JP3061457B2 - Organic electrolyte battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electrolyte battery,
Particularly, the present invention relates to an organic electrolyte battery having an improved explosion-proof mechanism.

[0002]

2. Description of the Related Art An organic electrolyte battery using a light metal such as lithium or sodium as a negative electrode active material is excellent in high voltage, high energy density, and long-term reliability, and the demand thereof is increasing. Such an organic electrolyte battery is required to have stable airtightness, particularly airtightness, over a long period of time in view of its performance. If the airtightness of the organic electrolyte battery is impaired, the organic electrolyte in the battery may leak or moisture may permeate in the battery, resulting in reduced reliability. Therefore, this organic electrolyte battery has a structure in which a very airtight sealing is made. Since such an organic electrolyte battery has an airtight structure, when it is internally short-circuited or externally short-circuited, or when charged due to leakage current or the like,
When gas is generated inside the battery, the gas increases the internal pressure of the battery and breaks the outer can or the like, which may lead to a battery explosion.

Conventionally, in order to prevent explosion due to an increase in battery internal pressure due to generation of gas, an organic electrolyte battery provided with an explosion-proof mechanism at a positive electrode terminal or a negative electrode terminal has been proposed (Japanese Utility Model Publication No. 59-15398). JP-A-62-25934
No. 2). That is, this organic electrolyte battery includes, for example, a cover plate 2 having a valve hole 1 as shown in FIG. 3, a membrane valve body 3 fixed so as to hermetically close the valve hole 1, and a membrane valve An electrode which clamps the body 3 together with the cover plate 2 and has a cutting blade 4 and a gas vent hole 5 facing the membrane valve body 3 and which is fixed by caulking by bending a peripheral portion of the cover plate 2. An assembly sealing body 7 including a terminal plate 6 is provided. This assembled sealing body 7
The bent portion of the cover plate 2 is provided with a packing 9 at the opening of the outer can 8.
It is fixed by airtight through airtight. The outer can 8 houses an electrode group 13 including a negative electrode 10, a separator 11 impregnated with an organic electrolyte, and a positive electrode 12, and a positive electrode lead 15 led out from the positive electrode 12 through an insulating ring 14 is provided on the bottom surface of the lid plate 2. Are connected by welding. In such an organic electrolyte battery, when the internal pressure of the battery increases, the membrane-shaped valve element 3 swells upward and breaks due to the stress caused by the swelling or the contact with the cutting blade 4. Valve hole 1, damaged portion of membrane-shaped valve element 3, and electrode terminal plate 6
The gas is discharged through the vent hole 5.

However, in the above-mentioned conventional organic electrolyte battery, the peripheral surface of the cover plate 2 is bent to fix the electrode terminal plate 6, so that the flat surface of the cover plate 2 is deformed. When the flat surface of the cover plate 2 is deformed, it is difficult to uniformly sandwich the membrane valve body 3 between the cover plate 2 and the electrode terminal plate 6, and the airtightness of the assembled sealing body 7 is reduced. Further, when the film-shaped valve element 3 is adhered on the cover plate 2, the film-shaped valve element 2 is easily peeled or cracked due to deformation of the flat surface of the cover plate 2. Therefore, in the conventional organic electrolyte battery, the membrane-shaped valve body 3 is not air-tightly fixed on the cover plate 2, and the easily vaporized organic electrolyte leaks from the inside of the battery, or moisture permeates into the battery. There was a problem of coming.

In order to solve the above-mentioned problem, the present applicant, for example, as shown in FIG.
A cover plate 24 having a valve hole 23, and a metal layer and a heat-fusible resin layer. A film-like valve body 25 in which a fusible resin layer is thermally fused;
The cutting blade 26 and the gas vent hole 2 are provided so as to surround the membrane-shaped valve body 25 and face the membrane-shaped valve body 25.
Has already been proposed (Japanese Patent Application No. 1-236644).
In such an organic electrolyte battery, since the cover plate 24 itself is not bent by caulking as in the related art, deformation of the flat surface of the cover plate 24 can be prevented. For this reason, the film-like valve body 25 thermally fused on the cover plate 24 does not peel or crack, and the film-like valve body 25 is placed on the cover plate 24 so that the valve hole 23 is airtightly closed. Can be bonded securely. As a result, it is possible to prevent leakage of the organic electrolytic solution and moisture permeability.

