JP2001229904A - Sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed body which enables prevention of expansion and bursting at overcharging or overdischarging, and also enables reducing of manufacturing costs. SOLUTION: The sealed battery 10 has a battery body 20, formed by laminating a positive pole 22 and a negative pole 23 with an electrolyte layer 21 therebetween, a positive pole terminal 26 and a negative pole terminal 27 connected with the positive pole 22 and the negative pole 23, a package 30 for sealed battery for aritightly sealing the battery body 20, and an explosion preventing part 41 for joining the positive pole terminal 26 and eh negative pole terminal 27 to the inside of the package 30 for sealed battery with a fusing resin 40 therebetween. The explosion preventing part 41 is removed from the positive pole terminal 26 and the negative pole terminal 27, when the internal pressure of the package 30 for sealed battery reaches a prescribed value or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, with the great progress in electronic technology, portable devices for general users have been reduced in size and weight.
Since the demand for a smaller and lighter battery is increasing, a nonaqueous electrolyte-based sealed battery is often used.
Generally, a nonaqueous electrolyte-based sealed battery has a battery body in which a positive electrode and a negative electrode are stacked via an electrolyte layer, and a positive electrode terminal and a negative electrode terminal connected to the positive electrode and the negative electrode, respectively.
A sealed battery package for hermetically sealing the battery body so that the open end of the positive terminal and the open end of the negative terminal are exposed outside;

[0003] A sealed battery of a non-aqueous electrolyte system is provided with a sealed battery package in which the battery body is securely hermetically sealed in order to prevent the electrolyte from leaking out or the ingress of moisture, oxygen or the like inside. There is a need for a structure that can be stopped. In response to this demand, for example, a solid electrolyte battery having a positive electrode terminal and a negative electrode terminal coated with an ionomer resin (Japanese Patent Application Laid-Open No. 60-65442)
Japanese Patent Application Laid-Open No. 63-232265: Conventional Example 1), or a flat battery in which a polyolefin aqueous dispersing film is formed on the positive electrode terminal and the negative electrode terminal. I have. According to these Conventional Example 1 and Conventional Example 2, it is described that a reliable airtightness is obtained in the sealed battery package.

[0004]

In the case of a non-aqueous electrolyte-based sealed battery, if the battery body generates heat during an abnormality such as overcharging or overdischarging, the gas generated from the electrolyte causes the sealed battery package to expand. Or it may burst. In order to avoid this problem, the applicant of the present application has proposed a battery (see Japanese Patent Application Laid-Open No. 9-320550: Conventional Example 3) in which a thin portion is provided at a predetermined position in a sealed battery package, or a sealed battery package. Proposed a thin battery (see Japanese Patent Application Laid-Open No. H10-55792: Conventional Example 4) in which the peel strength at a predetermined location was set low. Conventional example 3 and Conventional example 4
According to this, when the internal pressure of the sealed battery package reaches a certain level, an extremely excellent effect is obtained in that the hermetic sealing can be reliably released to prevent expansion and rupture.

[0005] However, in recent years, there has been a further demand for a reduction in the manufacturing cost of a nonaqueous electrolyte-based sealed battery. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a sealed battery that can prevent expansion and rupture at the time of overcharging or overdischarging and that can reduce manufacturing costs. .

[0006]

In order to achieve the above-mentioned object, the present invention provides a battery body in which a positive electrode and a negative electrode are stacked via an electrolyte layer, A sealed battery comprising: a pair of terminals respectively connected to the negative electrode; and a sealed battery package for hermetically sealing the battery body so that an open end of each terminal is exposed to the outside. An explosion-proof part in which at least one surface of the terminals and the inner surface of the sealed battery package are in close contact with each other via a fusible resin is provided, and the internal pressure of the sealed battery package has reached a predetermined value or more. In some cases, the fusible resin is peelable from at least one of the surface of the terminal and the inner surface of the sealed battery package.

Here, the surface of the terminal means, for example, at least a part of the entire surface including the end face when the terminal is strip-shaped, and at least one of the entire peripheral surface when the terminal is round bar-shaped. Refers to the department. Examples of the fusible resin constituting the explosion-proof part include modified polyethylene, polyethylene (PE), polypropylene (PP) and the like, which can be appropriately selected according to the material of the terminal and the inner surface of the sealed battery package. do it. Such an explosion-proof part may be provided at one or both of the positive electrode terminal connected to the positive electrode and the negative electrode terminal connected to the negative electrode. Area, film thickness,
The volume and the like may be set as appropriate.

