JP2000277093A - Thin battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a metallic positive electrode terminal and a negative electrode terminal from being brought into contact with the metal layers of an exterior body when they are extended to the outside from the seal section of the exterior body, to simply confirm the adhesion of the seal section of the exterior body, and to prevent the terminal made of a metal different from that of the metal layers of the exterior body from being kept in contact with the metal layers of the exterior body if both terminals are made of different metals. SOLUTION: An electrode body 20 having a positive electrode 21 and a negative electrode 22 and an electrolyte are stored in an exterior body 10 provided with thermally fusible resin layers 12a on the inner face side of metal layers 11, and a metallic positive electrode terminal 21a and a negative electrode terminal 12a are extended to the outside from the positive electrode 21 and the negative electrode 22 through a seal portion where the resin layers 12a of the exterior body 10 are stuck together in this thin battery. The positive electrode terminal 21a and the negative electrode terminal 22a are made different in thickness, the thicker terminal is kept in contact with the metal layers 11, and the terminal made of the same material as that of the metal layers 11 of the exterior body 10 is made thicker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a heat-fusible resin layer provided on at least one side of a metal layer, and a positive electrode and a negative electrode are provided in an outer package formed such that the resin layer is located on the inner surface side. An electrode body having an electrolyte and an electrolyte are accommodated, and a metal positive electrode terminal and a negative electrode terminal extended from the positive electrode and the negative electrode,
The present invention relates to a thin battery that extends outside through a sealing portion where resin layers are bonded to each other in an exterior body.

[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 positive electrode 21 made of metal having the same thickness from the positive electrode and the negative electrode in the electrode body 20.
a and the negative electrode terminal 22a are extended, and the positive electrode terminal 21a and the negative electrode terminal 22a thus extended
A thin battery that is extended to the outside through a sealing portion of a 0 has come to be used.

In recent years, in such a thin battery, in order to obtain a sufficient battery capacity, a non-aqueous electrolyte such as a non-aqueous electrolyte is used as an electrolyte and lithium oxidation and reduction reactions are used. A thin non-aqueous electrolyte battery that performs charging and discharging has been developed.

In the above-mentioned thin battery, as shown in FIGS.
As the metal layer 11, a sheet formed by laminating resin layers 12a and 12b on both surfaces is used to form a flat bag, and is extended from the positive electrode and the negative electrode of the electrode body 20 housed in the exterior body 10. The metal positive electrode terminal 21a and the negative electrode terminal 22a are extended to the outside through the space between the resin layers 12a and 12a on the inner surface side in the peripheral portion of the outer package 10, and in this state, the outer peripheral portion of the outer package 10 is The inner resin layers 12a, 12a are adhered to each other and sealed.

Here, when the resin layers 12a and 12a on the inner surface side in the peripheral portion of the outer package 10 are bonded to each other so as to sandwich the positive electrode terminal 21a and the negative electrode terminal 22a, the outer package 10 is sealed. The resin layer 12a,
If the conditions for bonding the 12a to each other are weak, the thin battery cannot be reliably sealed, and external moisture may penetrate into the thin battery, and the electrolyte or the like contained in the thin battery may not be sealed. There were problems such as electrolyte leakage.

In order to inspect whether the resin layers 12a on the inner surface side of the outer package 10 are sufficiently bonded to each other and the thin battery is securely sealed as described above, conventionally, the A destructive test for peeling off a portion where the resin layers 12a are bonded to each other is performed.
The manufactured thin batteries were wasted, and such inspection could not be performed on all manufactured thin batteries.

On the other hand, when the conditions for bonding the resin layers 12a, 12a on the inner surface side of the outer package 10 to each other are strengthened in order to securely seal the thin battery, a metal positive electrode terminal extending to the outside through the sealing portion is used. 21a and negative electrode terminal 22a
There is a problem that the short circuit contacts the metal layer 11 of the exterior body 10 to cause an internal short circuit.

