JP2013149435A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make sufficient sealing performance and high positioning accuracy to a current intercepting portion and the like compatible.SOLUTION: A battery 1 has a collector 3; an external connection terminal 4; a sealing body 5; a sealing body lead 6; a pressure-sensitive deformation element 7; an intercepting film 8; a first seal material 12; a second seal material 13. Between the sealing body 5 and the sealing body lead 6, the first seal material 12 is disposed near the external connection terminal 4. The second seal material 13 is disposed at a position separated from the external connection terminal 4, as compared with the first seal material 12. Between the first seal material 12 and the second seal material 13, a predetermined interval A is provided. The sealing body lead 6 and the second seal material 13 are respectively formed with tapered portions 17 and 18 for pressing in the sealing body lead 6 and the second seal material 13 each other.

Description

  The present invention relates to a battery such as a secondary battery, and more particularly to a structure around a connection portion of an external connection terminal.

  In patent document 1, the secondary battery provided with a current interruption part is shown. The current interrupting part is a pressure-sensitive deformation element (diaphragm) that deforms when the internal pressure of the housing reaches a predetermined value or more, and part of the current path from the current collector to the external connection terminal as the pressure-sensitive deformation element is deformed It is comprised from the shielding foil etc. which interrupt | block.

  In Patent Document 2, a gasket and a spacer intervening portion are disposed between the hole peripheral portion of the battery case and the base portion of the electrode terminal, and the spacer is provided with a side wall portion disposed radially outside the base portion of the electrode terminal. A battery is disclosed in which a notch portion is formed in a side wall portion of a spacer so as to prevent an interference with a gasket by notching the inner surface side thereof. Thereby, even if the radial dimension of the side wall of the spacer is reduced, the notch can prevent the gasket from interfering with the side wall, increase the outer diameter of the gasket, or the radial dimension of the side wall of the spacer. Can be made smaller.

JP 2008-66255 A (refer to FIGS. 1 to 3 and 5) JP 2011-23235 A

  When providing the current interrupting part as shown in the above-mentioned Patent Document 1, in order to accurately detect the internal pressure, high airtightness around the connecting part of the external connection terminal, pressure sensitive deformation element, interrupting foil, etc. High positioning accuracy is required.

  8 and 9 illustrate the problems of the conventional structure. In the battery 101 according to the first example shown in FIG. 8, a sealing body 103 and an external connection terminal 104 are disposed in the opening of the housing 102. The upper surface side (between the casing 102, the sealing body 103, and the external connection terminal 104) of the sealing body 103 is sealed with an upper sealing material 105.

  A current collector 108 is disposed inside the housing 102. Between the current collector 108 and the sealing body 103, a current interrupting part 110 and a sealing body lead 111 are arranged. The current interruption unit 110 includes a pressure-sensitive deformation element 115 and an interruption foil 116. The sealing body lead 111 is in contact with the blocking foil 116 and the external connection terminal 104. The current held by the current collector 108 is transmitted to the external connection terminal 104 via the blocking foil 116, the pressure-sensitive deformation element 115, and the sealing body lead 111.

  The sealing body 103 and the sealing body lead 111 are sealed with a first intermediate sealing material 121 and a second intermediate sealing material 122 arranged with a predetermined interval A therebetween. By the predetermined interval A, the extension in the D direction due to the compression of the first intermediate sealing material 121 at the time of assembly is absorbed. In this example, the thickness X1 of the first intermediate sealing material 121 is thinner than the thickness X2 of the second intermediate sealing material 122.

  A current collector holder 123 is disposed on the lower surface side of the pressure-sensitive deformation element 115 (between the sealing body 103, the current collector 108, the pressure-sensitive deformation element 115, and the shielding foil 116). The sealing body 103 is formed with a convex portion 125 for improving the sealing performance. The upper sealing material 105 and the first intermediate sealing material 121 are in contact with each other, and the second intermediate sealing material 122 and the current collector holder 121 are in contact with each other.

