WO2004020191A1

WO2004020191A1 - Aluminum/nickel clad material and method for manufacture thereof, and exterior terminal for electric cell

Info

Publication number: WO2004020191A1
Application number: PCT/JP2003/010999
Authority: WO
Inventors: Kazuhiro Shiomi; Masaaki Ishio; Kenichi Funamoto
Original assignee: Sumitomo Special Metals C0., Ltd.
Priority date: 2002-08-29
Filing date: 2003-08-28
Publication date: 2004-03-11
Also published as: KR101012530B1; KR20050058991A; AU2003257586A1; CN100398312C; CN1556751A

Abstract

An aluminum/nickel clad material (1) which comprises an aluminum layer (3) formed with pure aluminum and a nickel layer (2) formed with pure nickel being joined with each other by diffusion joining, wherein the nickel layer (2) has a hardness of Hv = 130 to 170; and the aluminum/nickel clad material (1), wherein the aluminum layer (3) and the nickel layer (2) are joined by diffusion joining via an Al - Ni based intermetallic compound layer having a thickness of 0.4 to 10.0 μm, preferably 1.0 to 6.0 μm. The latter clad material exhibits excellent peel strength. The aluminum/nickel clad material exhibits stable welding joinability towards an aluminum material even when ultrasonic welding is applied to it and is less prone to occurrence of failures in shape even when it is subjected to bending working, and thus is suitably used as a material for an exterior terminal for an electric cell.

Description

Description Aluminum Z nickel clad material, method for producing the same, and external terminal for battery

TECHNICAL FIELD The present invention relates to an external terminal joined to a battery outer can and an aluminum Z nickel clad material that can be suitably used as a material thereof. Background art

Small electronic devices such as mobile phones and notebook PCs ■ Small batteries are installed in electrical equipment. Some of these small batteries have an outer can made of pure aluminum. Electricity generated by the battery is supplied to various electronic components via an external terminal attached to the pure aluminum outer can and a conductive member joined thereto. The conductive member is usually formed of pure nickel having excellent corrosion resistance and durability.

The external terminal has a rectangular shape with a width of about 3 mnu and a length of about 20 m. As described in Japanese Unexamined Patent Application Publication No. 2001-6746, the external terminals are designed to take into consideration the connection with an outer can made of pure aluminum and a conductive member made of pure nickel. Then, there is an aluminum / nickel cladding material in which an aluminum layer formed of pure aluminum and a nickel layer formed of pure nickel are joined.

Conventionally, in this aluminum / nickel clad material, a nickel sheet formed of pure nickel and an aluminum sheet formed of pure aluminum are laminated, and the laminated sheet is passed through a pair of rolls. After cold-welding, the sheet is subjected to diffusion annealing, It is manufactured by diffusion bonding of a nickel layer and a nickel layer. The rolling reduction in cold pressure welding is set to about 60% or more so that the sheets can be joined so that they cannot be peeled off in a later step. It is also believed that high-temperature diffusion annealing generates a vulnerable AI-Ni-based intermetallic compound at the interface between the aluminum and nickel layers, degrading the peel strength between the aluminum and nickel layers. . For this reason, diffusion annealing is usually carried out by holding at a low annealing temperature of about 400 ° C. or less for a short time so that the intermetallic compound is not generated. The external terminal for the battery is usually obtained by slitting the aluminum / nickel clad material into a strip having the same width as the required external terminal width along the length direction. It is manufactured by further cutting to the required length.

Conventionally, the external terminal has been joined to a battery outer can by spot welding (resistance welding). At the spot weld, the aluminum and nickel of the clad material are melted and solidified to form an intermetallic compound, which increases the electrical resistance at the weld and reduces the efficiency of the battery. For this reason, in recent years, external terminals have been joined by ultrasonic welding. In ultrasonic welding, since the aluminum layer is pressed against the battery outer can without melting the welded portion, no intermetallic compound is generated, and a decrease in battery efficiency can be prevented.

