Battery packaging and battery

Abstract

To provide a battery casing body capable of improving a yield and a volume efficiency, and a battery with the same.SOLUTION: A battery casing body 10 comprises: a main body part 20 including an open part 20a on an upper surface and housing a battery element 40; and a lid part 30 blocking the open part 20a. The main body part 20 includes: a rectangular bottom surface board 21; side surface boards 22a to 22d bent from four sides of the bottom surface board 21 to stand respectively; connection parts 24a to 24d connecting adjacent side surface boards 22a to 22d; and flange boards 23a to 23d bent from an upper end of the side surface boards 22a to 22c to an outer side. The lid part 30 is bonded to the flange boards 23a to 23c by being bent from an upper end of the side surface board 22d, and the connection parts 24a to 24d are bonded on a first folding line 11 inclined and extended to the outer side from a corner part of the bottom surface board 21 toward an upper direction by double-folding in a valley shape.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a battery package and a battery.

Background Art

[0002] A conventional battery package is disclosed in Patent Document 1. This battery package is composed of a laminate in which at least a barrier layer made of a metal foil and a heat-sealing resin layer made of a heat-sealing resin disposed on the innermost layer are laminated.

[0003] The battery package has a main body portion and a lid portion that are overlapped by bending the laminate. The main body portion and the lid portion have a storage portion that opens an opening on the opposing surface to store a battery element, and a flange portion that extends outward from the periphery of the opening. The storage portion is formed by press-molding (drawing) the laminate.

[0004] The storage portion of the lid portion is placed over the battery element stored in the storage portion of the main body portion to close the lid, and the flange portions of the main body portion and the lid portion are heat-sealed. Thereby, the battery element is sealed inside the battery package.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, according to the above-described conventional battery package, when the storage portion is formed by press molding, the laminate may be stretched, and a part of the barrier layer may be thinned or the barrier layer may be cracked. For this reason, there has been a problem that the yield of the battery package decreases. On the other hand, if the radius of curvature of each corner of the mold for press molding is increased, thinning and cracking of the barrier layer can be prevented, but there is a problem that the volume efficiency of the battery package decreases.

[0007] In view of the above problems, an object of the present invention is to provide a battery package capable of improving the yield and volumetric efficiency, and a battery using the same.

Means for Solving the Problems

[0008] In order to achieve the above object, the present invention is composed of at least a laminate including a barrier layer and a heat-sealable resin layer disposed on the innermost layer, and has a main body portion that has an opening on the upper surface and houses a battery element, and a lid portion that closes the opening. In the battery package, the main body portion has a rectangular bottom plate, side plates that are bent from the four sides of the bottom plate and stand upright respectively, a first connecting portion that connects between adjacent side plates, a flange plate that is bent outward from the upper ends of three of the side plates, and a second connecting portion that is disposed at both ends of the flange plate. the lid portion is bent from the upper end of the side plate where the flange plate is not continuously provided and adhered to the flange plate. the first connecting portion is folded in half and adhered by a valley fold on the heat-sealable resin layer side along a first fold line that extends obliquely outward upward from the corner of the bottom plate. the second connecting portion is connected to the upper end of the first connecting portion via a second fold line that is folded in a mountain fold or valley fold on the heat-sealable resin layer side. The end of the flange plate is inclined and folded back by a valley fold on the heat-sealable resin layer side and adhered, and the second connecting portion adjacent to the end of the flange portion is disposed on top of it.

[0009] Also, in the battery package having the above configuration, it is preferable that the first fold line is inclined at 45° with respect to the vertical direction.

[0010] Also, in the battery package having the above configuration, it is preferable that the ratio of the thickness of the barrier layer at the intermediate position in the height direction of the side plate to the thickness of the barrier layer at the connecting portion of the side plate and the bottom plate is 100 ± 10% or less.

[0011] Further, the battery of the present invention is characterized in that a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the main body portion of the battery package having each of the above-described configurations.

[0012] Further, the battery of the present invention is characterized in that a battery element including at least a positive electrode and a negative electrode and integrated with a solid electrolyte is housed in the main body portion of the battery package having each of the above-described configurations.

[0013] Further, in the battery having the above-described configuration, it is preferable that the metal tabs of the positive electrode and the negative electrode protrude from between the flange plate at the upper end of the side plate adjacent to the side plate provided with the lid portion and the lid portion, and the flange plate is bent downward from the upper end of the side plate facing the side plate provided with the lid portion.

Advantages of the Invention

[0014] According to the present invention, the main body portion of the battery package has a bottom plate, side plates, and a flange plate, and a lid portion bent from the upper end of one of the side plates is adhered onto the flange plate. Further, a first connecting portion for connecting between adjacent side plates is double-folded by valley folding along an inclined first fold line and adhered. Thereby, a decrease in the barrier property of the gap between adjacent side plates is prevented, and the battery package can be formed by folding a laminate. Therefore, the yield and the volume efficiency of the battery package can be improved. Further, since the lid portion is bent from above one of the side plates, a flange plate is not formed on one side of the rectangular battery, so that the storage volume of a plurality of batteries can be reduced.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Mode for Carrying Out the Invention

[0016] <First Embodiment> The first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a battery 1 according to the first embodiment, and FIG. 2 is a perspective view of a battery packaging body 10 for the battery 1 according to the first embodiment.

[0017] The battery 1 hermetically houses a battery element 40 inside a battery package (hereinafter abbreviated as the package) 10. The battery 1 may be used as either a primary battery or a secondary battery, but a secondary battery is more preferable. Also, the type of secondary battery is not particularly limited, and examples include a lithium-ion battery, a lithium-ion polymer battery, a lead storage battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, a nickel-iron storage battery, a nickel-zinc storage battery, a silver oxide-zinc storage battery, a metal-air battery, a polyvalent cation battery, a capacitor, a capacitor, and the like. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries are mentioned as suitable application targets for the battery 1 of the present embodiment.

[0018] The battery element 40 includes a positive metal tab 41a and a negative metal tab 41b that protrude from the package 10. The metal tabs 41a and 41b are sandwiched and adhered by a flange plate 23c and a lid portion 30 described later in a state of protruding outside the package 10. When the electrolyte is liquid, the inside of the package 10 is filled with an electrolytic solution separately from the battery element 40, and when the electrolyte is solid, the solid electrolyte is integrated with the battery element 40.

[0019] In addition, in FIG. 1, the metal tabs 41a and 41b protrude in the same direction, but the metal tabs 41a and 41b do not have to protrude in the same direction. For example, the metal tab 41a may protrude from the flange plate 23c side, and the metal tab 41b may protrude from the flange plate 23a side.

[0020] The package 10 is formed by bending a packaging material 100 (see FIG. 4) made of a laminate described later into a box shape. The package 10 has a main body portion 20 that houses the battery element 40 and a lid portion 30 that covers the main body portion 20.

[0021] The main body part 20 has rectangular side plates 22a to 22d erected from the four sides of a rectangular bottom plate 21, and has an opening 20a on the upper surface. Further, rectangular flange plates 23a to 23c that are bent outward are continuously provided at the upper ends of the three side plates 22a to 22c. A rectangular lid part 30 is continuously provided at the upper end of one side plate 22d. The lid part 30 is bent toward the main body part 20 side, and the outer peripheral part of the lid part 30 is brought into contact with the flange plates 23a to 23c, and they are thermally adhered by a later-described thermal adhesion layer (heat-fusible resin layer) 103 (see FIG. 4). Thereby, the periphery of the opening 20a is sealed by the lid part 30.

