Battery package 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 comprises: first connection parts 24a to 24d connecting between adjacent side surface boards 22a to 22d; and flange boards 23a to 23d bent to an outer side from an upper end of the side surface boards 22a to 22d. In a lid part 30, an outer peripheral part is bonded to the flange boards 23a to 23d, and the first connection parts 24a to 24d are bonded on a first folding line 11 inclined and extended to an outer side from a corner part of a bottom surface board 21 toward an upper direction by double-folding in a valley shape. Second connection parts 26a to 26h connected to the upper end of the first connection parts 24a to 24d through a second folding line 12 of which a heat-seal resin layer 103 side is folded in a mountain shape is provided at both ends of the flange boards 23a to 23d. The second connection part 26a is overlapped to the adjacent flange board 23a, and the lid part 30 is bonded to the upper side of them.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 surfaces 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 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 become thinner or the barrier layer may crack. 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] 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 includes a main body portion having an opening on the upper surface for accommodating a battery element, and a lid portion for closing the opening. In the battery package, the main body portion has a rectangular bottom plate, side plates bent and erected from four sides of the bottom plate, a first connecting portion connecting adjacent side plates, a flange plate bent outward from the upper ends of the four side plates, and a second connecting portion disposed at both ends of the flange plate. the lid portion has an outer peripheral portion adhered to the flange plate. the first connecting portion is adhesively bonded by being folded in half by a valley fold on the heat-sealable resin layer side along a first fold line that extends obliquely outward upward from a 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 a valley fold on the heat-sealable resin layer side. It is characterized in that an end portion 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 portion of the flange plate is disposed thereon in an overlapping manner.

[0009] Further, 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] Further, in the battery package having the above configuration, it is preferable that the ratio of the thickness of the barrier layer at an 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 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 configurations.

[0013] Further, in the battery having the above configuration of the present invention, it is preferable that the metal tabs of the positive electrode and the negative electrode protrude from between the flange plate and the lid portion, and the flange plate where the metal tabs do not protrude is bent downward.

Effects of the Invention

[0014] According to the present invention, the main body portion of the battery package has a rectangular bottom plate, side plates, and a flange plate, and the outer peripheral portion of the lid portion is adhered onto the flange plate. Further, a first connecting portion connecting adjacent side plates is double-folded by valley folding along an inclined first folding 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 volume efficiency of the battery package can be improved.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Modes 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 package 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 can be used as either a primary battery or a secondary battery, but a secondary battery is more preferable. Also, the type of the secondary battery is not particularly limited, and examples thereof 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 metal tab 41a of the positive electrode and a metal tab 41b of the negative electrode 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, which will be described later, in a state where they protrude outside the package 10. Further, when the electrolyte is liquid, 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 side of the flange plate 23c, and the metal tab 41b may protrude from the side of the flange plate 23a.

[0020] The package 10 is formed by bending a packaging material 100 (see FIG. 4) made of a laminate, which will be 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 portion 20 is in a tray shape, with 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 23d that are bent outward are continuously provided at the upper ends of the four side plates 22a to 22d.

[0022] The lid portion 30 is in the shape of a rectangular sheet. The outer peripheral portion of the lid portion 30 is brought into contact with the flange plates 23a to 23d and thermally adhered by a later-described thermal adhesive layer (heat-fusible resin layer) 103 (see FIG. 4). Thereby, the periphery of the opening 20a is sealed by the lid portion 30.

[0023] Also, the adjacent side plates 22a to 22d are connected by connecting portions (first connecting portions) 24a to 24d (see FIG. 3) that are double-folded and have their inner surfaces thermally adhered. At both ends of the flange plates 23a to 23d, connecting portions (second connecting portions) 26a to 26h that are connected to the connecting portions (first connecting portions) 24a to 24d are respectively provided (see FIG. 3). The connecting portions 26a, 26d, 26e, and 26h are respectively arranged overlapping both ends of the flange plates 23a and 23c.

[0024] FIG. 3 is a developed view showing the main body portion 20 of the package 10. The main body portion 20 is formed by bending a sheet-shaped packaging material 100, and 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 adhesive layer 103 (see FIG. 4) on the inner surface, and the mountain fold line 12 is mountain-folded on the side of the thermal adhesive layer 103 (see FIG. 4) on the inner surface.

[0025] Rectangular side plates 22a to 22d are continuously provided on the four sides of the rectangular bottom plate 21 via the valley fold line 11. Rectangular flange plates 23a to 23d are continuously provided on each upper side of the side plates 22a to 22d via the mountain fold line 12.

[0026] The side edges of the adjacent side plates 22a to 22d are respectively connected via square connecting portions (first connecting portions) 24a to 24d indicated by broken-line hatching. Note that the connecting portion 24a is connected to the side plate 22a via the mountain fold line 12 and is connected to the side plate 22b without passing through a fold line.