[0008] In the sealed battery constructed as described above, when the internal pressure of the package for the sealed battery reaches a predetermined value or more, the fusible resin constituting the explosion-proof part can be peeled off. The same effect as that of the related art that expansion and rupture can be prevented can be obtained. In this sealed battery, the explosion-proof part can be installed by a very simple work of applying or interposing a fusible resin at a predetermined location when assembling the sealed battery, so that the manufacturing cost is reduced as compared with the conventional case. Therefore, the above-described object can be achieved.

In general, in a nonaqueous electrolyte sealed battery, a negative electrode terminal connected to a negative electrode is often formed of nickel, and a positive electrode terminal connected to a positive electrode is often formed of aluminum. Here, the peel strength to the fusible resin constituting the explosion-proof part, the aluminum positive electrode terminal is lower than the nickel negative electrode terminal,
And it is easy to set to a desired value. That is, the explosion-proof part of the present invention is preferably provided on the positive electrode terminal. For this reason, as set forth in claim 2, the present invention is characterized in that the explosion-proof part is provided at a positive electrode terminal connected to the positive electrode.

In the present invention, in order to quickly respond to an abnormality in the battery main body, it is preferable that the explosion-proof part operates at a stage where the internal pressure of the sealed battery package is low.
In other words, it is preferable that the peel strength for the fusible resin can be set to a low desired value. For this reason, the present invention is characterized in that the positive electrode terminal is made of aluminum or an aluminum alloy.

Next, since the sealed battery used for general portable equipment is small or thin, the package capacity of the sealed battery is relatively small. Therefore, the explosion-proof part of the present invention, if the peel strength of the fusible resin is higher than necessary,
There is a possibility that the hermetic sealing cannot be released unless the pressure inside the sealed battery package is increased for a long time after an abnormality occurs in the battery body. On the other hand, in the explosion-proof part of the present invention, if the peel strength of the fusible resin is too low, there is a possibility that the hermetic sealing may be released depending on the use environment of the portable device even if no abnormality has occurred in the battery body.

In view of these conditions, the present inventors have:
The preferred peel strength of the fusible resin was found to be 200 gf to 3000 gf per 10 mm width as measured by the T-peel method. For this reason, the present invention, as described in claim 4,
The peel strength of the fusible resin is 200 gf to 3000 per 10 mm width.
gf.

The explosion-proof part of the present invention preferably has a stable peeling strength of the fusible resin, and is provided in the sealed battery package when an abnormality occurs in the battery body. It is preferable that the fusible resin is peeled off prior to the portion. In view of such conditions, the present inventors have found that the surface of the terminal is preferably as smooth as possible, and specifically, the surface roughness of the terminal is preferably 5 μm or less.

Therefore, the present invention is characterized in that the terminal has a surface roughness of 5 μm or less. Here, the roughness is a height difference between peaks and valleys of fine unevenness generated on the surface of the terminal, and is a maximum value or an average value in an area in close contact with the fusible resin.

The expansion of the nonaqueous electrolyte sealed battery is caused by the generation of gas from the electrolyte due to the heat generated by the battery body. Therefore, in the explosion-proof part of the present invention, it is desirable that the fusible resin be peeled off at a predetermined temperature equal to or lower than a temperature at which a chemical reaction occurs in the electrolyte layer in order to avoid the expansion of the sealed battery at an early stage. Therefore, the present invention is characterized in that the melting temperature of the fusible resin is equal to or lower than the chemical reaction temperature of the electrolyte layer.

Further, the nonaqueous electrolyte-based sealed battery has a positive electrode formed of, for example, lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), etc.
A negative electrode is formed from a carbon-based material, and the solvent for the electrolyte layer is a combination of ethylene carbonate and ethyl methyl carbonate,
Or, when formed by a combination of ethylene carbonate and dimethyl carbonate, the temperature at which the chemical reaction occurs is about 200
℃ ~ about 300 ℃. Therefore, according to the present invention, as described in claim 7, the melting temperature is 150 ° C to 250 ° C.
It is characterized by being.

Also, in the present invention, if the fusible resin is polyethylene as described in claim 8, the melting point is relatively low, so that, for example, the battery body is relatively large, and from the heat-generating point to the explosion-proof part. When the distance is long, when the positive electrode is formed by lithium nickelate (LiNiO ₂ ) where the chemical reaction occurs at a relatively low temperature, or when the ratio of highly reactive chain carbonate is relatively high in the electrolyte layer And so on.

