JP2003331799A - Packed battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packed battery with excellent resistance characteristics against peeling off by an electrolyte solution of a joining part of a lead terminal and an outer package body. <P>SOLUTION: The packed battery made by laminating a plural number of a unit cell with a positive electrode lead terminal 11 and a negative electrode lead terminal 12 extended outside from a unit cell main body is provided with a means by which an electrolyte solution in the packed battery is prevented from contacting a joint part of the lead terminal and the outer package, for instance, a means for putting the side where the lead terminal is not extended headed downward. With this, an attack by the electrolyte solution on a joint interface of the lead/outer package in a battery is alleviated, and thus, a packed battery hardly affected by peeling off degradation of the lead/outer package and with an excellent sealing reliability can be provided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery formed by connecting a plurality of unit cells in a laminated manner.

[0002]

2. Description of the Related Art Conventionally, as a laminated laminate battery,
A film in which a metal layer and a heat-fusible resin layer are laminated,
That is, there is known a structure in which a power generator is covered with a laminate film and the heat-fusible resin layers are heat-sealed to hermetically seal. The positive electrode lead terminal and the negative electrode lead terminal of the laminated laminate battery are extended from the laminate film which is the outer package, and the lead terminal is shown in FIG.
As shown in FIG. 4A, the positive electrode lead 11 and the negative electrode lead 12 are pulled out in the opposite directions, or as shown in FIG. 4B, the positive electrode lead 11 and the negative electrode lead 12 are sealed on the same side of the four sides of the battery. It is common to pull out only from the stop.
An assembled battery is formed by connecting a plurality of the laminated laminate batteries. The assembled battery is configured by connecting the lead terminals to each other with the positive electrode lead contact portion 8 or the negative electrode lead contact portion 9 made of a conductive material so that the lead terminal portions of the laminated laminate battery are arranged in series or in parallel. Further, as shown in FIG. 5, this assembled battery is often used by being covered with a case 7 made of a metal such as a rectangular tube.

[0003]

In the inside of the laminated laminate battery, the electrolytic solution accumulates on the lower side in the direction of gravity. When the lead sealing part where the lead terminal and the laminated outer package are joined is located in the lower side of the battery, the electrolytic solution accumulates in the lead sealing part and the electrolytic solution attacks the lead / sheath bonding interface. As a result, peeling deterioration is caused and sealing reliability deteriorates. In particular, in the case of an assembled battery in which the battery is covered with a case such as a metal so as to be sandwiched under pressure, the laminated outer casing of the battery is pressed down, so the rise in internal pressure due to gas generation inside the battery causes lead sealing. As a result, the reliability of the sealing is deteriorated. Further, when the lead sealing portion is broken, the electrolytic solution is ejected to cause damage to the lead terminal connection portion between the batteries, which adversely affects the normal battery performance.
That is, as shown in FIGS. 6A, 6B, and 6C, at least one of the positive electrode lead terminal 11 and the negative electrode lead terminal 12 is assembled into a battery pack so that the lead sealing portion of the battery is on the lower side. When installed, the electrolytic solution accumulates inside the laminated laminate battery on the lower side in the direction of gravity. Then, the electrolytic solution accumulates in the lead sealing portion, and the electrolytic solution attacks the lead / exterior body adhesive interface to cause peeling deterioration, which deteriorates sealing reliability. Further, when the lead sealing is broken, the electrolyte solution is likely to be ejected, causing damage to the lead terminal connection portion, which is likely to adversely affect a normal battery.

The present invention solves the above-mentioned problems, mitigates the attack on the adhesive interface between the lead and the outer package by the electrolytic solution, makes it difficult for the lead / outer package to be peeled and deteriorated, and has a high sealing reliability. It is an object of the present invention to provide an excellent battery pack.

[0005]

The battery pack of the present invention comprises a battery main body in which a plurality of electrode plates are laminated and a lead terminal is connected to a power generator containing an electrolytic solution, and the lead terminal can conduct electricity to the outside. And a plurality of laminated laminated single cells that are hermetically sealed by sandwiching the lead terminals with an outer package, are stacked in the stacking direction, and an assembled battery formed by connecting the lead terminals to each other, It is characterized in that it has means for preventing the electrolytic solution from coming into contact with the joint between the lead terminal and the outer package.

