WO2019039409A1

WO2019039409A1 - Layered battery

Info

Publication number: WO2019039409A1
Application number: PCT/JP2018/030560
Authority: WO
Inventors: 大塚正博
Original assignee: 株式会社村田製作所
Priority date: 2017-08-24
Filing date: 2018-08-17
Publication date: 2019-02-28

Abstract

This layered battery has a configuration in which a layered body 10, having a structure in which a plurality of positive poles and negative poles are alternately layered, is sealed inside an outer case 20, and an edge section 21 of the outer case 20 is sealed. The layered battery is provided with a first main surface section 31, and a bent section 32 that is a bent region continuous from the first main surface 31. If the direction along the bent axis of the bent section 32 is the width direction, the bent section 32 has a portion with a smaller width than the first main surface section 31, and of the edge section 21 of the outer case 20, an edge section 21a of the first main surface 31 can be bent in a state where the flat surface area of the first main surface section 31 can be reduced.

Description

Stacked battery

The present invention relates to a stacked battery having a structure in which a plurality of positive electrodes and negative electrodes are alternately stacked.

BACKGROUND ART Conventionally, there has been known a laminated type battery having a structure in which a laminated body in which a plurality of positive electrodes and negative electrodes are alternately laminated is sealed in a laminated film (see Patent Document 1).

Moreover, in order to set it as the shape according to the shape of the space which accommodates a battery in patent document 2, the laminated type battery provided with the curved laminated body is described.

From Patent Document 1 and Patent Document 2, a laminate type battery having a structure in which a curved laminate is sealed in a laminate film can be considered.

Japanese Patent Application Publication No. 2005-501385 JP, 2014-11052, A

Here, in the case of a laminate type battery using a laminate film for the outer package, the periphery of the laminate film is sealed to seal the laminate. For example, when this laminated type battery is accommodated in the battery accommodating space of an electronic device, the accommodation volume of the laminated type battery can be reduced by accommodating the laminated film in a bent state of the peripheral portion, which is space effective. It is possible to improve the quality.

However, as described above, when the laminate has a curved shape, the peripheral portion of the curved portion can not be bent well. For this reason, it is necessary to prepare a space having a size in consideration of the peripheral portion of the curved portion as a space for housing the stacked type battery, and the space effectiveness can not be improved.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a laminated type battery which has a bent portion and can improve space effectiveness.

The laminated battery of the present invention is
A laminated battery having a structure in which a laminate having a structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked is enclosed in an outer package, and a peripheral portion of the outer package is sealed,
A first main surface portion,
A bent portion which is a region continuous with the first main surface portion and bent;
Equipped with
When the direction along the bending axis of the bent portion is taken as the width direction, the bent portion has a portion with a smaller width than the first main surface portion,
Among the peripheral portions of the exterior body, the peripheral portion of the first main surface portion is configured to be able to be bent in a mode in which the planar area of the first main surface portion can be reduced.
It is characterized by

At least one of the facing first end and the second end of the bent portion is continuous with the first main surface, as viewed in a direction orthogonal to the main surface of the stacked battery. It may be configured to have a shape that is recessed inward relative to the end.

In addition, a second main surface portion positioned to be continuous with the region on the opposite side to the region side continuous with the first main surface portion of the bent portion may be further provided.

Moreover, you may further provide the support layer for supporting the said laminated body.

The support layer may be bonded to the laminate.

The support layer may also include at least one material selected from the group consisting of stainless steel, copper and aluminum.

The support layer may be thicker than the positive electrode current collector included in the positive electrode and the negative electrode current collector included in the negative electrode.

The exterior body may be a laminate film.

According to the present invention, when the laminated battery is accommodated in the battery accommodation space, it is not necessary to bend the peripheral portion of the bent portion having a portion whose width dimension is smaller than the first main surface portion among the peripheral portions of the exterior body. By simply bending the peripheral portion of the first main surface portion, the storage volume of the stacked battery can be reduced, and space efficiency can be improved.