On the other hand, in the present invention, if the fusible resin is polypropylene as described in claim 9, for example, when the battery body is relatively small, the distance from the heat generating part to the explosion-proof part is short, When the positive electrode is formed of lithium cobaltate (LiCoO ₂ ), in which the reaction occurs at a relatively high temperature, or when the proportion of cyclic carbonate, which is less reactive than chain carbonate, is relatively high in the electrolyte layer And so on.

Next, in the present invention, in order to reliably prevent expansion and rupture at the time of overcharging or overdischarging, the heat generated in the battery main body is quickly transmitted to the explosion-proof part in the sealed battery package. A transmitted structure is preferred. In view of such conditions, the present inventors have obtained a desired effect by employing a sealed battery package having a metal foil core material made of aluminum or aluminum alloy having excellent thermal conductivity, Further, it has been found that when the thickness of the metal foil core material is 30 μm or more, the effect is remarkable. Therefore, the present invention provides, as described in claim 10, a resin film in which the sealed battery package has a fusible synthetic resin layer disposed on at least the inner surface of a metal foil core made of aluminum or an aluminum alloy. And the thickness of the metal foil core material is 30 μm or more.

In the present invention, when a package for a sealed battery having a metal foil core material is adopted in the present invention, if the thickness of the fusible synthetic resin layer exceeds 50 μm, the positive electrode or It has been found that heat conduction from the negative electrode to the metal foil core material is inhibited. Therefore, according to the present invention, as described in claim 11, the sealed battery package is formed of a resin film having a fusible synthetic resin layer disposed on at least the inner surface of a metal foil core material, The thickness of the conductive synthetic resin layer is not more than 50 μm.

Further, in the present invention, in order to shorten the time from the occurrence of an abnormality to the operation of the explosion-proof part, it is preferable that the distance from the heat-generating part to the explosion-proof part is short, and
In order to secure a certain capacity of the positive and negative electrodes,
It is preferable to secure the length dimension of the contour side to a certain value or more.
In view of such conditions, the present inventors have found that desired performance can be obtained by setting the maximum side length of the resin film forming the package for a sealed battery to 150 mm or less. For this reason, as set forth in claim 12, the present invention is characterized in that the maximum side length dimension of the resin film forming the sealed battery package is 150 mm or less.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to FIGS. As shown in FIGS. 1 and 2, a sealed battery 10 according to an embodiment of the present invention includes:
For example, a small non-aqueous electrolyte secondary battery used as a power source of a portable device or the like is provided. A substantially flat rectangular parallelepiped battery body 20 is hermetically sealed by a sealed battery package 30.

As shown in FIG. 2, the battery body 20 includes a positive electrode 22 and a negative electrode 23 stacked with an electrolyte layer 21 interposed therebetween, and a positive electrode 22 and a negative electrode 22.
And a positive electrode current collector 24 and a negative electrode current collector 25 that are in close contact with the negative electrode 23, respectively, and the long side length L, which is the maximum side length, is formed to be 150 mm or less. The electrolyte layer 21, for example, a combination of ethylene carbonate and ethyl methyl carbonate,
Alternatively, it is a polymer gel electrolyte using a combination of ethylene carbonate and dimethyl carbonate as a solvent. The positive electrode 22 is
For example lithium cobalt oxide (LiCoO ₂₎ and lithium nickel oxide (LiNiO ₂₎ it is formed by like. On the other hand, the negative electrode 23
Is formed of a carbon-based material such as a graphite-based carbon material and a coke-based carbon material.

A strip-shaped positive terminal 26 and a negative electrode terminal 27 are connected to the positive electrode current collector 24 and the negative electrode current collector 25, respectively. The positive electrode terminal 26 is made of aluminum foil or aluminum alloy foil, and the negative electrode terminal 27 is made of copper foil.
Here, the positive electrode terminal 26 and the negative electrode terminal 27 are finished to have a roughness such that the maximum value or the average value of the height difference between the peaks and valleys of the fine unevenness formed on the surface is about 5 μm or less.
Such a battery body 20 is hermetically sealed in a sealed battery package 30 so that the open end 26A of the positive terminal 26 and the open end 27A of the negative terminal 27 are exposed outside.

