JP2006244783A - Battery and battery with thermal element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight thin battery, capable of quickly transmitting heat generated in an electrode body and having high safety and high reliability, and to provide a battery having a thermal element. <P>SOLUTION: A laminate outer packaging battery 1 has an electrode body 10, formed by facing positive and negative electrodes 11, 12 through a separator 13. The electrode body 10 is housed in the inside space of an outer packaging body, comprising a laminate outer packaging element 20 and a metal outer packaging element 30. The metal outer packaging element 30 out of both outer packaging elements 20, 30 constituting the outer packaging body is a sheet body, formed with a metallic material, such as aluminum for example; and one main surface is faced to the electrode body 10 and the other main surface is exposed to the outside. The laminate outer packaging element 20 and the metal outer packaging element 30 are bonded with interposed sealing resin in the outer edge part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a battery and a battery with a thermal element, and more particularly, to a configuration of an exterior body in the battery.

  In recent years, with the widespread use of mobile devices such as mobile phones, batteries as these power sources, particularly secondary batteries that can be repeatedly charged and discharged, have come to be widely used. Among secondary batteries, a lithium polymer battery having an advantage of being lightweight and having a high energy density is often used. A lithium polymer battery used as a power source of a portable device has an exterior body made of a metal laminate sheet material from the viewpoint of reducing the weight and thickness and ensuring ease of manufacture. Here, the metal laminate sheet is a sheet body in which both main surfaces of a metal layer such as aluminum (Al) are sandwiched and integrated by a resin layer. By configuring the exterior body with a metal laminate material in this way, a lightweight battery can be obtained, and the outer peripheral portion only needs to be heat-welded when forming the exterior body, so that the manufacturing process can be simplified. It is done.

In addition, in a lithium polymer battery, a thermal element such as a thermal fuse element is attached in consideration of resistance during charge / discharge.
By the way, the metal laminate sheet used as an exterior body has a lower thermal conductivity than a metal plate used as an exterior body of a conventional cylindrical battery or the like, so the temperature of the electrode body housed inside the exterior body There is a problem that it is difficult to detect changes quickly and accurately by a thermal element. On the other hand, for example, a technique has been proposed in which a thermal element is joined to a tab in a lithium polymer battery to improve the heat detection performance of the thermal element (see Patent Document 1). Thus, by directly joining the lead of the heat sensitive element to the tab extending from the exterior body, the heat generated in the electrode body is transmitted through the tab of the battery and the lead of the element. The proposed technique attempts to improve the heat detection performance of the thermal element by utilizing such heat transfer via the tab and the lead.
JP 2003-308887 A

  However, in the technique proposed in Patent Document 1, there is a time lag between the heat generation at the electrode body and the heat detection at the thermosensitive element, which is insufficient from the viewpoint of battery protection. In addition, if it is intended to reliably protect the battery, it is necessary to use a thermal element that exhibits a safety function at a lower temperature, which causes a problem that the battery performance cannot be sufficiently brought out. .

Moreover, in the conventional battery including the above-mentioned Patent Document 1, since the metal laminate sheet material having a lower heat transfer property than the metal material is used, the heat generated in the electrode body is difficult to escape to the outside, and the electrode plate, etc. The problem also remains from the viewpoint of deterioration. In particular, in the current situation where higher capacity is required for batteries, it may be a big problem.
The present invention has been made to solve the above-described problems, is lightweight and thin, and can quickly transmit heat generated in the electrode body to the outside, with high safety. It is an object to provide a battery having high stability and a battery with a thermal element.

In order to achieve the above object, the present invention adopts the following configuration.
The battery according to the present invention has a configuration in which a positive electrode plate and a negative electrode plate have an electrode body arranged to face each other with a separator interposed therebetween, and the electrode body is housed in an internal space of an exterior body composed of a sheet body. The exterior body has a first region made of a metal laminate material and a second region made of a material having higher heat transfer characteristics from the electrode body to the outside than the metal laminate material. And the second region is arranged opposite to the electrode body.