[0022] Also, adjacent side plates 22a to 22d are connected by connecting parts (first connecting parts) 24a to 24d (see FIG. 3) that are folded in half and have their inner surfaces thermally adhered. Connecting parts (second connecting parts) 26a to 26f that are connected to the connecting parts (first connecting parts) 24a to 24d are respectively provided at both ends of the flange plates 23a to 23c (see FIG. 3). The connecting parts 26a, 26d to 26f are folded in half and have their inner surfaces thermally adhered.

[0023] FIG. 3 shows a developed view of the packaging material 100 that constitutes the package 10. The packaging material 100 is provided with a valley fold line 11 indicated by a dashed-dotted line and a mountain fold line 12 indicated by a broken line at predetermined positions. The valley fold line 11 is valley-folded on the side of the thermal adhesion layer 103 (see FIG. 4) on the inner surface, and the mountain fold line 12 is mountain-folded on the side of the thermal adhesion layer 103 (see FIG. 4) on the inner surface.

[0024] Rectangular side plates 22a to 22d are respectively continuously provided on the four sides of the rectangular bottom plate 21 via the valley fold line 11. Rectangular flange plates 23a to 23c are respectively continuously provided on the upper sides of the three side plates 22a to 22c via the mountain fold line 12. A rectangular lid part 30 is continuously provided on the upper side of one side plate 22d via the valley fold line 11. The lid part 30 protrudes in the left-right direction in the drawing from the side plate 22d so as to be adjacent to the later-described connecting parts 24c and 24d.

[0025] The side edges of the adjacent side panels 22a to 22d are connected via square connection parts (first connection parts) 24a to 24d indicated by dashed-line hatching respectively. Note that the connection part 24a is connected to the side panel 22a via the mountain fold line 12 and is connected to the side panel 22b without passing through a fold line.

[0026] Similarly, the connection part 24b is connected to the side panel 22c via the mountain fold line 12 and is connected to the side panel 22b without passing through a fold line. The connection part 24c is connected to the side panel 22c via the mountain fold line 12 and is connected to the side panel 22d without passing through a fold line. The connection part 24d is connected to the side panel 22a via the mountain fold line 12 and is connected to the side panel 22d without passing through a fold line.

[0027] Valley fold lines (first fold lines) 11 that symmetrically cross the connection parts 24a to 24d from the corners of the bottom panel 21 are formed in the connection parts 24a to 24d. This valley fold line 11 is inclined at 45° with respect to each side of the bottom panel 21. That is, when the bottom panel 21 is placed on a horizontal plane, it is inclined at 45° with respect to the vertical direction.

[0028] At this time, the valley fold lines 11 on the connection parts 24a to 24d are extended and formed up to the extension of the mountain fold line 12 between the side panels 22a to 22c and the flange plates 23a to 23c. Thereby, when the side panels 22a to 22d are erected, the upper ends of the valley fold lines 11 on the connection parts 24a to 24d are arranged at the same height as the side panels 22a to 22d.

[0029] Square connection parts (second connection parts) 26a to 26f indicated by dot hatching are provided at both ends of the flange plates 23a to 23c respectively. The connection parts 26a to 26f connect the flange plates 23a to 23c and the connection parts 24a to 24d. The connection part 26a is connected to the flange plate 23a and the connection part 24a via a mountain fold line (second fold line) 12.

[0030] Similarly, the connecting portion 26d is connected to the flange plate 23c and the connecting portion 24b via a mountain fold line (second fold line) 12. The connecting portion 26e is connected to the flange plate 23c and the connecting portion 24c via a mountain fold line (second fold line) 12. The connecting portion 26f is connected to the flange plate 23a and the connecting portion 24d via a mountain fold line (second fold line) 12.

[0031] Also, the connecting portion 26b is connected to the flange plate 23b without passing through a fold line and is connected to the connecting portion 24a via a mountain fold line (second fold line) 12. Similarly, the connecting portion 26c is connected to the flange plate 23b without passing through a fold line and is connected to the connecting portion 24b via a mountain fold line (second fold line) 12. That is, the mountain fold line (second fold line) 12 is a fold line that connects the connecting portions 24a to 24d and the connecting portions 26a to 26f.

[0032] Also, valley fold lines 11 that cross the connecting portions 26a, 26d, 26e, 26f from the corners of the side plates 22a, 22c are formed in the connecting portions 26a, 26d, 26e, 26f. This valley fold line 11 is inclined at 45° with respect to the mountain fold line (second fold line) 12 that connects the connecting portions 26a, 26d, 26e, 26f and the connecting portions 24a to 24d.

[0033] The widths W1 (the depth when the packaging body 10 is assembled) of the side plates 22a to 22d are formed to be the same as the widths W2 of the flange plates 23a to 23c. Thereby, when the packaging body 10 is assembled, the side ends of the lid portion 30 and the open ends of the flange plates 23a, 23c can be made to coincide, and the packaging body 10 can be formed compactly.

[0034] FIG. 4 is a cross-sectional view showing the layer structure of the packaging material 100. The packaging material 100 is composed of a laminate in which a base material layer 101, a barrier layer 102, and a heat adhesive layer 103 are laminated in this order. The base material layer 101 and the barrier layer 102 are adhered via an adhesive layer 104. The barrier layer 102 and the heat adhesive layer 103 are adhered via an adhesive layer 105.

[0035] The thickness of the packaging material 100 is not particularly limited, but from the viewpoint of strength, it can be 50 μm or more. Also, from the viewpoints of formability and miniaturization of the battery 1, it is desirable that the packaging material 100 be thinner, and the thickness of the packaging material 100 can be, for example, 200 μm or less. The thickness of the packaging material 100 can preferably be 150 μm or less, more preferably 100 μm or less, and even more preferably 80 μm or less.

[0036] It is preferable that a lubricant be disposed on the surfaces of the base material layer 101 and the thermal adhesive layer 103. Note that the lubricant may be applied to the surfaces of the base material layer 101 and the thermal adhesive layer 103. Further, in addition to application, a lubricant may be included in the resin constituting the base material layer 101 or the thermal adhesive layer 103 and heated to bleed out the lubricant on the surfaces of the base material layer 101 and the thermal adhesive layer 103. The type of the lubricant is not particularly limited, but preferably includes amide-based lubricants.

[0037] The base material layer 101 is disposed on the outer surface side of the package 10 and has insulating properties. Examples of the material for forming the base material layer 101 include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, polyetherimide, polyimide, polycarbonate, and mixtures and copolymers thereof. Among these, it is preferable that the base material layer 101 include a layer formed of polyester or polyamide.

[0038] The base material layer 101 may be formed of a resin film, or may be formed by coating the above-described material on the barrier layer 102. When the base material layer 101 is formed of a resin film, a uniaxially stretched film is desirable, and a biaxially stretched film is more desirable. Since the stretched film has improved heat resistance by orientation crystallization, it is suitably used as the base material layer 101. For this reason, a biaxially stretched nylon film and a biaxially stretched polyester film can be suitably used, and in particular, a biaxially stretched polyethylene terephthalate film can be more suitably used.

[0039] In addition, in order to improve pinhole resistance and insulation properties, the base material layer 101 may be formed by laminating a plurality of resin films made of different materials (multilayer structuring). Specifically, examples include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of polyester films are laminated.

[0040] When the base material layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate in which a plurality of biaxially stretched nylon films are laminated, and a laminate in which a plurality of biaxially stretched polyester films are laminated are preferable.

