JPH09171809A - Laser sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a welding process for electrically welding a current collector, and ensure the welding of the current collector. SOLUTION: In this battery, a spiral electrode body 1 is formed of a positive electrode plate and a negative electrode plate wound through a separator, the spiral electrode body 1 is housed in a battery facing can 4, and the opening edge of the battery facing can 4 is welded to a sealing plate 5 by laser welding, whereby the battery is sealed. The core body of the positive electrode plate or negative electrode plate is arranged on the outermost peripheral part of the spiral electrode body 1, and a current collector is taken out from the core body. The current collector is interposed between the opening edge of the battery facing can 4 and the sealing plate 5, and welded to the battery facing can opening edge and the sealing plate 5 by laser welding, and at least a part of the core body makes contact with the inner surface of the battery facing can 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser sealing battery in which a battery outer can opening edge and a sealing plate are laser-welded to seal the battery.

[0002]

2. Description of the Related Art Conventionally, in a laser-sealed battery, the positive electrode current collector is spot-welded to the battery outer can and the negative electrode current collector is spot-welded to the negative electrode terminal for electrical connection. Both the negative electrode current collector and the negative electrode current collector require a welding process with the outer shell of the battery, which makes the welding process of the current collector complicated.

On the other hand, as disclosed in Japanese Utility Model Laid-Open No. 59-12260, in a crimp-sealed battery, a tab terminal is provided between a battery lid and a gasket for insulating the battery outer can and the battery lid. It has been proposed to interpose and crimp and electrically connect in a crimp sealing step.

However, although the welding process of the tab terminal can be simplified by such a method, since it is a crimp seal, the electrolytic solution in the battery is inserted between the gasket and the battery lid in the vicinity where the tab terminal is interposed. There was a problem that was leaked.

Further, in the laser sealing battery as shown in FIG. 6, the outermost periphery of the spirally wound electrode body 1 is the positive electrode core body 2B, and the positive electrode core body 2B and the battery case 4 are electrically connected by contact. The negative electrode collector 3D is spot-welded to the negative electrode collector terminal for electrical connection. However, there is a problem in that it is difficult to effectively take out an electric current simply by contacting the positive electrode core with the battery outer can, and further, the contact is weakened due to deformation of the battery and the internal resistance increases.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser-sealed battery that simplifies the welding process for welding a current collector and ensures welding of the current collector.

[0007]

In the laser sealing battery of the present invention, a spiral electrode body is constituted by a positive electrode plate and a negative electrode plate with a separator interposed therebetween, and the spiral electrode body is housed in a battery outer can, In a laser-sealing battery in which a can opening edge and a sealing plate are laser-welded to seal a battery, a core body of the positive electrode plate or the negative electrode plate is arranged at the outermost peripheral portion of the spiral electrode body, and the core body is collected from the core body. The current collector is taken out, the current collector is interposed between the opening edge of the battery outer can and the sealing plate, and is welded to the opening edge of the battery outer can and the sealing plate by the laser welding, and the core. It is characterized in that at least a part of the body is in contact with the inner surface of the battery outer can.

[0008]

In the present invention, during laser welding of the opening edge of the battery outer can and the sealing plate, the current collector taken out from the core arranged at the outermost peripheral portion of the spirally wound electrode body is connected to the opening edge of the battery outer can and the sealing plate. Since the laser welding is used, the welding of the current collector and the sealing by the laser welding can be performed at the same time, so that the step of welding the current collector to the battery outer can can be omitted and the battery manufacturing process can be simplified.

Further, in order to widen the facing area of the positive electrode plate and the negative electrode plate, the positive electrode plate and the negative electrode plate are formed into a spiral electrode body through a separator, and the current collector is welded to the opening edge of the battery outer can and the sealing plate. Since it is taken out from the core at the outermost periphery of the spiral electrode body, it is possible to extend the current collector linearly along the inner surface of the battery exterior can from the outermost periphery of the spiral electrode body to the opening edge of the battery exterior can. It is possible, it is easy to take out the current collector,
The possibility that the current collector contacts the other polarity and short-circuits is reduced.

