JP2022138280A - Manufacturing method of power storage cell - Google Patents

Abstract

To provide a manufacturing method of a power storage cell, capable of reducing an amount of waste.SOLUTION: Sides 15a2-15a4 of a frame part 15a and sides 16a2-16a4 of a frame part 16a are welded to each other; an electrolyte E is injected in a space S between a current collector 20 and a current collector 21 through a portion between a side 15a1 of the frame part 15a and a side 16a1 of the frame part 16a; an outer edge 15be of an extension part 15b and an outer edge 16be of an extension part 16b are welded to each other while one end of a pipe 31 connected to a container 32 of a gas collection device 30 is arranged between the extension part 15b and the extension part 16b; initial charge/discharge is performed; the side 15a1 of the frame part 15a and the side 16a1 of the frame part 16a are welded to each other; and the extension part 15b and the extension part 16b are cut such that the gas collection device 30 is removed. Thus, a power storage cell 10 can be obtained.SELECTED DRAWING: Figure 9

Description

The present disclosure relates to a method for manufacturing a storage cell.

Patent Document 1 discloses a method of manufacturing a secondary battery by stacking a current collector provided with a positive electrode active material layer, a separator, and a current collector provided with a negative electrode active material layer. In this method, first, a positive electrode active material layer is formed on one side of a current collector so that a bonding region is formed over the entire circumference with substantially the same width, thereby obtaining a positive electrode laminate. Next, on one side of the current collector, the negative electrode active material layer is formed so that the bonding region has substantially the same width along the entire circumference and a part of the bonding region has a projecting portion that protrudes outward. to obtain a negative electrode laminate. Next, after inserting a sealing material larger than the negative electrode laminate and a separator between the negative electrode laminate and the positive electrode laminate, the projecting portion is sealed so as to have an open end. Form a laminate. Next, after injecting the electrolytic solution from the open end, the open end is sealed. Next, after charging the laminate, the projection is cut, the open end is formed again, and the gas is vented. The open ends are then resealed.

JP 2007-207438 A

As the size of the secondary battery increases, the amount of gas generated during charging increases. In that case, the above method requires a larger area of the protrusion to store a larger amount of gas. Since the projecting portion is removed by cutting, the amount of waste increases when manufacturing the secondary battery.

The present disclosure provides a method of manufacturing a storage cell that can reduce the amount of waste.

A method for manufacturing a storage cell according to one aspect of the present disclosure includes a positive electrode having a first current collector and a positive electrode active material layer provided on one side of the first current collector, a second current collector, and the A method for manufacturing a storage cell in which a negative electrode having a negative electrode active material layer provided on one surface of a second current collector is laminated in a direction in which the positive electrode active material layer and the negative electrode active material layer face each other, A rectangular first frame portion surrounding the positive electrode active material layer and a rectangular first frame portion extending outward from one side of the first frame portion at the edge portion of the one surface of the first current collector when viewed from the facing direction. a first resin member arranging step of providing a first resin member having a first extending portion; a second resin member arranging step of providing a second resin member having a rectangular second frame and a second extending portion extending outward from one side of the second frame; The positive electrode active material layer and the negative electrode active material layer are opposed to each other with the separator interposed therebetween, the first frame portion and the second frame portion are opposed to each other, and the first extension portion and the second extension portion are arranged to face each other. a lamination step of laminating the positive electrode and the negative electrode so that they face each other; After the first welding step and the first welding step, the first current collector and the second current collector are separated from each other through the space between the one side of the first frame portion and the one side of the second frame portion. After the electrolyte injection step of injecting an electrolyte into the space between and the first welding step, one end of the tube is arranged between the first extension portion and the second extension portion a second welding step of welding the outer edge portion of the first extension portion and the outer edge portion of the second extension portion to each other; and after the electrolytic solution injection step and the second welding step, the first an initial stage of a laminate including the positive electrode, the negative electrode and the separator, with the one end of the tube connected to the container of the gas collecting device being disposed between the extending portion and the second extending portion; an initial charging/discharging step of performing charging/discharging; after the initial charging/discharging step, a third welding step of welding the one side of the first frame portion and the one side of the second frame portion to each other; and a cutting step of cutting the first extension and the second extension such that the gas collection device is removed after the step.

According to the storage cell manufacturing method, the gas generated in the initial charging/discharging process moves through the tube to the container of the gas collecting device. Therefore, the areas of the first extending portion and the second extending portion can be reduced when viewed from the opposing direction. Therefore, the amount of waste (the first extension and the second extension) generated in the cutting process can be reduced.

In the electrolyte injection step, the electrolyte injection tube for injecting the electrolyte is arranged such that the tip of the electrolyte injection tube is positioned between the first extension portion and the second extension portion. may In this case, damage to the first frame portion and the second frame portion due to contact with the injection pipe can be suppressed.

The injection tube may be used as the tube connected to the container of the gas collection device. In this case, the initial charging/discharging process can be performed without removing the injection tube.