  In the battery 101 according to the second example shown in FIG. 9, the thickness X <b> 1 of the first intermediate sealing material 121 is thicker than the thickness X <b> 2 of the second intermediate sealing material 122. Other configurations are the same as those of the battery 101 according to the first example.

  As described above, when the sealing between the sealing body 103 and the sealing body lead 111 is performed by the two intermediate sealing materials 121 and 122, the thicknesses X1 and X2 of the both may differ due to variations in product shape and the like. As in the first example, in the case of X1 <X2, the second intermediate sealing material 122 is sufficiently compressed by the sealing body 103 and the sealing body lead 111, so that it can be reliably held. In addition, a sufficient sealing property can be obtained. However, about the 1st intermediate sealing material 121, compression becomes inadequate and possibility that a desired sealing performance will not be obtained becomes high.

  On the other hand, as in the second example, when X1> X2, the first intermediate seal member 121 is sufficiently compressed by the sealing body 103 and the sealing body lead 111, so that a desired sealing property is obtained. Becomes easy. However, the second intermediate sealing material 122 is not sufficiently compressed, and the holding thereof cannot be surely performed, and there is a high possibility that sufficient sealing performance cannot be obtained. The fact that the second intermediate seal material 122 is not securely held causes a decrease in the positioning accuracy of the current interrupting unit 110 and the like.

  As described above, when the sealing between the sealing body 103 and the sealing body lead 111 is performed by the two intermediate sealing materials 121 and 122, both the holding performance and the sealing performance of both the sealing materials 121 and 122 should be satisfied. It becomes difficult.

  Therefore, an object of the present invention is to achieve both sufficient sealing performance and high positioning accuracy with respect to the current interrupting portion and the like.

  One aspect of the present invention is an external connection terminal that is connected to a current collector housed in a housing and the current collector through a current path formed in the housing, and a part of the external connection terminal is exposed to the outside of the housing. A sealing body that seals the opening of the casing, a sealing body lead that is disposed on the inner side of the casing with respect to the sealing body, and forms a part of the current path, and a part of the current path. And a pressure-sensitive deformation element that deforms according to the internal pressure of the housing, and normally forms a part of the current path, and the current path is broken by breaking when the pressure-sensitive deformation element is deformed by a predetermined amount or more. A blocking foil for blocking, a first sealing material disposed in the vicinity of the external connection terminal between the sealing body and the sealing body lead, and the first sealing material between the sealing body and the sealing body lead. Placed away from the external connection terminal than the sealing material And a second sealing member that is said to sealing element leads and said second sealing member is a battery tapered portion is formed in order to press fit them together.

  According to the above configuration, since the member that seals between the sealing body and the sealing body lead is divided into two sealing materials at a predetermined interval, the first sealing material is expanded in the lateral direction due to compression. Is absorbed. Thereby, even if it compresses strongly in order to improve the sealing performance of the 1st sealing material, the said expansion does not change the 2nd sealing material, and other members, such as a pressure sensitive deformation element, intercepting foil, etc. There is no adverse effect on the positioning accuracy with respect to.

  In addition, due to the structure in which the sealing body lead and the second sealing material are press-fitted by the taper portion, the second sealing material is sufficient even if the second sealing material and the sealing body lead are not pressed so strongly. Holding and sealing properties can be realized. As a result, it is possible to achieve good sealing performance and holding performance without requiring the thicknesses of the first sealing material and the second sealing material to be the same with high accuracy.

  Moreover, it is preferable that parts other than the said taper part of the said 2nd sealing material are thinner than the said 1st sealing material.

  The sealing body includes a convex portion projecting toward the sealing body lead, the first sealing material abuts on the convex portion, and the second sealing material includes a current collector holder and It is preferable that they are in contact or integrated.

  Moreover, it is preferable that the said 1st sealing material is contact | abutted or integrated with the upper side sealing material which seals the upper surface side of the said sealing body.

  According to the present invention, it is possible to achieve both sufficient airtightness and high positioning accuracy with respect to the current interrupting portion and the like.

