JP2001126704A - Lead for cell, and cell pack or grouping cell using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light weight lead for a cell of a low electrical resistance and high reliability. SOLUTION: A lead for a cell comprises a lead body form from a rectangular shape aluminum or aluminum alloy and a connector form from a metal other than aluminum or aluminum alloy at one or both of ends of the lead body, with the connector, the cell or other parts are bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-weight, low-resistance battery lead and a battery pack or a group battery using the same.

[0002]

2. Description of the Related Art In recent years, portable electronic devices have increased, and there is a demand for a lighter and smaller battery pack as a power supply.
Conventionally, lead batteries, nickel cadmium batteries, and nickel hydrogen batteries have been the mainstream as secondary batteries, but recently,
2. Description of the Related Art Small and lightweight lithium-ion batteries are widely used as power sources for mobile phones. However, there is a strong demand for further reduction in the weight and size of the battery pack for the purpose of improving the convenience of the user.

For example, the structure of a battery pack for a portable telephone generally includes a cell, an electric circuit board having an electrical protection function (hereinafter referred to as a protection circuit board), a cell between the cell and the protection circuit board, or a cell. It comprises a metal lead (hereinafter simply referred to as a lead) for electrically connecting the battery and the unit cell, an input / output terminal, and a resin housing for housing these components.

[0004] The miniaturization and weight reduction of battery packs are being studied for each component. However, despite the strong demand for weight reduction of leads, due to restrictions in the battery pack assembly process, they are effective. Examination of means was not progressing. Note that miniaturization of the lead is not necessary because the volume occupying the battery pack is extremely small.

[0005] The battery pack is assembled by electrically connecting parts such as a unit cell and a protection circuit with a lead, and then housing the parts in a resin housing. In this case, the connection between the lead and the other parts is spot welding (electric resistance welding), which has little thermal effect on the cell and other parts and has remarkably good workability as compared with soldering or the like. It is generally done at

[0006] As a material for the lead, nickel is generally used which has good spot weldability and hardly causes welding defects. By connecting the components by spot welding using nickel leads, a low-cost and highly reliable battery pack was supplied.

[0007]

However, nickel is
From the viewpoint of the function of passing electricity, it is by no means the best material. In terms of conductivity, copper has better characteristics than nickel.However, copper leads have poor suitability for spot welding, and the strength of joints is weak or unstable. There was a problem with joining.

As another method of joining copper leads, there is soldering generally used for printed circuit boards of electric circuits. However, when soldering is used for assembling a battery pack, it can be compared with spot welding. As a result, the workability is greatly reduced and the manufacturing cost is increased, and there is a disadvantage that a thermal problem occurs. In addition, since components such as a single cell are attached after joining, it is difficult to enter a cleaning step, and there is also a disadvantage that solder balls may cause a failure.

[0009] Other than nickel, iron and stainless steel are known as materials having good spot weldability. However, since they are even lower in conductivity than nickel, they are rarely used as lead materials.

[0010] On the other hand, aluminum has lower conductivity than copper, and its spot welding suitability is as poor as copper.
In addition, since the surface is covered with a dense oxide film, it has no advantage as a lead material, such as having a high contact resistance. Therefore, it is hardly generally used as a lead material.

[0011] Therefore, there has been a demand for a battery lead which is lightweight, has low resistance and is excellent in reliability of spot welding with other parts in place of nickel.

[0012]

A battery lead according to the present invention comprises a strip-shaped lead body made of aluminum or an aluminum alloy, and a connecting body made of a metal other than aluminum or an aluminum alloy at one or both ends of the lead body. And bonding the connection body to a battery or other parts.

Further, according to the present invention, in the battery lead, the resistivity of the lead body is R1 (μΩ · cm), the volume ratio of the lead body to the whole lead is V1 (%), and the specific gravity of metal of the lead body is S1, the resistivity of the connection body is R2 (μ
Ω · cm), and the volume ratio of the connection body to the entire lead is V
2 (%), the specific gravity of the connector is S2, and when the coefficient α is represented by the following equation, the coefficient α <6.9.

Coefficient α = (R1 × V1 / 100 + R2 × V
2/100) × (S1 × V1 / 100 + S2 × V2 / 1
00) /8.9 Further, in the battery lead according to the present invention, the connection body is at least one selected from the group consisting of nickel, iron, and stainless steel.

