Method for manufacturing power storage device

Abstract

The present invention provides a method for manufacturing an electricity storage device capable of improving the ease of peeling of an adhesive tape after temporary sealing. The present invention provides a method for manufacturing a power storage device provided with a cover body having a liquid injection hole and closing an opening of a case main body. The manufacturing method comprises the following steps: a temporary sealing step of adhering an adhesive tape to the cover body so as to block the liquid injection hole; in the temporary sealing step, the adhesive tape is brought into close contact with the lid body at the peripheral edge of the liquid injection hole, and at least a part of the portion of the adhesive tape that is separated from the liquid injection hole is brought into a state of floating from the lid body.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an electric storage device. Background Art

[0002] The power storage device typically includes an electrode body, an electrolyte, a case body having an opening and accommodating the electrode body and the electrolyte, and a cover body having a liquid injection hole and closing the opening of the case body (for example, see Japanese Patent Application Publication No. 2022-139497 and Japanese Patent Application Publication No. 2017-117657).

[0003] For example, Japanese Patent Application Publication No. 2022-139497 discloses a method for manufacturing a storage battery device, comprising the following steps: a step of temporarily sealing an injection hole by a first sealing member (air-permeable membrane); a step of immersing an electrode body in an electrolyte while the injection hole is temporarily sealed by the first sealing member; a step of removing the first sealing member to open the injection hole; and a step of formally sealing the injection hole by a second sealing member (sealing plug).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-139497

[0007] Patent Document 2: Japanese Patent Application Publication No. 2017-117657 Summary of the invention

[0008] According to the research of the inventors, the first sealing member used in temporary sealing is an adhesive tape. If the adhesive tape is firmly attached to the cover, it is sometimes difficult to peel off the adhesive tape in the subsequent process. In addition, as described in Japanese Patent Application Publication No. 2022-139497, sometimes adhesive remains on the cover after peeling off the adhesive tape. As a result, it is sometimes difficult to embed the second sealing member into the injection hole during formal sealing.

[0009] The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a method for manufacturing an electrical storage device capable of improving the ease of peeling of an adhesive tape after temporary sealing.

[0010] According to the present invention, a method for manufacturing an electric storage device is provided, wherein the electric storage device comprises: an electrode body; an electrolyte; a shell body having an opening for storing the electrode body and the electrolyte; and a cover body having a liquid injection hole for blocking the opening of the shell body. The manufacturing method comprises: a temporary sealing step of sticking an adhesive tape to the cover body to block the liquid injection hole; and an unsealing step of peeling off the adhesive tape stuck to the cover body, wherein in the temporary sealing step, the adhesive tape is stuck to the peripheral edge of the liquid injection hole, and at least a part of the adhesive tape is made to float from the cover body in a portion away from the liquid injection hole.

[0011] The inventors of the present invention have repeatedly conducted in-depth research and have newly discovered the following. That is, when peeling the adhesive tape from the cover, the tip of a fingernail or a gripping tool such as tweezers is often hooked on the edge of the adhesive tape to lift it up. However, if the adhesive tape is tightly attached to the cover up to the edge, it is difficult for the tip of a fingernail or the like to hook the edge of the adhesive tape. As a result, a large external force is required at the beginning of the peeling, and it is particularly easy for the adhesive to remain (so-called residual adhesive) to remain.

[0012] Therefore, in the present invention, in the temporary sealing process, the adhesive tape at the portion away from the injection hole is made to float from the cover body. As a result, in the unsealing process, it is easy to peel off the adhesive tape starting from the portion floating from the cover body. Therefore, the external force required at the portion where peeling begins is suppressed. Furthermore, after peeling off the adhesive tape, it is difficult for adhesives to remain around the injection hole, and it is easy to fit the sealing member into the injection hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view schematically showing an electric storage device according to an embodiment.

[0014] Figure 2 It is a perspective view schematically showing an electrode body.

[0015] Figure 3 It is a schematic diagram showing the structure of an electrode body.

[0016] Figure 4 This is a flow chart of a manufacturing method according to one embodiment.

[0017] Figure 5 It is a side view schematically showing the main part of the tape applying device.

[0018] Figure 6 (A) to (F) are schematic diagrams for explaining the temporary sealing process.

[0019] Figure 7 (A) is a top view schematically showing the cover after the temporary sealing process. Figure 7 (B) is along Figure 7 A schematic longitudinal cross-sectional view taken along line VII(B)-VII(B) of (A).

[0020] Figure 8 It is a schematic diagram explaining the unsealing process.

[0021] Fig. 9 is a variant of Figure 8 Quite a picture. DETAILED DESCRIPTION

[0022] Hereinafter, some preferred embodiments of the technology disclosed herein are described with reference to the accompanying drawings. Matters other than those specifically mentioned in this specification and necessary for the implementation of the present invention (for example, the general structure and manufacturing process of the power storage device that do not give characteristics to the technology disclosed herein) can be grasped as design matters made by those skilled in the art based on the existing technology in the field. The technology disclosed herein can be implemented based on the contents disclosed in this specification and the technical common sense in the field.

[0023] In this specification, "electrical storage device" refers to all devices that can be repeatedly charged and discharged, and is a concept that includes capacitors such as lithium ion capacitors and electric double layer capacitors in addition to lithium ion secondary batteries, nickel metal hydride batteries, etc. In addition, the expression "A to B" indicating a numerical range in this specification includes the meaning of "above A and below B", and also includes the meaning of "greater than A" and "less than B".

[0024] <Electrical storage device 100>

[0025] First, the power storage device 100 manufactured by the manufacturing method disclosed herein will be described. Figure 1 It is a three-dimensional diagram of the power storage device 100. In addition, in the following description, the figure symbol X represents the "short side direction" of the power storage device 100, the figure symbol Y represents the "long side direction" perpendicular to the short side direction, and the figure symbol Z represents the "height direction" perpendicular to the short side direction and the long side direction. In addition, F in the short side direction X represents "front", and Rr represents "rear". L in the long side direction Y represents "left", and R represents "right". U in the height direction Z represents "up", and D represents "down". However, these directions are only for the convenience of explanation and do not limit the setting method of the power storage device 100.

