WO2013047778A1

WO2013047778A1 - Battery and method for manufacturing same

Info

Publication number: WO2013047778A1
Application number: PCT/JP2012/075144
Authority: WO
Inventors: 丹上　雄児; 眞一郎坂口; 愛佳木村; 水田　政智
Original assignee: オートモーティブエナジーサプライ株式会社
Priority date: 2011-09-29
Filing date: 2012-09-28
Publication date: 2013-04-04

Abstract

A battery (A) has: an electrode stacked body (3) in which a plurality of electrodes (1) and a plurality of separators (2) are alternately stacked; and exterior body films (4A, 4B) constituting a package into which the electrode stacked body (3) is sealed by overlapping and joining the rim portions with each other. The plurality of separators (2) includes a large planar-shaped separator (2A) and a small planar-shaped separator (2B). The large planar-shaped separator (2A) projects toward a side of the electrode stacked body (3) in a planar view and is joined to the exterior body films (4A, 4B) at a more inner side than the portion where the rim portions of the exterior body films (4A, 4B) are joined to each other. This structure can effectively prevent the electrode stacked body (3) from moving within the package while preventing the degradation of performance of sealing by the exterior body films (4A, 4B) constituting the package.

Description

Battery and manufacturing method thereof

The present invention relates to a battery and a manufacturing method thereof.

There exists a battery having a configuration in which an electrode laminate composed of a plurality of electrodes and a separator sandwiched between the electrodes is sealed with a pair of laminate films. In such a battery, if the electrode laminate moves in the laminate film package due to an impact or the like, there is a possibility that a malfunction may occur as the battery. Therefore, the electrode laminate moves within the package made of a pair of laminate films. It is desirable to suppress.

Therefore, techniques described in Patent Documents 1 to 4 have been proposed for the purpose of suppressing the movement of the electrode laminate inside a package made of a pair of laminate films.

In the configurations disclosed in

Patent Documents

1 and 2, at least one separator is formed in a larger planar shape than the other separators and electrodes constituting the electrode stack, and a part of the large planar separator is formed. It extends so as to protrude to the side of the electrode laminate. And the part which protrudes to the side of an electrode laminated body of this big planar separator is pinched | interposed into the peripheral part of a pair of laminate film. That is, when a part (extension part) of the separator has entered the peripheral part between the laminate films and the peripheral parts of the laminate film are joined together by thermal fusion or the like, The extending portion of the separator located between them is also heat-sealed, and the electrode laminate is fixed in a package made of a laminate film.

Moreover, in the structure currently disclosed by patent document 3, the electrode and the separator are alternately laminated | stacked on the laminate film of 1 sheet, and whenever the electrode or the separator is laminated | stacked, the tab film adhere | attached on the electrode, Alternatively, the separator itself is bonded to the laminate film by heat fusion or the like. Finally, another laminate film is covered, and the peripheral portions of the laminate film are joined to each other by heat fusion or the like. Also with this configuration, since the tab film and the separator bonded to the electrode are bonded to the laminate film, movement of the electrode laminate in the package can be suppressed.

Furthermore, in Patent Document 4, a through-hole is formed in the center portion of the electrode laminate including a plurality of electrode layers and a separator layer as viewed in plan, and this electrode laminate is covered with a pair of laminate films from both sides, A configuration is disclosed in which laminate films are brought into direct contact with each other through a through hole and fused together.

In the configurations of

Patent Documents

1 and 2, the extension portion of the separator is fixed by joining the peripheral portions of the laminate film positioned around the separator, so that the reliability of preventing the movement of the electrode laminate is increased. For example, depending on the material of the separator layer 22 that requires heat resistance, the fusing property may be poor with the heat fusible resin on the inner surface of the laminate film 20 that requires heat fusing property. Therefore, since the extending part of the separator is interposed between the peripheral parts of the laminate filmate, there is a problem that the bonding force between the peripheral parts of the laminate film is lowered and the sealing performance is lowered.

Further, Patent Document 3 neither discloses nor suggests a configuration in the case where there are a plurality of separators. Rather, assuming that there are a plurality of separators, there are not only a large number of joints between the separator and the laminate film in the space sealed by the laminate film, but also the joints to the laminate film for each separator. In order to ensure, the shape of a separator will become complicated. Therefore, in the case of Patent Document 2, it is not realistic to assume a plurality of separators.

Furthermore, as shown in Patent Document 3, in the case where the through hole is formed in the central portion of the electrode laminate as viewed in a plan view, electrical connection is made between the electrode layer and the metal layer of the laminate film. May cause a short circuit. One reason for this is that the edges of the inner surfaces of the through holes of the plurality of electrode layers come into contact with the inner surfaces of the laminate films that enter the inside of the through holes and are fused together, and the edges of the inner surfaces of the through holes are the laminate films. Is hurting the inner surface. In that case, there is a possibility that the electrode layer and the metal layer of the laminate film come into contact with each other at the damaged portion of the inner surface of the laminate film.

JP 2007-31323 A JP 2000-277062 A JP 2010-277925 A Japanese Utility Model Publication No. 03-079162

Accordingly, an object of the present invention is a battery using a plurality of separators, and effectively suppresses the movement of the electrode laminate in the package while preventing a decrease in sealing performance due to the outer package film serving as the package. It is in providing the battery which can be manufactured, and its manufacturing method.

Furthermore, another object of the present invention is to prevent the electrode laminate including the positive electrode layer, the negative electrode layer, and the separator layer from moving or being displaced within the exterior body, and to provide a metal layer and an electrode within the exterior body. An object of the present invention is to provide a battery capable of preventing an electrical short circuit with a laminate and a method for manufacturing the same.