Further, in the battery lead according to the present invention, when the lead body is made of aluminum and the connecting body is made of nickel, the volume ratio of aluminum to the entire lead is 1% or more. Is aluminum, and when the connection body is iron, the volume ratio of aluminum to the entire lead is 17% or more. When the lead body is aluminum and the connection body is stainless steel, the aluminum accounts for the entire lead. Is characterized by having a volume ratio of 76% or more,
When the lead body is made of aluminum alloy Aldry and the connection body is nickel, the volume ratio of Aldry to the entire lead is 1% or more.

Further, a battery pack or a group battery of the present invention is characterized by using the above-mentioned battery lead.

When an aluminum alloy is used as the material of the lead body, since the resistivity and the specific gravity vary depending on the type of the alloy, the appropriate volume ratio is determined by the coefficient α.
Can be calculated according to the characteristics of each alloy.

These leads have good spot welding suitability because the material of the connection body is nickel, iron or stainless steel. An object of the present invention is to provide a highly reliable lead structure for a battery lead or battery pack having high conductivity, small size, light weight, and good spot weldability.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Aluminum is known to have higher conductivity than copper and gold, although it is inferior in conductivity to copper, and to have a specific gravity much smaller than copper and nickel. ing.

For example, the resistivity (specific resistance: unit μΩ · cm) of aluminum is 1.72 for copper and 2.40 for gold.
After that, it is low at 2.82. Aldry, which is an aluminum alloy, also has a low property of 3.14.
The resistivity of nickel is as large as 6.9, four times that of copper, and about 2.4 times that of aluminum. The iron resistivity is 1
0.0 for stainless steel and 55.0 for SUS420.
The specific gravity of aluminum and Aldry is 2.7, which is only 30% of 8.9 of copper and nickel. The specific gravities of iron and stainless steel are 7.86 and 7.75, respectively.

From these facts, although aluminum has a problem that it is not suitable for spot welding, aluminum is an excellent material with respect to weight reduction and low resistance of the lead.

According to the present invention, there is provided a strip-shaped lead body made of aluminum or aluminum alloy, and a connecting body made of a metal other than aluminum or aluminum alloy at one or both ends of the lead body, wherein the connecting body and a battery or As a battery lead to be joined to another component, a battery lead having the lightness of aluminum or an aluminum alloy and the good spot weldability of aluminum or a metal other than aluminum can be obtained.

More importantly, the resistivity of copper is 1.
Since the coefficient α is 72 (μΩ · cm), the lead of the present invention is lighter and lower in resistance than the copper lead in a range where the coefficient α is smaller than 1.72. As a specific example, the following configuration is optimal.

When the lead body is made of aluminum and the connection body is made of nickel, the volume ratio of aluminum to the entire lead is 78% or more. When the lead body is made of aluminum and the connection body is made of iron, the volume ratio of aluminum to the entire lead is 82% or more. When the lead body is made of aluminum and the connection body is made of stainless steel, the volume ratio of aluminum to the entire lead is 96% or more. When the lead body is aluminum alloy Aldry and the connection body is nickel, the volume ratio of Aldry to the entire lead is 81% or more.

The connection body may be formed only at one end of the lead body made of aluminum or aluminum alloy, or may be formed at both ends, depending on the application.

As a material of the connection body made of a metal other than aluminum or an aluminum alloy, it is preferable to use a metal having good spot weldability such as nickel, iron and stainless steel.

Here, "good spot weldability" means that mechanical connection is reliably performed in spot welding and that the electric resistance of the spot welded portion is low.

Further, by appropriately controlling the volume composition ratio of the lead body made of aluminum or an aluminum alloy and the connecting body made of a metal other than aluminum or an aluminum alloy, the battery lead is appropriately controlled.
Electrical characteristics can be lighter and lower resistance than an ideal copper lead.

Next, the shape of the battery lead according to the present invention will be described. FIG. 1 shows an example of a battery lead according to the present invention. In FIG. 1, 1 is a lead body made of strip-shaped aluminum or aluminum alloy, and 2 and 3 are all other than strip-shaped aluminum or aluminum alloy. The connectors 2 and 3 are joined to a battery or other components.

