JP2001093486A - Square-type sealed battery and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a square-type sealed battery which can be much more slimed with keeping satisfactory function of a battery, and to provide a manufacturing method of the square-type sealed battery. SOLUTION: In a battery 60 comprising a metallic armored can 50 and an opening sealing body 40, a positive electrode terminal 41 and a return type safety valve 42 separated from the positive electrode terminal 41 are arranged on a main plane of the opening sealing body 40. A metallic valve cap 421 of the safety valve 42 is directly attached to the opening sealing body 40 for making the safety valve 42 play a role of a negative electrode terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prismatic sealed battery and a method for manufacturing the same, and more particularly, to a technique for improving the structure of a sealing body.

[0002]

2. Description of the Related Art In recent years, small electronic devices such as personal digital assistants (PDAs), such as mobile phones, have been rapidly spreading. Since these electronic devices are required to have a performance that can withstand continuous use for a relatively long time, research is being conducted to develop a battery having a high energy density as a power source thereof.

With this background, there is a tendency that a rectangular sealed battery is used in the electronic equipment. A prismatic sealed battery has excellent features such as a larger electric capacity per unit volume than other types of batteries. Here, FIG.
FIG. 1 is a partial cross-sectional view showing a configuration of a prismatic nickel-metal hydride storage battery that is one of prismatic sealed batteries. The nickel-metal hydride storage battery 10 mainly includes an outer can 20, a power generation element 200, a sealing body 30, and the like. The size is, for example, 6.1 mm thick × 17.0 mm wide × 35.5 mm high.

The outer can 20 and the sealing body 30 are both formed by press-forming a nickel steel plate, and constitute a metal battery case. Of these, approximately 3.
One electrode terminal 31 (in this figure, a positive electrode terminal) of about 5 mm square is arranged. In the positive electrode terminal 31, the cylindrical member 313 (see FIG. 6) is caulked through a gasket 312 inside the battery, and the hermeticity between the positive electrode terminal 31 and the sealing body 30 is secured in this portion. .

The power generating element 200 includes a strip-shaped positive electrode plate 20.
1. A separator 202 and a negative electrode plate 203 are stacked, and these are impregnated with an electrolytic solution. In the negative electrode plate 203, a hydrogen storage alloy is applied as an active material to a surface of a punched metal made of a nickel steel plate. In the positive electrode plate 201, an active material mainly containing nickel hydroxide or the like is applied to the surface of a punched metal made of a nickel steel plate.

The positive electrode plate 201 includes a tab 2010,
It is electrically connected to the positive electrode terminal 31 via the positive electrode current collector 303. The sealing body 30 is disposed in the opening 15 of the outer can 20 so that the spacer 21 and the insulating plate 302 face each other, and is laser-welded along the periphery of the opening 15. Thereby, the inside of the outer can 20 is sealed.

FIG. 6 is a detailed view of the sealing body 30.
(A) is a front view of the sealing body 30, (b) is a partial cross-sectional view along AA ', and (c) is a back view. As shown in (b), the valve body 3 made of elastic rubber is provided inside the terminal cap 310.
16 is built in, and normally presses the periphery of the vent 315 to seal the inside of the battery. When the internal pressure of the battery rises above a certain level, the valve body 316 is compressed upward by the gas pressure, and the gas inside the battery is exhausted from the exhaust port 311. As a result, the internal pressure of the battery decreases, and the valve element 316
Returns to its original position again.

[0008] Such a rectangular sealed battery is still required to have even higher energy density, and the thickness of the battery is reduced to achieve slimness.

[0009]

However, the above-mentioned prismatic nickel-metal hydride storage battery has a relatively large number of components around the positive electrode terminal, so that it is difficult to reduce the size of the terminal as a whole. It is seen. Therefore, if the thickness of the battery is simply reduced (slimmed), the positive electrode terminal approaches the periphery of the sealing body,
At the time of laser welding of the opening of the sealing body and the outer can, there is a possibility that the center of the resin component such as the gasket or the insulating plate of the positive terminal is affected by heat and deformed. This impairs the hermeticity of the inside of the battery and may cause deterioration of the battery performance.

As described above, it is necessary to solve a major problem in order to further reduce the size of a rectangular sealed battery while maintaining the performance of the battery in a good condition.
The present invention has been made in view of such problems, and an object of the present invention is to provide a prismatic sealed battery that can be made slimmer while maintaining good battery performance, and a method for manufacturing the same. .