[0041] For example, when the base material layer 1 is formed from two resin films, it is preferable to have a configuration in which a polyester resin and a polyester resin are laminated, a configuration in which a polyamide resin and a polyamide resin are laminated, or a configuration in which a polyester resin and a polyamide resin are laminated.

[0042] Moreover, it is more preferable to have a configuration in which polyethylene terephthalate and polyethylene terephthalate are laminated, a configuration in which nylon and nylon are laminated, or a configuration in which polyethylene terephthalate and nylon are laminated.

[0043] In addition, since the polyester resin is less likely to change color when, for example, an electrolytic solution adheres to the surface, in the said laminated structure, it is preferable to laminate the base material layer 1 so that the polyester resin is located in the outermost layer. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably about 2 to 25 μm. Also, resins made of different materials may be coated on the film.

[0044] The thickness of the base material layer 101 is formed to be, for example, 4 μm or more in order to improve the shape stability while reducing the thickness of the package 10. The thickness of the base material layer 101 can be preferably 10 μm or more and 75 μm or less, more preferably 10 μm or more and 50 μm or less.

[0045] The adhesive layer 104 preferably consists of a two-component curable adhesive or a one-component curable adhesive. The adhesive is not particularly limited and may be any of a chemical reaction type, a solvent evaporation type, a hot melt type, a hot press type, etc.

[0046] Specific examples of the adhesive components that can be used for forming the adhesive layer 104 include polyester resins, polyether adhesives, polyurethane adhesives, epoxy resins, phenolic resins, polyamide resins, polyolefin resins, polyvinyl acetate resins, cellulose adhesives, (meth)acrylic resins, polyimide resins, urea resins, amino resins, silicone resins, polycarbonates, rubbers, etc. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, polyurethane adhesives are more preferred. Also, pigments such as graphite and metal oxides, and additives described later may be added to the adhesive layer 104.

[0047] The thickness of the adhesive layer 104 is not particularly limited as long as it exhibits the function as an adhesive layer. For example, it can be 1 μm or more and 10 μm or less, preferably 2 μm or more and 5 μm or less.

[0048] The barrier layer 102 is a layer that has the function of preventing water vapor, oxygen, light, etc. from entering the inside of the battery 1 in addition to improving the strength of the package 10. The barrier layer 102 is formed of a metal foil such as aluminum, aluminum alloy, stainless steel, titanium, etc., and aluminum alloy foil and stainless steel foil are particularly preferred.

[0049] Examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. The stainless steel foil is preferably composed of austenitic stainless steel.

[0050] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferred.

[0051] The thickness of the stainless steel foil is not particularly limited, but preferable upper limits include 85 μm or less, 50 μm or less, 40 μm or less, and 25 μm or less. Preferable ranges include about 10 to 85 μm, about 10 to 50 μm, and about 15 to 25 μm.

[0052] Also, in order to prevent wrinkles and pinholes from occurring in the barrier layer 102 during the production of the packaging material 100, for example, it may be formed of a soft aluminum alloy foil that has been annealed.

[0053] The thickness of the barrier layer 102 is not particularly limited as long as it exhibits water vapor barrier properties. For example, it can be 10 μm or more and 100 μm or less, preferably 10 μm or more and 55 μm or less, and more preferably 10 μm or more and 38 μm or less.

[0054] For the stability of the adhesion of the barrier layer 102, prevention of dissolution and corrosion, etc., it is preferable that at least one surface, preferably both surfaces, are provided with an undercoat layer. The undercoat layer is formed, for example, by subjecting the surface of the barrier layer 102 to a chemical conversion treatment.

[0055] Examples of the chemical conversion treatment include chromate treatment and phosphoric acid chromate treatment. The undercoat layer can also be formed by coating a dispersion of fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, and barium sulfate in phosphoric acid, and then performing a baking treatment at 150 °C or higher. Further, a resin layer in which a cationic polymer is crosslinked with a crosslinking agent may be formed on the corrosion-resistant undercoat layer. When an undercoat layer is formed on the surface of the barrier layer 102 of the present invention, the undercoat layer is included in the barrier layer 102.

[0056] In addition, the barrier layer 102 can distinguish between MD (Machine Direction) and TD (Transverse Direction) in the manufacturing process. For example, when the barrier layer 102 is composed of an aluminum alloy foil, linear streaks called so-called rolling marks are formed on the surface of the aluminum alloy foil in the rolling direction (RD) of the aluminum alloy foil. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum alloy foil can be grasped by observing the surface of the aluminum alloy foil.

[0057] In addition, in the manufacturing process of the packaging material 100, usually, since the MD of the laminate coincides with the RD of the aluminum alloy foil, the MD of the laminate can be specified by observing the surface of the aluminum alloy foil of the laminate and specifying the rolling direction (RD) of the aluminum alloy foil. Also, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be specified.

[0058] The thermal adhesive layer 103 is arranged in the innermost layer, and the thermal adhesive layers 103 are heat-sealed to each other when the package 10 is assembled. The resin component used for the thermal adhesive layer 103 is not particularly limited as long as it can be heat-sealed. For example, polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin can be mentioned.

[0059] In addition, the thermal adhesive layer 103 may be formed of a single resin component alone, or may be formed of a blend polymer in which two or more resin components are combined. Furthermore, the thermal adhesive layer 103 may be formed of only one layer, or may be formed of two or more layers with the same or different resin components.

[0060] The thickness of the thermal adhesive layer 103 is not particularly limited as long as it exhibits heat-sealing properties, but preferably can be about 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less.

[0061] The subsequent layer 105 can use the same adhesive as the adhesive exemplified in the adhesive layer 104. Also, as the adhesive layer 105, polyolefin-based resins such as polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the thermal adhesive layer 103 can also be used. From the viewpoint of excellent adhesion between the barrier layer 102 and the thermal adhesive layer 103, carboxylic acid-modified polyolefin is preferable, and carboxylic acid-modified polypropylene is particularly preferable.

[0062] Also, in order to reduce the thickness of the package 10 while improving the shape stability, as the adhesive layer 105, a resin composition containing an acid-modified polyolefin and a curing agent is preferably used. Examples of the acid-modified polyolefin include carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin. The curing agent is not particularly limited, and examples thereof include epoxy-based curing agents, polyfunctional isocyanate-based curing agents, carbodiimide-based curing agents, and oxazoline-based curing agents.

[0063] The preferable range of the thickness of the adhesive layer 105 is 2 μm or more and 50 μm or less. Also, when using the adhesive exemplified in the adhesive layer 104, it can be preferably 2 μm or more and 10 μm or less, more preferably 2 μm or more and 5 μm or less. Also, when using the resin exemplified in the thermal adhesive layer 103, it can be preferably 2 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less.

[0064] Also, for the purpose of improving design, electrolyte resistance, scratch resistance, formability, etc., a surface coating layer (not shown) may be provided on the upper surface of the base material layer 101 (the surface of the base material layer 101 opposite to the barrier layer 102). The surface coating layer is the layer located on the outermost layer when the battery 1 is assembled. When providing the surface coating layer, a lubricant may be disposed on the surface of the surface coating layer.

[0065] The surface coating layer can be formed, for example, by polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, etc. Also, from the viewpoint of further enhancing the electrolyte resistance of the surface of the package 10, the surface coating layer may be formed of a mixed resin combining urethane resin and acrylic resin, etc. Among these, it is preferable to form the surface coating layer with a two-component curable resin. Examples of the two-component curable resin for forming the surface coating layer include two-component curable urethane resin, two-component curable polyester resin, two-component curable epoxy resin, etc.