FIG. 2 shows another example of a battery lead according to the present invention. In FIG. 2, reference numeral 4 denotes a strip-shaped lead body made of aluminum or aluminum alloy, and 5 and 6 denote strip-shaped leads. A connection body made of a metal other than aluminum or an aluminum alloy, the lead body 4 and the connection bodies 5 and 6 are partially joined and overlapped, and the connection bodies 5 and 6 join a battery or other parts. Is done.

FIG. 3 shows still another example of a battery lead according to the present invention. In FIG. 3, reference numeral 7 denotes a strip-shaped lead body made of aluminum or an aluminum alloy, and 8 and 9 denote strip-shaped leads. The lead body 7 and the connection bodies 8 and 9 are provided with through holes of the same size at the same position in the lead body 7 and the connection bodies 8 and 9 so that the battery lead can be connected to the battery and other parts It has a shape for joining with bolts and nuts.

The connection between the lead body made of aluminum or an aluminum alloy and the connection body made of a metal other than aluminum or an aluminum alloy can be made by a conventionally known method such as ultrasonic vibration, arc welding, laser welding, or coating by an arc buildup process. Can be performed in the following manner.

First, the relationship between the electrical resistance of the aluminum / nickel lead and the coefficient α will be described using a model in which the volume ratio between aluminum and nickel is changed. The lead for a model battery has a shape in which a lead body made of aluminum and a connection body made of nickel are provided at both ends of a lead body made of aluminum, as shown in FIG. Comparative products are conventional nickel leads and copper leads.

Here, in order to clarify the gist of the present invention, description will be made with the following shapes. Conventional nickel lead and copper lead models have a length of 1 cm and a cross-sectional area of 1 cm ² . That is, since the volume is 1 cm ³ , the weight of these leads is 8.9 g (in all cases, the specific gravity is 8.9).

The aluminum / nickel lead of the present invention is 1 cm long and weighs 8.9 g, the same as the nickel and copper leads. Therefore, as the content of aluminum increases, the weight per unit volume decreases, and the cross-sectional area increases. The characteristics of the aluminum / nickel lead of the present invention are shown in Table 1 by changing the volume ratio of aluminum.

In Table 1, lead type A is a nickel lead (conventional product), B is a copper lead (conventional product), and C is the aluminum / nickel lead of the present invention. The coefficient α indicates a resistance value when the weight and length are the same as those of the nickel or copper lead.

[0037]

[Table 1]

From Table 1, the volume ratio of aluminum is 1%.
In the above range, the coefficient α is less than 6.9, and it can be seen that the resistance value is lower than that of the nickel lead. Also,
When the volume ratio of aluminum is 81% or more, the coefficient α
Is less than 1.72, which indicates that the resistance value is lower than that of the copper lead.

The coefficient α coincides with the resistance value of the aluminum / nickel lead. This is because the lead model was selected so that the characteristics of the coefficient α could be easily understood, and the coefficient α had the same meaning as the resistivity. This is to show that

That is, for example, if the length of the battery lead is 2
If the value is doubled, the resistance value is doubled. However, the coefficient α is a value determined by the properties (resistivity and specific gravity) of the material and the volume ratio, and does not have a property that changes with dimensions or shape. Where the coefficient α
Is a value that can be used only for comparison with metals having a specific gravity of 8.9, such as nickel and copper.

That is, the coefficient α is calculated from the resistivity, specific gravity, and volume ratio of each metal of the lead body and the connection body, and this coefficient α is converted to the resistivity of nickel (6.9) or the resistivity of copper (1. By comparing with (72), it is possible to easily determine whether this lead is lighter in weight than a conventional nickel lead or copper lead.

In this model, resistance values of leads having the same weight were compared. In other words, the fact that the resistance value is lower than that of the nickel or copper lead means that in a state where the cross-sectional area is reduced and the resistance value is made the same,
This indicates that the lead will be lighter than nickel or copper leads.

As a second example, the aluminum of the present invention
The characteristics of the iron lead will be described. Table 2 shows the characteristics when the volume ratio between the lead body made of aluminum and the connection body made of iron is changed.

In Table 2, the type of lead A is an iron lead (conventional product), B is a copper lead (conventional product), and C is the aluminum / iron lead of the present invention. The coefficient α is
This shows the resistance value when the weight and length are the same as those of the nickel or copper lead.