It is a partial cross section figure which shows the structure of the connection part periphery of the external connection terminal of the battery which concerns on Embodiment 1 of this invention. 4 is a partial cross-sectional view showing a state before the first intermediate sealing material and the second intermediate sealing material are sandwiched between the sealing body and the sealing body lead in the battery according to Embodiment 1. FIG. It is a figure which shows the 1st structural example of the 2nd intermediate | middle sealing material which concerns on Embodiment 1. FIG. It is a figure which shows the 2nd structural example of the 2nd intermediate | middle sealing material which concerns on Embodiment 1. FIG. It is a figure which shows the 3rd structural example of the 2nd intermediate | middle sealing material which concerns on Embodiment 1. FIG. It is a figure which shows the 4th structural example of the 2nd intermediate | middle sealing material which concerns on Embodiment 1. FIG. 4 is a graph showing a relationship between a press-fitting amount and a press-fitting load when a sealing body lead is press-fitted into a second intermediate seal part in the battery according to the first embodiment. It is a figure which shows the 1st example of the problem which the conventional structure has. It is a figure which shows the 2nd example of the problem which the conventional structure has.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a structure around the connection portion of the external connection terminal 4 of the battery 1 according to Embodiment 1 of the present invention. The battery 1 is a secondary battery, and includes a housing 2, a current collector 3, an external connection terminal 4, a sealing body 5, a sealing body lead 6, a pressure-sensitive deformation element 7, a shielding foil 8, and a plurality of sealing materials 11, 12 and 13 and a current collector holder 14.

  The housing 2 is a hollow container made of an aluminum alloy or the like that constitutes the outer shell of the battery 1. The current collector 3 is housed in the housing 2 and is connected to an electrode that contacts the electrolytic solution.

  The external connection terminal 4 is electrically connected to the current collector 3 via a current path, which will be described later, in the housing 2, and a part of the external connection terminal 4 is exposed to the outside of the housing 2.

  The sealing body 5 is a member that seals the opening of the housing 2. At the end portion of the sealing body 5, a convex portion 9 protruding toward the sealing body lead control 6 is formed.

  The sealing body lead 6 is a member disposed below the sealing body 5 (inside the housing 2), and is made of a conductive material. The sealing body lead 6 constitutes a part of a current path that electrically connects the current collector 3 to the external connection terminal 4. A tapered portion 17 is formed on the outer edge portion of the sealing body lead 6.

  The pressure-sensitive deformation element 7 is a diaphragm or the like and deforms according to the internal pressure of the housing 2. Specifically, when the pressure in the portion below the pressure-sensitive deformation element 7 in the housing 2 (inside the housing 2) exceeds a predetermined value, as shown by the two-dot chain line in FIG. Transforms into Through holes 21 and 22 are formed in the current collector 3 and the current collector holder 14 so that the internal pressure of the housing 2 is transmitted to the pressure-sensitive deformation element 7. The pressure-sensitive deformation element 7 is made of a conductive material and constitutes a part of the current path.

  The shielding foil 8 is in contact with and fixed to the current collector 3 and the pressure-sensitive deformation element 7. The shielding foil 8 is made of a conductive material, and normally forms part of the current path. However, as described above, when the internal pressure of the housing 2 becomes a predetermined value or more and the pressure-sensitive deformation element 7 is deformed upward, the blocking foil 8 is broken and the current path is blocked. That is, the current path is blocked by the action of the pressure-sensitive deformation element 7 and the blocking foil 8.

  Each sealing material 11, 12, and 13 is a member for ensuring the airtightness between each said component. Specifically, it seals the upper surface side of the sealing body 5 and is disposed between the upper sealing material 11 disposed between the external connection terminal 4 and the sealing body 5, the sealing body 5, and the sealing body lead 6. The first intermediate sealing material 12 and the second intermediate sealing material 13 exist. A current collector holder 14 is disposed between the sealing body 5, the current collector 3, the pressure-sensitive deformation element 7, and the blocking foil 8.

