JP2002203538A - Mounting type lithium battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a short circuit between a sheath body and a current collector in a mounting type lithium battery. SOLUTION: At an inner side of the sheath body consisting of a metallic foil, a power generating element comprised by equipping an electrolyte between a positive electrode and a negative electrode is arranged and installed, and the current collector is equipped at least at one outside of the positive electrode and the negative electrode, and further an opening part is installed at the sheath body in order to expose the current collector, and a sheath part where this opening part is installed is adhered on the current collector via an insulating resin layer, and at least a part of this insulating resin layer is made to be protruded from an end of this current collector, and the mounting type lithium battery is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium battery, and more particularly to a mounted lithium battery having a structure in which a power generating element is housed in a metal foil outer casing and positive and negative terminals are taken out from the same surface.

[0002]

2. Description of the Related Art In recent years, as a power source for a semiconductor device represented by an IC card or a memory card, a thin lithium battery called a coin type or a flat type has been developed in view of energy density and thickness.

However, in the conventional thin lithium battery, the outer package is divided into a positive electrode and a negative electrode, and both electrodes are taken out from the surfaces facing each other. Therefore, when mounted on a semiconductor device, the wiring is reduced. As a result, the thickness of the semiconductor device is increased, and the cost is further increased.

In such a semiconductor device, an IC chip is incorporated, and a battery is used as a main power supply or a memory backup power supply for the IC chip. Therefore, if these batteries and the IC chip can be directly joined, wiring can be simplified, and increase in thickness and cost of the semiconductor device can be suppressed. In this case, the battery preferably has a battery structure that allows both terminals to be taken out from the same surface.

[0005] According to Japanese Patent Application Laid-Open No. 1-140553, a battery structure is proposed in which both positive and negative terminals are taken out from the same surface.

FIG. 3 is a schematic view of a flat type power supply element having a hermetically sealed structure proposed in the publication and having positive and negative terminals taken out from the same surface.

As a flat type power supply element, a first case half 1 and a second case half 2 made of metal foil are provided, and are sealed by welding at a peripheral portion 3 of the case. An opening 9 is formed in the first case half 1, and an electrode plate (current collector) 7 made of a metal foil is arranged so as to face the opening 9. Further, the electrode plate 7 and the first case half 1 are insulated from each other by the insulating resin layer 8,
It is in a sealed state. A power generation element in which the separator 6 is disposed between the first electrode 4 and the second electrode 5 is stored in the storage section sealed in this manner.

As described above, by providing the opening 9 in the first case half 1, both terminals are taken out from the same surface,
Can be directly bonded to the chip.

[0009]

However, according to the flat power supply element (mounting type lithium battery) having the above structure,
In the step of sealing the first case half 1 and the electrode plate 7 with the insulating resin layer 8 interposed therebetween, the first case half 1 is more likely to come into contact with the first case half 1 in the vicinity of the peripheral end 10 of the electrode plate 7. In addition, the end of the opening 9 provided in the first case half 1 is easily brought into contact with the electrode plate 7. As a result, it has been found that a short circuit between the electrode plate 7 and the first case half 1 frequently occurs.

In order to solve such a problem, a method of increasing the thickness of the insulating resin layer 8 can be considered. However, while short-circuiting can be prevented by doing so, the thickness of the whole battery increases, and the original thickness increases. The advantage as a thin lithium battery was reduced.

When the flat power supply element (mounting type lithium battery) having the above structure is mounted on a semiconductor device and subjected to a durability test, the battery is easily bent due to its thin structure.
Then, there is a problem that a force is directly applied to the IC chip and the IC chip is damaged.

In order to solve such a problem, a reinforcing plate is provided so as to overlap the IC chip to protect the IC chip,
Techniques have been proposed for preventing direct application of force to an IC chip.

FIG. 4 shows a cross-sectional structure in which a flat power supply device (mounted lithium battery) is mounted on a semiconductor device 11 using such a reinforcing plate.

In this semiconductor device 11, reference numeral 12 denotes a mountable lithium battery. An IC chip 13 is provided on the mountable lithium battery 12, and a reinforcing plate 14 is provided below the mountable lithium battery 12.