[0026] The power storage device 100 includes a battery case 10 (see Figure 1 )、Electrode body 20( Figure 1 Not shown, see Figure 2 , Figure 3 ) and an electrolyte (not shown). Here, the power storage device 100 is a lithium ion secondary battery.

[0027] The battery case 10 includes a case body 12 having an opening and a cover (sealing plate) 14 that blocks the opening. The battery case 10 is integrated by joining the cover 14 to the periphery of the opening of the case body 12, and is hermetically sealed (sealed). Here, the battery case 10 is a flat rectangular parallelepiped (square) with a bottom. However, in other embodiments, the battery case 10 may also be, for example, a cubic shape or a cylindrical shape.

[0028] The shell body 12 is a frame for storing the electrode body 20 and the electrolyte. The shell body 12 has a rectangular bottom surface 12a, a pair of wide surfaces 12b and a pair of narrow surfaces 12c. The pair of wide surfaces 12b rise from the two long sides of the bottom surface 12a respectively. The pair of narrow surfaces 12c rise from the two short sides of the bottom surface 12a respectively. The cover body 14 is a flat member. The cover body 14 faces the bottom surface 12a of the shell body 12. The cover body 14 has an upper surface 14u. The upper surface 14u is a surface on one side away from the shell body 12, constituting the outer surface of the battery shell 10. Here, the cover body 14 is roughly rectangular in shape. In addition, in this specification, "roughly rectangular shape" is a term that includes, in addition to a complete rectangular shape (rectangular shape), a shape in which the corners connecting the long and short sides of the rectangular shape are rounded, a shape with a cutout at the corner, etc.

[0029] The cover 14 is provided with a liquid injection hole 15, a safety valve 17, a positive external terminal 30, and a negative external terminal 40. The liquid injection hole 15 is a through hole for injecting electrolyte into the battery case 10 after the cover 14 is assembled to the case body 12. Here, the liquid injection hole 15 is formed to be circular when viewed from above. The liquid injection hole 15 is sealed by a sealing member 16. The sealing member 16 is preferably a sealing plug having a portion that can be inserted into the liquid injection hole 15. The safety valve 17 is a thin-walled portion configured to break when the pressure in the battery case 10 reaches a predetermined value or more and discharge the gas in the battery case 10 to the outside. The positive external terminal 30 and the negative external terminal 40 are electrically connected to the electrode body 20 housed in the battery case 10.

[0030] Although not particularly limited, the battery case 10 is made of metal, for example. Examples of the metal material constituting the battery case 10 include aluminum, aluminum alloys, iron, and iron alloys. Alternatively, the battery case 10 may be made of a heat-resistant resin material such as a polyimide resin.

[0031] Electrode body 20 (see Figure 2 , Figure 3 ) is housed in the battery case 10 (specifically, in the case body 12). The number of electrode bodies 20 disposed in one battery case 10 is not particularly limited, and may be one or more than two (plural).

[0032] Figure 2 It is a perspective view of the electrode body 20 . Figure 3 Schematic diagram showing the structure of the electrode body 20. Figure 2 , Figure 3 As shown, the positive electrode internal terminal 50 and the negative electrode internal terminal 60 are mounted on the electrode body 20. The positive electrode internal terminal 50 and the positive electrode external terminal 30 (see Figure 1 ) is connected. The negative electrode internal terminal 60 is connected to the negative electrode external terminal 40 (refer to Figure 1 )connect.

[0033] like Figure 3 As shown in FIG. 1 , the electrode body 20 includes a positive electrode 22 and a negative electrode 24. Here, the electrode body 20 is a flat wound electrode body in which a strip-shaped positive electrode 22 and a strip-shaped negative electrode 24 are stacked with a strip-shaped separator 26 interposed therebetween and wound around a winding axis WL. Figure 2 As shown, the electrode body 20 has a pair of flat portions 20a with flat outer surfaces and a pair of curved portions 20b with curved outer surfaces. However, in other embodiments, the electrode body 20 may also be a stacked electrode body in which a square-shaped (typically rectangular-shaped) positive electrode and a square-shaped (typically rectangular-shaped) negative electrode are stacked in an insulated state.

[0034] Although detailed illustration is omitted, the electrode body 20 is arranged inside the case body 12 in an orientation in which the winding axis WL is parallel to the longitudinal direction Y. Figure 1 When the electrode body 20 is housed in the battery case 10 , the pair of flat portions 20 a of the electrode body 20 faces the wide surface 12 b of the battery case 10 , and the pair of curved portions 20 b faces the narrow surface 12 c .

[0035] The positive electrode 22 has a strip-shaped positive electrode collector foil 22c (e.g., aluminum foil) and a positive electrode active material layer 22a fixed on at least one surface of the positive electrode collector foil 22c. Although not particularly limited, a positive electrode protective layer 22p may be provided on one side edge portion of the positive electrode 22 in the long side direction Y as required. In addition, the materials constituting the positive electrode active material layer 22a and the positive electrode protective layer 22p can be used without particular restrictions. The materials used in such a power storage device (in this embodiment, a lithium ion secondary battery) are omitted because they do not give characteristics to the technology disclosed herein.

[0036] At one end portion ( Figure 3 A plurality of positive electrode tabs 22t are provided at the left end portion of the longitudinal direction Y. The plurality of positive electrode tabs 22t are respectively oriented toward one side (the first side, Figure 3The plurality of positive electrode tabs 22t are arranged at intervals (intermittently) along the longitudinal direction of the positive electrode 22. The positive electrode tab 22t is a part of the positive electrode collector foil 22c, which is a part of the positive electrode collector foil 22c where the positive electrode active material layer 22a and the positive electrode protective layer 22p are not formed (the collector foil exposed part). The plurality of positive electrode tabs 22t are arranged at the end ( Figure 3 The positive electrode tab group 23 is stacked with a positive electrode internal terminal 50 (see Figure 2 ).

[0037] The negative electrode 24 has a strip-shaped negative electrode current collector foil 24c (e.g., copper foil) and a negative electrode active material layer 24a fixed on at least one surface of the negative electrode current collector foil 24c. In addition, the material constituting the negative electrode active material layer 24a can be used without particular limitation in the material used in such a power storage device (in this embodiment, a lithium ion secondary battery), and a detailed description thereof is omitted because it does not give characteristics to the technology disclosed herein.

