Battery exterior body, battery, battery pack, and method for manufacturing battery exterior body

Abstract

To provide a battery outer package that is applicable to the purpose of feeding large current, a battery, a battery pack, and a manufacturing method for a battery outer package.SOLUTION: A battery outer package 4 includes a first multilayer body 1 and a second multilayer body 2. Between the first multilayer body 1 and the second multilayer body 2, a housing space 17 is formed. A first opening 18 of a first resin layer 12 is formed so that a first metal layer 11 can be brought into contact with a positive electrode 32 of a battery main body 3. A second opening 28 of a second resin layer 22 is formed so that a second metal layer 21 can be brought into contact with a negative electrode 33 of the battery main body 3. A region of an outer surface of the first metal layer 11 that overlaps with an electrode surface 32a of the positive electrode 32 in a thickness direction is a first external electrode 34. A region of an outer surface of the second metal layer 21 that overlaps with an electrode surface 33a of the negative electrode 33 in a thickness direction is a second external electrode 35. At least one of a first outer surface region 15a that is flush with the first external electrode 34 and a second outer surface region 21c that is flush with the second external electrode 35 is exposed in a manner of being capable of conduction in the entire range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery exterior, a battery, a battery pack, and a method for manufacturing a battery exterior. [Background technology]

[0002] In recent years, secondary batteries such as lithium ion batteries have been attracting attention as storage batteries (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6649026 Summary of the Invention [Problem to be solved by the invention]

[0004] Such batteries have a high contact resistance at the electrodes, so it can be difficult to pass a large current through them.

[0005] An object of one aspect of the present invention is to provide a battery exterior body, a battery, a battery pack, and a method for manufacturing a battery exterior body that can be used in applications where a large current flows. [Means for solving the problem]

[0006] One aspect of the present invention includes a first laminate in which a first metal layer and a first insulating resin layer are laminated, and a second laminate in which a second metal layer and a second insulating resin layer are laminated, the first laminate and the second laminate being stacked such that the first resin layer and the second resin layer face each other, and a storage space for storing a battery main body having a positive electrode and a negative electrode is formed between the first laminate and the second laminate, a first opening exposing an inner surface of the first metal layer is formed in a region of the first resin layer facing the storage space, and a second opening exposing an inner surface of the second metal layer is formed in a region of the second resin layer facing the storage space, and the first opening is such that the exposed inner surface of the first metal layer is directly or indirectly the second opening is formed so that the exposed inner surface of the second metal layer can come into direct or indirect contact with the negative electrode; a region of the outer surface of the first metal layer that overlaps in the thickness direction with the electrode surface of the positive electrode facing the first metal layer is a first external electrode; a region of the outer surface of the second metal layer that overlaps in the thickness direction with the electrode surface of the negative electrode facing the second metal layer is a second external electrode; and at least one of a first outer surface region of the outer surface of the first metal layer that is flush with the first external electrode and a second outer surface region of the outer surface of the second metal layer that is flush with the second external electrode is exposed over the entire area to be conductive.

[0007] It is preferable that at least a portion of the portion including the outer peripheral edge of the first resin layer is formed to protrude outward from the outer peripheral edge of the first metal layer, and that at least a portion of the portion including the outer peripheral edge of the second resin layer is formed to protrude outward from the outer peripheral edge of the second metal layer.

[0008] It is preferable that the reference laminate, which is at least one of the first laminate and the second laminate, has a concave molded portion shaped like a container that bulges in a direction away from the other opposing laminate, the storage space is formed between the concave molded portion and the opposing laminate, the concave molded portion has a base wall portion and a peripheral wall portion extending from the periphery of the base wall portion toward the opposing laminate, and the first opening or the second opening is formed in the base wall portion.

[0009] Another aspect of the present invention provides a battery comprising the battery outer casing and a battery main body housed in the housing space, wherein the positive electrode is in direct or indirect conductive contact with the inner surface of the first metal layer exposed by the first opening, and the negative electrode is in direct or indirect conductive contact with the inner surface of the second metal layer exposed by the second opening.

[0010] Yet another aspect of the present invention provides a battery pack comprising a plurality of the batteries, the plurality of batteries including a stacked first battery and a stacked second battery, and the second external electrode of one of the first battery and the second battery being in conductive contact with the first external electrode of the other battery.

[0011] Yet another aspect of the present invention includes a first lamination step of laminating a first insulating resin layer having a first opening and a first metal layer to obtain a first laminate; a second lamination step of laminating a second insulating resin layer having a second opening and a second metal layer to obtain a second laminate; and an assembly step of laminating the first laminate and the second laminate with the first resin layer and the second resin layer facing each other so that a storage space for storing a battery main body having a positive electrode and a negative electrode is formed between the first laminate and the second laminate, wherein in the assembly step, the first laminate and the second laminate are laminated such that the first metal layer exposed by the first opening and the second metal layer exposed by the second opening face the storage space, and the first opening is the second opening is formed so that the exposed inner surface of the first metal layer can come into direct or indirect contact with the positive electrode, the second opening is formed so that the exposed inner surface of the second metal layer can come into direct or indirect contact with the negative electrode, a region of the outer surface of the first metal layer that overlaps in the thickness direction with the electrode surface of the positive electrode facing the first metal layer is a first external electrode, and a region of the outer surface of the second metal layer that overlaps in the thickness direction with the electrode surface of the negative electrode facing the second metal layer is a second external electrode, and at least one of a first outer surface region of the outer surface of the first metal layer that is flush with the first external electrode and a second outer surface region of the outer surface of the second metal layer that is flush with the second external electrode is exposed over the entire area so as to be conductive.

[0012] Yet another aspect of the present invention is a battery comprising a first laminate in which a first metal layer and a first insulating resin layer are laminated, and a second laminate in which a second metal layer and a second insulating resin layer are laminated, the first laminate and the second laminate being stacked such that the first resin layer and the second resin layer face each other, a storage space for storing a battery body having a positive electrode and a negative electrode is formed between the first laminate and the second laminate, a first opening exposing an inner surface of the first metal layer is formed in a region of the first resin layer facing the storage space, and a front opening is formed in a region of the second resin layer facing the storage space. The present invention provides a battery exterior body in which a second opening is formed to expose the inner surface of the second metal layer, the first opening is formed so that the exposed inner surface of the first metal layer can directly or indirectly come into contact with the positive electrode, the second opening is formed so that the exposed inner surface of the second metal layer can directly or indirectly come into contact with the negative electrode, at least a part of a portion including the outer peripheral edge of the first resin layer is formed to protrude outward from the outer peripheral edge of the first metal layer, and at least a part of a portion including the outer peripheral edge of the second resin layer is formed to protrude outward from the outer peripheral edge of the second metal layer. [Effects of the Invention]

[0013] One aspect of the present invention provides a battery exterior body, a battery, a battery pack, and a method for manufacturing a battery exterior body that can be used in applications where a large current flows. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a battery using a battery exterior body of a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the battery exterior body of the first embodiment. [Figure 3] 3A to 3C are process diagrams illustrating a method for manufacturing a battery exterior body according to the first embodiment. [Figure 4] This is a process diagram following the previous figure. [Figure 5] This is a process diagram following the previous figure. [Figure 6] This is a process diagram following the previous figure. [Figure 7] This is a process diagram following the previous figure. [Figure 8] This is a process diagram following the previous figure. [Figure 9] This is a process diagram following the previous figure. [Figure 10] This is a process diagram following the previous figure. [Figure 11] 1 is a cross-sectional view of a battery pack according to an embodiment. [Figure 12] FIG. 4 is a cross-sectional view of a battery using a battery exterior body of a second embodiment. [Figure 13] FIG. 3 is a cross-sectional view of a first modified example of the battery exterior body of the first embodiment. [Figure 14] FIG. 4 is a cross-sectional view of a second modified example of the battery exterior body of the first embodiment. [Figure 15] FIG. 10 is a cross-sectional view of a third modified example of the battery exterior body of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] [Battery] (First embodiment) Fig. 1 is a cross-sectional view of a battery 10 using a battery exterior body 4 of the first embodiment. Fig. 1 is a cross-sectional view taken along line II in Fig. 2. Fig. 2 is an exploded perspective view of the battery exterior body 4. 1, the battery 10 includes a battery exterior body 4 and a battery body 3. The battery exterior body 4 includes a first laminate 1 and a second laminate 2.