As described above, the thickness of the metal positive electrode terminal 21a and the negative electrode terminal 22a extending from the positive electrode and the negative electrode is the same, but the resin layer 12 on the inner surface side of the outer package 10 is formed.
Depending on the conditions for adhering a and 12a to each other, only one of the positive terminal 21a and the negative terminal 22a may come into contact with the metal layer 11 of the package 10.

Here, in order to increase the battery capacity as described above, in the case of a thin non-aqueous electrolyte battery using a non-aqueous electrolyte as an electrolyte, an aluminum-based metal is generally used for the positive electrode terminal 21a. In addition, metals such as copper and nickel are used for the negative electrode terminal 22a, and the types of metals used for the positive electrode terminal 21a and the negative electrode terminal 22a are different.

When the metal layer 11 of the outer package 10 is made of the same aluminum-based metal as the positive electrode terminal 21a, the positive electrode terminal 21a is
Although no particular problem occurs even if the negative electrode terminal 22a made of a metal such as copper or nickel is in contact with the metal layer 11 of the outer package 10, charging and discharging may be performed. There is a problem that the aluminum-based metal in the metal layer 11 of the body 10 gradually becomes alloyed with lithium and becomes brittle.

On the other hand, when the metal layer 11 of the outer package 10 is made of the same kind of copper or nickel as the negative electrode terminal 22a, even if the negative electrode terminal 22a comes into contact with the metal layer 11 of the outer package 10, Although no problem arises, if charging and discharging are performed in a state where the positive electrode terminal 21a made of an aluminum-based metal is in contact with the metal layer 11 of the exterior body 10, the non-aqueous electrolyte in the non-aqueous electrolyte is decomposed. was there.

However, conventionally, no inspection has been performed as to whether only one of the positive electrode terminal 21a and the negative electrode terminal 22a is in contact with the metal layer 11 of the exterior body 10 as described above. When such a thin battery is actually used, there is a problem that it is found as a defective product.

[0013]

SUMMARY OF THE INVENTION The present invention provides a metal positive electrode terminal and a negative electrode terminal extending from a positive electrode and a negative electrode,
It is an object of the present invention to solve the above-described various problems in a thin battery in which a resin layer provided on the inner surface side of an exterior body is extended to the outside through a sealing portion where the resin layers are bonded to each other.

That is, in the present invention, when the resin layers on the inner surface side of the outer package are bonded to each other via the positive electrode terminal and the negative electrode terminal made of metal and sealed, the resin layers on the inner surface side of the outer package are bonded. In addition to being able to easily inspect whether the thin battery is securely sealed by being sufficiently adhered, it also prevents both the positive electrode terminal and the negative electrode terminal from contacting the metal layer of the outer package and causing a short circuit. In a nonaqueous electrolyte battery in which the metal constituting the positive electrode terminal and the negative electrode terminal is different, the terminal composed of a metal of a different type from the metal layer of the outer package contacts the metal layer of the outer package, and the metal layer of the outer package is formed. It is an object of the present invention to prevent alloying of a non-aqueous electrolyte and decomposition of a non-aqueous electrolyte.

[0015]

In order to solve the above-mentioned problems, a first thin battery according to the present invention has a heat-fusible resin layer provided on at least one surface of a metal layer. An electrode body having a positive electrode and a negative electrode and an electrolyte are accommodated in an exterior body formed such that the resin layer is located on the inner surface side, and a metal positive electrode terminal extending from the positive electrode and the negative electrode And the negative electrode terminal are extended to the outside through a sealing portion where the resin layers of the outer package are bonded to each other. These terminals were brought into contact with the metal layer of the exterior body.

Here, as in the first thin battery of the present invention, the thickness of the metal positive electrode terminal and the thickness of the negative electrode terminal are made different from each other until the thicker terminal comes into contact with the metal layer of the outer package. When the resin layers on the inner surface side are bonded to each other, the bonding between the resin layers is sufficiently performed, and the thin battery is securely sealed, and external moisture may penetrate into the inside of the thin battery. In addition, the electrolyte in the thin battery is prevented from leaking to the outside.