As shown in FIG. 3 in an enlarged manner, the sealed battery package 30 includes a metal foil core material 31, an outer layer 32 along the surface of the metal foil core material 31, and a back surface of the metal foil core material 31. It is formed of a resin film 34 in which the inner layer 33 and the inner layer 33 are laminated. The metal foil core material 31 is, for example, aluminum foil and has a layer thickness of about 40
It is set to μm. The outer layer 32 is made of, for example, polyethylene terephthalate (PET) or polyamide, and has a thickness of about 10 μm. On the other hand, the inner layer 33 is made of, for example, polyethylene (PE) or polypropylene (PP),
The layer thickness is set to about 30 μm.

Such a sealed battery package 30 includes:
Two rectangular resin films 34 larger than the planar shape of the battery body 20 are prepared, and each of the resin films 34 is connected to the positive electrode current collector 24 and the negative electrode current collector of the battery body 20 so that the inner layer 33 faces the battery body 20. After being in close contact with the body 25, the open end 26 of the positive electrode terminal 26
A and the peripheral portion of each resin film 34 adhered to the positive electrode current collector 24 are bent toward each resin film 34 adhered to the negative electrode current collector 25 while the open end 27A of the negative electrode terminal 27 is exposed to the outside. Then, the battery body 20 is hermetically sealed by mutually welding the peripheral portions of the resin films 34 to each other. At this time, the surface of the positive electrode terminal 26 and the surface of the negative electrode terminal 27 are cleaned with an organic solvent degreasing agent, such as acetone or toluene, and the positive electrode terminal 26 and the negative electrode terminal 27 are adhered in a thickness direction so as to be sandwiched. Explosion-proof parts 41, 41 are provided by interposing resins 40, 40.

The explosion-proof part 41 selectively employs a plurality of types of fusible resins 40 having different compositions, and adjusts the interposed area, interposed layer thickness, interposed volume, and the like of the fusible resin 40 to thereby form a positive electrode. The peel strength per 10 mm width of the terminal 26 and the negative electrode terminal 27 is appropriately set in the range of 200 gf to 3000 gf. For example, if a maleic acid-modified polyethylene or polypropylene is used as the fusible resin 40, the adhesive strength to the positive electrode terminal 26 and the negative electrode terminal 27 is relatively high, so that a high peel strength in the range of 200 gf to 3000 gf is obtained. Can be On the other hand, if mere polyethylene or polypropylene is adopted as the fusible resin 40, the adhesive strength to the positive electrode terminal 26 and the negative electrode terminal 27 is relatively low.
Low values in the range from 200 gf to 3000 gf are obtained.

The explosion-proof parts 41, 41 are overcharged,
When the battery body 20 generates heat due to overdischarge, the fusible resin 40, at a temperature lower than the temperature at which a chemical reaction occurs in the electrolyte layer 21,
40 are to be melted. Specifically, in this embodiment, a chemical reaction occurs in the electrolyte layer 21 of the battery body 20, but the temperature is set to about 200 ° C. to about 300 ° C., so that the fusible resin 40 melts at 150 ° C. to 250 ° C. It has become.

According to the sealed battery 10 described above, when the battery body 20 generates heat due to overcharging and overdischarging and the internal pressure of the sealed battery package 30 reaches a predetermined value or more, the explosion-proof section is provided.
Since the fusible resin 40 constituting 41, 41 can be peeled off,
The same effect as that of the related art that expansion and rupture can be surely prevented can be obtained. According to the sealed battery 10, the explosion-proof part 41 is formed by an extremely simple operation of applying or interposing the fusible resin 40 at a predetermined location when assembling the battery.
Can be installed, so that the manufacturing cost can be reduced as compared with the related art.

According to this sealed battery 10, since the positive electrode terminal 26 is provided with the explosion-proof part 41, when the positive electrode terminal 26 is made of, for example, aluminum, the peel strength of the fusible resin 40 is reduced. It is easy to set a low desired value. According to the sealed battery 10, since the positive electrode terminal 26 is made of aluminum or an aluminum alloy, by setting the peel strength with respect to the fusible resin 40 to a low desired value, the battery main body 20 may be abnormally early. Can respond.

Next, according to the sealed battery 10 described above, since the peeling strength of the fusible resin 40 is 200 gf to 3000 gf per 10 mm in width, the sealed The hermetic sealing of the package 30 can be released, and the hermetic sealing is less likely to be released depending on the usage environment of the portable device. Furthermore, according to the sealed battery 10, since the surface roughness of the positive electrode terminal 26 and the negative electrode terminal 27 is 5 μm or less, the peel strength of the fusible resin 40 is stabilized, and an abnormality occurs in the battery body 20. Sometimes sealed battery package
The fusible resin 40 has priority over the other fusible parts provided in 30.
Are peeled off, thereby providing a reliable explosion-proof effect.