However, in the organic electrolyte battery already proposed, a peeling portion may be formed in the film-like valve body 25 thermally fused on the cover plate 24 due to the internal pressure of the battery under a normal use condition. For this reason, the adhesive force of the film-shaped valve body 25 gradually decreases when the film-shaped valve body 25 is used for a long period of time. As a result, the airtightness of the battery may be impaired, or the explosion-proof mechanism may operate at a pressure lower than the intended internal pressure of the battery,
It was not always possible to maintain good airtightness over a long period of time.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems, and has a high reliability organic electrolyte battery having an explosion-proof mechanism and capable of sufficiently maintaining good airtightness over a long period of time. It is intended to provide.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an organic electrolyte battery in which a positive electrode terminal or a negative electrode terminal having an explosion-proof mechanism is provided in a battery container containing an electrode group. A valve hole formed in the container, a film-shaped valve body made of a metal layer and a heat-fusible resin layer heat-sealed on the container so as to air-tightly close the valve hole, and this film-shaped valve body A terminal body welded to the container so as to be clamped together with the container; and a terminal body formed on the terminal body and facing the membrane valve body.
A cutting blade, a gas vent hole opened in the terminal body, and an elastic body interposed between the terminal body and the membrane valve so as to clamp the membrane valve together with the container. An organic electrolyte battery comprising an O-ring. It is preferable that the cutting blade is formed by welding to the terminal body or by cutting the terminal body and bending the cut portion toward the membrane valve body.

The battery case is made of a metal such as iron or stainless steel, and houses an electrode group therein. The electrode group is, for example, a metal such as lithium and sodium,
Alternatively, it has a negative electrode made of a material in which lithium, sodium or the like is supported on a carbonaceous material; a separator made of a nonwoven fabric impregnated with an organic electrolyte; and a positive electrode containing manganese dioxide, lithium cobalt oxide or the like as an active material.

[0010] The film-shaped valve element has a thickness of, for example, 10 to 100.
It is formed by laminating a heat-fusible resin such as polyethylene, polypropylene, modified polyethylene, modified polypropylene, ionomer, etc. on a metal foil of about μm such as aluminum, nickel, stainless steel or the like. The terminal body is formed of, for example, iron, a metal such as stainless steel,
It is fixed on the container by welding such as ultrasonic welding, laser welding, or resistance welding.

[0011]

The O-ring is made of, for example, rubber or the like.

[0013]

According to the present invention, in an organic electrolyte battery in which a positive electrode terminal or a negative electrode terminal having an explosion-proof mechanism is provided in a battery container accommodating an electrode group, the terminal having the explosion-proof mechanism is provided in the container. A valve hole, a film-shaped valve body made of a metal layer and a heat-fusible resin layer heat-sealed on the container so as to hermetically close the valve hole, and holding the film-shaped valve body together with the container. Terminal body welded to the container as described above.
Thus, when the internal pressure of the battery rises due to gas generation due to an internal short circuit or the like, pressure is applied to the membrane-shaped valve element through the valve hole of the container, and the membrane-shaped valve element swells upward and breaks. As a result, the gas inside the battery is released through the valve hole of the container, the damaged portion of the membrane-shaped valve element, and the gas vent hole of the terminal main body, thereby preventing the battery from exploding.

Further, a film-shaped valve body is heat-sealed on the battery container,
In addition, since the terminal body is fixed on the battery container by welding, the adhered surface of the membrane valve element is not bent and deformed by caulking as in the related art. For this reason, the valve hole can be airtightly closed without peeling or cracking of the film-shaped valve element. Further, since the terminal body sandwiches the membrane valve together with the battery container, peeling of the membrane valve can be prevented. Therefore, even when used for a long period of time, good airtightness can be sufficiently maintained without lowering the adhesive force of the film-shaped valve body, and the explosion-proof mechanism can be operated at a predetermined battery internal pressure.