Whether or not the thicker terminal is in contact with the metal layer of the outer package as described above is confirmed by measuring the conductivity between the thicker terminal and the metal layer of the outer package. It is possible to easily inspect whether or not the thin battery is securely sealed because the resin layers on the inner surface side of the exterior body are sufficiently bonded to each other and the thin battery is securely sealed.

In the second thin battery according to the second aspect of the present invention, in order to solve the above-mentioned problem, a heat-fusible resin layer is provided on at least one surface of the metal layer. In an exterior body formed so as to be located on the inner surface side, an electrode body having a positive electrode and a negative electrode and an electrolyte are accommodated, and a metal positive electrode terminal and a negative electrode terminal extended from the positive electrode and the negative electrode In the thin battery in which the resin layers of the outer package are respectively extended to the outside through the sealing portions where the resin layers are bonded to each other, the positive electrode terminal and the negative electrode terminal are formed of different types of metals, and the positive electrode terminal One of the negative electrode terminal and the negative electrode terminal is made of the same metal as the metal layer of the outer package, and the terminal made of the same metal as the metal layer of the outer package is made thicker than the other terminal.

When the terminal made of the same kind of metal as the metal layer of the outer package is made thicker than the other terminal as in the second thin battery, the resin on the inner surface side of the outer package is made as described above. In a state where the positive electrode terminal and the negative electrode terminal are sandwiched between the layers, when the resin layers are bonded to each other and sealed,
The thicker terminal made of the same kind of metal as the metal layer of the outer package comes into contact with the metal layer of the outer package first.

For this reason, when the types of metal used for the positive electrode terminal and the negative electrode terminal are different from each other as in the above-mentioned nonaqueous electrolyte battery, the terminal made of a metal different from the metal layer of the outer package is used. The contact with the metal layer of the exterior body is suppressed, and the metal layer of the exterior body is prevented from alloying and becoming brittle, and the non-aqueous electrolyte used for the non-aqueous electrolyte is prevented from being decomposed.

Further, since the above-mentioned resin layers of the outer package are strongly bonded to each other, a thin terminal made of a metal different from the metal layer of the outer package contacts the metal layer of the outer package. Naturally, terminals made of the same kind of metal as the metal layer of the outer package that is thicker will come into contact with the metal layer of the outer package. Will be discovered as.

For this reason, as described above, a thin battery in which a terminal made of a metal different from the metal layer of the outer package is in contact with the metal layer of the outer package is actually used, and the metal layer of the outer package is used. It becomes possible to prevent the alloy from becoming brittle or decomposing the non-aqueous electrolyte used as the non-aqueous electrolyte.

Here, as described in claim 4, the metal layer and the positive electrode terminal of the outer package are made of an aluminum-based metal, and the thickness of the positive electrode terminal is greater than that of the negative electrode terminal.
As described above, the negative electrode terminal made of a metal different from the metal layer of the exterior body is brought into contact with the metal layer of the exterior body, and the metal layer of the exterior body is prevented from alloying, and the thin battery is formed. The overall weight is reduced, the weight energy density is improved, and the exterior body is softened so that the processing can be easily performed.

Here, in making the thicknesses of the positive electrode terminal and the negative electrode terminal different as described above, only the thicker terminal is in contact with the outer package and the thinner terminal is not in contact with the outer package. Therefore, the thickness of the thinner terminal is set to 90% or less, preferably 70% or less of the thickness of the thicker terminal.

[0025]

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 21a and a negative electrode terminal 22a extending from the positive electrode and the negative electrode in the electrode body 20 are respectively attached to the exterior body 10 It is made to extend outside through the sealing part.

