JP6100035B2 - battery - Google Patents

Description

  The present invention relates to a battery, and more particularly, to a battery having a structure in which a laminated electrode body is housed in a laminate outer package.

Large-capacity batteries are used as power sources for vehicles such as hybrid electric vehicles (HEV) and electric vehicles (PEV) and robots, or as backup power sources in homes and stores. Among them, a battery having a structure in which an electrode body having a laminated structure is housed in a laminate outer package is used from the viewpoint of high volume efficiency and the like.
As shown in FIG. 13A, the laminated battery according to the related art has a configuration in which an electrode body 910 is housed in a cup portion (housing space) 920 a of the laminated exterior body 920. The laminate exterior body 920 is formed by deep drawing a part of a metal laminate sheet, and the peripheral portions 920b to 920e of the cup portion 920a that accommodates the electrode body 910 are heat-sealed to achieve internal sealing. Has been made.

  The electrode body 910 is configured by alternately stacking strip-shaped positive electrode plates and negative electrode plates with a separator interposed therebetween. And the positive electrode current collection terminal 931 and the negative electrode current collection terminal 932 electrically connected to each of the positive electrode plate and the negative electrode plate are extended across the peripheral part 920d. Sealing resin bodies 941 and 942 are inserted at respective locations where the positive electrode current collecting terminal 931 and the negative electrode current collecting terminal 932 cross the peripheral edge portion 920d.

  Like the portion indicated by the arrow F in FIG. 13A, each corner portion on the side surface surrounding the cup portion 920a in the laminate outer package 920 has a round shape (R shape) having a curvature. This is for suppressing the occurrence of cracks, pinholes, and the like at the corner portion when deep drawing or the like is performed on the metal laminate sheet.

Japanese Patent No. 3822445 JP 2000-149994 A

However, as shown in FIG. 13 (b), the laminate cased battery according to the prior art, abutting portion of the bottom side boundary line L _B between the inner surface which surrounds the cup portion 920a of the laminated outer body 920 is in R form On the other hand, the corner portion of the electrode plate (the negative electrode plate 902 in FIG. 13B) has a square shape. For this reason, when the corner portion (arrow G portion) of the electrode plate is crushed by pressing or breaks through the separator, a short circuit may occur.

In order to deal with such a problem, for example, Patent Document 1 proposes that the corner portion of the electrode plate has an R shape. Thus, by making the corner portion into an R shape, the gap between the bottom side boundary line L _{B of} the inner side surface surrounding the cup portion 920a in the laminate outer package 920 and the side of the electrode plate 902 does not have to be made too wide. The occurrence of a short circuit can be suppressed.
However, in the laminate-sheathed battery, further increase in capacity is required, and it is necessary to increase the electrode plate area.

  The present invention has been made to solve the above problems, and by increasing the electrode plate area while suppressing the occurrence of a short circuit due to the R shape of the corner portion of the laminate outer package. An object is to provide a battery capable of increasing the capacity.

The battery according to the present invention has the following configuration.
The battery according to the present invention includes an electrode body and an exterior body.
The electrode body is configured by alternately laminating positive and negative plates with a separator interposed therebetween.
Each of the positive electrode plate and the negative electrode plate has a strip shape in plan view, and at least one of the positive electrode plate and the negative electrode plate (hereinafter referred to as “first electrode plate”) has at least one corner. The portion (hereinafter referred to as “first corner portion”) is a hypotenuse that extends in a direction intersecting two sides that are continuous with the first corner portion. In plan view, an inner corner portion corresponding to the first corner portion is formed with an R shape on the side surface surrounding the storage space in the exterior body.

  In the battery according to the present invention, when the exterior body and the first electrode plate are viewed in plan, the center of curvature of the inner corner portion is a point Pa, and the virtual point orthogonal to the oblique side of the first electrode plate from the point Pa. When the straight line is drawn, the intersection point with the oblique side is a point Pb, the intersection point of the virtual straight line and the inner corner portion is a point Pc, and one of the two sides of the first electrode plate corresponds to that side. When the gap between the inner side surrounding the storage space is Ga and the gap between the other side of the two sides of the first electrode plate and the inner side surrounding the storage space corresponding to the side is Gb, The straight line distance Gc between the point Pb and the point Pc satisfies the following relationship.

[Equation 1] Gc> Ga
[Expression 2] Gc> Gb
In the battery according to the present invention, a separator is interposed between the oblique side of the first electrode plate and the inner corner portion of the exterior body.

  In the battery according to the present invention, the first corner portion of the first electrode plate is configured with a hypotenuse, and is further defined so as to satisfy the relationship of [Expression 1] and [Expression 2]. A separator is inserted between the first corner portion of the first electrode plate and the inner corner portion of the exterior body. Thus, in the battery according to the present invention, it is possible to suppress the occurrence of a short circuit due to the R shape of the inner corner portion in the exterior body. Here, the separator to be inserted serves as a buffer member between the first corner portion of the first electrode plate and the inner corner portion of the exterior body, and serves to reserve the electrolyte.