[0038] At one end portion ( Figure 3 A plurality of negative electrode tabs 24t are provided at the right end of the longitudinal direction Y. The plurality of negative electrode tabs 24t are oriented toward the other side (the second side, Figure 3 The plurality of negative electrode tabs 24t are arranged at intervals (intermittently) along the length direction of the negative electrode 24. Here, the negative electrode tab 24t is a part of the negative electrode collector foil 24c, which is a part of the negative electrode collector foil 24c where the negative electrode active material layer 24a is not formed (the collector foil exposed part). The plurality of negative electrode tabs 24t are at the end ( Figure 3 The negative electrode tab group 25 is stacked to form a negative electrode tab group 25. A negative electrode internal terminal 60 (see Figure 2 ).

[0039] The electrolyte is typically a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. As the non-aqueous solvent, various solvents for the electrolyte of such an electrical storage device (here, a lithium ion secondary battery) can be used without particular restrictions. As the non-aqueous solvent, for example, carbonates such as ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) can be cited. As the supporting salt, various electrolyte salts for the electrolyte of such an electrical storage device (here, a lithium ion secondary battery) can be used without particular restrictions. As the supporting salt, for example, lithium salts such as LiPF6 can be cited. The electrolyte can also contain conventionally known additives such as a film former, a thickener, and a dispersant as needed.

[0040] <Method of Manufacturing Electricity Storage Device 100>

[0041] Figure 4 This is a flow chart of a manufacturing method according to one embodiment. Figure 4 The manufacturing method shown includes the following steps in sequence: an electrode body storage step (step S1); a temporary sealing step (step S2); a shell joining step (step S3); an unsealing step (step S4); a leakage inspection step (step S5); a liquid injection step (step S6); and a formal sealing step (step S7). However, this is only one example of the technology disclosed herein. The temporary sealing step (step S2) and the unsealing step (step S4) can also be implemented at other time points. In addition, the order of the temporary sealing step (step S2) and the electrode body storage step (step S1) can also be reversed. In addition, the inspection step (step S5) is an arbitrary step and can also be omitted. In addition, other steps may also be included at any stage.

[0042] The electrode body storage process (step S1) is a process of preparing the electrode body 20 and storing it in the battery case 10. In a preferred embodiment, this process includes an electrode production process (step S11), an electrode body production process (step S12) and a storage process (step S13). In addition, other processes may also be included at any stage.

[0043] First, in the electrode manufacturing process (step S11), the positive electrode 22 and the negative electrode 24 are respectively manufactured by a conventionally known method. The positive electrode 22 can be prepared by, for example, mixing a positive electrode active material, a conductive material, a binder, and a dispersion solvent to prepare a positive electrode mixture slurry, and by a conventionally known method, the prepared positive electrode mixture slurry is applied on the positive electrode collector foil 22c, dried, and appropriately pressed to manufacture. The negative electrode 24 can be prepared by, for example, mixing a negative electrode active material, a binder, a dispersant, and a dispersion solvent to prepare a negative electrode mixture slurry, and by a conventionally known method, the prepared negative electrode mixture slurry is applied on the negative electrode collector foil 24c, dried, and appropriately pressed to manufacture. In addition, in the present embodiment, both the positive electrode 22 and the negative electrode 24 are manufactured, but in other embodiments, the positive electrode 22 and / or the negative electrode 24 can also be prepared by purchasing commercially available products.

[0044] Next, in the electrode body manufacturing process (step S12), the positive electrode 22 and the negative electrode 24 manufactured above are made to face each other with the separator 26 between them to manufacture the electrode body 20. In the case where the electrode body 20 to be manufactured is a flat-shaped wound electrode body, for example, first, the strip-shaped positive electrode 22 and the strip-shaped negative electrode 24 are stacked with the strip-shaped separator 26 between them, and are wound into a cylindrical shape with the winding axis WL as the center (winding process). Next, the electrode body (cylindrical body) wound into a cylindrical shape is punched into a flat shape (punching process). Next, the positive internal terminal 50 is installed on the positive electrode tab group 23 of the electrode body 20, and the negative internal terminal 60 is installed on the negative electrode tab group 25. Next, the positive external terminal 30 and the negative external terminal 40 are installed on the cover body 14. Then, these external terminals (positive electrode external terminal 30 and negative electrode external terminal 40) are connected to the same internal terminals (positive electrode internal terminal 50 and negative electrode internal terminal 60) by a conventionally known method (current collector bonding step). In this way, the electrode body 20 and the cover body 14 are integrated.

[0045] Next, in the housing step (step S13 ), the lid body 14 integrated with the electrode body 20 is fitted into the opening of the case body 12 . Thus, the electrode body 20 is housed inside the case body 12 .

[0046] The temporary sealing process (step S2) is to apply the adhesive tape 90 (refer to Figure 5 ) is attached to the cover body 14 to block the injection hole 15 of the cover body 14. The adhesive tape 90 is wider than the injection hole 15. The adhesive tape 90 is typically in a rolled-up state. Although not particularly limited, the average thickness of the adhesive tape 90 is approximately 1000 μm or less, typically 500 μm or less, for example, 250 μm or less. Here, the adhesive tape 90 is a component that prevents splashes from being mixed into the interior of the shell body 12 through the injection hole 15 when splashes are generated in the subsequent shell joining process (step S3).

[0047] The adhesive tape 90 typically includes a base layer and an adhesive layer, the adhesive layer being provided on the surface of the base layer on the cover body 14 side and having adhesiveness to the cover body 14. Although not particularly limited, the base layer is preferably composed of a resin material such as polyimide resin (e.g., Kapton (trademark)), fluororesin, polyethylene terephthalate (PET), or a glass material such as glass cloth. Among them, a resin material is preferred, and polyimide resin or fluororesin is particularly preferred because of its high heat resistance to splashes (not easy to burn).