The method for manufacturing a storage cell further includes the step of providing a reinforcing member on at least one of the outer surface of the first extension portion and the outer surface of the second extension portion. The outer surface extends along the one surface of the first current collector and is positioned on the side of the first current collector in the facing direction, and the outer surface of the second extending portion extends along the second surface. It may extend along the one surface of the current collector and be positioned on the second current collector side in the facing direction. In this case, the reinforcing member reinforces the first extending portion and the second extending portion. Therefore, damage to the first extending portion and the second extending portion due to contact with the pipe can be suppressed.

ADVANTAGE OF THE INVENTION According to this disclosure, the manufacturing method of the electrical storage cell which can reduce the amount of wastes is provided.

FIG. 1 is a schematic cross-sectional view showing a power storage device including power storage cells according to one embodiment. FIG. 2 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 3 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 4 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. 5 is a cross-sectional view taken along line VV of FIG. 4. FIG. FIG. 6 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 7 is a cross-sectional view taken along line VII--VII of FIG. FIG. 8 is a cross-sectional view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 9 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. 10 is a cross-sectional view taken along line XX of FIG. 9. FIG. FIG. 11 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 12 is a plan view showing one step in the method for manufacturing a storage cell according to one embodiment. FIG. 13 is a plan view showing a step in a method for manufacturing a storage cell according to another embodiment. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13. FIG. FIG. 15 is a plan view showing a step in a method for manufacturing a storage cell according to another embodiment. 16 is a cross-sectional view taken along line XVI--XVI of FIG. 15. FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and overlapping descriptions are omitted. The drawings show a coordinate system having X-, Y-, and Z-axis directions that intersect (eg, are orthogonal to) each other, where appropriate.

FIG. 1 is a schematic cross-sectional view showing a power storage device of one embodiment. A power storage device 1 shown in FIG. 1 is, for example, a power storage module used in batteries of various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 is, for example, a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery. The power storage device 1 may be an electric double layer capacitor or an all-solid battery. In this embodiment, the case where the power storage device 1 is a lithium ion secondary battery is illustrated.

The power storage device 1 includes a cell stack 5 (laminated body) in which a plurality of power storage cells 10 are stacked (laminated) in the stacking direction. Below, the stacking direction of the plurality of storage cells 10 is simply referred to as the stacking direction. When viewed from the stacking direction, the power storage device 1 has, for example, a rectangular shape with sides of 50 cm or more. Each storage cell 10 includes a positive electrode 11, a negative electrode 12, a separator 13, and a spacer 14, as shown in FIG. The positive electrode 11 includes a current collector 20 (first current collector) and a positive electrode active material layer 22 provided on one surface 20 a of the current collector 20 . The positive electrode 11 is, for example, a rectangular electrode when viewed from the stacking direction. The negative electrode 12 includes a current collector 21 (second current collector) and a negative electrode active material layer 23 provided on one surface 21 a of the current collector 21 . The negative electrode 12 is, for example, a rectangular electrode when viewed from the stacking direction. The negative electrode 12 is arranged such that the negative electrode active material layer 23 faces the positive electrode active material layer 22 in the stacking direction. That is, the direction in which the positive electrode 11 and the negative electrode 12 face each other coincides with the stacking direction. In this embodiment, both the positive electrode active material layer 22 and the negative electrode active material layer 23 are formed in a rectangular shape. The negative electrode active material layer 23 is formed to be one size larger than the positive electrode active material layer 22, and the entire formation region of the positive electrode active material layer 22 is positioned within the formation region of the negative electrode active material layer 23 when viewed from the stacking direction. is doing.

The current collector 20 has the other side 20b opposite to the one side 20a. The positive electrode active material layer 22 is not formed on the other surface 20b. The current collector 21 has the other side 21b opposite to the one side 21a. The negative electrode active material layer 23 is not formed on the other surface 21b. The cell stack 5 is configured by stacking the storage cells 10 such that the other surface 20b of the current collector 20 and the other surface 21b of the current collector 21 are in contact with each other. Thereby, the plurality of storage cells 10 are electrically connected in series. In the cell stack 5, the storage cells 10, 10 adjacent in the stacking direction form a pseudo bipolar electrode 2 having the current collector 20 and the current collector 21 in contact with each other as electrode bodies. That is, one bipolar electrode 2 includes current collector 20 , current collector 21 , positive electrode active material layer 22 and negative electrode active material layer 23 . A first terminal electrode is arranged at one end in the stacking direction, and the first terminal electrode includes a current collector 20 and a positive electrode active material layer 22 . A second terminal electrode is arranged at the other end in the stacking direction, and the second terminal electrode includes a current collector 21 and a negative electrode active material layer 23 .