  A predetermined distance A is secured between the first intermediate sealing material 12 and the second intermediate sealing material 13. A tapered portion 18 is formed on the outer edge portion of the second intermediate sealing material 13. The thickness T2 of the flat portion 25 of the second intermediate sealing material 13 is smaller than the thickness T1 of the first intermediate sealing material 12. The convex portion 9 formed on the sealing body 5 is in contact with the first intermediate sealing material 12. The first intermediate sealing material 12 is in contact with the upper sealing material 11. The second intermediate sealing material 13 is in contact with the current collector holder 14.

  FIG. 2 shows a state before the first intermediate sealing material 12 and the second intermediate sealing material 13 are sandwiched between the sealing body 5 and the sealing body lead 6. As described above, the member that seals between the sealing body 5 and the sealing body lead 6 is divided into the first intermediate sealing material 12 and the second intermediate sealing material 13.

  Further, the sealing body lead 6 and the second intermediate sealing material 13 have tapered portions 17 and 18, respectively. At the time of assembly, both the taper portions 17 and 18 come into contact with each other, and the sealing body lead 6 and the second intermediate sealing material 13 are press-fitted.

  With the above configuration, the first intermediate sealing material 12 is expanded in the horizontal direction when the first intermediate sealing material 12 is compressed by the sealing body 5 and the sealing body lead 7 during assembly (see arrow D in FIG. 1). Is absorbed by the predetermined interval A. As a result, even if the first intermediate sealing material 12 is strongly compressed in order to achieve a desired sealing performance, the extension of the first intermediate sealing material 12 in the D direction causes the second intermediate sealing material 13 to fluctuate. This does not adversely affect the positioning of the pressure-sensitive deformation element 7, the blocking foil 8, and the like.

  In addition, the structure in which the sealing body lead 6 and the second intermediate sealing material 13 are press-fitted by the taper portions 17, 18 allows the planar portion 25 other than the tapered portion 18 of the second intermediate sealing material 13 and the sealing body lead 6 to be sealed. Even if the upper surface portion is not so strongly pressed, sufficient holding and sealing performance of the second intermediate sealing material 13 can be realized. Thereby, even if the thickness T2 of the flat portion 25 of the second intermediate sealing material 13 is smaller than the thickness T1 of the first intermediate sealing material 12, sufficient sealing performance can be realized. That is, it is possible to achieve good sealing performance without requiring the thicknesses T1 and T2 of the first intermediate sealing material 12 and the second intermediate sealing material 13 to be the same with high accuracy.

  3 to 6 show structural examples of the second intermediate sealing material 13. In the second intermediate sealing material 13A according to the first example shown in FIG. 3, a tapered portion 18A is formed over the entire circumference of the outer edge portion 30. The taper portion 17 (see FIGS. 1 and 2) of the sealing body lead 6 has a shape corresponding to the taper portion 18A (the same applies to other examples described below). In the figure, reference numeral 27 denotes a hole through which the external connection terminal 4, the first intermediate sealing material 12 and the like are inserted.

  In the second intermediate sealing material 13B according to the second example shown in FIG. 4, the tapered portion 18B is formed only on the two side surface portions 31 and 32 facing each other among the outer edge portions.

  In the second intermediate sealing material 13C according to the third example shown in FIG. 5, the tapered portion 18C is formed only on a part of the two side surface portions 31 and 32.

  In the second intermediate seal material 13D according to the fourth example shown in FIG. 6, rib-shaped taper portions 18D are formed on the two side surface portions 31 and 32, respectively. The pair of taper portions 18D on one side surface are provided so that the interval gradually decreases toward the upper surface of the second intermediate sealing material 13D (the surface facing the sealing body 5).

  As described above, various variations can be considered for the tapered portion 18 of the second intermediate sealing material 13.