[0048] Figure 51 is a side view schematically showing the main part of the tape sticking device 200 used in this process. The tape sticking device 200 is arranged above the cover 14 and is configured to stick the adhesive tape 90 on the periphery of the injection hole 15 of the cover 14. Hereinafter, the method of using the tape sticking device 200 will be described with reference to the accompanying drawings as appropriate. However, in other embodiments, the adhesive tape 90 can also be stuck to the cover 14 by hand (manually) without using the tape sticking device 200.

[0049] The tape pasting device 200 includes a pasting unit 290. The pasting unit 290 is directly or indirectly supported by a supporting member not shown in the figure. When the pasting unit 290 is on standby, i.e., when not performing a pasting action, it is located at a preset original position (not shown in the figure). The pasting unit 290 includes a tape supply unit 210, a tape pasting unit 220, and a tape cutting unit 230. The pasting unit 290 is configured to be able to move from the original position to a lower pasting position by an up-and-down direction moving mechanism not shown in the figure. The pasting unit 290 is configured to be able to move in the long side direction Y by a long side direction moving mechanism not shown in the figure. The long side direction Y is an example of a "first direction along the surface of the cover body".

[0050] The structures of the vertical movement mechanism and the longitudinal movement mechanism can be the same as before. The vertical movement mechanism is, for example, a lifting cylinder. The vertical movement mechanism is electrically connected to a control unit not shown. The tape supply unit 210, the tape pasting unit 220, and the tape cutting unit 230 of the pasting unit 290 are driven by the lifting cylinder to move integrally toward the side (pasting position) close to the cover body 14.

[0051] The long-side moving mechanism includes, for example, a guide rail extending in the long-side direction and a drive motor. The pasting unit 290 is slidably engaged with the guide rail. The drive motor is connected to the pasting unit 290, for example, via a ball screw. The drive motor is electrically connected to a control unit not shown. The pasting unit 290, i.e., the tape supply unit 210, the tape pasting unit 220, and the tape cutting unit 230, are rotated and driven by the drive motor so as to move integrally on the guide rail along the long-side direction Y. In addition, Figure 5 In the figure, the right side is the front side of the pasting unit 290 in the moving direction, and the left side is the rear side of the pasting unit 290 in the moving direction.

[0052] The tape supply unit 210 is configured to supply the adhesive tape 90 to the pasting roller 221 described later. The tape supply unit 210 is arranged at a position to the right (front side in the direction of travel) of the pasting roller 221. The tape supply unit 210 includes a supply reel (not shown) on which the adhesive tape 90 is wound, a guide roller 211, a roller supporting member 212 supporting the guide roller 211, a tape supply path 213, a tape chuck 214, and a supply unit moving mechanism (not shown). The supply unit moving mechanism moves the tape supply unit 210 alone (in other words, separately from the tape pasting unit 220 and the tape cutting unit 230) from the pasting position to the upper side. The structure of the supply unit moving mechanism is not particularly limited, and is, for example, a drive motor. In this case, the roller supporting member 212 is moved in the up-down direction by driving the drive motor. As a result, the guide roller 211 moves in the up-down direction.

[0053] The guide roller 211 is a member that draws the adhesive tape 90 from the supply reel and guides it to the vicinity of the pasting roller 221. The guide roller 211 has a long cylindrical shape. The guide roller 211 is arranged in a manner such that its axis is along the short-side direction X. The guide roller 211 is supported on the roller supporting member 212 in a rotatable manner around an axis extending in the short-side direction X. The guide roller 211 can also be configured to rotate by a connected motor, etc., for example. In the short-side direction X, the length of the guide roller 211 is typically longer than the width of the adhesive tape 90. In the short-side direction X, the length of the guide roller 211 can also be shorter than the cover body 14.

[0054] The tape supply path 213 constitutes a moving path for the adhesive tape 90 drawn from the supply reel and laid on the guide roller 211. Here, the tape supply path 213 is a guide rail extending along the lower surface of the roller support member 212. Figure 5 As shown, at the sticking position, the angle θ between the tape supply path 213 and the upper surface 14u of the cover 14 is preferably 20 to 50°. This makes it easy to stick the adhesive tape 90 on the upper surface 14u of the cover 14.

[0055] An adsorption mechanism is provided on the tape supply path 213. Here, a plurality of adsorption holes are provided for adsorbing the adhesive tape 90 on the guide rail. The plurality of adsorption holes are connected to a suction pump not shown. The suction pump is electrically connected to a control unit not shown. When the suction pump is driven, the space between the tape supply path 213 and the adhesive tape 90 is depressurized through the plurality of adsorption holes. As a result, the adhesive tape 90 is adsorbed and fixed to the tape supply path 213.

[0056] A tape clamp 214 is provided in the middle of the tape supply path 213. The tape clamp 214 is usually in a closed state, and supports from below the adhesive tape 90 fixed by suction to the tape supply path 213. The tape clamp 214 is configured to move downward and automatically open during the sticking operation by an appropriate mechanism (not shown).

[0057] The tape pasting section 220 is configured to paste the adhesive tape 90 on the upper surface 14u of the cover body 14. The tape pasting section 220 includes a pasting roller 221, a roller supporting member 222 supporting the pasting roller 221, and a pasting section moving mechanism (not shown). The pasting section moving mechanism is a mechanism that moves the pasting roller 221 upward from the pasting position. The structure of the pasting section moving mechanism is not particularly limited, and it is, for example, a driving motor. In this case, by driving the driving motor, the roller supporting member 222 is moved in the up-down direction. As a result, the pasting roller 221 moves in the up-down direction.

[0058] The pasting roller 221 is a member that presses the adhesive tape 90 to the upper surface 14u of the cover 14. The pasting roller 221 is arranged side by side with the tape supply unit 210 (more specifically, the guide roller 211) in the long side direction Y. The pasting roller 221 is arranged at a position on the left side (rear side in the direction of travel) of the tape supply unit 210. The pasting roller 221 has a long cylindrical shape. The pasting roller 221 is arranged in a manner such that its axis is along the short side direction X. The pasting roller 221 is supported on the roller supporting member 222 in a rotatable manner around an axis extending in the short side direction X. The pasting roller 221 can also be configured to rotate, for example, by a connected motor or the like. In the short side direction X, the length of the pasting roller 221 is typically longer than the width of the adhesive tape 90. In the short side direction X, the length of the pasting roller 221 can also be shorter than the cover 14. The sticking roller 221 may be configured to press the adhesive tape 90 toward the upper surface 14 u of the cover 14 more strongly than the guide roller 211 by a biasing mechanism such as a spring.

