JP2000173565A - Sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealing of a battery can composed of a gasket and sealing electrode member by press-fitting the sealing electrode member into the cylindrical part of the gasket, while avoiding malfunction in assembling such as the sealing electrode member not entering in a cylindrical part (outer cylinder part) of the gasket and by closely adhering the outer circumferential face of the member and the cylindrical part of the gasket by a strong press contact force. SOLUTION: A rapture plate 7 is so constituted that its diameter D is smaller than the inside diameter d1 of the tip side of the outer cylinder part 3b of a gasket 3 but larger than the inside diameter d2 in the base side so as to be press-fitted into the base side of the outer cylinder 3b. A variable resistance plate and a positive electrode cap have almost same outside diameter as that of the rapture plate 7 and are press-fitted into the outer cylinder part 3b along with the rapture plate 7. The battery can have its open end calked inward with the gasket 3 and the sealing electrode member mounted thereon. When the rapture plate 7 is press-fitted into the outer cylinder part 3b of the gasket 3, the part in the base end side of the outer cylinder 3b is contracted radially.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a sealed battery,
In particular, the present invention relates to a measure for improving a structure in which an open end of a bottomed cylindrical battery can is sealed with a sealing electrode member and a gasket.

[0002]

2. Description of the Related Art A sectional structure of a conventional sealed battery is shown in FIG. In the figure, reference numeral 1 denotes a bottomed cylindrical battery can.
This sealed battery is prepared by filling a battery can 1 with a power generating element 11 such as an electrode or an electrolyte, and then using a gasket 3 and a sealing electrode member 2 composed of a plurality of disc-shaped members. The opening end 1a is sealed.

[0003] The battery can 1 has a battery can slightly larger than the open end 1a.
An annular gasket receiver 1b protruding toward the center of the battery can 1 is formed on the bottom side of the battery can 1. Gasket 3
FIG. 6 shows the structure of the gasket 3 and the sealing electrode member 2.
As shown in FIG. 3, an annular plate portion 3a abutting on the gasket receiver 1b of the battery can 1 and a battery can 1 connected to an outer peripheral edge of the annular plate portion 3a.
And an inner cylindrical portion 3c connected to the inner peripheral edge of the annular plate portion 3a and extending to the opposite side to the outer cylindrical portion 3b.

On the gasket 3, a terminal plate 4, a reinforcing plate 5, and an internal insulating plate 6 are mounted on the inner cylindrical portion 3c in order from the bottom side of the battery can 1, and a rupture plate 7 and a variable resistance plate are mounted on the outer cylindrical portion 3b. 8 and a positive electrode cap 9 are attached. And
The sealing electrode member 2 is formed by these six disk-shaped members 4 to 9.
Is configured.

The battery can 1 includes a gasket 3 and a sealing electrode member.
2, the open end 1a is crimped inward. As a result, the distal end side of the outer cylindrical portion 3b of the gasket 3 is bent toward the positive electrode cap 9. And
The peripheral edge of the sealing electrode member 2 is sandwiched between the ring plate portion 3a of the gasket 3 and the distal end portion of the outer cylindrical portion 3b, and the battery is sealed.

In this structure, if both the space between the battery can 1 and the gasket 3 and the space between the gasket 3 and the sealing electrode member 2 are securely sealed, leakage of liquid or gas can be prevented. Specifically, the main part acting as a seal in this structure is between the gasket 3 and the battery can 1
Portion where the open end 1a of the battery can 1 bites into the gasket 3.
A, and between the gasket 3 and the sealing electrode member 2,
The portion B1 on the lower surface side of the rupture plate 7 among the portions B1 and B2 in which the gasket 3 sandwiches and closes the sealing electrode member 2 from both sides.

As shown in FIG. 6, in the above structure, a slight gap is formed between the inner peripheral surface of the outer cylinder portion 3b of the gasket 3 and the outer peripheral surfaces of the rupture plate 7, the variable resistance plate 8 and the positive electrode cap 9. The dimensional tolerance is set so as to form a large gap C. This is to avoid a problem that the rupture plate 7 or the like does not enter the outer cylinder portion 3b of the gasket 3 when assembling the battery.

[0008]

In the above configuration,
Portion where the open end 1a of the battery can 1 bites into the gasket 3.
In A, the gasket 3 is sufficiently compressed so that a high sealing property can be obtained.However, in the portion B1 where the rupture plate 7 is in surface contact with the ring plate portion 3a of the gasket 3, the gasket 3 is difficult to be sufficiently compressed. Was sometimes insufficient. For this reason, gas and liquid leaking from this part B1
Further, through the gap C between the outer peripheral surface of the sealing electrode member 2 and the outer cylindrical portion 3b of the gasket 3, between the rupture plate 7 and the variable resistance plate 8, between the variable resistance plate 8 and the positive electrode cap 9, etc. There was a risk of leakage to the outside.

