ductility, formability, processability, and weldability.

[0039] The aluminum alloy material suitable for the aluminum alloy layer 20b is preferably a non-heat-treatable aluminum alloy, from the viewpoint of obtaining pressure bonding strength between the aluminum alloy layer 20a and the pure aluminum layer 20a by pressure welding and diffusion bonding strength by diffusion annealing. Non-heat-treatable aluminum alloys are alloys that obtain a predetermined strength mainly through cold working, such as rolling, such as the JIS A3000 series, A4000 series, and A5000 series. On the other hand, heat-treatable aluminum alloys are alloys that obtain a predetermined strength through heat treatment, such as quenching and tempering, such as the JIS A2000 series, A6000 series, and A7000 series. Note that the JIS A1000 series, which belongs to the non-heat-treatable aluminum alloys, and those with compositions similar thereto, are classified as pure aluminum, as described above.

[0040] Non-heat-treatable aluminum alloys suitable for the aluminum alloy layer 20b are those with compositions similar to those specified by the JIS A3000 and A5000 series, taking into consideration mechanical properties such as tensile strength, yield strength, elongation, and hardness, as well as electrical conductivity, thermal conductivity, ductility, formability, workability, and weldability. Examples include A3003, A3103, A3203, A5005, A5052, A5154, and A5454, which offer excellent mechanical properties, ductility, formability, workability, and weldability. Other suitable alloys include A3004, A3104, A3105, A5021, A5042, A5082, and A5182, which offer excellent mechanical properties, ductility, formability, and workability. Other suitable alloys include A5083 and A5086, which offer excellent mechanical properties and weldability.

[0041] In the clad structure 1A (battery negative electrode component 1A) shown in FIG. 1 , the copper layer 21 is preferably made of copper containing 98% or more by mass of Cu. Copper containing 98% or more by mass of Cu is generally classified as pure copper. Pure copper contains 98% or more by mass of Cu, which has low specific electrical resistance and high thermal conductivity, and therefore has excellent electrical and thermal conductivity. These properties unique to pure copper can be utilized by constructing the copper layer 21 from pure copper. Furthermore, by constructing the clad structure 1A (battery terminal component 1A) so that the copper layer 21 using pure copper with desired properties is dominant, it is possible to impart the desired properties attributable to pure copper to the clad structure 1A (battery terminal component 1A). For example, by using C1020 or C1100, described below, it is possible to construct a clad structure 1A (battery terminal component 1A) including a copper layer 21 with excellent mechanical properties, electrical conductivity, thermal conductivity, malleability, formability, workability, and weldability.

[0042] The copper material suitable for the copper layer 21 is preferably selected based on mechanical properties such as tensile strength, yield strength, elongation, and hardness, as well as electrical conductivity, thermal conductivity, malleability, formability, workability, and weldability. The copper material suitable for the copper layer 21 may be a JIS C1000 series copper alloy, which has excellent ductility and drawability, or a pure copper material with a composition similar thereto. In this case, copper alloys such as C1020, C1100, C1201, C1220, C1441, C1510, C1921, and C1940 are preferred. The copper material constituting the copper layer 21 may also be a JIS C2000 series copper alloy (e.g., C2600 or C2680) with excellent ductility and drawability, a JIS C7000 series copper alloy (e.g., C7250) with excellent ductility and plastic workability, or a material (copper alloy) with a composition similar thereto. For example, when high conductivity is important, pure copper is preferably selected, and when tensile strength and yield strength are important, copper alloys are preferably selected.

[0043] <Configuration example B> 2 shows a clad structure 1B (battery terminal component 1B) as configuration example B. Like the clad structure 1A (battery terminal component 1A), the clad structure 1B (battery terminal component 1B) is a molded body obtained by plastically deforming a clad plate according to the region.

[0044] As shown in FIG. 2, the cladding structure 1B (battery terminal component 1B) has a first shaft portion 10 and a flange portion 11, similar to the cladding structure 1A (battery terminal component 1A). Furthermore, the cladding structure 1B (battery terminal component 1B) has a first leg portion 12 and a first recess 13. The first leg portion 12 has a first shaft lower surface 10b as a first leg bottom surface 12a, a first leg inner surface 12b and a first leg outer surface 12c extending downward (toward the Z2 direction) from the outer edge of the first leg bottom surface 12a, and a first leg lower surface 12d at the end extending downward (toward the Z2 direction) from the first leg inner surface 12a and the first leg outer surface 12c. Furthermore, the first recess 13 is defined by the first leg bottom surface 12a and the first leg inner surface 12b. The shapes of the first shaft portion 10, the first recess 13, and the flange portion 11 as viewed from the Z direction are not particularly limited, and may be, for example, a round shape such as a circle or an oval, or a polygonal shape such as a square or a hexagon.

[0045] In the clad structure 1B (battery terminal component 1B), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a. This surface region made of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 2, this first surface occupies most of the surface of the aluminum layer 20. Furthermore, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, the first leg outer surface 12c (first shaft outer surface 10a), the first leg lower surface 12d (first shaft lower surface 10b), the first leg inner surface 12b, and the first leg bottom surface 12a. This surface region made of the copper material (copper layer 21) is referred to as the second surface. As shown in FIG. 2, this second surface occupies the entire surface of the copper layer 21. Furthermore, an aluminum material containing 99 mass % or more of Al is present between the aluminum alloy material and the copper material. A surface region of a pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1B (battery terminal component 1B).

[0046] The clad structure 1B (battery terminal component 1B) is the same as the clad structure 1A (battery terminal component 1A) in that it has a first shaft portion 10 and a flange portion 11. However, the clad structure 1B (battery terminal component 1B) differs from the clad structure 1A (battery terminal component 1A) in that it has a first leg portion 12 on the lower side (Z2 side) of the first shaft portion 10. For details of the configuration and materials of the first shaft portion 10 and flange portion 11 of the clad structure 1B (battery terminal component 1B), refer to the description of the clad structure 1A (battery terminal component 1A), and description thereof will be omitted here.