[0027] Similarly, the connecting portion 24b is connected to the side plate 22c via the mountain fold line 12 and is connected to the side plate 22b 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.

[0028] Valley fold lines (first fold lines) 11 that symmetrically cross the connecting portions 24a to 24d from the corners of the bottom plate 21 are formed on the connecting portions 24a to 24d. This valley fold line 11 is inclined at 45° with respect to each side of the bottom plate 21. That is, when the bottom plate 21 is placed on a horizontal plane, it is inclined at 45° with respect to the vertical direction.

[0029] At this time, the valley fold lines 11 on the connecting portions 24a to 24d are formed to extend up to the extension of the mountain fold line 12 between the side plates 22a to 22d and the flange plates 23a to 23d. Thereby, 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 arranged at the same height as the side plates 22a to 22d.

[0030] Square connecting portions (second connecting portions) 26a to 26h indicated by dot hatching are provided at both ends of the flange plates 23a to 23d, respectively. The connecting portions 26a to 26h connect the flange plates 23a to 23d and the connecting portions 24a to 24d. The connecting portion 26a is connected to the flange plate 23a and the connecting portion 24a via a mountain fold line (second fold line) 12.

[0031] 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 26h is connected to the flange plate 23a and the connecting portion 24d via a mountain fold line (second fold line) 12.

[0032] 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 via a valley 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 via a valley folding line (second folding line) 12. The connecting portion 26f is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24c via a valley folding line (second folding line) 12. The connecting portion 26g is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24d via a valley folding line (second folding line) 12. That is, the connecting portions 24a to 24d and the connecting portions 26a to 26h are connected via a valley folding line (second folding line) 12.

[0033] On both sides of the flange plates 23a and 23c, a pair of valley folding lines 11 are respectively 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 folding line 11 is inclined at 45° with respect to the mountain folding line (second folding line) connecting the connecting portions 26a, 26d, 26e, 26f and the connecting portions 24a to 24d.

[0034] The width W1 (depth when the package 10 is assembled) of the side plates 22a to 22d is formed to be the same as the width W2 of the flange plates 23a to 23d. Thereby, when the package 10 is assembled, the upper ends of the valley folding lines 11 on the connecting portions 24a to 24d are arranged at the same height as the side plates 22a to 22d. Note that the width W1 of the side plates 22a to 22d may be formed smaller than the width W2 of the flange plates 23a to 23d.

[0035] 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.

[0036] The thickness of the packaging material 100 is not particularly limited, but from the perspective of strength, it can be 50 μm or more. Also, from the perspectives 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 still more preferably 80 μm or less.

[0037] It is preferable that a lubricant be disposed on the surfaces of the base material layer 101 and the heat - adhesive layer 103. Note that the lubricant may be applied to the surfaces of the base material layer 101 and the heat - adhesive layer 103. Also, in addition to applying, the lubricant may be included in the resin constituting the base material layer 101 or the heat - adhesive layer 103 and heated to bleed out the lubricant on the surfaces of the base material layer 101 and the heat - adhesive layer 103. The type of the lubricant is not particularly limited, but preferably includes amide - based lubricants.

[0038] 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.

[0039] The base material layer 101 may be formed of a resin film, or may be formed by coating the above - mentioned 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.

[0040] 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 (multi-layer structuring). Specifically, examples include a multi-layer structure in which a polyester film and a nylon film are laminated, a multi-layer structure in which a plurality of nylon films are laminated, and a multi-layer structure in which a plurality of polyester films are laminated.

[0041] When the base material layer 1 has a multi-layer 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.

[0042] 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.

[0043] 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.

[0044] In addition, since the polyester resin is difficult to discolor 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 multi-layer structure, the thickness of each layer is preferably about 2 to 25 μm. Also, resins of different materials may be coated on the film.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferred.

[0052] 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.

[0053] 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 subjected to a heat treatment.

[0054] 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.

[0055] 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.

[0056] 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, or 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.

[0057] In addition, the barrier layer 102 can distinguish between the 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.

[0058] 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, by observing the surface of the aluminum alloy foil of the laminate and specifying the rolling direction (RD) of the aluminum alloy foil, the MD of the laminate can be specified. Also, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be specified.

[0059] 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.

[0060] In addition, the thermal adhesive layer 103 may be formed of a single resin component alone, or may be formed of a blend polymer combining two or more resin components. 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.

[0061] The thickness of the thermal adhesive layer 103 is not particularly limited as long as it exhibits heat-sealing properties, but it can preferably be about 100 μm or less, more preferably 80 μm or less, and still more preferably 60 μm or less.

[0062] 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 resins such as polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the heat adhesive layer 103 can be used. From the viewpoint of excellent adhesion between the barrier layer 102 and the heat adhesive layer 103, carboxylic acid-modified polyolefin is preferable, and carboxylic acid-modified polypropylene is particularly preferable.