The present invention will be described in more detail below. According to the means for preventing the above-mentioned electrolytic solution from coming into contact with the joint between the lead terminal and the exterior body (hereinafter referred to as non-contact means) of the present invention, the attack on the lead / exterior body adhesive interface by the electrolytic solution is mitigated,
It is possible to obtain an assembled battery that is less likely to cause peeling deterioration of the lead / sheath body and has excellent sealing reliability. In particular, when the assembled battery is housed in a case made of metal or the like and each electrode plate of the unit cell is housed under pressure, the sealing reliability is significantly reduced as described above. Since the contact between the electrolyte solution and the lead / exterior body adhesive interface is avoided as much as possible, the decrease in the sealing reliability can be minimized.

[0007] As the specific non-contact means, the lead terminals are not installed downward, in other words, when the battery is installed, one side of the unit cell in which the lead terminals do not extend is installed on the lower side. included. Another approach is
Means for preventing the electrolytic solution leaching from the power generation body from reaching the lead / exterior body adhesion interface between the power generation body and the lead / exterior body adhesion interface, for example, a cotton-like substance that absorbs the electrolyte solution, within a range that does not impair the battery function. Or the installation of a block plate that blocks the movement of the electrolytic solution.

Next, each member usable in the assembled battery of the present invention will be described.

[Lead Terminal] The lead terminal may be made of Al, Cu, phosphor bronze, Ni, Ti, Fe, brass, stainless steel, or the like, and may be annealed if necessary. The plate-like shape is preferable, and the thickness is preferably in the range of 20 μm to 2 mm. As shown in FIG. 4A, the positive electrode lead and the negative electrode lead may be pulled out in the opposite directions, or
As shown in (b), two terminals may be led out only from the sealing portion on one side of the four sides of the battery, and may be routed through the sealing portion of the exterior body.

[Exterior body] The exterior body of the laminated laminate battery is a film-like one, that is, a metal foil, a resin thin film, a thin member having flexibility exemplified by a laminate of these, and a concave portion is formed. Can be used. Here, the film refers to a thin member having flexibility against bending deformation. The thickness is preferably 10 to 300 μm, more preferably 50 to 200 μm. When it is less than 10 μm, mechanical strength as a battery outer package is poor and it easily breaks, and when it is more than 300 μm, it becomes poor in flexibility and in receiving gas without increasing internal pressure. It will be inconvenient. The recess is preferably formed by draw forming (deep draw forming) in which the film around the planned forming portion is pressed in a slidable state and the film is pushed in with a punch and a die. The recess may be formed by a stretch molding method in which the film around the planned molding portion is fixed without slipping and the film is stretched and stretched with a die. Alternatively, an outer package having a recess may be manufactured by an injection molding method.

[Power Generator] The structure and form of the power generator are particularly limited.
Not, for example, a positive electrode, a negative electrode, a separator, a flat plate
Shaped, or simply stacked two or more sets
It The positive electrode absorbs positive ions during discharge or negative ions.
It is not particularly limited as long as it emits nitrogen (i) LiM
nO₂, LiMn₂O_Four, LiCoO₂, LiNiO₂Etc.
Conducting metal oxides, (ii) polyacetylene, polyaniline, etc.
Electroconductive polymer, (iii) general formula (RS_m) _n(R is aliphatic
Group, or an aromatic group, S is sulfur, m, n
Is an integer of m ≧ 1 and n ≧ 1)
Compound (dithioglycol, 2,5-dimercapto
-1,3,4-thiadiazole, S-triazine-2,
4,6-trithiol, etc.) as a positive electrode material for secondary batteries
Conventionally known ones can be used.

Further, the positive electrode can be formed by mixing a positive electrode active material with a suitable binder or a functional material. Halogen-containing polymers such as polyvinylidene fluoride are used as these binders, and conductive polymers such as acetylene black, polypyrrole, and polyaniline are used as functional materials to ensure electron conductivity, and ion conductivity is ensured. Examples thereof include polymer electrolytes and composites thereof. The negative electrode is
It is not particularly limited as long as it is a material capable of occluding and releasing cations, crystalline graphite such as natural graphite, graphitized carbon obtained by heat treatment of coal, petroleum pitch, etc. at high temperature, coal, petroleum pitch coke, acetylene pitch coke Conventionally known materials can be used as the negative electrode active material of the secondary battery, such as amorphous carbon obtained by heat-treating etc., lithium alloys such as metallic lithium and AlLi.

