JP2000277064A - Thin battery - Google Patents

Abstract

(57) [Problem] To provide a sealed thin battery in which a positive electrode terminal and a negative electrode terminal extend to the outside through a sealing portion in a peripheral portion of an outer package, when the battery is excessively charged, etc. A simple structure can reliably prevent a battery from being damaged. SOLUTION: A positive electrode terminal 21 and a negative electrode terminal 22 extended from an electrode body 20 housed in an exterior body 10 provided with a resin layer 12a on the inner surface side of a metal layer 11 are passed through a sealing portion of the exterior body. In the thin battery extended to the outside, at least one of the positive electrode terminal and the negative electrode terminal is connected to the first terminals 21a and 22a extending from the electrode body to the sealing portion of the outer package, and the first terminal 21a and 22a extending from the sealing portion to the outside. The first terminal and the second terminal are connected so as to overlap each other at the sealing portion, and an insulating separation sheet is provided around the connection portion between the first terminal and the second terminal. 30 were provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electrode body having a positive electrode and a negative electrode and an electrolyte contained in an outer package in which a resin layer is provided on at least the inner surface side of a metal layer. The positive electrode terminal and the negative electrode terminal extended from the outer surface through a sealing portion where the resin layers on the inner surface side of the outer package are bonded to each other, the sealed thin battery, this thin battery is excessive The feature is that the safety in the case of being charged or the like can be enhanced by a simple structure.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic equipment and the like, as shown in FIG. 1, an electrode body 20 having a positive electrode and a negative electrode, and an electrolyte And a metal positive electrode terminal 21 having the same thickness from the positive electrode and the negative electrode in the electrode body 20.
A thin battery in which the negative electrode terminal 22 is extended, and the positive electrode terminal 21 and the negative electrode terminal 22 thus extended are respectively extended to the outside through the sealing portion of the exterior body 10 has been used. Was.

Conventionally, as such a thin battery, as shown in FIGS. 2A and 2B, a resin layer 12a, 12a
a metal positive electrode terminal 21 and a negative electrode extending from the positive electrode and the negative electrode of the electrode body 20 housed in the exterior body 10 using a sheet formed by laminating the sheet into a flat bag shape. The terminal 22 is extended to the outside through the space between the inner resin layers 12a, 12a in the peripheral portion of the outer package 10, and in this state, the inner resin layers 12a, 12a in the peripheral portion of the outer package 10 are bonded to each other. Thus, the periphery of the exterior body 10 is sealed, and the thin battery is hermetically sealed so that the electrolyte such as the electrolyte contained in the exterior body 10 does not leak.

However, when the thin battery sealed as described above is excessively charged, gas is generated in the electrode body 20 and the electrolyte, whereby the internal pressure of the thin battery rises, and the inside of the thin battery is increased. The stored electrolyte leaks,
There was a possibility that troubles such as breakage of the thin battery would occur.

For this reason, in recent years, Japanese Patent Application Laid-Open
As shown in Japanese Patent No. 294097, at least one of a positive electrode terminal and a negative electrode terminal is constituted by two terminals, and when the internal pressure of the thin battery increases, the two terminals are separated by a safety device. was suggested.

However, the safety device disclosed in the above publication has a complicated structure, requires a high manufacturing cost, and
There have been problems such as an increase in the size of the thin battery.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a hermetically sealed thin type in which a positive electrode terminal and a negative electrode terminal extending from a positive electrode and a negative electrode are extended outside through a sealing portion in a peripheral portion of an outer package. It is an object of the present invention to solve the above-described problems in a battery.

That is, in the present invention, when using the above-described sealed thin battery, when the thin battery is excessively charged, the electrolyte contained in the thin battery is leaked. It is an object of the present invention to reliably prevent the occurrence of troubles such as breakage of a thin battery or the like by a simple structure.