The battery according to the present invention includes an electrode laminate in which a plurality of electrodes and a plurality of separators are alternately laminated, and a package film that forms a package that encloses the electrode laminate by joining the peripheral portions to each other. The plurality of separators include a large planar separator and a small planar separator, the large planar separator projecting to the side of the electrode stack when viewed in plan, and the periphery of the film It is characterized in that the film is bonded to the film on the inner side of the bonding part between the parts.

According to the structure of this battery, since the separator and the exterior body film are joined, the movement of the electrode laminate in the package can be suppressed, and more than the joint portion between the peripheral portions of the exterior body film. Since the separator having a large planar shape and the exterior body film are bonded to each other on the inner side, the separator does not intervene at the joint portion between the peripheral portions of the exterior body film, and the deterioration of the sealing performance can be suppressed. Furthermore, even in a battery having a plurality of separators, only a large planar separator, which is a part of them, is bonded to the exterior body film, so that the energy required for joining can be reduced, and the exterior body film It is possible to reduce damage to the joint portion between the peripheral portions.

Another battery of the present invention includes an electrode laminate including a separator layer and a positive electrode layer and a negative electrode layer that are overlapped with each other with the separator layer interposed therebetween, and an exterior body that surrounds the electrode laminate. The layer has a non-covered portion that is not covered by the positive electrode layer and the negative electrode layer on a part of the outer periphery of the separator layer, and a through hole is provided in the non-covered portion. The laminate film is composed of a pair of laminated sheets including a metal layer and a single folded laminated film, and the laminated films are fused to each other through a through-hole of an uncoated portion of the separator layer.

According to this battery, since the through-hole is provided in the non-covered portion of the separator layer, and the laminate films are fused to each other through the through-hole, movement and displacement of the electrode stack in the exterior body are suppressed. It is done. Moreover, since no electrode is present in the through hole, there is little risk of an electrical short circuit between the electrode layer and the metal layer included in the laminate film. In addition, the through hole is formed only in the separator layer, the portion where the through hole is formed is thinner than the total thickness of the electrode laminate, and the separator layer is made of a material softer than the electrode layer. The possibility of damaging the heat-fusible resin due to the end portions is also reduced.

Furthermore, after constructing the electrode laminate, through-holes can be formed in the non-covered portion of the separator layer. In particular, when there are a plurality of separator layers in the non-covered portion, the through holes can be formed in the plurality of separator layers all at once, so that the working efficiency is very good and the manufacturing cost can be reduced.

(A) is a schematic plan view showing a state in which one laminate film is removed from the battery according to the first embodiment of the present invention, and (b) is a cross-sectional view taken along line XX of FIG. (A), (b) is typical sectional drawing which shows the manufacturing process of the battery shown in FIG. 1 in order. (A) is a plan view schematically showing an electrode laminate of a battery according to a second embodiment of the present invention, (b) is a cross-sectional view taken along line YY of (a), and (c) is a set of FIG. 2 is an enlarged cross-sectional view schematically showing the intermediate electrode laminate and the electrode, taken along line YY in FIG. FIG. 4 schematically shows a battery including the electrode stack shown in FIGS. 3A and 3B, and is a cross-sectional view taken along line YY in FIG. It is sectional drawing which shows the battery unit of the 3rd Embodiment of this invention. It is a top view which shows typically the battery of the 4th Embodiment of this invention. FIG. 7 is an enlarged cross-sectional view of a main part of the battery shown in FIG. 6 cut along line AA. (A) is a principal part expanded sectional view which shows the state which comprised the electrode laminated body in the manufacturing method of the battery shown in FIG. 6, (b) is a principal part expanded sectional view which shows the process of forming a through-hole. It is a top view which shows typically the battery of the 5th Embodiment of this invention. It is a top view which shows typically the battery of the 6th Embodiment of this invention. It is a top view which shows typically the battery of the 7th Embodiment of this invention. It is a top view which shows typically the battery of the 8th Embodiment of this invention. It is a top view which shows typically the battery of the 9th Embodiment of this invention. It is a top view which shows typically the battery of the 10th Embodiment of this invention. (A) is a top view which shows typically the battery of the 11th Embodiment of this invention, (b), (c) is the top view and side view which respectively show two types of battery holders which hold | maintain the battery. . (A) is a perspective view which shows the principal part of the battery module containing the battery and battery holder shown in FIG. 15, (b) is the sectional drawing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1A and 1B are schematic views of a battery according to a first embodiment of the present invention. FIG. 1A shows a state in which one laminate film is removed for easy understanding.

The battery A of the present embodiment is an example of a lithium ion secondary battery. An electrode laminate 3 in which a plurality of electrodes 1 and a plurality of separators 2 are alternately laminated is enclosed in a package composed of a pair of exterior body films (laminate films) 4A and 4B joined together. Specifically, the electrode laminate 3 is configured by stacking the positive electrode 1A and the negative electrode 1B so as to overlap each other with the separator 2 interposed therebetween. Here, as the positive electrode 1A, lithium manganese oxide, lithium nickel oxide, or the like can be used. As the negative electrode 1B, graphite, amorphous carbon, or the like can be used. As the separator 2, a polyolefin sheet such as polypropylene can be used.

There are two types of separators 2, a large planar separator 2 A and a small planar separator 2 B. Specifically, as shown in FIG. 1B, the large planar separators 2A and the small planar separators 2B are alternately arranged along the stacking direction. In the present embodiment, the small planar shape separator 2B has a slightly larger planar shape and size than both

electrodes

1A and 1B, and the large planar shape separator 2A corresponds to both the

electrodes

1A and 1B and the small planar shape separator 2B. In comparison, it has a long shape in the longitudinal direction (left-right direction in FIG. 1). Accordingly, a part (extended portion) of the large planar separator 2 A protrudes toward the side of the electrode laminate 3.