However, by the conventional cold welding ·? When ultrasonic welding is performed using an external battery terminal made of aluminum / nickel clad material that has been joined by welding, there is a problem that the joining strength varies greatly and the joining properties are unstable.

In recent years, external terminals of various bending shapes such as a Z-shape have been required. When such external terminals are made of a conventional cladding material, a large springback is required during bending. There is a problem that the shape is easily generated and the shape defect is easily generated.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and as a material for a battery external terminal, which is capable of obtaining stable weld bonding even when ultrasonic welding is applied, and hardly causing a shape defect even when subjected to bending, as a material thereof. It is an object of the present invention to provide a suitable aluminum / nickel clad material and a method for producing the same. Disclosure of the invention

The inventors of the present invention have found that when ultrasonic welding is performed using external terminals for a battery made of a conventional aluminum / nickel clad material, the bondability becomes unstable. After a thorough investigation into the causes of failure, the team found that the nickel layer of the aluminum / nickel clad was too hard. Conventionally, it has been thought that the peel strength between the aluminum layer and the nickel layer is degraded if an Al-N 系 -based intermetallic compound is formed at the interface between the aluminum layer and the nickel layer during diffusion annealing. However, it has been found that the peel strength is rather improved in the region where the thickness of the AI—Ni-based intermetallic compound layer is particularly small. The present invention has been made based on such findings. That is, the aluminum / nickel clad material of the present invention comprises an aluminum layer formed of pure aluminum having an aluminum purity of 98 mass% or more, and a pure nickel having a nickel purity of 98 mass% or more. The formed nickel layer is diffusion-bonded, and the hardness of the nickel layer is set to HVΊ30 to 170. The thickness of the aluminum layer is preferably 25 to Ί100 m, and the thickness of the nickel layer is preferably 50 to 200 μm.

According to this aluminum / nickel clad material, the hardness of the nickel layer is HV130 to 170, and the nickel layer is not excessively hard. During the wave welding, the ultrasonic vibration is quickly transmitted from the ultrasonic vibration output end (horn tip) to the aluminum layer through the nickel layer, so that stable weldability can be obtained. In addition, since no excessive springback occurs, good moldability can be obtained. On the other hand, since the nickel layer is not excessively soft, projections (burrs) are less likely to occur on the sheared edge of the work piece when a work piece such as a battery external terminal or its material is obtained by shearing the clad material. If there is a burr, the work piece does not adhere to the welding partner, making it difficult to transmit ultrasonic vibration. In the clad material, since the burrs are not easily generated on the work piece, the ultrasonic vibration is quickly transmitted, and good ultrasonic weldability is obtained.

In the aluminum Z nickel clad material, the aluminum layer and the nickel layer have an Al—Ν-based metal having a thickness of 0.4 to 10. O Atm, preferably 1.0 to 6. It is desirable to perform diffusion bonding via an inter-compound layer. The AI—Ni-based intermetallic compound itself is brittle, but no brittleness appears in the area near the boundary between the nickel layer or aluminum layer and the intermetallic compound layer. Good bonding with the compound layer. When the thickness of the intermetallic compound layer is about 0.4 to 10. Ημηι, the brittleness of the intermetallic compound layer itself hardly appears, so that the bonding property between the aluminum layer and the nickel layer is relatively good. is there. Further, by setting the thickness of the intermetallic compound layer to be 1.0 to 6.0 m, particularly excellent bonding properties can be obtained. For this reason, even if the clad material or its work piece is subjected to severe forming processing, the aluminum layer and the nickel layer are not easily separated from each other, and excellent forming workability can be obtained.

The aluminum / nickel clad material is suitable as a material for the battery external terminal, and the aluminum / nickel clad material is subjected to shearing such as cutting or punching with a shear to easily manufacture the battery external terminal. can do. The aluminum / nickel clad material is obtained by heating a nickel sheet formed of pure nickel having a nickel purity of 98 mass% or more to 100 to 300 ° C., and heating the heated nickel sheet and the aluminum sheet. The aluminum sheet made of pure aluminum with a purity of 98 mass% or more is overlapped and pressed at a rolling reduction of 10 to 17%, and then the obtained pressed sheet is easily annealed by diffusion annealing. Can be manufactured. The diffusion annealing is preferably performed in a temperature range of 500 to 600 ° C.