However, the semiconductor device 11 having the above configuration
According to the above, even when the reinforcing plate 14 is used, a predetermined thickness of the semiconductor device 11 (for example, 0.76
mm) and there is a problem in practical use.

Incidentally, in an actual semiconductor device,
The combination of the mountable lithium battery 12 and the IC chip 13 and the reinforcing plate 14 are housed separately and separately.
3 and the mounting type lithium battery 12 are connected by wiring.

As described above, the use of the reinforcing plate 14 significantly increases the thickness of the semiconductor device 11 and does not meet the market needs of recent thinner and smaller devices. Moreover, the increase in the number of parts has increased the cost.

Accordingly, an object of the present invention is to provide a high-performance and low-cost mounted lithium battery which prevents short-circuit between an outer package and a current collector without increasing the thickness, thereby improving reliability. And

[0019]

According to the present invention, there is provided a mounted lithium battery having a structure in which a power generating element having an electrolyte disposed between a positive electrode and a negative electrode is provided inside an outer package made of metal foil. A current collector is provided outside at least one of the positive electrode and the negative electrode, and an opening is provided in the exterior body to further expose the current collector, and the exterior part having the opening is provided via an insulating resin layer. It is characterized in that it is adhered on the current collector and at least a part of the insulating resin layer is protruded from an end of the current collector.

Further, at least a part of the insulating resin layer protrudes inward from an opening of the exterior body.

Further, the present invention is characterized in that a current collector is provided outside each of the positive electrode and the negative electrode, and the exterior body is formed by folding a single metal foil into two.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a mounted lithium battery according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view of a mounted lithium battery 15, and FIG. 2 is a sectional view of another mounted lithium battery 16. The same parts as those of the mounted lithium battery shown in FIG. 3 are denoted by the same reference numerals.

In the mounted lithium battery 15 shown in FIG. 1, the outer case is made of a first case half 1 made of metal foil.
And the second case half 2, and one of the outer parts of the outer case corresponds to the first case half 1, and the first case half 1 and the second case half 2 Sealed by welding at the part 3.

An opening 9 is formed in the first case half 1, and an electrode plate 7 made of metal foil is provided as a current collector so that a part of the opening 9 is exposed. Further, the electrode plate 7 and the first case half 1 are insulated from each other by the insulating resin layer 8 and are sealed.

The first electrode 4 and the second electrode 4
A power generating element in which a separator 6 containing an electrolyte is disposed between the electrode 5 and the electrode 5 is housed. The first electrode 4 and the second electrode 5 form a positive electrode and a negative electrode. The first electrode 4 is connected to an electrode plate 7 serving as a current collector and is exposed from an opening 9. The second electrode 5 is connected to the second case half 2 and the first case half 1 and is led out on the same plane as the opening 9.

The short-circuit between the first case half 1 and the electrode plate 7 is prevented by forming at least a part of the insulating resin layer 8 as a protrusion protruding from the end face of the electrode plate 7. In the example of FIG. 1, an insulating film 17 made of a window frame-like or donut-like heat-resistant resin layer made of polyethylene terephthalate or the like is formed as a short-circuit prevention film and provided as a protruding portion. It may extend further than the end.

The amount of protrusion of the insulating film 17 is exactly the same as or greater than the end of the electrode plate 7, and the thickness of the power generating element (in FIG. 1,
It is desirable that the thickness be equal to or less than twice the sum of the respective thicknesses of the first electrode 4, the second electrode 5, and the separator 6.

The insulating resin layer 8 has at least a portion protruding inward from the opening 9 of the first case half 1 so that the first case half 1 and the electrode plate are also formed in this portion. 7 is prevented from being short-circuited.

The amount of protrusion of the insulating resin layer 8 with respect to the opening 9 of the first case half 1 is such that the opening 9 of the insulating resin layer 8 does not hinder the connection between the load and the electrode plate 7. Good.
Furthermore, the shape of the opening 9 of the insulating resin layer 8 is not particularly limited as long as it does not affect the connection with the load.