One side (front side of FIG. 1A) of the electrode laminate 3 is covered with a laminate film 4A, and the other side (back side of FIG. 1A) is covered with a laminate film 4B. . Laminate film 4A and laminate film 4B have their peripheral portions overlapped and joined to each other by thermal fusion or the like (in FIG. 1 (a), the joined portion is shown by hatching). Thus, the package which accommodates the electrode laminated body 3 is comprised by the

laminate films

4A and 4B by which the peripheral parts were mutually joined. Although not shown, an electrolytic solution is also enclosed in the package. Here, the

laminate films

4A and 4B are laminated in the order of a polyolefin resin layer such as polypropylene, a metal layer, and a protective layer from the bonded side to the outside.

Further, the lead electrode 5A connected to the positive electrode 1A and the lead electrode 5B connected to the negative electrode 1B extend to the outside of the package through the joint portions of the peripheral portions of the

laminate films

4A and 4B. .

And in this Embodiment, the part which protrudes to the side of the electrode laminated body 3 of the separator 2A with a large planar shape inside a package, ie, the inner side of the junction part of the peripheral parts of

laminate film

4A, 4B ( The extending portion) is joined to the

laminate films

4A and 4B by a method such as ultrasonic welding (the joining portion is shown by hatching in FIG. 1A).

Next, with reference to FIGS. 2A and 2B, a method for manufacturing the battery A of the present embodiment will be described. First, as shown in FIG. 2A, a plurality of electrodes 1 and separators 2 are laminated to form an electrode laminate 3. Specifically, as described above, the negative electrode 1B, the large planar separator 2A, the positive electrode 1A, and the small planar separator 2B are repeatedly laminated in this order. Then, the extraction electrode 5B is connected to the negative electrode 1B, and the extraction electrode 5A is connected to the positive electrode 1A. As shown in FIG. 2B, the laminate film 4A is disposed on one side of the electrode laminate 3, the laminate film 4B is disposed on the other side, and the electrode laminate 3 is formed by the

laminate films

4A and 4B. Sandwich. Then, the peripheral portions of the

laminate films

4A and 4B are brought into close contact with each other leaving one side for injecting the electrolytic solution, and bonded by a method such as heat fusion. The side into which the electrolytic solution is injected is a side where the large planar separator 2 A does not protrude from the electrode stack 3. And when injection | pouring is completed, the remaining one side will be joined by methods, such as heat sealing | fusion.

Subsequently, the

laminate films

4A and 4B are formed on the extended portions of the separator 2A having a large planar shape protruding to the side of the electrode laminate 3 inside the periphery of the

laminate films

4A and 4B when viewed in a plan view. Are brought into contact with each other and joined together by a method such as ultrasonic welding. Thereby, the laminated film 4A, the large planar separator 2A in the outermost layer, the large planar separator 2A at the intermediate position in the laminating direction, the large outer planar separator 2A, and the laminated film 4B are laminated together. Be joined. Thus, the battery A shown in FIGS. 1A and 1B is completed.

According to this battery A, since the large planar separator 2A and the

laminate films

4A and 4B are joined in the package made of the

laminate films

4A and 4B, the movement of the electrode laminate 3 is suppressed in the package. At the same time, since the separator is not interposed at the joint portion between the peripheral portions of the

laminate films

4A and 4B, it is possible to suppress a decrease in joint reliability at the peripheral portions of the

laminate films

4A and 4B. Furthermore, even a battery having a plurality of separators, only a large planar separator, which is a part of them, is joined to the

laminate filmnates

4A and 4B, so that the energy required for joining can be reduced. The influence which it has on the junction part of the peripheral parts of

film

4A, 4B can be reduced.

Further, according to the manufacturing method of the battery A, since the peripheral portions of the

laminate films

4A and 4B are bonded to each other before the separator 2A having a large planar shape and the

laminate films

4A and 4B are bonded, the separator When joining 2A and

laminate films

4A and 4B, the influence of, for example, heat and vibration does not affect the joining of the peripheral portions of

laminate films

4A and 4B, and sealing performance can be ensured.

In the electrode laminate 3, when the large planar separators 2A and the small planar separators 2B are alternately arranged along the laminating direction, every other separator 2 is bonded to the

laminate films

4A and 4B. Therefore, it is effective for suppressing the movement of the electrode laminate 3 in the package. Further, the configuration is not limited to every other sheet, and a configuration in which large planar separators 2A bonded to the

laminate films

4A and 4B at intervals such as every two sheets or every three sheets may be arranged. As the number of sheets, one large planar separator 2A joined to the

laminate films

4A and 4B may be one, or two or more. In the case of two sheets, when the outermost separators 2A of the large planar separators 2A are joined together, the space sandwiched between the two planar large separators 2A joined to the

laminate films

4A and 4B Since all the other electrodes 1 and separators 2 are sandwiched between the electrodes, it is effective in suppressing the movement of the electrode laminate 3 in the package.

The location where the separator 2A having a large planar shape is joined to the

laminate films

4A and 4B may be located anywhere other than the joining location of the peripheral portions of the

laminate films

4A and 4B, as shown in FIG. When the location where the separator 2A having a large planar shape is joined to the

laminate films

4A and 4B is at a position opposite to the

lead electrodes

5A and 5B with respect to the electrode laminate, the pole laminate is formed in the package in the same direction. There is an inhibitory effect on the movement of 3.

The separator 2A having a large planar shape and the

laminate films

4A and 4B may be joined by any method (for example, ultrasonic welding or spot welding), but is a method that does not involve heating such as ultrasonic welding. It is preferable. In general, bonding between the peripheral portions of the

laminate films

4A and 4B is often performed by thermal fusion. In this embodiment, a separator having a large planar shape is formed after bonding between the peripheral portions of the

laminate films

4A and 4B. This is because 2A and the

laminate films

4A and 4B are joined. That is, if the separator 2A having a large planar shape and the

laminate films

4A and 4B are joined by a method such as heat fusion and heat is generated, the peripheral edges of the

laminate films

4A and 4B that have been joined first are formed. This is because there is a possibility that the influence of heat on the joint (heat-sealed part) and the joint strength may decrease.