[0047] As described above, the first leg portion 12 has the first shaft lower surface 10b of the first shaft portion 10 as the first leg bottom surface 12a, and includes the first leg outer surface 12c, the first leg inner surface 12a, and the first leg bottom surface 12d. The first leg bottom surface 12a and the first leg inner surface 12b define the first recess 13. The first leg bottom surface 12a, the first leg outer surface 12c, the first leg inner surface 12a, and the first leg bottom surface 12d of the first leg portion 12 are all made of copper material. That is, the first leg portion 12 is made of the copper layer 21. Therefore, the first leg bottom surface 12a, the first leg outer surface 12c, the first leg inner surface 12a, and the first leg bottom surface 12d are the surfaces of the copper layer 21. In addition, when the first leg portion 12 is formed from the original shape of the first shaft portion 10 (see Figure 9) through rough forming, finish forming, etc. to obtain the target shape, the copper layer 21 of the original shape of the first shaft portion 10 is significantly plastically deformed.

[0048] The first leg outer surface 12c, the first leg lower surface 12d, the first leg inner surface 12b, and the first leg bottom surface 12a of the first leg 12 are included in the surface that constitutes the second surface made of copper and can be made of substantially the same copper material (copper layer 21) as the negative-electrode-side component 2 (see FIGS. 12 and 13 ). Therefore, because the first leg outer surface 12c, the first leg lower surface 12d, the first leg inner surface 12b, and the first leg bottom surface 12a of the first leg 12 are made of substantially the same copper material as the negative-electrode-side component 2, even when a terminal connection structure (see FIGS. 12 and 13 ) is adopted in which the negative-electrode-side component 2 contacts one or more of the first leg outer surface 12c, the first leg lower surface 12d, the first leg inner surface 12b, and the first leg bottom surface 12a, ... are in contact with the negative-electrode-side component 2, an increase in electrical resistance at the contact interface between the two is suppressed, and good conductivity can be ensured between the first leg 12 and the connection component 3.

[0049] From another perspective, the first leg portion 12 defines a first recess 13 by a first leg bottom surface 12a and a first leg inner surface 12b of the first leg portion 12. This first recess 13 can be used to electrically connect the clad structure 1B (battery terminal component 1B) to a negative electrode side component 2 of a battery (see FIGS. 12 and 13). For example, the clad structure 1B (battery terminal component 1B) can be electrically connected to the negative electrode side component 2 simply and stably by a fitting structure (see FIG. 12) in which the negative electrode side component 2 is inserted and fitted into the first recess 13, or by a crimping structure (see FIG. 13) in which the first recess 13 is bent outward to fix the negative electrode side component 2.

[0050] <Configuration example C> 3 shows a clad structure 1C (battery terminal component 1C) as configuration example C. Like the clad structures 1A to 1B (battery terminal components 1A to 1B), the clad structure 1C (battery terminal component 1C) is a molded body obtained by plastically deforming a clad plate according to the region.

[0051] As shown in FIG. 3, the cladding structure 1C (battery terminal component 1C) has a first shank 10 and a flange 11, similar to the cladding structure 1A (battery terminal component 1A). Furthermore, the cladding structure 1C (battery terminal component 1C) has a second shank 14 on the upper side (Z1 side) of the first shank 10 and the flange 11. The second shank 14 has a second outer shank surface 14a extending upward (toward the Z1 side) from the flange upper surface 11a, and a second upper shank surface 14b at the end extending upward (toward the Z1 side) from the second outer shank surface 14a. The shapes of the first shank 10, the flange 11, and the second shank 14 as viewed from the Z direction are not particularly limited, and may be, for example, a round shape such as a circle or an ellipse, or a rectangular shape such as a square or a hexagon.

[0052] In the clad structure 1C (battery terminal component 1C), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a, the second shaft outer surface 14a, and the second shaft upper surface 14b. This surface region made of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 3, this first surface occupies most of the surface of the aluminum layer 20. Furthermore, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, and the first shaft lower surface 10b. This surface region made of the copper material (copper layer 21) is referred to as the second surface. As shown in FIG. 3, this second surface occupies the entire surface of the copper layer 21. Furthermore, an aluminum material containing 99 mass % or more of Al is present between the aluminum alloy material and the copper material. The surface region of the pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1C (battery terminal component 1C).

[0053] The clad structure 1C (battery terminal component 1C) is the same as the clad structure 1A (battery terminal component 1A) in that it has a first shaft portion 10 and a flange portion 11. However, the clad structure 1C (battery terminal component 1C) differs from the clad structure 1A (battery terminal component 1A) in that it has a second shaft portion 14 on the upper side (Z1 side) of the first shaft portion 10 and the flange portion 11. For details of the configuration and materials of the first shaft portion 10 and the flange portion 11 of the clad structure 1C (battery terminal component 1C), refer to the description of the clad structure 1A (battery terminal component 1A), and description thereof will be omitted here.

[0054] As described above, the second shank portion 14 is located above (on the Z1 side of) the first shank portion 10 and the flange portion 11, and includes a second shank outer surface 14a and a second shank upper surface 14b. The second shank outer surface 14a and the second shank upper surface 14b of the second shank portion 14 are entirely made of an aluminum alloy material. That is, the second shank portion 14 is made of an aluminum alloy layer 20b. Therefore, the second shank outer surface 14a and the second shank upper surface 14b are the surfaces of the aluminum alloy layer 20b. Note that when the second shank portion 14 is formed into a target shape through rough forming and finish forming from the original shape of the second shank portion 10 (see FIG. 9), the aluminum layer 20 of the original shape of the second shank portion 14 is significantly plastically deformed.