[0016] (Battery exterior body) (First embodiment) 1 and 2, the X direction is the width direction of the first laminate 1 and the second laminate 2. The Y direction is the length direction perpendicular to the X direction in a plane along the second laminate 2. The Z direction is the direction perpendicular to the X direction and the Y direction. The Z direction is the thickness direction of the first laminate 1 and the second laminate 2. The plane along the X direction and the Y direction is called the XY plane. Planar view means viewing from the Z direction. In the following description, the vertical positional relationship of the battery 10 will be tentatively defined based on Fig. 1. The first stack 1 is located above the second stack 2. Note that the positional relationship defined here does not limit the orientation of the battery 10 during use.

[0017] The first laminate 1 includes a first metal layer 11 and a first resin layer 12. The first laminate 1 is a laminate film in which the first resin layer 12 is laminated on one surface of the first metal layer 11. The first laminate 1 is an example of a "reference laminate." The first laminate 1 has, for example, a rectangular shape in a plan view (see FIG. 2). Note that the first laminate 1 may have other layers laminated thereon in addition to the first metal layer 11 and the first resin layer 12.

[0018] A foil made of a metal such as aluminum or an aluminum alloy can be used as the first metal layer 11. The first metal layer 11 made of a metal such as aluminum or an aluminum alloy has excellent electrical and mechanical properties. The first metal layer 11 may be subjected to a surface treatment such as a chemical conversion treatment. An electrically conductive functional coating (not shown) may be formed on the inner surface 11b of the first metal layer 11 for the purposes of protection from the electrolyte, etc., electrolytic corrosion protection, etc. The outer surface 11c of the first metal layer 11 may be subjected to anti-rust treatment.

[0019] The first resin layer 12 is formed on the inner surface 11b of the first metal layer 11. The resin forming the first resin layer 12 is, for example, a thermoplastic resin that can be fused to the second resin layer 22 (described later). Examples of this resin include metal adhesive resins (such as modified polyolefins). The resin forming the first resin layer 12 can be a polypropylene homopolymer, a copolymer of polypropylene and ethylene, or the like. The first resin layer 12 has insulating properties.

[0020] The first laminate 1 includes a flange portion 13 and a recessed molded portion 14 . The flange portion 13 includes the peripheral edge of the first laminate 1. The flange portion 13 is formed in a rectangular frame shape (see FIG. 2). The flange portion 13 is formed flat along the XY plane. The flange portion 13 extends outward from the lower end of a peripheral wall portion 16 (described later). The flange portion 13 abuts against the second laminate 2.

[0021] The recessed molded portion 14 is molded in a container shape that bulges upward (that is, in the direction away from the second laminate 2). The recessed molded portion 14 includes a base wall portion 15 and a peripheral wall portion 16. The base wall portion 15 is formed flat along the XY plane. The base wall portion 15 has a rectangular shape (see FIG. 2). The peripheral wall portion 16 extends from the peripheral edge of the base wall portion 15 toward the second stacked body 2. The peripheral wall portion 16 may be perpendicular to the base wall portion 15. The peripheral wall portion 16 may have a shape (skirt-like) that approaches the second stacked body 2 as its outer dimensions (dimensions in the X and Y directions) increase.

[0022] The internal space of the concave molded portion 14 is a storage space 17. The storage space 17 is the space between the concave molded portion 14 and the second stack 2. The storage space 17 can store the battery body 3. The height (distance in the Z direction) of the concave molded portion 14 is equal to the thickness of the battery body 3 (the distance between the electrode surface 32a and the electrode surface 33a), for example.

[0023] A first opening 18 is formed in the first resin layer 12 in a region facing the storage space 17. The first opening 18 is formed in the base wall portion 15. The first opening 18 exposes the inner surface 11b of the first metal layer 11. The shape of the first opening 18 in a plan view is not particularly limited, and may be, for example, rectangular or circular. In this embodiment, the first opening 18 has a rectangular shape similar to that of the base wall portion 15 (see FIG. 2). The width (X-direction dimension) of the first opening 18 is smaller than the width of the base wall portion 15. The length (Y-direction dimension) of the first opening 18 is smaller than the length of the base wall portion 15.

[0024] The first opening 18 is formed so that the exposed inner surface 11b of the first metal layer 11 can come into contact with the positive electrode 32 of the battery body 3. The first opening 18 is formed at a position that encompasses the electrode surface 32a of the positive electrode 32 in a plan view.

[0025] The second laminate 2 includes a second metal layer 21 and a second resin layer 22. The second laminate 2 is a laminate film in which the second resin layer 22 is laminated on one surface of the second metal layer 21. The second laminate 2 is formed flat. The second laminate 2 is an example of a "facing laminate." The second laminate 2 has, for example, a rectangular shape in a plan view (see FIG. 2). Note that the second laminate 2 may have other layers laminated thereon in addition to the second metal layer 21 and the second resin layer 22.

[0026] Foil made of metal such as stainless steel, nickel, nickel alloy, copper, or copper alloy can be used as the second metal layer 21. The second metal layer 21 made of metal such as stainless steel, nickel, nickel alloy, copper, or copper alloy has excellent electrical and mechanical properties. The second metal layer 21 may be subjected to a surface treatment such as a chemical conversion treatment. An electrically conductive functional coating (not shown) may be formed on the inner surface 21b of the second metal layer 21 for the purposes of protection from the electrolyte and the like, and electrolytic corrosion protection.

[0027] The second resin layer 22 is formed on the inner surface 21b of the second metal layer 21. As the resin forming the second resin layer 22, for example, a thermoplastic resin that can be fused to the first resin layer 12 is used. Examples of this resin include a metal adhesive resin (such as a modified polyolefin). As the resin forming the second resin layer 22, a polypropylene homopolymer, a copolymer of polypropylene and ethylene, etc. can be used. The second resin layer 22 has insulating properties.

[0028] A second opening 28 is formed in the second resin layer 22 in a region facing the storage space 17. The second opening 28 exposes the inner surface 21b of the second metal layer 21. The shape of the second opening 28 in a plan view is not particularly limited, and may be, for example, rectangular or circular. In this embodiment, the second opening 28 has a rectangular shape, which is the same shape as the first opening 18 of the first laminate 1 (see FIG. 2). The second opening 28 is preferably formed in a position overlapping the first opening 18 in a plan view.