Next, a second embodiment of the present invention will be described. Portions common to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the present embodiment, as shown in FIGS. 3A to 3C, the two adjacent separators 2 are joined in a state where at least one side is not joined and several other sides are joined together in advance. An intermediate electrode body 6 is configured by interposing a first electrode (for example, positive electrode 1A) between the two separators 2. The intermediate electrode body 6 and the electrode of the second electrode (for example, the negative electrode 1B) are stacked on each other to constitute the electrode stack 3. And, as shown in FIG. 4, in the state where the electrode laminate 3 is sandwiched between the

laminate films

4A and 4B as in the first embodiment, the peripheral portions of the

laminate films

4A and 4B are joined to each other, Thereafter, a separator 2A having a large planar shape in the electrode laminate 3 is bonded to the

laminate films

4A and 4B.

More specifically, in the present embodiment, the separator 2A having a large planar shape and the separator 2B having a small planar shape are arranged at two locations on two sides perpendicular to the side where the

extraction electrodes

5A and 5B are located in a plan view. At a total of four joint points 7 each, they are joined together by thermal fusion. Thereby, the two

separators

2A and 2B are formed in a bag shape. A positive electrode 1A is disposed between the bag-

like separators

2A and 2B. Thus, the intermediate electrode body 6 (see FIG. 3C) is configured. Further, as shown in FIGS. 3A and 3B, the electrode laminate 3 is configured by alternately laminating a plurality of intermediate electrode bodies 6 and a plurality of negative electrodes 1B. Thereafter, as shown in FIG. 4, the joining of the peripheral portions of the

laminate films

4A and 4B and the joining of the separator 2A having a large planar shape and the

laminate films

4A and 4B are performed in the same manner as in the first embodiment. Is called.

According to the present embodiment, in addition to the same effects as those of the first embodiment, when a force is applied to the electrode laminate 3, the separator 2A is pulled by the joining of the separator 2A and the laminate films 4A and 4b. In addition, the separator 2 B that has been joined and is similarly pulled is effective in suppressing movement of the electrode laminate 3 within the package.

A third embodiment of the present invention will be described. In the present embodiment, a plurality of batteries A similar to those in the first embodiment or the second embodiment are stacked in the housing 8 to constitute a battery unit. The casing 8 of the present embodiment has an upper plate 9 and a lower plate 10 each including pressurizing

portions

9a and 10a shaped to elastically pressurize a plurality of stacked batteries A. The upper plate 9 and the lower plate 10 are fixed to each other by a fixing tool (for example, a bolt 11 and a nut 12). Therefore, in the present embodiment, each battery A is held in a pressurized state. This applied pressure acts as a force for suppressing the movement of the electrode laminate 3 in the package of each battery A. Therefore, the effect of preventing movement of the electrode laminate 3 is further improved.

In the first and second embodiments described above, a package of a type in which two laminate films are bonded to each other has been described. However, a single laminate film is bent on one side and the periphery is bonded. A type of package configured as described above may be adopted. Further, if the package is a film, the battery type is not limited to the lithium ion secondary battery.

Next, a fourth embodiment of the present invention will be described.

FIG. 6 shows a schematic plan view of the battery 100 of the present embodiment, and FIG. 7 shows an enlarged view of the AA cross section of FIG. In addition, in each drawing in which the battery 100 of each embodiment described below is viewed in plan, the laminate films are shown while clearly showing each member such as an electrode laminate inside the exterior body for easy viewing. The fused part is also clearly indicated by hatching.

In the battery 100 according to the present embodiment, an electrode laminate 33 in which a plurality of positive electrode layers 31a and a plurality of negative electrode layers 31b and a separator layer 32 interposed therebetween are laminated includes a pair of laminate films 34a. 34 is surrounded by 34. The plurality of positive electrode layers 31a of the electrode laminate 33 are connected to the positive electrode terminal 35a, and the plurality of negative electrode layers 31b are connected to the negative electrode terminal 35b.

As the separator layer 32, for example, a layer made of a polyolefin resin such as polyethylene or polypropylene can be used. Furthermore, a film obtained by making a polyester resin material such as polyethylene terephthalate or a polyamide resin material porous by stretching or the like, or a nonwoven fabric made of the resin material described above can also be used.

Furthermore, inorganic fine powders such as silica and alumina adhered to the surface of these films and nonwoven fabrics in a porous state, and inorganic fine powders such as silica and alumina were dispersed inside these films and nonwoven fabrics. Those can also be used as the separator layer 32.

As will be described later, in the present embodiment, when the separator layer 32 is fixed to the exterior body 34 made of the laminate film 34a, the laminate films 34a are fused together through the through holes 36. There is no need to consider a combination with a good fusibility between the material of the heat fusible resin and the material of the separator layer 32.

As the laminated film 34a constituting the exterior body 34, for example, a polyester resin is provided on one side of a metal layer such as aluminum, and a polyolefin resin such as polyethylene or polypropylene is provided on the other side. A heat-sealable resin can be used.

In the present embodiment, an uncovered portion 32a that is not covered by the positive electrode layer 31a and the negative electrode layer 31b is provided on a part of the outer periphery of the separator layer 32. Specifically, as shown in FIG. 6, the positive electrode layer 31a and the negative electrode layer 31b of the present embodiment have a square (rectangular) planar shape, and the uncovered portion 32a of the separator layer 32 is seen in a plan view. Thus, the positive electrode layer 31a and the negative electrode layer 31b protrude outward from the rectangular planar shape. And the through-hole 36 is opened in this non-coating part 32a. Thus, since the through-hole 36 is opened in the non-covered portion 32a that is not covered with the positive electrode layer 31a and the negative electrode layer 31b, the laminate films 34a constituting the exterior body 34 are directly connected to each other through the through-hole 36. Contact. Laminate films 34 a are fused together at an outer peripheral portion 37 located outside the electrode laminate 33 to form a bag-shaped exterior body 34.