[0059] The tape cutting unit 230 includes a cutter 231, a cutter supporting member 232 supporting the cutter 231, a cutter moving mechanism (not shown) and a cutting mechanism (not shown). The cutter moving mechanism is a mechanism for moving the cutter 231 upward from the pasting position. The structure of the cutter moving mechanism is not particularly limited, and it is, for example, a drive motor. In this case, the cutter supporting member 232 is moved in the up and down direction by driving the drive motor. The cutting mechanism is a mechanism for moving the cutter 231 from the pasting position to a cutting position obliquely below. The structure of the cutting mechanism is not particularly limited, and it is, for example, a piston cylinder. The cutting mechanism is configured to reciprocate between the pasting position and the cutting position located obliquely below the pasting position by driving the piston cylinder to cut the adhesive tape 90.

[0060] The cutter 231 is a member for cutting the adhesive tape 90. The cutter 231 extends obliquely downward toward the upper surface 14u of the cover 14. At the pasting position, the lower end 231d of the cutter 231 is arranged at a height substantially the same as the upper end of the guide roller 211 and the upper end of the pasting roller 221. At the pasting position, the lower end 231d of the cutter 231 is arranged between the guide roller 211 and the pasting roller 221 in the longitudinal direction Y.

[0061] Figure 6 (A) to (F) are schematic diagrams for explaining this process. Figure 6 In (A) to (F) of FIG. 1 , the cover 14 is omitted. Figure 6 Reference numerals are not shown in (A) to (F) of FIG. 1 , and therefore, reference numerals of the various parts of the tape applying device 200 refer to Figure 5 In this process, first, Figure 5 As shown, the pasting unit 290 (i.e., the tape supply unit 210, the tape pasting unit 220, and the tape cutting unit 230) moves from the original position to the pasting position by means of an up-down moving mechanism. When the pasting unit 290 moves from the original position to the pasting position, the lower ends of the guide roller 211 and the pasting roller 221 abut against the upper surface 14u of the cover body 14. However, in the case where the guide roller 211 is configured to rotate by a motor or the like, the guide roller 211 may not abut against the upper surface 14u of the cover body 14. When the pasting unit 290 moves from the original position to the pasting position, the tape clamp 214 of the tape supply unit 210 is in a closed state, and the suction pump is in a driven state. Therefore, the adhesive tape 90 is fixed to the tape supply path 213.

[0062] Then, if Figure 6 As shown in (A), the tape clamp 214 of the tape supply unit 210 is released, and although not shown in the figure, the suction pump is stopped. In this state, the pasting operation is performed. Figure 6 As shown by the arrow in (B), the pasting unit 290 moves a predetermined first distance in a first direction (here, from left to right in the long side direction Y) through a long side moving mechanism. The first distance is longer than the length of the injection hole 15 in the long side direction Y. Therefore, when the guide roller 211 rotates, the adhesive tape 90 is pulled out from the supply reel in an amount corresponding to the first distance, and is transported to the vicinity of the pasting roller 221 through the tape supply path 213. Thus, the adhesive tape 90 is sequentially supplied to the pasting roller 221. The adhesive tape 90 is pressed to the upper surface 14u of the cover body 14 by the pasting roller 221, and is pasted to the upper surface 14u to block the injection hole 15. In Figure 6 In (B), during the sticking operation, the angle θ formed by the tape supply path 213 and the cover body 14 is 20 to 50 degrees. This allows for appropriate and stable sticking.

[0063] Then, if Figure 6 As shown in (C), the tape clamp 214 of the tape supply unit 210 is closed and the suction pump is driven. As a result, the adhesive tape 90 is fixed to the tape supply path 213 again. Figure 6 As shown by the arrow in (D), the roller support member 212 is moved upward from the pasting position by the supply unit moving mechanism. Figure 6In (D), the roller support member 212 moves upward so that the lower end of the guide roller 211 comes to a position above the upper end of the sticking roller 221. Thereby, between the tape supply unit 210 (specifically, the tape clamp 214) and the sticking roller 221, the adhesive tape 90 is in a state of floating from the tape supply path 213. The floating portion of the adhesive tape 90 assumes a posture extending obliquely upward. Therefore, the floating portion of the adhesive tape 90 is bent (Japanese: 癖付け) upward with the sticking roller 221 as a fulcrum. Thereby, it is possible to more reliably make a part of the adhesive tape 90 in a floating state.

[0064] Next, as Figure 6 shown in (E), the cutting blade 231 is moved by the cutting mechanism to a cutting position obliquely downward. At the cutting position, the lower end 231d of the cutting blade 231 is disposed at a position below the lower end of the guide roller 211. At the cutting position, the lower end 231d of the cutting blade 231 is disposed at substantially the same height as the lower end of the sticking roller 221. At the cutting position, in the longitudinal direction Y, the lower end 231d of the cutting blade 231 is disposed at a position to the right (front side in the traveling direction) of the guide roller 211. Therefore, between the tape supply unit 210 (specifically, the tape clamp 214) and the sticking roller 221, the adhesive tape 90 is cut. In Figure 6 (E), by moving the roller support member 212 upward, when viewed in side view, the angle formed by the cutting blade 231 and the adhesive tape 90 is substantially perpendicular (90° ± 5°). Thereby, stable cutting can be achieved.

[0065] Next, as Figure 6 shown by the arrow in (F), the sticking unit 290 moves in the first direction (here, from left to right in the longitudinal direction Y) by a longitudinal direction moving mechanism by a preset second distance. Thereby, the adhesive tape 90 near the cut sticking roller 221 is stuck to the upper surface 14u of the lid body 14 by the sticking roller 221. The second distance is shorter than the total length of the floating portion of the cut adhesive tape 90. The second distance is typically shorter than the first distance. By pressing the end portion of the portion stuck after cutting the adhesive tape 90, the adhesive tape 90 can be made to adhere better to the upper surface 14u of the lid body 14. After the operations as described above are completed, the cutting blade 231 moves upward by the cutting blade moving mechanism. The sticking roller 221 moves upward from the sticking position by the sticking portion moving mechanism. Therefore, a part of the cut adhesive tape 90 remains in a state of floating from the upper surface 14u of the lid body 14.