According to another aspect of the present invention, there is provided an organic electrolyte battery provided with one electrode terminal having an explosion-proof mechanism and another electrode terminal on the same surface of a battery container accommodating an electrode group.
The one-electrode terminal is a film-shaped valve element including a valve hole formed in the container, a metal layer and a heat-fusible resin layer which are heat-sealed on the container so as to hermetically close the valve hole. And a terminal body welded to the container so as to clamp the membrane valve together with the container. (2) The other terminal is
A rivet mounting hole drilled in the container, and a rivet fixed to hermetically close the rivet mounting hole,
A structure including an insulating member made of a synthetic resin interposed between the container and the rivet. This allows
Equipped with an explosion-proof mechanism, and has the same operational effects as the battery of the invention described above, such as being able to sufficiently maintain good airtightness over a long period of time, and has a similar height on the same surface of the battery container. Both terminals of the positive and negative electrodes can be easily provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. Example 1

FIG. 1 is a sectional view showing a cylindrical lithium organic electrolyte primary battery. That is, the battery container 31 is made of an iron outer can 32 having a bottomed elliptic cylindrical shape, and the lid plate 3 airtightly fixed by resistance welding to the opening of the iron outer can 32.
3. The cover plate 33 is made of SUS4
30 are formed. The electrode group 34 is housed in the battery container 31. The electrode group 34 has a structure in which a laminate of a metal lithium negative electrode 35, a separator 36 made of a polypropylene nonwoven fabric impregnated with an electrolytic solution, and a positive electrode 37 containing manganese dioxide as an active material is spirally wound.

The valve hole 38 is formed on the long axis of the cover plate 33. The film-shaped valve element 39 is air-tightly bonded on the cover plate 33 so as to close the valve hole 38. The film-shaped valve element 39 is formed on a 50 μm-thick aluminum thin plate 40 with a thickness of 5 μm.
It has a structure in which a denatured polypropylene sheet 41 having good metal adhesion of 0 μm is laminated, and the denatured polypropylene sheet 41 is arranged on the lid plate 33 side and bonded by heating and fusion. A hat-shaped negative electrode terminal plate 42, which is a negative electrode terminal body, is fixed on the lid plate 33 by resistance welding so as to sandwich the peripheral portion of the membrane valve body 39 together with the lid plate 33. The negative electrode terminal plate 42 is formed of nickel-plated SUS430, and its center is bent in two steps toward the opposite side of the cover plate 33,
The membrane-shaped valve body 39 is sandwiched by the first bent portion (small bend). Further, a cutting blade 43 facing the membrane valve body 39 side is welded to the center of the negative electrode terminal plate 42, and two gas vent holes 44 are formed around the cutting blade 43.

The rivet mounting hole 45 is formed at a predetermined distance from the valve hole 38 on the long axis of the cover plate 33. The first positive electrode terminal insulating ring 46 is provided on the cover plate 33 around the rivet mounting hole 45 and the hole 45.
It is arranged so as to cover the inner surface. The metal ring 47
It is arranged on the first positive electrode terminal insulating ring 46. The metal ring 47 is formed from SUS430. The second positive electrode terminal insulating ring 48 is arranged so as to cover the inner surface of the cover plate 33 around the rivet mounting hole 45. The rivet 49 is provided in the rivet mounting hole 4.
After being inserted into the hole 45 from above so as to airtightly close the cover 5, the lower portion is crushed to rivet the cover plate 33, the first and second positive electrode terminal insulating rings 46 and 48, and the metal ring 47. Fixed). The rivet 49
Is formed from aluminum. A hat-shaped positive electrode terminal plate 50 surrounds the rivet 49 and is fixed on the metal ring 47 by resistance welding so as to contact the upper surface of the rivet 49.

The negative electrode lead 51 is led out from the negative electrode 35, is bent on the lower surface of the electrode group 34 via an insulating plate 52, and is connected to the bottom surface of the outer can 32 by resistance welding. The insulating ring 53 is disposed on the electrode group 34. The positive electrode lead 54 extends upward from the positive electrode 37, extends through the insulating ring 53 to the bottom surface side of the rivet 49, and is connected to the bottom surface of the rivet 49 by resistance welding.

According to the above-described organic electrolyte battery, when the internal pressure of the battery rises due to gas generation due to an internal short circuit or the like, the membrane valve body 39 swells upward, and the stress caused by the swelling or the cutting edge 43 The gas inside the battery is released through the valve hole 38 of the cover plate 33, the damaged portion of the membrane valve element 39, and the gas vent hole 44 of the negative electrode terminal plate 42. Therefore, battery explosion can be prevented.