The positive electrode terminal 35a and the negative electrode terminal 35b are drawn out from one side of the outer peripheral portion 37 of the exterior body 34 via the fusion portion. The positive electrode terminal 35a and the negative electrode terminal 35b are fused to the laminate film 34a via a metal fusible resin (not shown), so that the positive electrode terminal 35a and the negative electrode terminal 35b are fixed to the exterior body 34. The laminate films 34 a are fused not only at the outer peripheral portion 37 but also at the portions that are in contact with each other through the through hole 36. This fusion part is referred to as “separator layer fixing fusion part 38” for convenience. Thus, since the laminate films 34a are joined to each other inside the through hole 36, the separator layer 32 is planar only within the range of play between the through hole 36 and the separator layer fixing fusion portion 38. Cannot be moved to and is substantially fixed. That is, the through hole 36 and the separator layer fixing fused portion 38 substantially prevent the electrode stack 33 from moving and misaligned inside the exterior body 34.

In particular, in this embodiment, the positive electrode terminal 35a and the negative electrode terminal 35b are formed on the side portion (the right side in FIG. 6) opposite to the side portion (the left side in FIG. 6) that protrudes outside the electrode stack 33. 36 and the separator layer fixing fusion part 38 are located. That is, the positive electrode terminal 35a and the negative electrode terminal 35b fixed to the positive electrode layer 31a and the negative electrode layer 31b are sandwiched between the pair of laminate films 34a, thereby contributing to the fixing of the electrode laminate 33, as described above. The through holes 36 and the separator layer fixing fusion portion 38 are provided on the opposite side portions, not on the same side portion in a plan view, but on the portions that contribute to fixing the electrode laminate 33. . This means that the electrode laminate 33 is fixed on both sides, and prevents the electrode laminate 33 from moving and misaligned due to the force applied in the direction in which the positive electrode terminal 35a and the negative electrode terminal 35b extend. Therefore, it is more effective.

As will be described later with reference to FIG. 12, there are a plurality of through-holes 36 and separator layer fixing fusion portions 38, and one of the fusion portions 38 and another fusion portion 38 are provided. Even in the opposite side portions of the electrode stack 33, the electrode stack 33 is similarly effective in preventing the movement and displacement of the electrode stack 33.

Furthermore, in the present embodiment, the plurality of through holes 36 and the separator layer fixing fused portion 38 are arranged side by side in a direction orthogonal to the extending direction of the positive electrode terminal 35a and the negative electrode terminal 35b. Therefore, even when a tensile or compressive force is applied to the positive electrode terminal 35a and the negative electrode terminal 35b, a plurality of fixing portions (separator layer fixing fusion portions 38) arranged in a direction orthogonal to the direction of the force are provided in the electrode laminate 33. Suppresses movement and displacement.

Further, as shown in FIG. 7, in the present embodiment, the fixing hole of the electrode laminate 33 is formed in the uncovered portion 32a of the separator layer 32 located in the region outside the

electrodes

31a and 31b. In the through hole 36, there is no electrode that may cause a short circuit, and a short circuit with the metal layer of the laminate film 34a can be prevented.

That is, since the laminate films 34a are fused to each other through the through holes 36 provided in the non-covered portion 32a of the separator layer 32, the laminate film 32 can be used to suppress planar movement and displacement of the separator layer 32. The combination range of the material of the fusion layer and the separator layer 32 can be widened, and there is no electrode in the through hole 36 where the laminate films 34a are fused together, and an insulating separator layer 32 is provided between the electrodes. Since the through-hole 36 is arranged with the interposition, the possibility of causing an electrical short can be reduced.

The method for manufacturing the battery 100 will be described. First, the electrode layer 33 is formed by superposing the positive electrode layer 31a and the negative electrode layer 31b with the separator layer 32 interposed therebetween. The electrode laminate 33 may be a combination of the positive electrode layer 31a, the negative electrode layer 31b, and one separator layer 32, but may be a combination of a plurality of positive electrode layers 31a and negative electrode layers 31b and two or more separator layers 32. There may be. A part of the outer periphery of the separator layer 32 is provided with an uncoated portion 32a that is not covered by the positive electrode layer 31a and the negative electrode layer 31b. As an example, as shown in FIG. 6, the portion where the separator layer 32 protrudes outward from the rectangular electrode layers 31a and 31b when viewed in plan is the non-covered portion 32a. Each positive electrode layer 31a is electrically connected to the positive electrode terminal 35a and each negative electrode layer 31b is electrically connected to the negative electrode terminal 35b on the side opposite to the non-covered portion 32a in plan view. And the through-hole 36 is formed in the non-coating part 32a of the electrode laminated body 33. FIG. As shown in FIG. 8 (a), a plurality of separator layers 32 are stacked on the non-covering portion 32a. For example, as shown in FIG. 8 (b), a plurality of separator layers 32 are formed using a punch 39 and a die 40. The through holes 36 are formed collectively. Even when the electrode laminate 33 includes a plurality of separator layers 32, only one separator layer 32 of the plurality is positive electrode so that only one separator layer 32 exists in the uncovered portion 32a. You may make it the structure extended to the outer side of the layer 31a and the negative electrode layer 31b.

