WO2012160965A1

WO2012160965A1 - Method of manufacturing power storage device

Info

Publication number: WO2012160965A1
Application number: PCT/JP2012/061816
Authority: WO
Inventors: 雄二水口
Original assignee: 株式会社村田製作所
Priority date: 2011-05-25
Filing date: 2012-05-09
Publication date: 2012-11-29

Abstract

Provided is a method of manufacturing a power storage device, wherein separators can be prevented from being sealed together with enveloping members. In a method of manufacturing a laminated type nonaqueous electrolytic-solution rechargeable battery (100), enveloping members (20a, 20b) that constitute an enveloping body (20) are superimposed, and sealed together by heat-welding at a sealing portion (21b). After that, the superimposed enveloping members (20a, 20b) are arranged so as to sandwich an electrode structure (10). Then, the superimposed enveloping members (20a, 20b) are sealed together by heat-welding at sealing portions (21a).

Description

Method for manufacturing power storage device

The present invention generally relates to a method for manufacturing an electricity storage device, and specifically, an electricity storage element such as a non-aqueous electrolyte secondary battery or an electric double layer capacitor is sealed by overlapping a plurality of outer packaging members. The present invention relates to a method for manufacturing an electricity storage device to be accommodated.

Conventionally, for example, regarding power storage devices such as non-aqueous electrolyte secondary batteries, demands such as weight reduction, thickness reduction, and degree of freedom of shape are increasing with the expansion of various applications.

Therefore, as a non-aqueous electrolyte secondary battery excellent in weight reduction and thickness reduction, a non-aqueous electrolyte secondary battery containing an electrode structure using a flexible laminate film (also referred to as a laminated sheet) as an outer packaging member Is used. The laminate film is positioned on the inner surface facing the electrode structure, and is positioned on the outer surface of the synthetic resin, the outer surface of the non-aqueous electrolyte secondary battery, the outer surface layer of the synthetic resin, the inner layer and the outer surface. It is comprised from the intermediate | middle layer arrange | positioned between layers. The inner surface layer is made of, for example, a thermoplastic resin excellent in electrolytic solution resistance and heat welding properties such as polyethylene and polypropylene. An intermediate | middle layer consists of a metal layer excellent in flexibility and intensity | strength, such as aluminum foil, for example. The outer surface layer is made of, for example, an insulating resin excellent in electrical insulation, such as nylon or polyamide. An electrode structure (also referred to as a battery element) is configured by winding a positive electrode member and a negative electrode member with a separator interposed therebetween or alternately laminating them.

For example, International Publication No. 2005/086258 (hereinafter referred to as Patent Document 1) discloses a configuration of a film-covered battery as the non-aqueous electrolyte secondary battery. This film-clad battery includes an outer package that houses the electrode structure together with the electrolytic solution. The electrode structure is configured by alternately laminating a plurality of positive plates and a plurality of negative plates via separators. The outer package is composed of two laminated films that surround the electrode structure from both sides in the thickness direction. By sealing the outer peripheral edge portions (four sides in the case of a rectangular planar shape) of the two laminated laminate films by heat welding, the electrode structure is sealed inside the outer package. Such a configuration is a desirable form when accommodating an electrode structure having a thickness of 5 mm or more.

International Publication No. 2005/086258

In the film-clad battery described in Patent Document 1, the electrode structure is disposed between two laminated films, and then the three sides other than the opening for containing the electrolytic solution are sealed by thermal welding. And after inject | pouring electrolyte solution, the one side of an opening part is sealed by heat welding.

However, when the electrode structure is disposed between two laminate films, the electrode structure may be misaligned. In this case, the separator constituting the electrode structure is laminated when sealing one side other than the side including the portion where the positive electrode terminal (also referred to as positive electrode tab) or the negative electrode terminal (also referred to as negative electrode tab) is arranged and led out. May be sealed with film.

When the separator is sealed together with the laminate film, the laminate film is insufficiently welded. For this reason, there is a risk of causing problems such as a decrease in battery reliability due to a decrease in sealing strength or sealing property, and an internal short circuit due to a separator being damaged.

Therefore, an object of the present invention is to provide a method for manufacturing an electricity storage device capable of preventing the separator from being sealed together with the outer packaging member.

