JP2001266827A - Sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed battery in which the explosion proof portion operates steadily when the inner pressure of the container has reached a relatively low pressure, without increasing the process cost of the cut-out groove. SOLUTION: The explosion proof portion 15 of a sealed battery 10 comprises a connecting hole 50 which passes the inside and outside of the lid portion 47 composing a container 44, a thin member 21 closing the connecting hole 50, a first and second cut-out grooves 11, 12 which continue to surround a certain area along the surface direction of the thin member 21. A bending portion 13 at which the continuing direction of the first cut-out groove 11 and the second cut-out groove 12 cross each other at a prescribed angle is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery,
In particular, the present invention relates to a sealed battery capable of preventing expansion and rupture during overcharge, overdischarge or overload.

[0002]

2. Description of the Related Art As shown in FIG. 4, a general sealed battery 40 using a non-aqueous electrolyte is composed of a battery body 43 in which a positive electrode 41 and a negative electrode 42 are laminated via an electrolyte layer, and a battery body 43. And an explosion-proof part 45 that is activated when the internal pressure of the container 44 reaches a certain level or higher. The container 44 has a flattened rectangular cylindrical body 46 with a bottom, and a substantially rectangular flat lid 47 attached to the opening of the main body 46. The lid 47 is provided with the positive electrode 41
A positive electrode terminal 48 and a negative electrode terminal 49 connected to the negative electrode 42 respectively penetrate and protrude, and an injection port (not shown) for injecting an electrolyte into the container 44 is provided.

As shown in FIGS. 5 and 6, an explosion-proof part 45 is provided.
Has a circular communication hole 50 penetrating the lid 47, a thin member 51 along the back surface of the lid 47 and closing the communication hole 50, and a cutout groove 52 continuous along the surface direction of the thin member. are doing. The thin member 51 is, for example, a stainless steel foil having a thickness of about 0.1 mm, and is fixed to the lid 47 by an appropriate method such as laser welding, cold welding, or resistance welding. The notch groove 52 has a substantially V-shaped cross section, and is provided in a plane circular shape substantially concentric with the communication hole 50 so as to surround a certain region of the thin member 51. Such a notch groove 52 is formed in the container 44 through the communication hole 50.
Is provided on the surface of the thin member 51 by an appropriate method such as press working, etching work or the like so as to be visible from the outside.

In such a sealed battery 40, gas is generated inside the container 44 due to overcharge, overdischarge, internal short circuit, or the like, and when the internal pressure of the container 44 reaches a certain level or more, the battery is surrounded by a notch groove 52. The region is cut off from the thin member 51 as a disk-shaped explosion-proof lid 53 to allow communication between the inside and outside of the container 44, thereby preventing the container 44 from expanding and bursting.

[0005]

The above-mentioned sealed battery 40 is provided such that the notch groove 52 constituting the explosion-proof portion 45 is circular in a plane, in other words, the notch groove 52 circulates at a constant curvature. Therefore, the internal pressure of the container 44 uniformly acts on the entire area of the notch groove 52, and the shearing force does not concentrate on a specific portion of the notch groove 52. That is, in such a sealed battery 40, in order for the explosion-proof lid 53 to break from the thin member 51,
Since the entire area of the cutout groove 52 needs to be simultaneously sheared, the internal pressure of the container 44 needs to be relatively high. Therefore, the above-mentioned sealed battery 40 has a disadvantage that it is difficult to set the internal pressure of the container 44 in which the explosion-proof part 45 should operate at a relatively low pressure of, for example, about 15 kgf / cm ² .

To solve this problem, the notch groove is provided so that the explosion-proof part 45 operates when the internal pressure of the container 44 reaches a relatively low pressure.
Although a method of appropriately selecting the depth dimension of 52 is conceivable, it is difficult to process the thin-walled member 51, so that there is a problem that the processing cost increases. The present invention has been made in view of the above-described problems, and has as its object the explosion-proof part operates reliably when the internal pressure of the container reaches a relatively low pressure without increasing the processing cost of the notch groove. An object of the present invention is to provide a sealed battery.

[0007]

In order to achieve the above-mentioned object, the present invention provides an explosion-proof part provided in a container for accommodating a battery body, wherein the explosion-proof part is provided. A communication hole communicating between the inside and the outside of the container, a thin member arranged along the container to close the communication hole, and a notch groove continuous to surround a certain region along a surface direction of the thin member. A sealed battery that can be opened as an explosion-proof lid by breaking the notch groove when the internal pressure of the container reaches a certain value or more, wherein the continuous direction of the notch groove is It is characterized by having bent portions that intersect at a predetermined angle.