[0045]

[Table 2]

From Table 2, it can be seen that the volume ratio of aluminum is 17
%, The coefficient α is less than 6.9, indicating that the resistance value is lower than that of the nickel lead. Further, in the range where the volume ratio of aluminum is 82% or more, the coefficient α is less than 1.72, and it can be seen that the resistance value is lower than that of the copper lead.

As a third example, the aluminum of the present invention
The characteristics of the stainless steel lead will be described. Table 3 shows the characteristics when the volume ratio between the lead body made of aluminum and the connection body made of stainless steel was changed.

In Table 3, type A of the lead is stainless steel lead (conventional product), type B is copper lead (conventional product), and type C is the aluminum / stainless steel lead of the present invention. The coefficient α indicates a resistance value when the weight and length are the same as those of the nickel or copper lead.

[0049]

[Table 3]

From Table 3, it can be seen that the volume ratio of aluminum is 76
%, The coefficient α is less than 6.9, indicating that the resistance value is lower than that of the nickel lead. In addition, in the range where the volume ratio of aluminum is 96% or more, the coefficient α is less than 1.72, which indicates that the resistance value is lower than that of the copper lead.

As a fourth example, the characteristics of the aluminum alloy (Aldry) / nickel lead of the present invention will be described. Table 4 shows the characteristics when the volume ratio between the lead body made of an aluminum alloy and the connection body made of nickel is changed. The resistivity of Aldry is 3.14,
The specific gravity is 2.7.

In Table 4, lead type A is a nickel lead (conventional product), B is a copper lead (conventional product), and C is the aluminum alloy (Aldry) / nickel lead of the present invention. The coefficient α indicates a resistance value when the weight and length are the same as those of the nickel or copper lead.

[0053]

[Table 4]

From Table 4, it can be seen that the volume ratio of aluminum is 1%.
In the above range, the coefficient α is less than 6.9, and it can be seen that the resistance value is lower than that of the nickel lead. Also,
When the volume ratio of aluminum is 81% or more, the coefficient α
Is less than 1.72, which indicates that the resistance value is lower than that of the copper lead.

Although the characteristics in the case where Aldry is used as the aluminum alloy have been described above, there are various types of aluminum alloys that can be used, such as Alzur and Duralumin.

It is important to note that even if the resistivity and the specific gravity are different for each aluminum alloy, a nickel or copper lead is selected by selecting a region where the lead coefficient α is smaller than 6.9 for nickel or 1.72 for copper. Lighter or lower resistance than that.

The characteristics of the four types of leads according to the present invention have been described above. Since the joints of these leads are made of nickel, iron or stainless steel, the spot weldability is good.

As described above, according to the present invention, it is possible to obtain a battery lead which is lightweight and has excellent spot weldability.
INDUSTRIAL APPLICABILITY The battery lead of the present invention can be used for electrical connection between cells or between cells and a protection circuit board in a battery pack containing a plurality of batteries.

By using the battery lead of the present invention, a battery pack having good assembling workability, light weight and high reliability of electrical connection can be obtained.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail using preferred embodiments.

Example 1 A plate thickness of 0.45 mm and a length of 96
mm, 10 mm width, aluminum plate as lead body at both ends, 0.30 mm thickness, 4 mm length, 10 mm width
Stainless steel plate (SUS420)
0 mm of the battery lead A of the present invention having the shape shown in FIG.
Was made. In FIG. 2, reference numeral 4 denotes an aluminum plate of the lead body, and reference numerals 5 and 6 denote stainless plates as connection bodies. The overlap margin for joining the aluminum plate and the stainless steel plate was 2 mm, and a method using ultrasonic vibration was used for joining. The volume ratio of aluminum is about 95% and the coefficient α
Was set to 1.85.

Example 2 A plate thickness of 0.20 mm and a length of 96
0.15 mm, length 4 mm, width 10 mm at both ends of an aluminum plate as a lead body having a width of 10 mm and a width of 10 mm
A total length of 100 mm by joining a nickel plate as a connector
A battery lead B of the present invention having a shape similar to that of Example 1 was manufactured. The overlap margin for joining the aluminum plate and the nickel plate was 2 mm, and a method using arc welding was used for joining. The volume ratio of aluminum is about 94%,
The coefficient α was set to 1.05.