[0066] Also, additives may be blended in the surface coating layer. Examples of the additives include fine particles having a particle size of 0.5 nm or more and 5 μm or less. The material of the additives is not particularly limited, and examples include metals, metal oxides, inorganic substances, organic substances, etc. Also, the shape of the additives is not particularly limited, and examples include spherical, fibrous, plate-like, amorphous, balloon-like, etc. Also, pigments such as graphite and metal oxides may be added to the surface coating layer. Also, for example, a matting agent that forms irregularities on the surface of the surface coating layer may be added to the surface coating layer. At this time, the surface coating layer with an uneven surface can function as a mat layer. As the matting agent, the additives shown above can be used.

[0067] The packaging material 100 is formed, for example, by punching a roll-shaped laminate into a predetermined shape by punching. At this time, it is preferable that the valley fold line 11 and the mountain fold line 12 are formed by a die line. The valley fold line 11 is formed by a die line pressed from the side of the heat adhesive layer 103 of the packaging material 100. The mountain fold line 12 is formed by a die line pressed from the side of the base material layer 101 of the packaging material 100. By providing the die line, the packaging material 100 can be surely bent along the valley fold line 11 and the mountain fold line 12.

[0068] The packaging material 100 with the above structure is bent along the valley fold line 11 and the mountain fold line 12 to form the package 10. That is, the side plates 22a to 22d are erected by valley folding from the periphery of the bottom plate 21. At this time, the connecting parts 24a to 24d are folded in half on the valley fold line 11 (the first fold line) and thermally adhered by the thermal adhesive layer 103 on the inner surface. As a result, the folded connecting parts 24a and 24b are arranged along the side plate 22b, and the folded connecting parts 24c and 24d are arranged along the side plate 22d.

[0069] Next, the flange plates 23a to 23c are mountain-folded from the upper ends of the side plates 22a to 22c, and the connecting parts 26a to 26f are mountain-folded from the upper ends of the connecting parts 24a to 24d. At this time, the connecting parts 26a, 26d to 26f are folded in half on the valley fold line 11 and thermally adhered by the thermal adhesive layer 103 on the inner surface.

[0070] As a result, one of the adjacent connecting parts 26a and 26b sandwiching the connecting part 24a is folded, and one of the adjacent connecting parts 26c and 26d sandwiching the connecting part 24b is folded. As a result, a U-shaped flange F (see Fig. 2) in which the flange plates 23a to 23c and the connecting parts 26b and 26c are connected is formed around the opening 20a. Also, the connecting parts 26e and 26f are folded, and the lid part 30 is adjacent to the flange plates 23a and 23c.

[0071] Next, the battery element 40 is housed in the main body part 20. At this time, for example, the metal tabs 41a and 41b are arranged on the flange plate 23c. When the battery element 40 is housed, the lid part 30 is valley-folded from the upper end of the side plate 22d, and the outer peripheral part of the lid part 30 and the flange plates 23a to 23c are thermally adhered by the thermal adhesive layer 103 leaving a partially unsealed part. Then, after the electrolyte is injected from the unsealed part, the unsealed part is thermally adhered by the thermal adhesive layer 103 to form the battery 1. At this time, when the bottom plate 21 is placed on a horizontal plane, the lid part 30 is arranged above the bottom plate 21.

[0072] Note that the method of injecting the above electrolyte is just an example and is not limited to this method. For example, one side of the flange plate 23c may be left as an unsealed part. In this case, two sides of the other flange plates 23a and 23b are heat-sealed, and after the electrolyte is injected from the unsealed part, one side of the flange plate 23c of the unsealed part is heat-sealed.

[0073] Since the package 10 is formed by bending the packaging material 100, it is possible to prevent the thinning and cracking of the barrier layer 102. In addition, the radius of curvature during the bending of the side plates and the flange plates can be reduced. Therefore, the yield and volume efficiency of the package 10 can be improved.

[0074] Also, when the thickness of the barrier layer 102 is B at the middle position of the height (depth) of the side plates 22a to 22d and C at the connecting portion of the side plates 22a to 22d and the bottom plate 21, the ratio (%) of the thickness of B to C calculated by (B / C)×100 is 100±10% or less, so that the thickness of the barrier layer 102 is made substantially the same in the height direction, and a package 10 with high volume efficiency can be formed while preventing a decrease in strength. Further, the ratio (%) of the thickness of B to C is preferably 100±5% or less, and more preferably 100±2% or less.

[0075] Also, since the connecting portions 24a to 24d are folded in half along the valley fold line 11 and heat-bonded, it is possible to prevent a decrease in the barrier property of the gap between the adjacent side plates 22a to 22d. At this time, the valley fold line 11 on the folded connecting portions 24a to 24d is inclined outward upward, and the upper end of the valley fold line 11 is arranged at the same height as the upper ends of the side plates 22a to 22d. For this reason, the outer end face of the outer shape of the packaging material 100 is not exposed at the upper end portions of the connecting portions 24a to 24d, and it is possible to prevent water vapor and the like from entering the main body portion 20 through the heat-bonding layer 103.

[0076] Further, the connecting portion 26b is thermally bonded to the lid portion 30 together with the flange plate 23b, and the connecting portion 26a disposed between the connecting portion 24a and the flange plate 23a is folded in half and thermally bonded. Therefore, it is possible to prevent a gap from being formed at the upper end of the ridge line between the adjacent side plates 22a and 22b. Similarly, it is possible to prevent a gap from being formed at the upper ends between the adjacent side plates 22a to 22d by the connecting portions 26c to 26f. Therefore, it is possible to more reliably prevent a decrease in barrier properties.

[0077] According to the present embodiment, the main body portion 20 of the package 10 has a bottom plate 21, side plates 22a to 22d, and flange plates 23a to 23c, and a lid portion 30 bent from the upper end of one side plate 22d is adhered onto the flange plates 23a to 23c. Further, the connecting portions 24a to 24d (first connecting portions) connecting between the adjacent side plates 22a to 22d are folded in half by valley folding on the inclined valley fold line 11 (first fold line) and adhered.

[0078] Thereby, a decrease in the barrier property of the gap between the adjacent side plates 22a to 22d is prevented, and the package 10 can be formed by folding a packaging material 100 made of a laminate. Therefore, the yield and volume efficiency of the package 10 can be improved.

[0079] Further, since the lid portion 30 is bent from above one side plate 22d, a flange plate is not formed on the side plate 22d on one side of the rectangular package 10. Therefore, a plurality of batteries 1 standing upright with the side plate 22d facing downward can be arranged in a stacked manner, and the storage volume of the plurality of batteries 1 can be reduced.

[0080] When the flange plate 23b on the side plate 22b facing the side plate 22d to which the lid portion 30 is continuously provided is bent downward, the storage volume of the battery 1 can be further reduced. Thereby, when a plurality of batteries 1 are arranged side by side and enlarged, the storage volume of each battery 1 can be reduced to improve the volume energy density of the entire battery. Note that the flange plate 23a facing the flange plate 23c provided with the metal tabs 41a and 41b may be bent downward.

[0081] In addition, connecting portions (second connecting portions) 26a to 26f are provided at both ends of the flange plates 23a to 23c, and the connecting portions (second connecting portions) 26a to 26f are connected to the upper ends of the connecting portions (first connecting portions) 24a to 24d via a mountain fold line (second fold line) 12. Thereby, it is possible to prevent a decrease in the barrier property at the upper end of the ridge line between adjacent side plates 22a to 22d.