[0029] The second opening 28 is formed so that the exposed inner surface 21b of the second metal layer 21 can come into contact with the negative electrode 33 of the battery body 3. The second opening 28 is formed at a position that encompasses the electrode surface 33a of the negative electrode 33 in a plan view.

[0030] The first laminate 1 and the second laminate 2 are stacked so that the first resin layer 12 and the second resin layer 22 face each other. The first resin layer 12 and the second resin layer 22 are welded (thermally sealed) at a welded portion 20. The welded portion 20 surrounds at least a portion of the storage space 17. The welded portion 20 can be formed to surround the entire periphery of the storage space 17. The welded portion 20 is formed in a rectangular frame-shaped region where the flange portion 13 and the second laminate 2 overlap in a plan view (see FIG. 2).

[0031] The first resin layer 12 and the second resin layer 22 are interposed between the first metal layer 11 and the second metal layer 21 of the flange portion 13, and insulate the first metal layer 11 from the second metal layer 21. In this embodiment, both the first resin layer 12 and the first resin layer 12 are interposed between the first metal layer 11 and the second metal layer 21, but only one of the first resin layer 12 and the first resin layer 12 may be interposed between the first metal layer 11 and the second metal layer 21. In other words, it is sufficient that at least one of the first resin layer 12 and the first resin layer 12 is interposed between the first metal layer 11 and the second metal layer 21 to insulate the first metal layer 11 from the second metal layer 21.

[0032] A portion of the first resin layer 12 including the outer peripheral edge 12a is formed to protrude outward from the outer peripheral edge 11a of the first metal layer 11. The dimension (protrusion length) of the flange portion 13 protruding outward from the outer surface of the peripheral wall portion 16 is defined as B. In plan view, the dimension (protrusion length) A1 of the first resin layer 12 of the flange portion 13 protruding outward from the outer surface of the peripheral wall portion 16 is preferably greater than the protrusion length B of the first metal layer 11. In other words, the protrusion length A1 and the protrusion length B preferably satisfy the relationship A1>B. It is preferable that the portion including the outer peripheral edge 12a of the first resin layer 12 satisfies A1 > B over the entire circumference, but it is sufficient that at least a part of the entire circumference of the portion including the outer peripheral edge 12a of the first resin layer 12 satisfies A1 > B.

[0033] The portion including the outer peripheral edge 22a of the second resin layer 22 is formed to project outward from the outer peripheral edge 21a of the second metal layer 21. In a plan view, the dimension (projection length) by which the second metal layer 21 projects outward from the outer surface of the peripheral wall portion 16 is defined as C. In a plan view, the dimension (projection length) A2 by which the second resin layer 22 projects outward from the outer surface of the peripheral wall portion 16 is preferably greater than the projection length C. That is, it is preferable that the projection length A2 and the projection length C satisfy A2 > C. It is preferable that the portion including the outer peripheral edge 22a of the second resin layer 22 satisfies A2 > C over the entire circumference, but it is sufficient that at least a part of the entire circumference of the portion including the outer peripheral edge 22a of the second resin layer 22 satisfies A2 > C. The projection length A2 may be equal to the projection length A1.

[0034] The projection length B of the first metal layer 11 is preferably different from the projection length C of the second metal layer 21. In the present embodiment, the projection length B and the projection length C satisfy B > C. This makes it easier to avoid a short circuit due to contact between the first metal layer 11 and the second metal layer 21. Note that the projection length B and the projection length C may satisfy B < C.

[0035] In the present embodiment, the projection length A1 of the first resin layer 12 and the projection length A2 of the second resin layer 22 are equal, but the projection length A1 may be greater than the projection length A2, or conversely, the projection length A1 may be smaller than the projection length A2.

[0036] In the present embodiment, both the projection length A1 of the first resin layer 12 and the projection length A2 of the second resin layer 22 are greater than the projection lengths B and C of the metal layers 11 and 21, but either one of the projection length A1 and the projection length A2 may be greater than the projection lengths B and C. In other words, at least one of the projection length A1 and the projection length A2 may be greater than the projection lengths B and C. When at least one of the protruding length A1 of the first resin layer 12 and the protruding length A2 of the second resin layer 22 is greater than the protruding lengths B and C, it is possible to prevent the first metal layer 11 and the second metal layer 21 from accidentally coming into contact with each other. This makes it easier to avoid a short circuit between the first metal layer 11 and the second metal layer 21.

[0037] The outer surface 11c of the first metal layer 11 is the surface opposite to the inner surface 11b. Of the outer surface 11c of the first metal layer 11, a region that overlaps with the electrode surface 32a of the positive electrode 32 in the thickness direction (thickness direction of the first metal layer 11) is a first external electrode 34. The first external electrode 34 is a partial region of the outer surface 15a of the base wall portion 15. The first external electrode 34 is an electrode that is exposed to the outside and is conductive.

[0038] The outer surface 15a of the base wall portion 15 includes the first external electrode 34 and is a region that is flush with the first external electrode 34. The outer surface 15a is a flat surface along the XY plane. The entire outer surface 15a is exposed to the outside to allow electrical continuity. Because the outer surface 15a is an exposed flat surface, when stacked with another battery 10, it can come into surface contact with the second metal layer 21 of that battery 10 (see FIG. 11). The outer surface 15a of the base wall portion 15 of the first metal layer 11 is an example of a "first outer surface region."

[0039] The outer surface 21c of the second metal layer 21 is the surface opposite to the inner surface 21b. The region of the outer surface 21c of the second metal layer 21 that overlaps with the electrode surface 33a of the negative electrode 33 in the thickness direction (thickness direction of the second metal layer 21) is the second external electrode 35. The second external electrode 35 is a partial region of the outer surface 21c of the second metal layer 21. The second external electrode 35 is an electrode that is exposed to the outside and is conductive. The outer surface 21c is an example of a "second external surface region."

[0040] The outer surface 21c of the second metal layer 21 includes the second external electrode 35 and is an area flush with the second external electrode 35. The outer surface 21c is a flat surface along the XY plane. The outer surface 21c is externally exposed so as to be conductable over the entire area. Since the outer surface 21c is an exposed flat surface, when stacked with other batteries 10, it can be surface-contacted with the first metal layer 11 of the battery 10 (see FIG. 11).

[0041] The area of the outer surface 21c is larger than the area of the outer surface 15a of the base wall portion 15. That is, when comparing the area S1 of the outer surface 15a and the area S2 of the outer surface 21c, "S1 < S2". The outer surface 21c includes the outer surface 15a in plan view.

[0042] The outer surface 21c only needs to be externally exposed so as to be conductable over the entire area of at least the region overlapping with the outer surface 15a of the base wall portion 15 in plan view. Thereby, when stacked with other batteries 10, the outer surface 21c can be surface-contacted with the outer surface 15a of the battery 10. That is, when a plurality of batteries 10 are stacked, the outer surface 21c of one battery 10 and the outer surface 15a of the other battery 10 can be surface-contacted (see FIG. 11).