Each of current collector 20 and current collector 21 (hereinafter also simply referred to as “collector”) supplies current to positive electrode active material layer 22 and negative electrode active material layer 23 during discharging or charging of the lithium ion secondary battery. It is a chemically inert electrical conductor that keeps the current flowing. As a material constituting the current collector, for example, a metal material, a conductive resin material, a conductive inorganic material, or the like can be used. Examples of conductive resin materials include conductive polymer materials and resins obtained by adding conductive fillers to non-conductive polymer materials. The current collector may have multiple layers including one or more layers containing the aforementioned metal material, conductive resin material, conductive inorganic material, or the like. The surface of the current collector may be covered with a known protective layer. A coating layer may be formed on the surface of the current collector by a known method such as plating or spray coating. For example, a carbon film may be provided on the surface of the current collector (for example, one surface 20a and one surface 21a). The current collector may be formed in a plate-like, foil-like, sheet-like, film-like, mesh-like, or other shape, for example. When the current collector is a metal foil, for example, aluminum foil, copper foil, nickel foil, titanium foil, stainless steel foil, or the like can be used. When aluminum foil, copper foil, or stainless steel foil (for example, SUS304, SUS316, SUS301, etc. defined in JIS G4305:2015) is used as the current collector, the mechanical strength of the current collector can be ensured. The current collector may be an alloy foil or clad foil of the metal material of the metal foil. Moreover, the current collector 20 and the current collector 21 may be integrated. As the integrated current collector 20 and current collector 21, metal foils having different types of metals exposed on both sides of the foil may be used. For example, an aluminum foil having one surface plated with copper may be used. In this embodiment, current collector 20 is aluminum foil and current collector 21 is copper foil. When a foil-shaped current collector is used, its thickness may be, for example, 1 μm to 100 μm.

The positive electrode active material layer 22 contains a positive electrode active material capable of intercalating and deintercalating charge carriers such as lithium ions. As the positive electrode active material, a lithium composite metal oxide having a layered rock salt structure, a metal oxide having a spinel structure, a polyanion compound, or the like, which can be used as a positive electrode active material for a lithium ion secondary battery, may be adopted. Moreover, you may use together 2 or more types of positive electrode active materials. In this embodiment, the positive electrode active material layer 22 contains olivine-type lithium iron phosphate as a polyanionic compound.

The negative electrode active material layer 23 is not particularly limited and can be used as long as it is a simple substance, an alloy, or a compound that can occlude and release charge carriers such as lithium ions. Examples of negative electrode active materials include Li, carbon, metal compounds, elements that can be alloyed with lithium, and compounds thereof. Examples of carbon include natural graphite, artificial graphite, hard carbon (non-graphitizable carbon) and soft carbon (easily graphitizable carbon). Artificial graphite includes highly oriented graphite and mesocarbon microbeads. Examples of elements that can be alloyed with lithium include silicon (silicon) and tin. In this embodiment, the negative electrode active material layer 23 contains graphite as carbon.

Each of the positive electrode active material layer 22 and the negative electrode active material layer 23 (hereinafter also simply referred to as “active material layer”) contains a conductive aid, a binder, an electrolyte (polymer matrix , ion-conducting polymers, electrolytes, etc.), electrolyte-supporting salts (lithium salts) for enhancing ion conductivity, and the like. The components contained in the active material layer, the compounding ratio of the components, and the thickness of the active material layer are not particularly limited, and conventionally known knowledge about lithium ion secondary batteries can be appropriately referred to. The thickness of the active material layer is, for example, 2 μm to 150 μm. A conventionally known method such as a roll coating method may be used to form the active material layer on the surface of the current collector. In order to improve the thermal stability of the positive electrode 11 or the negative electrode 12, a heat-resistant layer may be provided on the surface (one side or both sides) of the current collector or the surface of the active material layer. The heat-resistant layer contains, for example, inorganic particles and a binder, and may contain additives such as a thickener.

A conductive aid is added to increase the conductivity of the positive electrode 11 or the negative electrode 12 . Conductive aids include, for example, acetylene black, carbon black, and graphite.

Binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber; thermoplastic resins such as polypropylene and polyethylene; imide resins such as polyimide and polyamideimide; resins containing alkoxysilyl groups; Acids, acrylic resins such as polymethacrylic acid, styrene-butadiene rubber, carboxymethyl cellulose, alginates such as sodium alginate and ammonium alginate, water-soluble cellulose ester crosslinked products, and starch-acrylic acid graft polymers can be exemplified. These binders may be used singly or in combination. Examples of the solvent include water, N-methyl-2-pyrrolidone, and the like.

The separator 13 separates the positive electrode 11 and the negative electrode 12 and allows charge carriers such as lithium ions to pass through while preventing short circuits due to contact between the two electrodes. A separator 13 is arranged between the positive electrode 11 and the negative electrode 12 . The separator 13 prevents a short circuit between the adjacent bipolar electrodes 2, 2 when the storage cells 10 are stacked.

The separator 13 may contain, for example, a polymer that absorbs and retains the electrolyte. As a material forming the separator 13, for example, polypropylene, polyethylene, methyl cellulose, or the like can be used. The separator 13 may be configured as a porous sheet, woven fabric, non-woven fabric, or the like. The separator 13 may have a single layer structure or a multilayer structure. The multilayer structure may have, for example, adhesive layers, ceramic layers as heat-resistant layers, and the like. The separator 13 may be impregnated with an electrolyte. The separator 13 itself may be composed of an electrolyte such as a polymer solid electrolyte or an inorganic solid electrolyte.