[0063] Also, in order to reduce the thickness of the package 10 while improving the shape stability, a resin composition containing an acid-modified polyolefin and a curing agent is preferably used for the adhesive layer 105. 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.

[0064] The preferable range of the thickness of the adhesive layer 105 is 2 μm or more and 50 μm or less. Also, in the case of 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, in the case of using the resin exemplified in the heat 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.

[0065] Also, for the purpose of improving design, electrolytic solution resistance, scratch resistance, moldability, etc., a surface coating layer (not shown) may be provided on the upper surface of the base material layer 101 (the surface on the side opposite to the barrier layer 102 of the base material layer 101). The surface coating layer is the layer located on the outermost layer when the battery 1 is assembled. When the surface coating layer is provided, a lubricant may be disposed on the surface of the surface coating layer.

[0066] 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 electrolytic solution 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.

[0067] 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.

[0068] 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 die lines. 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.

[0069] 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 main body 20 of 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.

[0070] Next, the flange plates 23a to 23d are mountain-folded from the upper ends of the side plates 22a to 22d, and the connecting parts 26a to 26h are mountain-folded from the upper ends of the connecting parts 24a to 24d.

[0071] Also, the connecting parts 26a, 26d, 26e, and 26h are respectively mountain-folded from both side ends of the flange plates 23a and 23c, and both side portions of the flange plates 23a and 23c are inclined and folded back on the valley fold line 11 and thermally adhered by the thermal adhesive layer 103 on the inner surface.

[0072] As a result, the connecting parts 26a and 26h respectively overlap on both side portions of the flange plate 23a, and the connecting parts 26d and 26e respectively overlap on both side portions of the flange plate 23c. As a result, an annular flange F (see FIG. 2) in which the flange plates 23a to 23d and the connecting parts 26a to 26h are connected is formed around the opening 20a.

[0073] Next, the battery element 40 is housed in the main body 20. At this time, for example, the metal tabs 41a and 41b are arranged on the flange plate 23c. After the battery element 40 is housed, the lid 30 is placed on the flange plates 23a to 23d, and the outer peripheral portion of the lid 30 and the flange plates 23a to 23d are thermally adhered by the thermal adhesive layer 103 leaving a partially unsealed portion. Then, after the electrolyte is injected from the unsealed portion, the unsealed portion 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 30 is arranged above the bottom plate 21.

[0074] Note that the method of injecting the above electrolyte is only an example and is not limited to this method. For example, one side of the flange plate 23c may be left as an unsealed portion. In this case, three sides of the other flange plates 23a, 23b, and 23d are heat-sealed, and after the electrolyte is injected from the unsealed portion, one side of the flange plate 23c of the unsealed portion is heat-sealed.

[0075] Since the main body portion 20 of the package 10 is formed by bending the packaging material 100, it is possible to prevent thinning and cracking of the barrier layer 102. In addition, the radius of curvature at the time of bending the side plates and the flange plates can be reduced. Therefore, the yield and volume efficiency of the package 10 can be improved.

[0076] Further, 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 the thickness of the barrier layer 102 at the connecting portion of the side plates 22a to 22d and the bottom plate 21 is C, 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 to form a package 10 with high volume efficiency while preventing a decrease in strength. Furthermore, the ratio (%) of the thickness of B to C is preferably 100±5% or less, and more preferably 100±2% or less.

[0077] In addition, 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. Therefore, the outer shape end surface 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.

[0078] 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 disposed overlapping the side portion of the flange plate 23a and thermally bonded to the lid portion 30. Therefore, it is possible to prevent a gap from being formed between the upper end of the ridge line between the adjacent side plates 22a and 22b and the lid portion 30. 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 26h. Therefore, it is possible to more reliably prevent a decrease in the barrier property.

[0079] Further, the bonding surfaces of the connecting portions 24a to 24d that are double-folded and thermally bonded along the valley fold line 11 do not overlap with the bonding surfaces of the flange plates 23a and 23c that are inclined and folded back and thermally bonded on the valley fold line 11. Therefore, the connecting portions 24a to 24d and the flange plates 23a and 23c can be easily thermally bonded in separate steps, and it is possible to prevent wrinkles from occurring on the bonding surfaces.

[0080] 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 23d, and the outer peripheral portion of the lid portion 30 is adhered onto the flange plates 23a to 23d. Further, the connecting portions 24a to 24d (first connecting portions) that connect between the adjacent side plates 22a to 22d are double-folded by valley folding on the inclined valley fold line 11 (first fold line) and adhered.

[0081] 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 the packaging material 100 made of a laminate. Therefore, the yield and volume efficiency of the package 10 can be improved.