[0043] (Battery exterior body: First modification example) Assume a battery exterior body in which the area S1 of the first outer surface region and the area S2 of the second outer surface region are "S1 > S2". For example, assume a case where, contrary to the battery 10 shown in FIGS. 1 and 2, a concave molding portion is not formed in the first laminate and a concave molding portion is formed in the second laminate. The outer surface of the first metal layer includes the first external electrode and is an area (first outer surface region) flush with the first external electrode. The outer surface of the base wall portion of the second laminate includes the second external electrode and is an area (second outer surface region) flush with the second external electrode. The area of the outer surface (first outer surface region) of the first metal layer is larger than the area of the outer surface (second outer surface region) of the base wall portion of the second laminate.

[0044] The entire outer surface of the base wall portion of the second stack is electrically conductively exposed to the outside, and at least a region of the outer surface of the first metal layer of the first stack that overlaps with the outer surface of the base wall portion of the second stack in a plan view is electrically conductively exposed to the outside. This allows the outer surface (first outer surface region) of the first stack of one battery to come into surface contact with the outer surface (second outer surface region) of the base wall portion of the second stack of the other battery when multiple batteries are stacked. The outer surface of the first metal layer of the first laminate may be exposed over the entire area to allow electrical continuity.

[0045] (Battery exterior: second modified example) Assume a battery exterior body in which the area S1 of the first outer surface region and the area S2 of the second outer surface region are equal to each other. For example, assume a case in which a recessed molded portion is formed in both the first laminate and the second laminate. The outer surface of the base wall portion of the first laminate includes a first external electrode and is a region (first outer surface region) that is flush with the first external electrode.The outer surface of the base wall portion of the second laminate includes a second external electrode and is a region (second outer surface region) that is flush with the second external electrode. The area of ​​the outer surface (first outer surface region) of the base wall portion of the first laminate is equal to the area of ​​the outer surface (second outer surface region) of the base wall portion of the second laminate. The outer surface of the base wall portion of the first laminate and the outer surface of the base wall portion of the second laminate overlap in a plan view.

[0046] In this case, the outer surface of the base wall portion of the first stack and the outer surface of the base wall portion of the second stack are exposed to the outside over their entire areas so as to be electrically conductive. This allows the outer surface (first outer surface region) of the base wall portion of the first stack of one battery to come into surface contact with the outer surface (second outer surface region) of the base wall portion of the second stack of the other battery when multiple batteries are stacked.

[0047] (Battery body) The battery body 3 is housed in the housing space 17 of the battery exterior body 4. The battery body 3 is, for example, a lithium ion battery. The battery body 3 has a main portion 31, a positive electrode 32, and a negative electrode 33. The main portion 31 has, for example, a separator (not shown), an electrolyte (not shown), a positive electrode active material layer (not shown), and a negative electrode active material layer (not shown). The main portion 31 is interposed between the positive electrode 32 and the negative electrode 33. The main portion 31 is, for example, sheet-shaped or plate-shaped. The positive electrode active material layer contains a positive electrode active material such as a lithium-based material. The negative electrode active material layer contains a negative electrode active material such as a carbon-based material.

[0048] The positive electrode 32 is provided on one surface 31a (the upper surface in FIG. 1) of the main portion 31. The positive electrode 32 is, for example, in the form of a sheet or plate along the XY plane. The entire area of ​​the electrode surface 32a (the upper surface in FIG. 1) of the positive electrode 32 faces the inner surface 11b of the first metal layer 11. The electrode surface 32a is in conductive contact with the inner surface 11b of the first metal layer 11 exposed by the first opening 18. In this embodiment, the positive electrode 32 is in direct contact with the inner surface 11b of the first metal layer 11. Since the positive electrode 32 is in contact with the first metal layer 11, the first metal layer 11 functions as a current collector.

[0049] The positive electrode 32 is electrically connected to the positive electrode active material layer (not shown) of the main portion 31 . The positive electrode 32 may be in indirect contact with the inner surface 11b of the first metal layer 11 via a conductive connector (not shown). The connector is, for example, a conductive layer formed of a conductive paste.

[0050] The negative electrode 33 is provided on the other surface 31b (the lower surface in FIG. 1) of the main portion 31. The negative electrode 33 is, for example, in the form of a sheet or plate along the XY plane. The entire area of ​​the electrode surface 33a (the lower surface in FIG. 1) of the negative electrode 33 faces the inner surface 21b of the second metal layer 21. The electrode surface 33a is in conductive contact with the inner surface 21b of the second metal layer 21 exposed by the second opening 28. In this embodiment, the negative electrode 33 is in direct contact with the inner surface 21b of the second metal layer 21. The negative electrode 33 is in contact with the second metal layer 21, so that the second metal layer 21 functions as a current collector.

[0051] The negative electrode 33 is electrically connected to the negative electrode active material layer (not shown) of the main portion 31 . The negative electrode 33 may be in indirect contact with the inner surface 21b of the second metal layer 21 via a conductive connector (not shown). The connector is, for example, a conductive layer formed of a conductive paste.

[0052] The battery body 3 is housed in the housing space 17 of the battery exterior body 4 with its thickness direction facing the Z direction. The battery body 3 has a flat shape along the XY plane. A flat shape means that the thickness dimension (dimension in the Z direction) is smaller than the dimensions in the X direction and the Y direction. Because the battery body 3 has a flat shape, the battery 10 can be made thinner. The battery body 3 is preferably stored in the storage space 17 so that it can be freely taken in and out.

[0053] [Battery exterior body and battery manufacturing method] Next, a method for manufacturing a battery exterior body and a battery according to an embodiment will be described with reference to FIGS. 3 to 10, taking the case of manufacturing a battery exterior body 4 and a battery 10 as an example. The method for manufacturing a battery outer casing of this embodiment includes a first lamination step, a second lamination step, a molding step, an assembly step, and a welding step.

[0054] (1) First lamination process 3 and 4, first openings 18 are formed in resin sheet 12A by punching or the like to obtain first resin layer 12. As shown in Fig. 5, first resin layer 12 with first openings 18 formed therein is laminated on first metal layer 11 to obtain first laminate 1. In this step, first resin layer 12, in which first openings 18 have been formed prior to lamination, is laminated on first metal layer 11.

[0055] To laminate the first resin layer 12 and the first metal layer 11, the first resin layer 12 and the first metal layer 11 may be laminated while being unwound from a roll. To laminate the first resin layer 12 and the first metal layer 11, the first resin layer 12 and the first metal layer 11 may be laminated from sheet-like sheets.

[0056] (2) Molding process 6, the first laminate 1 is drawn using a mold and a press machine to form a recessed portion 14. The recessed portion 14 is formed so that the first opening 18 is located in the base wall portion 15. Since the first opening 18 is formed in the base wall portion 15, the first resin layer 12 is formed on the peripheral wall portion 16. Therefore, when forming the recessed molded portion 14 by drawing or the like, the workability of the recessed molded portion 14 can be improved.

[0057] (3)Second lamination process 7 and 8, second openings 28 are formed in resin sheet 22A by punching or the like to obtain second resin layer 22. As shown in Fig. 9, second resin layer 22 with second openings 28 formed therein is laminated on second metal layer 21 to obtain second laminate 2. In this step, first resin layer 12, in which second openings 28 have been formed prior to lamination, is laminated on first metal layer 11.

[0058] To laminate the second resin layer 22 and the second metal layer 21, the second resin layer 22 and the second metal layer 21 may be laminated while being unwound from a roll. To laminate the second resin layer 22 and the second metal layer 21, the second resin layer 22 and the second metal layer 21 may be laminated from sheet-like sheets.