As described above, according to the aluminum / nickel clad material of the present invention, since the nickel layer is adjusted to have a hardness of HV130 to 170, stable welding can be performed during ultrasonic welding. Bondability is obtained, excessive springback is suppressed, and bending workability is excellent. Therefore, it is suitable as a material for external terminals for batteries and the like. Further, according to the production method of the present invention, an aluminum Z nickel clad material provided with a nickel layer having a predetermined hardness can be easily produced without requiring special equipment. BRIEF DESCRIPTION OF THE FIGURES

Japan is a schematic sectional view of the aluminum / nickel clad material according to the present invention.

FIG. 2 is an explanatory view of the procedure for measuring the bonding strength of the pressure-welded sheet and the peel strength of the clad sheet after diffusion annealing.

Figure 3 is an explanatory diagram of the bending test procedure for aluminum / nickel clad specimens.

FIG. 4 is an explanatory diagram of a 180 ° bending test procedure of an aluminum / nickel clad material test piece. BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 2, the aluminum / nickel clad material 1 according to the embodiment of the present invention has an aluminum layer 3 and a nickel layer 2 pressed together and diffusion-bonded. The hardness of the nickel layer 2 is assumed to be HVI 3 to 170.

The aluminum layer 3 and the nickel layer 2 are made of pure aluminum and pure nickel, respectively. Although the purity of aluminum and nickel is preferably as high as possible, the present invention allows impurities up to about 2 mass%, and the purity of aluminum and nickel is 98 mass% or more, preferably 9.9 mass% or more, and more preferably 9 mass% or more. 9.9 mass% or more is preferably used.

The hardness of the nickel layer 2 is important in the present invention, and is set to ビ νΐ30 to Ί70 in Vickers hardness. The hardness of the nickel layer 2 has a great effect on the ultrasonic weldability, formability, etc. では When it exceeds V170, the shape defect due to the springback during forming tends to be excessive, and the ultrasonic melting Ultrasonic waves are difficult to transmit from the nickel layer 2 to the aluminum layer 3 at the time of contact, and the welding between the aluminum layer 3 and the battery outer can becomes unstable, so that stable weldability cannot be obtained. . On the other hand, if it is less than Hvl30, the strength is reduced, and large burrs are generated at the end of the cut surface when shearing a slit or the like. When burrs are formed on the outer peripheral edge of the external terminal, a gap is formed between the outer case of the battery and the ultrasonic vibration output end of the ultrasonic welding device, and it is difficult to adhere to the terminal. It may cause poor welding. Therefore, in the present invention, the hardness of the nickel layer 2 is set to Hv 30 to 170, preferably Hv 140 to 160.

The aluminum layer and the nickel layer are diffusion-bonded by diffusion annealing. Along with this diffusion bonding, an AI-Ν 間 intermetallic compound may be generated at the bonding interface. AI — Ν 間 Intermetallic compounds themselves are fragile However, it has been considered that the peel strength between the aluminum layer and the nickel layer is reduced. However, it was found that in the region where the thickness of the AI-Ni-based intermetallic compound layer formed at the interface between the aluminum layer and the nickel layer was extremely thin, the bonding strength did not decrease, but rather improved in some cases. When the thickness of the intermetallic compound layer is about 0.4 to 10.0 tm, the peel strength is practically satisfactory. Particularly, by setting the thickness of the intermetallic compound layer to about 1.0 to 6.0 m, the peel strength becomes extremely high, It can be applied sufficiently.