Further, the core body arranged at the outermost peripheral portion of the spiral electrode body is in contact with the inner surface of the battery outer can, and the current collector taken out from the core body is laser welded to the battery outer can and the sealing plate. Therefore, it is possible to reliably collect current in the battery outer can and the sealing plate.

As in the prior art, in the current collection only by contact between the core body and the inner surface of the battery outer can, when the battery outer can is deformed due to an increase in battery internal pressure or the like, the contact between the core body and the inner surface of the battery outer can. However, it is not possible to reliably collect current.

In the present invention, during laser welding, the current collector, which is sandwiched between the opening edge of the battery outer can and the sealing plate and welded to the battery outer can and the sealing plate, is the outermost peripheral portion of the spiral electrode body. It is configured by reversing the notch of the core body arranged at. With such a configuration, a separate step of supplying and fixing the current collector to the electrode plate is not necessary, and a production trouble due to a defect of the current collector does not occur when the current collector is supplied. Further, since the current collector is formed by reversing the notches of the core body, defective products due to poor connection between the current collector and the core body are reduced.

Further, in the current collector constituted by reversing the notch of the core body, the current collector is sandwiched between the opening edge of the battery outer can and the sealing plate and laser welded. Since the current collector terminal having a polarity different from that of the current collector is fixed via the insulating member including the insulating gasket and the insulating plate, the one-pole current collector terminal and the other-pole current collector are close to each other. Therefore, when an external force such as a drop or shock is applied to the battery, the spiral electrode body moves and the current collector or current collector terminal bends, and the adjacent one-pole current collector terminal and the other pole current collector come into contact with each other. It may cause a short circuit. Therefore, an external force is applied to the battery by interposing a wall portion provided on the insulating member for insulating the sealing plate and the one-pole current collector terminal between the one-pole current collector terminal and the other-pole current collector. However, it is possible to prevent contact between the one-pole current collector terminal and the other-pole current collector, and reduce internal short circuits.

Further, when the core body is provided with a notch, a burr may be formed in the notch, and the burr may penetrate the separator and come into contact with the counter electrode to cause an internal short circuit. Therefore, if a member having the same polarity as that of the core body provided with the notch on the lower surface of the notch, there is no fear that the burr due to the notch will cause a short circuit even if the core body comes into contact with the member below the notch. That is, when the positive electrode core body is provided with the cutout, the lower surface of the cutout constitutes the spiral electrode body such that the positive electrode core body or the positive electrode plate is present. Similarly, when disposing the negative electrode core body on the outermost periphery, the lower surface of the cutout is configured so that the negative electrode core body or the negative electrode plate is present.

FIG. 12 shows an enlarged sectional view of a main part of the spirally wound electrode body. In the figure, 2B is a positive electrode core, 2C is a positive electrode active material layer, 3C
A indicates a negative electrode plate, and 12 indicates a separator.

Here, when the notch is provided at the position A in FIG. 12 (the winding end position of the spiral electrode body at this time is a),
Since the positive electrode core body 2B having the same polarity as that of the notch is arranged on the lower surface of the notch, the withstand voltage defective rate due to an internal short circuit, which is considered to be caused by the burr of the notch, is 0% by winding. When a notch is provided at the position of B in FIG. 12 (the winding end position of the spiral electrode body at this time is b), a negative electrode plate having a polarity different from that of the notch is formed on the lower surface of the notch through the separator 12. It is understood that since the withstand voltage failure rate is 1%, the lower surface of the cutout is preferably a member having the same polarity as the cutout. The withstand voltage failure rate is a value obtained by measuring 50 batteries.

Further, according to the present invention, before manufacturing the spiral electrode body,
A notch is provided in advance in the core part of the positive electrode plate, but the notch provided in the core of the outermost peripheral part of the spirally wound electrode body should be substantially U-shaped so that it can be easily inverted and handled as a current collector. Suitable for Further, when the two opposite sides of the cutout are both perpendicular to the winding direction, the spiral electrode itself has a curvature, so that the slit in the vertical direction of the cutout previously wound is in a floating state. Then, when the spiral electrode body is formed into a non-round shape, the notch may be deformed (folded). Therefore, with respect to the winding direction of the spirally wound electrode body, one side of the notch that is wound up first has a slit inclined from the upper direction to the lower side of the spirally wound electrode body. Can be effectively prevented from being deformed (folded).