[0082] Further, the adjacent connecting portions (second connecting portions) 26a and 26d of the connecting portions (second connecting portions) 26b and 26c are folded in two by valley folding and adhered. Thereby, it is possible to easily form the flange F that is continuously U-shaped.

[0083] Further, the connecting portions (second connecting portions) 26e and 26f adjacent to the lid portion 30 with the doubled connecting portions 24c and 24d interposed therebetween are folded in two by valley folding and adhered. Thereby, it is possible to easily form the lid portion 30 that is superimposed on the U-shaped flange F.

[0084] In addition, the upper ends of the valley fold lines (first fold lines) 11 on the connecting portions 24a to 24d are arranged at the same height as the upper ends of the side plates 22a to 22d. Thereby, the outer shape end surface of the packaging material 100 is not exposed at the upper end portion of the connecting portion (first connecting portion) that is folded in two, and it is possible to prevent water vapor or the like from entering the main body portion 20 through the heat adhesive layer 103.

[0085] In addition, the ratio of the thickness of the barrier layer 102 at the intermediate position in the height direction of the side plates 22a to 22d to the thickness of the barrier layer 102 at the connecting portion between the side plates 22a to 22d and the bottom plate 21 is 100 ± 10% or less, so that the thickness of the barrier layer 102 is made substantially the same in the height direction, and it is possible to form the packaging body 10 with high volume efficiency while preventing a decrease in strength.

[0086] Note that FIG. 5 is a development view showing a modified example of the package 10 of the present embodiment. The width W1 of the side plates 22a to 22d may be formed smaller than the width W2 of the flange plates 23a to 23c. In this case, the valley fold lines 11 formed at the connecting portions 26a, 26d, 26e, 26f are inclined at 45° with respect to the mountain fold lines 12 that connect the connecting portions 26a, 26d, 26e, 26f and the connecting portions 24a to 24d.

[0087] <Second Embodiment> FIG. 6 shows a development view of the package 10 of the battery 1 of the second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals. In this embodiment, the shapes of the connecting portions 24a to 24d are different from those of the first embodiment. Other parts are the same as those of the first embodiment.

[0088] The width W1 of the side plates 22a to 22d is formed larger than the width W2 of the flange plates 23a to 23c. Since the width W2 of the flange plates 23a to 23c is small, the battery 1 can be miniaturized and the volume efficiency can be improved.

[0089] Further, the distance W3 between the extension line of the valley fold line 11 connecting the bottom plate 21 and the side plates 22a, 22c and the outer periphery of the lid portion 30 is formed to be the same as the width W2 of the flange plates 23a to 23c. Thereby, when the lid portion 30 is disposed on the flange F, the outer edge of the lid portion 30 can be made to coincide with the outer edges of the flange plates 23a, 23c and the connecting portions 26b, 26c. At this time, the connecting portions 24a to 24d (first connecting portions) are formed in an L shape with a rectangular notch K1 shown by solid-line hatching provided at the corners.

[0090] Since the connecting portions 24a to 24d are L-shaped, the valley fold lines 11 on the connecting portions 24a to 24d do not reach the extension of the mountain fold line 12 between the side plates 22a to 22c and the flange plates 23a to 23c. Therefore, when the side plates 22a to 22d are erected, the upper ends of the valley fold lines 11 on the connecting portions 24a to 24d are lower than the side plates 22a to 22d.

[0091] <Third Embodiment> FIG. 7 shows a developed view of the package 10 of the battery 1 according to the third embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals. In this embodiment, the arrangement of the valley fold line 11 and the mountain fold line 12 with respect to the connecting portions 26a to 26d is different from that in the first embodiment. Other parts are the same as those in the first embodiment.

[0092] The side edges of the adjacent side plates 22a to 22d are connected via square connecting portions (first connecting portions) 24a to 24d, respectively. Note that the connecting portion 24a is connected to the side plate 22b via the mountain fold line 12 and is connected to the side plate 22a without passing through a fold line.

[0093] Similarly, the connecting portion 24b is connected to the side plate 22b via the mountain fold line 12 and is connected to the side plate 22c without passing through a fold line. The connecting portion 24c is connected to the side plate 22c via the mountain fold line 12 and is connected to the side plate 22d without passing through a fold line. The connecting portion 24d is connected to the side plate 22a via the mountain fold line 12 and is connected to the side plate 22d without passing through a fold line.

[0094] Also, the connecting portion 26b is connected to the flange plate 23b and the connecting portion 24a via the mountain fold line (second fold line) 12. The connecting portion 26c is connected to the flange plate 23b and the connecting portion 24b via the mountain fold line (second fold line) 12. The connecting portion 26e is connected to the flange plate 23c and the connecting portion 24c via the mountain fold line (second fold line) 12. The connecting portion 26f is connected to the flange plate 23a and the connecting portion 24d via the mountain fold line (second fold line) 12.

[0095] Also, the connecting portion 26a is connected to the flange plate 23a without passing through a fold line and is connected to the connecting portion 24a via the mountain fold line (second fold line) 12. Similarly, the connecting portion 26d is connected to the flange plate 23c without passing through a fold line and is connected to the connecting portion 24b via the mountain fold line (second fold line) 12.

[0096] Further, valley fold lines 11 are formed in the connecting portions 26b, 26c, 26e, 26f so as to cross the connecting portions 26b, 26c, 26e, 26f from the corners of the side plates 22b, 22c, 22a. The valley fold lines 11 are inclined at 45° with respect to mountain fold lines (second fold lines) 12 that connect the connecting portions 26b, 26c, 26e, 26f and the connecting portions 24a to 24d.

[0097] The flange plates 23a to 23c are mountain-folded from the upper ends of the side plates 22a to 22c, and the connecting portions 26a to 26f are mountain-folded from the upper ends of the connecting portions 24a to 24d. At this time, the connecting portions 26b, 26c, 26e, 26f are double-folded on the valley fold lines 11 and thermally adhered by the inner heat adhesive layer 103.

[0098] As a result, one of the adjacent connecting portions 26a and 26b sandwiching the connecting portion 24a is folded, and one of the adjacent connecting portions 26c and 26d sandwiching the connecting portion 24b is folded. As a result, a U-shaped flange F in which the flange plates 23a to 23c and the connecting portions 26a and 26d are connected is formed around the opening 20a. Further, the connecting portions 26e and 26f are folded, and the lid portion 30 is adjacent to the flange plates 23a and 23c. Therefore, the same effect as that of the first embodiment can be obtained also in this embodiment.

[0099] In this embodiment, the connecting portions 24a to 24d may be formed in an L shape as in the second embodiment.

[0100] <Fourth Embodiment> FIG. 8 shows a developed view of the package 10 of the battery 1 according to the fourth embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those in the first embodiment shown in FIGS. 1 to 4 described above. In this embodiment, the arrangement of the valley fold lines 11 is different with respect to the connecting portions 26a, 26d, 26e, 26f and the flange plates 23a, 23c. Other parts are the same as those in the first embodiment.

[0101] On both sides of the flange plates 23a and 23c, a pair of valley fold lines 11 are formed which extend from the corners of the side plates 22a and 22c in a direction approaching each other and obliquely cross the flange plates 23a and 23c. This valley fold line 11 is inclined at 45° with respect to the mountain fold line 12 connecting the flange plates 23a and 23c and the side plates 22a and 22c.