Further, according to the sealed battery 10 of the present invention, the melting temperature of the fusible resin 40 is lower than the chemical reaction temperature of the electrolyte layer 21, that is, 150 ° C. to 250 ° C.
The hermetic sealing can be released before gas is generated from 21, whereby the expansion and rupture of the sealed battery package 30 can be reliably prevented.

In the sealed battery 10, if the fusible resin 40 is polyethylene, the melting point of the fusible resin 40 is relatively low. , 41, or when the chemical reaction takes place at relatively low temperatures.
This is suitable when the positive electrode 22 is formed by O ₂ ) or when the ratio of the highly reactive chain carbonate in the electrolyte layer 21 is relatively high.

On the other hand, in the sealed battery 10, the fusible resin
If 40 is polypropylene, for example, when the battery body 20 is relatively small and the distance from the heat-generating part to the explosion-proof parts 41 and 41 is short, or when the chemical reaction occurs at a relatively high temperature, lithium cobalt oxide (LiCoO ₂ ) This is suitable for the case where 22 is formed, or the case where the ratio of the cyclic carbonate having lower reactivity than the chain carbonate is relatively high in the electrolyte layer 21.

Further, in the above-described embodiment, the sealed battery package 30 has the metal foil core 31 made of aluminum or aluminum alloy having excellent thermal conductivity, and Since the thickness is 30 μm or more, the heat generated by the battery body 20 due to overcharge and overdischarge is transmitted to the explosion-proof part 41 via the metal foil core material 31 quickly and reliably, thereby reliably preventing expansion and rupture. it can.

Further, in the above-described embodiment, the sealed battery package 30 has an inner layer made of a fusible synthetic resin layer.
Since the thickness of 33 is not more than 50 μm, the conduction of heat from the battery body 20 to the metal foil core material is not hindered, which can also reliably prevent expansion and rupture.

According to such a sealed battery 10, since the maximum length of the side of the resin film 34 is 150 mm or less, the capacity for accommodating the positive electrode 21 and the negative electrode 22 can be secured to a certain level or more. Explosion-proof part 41,
The time until 41 operates can be shortened.

Note that the sealed battery of the present invention is not limited to the above-described embodiment, but can be appropriately modified and improved. That is, in the present invention, for example, an electrolyte layer, a positive electrode, a negative electrode, a battery body, a positive terminal, a negative terminal, an open end, a sealed battery package, a fusible resin, an explosion-proof part,
The material, shape, size, form, number, location, quantity, peel strength, surface roughness, melting temperature, maximum side length, etc. of the metal foil core material are arbitrary as long as the present invention can be achieved. , But not limited to.

[0039]

As described above, according to the present invention, expansion and rupture can be reliably prevented by peeling off the fusible resin constituting the explosion-proof part as described in claim 1. At the same time, when assembling a sealed battery, an explosion-proof part can be installed by applying or interposing a fusible resin at a predetermined location, providing a sealed battery that can reduce the manufacturing cost compared to the past. it can.

Further, according to the present invention, as described in claim 2, since the explosion-proof portion is provided on the positive electrode terminal, if the positive electrode terminal is formed of aluminum, the peel strength with respect to the fusible resin is provided. Can be set to a low desired value. In addition, according to the present invention, as described in claim 3, since the positive electrode terminal is made of aluminum or an aluminum alloy, the peel strength to the fusible resin is set to a low desired value, so that the battery body Early response to abnormalities.

Furthermore, according to the present invention, as described in claim 4, the peel strength of the fusible resin is 200 mm per 10 mm width.
Since it is gf to 3000 gf, the hermetic sealing of the hermetically sealed battery package can be quickly released after an abnormality has occurred in the battery main body, and there is little possibility that the hermetic sealing is released depending on the usage environment of the portable device. And according to the present invention, claim 5
As described in the above, since the surface roughness of the terminal is 5 μm or less, the peel strength of the fusible resin is stabilized, and when an abnormality occurs in the battery main body, other terminals provided in the sealed battery package. The fusible resin is peeled off in preference to the fused portion, thereby providing a reliable explosion-proof effect.

According to the present invention, as described in claim 6, the melting temperature of the fusible resin is equal to or lower than the chemical reaction temperature of the electrolyte layer, in other words, the temperature at which the chemical reaction occurs in the electrolyte layer. At the following predetermined temperature, the fusible resin peels off. Therefore, according to the present invention, expansion and rupture of the sealed battery can be avoided at an early stage. According to the present invention, as described in claim 7, the melting temperature of the fusible resin is 150 ° C or more.
Since the temperature is 250 ° C., expansion and rupture of a general nonaqueous electrolyte-based sealed battery can be avoided at an early stage.