[0059] (4) Assembly process 10, the first laminate 1 and the second laminate 2 are stacked together with the first resin layer 12 and the second resin layer 22 facing each other. This forms a storage space 17 between the first laminate 1 and the second laminate 2. The storage space 17 accommodates the battery body 3 (see FIG. 1).

[0060] (5) Welding process The first resin layer 12 and the second resin layer 22 are welded (thermally fused) at the welded portion 20 (see FIG. 1) by heat sealing or the like, thereby obtaining the battery 10 shown in FIG.

[0061] [Battery pack] FIG. 11 is a cross-sectional view showing a battery pack 110 according to an embodiment. The battery pack 110 includes a plurality of batteries 10 (see FIG. 1). In this embodiment, the number of batteries 10 is two. The two batteries 10 are stacked in the thickness direction (the vertical direction in FIG. 11) of the first stack 1 and the second stack 2. The upper battery 10 of the two batteries 10 is referred to as the first battery 10A (first battery). The lower battery 10 of the two batteries 10 is referred to as the second battery 10B (second battery).

[0062] The outer surface 21c of the second metal layer 21 of the first battery 10A is an exposed flat surface, and the outer surface 15a of the base wall portion 15 of the second battery 10B is also an exposed flat surface. Therefore, the outer surface 21c of the first battery 10A and the outer surface 15a of the second battery 10B are in surface contact. This brings the second external electrode 35 of the first battery 10A and the first external electrode 34 of the second battery 10B into conductive contact. In the battery pack 110, the negative electrode of the first battery 10A and the positive electrode of the second battery 10B are electrically connected, so that the first battery 10A and the second battery 10B are connected in series. In this embodiment, the first battery 10A is an example of "one of the first battery and the second battery." The second battery 10B is an example of "the other of the first battery and the second battery."

[0063] [Effects of the battery exterior body, battery, and battery pack according to the embodiment] As shown in Fig. 1, the battery outer casing 4 has the outer surface 15a (first outer surface region) of the first stack 1 exposed over the entire area so as to be electrically conductive. This ensures a wide conductive connection surface. When multiple batteries 10 are stacked, the outer surface 21c of one battery 10 and the outer surface 15a of another battery 10 can come into surface contact (see Fig. 11). This reduces contact resistance at the electrodes, providing a battery 10 suitable for applications requiring large currents. The battery exterior casing 4 has the advantage of being able to suppress contact resistance at the electrodes and therefore able to suppress heat generation at the electrodes.

[0064] Batteries 10 using the battery exterior housing 4 can be connected in series simply by stacking them (see FIG. 11). This simplifies the structure of the batteries 10 and makes it easy to connect the batteries 10 together. Because the battery 10 using the battery exterior housing 4 has a simple structure and is easy to connect, it is possible to reduce manufacturing costs. The batteries 10 can be connected in series simply by stacking them (see FIG. 11), which makes it possible to reduce the number of connecting members such as bus bars, thereby simplifying the connection structure of the batteries 10.

[0065] In a battery 10 using the battery outer casing 4, the first metal layer 11 and the second metal layer 21 each function as a current collector. Therefore, a tab lead for connection to the battery body 3 is not required. This allows for the realization of a battery 10 that has a simple structure and is easy to manufacture. Because the battery outer casing 4 does not require tab leads, there are no problems with forming through-holes for tab leads, poor sealing, or malfunctions due to terminal resistance. The battery outer casing 4 also does not have the problem of increased thickness due to tab leads. There are also no structural restrictions associated with the installation of tab leads.

[0066] In the battery outer casing 4, a portion including the outer peripheral edge 12a of the first resin layer 12 is formed to protrude outward from the outer peripheral edge 11a of the first metal layer 11. A portion including the outer peripheral edge 22a of the second resin layer 22 is formed to protrude outward from the outer peripheral edge 21a of the second metal layer 21. This makes it possible to prevent the first metal layer 11 and the second metal layer 21 from accidentally coming into contact with each other. This makes it possible to avoid a short circuit between the first metal layer 11 and the second metal layer 21.

[0067] In the battery outer casing 4, the first opening 18 of the first resin layer 12 is formed in the base wall portion 15. Therefore, the first resin layer 12 is formed in the peripheral wall portion 16. Therefore, when forming the recessed molded portion 14 by drawing or the like, the workability of the recessed molded portion 14 can be improved (see FIGS. 5 and 6). Therefore, the accuracy of forming the recessed molded portion 14 can be improved.

[0068] The first laminate 1 has a two-layer structure having a first metal layer 11 and a first resin layer 12. The second laminate 2 has a two-layer structure having a second metal layer 21 and a second resin layer 22. The first laminate 1 and the second laminate 2 have a small number of layers and a simple structure, so that the number of manufacturing steps is small and they are easy to manufacture (see FIGS. 5 and 9).

[0069] The battery pack 110 shown in Fig. 11 has a simple structure in which multiple batteries 10 are stacked so that they are in contact with each other. This reduces manufacturing costs. The battery pack 110 is easy to manufacture because the batteries 10 can be connected to each other simply by stacking them. This makes it easy to modularize and pack the batteries.

[0070] [Effects of the manufacturing method of the battery exterior body according to the embodiment] 3 to 10, as described above, the manufacturing method for the battery outer casing 4 does not require a tab lead to be connected to the battery body 3, thereby simplifying the manufacturing process. As a result, the battery 10 can be manufactured easily.

[0071] In the first lamination step, a first resin layer 12 having a first opening 18 formed therein is laminated onto a first metal layer 11 to produce a first laminate 1. In the second lamination step, a second resin layer 22 having a second opening 28 formed therein is laminated onto a second metal layer 21 to produce a second laminate 2. This allows for more reliable opening formation than in a manufacturing method in which openings are formed in a resin layer by laser processing or the like after lamination with a metal layer. This ensures reliable connection between the first metal layer 11 and the second metal layer 21 and the battery body 3. Furthermore, the manufacturing method of this embodiment more easily avoids damage to the metal layer than in a manufacturing method in which openings are formed in a resin layer by laser processing.

[0072] [Battery] (Second embodiment) 12 is a cross-sectional view of a battery 210 using the battery exterior body 104 of the second embodiment. Hereinafter, the same reference numerals will be used to designate components common to the battery exterior body 4 and battery 10 of the first embodiment, and descriptions thereof will be omitted. 12, the battery 210 includes a battery outer casing 104 and a battery body 103. The battery outer casing 104 includes a first stack 1 and a second stack .

[0073] (Battery exterior body) (Second embodiment) The second laminate 102 includes a second metal layer 121 and a second resin layer 122. The second laminate 102 is a laminate film in which the second resin layer 122 is laminated on one surface of the second metal layer 121. The materials of the second metal layer 121 and the second resin layer 122 are similar to those of the second metal layer 21 and the second resin layer 22 in the first embodiment.

[0074] The second laminate 102 includes a flange portion 113 and a recessed portion 114 . The flange portion 113 includes the periphery of the second stack 102. The flange portion 113 is formed in a rectangular frame shape. The flange portion 113 is formed flat along the XY plane. The flange portion 113 extends outward from the upper end of a peripheral wall portion 116 (described below).

