JP2001283800A - Thin battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin battery capable of minimizing the lowering of sealing force during the period of storing a battery (particularly at the high temperature storage) and preventing the increase of the battery manufacturing cost and preventing the solution leakage, leap of the generating elements from the battery and damage to the external equipment when the battery is dropped. SOLUTION: The thin battery specifies that a positive electrode and a negative electrode are provided with a generating elements 4 wound flat spiral by a separator and that the generating element 4 is accommodated in the laminated armor 1 produced by the thermal deposition of a laminated material in which the internal resin layer 1c and external resin layer 1b are coated on both side of aluminum layer 1c respectively. The aluminum laminated material is thermally fused in the state that the gas releasing valve 5 having a smaller width than the generating element 4 and consisting of a resin having a lower melting point than the internal resin layer 1c, is caught between the internal resin layers 1c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for forming a positive electrode and a negative electrode,
It has a flat spiral power generating element wound through a separator, and has an inner resin layer formed on one side of the aluminum layer and an aluminum laminate material formed with an outer resin layer formed on the other side by heat welding. The present invention relates to a thin battery in which the above-described power generation element is housed in an aluminum laminate exterior body.

[0002]

2. Description of the Related Art Heretofore, as an exterior body of a non-aqueous electrolyte battery, one entirely made of metal such as stainless steel has been used. However, in a battery using such an exterior body, the metal exterior body has to be thickened, and the mass of the battery increases accordingly. As a result, there are problems that it is difficult to reduce the thickness of the battery and that the mass energy density of the battery is reduced. Therefore, as shown in FIG. 4 and FIG. 5, the present inventors made a bag-shaped aluminum laminate material in which a resin layer was formed on both sides of a metal layer made of aluminum via an adhesive layer, and formed an aluminum laminate exterior body. A thin battery has been proposed which comprises a power generating element 14 having current collecting tabs 12 and 13 extending from both positive and negative electrodes in a storage space of the aluminum laminate exterior body 11. A battery having such a structure has the advantages that the size of the battery can be dramatically reduced and the mass energy density of the battery increases. However, in the battery using the aluminum laminate exterior body, when gas is generated inside the battery and the internal pressure of the battery increases at the time of overcharging or overheating, the sealing portions (heat welding portions) 15 and 16 of the battery. Is opened, and the power generation element 14 jumps out of the opening,
There is a problem that external devices may be damaged.

In consideration of the above, FIGS. 6 and 7
As shown in FIG.
There has been proposed a thin battery in which a vent valve 17 provided with a notch is formed. However, a battery provided with such a gas vent valve 17 requires a high-precision notch, so that the manufacturing cost of the battery increases, and
The notch has a smaller thickness than other parts of the aluminum laminate exterior body, so when storing the battery (especially,
There is a problem that the sealing force at the time of high-temperature storage may be weakened, and in addition, when the battery is dropped, liquid may leak from the vent valve.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to suppress the increase in the manufacturing cost of a battery while maintaining the sealing force during storage of the battery (particularly, during high-temperature storage). It is an object of the present invention to provide a thin battery capable of suppressing a decrease in power generation, preventing a liquid from leaking when the battery falls, and preventing a power generation element from jumping out of the battery to prevent damage to external devices.

[0005]

In order to achieve the above object, the invention according to claim 1 of the present invention provides a flat spiral power generating element in which a positive electrode and a negative electrode are wound via a separator. The power generation element is housed in an aluminum laminate exterior body formed by heat welding an aluminum laminate material having an inner resin layer on one side of an aluminum layer and an outer resin layer on the other side. In the thin battery, a gas vent valve having a width smaller than the width of the power generating element and having a lower melting point than the inner resin layer,
An aluminum laminate material is heat-welded in a state sandwiched between the inner resin layers.