Further, according to the present invention, considering that the core body arranged at the outermost peripheral portion of the spirally wound electrode body is in contact with the battery outer can, aluminum or aluminum alloy is inexpensive as the battery outer can and the core body. It is optimal because it has good conductivity. Furthermore, in the case of a non-aqueous electrolyte battery or the like in which the battery voltage is high, if the battery outer can is aluminum or an aluminum alloy, corrosion of the battery outer can can be prevented and high corrosion resistance is obtained, which is optimal.

Further, when the laser sealing battery of the present invention is incorporated in a device to be used, it is very preferable that the battery has a rectangular outer shape, particularly a rectangular or oval shape, in order to effectively utilize the limited space. It is valid.

Further, when the cross section of the battery outer can is rectangular or oval, it is advantageous that the spiral electrode body to be inserted into the battery outer can has an oval shape instead of a perfect circle.

[0021]

【Example】

[Embodiment 1] FIG. 1 is a perspective view of a main part of a battery of the present invention.
3 is a front view and bottom view of the positive electrode plate, FIG. 3 is a front view and bottom view of the negative electrode plate, and FIG. 4 is a partial cross-sectional view of the sealing plate. In the figure, 1
Is a spiral electrode body including a positive electrode plate 2A and a negative electrode plate 3A with a separator 12 interposed therebetween. 4 is a battery outer can made of aluminum, and 5 is a sealing plate. The sealing plate 5 has a battery cap 6 protruding on the upper surface.

As shown in FIG. 4, the sealing plate 5 has a through hole near the center thereof, and the insulating gasket 10 is provided in the through hole.
The metal hollow cap 11 is arranged via the. The hollow cap 11 is fixed to the sealing plate 5 by caulking the upper end and the lower end. The upper end of the hollow cap 11 is connected to the battery cap 6, and the current collector terminal 8 is fixed to the lower surface of the sealing plate 5 by caulking the hollow cap 11. The current collecting terminal 8 and the hollow cap 11 are made of metal because conductivity is required, and the hollow cap 11 is connected to the current collecting terminal 8. An insulating plate 9 is sandwiched between the current collecting terminal 8 and the sealing plate 5 to insulate the current collecting terminal 8 from the sealing plate 5. Spacers 9A are integrally formed on both ends of the insulating plate 9, and the spacers 9A are located on the spiral electrode body.
The collector terminal 8 is connected to the negative electrode collector 3D of the spirally wound electrode body.

Reference numeral 2D is a notch 2E having a substantially U shape in the positive electrode core body 2B.
It is a positive electrode current collector provided and inverted. Reference numeral 7 is a protective tape for fixing the positive electrode current collector 2D.

The method for producing the battery of the present invention will be described below.

[Production of Positive Electrode Plate] LiCo as a positive electrode mixture
After thoroughly mixing 85 parts by weight of O ₂ , 5 parts by weight of artificial graphite powder and 5 parts by weight of carbon black, N-methyl-2-
Polyvinylidene fluoride dissolved in pyrrolidone (PVd
F) was added so that the solid content was 5 parts by weight to obtain an ink-like positive electrode slurry.

This positive electrode slurry has a length of 335 mm and a width of 3
It is applied onto the aluminum foil of the positive electrode core body 2B having a thickness of 8 mm and a thickness of 20 μm to form a positive electrode active material layer 2C.

Next, after drying, it is rolled by a roller press and vacuum dried at 110 ° C. for 3 hours to obtain a positive electrode plate 2A.
Was prepared. This positive electrode plate 2A is shown in FIG.

From the end of the positive electrode core to 20 mm, the positive electrode active material layer was not applied to both sides of the positive electrode core to expose the core, and 50 mm to one side of the positive electrode core. Only the area where the positive electrode active material layer is applied. When the positive electrode plate 2A is wound, by winding a portion of the positive electrode core body coated with the positive electrode active material layer so as to face the inner side of the spirally wound electrode body, A core body can be used, and the positive electrode core body and the inner surface of the battery outer can can be brought into contact with each other.