[0102] While bending the mountain fold line 12 connecting the flange plates 23a and 23c and the connecting portions 26a, 26d, 26e, and 26f, the valley fold line 11 that obliquely crosses the flange plates 23a and 23c is bent to fold both side portions of the flange plates 23a and 23c and thermally bond them with the thermal adhesive layer 103 on the inner surface. At this time, the connecting portions 26a and 26d respectively overlap one side portion of the flange plates 23a and 23c. As a result, a U-shaped flange F in which the flange plates 23a to 23c and the connecting portions 26a to 26d are connected is formed around the opening 20a. Further, the connecting portions 26e and 26f respectively overlap the other side portion of the flange plates 23a and 23c, and the lid portion 30 is adjacent to the flange plates 23a and 23c. Therefore, also in this embodiment, the same effects as those of the first embodiment can be obtained.

[0103] Further, the flange plates 23a and 23c are not continuously provided with the connecting portions 24a and 24b via a fold line. For this reason, since the flange plates 23a and 23c and the connecting portions 24a and 24b that are valley-folded and thermally bonded do not adjoin each other, the flange plates 23a and 23c and the connecting portions 24a and 24b can be easily thermally bonded in separate steps respectively.

[0104] In this embodiment, the connecting portions 24a to 24d may be formed in an L shape in the same manner as in the second embodiment.

[0105] Note that FIG. 9 is a developed view showing a modified example of the package 10 of this embodiment. On both sides of the flange plates 23a and 23c, a pair of mountain fold lines 12 are formed which extend from the corners of the side plates 22a and 22c in a direction approaching each other and obliquely cross the flange plates 23a and 23c. Further, the flange plates 23a and 23c and the connecting portions 26a, 26d, 26e, and 26f are continuously provided via the valley fold line 11.

[0106] Fold the valley fold line 11 connecting the flange plates 23a and 23c and the connecting parts 26a, 26d, 26e, and 26f, and fold the mountain fold line 12 that obliquely crosses the flange plates 23a and 23c to fold both side portions of the flange plates 23a and 23c and thermally bond them to the connecting parts 26a, 26d, 26e, and 26f with the thermal adhesive layers 103 respectively. At this time, the connecting parts 26a and 26d overlap one side portion of the flange plates 23a and 23c respectively. Therefore, the same effects as those of the present embodiment can be obtained in this modified example as well.

[0107] <Fifth Embodiment> FIG. 10 shows a developed view of the package 10 of the battery 1 according to the fifth embodiment. For convenience of explanation, the same parts as those in the fourth embodiment shown in FIG. 8 described above are denoted by the same reference numerals. In this embodiment, the arrangements of the valley fold line 11 and the mountain fold line 12 are different with respect to the connecting parts 26a to 26f and the flange plates 23a to 23c. Other parts are the same as those in the fourth embodiment.

[0108] A pair of valley fold lines 11 extending in a direction approaching each other from the corners of the side plates 22b and obliquely crossing the flange plate 23b are formed on both side portions of the flange plate 23b. This valley fold line 11 is inclined at 45° with respect to the mountain fold line 12 connecting the flange plate 23b and the side plate 22b.

[0109] Also, the connecting part 24a is connected to the side plate 22b via the mountain fold line 12 and is connected to the side plate 22a without passing through a fold line. Similarly, the connecting part 24b is connected to the side plate 22b via the mountain fold line 12 and is connected to the side plate 22c without passing through a fold line. The connecting part 24c is connected to the side plate 22c via the mountain fold line 12 and is connected to the side plate 22d without passing through a fold line. The connecting part 24d is connected to the side plate 22a via the mountain fold line 12 and is connected to the side plate 22d without passing through a fold line.

[0110] Further, the connecting portion 26b is connected to the flange plate 23b and the connecting portion 24a via a mountain fold line (second fold line) 12. The connecting portion 26c is connected to the flange plate 23b and the connecting portion 24b via a mountain fold line (second fold line) 12. The connecting portion 26e is connected to the flange plate 23c and the connecting portion 24c via a mountain fold line (second fold line) 12. The connecting portion 26f is connected to the flange plate 23a and the connecting portion 24d via a mountain fold line (second fold line) 12.

[0111] Also, the connecting portion 26a is connected to the flange plate 23a without passing through a fold line and is connected to the connecting portion 24a via a mountain fold line (second fold line) 12. Similarly, the connecting portion 26d is connected to the flange plate 23c without passing through a fold line and is connected to the connecting portion 24b via a mountain fold line (second fold line) 12.

[0112] While bending the mountain fold line 12 that connects the flange plate 23b and the connecting portions 26b and 26c, the valley fold line 11 that traverses the flange plate 23b obliquely is bent to fold both side portions of the flange plate 23b and thermally bond them with the thermal adhesive layer 103 on the inner surface. At this time, the connecting portions 26b and 26c overlap the both side portions of the flange plate 23b respectively. As a result, a U-shaped flange F in which the flange plates 23a to 23c and the connecting portions 26a to 26d are connected is formed around the opening 20a. Therefore, in this embodiment as well, the same effects as those of the first embodiment can be obtained.

[0113] Also, the flange plate 23b is not continuously provided with the connecting portions 24a and 24b via a fold line. For this reason, since the flange plate 23b and the connecting portions 24a and 24b that are valley-folded and thermally bonded do not abut on each other, the flange plate 23b and the connecting portions 24a and 24b can be easily thermally bonded in separate steps respectively.

[0114] In this embodiment, the connecting portions 24a to 24d may be formed in an L shape as in the second embodiment.

[0115] Note that FIG. 11 is a development view showing a modified example of the package 10 of the present embodiment. On both sides of the flange plate 23b, a pair of mountain fold lines 12 are formed which extend from the corners of the side plates 22b in a direction approaching each other and obliquely cross the flange plate 23b. Further, the flange plate 23b and the connecting portions 26b, 26c are connected continuously via a valley fold line 11.

[0116] While bending the valley fold line 11 that connects the flange plate 23b and the connecting portions 26b, 26c, and bending the mountain fold line 12 that obliquely crosses the flange plate 23b to fold both sides of the flange plate 23b, the connecting portions 26b, 26c are heat-bonded to the heat-bonding layer 103 respectively. At this time, the connecting portions 26b, 26c overlap the both sides of the flange plate 23b respectively. Therefore, also in this modified example, the same effect as that of the present embodiment can be obtained.

[0117] <Sixth Embodiment> FIG. 12 shows a development view of the package 10 of the battery 1 of the sixth embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals. In this embodiment, the arrangement of the valley fold line 11 and the mountain fold line 12 is different with respect to the connecting portions 26a, 26d, 26e, 26f. Other parts are the same as those in the first embodiment.

[0118] Mountain fold lines 12 that cross the connecting portions 26a, 26d, 26e, 26f from the corners of the side plates 22a, 22c are formed in the connecting portions 26a, 26d, 26e, 26f. This mountain fold line 12 is inclined at 45° with respect to the fold line that connects the connecting portions 26a, 26d, 26e, 26f and the connecting portions 24a to 24d.

[0119] Further, the connecting portion 26a is connected to the flange plate 23a without passing through a fold line, and is connected to the connecting portion 24a via a valley fold line (second fold line) 11. Similarly, the connecting portion 26d is connected to the flange plate 23c without passing through a fold line, and is connected to the connecting portion 24b via a valley fold line (second fold line) 11.