In the thin battery of this embodiment, as the electrode body 20, as shown in FIG. 3, a cathode 21 having a cathode active material layer provided on both surfaces of a cathode current collector (not shown) A separator 23 is interposed between a negative electrode current collector (not shown) and a negative electrode 22 having a layer of a negative electrode active material provided on both surfaces thereof, and these are wound. However, the form of the electrode body 20 used in the thin battery of the present invention is not limited to the above-described one,
One that is folded many times with a separator 23 interposed between 1 and the negative electrode 22 or one that is provided with a plurality of layers with the separator 23 interposed between the positive electrode 21 and the negative electrode 22 may be used. it can.

Further, in the thin battery of this embodiment, as shown in FIGS. 3 and 4, a metal positive electrode terminal 21a and a negative electrode terminal 21a extending from the positive electrode 21 and the negative electrode 22 in the electrode body 20 are used. 22a and the positive electrode terminal 21a and the negative electrode terminal 22a.
Appropriate positions are respectively set to the heat-fusible resin layers 21b and 22b.
It is covered with.

Here, the material used for the positive electrode 21 and the negative electrode 22 is not particularly limited. In the case of a non-aqueous electrolyte battery, for example, manganese, cobalt, nickel, iron, vanadium,
A lithium transition metal composite oxide containing at least one kind of niobium or the like is used. As the negative electrode active material in the negative electrode 22, for example, in addition to metallic lithium and a lithium alloy, graphite capable of inserting and extracting lithium ions, A carbon material such as coke and a fired organic material 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 21a is made of an aluminum-based metal, while the negative electrode terminal 22a is made of a metal such as copper or nickel. Is used.

On the other hand, as shown in FIG. 5, resin layers 12a, 12b
Using a laminated sheet, 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 21a and negative electrode terminal 22a extended from this electrode body 20 are connected to each other. It extends from the exterior body 10 to the outside.

Here, when the thin battery is a non-aqueous electrolyte battery as described above, the metal layer 11 of the outer package 10 is connected to the thicker terminal of the positive terminal 21a and the negative terminal 22a. When the positive electrode terminal 21a is thick, the same metal as that of the metal 21a or 22a is used.
While the metal layer 11 is made of an aluminum-based metal, when the negative electrode terminal 22a is thick, the metal layer 11 is made of a metal such as copper or nickel.

In this embodiment, as described above, the exterior body 10 excluding the folded portion of the sheet in which the resin layers 12a and 12b are laminated on both surfaces of the metal layer 11 as described above.
The resin layer 1 on the inner surface side of the metal layer 11
2a are adhered to each other to seal the exterior body 10.

Here, as shown in FIGS. 6A and 6B, the positive electrode terminal 21a and the negative electrode terminal 22a extend to the outside from the exterior body 10 as described above. The resin layer 12a on the inner surface side of the metal layer 11 is bonded together with the resin layers 21b, 22b provided on the negative electrode terminal 22a, and the thicker terminal 21a
Or 22a is made to contact the metal layer 11 of the exterior body 10.

The terminal 2 having the larger thickness is used.
When the resin layer 12a on the inner surface side of the metal layer 11 is adhered to each other to seal the exterior body 10 until 1a or 22a contacts the metal layer 11 of the exterior body 10, the thin battery is securely sealed. It is possible to prevent external moisture from penetrating into the thin battery and prevent the electrolyte solution inside the thin battery from leaking to the outside.

Whether the thicker terminal 21a or 22a is in contact with the metal layer 11 of the exterior body 10 as described above is determined by peeling a part of the resin layer 12b on the outer surface side of the exterior body 10 It can be easily confirmed by measuring the conductivity between the terminal 21a or 22a and the metal layer 11 of the exterior body 10.

When the thin battery of this embodiment is a non-aqueous electrolyte battery, the metal layer 11 of the outer package 10 is made of the same metal as the thicker terminal 21a or 22a as described above. Therefore, it is possible to prevent the metal layer 11 of the exterior body 10 from being alloyed and becoming brittle, and from decomposing the non-aqueous electrolyte used as the non-aqueous electrolyte.

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.

In the thin battery according to this embodiment, the terminal 21a or 22a, which has a larger thickness, is brought into contact with the metal layer 11 of the package 10 when the package 10 is sealed. It is not necessary to contact the thicker terminal 21a or 22a with the ten metal layers 11.