  FIG. 7 shows the relationship between the press-fitting amount and the press-fitting load when the sealing body lead 6 is press-fitted into the second intermediate sealing material 13. P1 and P2 are states in which the taper portion 17 of the sealing body lead 6 and the taper portion 18 of the second intermediate seal material 13 are press-fitted. P2 is a state in which the upper surface portion of the sealing body lead 6, the first intermediate sealing material 12, and the convex portion 9 of the sealing body 5 are in contact with each other. P <b> 2 to P <b> 3 are states in which the convex portion 9 of the sealing body 5 compresses the first sealing material 12. P3 is a state in which the upper surface of the sealing body lead 6 and the lower surface of the first intermediate sealing material 12 are in contact with the upper surface of the first intermediate sealing material 12 and the lower surface of the sealing body 5. P3 to P4 are states in which the upper surface of the sealing body lead 6 compresses the lower surface of the second intermediate sealing material 13. Further, by stopping the press-fitting operation at the point where the press-fitting amount enters the state of P3 to P4, that is, the press-fitting amount in the vicinity of P3, sufficient sealing performance can be obtained without applying an unnecessary large press-fitting load.

  According to the battery 1 having the above configuration, the member that seals between the sealing body 5 and the sealing body lead 6 is divided into the first intermediate sealing material 12 and the second intermediate sealing material 13. The extension of the intermediate sealing material 12 in the lateral direction (D direction in FIG. 1) is absorbed. Thus, even if the first intermediate sealing material 12 is strongly compressed to enhance the sealing performance, the expansion does not cause the second intermediate sealing material 13 to fluctuate. It does not adversely affect the positioning.

  Further, due to the structure in which the sealing body lead 6 and the second intermediate sealing material 13 are press-fitted by the taper portions 17 and 18, the flat portion 25 of the second intermediate sealing material 13 and the upper surface portion of the sealing body lead 6 are not so much. Even if it is not strongly pressed, sufficient holding and sealing performance of the second intermediate sealing material 13 can be realized. As a result, it is possible to realize good sealing performance without requiring the thicknesses T1 and T2 of the first intermediate sealing material 12 and the second intermediate sealing material 13 to be the same with high accuracy. .

  As described above, according to the battery 1 according to the present embodiment, it is possible to simultaneously realize improvement in sealing performance, improvement in positioning accuracy, absorption of dimensional variations between members, and the like.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Battery 2 Housing | casing 3 Current collector 4 External connection terminal 5 Sealing body 6 Sealing body lead 7 Pressure sensitive deformation element 8 Barrier foil 9 Convex part 11 Upper sealing material 12 1st intermediate sealing material 13, 13A, 13B, 13C, 13D Second intermediate sealing material 14 Current collector holder 17, 17A, 17B, 17C, 17D Tapered portion 18, 18A, 18B, 18C, 18D Tapered portion 21, 22 Through hole 25 Planar portion 27 Hole 30 Outer edge portion 31, 32 Side surface portion A Predetermined distance D Extension direction of the first intermediate sealing material T1 Thickness of the first intermediate sealing material T2 Thickness of the second intermediate sealing material

Claims (4)

A current collector housed in the housing;
An external connection terminal that is connected to the current collector through a current path formed in the housing and is partially exposed to the housing;
A sealing body for sealing the opening of the housing;
A sealing body lead that is disposed on the inner side of the housing than the sealing body and forms a part of the current path;
A pressure-sensitive deformation element that constitutes a part of the current path and deforms according to the internal pressure of the housing;
A part of the current path is normally configured, and a blocking foil that interrupts the current path by breaking when the pressure-sensitive deformation element is deformed by a predetermined amount or more,
A first sealing material disposed in the vicinity of the external connection terminal between the sealing body and the sealing body lead;
A second sealing material disposed between the sealing body and the sealing body lead at a position farther from the external connection terminal than the first sealing material;
With
The sealing body lead and the second sealing material are formed with a tapered portion for press-fitting them together.
A battery comprising: The portion other than the tapered portion of the second sealing material is thinner than the first sealing material,
The battery according to claim 1. The sealing body includes a convex portion protruding to the sealing body lead side,
The first sealing material is in contact with the convex portion,
The second sealing material is in contact with or integrated with the current collector holder;
The battery according to claim 1 or 2. The first sealing material is in contact with or integrated with an upper sealing material that seals the upper surface side of the sealing body,
The battery according to any one of claims 1 to 3.

Images