The power storage device targeted by the manufacturing method of the present invention includes an electrode structure formed by alternately arranging a positive electrode member and a negative electrode member with separators interposed between the electrode structure and the outer peripheral edge. A sealed outer package. The positive electrode member includes a positive electrode current collector, and the negative electrode member includes a negative electrode current collector. Furthermore, the electricity storage device is electrically connected to the end portion of the positive electrode current collector and electrically connected to the positive electrode terminal derived from the outer peripheral edge of the outer package and the end portion of the negative electrode current collector. And a negative electrode terminal derived from the outer peripheral edge of the outer package. The outer peripheral edge of the outer package has a first sealing location that does not include a location from which the positive electrode terminal and the negative electrode terminal are derived, and a second sealing location that includes a location from which the positive electrode terminal and the negative electrode terminal are derived. .

The method for manufacturing an electricity storage device configured as described above includes the following steps.

(A) A first sealing step in which the first and second outer packaging members constituting the outer packaging body are overlapped and sealed at the first sealing location.

(B) After the first sealing step, the electrode structure housing step in which the electrode structure is placed between the first and second outer packaging members that are overlapped.

(C) Second sealing step of sealing the overlapped first and second outer packaging members at the second sealing location after the electrode structure housing step

In the method for manufacturing the electricity storage device of the present invention, the first and second outer packaging members constituting the outer packaging body are overlapped and sealed in advance at the first sealing location that does not include the location where the positive electrode terminal and the negative electrode terminal are led out. After being attached, the electrode structure is disposed so as to be sandwiched between the superimposed first and second outer packaging members. Thereafter, the overlapped first and second outer packaging members are sealed at a second sealing location including a location where the positive electrode terminal and the negative electrode terminal are led out. Thereby, it can prevent that the separator which comprises an electrode structure is sealed with the 1st and 2nd outer packaging member in a 1st sealing location.

In the electricity storage device targeted by the manufacturing method of the present invention, the electrode structure is preferably formed by alternately laminating a plurality of positive electrode members and a plurality of negative electrode members with a separator interposed therebetween.

Moreover, the manufacturing method of the present invention further includes the following steps.

(D) After the second sealing step, an electrolytic solution injection step for injecting the electrolytic solution with the unsealed third sealing portion facing up

(E) Third sealing step of sealing at the third sealing location after the electrolyte injection step

According to the present invention, it is possible to prevent the separator constituting the electrode structure from being sealed together with the outer packaging member at a sealing location that does not include a location where the positive electrode terminal and the negative electrode terminal are led out. It is possible to prevent a decrease in battery reliability due to a decrease in strength or sealing property, an internal short circuit due to a breakage of the separator, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing an example of a laminated nonaqueous electrolyte secondary battery that is an embodiment of an electricity storage device of the present invention. FIG. 2 is a partial cross-sectional view showing, in an enlarged manner, a cross section viewed from a direction along the line II-II in FIG. 1 in a laminated nonaqueous electrolyte secondary battery before sealing. FIG. 3 is a schematic partial cross-sectional view showing, in an enlarged manner, a cross section of the electrode structure viewed from the direction along the line III-III in FIG. 1 inside the laminated nonaqueous electrolyte secondary battery before sealing. It is a top view which shows arrangement | positioning of a positive electrode member, a negative electrode member, a separator, a positive electrode terminal, and a negative electrode terminal inside the lamination type nonaqueous electrolyte secondary battery as one embodiment of this invention. FIG. 2 is an exploded perspective view of the laminate type nonaqueous electrolyte secondary battery shown in FIG. 1. As another embodiment of the present invention, an enlarged cross section of the electrode structure viewed from the direction along the line VI-VI in FIG. 1 inside the laminated non-aqueous electrolyte secondary battery before sealing. It is a schematic fragmentary sectional view shown.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 5, as one embodiment of the electricity storage device, a laminated nonaqueous electrolyte secondary battery 100 which is an example of a nonaqueous electrolyte secondary battery includes an electrode structure 10 and an illustrated structure. A non-aqueous electrolyte solution, a rectangular shape, and an outer packaging body 20 composed of an electrode structure 10 and two upper and lower