It is an external appearance perspective view of the laminated type battery in 1st Embodiment. It is sectional drawing which shows the main structure of the 1st main surface part of the laminated type battery in 1st Embodiment. It is sectional drawing which shows the main structure of the bending part of the laminated type battery in 1st Embodiment. FIG. 6 is a development view of the laminated battery shown in FIG. 1 developed with the first main surface portion, the bending portion, and the second main surface portion positioned on the same plane. (A) is a plan view of the laminated battery as viewed from the direction of arrow Y1 of FIG. 1 in a state where the peripheral portion of the first main surface is bent, (b) is from the direction of arrow Y2 of FIG. It is a figure which shows the state which bend | folded the peripheral part in the width direction of a 1st main surface part when it sees. It is the top view which looked at the laminated type battery from the direction of arrow Y 2 of FIG. 1 in the state which bend | folded the peripheral part of the 2nd main surface part. It is sectional drawing which shows the lamination structure of the 1st main surface part of the laminated type battery in 2nd Embodiment. It is sectional drawing which shows the laminated structure of the bending part of the laminated type battery in 2nd Embodiment. It is the elements on larger scale of the bending part which has another shape at the time of expand | deploying so that a 1st main surface part, a bending part, and a 2nd main surface part may be located on the same plane. It is the elements on larger scale of the bending part which has another shape at the time of expand | deploying so that a 1st main surface part, a bending part, and a 2nd main surface part may be located on the same plane. FIG. 10 is a perspective view showing a laminated type battery of Modification 2; The stack type battery shown in FIG. 10 is developed so that the first main surface portion, the first bent portion, the second main surface portion, the second bent portion, and the third main surface portion are located on the same plane. FIG. FIG. 18 is a perspective view showing a laminated type battery of Modification 3;

Hereinafter, the features of the present invention will be described more specifically by showing embodiments of the present invention.

First Embodiment
Here, a lithium ion secondary battery will be described as an example of the laminated battery of the present invention. However, the laminated battery according to the present invention is not limited to the lithium ion secondary battery.

FIG. 1 is an external perspective view of the stacked battery 100 according to the first embodiment. As shown in FIG. 1, the stacked battery 100 according to the first embodiment includes a first main surface portion 31 and a bent portion 32 which is a continuous and bent region of the first main surface portion 31 and a bent portion 32. And a second main surface portion 33 positioned to be continuous with the region on the opposite side to the region continuous with the first main surface portion 31.

That is, the first main surface portion 31, the bending portion 32, and the second main surface portion 33 are integrally formed.

FIGS. 2 and 3 are diagrams for explaining the laminated structure of the laminated battery 100. FIG. 2 is a cross-sectional view of the first main surface portion 31. FIG. 3 is a laminated structure of the bent portion 32. It is sectional drawing which shows mainly. FIG. 4 is a development view of the laminated battery 100 shown in FIG. 1 developed with the first main surface portion 31, the bent portion 32 and the second main surface portion 33 positioned on the same plane. .

As shown in FIGS. 2 and 3, in the stacked battery 100, a stack 10 formed by alternately stacking a plurality of positive electrodes 11 and a plurality of negative electrodes 12 with a separator 13 interposed therebetween, and a non-aqueous electrolyte 14 It has a structure housed in the laminate case 20.

The positive electrode 11 has a positive electrode current collector and a positive electrode mixture layer formed on both sides of the positive electrode current collector. As the positive electrode current collector, for example, a metal foil such as aluminum can be used. The positive electrode mixture layer contains a positive electrode active material, and may further contain a binder and a conductive additive. For example, lithium cobaltate can be used as the positive electrode active material.

Each positive electrode 11 is electrically connected to a positive electrode terminal (not shown) protruding from the laminate case 20.

When the electrode positioned on the outermost side in the stacking direction is the positive electrode 11, the positive electrode mixture layer is formed only on the surface on the inner side in the stacking direction of both surfaces of the positive electrode current collector for the positive electrode 11 positioned on the outer side. The structure may be

The negative electrode 12 has a negative electrode current collector and a negative electrode mixture layer formed on both sides of the negative electrode current collector. As the negative electrode current collector, for example, metal foil such as copper can be used. The negative electrode mixture layer contains a negative electrode active material, and may further contain a binder and a conductive additive. For example, graphite can be used as the negative electrode active material.

Each negative electrode 12 is electrically connected to a not-shown negative electrode terminal protruding from the laminate case 20.