The thinner the insulating resin layer 8 is, the less the thickness of the insulating resin layer 8 affects the thickness of the whole battery. 7 and the first half case 1 may be short-circuited. Therefore, the thickness of the insulating resin layer 8 is 1 μm or more and 1 μm or more.
It is preferably not more than 00 μm.

Thus, the mounted lithium battery 1 having the above structure
According to 5, in the step of sealing the first case half 1 and the electrode plate 7 with the insulating resin layer 8 interposed therebetween, an insulating film 17 as a protruding portion is arranged near the periphery of the electrode plate 7, Further, since the insulative resin layer 8 protrudes inward from the opening 9 of the first case half 1, the electrode plate 7 and the first case half 1 are not in contact with each other. No short circuit.

It should be noted that another insulating film 17 as in this example is used.
However, instead of this, the insulating resin layer 8 may be extended, may be extended almost all around the electrode plate 7, or may be partially extended.

Next, another embodiment of the present invention will be described.

In the mounted lithium battery 16 shown in FIG. 2, a current collector made of a metal foil is bonded to the outside of each of the positive electrode and the negative electrode with a conductive adhesive, and the outer package is folded in two. By combining with the configuration, the bending of the semiconductor device is prevented while the thickness of the semiconductor device is reduced.

The exterior body 18 includes the folded portion 19 and the joint 2
0, an electrolyte 23 is disposed between the positive electrode 21 and the negative electrode 22, and a positive electrode current collector 24 and a negative electrode current collector 25
Are bonded by conductive adhesives 26a, 26b, and 26c, and the positive electrode current collector 24 and the exterior body 18 are insulated by an insulating resin layer 27. The exterior body 18 has an opening that exposes the positive electrode current collector 24. 2
8 is provided. Here, the positive electrode 21, the negative electrode 22, and the electrolyte 23 may be collectively referred to as a power generation element.

At least a part of the insulating resin layer 27 is formed as a protruding portion protruding from an end of the positive electrode current collector 24. In the example of FIG. 2, the insulating film 17 is provided as the protruding portion, but the insulating resin layer 27 may further extend.

The projecting amount of the insulating resin layer 27 is exactly the same as or greater than the end of the positive electrode current collector 24, and the thickness of the power generating element (FIG. 2)
In this case, it is preferable that the thickness be equal to or less than twice the sum of the thicknesses of the positive electrode 21, the negative electrode 22, and the electrolyte 23).

Further, at least a part of the insulating resin layer 27 is protruded inward from the opening 28 of the exterior body 18.

The amount of protrusion of the insulating resin layer 27 with respect to the opening 28 of the exterior body 18 may be within a range in which the opening 28 of the insulating resin layer 27 does not prevent the connection between the load and the positive electrode current collector 24. Further, the shape of the opening 28 of the insulating resin layer 27 is not particularly limited as long as it does not affect the connection with the load.

Further, as the thickness of the insulating resin layer 27 is smaller, the influence on the thickness of the whole battery is less. The electric body 24 and the exterior body 18 may be short-circuited. Therefore, the thickness of the insulating resin layer 27 is preferably 1 μm or more and 100 μm or less.

Further, the mounted lithium battery 16 is
A positive electrode current collector 2 is provided outside each of the positive electrode 21 and the negative electrode 22.
4. Since the negative electrode current collector 25 is provided and the exterior body 18 is formed by folding one metal foil into two, the mechanical strength can be improved.

In the method of manufacturing the mounted lithium battery according to the present invention shown in FIG. 2, first, the sheet-shaped positive electrode 21 is formed.
A positive electrode current collector 24 and a negative electrode current collector 25 are respectively applied to the negative electrode 22 formed in a sheet
26b.

Next, a non-woven fabric impregnated with a gel electrolyte solution is sandwiched between the positive electrode 21 and the negative electrode 22 to solidify the gel electrolyte solution, thereby producing a power generating element having an electrolyte 23 disposed between the positive electrode 21 and the negative electrode 22. .

The power generation element to which the current collector was adhered was used as an exterior body 1
The negative electrode 8 was adhered to the negative electrode side using a conductive adhesive 26c, and the positive-electrode-side exterior body 18 having an opening 28 in which the portion facing the power generation element was processed into a concave shape was folded in two at the folded portion 19, After covering one exterior part on the power generation element and bonding it to the positive electrode current collector 24 with the insulating resin layer 27, the three-sided joint 2
0 are sequentially laser-welded.