Example 3 A plate thickness of 0.20 mm and a length of 96
0.20 mm, length 4 mm, width 10 mm at both ends of an aluminum plate as a lead body having a width of 10 mm and a width of 10 mm
The battery lead C of the present invention having the same shape as that of Example 1 having a total length of 100 mm was manufactured by joining an iron plate as a connecting body of the present invention. The overlap allowance for joining aluminum plate and iron plate is 2
mm, and a method using laser welding was used for joining.
The volume ratio of aluminum was about 92%, and the coefficient α was 1.17.

Example 4 A plate thickness of 0.20 mm and a length of 96
A nickel plate as a connector having a thickness of 0.20 mm, a length of 4 mm, and a width of 10 mm was joined to both ends of an aluminum alloy (Aldry) plate as a lead body having a length of 10 mm and a width of 10 mm, as in Example 1 having a total length of 100 mm The battery lead D of the present invention having the shape of was prepared. The overlap margin for joining the aluminum plate and the nickel plate was set to 2 mm, and a method using ultrasonic vibration was used for joining. The volume ratio of the aluminum alloy was about 92%, and the coefficient α was 1.12.

Example 5 A plate thickness of 9.2 mm and a length of 100
1 mm thick, 10 mm long, 10 m wide on both ends of an aluminum plate as a lead body having a width of 10 mm and a width of 10 mm.
Then, a nickel plate as a connector having a through hole with a diameter of 4 mm at the center was joined to produce a battery lead E of the present invention having a shape shown in FIG. The aluminum plate was also provided with a through hole of the same size at the same position as the through hole of the nickel plate.

The lead is designed to be joined to other parts by bolts and nuts, and a large number of wedge-shaped projections are provided on the surface of the nickel plate in contact with the aluminum plate. By pressing the nickel plate and the aluminum plate from above and below, the wedge-like structure of the nickel plate cuts into the aluminum surface, breaks through the oxide film layer on the surface, and increases the conductivity. Aluminum volume ratio is about 9
8%, and the coefficient α was 0.92.

Example 6 A plate thickness of 9.4 mm and a length of 100
1 mm thick, 10 mm long, 10 m wide on both surfaces of an aluminum plate as a lead body having a width of 10 mm and a width of 10 mm
A stainless steel plate as a connector having a through hole having a diameter of 4 mm at the center and having a diameter of m was joined to produce a battery lead F of the present invention having the same shape as that of Example 5. The aluminum plate was provided with a through hole of the same size at the same position as the through hole of the stainless steel plate.

The lead is designed to be connected to other parts by bolts and nuts, and a large number of wedge-shaped projections are provided on the surface of the stainless plate in contact with the aluminum plate. By pressing the stainless plate and the aluminum plate from above and below, the wedge-shaped structure of the stainless plate cuts into the aluminum surface and breaks through the oxide film layer on the surface,
It enhances conductivity. The volume ratio of aluminum was about 98%, and the coefficient α was 1.19.

[Conventional Example 1] As a counterpart to the first, second, third and fourth embodiments, a plate thickness of 0.4 mm and a length of 100 m
A conventional lead G made of a single nickel plate having a width of 10 mm and a width of 10 mm was manufactured.

[Conventional Example 2] As a counterpart to Examples 1, 2, 3 and 4, a plate thickness of 0.1 mm and a length of 100 m
A conventional lead H made of a single copper plate having a width of 10 mm and a width of 10 mm was manufactured.

[Conventional Example 3] As a counterpart to Examples 5 and 6, a plate thickness of 3 mm, a length of 100 mm, and a width of 10 mm
A conventional lead I made of a single nickel plate was manufactured.
The shape of this battery lead was the same as that shown in FIG. 3 in which two through holes for fastening with bolts and nuts were provided, as in Examples 5 and 6.

[Conventional Example 4] Corresponding to Examples 5 and 6, a plate thickness of 3 mm, a length of 100 mm, and a width of 10 mm
A conventional lead J made of a single copper plate was manufactured. The shape of the lead was the same as that shown in FIG. 3 in which two through holes for fastening with bolts and nuts were provided, as in Examples 5 and 6.

Tables 5 and 6 summarize the characteristics of these leads, such as weight and electric resistance.