The non-aqueous electrolyte solution contained in the power generator is, for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone,
L, N, N′-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, m-cresol and the like can be used as a highly polar basic solvent that can be used as an electrolytic solution of a secondary battery.
Alkali metal cations such as i, K, and Na, and Cl
O ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) _{2
^{N -, (C 2 F 5}} SO 2) 2 N -, (CF 3 SO 2) 3 C -, (C
₂ F ₅ SO ₂ ) ₃ C ^{− and the} like in which a salt composed of an anion of a compound containing a halogen is dissolved. Further, a solvent composed of these basic solvents and an electrolyte salt may be used alone or in combination. Alternatively, a gel electrolyte that is a polymer gel containing an electrolytic solution may be used.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

First, a unit cell constituting a laminated laminate battery will be described with reference to FIG. A power generator 3 having a plurality of electrode plates 1 stacked on each other with a separator 2 is placed in the recess of the lower exterior body 5 in which the recess is formed in advance. The positive electrode lead 11 and the negative electrode lead 12 are previously welded to the collector foil 4 extending from the power generator 3. Next, a flat film having no recess as the upper exterior body 6 is covered on the power generator 3 and both lead terminals 11 and 12, and then heat-sealed under reduced pressure, and the laminated type of FIG. 1 sealed under reduced pressure. A laminate type single battery 7 is obtained. As mentioned above, the film is
It refers to a thin member that is flexible against bending deformation.

The unit cells 7 are connected at the lead connecting portions so that the lead terminal portions are connected in series or in parallel to form a laminated battery pack. An example of parallel connection is shown in FIG.
It is shown in (b), (c) and (d). These assembled batteries are characterized by the positive electrode lead terminal 11 and the negative electrode lead terminal 1.
2 so that the side having the lead sealing portion formed by extending from the outer casings 5 and 6 does not face downward, in other words, the sides other than the side having the lead sealing portion face downward. It is installed.

That is, in FIG. 2A, both the positive electrode lead terminal 11 and the negative electrode lead terminal 12 are installed so as to face the upper side opposite to the direction of gravity, and the plurality of positive electrode lead terminals 11 are connected to the positive electrode lead terminal connecting portion. 8 and a plurality of negative electrode lead terminals 12 are connected to the negative electrode lead terminal connection portion 9. In addition, in FIG. 2B, both the positive electrode lead terminal 11 and the negative electrode lead terminal 12 face the side surface of the battery pack which is a direction perpendicular to the gravity direction and the positive electrode lead terminal 11 is positioned above the negative electrode lead terminal 12. is set up.
In FIG. 2C, the positive electrode lead terminal 11 and the negative electrode lead terminal 12 both face the side surface of the battery pack that is perpendicular to the direction of gravity, and the positive electrode lead terminal 11 is located below the negative electrode lead terminal 12. Has been done. Furthermore, FIG.
In (d), the positive electrode lead terminal 11 and the negative electrode lead terminal 1
Both of them are installed so as to face in opposite directions to each other on the side surface of the battery pack, which is perpendicular to the direction of gravity.

The lead connecting portions 8 and 9 are made of a conductive material, and generally a copper plate is often used. Lead terminal 1
The connection between 1 and 12 and the lead connection portions 8 and 9 is performed by ultrasonic welding, resistance welding, caulking with rivets, or the like. In the case of the assembled battery of the form shown in FIG. 2A, the entire assembled battery may be housed in a case 10 made of metal or resin to sandwich the power generator 3 under pressure as shown in FIG. As a result, the adhesion between the electrode plates 1 of the power generator 3 of the battery can be maintained.

[0019]

EXAMPLES The details of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Example 1> Lithium manganate powder having a spinel structure, carbonaceous conductivity-imparting material, and polyvinylidene fluoride were mixed with NMP (N-methyl-2-pyrrolidinone) in a weight ratio of 90: 5: 5. Dispersed and stirred to obtain a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. Using a doctor blade, this slurry was uniformly applied to one surface of a 20-micron-thick aluminum foil that was a positive electrode current collector. At the time of application, a slightly uncoated part (a part where the current collector is exposed) was made to be streaky. Next, this was vacuum dried at 100 ° C. for 2 hours.
Similarly, the other surface was coated with the slurry and vacuum dried. At this time, the uncoated portions on the front and back were made to coincide.
The sheet thus coated with the active material on both sides was roll-pressed. Eight sheets were prepared by cutting this into a rectangular shape including the uncoated portion. The portion not coated with the active material was the portion to be connected to the lead terminal. In this way, a positive electrode having a total theoretical capacity of 3 Ah was prepared.