[0055] The second outer shaft surface 14a and the second upper shaft surface 14b of the second shank portion 14 are included in the surface constituting the first surface made of an aluminum alloy material (aluminum alloy layer 20b), and can be made of approximately the same aluminum alloy material (aluminum alloy layer 20b) as the connecting part 3 (see FIGS. 12 and 13) made of pure aluminum or an aluminum alloy material. Therefore, since at least the second outer shaft surface 14a of the second shank portion 14, in addition to the flange upper surface 11a of the flange portion 11, is made of approximately the same aluminum alloy material as the connecting part 3, even when a terminal connection structure (see FIG. 12) is adopted in which the second outer shaft surface 14a and the connecting part 3 come into contact with each other, an increase in electrical resistance at the contact interface between them is suppressed, and good conductivity can be ensured between the flange 11 and the second shank portion 14 and the connecting part 3.

[0056] <Configuration example D> 4 shows a clad structure 1D (battery terminal component 1D) as configuration example D. Like the clad structures 1A to 1C (battery terminal components 1A to 1C), the clad structure 1D (battery terminal component 1D) is a molded body obtained by plastically deforming a clad plate according to the region.

[0057] As shown in Fig. 4, the cladding structure 1D (battery terminal component 1D) has a first shaft portion 10, a flange portion 11, and a second shaft portion 14, similar to the cladding structure 1C (battery terminal component 1C). The cladding structure 1D (battery terminal component 1D) has a first leg portion 12 and a first recessed portion 13, similar to the cladding structure 1B (battery terminal component 1B). The shapes of the first shaft portion 10, the first recessed portion 13, the flange portion 11, and the second shaft portion 14 as viewed from the Z direction are not particularly limited, and may be, for example, a round shape such as a circle or an oval, or a polygonal shape such as a square or a hexagon.

[0058] In the clad structure 1D (battery terminal component 1D), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a, the second shaft outer surface 14a, and the second shaft upper surface 14b. This surface region made of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 4, this first surface occupies most of the surface of the aluminum layer 20. Furthermore, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, the first leg outer surface 12c, the first leg lower surface 12d (first shaft lower surface 10b), the first leg inner surface 12b, and the first leg bottom surface 12a. This surface region made of the copper material (copper layer 21) is referred to as the second surface. As shown in FIG. 4, this second surface occupies the entire surface of the copper layer 21. Furthermore, an aluminum material containing 99 mass % or more of Al is present between the aluminum alloy material and the copper material. A surface region of a pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1C (battery terminal component 1C).

[0059] Clad structure 1D (battery terminal component 1D) is the same as clad structure 1C (battery terminal component 1C) in that it has a first shaft portion 10, a flange portion 11, and a second shaft portion 14. Clad structure 1D (battery terminal component 1D) is also the same as clad structure 1B (battery terminal component 1B) in that it has a first leg portion 12 and a first recessed portion 13. For details of the configuration and materials of the first shaft portion 10, flange portion 11, first leg portion 12, first recessed portion 13, and second shaft portion 14 of clad structure 1D (battery terminal component 1D), refer to the descriptions of clad structures 1A to 1C (battery terminal components 1A to 1C), and description thereof will be omitted here.

[0060] <Configuration example E> 5 shows a clad structure 1E (battery terminal component 1E) as configuration example E. Like the clad structures 1A to 1D (battery terminal components 1A to 1D), the clad structure 1E (battery terminal component 1E) is a molded body obtained by plastically deforming a clad plate according to the region.

[0061] As shown in FIG. 5, the cladding structure 1E (battery terminal component 1E) has a first shaft portion 10, a flange portion 11, and a second shaft portion 14, similar to the cladding structure 1C (battery terminal component 1C). The cladding structure 1E (battery terminal component 1E) also has a second leg portion 15 and a second recess 16. The second leg portion 15 has a second shaft upper surface 14b as a second leg bottom surface 15a, a second leg inner surface 15b and a second leg outer surface 15c extending upward (toward the Z1 side) from the outer edge of the second leg bottom surface 15a, and a second leg lower surface 15d at the end extending upward (toward the Z1 side) from the second leg inner surface 15b and the second leg outer surface 15c. The second recess 16 is defined by the second leg bottom surface 15a and the second leg inner surface 15b. The shapes of the first shaft portion 10, the flange portion 11, the second shaft portion 14, and the second recess 16 as viewed from the Z direction are not particularly limited, and may be, for example, a round shape such as a circle or an oval, or a polygonal shape such as a square or a hexagon.

[0062] In the clad structure 1E (battery terminal component 1E), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a, the second leg outer surface 15c (second shaft outer surface 14a), the second leg lower surface 15d (second shaft upper surface 14b), the second leg inner surface 15b, and the second leg lower surface 15a. This surface region made of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 5, this first surface occupies most of the surface of the aluminum layer 20. Furthermore, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, and the first shaft lower surface 10b. This surface region made of the copper material (copper layer 21) is referred to as the second surface. As shown in FIG. 5, this second surface occupies the entire surface of the copper layer 21. Furthermore, an aluminum material containing 99 mass % or more of Al is present between the aluminum alloy material and the copper material. A surface region of a pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1E (battery terminal component 1E).

[0063] The clad structure 1E (battery terminal component 1E) is the same as the clad structure 1C (battery terminal component 1C) in that it has a first shaft portion 10, a flange portion 11, and a second shaft portion 14. However, the clad structure 1E (battery terminal component 1E) differs from the clad structure 1C (battery terminal component 1C) in that it has a second leg portion 15 on the upper side (Z1 side) of the second shaft portion 14. For details of the configuration and materials of the first shaft portion 10, flange portion 11, and second shaft portion 14 of the clad structure 1E (battery terminal component 1E), please refer to the descriptions of the clad structures 1A to 1C (battery terminal components 1A to 1C), and description thereof will be omitted here.

[0064] <Configuration example F> 6 shows a clad structure 1F (battery terminal component 1F) as configuration example F. Like the clad structures 1A to 1E (battery terminal components 1A to 1E), the clad structure 1F (battery terminal component 1F) is a molded body obtained by plastically deforming a clad plate according to the region.