When disposing the insulating resin layer 27, the insulating film 17 is formed.

The metal foil used for the exterior body 18 is not particularly limited, but any of stainless steel, aluminum, nickel, copper, kovar, iron, titanium, and aluminum alloys may be industrially produced. This is advantageous in terms of availability and cost. Further, the manufacturing method and the purity of such an exterior body 18 are not particularly limited.

The thickness of the metal foil is desirably thin from the viewpoint of the energy density of the battery. However, an appropriate thickness should be selected in view of the presence or absence of pinholes and the strength of the exterior material. For example, in the case of aluminum, the thickness is desirably 30 μm or more.

One or both of the facing portions of the exterior body 18 facing the current collector may be formed in a concave shape. By processing the facing portion into a concave shape, a gap is not formed in the exterior body 18 at the joint portion 20, and it is possible to reduce poor welding and poor bonding due to resin.

In the case of resin bonding, since a gap can be formed in consideration of the thickness of the resin in advance, the resin may be crushed and flow more than necessary at the time of bonding, or the exterior may be forcibly distorted and peeled off from the resin at the joint. It is possible to reduce occurrence of stress and poor adhesion.

An existing conventional technique can be used for this concave forming method. For example, press working with a molding die is common. The shape may be concave as viewed from the power generation element housing, and the depth and dimensions are not particularly limited,
In consideration of the thickness of the power generation element including the current collector and the gap required between the exterior bodies 18 due to the difference in the sealing method described above, it is preferable that the dimensions and the shape are such that the power generation element and the exterior body can come into contact with each other.

Further, depending on the molding method, the concave power generation element accommodating portion of the exterior body 18 as shown in FIG. The four corners may be curved at adjacent portions, and any design suitable for the molding method may be used.

The opening 28 of the exterior body 18 is used for connection with the chip, and has an arbitrary size according to the interval and size of the positive and negative terminals coming out of the chip, and the connection method.
What is necessary is just to make an area.

However, since water penetrates into the mounted lithium battery through the resin cross section of the opening 28, it is desirable that the resin cross section of the opening 28 be as small as possible to suppress the penetration of water. The opening 28
It can be said that the shape is preferably a circle that can minimize the resin cross section. However, the shape of the opening 28 is not particularly limited, and may be any shape in consideration of other processing conditions, battery design, and the like.

An existing conventional technique can be used for forming the opening 28. For example, punching using a molding die or cutting using a laser is used.

The constituent members of the positive electrode 21, the negative electrode 22, and the electrolyte 23 which are constituent members of the power generating element, that is, the active material and the conductive agent,
The constituent materials and compositions such as the binder and the electrolyte are not limited, and all materials usable in conventional lithium batteries and combinations thereof can be used. In addition, all the methods used in the conventional lithium battery can be applied to the method of manufacturing the power generation element, and a new sintered body electrode obtained by sintering the active material is also applicable.

Further, the same metal foil as that of the outer package 18 can be used for the positive electrode current collector 24 and the negative electrode current collector 25. It is desirable to use a thin metal foil from the viewpoint of the energy density of the battery, but an appropriate thickness is selected for each material from the viewpoint of providing the battery with a function as a reinforcing plate. For example, in the case of aluminum, it is desirable to be 20 μm or more. Note that the material of the current collector may be selected in consideration of the operating voltage range of each electrode and the like, and does not necessarily have to be the same material and thickness.

When a plurality of power generating elements are used in series and stacked, a metal foil is arranged between the power generating elements, and the metal foil and the power generating element are fixed for the purpose of fixing the power generating element and the metal foil and improving the strength of the laminate. The electrodes were bonded with a conductive adhesive.

The positive electrode 21 and the positive electrode current collector 24 or the negative electrode 2
For the conductive adhesives 26a, 26b, 26c used for bonding the second electrode 2 and the negative electrode current collector 25, a commercially available conductive adhesive in which metal powder such as gold, silver, and aluminum or carbon is dispersed is used. it can. In particular, since the solvent is difficult to volatilize due to surface bonding, it is manufactured by Three Bond Co., Ltd. 33
A type that can be bonded by applying heat and pressure after coating, drying, and the like as in 15E is desirable.