Examples of the electrolyte impregnated in the separator 13 include a liquid electrolyte (electrolytic solution) containing a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent, or a polymer gel electrolyte containing an electrolyte held in a polymer matrix. is mentioned.

When the separator 13 is impregnated with an electrolyte, the electrolyte salt may be LiClO ₄ , LiAsF ₆ , LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN(FSO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ or the like. Known lithium salts can be used. As the non-aqueous solvent, known solvents such as cyclic carbonates, cyclic esters, chain carbonates, chain esters and ethers can be used. Two or more of these known solvent materials may be used in combination.

Spacer 14 is arranged between current collector 20 and current collector 21 so as to surround negative electrode active material layer 23 when viewed in the thickness direction of negative electrode active material layer 23 . The spacer 14 is arranged so as to surround the positive electrode active material layer 22 when viewed from the thickness direction of the positive electrode active material layer 22 . The spacer 14 is joined or fixed to the current collector 20 and the current collector 21 . Spacers 14 contain an insulating material and prevent short circuits by providing insulation between current collectors 20 and 21 . Examples of the material forming the spacer 14 include polyethylene, polypropylene, polystyrene, modified polypropylene, ABS resin, acrylonitrile styrene resin, and the like. In this embodiment, the spacer 14 contains polyethylene, which is a resin, as an insulating material.

In this embodiment, the spacer 14 extends along at least one of the edge 20 e of the current collector 20 and the edge 21 e of the current collector 21 , and extends along at least one of the positive electrode active material layer 22 and the negative electrode active material layer 23 . It is a frame that surrounds the

In this embodiment, the spacer 14 also functions as a sealing portion that seals the space S between the positive electrode 11 and the negative electrode 12 . In this embodiment, the spacer 14 arranged in each storage cell 10 includes a first portion 14b arranged between the current collector 20 and the current collector 21 and an edge portion 21e of the current collector 21 (or a collector). and a second portion 14c extending outside the edge 20e) of the electrical body 20. As shown in FIG. The outer second portions 14c of the spacers 14 adjacent to each other in the stacking direction of the cell stack 5 are joined and integrated. A plurality of spacers 14 are integrated to form a sealing body 14a. A space S surrounded by the spacer 14 , the positive electrode 11 and the negative electrode 12 contains an electrolyte (electrolyte solution) with which the separator 13 is impregnated. The spacer 14 has a rectangular frame shape when viewed in the stacking direction, and is adhered to the edge 21 e of the current collector 21 . The sealing body 14a extends in the stacking direction from the current collector 20 arranged at one end in the stacking direction of the cell stack 5 to the current collector 21 arranged at the other end in the stacking direction. The sealing body 14a is a cylindrical member.

The spacer 14 can prevent the electrolyte from being exposed from the space S to the outside by sealing the space S between the positive electrode 11 and the negative electrode 12 . Moreover, the spacer 14 seals the space S between the positive electrode 11 and the negative electrode 12 , thereby preventing moisture from entering the space S from the outside of the power storage device 1 . Furthermore, the spacer 14 can prevent the gas generated from the positive electrode 11 or the negative electrode 12 from leaking to the outside of the power storage device 1 , for example, due to charge/discharge reactions or the like.

Hereinafter, a method for manufacturing a storage cell according to one embodiment will be described with reference to FIGS. 2 to 12. FIG. The storage cell 10 shown in FIG. 1 can be manufactured as follows. In the storage cell 10, the positive electrode 11 and the negative electrode 12 are stacked in the facing direction (Z-axis direction) in which the positive electrode active material layer 22 and the negative electrode active material layer 23 face each other.

(First resin member placement step)
First, as shown in FIG. 2, the first resin member 15 is provided on the edge portion 20ae of the one surface 20a of the current collector 20 when viewed in the Z-axis direction. The first resin member 15 includes a rectangular frame portion 15a (first frame portion) surrounding the positive electrode active material layer 22 and an extension portion 15b (first frame portion) extending outward from a side 15a1 (one side) of the frame portion 15a. extension). In this embodiment, the frame portion 15 a is welded to the edge portion 20 ae of the one surface 20 a of the current collector 20 . In the X-axis direction along one surface 20a, the extending portion 15b extends away from the side 15a1 of the frame portion 15a. The frame portion 15a and the extension portion 15b are connected at a boundary B and integrated. The outer edge portion 15be of the extension portion 15b has, for example, a rectangular shape, but may have a triangular shape that tapers away from the side 15a1. The frame portion 15a has an inner edge portion 15as having, for example, a rectangular shape. The inner edge portion 15as is separated from the positive electrode active material layer 22 when viewed from the Z-axis direction. The frame portion 15a has the same width D1 on each of the sides 15a1 to 15a4. The width D1 is the distance from the inner edge 15as to the outer edge. The extending portion 15b has, for example, a length D2 that is greater than the width D1 of the frame portion 15a in the X-axis direction. The length D2 of the extension portion 15b may be, for example, two to four times the width D1 of the frame portion 15a, and may be equal to or less than the width D1 of the frame portion 16a. The width D1 of the frame portion 15a is, for example, 10 to 15 mm. The length D2 of the extension portion 15b is, for example, 40-45 mm.