[0075] The recessed molded portion 114 is molded in a container shape that bulges downward (that is, in the direction away from the first laminate 1). The recessed molded portion 114 includes a base wall portion 115 and a peripheral wall portion 116. The base wall portion 115 is formed flat along the XY plane. The base wall portion 115 has a rectangular shape. The peripheral wall portion 116 extends from the peripheral edge of the base wall portion 115 toward the first stacked body 1. The peripheral wall portion 116 may be perpendicular to the base wall portion 115. The peripheral wall portion 116 may have a shape (skirt-like) that approaches the first stacked body 1 as its outer dimensions (dimensions in the X and Y directions) increase.

[0076] The space surrounded by the recessed molded portion 114 and the recessed molded portion 14 of the first stack 1 is a storage space 117. The storage space 117 can store the battery body 103 therein.

[0077] A second opening 128 is formed in the second resin layer 122 in a region facing the storage space 117. The second opening 128 is formed in the base wall portion 115. The second opening 128 exposes the inner surface 121b of the second metal layer 121. The shape of the second opening 128 in a plan view is not particularly limited, and may be, for example, rectangular or circular. The second opening 128 may have the same shape as the first opening 18 of the first laminate 1.

[0078] The second opening 128 is formed so that the exposed inner surface 121b of the second metal layer 121 can come into contact with the negative electrode 133 of the battery body 103. The second opening 128 is formed at a position that encompasses the electrode surface 133a of the negative electrode 133 in a plan view.

[0079] Since both the first laminate 1 and the second laminate 102 have a concave molded portion, either one can be the reference laminate or the opposing laminate. That is, when the first laminate 1 is the reference laminate, the second laminate 102 is the opposing laminate, and when the first laminate 1 is the opposing laminate, the second laminate 102 is the reference laminate.

[0080] The first laminate 1 and the second laminate 102 are stacked so that the first resin layer 12 and the second resin layer 122 face each other. The first resin layer 12 and the second resin layer 122 are welded (thermally sealed) at a welding portion 120. The welding portion 120 surrounds at least a portion of the storage space 117. The welding portion 120 can be formed to surround the entire periphery of the storage space 117. The welding portion 120 is formed in a rectangular frame-shaped region where the flange portion 13 of the first laminate 1 and the flange portion 113 of the second laminate 102 overlap in a plan view.

[0081] The first resin layer 12 and the second resin layer 122 are interposed between the first metal layer 11 of the flange portion 13 and the second metal layer 121 of the flange portion 113 , and insulate the first metal layer 11 from the second metal layer 121 .

[0082] A portion of the first resin layer 12 including its outer peripheral edge is formed to protrude outward from the outer peripheral edge of the first metal layer 11. A portion of the second resin layer 122 including its outer peripheral edge is formed to protrude outward from the outer peripheral edge of the second metal layer 121. This makes it possible to prevent the first metal layer 11 and the second metal layer 121 from accidentally coming into contact with each other. Therefore, it is possible to avoid a short circuit between the first metal layer 11 and the second metal layer 121.

[0083] Of the outer surface 11c of the first metal layer 11, the region that overlaps with the electrode surface 132a of the positive electrode 132 in the thickness direction (thickness direction of the first metal layer 11) is a first external electrode .

[0084] Of the outer surface 121c of the second metal layer 121, a region that overlaps with the electrode surface 133a of the negative electrode 133 in the thickness direction (thickness direction of the second metal layer 121) is a second external electrode 135. The second external electrode 135 is a partial region of the outer surface 115a of the base wall portion 115. The second external electrode 135 is an electrode that is exposed to the outside and is conductive.

[0085] The outer surface 115a of the base wall portion 115 of the second stack 102 includes the second external electrode 135 and is a region that is flush with the second external electrode 135. The outer surface 115a is a flat surface along the XY plane. The entire outer surface 115a is exposed to the outside to allow electrical continuity. Because the outer surface 115a is an exposed flat surface, when stacked with another battery 210, it can come into surface contact with the first metal layer 11 (outer surface 15a) of that battery 210. The outer surface 115a is an example of a "second outer surface region."

[0086] The outer surface 115a of the second stack 102 has the same area as the outer surface 15a of the first stack 1. The outer surface 115a of the second stack 102 and the outer surface 15a of the first stack 1 overlap in a plan view.

[0087] (Battery body) The battery body 103 is housed in a housing space 117 of the battery exterior body 104. The battery body 103 is, for example, a lithium ion battery. The battery body 103 has a main portion 131, a positive electrode 132, and a negative electrode 133. The main portion 131 has, for example, a separator (not shown). The main portion 131 is interposed between the positive electrode 132 and the negative electrode 133. The main portion 131, the positive electrode 132, and the negative electrode 133 are in a sheet shape. The main portion 131, the positive electrode 132, and the negative electrode 133 are folded back and stacked at multiple locations.

[0088] The entire area of ​​the electrode surface 132a (upper surface in FIG. 12) of the positive electrode 132 faces the inner surface 11b of the first metal layer 11. The electrode surface 132a is in conductive contact with the inner surface 11b of the first metal layer 11 exposed by the first opening 18. In this embodiment, the positive electrode 132 is in direct contact with the inner surface 11b of the first metal layer 11.

[0089] The entire area of ​​the electrode surface 133a (the lower surface in FIG. 12) of the negative electrode 133 faces the inner surface 121b of the second metal layer 121. The electrode surface 133a is in conductive contact with the inner surface 121b of the second metal layer 121 exposed by the second opening 128. In this embodiment, the negative electrode 133 is in direct contact with the inner surface 121b of the second metal layer 121. The battery body 103 is housed in a housing space 117 of the battery exterior body 104 .

[0090] [Effects of the battery exterior body, battery, and battery pack according to the embodiment] In the battery outer casing 104, the outer surface 15a (first outer surface region) of the first stack 1 is exposed over its entire area so as to be conductive. The outer surface 115a (second outer surface region) of the second stack 102 is exposed over its entire area so as to be conductive. This ensures a wide connection surface for conductive connection between the positive and negative electrodes. When multiple batteries 210 are stacked, the outer surface 115a of the second stack 102 of one battery 210 and the outer surface 15a of the first stack 1 of the other battery 210 can be in planar contact. This reduces contact resistance at the electrodes, making it possible to provide a battery 210 that can be used in applications that require large currents.

[0091] Batteries 210 using the battery exterior housing 104 can be connected in series simply by stacking them. This simplifies the structure of the batteries 210 and makes it easy to connect the batteries 210 together. Because the battery 210 using the battery exterior housing 104 has a simple structure and is easy to connect, it is possible to reduce manufacturing costs. The batteries 210 can be connected in series simply by stacking them, which makes it possible to reduce the number of connecting members such as bus bars, and thus simplify the connection structure of the batteries 210.

[0092] In battery 210 using battery outer casing 104, first metal layer 11 and second metal layer 121 each function as a current collector. Therefore, there is no need for a tab lead to connect to battery body 103. This makes it possible to realize battery 210 that has a simple structure and is easy to manufacture.

[0093] In the battery outer casing 104, a portion including the outer peripheral edge of the first resin layer 12 is formed so as to protrude outward from the outer peripheral edge of the first metal layer 11. A portion including the outer peripheral edge of the second resin layer 122 is formed so as to protrude outward from the outer peripheral edge of the second metal layer 121. This makes it possible to prevent the first metal layer 11 and the second metal layer 121 from accidentally coming into contact with each other. This makes it possible to avoid a short circuit between the first metal layer 11 and the second metal layer 121. The protruding length (projection length) of the first resin layer 12 from the outer peripheral edge of the first metal layer 11 and the protruding length (projection length) of the second resin layer 122 from the outer peripheral edge of the second metal layer 121 are not particularly limited, but are preferably 0.3 mm or more.