The thickness of the aluminum layer 3 is preferably from 25 to 100 °. If the aluminum layer 3 is too thin, it will be difficult to press the nickel layer 2 in the manufacturing process, while if it is too thick, it will be difficult to ultrasonically weld it to the battery outer can. For this reason, it is preferably from 25 to 100 / ttm, and more preferably from about 30 to 70 Atm. The thickness of the nickel layer 2 is preferably 50 tm or more in order to ensure ultrasonic weldability and durability, but if it is too thick, it will only increase the cost, so it is less than 200 μm. Preferably, it is 150 m or less.

Next, a method of manufacturing the aluminum Z nickel clad material of the embodiment will be described.

The aluminum / nickel clad material is prepared by preparing an aluminum sheet formed of pure aluminum and a nickel sheet formed of pure nickel, and heating the nickel sheet to 100 to 300 ° C. The heated nickel sheet is superimposed on the aluminum sheet, and roll-pressed at a rolling reduction of 10 to 17% through a gap between the pair of rolls, whereby the obtained aluminum layer and nickel layer are bonded. Manufactured by diffusion annealing the welded sheet. The rolling reduction (%) is , (Thickness reduced by reduction) / (original total thickness) By heating the nickel sheet, calculated by XI 00, to 100-300 ° C, 10-17 %, It is possible to obtain a pressure-welded sheet having a sufficient bonding strength of about 2 N / mm or more. If the heating temperature of the nickel sheet is lower than 100 ° C., the bonding strength with the aluminum sheet is insufficient even if the roll is pressed at a rolling reduction of 17%, which may cause peeling in a process after the pressure welding. On the other hand, when the temperature exceeds 300 ° C., the lubrication of the roll at the time of pressing becomes severe, which causes poor lubrication and makes the pressing difficult. For this reason, the heating temperature of the nickel sheet is set to 100 to 300 ° C., preferably 150 to 250 ° C. After the nickel sheet is heated to a predetermined temperature, it is desirable that the roll be pressed as quickly as possible, and that the sheet be pressed against the aluminum sheet within 5 seconds, preferably 3 seconds after heating. Recommended.

On the other hand, aluminum sheets do not need to be heated in principle and can be left at room temperature. Even if it is heated, it is preferable to keep it at 200 ° C. or less. Since the rolling reduction in roll welding uses a low rolling reduction, the thickness of the aluminum sheet before rolling is necessarily reduced. For example, if the thickness of the aluminum layer of the cladding material is 25 to 1 OO Atm, the thickness of the aluminum sheet is 28 to 1111 Atm. When using aluminum sheet with a thickness of about 25 to 120 μηι, the aluminum sheet is heated to more than 200 ° C when the aluminum sheet is welded by pressure. The sheet will not be able to withstand the tension applied to the sheet due to the tension applied to the sheet during roll welding, causing problems such as partial elongation and breakage in severe cases. Occurs.

As described above, the rolling reduction in the roll pressing needs to be in a very narrow range of 10 to 17%. At less than 5%, heat nickel to 300 ° C. In this state, the bonding strength between the aluminum sheet and the nickel sheet is about 2 N / mm or less, and sufficient bonding strength cannot be obtained, which may cause peeling. Also, if it is 5% or more and less than 10%, burrs become high and ultrasonic weldability decreases. On the other hand, when the nickel sheet is reduced by more than 17%, the hardness after the reduction exceeds HV170 even when the nickel sheet is heated to 300 ° C, and the formability and ultrasonic weldability are reduced. Problems arise. Therefore, the rolling reduction is set to 10 to 17%, preferably to 1 to 5%.

The pressure-welded sheet joined by roll pressure welding becomes a clad material by diffusion bonding of the aluminum layer and the nickel layer by diffusion annealing. The peel strength between the aluminum layer and the nickel layer in the clad material varies depending on the diffusion annealing conditions, but the peel strength of the clad material is practically required to be about 4.0 mm2 or more. In particular, when the clad material is subjected to severe processing, it is preferable to have a sufficient peel strength of about 8.0 N / mm or more, more preferably about 10 O N / mm or more. In order to obtain sufficient peel strength in a relatively short time, it is preferable to perform diffusion annealing at a temperature of 500 to 600 ° C. Diffusion annealing can be performed even at 400 to 450 ° C, but in order to obtain sufficient peel strength, the annealing time is required to be 1 hr or more, and the productivity is significantly reduced. On the other hand, sufficient annealing strength can be obtained in a relatively short time of about 3 to 20 min at 500 ° C. and about 1 to 5 min at 600 ° C. The hardness of the nickel layer tends to decrease slightly due to diffusion annealing, but the degree increases as the annealing temperature increases and the annealing time increases.