[0009]

In order to solve the above-mentioned problems, a thin battery according to the present invention has a positive electrode and a negative electrode in an outer package in which a resin layer is provided on at least an inner surface side of a metal layer. The electrode body and the electrolyte are accommodated, and the positive electrode terminal and the negative electrode terminal extending from the positive electrode and the negative electrode in the electrode body are externally connected to each other through a sealing portion where the inner resin layers of the outer body are bonded to each other. In a thin battery that is extended to at least one of the positive electrode terminal and the negative electrode terminal, a first terminal extending from the electrode body to the sealing portion and a second terminal extending to the outside from the sealing portion. The first terminal and the second terminal are connected so as to be overlapped with each other at the sealing portion of the exterior body, and an insulating material is provided around the connection portion between the first terminal and the second terminal. Minute It was so upcoming provided with a sheet.

Here, like the thin battery according to the present invention, at least one of the positive electrode terminal and the negative electrode terminal is extended to the outside from the first terminal from the electrode body to the sealing portion of the outer package and the sealing portion. The first terminal and the second terminal are connected so as to overlap each other at the sealing portion of the exterior body, and the first terminal and the second terminal are connected around the connection portion between the first terminal and the second terminal. When the insulating separation sheet is provided, the periphery of the sealing portion of the exterior body except for the connection portion between the first terminal and the second terminal is separated by the insulating separation sheet.

Therefore, when the thin battery according to the present invention is excessively charged and gas is generated in the electrode body and the electrolyte, and the internal pressure of the thin battery starts to increase, the thin battery is separated by the insulating separating sheet. First terminal and second terminal
A pressure acts in the direction of separating the first terminal and the second terminal around the connection portion with the terminal, whereby the connection between the first terminal and the second terminal is disconnected, and the charging current stops flowing to the electrode body. The internal pressure of the thin battery is suppressed from excessively rising, and the electrolyte contained in the thin battery leaks,
This prevents the thin battery from being damaged.

Further, in the thin battery according to the present invention, as described above, an insulating separation sheet is provided around the connection portion between the first terminal and the second terminal connected so as to overlap in the sealing portion of the outer package. , The configuration is simple, the manufacturing cost does not increase, and the thin battery does not increase in size.

Further, when the internal pressure of the thin battery starts to rise as described above, the above-mentioned pressure applied around the connection portion between the first terminal and the second terminal separated by the insulating separation sheet causes: In order for the connection between the first terminal and the second terminal to be quickly separated, the insulating separating sheet may be made of a material having a weak adhesive force with the resin layer on the inner surface side of the outer package. preferable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a thin battery according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings, and examples will be given to clarify the advantages of the thin battery according to the present invention. I do. In addition, the thin battery according to the present invention is not limited to those shown in the following embodiments and examples, and can be implemented by appropriately changing the gist thereof without changing the gist thereof.

In the thin battery according to this embodiment, as shown in FIG.
Inside, an electrode body 20 having a positive electrode and a negative electrode and an electrolyte are accommodated, and a metal positive electrode terminal 21 and a negative electrode terminal 22 extending from the positive electrode and the negative electrode in the electrode body 20 are respectively attached to the exterior body 10. Is extended to the outside through a sealing portion around the periphery.

In the thin battery of this embodiment, a sheet in which resin layers 12a and 12b are laminated on both sides of a metal layer 11 is used to form the above-mentioned outer package 10, as shown in FIG. Then, the above-mentioned electrode body 20 is accommodated in an exterior body 10 formed by folding this sheet, and the above-mentioned positive electrode terminal 2 extended from this electrode body 20 is accommodated.
1 and the negative electrode terminal 22 are extended to the outside from a sealing portion where the resin layers 12a are adhered to each other on the inner surface side of the peripheral portion of the outer package 10.

Here, in the thin battery of this embodiment, the positive electrode terminal 2 extended from the electrode body 20 as described above is used.
In extending the negative electrode terminal 1 and the negative electrode terminal 22 from the sealing portion of the exterior body 10, at least one of the positive electrode terminal 21 and the negative electrode terminal 22 is separated from the electrode body 20 as shown in FIG. First terminal 21a (22a) reaching sealing portion
And a second terminal 21b extending outside from the sealing portion
(22b) and the first terminal 21a (22a).
And the second terminal 21b (22b) are connected so as to partially overlap each other in the above-mentioned sealing portion.