[0082] In addition, when the metal tabs 41a and 41b bend the non-protruding flange plates 23a, 23b, and 23d downward, the storage volume of the battery 1 can be reduced. Thereby, when a plurality of batteries 1 are arranged in parallel and enlarged, the storage volume of each battery 1 can be reduced to improve the volume energy density of the entire battery.

[0083] In addition, connecting portions (second connecting portions) 26a to 26h are provided at both ends of the flange plates 23a to 23d, and the connecting portions (second connecting portions) 26a to 26h 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. Further, the connecting portions (second connecting portions) 26a, 26d, 26e, and 26h are overlapped on the adjacent flange plates 23a and 23c, and a lid portion 30 is adhered thereon. Thereby, it is possible to prevent a gap from being formed between the upper end of the ridge line between the adjacent side plates 22a to 22d and the lid portion 30, and to prevent a decrease in the barrier property.

[0084] In addition, the end portions of the flange plates 23a and 23c are inclined and folded back by valley folds on the side of the heat adhesive layer 103 and adhered, and the connecting portions (second connecting portions) 26a, 26d, 26e, and 26h are overlapped on the adjacent flange plates 23a and 23c. Thereby, an annularly continuous flange F can be easily formed.

[0085] 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 double-folded connecting portion (first connecting portion), and it is possible to prevent water vapor or the like from entering the main body portion 20 through the heat adhesive layer 103.

[0086] In addition, by making 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 of the side plates 22a to 22d and the bottom plate 21 be 100 ± 10% or less, 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.

[0087] Note that FIG. 5 is a developed view showing a modified example of the main body portion 20 of the packaging body 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 23d. In this case, the valley fold lines 11 formed on both sides of the flange plates 23a and 23c are inclined by 45° with respect to the mountain fold line 12 connecting the flange plates 23a and 23c and the side plates 22a and 22c.

[0088] FIG. 6 is a development view showing a modified example of the main body portion 20 of the package 10 of the present 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 26h are connected in series via valley fold lines 11.

[0089] While bending the valley fold lines 11 that connect the flange plates 23a and 23c and the connecting portions 26a, 26d, 26e, and 26h, and bending the mountain fold lines 12 that obliquely cross the flange plates 23a and 23c, the both side portions of the flange plates 23a and 23c are folded and thermally adhered to the connecting portions 26a, 26d, 26e, and 26h respectively by the thermal adhesive layer 103. At this time, the connecting portions 26a, 26d, 26e, and 26h overlap the both side portions of the flange plates 23a and 23c respectively. Therefore, also in this modified example, the same effects as those of the present embodiment can be obtained.

[0090] <Second Embodiment> FIG. 7 is a development view showing the main body portion 20 of the package 10 of the battery 1 of the second embodiment. For convenience of explanation, the same reference numerals are given to the same portions as those in the first embodiment shown in FIGS. 1 to 4 described above. In the present embodiment, the shapes of the connecting portions 24a to 24d are different from those in the first embodiment. Other portions are the same as those in the first embodiment.

[0091] The widths W1 of the side plates 22a to 22d are formed larger than the widths W2 of the flange plates 23a to 23d. Since the widths W2 of the flange plates 23a to 23d are small, the battery 1 can be miniaturized and the volumetric efficiency can be improved.

[0092] In addition, the distance W3 between the extension line of the valley fold line 11 connecting the bottom plate 21 and the side plate 22a and the outer periphery of the connecting portion 26b and the distance W4 between the extension line of the valley fold line 11 connecting the bottom plate 21 and the side plate 22a and the outer periphery of the connecting portion 26g are formed to be the same as the width W2 of the flange plate 23a. Further, the connecting portions 24a, 24d (first connecting portions) are formed in an L shape with a rectangular notch K1 shown by solid-line hatching provided at the corner. Thereby, when the side plate 22a is erected and the flange plate 23a is bent outward, the side ends of the connecting portions 26b, 26g can be arranged on the extension of the open end of the flange plate 23a.

[0093] Similarly, the distances between the extension lines of the valley fold lines 11 connecting the bottom plate 21 and the side plates 22b to 22d and the outer peripheries of the connecting portions 26a to 26h are formed to be the same as the widths of the flange plates 23b to 23d. Further, the connecting portions 24b to 24d (first connecting portions) are formed in an L shape with a rectangular notch K1 shown by solid-line hatching provided at the corner. Thereby, when the side plates 22b to 22d are erected and the flange plates 23b to 23d are bent outward, the side ends of the connecting portions 26a to 26h can be arranged on the extensions of the open ends of the flange plates 23b to 23d. Thereby, the main body portion 20 can be formed compactly.

[0094] 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 22d and the flange plates 23a to 23d. 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.