The insulating resin layer 27 for bonding the positive electrode current collector 24 and the package 18 is preferably made of an insulating heat-sealing resin made of modified polyethylene or modified polypropylene. With these heat-fusible resins, the solvent does not volatilize during bonding and the solvent does not remain in the mounted lithium battery, and it is also excellent in productivity because it can be bonded by short-time pressurized heating from the outside. I have.

Peripheral portion 3 of exterior body 18 containing power generation element
An existing bonding method such as a welding method such as laser welding or resistance welding, or a bonding method using a heat-fusible resin or a resin adhesive can be used for bonding the side (joining portion 20). Regarding the joint portion 20, the conduction between the positive electrode side and the negative electrode side exterior body 18 is ensured by the folded portion 19, so that it is not particularly necessary to ensure the conduction.

Thus, in the mounting type lithium battery of the present invention, the positive electrode current collector 24 and the negative electrode current collector 25 are bonded by the conductive adhesive 26, and then the outer package 18 is folded in two. Since one of the exterior parts is adhered to the positive electrode current collector 24 via the insulating resin layer 27, the thickness can be reduced even when the semiconductor device is mounted on a semiconductor device because a reinforcing plate is not used unlike the conventional case. However, the bending was prevented, and as a result, the reliability was improved.

Further, the outer package 18 is folded in two at the folded portion 19, is placed over the power generating element, and is interposed by the insulating resin layer 27 made of heat-fused modified polypropylene via the window frame-shaped insulating film 17 made of polyethylene terephthalate. Due to the adhesion, the positive electrode current collector 24 and one of the exterior parts of the exterior body 18 did not come into contact with each other, and no short circuit occurred between them.

As described above, when the positive electrode current collector 24 and the outer package 18 are bonded using the insulating resin layer 27, a short-circuit preventing film made of a heat-resistant resin having the same thickness as the insulating resin layer 27 or a thin film is also used. By bonding, a short circuit at the peripheral edge of the current collector can be completely prevented. Here, for the short-circuit prevention film, any resin can be used as long as it can maintain its shape stably with respect to heating and pressure during the battery assembly process and battery mounting, and the type of heat-resistant resin is not particularly limited,
Polyethylene terephthalate is industrially produced in films of various thicknesses, and is advantageous in terms of availability and cost.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements may be made without departing from the scope of the present invention. For example, in the above-described embodiment, the electrode facing the opening 28 is the positive electrode 21. Alternatively, the electrode facing the opening 28 may be the negative electrode 22.

[0065]

(Example 1) In this example, the difference between the thickness of the mountable lithium battery 16 and the thickness of the mountable lithium battery 15 was determined, and the thinning of the mountable lithium battery 16 was evaluated. .

By using LiMn ₂ O ₄ as the positive electrode active material and Li ₄ Ti ₅ O ₁₂ as the negative electrode active material, a mounted lithium battery according to the present invention was produced as follows.

LiMn_TwoO_FourAnd Li_FourTi_FiveO₁₂Each of
And low melting glass, here 10Li _TwoO-25B_TwoO_Three−
15SiO_TwoDrying with -50 ZnO at a weight ratio of 80:20
It was mixed to make a mixed powder. Molding aid for this mixed powder 100
So that the weight ratio of polyvinyl butyral of the agent is 10
In addition, toluene was further added to prepare a slurry.

The slurry was applied on a polyethylene terephthalate (PET) film, dried and formed into a sheet. The resulting sheet was press-compressed by a roll press, and the positive electrode was 0.2 mm thick and the negative electrode was 0 mm thick. .2 mm sheet. Each sheet is punched with a die 20
A sheet-shaped positive electrode and negative electrode molded body having a square shape of mm were obtained.

By heating these compacts at 550 ° C. in the air, the positive electrodes 21 and 1 each having a size of 18 mm square and 0.15 mm thick were heated.
A negative electrode 22 having a size of 8 mm square and a thickness of 0.15 mm was produced.