[0065] As shown in FIG. 6, the cladding structure 1F (battery terminal component 1F) has a first axial portion 10, a flange portion 11, a second axial portion 14, a second leg portion 15, and a second recess 16, similar to the cladding structure 1E (battery terminal component 1E). The cladding structure 1F (battery terminal component 1F) has a first leg portion 12 and a first recess 13, similar to the cladding structure 1B (battery terminal component 1B). The shapes of the first axial portion 10, the first axial portion 13, the flange portion 11, the second axial portion 14, and the second recess 16 as viewed from the Z direction are not particularly limited, and may be, for example, a round shape such as a circle or an ellipse, or a polygonal shape such as a square or a hexagon.

[0066] In the clad structure 1F (battery terminal component 1F), a surface region made of an aluminum alloy material (aluminum alloy layer 20b) extends from the flange outer surface 11c to the flange upper surface 11a, the second leg outer surface 15c (second shaft outer surface 14a), the second leg lower surface 15d (second shaft upper surface 14b), the second leg inner surface 15b, and the second leg bottom surface 15a. This surface region made of the aluminum alloy material (aluminum alloy layer 20b) is referred to as the first surface. As shown in FIG. 6, this first surface occupies most of the surface of the aluminum layer 20. In addition, a surface region made of a copper material (copper layer 21) extends from the flange outer surface 11c to the flange lower surface 11b, the first shaft outer surface 10a, the first leg outer surface 12c, the first leg lower surface 12d (first shaft lower surface 10b), the first leg inner surface 12b, and the first leg bottom surface 12a. The surface region made of this copper material (copper layer 21) is referred to as the second surface. As shown in Fig. 6, this second surface occupies the entire surface of the copper layer 21. Between the aluminum alloy material and the copper material, there is an aluminum material containing 99 mass % or more of Al. A surface region of the pure aluminum layer 20a is present on the flange outer surface 11c of the clad structure 1E (battery terminal component 1E).

[0067] The clad structure 1F (battery terminal component 1F) is the same as the clad structure 1E (battery terminal component 1E) in that it has a first axial portion 10, a flange portion 11, a second axial portion 14, and a second leg portion 15. However, the clad structure 1F (battery terminal component 1F) differs from the clad structure 1E (battery terminal component 1E) in that it has a first leg portion 12 on the lower side (Z2 side) of the first axial portion 10. For details of the configurations and materials of the first axial portion 10, flange portion 11, second axial portion 14, first leg portion 12, and second leg portion 15 of the clad structure 1F (battery terminal component 1F), refer to the descriptions of the clad structures 1A to 1E (battery terminal components 1A to 1E), and description thereof will be omitted here.

[0068] Next, a manufacturing method of the clad structure 1 shown in Fig. 1 will be described with reference to a manufacturing process diagram (flow chart) that is considered to be preferable, while referring to the drawings as appropriate. Note that the battery terminal components configured using the above-described clad structures 1A to 1F may be configured using the clad structures 1A to 1F as they are, as in the case of the above-described battery terminal components 1A to 1F, or may be configured by performing minor processing on the clad structures 1A to 1F, so measures may be taken as needed.

[0069] FIG. 7 shows a manufacturing process diagram (flow chart) for clad structures 1A to 1F (battery terminal components 1A to 1F). This manufacturing process includes, as main processes, a material preparation process, a first molding process, a second molding process, and a third molding process, and includes, as an optional process, a fourth molding process, as needed. Below, the manufacturing process will be described in detail using, as an example, a clad structure 1F (battery terminal component 1F) having a more complex shape among the above-mentioned clad structures 1A to 1F (battery terminal components 1A to 1F). Note that if a manufacturing method that can easily manufacture a clad structure 1F (battery terminal component 1F) having a more complex shape is used, clad structures 1A to 1E (battery terminal components 1A to 1E) having a simpler shape can be easily manufactured.

[0070] <Material preparation process> The material preparation step is a step of preparing a clad piece 100 as shown in FIG. 8 using a clad plate as a material, as shown in FIG. 7. The clad piece 100, which serves as the starting material for forming the clad structures 1A to 1F, is a small piece of clad plate composed of an aluminum layer 120 made of an aluminum material and a copper layer 121 made of a copper material. In detail, the aluminum layer 120 constituting the clad piece 100 is composed of an aluminum alloy layer 120b located on the outer side (Z1 side) and made of an aluminum alloy material, and a pure aluminum layer 120a located on the copper layer 121 side (Z2 side) of the aluminum alloy layer 120b and made of a pure aluminum material containing 99% or more by mass of Al. Therefore, the clad piece 100 is a small piece of clad plate with a three-layer structure composed of the aluminum alloy layer 120b, the pure aluminum layer 120a, and the copper layer 121. The clad piece 100 can be formed by using a clad plate having substantially the same layer structure as the clad piece 100 and processing means such as punching or wire cutting.

[0071] The pure aluminum layer 120a, aluminum alloy layer 120b, and copper layer 121 constituting the clad piece 100 may be designed taking into consideration the shapes and volumes of the pure aluminum layer 20a, aluminum alloy layer 20b, and copper layer 21 of the clad structures 1A-1F (battery terminal components 1A-1F) that will become the finished products. The pure aluminum layer 120a constituting the clad piece 100 is also designed taking into consideration the desired bonding strength between the aluminum alloy layer 120b and the copper layer 121. It is preferable that the pure aluminum layer 120a in the clad piece 100 is formed as a single continuous layer, since this facilitates the desired bonding strength, but it does not have to be formed as a single continuous layer. The pure aluminum layer 120a in the clad piece 100 may have, for example, multiple evenly distributed cracks where the aluminum alloy layer 120b and the copper layer 121 come into contact with each other to the extent that the desired bonding strength is achieved.

[0072] The clad plate (not shown) used as the material for the clad piece 100 is made by laminating a suitably tempered aluminum alloy plate, a pure aluminum plate containing 99% or more by mass of Al, and a copper plate in this order in the thickness direction (Z direction) and pressing them together (clad rolling), followed by a moderate heating diffusion reaction at the pressed-welded interface. The aluminum alloy plate used to form the clad plate is the material that forms the aluminum alloy layer 20b of the clad structures 1A-1F (battery terminal components 1A-1F). The pure aluminum plate used to form the clad plate is the material that forms the pure aluminum layer 20a of the clad structures 1A-1F (battery terminal components 1A-1F). The copper plate used to form the clad plate is the material that forms the copper layer 21 of the clad structures 1A-1F (battery terminal components 1A-1F).