flexible packaging members

20a and 20b that contain and seal the non-aqueous electrolyte solution, and an electrode The structure is composed of a positive electrode terminal 30 and a negative electrode terminal 40 that are electrically connected to the structure 10 by ultrasonic welding and led out from the outer peripheral edge of the outer package 20 in opposite directions. The outer peripheral edge of the outer package 20 is sealed by thermal welding (heat sealing) at four

sealing locations

21a, 21a, 21b, and 21c. Either one of the

sealing locations

21b or 21c is a first sealing location that does not include a location from which the positive electrode terminal 30 and the negative electrode terminal 40 are led out, and the other is a third sealing location. Further, the

sealing locations

21a and 21a are second sealing locations including a location where the positive electrode terminal 30 and the negative electrode terminal 40 are led out. Each of the positive electrode terminal 30 and the negative electrode terminal 40 is positioned at the center in the width direction of the electrode structure 10, but may be positioned at one end in the width direction. Further, in this embodiment, as shown in FIG. 5, one outer packet member 20b constituting the outer packet body 20 has a cup-shaped convex part, but both

outer packet members

20a and 20b are cup-shaped convex parts. May have a part.

2 and 3, the electrode structure 10 includes a plurality of strip-shaped positive electrode members 11, a plurality of strip-shaped negative electrode members 12, and a plurality of strip-shaped separators 13. The positive electrode members 11 and the negative electrode members 12 are alternately stacked with the separators 13 interposed therebetween. The positive electrode member 11 includes a positive electrode current collector 111, and the plurality of positive electrode members 11 are electrically connected to the positive electrode terminal 30 by ultrasonic welding via end portions 111a in which the plurality of positive electrode current collectors 111 are integrated. . The negative electrode member 12 includes a negative electrode current collector 121. Similarly to the positive electrode member, the plurality of negative electrode members 12 are electrically connected to the negative electrode terminal 40 by ultrasonic welding through an end portion where the plurality of negative electrode current collectors 121 are integrated. It is connected. In the example of the laminate-type nonaqueous electrolyte secondary battery 100 described above, one separator 13 is interposed between the positive electrode member 11 and the negative electrode member 12 as a configuration of the electrode structure 10. A separator may be interposed. The material of the plurality of separators may be the same or different. As the material of the separator, a polyolefin resin such as polypropylene or polyethylene, or a combination thereof, a polyolefin resin added with a ceramic such as silica or alumina, polyethylene terephthalate, cellulose, nonwoven fabric, or the like is used. Further, for example, the positive electrode member 11 may be disposed in a bag-shaped separator, and a separator may be interposed between the positive electrode member 12 and the long separator 13 may be replaced by 90 as shown in FIG. Nine folds may be interposed. 6B, a long separator 13 may be interposed between the long positive electrode member 11 and the negative electrode member 12 and wound.

The

outer packaging members

20 a and 20 b constituting the outer packaging body 20 are positioned on the inner surface side facing the electrode structure 10, and are positioned on the inner surface layer made of synthetic resin and the outer surface of the laminated nonaqueous electrolyte secondary battery 100. , A single film composed of an outer surface layer made of a synthetic resin and a metal layer disposed between the inner surface layer and the outer surface layer, that is, a laminate film having a three-layer structure (in FIG. 2) The three-layer structure is omitted). For example, the inner surface layer is made of polypropylene which is a heat-sealable thermoplastic resin and has a thickness of 30 to 120 μm. For example, the metal layer is made of an aluminum foil or an aluminum alloy foil and has a thickness of 30 to 50 μm. For example, the outer surface layer is made of nylon (registered trademark) and has a thickness of 20 to 40 μm. The

outer packaging members

20a and 20b configured in this way are easily deformable materials and have flexibility. In addition, the laminate film should just have an inner surface layer and the metal layer arrange | positioned on the outer side at least, and should just provide an outer surface layer as needed. Moreover, you may provide adhesive layers, such as a urethane resin, another synthetic resin layer, etc. between layers as needed. As shown in FIG. 1 and FIG. 5, the outer package 20 is heated at the four sides of the sealing

locations

21a, 21a, 21b, and 21c by overlapping the outer peripheral edges of the two

outer packaging members

20a and 20b made of a laminate film. It is formed by welding.