[0095] <Third Embodiment> FIG. 8 is a developed view showing the main body portion 20 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 arrangements of the valley fold lines 11 and the mountain fold lines 12 with respect to the connecting portions 26a to 26h and the flange plates 23a to 23d are different from those in the first embodiment. Other parts are the same as those in the first embodiment.

[0096] On both sides of the flange plates 23b and 23d, a pair of valley fold lines 11 are formed which extend from the corners of the side plates 22b and 22d in a direction approaching each other and obliquely cross the flange plate 23b. These valley fold lines 11 are inclined at 45° with respect to the mountain fold lines 12 connecting the flange plate 23b and the side plate 22b and the mountain fold lines 12 connecting the flange plate 23d and the side plate 22d, respectively.

[0097] Also, 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. 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.

[0098] 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 26f is connected to the flange plate 23d and the connecting portion 24c via the mountain fold line (second fold line) 12. The connecting portion 26g is connected to the flange plate 23d and the connecting portion 24d via the mountain fold line (second fold line) 12.

[0099] 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. The connecting portion 26e is connected to the flange plate 23c without passing through a fold line and is connected to the connecting portion 24c via the mountain fold line (second fold line) 12. The connecting portion 26h is connected to the flange plate 23a without passing through a fold line and is connected to the connecting portion 24d via the mountain fold line (second fold line) 12.

[0100] The connecting parts 26b, 26c, 26f, and 26g are respectively mountain-folded from both side ends of the flange plates 23b and 23d, and both side portions of the flange plates 23b and 23d are inclined and folded back on the valley fold line 11 and thermally adhered by the thermal adhesive layer 103 on the inner surface.

[0101] As a result, the connecting parts 26b and 26c respectively overlap on both side portions of the flange plate 23b, and the connecting parts 26f and 26g respectively overlap on both side portions of the flange plate 23d. As a result, an annular flange F in which the flange plates 23a to 23d and the connecting parts 26a to 26h are connected is formed around the opening 20a. Therefore, in this embodiment, the same effect as in the first embodiment can be obtained.

[0102] In addition, the adhesive surfaces of the connecting parts 24a to 24d that are folded in half and thermally adhered at the valley fold line 11 and the flange plates 23b and 23d that are inclined and folded back and thermally adhered on the valley fold line 11 do not overlap each other. For this reason, the connecting parts 24a to 24d and the flange plates 23b and 23d can be easily thermally adhered in separate steps, respectively, and it is possible to prevent wrinkles from occurring on the adhesive surface.

[0103] 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.

[0104] Note that FIG. 9 is a developed view showing a modified example of the main body 20 of the package 10 of this embodiment. A pair of mountain fold lines 12 are formed on both side portions of the flange plates 23b and 23d, extending from the corners of the side plates 22b and 22d in a direction approaching each other and obliquely crossing the flange plates 23b and 23d. In addition, the flange plates 23b and 23d and the connecting parts 26b, 26c, 26f, and 26g are continuously provided via the valley fold line 11.

[0105] Fold the valley fold line 11 that connects the flange plates 23b and 23d and the connecting portions 26b, 26c, 26f, and 26g, and fold the mountain fold line 12 that traverses the flange plates 23b and 23d obliquely to fold both side portions of the flange plates 23b and 23d and thermally bond them to the connecting portions 26b, 26c, 26f, and 26g with the thermal adhesive layer 103, respectively. At this time, the connecting portions 26b, 26c, 26f, and 26g overlap both side portions of the flange plates 23b and 23d, respectively. Therefore, the same effects as those of the present embodiment can also be obtained in this modified example.

[0106] <Fourth Embodiment> FIG. 10 is a development view showing the main body portion 20 of the package 10 of the battery 1 according to the fourth 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 arrangements of the valley fold line 11 and the mountain fold line 12 are different with respect to the connecting portions 26a, 26d, 26e, 26h and the flange plates 23a, 23c. Other parts are the same as those in the first embodiment.

[0107] Mountain fold lines 12 that traverse the connecting portions 26a, 26d, 26e, 26h from the corners of the side plates 22a, 22c are formed in the connecting portions 26a, 26d, 26e, 26h. This mountain fold line 12 is inclined at 45° with respect to the fold line (second fold line) that connects the connecting portions 26a, 26d, 26e, 26h and the connecting portions 24a to 24d.

[0108] 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 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. The connecting portion 26e is connected to the flange plate 23c without passing through a fold line, and is connected to the connecting portion 24c via a valley fold line (second fold line) 11. The connecting portion 26h is connected to the flange plate 23a without passing through a fold line, and is connected to the connecting portion 24d via a valley fold line (second fold line) 11.

[0109] 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 via a valley fold 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 via a valley fold line (second folding line) 12. The connecting portion 26f is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24c via a valley fold line (second folding line) 12. The connecting portion 26g is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24d via a valley fold line (second folding line) 12.