Further, a substantially U-shaped cutout 2E is formed in the exposed portion of the positive electrode core body where the positive electrode active material layer is not applied on both surfaces of the positive electrode core body. The notch 2E becomes the positive electrode current collector 2D by forming the spiral electrode body and then reversing the notch.

[Preparation of Negative Electrode Plate] As a negative electrode mixture, PVdF dissolved in N-methyl-2-pyrrolidone was added to 95 parts by weight of natural graphite powder having a particle size of 5 to 25 μm as a solid content.
Ink-like negative electrode slurry was added in an amount of about 1 part by weight.

This negative electrode slurry has a length of 315 mm and a width of 3
Both surfaces are coated on a copper foil of a negative electrode core body 3B having a thickness of 9 mm and a thickness of 18 μm to form a negative electrode active material layer 3C. After drying this negative electrode active material layer, it was rolled by a roller press machine, spot-welded with nickel leads as the negative electrode current collector 3D at the end portion,
Vacuum drying treatment was performed at 110 ° C. for 3 hours to produce a negative electrode plate 3A. This negative electrode plate 3A is shown in FIG.

[Preparation of Electrolyte Solution] LiPF ₆ was dissolved in a mixed solvent having a volume mixing ratio of ethylene carbonate and diethyl carbonate of 40:60 so as to have a concentration of 1 mol / l to prepare a non-aqueous electrolyte solution. .

[Preparation of spiral electrode body] The above positive electrode plate 2A
And the negative electrode plate 3A with a polyethylene separator 12
The spirally wound electrode body 1 was manufactured by winding through. In manufacturing the spiral electrode body 1, the spirally wound electrode body 1 is wound so that the exposed portion of the positive electrode core body is arranged at the outermost peripheral portion of the spirally wound electrode body 1. or,
At the winding end portion of the spirally wound electrode body, the electrode body is fixed by a winding end tape 13. Further, the bottom of the spiral electrode body is covered with an insulating tape 14.

[Manufacturing of Battery] FIG. 5 shows a manufacturing process of the battery of the present invention.

The sealing plate 5 is arranged on the upper part of the spiral electrode body 1, and the negative electrode current collector 3D and the current collecting terminal 8 arranged on the sealing plate 5 are electrically welded. Next, the substantially U-shaped notch 2E provided in advance on the exposed portion of the positive electrode core body located at the outermost peripheral portion of the spirally wound electrode body is inverted, and this is cut off.
D. The protective tape 7 is attached to the inverted portion of the notch 2E to fix the positive electrode current collector 2D. At this time,
The tip of the positive electrode current collector 2D is adjusted to slightly exceed the upper surface of the sealing plate.

Next, this spiral electrode body 1 is inserted into a prismatic battery outer can 4 made of aluminum. At this time, the positive electrode core body located at the outermost periphery of the spirally wound electrode body is in contact with the inner surface of the battery outer can, and the positive electrode current collector 2D is sandwiched between the open end of the battery outer can and the sealing plate 5. . When the tip portion of the positive electrode current collector 2D projects considerably beyond the top surface of the sealing plate, it is adjusted by cutting it into an appropriate length.

Finally, the junction between the battery case 4 and the sealing plate 5 or the vicinity of the junction is irradiated with laser light to weld them together. At this time, the positive electrode collector 2D is also electrically connected to the battery outer can 4 and the sealing plate 5 by laser light at the same time. After the laser welding, before fixing the battery cap 6 to the crimped upper end of the hollow cap 11 on the upper surface of the sealing body, a nonaqueous electrolytic solution is injected into the electric outer can from the through hole of the sealing plate. After injecting the electrolytic solution, the battery cap 6 is fixed to manufacture a battery.

Since the thickness of the positive electrode current collector 2D is as thin as 20 μm, the spirally wound electrode body can be easily inserted into the battery outer can and, even if sandwiched between the battery outer can and the sealing plate, has a large fitting surface. Since no gap is generated, the positive electrode current collector can be reliably welded to the battery outer can and the sealing plate by laser welding. The battery manufactured as described above is referred to as Battery A1 of the invention.