Then, as described above, the first terminals 21a (22
In order to connect a) and the second terminal 21b (22b) so as to partially overlap with each other, as shown in FIG.
Insulating separation sheet 3 having an opening 31 in the center
0 at the opening 31 of the separation sheet 30
The first terminal 21a (22a) and the second terminal 21b (2
2b) and the first terminal 2
An insulating separation sheet 30 is positioned around the connection between the first terminal 22a and the second terminal 21b (22b). Here, as the insulating separation sheet 30,
The heat-fusible resin layer 1 on the inner surface side of the exterior body 10
A material made of a resin or the like having low adhesion to 2a is used.

In the thin battery according to this embodiment, the first terminal 21a (22a) and the second terminal 21b are located at positions corresponding to the sealing portions of the outer package 10.
(22b) is covered with a heat-fusible resin layer 23.

Then, as described above, the second terminal 21b (2
2b) is extended from the sealing portion of the exterior body 10 to the outside. In this state, in the exterior body 10 folded as described above, the metal layer 11 is formed on three sides excluding the folded portion.
The resin layers 12a on the inner surface side are bonded to each other to seal the periphery of the exterior body 10.

As described above, when the resin layer 12a on the inner surface side of the metal layer 11 is adhered to each other to seal the periphery of the outer package 10, the first terminal is formed as shown in FIGS. 4A and 4B. An insulating separation sheet 30 exists around a portion where the first terminal 21a (22a) and the second terminal 21b (22b) are connected, and the first terminal 21a (22a) and the second terminal 21b (22
The separation sheet 30 whose periphery is insulative except for the connection part with b)
To become separated.

When such a thin battery is excessively charged and gas is generated in the electrode body 20 and the electrolyte, and the internal pressure of the thin battery starts to increase, the thin battery is separated by the insulating separation sheet 30 described above. The first terminal 21a (22
a) and the second terminal 21b (22b) around the connection between the first terminal 21a (22a) and the second terminal 21b (22b).
b) is applied in such a direction as to separate the first terminal 21a (22a) and the second terminal 21b (22b), and the charging current stops flowing to the electrode body 20. An excessive increase in the internal pressure of the fuel cell is suppressed.

Here, the form of the electrode body 20 used in the above-mentioned thin battery is not particularly limited, and the electrode body 20 is wound with a separator interposed between the positive electrode and the negative electrode, or the separator is interposed between the positive electrode and the negative electrode. The thing that turned back many times with
It is also possible to use one having a plurality of layers in which a separator is interposed between a positive electrode and a negative electrode.

The material used for the positive electrode and the negative electrode in the electrode body 20 is not particularly limited. For example, in the case of a non-aqueous electrolyte battery, manganese, cobalt, nickel, iron, vanadium,
A lithium transition metal composite oxide containing at least one niobium or the like may be used. As a negative electrode active material for the negative electrode, in addition to metallic lithium and a lithium alloy, graphite, coke, and organic substances capable of absorbing and releasing lithium ions may be used. A carbon material such as a fired body is used.

In the case of a non-aqueous electrolyte battery, a non-aqueous electrolyte or a solid electrolyte in which a solute is dissolved in an organic solvent is used as the electrolyte.

The organic solvent used for the non-aqueous electrolyte includes, for example, cyclic carbonates such as ethylene carbonate, propylene carbonate, vinylene carbonate and butylene carbonate, and chains such as dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate. Carbonates, sulfolane, tetrahydrofuran,
1,3-dioxolan, 1,2-diethoxyethane,
Solvents such as 1,2-dimethoxyethane and ethoxymethoxyethane can be used alone or as a mixture of two or more.