  In the battery according to the present invention, since the first corner portion is not an R shape but a hypotenuse, the area of the first electrode plate is increased while satisfying both the relations [Equation 1] and [Equation 2]. Can take. For this reason, it is possible to increase the capacity. In addition, by using the hypotenuse instead of the R shape, it is possible to reduce the cost of jigs and molds for machining the first corner portion of the first pole plate, and the maintenance such as assembling becomes easy and the manufacturing cost is reduced. Reduction can be achieved.

As described above, in the battery according to the present invention, the capacity can be increased by increasing the electrode plate area while suppressing the occurrence of a short circuit due to the R shape of the corner portion of the laminate outer package.
In the battery according to the present invention, the following variations can be adopted.
In the battery according to the present invention, in the above configuration, the storage space in the exterior body is formed by recessing a part of the metal laminate sheet by deep drawing, and has a substantially rectangular bottom surface and the bottom surface of the bottom surface. It is constituted by an enclosure with four sides of a substantially rectangular shape that rises from each side. The points Pa, Pb, and Pc are defined with reference to an electrode plate (first electrode plate) disposed on the side closest to the bottom surface facing the storage space in the exterior body.

  When forming a storage space by deep drawing a part of a metal laminate sheet, it is necessary to increase the radius of curvature of the inner corner part closer to the bottom surface in consideration of stress and strain during processing. It becomes. On the other hand, in the battery according to the present invention, since the point Pa, the point Pb, and the point Pc are defined based on the first electrode plate closest to the bottom surface among the electrode plates in the electrode body, the above effect is obtained. In obtaining it, its certainty increases. In other words, by defining the first electrode plate on the bottom surface side of the electrode body that is most likely to be crushed, the electrode plate disposed on the opening side of the storage space can be crushed. Can be suppressed.

  In the battery according to the present invention, a lead electrically connected to each of the positive electrode plate and the negative electrode plate extends from one side of the electrode body in a direction intersecting with one side of the electrode body. Has been. When the first electrode plate is viewed in plan, the hypotenuses are two corner portions on the opposite side to the side where the leads extend. The occurrence of a short circuit can be effectively suppressed by applying the above configuration to the two corner portions that are likely to cause a short circuit due to a collapse of the electrode plate.

In the battery according to the present invention, a positive electrode plate is packaged in a bag-like separator, and the negative electrode plate has a larger planar size than the positive electrode plate. And about all the negative electrode plates contained in the structure of an electrode body, the 1st corner part is comprised by the hypotenuse. Thereby, it is desirable to increase the capacity while suppressing the occurrence of a short circuit due to the collapse of the electrode plate.
In the battery according to the present invention, the corner portions of all the positive plates included in the configuration of the electrode body are configured with oblique sides. Thereby, generation | occurrence | production of the short circuit resulting from crushing of a positive electrode plate etc. can also be suppressed.

  In the battery according to the present invention, the depth of the storage space is 5 mm or more. By applying the configuration of the present invention to a high-capacity battery having a storage space depth of 5 mm or more, the above effects can be remarkably obtained. However, application of the configuration of the present invention to a battery having a storage space depth of less than 5 mm is not excluded.

It is a schematic plan view which shows the external appearance structure of the laminate-clad battery 1 which concerns on embodiment of this invention. It is a schematic plan view (partially cutaway view) showing the electrode body 10 formed by joining the current collecting terminals 31 and 32. (A) is a schematic perspective view which shows the structure of the insulating spacer 40, (b) is a schematic side view which shows the mounting form of the insulating spacer 40 with respect to the electrode body 10. FIG. 3 is a schematic plan view showing a relationship between a bottom portion in a laminate outer package 20 and a corner portion of a negative electrode plate 102 in an electrode body 10. FIG. 3 is a schematic cross-sectional view showing an arrangement form of a separator 103 in a bottom portion of a laminate exterior body 20. FIG. 3 is a schematic plan view showing a positional relationship between a bottom portion in a laminate outer package 20 and a corner portion of a negative electrode plate 102 in an electrode body 10. FIG. (A) is a schematic plan view showing the positive electrode plate 101, and (b) is a schematic plan view showing the negative electrode plate 102. FIG. 6 is a schematic plan view showing a process of packing the positive electrode plate 101 with a separator 103. 3 is a schematic plan view showing a positive electrode bag body 108 in which a positive electrode plate 101 is packed in a bag made of a separator 103. FIG. (A) is a schematic perspective view showing a process of alternately laminating positive electrode bag bodies 108 and negative electrode plates 102, and (b) is a schematic plan view showing electrode body 10. (A) is a schematic plan view which shows the arrangement | positioning relationship between the bottom part of the laminate exterior body 20 in the laminate exterior battery which concerns on a modification, and the corner part of the negative electrode plate 202 in an electrode body, (b) is a reference example. It is a schematic plan view which shows the arrangement | positioning relationship between the bottom part of the laminate exterior body 20, and the corner part of the negative electrode plate 302 in an electrode body in the laminated exterior battery which concerns. It is a schematic top view which shows the corner part shape of the negative electrode plate 502 in the laminated external battery which concerns on an Example, and the corner partial shape of the negative electrode plate 402 in the laminated external battery which concerns on a reference example. (A) is a top view which shows the external appearance structure of the laminated exterior battery which concerns on a prior art, (b) is the bottom part of the laminated exterior body 920 when the arrow F part of (a) is seen from the battery inner side. FIG. 6 is a plan view showing the relationship between and the corner portion of the negative electrode plate 902 of the electrode body 910.