Comparative Example 1 As shown in FIG. 6, instead of the positive electrode current collector 2D of the battery A1 of the present invention, only the contact between the positive electrode core 2B at the outermost peripheral portion of the spirally wound electrode body and the inner surface of the battery outer can. Other than providing the electrical connection between the positive electrode plate and the battery outer can,
A battery was manufactured in the same manner as in Example 1. This battery is referred to as a comparative battery X1. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals.

[Experiment 1] Inventive Battery A1 and Comparative Battery X
Experiments were conducted on the high temperature storage characteristics of No. 1. The measurement method is
First, the battery capacities of the present invention battery A1 and the comparative battery X1 were 5
Each open circuit voltage was measured with the battery charged to 0%. Then, in this state, each battery was allowed to stand in a constant temperature bath at 60 ° C. for 10 days, and after standing, the closed circuit voltage when a resistance of 10 Ω was connected to each battery was measured, and the battery voltage was measured during storage at high temperature. An experiment was conducted to see how much it decreased. Table 1 shows the results.

[0041]

[Table 1]

As can be seen from Table 1, the battery A1 of the present invention is
It can be seen that the decrease in battery voltage is suppressed even after storage at high temperature.

[Experiment 2] Battery A1 of the invention and comparative battery X
An experiment was conducted on the internal resistance of Sample No. 1 after storage at high temperature. The high temperature storage state of each battery was the same as in Experiment 1. For the measurement of the internal resistance, the measured value by the alternating current method at 1 kHz is shown. The results are shown in Table 2.

[0044]

[Table 2]

As can be seen from Table 2, the battery A1 of the present invention is
It can be seen that the increase in the internal resistance of the battery is suppressed even after storage at high temperature.

From Experiment 1 and Experiment 2 as described above, in both the present invention battery A1 and comparative battery X1, the positive electrode core body at the outermost peripheral portion of the spirally wound electrode body and the battery outer can are brought into contact with each other to collect current. The invention battery A1 has the result that the decrease in the closed circuit voltage after the high temperature storage and the increase in the internal resistance are suppressed as compared with the comparative battery X1. In the battery A1 of the present invention, in addition to the current collection by contact between the positive electrode core body and the battery outer can, the positive electrode current collector obtained by inverting the positive electrode core body by providing a notch,
This is because the battery outer can and the sealing plate are simultaneously welded to the battery outer can and the sealing plate at the time of laser welding. This indicates that the battery A1 of the invention has more reliable current collection between the positive electrode current collector, the battery outer can and the sealing plate, in addition to the current collection by contact. Like the comparative battery X1, in the current collection only by the contact between the positive electrode core body at the outermost peripheral portion of the spirally wound electrode body and the inner peripheral surface of the battery outer can, when the battery is placed in a high temperature storage state, the pressure inside the battery is If it rises and the battery outer can is deformed even a little (the battery outer can swells), the contact between the spirally wound electrode body and the inner surface of the battery outer can is obviously reduced, the closed circuit voltage is lowered, and the internal resistance is increased. It is thought to occur.

On the other hand, in the battery A1 of the present invention, even if the outer can of the battery is slightly deformed and the contact between the outermost peripheral surface of the spirally wound electrode body and the inner peripheral surface of the outer can of the battery is reduced, the positive electrode current collector is , Securely welded to the battery outer can and the sealing plate by laser welding,
Since the current is collected, it is possible to suppress a decrease in closed circuit voltage and an increase in internal resistance.

[Embodiment 2] Sealing plate 51 as shown in FIG.
A battery was produced in the same manner as in Example 1 except that was used. This battery is referred to as Battery A2 of the invention. FIG. 9 shows an external view of the spiral electrode body and the sealing plate of the battery A2 of the invention.