Next, in the thin battery of the above embodiment, the length of the long side is 60 mm and the length of the short side is 35 mm.
mm, the metal layer 11 of the outer package 10 is made of aluminum.
As the resin layer 12a on the inner surface side of the metal layer 11, a laminated layer of a 5 μm-thick modified polypropylene layer and a 50 μm-thick polypropylene layer was used.

On the other hand, the positive electrode terminal 21a of the electrode body 20 is made of aluminum having a thickness of 100 μm, while the negative electrode terminal 22a has a thickness of 50 to 100 μm as shown in Table 1 below. The appropriate positions of the positive electrode terminal 21a and the negative electrode terminals 22a are adjusted to the resin layers 21b, 22b each made of modified polypropylene and having a thickness of 50 μm as described above. To cover.

Then, such a positive electrode terminal 21a and each negative electrode terminal 22a are respectively extended from the short side portion of the above-mentioned outer package 10, and the short side portion is formed by using a hot plate having a width of 5 mm at 235 ° C. For 2 seconds, and each
Are sealed at the short sides, thus each 100
Pieces of the thin battery, and the positive electrode terminal 21a and the negative electrode terminal 22
a contacted the metal layer 11 of the exterior body 10 to determine the number of batteries in which an internal short-circuit occurred.
Indicated according to

[0047]

[Table 1]

As is apparent from the results, the positive terminal 2
When the thickness of the negative electrode terminal 1a is different from that of the negative electrode terminal 22a, the occurrence of a battery in which both the positive electrode terminal 21a and the negative electrode terminal 22a are in contact with the metal layer 11 of the exterior body 10 and short-circuits inside the battery is suppressed, and particularly a positive electrode having a large thickness When the thickness of the negative electrode terminal 22a is set to 70% or less of the terminal 21a,
a and the negative electrode terminal 22a are both connected to the metal layer 11 of the exterior body 10.
The internal short circuit caused by contact with the contact is reliably prevented.

[0049]

As described above in detail, in the first thin battery of the present invention, the metal positive electrode terminal and the negative electrode terminal extending from the positive electrode and the negative electrode are connected to the resin on the inner surface side of the outer package. In extending the outside through the sealing part where the layers are bonded to each other, the thickness of the positive terminal and the negative terminal is made different, until the thicker terminal contacts the metal layer of the exterior body,
Since the resin layers of the outer package are bonded to each other, the resin layers of the outer package are sufficiently bonded to each other, and the thin battery is securely sealed. And the electrolyte in the thin battery is prevented from leaking to the outside.

Whether or not the thicker terminal is in contact with the metal layer of the outer package as described above is confirmed by measuring the conductivity between the thicker terminal and the metal layer of the outer package. As a result, the resin layers on the inner surface side of the exterior body are sufficiently bonded to each other, so that the thin battery is securely sealed, and the inspection can be easily performed without breaking the thin battery.

Further, in the second thin battery according to the present invention, the metal positive electrode terminal and the negative electrode terminal extending from the positive electrode and the negative electrode are connected to each other through a sealing portion where the resin layers of the outer package are bonded to each other. In extending the terminal, one of the positive electrode terminal and the negative electrode terminal is made of the same type of metal as the metal layer of the outer package, and the thickness of the terminal made of the same type of metal as the metal layer of the outer package is made larger than that of the other terminal. Because it was thick, with the positive electrode terminal and the negative electrode terminal sandwiched between the resin layers of the exterior body,
When the resin layers are adhered to each other and sealed, the thicker terminal made of the same kind of metal as the metal layer of the outer package comes into contact with the metal layer of the outer package first.

Therefore, when the types of metal used for the positive electrode terminal and the negative electrode terminal are different from each other as in a non-aqueous electrolyte battery, the terminal made of a metal different from the metal layer of the outer package is replaced with the metal layer of the outer package. This prevents the metal layer of the exterior body from alloying and becoming brittle, and prevents the non-aqueous electrolyte used for the non-aqueous electrolyte from decomposing.