On the other hand, amorphous carbon powder and polyvinylidene fluoride were mixed in NMP at a weight ratio of 91: 9, dispersed and stirred to form a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. Using a doctor blade, this slurry was uniformly applied to one surface of a copper foil having a thickness of 10 μm and serving as a negative electrode current collector. At the time of application, a slightly uncoated part (a part where the current collector is exposed) was made to be streaky. Then, this was vacuum dried at 100 ° C. for 2 hours. At this time, the film thickness of the active material layer was adjusted so that the theoretical capacity per unit area of the negative electrode layer and the theoretical capacity per unit area of the positive electrode layer were 1: 1. Similarly, the same slurry was applied to the other surface and vacuum dried. The sheet thus coated with the active material on both sides was roll-pressed.
Nine sheets were prepared by cutting each of these into a rectangular shape including the uncoated portion into a size larger by 2 mm in length and width than the size of the positive electrode, and used as a negative electrode. The portion not coated with the active material was the portion to be connected to the lead terminal.

Between the positive electrode and the negative electrode prepared as described above, a microporous separator having a three-layer structure of polypropylene / polyethylene / polypropylene (Hoechst Celanese Co. Manufactured by Celgard 2300). The outermost side of the electrode was the negative electrode, and a separator was placed further outside the negative electrode (separator /
Negative electrode / separator / positive electrode / separator / ...
Negative electrode / separator order). The positive electrode active material-uncoated portion and the negative electrode active material-uncoated portion were aligned so as to be located on the same side of the four sides of the battery. Next, a thickness of 0.
An aluminum plate having a width of 1 mm, a width of 50 mm, and a length of 50 mm was ultrasonically welded together with eight active material-uncoated portions of the positive electrode. Similarly, a nickel plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm, which serves as a negative electrode lead terminal, and nine negative electrode active material-uncoated portions were collectively ultrasonically welded. Prior to the above-mentioned welding connection, the positive electrode lead terminal and the negative electrode lead terminal were heat-sealed in advance with a sealing material made of a film-like acid-modified polypropylene having a thickness of 30 μm at a portion to be sealed by the outer package.

On the other hand, as a laminate film for the outer package, a film composed of a laminate of nylon 25 μm, soft aluminum 40 μm, and acid-modified polypropylene 30 μm was prepared, cut into a predetermined size, and deep-drawn into a cup shape. In the cup molding part of this laminated film,
The above laminate was stored. Next, the above laminated film, which was just cut into a predetermined size without molding, was placed so as to cover the cup molding portion in which the above-mentioned power generation element was housed with the sealing surface facing inward. . Next, the lead terminal lead-out portion is heat-sealed by sandwiching the lead terminal pulled out via the upper portion of the cup-formed film by the film collar portion and the lid, and then facing the lead terminal lead-out portion. One side (hereinafter referred to as long side A) out of the sides and long sides (hereinafter referred to as long side A and long side B) that is not the lead terminal lead-out portion was heat-sealed. The lead terminal lead-out portion was heat-sealed under a slightly weaker condition so that the seal strength of the lead terminal sealing portion could be easily compared between levels.

Next, the long side A was tilted downward, and the electrolytic solution was injected into the electrode laminate through the gap between the long sides B which is the last unsealed portion. The electrolytic solution uses 1 mol / liter of LiPF ₆ as a supporting salt and a mixed solvent of propylene carbonate and methyl ethyl carbonate (weight ratio 50:50) as a solvent. The liquid injection amount was set to an amount corresponding to 5% of the volume of the power generation element. After the injection, defoaming under reduced pressure was performed. Finally, the long side B was heat-sealed under reduced pressure using a vacuum sealing machine to complete the battery. The assembled battery of Example 1 was produced by connecting the lead terminal portions of the thus-produced batteries in parallel with the lead connection portions. A copper plate, which is a conductive material, was used for the lead connection portion and was connected by ultrasonic welding.