The battery A2 of the present invention is characterized in that a part of the spacer 91A of the insulating plate 91 provided on the lower surface of the sealing plate 51 is extended as a wall portion 91B. This wall 91B
Is a notch 2E of the core body arranged on the outermost peripheral surface of the spiral electrode body.
The current collector 2D provided by reversing the current collector is provided to prevent contact with a current collector terminal having a polarity different from that of the current collector. Therefore, the current collector 2D is attached to the wall 91.
By being arranged on the upper surface of B, the current collector 2D can be laser-welded to the sealing plate and the battery outer can without contacting a member having a polarity different from that of the current collector.

Example 3 A battery was prepared in the same manner as in Example 1 except that the spirally wound electrode body having a notch shape as shown in FIG. 10 was used. This battery is referred to as Battery A3 of the invention.

As can be seen from FIG. 10, the cutout 21E is composed of a vertical slit 201E, a parallel slit 202E, and an inclined slit 203E. The cutout 21E is inverted to form a current collector 21D. Here, when constructing the spirally wound electrode body, the slit of the notch wound first is the inclined slit 203E, and when the notch is inverted, the slit is inclined so that the root portion is wound first. Therefore, it is possible to effectively prevent the deformation (folding) of the slit of the notch when forming the spiral electrode body.

Example 4 Next, a battery was manufactured in the same manner as in Example 2 except that the spirally wound electrode body having the same notch shape as the battery A3 of the present invention was used. This battery is referred to as Battery A4 of the invention. FIG. 11 shows an external view of the spiral electrode body and the sealing plate of the battery A4 of the invention.

[Experiment 3] The rates of internal short circuit when the batteries A1, A2, A3 and A4 of the present invention were dropped were compared. The present invention batteries A1, A2, A3 and A
External views in which a sealing plate is arranged on the spiral electrode body of No. 4 are shown in FIGS. 8, 9, 10, and 11, respectively. In addition, the drop test is performed from the height of 1.5 m with the battery cap facing down.
The rate of internal short circuit when dropped on the tile was determined. The number of tests is 50 each. Table 3 shows the results of the drop test.

[0054]

[Table 3]

It can be seen from Table 3 that the batteries A2 and A4 of the present invention have fewer internal short circuits due to dropping than the batteries A1 and A3 of the present invention. This is because, as described above, the wall portion 91B provided on the insulating plate 91 prevents the current collector 2D from coming into contact with a member having a polarity different from that of the adjacent current collector due to the external force caused by the drop.
It is believed that this is due to the prevention.

[Experiment 4] The appearance defect rates when the batteries A1, A2, A3 and A4 of the present invention were respectively wound up will be compared. It should be noted that the poor appearance means deformation of the current collector in the notch during winding. The number of tests is 50 each. Table 4 shows the results of the appearance defect rate.

[0057]

[Table 4]

From Table 4, it can be seen that the present invention batteries A3 and A4 have a lower appearance defect rate than the present invention batteries A1 and A2. This is because, as described above, when manufacturing the spirally wound electrode body, by providing the inclined slit 203E in the notch 21E as in the battery A3 of the present invention, deformation (bending) of the slit of the notch can be effectively prevented. I understand.

[0059]

According to the present invention, a spirally wound electrode body is constructed by interposing a separator between a positive electrode plate and a negative electrode plate, the spirally wound electrode body is housed in a battery outer can, and an opening edge of the battery outer can and a sealing plate are provided. In a laser sealing battery for sealing a battery by laser welding, a core body of the positive electrode plate or the negative electrode plate is arranged at the outermost peripheral portion of the spirally wound electrode body, and a current collector is taken out from the core body and The electric body is interposed between the opening edge of the battery outer can and the sealing plate, and is welded to the opening edge of the battery outer can and the sealing plate by laser welding, and at least a part of the core and the inner surface of the battery outer can. Since the and are in contact with each other, it is possible to suppress the decrease in the closed circuit voltage and the increase in the internal resistance, and it is possible to omit the step of welding the current collector to the battery outer can and simplify the battery manufacturing process.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a battery of the present invention.

FIG. 2 is a front view and a bottom view of a positive electrode plate of the battery of the present invention.

FIG. 3 is a front view and a bottom view of a negative electrode plate of the battery of the present invention.

FIG. 4 is a partial sectional view of a sealing plate of the battery of the present invention.