In the second thin battery according to the present invention, when the thinner terminal made of a metal different from the metal layer of the outer package contacts the metal layer of the outer package, The thicker terminal made of the same kind of metal as the metal layer came into contact with the metal layer of the package, and such a thin battery was found to be defective as a result of an internal short-circuit test.

As a result, only the terminal made of a metal different from the metal layer of the exterior body is prevented from coming into contact with the metal layer of the exterior body, and when a thin battery is actually used as in the prior art, , The metal layer of the exterior body alloys and becomes brittle,
The trouble that the non-aqueous electrolyte used for the non-aqueous electrolyte is decomposed can be prevented beforehand.

[Brief description of the drawings]

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

FIG. 2 shows a conventional thin battery in which a positive electrode terminal and a negative electrode terminal are extended from an exterior body to the outside, and a resin layer on an inner surface side in a peripheral portion of the exterior body is adhered to each other to be sealed. FIG.

FIG. 3 is a partial explanatory view in which a separator is provided between a positive electrode and a negative electrode in the thin battery according to the embodiment of the present invention.

FIG. 4 is a schematic view showing a state in which a positive electrode terminal and a negative electrode terminal are extended from an electrode body formed by winding a thin battery provided with a separator between a positive electrode and a negative electrode in the same embodiment; FIG.

FIG. 5 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.

FIG. 6 shows a state in which the positive electrode terminal and the negative electrode terminal are extended from the exterior body to the outside and the resin layers on the inner surface side in the peripheral part of the exterior body are adhered to each other and sealed in the thin battery according to the embodiment. It is sectional explanatory drawing which showed.

[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 electrode 21a Positive terminal 22 Negative electrode 22a Negative electrode terminal

Continuing from the front page (72) Inventor Ikuro Nakane 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Satoru Fukuoka 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka F-term (reference) in Sanyo Electric Co., Ltd. BJ04 DJ03 DJ05 DJ07 EJ01 EJ12 HJ04

Claims (6)

[Claims] 1. An electrode body having a positive electrode and a negative electrode, and an electrolyte, wherein a heat-fusible resin layer is provided on at least one surface of a metal layer, and the resin layer is formed on the inner surface side. Are accommodated, and the metal positive electrode terminal and the negative electrode terminal extended from the positive electrode and the negative electrode are respectively extended to the outside through a sealing portion where the resin layers are bonded to each other in the outer package. In the thin battery, the positive electrode terminal and the negative electrode terminal have different thicknesses, and the thicker terminal is in contact with the metal layer of the exterior body. 2. An electrode body having a positive electrode and a negative electrode, and an electrolyte, wherein a heat-fusible resin layer is provided on at least one surface of the metal layer, and the resin layer is formed on the inner surface side. Are accommodated, and the metal positive electrode terminal and the negative electrode terminal extended from the positive electrode and the negative electrode are respectively extended to the outside through a sealing portion where the resin layers are bonded to each other in the outer package. In the thin battery, the positive electrode terminal and the negative electrode terminal are formed of different types of metals, and one of the positive electrode terminal and the negative electrode terminal is formed of the same type of metal as the metal layer of the outer package. A thin battery wherein a terminal made of the same kind of metal as the layer has a greater thickness than the other terminal. 3. The thin battery according to claim 1, wherein the thin battery is a non-aqueous electrolyte battery. 4. The thin battery according to claim 1, wherein the metal layer of the outer package and the positive electrode terminal are made of an aluminum-based metal, and the thickness of the positive electrode terminal is larger than that of the negative electrode terminal. A thin battery characterized by being thick. 5. The thin battery according to claim 1, wherein the thickness of the thicker terminal is:
A thin battery wherein the thickness of the thinner terminal is 90% or less. 6. The thin battery according to claim 1, wherein the thickness of the thicker terminal is:
A thin battery wherein the thickness of the thinner terminal is 70% or less.