Thus, as shown in FIG. 7, the electrode laminate 33 in which the positive electrode terminal 35a and the negative electrode terminal 35b are connected and the through hole 36 is formed in the uncovered portion 32a is covered from both the front and back surfaces with a pair of laminate films 34a. . Subsequently, the laminate films 34a are joined to each other by a method such as heat fusion or ultrasonic fusion in the outer peripheral portion 37, leaving one side that becomes a liquid injection port. Furthermore, in the through-hole 36 of the non-coating part 32a, the laminate films 34a are brought into direct contact with each other and fused together. As an example, an elongated heater having a diameter smaller than that of the through hole 36 is brought into contact with the outside to heat-bond the laminate films 34a to each other. Next, an electrolyte solution (not shown) is injected from the injection port, and the final sealing side is fused. Note that the laminate films 34a may be fused together in the through holes 36 after injecting the electrolytic solution.

In the manufacturing method of the present embodiment, since the hole forming process for forming the through hole 36 is only required once, the working efficiency is very good and the manufacturing cost is reduced.

In the fifth embodiment of the present invention shown in FIG. 9, a large number of through-holes 36 and separator layer fixing fused portions 38 are formed and arranged so as to form two staggered rows. Therefore, an uncovered portion 32a having a larger area than that of the fourth embodiment is provided. According to this configuration, since there are many separator layer fixing fused portions 38, the effect of preventing the movement and displacement of the electrode laminate 33 is great. Further, even if the separator layer 32 between the separator layer fixing fusion portions 38 in one row receives a force to move parallel to the extending direction of the positive electrode terminal 35a and the negative electrode terminal 35b, the other row Since the separator layer fixing fused portion 38 resists the force, the electrode laminate 33 can be fixed more firmly. Also in the present embodiment, the plurality of through holes 36 and the separator layer fixing fusion portion 38 are formed on the side opposite to the side where the positive electrode terminal 35 a and the negative electrode terminal 35 b protrude from the electrode stack 33. Since the terminal 35a and the negative electrode terminal 35b are located side by side in a direction orthogonal to the protruding direction, the electrode laminate 33 is unlikely to move or shift. The through holes 36 and the separator layer fixing fusion portions 38 may be formed in three or more rows.

In the sixth embodiment of the present invention shown in FIG. 10, the positive electrode layer 31a and the negative electrode layer 31b have a rectangular planar shape, and the separator layer 32 is a rectangular plane that is slightly larger than the positive electrode layer 31a and the negative electrode layer 31b. The separator layer 32 is on the opposite side of the positive electrode layer 31a and the negative electrode layer 31b from the side (the left side in FIG. 9) from which the positive electrode terminal 35a and the negative electrode terminal 35b protrude outside the electrode stack 33. It protrudes toward the part (right side of FIG. 9). The protruding portion is an uncovered portion 32 a, and a plurality of through holes 36 and a separator layer fixing fusion portion 38 are provided in a line over the entire length of the separator layer 32. Also in the present embodiment, the plurality of through holes 36 and the separator layer fixing fusion portion 38 are formed on the side opposite to the side where the positive electrode terminal 35 a and the negative electrode terminal 35 b protrude from the electrode stack 33. Since the terminal 35a and the negative electrode terminal 35b are located side by side in a direction orthogonal to the protruding direction, the electrode laminate 33 is unlikely to move or shift. Furthermore, in the case of the present embodiment, the planar shape of the electrode laminate 33, and hence the planar shape of the battery 100, can be made into a quadrangle, and storage, handling, and arrangement are easy.

The portion where the separator layer 32 protrudes beyond the positive electrode layer 31a and the negative electrode layer 31b, that is, the non-covered portion 32a may be provided on any side of the quadrangular separator layer 32 when viewed in plan, and a plurality of sides May be provided respectively.

In the seventh embodiment of the present invention shown in FIG. 11, the separator layer 32 has a square planar shape, and part of the outer periphery of the positive electrode layer 31 a and the negative electrode layer 31 b is from the rectangular planar shape of the separator layer 32. It is formed in a shape that recedes inward. In this way, the separator layer 32 faces the portion of the outer periphery of the positive electrode layer 31a and the negative electrode layer 31b that has receded inward in plan view, and the opposite portion of the separator layer 32 covers the positive electrode layer 31a and the negative electrode layer 31b. The uncovered portion 32a is not broken. Therefore, a through-hole 36 is formed in the uncovered portion 32a, and the laminate films 34a are brought into direct contact with each other through the through-hole 36 to be fused. In the case of the present embodiment, similarly to the fifth embodiment, the planar shape of the electrode laminate 33 and the battery 100 can be made square to facilitate storage, handling and arrangement. In addition, it is space efficient and suitable for downsizing. Further, the shapes of the positive electrode layer 31a and the negative electrode layer 31b that are receded inward from the rectangular planar shape of the separator layer 32 have a curved (arc-shaped) outline 41. The possibility of damaging the inner surface is low.

As a modification of the present embodiment, portions of the positive electrode layer 31a and the negative electrode layer 31b that are receded inward from the rectangular planar shape of the separator layer 32 are arranged so that the positive electrode layer 31a and the negative electrode layer 31b face each other. It can also be provided on the sides or on all four sides of the electrode 31.

In the eighth embodiment of the present invention shown in FIG. 12, two separator layer fixing fusion portions 38 are provided not on the same side portion but on the opposite side portions in plan view. . In this case, the electrode laminate 33 is fixed on both sides, which is effective for preventing the movement and displacement of the electrode laminate 33 due to the vertical force in FIG.