The bonding strength of the pressure-welded sheet and the peel strength of the same sheet (cladding sheet) after diffusion annealing are measured in the following manner. As shown in Fig. 2, the aluminum layer 13 and the nickel layer 12 were partially peeled off at the end of the test piece 11 taken from the insulation displacement sheet, and the peeled part was bent vertically, Pull the end of the plate with a tensile tester to determine the peeling force required to peel it off. Divide the value by the width of the test piece to determine the peeling force per unit width as the bonding strength. In the case of a clad sheet in which the aluminum layer and the nickel layer are diffusion-bonded by diffusion annealing, it is difficult to peel off each layer at the end of the test piece. After peeling in advance, and after diffusion annealing, the peeled part peeled off in advance is bent vertically, and the peeling force per unit width is calculated in the same manner as above, and this is defined as the peel strength.

The aluminum Z nickel clad material manufactured as described above is slit into an appropriate width, for example, a strip having the same width as the width of the external terminal. For external terminals, the strip slit to the terminal width is sheared to the required external terminal length, or the strip stripped to a width wider than the terminal width is punched. Produced by Further, the plate-shaped workpiece processed in such a manner is subjected to a forming process such as a bending process as required, and is processed into an intended shape.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not construed as being limited to such Examples. Example

Various samples of the cladding material were manufactured in the following manner.

Nickel sheet with a width of 60 mm and a thickness of 50 Atm, nickel nickel (nickel purity of 99.9% or more) and pure aluminum of the same width and thickness of 50 ym (aluminum purity of 99 9% or more) aluminum sheet was prepared. After heating the nickel sheet in a tunnel furnace, the aluminum sheet was overlapped with the aluminum sheet within about 2 seconds after exiting the tunnel furnace, and passed through a pair of reduction rolls. Heating temperature of nickel sheet of each sample, Table 2 shows the rolling reduction at this time.

A test piece with a width of 100 mm and a length of 100 mm was sampled from a pressure-welded sheet where the aluminum layer and the nickel layer were pressed by roll pressing, and the bonding strength between the aluminum layer and the nickel layer was described above. Measured according to the measurement procedure. The bonding strength needs to be about 2 N / mm or more to process the subsequent steps without any problem.

Next, the pressure-welded sheet was subjected to diffusion annealing under the annealing conditions shown in the same table to obtain a clad material in which the aluminum layer and the nickel layer were diffusion-bonded. The peel strength of this clad material and the hardness of the nickel layer were measured. The peel strength was measured according to the measurement procedure described above using a test piece with a width of about 0 mm and a length of 100 mm, and the hardness was 0.2 kgf (1.96 N) with a Pikkas hardness tester. The load was applied and measured.

Also, a cross-sectional observation specimen was collected from the clad material, and the average thickness of the AI—Ni intermetallic compound layer formed between the aluminum layer and the nickel layer of the clad material was determined as follows. It was measured. The cross-section observation test piece is embedded in a synthetic resin so that a cross section (plate thickness cross section) along the thickness direction is set as an observation surface, and the embedded test piece is polished so that the thickness cross section is exposed. (Scanning electron microscope) The cross section was observed at 400 × magnification. The measurement results are also shown in Table 1. The observed intermetallic compound layer was subjected to elemental analysis by EPMA, and it was confirmed that the layer was formed by an AI-Ni-based intermetallic compound.