Further, according to the present invention, as described in claim 8, when the fusible resin is polyethylene, when the battery body is relatively large, lithium nickelate (LiNiNi) is used.
This is suitable when the positive electrode is formed by O ₂ ) or when the ratio of the highly reactive chain carbonate is relatively high in the electrolyte layer. On the other hand, according to the present invention, as described in claim 9, when the fusible resin is polypropylene, the positive electrode is formed when the battery body is relatively small or when lithium cobaltate (LiCoO ₂ ) is used. If
Alternatively, it is suitable when the ratio of the cyclic carbonate having lower reactivity than the chain carbonate is relatively high in the electrolyte layer.

According to the present invention, there is provided a metal foil core made of aluminum or an aluminum alloy having excellent thermal conductivity and a thickness of the metal foil core as described in claim 10. Since the size is 30μm or more,
The heat generated by the battery body due to the overdischarge is reliably and promptly transmitted to the explosion-proof part via the metal foil core material 31, thereby expanding and
Burst can be reliably prevented. Further, according to the present invention, as described in claim 11, since the thickness of the fusible synthetic resin layer is 50 μm or less, the conduction of heat from the battery body to the metal foil core material is not hindered. This can reliably prevent expansion and rupture.

According to the present invention, since the maximum side length of the resin film is 150 mm or less as described in claim 12, the capacity for accommodating the positive electrode and the negative electrode can be secured to a certain level or more, and the battery main body can be secured. Can reduce the time from when heat is generated until the explosion-proof part operates.

[Brief description of the drawings]

FIG. 1 is a schematic overall perspective view showing an embodiment according to the present invention.

FIG. 2 is a sectional view showing an embodiment according to the present invention.

FIG. 3 is an enlarged sectional view of a main part showing an explosion-proof part.

[Explanation of symbols]

 10 Sealed lead-acid battery 20 Battery body 21 Electrolyte layer 22 Positive electrode 23 Negative electrode 26 Positive terminal 26A, 27A Open end 27 Negative terminal 30 Package for sealed battery 31 Metal foil core material 40 Fusing resin 41 Explosion-proof part

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (12)

[Claims] 1. A battery body in which a positive electrode and a negative electrode are stacked via an electrolyte layer, a pair of terminals respectively connected to the positive electrode and the negative electrode, and the open end of each terminal is exposed to the outside. A sealed battery having a sealed battery package for hermetically sealing a battery body, wherein at least one surface of each of the terminals and an inner surface of the sealed battery package are interposed with a fusible resin. When the internal pressure of the sealed battery package reaches a predetermined value or more, the fusible resin is at least one of the surface of the terminal and the inner surface of the sealed battery package. A sealed battery characterized by being detachable from one side. 2. The sealed battery according to claim 1, wherein the explosion-proof portion is provided at a positive electrode terminal connected to the positive electrode. 3. The sealed battery according to claim 2, wherein the positive electrode terminal is made of aluminum or an aluminum alloy. 4. The sealed battery according to claim 1, wherein the peel strength of the fusible resin is 200 gf to 3000 gf per 10 mm width. 5. The sealed battery according to claim 1, wherein the terminal has a surface roughness of 5 μm or less. 6. The method according to claim 1, wherein a melting temperature of the fusible resin is lower than a chemical reaction temperature of the electrolyte layer.
The sealed battery described in 1. 7. The sealed battery according to claim 6, wherein the melting temperature is 150 ° C. to 250 ° C. 8. The sealed battery according to claim 1, wherein the fusible resin is polyethylene. 9. The sealed battery according to claim 1, wherein the fusible resin is polypropylene. 10. The sealed battery package is formed of a resin film in which a fusible synthetic resin layer is provided on at least an inner surface of a metal foil core material made of aluminum or an aluminum alloy, and the thickness of the metal foil core material is 2. The sealed battery according to claim 1, wherein the size is 30 μm or more. 11. The sealed battery package is formed of a resin film in which a fusible synthetic resin layer is disposed on at least an inner surface of a metal foil core material, and the fusible synthetic resin layer has a thickness of 50 μm or less. The sealed battery according to claim 1, wherein: 12. The sealed battery according to claim 1, wherein the resin film forming the sealed battery package has a maximum side length of 150 mm or less.