Below, the form for implementing this invention is demonstrated using drawing. In addition, the specific example shown below is an example used for easily explaining the configuration of the present invention and the operations and effects produced from the configuration, and the present invention is not limited to the components essential to the invention. The following specific examples are not limited at all.
[Embodiment]
1. Appearance Configuration of Laminated Exterior Battery 1 The appearance configuration of the laminate exterior battery 1 according to the embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, a laminate-clad battery 1 according to an embodiment of the present invention includes a laminate-clad body 20 obtained by processing a metal laminate sheet. The laminate exterior body 20 includes a cup portion 20a that is a storage space for storing the electrode body, and sealing portions 20b, 20c, 20d, and 20e formed by thermally welding the outer edges thereof. The cup part 20a is internally sealed by forming the sealing parts 20b, 20c, 20d, and 20e.

The cup portion 20a in the laminate outer package 20 has a flat and substantially rectangular shape, and is surrounded by four side surfaces and a bottom surface on the front side of the paper. The abutting portion (each inner corner portion) between the inner side surfaces has an R (round) shape with a curvature.
A positive electrode current collector terminal 31 and a negative electrode current collector terminal 32 extend from the laminate outer package 20 across the sealing portion 20d. Sealing resin bodies (tab resins) 41 and 42 are inserted between the positive electrode current collecting terminal 31 and the negative electrode current collecting terminal 32 across the sealing portion 20d and the inner surface of the laminate outer package 20. Yes.

2. Electrode body 10
The structure of the electrode body 10 accommodated in the cup part 20a of the laminate outer package 20 will be described with reference to FIG.
As shown in FIG. 2, the electrode body 10 has a configuration in which a substantially rectangular positive electrode plate 101 and a negative electrode plate 102 are alternately stacked with a separator 103 interposed therebetween, and has a substantially rectangular planar shape as a whole. It has a laminated part. And the insulating sheet 109 is laminated | stacked on the both outer parts of the lamination direction (direction orthogonal to a paper surface) in the electrode body 10, and the insulating tape 104 is affixed on the multiple places of the outer edge of a lamination | stacking part. In the electrode body 10, electrode plate displacement is suppressed by sticking the insulating tape 104.

  From the laminated portion of the electrode body 10, a positive electrode lead 105 and a negative electrode lead 106 that are electrically connected to the positive electrode plate 101 and the negative electrode plate 102 respectively extend upward in the Y-axis direction. The positive electrode lead 105 is connected to the positive electrode current collecting terminal 31 in a state where each extending end portion is converged, and the negative electrode lead 106 is also connected to the negative electrode current collecting terminal 32 in a state where each extending end portion is converged. Yes. The sealing resin bodies 41 and 42 are attached to the positive electrode current collector terminal 31 and the negative electrode current collector terminal 32, respectively.

In addition, in the electrode body 10 according to the present embodiment, the thickness in the laminated portion (thickness in the direction perpendicular to the paper surface of FIG. 2) is 5 mm or more. Thus, the laminate-clad battery 1 according to the present embodiment is a high-capacity battery, and is intended for use as a power source for a robot, an electric vehicle, or a backup power source.
3. Insulating spacer 40
In the laminated exterior battery 1 according to the embodiment of the present invention, the insulating spacer 40 and the electrolytic solution are accommodated in the cup portion 20a of the laminated exterior body 20 in addition to the electrode body 10. Among these, the structure of the insulating spacer 40 will be described with reference to FIG.

As shown in FIG. 3A, the insulating spacer 40 has a configuration in which two rectangular wall portions 40a and 40b having substantially the same length in the X-axis direction are integrally formed sharing a long side. . In other words, the YZ cross-sectional shape is L-shaped and has an elongated shape in the X-axis direction.
The insulating spacer 40 is formed using, for example, a resin material such as polypropylene or insulating paper.

As shown in FIG. 3B, the bottom surface 10 a of the electrode body 10 (the outer surface of one insulating sheet 109) and the positive electrode current collecting terminal 31 in the cup portion 20 a (see FIG. 1) of the laminate exterior body 20. The negative electrode current collector terminal 32 is mounted so as to circumscribe each connection region 31a (the negative electrode current collector terminal 32 is not shown).
As shown in FIG. 3A, an insulating tape 43 is stuck on the opposite side of the focused portion of the positive electrode lead 105 from the positive electrode current collecting terminal 31. Although not shown, the insulating tape 43 is similarly attached to the corresponding portion of the negative electrode lead 106.