[0011]

Means for Solving the Problems In order to achieve the above object, the present invention provides a prismatic sealed battery in which a power generating element is housed in an outer can and the opening of the outer can is sealed with a sealing body. A battery case comprising a can and a sealing body, an electrode terminal having a polarity opposite to that of the battery housing, a cap having an exhaust port, and a chamber having the cap having the exhaust port and the sealing body, are disposed in a room formed by the cap, and A safety valve composed of a valve element that closes the exhaust port and a safety valve configured at different locations,
The cap having the exhaust port has the same polarity as the battery case.

As a result, the structure of the electrode terminal is simpler than that of the conventional structure with a built-in safety valve, so that the number of components is reduced and the size of the electrode terminal can be reduced.
This has the effect that the battery can be slimmed down satisfactorily. Also, by charging the safety valve to the same polarity as that of the battery housing, the safety valve can be used as the other electrode terminal, so that the battery can be small and easy to use when a plurality of batteries are connected.

Further, according to the present invention, since the size of the electrode terminal with respect to the sealing member can be small, when, for example, a metal outer can is welded to the sealing member to seal the inside, heat transfer to the electrode terminal is performed. Heat effects can be suppressed. Therefore, deformation of the resin parts of the electrode terminals can be prevented, and good sealing performance can be ensured. Further, if the shape of the electrode terminal and the shape of the safety valve are made different, the danger of erroneously recognizing the polarity during use can be avoided.

The inventors have found that such a rectangular sealed battery of the present invention is particularly effective for a battery having a battery thickness of about 6 mm or less.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 1. Embodiment 1 1-1. Configuration of Prismatic Nickel-Metal Hydride Battery FIG.
H) An external perspective view of a storage battery 60 (hereinafter, referred to as “battery 60”). The present battery 60 has substantially the same power generation elements as the above-described conventional rectangular nickel-metal hydride storage battery 10, but has a feature that the configuration near the sealing body 40 is clearly different from the conventional one.

That is, as shown in this figure, in the present battery 60, a positive electrode terminal 41 protruding from the surface of the sealing body 40 and a safety valve 42 are provided separately from the positive electrode terminal 41. The safety valve 42 has a negative polarity opposite to the positive electrode terminal 41. That is, in the present embodiment, the positive electrode (electrode) terminal 41 and the safety valve 42, which are conventionally configured as an integrated type, are provided independently of each other.
Is also used as a negative electrode terminal.

The periphery of the sealing body 40 is laser-welded to the opening 51 of the outer can 50, and the inside of the battery is closed. Here, FIG. 2 is a detailed view of the sealing body 40. (A) is a front view of the sealing body 40, (b) is a BB 'partial sectional view, (c)
Indicates a back view. The safety valve 42 incorporates a valve body 423 made of elastic rubber in a valve cap 421 as shown in FIG.
Although communicating with the inside of the battery through the exhaust hole 422, the valve body 423 normally presses the opening 402 to close and close it. The valve cap 421 shown in FIG.
To the sealing plate 40 by welding or the like.
1 and the outer can 50 are charged to the same polarity (negative polarity).

FIG. 3 shown below is a partial cross-sectional view of the sealing body 40 showing the structure centered on the positive electrode terminal 41 in detail.
The positive electrode terminal 41 has a configuration in which a terminal rivet 411 is fitted into a ring 414 at a cylindrical protrusion 412 formed by drawing a sealing plate 401.
A gasket 413 is interposed between the first ring 1 and the ring 414.

More specifically, the terminal rivet 411 is sequentially passed through the insulating plate 410, the sealing plate 401, the gasket 413, and the ring 414 from the inside of the battery, and
The tip of one shaft is caulked, forming a deformed portion 4111 and connected to the ring 414. Since the positive electrode terminal 41 does not have a built-in safety valve inside, it can be made with a simple component structure while being very compact as compared with a conventional terminal having a built-in safety valve.