In the ninth embodiment of the present invention shown in FIG. 13, the separator layer 32 has a square planar shape, and the positive electrode layer 31a and the negative electrode layer 31b are chamfered at portions located at two corners of the square. It is retreating. Thereby, the opposing part of the separator layer 32 is formed in the area | region outside an electrode, and becomes the non-coating part 32a. A through hole 36 is formed in the non-covered portion 32a, and the laminate films 34a are brought into direct contact with each other through the through hole 36 and fused. Also in the present embodiment, a plurality of through holes 36 and separator layer fixing fusion portions 38 are provided at both ends of the side portion opposite to the side portion where the positive electrode terminal 35 a and the negative electrode terminal 35 b protrude from the electrode stack 33. In addition, since the positive electrode terminal 35a and the negative electrode terminal 35b are arranged side by side in a direction orthogonal to the protruding direction, the electrode laminate 33 is unlikely to move or shift. In addition, in the present embodiment, the planar shape of the electrode laminate 33 and the battery 100 can be made square to facilitate storage, handling, and arrangement, and space efficiency is further improved, which is suitable for downsizing. In addition, the shapes of the positive electrode layer 31a and the negative electrode layer 31b that are recessed inward from the rectangular planar shape of the separator layer 32 have curved (arc-shaped) contours 41, and thus damage the inner surface of the laminate film 34a. Less likely.

As a modification of the ninth embodiment, although not shown, the positive electrode layer 31a and the negative electrode layer 31b have a square planar shape, and the separator layer 32 is formed at two square corners of the positive electrode layer 31a and the negative electrode layer 31b. However, the positive electrode layer 31a and the negative electrode layer 31b may have a shape protruding outward from the rectangular planar shape. It is only necessary to appropriately determine which of the positive electrode layer 31a, the negative electrode layer 31b, and the separator layer 32 is formed into a quadrangular planar shape, and determine whether or not to adopt this modification.

By combining the previous seventh embodiment and the ninth embodiment, a separator is formed on one side of the positive electrode layer 31a and the negative electrode layer 31b in the vicinity of the center of the side, as in the seventh embodiment. A portion having a shape retreated inward from the rectangular planar shape of the layer 32 is provided, and the opposite side to the side is formed from the rectangular planar shape of the separator layer 32 at both ends, as in the ninth embodiment. You may provide the part of the shape retreated inside. In this case, non-covered portions 32a are provided at a total of three locations near the center of one side and both ends of the opposite sides, and each through-hole 36 and separator layer fixing fusion portion 38 are provided in each non-covered portion 32a. Is formed. In this configuration, the effect of preventing the movement and displacement of the electrode stack 33 is great by fixing at three positions.

In the tenth embodiment of the present invention shown in FIG. 14, the separator layer 32 has a square planar shape, and the separator layer 32 includes the positive electrode layer 31 a and the negative electrode layer 31 b at the four corners. In this configuration, a shape retreated inward from the 32 rectangular planar shapes is located. According to the present embodiment, in addition to the effects of the ninth embodiment, the effect of being able to more firmly fix the electrode laminate 33 by positioning the separator layer fixing fused portions 38 at the four corners is great.

Further, in the ninth and tenth embodiments and modifications thereof, although not shown, the shapes of the positive electrode layer 31a and the negative electrode layer 31b that are receded from the square planar shape of the separator layer 32 are curved (arc-shaped). ) May be a shape in which corners are linearly cut into triangles.

15 and 16 show a battery module including the battery 100 according to the eleventh embodiment of the present invention. This battery module is configured to include a plurality of batteries 100 superimposed on each other. As shown in FIG. 16B, the battery module includes a module case 42 that is a housing that houses a plurality of batteries 100, and a plurality of battery holders 43 for holding individual batteries 100 in the module case 42. A through bolt 44 for positioning through the module case 42 while penetrating the positioning holes 43a respectively provided in the plurality of stacked battery holders 43, and a nut 45 into which the through bolt 44 passing through the module case 42 is screwed. And.

In the battery 100 of the present embodiment, the through hole 36 is provided in the non-covering portion 32a of the separator layer 32, and the inside of the through hole 36 is the separator layer fixing fusion portion, as in the above-described embodiments. It is 38. In the present embodiment, a hole 46 penetrating the separator layer fixing fused portion 38 is further provided. In addition, a hole 46 is provided in the outer peripheral portion 37 in a side portion where the non-covering portion 32a does not exist (a side portion where the positive electrode terminal 35a and the negative electrode terminal 35b are connected). Then, the battery 100 is placed on the battery holder 43 while the pins 43 b provided on the battery holder 43 are respectively passed through the holes 46.

In this embodiment, one battery 100 is configured to be held by two battery holders 43 positioned on both sides thereof. As described above, in the present embodiment, the pin 43 b of the battery holder 43 passes through the hole 46 of the battery 100, so that the battery 100 is aligned with the battery holder 43. And the penetration bolt 44 penetrates the positioning hole 43a each provided in the some battery holder 43 continuously. In a state where a plurality of battery holders 43 that hold the battery 100 with high precision are fitted together by fitting the pins 43b and the holes 46, the through bolts 44 pass through the positioning holes 43a provided in the battery holders 43, respectively. As a result, each battery holder 43 is held in the module case 42 with high positional accuracy, and as a result, each battery 100 is held with high positional accuracy. In addition, as described in each of the embodiments described above, in each battery 100, the electrode stack 33 including the positive electrode layer 31a and the negative electrode layer 31b can be prevented from moving and misaligned. This leads to preventing the movement and displacement of the electrode stack 33 of the battery 100 at once.

In this embodiment, since the hole 46 used for positioning of the battery 100 is provided in the fusion part of the laminate film 34a (particularly the fusion part 38 for fixing the separator layer), a hole for alignment is separately formed. There is no need to do this, and space efficiency is high, contributing to downsizing. In addition, since the pin 43 b of the battery holder 43 is inserted into the hole 46, the battery holder 43 directly contributes to preventing the battery stack 33 from being displaced. This is because the position of the hole 46 contributes not only to the exterior body 34 of the battery 100 but also to the fixing of the separator layer 32.