  Further, the battery with a thermal element according to the present invention includes a unit cell in which an electrode body in which a positive electrode plate and a negative electrode plate are arranged to face each other with a separator interposed therebetween is housed in an internal space of an exterior body composed of a sheet body. A heat-sensitive element interposed in the power flow path between the unit cell and the external device, and the exterior body of the unit cell is formed of a metal laminate material on its main surface. 1 region and a second region made of a material whose heat transfer characteristic from the electrode body to the outside is higher than that of the metal laminate material, the second region is arranged opposite to the electrode body, An element main body that senses the heat of the element and a lead that extends from the element main body, and the element main body is arranged in a state of being in proximity to or in contact with the outer surface of the second region of the exterior body. It is characterized by being.

  The unit cell of the battery and the battery with a thermal element according to the present invention includes a first region made of a metal laminate material and a second region made of a material having a higher heat transfer performance than the metal laminate material in the exterior body. The main feature is that the inner main surface in the second region is in a state facing the electrode body to be housed. As a result, in the battery and the unit cell according to the present invention, heat generated in the electrode body at the time of charging / discharging the battery is transmitted to the outside of the exterior body through the second region with high efficiency. In the battery according to the present invention, since the first region of the exterior body is made of a metal laminate material, an exterior body that can seal the electrode body by thermally welding the outer periphery in the manufacture of the battery is provided. Can be formed. For this reason, the battery according to the present invention can be obtained by a simple manufacturing method.

Further, in the battery with a heat sensitive element according to the present invention, the element main body of the heat sensitive element is arranged in contact with or close to the second region made of a material having a higher heat transfer performance than the metal laminate material. Compared with the conventional battery represented by the said patent document 1 etc., the thermal fluctuation of an electrode body can be rapidly detected with a thermal element.
Further, in the battery and the unit cell according to the present invention, the heat of the electrode body is quickly and efficiently released from the exterior body, so that deterioration of the electrode body is suppressed, and from the viewpoint of battery stability. Are better.

Furthermore, in the battery according to the present invention and the battery with a thermosensitive element, the exterior body is formed of a sheet body, so that the weight and appearance size equivalent to those of conventional batteries can be maintained, and the ease of manufacturing has also been conventionally It is equivalent to the laminated outer battery.
Therefore, the battery and the battery with a thermal element according to the present invention are lightweight and thin, and can quickly transfer heat generated by the electrode body to the outside, and have high safety and high stability. .

In the battery and the battery with a thermal element according to the present invention, a metal material can be adopted as a material constituting the entire thickness direction of the second region.
In the battery and the battery with a thermal element according to the present invention, it is desirable that the outer surface of the electrode body is in contact with the inner surface of the exterior body in the second region from the viewpoint of heat transfer performance.
Further, in the battery and the battery with a thermal element according to the present invention, as a specific configuration of the exterior body, a cup-shaped first element in which a concave portion capable of accommodating an electrode body is formed on the main surface, and the first element On the other hand, a structure composed of a second element as a lid is adopted, and the entire first element has a structure corresponding to the first region, and the second element is the first element and The joining margin portion of the first portion corresponds to the first region, and all portions except the joining margin portion may have a configuration corresponding to the second region.

The best mode for carrying out the present invention will be described below with reference to the drawings. In addition, the form used in the following description is an example for easy understanding of the structural features of the present invention and the effects achieved by the present invention, and the present invention is not limited thereto. Instead, it is possible to employ various variations in which the configuration other than the main features of the invention as described above is appropriately changed.
(Embodiment 1)
1. Battery Configuration First, the configuration of the laminated exterior battery 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is an exploded perspective view for explaining the configuration of a laminated battery 1.

  As shown in FIG. 1, the laminate-cased battery 1 includes an electrode body 10, and the electrode body 10 is configured to be housed in an internal space formed by two exterior elements 20 and 30. The electrode body 10 is configured such that the positive and negative electrode plates 11 and 12 are opposed to each other with the separator 13 interposed therebetween, and are wound in the opposed arrangement state. The electrode body 10 has positive and negative tabs 14 and 15 extending toward one side in the winding axis direction, and tab resins 16 and 17 are respectively attached to portions corresponding to sealing portions of the exterior body. Yes.