[0073] <First molding process> The first molding step is a step of forming a first molded body 200F as shown in FIG. 9 using a clad piece 100 as shown in FIG. 7. The shape of this first molded body 200F is an example of a shape for finally obtaining a clad structure 1F (battery terminal component 1F). In the first molding step, a general press molding method is used to mainly mold a first shank portion 210, a flange portion 211, and a second shank portion 214, which are the original shapes of the first shank portion 10, the flange portion 11, and the second shank portion 14 shown in FIG. 6. During this process, the clad piece 100 is plastically deformed to correspond to the shapes of each part of the first molded body 200F, which is the target shape. As a result, the first molded body 200F has a configuration including the first shank portion 210, the flange portion 211, and the second shank portion 214, as shown in FIG. 9. The first shaft portion 210, the flange portion 211, and the second shaft portion 214 of the first molded body 200F are portions corresponding to the first shaft portion 10, the flange portion 11, and the second shaft portion 14 of the cladding structure 1F.

[0074] In this first molded body 200F, the aluminum alloy layer 220b located on the upper side (Z1 side) extends from the flange outer surface 211c to the flange upper surface 211a of the flange portion 211, and further extends from the second shaft outer surface 214a to the second shaft upper surface 214b. Meanwhile, the copper layer 221 located on the lower side (Z2 side) extends from the flange outer surface 211c to the flange lower surface 211b of the flange portion 211, and further extends from the first shaft outer surface 210a to the first shaft lower surface 210b of the first shank portion 210. Then, the pure aluminum layer 220a located between the aluminum alloy layer 220b and the copper layer 221 extends downward (Z2 side) to form the original shape of the in-shaft convex portion 210c that convex downward (Z2 side) inside the first shank portion 210.

[0075] <Second forming process> The second molding step is a step of forming a second molded body 300F as shown in Fig. 10 using a first molded body 200F as shown in Fig. 7. In the second molding step, a general press molding method is used to mainly mold first leg portion 312 and second leg portion 315, which are the original shapes of first leg portion 12 and second leg portion 15 shown in Fig. 6, and in addition, first shaft portion 310 is molded so that it has approximately the same shape as first shaft portion 10 shown in Fig. 6. During this process, first molded body 200F is plastically deformed so as to correspond to the shapes of each portion of second molded body 300F, which is the target shape. As shown in Figure 10, the second molded body 300F includes a flange portion 311, a first shaft portion 310, a first leg portion 312, a first recess 313, a second shaft portion 314, a second leg portion 315, and a second recess 316, which are the original shapes of the flange portion 11, the first shaft portion 10, the first leg portion 12, the first recess 13, the second shaft portion 14, the second leg portion 15, and the second recess 16 of the clad structure 1F.

[0076] In this second molded body 300F, the aluminum alloy layer 320b located on the upper side (Z1 side) extends from the flange outer surface 311c of the flange portion 311 to the flange upper surface 311a, and further extends from the second leg outer surface 315c (second shaft outer surface 314a) of the second leg portion 314 to the second leg lower surface 315d (second shaft upper surface 311a), the second leg inner surface 315b, and the second leg bottom surface 315a. Furthermore, copper layer 321 located on the lower side (Z2 side) extends from flange outer surface 311c to flange lower surface 311b of flange portion 311, and further extends from first shaft outer surface 310a of first shaft portion 310 to first leg outer surface 312c (first shaft lower surface 310a), first leg lower surface 312d (first shaft lower surface 310b), first leg inner surface 312b, and first leg bottom surface 312a of first leg portion 312. Then, pure aluminum layer 320a located between aluminum alloy layer 320b and copper layer 321 extends further downward (Z2 side) to form intra-shaft convex portion 310c that convex further downward (Z2 side) inside first shaft portion 310.

[0077] <Third molding process> The third molding step is a step of forming a third molded body 400F as shown in Fig. 11 using a second molded body 300F, as shown in Fig. 7. In the third molding step, a general press molding method is used to plastically deform mainly the first shaft portion 310, flange portion 311, and second shaft portion 314 of the second molded body 300F to form a first shaft portion 410, flange portion 411, first leg portion 412, second shaft portion 414, and second leg portion 415 corresponding to the first shaft portion 10, flange portion 11, first leg portion 12, second shaft portion 14, and second leg portion 15 shown in Fig. 1. During this step, the second molded body 300F is plastically deformed to correspond to the shapes of each portion of the third molded body 400F, which is the target shape. This completes a first shaft portion 410, a flange portion 411, a first leg portion 412, a second shaft portion 414, and a second leg portion 415, which substantially correspond to the first shaft portion 10, the flange portion 11, the first leg portion 12, the second shaft portion 14, and the second leg portion 15 shown in Fig. 1. Also, a first recess 413 and a second recess 416, which substantially correspond to the first recess 13 and the second recess 16, are defined.

[0078] The third molded body 400F can have a shape substantially identical to that of the first shank 10, the flange 11, the first leg 12, the second shank 14, and the second leg 15 of the cladding structure 1F. As shown in Fig. 11, the third molded body 400F includes a first shank 410, a first leg 412, and a first recess 413 located below (on the Z2 side of) the flange 411, and also includes a second shank 414, a second leg 415, and a second recess 416 located above (on the Z1 side of) the flange 411. The pure aluminum layer 420a located between the aluminum alloy layer 420b and the copper layer 421 extends further downward (toward the Z2 side), forming an in-shank protrusion 410c that protrudes further downward (toward the Z2 side) inside the first shank 410.