Further, the clad material was supplied and slit all at once so that the nickel layer was on the lower side, and a strip having a width of 3 mm was obtained. The slitter has a plurality of cutting portions each including a pair of upper and lower rotary blades, and the rotary blades cut the clad material by rotating and approaching each other so as to cross each other. Therefore, one of the cut surfaces of the cut strip is made of nickel. Burrs were formed at the lower end of the layer, and burrs were formed at the upper end of the aluminum layer on the other cut surface. The height (tm) of burrs formed at the ends of the nickel layer and the aluminum layer was measured by a surface roughness meter. If the burr height exceeds 1Ομηι, ultrasonic weldability will be adversely affected. Therefore, the glue height shall be 10 m or less.

The aluminum / nickel clad strip thus obtained was sheared to a length of 20 mm to obtain a welded test piece. The aluminum layer side surface of the welded specimen was brought into contact with a 0.5 mm pure aluminum plate (5 mm wide × 30 mm long), and the center in the width direction was ultrasonically welded. The welding conditions are as follows.

Ultrasonic welding machine: manufactured by Ultrasonic Industry Co., Ltd., Model U SW-2410Z15S Pressing force: 200N

Application time: 0.3 seconds

Peak power: 250 W

Energy: 6 3 J

After ultrasonic welding, the joining strength of the weld was measured. As shown in Fig. 3, the measurement procedure was as follows: the welded test piece 21 and the pure aluminum plate 22 after welding were each bent perpendicularly at the end of the welded portion W into a U-shape, the ends were pulled, and the joint was peeled off. The tensile strength required to make the joint work was measured as the joining force. Five such measurements were performed for each sample, and the difference ΔF between the maximum value and the minimum value of the bonding force was determined. It is important that stable welded joints are obtained at the joints.If the above value exceeds 0.5 kgf (4.9 N), the joining stability of ultrasonic welding becomes a problem. F≤4 · 9 N is accepted.

Further, a bending test piece S having a length of 50 mm was sampled from the strip, and a stiffness tester (manufactured by PCA, model 719 type) was used to make it easy to observe the springback. Opening angle 60 ° (bending radius of bending part 0.3 8 mm), and the open angle of the V-shaped part of the test specimen was measured at 0 ° to determine the amount of springback Δ 0 = 0 — 60. When the above exceeds 20 °, the bending accuracy is remarkably deteriorated when performing the bending process in which the angle formed by the two sides adjacent to each other is bent to 90 °, so that the bending workability is Δ Θ ≤ 20 °. Is passed. Table 1 shows the measurement results.

Using the bending test piece S, a 180 ° bending test was performed in the following manner. As shown in Fig. 4, the test piece S was folded 180 ° around the center in the longitudinal direction so that the aluminum layer was on the inside, and then returned to the original state. The state of occurrence of local peeling between the metal and the nickel layer was visually observed. The observation results are shown in Table 1 as もの when no local peeling occurred, Α when slight local peeling occurred, and を when clear local peeling occurred.

Table 1 shows that the examples (sample Nos. 4 to 6, 10 to 13, 15 to 19, 21 and 22) in which the hardness of the nickel layer is Hvl 30 to 170 are ultrasonic. It can be seen that the weldability and bending workability are good. On the other hand, for sample Nos., Ί, 7, 8, and 23 in which the hardness of the nickel layer exceeds Hvl 70, there are problems with both ultrasonic weldability and bending workability. Also, since the rolling reduction is low, in Sample No. 3 in which the hardness of the nickel layer is νν120, the burr height on the aluminum layer side exceeds 10 μηι, and the weldability is reduced. In Samples Nos. 2 and 9, the reduction rate or the heating temperature of the nickel sheet was unsuitable, and the peel strength of the pressure-welded sheet was too low. The nickel layer and the aluminum layer peeled during handling, causing diffusion annealing. Could not be performed. Sample No. 14 could not be press-welded because the heating temperature of the nickel shell was too high and the lubrication was poor.