(Second resin member placement step)
Next, as shown in FIG. 3, the second resin member 16 is provided on the edge portion 21ae of the one surface 21a of the current collector 21 when viewed in the Z-axis direction. The second resin member 16 has the same shape as the first resin member 15 . The second resin member 16 includes a rectangular frame portion 16a (second frame portion) surrounding the negative electrode active material layer 23 and an extension portion 16b (second frame portion) extending outward from a side 16a1 (one side) of the frame portion 16a. extension). In this embodiment, the frame portion 16 a is welded to the edge portion 21 ae of the one surface 21 a of the current collector 21 . In the X-axis direction along one surface 21a, the extending portion 16b extends away from the side 16a1 of the frame portion 16a. The frame portion 16a and the extension portion 16b are connected at a boundary B and integrated. The outer edge portion 16be of the extension portion 16b has, for example, a rectangular shape, but may have a triangular shape that tapers away from the side 16a1. The frame portion 16a has an inner edge portion 16as having a rectangular shape, for example. The inner edge portion 16as is separated from the negative electrode active material layer 23 when viewed from the Z-axis direction. The frame portion 16a has a width D1 on each of the sides 16a1 to 16a4. The width D1 is the distance from the inner edge 16as to the outer edge. The extending portion 16b has, for example, a length D2 that is greater than the width D1 of the frame portion 16a in the X-axis direction. The length D2 of the extension portion 16b may be, for example, two to four times the width D1 of the frame portion 16a, and may be equal to or less than the width D1 of the frame portion 16a. The width D1 of the frame portion 16a is, for example, 10 to 15 mm. The length D2 of the extension portion 16b is, for example, 40-45 mm.

(Lamination process)
Next, as shown in FIGS. 4 and 5, in the Z-axis direction, the positive electrode active material layer 22 and the negative electrode active material layer 23 face each other with the separator 13 interposed therebetween. The positive electrode 11 and the negative electrode 12 are stacked such that the electrodes 16 face each other. The frame portion 15a and the frame portion 16a face each other. The extending portion 15b and the extending portion 16b face each other. That is, the first resin member 15 and the second resin member 16 overlap each other when viewed from the Z-axis direction.

The lamination process is performed, for example, as follows. A positive electrode unit including the first resin member 15 and the positive electrode 11, and a negative electrode unit including the separator 13, the second resin member 16 and the negative electrode 12 are laminated in this order. In this stacking step, the first resin member 15 and the second resin member 16 are brought into contact with each other.

(First welding step)
Next, as shown in FIGS. 6 and 7, the sides 15a2 to 15a4 (three sides) of the frame portion 15a and the sides 16a2 to 16a4 (three sides) of the frame portion 16a are welded to each other. In this manner, welded portions W1 to W3 indicated by oblique lines in FIG. 6 are formed. The welded portion W1 is formed by welding a side 15a3 of the frame portion 15a and a side 16a3 of the frame portion 16a to each other. Welded portion W2 is formed by welding together side 15a2 of frame portion 15a and side 16a2 of frame portion 16a. The welded portion W3 is formed by welding a side 15a4 of the frame portion 15a and a side 16a4 of the frame portion 16a to each other.

In this embodiment, a portion of the outer edge portion 15be of the extension portion 15b and a portion of the outer edge portion 16be of the extension portion 16b are welded to each other. Specifically, when viewed from the Z-axis direction, in the first edge region R1 connected to the side 16a2 of the frame portion 16a and the second edge region R2 connected to the side 16a4 of the frame portion 16a, the extension portion An outer edge portion 15be of 15b and an outer edge portion 16be of extension portion 16b are welded to each other. Therefore, the welded portion W2 is also formed in the first edge region R1 and the second edge region R2. When viewed from the Z-axis direction, it extends in a third edge region R3 connecting the first edge region R1 and the second edge region R2, and in a central region Rc surrounded by the first edge region R1 to the third edge region R3. The portion 15b and the extension portion 16b are not welded to each other.

The welded portions W1 to W3 may be formed by pressing a hot plate against the outer surfaces (surfaces extending in the Z-axis direction) of the first resin member 15 and the second resin member 16. It may be formed by heating while sandwiching the first resin member 15 and the second resin member 16 . In order to position the separator 13, the first resin member 15 and the second resin member 16 may be temporarily fixed to each other along the boundary B. As shown in FIG.