Here, current collectors of the same size, each made of a titanium foil having a thickness of 20 μm, were adhered to the positive electrode 21 and the negative electrode 22 using a conductive adhesive 3315E manufactured by Three Bond Co., Ltd.

A gel electrolyte used for the electrolyte 23 was prepared by the following method.

First, LiBF was added to propylene carbonate.
₄ was dissolved at a concentration of 1 mol / l to prepare an electrolytic solution. The electrolytic solution: polyacrylonitrile was added therein in a weight ratio of 3%.
Polyacrylonitrile was added so that the ratio became 0:70, and the mixture was sufficiently stirred while heating to obtain a gel electrolyte solution. The gel electrolyte solution is impregnated into a non-woven fabric cut into a square of 20 mm, and cooled by being sandwiched between the positive electrode 21 and the negative electrode 22 to form a gel electrolyte. A power generating element having the electrolyte 23 between the positive electrode 21 and the negative electrode 22 is formed. Produced.

As the outer package 18, a 50 μm-thick stainless steel foil cut to 50 mm in length and 25 mm in width was used.
A hole having a diameter of 5 mm was formed in the opening 28 by punching with a press. The surface facing the positive electrode current collector 24 having the opening 28 was processed into a concave shape by press molding.

The negative electrode-side flat surface of the outer package 18 thus formed was bonded to the negative electrode current collector 25 using a conductive adhesive 26c. Next, the outer package 18 is folded in two at the folded portion 19, and the positive electrode-side flat surface having the opening 28 and the positive electrode current collector 24 are bonded to the power generating element with an insulating resin layer made of heat-fusible modified polypropylene. The film 17 was provided.

Finally, the junction 20 consisting of the three peripheral edges was laser-welded to complete the mounted lithium battery according to the present invention shown in FIG.

On the other hand, the mounted lithium battery 15 shown in FIG.
Was produced by the following method.

A positive electrode 4 and a negative electrode 5 were produced in the same manner as described above. The non-woven fabric impregnated with the gel electrolyte solution was sandwiched between the positive electrode 4 and the negative electrode 5 and cooled, and the gel electrolyte solution was solidified to form a power generating element.

The first half case 1 and the second half case 2 were made of stainless steel having a thickness of 50 μm, and each of the cases had a recessed power generation element housing. An opening 9 having a diameter of 5 mm was provided in the first half case 1 in the same manner as in the example. A 30 μm thick stainless steel foil was used for the electrode plate 7. The second half case 2 and the electrode plate 7 were bonded to the power generating element using the same conductive adhesive as described above. Next, the insulating film 17 was disposed, and the outer surface of the electrode plate 7 was bonded to the first half case 1 using the insulating resin layer 8 made of the heat-fusible modified polypropylene similarly used in the example.

The peripheral portions 3 of the first and second case halves 1 and 2 were sealed by laser welding to complete the mounted lithium battery 15.

Thus, according to the mounted lithium battery 16 manufactured in the above embodiment, since the current collectors are adhered to both ends of the power generating element and the exterior body 18 made of one sheet of metal foil is used, Even when mounted on the device, it became difficult to bend.

Therefore, the present inventor mounted a mounted lithium battery and an IC chip on an IC card made of vinyl chloride and performed a bending durability test to confirm the presence or absence of chip breakage.

Each mounting type lithium battery 1 manufactured in the example
5 and 16 are 86mm length of vinyl chloride IC card board,
The mounting was performed 54 mm in width and 0.76 mm in thickness, and the operation of applying a force from the vertical direction to bend and return the IC card was repeated 20 times, and the presence or absence of breakage of the IC chip was examined. In addition, five were produced and used for the test, respectively.

As a result of performing the bending durability test on each of the five batteries, the IC chip was partially damaged in the mounted lithium battery 15 in FIG. 1, but the mounted lithium battery 16 in FIG. When no was used, no breakage of all IC chips was confirmed.

It is considered that the difference between the results is due to the fact that the current collector is firmly adhered to the power generating element, and the exterior body is formed by folding one metal foil in two.

As described above, in the structure of the mounted lithium battery 16 shown in FIG. 2, the mechanical strength is dramatically improved.