As described above, if the vent valve is made of a resin having a lower melting point than the inner resin layer of the aluminum laminate exterior, gas is generated inside the battery during overcharging or overheating. When the internal pressure of the battery rises, the vent valve melts before the aluminum laminate exterior, and the vent valve opens reliably, and the width of the vent valve is smaller than the width of the power generating element. When the valve is opened, it is possible to prevent the power generating element from jumping out of the battery and damaging external devices.

Further, since the gas vent valve has a structure located between the inner resin layers and does not have a thin portion in the aluminum laminate exterior body, the sealing force when the battery is stored (particularly during high temperature storage). It is sufficient to heat weld an aluminum laminate with the gas release valve sandwiched between the inner resin layers, thus reducing battery manufacturing costs. The rise can be suppressed.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, the difference in melting point between the vent valve and the inner resin layer is 1 to 60 ° C.

The reason for this restriction is that if the difference between the melting points of the vent valve and the inner resin layer is less than 1 ° C., the welded portion between the inner resin layers of the aluminum laminate exterior body is opened simultaneously with the vent valve. And the power generation element may fly out,
If the difference between the melting points of the vent valve and the inner resin layer exceeds 60 ° C., the melting point of the vent valve becomes too low and the storage characteristics at high temperatures are reduced.

[0010] The invention according to claim 3 is the invention according to claim 1 or 2, wherein the degassing valve has a melting point of 80 ° C.
It is characterized by exceeding.

The reason for this restriction is that if the melting point of the vent valve is 80 ° C. or less, the melting point of the vent valve becomes too low and the storage characteristics at high temperatures deteriorate.

The invention described in claim 4 is the first or second invention.
Alternatively, in the invention described in Item 3, the inner resin layer is made of polypropylene, and the vent valve is made of modified polyethylene.

The invention described in claim 5 is the first or second invention.
Alternatively, in the invention described in Item 3, the inner resin layer is made of polypropylene, and the vent valve is made of a blend resin of polypropylene and polyethylene or ethylene vinyl acetate.

According to a sixth aspect of the present invention, when the vent valve is made of a blend resin of polypropylene and polyethylene, the weight ratio of polypropylene to polyethylene is 10:90 to 90. :
It is characterized by being 10.

The reason for this restriction is that, when the proportion of polypropylene is less than 10, the difference in melting point between the vent valve and the inner resin layer becomes too small, and the inner resin of the aluminum laminate outer casing is simultaneously formed with the vent valve. This is because the welded portion between the layers may open and the power generating element may fly out, while if the proportion of polypropylene exceeds 90, the melting point of the vent valve becomes too low and the storage characteristics at high temperatures deteriorate.

The invention described in claim 7 is the first or second invention.
Alternatively, in the invention described in Item 3, the inner resin layer is made of polyolefin, and the vent valve is made of modified polyolefin.

The invention described in claim 8 is the first or second invention.
Alternatively, in the invention described in Item 3, the inner resin layer is made of a polyolefin, and the vent valve is made of a blend resin of polypropylene and polyethylene.

Further, the invention according to claim 9 is the invention according to claim 1,
In the invention described in 2, 3, 4, 5, 6, 7, or 8, the thickness of the degassing valve is 10 to 500 μm.

The reason for this restriction is that in the case of a battery having a thickness of less than 10 μm, the opening area of the gas vent valve is small, so that even when the gas vent valve is opened at an excessive temperature rise, the internal pressure of the battery is sufficiently increased. The battery cannot be lowered, and the power generation element may pop out. On the other hand, in the case of a battery with a gas vent valve thickness of more than 500 μm, the adhesion between the gas vent valve and the inner resin layer becomes insufficient, and the liquid leaks during storage. This is because there may be cases where

The invention according to claim 10 is the first invention.
In the invention described in 2, 3, 4, 5, 6, 7, 8 or 9, the width of the vent valve is 3 to 50 mm.