Here, the communication hole may be any shape as long as the inside and outside of the container communicate with each other, and the opening shape, the opening size and the like are arbitrary, and the opening shape and the opening size are constant along the thickness direction of the container. You don't have to. In addition, as a thin member,
A metal, a resin, or the like capable of forming a notch groove can be adopted, and the thickness dimension is arbitrary as long as the explosion-proof lid surrounded by the notch groove can be broken.

On the other hand, as the cross-sectional shape of the cutout groove, a substantially V shape, a substantially concave shape, a substantially C shape, a substantially U shape, etc. can be adopted.
A substantially V-shape or a substantially concave shape is preferable so that the shearing force is easily concentrated at a specific location. Further, it is desirable that the fixed region surrounded by the cutout groove has as large an area as possible so that the internal pressure of the container acts as much as possible, and that the aspect ratio is as close as possible. Therefore, as the fixed region surrounded by the cutout groove, a shape similar to the exposed shape of the thin member exposed from the communication hole is preferable, and more than half of the opening area of the communication hole is preferable.

[0010] Examples of the bent portion include, for example, a form in which cutout grooves are continuous in a closed line having one corner, or a form in which a plurality of cutout grooves intersect and connect at a predetermined angle. Such a notch groove may be formed on one or both of the front surface and the back surface of the thin member, and when forming the notch grooves on both surfaces of the thin member, each notch groove is formed on the front surface and the back surface of the thin member. The positions, shapes and dimensions corresponding to each other may be selected.

In the sealed battery constructed as described above, since the shearing force concentrates on the bent portion where the continuous direction of the notch grooves intersect at a predetermined angle, the bent battery is bent even when the internal pressure of the container is relatively low. The notch groove is continuously broken starting from the portion, thereby opening a certain area surrounded by the notch groove as an explosion-proof lid. That is, in this sealed battery, the internal pressure of the container in which the explosion-proof part is to operate is, for example, about 15 kgf / cm ² without adjusting the depth of the notch groove by appropriately selecting the planar shape and the like of the bent part. Can be set at a relatively low pressure, thereby achieving the object described above.

Further, according to the present invention, as set forth in claim 2, the explosion-proof portion has a plurality of the notched grooves, and the bent portions are provided by intersecting the notched grooves. It is characterized by. Here, each notched groove may be linear or curved, and has the same shape, similar shape,
It need not be symmetric.

[0013] In the sealed battery thus configured, the notched grooves are arranged so as to cross each other in a substantially cross-shaped plane, so that the bottom of the intersecting portion is separated from the inner side surface of the notched groove and is not reinforced. It has become. That is, in this sealed battery, the difference in shear strength between the bent portion and the other portion can be increased as compared with, for example, a case where a specific portion of the cutout groove is bent, whereby the internal pressure of the container is relatively low. Even if there is, the explosion-proof lid will be reliably opened with the bent portion as a starting point.

Further, according to the present invention, the bent portion is provided by arranging one end of each of the notched grooves in the continuous direction so as to cross each other.
A separation portion is provided by arranging the other end portions in the continuous direction of the notch grooves so as to be separated from each other, and the explosion-proof lid can be opened without breaking the separation portion. In this sealed battery, since the separated portion functions as a hinge of the explosion-proof cover, there is little possibility that the explosion-proof cover is scattered when the explosion-proof portion is operated.

According to the present invention, as described in claim 4, if the bent portion and the separated portion are provided at relatively farthest positions along the surface direction of the thin member, the bent portion is provided. Since the length can be made the shortest from the portion to the end of each notch groove, in other words, the opening of the explosion-proof lid is completed in a short time starting from the bent portion, and the internal pressure of the container can be rapidly reduced.

In the present invention, as described in claim 5, if the thin member is a metal foil, the notched groove can be formed with high precision and in an arbitrary shape by, for example, etching.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the embodiments described below, the members and the like already described in FIGS. 4 to 6 are denoted by the same reference numerals or corresponding reference numerals in the drawings to simplify or omit the description.

As shown in FIGS. 1 and 2, the sealed battery 10 according to the embodiment of the present invention has an explosion-proof part 15 provided on a container 44 for accommodating a battery body (not shown).
A thin member 21 disposed along the back side of the lid 47 to close the communication hole 50;
Has a first notch groove 11 and a first notch groove 12 continuous to surround a certain area along the surface.