As shown in FIG. 2 and FIG. 3, when the electrode positioned on the outermost side in the stacking direction is the negative electrode 12, for the negative electrode 12 positioned on the outer side, of the both sides of the negative electrode current collector, the inner side in the stacking direction. The negative electrode mixture layer may be formed only on the surface of

The separator 13 is interposed between the positive electrode 11 and the negative electrode 12. As the separator 13, various separators usable for the battery can be used without particular limitation. The separator 13 shown in FIG. 1 has a bag-like shape, but may have a sheet-like shape or may have a ninety-nine fold shape.

The non-aqueous electrolyte 14 may also be any as long as it can be used in a battery, and for example, known non-aqueous electrolytes can be used. A solid electrolyte may be used as the non-aqueous electrolyte 14. In addition, when using a solid electrolyte as the non-aqueous electrolyte 14, the separator 13 may become unnecessary.

Laminate case 20 which is an exterior body is formed by thermocompression-bonding and joining the peripheral parts of a pair of

laminate films

20a and 20b. That is, the laminate 10 and the non-aqueous electrolyte 14 are enclosed in the laminate case 20 by sealing the peripheral portion 21 of the laminate case 20.

The inside of the laminate case 20 is decompressed relative to the outside. As a result, the laminate case 20 can be brought into close contact with the laminate 10, and the space effectiveness of the stacked battery 100 can be improved.

Laminated battery 100 in the present embodiment has a shape in which a plane extending first main surface portion 31 and a plane extending second main surface portion 33 are orthogonal to each other. The bending portion 32 has a curved shape that smoothly connects the first main surface portion 31 and the second main surface portion 33 when viewed from the direction along the bending axis X (see FIG. 1).

As shown in FIGS. 1 and 4, the bending portion 32 has a portion narrower than the first major surface portion 31. That is, when the direction along the bending axis X of the bending portion 32 is taken as the width direction, the bending portion 32 has a portion with a smaller width than the first main surface portion 31. In other words, the width L 2 of the narrowest portion of the widths of the portions constituting the bent portion 32 is narrower than the width L 1 of the first major surface portion 31. In addition, about the said width dimension, it also only calls it width below.

Further, in the present embodiment, the width L1 of the first major surface portion 31 and the width L3 of the second major surface portion 33 are the same. Therefore, the width L 2 of the narrowest portion of the widths of the portions constituting the bent portion 32 is narrower than the width L 3 of the second major surface portion 33.

As shown in FIG. 4, when viewed from the direction orthogonal to the main surface of the stacked battery 100, the bent portion 32 is a first member facing the opposing

end portions

31 a and 31 b of the first main surface portion 31. The end 32a and the second end 32b have an inwardly concave shape. Thus, the width L2 of the narrowest portion of the bent portion 32 is narrower than the width L1 of the first major surface portion 31.

In the present embodiment, the first end 32a and the second end 32b have a curved shape.

Of the first end 32a of the bent portion 32, the innermost 321 is at the same position in the width direction as the inner end 311 of the peripheral edge 21a on the end 31a side of the first major surface 31, or It is preferable to be located inside in the width direction. Similarly, of the second end 32 b of the bending

portion

32, 322 located at the innermost position is the same position in the width direction as the inner end 312 of the peripheral edge 21 a on the end 31 b side of the first major surface 31. Or, it is preferable to be located inside in the width direction.

In the laminated battery 100 according to the present embodiment, the peripheral area 21 a of the first main surface 31 of the peripheral area 21 of the laminate case 20 is a plane area of the first main surface 31 in order to improve space effectiveness. Are configured to be foldable in a manner that can reduce Similarly, in the peripheral portion 21 of the laminate case 20, the peripheral portion 21b of the second main surface 33 can be bent in such a manner that the planar area of the second main surface 33 can be reduced. Is configured. The bending direction of the

peripheral portions

21a and 21b can be any direction, and is, for example, the direction of the arrow Y3 in FIG.

FIG. 5A (a) is a plan view of the laminated battery 100 seen from the direction of the arrow Y1 in FIG. 1 with the peripheral edge 21a of the first main surface 31 bent, and FIG. 5A (b) is a view It is a figure which shows the state which bend | folded the peripheral part 21a in the width direction of the 1st main surface part 31 when it sees from the direction of arrow Y 2 of 1. FIG. 5B is a plan view of laminated battery 100 as viewed in the direction of arrow Y2 in FIG. 1 in a state where peripheral portion 21b of second main surface portion 33 is bent. In FIG. 5A and FIG. 5B, the outline in the state which does not bend

peripheral part

21a, 21b is shown by the dotted line.