Further, since the film-shaped valve body 39 is heat-sealed on the cover plate 33 and the negative electrode terminal plate 42 is fixed on the cover plate 33 by welding, the cover plate 33 has The adhered surface of the film-shaped valve body 39 is not bent and deformed by caulking. Therefore, the valve hole 33 can be hermetically closed without peeling or cracking of the film-shaped valve body 39. Further, since the negative electrode terminal plate 42 sandwiches the membrane valve body 39 together with the lid plate 33, the peeling of the membrane valve body 39 can be prevented. Therefore, even if the film-shaped valve body 39 is used for a long period of time, good airtightness can be sufficiently maintained without lowering the adhesive force of the film-shaped valve body 39, and the explosion-proof mechanism can be operated at a predetermined battery internal pressure.

Further, in the case of a modified battery in which the top and bottom surfaces of the battery have shapes other than a perfect circle such as an elliptical shape and a square shape, it is difficult to uniformly caulk the cover plate to the opening of the outer can, so it is preferable. Although it may not be possible to obtain a high airtightness, it is ensured that the lid plate 32 is welded to the opening of the outer can 31 by ultrasonic welding, laser welding, resistance welding or the like as in the organic electrolyte battery of Example 1. Good airtightness is obtained. Example 2

FIG. 2 shows a width of 6 mm, a length of 24 mm and a height of 7 mm.
It is sectional drawing which cut | disconnected the square lithium organic electrolyte primary battery of 4 mm in length x height. That is, the battery container 61
A rectangular cylindrical iron outer can 62 having upper and lower portions penetrated; a first lid plate 63 hermetically fixed by resistance welding to a lower opening of the outer can 62; and an upper opening of the outer can 62 And a second lid plate 64 hermetically fixed by resistance welding. The first and second cover plates 63 and 64 are formed of SUS430. The electrode group 65 is housed in the battery container 61. The electrode group 65 has a structure in which a metal lithium negative electrode plate and a positive electrode plate containing manganese dioxide as an active material are alternately vertically stacked via a separator made of a polypropylene nonwoven fabric impregnated with an electrolytic solution, and are laminated in the width direction. It has become.

The valve hole 66 is formed at the center of the first cover plate 63. The membrane-shaped valve element 67 is hermetically bonded on the cover plate 63 so as to close the valve hole 66. The film-shaped valve element 67 has a structure in which a 50 μm-thick aluminum thin plate 68 is laminated with a 50 μm-thick modified polypropylene sheet 69 having good metal adhesion, and the modified polypropylene sheet 69 is placed on the lid plate 63 side. They are adhered by arranging and heat-sealing. A hat-shaped positive electrode terminal plate 70, which is a positive electrode terminal body, is fixed on the lid plate 63 by resistance welding so as to sandwich the peripheral edge of the membrane valve body 67 together with the lid plate 63. The positive electrode terminal plate 70 is made of nickel-plated SUS430, and the center portion is bent in two steps toward the opposite side of the lid plate 63, and is bent at the first bent portion (small bend). The membrane valve element 67
Is sandwiched. At the center of the positive electrode terminal plate 70, a cutting blade 71 and a gas vent hole 72 bent toward the membrane valve 67 are provided. The cutting blade 71 and the vent hole 72 are
A portion corresponding to two sides of a triangle at the center of the positive electrode terminal plate 70 is cut, and this cut portion of the triangle is cut into the film-shaped valve element 67.
It is formed by bending to the side. An O-ring 73 made of rubber elastic material is interposed between the second bent portion of the positive electrode terminal plate 70 and the membrane valve 67 so as to sandwich the membrane valve 67 together with the cover plate 63. ing.

A rivet mounting hole 74 is formed in the center of the second cover plate 64. The first negative electrode terminal insulating ring 75 is attached to the cover plate 6 around the rivet mounting hole 74.
4 so as to cover the upper side. First metal ring 7
6 is disposed on the first insulating ring 75 for the negative electrode terminal. The metal ring 76 is formed from SUS430. The second insulating ring 77 for the negative electrode terminal is provided on the lower surface of the lid plate 64 around the rivet mounting hole 74 and the hole 7.
4 so as to cover the inner surface. The second metal ring 78 is disposed on the second insulating ring 77 for the negative electrode terminal. The metal ring 78 is formed from SUS430. The rivet 79 is inserted from above into the rivet mounting hole 74 so as to airtightly close the rivet mounting hole 74, and then the lower portion is crushed so that the lid plate 65, the first and second rivets 79 are closed.
The negative electrode terminal insulating rings 75 and 77 and the first and second metal rings 76 and 78 are riveted (fixed). The rivet 79 is formed from aluminum. The hat-shaped negative electrode terminal plate 80 is
And is fixed on the first metal ring 76 by resistance welding so as to contact the upper surface of the rivet 79.