The reason for this restriction is that in the case of a battery having a gas vent valve having a width of less than 3 mm, the open area of the gas vent valve is small. It cannot be lowered, the power generation element may pop out, and in the case of batteries exceeding 50 mm in width of the vent valve,
Insufficient adhesion between the vent valve and the inner resin layer,
This is because liquid leakage may occur during storage.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view of the thin battery according to the first embodiment, FIG. 2 is a front view of the thin battery according to the first embodiment, and FIG. 3 is an aluminum laminate exterior body used for the thin battery according to the first embodiment. FIG. As shown in FIGS. 1 and 2, the thin battery of the present invention has a power generating element 4, which is arranged in a storage space 6 of the aluminum laminate exterior body 1. The power generating element 4 has a structure in which a positive electrode mainly composed of LiCoO ₂ , a negative electrode mainly composed of natural graphite, and a separator that separates these electrodes are wound in a flat spiral shape. On the other hand, the aluminum laminate exterior body 1
Is, as shown in FIG. 3, an aluminum layer 1b (thickness: 4
0 μm), an outer resin layer (thickness: 25 μm) 1a made of nylon is adhered to one surface and an inner resin layer (thickness: 4 ° C.) made of polypropylene (melting point: 150 ° C.) to the other surface.
0 μm) 1c is formed of an aluminum laminate material having a three-layer structure adhered thereto. At the upper and lower ends of the battery, the sealing portions 7a and 7b in which the inner resin layers 1c of the aluminum laminated material were thermally welded to each other, and at the side edges of the battery, the inner resin layers 1c of the aluminum laminated material were thermally welded to each other. The battery is sealed by a sealing portion (not shown).

From the upper end of the battery, a positive current collecting terminal 2a connected to the positive electrode and a negative current collecting terminal 2b connected to the negative electrode extend. These two collecting terminals 2
A part of a and 2b is wound with a current-collecting terminal welding resin 3a and 3b, and the current-collecting terminal welding resin 3a and 3b is thermally welded to the inner resin layer 1c at the sealing portion 7a. A gas vent valve 5 (width L ₁ : 8 mm, thickness L ₂ : 50 μm) heat-welded to the inner resin layer 1 c at the sealing portion 7 a is provided between the current collecting terminals 2 a and 2 b. The welding strength between the gas release valve 5 and the inner resin layer 1c is 1.5 kgf / 15.
mm. The degassing valve 5 is made of modified polyethylene (melting point: 120 ° C.) and has a configuration lower than the melting point of the inner resin layer 1c.

The storage space 6 contains an ethylene car.
Bonate (EC) and diethyl carbonate (DEC)
Was mixed in a mixed solvent of 3: 7 in a volume ratio of 3: 7.
95 mol / L LiN (C₂F₅SO₂)₂When
0.05 mol / L LiPF₆And was also dissolved
An electrolyte mixed with a prepolymer is injected into the above.
The size of the battery of the present invention is the width L._Three: 35mm, height
L_Four: 62mm, thickness L _Five: 3.6 mm.
Here, a battery having the above structure was fabricated as follows.
Was.