The thin member 21 is made of stainless steel foil having a thickness of about 0.1 mm, and is formed by, for example, wet etching, gas etching or the like so that the first notch groove 11 and the second notch have a depth of 0.05 mm. A groove 12 is formed. The first notch groove 11 and the second notch groove 12 have a substantially V-shaped cross section that continues in an arc shape that curves with a plurality of curvatures, and is symmetrical to each other.

The explosion-proof part 15 is provided with the first notch groove 11 and the second notch groove 12 by arranging the first notch groove 11 and the second notch groove 12 so as to face each other along the circumferential direction of the communication hole 50.
A bent portion 13 is provided by intersecting one end portion of each other at a predetermined angle, and a separating portion 14 is provided in which the other end portions of the first cutout groove 11 and the second cutout groove 12 are separated from each other. Have been. Here, the bent portion 13 and the separated portion 14
In the surface of the thin member 21 which is circularly exposed from the communication hole 50 to the outside, the thin member 21 is formed at the farthest position relative to each other.

In the sealed battery 10 as described above, the explosion-proof part 15 is bent by the first notch groove 11 and the second notch groove 12.
When the internal pressure of the container 44 reaches a certain level or more, the shear force on the first notch groove 11 and the second notch groove 12 concentrates on the bent portion 13. In the sealed battery 10, the first cutout groove 11 and the second cutout groove 12 are continuously sheared from the bent portion 13 to the other end, and the first cutout groove 11 and the second cutout groove 12 The enclosed area is opened as an explosion-proof lid 23.

Therefore, according to the sealed battery 10, the container
Explosion-proof part due to the shearing force caused by the rise in internal pressure of 44 concentrated on bent part 13
15 operates, so that the explosion-proof part 15 can be operated even if the internal pressure of the container 44 slightly increases, compared to the case where the notch groove is provided so as to circulate at a constant curvature as in the conventional case, Thereby, the internal pressure of the container 44 in which the explosion-proof unit 15 should operate can be set lower than in the related art. The sealed battery 10 has a very simple structure in which the bent portion 13 is provided in order to set a low internal pressure of the container 44 in which the explosion-proof portion 15 is to operate. The processing cost can be reduced as compared with the case where a method of appropriately selecting the depth dimension of the groove 11 and the second notch groove 12 is adopted.

Further, in the above-mentioned sealed battery 10, the bent portion 13 is provided by arranging the first notch groove 11 and the second notch groove 12 in a substantially cross-shaped plane.
The bent portion 13 has a first cutout groove 11 and a second cutout groove 12
It is a fragile part that is separated from the inner surface of the and is not reinforced. That is, according to the sealed battery 10, for example, as compared with a case where a specific portion of the notch groove is simply bent,
The difference in shear strength between the bent portion 13 and other portions is large, so that even when the internal pressure of the container 44 is relatively low, the explosion-proof lid 23 is reliably opened starting from the bent portion 13.

Further, according to the sealed battery 10, the first
Since the end portions of the notch groove 11 and the second notch groove 12 are spaced apart from each other, the separation portion 14 is provided.
Functions as a hinge for the explosion-proof lid 23,
Is less likely to be scattered from the thin member 21 even if it is opened. In particular, the explosion-proof lid 23 has the first cutout groove from the bent portion 13 because the bent portion 13 and the separated portion 14 are provided at the relatively farthest places.
The length up to the end of 11 and the second cutout groove 12 is the shortest. Therefore, according to this sealed battery 10, the bent portion 13
Opening of the explosion-proof lid 23 is completed in a short time
Can be quickly reduced.

According to such a sealed battery 10,
In the present invention, since the thin member 21 is a metal foil, in forming the first notch groove 11 and the second notch groove 12,
Wet etching, gas etching, and the like can be employed.
The depth dimensions of the notch groove 11 and the second notch groove 12 can be set with high precision and any shape.

It should be noted that the present invention is not limited to the above-described embodiment, and appropriate modifications and improvements can be made.
For example, explosion-proof parts 15A to 15F shown in FIG. 3 are also included in the present invention. That is, the explosion-proof part 15A shown in FIG.
Has an arc-shaped notch groove 30A curved with a plurality of curvatures,
A bent portion 13A is provided by intersecting both ends of the cutout groove 30A at a predetermined angle, and a separation portion is omitted.