[0110] The flange plates 23a to 23d are valley-folded from the upper ends of the side plates 22a to 22d, and the connecting portions 26a, 26d, 26e, 26h are valley-folded from the upper ends of the connecting portions 24a to 24d. Further, the connecting portions 26b, 26c, 26f, 26g are mountain-folded from the upper ends of the connecting portions 24a to 24d. At this time, the connecting portions 26a, 26d, 26e, 26h are double-folded on the mountain fold line 12 and thermally adhered to the adjacent connecting portions 26b, 26c, 26f, 26g by the thermal adhesive layer 103, and the lid portion 30 is adhered thereon.

[0111] As a result, one of the adjacent connecting portions 26a and 26b sandwiching the connecting portion 24a is folded by a mountain fold and adhered to the other. Similarly, one of the adjacent connecting portions 26c and 26d sandwiching the connecting portion 24b is folded by a mountain fold and adhered to the other. Also, one of the adjacent connecting portions 26e and 26f sandwiching the connecting portion 24c is folded by a mountain fold and adhered to the other. Further, one of the adjacent connecting portions 26g and 26h sandwiching the connecting portion 24d is folded by a mountain fold and adhered to the other. As a result, an annular flange F in which the flange plates 23a to 23d and the connecting portions 26a to 26h are connected is formed around the opening portion 20a. Therefore, in this embodiment as well, the same effect as in the first embodiment can be obtained.

[0112] Also, the bonding surfaces of the connecting portions 24a to 24d that are double-folded and thermally bonded along the valley fold line 11 do not overlap with the bonding surfaces of the connecting portions 26a, 26d, 26e, 26h that are thermally bonded onto the adjacent connecting portions 26b, 26c, 26f, 26g. For this reason, the connecting portions 24a to 24d and the connecting portions 26a, 26d, 26e, 26h can be easily thermally bonded in separate steps, respectively, and it is possible to prevent wrinkles from occurring on the bonding surfaces.

[0113] In the present embodiment, the connecting portions 24a to 24d may be formed in an L shape in the same manner as in the second embodiment.

[0114] <Fifth Embodiment> FIG. 11 is a developed view showing the main body portion 20 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. 10 described above are denoted by the same reference numerals. In the present embodiment, the arrangements of the valley fold line 11 and the mountain fold line 12 are different with respect to the connecting portions 26a to 26h. Other parts are the same as those in the fourth embodiment.

[0115] Mountain fold lines 12 that cross the connecting portions 26b, 26c, 26f, 26g from the corners of the side plates 22b, 22d are formed in the connecting portions 26b, 26c, 26f, 26g. This mountain fold line 12 is inclined at 45° with respect to the fold line (second fold line) that connects the connecting portions 26b, 26c, 26f, 26g and the connecting portions 24a to 24d.

[0116] 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. The connecting portion 26e is connected to the flange plate 23c without passing through a fold line, and is connected to the connecting portion 24c via a mountain fold line (second fold line) 12. The connecting portion 26h is connected to the flange plate 23a without passing through a fold line, and is connected to the connecting portion 24d via a mountain fold line (second fold line) 12.

[0117] 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 via a valley folding line (second folding line) 11. 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 via a valley folding line (second folding line) 11. The connecting portion 26f is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24c via a valley folding line (second folding line) 11. The connecting portion 26g is connected to the flange plate 23d without passing through a folding line, and is connected to the connecting portion 24d via a valley folding line (second folding line) 11.

[0118] The flange plates 23a to 23d are mountain-folded from the upper ends of the side plates 22a to 22d, and the connecting portions 26b, 26c, 26f, 26g are valley-folded from the upper ends of the connecting portions 24a to 24d. Also, the connecting portions 26a, 26d, 26e, 26h are mountain-folded from the upper ends of the connecting portions 24a to 24d. At this time, the connecting portions 26b, 26c, 26f, 26g are double-folded on the mountain folding line 12 and thermally adhered to the adjacent connecting portions 26a, 26d, 26e, 26h by the thermal adhesive layer 103, and the lid portion 30 is adhered thereon.

[0119] As a result, one of the adjacent connecting portions 26a and 26b sandwiching the connecting portion 24a is folded by mountain folding and adhered to the other. Similarly, one of the adjacent connecting portions 26c and 26d sandwiching the connecting portion 24b is folded by mountain folding and adhered to the other. Also, one of the adjacent connecting portions 26e and 26f sandwiching the connecting portion 24c is folded by mountain folding and adhered to the other. Further, one of the adjacent connecting portions 26g and 26h sandwiching the connecting portion 24d is folded by mountain folding and adhered to the other. As a result, an annular flange F in which the flange plates 23a to 23d and the connecting portions 26a to 26h are connected is formed around the opening portion 20a. Therefore, the same effect as that of the first embodiment can be obtained in this embodiment as well.