[0094] In the battery outer casing 104, the first opening 18 of the first resin layer 12 is formed in the base wall portion 15. Therefore, the first resin layer 12 is formed in the peripheral wall portion 16. The second opening 128 of the second resin layer 122 is formed in the base wall portion 115. Therefore, the second resin layer 122 is formed in the peripheral wall portion 116. Therefore, when forming the concave molded portions 14, 114 by drawing or the like, the processability of the concave molded portions 14, 114 can be improved. Therefore, the formation accuracy of the concave molded portions 14, 114 can be improved.

[0095] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. 11 includes two batteries 10, the number of batteries constituting the battery assembly may be any number equal to or greater than 2. For example, a battery assembly in which three batteries are stacked in the thickness direction (thickness direction of the first stack and second stack), a battery assembly in which four batteries are stacked in the thickness direction, etc. can be exemplified. For example, in a battery pack in which first, second, and third batteries are stacked in this order in the thickness direction, the negative electrode of the first battery is electrically connected to the positive electrode of the second battery, and the negative electrode of the second battery is electrically connected to the positive electrode of the third battery. Therefore, this battery pack has a configuration in which multiple batteries are connected in series.

[0096] 13 is a cross-sectional view of a battery exterior body 204 that is a first modified example of the battery exterior body 4 of the first embodiment. The same reference numerals are used to designate components common to the battery exterior body 4 shown in FIG. 1 and the like, and descriptions thereof will be omitted. The battery outer casing 204 includes a first laminate 201 and a second laminate 202 .

[0097] The first laminate 201 includes a first metal layer 11 and a first resin layer 212. The first resin layer 212 includes a metal adhesive layer 213 and a welding layer 214. The metal adhesive layer 213 is formed on the inner surface 11b of the first metal layer 11. The metal adhesive layer 213 is interposed between the first metal layer 11 and the welding layer 214. As a resin for forming the metal adhesive layer 213, for example, a thermoplastic resin that can be fused to the first metal layer 11 is used. As this resin, for example, a polypropylene-based resin (for example, acid-modified polypropylene) can be used.

[0098] The welding layer 214 is formed by being laminated on the inner surface 213b of the metal adhesive layer 213. As the resin for forming the welding layer 214, for example, a thermoplastic resin that can be fused to the welding layer 224 of the second laminate 202 is used. As this resin, for example, a polypropylene-based resin can be used.

[0099] The second laminate 202 includes a second metal layer 21 and a second resin layer 222. The second resin layer 222 includes a metal adhesive layer 223 and a welding layer 224. The metal adhesive layer 223 is formed on the inner surface 21b of the second metal layer 21. The metal adhesive layer 223 is interposed between the second metal layer 21 and the welding layer 224. As a resin for forming the metal adhesive layer 223, for example, a thermoplastic resin that can be fused to the second metal layer 21 is used. As this resin, for example, a polypropylene-based resin (for example, acid-modified polypropylene) can be used.

[0100] The welding layer 224 is formed by being laminated on the inner surface 223b of the metal adhesive layer 223. As the resin for forming the welding layer 224, for example, a thermoplastic resin that can be fused to the welding layer 214 of the first laminate 201 is used. As this resin, for example, a polypropylene-based resin can be used. The welding layer 214 of the first laminate 201 and the welding layer 224 of the second laminate 202 are welded (thermally fused).

[0101] In the battery outer casing 204, the resin layers 212, 222 have a metal adhesive layer and a welding layer, and therefore, by selecting appropriate materials for the metal adhesive layer and the welding layer, the adhesive strength between the metal layer and the resin layer, and the adhesive strength between the resin layers themselves, can be increased.

[0102] Fig. 14 is a cross-sectional view of a battery exterior body 304 which is a second modified example of the battery exterior body 4 of the first embodiment. The same reference numerals are used to designate components common to the battery exterior body 204 shown in Fig. 13, and descriptions thereof will be omitted. The battery outer casing 304 includes a first laminate 301 and a second laminate 302 .

[0103] The first laminate 301 includes a first metal layer 11 and a first resin layer 312. The first resin layer 312 includes a metal adhesive layer 213, a welding layer 214, and an intermediate layer 315. The intermediate layer 315 is interposed between the metal adhesive layer 213 and the welding layer 214. The intermediate layer 315 is formed of, for example, a resin having higher heat resistance than the metal adhesive layer 213 and the welding layer 214. The intermediate layer 315 is formed of, for example, a polyolefin resin.

[0104] The second laminate 302 includes a second metal layer 21 and a second resin layer 322. The second resin layer 322 includes a metal adhesive layer 223, a welding layer 224, and an intermediate layer 325. The intermediate layer 325 is interposed between the metal adhesive layer 223 and the welding layer 224. The intermediate layer 325 is formed of, for example, a resin having higher heat resistance than the metal adhesive layer 223 and the welding layer 224. The intermediate layer 325 is formed of, for example, a polyolefin resin.

[0105] In the battery outer casing 304, the resin layers 312, 322 have the intermediate layers 315, 325, so by selecting an appropriate material for the intermediate layers 315, 325, the heat resistance and electrolyte resistance of the resin layers 312, 322 can be improved.

[0106] An outer resin layer may be formed on the outer surface of at least one of the first metal layer and the second metal layer. The outer resin layer may be formed on, for example, the peripheral wall or flange of the recessed molded portion. 15 is a cross-sectional view of a battery exterior body 404 that is a third modified example of the battery exterior body 4 of the first embodiment. The battery exterior body 404 has an insulating outer surface resin layer 413 formed on the outer surface of the peripheral wall portion 16 and the outer surface of the flange portion 13. Battery exterior body 404 can protect a part of first metal layer 11 with outer surface resin layer 413 .

[0107] In a battery pack in which a plurality of batteries are stacked, the flange portions of the battery exterior bodies of adjacent batteries may be joined via a resin layer. The first metal layer and the second metal layer may be conductive layers made of a conductive material such as a carbon material. In the above-described embodiment, both the first outer surface region and the second outer surface region are exposed to be conductive over their entirety, but the battery exterior body of the embodiment may be configured such that only one of the first outer surface region and the second outer surface region is exposed to be conductive over its entirety. That is, the battery exterior body of the embodiment may be configured such that at least one of the first outer surface region and the second outer surface region is exposed to be conductive over its entirety. [Example]

[0108] (Test Example 1) A battery exterior body 4 shown in Fig. 1 was produced. The battery exterior body 4 was inspected for the presence or absence of short circuits in the thickness direction and on the sides, as described below. The protrusion length of the first resin layer 12 from the outer peripheral edge of the first metal layer 11 and the protrusion length of the second resin layer 122 from the outer peripheral edge of the second metal layer 121 were both set to −2 mm. Because the protrusion lengths are negative, the outer peripheral edges of the resin layers 12, 122 are located inward from the outer peripheral edges of the metal layers 11, 121 in a plan view.