The insulating plate 410 and the gasket 413 are made of nylon resin, and the terminal rivets 411 and the ring 414 are made of nickel steel. The insulating plate 410 has a thickness in the z direction so as to fix the power generating element 200 in the outer can 50, and has an inverted concave along the BB 'cross section to attach the terminal rivet 411 at a central portion thereof. It has a character shape (see FIG. 2). The projecting portion 412 is formed in advance so that the edge section of the tip portion 4121 is inclined.
121 functions to ensure good airtightness inside the battery by digging into the gasket 413. Further, at the time of the crimping process, the hook portion 4112 of the terminal rivet 411 becomes
0 to ensure further airtightness between the terminal rivet 411 and the insulating plate 410. Here, in the drawing, reference numeral 4113 denotes a driving mark generated during the caulking processing.

As described above, in the battery 50, since the crimping process which was conventionally performed on the inside of the battery of the sealing plate 401 is performed at the tip of the positive electrode terminal 41, the shape of the positive electrode terminal 41 on the inside of the battery near the sealing plate 401 is changed. Can be set relatively freely. For example, the lower end of the positive electrode terminal 41 is flattened and the positive electrode tab is set to 20
10 can also be made into a shape which is easy to connect directly. According to the battery 50 having the above-described configuration, the structure near the terminal rivet 411 is relatively simple as described above, so that the size of the positive electrode terminal 41 is reduced in size (specifically, about 3. (From 5 mm square to a diameter of about 3.0 mm or less). If the size of the positive electrode terminal 41 is reduced, there is a margin between the welded portion of the sealing body 40 and the positive electrode terminal 41. Therefore, the components constituting the positive electrode terminal 41 (mainly, resin parts such as the insulating plate 410 and the gasket 413). Is less likely to be affected by heat during laser welding between the periphery of the sealing body 40 and the opening 51.

The safety valve 42 (specifically, the valve cap 4
21) is fixed without the gasket 413 therebetween, so that the safety valve 42 is hardly affected by heat during laser welding, and the sealing performance of the battery does not decrease. Therefore, even if the size of the battery is reduced, the inside of the battery can be kept airtight and the battery 60 having excellent performance can be obtained.

Further, since the valve cap 421 of the safety valve 42 is directly attached to the sealing plate 401, the safety valve 42 can be used as a negative electrode terminal. Thereby, the present battery 6
A value of 0 means that two polarity electrode terminals are arranged on the sealing body 40 in parallel. Accordingly, when a plurality of batteries are arranged in the same direction, adjacent batteries can be easily connected to each other, and the usability is good. As described above, the battery 60 exhibits performance comparable to that of the conventional battery even when the battery is slim.

2. Embodiment 2 2-1. Structure of Prismatic Nickel-Metal Hydride Battery (Near Sealing Body) FIG. 4 is a view showing a structure of a sealing body 70 of a prismatic nickel-metal hydride battery according to a second embodiment. . As shown in this figure,
The second embodiment differs from the first embodiment in that the positive electrode terminal is arranged at the center of the sealing plate 701.
In the present invention, since the configuration centering on the positive electrode terminal 71 is very compact as compared with the related art, the position of the positive electrode terminal 71 is further shifted on the sealing plate 701 while securing the same effect as in the first embodiment. It is also possible to change it. This flexibility seems to be particularly effective in designing the shape of the battery according to the application.

2. Method of Manufacturing Prismatic Nickel-Metal Hydride Battery Next, an example of a method of fabricating the rectangular nickel-metal hydride storage batteries of the above embodiments will be described. 2-1. Production of outer can The outer can is made of nickel-plated steel plate (0.45 thick).
mm) is formed by deep drawing using a punching die. As an example of the size of the outer can, the size of the outer can is made smaller than that of the conventional type (FIG. 5), and the thickness of the steel plate is about 0.4 mm, the final thickness is 4.2 mm × the width 26.0 mm × the height 35.0 mm. be able to.

2-2. Manufacture of Sealing Body The sealing plate of the sealing body can be formed, for example, by punching a nickel-plated steel plate into a predetermined shape using a die. However, the protruding portion is formed by performing a deep drawing process. Here, the protrusion amount of the protrusion is 1 mm from the surface of the sealing plate.
And the thickness of the steel sheet is 0.2 mm. At this time, the edge section of the tip of the protruding portion is inclined by sharpening or the like.