[0079] In this third molded body 400F, the aluminum alloy layer 420b located on the upper side (Z1 side) extends from the flange outer surface 411c of the flange portion 411 to the flange upper surface 411a, and further extends from the second leg outer surface 415c (second shaft outer surface 414a) of the second leg portion 414 to the second leg lower surface 415d (second shaft upper surface 411a), the second leg inner surface 415b, and the second leg bottom surface 415a. Furthermore, the copper layer 421 located on the lower side (Z2 side) extends from the flange outer surface 411c to the flange under surface 411b of the flange portion 411, and further extends from the first shaft outer surface 410a of the first shaft portion 410 to the first leg outer surface 412c (first shaft under surface 410a), the first leg under surface 412d (first shaft under surface 410b), the first leg inner surface 412b, and the first leg bottom surface 412a of the first leg portion 412. As a result, the first surface where the aluminum alloy layer 420b of the third molded body 400F is exposed and the second surface where the copper layer 421 is exposed essentially correspond to the first surface and second surface of the clad structure 1F (battery terminal component 1F).

[0080] The third molded body 400 obtained through the above steps is, for example, surface-washed to remove contaminants (metal powder, dirty oil, dust, etc. resulting from molding), and if it passes a predetermined inspection, it becomes a finished product. This finished product is the clad structure 1F (battery terminal component 1F). Note that, for example, if the flange portion 411 of the third molded body 400F is long in the X direction (has excess thickness), a fourth molding step shown in FIG. 7 can be added.

[0081] <4th molding process> In the fourth molding step, when the flange portion 411 of the third molded body 400F is long in the X direction (has excess thickness), the flange outer surface 411C is partially removed by a general press molding method (trimming molding method) to mold it into a predetermined shape. In the fourth molding step, the flange outer surface 411C of the flange portion 411 of the third molded body 400F is trimmed to obtain a shape equivalent to the flange outer surface 11C of the flange portion 11 of the cladding structure 1F. The fourth molded body (not shown) obtained in the fourth molding step is then subjected to the surface cleaning and inspection described above to become a finished product. This finished product is the cladding structure 1F (battery terminal component 1F).

[0082] As described above, the clad structure 1F (battery terminal component 1F) according to the present invention can be manufactured by a simple press-forming method shown in the manufacturing process diagram (flow chart) of FIG. 7. In the manufacturing process shown in FIG. 7, the clad structure 1F (battery terminal component 1F) can be obtained from a clad piece 100, which is made from a three-layer clad plate consisting of an aluminum alloy layer, a pure aluminum layer, and a copper layer. The clad plate that is the material for the clad piece 100 can be easily manufactured by a typical clad plate manufacturing method that involves rolling dissimilar metals (clad rolling) and diffusion annealing. A clad plate that has undergone appropriate rolling (clad rolling) and diffusion annealing has an aluminum alloy layer, a pure aluminum layer, and a copper layer that are appropriately heat-diffusion bonded, and has sufficient bonding strength to prevent peeling between the layers. Therefore, when the clad plate is used to form the clad piece 100, the aluminum alloy layer 120b, the pure aluminum layer 120a, and the copper layer 121 of the clad piece 100 do not easily peel off. By using the clad plate as the starting material for the clad piece 100, the clad piece 100 can sufficiently withstand the above-mentioned plastic deformation, and the aluminum alloy layer 20b, the pure aluminum layer 20a, and the copper layer 21 that constitute the clad structure 1F (battery terminal component 1F) do not easily peel off.

[0083] Therefore, the clad structure 1F (battery terminal component 1F) according to the present invention can use the clad piece 100 made of a clad plate as a starting material. From this perspective, productivity as a finished product can be expected, and it is easy to ensure the bonding strength between the aluminum alloy material (aluminum alloy layer 20b), the pure aluminum material (pure aluminum layer 20a), and the copper material (copper layer 21). As a result, the battery terminal component 1F constructed using the clad structure 1F can be expected to have long-term reliability even when used in batteries such as automobiles.

[0084] The simple press-molding method shown in the manufacturing process diagram (flow chart) of Fig. 7 is not limited to the manufacturing method of the clad structure 1F (battery terminal component 1F). The simple press-molding method shown in the manufacturing process diagram (flow chart) of Fig. 7 is applicable to the manufacturing method of the clad structures 1A to 1E (battery terminal components 1A to 1E). Therefore, the simple press-molding method shown in the manufacturing process diagram (flow chart) of Fig. 7 is suitable as a manufacturing method of the clad structure (battery terminal component) according to the present invention.

[0085] Here, the terminal connection structure on the negative electrode side of the battery will be described with an example of its configuration.

[0086] <Configuration example 1> As Configuration Example 1, FIG. 12 shows a terminal connection structure on the negative electrode side of a battery in which the clad structure 1D shown in FIG. 4 is used as a battery terminal component. In this Configuration Example 1, the battery terminal component 1D electrically connects the negative electrode side component 2 and the connection component 3. The negative electrode side component 2 shown in Configuration Example 1 is inserted into the first recess 13 of the clad structure 1D (battery terminal component 1D). This insertion structure is preferably an interference fit, and more preferably, the negative electrode side component 2 and the first leg portion 12 are joined by laser welding or the like. The negative electrode side component 2 is a conductive component electrically connected to the negative electrode in the battery and is an outlet port on the negative electrode side. The negative electrode side component 2 is generally made of a copper material.

[0087] On the other hand, the connection part 3 is joined to the flange upper surface 11a of the flange portion 11 of the clad structure 1D (battery terminal part 1D) by laser welding, ultrasonic welding, or the like. The connection part 3 is a conductive part used outside the battery. The connection part 3 is a conductive part such as a bus bar for electrically connecting to other batteries, and can electrically connect multiple batteries to form a battery pack. The connection part 3 is generally made of copper, nickel, pure aluminum, or aluminum alloy material, but in recent years, aluminum material has been preferred for its weight reduction and other reasons. Furthermore, aluminum alloy material is preferred for its strength in addition to its weight reduction.