— Example, AI — Examples in which the average thickness of the Ni-based intermetallic compound layer is Ί0.0 to 6.0 Atm (Sample Nos. 4 to 6, 10 to Ί3, 15, 15, 18, 2 In 1), excellent diffusion bondability was obtained with a peel strength of 8 N / mm or more after diffusion annealing. Sample Nos. 17 and 9.8 with an average thickness of 0.4 μηι and 17 and 9.8 m had slightly lower peel strengths of about 5 Nzmm, but the 180 ° bending test In this case, local peeling was slight, and the moldability was satisfactory without practical problems. On the other hand, in sample No. 16 in which the intermetallic compound layer was not formed and in sample No. 22 having an excessive thickness, the ultrasonic weldability and bending workability were good, but the peel strength was low. Then, the degree of local peeling is large. For this reason, the cladding materials of these samples are not well suited for applications where severe forming is performed. Since the annealing time of Sample No. 20 was too long at the annealing temperature of 550 ° C, the generation of intermetallic compounds was excessive and the measurement of peel strength was impossible. Sample No. 23 corresponds to the conventional cladding material, and has a high rolling reduction at the time of pressure welding, so that it can be peeled well even at a diffusion annealing temperature of 350 ° C. Although strength was obtained, the ultrasonic weldability and bending workability deteriorated significantly due to the high hardness of the nickel layer.

Claims

The scope of the claims

1. An aluminum / nickel alloy formed by diffusion bonding an aluminum layer made of pure aluminum with an aluminum purity of 98 mass% or more and a nickel layer made of pure nickel with a nickel purity of 98 mass% or more. With lad wood,

An aluminum / nickeloleclad material wherein the nickel layer has a hardness of Hv130 to 170.

2. The aluminum / nickel according to claim 1, wherein the aluminum layer and the nickel layer are diffusion-bonded via an AI—Ni-based intermetallic compound layer having a thickness of 0.4 to 10 · O Atm. Clad wood.

3. The aluminum / nickel cladding according to claim 1, wherein the aluminum layer and the nickel layer are diffusion-bonded via an AI—Nί intermetallic compound layer having a thickness of 1.0 to 6. O tm. Wood.

4. The aluminum // nickel clad material according to claim 1, wherein the aluminum layer has a thickness of 25 to 10Ομηι.

5. The aluminum Z nickel clad material according to claim 2, wherein the aluminum layer has a thickness of 25 to 10 O / m.

6. The aluminum Z nickel clad material according to claim 3, wherein the aluminum layer has a thickness of 25 to 100 tm.

7. The aluminum / nickel clad material according to claim 4, wherein the nickel layer has a thickness of 50 to 200 at ni.

8. The aluminum Z nickel clad material according to claim 5, wherein the nickel layer has a thickness of 50 to 200 Atm.

9. The aluminum / nickel clad material according to claim 6, wherein the nickel layer has a thickness of 50 to 200 Atm.

1 0. The aluminum / nickel clad material according to claim 1. External terminals for the battery.

11. An external battery terminal formed of the aluminum nickel nickel clad material according to claim 2.

1 2. An external battery terminal formed of the aluminum nickel clad material according to claim 3.

1 3. External terminals for batteries formed of the aluminum Z nickel clad material according to claim 7.

1 4. Battery external terminals formed from the aluminum / nickel clad material according to claim 8.

1 5. An external battery terminal formed of the aluminum / nickel clad material according to claim 9.

1 6. A heating step of heating a nickel sheet formed of pure nickel having a nickel purity of 98 mass% or more to 100 to 300 ° C, and the purity of the heated nickel sheet and aluminum An aluminum sheet formed of 98 mass% or more pure aluminum is overlapped and pressed at a rolling reduction of 10 to 17% to obtain a pressed sheet, and diffusion annealing of the pressed sheet is performed. A method for producing an aluminum / nickel clad material having a diffusion annealing step.

17. The method for producing an aluminum / nickel clad material according to claim 16, wherein the diffusion annealing is performed in a temperature range of 500 to 600 ° C.