The present invention has been made in view of such conventional problems, and an object of the present invention is to improve the sealing structure of a sealed battery and improve the structure of a battery can by a gasket and a sealing electrode member. An object of the present invention is to enhance the sealing performance and reduce the risk of liquid leakage and the like.

[0010]

SUMMARY OF THE INVENTION According to the present invention, the sealing electrode member is prevented from being mounted on the gasket by preventing the sealing electrode member from entering the cylindrical portion (outer cylindrical portion) of the gasket. The gasket is press-fitted into the cylindrical portion so that the outer peripheral surface of the sealing electrode member and the cylindrical portion of the gasket are brought into close contact with a strong pressing force.

Specifically, a first solution taken by the present invention is to provide a bottomed cylindrical battery can filled with a power generating element and a battery can at a position closer to the bottom of the battery can than the open end of the battery can. An annular gasket receiver protruding radially inward of the battery can; a ring plate portion abutting the gasket receiver from the open end side of the battery can; and a cylindrical shape fitted to the inner peripheral surface of the open end of the battery can. A gasket having a gasket and a sealing electrode member mounted in the cylindrical portion of the gasket, and the gasket and the sealing electrode member are attached to the opening end of the battery can. It is premised on a sealed battery in which the battery can is sealed by caulking inward together with the cylindrical portion of the above.

The inner peripheral surface of the cylindrical portion of the gasket is
The outer diameter of the sealing electrode member is smaller than the inner diameter of the distal end of the cylindrical portion of the gasket, and is formed in a tapered shape so that the diameter increases from the base end on the ring plate portion side to the open end. It is configured to be larger than the inner diameter on the proximal end side so as to be pressed into the proximal end side of the cylindrical portion.

[0013] The second solution taken by the present invention is:
In the first solution, the sealing electrode member is connected to the power generating element and has a rim plate whose peripheral edge is in contact with the annular plate portion of the gasket; and a cap which is overlapped on the rupture plate and constitutes a connection terminal to an external electrode. The outer diameter of the rupture plate is smaller than the inner diameter of the distal end of the tubular portion of the gasket, and is larger than the inner diameter of the proximal end side so as to be pressed into the proximal end side of the tubular portion. It is composed. The cap-shaped electrode may be directly stacked on the rupture plate, or may be stacked via the above-described variable resistance plate or the like.

In the first solution, the outer diameter of the sealing electrode member is smaller than the inner diameter of the tip of the tubular portion of the gasket, so that the sealing electrode member can be easily inserted into the tubular portion. When the sealing electrode member is inserted into the ring plate portion side, the inner peripheral surface of the cylindrical portion is tapered and has a smaller diameter toward the ring plate portion side. Contacts the inner peripheral surface of the cylindrical portion. Then, when the sealing electrode member is further pushed into the annular plate portion side, the sealing electrode member is pressed into the cylindrical portion while deforming so as to expand the inner peripheral surface of the cylindrical portion radially outward. Become. After the sealing electrode member is attached to the gasket in this manner, the battery can is hermetically sealed by caulking the open end of the battery can.

In the second solution, when the rupture plate is inserted into the cylindrical portion of the gasket, the above-described action is generated.

[0016]

According to the first aspect of the present invention, the outer peripheral surface of the sealing electrode member is pressed into the base end side of the tubular portion of the gasket to compress the tubular portion in the radial direction. The gasket can be sufficiently deformed as compared with the example of FIG. 5 in which the annular plate portion of the gasket is compressed in the direction perpendicular to the plane. Therefore, the sealing performance between the gasket and the sealing electrode member can be improved as compared with the conventional case, and the sealing performance of the battery can be improved.

Further, the sealing electrode member is formed to have an outer diameter smaller than the inner diameter of the distal end of the tubular portion of the gasket, and can be easily inserted into the tubular portion. Also, there is no problem in assembling such that no crack occurs.

According to the second solution, a high sealing property can be obtained between the outer peripheral surface of the rupture plate and the cylindrical portion of the gasket. Therefore, leakage of gas or liquid between the rupture plate and the gasket which may occur in a sealed battery in which the sealing electrode member includes the rupture plate and the cap-shaped electrode (the positive electrode cap in FIGS. 5 and 6) is prevented. Thus, the hermeticity of the battery can be improved.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, this sealed battery has a closed cylindrical battery can 1 in which a power generating element 11 such as an electrode or an electrolyte is filled, and an open end 1a of the battery can 1. Sealing electrode member 2 and a gasket located between battery can 1 and sealing electrode member 2 to seal the inside of battery can 1 to the outside.
And 3. In this embodiment, the battery can 1 is formed of a thin iron plate. The bottom (not shown) is used as a negative electrode, and the sealing electrode member 2 constitutes a positive electrode.