(Electrolyte injection step)
Next, as shown in FIG. 8, the space S between the current collectors 20 and 21 is interposed between the side 15a1 of the frame portion 15a and the side 16a1 of the frame portion 16a in the Z-axis direction. Electrolyte E is injected into the inside. In this embodiment, as shown in FIG. 6, the third edge regions R3 are not welded together. As a result, an opening OP is formed between the outer edge portion 15e of the first resin member 15 and the outer edge portion 16e of the second resin member 16, and the electrolytic solution E is injected into the space S through the opening OP. The opening OP can be formed by moving the outer edge portion 15e of the first resin member 15 and the outer edge portion 16e of the second resin member 16 away from each other in the third edge region R3. In the electrolytic solution injection step, for example, the electrolytic solution E can be injected by inserting an injection pipe into the opening OP.

In this embodiment, the electrolytic solution E is injected while the positive electrode 11 and the negative electrode 12 are inclined at an angle θ with respect to the horizontal direction H so that the opening OP faces upward. Thereby, backflow of the electrolytic solution E can be prevented. The angle θ may be greater than 0° and less than or equal to 90°.

(Second welding process)
Next, as shown in FIGS. 9 and 10, one end (tip 31t) of the tube 31 connected to the container 32 of the gas collector 30 is arranged between the extension 15b and the extension 16b. In this state, the outer edge portion 15be of the extension portion 15b and the outer edge portion 16be of the extension portion 16b are welded to each other. The other end of the pipe 31 is located outside the first resin member 15 and the second resin member 16 when viewed in the Z-axis direction. In this manner, a welded portion W4 indicated by oblique lines in FIG. 9 is formed. The welded portion W4 is formed by welding together the outer edge portion 15be of the extension portion 15b and the outer edge portion 16be of the extension portion 16b in the third edge region R3. The welded portion W4 can be formed by a method similar to that of the welded portions W1 to W3.

The gas collection device 30 comprises a tube 31 having a channel therein and a container 32 connected to the tube 31 . When the tube 31 and the container 32 are configured separately, the connecting portion is hermetically sealed. The inside of the container 32 and the space S are connected via the channel of the pipe 31 . The tube 31 may, for example, have a nozzle that tapers into the cell. The container 32 may be, for example, a bag-shaped gas collection bag made of laminated film, metal foil, or the like. In the present embodiment, the pipe 31 is arranged such that the tip 31t of the pipe 31 is positioned between the extending portion 15b of the first resin member 15 and the extending portion 16b of the second resin member 16. As shown in FIG. The tip 31t of the tube 31 does not reach the boundary B. A tip 31t of the tube 31 is located between the third edge region R3 and the boundary B when viewed from the Z-axis direction.

(Initial charging/discharging step)
Next, with one end (tip 31t) of the tube 31 connected to the container 32 of the gas collection device 30 disposed between the extension portion 15b and the extension portion 16b, the positive electrode 11, the negative electrode 12 and the separator were assembled. An initial charge/discharge (activation or conditioning) of the laminate containing 13 is performed. The gas generated in the space S due to the initial charge/discharge is collected in the container 32 of the gas collector 30 through the pipe 31 from between the extension portions 15b and 16b that are not welded to each other. The amount of gas generated increases with an increase in size of the storage cell 10 formed from the laminate.

(Third welding step)
Next, as shown in FIG. 11, the side 15a1 of the frame portion 15a and the side 16a1 of the frame portion 16a are welded together. In this manner, the welded portion W5 indicated by diagonal lines in FIG. 11 is formed. The welded portion W5 is formed along the boundary B. As shown in FIG. A welded portion W5 may be formed in a portion along the boundary B of the extension portion 15b and the extension portion 16b. The welded portion W5 can be formed by heating while sandwiching the first resin member 15 and the second resin member 16 in the Z-axis direction. A space S between the current collector 20 and the current collector 21 is sealed by the welded portions W1 to W3 and W5.

(Cutting process)
Next, as shown in FIG. 12, the extensions 15b and 16b are cut so that the gas collection device 30 is removed. In this embodiment, the extending portions 15b and 16b are cut at the boundary B, so that the spacer 14 composed of the frame portion 15a and the frame portion 16a is obtained. If the cutting step is performed after the third welding step, the cutting can be performed in a state where the space S is sealed, so leakage of the electrolytic solution E in the cutting step can be suppressed. One outer side surface (surface extending in the Z-axis direction) of the rectangular frame-shaped spacer 14 is a cut surface different from the other three outer side surfaces. Thus, the storage cell 10 can be manufactured. The sealing body 14a of the power storage device 1 is obtained by stacking the plurality of power storage cells 10 and welding the spacers 14 adjacent to each other. Thus, the power storage device 1 can be manufactured.