As shown in FIG. 5A, by bending the peripheral portion 21a of the first main surface portion 31, the volume of the portion where the peripheral portion 21a exists can be reduced. Similarly, as shown in FIG. 5B, by bending the peripheral portion 21b of the second main surface portion 33, the volume of the portion where the peripheral portion 21b exists can be reduced.

That is, in the stacked battery 100 according to the present embodiment, the first end 32 a and the second end 32 b of the bent portion 32 are recessed inward when viewed from the direction orthogonal to the main surface of the stacked battery 100. Thus, the peripheral portion 21a of the first main surface portion 31 and the peripheral portion 21b of the second main surface portion 33 are easily bent without the need to bend the peripheral portion 21c of the bent portion 32 in the peripheral portion 21 of the laminate case 20 be able to. Thereby, the laminated battery 100 is accommodated in the battery accommodation space, for example, the battery accommodation space of the electronic device in a state where the peripheral edge 21a of the first main surface 31 and the peripheral edge 21b of the second main surface 33 are bent. Therefore, the storage capacity of the battery can be reduced, and space efficiency can be improved.

In the laminate 10 constituting the laminate type battery 100, for example, a support plate curved in a desired shape is prepared, and a plurality of negative electrodes, separators and positive electrodes are laminated in this order on the support plate, It can be produced by removing the support plate. However, a plurality of flat negative electrodes, separators and positive electrodes may be stacked in this order and then bent to form a shape as shown in FIG. That is, the present invention is not limited by the method of manufacturing the laminate 10.

In addition, unlike the flexible battery whose shape can be freely changed, the stacked battery 100 in the present embodiment is a stacked battery having a fixed shape, that is, a curved shape, in the laminate 10, Its shape can not be changed freely. However, since the shape corresponding to the shape of the space in which the battery is accommodated can be stably maintained, the space in which the battery should be accommodated can be used without waste, which is significant.

Second Embodiment
The stacked battery 100A according to the second embodiment further includes a support layer 60 for supporting the stack 10, as compared to the configuration of the stacked battery 100 according to the first embodiment.

FIG. 6 is a cross-sectional view showing the stack structure of the first main surface portion 31 of the stack type battery 100A, and FIG. 7 is a cross-sectional view showing the stack structure of the bent portions 32 of the stack type battery 100A.

The support layer 60 is provided between the electrode (in this example, the negative electrode 12) in the outermost layer and the laminate film 20b constituting the laminate case 20.

The support layer 60 is bonded to the laminate 10 via, for example, an adhesive layer formed by an adhesive. Thereby, the negative electrode, the separator, and the positive electrode can be stably stacked on the support layer 60 when the stacked battery 100A is manufactured. However, the support layer 60 and the laminate 10 may not be bonded to each other.

The support layer 60 is preferably formed of a highly rigid material to support the laminate 10, and includes, for example, at least one material selected from the group consisting of stainless steel, copper and aluminum.

In addition, the support layer 60 is thicker than the positive electrode current collector included in the positive electrode 11 and the negative electrode current collector included in the negative electrode 12. With such a configuration, the positive electrode 11 and the negative electrode 12 stacked thereon can be reliably supported and fixed by the support layer 60.

According to the stacked battery 100A in the second embodiment, the support layer 60 curved in a desired shape is prepared, and a plurality of negative electrodes, separators, and positive electrodes are stacked in this order on the support layer 60. The laminate 10 can be produced. Thereby, the laminated body 10 which has the bending part 32 can be produced easily.

Although the support layer 60 shown in FIGS. 6 and 7 is provided between the electrode in the outermost layer and the laminate case 20, the arrangement position of the support layer 60 is not limited to this position. For example, it may be at the center in the stacking direction of the stack 10.

<Modification 1>
Although the first end 32a and the second end 32b of the bending portion 32 in the first and second embodiments described above have a curvilinear shape that is recessed inward, the shape of the bending portion 32 is the same as described above. The shape is not limited to the above.