In the present invention, it is apparent that the same effect can be obtained by adopting the structure of the present invention even in a mounted lithium battery having a plurality of power generating elements.

Example 2 In this example, a short circuit was evaluated for the mounted lithium battery 16 using a mounted lithium battery without the insulating film 17 as a comparative example.

In this comparative example, the insulating film 17
The mounting type lithium battery was manufactured in the same manner as in the example except that the package 18 and the positive electrode current collector 24 which were folded in two with the insulating resin layer 27 having the same size as the positive electrode current collector 24 were bonded. Produced.

Then, 30 pieces each of this example and the comparative example were prepared, and the presence or absence of a short circuit was confirmed. The presence or absence of a short circuit was confirmed by the voltage and the resistance value.

As a result, no short circuit occurred in all of the 30 mounted lithium batteries of the present invention, while a short circuit occurred in 22 of the mounted lithium batteries of the comparative example. .

Therefore, it can be seen that the mounted lithium battery 16 of the present invention has an excellent effect of preventing a short circuit.

[0092]

As described above, according to the mounting type lithium battery according to the present invention, the power generating element having the electrolyte between the positive electrode and the negative electrode is disposed inside the outer casing made of the metal foil. A current collector outside at least one of the positive electrode and the negative electrode, further providing an opening in the exterior body so as to expose the current collector, and collecting the exterior part having the opening through an insulating resin layer. At least a part of the insulating resin layer is made to protrude from the end of the current collector while being adhered on the body, and at least a part of the insulating resin layer is made to protrude inward from the opening of the exterior body. As a result, a short circuit between the exterior body and the current collector was prevented without increasing the thickness, thereby providing a high-performance and low-cost mounted lithium battery with improved reliability.

Further, in the present invention, a short circuit can be reliably prevented particularly in the battery assembling step, thereby increasing the production yield, and as a result, a low-cost mounted lithium battery can be provided.

Further, according to the mounting type lithium battery of the present invention, a current collector made of a metal foil is provided outside each of the positive electrode and the negative electrode, and the outer package is folded in two. Although the thickness of the device was reduced, its mechanical strength was improved, thereby providing a low-cost mounted lithium battery with improved reliability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a mounted lithium battery according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the mountable lithium battery of the present invention.

FIG. 3 is a cross-sectional view of a conventional mounted lithium battery.

FIG. 4 is a cross section of a conventional semiconductor device.

[Explanation of symbols]

 1: First half case 1 2: Second half case 2 3: Peripheral part 4: First electrode 5: Second electrode 6: Separator 7: Electrode plate 8: Insulating resin layer 9, 28 : Opening 10: End 15, 16: Mounting type lithium battery 17: Insulating film 18: Outer body 19: Folding portion 20: Joint 21: Positive electrode 22: Negative electrode 23: Electrolyte 24: Positive electrode collector 25: Negative electrode collector Conductors 26a, 26b, 26c: conductive adhesive 27: insulating resin layer

Continued on the front page F term (reference) 2C005 MA06 MA07 MA10 NB34 PA18 PA25 PA27 5H011 AA01 AA03 AA07 AA09 CC06 DD06 DD13 DD23 5H022 AA09 BB11 CC03 EE01 EE06 KK03 5H024 AA02 AA03 AA12 BB14 CC03 CC06 CC20 DD01 DD12

Claims (3)

[Claims] 1. A mountable lithium battery having a power generating element having an electrolyte between a positive electrode and a negative electrode disposed inside a package made of a metal foil, wherein at least one of the positive electrode and the negative electrode is disposed outside. A current collector is provided, an opening is provided in the exterior body to expose the current collector, and the exterior part provided with the opening is adhered onto the current collector via an insulating resin layer, and A mounted lithium battery, wherein at least a part of the insulating resin layer protrudes from an end of the current collector. 2. The mounted lithium battery according to claim 1, wherein at least a part of the insulating resin layer protrudes inward from an opening of the exterior body. 3. The device according to claim 1, wherein a current collector is provided outside each of the positive electrode and the negative electrode, and the exterior body is formed by folding one metal foil into two. Mountable lithium battery.