As shown in FIG. 3, the assembled battery was covered with a case of an aluminum plate having a thickness of 1 mm so that the power generator was sandwiched in a pressurized state by the pressure of the aluminum outer casing. By doing so, the electrode plate adhesion of the battery power generator was maintained. The side surface of the battery and the heat-sealed portion of the laminate film were not in contact with the inner wall of the aluminum outer package, and were not applied with pressure. When the assembled battery was fully charged at a voltage of 4.3 V, the lead terminal lead-out side was placed on the upper side as shown in FIG. 2A, and the battery was left for 3 months at 60 ° C. and 90% environment. No leak occurred in both the positive electrode and negative electrode terminal portions. In addition, about the evaluation performed in this Example and the comparative example, the result was judged based on the following criteria. A leak first occurs due to the deterioration due to peeling, and the presence or absence of the leak was checked by confirming a leak mark (precipitate or the like) at the root of the lead terminal lead portion. When the peeling deterioration progresses and the electrolytic solution is accumulated near the peeling portion, the electrolytic solution is ejected from the peeling portion.In this case, the lead terminal connecting portion where the lead terminals of each battery are connected is damaged. receive. The presence or absence of this leak and the damage of the lead terminal connection portion were observed and used as a criterion for the sealing reliability.

Example 2 The same assembled battery as in Example 1 was fully charged to a voltage of 4.3 V, and the lead terminal lead-out side was a side surface as shown in FIG. 2B, and the Al positive electrode lead terminal was used. Is placed above the Ni negative electrode lead terminal and left for 3 months at 60 ° C. and 90% environment.
Leaks occurred first in the Al positive electrode lead terminal and then in the Ni negative electrode lead terminal, but no electrolytic solution was ejected and the lead terminal connection portion was not damaged.

<Embodiment 3> The same assembled battery as in Embodiment 1 is fully charged to a voltage of 4.3 V so that the lead terminal lead-out side is the side surface and the Ni negative lead terminal is as shown in FIG. 2 (c). Was placed so that it was on the upper side of the Al positive electrode lead terminal and left for 3 months at 60 ° C. and 90% environment.
Leaks occurred first in the Al positive electrode lead terminal and then in the Ni negative electrode lead terminal, but no electrolytic solution was ejected and the lead terminal connection portion was not damaged.

Example 4 A laminated type laminate battery in which the positive electrode lead terminal and the negative electrode lead terminal were drawn out from the sides facing each other was made into an assembled battery by the same method as in Example 1. This battery pack was fully charged to a voltage of 4.3 V, and was installed so that the side without the lead terminals was the bottom surface as shown in FIG.
When left at 0 ° C and 90% for 3 months,
Although leakage occurred at the positive electrode lead terminal and then at the Ni negative electrode lead terminal, no electrolytic solution was ejected and the lead terminal connection portion was not damaged.

<Comparative Example 1> A laminated laminate battery in which a positive electrode lead terminal and a negative electrode lead terminal were drawn out from opposite sides was formed into an assembled battery in the same manner as in Example 1. The battery pack was fully charged to a voltage of 4.3 V, and the Ni negative electrode lead terminal was placed on the lower side as shown in FIG.
When left for 3 months in an environment of 0 ° C. and 90%, a leak occurred in the Ni negative electrode lead terminal, the electrolytic solution was ejected, and the lead terminal connection part was damaged.

<Comparative Example 2> A laminated laminate battery in which the positive electrode lead terminal and the negative electrode lead terminal were drawn out from the sides facing each other was made into an assembled battery by the same method as in Example 1. The assembled battery was fully charged at a voltage of 4.3 V, and was installed so that the Al positive electrode lead terminal was on the lower side as shown in FIG.
When left for 3 months in an environment of 0 ° C. and 90%, a leak occurred in the Al positive electrode lead terminal, the electrolytic solution was ejected, and the lead terminal connection part was damaged.

<Comparative Example 3> The same assembled battery as in Example 1 was fully charged to a voltage of 4.3 V, and the positive and negative lead terminal lead-out sides were set downward as shown in FIG. 6 (c). ,
When left in an environment of 60 ° C. and 90% for 3 months, leakage occurred first in the Al positive electrode lead terminal and then in the Ni negative electrode lead terminal, and both lead terminal connection parts were damaged.