As in the example shown in FIGS. 5 and 6, the battery can 1 has an annular gasket receiver projecting inward from the battery can 1 at a position slightly closer to the bottom of the battery can 1 than the open end 1a. 1b
Are formed by drawing of the battery can 1. Then, with the gasket 3 and the sealing electrode member 2 attached to the battery can 1, the open end 1a of the battery can 1 is caulked.

The material of the gasket 3 is polypropylene. The gasket 3 includes an annular plate portion 3a that contacts the gasket receiver 1b of the battery can 1, an outer cylindrical portion (cylindrical portion) 3b connected to the outer peripheral edge of the annular plate portion 3a, and an inner peripheral edge of the annular plate portion 3a. And an inner cylindrical portion 3c extending to the opposite side from the outer cylindrical portion 3b. The outer cylindrical portion 3b of the gasket 3 is formed such that the outer peripheral surface is fitted to the inner peripheral surface of the open end 1a of the battery can 1. Also, as shown in FIG. 3, the inner peripheral surface of the outer cylindrical portion 3b gradually increases in diameter from a base end side (ring plate portion 3a side) to a distal end side (open side). It is formed in a tapered shape.

The sealing electrode member 2 is mounted in order from the bottom side of the battery can 1 to the terminal plate 4, the reinforcing plate 5, the inner insulating plate 6 mounted on the inner cylindrical portion 3c of the gasket 3, and the outer cylindrical portion 3b. It comprises a rupture plate 7, a variable resistance plate 8, and a positive electrode cap (cap-shaped electrode) 9.

The terminal plate 4 is a thin disk-shaped member made of aluminum and has a positive electrode tab 10 fixed to the bottom surface by welding or the like.
Through the power generation element 11. The reinforcing plate 5 superposed on the terminal plate 4 is also a thin disk-shaped member made of aluminum, and the internal insulating plate 6 is a thin disk-shaped member made of polypropylene. Reference numeral 12 denotes an insulating plate having a hole formed in the center, and the lower end of the positive electrode tab 10 is in contact with the power generating element 11 through the hole.

On the other hand, the rupture plate 7 is a conductor made of aluminum, and the center portion 7a recessed toward the bottom of the battery can 1 passes through the center holes 5a, 6a of the reinforcing plate 5 and the internal insulating plate 6. It comes into contact with the terminal plate 4, and its peripheral edge is in contact with the ring plate portion 3 a of the gasket 3. The variable resistance plate 8 is formed of a material having a characteristic that the resistance increases as the temperature rises, and is used to make it difficult for current to flow when the temperature rises abnormally. The positive electrode cap 9 is a member made of a conductive material such as nickel-plated iron, and is used as a positive electrode terminal of the battery.

The rupture plate 7 is a member for preventing the battery can 1 from being ruptured when the internal pressure is increased due to an abnormality of the battery or the like, before the battery can 1 is ruptured. For this reason,
As shown in FIG. 4, the rupture plate 7 has a circular groove 7b and a plurality of linear grooves 7c extending radially from the circular groove 7b around a central portion 7a. By reducing the plate pressure of the portion 7c, the portions of the grooves 7b and 7c are broken when the internal pressure of the battery reaches a predetermined value.

In this embodiment, the rupture plate 7 has an outer diameter
D is smaller than the inner diameter d1 on the distal end side of the outer cylindrical portion 3b of the gasket 3, but is larger than the inner diameter d2 on the proximal end side, and is configured to be press-fitted into the proximal end side of the outer cylindrical portion 3b. . The variable resistance plate 8 and the positive electrode cap 9 have substantially the same outer diameter as the rupture plate 7, and are press-fit into the outer cylinder portion 3b together with the rupture plate 7.

The battery can 1 is, as described above, a gasket.
The opening end 1a is crimped inward with 3 and the sealing electrode member 2 mounted. In the present embodiment, the rupture plate 7, the variable resistance plate 8, and the outer diameter D of the positive electrode cap 9 and the inner diameter d1, d2 of the outer cylindrical portion 3b of the gasket 3 are restricted as described above. Fig. 3
When the gasket 3 is press-fitted into the outer cylinder portion 3b as shown in FIG. 7, the base end portion of the outer cylinder portion 3b is compressed in the radial direction. Therefore, the battery can 1 is sealed with the outer peripheral surface of the rupture plate 7 and the inner peripheral surface of the outer cylinder portion 3b of the gasket 3 strongly pressed against each other.