On the other hand, a solute dissolved in the above organic solvent
For example, for example, LiPF₆, LiBF_Four, LiCF_Three
SO_Three, LiN (CF_ThreeSO_Two)_Two, LiN (C_TwoF_Five
SO _Two)_Two, LiN (CF_ThreeSO_Two) (C_FourF₉S
O_Two), LiC (CF_ThreeSO_Two) _Three, LiC (C_TwoF_Five
SO_Two)_ThreeAnd the like.

Examples of the solid electrolyte include a polymer electrolyte in which the above solute is contained in a polymer such as polyethylene oxide and polyacrylonitrile, and a gel polymer electrolyte in which the above polymer is impregnated with the above nonaqueous electrolyte. , LiI, Li ₃ N, etc. can be used.

In the case of a non-aqueous electrolyte battery, the positive electrode terminal 21 is made of an aluminum-based metal, while the negative electrode terminal 22 is made of a metal such as copper or nickel. Is used.

Here, as described above, the first terminal 21a (22a) and the second terminal 21b
(22b), the first terminal 21a (22a) and the second terminal 21b (22b).
May come into contact with the metal layer 11 of the outer package 10, and in the above-described nonaqueous electrolyte battery,
When the terminal 21 (22) made of a different kind of metal comes into contact, the metal layer 11 of the exterior body 10 is alloyed and becomes brittle, or the non-aqueous electrolyte in the non-aqueous electrolyte battery is decomposed. The first terminal 21a (22a) and the second terminal
It is preferable that the metal layer 11 of the exterior body 10 be made of the same kind of metal as the terminals 21b (22b).

In the thin battery according to this embodiment, the metal layer 11
The sheet in which the resin layers 12a and 12b are laminated on both sides of the sheet is folded, and the three sides excluding the folded part are
Although the resin layers 12a and 12a on the inner surface side of the metal layer 11 are bonded to each other, a method for sealing the exterior body 10 is not particularly limited, and a conventionally known method can be used.

Next, in the thin battery of the above embodiment, a positive electrode having a weight ratio of LiCoO ₂ , acetylene black, graphite and polyvinylidene fluoride of 90: 2: 3: 5, a natural graphite and polyvinylidene fluoride were used. And a negative electrode having a weight ratio of 95: 5, a separator was interposed therebetween, and the wound electrode body 20 was used, and ethylene carbonate and diethyl carbonate were mixed as electrolytes in a volume ratio of 4: 6. A non-aqueous electrolyte in which lithium hexafluorophosphate LiPF ₆ was dissolved at a rate of 1 mol / l in the mixed solvent was used.

On the other hand, as the package 10, a laminate of a layer of modified polypropylene and a layer of polypropylene as the resin layer 12a on the inner surface side of the metal layer 11 made of aluminum was used.

Then, the positive electrode terminal 21 extending from the positive electrode of the electrode body 20 is separated into a first terminal 21a and a second terminal 21b, and the first terminal 21a is The second terminal 21b is connected so as to partially overlap with the second terminal 21b, and an insulating material made of Teflon resin having a weak adhesive force with the resin layer 12a on the inner surface side of the exterior body 10 is provided around the connection portion. The separation sheet 30 is provided, and in this state, the resin layers 12a on the inner surface side of the exterior body 10 are adhered to each other and sealed, and the length of the long side is 60 mm and the length of the short side is 45 mm. Twenty thin batteries according to the present example were manufactured.

On the other hand, as a comparative example, FIG.
As shown in (A) and (B), the positive terminal 21 and the negative terminal 22 extending from the electrode body 20 are
20 thin batteries which were extended to the outside through the sealing portion of were manufactured.

Then, each of the thin batteries of the above Examples and Comparative Examples was charged at a charging current of 500 mA (1 C) for 3 hours so as to reach 12 V, and changes in each thin battery were examined.

As a result, in the case of the thin battery of the comparative example, the non-aqueous electrolyte leaked during charging and the thin battery was damaged in 18 of the 20 thin batteries. On the other hand, in the thin batteries of the above embodiments, the first terminal 21a and the second terminal 21b of the positive electrode terminal 21 are separated during the charging, and the charging current is reduced. In this case, the non-aqueous electrolyte did not leak and the thin battery was not damaged.