4). Arrangement of Electrode Body 10 and Laminate Exterior Body 20 The arrangement relationship between the electrode body 10 and the laminate exterior body 20 at the bottom portion of the laminate exterior battery 1 will be described with reference to FIGS. 4 and 5. 4 is a schematic plan view of a portion indicated by an arrow A in FIG. 1 as viewed from the inside of the cup portion 20a, and FIG. 5 is a schematic cross-sectional view showing a CC cross section of the arrow B portion in FIG.

As shown in FIG. 4, the negative electrode plate 102 in the electrode body 10 is configured such that the corner portion on the bottom side (the Y axis lower side in FIG. 2) is a hypotenuse (C surface). In contrast, the inner corner portion of the bottom side boundary line L _B of the inner surface which surrounds the cup portion 20a of the laminate casing 20 is configured drives out round (R) shape.
Although not shown, in the laminated battery 1 according to the present embodiment, the bottom corner portion of the positive electrode plate 101 (see FIG. 2) is also formed on the hypotenuse (C surface). Yes. However, with respect to the separator 103 (see FIG. 2), the corner portion remains in a square shape and extends from the corner portion formed by the oblique side of the negative electrode plate 102.

As shown in FIG. 5, a bundle of separators 103 is narrowly inserted into the gap portion (arrow D portion) between the positive electrode plate 101 and the negative electrode plate 102 and the inner side surface of the laminate outer package 20 at the bottom corner portion. ing. Thereby, the buffer part of the positive electrode plate 101 and the negative electrode plate 102 with respect to the inner surface of the laminate exterior body 20 is provided.
In addition, in the laminate-clad battery 1 according to the present embodiment, the laminate-clad body 20 is composed of a laminate member (lid side member) 201 and a laminate member (cup side member) 202, and a cup portion 20a (see FIG. 1). Is formed by subjecting the laminate member 202 to deep drawing. And the clearance gap part becomes large as it goes to the lamination member 201 side from the bottom face side of the cup part 20a.

The separator 103 in the electrode body 10 is closely inserted also on the laminate member (lid side member) 201 side in the gap portion. FIG. 5 is a schematic view, and in reality, the state is more closely confined.
5. Definition of the hypotenuse of the corner portions of the positive electrode plate 101 and the negative electrode plate 102 A method of defining the hypotenuse of the corner portions of the positive electrode plate 101 and the negative electrode plate 102 will be described with reference to FIG. In FIG. 6, only the relationship between the negative electrode plate 102 and the laminate outer package 20 is shown, and the positive electrode plate 101 is not shown, but the positive electrode plate 101 is basically defined in the same manner. .

As shown in FIG. 6, the negative electrode plate 102 has a C plane (C ₁ ) such that the oblique side L _{6 of the} corner portion intersects the side sides L ₁ and L ₃ that are continuous with each other at 45 °. It is formed with. Here, C _1, for example, are provided at C2 (chamfer at 2 mm). In other words, the lengths of the line segments of the virtual straight lines L ₂ and L ₄ extending from the side edges L ₁ and L ₃ are both 2 mm.
Next, both the boundary lines L _B and L _{U on} the inner surface of the cup portion 20a (see FIG. 1) in the laminate outer package 20 are formed with round (R) corner portions (inner corner portions). . Of these, there is the boundary line L _B of the bottom surface side surrounding the cup portion 20a, the radius of curvature R ₁ at its corner portion, for example, is set to 3 mm.

The center of curvature of the corner portion at the boundary line L _B is a point P _1. Next, a perpendicular line is drawn from the point P ₁ to the hypotenuse L ₆ of the negative electrode plate 102 (virtual line L ₅ ). Then, an intersection between the virtual line L ₅ and hypotenuse L ₆ and the point P _3, the intersection of the boundary line L _B and the point P _4. The hypotenuse L ₆ is arranged at an angle of 45 ° with respect to the side sides L ₁ and L ₃ , so that the virtual line L ₅ also passes through the point P ₂ that is the intersection of the virtual straight lines L ₂ and L _4. It will be.

In the laminate-cased battery 1 according to this embodiment, the sides L ₁ and G ₁ a gap between the boundary line L _B, sides L ₂ and G ₂ the gap between the boundary line L _B, the point P ₃ and the point P _When the linear distance to ₄ is G ₃ , the corner portions of the positive electrode plate 101 and the negative electrode plate 102 are set so as to satisfy the following relationship.
[Equation 3] G ₃ > G ₁
[Equation 4] G ₃ > G ₂
6). Effect In the laminate-clad battery 1 according to the present embodiment, it is possible to suppress the occurrence of a short circuit due to the R shape of the inner corner portion on the bottom side of the laminate-clad body 20. This is because the corners on the bottom side of the positive electrode plate 101 and the negative electrode plate 102 are set as the hypotenuse (C surface) so as to satisfy the relationship of the above [Equation 3] and [Equation 4]. At this time, the separator 103 which is narrowly inserted into the corner portion on the bottom side serves as a buffer member between each corner portion (slanted side) of the positive electrode plate 101 and the negative electrode plate 102 and the inner corner portion of the laminate outer package 20. And serves as a region for reserving (retaining liquid) the electrolyte.