[0088] When electrically connecting a negative electrode side component 2 made of copper and a connecting component 3 made of aluminum (particularly aluminum alloy material) as in Configuration Example 1, it is preferable to use a clad structure 1D (battery terminal component 1D) having one surface formed of a copper layer 21 made of substantially the same copper material as the negative electrode side component 2 and the other surface formed of an aluminum alloy layer 20b made of substantially the same aluminum alloy material as the connecting component 3. This facilitates electrical connection between the negative electrode side component 2 and the copper layer 21 and between the connecting component 3 and the aluminum alloy layer 20b, and also sufficiently increases the bonding strength of both connections. In Configuration Example 1, a pure aluminum layer 20a is present between the aluminum alloy layer 20b and the copper layer 21. However, pure aluminum generally has better electrical conductivity than aluminum alloy materials. Therefore, the pure aluminum layer 20a does not impair the electrical conductivity of the clad structure 1D (battery terminal component 1D).

[0089] <Configuration example 2> As Configuration Example 2, FIG. 13 shows a terminal connection structure on the negative electrode side of a battery using the clad structure 1B shown in FIG. 2 as a battery terminal component. The negative electrode side component 2 shown in Configuration Example 2 is plate-shaped with a through-hole, and the battery terminal component 1B is inserted into the through-hole. This insertion structure can be made into a loose fit or a clearance fit by providing a seal 4 between the negative electrode side component 2 and the flange portion 11 of the clad structure 1B (battery terminal component 1B). Also, Configuration Example 2 employs a crimping structure in which the first leg portion 12 of the clad structure 1B (battery terminal component 1B) is bent outward. This crimping structure sandwiches and stably fixes the negative electrode side component 2 between the first leg portion 12 and the flange portion 11. In this case, the negative electrode side component 2 and the first leg portion 12 are preferably joined by laser welding or the like.

[0090] On the other hand, the connection part 3 is joined to the flange upper surface 11a of the flange portion 11 of the clad structure 1D (battery terminal part 1D) by laser welding, ultrasonic welding, or the like. The connection part 3 is a conductive part used outside the battery. The connection part 3 is a conductive part such as a bus bar for electrically connecting to other batteries, and can electrically connect multiple batteries to form a battery pack. The connection part 3 is generally made of copper, nickel, pure aluminum, or aluminum alloy material, but in recent years, aluminum material has been preferred for its weight reduction and other reasons. Furthermore, aluminum alloy material is preferred for its strength in addition to its weight reduction.

[0091] When electrically connecting a negative electrode side component 2 made of copper and a connecting component 3 made of aluminum (particularly aluminum alloy material) as in Configuration Example 2, it is preferable to use a clad structure 1B (battery terminal component 1B) having one surface formed of a copper layer 21 made of substantially the same copper material as the negative electrode side component 2 and the other surface formed of an aluminum alloy layer 20b made of substantially the same aluminum alloy material as the connecting component 3. This facilitates both the electrical connection between the negative electrode side component 2 and the copper layer 21 and the electrical connection between the connecting component 3 and the aluminum alloy layer 20b, and also sufficiently increases the bonding strength of both connections. Note that in Configuration Example 2, for the same reasons as in Configuration Example 1, the pure aluminum layer 20a does not impair the conductivity of the clad structure 1B (battery terminal component 1B).

[0092] As described above, the battery terminal components 1D and 1B according to the present invention can electrically connect the negative electrode side component 2 and the connection component 3, even if the negative electrode side component 2 has a different shape or connection method, as in the above-described configuration examples 1 and 2. From this perspective, the battery terminal components 1D and 1B are expected to be put to practical use. Similarly, the battery terminal components 1A, 1C, 1E, and 1F are expected to be put to practical use. Therefore, the clad structure (battery terminal component) according to the present invention is expected to be put to practical use. [Explanation of symbols]

[0093] <Figures 1 to 6, 12, and 13> 1, 1A to 1F: Clad structure (battery terminal parts) 2: Negative electrode part 3: Connection parts 4: Sticker 10: Shaft part (first shaft part), 10a: Shaft outer surface, 10b: Shaft bottom surface, 10c: Shaft inner convex part 11: flange portion, 11a: flange upper surface, 11b: flange lower surface, 11c: flange outer surface 12: Leg (first leg), 12a: Bottom surface of the leg, 12b: Inner surface of the leg, 12c: Outer surface of the leg, 12d: Lower surface of the leg 13: Recess (first recess) 14: Shaft part (second shaft part), 14a: Shaft outer surface, 14b: Shaft top surface 15: Foot part (second foot part), 15a: Bottom surface of foot, 15b: Inner surface of foot, 15c: Outer surface of foot, 15d: Lower surface of foot 16: Recess (second recess) 20: Aluminum layer (Al layer), 20a: Pure aluminum layer (pure Al layer), 20b: Aluminum alloy layer (Al alloy layer) 21: Copper layer (Cu layer) CL: Center line of shaft part (axis) <Figure [8]> 100: Clad piece 120: Aluminum layer (Al layer), 120a: Pure aluminum layer (pure Al layer), 120b: Aluminum alloy layer (Al alloy layer) 121: Copper layer (Cu layer) <Figure [9]> 200F: First formed body 210: Shaft part (first shaft part), 210a: Outer surface of shaft, 210b: Lower surface of shaft, 210c: Inner convex part of shaft 211: Flange part, 211a: Upper surface of flange, 211b: Lower surface of flange, 211c: Outer surface of flange 214: Shaft part (second shaft part), 214a: Outer surface of shaft, 214b: Upper surface of shaft 220: Aluminum layer (Al layer), 220a: Pure aluminum layer (pure Al layer), 220b: Aluminum alloy layer (Al alloy layer) 221: Copper layer (Cu layer) CL: Center line of shaft part (axis) <Figure