[0066] Figure 7 (A) is a top view schematically showing the upper surface 14u of the lid body 14 after this process. Figure 7 (B) is along Figure 7A schematic longitudinal cross-sectional view of line VII(B)-VII(B) of (A). Figure 7 As shown in (A), the adhesive tape 90 disposed on the upper surface 14u of the cover body 14 is in a generally rectangular shape when viewed from above. The adhesive tape 90 is disposed on the upper surface 14u of the cover body 14 in such a manner that the direction in which the long sides of the generally rectangular adhesive tape 90 extend is consistent with the long side direction Y of the power storage device 100. However, the shape of the adhesive tape 90 when viewed from above is not particularly limited. The adhesive tape 90 is divided into two parts in the long side direction Y, and has a peripheral edge portion 90a surrounding the injection hole 15 and a side extending from the peripheral edge portion 90a in the long side direction Y (the front side in the direction of travel, Figure 7 The extension portion 90b extends from the right side of (A). The extension portion 90b is an example of a "portion away from the injection hole".

[0067] like Figure 7 As shown in (B), the peripheral portion 90a blocks the injection hole 15. In the peripheral portion 90a, there is an adhesive tape 90 on the upper part of the injection hole 15 and around it. In the peripheral portion 90a, the adhesive tape 90 is adhered to the upper surface 14u of the cover body 14 and is in close contact with the upper surface 14u of the cover body 14. As a result, when the cover body 14 and the shell body 12 are welded in the shell joining process (step S3) described later, it is possible to prevent splashes from mixing into the interior of the shell body 12 through the injection hole 15.

[0068] The extension portion 90b is in a state of being separated from the upper surface 14u of the cover body 14 and floating from the upper surface 14u of the cover body 14. Since the adhesive tape 90 has the extension portion 90b, the center position of the adhesive tape 90 is offset from the center position of the liquid injection hole 15 to the right side in the long side direction Y. This positional relationship is maintained until the adhesive tape 90 is removed in the unsealing process (step S4) described later. By making a part of the adhesive tape 90 (the extension portion 90b) float from the upper surface 14u of the cover body 14, it is easy to peel off the adhesive tape 90 in the unsealing process (step S4) by using the part (the extension portion 90b) floating from the cover body 14.

[0069] Furthermore, according to the research of the present inventors, as described in Japanese Patent Application Publication No. 2017-117657, when a reusable resin cap is washed and repeatedly used instead of adhesive tape 90 as a means of temporarily sealing the injection hole 15, foreign matter tends to gradually adhere to the surface of the cap due to wear, and the foreign matter may be mixed in. In addition, if the cap is repeatedly washed or used, it may be deformed and cannot maintain close contact with the injection hole 15 or easily move in the injection hole 15. By using disposable adhesive tape 90, such a situation can be appropriately avoided.

[0070] The shell joining process (step S3) is a process of welding and joining the cover body 14 to the periphery of the opening of the shell body 12. In this process, for example, the cover body 14 is first arranged at the opening of the shell body 12. Then, the outer peripheral edge of the cover body 14 is welded to the inner peripheral edge of the opening of the shell body 12 over the entire circumference. Welding can be performed by a conventionally known method (such as laser welding). In this way, the opening of the shell body 12 is sealed, and the shell body 12 and the cover body 14 are integrated. In addition, during laser welding, sometimes the high-temperature molten metal becomes microparticles (so-called spatters) and is generated from the welding site, but in the technology disclosed herein, the injection hole 15 is blocked by the adhesive tape 90, so that the spatters can be prevented from mixing into the interior of the shell body 12 through the injection hole 15.

[0071] The unsealing step (step S4) is a step of peeling off the adhesive tape 90 attached to the lid body 14. As a result, the liquid injection hole 15 is opened. Figure 8 : is a schematic diagram for explaining this process. In this embodiment, first, a holding piece 300 for holding the adhesive tape 90 is prepared. By using the holding piece 300, the productivity and workability of this process can be improved. The holding piece 300 can be the same structure as the holding piece commonly used in the past, without any special limitation. Here, the holding piece 300 has a pair of thin plate-like sheet members (blade) 310. The adhesive tape 90 side of the sheet member 310 is in a pointed shape. Thereby, it becomes easy to lift up the adhesive tape 90. However, in other embodiments, the adhesive tape 90 can also be held by a person's fingertips and peeled off from the cover body 14 without using the holding piece 300.

[0072] Then, if Figure 8 As shown in FIG. 1 , one sheet member 310 is inserted between the cover 14 and the portion of the adhesive tape 90 that floats from the cover 14 (the extension portion 90b), and the extension portion 90b is clamped by the other sheet member 310. Thus, the extension portion 90b of the adhesive tape 90 is gripped by the gripping member 300. Then, while the adhesive tape 90 is gripped, Figure 8 As shown by the middle arrow, the holding member 300 is moved in the horizontal direction. As a result, the adhesive tape 90 moves along the cover body 14, and the adhesive tape 90 is peeled off from the cover body 14 with the extension portion 90b as the starting point. As described above, by holding the extension portion 90b, it is easy to peel off the adhesive tape 90. Therefore, it is less likely that adhesives will remain around the injection hole 15. In addition, by moving the adhesive tape 90 along the cover body 14, the adhesive tape 90 is peeled off little by little in the long side direction Y, and the peeling area is stable, so the occurrence of uneven peeling can be reduced.

[0073] The leakage inspection process (step S5) is a process for inspecting the airtightness of the battery case 10. This process can be implemented by conventionally known steps. For example, first, the battery case 10 is filled with an inspection gas (e.g., helium) for leak inspection through the opened injection hole 15. Then, the leakage of the inspection gas from the battery case 10 is detected by the inspection device. Thus, the presence or absence of leakage and the leakage location of the battery case 10 (e.g., the safety valve 17, the joint between the case body 12 and the cover body 14, etc.) can be inspected.