[0120] Also, the adhesive surfaces of the connecting parts 24a to 24d that are double-folded and heat-bonded along the valley fold line 11 do not overlap with the adhesive surfaces of the connecting parts 26b, 26c, 26f, 26g that are heat-bonded onto the adjacent connecting parts 26a, 26d, 26e, 26h. For this reason, the connecting parts 24a to 24d and the connecting parts 26b, 26c, 26f, 26g can be easily heat-bonded in separate processes, and the occurrence of wrinkles on the adhesive surfaces can be prevented.

[0121] In the present embodiment, the connecting parts 24a to 24d may be formed in an L shape in the same manner as in the second embodiment.

[0122] <Sixth Embodiment> FIG. 12 is a developed view showing the main body portion 20 of the package 10 of the battery 1 according to the sixth embodiment. For convenience of explanation, the same reference numerals are given to the same parts as those shown in FIGS. 1 to 4 of the first embodiment described above. In the present embodiment, the arrangement of the valley fold line 11 is different with respect to the connecting parts 26a, 26d, 26e, 26h and the flange plates 23a, 23c. Other parts are the same as those in the first embodiment.

[0123] Valley fold lines 11 that cross the connecting parts 26a, 26d, 26e, 26h from the corners of the side plates 22a, 22c are formed in the connecting parts 26a, 26d, 26e, 26h. This valley fold line 11 is inclined at 45° with respect to the mountain fold line (second fold line) 12 that connects the connecting parts 26a, 26d, 26e, 26h and the connecting parts 24a to 24d.

[0124] The flange plates 23a to 23d are mountain-folded from the upper ends of the side plates 22a to 22d, and the connecting parts 26a to 26h are mountain-folded from the upper ends of the connecting parts 24a to 24d. At this time, the connecting parts 26a, 26d, 26e, 26h are double-folded on the valley fold line 11 and heat-bonded by the heat-bonding layer 103 on the inner surface.

[0125] As a result, one of the connecting parts 26a and 26b adjacent to each other with the connecting part 24a therebetween is folded, and one of the connecting parts 26c and 26d adjacent to each other with the connecting part 24b therebetween is folded. Also, one of the connecting parts 26e and 26f adjacent to each other with the connecting part 24c therebetween is folded, and one of the connecting parts 26g and 26h adjacent to each other with the connecting part 24d therebetween is folded. As a result, an annular flange F in which the flange plates 23a to 23d and the connecting parts 26b, 26c, 26f, 26g are connected is formed around the opening 20a. Therefore, also in the present embodiment, the same effects as those of the first embodiment can be obtained.

[0126] In the present embodiment, the connecting parts 24a to 24d may be formed in an L shape as in the second embodiment.

[0127] <Seventh Embodiment> FIG. 13 is a developed view showing the main body part 20 of the package 10 of the battery 1 of the sixth embodiment. For convenience of explanation, the same parts as those in the sixth embodiment shown in FIG. 12 described above are denoted by the same reference numerals. In the present embodiment, the arrangement of the valley fold lines 11 and the mountain fold lines 12 is different with respect to the connecting parts 26a to 26h. Other parts are the same as those in the sixth embodiment.

[0128] Valley fold lines 11 that cross the connecting parts 26b, 26c, 26f, 26g from the corners of the side plates 22b, 22d are formed in the connecting parts 26b, 26c, 26f, 26g. This valley fold line 11 is inclined by 45° with respect to a mountain fold line (second fold line) 12 that connects the connecting parts 26b, 26c, 26f, 26g and the connecting parts 24a to 24d.

[0129] 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 22d via the mountain fold line 12 and is connected to the side plate 22c without passing through a fold line. The connecting part 24d is connected to the side plate 22d via the mountain fold line 12 and is connected to the side plate 22a without passing through a fold line.

[0130] 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 26f is connected to the flange plate 23d and the connecting portion 24c via a mountain fold line (second fold line) 12. The connecting portion 26g is connected to the flange plate 23d and the connecting portion 24d via a mountain fold line (second fold line) 12.

[0131] 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. The connecting portion 26e is connected to the flange plate 23c without passing through a fold line and is connected to the connecting portion 24c via a mountain fold line (second fold line) 12. The connecting portion 26h is connected to the flange plate 23a without passing through a fold line and is connected to the connecting portion 24d via a mountain fold line (second fold line) 12.

[0132] The flange plates 23a to 23d are mountain-folded from the upper ends of the side plates 22a to 22d, and the connecting portions 26a to 26h are mountain-folded from the upper ends of the connecting portions 24a to 24d. At this time, the connecting portions 26b, 26c, 26f, 26g are double-folded on the valley fold line 11 and thermally adhered by the inner heat adhesive layer 103.