According to the method for manufacturing the storage cell 10 according to this embodiment, the gas generated in the initial charging/discharging process moves through the pipe 31 to the container 32 of the gas collecting device 30 . Therefore, when viewed from the Z-axis direction, the areas of the extending portions 15b and 16b can be reduced. Therefore, the amount of waste (extending portion 15b and extending portion 16b) generated in the cutting process can be reduced. Therefore, the manufacturing cost of the storage cell 10 can be reduced. Moreover, even if the extending portions 15b and 16b are damaged due to contact with the pipe 31 of the gas collecting device 30, the extending portions 15b and 16b are removed by cutting. Therefore, it is possible to reduce the possibility of the spacers 14 being damaged in the obtained electric storage cell 10 . Further, even if the extending portion 15b and the extending portion 16b are deformed due to contact with the tube 31, the stress applied to the current collectors 20 and 21 is small. Therefore, deformation, breakage, etc. of the current collectors 20 and 21 can be prevented. Moreover, in this embodiment, since gas is collected using the gas collection device 30, a large amount of gas can be collected. When the storage cell 10 has a rectangular shape including sides of, for example, 50 cm or more when viewed from the Z-axis direction, the increase in the size of the storage cell 10 increases the amount of gas generated. Even in such a case, the pressure rise in the space S can be suppressed. Therefore, it is possible to reduce the possibility that the first resin member 15 and the second resin member 16 are damaged by the internal pressure of the gas. Also, the gas collector 30 can be reused.

When the tip 31t of the pipe 31 is positioned between the extension portion 15b and the extension portion 16b, damage to the frame portions 15a and 16a due to the contact of the pipe 31 can be suppressed.

Next, a method for manufacturing a storage cell according to another embodiment will be described with reference to FIGS. 13 and 14. FIG. In the method for manufacturing a storage cell of the present embodiment, the same steps as those of the above embodiment are performed except that the electrolytic solution injection step is performed as follows. Thereby, the storage cell 10 shown in FIG. 1 is manufactured.

(Electrolyte injection step)
A plurality of injection tubes C may be inserted into the opening OP to inject the electrolyte E into the space S between the current collectors 20 and 21 . At this time, the liquid injection tube C is arranged so that the tip Ct of the liquid injection tube C is positioned between the extension part 15b and the extension part 16b. After the injection of the electrolytic solution E is completed, the injection tube C is removed from the opening OP.

According to the present embodiment, damage to the frame portions 15a and 16a due to the contact of the injection pipe C can be suppressed.

The second welding step may be performed before the electrolyte injection step. For example, the extension portions 15b and 16b are welded to each other with a communication member disposed between the extension portions 15b and 16b. Specifically, in the third edge region R3, the outer edge portion 15be of the extension portion 15b and the outer edge portion 16be of the extension portion 16b, the outer edge portion 15be of the extension portion 15b and the communicating member, and the outer edge of the extension portion 16b The portion 16be and the communicating member are welded together. The communication member is a tubular member having a flow path inside, one open end of which is located within the space S, and the other open end of which is located outside the extending portions 15b and 16b. The communication member functions as a liquid injection pipe C by connecting a liquid injection device to the opening end of the communication member positioned outside the extension part 15b and the extension part 16b. After the electrolyte solution injection step, the liquid injection device is removed from the communication member, and the container 32 of the gas collection device 30 is connected to the communication member. The communicating member functions as the tube 31 of the gas collector 30 . By performing the initial charging/discharging process in this state, the gas is collected in the container 32 via the communicating member. In this case, the injection tube C is used as the tube 31 connected to the container 32 of the gas collection device 30 . As a result, the initial charging/discharging process can be performed without removing the injection tube C. FIG.

Next, a method for manufacturing a storage cell according to another embodiment will be described with reference to FIGS. 15 and 16. FIG. The method for manufacturing a storage cell according to this embodiment is the same as the method for manufacturing a storage cell according to the above-described embodiment, except that a step of arranging a reinforcing member is further included. Thereby, the storage cell 10 shown in FIG. 1 is manufactured.

(Reinforcing member placement process)
As shown in FIGS. 15 and 16, reinforcing members 40 are provided on the outer surface 15bs of the extension portion 15b and the outer surface 16bs of the extension portion 16b, respectively. An outer surface 15bs of the extension portion 15b extends along one surface 20a of the current collector 20 and is positioned on the current collector 20 side in the Z-axis direction. An outer surface 16bs of the extension portion 16b extends along one surface 21a of the current collector 21 and is positioned on the current collector 21 side in the Z-axis direction.

In the present embodiment, the reinforcing member arranging step is performed simultaneously with the first resin member arranging step and the second resin member arranging step. The reinforcing member 40 is welded to each of the outer surface 15bs and the outer surface 16bs. For example, when the current collector 20 is welded to the frame portion 15a, the reinforcing member 40 is welded to the outer surface 15bs of the extension portion 15b. When the current collector 21 is welded to the frame portion 16a, the reinforcing member 40 is welded to the outer surface 16bs of the extension portion 16b. The reinforcing member 40 is arranged apart from the current collector 20 or the current collector 21 in the X-axis direction. Boundary B is located in the gap between reinforcing member 40 and current collector 20 or current collector 21 in the X-axis direction. The reinforcing member 40 may have a higher melting point than the higher one of the melting points of the first resin member 15 and the second resin member 16 . The reinforcing member 40 may be a metal member such as a metal plate, or may be a resin member such as a resin plate. The metal member may be the same current collector as the current collector 20 or the current collector 21 . Examples of materials for the resin member may include polypropylene and polyethylene terephthalate. The reinforcing member 40 may be provided on only one of the extension portion 15b and the extension portion 16b.