  The laminate exterior element 20 constituting the exterior body is provided with a concave portion 20a in which the electrode body 10 can be accommodated, and an outer edge portion 20b is provided so as to surround this. As shown in the lower enlarged portion of FIG. 1, the laminate exterior element 20 is composed of a metal laminate sheet material having a four-layer structure. Specifically, the sheet body constituting the laminate exterior element 20 includes a metal layer 21 made of Al, a resin layer 22 covering one main surface, an adhesive layer 23 and a resin covering the other main surface. Layer 24.

  On the other hand, the other metal exterior element 30 constituting the exterior body is composed of a thin metal sheet, and is covered with a resin layer like the laminate exterior element 20 as shown in the upper enlarged portion of FIG. Absent. As a specific metal material, stainless steel (SUS) or the like can be used. Although the laminate exterior element 20 and the metal exterior element 30 are joined at the outer edge portions of each other, a ring-shaped seal resin 40 is interposed therebetween to ensure the sealing performance. Joining of the laminate exterior element 20 and the metal exterior element 30 is performed by heat welding by heating the joining portion with the sealing resin 40 interposed. The seal resin 40 is made of, for example, modified polypropylene (CPP).

2. Attaching Form of Thermal Fuse 100 Next, a mounting form of the thermal fuse 100 as a thermal element for the laminated battery 1 configured as described above will be described with reference to FIG. FIG. 2 is a perspective view of the laminated battery 1 as viewed from the metal exterior element 30 side.
As shown in FIG. 2, in the present embodiment, the thermal fuse 100 is directly attached to the tab 14 of the laminated battery 1. The thermal fuse 100 includes an element main body 101 serving as a main body of the element and element leads 102 and 103 extending from both ends thereof. As shown in the enlarged portion of FIG. 2, in the thermal fuse 100, one element lead 102 is bonded to one tab 14 of the laminated exterior battery 1. As shown in the overall view of FIG. 2, in the thermal fuse 100, the element main body 101 is arranged at a position close to the main surface of the metal exterior element 30 of the laminated exterior battery 1 by bending the tab 14 by approximately 180 °. ing.

  As shown in the enlarged portion of FIG. 2, in the laminated battery 1 according to the present embodiment, one main surface of the electrode body 10 is in proximity to or in contact with the inner main surface of the metal exterior element 30 (preferably a contact). State). Thus, the thermal fuse 100 arranged in the above state is in a state in which the element main body 101 is close to the electrode body 10 with the metal exterior element 30 interposed therebetween.

3. Advantages of Laminated Exterior Battery 1 As described above, in the laminated exterior battery 1 according to the present embodiment, the entire exterior body is not formed of a metal laminate as in the conventional battery, but a part of the exterior body is formed. The metal exterior element 30 is made of a metal material. The metal material used for the configuration of the metal exterior element 30 has a thermal conductivity that is two to three orders of magnitude higher than the resin layers 22 and 24 in the metal laminate material that is usually used as an exterior body of a battery. For this reason, the metal exterior element 30 can easily release the heat generated in the electrode body 10 to the outside as compared with the laminate exterior element 20. For this reason, in the laminated battery 1 according to the present embodiment, deterioration of the electrode plates 11 and 12 or the electrolytic solution due to heat generation is suppressed, and the quality stability is high.

  Moreover, in the laminate-clad battery 1 which concerns on this Embodiment, reliable sealing performance can be ensured by insertion of the sealing resin 40 between the laminate-clad element 20 and the metal-clad element 30, and it is called battery performance. From the viewpoint, it is equivalent to a conventional laminated battery. Moreover, the laminate-cased battery 1 has the same advantage as the conventional laminate-cased battery in both weight and size. And the laminated exterior battery 1 which concerns on this Embodiment is excellent also from a viewpoint of the ease of manufacture, without the man-hour etc. which concern on the manufacture increase compared with the past.