[0074] The injection process (step S6) is a process of injecting electrolyte into the interior of the battery case 10. Here, it is a process of injecting electrolyte into the interior of the shell body 12 from the injection hole 15 of the cover body 14. The injection can be carried out under atmospheric pressure, or it can be carried out in a state where the battery case 10 is depressurized, for example, for the purpose of improving the impregnation of the electrolyte into the electrode body 20. Thus, an assembly (a combination of the battery case 10 and the electrode body 20) is constructed. After the injection, the assembly can also be placed (kept) for a specified time. Thus, for example, the electrolyte is evenly distributed in the long side direction Y of the electrode body 20.

[0075] The formal sealing process (step S7) is a process of sealing the injection hole 15 by the sealing member 16. In a preferred embodiment, first, the gas in the battery case 10, such as air or gas generated by the decomposition of the electrolyte, is exhausted to the outside of the battery case 10. The exhaust of the gas can be performed by, for example, reducing the pressure in the battery case 10. Then, while the battery case 10 is maintained at normal pressure or under reduced pressure, the sealing member 16 is embedded in the injection hole 15. Then, the sealing member 16 is welded to the injection hole 15 to seal the injection hole 15. Thus, the battery case 10 is sealed. As described above, the storage device 100 can be appropriately manufactured.

[0076] The power storage device 100 can be used for various purposes. Preferred uses include, for example, a power source (driving power source) for a motor mounted on a vehicle such as a plug-in hybrid electric vehicle (PHEV), a hybrid electric vehicle (HEV), or an electric vehicle (BEV). In addition, the power storage device 100 can be used as a storage battery for a small power storage device or the like. The power storage device 100 can also be typically used in the form of a battery pack consisting of a plurality of batteries connected in series and / or in parallel.

[0077] The preferred embodiment of the present invention has been described above, but the above embodiment is only an example. The present invention can also be implemented in various ways besides this. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in this field. The technology recorded in the claims includes the technology obtained by variously deforming and changing the above-mentioned exemplified embodiments. For example, part of the above-mentioned embodiment can be replaced with other variations, and other variations can be added to the above-mentioned embodiment. In addition, if the technical feature is not described as a necessary technical feature, it can be deleted appropriately.

[0078] For example, in the above-mentioned embodiment, in the temporary sealing process (step S2), as Figure 6 As shown in (D), the guide roller 211 is moved upward to bend the adhesive tape 90, so that a part of the adhesive tape 90 (the extension part 90b) is in a floating state. However, this is not limited to this. In a modified example, for example, the bending of the supply reel during winding can be used to make a part of the adhesive tape 90 in a floating state, or the adhesive tape 90 can be bent by hand to make a part of the adhesive tape 90 in a floating state. In addition, the adhesive layer can also be not applied to the extension part 90b.

[0079] For example, in the above-described embodiment, in the unsealing step (step S4 ), the portion (extending portion 90 b ) of the adhesive tape 90 that floats from the lid 14 is gripped by the gripper 300 to peel off the adhesive tape 90 . However, the present invention is not limited thereto.

[0080] Fig. 9 is a variant of Figure 8 In this modification, first, an adsorption device 400 is prepared to replace the holding member 300. By using the adsorption device 400, the risk of damaging the cover 14 can be reduced. The adsorption device 400 can be the same structure as the device commonly used in the past, and is not particularly limited. Here, the adsorption device 400 includes an adsorption portion 410 and a moving mechanism not shown. The adsorption portion 410 is provided on the surface facing the adhesive tape 90 ( Fig. 9 The lower surface of the adsorption portion 410). The outer shape of the adsorption portion 410 is preferably smaller than the outer shape of the extension portion 90b. Although not shown in the figure, a plurality of adsorption holes for adsorbing the adhesive tape 90 (specifically, the extension portion 90b) are provided in the adsorption portion 410. The adsorption holes are connected to a suction pump not shown in the figure. The adsorption action of the adsorption device 400 is controlled by controlling the suction pump. Specifically, the adsorption and release of the adhesive tape 90 are controlled by controlling the driving and stopping of the suction pump. The moving mechanism is a mechanism that moves the adsorption portion 410 to the side close to the adhesive tape 90 and the side away from the adhesive tape 90 (here, to lower and raise it). The moving mechanism is, for example, a piston cylinder.

[0081] Next, the adsorption unit 410 is lowered by the moving mechanism so that the adsorption unit 410 contacts the portion (extending portion 90b) of the adhesive tape 90 that floats from the cover 14. Fig. 9 As shown by the upward arrow extending from the extension portion 90b in FIG. 1 , the extension portion 90b is attracted and adsorbed by the adsorption portion 410. Fig. 9 As shown by the upward arrow extending from the adsorption part 410, the adsorption part 410 is moved upward or obliquely upward by the moving mechanism while the extension part 90b is adsorbed. As a result, the extension part 90b is pulled up together with the adsorption part 410, and the adhesive tape 90 is peeled off from the cover body 14 with the extension part 90b as the starting point. The injection hole 15 can also be opened in this way.

[0082] As described above, as specific aspects of the technology disclosed herein, the aspects described in the following items can be cited.

[0083] Item 1: A method for manufacturing an electrical storage device, the electrical storage device comprising: an electrode body; an electrolyte; a shell body having an opening for accommodating the electrode body and the electrolyte; and a cover body having an injection hole for blocking the opening of the shell body, wherein the method comprises: a temporary sealing step of sticking an adhesive tape to the cover body to block the injection hole; and an unsealing step of peeling off the adhesive tape stuck to the cover body, wherein in the temporary sealing step, the adhesive tape is stuck to the peripheral edge of the injection hole, and at least a portion of the adhesive tape away from the injection hole is made to float from the cover body.

[0084] Item 2: In the manufacturing method described in Item 1, the adhesive tape has a rectangular shape, and in the temporary sealing step, an end portion on one side in the longitudinal direction of the rectangular shape is made to float from the cover.