[0109] [Presence or absence of short circuits in the thickness direction] The presence or absence of short circuits (short circuits in the thickness direction) between the first metal layer 11 and the second metal layer 121 was examined. The "number of short circuits" is the number of samples in which short circuits occurred. The "short circuit rate" is the ratio of samples in which short circuits occurred to the total number of samples. The results are shown in Table 1.

[0110] [Presence or absence of lateral short circuit] Two battery exterior bodies 4 were lined up side by side, and the side edges were butted together to check for the presence or absence of short circuits (side short circuits) in the metal layers between the two battery exterior bodies 4. The "number of short circuits" is the number of samples in which short circuits occurred. The "short circuit rate" is the ratio of samples in which short circuits occurred to the total number of samples. The results are shown in Table 1.

[0111] (Test Examples 2 to 9) The protrusion length of first resin layer 12 from the outer peripheral edge of first metal layer 11 and the protrusion length of second resin layer 122 from the outer peripheral edge of second metal layer 121 were set as shown in Table 1. When the protrusion length is positive, the portion including the outer peripheral edge of resin layers 12, 121 protrudes outward from the outer peripheral edges of metal layers 11, 121 in plan view. The presence or absence of short circuits in the thickness direction and the presence or absence of short circuits in the lateral direction were examined in the same manner as in Test Example 1. The results are shown in Table 1.

[0112] [Table 1]

[0113] As shown in Table 1, when the resin layers 12, 121 protruded from the metal layers 11, 121, short circuits were unlikely to occur in either the thickness direction or the sides. [Explanation of symbols]

[0114] 1,201,301...first laminate (reference laminate), 2,202,302...second laminate (opposing laminate), 3...battery body, 4,104,204,304,404...battery exterior body, 10,210...battery, 10A...first battery (one of the first battery and the second battery), 10B...second battery (the other of the first battery and the second battery), 11...first metal layer, 11a...outer periphery, 11b...inner surface, 11c...outer surface, 12,212,312...first resin layer, 12a...outer periphery, 14,114...recess Shaped molded portion, 15,115...base wall portion, 15a...outer surface (first outer surface region), 16,116...peripheral wall portion, 17,117...storage space, 18...first opening, 21...second metal layer, 21a...outer peripheral edge, 21b...inner surface, 21c...outer surface (second outer surface region), 22,222,322...second resin layer, 22a...outer peripheral edge, 28...second opening, 32...positive electrode, 32a...electrode surface, 33...negative electrode, 33a...electrode surface, 34...first external electrode, 35...second external electrode, 110...battery assembly, 115a...outer surface (second outer surface region).

Claims

1. a first laminate including a first metal layer and a first insulating resin layer; a second laminate in which a second metal layer and a second insulating resin layer are laminated; Equipped with the first laminate and the second laminate are stacked such that the first resin layer and the second resin layer face each other, a storage space for storing a battery body having a positive electrode and a negative electrode is formed between the first stack and the second stack, a first opening exposing an inner surface of the first metal layer is formed in a region of the first resin layer facing the storage space; a second opening exposing an inner surface of the second metal layer is formed in a region of the second resin layer facing the storage space; the first opening is formed so that the exposed inner surface of the first metal layer can directly or indirectly contact the positive electrode; the second opening is formed so that the exposed inner surface of the second metal layer can directly or indirectly contact the negative electrode; a region of an outer surface of the first metal layer that overlaps with an electrode surface of the positive electrode facing the first metal layer in a thickness direction is a first external electrode, a region of an outer surface of the second metal layer that overlaps in a thickness direction with an electrode surface of the negative electrode that faces the second metal layer is a second external electrode, A battery exterior body in which at least one of a first outer surface region of the outer surface of the first metal layer that is flush with the first external electrode and a second outer surface region of the outer surface of the second metal layer that is flush with the second external electrode is exposed over the entire area and is capable of being conductive.

2. at least a part of a portion including an outer peripheral edge of the first resin layer is formed to protrude outward from an outer peripheral edge of the first metal layer, The battery exterior according to claim 1 , wherein at least a part of a portion including the outer periphery of the second resin layer is formed to protrude outward from the outer periphery of the second metal layer.

3. a reference laminate, which is at least one of the first laminate and the second laminate, has a recessed portion formed in a container shape that bulges in a direction away from the opposing laminate, which is the other laminate; The storage space is formed between the concave molding portion and the opposing laminate, the recessed molding portion includes a base wall portion and a peripheral wall portion extending from a peripheral edge of the base wall portion toward the opposing laminate, The battery exterior body according to claim 1 , wherein the first opening or the second opening is formed in the base wall portion.

4. A battery pack comprising: a battery exterior body according to any one of claims 1 to 3; and a battery body housed in the housing space; the positive electrode is in direct or indirect conductive contact with the inner surface of the first metal layer exposed by the first opening; The negative electrode is in direct or indirect conductive contact with the inner surface of the second metal layer exposed by the second opening.

5. A battery comprising a plurality of the batteries according to claim 4; the plurality of batteries include a stacked first battery and a stacked second battery; The first battery and the second battery are batteries according to claim 4, the second external electrode of one of the first battery and the second battery is in conductive contact with the first external electrode of the other battery.

6. a first lamination step of laminating a first insulating resin layer having a first opening formed therein and a first metal layer to obtain a first laminate; a second lamination step of laminating a second insulating resin layer having a second opening formed therein and a second metal layer to obtain a second laminate; an assembling process of stacking the first laminate and the second laminate with the first resin layer and the second resin layer facing each other so that a storage space for storing a battery main body having a positive electrode and a negative electrode is formed between the first laminate and the second laminate; Including, in the assembling step, the first laminate and the second laminate are stacked so that the first metal layer exposed through the first opening and the second metal layer exposed through the second opening face the storage space; the first opening is formed so that the exposed inner surface of the first metal layer can directly or indirectly contact the positive electrode; the second opening is formed so that the exposed inner surface of the second metal layer can directly or indirectly contact the negative electrode; a region of an outer surface of the first metal layer that overlaps with an electrode surface of the positive electrode facing the first metal layer in a thickness direction is a first external electrode, a region of an outer surface of the second metal layer that overlaps in a thickness direction with an electrode surface of the negative electrode that faces the second metal layer is a second external electrode, A method for manufacturing a battery outer casing, wherein at least one of a first outer surface region of the outer surface of the first metal layer that is flush with the first external electrode and a second outer surface region of the outer surface of the second metal layer that is flush with the second external electrode is exposed over the entire area and is capable of conducting electricity.

7. a first laminate including a first metal layer and a first insulating resin layer; a second laminate in which a second metal layer and a second insulating resin layer are laminated; Equipped with the first laminate and the second laminate are stacked such that the first resin layer and the second resin layer face each other, a storage space for storing a battery body having a positive electrode and a negative electrode is formed between the first stack and the second stack, a first opening exposing an inner surface of the first metal layer is formed in a region of the first resin layer facing the storage space; a second opening exposing an inner surface of the second metal layer is formed in a region of the second resin layer facing the storage space; the first opening is formed so that the exposed inner surface of the first metal layer can directly or indirectly contact the positive electrode; the second opening is formed so that the exposed inner surface of the second metal layer can directly or indirectly contact the negative electrode; at least a part of a portion including an outer peripheral edge of the first resin layer is formed to protrude outward from an outer peripheral edge of the first metal layer, At least a portion of the portion including the outer peripheral edge of the second resin layer is formed to protrude outward from the outer peripheral edge of the second metal layer.

Images