Six assembled batteries of Examples 1 to 4 and Comparative Examples 1 to 3 were used.
Table 1 summarizes the leakage state of the Al positive electrode lead terminal, the Ni negative electrode lead terminal sealing part and the damage state of the terminal connecting part when left for 3 months at 0 ° C. and 90% environment. Al terminal part, N
Leakage occurred in the i terminal portion in the order shown in the table.
That is, at the same time at the Al terminal portions of the assembled batteries of Comparative Examples 2 and 3,
Then, at the same time in the Ni terminal portions of Comparative Examples 1 and 3, further sequentially, the Al terminal portion of the assembled battery of Example 3, the Al terminal portion of the assembled battery of Example 4, and the Al terminal portion of the assembled battery of Example 2. so,
Leakage occurred at the Ni terminal of the assembled battery of Example 2, at the Ni terminal of the assembled battery of Example 4, and finally at the Ni terminal of the assembled battery of Example 3. No leakage occurred in the Al terminal portion and Ni terminal portion of the assembled battery of Example 1, the Al terminal portion of the assembled battery of Comparative Example 1, and the Ni terminal portion of the assembled battery of Comparative Example 2.

Further, among the battery packs in which the lead terminals are provided on the lower side of Comparative Examples 1 to 3, the Ni connecting portion of Comparative Example 1, the Al connecting portion of Comparative Example 2, the Al connecting portion of Comparative Example 3, and Ni.
At the connecting portion, the electrolyte leaked due to the leak, and the lead terminal connecting portion was damaged. From these results, the lower the lead terminal portion is, the more wet the lead sealing portion is with the electrolytic solution,
It was confirmed that the electrolytic solution attacked the lead / exterior body adhesive interface to cause peeling deterioration. It was also confirmed that Al was more likely to be attacked by the electrolytic solution in the lead terminal than in Ni.

[0034]

[Table 1]

[0035]

As described above, according to the present invention,
By providing a means for preventing the electrolytic solution from coming into contact with the joint between the lead terminal and the outer package, the attack of the electrolytic solution on the adhesive interface between the lead and the outer package is mitigated, resulting in deterioration of peeling of the lead / outer package. It is difficult to obtain an assembled battery having excellent sealing reliability. In addition, it is possible to prevent damage to the lead terminal connecting portion due to ejection of the electrolytic solution from the lead sealing portion.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a unit cell that can be used in the present invention.

2 (a) to 2 (d) are schematic perspective views showing an embodiment of the present invention.

FIG. 3 is a schematic perspective view showing a mode in which the assembled battery which is an example of the present invention is covered with a metal case.

FIG. 4A and FIG. 4B are schematic perspective views illustrating a conventional unit cell.

FIG. 5 is a schematic cross-sectional view showing an example of a conventional assembled battery covered with a metal case.

FIG. 6A to FIG. 6C are schematic perspective views of a conventional assembled battery.

[Explanation of symbols]

1 ... electrode plate 2 ... Separator 3 ... Power generator 4 ... Current collector foil 5 ... Lower exterior body 6 ... Upper exterior body 7 ... Single battery 8 ··· Positive electrode lead connection part 9 ... Negative electrode lead connection 10 ... Case 11 ... Positive electrode lead 12 ... Negative electrode lead

Continued front page    (72) Inventor Nobuaki Yoshioka             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company (72) Inventor Hiroshi Yagada             5-7 Shiba 5-1, Minato-ku, Tokyo NEC Corporation             Inside the company F-term (reference) 5H011 AA17 EE04 FF02 GG00

Claims (4)

[Claims] 1. A battery body having a lead terminal connected to a power generator containing a plurality of electrode plates and containing an electrolytic solution is extended so that the lead terminal can be electrically connected to the outside, and an exterior body is used. In a battery pack in which a plurality of laminated laminated single cells sandwiching the lead terminals and hermetically sealed are stacked in the stacking direction, and the lead terminals are connected to each other, the electrolytic solution is added to the lead terminals and an outer package. An assembled battery, characterized in that it has means for preventing it from coming into contact with the joint portion of the battery. 2. The assembled battery according to claim 1, wherein the means for preventing the electrolytic solution from coming into contact with the joint between the lead terminal and the outer casing is that the lead terminal is not installed downward. 3. The assembled battery according to claim 1, wherein the electrode plates are housed in a case under pressure. 4. The lead terminal is made of nickel.
The assembled battery according to any one of 1 to 3.