Further, in the laminated battery 1, the corners on the bottom side of the positive electrode plate 101 and the negative electrode plate 102 are not round (R) shapes but oblique sides (C surfaces), so the above [Equation 3] and [Equation 4] While satisfying these two relationships, the area of the square electrode plate can be increased, and the capacity can be increased.
In addition, by using the hypotenuse (C surface) instead of the R shape, it is possible to reduce the cost of jigs and tools for processing each corner portion of the positive electrode plate 101 and the negative electrode plate 102, and maintenance such as assembly is also possible. It becomes easy and reduction of manufacturing cost can be aimed at.

Therefore, in the laminate-clad battery 1 according to the present embodiment, the electrode plate areas of the positive electrode plate 101 and the negative electrode plate 102 while suppressing the occurrence of a short circuit due to the R shape of the inner corner portion on the bottom side of the laminate outer package 20. By increasing the (opposite area), the capacity can be increased.
7). Manufacturing Method Next, a manufacturing method of the laminated battery 1 according to the present embodiment will be described with reference to FIGS. It should be noted that the drawings attached to the present specification are schematic, and dimensions and the like in the drawings are different from actual ones including ratios.

(1) Preparation of positive electrode plate 101 After applying a positive electrode active material to the core which is a positive electrode collector and drying it, it is compressed using a roller until the thickness becomes 0.1 mm. Then, the positive electrode plate 101 on which the active material application portion 101a as shown in FIG. 7A is formed is manufactured by cutting with a height H ₁ of 115 mm and a width W _{1 of} 115 mm.

As shown in FIG. 7 (a), in the positive electrode plate 101, the active material is not applied, and the positive electrode lead 105 having a height H ₂ of 20 mm and a width W ₂ of 30 mm is connected to the active material application portion. It is formed so as to extend upward from 101a in the Y-axis direction.
Further, in the positive electrode plate 101, chamfering is performed at C2 on both corner portions on the lower side in the Y-axis direction opposite to the side where the positive electrode lead 105 is extended (enclosed by a two-dot chain line in FIG. 7A). Part).

Here, in the present embodiment, for example, an aluminum foil having a thickness of 15 μm can be used as the core used for manufacturing the positive electrode plate 101. In forming the active material application portion 101a, first, 90 parts by weight of LiCoO ₂ , 5 parts by weight of carbon black as a conductive agent, 5 parts by weight of polyvinylidene fluoride as a binder, An N-methyl-2-pyrrolidone (NMP) solution as a solvent is mixed to prepare a positive electrode slurry. And this slurry for positive electrodes is apply | coated to both the main surfaces of a core. When drying, the temperature and time are set so that the solvent can be removed. Thereby, the active material application part 101a can be formed.

In addition to the above LiCoO ₂ , for example, LiNiO ₂ , LiMnO ₄ , or a composite thereof can be used as the positive electrode active material.
Further, the positive electrode lead 105 in the positive electrode plate 101 may be formed by bonding a metal foil separate from the core body to the core body, or a part of the core body may be directed upward in the Y-axis direction. It is good also as forming so that it may extend.

(2) Production of negative electrode plate 102 After applying and drying a negative electrode active material to the core which is the negative electrode current collector, the core is compressed using a roller until the thickness becomes 0.08 mm. Then, by cutting with a height H ₃ of 120 mm and a width W _{3 of} 120 mm, the negative electrode plate 102 on which the active material application portion 102a as shown in FIG. 7B is formed is produced.

As shown in FIG. 7B, also in the negative electrode plate 102, the negative electrode lead 106 which is an uncoated portion of the active material and has a height H ₄ of 20 mm and a width W ₄ of 30 mm is applied with the active material. It is formed so as to extend upward from the portion 102a in the Y-axis direction.
In addition, also in the negative electrode plate 102, chamfering is performed at C2 on both corners on the lower side in the Y-axis direction opposite to the side where the negative electrode lead 106 is extended (indicated by a two-dot chain line in FIG. 7B). Enclosed part).

  Here, in the present embodiment, for example, a copper (Cu) foil having a thickness of 10 μm can be used as the core used for manufacturing the negative electrode plate 102. In forming the active material coated portion 102a, first, 95 parts by weight of graphite powder, 5 parts by weight of styrene butadiene rubber (SBR) as a binder, and pure water as a solvent are mixed to form a negative electrode. A slurry is prepared. And this slurry for negative electrodes is apply | coated to both the main surfaces of a core. When drying, the temperature and time are set so that the solvent can be removed. Thereby, the active material application part 102a can be formed.

In addition, as a material of a negative electrode active material, natural graphite, artificial graphite, etc. can be used, for example.
Similarly to the positive electrode lead 105 in the positive electrode plate 101, the negative electrode lead 106 in the negative electrode plate 102 can be separated from the core body, and a part of the core body extends upward in the Y-axis direction. It can also be formed.