[0120] Further, the connecting portion 26b is connected to the flange plate 23b without passing through a folding line, and is connected to the connecting portion 24a through a mountain folding line (second folding line) 12. Similarly, the connecting portion 26c is connected to the flange plate 23b without passing through a folding line, and is connected to the connecting portion 24b through a mountain folding line (second folding line) 12.

[0121] Further, the connecting portion 26e is connected to the flange plate 23c through a valley folding line 11, and is connected to the connecting portion 24c through a mountain folding line (second folding line) 12. Similarly, the connecting portion 26f is connected to the flange plate 23a through a valley folding line 11, and is connected to the connecting portion 24d through a mountain folding line (second folding line) 12.

[0122] Fold along the mountain folding line 12 connecting the flange plates 23a, 23c and the side plates 22a, 22c, and fold the connecting portions 26a, 26d along the mountain folding line 12. Next, overlap the double-folded connecting portions 26a, 26d with the connecting portions 26b, 26c arranged on both sides of the flange plate 23b, respectively, and thermally bond them with the thermal adhesive layer 103. As a result, a U-shaped flange F in which the flange plates 23a to 23c and the connecting portions 26a to 26d are connected is formed around the opening 20a.

[0123] Further, fold the connecting portions 26e, 26f along the mountain folding line 12 and overlap them with one side of the flange plates 23a, 23c, respectively, and thermally bond them with the thermal adhesive layer 103. As a result, the lid portion 30 is adjacent to the flange plates 23a, 23c. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment as well.

[0124] Further, the connecting portions 26a, 26d are mountain-folded and thermally bonded, and there is no region that is valley-folded and thermally bonded in the region where they are connected to the connecting portions 24a, 24b that are valley-folded and thermally bonded through a folding line. Therefore, the connecting portions 26a, 26d and the connecting portions 24a, 24b can be easily thermally bonded in separate steps.

[0125] In this embodiment, the connecting portions 24a to 24d may be formed in an L shape in the same manner as in the second embodiment.

[0126] <Seventh Embodiment> FIG. 13 shows a developed view of the package 10 of the battery 1 of the sixth embodiment. For convenience of explanation, the same parts as those of the sixth embodiment shown in FIG. 12 described above are denoted by the same reference numerals. In this embodiment, the arrangements of the valley fold lines 11 and the mountain fold lines 12 are different with respect to the connecting portions 26a to 26f. Other parts are the same as those of the sixth embodiment.

[0127] Mountain fold lines 12 that cross the connecting portions 26b and 26c from the corners of the side plate 22b are formed in the connecting portions 26b and 26c. This mountain fold line 12 is inclined at 45° with respect to the fold line that connects the connecting portions 26b and 26c and the connecting portions 24a and 24b.

[0128] Further, the connecting portion 26a is connected to the flange plate 23a without passing through a fold line, and is connected to the connecting portion 24a via a mountain fold line (second fold line) 12. Similarly, the connecting portion 26d is connected to the flange plate 23c without passing through a fold line, and is connected to the connecting portion 24b via a mountain fold line (second fold line) 12.

[0129] Further, the connecting portion 26b is connected to the flange plate 23b without passing through a fold line, and is connected to the connecting portion 24a via a valley fold line (second fold line) 11. Similarly, the connecting portion 26c is connected to the flange plate 23b without passing through a fold line, and is connected to the connecting portion 24b via a valley fold line (second fold line) 11.

[0130] Further, the connecting portion 26e is connected to the flange plate 23c via a valley fold line 11, and is connected to the connecting portion 24c via a mountain fold line (second fold line) 12. Similarly, the connecting portion 26f is connected to the flange plate 23a via a valley fold line 11, and is connected to the connecting portion 24d via a mountain fold line (second fold line) 12.

[0131] Fold along the mountain fold line 12 connecting the flange plate 23b and the side plate 22b, and fold the connecting parts 26b and 26c along the mountain fold line 12. Next, overlap the double-folded connecting parts 26b and 26c with the connecting parts 26a and 26d arranged on one side of the flange plates 23a and 23c respectively, and thermally bond them with the thermal adhesive layer 103. As a result, a U-shaped flange F in which the flange plates 23a to 23c and the connecting parts 26a to 26d are connected is formed around the opening 20a.

[0132] Also, fold the connecting parts 26e and 26f along the mountain fold line 12, overlap them with one side of the flange plates 23a and 23c respectively, and thermally bond them with the thermal adhesive layer 103. As a result, the lid portion 30 is adjacent to the flange plates 23a and 23c. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment as well.

[0133] In addition, the connecting parts 26b and 26c are mountain-folded and thermally bonded, and there is no valley-folded and thermally bonded area in the area where they are connected to the connecting parts 24a and 24b which are valley-folded and thermally bonded via a fold line. For this reason, the connecting parts 26b and 26c and the connecting parts 24a and 24b can be easily thermally bonded in separate steps.

[0134] In this embodiment, the connecting parts 24a to 24d may be formed in an L shape in the same manner as in the second embodiment.

[0135] Note that a part of the connecting parts 26a to 26f and the flange plates 23a to 23c in the first to seventh embodiments may be replaced with the connecting parts 26a to 26f and the flange plates 23a to 23c in other embodiments, and the arrangements of the valley fold lines 11 and the mountain fold lines 12 on the connecting parts 26a to 26f and the flange plates 23a to 23c may be combined.

[0136] Also, the present invention is not limited to the above-described embodiments, and various other modifications are possible. For example, in the above embodiments, the rectangular shape means a substantially rectangular shape and a rectangular shape. Similarly, the connecting parts (first connecting parts) 24a to 24d may be substantially square. Also, the valley fold line 11 inclined at 45° may be slightly deviated within the range of error.

[0137] In addition, the sizes of the width W1, width W2, and distance W3 may also deviate slightly within the range of error. For example, in the first embodiment, the width W1 (depth when the package 10 is assembled) of the side plates 22a to 22d may deviate slightly from the width W2 of the flange plates 23a to 23c within the range of error. Also, the distance W3 between the extension line of the valley fold line 11 connecting the bottom plate 21 and the side plates 22a and 22c and the outer periphery of the lid portion 30 may deviate slightly from the width W2 of the flange plates 23a to 23c within the range of error.

Example

[0138] Hereinafter, the effects of the present invention will be described in more detail using examples.

[0139] Examples 1 to 7 are the packages 10 of the first embodiment, and the package 10 was formed by bending a single packaging material 100 along the valley fold line 11 and mountain fold line 12 formed by engraving. The opening 20a of the main body 20 was set to 100 mm × 240 mm, and the radius of curvature of the connecting portion between the bottom plate 21 and the side plates 22a to 22d was set to 0.5 mm. Also, the radius of curvature of the connecting portion between the side plates 22a to 22d and the flange plates 23a to 23c was set to 0.5 mm. Further, in Examples 1 to 7, the depth H of the package 10 (corresponding to the width W1 in FIG. 3) was set to 3 mm, 4 mm, 5 mm, 6 mm, 10 mm, 15 mm, and 20 mm, respectively.

[0140] The base material layer 101 of the packaging material 100 was formed by adhering a polyethylene terephthalate film (thickness 12 μm) and a stretched nylon film (thickness 15 μm) via a dry laminating adhesive (thickness 3 μm). The barrier layer 102 used an aluminum alloy foil (thickness 40 μm). For the adhesive layer 104, an aluminum alloy foil and a stretched nylon film were adhered using a dry laminating adhesive (thickness 3 μm). The heat adhesive layer 103 used a polypropylene film (thickness 40 μm). The adhesive layer 105 used acid-modified polypropylene (thickness 40 μm).