[0133] As a result, an annular flange F in which the flange plates 23a to 23d and the connecting portions 26a, 26d, 26e, 26h are connected is formed around the opening 20a. Therefore, in this embodiment as well, the same effect as in the first embodiment can be obtained.

[0134] 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.

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

[0136] In addition, 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 substantially rectangular and rectangular. 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] Also, the sizes of the width W1, the width W2, the distance W3, and the distance W4 may be slightly deviated 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 be slightly deviated 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 be slightly deviated from the width W2 of the flange plates 23a to 23c within the range of error.

[0138] In addition to the sheet shape, the lid portion 30 may be formed by bending the packaging material 100 into a tray shape in the same manner as the main body portion 20.

Example

[0139] Hereinafter, the effects of the present invention will be described in more detail using examples.

[0140] Examples 1 to 7 are the package 10 of the first embodiment. A single packaging material 100 was bent along the valley fold line 11 and the mountain fold line 12 formed by printing to form the package 10. The opening 20a of the main body 20 was set to 100 mm × 240 mm, and the radius of curvature of the continuous part 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 continuous part between the side plates 22a to 22d and the flange plates 23a to 23d was set to 0.5 mm. Further, in Examples 1 to 7, the depth H (corresponding to the width W1 in FIG. 3) of the package 10 was set to 3 mm, 4 mm, 5 mm, 6 mm, 10 mm, 15 mm, and 20 mm, respectively.

[0141] The base material layer 101 of the packaging material 100 was obtained by bonding 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 bonded using a dry laminating adhesive (thickness 3 μm). The heat-sealing layer 103 used a polypropylene film (thickness 40 μm). The adhesive layer 105 used acid-modified polypropylene (thickness 40 μm).

[0142] Also, in Comparative Examples 1 to 4, the same laminate as the packaging material 100 of Examples 1 to 7 was cold-press formed to form a tray having the same volume as in Examples 1 to 7. Specifically, in 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.

[0143] In addition, the female mold has an opening with a rectangular shape (100 mm × 240 mm) and is made of a mold with a maximum height roughness (designated value of Rz) of 3.2 μm as defined in Table 2 of "Appendix 1 (Reference) Standard Specimens for Surface Roughness Comparison" in JIS B 0659-1:2002. Also, the corners of the female mold are 0.5 mm, and the ridge lines are 0.5 mm. These values correspond to the radii of curvature of the connected portion between the side panel and the flange plate after press forming.

[0144] In addition, the male mold is made of a mold with a maximum height roughness (designated value of Rz) of 1.6 μm as defined in Table 2 of "Appendix 1 (Reference) Standard Specimens for Surface Roughness Comparison" in JIS B 0659-1:2002. Also, the corners of the male mold are 0.5 mm, and the ridge lines are 0.5 mm. These values correspond to the radii of curvature of the connected portion between the bottom panel and the side panel after press forming. Also, the clearance between the male mold and the female mold is set to 0.3 mm.

[0145] Also, the packaging material 100 is placed so as to cover the opening of the female mold, and cold press forming is performed using the male mold. At this time, the MD of the packaging material 100 is aligned with the short side of the opening of the mold, and the TD of the packaging material 100 is aligned with the long side of the opening of the mold. The packaging material 100 is placed on the female mold so that the thermally adhesive resin layer contacts the male mold side, and press forming is performed.

[0146] In addition, in Comparative Examples 1 to 4, the forming depths (the depth H of the tray) were formed to be 3 mm, 4 mm, 5 mm, and 6 mm, respectively.

[0147] 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 into two parts 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, and the results are shown in Table 1.

[0148] 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 in 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.

[0149] 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. Regarding the presence or absence of cracks in 10 samples, when cracks were not confirmed in all samples, it is represented by "○", and when cracks were confirmed in any sample, it is represented by "×".

[0150]

Table 1

[0151] As is clear from Table 1, by forming the packaging body 10 along the valley fold line 11 and the mountain fold line 12 formed by printing, the depth of the main body 20 can be increased to increase the capacity of the packaging body 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 form a packaging body 10 with high volume efficiency while preventing a decrease in strength.

Industrial Applicability

[0152] The present invention can be used for a battery packaging body for packaging a battery element.

Explanation of Symbols

[0153] 1 Battery 10 Battery packaging body (packaging body) 11 Valley fold line 12 Mountain fold line 20 Main body 20a Opening 21 Bottom plate 22a~22d Side plates 23a~23d Flange plates 24a~24d Connection part (first connection part) 26a~26h 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 (heat-fusible resin layer) 104 Adhesive layer 105 Adhesion 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 four side plates, and second connecting portions disposed on both ends of the flange plates, The lid portion has an outer periphery 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. 6. The battery according to claim 4, wherein metal tabs of the positive and negative electrodes protrude from between the flange plate and the lid portion, and the flange plate from which the metal tabs do not protrude is bent downward.

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