In the above embodiment, as shown in FIGS. 2 and 4, each of the positive electrode terminal 30 and the negative electrode terminal 40 is a portion where the end portions of the positive electrode current collector 111 and the negative electrode current collector 121 are integrated. Although connected by ultrasonic welding on the lower surface, each of the positive electrode terminal 30 and the negative electrode terminal 40 may be connected by ultrasonic welding on the upper surface of the portion where the ends of the current collector are integrated, or It may be arranged so that the end of the current collector is inserted into the integrated portion and connected by ultrasonic welding.

In the above embodiment, the positive electrode terminal 30 and the negative electrode terminal 40 are led out from the outer peripheral edge portion of the outer package 20 in opposite directions, but the positive electrode terminal 30 and the negative electrode terminal 40 are the outer peripheral edge portion of the outer packaging member. May be derived in the same direction. In this case, the positive terminal 30 is positioned at one end in the width direction of the electrode structure 10, and the negative terminal 40 is positioned at the other end opposite to the one end in the width direction of the electrode structure 10.

The laminate type non-aqueous electrolyte secondary battery 100 of the present invention configured as described above is manufactured by housing and enclosing the electrode structure 10 in the outer package 20 in the following steps. . In addition, before performing the following manufacturing process, the positive electrode terminal 30 and the negative electrode terminal 40 are previously connected to the electrode structure 10 by ultrasonic welding.

First, the

outer packaging members

20a and 20b constituting the outer packaging body 20 are overlapped and heat-sealed at a sealing location 21b as a first sealing location (first sealing step).

Thereafter, the electrode structure 10 is disposed so as to be sandwiched between the overlapped

outer packaging members

20a and 20b (electrode structure accommodation step).

Then, the overlapped

outer packaging members

20a and 20b are sealed as a second sealing location by heat welding at the sealing location 21a (second sealing step).

The sealing part 21c (third sealing part) is sealed by thermal welding after injecting the electrolytic solution with the sealing part 21c facing upward (electrolyte injection process / third sealing). Process).

As described above, in the method for manufacturing the laminate-type nonaqueous electrolyte secondary battery 100 of the present invention, the sealing part does not include the part from which the positive electrode terminal 30 and the negative electrode terminal 40 are led by overlapping the

outer packaging members

20a and 20b. After sealing in advance at 21b, the electrode structure 10 is disposed so as to be sandwiched between the overwrapped

outer packaging members

20a and 20b. Thereafter, the overlapped

outer packaging members

20a and 20b are sealed at a sealing location 21a including a location where the positive electrode terminal 30 and the negative electrode terminal 40 are led out. Thereby, it can prevent that the separator 13 which comprises the electrode structure 10 is sealed with the

outer packaging members

20a and 20b in the sealing location 21b. Specifically, the portion 131 (FIGS. 3, 4, and 6) of the separator 13 can be prevented from being sealed together with the

outer packaging members

20a and 20b at the sealing location 21b.

Therefore, the separator 13 constituting the electrode structure 10 is sealed together with the

outer packaging members

20a and 20b at the sealing portion 21b, and thus the reliability of the battery due to the decrease in the sealing strength or the sealing property. It is possible to prevent a decrease, an internal short circuit due to a breakage of the separator, and the like.

As an example, in the form shown in FIG. 5, the outer dimensions of the

outer packaging members

20a and 20b are 160 mm × 160 mm, and the thickness of the laminated nonaqueous electrolyte secondary battery 100 is about 5 mm. The electrode structure 10 shown in FIGS. 2 and 3 is configured such that 20 positive electrode members 11 and 21 negative electrode members 12 are alternately stacked with separators 13 interposed therebetween.

In the laminate type nonaqueous electrolyte secondary battery 100 of the present invention, the positive electrode member 11 has a positive electrode mixture layer containing a positive electrode active material, except for an end portion on the side connected to the positive electrode terminal 30. It is configured by being formed on both surfaces of the body 111. The negative electrode member 12 is configured by forming a negative electrode mixture layer containing a negative electrode active material on both surfaces of the negative electrode current collector 121 except for an end portion on the side connected to the negative electrode terminal 40.

For example, the positive electrode member 11 includes a positive electrode current collector 111 made of an aluminum foil or a copper foil, and a positive electrode mixture slurry formed by kneading a positive electrode active material, a binder, and, if necessary, a conductive agent in an organic solvent. It is produced by coating uniformly on both surfaces of the substrate and drying to form a positive electrode mixture layer on both surfaces of the positive electrode current collector 111.