The explosion-proof part 15B shown in FIG. 3B has a first notch groove 31B and a second notch groove 32B which are curved with a plurality of curvatures and are symmetrical with each other. First
The notch groove 31B and the second notch groove 32B are arranged in a substantially water-drop shape, so that the bent portions 13B are provided by connecting one end portions so as to merge at a predetermined angle, and
A separation portion 14B is provided by separating the other end portions from each other.

Further, the explosion-proof part 15C shown in FIG.
It has a first cutout groove 31C and a second cutout groove 32C that are curved at a plurality of curvatures and are symmetrical with each other. The explosion-proof part 15C has a first notch groove 31C and a second notch groove 32C.
Are arranged in a substantially heart shape, so that one end portions are connected so as to merge at a predetermined angle, thereby forming a bent portion.
13C is provided, and the separated portion 14C is provided by arranging the other end portions separately.

The explosion-proof part 15D shown in FIG.
It has a C-shaped first cutout groove 31D curved at a constant curvature and a linear second cutout groove 32D. This explosion-proof part 15D
At the center of the first notch groove 31D in the continuous direction, the first notch groove
A bent portion 13D is provided by forming a second cutout groove 32D along the radial direction of 31D, and a separation portion 14D is provided between both ends of the first cutout groove 31D.

Further, the explosion-proof part 15E shown in FIG.
C-shaped first cutout groove 31E curved at a constant curvature and second
It has a notch groove 32E and a straight third notch groove 33E. The explosion-proof part 15E has a first cutout groove 31E and a second cutout groove 32E arranged symmetrically, and the first cutout groove 31E.
A third notch groove 33E is formed so as to connect the central portions of the second notch grooves 32E in the continuous direction. Such an explosion-proof part 15E includes a first notch groove 31E and a third notch groove 33E.
E, the second notch groove 32E and the third notch groove 33E
Are the bent portions 13E and 13E, respectively, and
Separated portion between the ends of the first notch groove 31E and the second notch groove 32E
14E and 14E are provided.

The explosion-proof part 15F shown in FIG. 3 (F) has a substantially spiral first cutout groove 31F curved with a plurality of curvatures and a straight second cutout groove 32F. This explosion-proof part 15F
At the center of the first notch groove 31F in the continuous direction, the first notch groove
A bent portion 13D is provided by forming a second cutout groove 32F along the radial direction of 31F, and a separation portion 14F is provided between both ends of the first cutout groove 31F.

In addition, the materials, shapes, dimensions, and shapes of the sealed batteries, battery bodies, containers, explosion-proof parts, communication holes, thin members, notched grooves, bent parts, intersections, and separation parts exemplified in the above-described embodiment. The number, location, location, etc. are arbitrary and not limited as long as the present invention can be achieved.

EXAMPLE Next, a sealed battery according to the present invention and a conventional sealed battery were manufactured, and the operating pressure of the explosion-proof part was measured by increasing the internal pressure of the container for each sealed battery. At the same time, the explosion-proof lid was scattered along with the operation of the explosion-proof part. The results are shown in Table 1 and will be described.

[0034]

[Table 1]

In Examples 1 and 2 and Comparative Example 1, predetermined notched grooves were formed in a thin stainless steel foil by wet etching, gas etching, or the like. In Examples 1 and 2 and Comparative Example 1, the stainless steel foil was fixed to the lid constituting the container by laser welding, and then a red check method was performed as a penetration test to seal the communication hole. After confirming that, the lid is attached to the main body of the container, water is filled into the container from the injection port, the internal pressure of the container is increased by applying water pressure, and the internal pressure at the time when the explosion-proof part was activated was recorded It is. Table 1
The working internal pressure at which the explosion-proof part operates is the same as in the first and second embodiments.
This is the average value when 10 explosion-proof parts were operated by preparing 10 pieces each of Comparative Example 1 and Comparative Example 1.

(Example 1) As a result of forming the notched grooves illustrated in FIGS. 1 and 2 as the explosion-proof part, when the internal pressure of the container reaches 5.5 kgf / cm ^{2 to} 7.5 kgf / cm ² , Operated and all explosion-proof lids did not splatter.

(Embodiment 2) FIG.
As a result of forming the notch grooves illustrated in FIG.
The explosion-proof part was activated when the pressure reached 5.5 kgf / cm ^{2 to} 7.5 kgf / cm ^2, and the scattering of the explosion-proof lid was 6 out of 10 pieces.

(Comparative Example 1) As a result of forming a circular cutout groove as an explosion-proof part, the internal pressure of the container was 7.5 kgf / cm ² to 11.5 kgf / cm ^2.
When the explosion-proof part was reached, the explosion-proof lid was scattered in four out of ten.