[0038]

As described above in detail, in the thin battery according to the present invention, at least one of the positive electrode terminal and the negative electrode terminal is connected to the first terminal from the electrode body to the sealing portion of the package and the sealing portion. The first terminal and the second terminal are connected so as to overlap each other at the sealing portion of the exterior body, and the first terminal and the second terminal are connected to each other.
Since the insulating separation sheet is provided around the connection portion with the terminal, when the thin battery is excessively charged and the internal pressure of the thin battery starts to rise, the insulating separation sheet is placed around the thin battery. Pressure in the direction of separation acts on the provided connection portion between the first terminal and the second terminal, whereby the connection between the first terminal and the second terminal is disconnected, and the charging current stops flowing to the electrode body.

As a result, in the thin battery according to the present invention, an excessive increase in the internal pressure is suppressed, and troubles such as breakage of the thin battery are prevented from occurring.

Further, in the thin battery according to the present invention, an insulating separation sheet is provided around the connection portion between the first terminal and the second terminal which are connected so as to overlap each other at the sealing portion of the outer package as described above. , The structure is simple, the manufacturing cost does not increase as in the prior art, and the thin battery does not increase in size.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a thin battery.

FIG. 2 is a cross-sectional explanatory view showing a conventional thin battery in which a positive electrode terminal and a negative electrode terminal are extended outside from a sealing portion where resin layers on the inner surface side in a peripheral portion of an outer package are bonded to each other; It is.

FIG. 3 is an explanatory cross-sectional view of an outer package formed by folding a sheet in which a resin layer is laminated on both surfaces of a metal layer in the thin battery according to the embodiment of the present invention.

FIG. 4 is a perspective view of the thin battery according to the embodiment, in which the first terminal and the second terminal are connected so as to partially overlap with each other at the sealing portion of the exterior body, and a connection portion between the first terminal and the second terminal. FIG. 3 is an explanatory cross-sectional view showing a state in which an insulating separation sheet is provided around the sheet.

FIG. 5 is a plan view of an insulating separation sheet provided around a portion where the first terminal and the second terminal are connected in the thin battery according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Outer body 11 Metal layer 12a Resin layer on the inner surface side of metal layer 20 Electrode body 21 Positive terminal 22 Negative terminal 21a (22a) First terminal 21b (22b) Second terminal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ikuo Nakane 2-5-5 Keihanhondori, Moriguchi City, Osaka Prefecture Inside Sanyo Electric Co., Ltd. (72) Inventor Satoru Fukuoka 2-5-5 Keihanhondori, Moriguchi City, Osaka Prefecture No. 5 Sanyo Electric Co., Ltd. F-term (reference) 5H011 AA13 CC02 CC06 CC10 DD13 EE04 GG01 HH02 5H024 AA00 AA02 AA12 CC04 CC19 DD03 DD11 5H029 AJ12 AJ14 AK03 AL06 AL07 AL12 AM00 AM02 AM03 AM04 AM05 AM04 AM03 DJ05 DJ04 DJ05 EJ12

Claims (1)

[Claims] An electrode body having a positive electrode and a negative electrode and an electrolyte are accommodated in an exterior body having a resin layer provided on at least an inner surface side of a metal layer, and are extended from the positive electrode and the negative electrode in the electrode body. In a thin battery in which a positive electrode terminal and a negative electrode terminal are respectively extended outside through a sealing portion where the resin layers on the inner surface side of the outer package are bonded to each other,
At least one of the positive electrode terminal and the negative electrode terminal includes a first terminal extending from the electrode body to the sealing portion and a second terminal extending from the sealing portion to the outside.
The terminal and the second terminal are connected so as to overlap each other at the sealing portion of the exterior body, and the first terminal and the second terminal are connected to each other.
A thin battery comprising an insulating separation sheet provided around a portion connected to a terminal.