The battery 100 according to the present embodiment is a battery in which a hole 46 is formed in the separator layer fixing fused portion 38 of the fourth to tenth embodiments and the modifications described above (the outer periphery if necessary) The portion 37 may be formed with a hole), and the arrangement of the non-covered portion 32a, the through hole 36, and the separator layer fixing fusion portion 38 is described in the fourth to tenth embodiments described above. And any one of the modified examples.

The fourth to tenth embodiments of the present invention are not limited to the above-described embodiments. The electrode laminate may be a wound type or a folded type. The exterior body may be configured by folding a single laminate film and fusing three sides. Further, in order to suppress the movement of the electrode stack 33, it is sufficient that there is an uncovered portion 32a provided with a through hole 36 on at least one side of the electrode stack 33. In each of the above-described embodiments, the positive electrode terminal 35 a and the negative electrode terminal 35 b and the through hole 36 are on the opposite sides of the electrode stack 33, and the through holes 36 are on the opposite sides of the electrode stack 33. An example is shown.

Claims

An electrode laminate in which a plurality of electrodes and a plurality of separators are alternately laminated, and an outer package film that constitutes a package that encloses the electrode laminate by joining the peripheral edge portions to each other. ,
The plurality of separators include a large planar separator and a small planar separator, and the large planar separator protrudes to the side of the electrode stack when seen in a plan view, and the periphery of the exterior body film The battery joined to the said exterior body film inside the junction part of parts.
2. The battery according to claim 1, wherein a plurality of large planar separators and a plurality of small planar separators are alternately arranged in the stacking direction.
The battery according to claim 1 or 2, wherein the peripheral portions of the exterior body film are joined to each other by thermal fusion, and the large planar separator is joined to the exterior body film by ultrasonic joining.
One electrode and the separator in the electrode laminate are at least partially joined at least one side of the two adjacent separators, and the one electrode is interposed between the two joined separators. The battery according to any one of claims 1 to 3.
A battery unit comprising the battery according to any one of claims 1 to 4,
A plurality of said batteries superimposed on each other;
A housing that accommodates the plurality of batteries while applying a pressing force along the stacking direction to the plurality of batteries,
A battery unit.
A step of covering an electrode laminate in which a plurality of separators and a plurality of electrodes including a plane-shaped small separator and a plane-shaped large separator are alternately laminated with an exterior body film;
Forming a package enclosing the electrode laminate by bonding the peripheral portions of the outer package film covering the electrode laminate together;
After joining the peripheral portions of the exterior body film to each other, the planar separator of the plurality of separators is seen from the side of the electrode laminate and the peripheral portions of the exterior body film. A step of bonding to the exterior body film inside the bonding portion of
The manufacturing method of the battery containing this.
The step of configuring the package enclosing the electrode laminate includes a step of bonding the peripheral portions of the exterior body film to each other by thermal fusion,
The battery manufacturing method according to claim 6, wherein the step of bonding the large planar separator to the outer package film is performed by bonding the large planar separator to the outer package film by ultrasonic bonding.
An electrode laminate including a separator layer and a positive electrode layer and a negative electrode layer that are overlapped with each other with the separator layer interposed therebetween, and an exterior body that surrounds the electrode laminate,
The separator layer has a non-covered portion that is not covered by the positive electrode layer and the negative electrode layer on a part of the outer periphery of the separator layer, and a through hole is provided in the non-covered portion,
The exterior body is composed of a pair of folded laminate films including a heat-fusible resin and a metal layer, and the laminate films are mutually connected via the through holes of the non-covered portion of the separator layer. Fused battery.
The positive electrode layer and the negative electrode layer have a rectangular planar shape, and the uncovered portion of the separator layer is a portion protruding outward from the rectangular planar shape of the positive electrode layer and the negative electrode layer when viewed in a plan view. The battery according to claim 8.
The separator layer has a quadrangular planar shape, and the uncovered portion of the separator layer has a shape in which the positive electrode layer and the negative electrode layer recede inward from the quadrangular planar shape of the separator layer when viewed in plan. The battery according to claim 8, wherein the battery is a part facing a part formed on the battery.
The battery according to claim 10, wherein the non-covered portion of the separator layer is located at at least one corner of the quadrangular planar shape of the separator layer.
The portion where the positive electrode layer and the negative electrode layer are formed in a shape that recedes inwardly from a quadrangular planar shape of the separator layer as viewed in a plan view has a curved outline. Battery.
Connected to the positive electrode layer and the negative electrode layer, further having a terminal penetrating the exterior body and projecting to the outside;
The battery according to any one of claims 8 to 12, wherein the non-covering portion is located on a side portion of the separator layer opposite to a side portion where the terminal protrudes to the outside in plan view.
14. The battery according to claim 13, wherein the battery has a plurality of through holes, and the plurality of through holes are arranged side by side in a direction orthogonal to a direction in which the terminals protrude.
The battery according to any one of claims 8 to 14, wherein the laminated film that is fused to each other through the through hole is provided with a hole that penetrates the fused portion.
A battery module in which a plurality of combinations of the battery according to claim 15 and a battery holder including a pin penetrating the hole provided in the fusion part of the battery are held in an overlapping manner.
Superposing the positive electrode layer and the negative electrode layer on each other with the separator layer in between to form an electrode laminate;
Forming a through hole in a part of the outer periphery of the separator layer in the electrode laminate, and not covered with the positive electrode layer and the negative electrode layer;
After the step of forming the through hole, the step of covering the electrode laminate with a pair or one folded laminate film;
The portions of the laminate films that are in contact with each other through the through-holes are fused together;
The manufacturing method of the battery containing this.
In the step of forming the electrode stack, a plurality of the positive electrode layer and the negative electrode layer and two or more separator layers are stacked to form the electrode stack,
The method for manufacturing a battery according to claim 17, wherein in the step of forming the through hole, the through hole is collectively formed with respect to the uncovered portion of the two or more separator layers.