  As shown in FIG. 2, when a heat sensitive element such as a thermal fuse 100 is attached to the laminated battery 1 according to the present embodiment, the heat generated in the electrode body 10 is in a state through the metal armor element 30. This is transmitted to the element main body 101 of the thermal fuse 100. For this reason, in this Embodiment, the problem of the low heat transfer performance by passing a metal laminate sheet like the conventional lamination exterior battery does not arise, but the heat which generate | occur | produced in the electrode body 10 rapidly Is transmitted to. For this reason, in the battery with a thermal element according to the present embodiment, the thermal element (in this embodiment, the thermal fuse 100) can sense the thermal fluctuation of the electrode body 10 quickly and reliably. Thus, the battery with a thermal element according to the present embodiment can have high safety without sacrificing battery performance.

  In the laminated battery 1 according to the present embodiment, the metal exterior element 30 is used as one element constituting the exterior body, but the sealing resin 40 is inserted in the sealing portion, and the tabs 14 and 15 are inserted. Electrical insulation with the metal exterior element 30 at the crossing portion is reliably ensured. Although not shown, in the present embodiment, the tab resins 16 and 17 have a three-layer structure, and a layer located in the middle of the stacking direction is used as a high melting point type resin material. Therefore, the internal short circuit of the laminated battery 1 according to the present embodiment does not occur from this point.

4). Confirmation of Superiority Hereinafter, the results of confirming the superiority of the laminated battery 1 according to the present embodiment and the battery with the thermal element in which the thermal fuse 100 is attached to the battery 1 will be described.
4-1. Example 1
A laminated battery 1 according to Embodiment 1 shown in FIG. 1 was used. The constituent materials and sizes of the laminate exterior element 20 and the metal exterior element 30 constituting the exterior body were as follows.
(1) Laminate exterior element 20
Total thickness of metal laminate sheet: 113 μm
Overall size: 57mm ^W x 67mm ^L
Metal layer 21: Al (thickness: 40 μm)
Resin layer 22: CPP (thickness: 45 μm)
Adhesive layer 23: Urethane material (thickness: 3 μm)
Resin layer 24: nylon (thickness: 25 μm)
Concave 20a size: 50.9 mm ^W × 63.5 mm ^L × 3.2 mm ^H
The laminated battery according to Example 1 was a lithium polymer battery, and 1 It = 1400 mAh.
(2) Metal exterior element 30
Size: 57mm ^W x 67mm ^L x 0.1mm ^T
Opposite size with the electrode body 10: 47.2 mm ^W × 59 mm ^L
Constituent material: SUS301
4-2. Example 2
Using the laminate-coated battery 1 according to Example 1, a battery with a thermal element having the configuration shown in FIG. 2 was prepared. In addition, about the thermal fuse 100 as a thermosensitive element, the element main-body part 101 was arrange | positioned in the state which contacts with respect to the outer main surface of the metal exterior element 30. FIG. A thermal fuse having an operating temperature of 92 ° C. was used.

4-3. Comparative Example 1
In the laminate-cased battery according to Comparative Example 1, the entire package was configured from a metal laminate sheet, and the components other than the constituent materials of the package were the same as those of the laminate-coated battery according to Example 1 including the size. In addition, about the metal laminated sheet which comprises the exterior body of the laminate-clad battery which concerns on the comparative example 1, it was set as the same as the laminate exterior element 20 of the laminate-clad battery of the said Example 1. FIG.

4-4. Comparative Example 2
A battery with a thermal element was produced using the laminate-cased battery according to Comparative Example 1 having the same configuration as that of Example 2.
4-5. Evaluation 1
Each laminated battery according to Example 1 and Comparative Example 1 was overcharged with 1.2 It, and the maximum temperature in each battery at this time was measured. The results are shown in Table 1.