[0074]

[Table 5]

[0075]

[Table 6]

First, in Table 5, Examples 1, 2, 3 and 4 were compared with Conventional Examples 1 and 2. These examples are for clarifying the weight difference when the resistance values are equal. From Table 5, it was found that the battery lead A of the present invention had a coefficient α of 1.85, and was about 60% lighter than the nickel lead G of Conventional Example 1. Further, since the coefficients α of the battery leads B, C and D of the present invention are less than 1.05, 1.17, 1.11 and 1.72, respectively, About 30% each compared with the copper lead H of the conventional example 2,
It was found to be about 25% and about 26% lighter.

Next, in Table 6, Examples 5 and 6 were compared with Conventional Examples 3 and 4. These examples are to clarify the difference in resistance value when the weight is equal.
From Table 6, it can be seen that the battery leads E and F of the present invention have a coefficient α
Are 0.92, 1.19 and 1.72, respectively, so that they are about 43% respectively as compared with the nickel lead I of the conventional example 3 as well as the copper lead J of the conventional example 4.
And about 24% lower resistance. As described above, the lead of the present invention was lighter in weight and lower in resistance than the conventional nickel lead and copper lead.

Next, an embodiment using a battery pack will be described.

Example 7 A battery pack K of the present invention having a nominal capacity of 1.3 Ah was manufactured using the aluminum / nickel lead B of the present invention, a lithium ion cell, a protection circuit and a resin housing of Example 2.

Example 8 A battery pack L of the present invention having a nominal capacity of 1.3 Ah was manufactured in the same manner as in Example 7 except that the aluminum / iron lead C of the present invention of Example 3 was used.

[Embodiment 9] Thirty lithium ion cells having a nominal capacity of 100 Ah were replaced with the aluminum / metal of the present invention of Embodiment 5.
The battery group M of the present invention was manufactured by connecting with the nickel lead E.

Example 10 A group battery N of the present invention was manufactured in the same manner as in Example 9 except that the aluminum / stainless steel lead F of the present invention of Example 6 was used.

[Conventional Example 5] A battery pack P of a conventional example was manufactured in the same manner as in Example 7 except that the nickel lead G of the conventional example 1 was used as corresponding to the examples 7 and 8.

[Conventional Example 6] A battery pack Q of a conventional example was manufactured in the same manner as in Example 7 except that the copper lead H of the conventional example 2 was used, corresponding to Examples 7 and 8.

[Conventional Example 7] A conventional group battery R was manufactured in the same manner as in Example 9 except that the nickel lead I of Conventional Example 3 was used, corresponding to Examples 9 and 10.

[Conventional Example 8] As corresponding to Embodiments 9 and 10, except that the copper lead J of Conventional Example 4 was used.
A conventional group battery S was manufactured in the same manner as in Example 9.

Tables 7 and 8 summarize the characteristics of these leads, such as weight and electric resistance.

[0088]

[Table 7]

[0089]

[Table 8]

First, in Table 7, Examples 7 and 8 and Conventional Example 5 are shown.
And 6 were compared. These examples are for clarifying the difference in weight of the battery pack when the resistance values are equal. From Table 7, it can be seen that the battery packs K and L of the present invention were obtained.
Uses a lead having a coefficient α of 1.05 or 1.17, which is lighter than the battery pack P using the nickel lead of the conventional example 5, and using the copper lead of the conventional example. In comparison with the battery pack Q, 0.2
6g and 0.25g were found to be lightweight.

Next, in Table 8, Examples 9 and 10 were compared with Conventional Examples 7 and 8. These examples are for clarifying the difference in resistance value when the weight is the same, that is, the difference in discharge characteristics. From Table 8, it can be seen that the group batteries M and N of the present invention use leads having coefficients α of 0.92 and 1.19, respectively. It was found that the intermediate voltage at the time of discharging was higher and the discharge duration was longer than that of the group battery S using the copper lead of No. 8.

As described above, the battery pack and the group battery of the present invention were lighter in weight and lower in resistance than those using the conventional nickel lead or copper lead.

In the above embodiment, the effect of the present invention has been described from the viewpoint of weight reduction and reduction of the resistance value. However, this effect can be converted to miniaturization as required. That is, the present invention is effective for weight reduction, resistance value reduction, and size reduction.

In the embodiment, the method of joining the aluminum part and the nickel / iron / stainless steel part by the ultrasonic vibration method, arc welding, laser welding, or the bolting / nut tightening method is used. A commonly used joining method can be used.