After the sealing plate is formed, a terminal rivet made of nickel steel is inserted through a resin gasket and an insulating plate.
Pass each ring (approximately 3.0mm in diameter) through the protrusions,
The tip of the terminal rivet is deformed and fixed by caulking, thereby completing the positive electrode terminal. In addition, ethylene
-Fix a nickel steel valve cap (approximately 3 mm square) to the sealing plate from above while pressing a valve body (diameter 2.1 mm) made of propylene (EPDM) cylindrical elastic rubber into the ventilation hole of the sealing plate. Then, a safety valve that doubles as a negative electrode terminal is completed.

Thus, a sealing body is manufactured. 2-3. Production of power generation element A positive electrode plate is prepared by applying a positive electrode active material containing nickel hydroxide as a main component to a punching metal made of a nickel steel sheet, and a negative electrode plate is prepared by applying a hydrogen storage alloy to the punching metal. Respectively. Then, these electrode plates are alternately laminated with a porous sheet separator made of a nylon resin interposed therebetween to form a power generating element. At this time, a tab is attached to each punching metal of the negative electrode plate and the positive electrode plate. Note that a separator or a negative electrode plate (a polarity different from that of the electrode terminal) is located on the outermost main surface of the power generating element. When the negative electrode plate is located on the outermost main surface, the negative electrode plate directly contacts the outer can, so that the negative electrode tab does not need to be attached.

2-4. Completion of Battery The power generation element prepared above is housed in an outer can, and a tab extending from the positive electrode plate is connected to the positive electrode terminal by spot welding or the like. Thereafter, 30 wt% of potassium hydroxide (K
OH) An electrolytic solution composed of an aqueous solution is injected. Then, a sealing body is arranged at the opening of the outer can, and the vicinity of the boundary between the both is sealed by laser welding to seal the inside of the battery.

Thus, a prismatic nickel-metal hydride storage battery is completed. In this embodiment, the electrode terminal and the tab of the positive electrode plate of the power generating element may be connected (welded) first, and then the terminal rivet may be passed through the sealing plate and fixed. In this case, the workability is improved as compared with the case where the power generation element is connected to the electrode terminal fixed to the sealing plate, and an effect such that the yield is improved can be expected.

3. Other Matters In the above embodiments, examples were given of nickel-metal hydride storage batteries. However, the present invention is not limited to this, and non-aqueous batteries such as nickel-cadmium storage batteries and Li-ion batteries can be used. Other types of sealed rectangular batteries using an electrolytic solution may be used. Also, an example has been described in which the electrode terminal is charged to the positive electrode and the safety valve is charged to the negative electrode. However, the negative electrode tab may be connected to the terminal rivet, and the positive electrode may be connected to the outer can.

Further, the positions of the positive electrode terminal and the safety valve are not limited to the positions of the above-described embodiments. For example, the positive electrode terminal and the safety valve can be provided on the outer can. However,
Considering the improvement in productivity and ease of use as an assembled battery, it is considered desirable to arrange both of them on a sealing body. Further, the size of the battery of the present invention is not limited to the size manufactured in the example, but may be other sizes. Here, the present invention relates to the case where the thickness of the battery (x-direction thickness) is about 6 mm, which is smaller than the thickness of the current rectangular nickel-metal hydride storage battery having the metal outer can and the sealing body. It has been found by the inventors that the present invention is particularly effective. Further, the diameter of the positive electrode terminal (the diameter of the ring 414) can be further smaller than the 3.0 mm illustrated in the embodiment.

[0033]

As is apparent from the above, the present invention relates to a prismatic sealed battery in which a power generating element is housed in an outer can and the opening of the outer can is sealed with a sealing body. And a battery housing comprising a sealing body, an electrode terminal having a polarity opposite to that of the battery housing, a cap having an exhaust port, and being disposed in a room formed by the cap having the exhaust port and the sealing body, A safety valve including a valve body that closes an exhaust port is disposed at different locations from each other, and a cap having the exhaust port has the same polarity as a battery housing. It is easier than ever, and the battery can be slimmed down.

Further, according to the present invention, since the size of the electrode terminal with respect to the sealing member can be reduced, for example, when a metal outer can is welded to the sealing member to seal the inside, heat generated by heat transfer to the electrode terminal can be obtained. The influence can be suppressed. Therefore, deformation of the resin parts of the electrode terminals can be prevented, and good sealing performance can be ensured. In addition, since the safety valve is charged with a polarity different from that of the electrode terminal, a safety valve can be used as the other electrode terminal, and even if the battery is made slim, a battery that is easy to use can be provided.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a prismatic nickel-metal hydride storage battery according to Embodiment 1 of the present invention.