表１に示すように、実施例１に係るラミネート外装電池では、１．２Ｉｔの条件での過充電試験での最高温度が１３３℃であったのに対して、比較例１に係るラミネート外装電池では、１４２℃であった。この結果より、外装体の一部領域を金属外装要素３０である実施例１に係るラミネート外装電池では、電極体１０で生じた熱が高効率に且つ迅速に電池外方へと放出されたことが分かる。よって、実施例１に係るラミネート外装電池では、過充電の場合にも比較例１に比べてその温度上昇が少なく、安定した電池品質が維持されると考えられる。

As shown in Table 1, in the laminated outer battery according to Example 1, the maximum temperature in the overcharge test under the condition of 1.2 It was 133 ° C., whereas the laminated outer battery according to Comparative Example 1 was used. Then, it was 142 degreeC. As a result, in the laminate-cased battery according to Example 1 in which a partial region of the exterior body is the metal exterior element 30, heat generated in the electrode body 10 was released to the outside of the battery quickly and efficiently. I understand. Therefore, in the laminated exterior battery according to Example 1, the temperature rise is less than that in Comparative Example 1 even in the case of overcharging, and it is considered that stable battery quality is maintained.

4-6. Evaluation 2
The batteries with thermal elements according to Example 2 and Comparative Example 2 were overcharged under two conditions of 1.2 It and 1.4 It, and the time until the thermal fuse was activated was measured. The results are shown in Table 2.

表２に示すように、実施例２に係る感熱素子付き電池では、温度ヒューズが作動するまでに要した時間が比較例２に係る感熱素子付き電池に比べて５〜７ｍｉｎ．短かった。この結果より、実施例２に係る感熱素子付き電池の温度ヒューズは、電極体１０の温度変動に対して高い追従性をもっており、電池の安全性という観点から優位であることが分かる。
（実施の形態２）
以下では、実施の形態２に係るラミネート外装電池２について、図３を用いて説明する。なお、図３では、上記実施の形態１に係るラミネート外装電池１と同一の構成を有している部分については、同一符号を付し、以下での説明を省略する。

As shown in Table 2, in the battery with a thermal element according to Example 2, the time required until the thermal fuse was activated was 5 to 7 min. Compared with the battery with a thermal element according to Comparative Example 2. It was short. From this result, it can be seen that the thermal fuse of the battery with a thermosensitive element according to Example 2 has high followability to the temperature fluctuation of the electrode body 10 and is superior from the viewpoint of the safety of the battery.
(Embodiment 2)
Below, the laminate-clad battery 2 which concerns on Embodiment 2 is demonstrated using FIG. In FIG. 3, portions having the same configuration as that of the laminate-coated battery 1 according to Embodiment 1 are given the same reference numerals, and description thereof will be omitted below.

  As shown in FIG. 3, the laminated exterior battery 2 according to the present embodiment is different from the laminated exterior battery 1 in the configuration of the exterior body 50. In the outer package 50 of the laminate-coated battery 2 according to the present embodiment, a cup-forming region 50c formed of a metal laminate sheet with a recess 50a and a flat plate region 50d in which the metal layer 51 exists alone are integrated. By the way. In other words, the outer package 50 is configured in a state where the resin layers 52 and 54 and the adhesive layer 53 are removed in the flat plate region 50d, leaving only the metal layer 51 in the metal laminate sheet.

When the flat plate region 50d is folded and joined to the cup molding region 50c, a sealing resin 60 for joining is inserted between them as in the above embodiment.
In the laminated battery 2 according to the present embodiment, a partial region (flat plate region 50d) of the outer package 50 is made of a metal material, and the metal layer 51 is present in the entire region in the thickness direction in the region 50d. . For this reason, the laminate-clad battery 2 according to the present embodiment also has the same superiority as the first embodiment.

Further, in the laminated battery 2 according to the present embodiment, the cup molding region 50c made of a metal laminate sheet and the flat plate region 50d made of the metal layer 51 are integrally formed. It has the advantage of ease of management and manufacturing.
(Other matters)
The first and second embodiments show examples of the present invention, and the present invention is not limited to these configurations. For example, in the first and second embodiments, the lithium polymer battery is adopted as the battery type, but the present invention can be applied to other types of batteries. In addition, the present invention can be applied to a battery in which a metal laminate sheet is used for an exterior body and the like.