(3) Packing of Positive Electrode Plate 101 As shown in FIG. 8, both main surfaces of the produced positive electrode plate 101 are covered with two separators 103, and as shown in FIG. Welded portion 103a). The separator 103 to be used is made of polypropylene, and as shown in FIG. 8, a separator having a height H ₅ of 120 mm, a width W ₅ of 120 mm, and a thickness of 30 μm is used. In addition, as shown in the part (arrow E part) enclosed with the dashed-two dotted line of FIG. 8, about the corner part of the bottom side of the separator 103, it does not cut.

As shown in FIG. 9, an insulating layer 107 may be formed between the inner surface of the separator 103 and the positive electrode plate 101 in a portion where the positive electrode lead 105 extends from the upper side of the separator 103.
As described above, the positive electrode bag 108 can be manufactured.
(4) Production of Electrode Body 10 As shown in FIG. 10A, the positive electrode bag bodies 108 and the negative electrode plates 102 are alternately stacked, and the insulating sheets 109 having the same size as the separator 103 are stacked on the upper and lower sides. The insulating sheet 109 is formed using, for example, polypropylene (PP).

In this embodiment, 25 positive electrode bags 108 and 26 negative electrode plates 102 are used to form the electrode body 10.
Next, as illustrated in FIG. 10B, the insulating tape 104 is attached to a plurality of locations on the outer edge portion of the laminate in which the positive electrode bag body 108, the negative electrode plate 102, and the insulating sheet 109 are laminated. The insulating tape 104 is attached for the purpose of shape retention.

The electrode body 10 is completed as described above.
(5) Focusing of positive and negative electrode leads 105 and 106 and joining of positive and negative electrode current collecting terminals 31 and 32 As shown in FIG. 3B, the positive electrode lead 105 and the negative electrode lead 106 of the electrode body 10 manufactured as described above. And the positive and negative current collecting terminals 31 and 32 are joined to each of the converged connection regions 31a by ultrasonic welding (the illustration of the side of the negative electrode lead 106 is omitted).

The positive electrode current collecting terminal 31 is, for example, an aluminum plate having a thickness of 0.4 mm, and the negative electrode current collecting terminal 32 is, for example, a copper plate having a thickness of 0.4 mm.
The positive and negative current collector terminals 31 and 32 are bent as shown in FIG. 3 (b) for storage in the laminate outer package 20, and further, in each connection region 31a, the current collector terminals 31, An insulating tape 43 is stuck on the side opposite to the side where 32 is joined. Further, an insulating spacer 40 is attached.

(6) Storage in Laminated Outer Body 20 As described above, the electrode body 10 to which the positive and negative current collecting terminals 31 and 32 are connected and the insulating spacer 40 is mounted is connected to the cup side member 202 cup in the laminated outer body 20. It is stored in the part 20a. The cup part 20a in the cup side member 202 is formed by deep drawing a part of the metal laminate sheet.

Then, the opening side of the cup side member 202 is covered with the lid side member 201, and the outer edge portions of the three sides excluding the outer edge portion where the positive and negative electrode current collecting terminals 31 and 32 extend are thermally welded (sealing portions 20b, 20c, 20e).
(7) Injection and sealing of electrolyte solution Next, the electrolyte solution is injected into the cup portion 20a from the outer edge portion of the laminate outer package 20 from which the positive and negative electrode current collecting terminals 31 and 32 are extended. As an electrolytic solution, for example, LiPF ₆ is dissolved at a rate of 1 M (mol / L) in a mixed solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are mixed at a volume ratio of 30:70. The liquid can be used.

Then, after the electrolyte solution is poured, the remaining outer edge portion of one side is thermally welded (sealing portion 20d).
As described above, the laminated battery 1 is completed.
[Modification]
The structure of the laminated exterior battery which concerns on a modification is demonstrated using Fig.11 (a). In the laminated battery according to this modification, the chamfering configuration of the corner portions on the bottom sides of the positive electrode plate and the negative electrode plate in the electrode body is different. The rest is the same as the above embodiment.

As shown in FIG. 11 (a), the negative electrode plate 202 of the laminate-sheathed cell according to this modification also, the corner portion of the bottom side is a hypotenuse L _16. Here, the hypotenuse L ₁₆ is oblique to the side L ₁₁ and the base L ₁₃ in the same manner as in the above embodiment, but the intersection angle is not 45 °. In other words, in the above embodiment, the lengths of the virtual straight lines L ₂ and L ₄ are both 2 mm, but in this modification, the height H ₁₁ and the width W ₁₁ of the hypotenuse L ₁₆ are Are not the same, and H ₁₁ > W ₁₁ or H ₁₁ <W ₁₁ .