-Effects of Embodiment- According to this embodiment,
Since the outer peripheral surface of the rupture plate 7 is pressed into the base end side of the outer cylindrical portion 3b of the gasket 3 to compress the outer cylindrical portion 3b in the radial direction, the gasket 3 can be sufficiently deformed. For this reason, the sealing performance between the gasket 3 and the rupture plate 7 can be improved as compared with the conventional case, and the occurrence of problems such as liquid leakage can be more reliably prevented.

Further, the gasket 3 is connected to the annular plate portion of the outer cylindrical portion 3b.
On the 3a side, the outer peripheral surface of the rupture plate 7 is pressed against, while the inner diameter d1 on the distal end side of the outer cylindrical portion 3b is made larger than the outer diameter D of the rupture plate 7 or the like, so that the rupture plate 7 or the like is Since it can be easily inserted into the device, there is no problem that the assemblability is impaired.

[0031]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment. For example, in the above embodiment, the battery can was described as being cylindrical,
It may be a rectangular tube.

Further, in the above embodiment, the variable resistance plate 8 and the positive electrode cap 9 are formed so that the outer diameter D is substantially the same as that of the rupture plate 7.
The variable resistance plate 8 and the positive electrode cap 9 are also gasket
Although the outer cylindrical portion 3b of Fig. 3 is slightly compressed, the variable resistance plate 8 and the positive electrode cap 9 may be slightly smaller in outer diameter than the rupture plate 7 to reduce the amount of compression, thus facilitating assembly. Alternatively, the sealing performance may be enhanced by forming the outer diameter to be somewhat larger than that of the rupture plate 7 and increasing the compression amount.

In the above embodiment, the sealing electrode member 2
Is composed of six laminated plate-like members 4 to 9, but this configuration can be changed as appropriate. For example, in the above embodiment, the rupture plate 7 and the positive electrode cap 9 are formed as separate components with the variable resistance plate 8 interposed therebetween, but the rupture plate 7 and the positive electrode cap 9 are formed as an integrated component,
The variable resistance plate 8 can be arranged between the variable resistance plate 8 and the terminal plate 4.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sealed structure of a sealed battery according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a gasket and a sealing electrode member of the sealed battery of FIG.

FIG. 3 is a sectional view showing a state in which a rupture plate is attached to the gasket of FIG. 2;

FIG. 4 is a partial plan view of the rupture plate of FIG. 2;

FIG. 5 is a sectional view showing a sealed structure of a conventional sealed battery.

6 is a cross-sectional view showing a configuration of a gasket and a sealing electrode member of the sealed battery of FIG.

[Explanation of symbols]

 1 Battery can 1a Open end 1b Gasket receiver 2 Sealing electrode member 3 Gasket 3a Ring plate 3b Outer tube (cylinder) 3c Inner tube 4 Terminal plate 5 Reinforcement plate 6 Internal insulating plate 7 Rupture plate 7a Center 7b Round Groove 7c Straight groove 8 Variable resistance plate 9 Positive electrode cap (cap-shaped electrode) 10 Positive electrode tab 11 Power generation element 12 Insulation plate

Claims (2)

[Claims] 1. A bottomed cylindrical battery can filled with a power generating element, and an annular gasket protruding radially inward of the battery can at a position closer to the bottom of the battery can than the open end of the battery can. A gasket integrally including a receiver, a ring plate portion abutting against the gasket receiver from the open end side of the battery can, and a cylindrical portion fitted to the inner peripheral surface of the open end of the battery can; A sealing electrode member attached to the inside of the battery can, the gasket and the sealing electrode member are attached to the opening end of the battery can, and the opening end is crimped inward together with the tubular portion of the gasket to form the battery can. A sealed battery, wherein the inner peripheral surface of the tubular portion of the gasket is formed in a tapered shape such that its diameter increases from a base end on the ring plate portion side to a distal end on the open side. The outer diameter of the member is smaller than the inner diameter of the tip of the tubular portion of the gasket, And a sealed battery configured to be larger than the inner diameter of the base end side so as to be pressed into the base end side of the cylindrical portion. 2. A sealing electrode member which is electrically connected to a power generating element and has a peripheral portion in contact with an annular plate portion of a gasket, and a cap-shaped electrode which is superposed on the rupture plate and constitutes a connection terminal to an external electrode. The outer diameter of the rupture plate is configured to be smaller than the inner diameter of the distal end of the tubular portion of the gasket and larger than the inner diameter of the proximal end so as to be pressed into the proximal end of the tubular portion. The sealed battery according to claim 1.