The negative electrode lead 81 extends upward from each negative electrode plate of the electrode group 65, extends to the bottom surface side of the rivet 79, and is connected to the bottom surface of the rivet 79 by resistance welding. Each positive electrode plate of the electrode group 65 is connected to the outer can 61 and the first lid plate 63 by a positive electrode lead (not shown).

According to the organic electrolyte battery described above, when the internal pressure of the battery rises due to an internal short circuit or the like, the membrane valve 67 swells and is broken by the stress caused by the swelling or the contact with the cutting blade 71. The gas inside the battery is the first lid plate 63
Are discharged through the valve hole 66, the broken portion of the membrane-shaped valve body 67, and the gas vent hole 72 of the positive electrode terminal plate 70. For this reason,
Battery explosion can be prevented beforehand.

Further, the film-shaped valve element 67 is heat-sealed on the first cover plate 63 and the positive electrode terminal plate 70 is fixed on the cover plate 63 by welding. The surface of the plate 63 to which the film-shaped valve body 67 is adhered is not bent and deformed by caulking. For this reason, the valve hole 66 can be airtightly closed without peeling or cracking of the film-shaped valve body 67. Further, the positive electrode terminal plate 70 is
Together with the membrane-shaped valve element 67,
Can be prevented from peeling off. Therefore, even when used for a long period of time, good airtightness can be sufficiently maintained without lowering the adhesive force of the membrane valve element 67, and the explosion-proof mechanism can be operated at a predetermined battery internal pressure. The O-ring 7
3 also sandwiches the membrane valve element 67 together with the lid plate 63,
The peeling of the film-shaped valve element 67 can be more sufficiently prevented. In the use of such an O-ring, since the size of the battery is small and the area of the membrane valve is small, the effect of preventing peeling of the membrane valve is insufficient only by clamping the periphery of the membrane valve by the positive electrode terminal plate. This is particularly effective in cases.

The container in the organic electrolyte battery according to the second embodiment has a structure in which lid plates 63 and 64 are hermetically fixed by welding to upper and lower openings of an outer can 61 penetrating vertically. Although used, a container having a structure in which a lid plate is attached to an opening of a bottomed cylindrical outer can may be used.
In Embodiments 1 and 2 described above, the organic electrolyte primary battery has been described. However, a similar effect can be obtained with an organic electrolyte secondary battery.

[0031]

As described above in detail, according to the present invention, it is possible to provide a highly reliable organic electrolyte battery having an explosion-proof mechanism and capable of sufficiently maintaining good airtightness over a long period of time. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an organic electrolyte battery of Example 1.

FIG. 2 is a sectional view showing an organic electrolyte battery of Example 2.

FIG. 3 is a cross-sectional view showing a part of a conventional organic electrolyte battery.

FIG. 4 is a sectional view showing a part of an organic electrolyte battery already proposed.

[Explanation of symbols]

31, 61: battery container, 32, 62: outer can, 33, 6
3, 64: lid plate, 34, 65: electrode group, 38, 66: valve hole, 39, 67: membrane valve element, 40, 68: metal layer (aluminum thin plate), 41, 69: heat-fusible resin Layer (modified polypropylene sheet), 42: negative electrode terminal body (negative electrode terminal plate), 70: positive electrode terminal body (positive electrode terminal plate), 45, 74
... Rivet mounting holes, 47, 48, 75, 77 ... insulating members (insulating rings), 49, 79 ... rivets, 73 ... O-rings.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 4-46358 (JP, U) JP-A 50-103128 (JP, U) JP-A 63-38260 (JP, U) JP-A 59- 41868 (JP, U) J. 45-15687 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 2/12

Claims (1)

(57) [Claims] 1. An organic electrolyte battery in which a battery container containing an electrode group is provided with a positive electrode terminal or a negative electrode terminal having an explosion-proof mechanism, wherein the terminal having the explosion-proof mechanism has a valve hole formed in the container. A film-shaped valve body comprising a metal layer and a heat-fusible resin layer which are heat-sealed on the container so as to hermetically close the valve hole; and A terminal body welded to the container and formed on the terminal body
And a cutting blade facing the film-shaped valve body and the terminal body.
It is provided with an opened gas vent hole and an O-ring made of an elastic body interposed between the terminal body and the membrane valve so as to clamp the membrane valve together with the container. Organic electrolyte battery.