[10] > 300F: Second formed body 310: Shaft part (first shaft part), 310a: Outer surface of shaft, 310b: Lower surface of shaft, 310c: Inner convex part of shaft 311: Flange part, 311a: Upper surface of flange, 311b: Lower surface of flange, 311c: Outer surface of flange 312: Foot part (first foot part), 312a: Bottom surface of foot, 312b: Inner surface of foot, 312c: Outer surface of foot, 312d: Lower surface of foot 313: Recess (first recess) 314: Shaft part (second shaft part), 314a: Outer surface of shaft, 314b: Upper surface of shaft 315: Foot part (second foot part), 315a: Bottom surface of foot, 315b: Inner surface of foot, 315c: Outer surface of foot, 315d: Lower surface of foot 316: Recess (second recess) 320: aluminum layer (Al layer), 320a: pure aluminum layer (pure Al layer), 320b: aluminum alloy layer (Al alloy layer) 321: Copper layer (Cu layer) CL: Center line of shaft (shaft center) <Figure 11> 400F: Third molding 410: Shaft part (first shaft part), 410a: Shaft outer surface, 410b: Shaft lower surface, 410c: Shaft inner convex part 411: flange portion, 411a: flange upper surface, 411b: flange lower surface, 411c: flange outer surface 412: Leg part (first leg part), 412a: Leg bottom surface, 412b: Leg inner surface, 412c: Leg outer surface, 412d: Leg lower surface 413: Recess (first recess) 414: Shaft part (second shaft part), 414a: Shaft outer surface, 414b: Shaft top surface 415: Leg part (second leg part), 415a: Leg bottom surface, 415b: Leg inner surface, 415c: Leg outer surface, 415d: ​​Leg lower surface 416: Recess (second recess) 420: aluminum layer (Al layer), 420a: pure aluminum layer (pure Al layer), 420b: aluminum alloy layer (Al alloy layer) 421: Copper layer (Cu layer) CL: Center line of shaft (shaft center)

Claims

1. a first shank portion having a downwardly extending first shank outer surface and a downwardly extending end first shank lower surface; a flange portion including an upper flange surface and a lower flange surface extending in a radial direction perpendicular to the first shaft portion from an upper end of the first shaft portion, and outer flange surfaces at ends extending in the radial direction of the upper flange surface and the lower flange surface, a first surface made of an aluminum alloy material extending from the flange outer surface to the flange upper surface; a second surface made of copper material extends from the flange outer surface to the flange lower surface, the first shaft outer surface, and the first shaft lower surface; The clad structure has an aluminum material containing 99% by mass or more of Al present between the aluminum alloy material and the copper material.

2. The first shaft portion; The flange portion; a first leg portion including: a first leg inner surface and a first leg outer surface extending downward from an outer edge of the first leg bottom surface, the first shaft lower surface being a first leg bottom surface; and a first leg lower surface at an end extending downward from the first leg inner surface and the first leg outer surface; a first recess defined by the first leg bottom surface and the first leg inner surface; a first surface made of an aluminum alloy material extending from the flange outer surface to the flange upper surface; The clad structure of claim 1, wherein a second surface made of copper material extends from the flange outer surface to the flange undersurface, the first axis outer surface, the first leg outer surface, the first leg undersurface, the first leg inner surface, and the first leg bottom surface.

3. The first shaft portion; The flange portion; a second shank portion having an upwardly extending second outer shank surface and an upwardly extending end second upper shank surface; a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, and the second shaft upper surface; The clad structure of claim 1, wherein a second surface made of copper material extends from the flange outer surface to the flange undersurface, the first axis outer surface, the first leg outer surface, the first leg undersurface, the first leg inner surface, and the first leg bottom surface.

4. The first shaft portion; The flange portion; The second shaft portion; a first leg portion including a first leg bottom surface at a central portion of the first shaft bottom surface, a first leg inner surface and a first leg outer surface extending downward from an outer edge of the first leg bottom surface, and a first leg lower surface at an end extending downward from the first leg inner surface and the first leg outer surface; a first recess defined by the first leg bottom surface and the first leg inner surface; a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, and the second shaft upper surface; The clad structure of claim 3, wherein a second surface made of copper material extends from the flange outer surface to the flange undersurface, the first axis outer surface, the first leg outer surface, the first leg undersurface, the first leg inner surface, and the first leg bottom surface.

5. The first shaft portion; The flange portion; The second shaft portion; a second leg portion including a second leg bottom surface at a central portion of the second shaft upper surface, a second leg inner surface and a second leg outer surface extending upward from an outer edge of the second leg bottom surface, and a second leg upper surface at an end extending upward from the second leg inner surface and the second leg outer surface; a second recess defined by the second leg bottom surface and the second leg inner surface; a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, the second leg outer surface, the second leg upper surface, the second leg inner surface, and the second leg bottom surface; 4. The cladding structure of claim 3, wherein a second surface made of copper material extends from the collar outer surface to the collar undersurface, the first off-axis surface, and the first leg undersurface.

6. The first shaft portion; The flange portion; The second shaft portion; The first leg portion; the first recess; a second leg portion including a second leg bottom surface at a central portion of the second shaft upper surface, a second leg inner surface and a second leg outer surface extending upward from an outer edge of the second leg bottom surface, and a second leg upper surface at an end extending upward from the second leg inner surface and the second leg outer surface; a second recess defined by the second leg bottom surface and the second leg inner surface; a first surface made of an aluminum alloy material extends from the flange outer surface to the flange upper surface, the second shaft outer surface, the second leg outer surface, the second leg upper surface, the second leg inner surface, and the second leg bottom surface; The clad structure of claim 4, wherein a second surface made of copper material extends from the flange outer surface to the flange undersurface, the first axis outer surface, the first leg outer surface, the first leg outer surface, the first leg undersurface, the first leg inner surface, and the first leg bottom surface.

7. A clad structure according to any one of claims 1 to 6, wherein the outer flange surface of the flange portion has a boundary between the first surface continuing from the upper flange surface and the second surface continuing from the lower flange surface.

8. A terminal part for a battery, which is constructed using the clad structure according to any one of claims 1 to 6.

9. The battery terminal part according to claim 8 , wherein the flange outer surface of the flange portion has a boundary between the first surface continuing from the flange upper surface and the second surface continuing from the flange lower surface.

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