In Table 1, in Examples 1 and 2, Comparative Example 1 was used because the explosion-proof portion was provided with a bent portion.
It can be seen that the internal pressure of the container in which the explosion-proof part is to operate can be set lower than that of. Further, in the first embodiment, since the explosion-proof part is provided with the separation part, even if the explosion-proof part operates, the explosion-proof lid does not scatter, and there is less possibility that the peripheral equipment is adversely affected as compared with the second embodiment. You can see that. Therefore, it is understood that the best mode of the explosion-proof part is to provide a bent part in the notch groove and to provide a separation part.

[0040]

As described above, according to the present invention, as described in claim 1, since the shearing force concentrates on the bent portion of the notch groove, the internal pressure of the container is relatively low. In addition, a certain region surrounded by the notch groove starting from the bent portion can be opened as an explosion-proof lid, and the manufacturing cost does not increase because there is no need to adjust the depth dimension of the notch groove.

According to the present invention, as described in claim 2, the plurality of notch grooves are arranged so as to cross each other in a substantially cross-shaped plane, so that the difference in shear strength between the bent portion and the other portion is reduced. This allows the explosion-proof lid to open reliably from the bent portion even if the internal pressure of the container is relatively low.

Further, according to the present invention, as described in claim 3, the separated portion provided by separating the other ends of the notched grooves in the continuous direction functions as a hinge of the explosion-proof lid. The explosion-proof lid is less likely to be scattered during the operation of the explosion-proof part. According to the present invention, as described in claim 4, since the bent portion and the separated portion are provided at the relatively farthest points, the opening of the explosion-proof lid is completed in a short time from the bent portion. Then, the internal pressure of the container can be quickly reduced.

Further, according to the present invention, as described in claim 5, since the thin member is a metal foil, the cutout groove can be formed with high precision and an arbitrary shape by, for example, etching.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a main part showing an embodiment according to the present invention.

FIG. 2 is a plan view of a main part showing an embodiment according to the present invention.

FIG. 3 is a schematic plan view showing a modification of the present invention.

FIG. 4 is a sectional view schematically showing a sealed battery.

FIG. 5 is a cross-sectional perspective view of a main part of a conventional explosion-proof part in a sealed battery.

FIG. 6 is a main part plan view showing a conventional explosion-proof part in a sealed battery.

[Explanation of symbols]

10 Sealed batteries 11, 31B, 31C, 31D, 31E, 31F First cutout groove (cutout groove) 12, 32B, 32C, 32D, 31E, 31F Second cutout groove (cutout groove) 13, 13A, 13B, 13C, 13D, 13E, 13F Bent part 14, 14B, 14C, 14D, 14E, 14F Separation part 15, 15A, 15B, 15C, 15D, 15E, 15F Explosion-proof part 21 Thin member 30A Notch groove 33E Third notch groove (notch groove) 44 Container 50 Communication hole

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Kazuya Okabe, Inventor Kazuya Okabe 2-3-1-21, Kosobe-cho, Takatsuki-shi, Osaka Inside Yuasa Corporation (72) Inventor Hiroshi Yufube 2-3-1, Kosobe-cho, Takatsuki-shi, Osaka No. F-term in Yuasa Corporation (reference) 5H012 AA07 BB02 DD01 DD05 EE04 FF01

Claims (5)

[Claims] 1. An explosion-proof part provided in a container for accommodating a battery body, wherein the explosion-proof part is disposed along the container and communicates with the inside and outside of the container, and closes the communication hole. A thin member, and a notch groove continuous to surround a certain area along a surface direction of the thin member, wherein the notch groove breaks when the internal pressure of the container reaches a certain value or more, and the constant value is obtained. A sealed battery in which a region serves as an explosion-proof lid and can be opened, wherein the sealed battery has a bent portion in which a continuous direction of the notched grooves intersects at a predetermined angle. 2. The sealed battery according to claim 1, wherein the explosion-proof portion has a plurality of the notched grooves, and the bent portions are provided by intersecting the notched grooves. . 3. The bent portion is provided by intersecting one end in the continuous direction of each notch groove, and the separating portion is arranged by separating the other end in the continuous direction of each notch groove from each other. 3. The sealed battery according to claim 2, wherein the explosion-proof lid is openable without breaking the separated portion. 4. 4. The sealed battery according to claim 3, wherein the bent portion and the separated portion are provided at a relative farthest position along a surface direction of the thin member. 5. The sealed battery according to claim 1, wherein the thin member is a metal foil.