When configuring a non-aqueous electrolyte secondary battery, the positive electrode active materials include lithium cobaltate composite oxide, lithium manganate composite oxide, lithium nickelate composite oxide, lithium-nickel-manganese-cobalt composite oxide, A lithium-manganese-nickel composite oxide, a lithium-manganese-cobalt composite oxide, a lithium-nickel-cobalt composite oxide, or the like can be used. Further, the positive electrode active material may be a mixture of the above materials. Specifically, LiM _x O ₂ (in the chemical formula, M represents one or more transition metals, x represents a charge / discharge state of the battery, and is usually 0.05 or more as a positive electrode active material of a non-aqueous electrolyte secondary battery. Or a lithium composite oxide mainly composed of 1.10 or less). As the transition metal M constituting this lithium composite oxide, Co, Ni, Mn and the like are preferable. _{_{_{LiCoO 2, LiNiO 2, LiNi y}}} Co 1-y O 2 Specific examples of the lithium composite oxide (in the chemical formula, 0 <y <a _{1), Li 1 + a (} Ni x Mn y Co z ) O _2-b (in the chemical formula, −0.1 <a <0.2, x + y + z = 1, −0.1 <b <0.1), LiMn ₂ O _{4 and the} like. These lithium composite oxides can generate a high voltage and become a positive electrode active material having an excellent energy density. In order to produce the positive electrode member 11, a plurality of these positive electrode active materials may be used in combination. The positive electrode active material may be a lithium-containing phosphate compound having an olivine type structure such as lithium iron phosphate represented by LiFePO ₄ . If it has an olivine type structure, in the lithium iron phosphate represented by LiFePO ₄ , a part of Fe is replaced with Al, Ti, V, Cr, Mn, Co, Ni, Zr, Nb, etc. Also good. A part of P may be replaced with B, Si, or the like.

In addition, as the binder contained in the positive electrode mixture, a known binder that is usually used in the positive electrode mixture of a non-aqueous electrolyte secondary battery can be used. Known additives such as a conductive agent and an oxide can be added to the material. As the conductive agent contained in the positive electrode mixture, carbon materials such as furnace black, acetylene black, carbon fiber, and carbon nanotube are used. As a binder for binding the positive electrode active material and the conductive agent, polyvinylidene fluoride (PVDF), polyamideimide (PAI), polyacrylonitrile (PAN), polyethylene (PE), polypropylene (PP), polytetrafluoro Ethylene (PTFE) or fluorine-based latex is used.

For example, the negative electrode member 12 is formed by uniformly applying a negative electrode slurry obtained by kneading a negative electrode active material, a binder, and, if necessary, a conductive agent in an organic solvent on both surfaces of a negative electrode current collector made of copper foil. It is produced by applying and drying to form a negative electrode mixture layer on both sides of the negative electrode current collector.

When constituting a non-aqueous electrolyte secondary battery, a carbon material such as a non-graphitizable carbon material, a graphitizable carbon material (soft carbon), or a graphite-based carbon material can be used as the negative electrode active material. Specifically, carbon materials such as pyrolytic carbons, cokes, graphites, glassy carbon fibers, organic polymer compound fired bodies, carbon fibers, carbon nanotubes, and activated carbon can be used. Examples of the cokes include pitch coke, needle coke, and petroleum coke. Moreover, said organic polymer compound fired body means what carbonized by baking a phenol resin, furan resin, etc. at a suitable temperature. In addition to the carbon material described above, materials that can be doped or dedoped with lithium include polymers such as polyacetylene and polypyrrole, Sn oxides such as SnO ₂ , Sn alloys such as Sn ₅ Cu ₆ , and SiMg _2. An oxide such as an alloy or Li ₄ Ti ₅ O ₁₂ (lithium titanate) can also be used.

In addition, as the binder contained in the negative electrode mixture, a known binder that is usually used in a negative electrode mixture of a non-aqueous electrolyte secondary battery can be used. Known additives such as a conductive agent and an oxide can be added to the material. As the binder for binding the negative electrode active material, polyvinylidene fluoride, polyacrylonitrile, polyamideimide, polyacrylonitrile, polyethylene, polypropylene or polytetrafluoroethylene is used, or a latex binder such as styrene butadiene rubber and the like. A mixture of thickeners such as carboxymethylcellulose is used.