FIG. 8 is a partially enlarged view of a bent portion 32X having another shape when the first main surface portion 31, the bent portion 32X, and the second main surface portion 33 are developed so as to be located on the same plane. The bent portion 32X is a first straight portion 81 extending inward from the end portion 31a of the first main surface portion 31, and a second straight portion extending inward from the end portion 33a of the second main surface portion 33. A second portion parallel to the end portion 31a of the first major surface portion 31 and the end portion 33a of the second major surface portion 33, and connecting the first linear portion 81 and the second linear portion 82 And three straight portions 83. That is, the bent portion 32X shown in FIG. 8 is formed by providing an inverted trapezoidal cut on the side.

The position of the third straight portion 83 of the bent portion 32X, in other words, the position of the deepest portion of the above-described inverted trapezoidal cut is the width of the inner end portion 311 of the peripheral portion 21a on the end 31a side of the first main surface portion 31 It is preferable to be located at the same position in the direction or inside in the width direction.

Although only the end on one side of the bent portion 32X is shown in FIG. 8, the other end may have the same configuration.

FIG. 9 is a partially enlarged view of a bending portion 32Y having another shape when the first main surface portion 31, the bending portion 32Y and the second main surface portion 33 are developed so as to be located on the same plane. . The bent portion 32Y has a shape in which the third straight portion 83 is omitted from the bent portion 32X shown in FIG. 8 and two

straight portions

91 and 92 extending inward are connected. That is, the bent portion 32Y shown in FIG. 9 is formed by providing a V-shaped cut on the side.

The connection position 910 of the two

straight portions

91 and 92 of the bent portion 32Y, in other words, the position of the deepest portion of the V-shaped notch is the inner end of the peripheral portion 21a on the end 31a side of the first main surface 31 It is preferable to be located at the same position as the portion 311 in the width direction, or at the inner side in the width direction.

<Modification 2>
FIG. 10 is a perspective view showing a stacked battery 100B of Modification 2. 11 shows the laminated battery 100B shown in FIG. 10 in the first main surface portion 101, the first bent portion 102, the second main surface portion 103, the second bent portion 104, and the third main surface portion 105. Is a development view in the case of being developed so as to be located on the same plane.

Stacked battery 100B includes a first main surface portion 101, a first bent portion 102, a second main surface portion 103, a second bent portion 104, and a third main surface portion 105. The first main surface portion 101, the first bent portion 102, and the second main surface portion 103 are the first main surface portion 31, the bent portion 32, and the second main surface portion 33 of the multilayer battery 100 in the first embodiment. , And have the same structure.

The second bent portion 104 is positioned so as to be continuous with the region of the second major surface portion 103 opposite to the region continuous with the first bent portion 102. The third main surface portion 105 is formed to be continuous with the second bent portion 104. That is, the third main surface portion 105 is continuous with the first main surface portion 101 in such a manner that the first bent portion 102, the second main surface portion 103, and the second bent portion 104 are interposed therebetween. It is formed.

That is, the first main surface portion 101, the first bent portion 102, the second main surface portion 103, the second bent portion 104, and the third main surface portion 105 are integrally formed.

As shown in FIGS. 10 and 11, the second bent portion 104 has a portion narrower than the second major surface portion 103. That is, the width L 4 of the narrowest portion of the widths of the portions forming the second bent portion 104 is narrower than the width L 3 of the second major surface portion 103.

In the present embodiment, the width L3 of the second major surface portion 103 and the width L5 of the third major surface portion 105 are the same. Therefore, the width L 4 of the narrowest portion of the widths of the portions forming the second bent portion 104 is narrower than the width L 5 of the third major surface portion 105.

In the developed view of FIG. 11, the second bent portion 104 has the same shape as the first bent portion 102, that is, the end portion is curved and has an inwardly concave shape. Thus, the width L4 of the narrowest portion of the second bent portion 104 is smaller than the width L3 of the second main surface portion 103 and the width L5 of the third main surface portion 105.

Also in the stacked battery 100B, it is not necessary to bend the peripheral portion 21c of the first bent portion 102 and the peripheral portion 21e of the second bent portion 104 in the peripheral portion 21 in order to improve the space effectiveness. The peripheral portion 21a of the main surface portion 101, the peripheral portion 21b of the second main surface portion 103, and the peripheral portion 21d of the third main surface portion 105 are divided into a first main surface portion 101, a second main surface portion 103, and The third main surface portion 105 is configured to be able to be bent in a manner capable of reducing the planar area.