In this modification, the center of curvature of the point P ₁₁ of the corner portion at the boundary line L _B of the bottom surface side surrounding the cup portion 20a, dropping a perpendicular against hypotenuse L ₁₆ of the negative electrode plate 202 from the point P ₁₁ (imaginary line L ₁₅₎ when, when the virtual line L ₁₅ and the hypotenuse point of intersection between L ₁₆ P _13, the point P ₁₄ to the intersection of the boundary line L _B, the gap G _11, G _12, G _13, the following relationship Meet.
[Equation 5] G ₁₃ > G ₁₁
[Equation 6] G ₁₃ > G ₁₂
Although not shown, a separator is tightly inserted between the hypotenuse L _{16 of the} negative electrode plate 202 and the inner surface of the cup portion 20a of the laminate outer package 20 at the bottom corner portion. Yes.

Here, with respect to the positive electrode plate, the corner portion on the bottom side is constituted by a hypotenuse with the same relationship. However, as described above, the positive electrode plate is set to have a smaller electrode plate size than the negative electrode plate 202.
The angle formed by the hypotenuse L ₁₆ with respect to the side L ₁₁ and the side L ₁₃ may be defined so that the electrode plate area is maximized in consideration of the plate collapse mode.

(Reference example)
As shown in FIG. 11B, from the viewpoint of suppressing the collapse of the electrode plate at the bottom corner portion, the corner portion of the electrode plate (the negative electrode plate 302 in FIG. 11B) is rounded (R ) It is also possible to use a shape. For example, the corner portion on the bottom side of the negative electrode plate 302 can be a curve L ₂₆ having a radius R ₂₂ centered at the point P ₅₂ . Then, the inner surface which surrounds the cup portion 20a of the laminate casing 20, a corner portion of the bottom side, the curve of radius R ₂₁ centered at point P _21. For example, the radius R ₂₁ and the radius R ₂₂ satisfy the following relationship.

[Equation 7] R ₂₁ <R ₂₂
At this time, when considering an imaginary straight line connecting the point P ₂₁ and the point P ₂₅ , an intersection point with the curve L _{26 of the} negative electrode plate 302 is a point P ₂₃ , and an intersection point with the inner surface of the laminate outer package 20 is a point P ₂₄ . therebetween linear distance when a G _23, and satisfy the following relationship.
[Number 8] G _23> G ₂₁
[Equation 9] G ₂₃ > G ₂₂
Note that the definitions of G ₂₁ and G ₂₂ are the same as G ₁ , G ₂ , G ₁₁ , and G _{12 in} the above-described embodiments and modifications.

In the laminated exterior battery according to the reference example, the corner portion on the bottom side is formed with a curve on the positive electrode plate based on the same concept.
As described above, in the laminated exterior battery including the positive electrode plate and the negative electrode plate 302, occurrence of a short circuit due to the collapse of the corner portion on the bottom side of the positive electrode plate and the negative electrode plate 302 is the same as in the above-described embodiment and modification. It is suppressed.

However, from the viewpoint of increasing the area of the electrode plate, there is a problem compared to the case where the corner portion on the bottom side of the electrode plate is formed with the hypotenuses L ₆ and L ₁₆ as in the above-described embodiments and modifications. Will remain.
FIG. 12 is a schematic diagram in which the bottom corner portion when the gap G ₃₃ is the same is constituted by the hypotenuse L ₃₃ and the case where the corner portion is constituted by the curve L ₃₂ . The hypotenuse L ₃₃ is configured by the C plane (C ₃ ) as in the above embodiment, and the curve L ₃₂ has a curvature of a radius R ₃₂ centered on the point P ₃₅ . The gap G ₃₁ between P ₃₃ and the point P ₃₄ satisfies the following relationship with respect to the gaps G ₃₂ and G ₃₃ .

[Equation 10] G ₃₃ > G ₃₁
[Equation 11] G ₃₃ > G ₃₂
In addition, it is assumed that the corner portion on the bottom side of the inner side surface surrounding the cup portion in the laminate outer package is configured with an R shape having a radius R ₃₁ with the point P ₃₁ as the center.
As shown in FIG. 12, toward the plate 402 to constitute a corner portion of the bottom side hypotenuse L _33, compared to corners of the bottom side electrode plate configured in R shape, the amount corresponding area of the region 502 Can be wide. That is, the area of the electrode plate can be increased by the hatched portion A _{502 in} FIG.

As described above, when the corner portion on the bottom side of the electrode plate is configured with a hypotenuse, the area of the electrode plate can be increased as compared with the case of configuring with an R shape, and a large battery capacity can be ensured. it can.
[Other matters]
In the above-described embodiment and modification, the bottom corner portion of the positive electrode plate and the negative electrode plate is formed by the oblique side, but the bottom corner portion of one of the electrode plates (for example, the negative electrode plate). It is good also as comprising only a hypotenuse. In this case, if the bottom-side corner portion is configured with a hypotenuse for the larger electrode plate area, problems such as short-circuiting due to electrode plate collapse are unlikely to occur.

  Further, as shown in FIG. 1 and the like, in the above embodiment, both the positive electrode current collecting terminal 31 and the negative electrode current collecting terminal 32 extend upward in the Y-axis direction across the sealing portion 20d of the laminate outer package 20. Although the extended configuration is adopted, a configuration in which the positive electrode current collector terminal and the negative electrode current collector terminal are respectively extended across different sealing portions may be employed. For example, the positive electrode current collector terminal extends upward in the Y-axis direction across the sealing portion 20d, and the negative electrode current collector terminal extends in the Y-axis direction downward across the sealing portion 20e. You can also.