In the embodiment, the material of the metal other than aluminum or aluminum alloy of the connecting body is the same at both ends of the lead (in the first embodiment, stainless steel / aluminum / stainless steel). Alternatively, it may be different at both ends of the lead, for example, nickel / aluminum / stainless. In some cases, the connection body may be provided only at one end of the lead.

Although Aldry is used as the aluminum alloy in the embodiment, other aluminum alloys such as Alzur can be used.

Further, in the examples, the battery lead of the present invention was formed by joining the aluminum of the lead body with the nickel, iron, and stainless steel of the connection body.
It is also possible to form a layer of a material suitable for spot welding, such as nickel, directly on the surface of one or both ends of an aluminum plate as a lead body by a coating method such as an arc overlay process. The joining method can be selected according to the shape and structure.

Examples of the method of manufacturing the battery lead of the present invention include, as used in Examples 1, 2, 3 and 4, a portion of aluminum or aluminum alloy and nickel,
After manufacturing a battery lead having the structure of the present invention by joining a part made of iron or stainless steel by ultrasonic vibration, arc welding, laser welding, or the like, means for joining with a unit cell or a protection circuit is used. be able to.

As another manufacturing method, an aluminum portion and nickel, as used in Examples 5 and 6, were used.
A battery lead of the present invention can be formed by separately preparing a portion made of either iron or stainless steel and tightening it together with bolts and nuts when connecting to a unit cell or the like.

[0100]

According to the present invention, a light-weight, low-resistance and highly reliable battery lead can be obtained. These effects are finally obtained in the battery pack, and increase as the amount of the battery lead used increases. In particular, the amount by which the lead is reduced in weight and the amount by which the resistance is reduced is such that 100% can be directly reflected in the characteristics of the battery pack.

The battery lead according to the present invention has been developed so that it can be joined to other parts by spot welding with good workability. However, in addition, arc welding, laser welding, ultrasonic joining, Similar effects can be obtained in soldering or joining such as a tightening method using bolts and nuts used in a large-capacity battery group.

Therefore, the effect of the present invention is not limited to a battery pack for a portable device, and a large number of large-capacity cells such as a stationary emergency power supply and an electric vehicle power supply are electrically connected. It can be obtained in the same manner even if it is placed in a structure that connects to.

As described above, by using the battery lead of the present invention, the weight and resistance of the battery pack and the battery group can be reduced.

[0104]

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a shape of a battery lead of the present invention.

FIG. 2 is a view showing another example of the shape of the battery lead of the present invention.

FIG. 3 is a view showing still another example of the shape of the battery lead of the present invention.

[Explanation of symbols]

 1, 4, 7 Battery lead body 2, 3, 5, 6, 8, 9 Battery lead connector

Claims (8)

[Claims] 1. A lead body made of a strip of aluminum or aluminum alloy, and a connecting body made of a metal other than aluminum or aluminum alloy at one or both ends of the lead body, wherein the connecting body and a battery or other parts are provided. And a battery lead. 2. The resistance of a lead body is set to R1 (μΩ · c).
m), the volume ratio of the lead body to the entire lead is V1
(%), The specific gravity of the metal of the lead body is S1, the resistivity of the connection body is R2 (μΩ · cm), the volume ratio of the connection body to the entire lead is V2 (%), the specific gravity of the connection body is S2, and the coefficient is 2. The battery lead according to claim 1, wherein when α is represented by the following equation, the coefficient α <6.9. Coefficient α = (R1 × V1 / 100 + R2 × V2 / 100)
× (S1 × V1 / 100 + S2 × V2 / 100) / 8.
9 3. The battery lead according to claim 1, wherein the connection body is at least one selected from the group consisting of nickel, iron and stainless steel. 4. The battery lead according to claim 2, wherein the lead body is aluminum, the connection body is nickel, and the volume ratio of aluminum is 1% or more. 5. The battery lead according to claim 2, wherein the lead body is aluminum, the connection body is iron, and the volume ratio of aluminum is 17% or more. 6. The battery lead according to claim 2, wherein the lead body is aluminum, the connection body is stainless steel, and the volume ratio of aluminum is 76% or more. 7. The battery lead according to claim 2, wherein the lead body is Aldry, the connection body is nickel, and the volume ratio of Aldry is 1% or more. 8. The method of claim 1, 2, 3, 4, 5, 6, or 7.
A battery pack or a group battery using the battery lead described in (1).