[0141] Further, for Comparative Examples 1 to 4, the same laminate as the packaging material 100 of Examples 1 to 7 was cold press formed to form trays having the same volume as those of Examples 1 to 7. Specifically, for Comparative Examples 1 to 4, the packaging material 100 was cut into a rectangle (150 mm × 300 mm), and a tray was formed by cold press forming using male and female molding dies. Note that the short side of the cut packaging material 100 coincides with the MD (flow direction) of the packaging material 100, and the long side coincides with the TD (width direction) of the packaging material 100.

[0142] Further, the female molding die has a rectangular opening (100 mm × 240 mm) and is made of a die having a maximum height roughness (designated value of Rz) of 3.2 μm as defined in "Table 2 of Supplementary Book 1 (Reference) Comparison Surface Roughness Standard Pieces" of JIS B 0659-1:2002. Also, the corner of the female molding die is 0.5 mm, and the ridge line is 0.5 mm. These values correspond to the radius of curvature of the continuous portion between the side plate and the flange plate after press forming.

[0143] Further, the male molding die is made of a die having a maximum height roughness (designated value of Rz) of 1.6 μm as defined in "Table 2 of Supplementary Book 1 (Reference) Comparison Surface Roughness Standard Pieces" of JIS B 0659-1:2002. Also, the corner of the male molding die is 0.5 mm, and the ridge line is 0.5 mm. These values correspond to the radius of curvature of the continuous portion between the bottom plate and the side plate after press forming. Also, the clearance between the male molding die and the female molding die was set to 0.3 mm.

[0144] Also, the packaging material 100 is placed so as to cover the opening of the female molding die and cold press formed with the male molding die. At this time, the MD of the packaging material 100 is made to coincide with the short side of the opening of the molding die, and the TD of the packaging material 100 is made to coincide with the long side of the opening of the molding die, and the packaging material 100 is placed on the female molding die so that the thermally adhesive resin layer abuts against the male molding die side and press formed.

[0145] Further, for Comparative Examples 1 to 4, the forming depth (depth H of the tray) was formed to be 3 mm, 4 mm, 5 mm, and 6 mm, respectively.

[0146] FIG. 14 is a top view of the package 10, and FIG. 15 is a cross-sectional view taken along the line X-X in FIG. 14. Note that FIG. 15 shows the layer structure of the package 100. For the packages formed in Examples 1 to 7 and Comparative Examples 1 to 4, as shown in FIG. 14, along the straight line L passing through the corner P1 of the connecting portion 26b and the corner P2 of the opening 20a when viewing the opening 20a from above in a plan view, the package was cut in half in the thickness direction using a microtome (product number: REM-710 Retratome, manufactured by Yamato Koki Co., Ltd.), and the obtained cross-section was observed with a laser microscope (product number: VK-9700, manufactured by Keyence Corporation) to measure the thickness of the barrier layer 102. The results are shown in Table 1.

[0147] Note that the thickness of the barrier layer 102 was measured at the connecting portion of the side plate and the flange plate (indicated by A in Table 1), the middle position of the height of the side plate (indicated by B in Table 1), and the connecting portion of the side plate and the bottom plate (indicated by C in Table 1), respectively. Also, for the packages 10 of Examples 1 to 7, the thickness of the barrier layer 102 was measured at the connecting portion of the connecting portion 24a and the connecting portion 26b (indicated by A in Table 1), the middle position of the height of the connecting portion 24a (indicated by B in Table 1), and the connecting portion of the connecting portion 24a and the bottom plate 21 (indicated by C in Table 1), respectively.

[0148] Also, from the thicknesses A to C at each measured position, the ratio (%) of the thickness of A to C was calculated as (A / C)×100 and summarized in Table 1. Also, the ratio (%) of the thickness of B to C was calculated as (B / C)×100 and summarized in Table 1. Also, the presence or absence of cracks in the barrier layer 102 after molding was visually confirmed by shining light in a dark room. The presence or absence of cracks was confirmed for 10 samples, and when no cracks were confirmed in all samples, it is represented by "○", and when cracks were confirmed in any of the samples, it is represented by "×".

[0149]

Table 1

[0150] As is clear from Table 1, by forming the package 10 along the valley fold line 11 and the mountain fold line 12 formed by engraving, the depth of the main body 20 can be increased to increase the capacity of the package 10. Further, the ratio of the thickness of A to C and the ratio of the thickness of B to C (%) are 100 ± 2% or less, and the thickness of the barrier layer 102 is made substantially the same in the height direction to prevent a decrease in strength while forming a highly volumetrically efficient package 10.

Industrial Applicability

[0151] The present invention can be used for a battery package for packaging a battery element.

Explanation of Signs

[0152] 1 Battery 10 Battery package (package) 11 Valley fold line 12 Mountain fold line 20 Main body 20a Opening 21 Bottom plate 22a - 22d Side plates 23a - 23c Flange plates 24a - 24d Connection part (first connection part) 26a - 26f Connection part (second connection part) 30 Lid part 40 Battery element 41a, 41b Metal tabs 100 Packaging material 101 Base material layer 102 Barrier layer 103 Heat - adhesive layer 104 Adhesive layer 105 Adhesive layer K1 Notch F Flange P Corner L Straight line

Claims

1. A battery packaging body is constructed of a laminate including at least a barrier layer and a heat-sealable resin layer disposed as an innermost layer, the battery packaging body including a main body having an opening on an upper surface thereof and configured to house a battery element, and a lid for closing the opening, The main body portion has a rectangular bottom plate, side plates bent from four sides of the bottom plate and erected, a first connecting portion connecting adjacent side plates, flange plates bent outward from upper ends of the three side plates, and second connecting portions disposed on both ends of the flange plates, The lid portion is bent from an upper end of the side panel to which the flange plate is not connected and bonded to the flange plate, The first connecting portion is folded in half by a valley fold on the thermal adhesive resin layer side at a first fold line that extends from a corner of the bottom plate at an inclination outwardly upward, and is bonded to the bottom plate; The second connecting portion is connected to an upper end of the first connecting portion via a second fold line formed by folding the heat-sealable resin layer side in a mountain shape, A battery packaging body characterized in that the end of the flange plate is folded back and adhered at an angle by a valley fold on the heat-sealable resin layer side, and the second connecting portion adjacent to the end of the flange plate is overlapped on top of it.

2. 2. The battery packaging according to claim 1, wherein the first fold line is inclined at an angle of 45 degrees with respect to the vertical direction.

3. The battery packaging body according to claim 1 or claim 2, characterized in that the ratio of the thickness of the barrier layer at the intermediate position in the height direction of the side panel to the thickness of the barrier layer at the connecting portion between the side panel and the bottom panel is 100±10% or less.

4. A battery comprising a battery element including at least a positive electrode, a negative electrode, and an electrolyte housed within the main body of the battery packaging according to any one of claims 1 to 3.

5. A battery comprising a battery element including at least a positive electrode and a negative electrode and integrated with a solid electrolyte, the battery element being housed within the main body of the battery packaging according to any one of claims 1 to 3.

6. The battery according to claim 4 or claim 5, characterized in that metal tabs of the positive and negative electrodes protrude from between the flange plate and the lid portion at the upper end of the side panel adjacent to the side panel to which the lid portion is connected, and the flange plate is bent downward from the upper end of the side panel facing the side panel to which the lid portion is connected.

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