In the first and second embodiments, the configuration in which one main surface of the exterior body is made of a metal material in consideration of the performance of releasing heat generated in the electrode body 10 is used. From the viewpoint of thermal sensing performance, only a part of the element body close to the body may be made of a metal material.
In the first and second embodiments, a metal material such as SUS301 is applied as a material having higher thermal conductivity than the metal laminate sheet among the components of the exterior body, but the present invention adopts other than the metal material. It is also possible to do. For example, a ceramic material or the like can be used.

  In the first embodiment, as shown in FIG. 2, one element lead of the thermal fuse 100 is directly bonded to one tab 14 of the laminated battery 1, but the thermal element is mounted on the substrate. It is good also as mounting and arrange | positioning this in the state which contacts or adjoins to the main surface of the metal exterior element 30. FIG. In addition to the thermal fuse 100, other types of elements such as a PTC (Positive Temperature Coefficient) element can be applied as the thermal element.

In addition, the metal exterior element 30 of the laminated exterior battery 1 and the element main body of the heat sensitive element may be joined using a silicone resin or the like to achieve thermal coupling.
Further, the dimensions and materials used in the first and second embodiments can be appropriately changed.

  The present invention relates to a laminated outer battery that is used in portable devices and the like, and is required to achieve both high safety and high quality stability as well as a small size and light weight, and a battery in which a thermal element such as a thermal fuse is attached. It is effective to realize.

1 is a developed perspective view of a laminated battery 1 according to Embodiment 1. FIG. 1 is an external perspective view of a battery with a thermosensitive element in which a laminated battery 1 is a unit cell and a thermal fuse 100 is attached to the unit battery. FIG. FIG. 5 is a developed perspective view of a laminate-cased battery 2 according to Embodiment 2.

Explanation of symbols

1,2. Laminated exterior battery 10. Electrode body 11,12. Electrode 13. Separator 14,15. Tabs 16,17. Tab resin 20. Laminate exterior element 21, 51. Metal layers 22, 24, 52, 54. Resin layer 23, 53. Adhesive layer 30. Metal exterior element 40,60. Seal resin 50. Exterior body 100. Thermal fuse 101. Element body 102, 103. Element lead

Claims (6)

A battery in which a positive electrode plate and a negative electrode plate have an electrode body disposed opposite to each other with a separator interposed therebetween, and the electrode body is housed in an internal space of an exterior body composed of a sheet body,
The exterior body includes, on its main surface, a first region made of a metal laminate material, and a second region made of a material whose heat transfer characteristic from the electrode body to the outside is higher than that of the metal laminate material, The battery, wherein the second region is disposed to face the electrode body. The battery according to claim 1, wherein the second region is made of a metal material over the entire thickness direction of the sheet body. 3. The battery according to claim 1, wherein in the second region, an outer surface of the electrode body is in contact with an inner surface of the exterior body. The exterior body includes a cup-shaped first element in which a concave portion capable of accommodating the electrode body is formed on a main surface, and a second element as a lid body with respect to the first element,
The first element has a configuration corresponding to the first region as a whole,
The second element has a structure in which a joint margin with the first element corresponds to the first region, and all parts except the part correspond to the second region. The battery according to any one of claims 1 to 3. A unit cell in which an electrode body in which a positive electrode plate and a negative electrode plate are arranged to face each other with a separator interposed therebetween is housed in an internal space of an exterior body composed of a sheet body;
A battery with a thermal element having a thermal element inserted in a power flow path between the unit cell and an external device,
The exterior body in the unit cell has, on its main surface, a first region made of a metal laminate material, and a second region made of a material having higher heat transfer characteristics from the electrode body to the outside than the metal laminate material. The second region is disposed relative to the electrode body,
The thermosensitive element has an element main body that senses heat outside the element, and a lead portion that extends from the element main body.
The element body portion is arranged in a state of being in proximity to or in contact with an outer surface of the second region in the exterior body. 6. The battery with a thermal element according to claim 5, wherein the second region of the exterior body is made of a metal material over the entire thickness direction of the sheet body.

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