In the case of adopting such a form, in each of the positive electrode plate and the negative electrode plate, if the corner portion on the side opposite to the side where the current collecting terminal is extended is configured with a hypotenuse, the same effect as described above Can be obtained.
In the above embodiment, the bottom corner portion of the negative electrode plate 102 is the C plane of C2, and the corresponding corner portion of the laminate exterior body 20 is R3. However, the relationship is not limited to this. However, it is desirable that the value C of the C plane and the radius of curvature R satisfy the following relationship from the viewpoint of setting the electrode plate area large while suppressing the collapse of the electrode plate.

[Equation 12] C ≦ R
In the above embodiment, the laminate exterior body 20 is configured by joining the two members of the lid side member 201 and the cup side member 202. However, it may be configured by folding a single member. it can.
In addition, the materials used, dimensions, and the like of each member shown in the above embodiment are shown as an example, and can be appropriately selected.

Further, in the above embodiment and modification, the dimension of the hypotenuse of the corner portion on the bottom side of the electrode plate is defined with reference to the bottom surface surrounding the cup portion of the laminate outer package, but the present invention is not limited thereto. The shape of the hypotenuse of the corner portion on the bottom side of the electrode plate can also be defined based on the edge shape of the opening side portion of the cup portion.
Further, in the above-described embodiment and modification, for all the positive plates and negative plates included in the configuration of the electrode body, the corner portion on the bottom side is the hypotenuse, but the corner portion of at least some of the polar plates is the hypotenuse. It can also be. Specifically, with respect to the inner surface surrounding the cup portion in the laminate outer package, the corner portion can be a hypotenuse only for the electrode plate disposed near the bottom surface where the curvature increases.

  The present invention is useful for realizing a large-capacity battery used as a power source for a robot, an electric vehicle, or the like, or as a backup power source.

1. Laminated exterior battery 10. Electrode body 20. Laminated exterior body 31. Positive electrode current collecting terminal 32. Negative electrode current collector terminal 40. Insulating spacer 41, 42. Sealing resin body 43. Insulating tape 101. Positive plate 102,202,302,402,502. Negative electrode plate 103. Separator 104. Insulating tape 105. Positive electrode lead 106. Negative electrode lead 107. Insulating layer 108. Positive electrode bag 109. Insulating sheet 201. Lid side member 202. Cup side member

Claims (6)

An electrode body in which a positive electrode plate and a negative electrode plate are alternately laminated with a separator interposed therebetween;
It is composed of a metal laminate sheet and has a storage space corresponding to the external shape of the electrode body,
An exterior body internally sealed in a state where the electrode body is stored in the storage space;
With
Each of the positive electrode plate and the negative electrode plate has a strip shape in plan view,
At least one electrode plate of the positive electrode plate and the negative electrode plate has a hypotenuse extending at least one corner portion in a direction intersecting with two sides continuing to the corner portion,
In plan view,
The side surface surrounding the storage space in the exterior body has an inner corner portion corresponding to the at least one corner portion formed with an R shape,
The center of curvature of the inner corner portion is a point Pa, the intersection point with the hypotenuse when a virtual straight line orthogonal to the hypotenuse is drawn from the point Pa is the point Pb, and the intersection of the virtual straight line and the inner corner portion is Let Ga be the gap between one side of the two sides and the inner side surface surrounding the storage space corresponding to the side, and store the other side of the two sides and the side corresponding to the side. When the gap between the inner surface surrounding the space is Gb,
The linear distance Gc between the point Pb and the point Pc is
Gc> Ga
Gc> Gb
Satisfy both relationships
and,
The battery is characterized in that a bundle of the separators is stacked between the oblique side and the inner corner portion. The storage space is formed by recessing a part of the metal laminate sheet by deep drawing, and has a substantially rectangular bottom surface and substantially rectangular four side surfaces rising from each side of the bottom surface. It is composed of Go
The battery according to claim 1, wherein the point Pa, the point Pb, and the point Pc are defined based on an electrode plate disposed on a side closest to a bottom surface facing the storage space. From one side of the electrode body, a lead electrically connected to each of the positive electrode plate and the negative electrode plate extends in a direction intersecting with one side of the electrode body. ,
When the at least one electrode plate is viewed in plan, the hypotenuse is the two corner portions opposite to the side from which the lead extends. 2. The battery according to 2. The positive electrode plate is packaged in a bag-like separator,
The negative electrode plate has a larger planar size than the positive electrode plate,
The battery according to any one of claims 1 to 3, wherein the corner portion is formed of a hypotenuse for all of the negative plates included in the configuration of the electrode body. 5. The battery according to claim 4, wherein the corner portion is formed of a hypotenuse for all the positive plates included in the configuration of the electrode body. The battery according to any one of claims 1 to 4, wherein a depth of the storage space is 5 mm or more.

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