According to this embodiment, the reinforcing member 40 reinforces the extending portion 15b and the extending portion 16b. In the sealing process, the reinforcing member 40 is positioned above the tube 31 in the Z-axis direction. Therefore, damage to the extending portions 15b and 16b due to contact with the pipe 31 can be suppressed. In addition, since the reinforcing member 40 is not positioned on the boundary B in the Z-axis direction, alignment of the boundary B is facilitated in the cutting process, and cutting of the extending portions 15b and 16b is also facilitated.

Although the preferred embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments.

For example, in the above embodiment, the cutting process is performed after the third welding process, but the third welding process may be performed after the cutting process. In this case, the welded portion W5 can be formed by pressing a hot plate against the cut surfaces of the frame portion 15a and the frame portion 16a formed at the boundary B for welding. The cutting step is performed with the positive electrode 11 and the negative electrode 12 inclined with respect to the horizontal direction so that the third edge region R3 faces upward. Thereby, leakage of the electrolytic solution E at the time of cutting can be suppressed.

Further, in the above embodiment, the extending portions 15b and 16b are cut at the boundary B. may be cut.

DESCRIPTION OF SYMBOLS 10... Storage cell, 11... Positive electrode, 12... Negative electrode, 13... Separator, 15... First resin member, 15a... Frame (first frame), 15a1... Side (one side), 15a2 to 15a4... Sides (three sides) ), 15b... Extension part (first extension part), 15bs, 16bs... Outer surface, 15be, 16be... Outer edge part, 16... Second resin member, 16a... Frame part (second frame part), 16a1... Side (one side), 16a2 to 16a4... Side (three sides), 16b... Extension portion (second extension portion), 20... Current collector (first current collector), 20a, 21a... One side, 20ae, 21ae Edge 21 Current collector (second current collector) 22 Positive electrode active material layer 23 Negative electrode active material layer 30 Gas collector 31 Tube 31t Tip 32 Container 40 Reinforcement member E Electrolyte solution C Injection tube Ct tip

Claims (4)

A positive electrode having a first current collector and a positive electrode active material layer provided on one side of the first current collector, and a second current collector and a negative electrode active material layer provided on one side of the second current collector. A method for manufacturing a storage cell in which a negative electrode having a material layer and a negative electrode are laminated in a direction in which the positive electrode active material layer and the negative electrode active material layer face each other,
A rectangular first frame portion surrounding the positive electrode active material layer and a rectangular first frame portion extending outward from one side of the first frame portion at the edge portion of the one surface of the first current collector when viewed from the facing direction. a first resin member arranging step of providing a first resin member having a first extension;
A rectangular second frame portion surrounding the negative electrode active material layer and a rectangular second frame portion extending outward from one side of the second frame portion at the edge portion of the one surface of the second current collector when viewed from the facing direction. a second resin member arranging step of providing a second resin member having a second extension;
In the facing direction, the positive electrode active material layer and the negative electrode active material layer face each other with the separator interposed therebetween, the first frame portion and the second frame portion face each other, and the first extension portion and the first extension portion face each other. a stacking step of stacking the positive electrode and the negative electrode such that the second extension portions face each other;
a first welding step of welding together three sides of the first frame portion excluding the one side and three sides of the second frame portion excluding the one side;
After the first welding step, the space between the first current collector and the second current collector through the space between the one side of the first frame and the one side of the second frame an electrolytic solution injection step of injecting an electrolytic solution into the
After the first welding step, the outer edge portion of the first extension portion and the second extension portion are separated from each other with one end of the pipe disposed between the first extension portion and the second extension portion. a second welding step of welding the outer edges of the parts to each other;
After the electrolyte injection step and the second welding step, the one end of the pipe connected to the container of the gas collecting device was arranged between the first extension portion and the second extension portion. an initial charging/discharging step of performing initial charging/discharging of a laminate including the positive electrode, the negative electrode, and the separator in a state;
a third welding step of welding the one side of the first frame and the one side of the second frame to each other after the initial charging/discharging step;
a cutting step of cutting the first extending portion and the second extending portion so that the gas collecting device is removed after the initial charging/discharging step;
A method of manufacturing a storage cell, comprising: In the electrolyte injection step, the electrolyte injection tube for injecting the electrolyte is arranged such that the tip of the electrolyte injection tube is positioned between the first extension portion and the second extension portion. The method for manufacturing the storage cell according to claim 1. 3. The method of manufacturing a storage cell according to claim 2, wherein said liquid injection pipe is used as said pipe connected to said container of said gas collection device. The step of providing a reinforcing member on at least one of the outer surface of the first extension portion and the outer surface of the second extension portion is further included, wherein the outer surface of the first extension portion extending along the one surface of the current collector and positioned on the side of the first current collector in the facing direction; 4. The method for manufacturing a storage cell according to claim 1, wherein the second current collector side extends along the opposite direction.

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