First, LiCoO as a positive electrode active material
₂ , an acetylene black and graphite as a conductive agent, and polyvinylidene fluoride (PVdF) as a binder in a mass ratio of 90: 2: 3: 5 to an organic solvent composed of N-methylpyrrolidone. The mixture was dissolved and mixed to prepare a positive electrode active material slurry. Next, the positive electrode active material slurry was applied to both sides of a belt-shaped positive electrode core body made of aluminum by using a doctor blade method or the like, dried, and further rolled by a roll press to produce a positive electrode. . In parallel with this, natural graphite as a negative electrode active material and polyvinylidene fluoride (PVdF) as a binder are dissolved in an organic solvent composed of N-methylpyrrolidone at a weight ratio of 90:10. Mix
A negative electrode active material slurry was prepared. Next, the negative electrode active material slurry was applied to both sides of a strip-shaped negative electrode core body made of copper using a doctor blade or the like, dried, and further rolled by a roll press machine to prepare a negative electrode. Next, the positive electrode and the negative electrode were attached with the positive electrode current collecting tab 2b and the negative electrode current collecting tab 2a, respectively, and then the positive and negative electrodes were wound in a flat spiral shape via a separator, thereby producing the power generating element 4.
Next, after preparing a sheet-like aluminum laminate material having a three-layer structure, the vicinity of the end of the aluminum laminate material is overlapped, and the inner resin layers 1c in the overlap portion are further joined to each other using a hot plate heating device. By heat welding (sealing width: 10 mm), a cylindrical aluminum laminate was produced. Thereafter, the power generating element 4 was inserted into the storage space 6 of the cylindrical aluminum laminate material. At this time, the power generating element 4 is arranged so that the two current collecting tabs 2a and 2b project from one opening of the cylindrical aluminum laminate material, and the two current collecting tabs 2a and 2b are formed.
A degassing valve 5 made of modified polyethylene was arranged between a and 2b. Next, in this state, the inner resin layers 1c of the aluminum laminate material in the opening are heat-welded (welding temperature:
(At 230 ° C., welding time: 3 seconds) and sealing, and the sealing portion 7a
(Sealing width L ₆ : 10 mm). At this time, welding was performed using a hot plate heating device. Thereafter, 0.9% was added to a mixed solvent in which ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed at a volume ratio of 3: 7.
5 mol / l of LiN (C ₂ F ₅ SO ₂ ) ₂ and 0.
After injecting an electrolytic solution obtained by mixing a prepolymer into a solution in which LiPF _{6 of} 0.05 mol / liter is dissolved, the inner resin layer 1 of the aluminum laminate material on the opposite side to the sealing portion 7a
c were welded together using a hot plate heating device to form a sealing portion 7b, thereby producing a thin battery. [Second embodiment] The degassing valve 5 has a weight ratio of 50: 5.
A thin battery was manufactured in the same manner as in the first embodiment except that a blend resin of polyethylene and polypropylene was used. The welding strength between the gas release valve 5 and the inner resin layer 1c is 0.5 kgf / 15 mm. In addition, the material of the inner resin layer and the vent valve of the aluminum laminate exterior body is not limited to those described above, and a resin having a melting point as shown in Table 1 below may be appropriately combined.
For example, polyolefin as the inner resin layer, modified polyolefin as the vent valve, polyolefin as the inner resin layer, blended resin of modified polypropylene and polyethylene as the vent valve, or polypropylene as the inner resin layer, polypropylene and ethylene vinyl acetate as the vent valve It is sufficient that the vent valve has a lower melting point than the inner resin layer such as a resin blended with the above.

[0027]

[Table 1]

As the positive electrode material, the above-mentioned LiCoO ₂
In addition, for example, LiNiO ₂ , LiMn ₂ O ₄ or a composite thereof, or a conductive polymer such as polyaniline or polypyrrole is suitably used. In addition to the above-mentioned natural graphite, carbon black, coke , Glassy carbon, carbon fiber, or a fired body thereof is preferably used.

Further, the solvent of the electrolytic solution is not limited to those described above. For example, ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, tetrahydrofuran, 1,2-dimethoxyethane, 1,3-dioxolan, 2-methoxytetrahydrofuran, diethyl A solvent in which a low-viscosity low-boiling solvent such as ether is mixed at an appropriate ratio can be used. Also, as the solute of the electrolyte,
In addition to the above LiPF ₆ , LiAsF ₆ , LiClO ₄ , L
iBF ₄ , LiCF ₃ SO ₃ or the like can be used.

[0030]

EXAMPLES Example 1 In Example 1, the battery shown in the first embodiment was used.

The battery fabricated in this manner is hereinafter referred to as Battery A1 of the present invention. Example 2 In Example 2, the battery shown in the second embodiment was used.

The battery fabricated in this manner is hereinafter referred to as Battery A2 of the present invention. Comparative Example 1 As shown in FIGS. 4 and 5 of the related art,
A battery was fabricated in the same manner as in Example 1 except that no vent valve was provided between the inner resin layers.