FIG. 2 is a view showing a sealing body of the rectangular nickel-metal hydride storage battery. (A) It is the front view which looked down from the upper part of the sealing body. (B) It is a partial sectional view of a closure. (C) It is a back view of a sealing body.

FIG. 3 is a cross-sectional view near a positive electrode terminal.

FIG. 4 is a view showing a sealing body of a square nickel-metal hydride storage battery according to Embodiment 2 of the present invention.

FIG. 5 is a partial cross-sectional perspective view showing a main configuration of a conventional square nickel-metal hydride battery.

FIG. 6 is a view showing a sealing body of a conventional square nickel-metal hydride storage battery. (A) It is the front view which looked down from the upper part of the sealing body. (B) It is a partial sectional view of a closure. (C) It is a back view of a sealing body.

[Explanation of symbols]

 40, 70 Sealing body 41, 71 Positive electrode terminal 42, 72 Safety valve 50 Outer can 60 Square alkaline storage battery 401, 701 Sealing plate 402, 702 Opening 410, 710 Insulating plate 411, 711 Terminal rivet 412 Projection 413 Gasket 414 Ring 421 Valve Cap 422 Exhaust hole 423, 723 Valve body

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Inoue 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Hideyuki Asanuma 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Naoyoshi Hinotsu 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5H011 AA06 CC06 DD13 EE02 FF04 GG02 HH02 JJ12 KK01 5H012 AA07 BB02 CC01 DD04 EE01 EE09 GG01 JJ01 JJ10 5H022 AA04 BB03 CC03 CC16 CC21 CC30 5H028 AA01 BB01 BB04 BB05 CC10 EE01 HH05

Claims (12)

[Claims] 1. A rectangular sealed battery in which a power generating element is housed in an outer can and an opening of the outer can is sealed with a sealing body, wherein a battery housing including the outer can and the sealing body has a battery housing. An electrode terminal having a polarity opposite to that of the body, a cap having an exhaust port, and a valve disposed in a chamber formed by the cap having the exhaust port and the sealing body, and closing the exhaust port. A rectangular sealed battery, wherein the safety valve and the safety valve are arranged at different positions, and the cap having the exhaust port has the same polarity as the battery housing. 2. The sealed rectangular battery according to claim 1, wherein the sealed rectangular battery is an alkaline storage battery. 3. The rectangular sealed battery according to claim 1, wherein the valve body is an elastic body. 4. The prismatic sealed battery according to claim 1, wherein the outer can and the sealing body are made of metal. 5. The sealed rectangular battery according to claim 4, wherein the electrode terminal and the safety valve are arranged on a main surface of a sealing body. 6. The sealed rectangular battery according to claim 1, wherein the electrode terminal and the safety valve have different shapes. 7. The device according to claim 1, wherein the electrode terminal and the safety valve are arranged at asymmetric positions on a sealing body.
A sealed rectangular battery according to any one of claims 1 to 6. 8. The sealed rectangular battery according to claim 1, wherein the thickness of the battery housing is 6 mm or less. 9. A return-type safety valve in which a metal battery case including a sealing body and an outer can is provided with an electrode terminal insulated from the battery case and charged to a polarity different from that of the electrode terminal. Arranging; connecting the power generating element and the electrode terminal; and housing the power generating element inside the battery housing; and welding and sealing the opening of the sealing body and the outer can. A method for producing a prismatic sealed battery. 10. A state in which one of the positive and negative electrodes of a power generating element is electrically connected to an electrode terminal, and then the electrode terminal is passed through a perforated sealing body to electrically insulate the sealing body from the electrode terminal. The method for producing a prismatic sealed battery according to claim 9, further comprising a step of housing the power generating element in an outer can through a step of fixing with a, and sealing an opening of the outer can with a sealing body. 11. The method for manufacturing a rectangular sealed battery according to claim 9, wherein the sealing body and the electrode terminals are fixed by caulking from the outside of the battery via an insulating member. 12. A projecting portion is formed on the main surface of the sealing body by drawing, and the edge cross section of the tip of the projecting portion is inclined.
The method for manufacturing a prismatic sealed battery according to any one of claims 9 to 11, wherein the tip of the protruding portion and the electrode terminal are caulked through a gasket.