<Modification 3>
FIG. 12 is a perspective view showing a stacked battery 100C of Modification 3. The stacked battery 100 shown in FIG. 12 has a shape in which the third main surface portion 105 of the stacked battery 100B shown in FIG. 10 faces the first main surface portion 101. That is, the third main surface portion 105A faces the first main surface portion 101.

The present invention is not limited to the above embodiment and modifications, and various applications and modifications can be made within the scope of the present invention.

For example, in the configurations of the first and second embodiments described above, the second major surface portion 33 may be omitted.

Further, in the first and second embodiments, the shapes of the first major surface portion 31 and the second major surface portion 32 may be curved shapes instead of planar shapes. Similarly, in the second modification and the third modification, the shapes of the first major surface portion 101, the second major surface portion 103, and the third

major surface portions

105 and 105A are not planar shapes but curved shapes. It is also good.

In the laminated battery 100 shown in FIG. 1, the first end 32 a and the second end 32 b of the bent portion 32 facing each other have a shape in which the first end 32 a and the second end 32 b face each other when viewed in the direction orthogonal to the main surface. However, only one of the ends may be configured to have an inwardly recessed shape. Similarly, in the other configurations, only one of the opposing ends of the bent portion may be configured to have an inwardly concave shape.

The shape of the bending portion continuous with the first main surface portion is not limited to the shapes of the above-described embodiment and the modification.

DESCRIPTION OF SYMBOLS 10 Laminated body 11 Positive electrode 12 Negative electrode 13 Separator 14 Non-aqueous electrolyte 20

Lamination case

20a, 20b Laminating film 21 (21a, 21b, 21c, 21d, 21e) Peripheral part 31 of the laminating case First main surface part 32 Bending part 32X Bending portion 32Y having a shape Further, a bending portion 33 having another shape Second main surface portion 60 Support layer 100 Stacked battery 100A in the first embodiment Stacked battery 100B in the second embodiment Stacked type of Modification 2 Battery 100C Multi-Layered Battery 101 of Modified Example 3 First Main Surface Portion 102 in Stacked-Type Battery of Modified Examples 2 and 3 First Curved Portion 103 in Stacked-Type Battery of Modified Examples 2 and 3 Stacked-Type of Modified Examples 2 and 3 Second principal surface portion 104 in battery Second bent portion 10 in laminated battery of Modifications 2 and 3 The third main surface of the third stacked battery main surface portion 105A Modification 3 in the stacked cell of Modification 2

Claims

A laminated battery having a structure in which a laminate having a structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked is enclosed in an outer package, and a peripheral portion of the outer package is sealed,
A first main surface portion,
A bent portion which is a region continuous with the first main surface portion and bent;
Equipped with
When the direction along the bending axis of the bent portion is taken as the width direction, the bent portion has a portion with a smaller width than the first main surface portion,
Among the peripheral portions of the exterior body, the peripheral portion of the first main surface portion is configured to be able to be bent in a mode in which the planar area of the first main surface portion can be reduced.
Stack type battery characterized by
At least one of the facing first end and the second end of the bent portion is continuous with the first main surface, as viewed in a direction orthogonal to the main surface of the stacked battery. The stacked battery according to claim 1, wherein the stacked battery has a shape that is recessed inward compared to the end portion.
3. The device according to claim 1, further comprising a second main surface portion positioned to be continuous with a region on the opposite side to the region side continuous with the first main surface portion of the bending portion. Stacked battery as described.
The laminated battery according to any one of claims 1 to 3, further comprising a support layer for supporting the laminate.
The laminated battery according to claim 4, wherein the support layer is bonded to the laminate.
The stack type battery according to claim 4 or 5, wherein the support layer contains at least one material selected from the group consisting of stainless steel, copper and aluminum.
The stack type battery according to any one of claims 4 to 6, wherein the support layer is thicker than a positive electrode current collector included in the positive electrode and a negative electrode current collector included in the negative electrode.
The stack type battery according to any one of claims 1 to 7, wherein the outer package is a laminate film.