The battery thus manufactured is hereinafter referred to as Comparative Battery X1. Comparative Example 2 As shown in FIGS. 6 and 7 of the related art,
Unlike the vent valve of the present invention, a vent valve was formed in the same manner as in Example 1 except that a vent valve having an X-shaped cut (length of one side: 10 mm) was formed in a part of the aluminum laminate exterior body. To produce a battery.

The battery fabricated in this manner is hereinafter referred to as Comparative Battery X2. [Experiment 1] Batteries A1 and A2 of the present invention and comparative battery X
1, an overheating test (sample number:
200 each), storage test (number of samples: 200 each),
The drop test (the number of samples: 10 each) was performed, and the production cost per cell of each battery was calculated. The results are shown in Table 2.・ Conditions for overheating test Each battery is heated from room temperature by 5 ° C per minute, and finally heated to a hundred and several tens of degrees Celsius. Of the power generating element was examined. Conditions for Storage Test The conditions were such that each battery was stored for 10 days in a thermostat at 80 ° C. and 90% humidity, and the weight loss of the battery after storage was examined. -Condition of drop test The condition was that each battery was dropped on concrete from a height of 1 m. After dropping, the presence or absence of liquid leakage due to the opening of the sealing portion or the vent valve was examined.

[0035]

[Table 2]

As is clear from Table 2, in the comparative battery X1, the weight loss of the battery was small in the storage test (−2).
mg), no liquid leakage due to the opening of the sealing part was observed in the drop test, but the temperature was 15 in the overheating test.
When the temperature reached 0 ° C., rapid heat generation and a rise in internal pressure of the battery due to gas generation occurred, and the power generating element jumped out of the battery, possibly causing damage to peripheral devices.

In the comparative battery X2, the degassing valve was opened at 120 ° C. in the overheating test, so that the power generating element did not jump out of the battery, but the weight loss of the battery was extremely small in the storage test. Many (-100 to 500m
g) In addition, in the drop test, liquid leakage due to the opening of the gas vent valve is observed, and further precise cutting is required, so that the production cost of the gas vent valve is as high as 1.0 yen / cell.

On the other hand, in the batteries A1 and A2 of the present invention, the weight loss of the batteries in the storage test was small (−2).
mg), no liquid leakage due to the opening of the sealing part was observed in the drop test, and the degassing valve was opened at 120 ° C. in the overheating test, so that the power generation element did not jump out of the battery. Moreover, since it is only necessary to weld the gas release valve to the sealing portion, the production cost of the gas release valve is 0.6 or 0.1.
It is recognized that the price is as low as 7 yen / cell. [Experiment 2] Batteries different from the above-described battery A1 of the present invention only in the thickness of the degassing valve were prepared. Using these batteries, an overheating test (200 samples each) and a storage test (200 samples each) 2
00), and the presence or absence of the power generation element jumping out when the temperature became excessively high and the rate of occurrence of liquid leakage during storage were examined.
Table 3 shows the results. Note that the conditions of the overheating test and the conditions of the storage test are the same as those in Experiment 1 described above.

[0039]

[Table 3]

As is apparent from Table 3, in the case of a battery having a thickness of 8 μm, the opening area of the gas vent valve is small, so that the internal pressure of the battery is sufficiently reduced even if the gas vent valve is opened when the temperature rises excessively. In some cases, the power generation element may fly out, and in the case of a battery having a thickness of the gas vent valve of 600 μm, the adhesion between the gas vent valve and the inner resin layer becomes insufficient, and liquid leakage occurs during storage. Sometimes. On the other hand, in the case of a battery having a thickness of 10 to 500 μm, the open area of the gas vent valve is sufficiently ensured. In addition, since the power generating element can be prevented from jumping out and the adhesion between the gas release valve and the inner resin layer is sufficient, it is possible to prevent the occurrence of liquid leakage during storage.