The nonaqueous electrolytic solution is prepared by dissolving the supporting electrolyte in a nonaqueous solvent. As the non-aqueous electrolyte, for example, a solution obtained by dissolving LiPF ₆ in a non-aqueous solvent at a concentration of 1.0 mol / L is used. Examples of supporting electrolytes other than LiPF ₆ include lithium salts such as LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , and LiSiF _6. Can be mentioned. Among these, LiPF ₆ and LiBF ₄ are particularly preferably used as the supporting electrolyte from the viewpoint of oxidation stability. Such a supporting electrolyte is preferably used by being dissolved in a nonaqueous solvent at a concentration of 0.1 mol / L to 3.0 mol / L, and at a concentration of 0.5 mol / L to 2.0 mol / L. More preferably, it is used after being dissolved. Examples of the non-aqueous solvent include cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC), which are low viscosity solvents. And a lower chain carbonate of the above are used.

In the above embodiment, an example in which the present invention is applied to the laminated nonaqueous electrolyte secondary battery 100 as an example of an electricity storage device has been described. However, an electricity storage device using an outer packaging member to accommodate at least an electrode structure If so, the present invention can be applied. For example, the present invention can be applied to an electric double layer capacitor in addition to a non-aqueous electrolyte secondary battery. The outer packaging member is not limited to a flexible member made of a laminate film having a three-layer structure.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above, and is intended to include any modifications or variations within the scope and meaning equivalent to the terms of the claims.

According to the present invention, it is possible to prevent a decrease in battery reliability due to a decrease in sealing strength or sealing property, an internal short circuit due to a breakage of a separator, and the like, so that a flexible outer packaging member can be used. This contributes to improving the reliability of an electricity storage device, for example, an electricity storage device that houses various electricity storage elements such as an electric double layer capacitor in addition to a non-aqueous electrolyte secondary battery as an electricity storage element.

DESCRIPTION OF SYMBOLS 10: Electrode structure, 11: Positive electrode member, 12: Negative electrode member, 13: Separator, 20: Outer package, 20a, 20b: Outer package member, 21a, 21b, 21c: Sealing location, 30: Positive electrode terminal, 40: Negative electrode Terminal: 100: Laminated non-aqueous electrolyte secondary battery, 111: Positive electrode current collector, 121: Negative electrode current collector.

Claims

An electrode structure formed by alternately arranging a positive electrode member and a negative electrode member with a separator interposed therebetween; and an outer package that contains the electrode structure and is sealed at an outer peripheral edge, The member includes a positive electrode current collector, the negative electrode member includes a negative electrode current collector, and is further electrically connected to an end of the positive electrode current collector and led out from the outer peripheral edge of the outer package A terminal, and a negative electrode terminal electrically connected to an end of the negative electrode current collector and led out from an outer peripheral edge of the outer envelope, the outer peripheral edge of the outer envelope being connected to the positive terminal and the positive electrode A method for manufacturing an electricity storage device having a first sealing location that does not include a location from which a negative electrode terminal is derived, and a second sealing location that includes a location from which the positive electrode terminal and the negative electrode terminal are derived,
A first sealing step in which the first and second outer packaging members constituting the outer packaging body are overlapped and sealed at the first sealing location;
After the first sealing step, an electrode structure housing step of arranging the electrode structure so as to be sandwiched between the superimposed first and second outer packaging members;
A method for manufacturing an electricity storage device, comprising: a second sealing step of sealing the overlapped first and second outer packaging members at the second sealing location after the electrode structure housing step .
The method for manufacturing an electricity storage device according to claim 1, wherein the electrode structure is formed by alternately laminating a plurality of positive electrode members and a plurality of negative electrode members with a separator interposed therebetween.
The method for manufacturing an electricity storage device according to any one of claims 1 and 2, wherein the positive electrode terminal and the negative electrode terminal extend in directions opposite to each other from an outer peripheral edge portion of the outer package.
After the second sealing step, an electrolytic solution injection step of injecting an electrolytic solution with the unsealed third sealing portion facing up,
The manufacturing of the electricity storage device according to any one of claims 1 to 3, further comprising a third sealing step of sealing at the third sealing location after the electrolyte injection step. Method.