FIG. 5 is a diagram showing a manufacturing process of the battery of the present invention.

FIG. 6 is a perspective view of a main part of a comparative battery.

FIG. 7 is a partial cross-sectional view of a sealing plate according to another embodiment of the battery of the present invention.

FIG. 8 is a view in which a sealing plate is arranged on the spirally wound electrode body of Battery A1 of the invention.

FIG. 9 is a view in which a sealing plate is arranged on the spirally wound electrode body of Battery A2 of the invention.

FIG. 10 is a view showing a sealing plate arranged on the spirally wound electrode body of Battery A3 of the invention.

FIG. 11 is a view in which a sealing plate is arranged on the spirally wound electrode body of Battery A4 of the invention.

FIG. 12 is a cross-sectional view of a spiral electrode body according to another embodiment of the battery of the present invention.

[Explanation of symbols]

1 ・ ・ ・ ・ Swirl electrode body 2A ・ ・ ・ ・ ・ ・ ・ ・ Positive plate 3A ・ ・ ・ ・
・ ・ Negative electrode plate 2B ・ ・ ・ ・ Positive electrode core 3B ・ ・ ・ ・
..Negative electrode core 2C ..... Positive electrode active material layer 3C ..
..Negative electrode active material layers 2D, 21D ..
・ ・ Negative electrode current collector 2E, 21E ・ ・ Notch 201E ・ ・ ・ ・ Vertical slit 202E ・ ・ ・ ・ Parallel slit 203E ・ ・ ・ ・ ・ ・ Inclined slit 4 ・ ・ ・ ・ ・ ・ ・ ・ Battery exterior can 5, 51 ・ ・ ・・ Sealing plate 6 ・ ・ ・ ・ Battery cap 7 ・ ・ ・ ・ Protection tape 8 ・ ・ ・ ・ ・ Collector terminal 9, 91 ・ ・ ・ ・ Insulating plate 9A, 91A ・ ・ Spacer 91B・ ・ ・ ・ ・ Wall 10 ・ ・ ・ ・ ・ ・ Gasket 11 ・ ・ ・ ・ ・ Hollow cap 12 ・ ・ ・ ・ Separator 13 ・ ・ ・ ・ Wind end tape 14 ・ ・ ・ ・ ・ ・ Insulation tape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Yamauchi 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Hiyoshi Tamaki 2-chome, Keihan-hondori, Moriguchi-shi, Osaka No. 5-5 Sanyo Electric Co., Ltd.

Claims (6)

[Claims] 1. A positive electrode plate and a negative electrode plate constitute a spiral electrode body with a separator interposed therebetween, the spiral electrode body is housed in a battery outer can, and the opening edge of the battery outer can and a sealing plate are laser-welded. In a laser sealing battery for sealing a battery, a core body of the positive electrode plate or the negative electrode plate is arranged at the outermost peripheral portion of the spirally wound electrode body, and a current collector is taken out from the core body, and the current collector is It is interposed between the opening edge of the battery outer can and the sealing plate, and is welded to the opening edge of the battery outer can and the sealing plate by the laser welding, and at least a part of the core body contacts the inner surface of the battery outer can. Laser-sealed battery characterized by having. 2. The sealing plate has an insulating plate disposed between the sealing plate and a one-pole current collector terminal fixed to the lower surface of the sealing plate, and the insulating plate is the other-pole current collector. The laser-sealed battery according to claim 1, further comprising a wall portion that insulates the one-pole current collecting terminal from the other. 3. The current collector according to claim 1, wherein a cutout is formed in a part of the core body of the one-side electrode plate, and the cutout is folded back. Laser sealing battery. 4. A member having the same polarity as that of the core body of the outermost peripheral portion is located on the lower surface of the cutout.
The laser sealing battery described. 5. The laser sealing battery according to claim 3, wherein the notch has a substantially U shape. 6. The notch has a slit in which one side of the notch wound first is inclined with respect to a winding direction of the spirally wound electrode body from an upper direction of the spirally wound electrode body to a lower direction thereof. The laser sealing battery according to claim 3 or claim 4.