Therefore, in order to reliably prevent the power generation element from jumping out when the temperature rises excessively and to prevent liquid leakage during storage, it is desirable that the thickness of the gas vent valve is 10 to 500 μm. [Experiment 3] Batteries differing only in the width of the degassing valve from the battery A1 of the present invention were prepared. Using these batteries, an overheating test (sample number: 200 each) and a storage test (sample number: each) 20
0), and the presence or absence of the power generation element jumping out when the temperature was excessively raised and the rate of occurrence of liquid leakage during storage were examined. The results are shown in Table 4. Note that the conditions of the overheating test and the conditions of the storage test are the same as those in Experiment 1 described above.

[0042]

[Table 4]

As is clear from Table 4, in a battery having a gas vent valve having a width of 2 mm, since the open area of the gas vent valve is small, the internal pressure of the battery is sufficiently reduced even when the gas vent valve is opened at an excessive temperature rise. And the power generating element may pop out, and in the case of a battery having a width of 60 mm for the gas release valve, the adhesiveness between the gas release valve and the inner resin layer is insufficient, and liquid leakage occurs during storage. There is. On the other hand, in a battery having a width of the degassing valve of 3 to 50 mm, the open area of the degassing valve is sufficiently secured, so that when the degassing valve is opened at an excessive temperature rise, the internal pressure of the battery is sufficiently reduced. In addition, since the power generating element can be prevented from jumping out and the adhesion between the gas release valve and the inner resin layer is sufficient, it is possible to prevent the occurrence of liquid leakage during storage.

Therefore, in order to reliably prevent the power generation element from jumping out when the temperature is excessively raised and to prevent liquid leakage during storage, it is desirable that the width of the gas vent valve is 3 to 50 mm. [Experiment 4] The battery A1 of the present invention was different from the battery A1 only in the melting point of the vent valve (a battery in which the melting point was changed by changing the type of the modified polyethylene of the vent valve), and these batteries were used for overheating. A temperature test (number of samples: 200 each) and a storage test (number of samples: 200 each) were performed. The results are shown in Table 5. Note that the conditions of the overheating test and the conditions of the storage test are the same as those in Experiment 1 described above.

[0045]

[Table 5]

As is clear from Table 5, the difference between the melting point of the vent valve and the melting point of the inner resin layer (hereinafter referred to as the melting point difference).
In a battery having a temperature of 0 ° C., the welding portion between the inner resin layers of the aluminum laminate exterior body is opened at the same time as the degassing valve, which may cause the power generating element to fly out. The melting point of the valve may be too low and liquid leakage may occur during storage at high temperatures. On the other hand, in a battery having a melting point difference of 1 to 60 ° C., since the welded portion between the inner resin layers of the aluminum laminate exterior body does not open before the vent valve, the power generation element can be prevented from jumping out. In addition, since the melting point of the vent valve does not become too low, it is possible to prevent the occurrence of liquid leakage during storage.

Therefore, in order to surely prevent the power generation element from jumping out when the temperature rises excessively and to generate liquid leakage during storage, it is desirable that the difference in melting point is 1 to 60 ° C. [Experiment 5] Batteries of the present invention A2 were different from the above-described battery A2 only in the composition of the vent valve (different proportions of polypropylene and polyethylene), and an overheating test (number of samples: 200 each) was performed using these batteries. ) And storage test (number of samples: 20 each)
0), and the presence or absence of the power generation element jumping out when the temperature became excessively high and the rate of occurrence of liquid leakage during storage were examined. The results are shown in Table 6. Note that the conditions of the overheating test and the conditions of the storage test are the same as those in Experiment 1 described above.

[0048]

[Table 6]

As is evident from Table 6, when the proportion of polypropylene becomes 95%, the difference in melting point becomes smaller, and the welded portion between the inner resin layers of the aluminum laminate exterior body is opened at the same time as the degassing valve. When the power generation element may fly out, and when the proportion of the polypropylene becomes 8%, the melting point of the vent valve becomes too low, and liquid leakage may occur during storage at a high temperature. On the other hand, if the proportion of polypropylene is 10 to 90%, the welded portion between the inner resin layers of the aluminum laminate exterior body does not open before the vent valve, so that the power generation element is prevented from jumping out. Since the melting point of the vent valve does not become too low, it is possible to prevent the occurrence of liquid leakage during storage.

Therefore, in order to reliably prevent the power generation element from jumping out at the time of excessive temperature rise and the occurrence of liquid leakage at the time of storage, it is desirable that the proportion of polypropylene is 10 to 90%.

[0051]

As described above, according to the present invention,
While suppressing the increase in the manufacturing cost of the battery, the sealing force during storage of the battery (particularly during high-temperature storage) is suppressed, the liquid leakage is prevented when the battery is dropped, and the power generation element jumps out of the battery. This provides an excellent effect of preventing damage to external devices.

[Brief description of the drawings]

FIG. 1 is a plan view of a thin battery according to a first embodiment.

FIG. 2 is a front view of the thin battery according to the first embodiment.

FIG. 3 is a sectional view of an aluminum laminate exterior body used for the thin battery according to the first embodiment.

FIG. 4 is a plan view of a thin battery according to a conventional technique.

FIG. 5 is a front view of a thin battery according to the related art.

FIG. 6 is a plan view of a thin battery according to another related art.

FIG. 7 is a front view of a thin battery according to another conventional technique.

[Explanation of symbols]

 1: Aluminum laminate exterior body 1a: Aluminum layer 1b: Outer resin layer 1c: Inner resin layer 4: Power generation element 5: Gas release valve 6: Storage space 7a: Sealing part 7b: Sealing part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroshi Nakagawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Ikuo Nakane 2-5-5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. F-term (reference) 5H011 AA01 AA13 BB04 CC02 CC06 CC10 DD13 KK01 KK04 5H012 AA03 BB01 CC01 DD01 EE01 FF03 FF08 GG01 JJ02 JJ10 5H029 AJ11 AJ12 AJ14 AJ15 AM04 AM06 AL08 BJ04 BJ14 BJ27 CJ02 CJ03 CJ05 CJ06 DJ02 DJ03 EJ12 HJ01 HJ04 HJ14

Claims (10)

[Claims] A positive electrode and a negative electrode each having a flat spiral power generating element wound with a separator interposed therebetween, and an inner resin layer formed on one surface of the aluminum layer and an outer resin layer formed on the other surface. A thin battery in which the power generation element is housed in an aluminum laminate outer casing formed by heat welding an aluminum laminate material, wherein the resin has a width smaller than the width of the power generation element and a lower melting point than the inner resin layer. A thin battery, wherein an aluminum laminate material is thermally welded in a state in which a vent valve made of aluminum is sandwiched between the inner resin layers. 2. The thin battery according to claim 1, wherein a difference in melting point between the vent valve and the inner resin layer is 1 to 60 ° C. 3. The thin battery according to claim 1, wherein the melting point of the vent valve exceeds 80 ° C. 4. The thin battery according to claim 1, wherein the inner resin layer is made of polypropylene, and the vent valve is made of modified polyethylene. 5. The thin battery according to claim 1, wherein the inner resin layer is made of polypropylene, and the vent valve is made of a blend resin of polypropylene and polyethylene or ethylene vinyl acetate. 6. When the vent valve is made of a blend resin of polypropylene and polyethylene, the weight ratio of polypropylene to polyethylene is 10:90 to 90: 1.
The thin battery according to claim 5, which is 0. 7. The thin battery according to claim 1, wherein the inner resin layer is made of a polyolefin, and the vent valve is made of a modified polyolefin. 8. The thin battery according to claim 1, wherein the inner resin layer is made of polyolefin, and the vent valve is made of a blend resin of polypropylene and polyethylene. 9. The thickness of the vent valve is 10 to 500.
Claim 1, 2, 3, 4, 5, 6, 7 or 8
The thin battery as described. 10. The width of the vent valve is 3 to 50 mm.
10. The method of claim 1, 2, 3, 4, 5, 6, 7, 8, or 9.
The thin battery as described.