[0085] Item 3: In the manufacturing method described in Item 1 or Item 2, in the above-mentioned temporary sealing step, a tape pasting device is prepared that includes a pasting unit that can move in a first direction along the surface of the above-mentioned cover body, and the above-mentioned pasting unit includes: a pasting roller that presses the above-mentioned adhesive tape against the surface of the above-mentioned cover body; and a tape supplying section that is arranged at a position closer to the front side of the above-mentioned pasting roller in the above-mentioned first direction and supplies the above-mentioned adhesive tape to the above-mentioned pasting roller. The above-mentioned adhesive tape is pasted to the above-mentioned cover body by a pasting action in which the above-mentioned pasting unit is moved in the above-mentioned first direction, the above-mentioned adhesive tape is supplied in sequence from the above-mentioned tape supplying section, and the above-mentioned adhesive tape is pasted to the above-mentioned cover body by a pasting action in which the above-mentioned adhesive tape is pressed against the above-mentioned cover body by the above-mentioned pasting roller.

[0086] Item 4: In the manufacturing method described in Item 3, the tape supply unit includes a supply unit moving mechanism capable of moving the tape supply unit upward. After the pasting action, the tape supply unit is moved upward so that the portion of the adhesive tape located between the tape supply unit and the pasting roller is bent upward.

[0087] Item 5: In the manufacturing method described in Item 3 or Item 4, the sticking unit further includes a cutter for cutting the adhesive tape, and the cutter cuts a portion of the adhesive tape located between the tape supply unit and the sticking roller.

[0088] Item 6: In the manufacturing method described in any one of Items 3 to 5, the tape supply unit comprises: a guide roller that guides the adhesive tape to the vicinity of the pasting roller; a tape supply path that sets the adhesive tape on the guide roller; an adsorption mechanism that is disposed on the tape supply path and adsorbs the adhesive tape; and a tape clamp that is disposed on the tape supply path and supports the adhesive tape from below, and in the pasting action, the pasting unit is moved in the first direction with the adsorption mechanism stopped and the tape clamp opened.

[0089] Item 7: In the manufacturing method described in Item 6, in the sticking operation, an angle formed by the tape supply path and the cover is set to be greater than or equal to 20° and less than or equal to 50°.

[0090] Item 8: In the manufacturing method described in any one of Items 1 to Item 7, in the unsealing step, the portion of the adhesive tape that floats from the cover body in the temporary sealing step is sucked by a suction device, and the adhesive tape is peeled off starting from the floated portion.

[0091] Item 9: In the manufacturing method according to any one of Items 1 to Item 7, in the unsealing step, the portion of the adhesive tape that floats from the lid in the temporary sealing step is grasped, and the adhesive tape is peeled off starting from the floated portion.

[0092] Item 10: In the manufacturing method described in Item 9, in the unsealing step, the adhesive tape is peeled off by moving the adhesive tape along the cover body.

[0093] Item 11: The manufacturing method according to any one of Items 1 to 10, further comprising, between the temporary sealing step and the unsealing step, a shell joining step of welding the lid to a periphery of the opening of the shell body.

[0094] Item 12: The manufacturing method described in any one of Items 1 to Item 11 further includes: a liquid injection process of injecting the electrolyte into the interior of the shell body from the liquid injection hole after the above-mentioned unsealing process; and a formal sealing process of sealing the liquid injection hole by a sealing component after the above-mentioned liquid injection process.

[0095] Description of Reference Numerals

[0096] 10 Battery housing

[0097] 12 Shell body

[0098] 14 Cover

[0099] 15 Injection hole

[0100] 20 Electrode body

[0101] 90 Adhesive Tape

[0102] 90a Peripheral part

[0103] 90b Extension

[0104] 100 Power storage equipment

[0105] 210 Tape supply unit

[0106] 211 Guide Roller

[0107] 213 Tape supply path

[0108] 214 Tape Clamp

[0109] 220 Tape sticking department

[0110] 221 Pasting roller

[0111] 230 Tape Cutting Department

[0112] 231 Cutter

[0113] 290 Paste Unit

[0114] 300 Handle

[0115] 400 Adsorption device

[0116] 410 Adsorption section.

Claims

1. A method for manufacturing an electric storage device, the electric storage device comprising: Electrode body; Electrolyte; A shell body having an opening for accommodating the electrode body and the electrolyte; as well as A cover having a liquid injection hole for blocking the opening of the shell body. in, The method for manufacturing the power storage device comprises: A temporary sealing step of sticking an adhesive tape to the cover to block the liquid injection hole; as well as An unsealing step of peeling off the adhesive tape attached to the cover, In the temporary sealing step, the adhesive tape is attached to the peripheral edge of the liquid injection hole, and at least a portion of the adhesive tape away from the liquid injection hole is placed in a state of floating from the cover.

2. The method for manufacturing an electric storage device according to claim 1, wherein: The adhesive tape has a rectangular shape, and in the temporary sealing step, an end portion on one side in the longitudinal direction of the rectangular shape is placed in a state of floating from the cover.

3. The method for manufacturing an electrical storage device according to claim 1 or 2, wherein: In the temporary sealing step, a tape applying device is prepared, the tape applying device including an applying unit movable in a first direction along the surface of the cover body, The pasting unit comprises: an adhesive roller, which presses the adhesive tape onto the surface of the cover; and an adhesive tape supply unit arranged at a front side of the sticking roller in the first direction and supplying the adhesive tape to the sticking roller; The adhesive tape is attached to the cover body by an attaching operation in which the adhesive tape is sequentially supplied from the tape supply section while the attaching unit is moved in the first direction and the adhesive tape is pressed by the attaching roller.

4. The method for manufacturing an electric storage device according to claim 3, wherein: The tape supply unit includes a supply unit moving mechanism capable of moving the tape supply unit upward. After the sticking operation, the tape supply unit is moved upward to bend the adhesive tape so as to be curled upward at a portion located between the tape supply unit and the sticking roller.

5. The method for manufacturing an electric storage device according to claim 3, wherein: The pasting unit further includes a cutter for cutting the adhesive tape. The cutter cuts a portion of the adhesive tape between the tape supply unit and the application roller.

6. The method for manufacturing an electric storage device according to claim 3, wherein: The tape supply unit comprises: A guide roller, which guides the adhesive tape to the vicinity of the pasting roller; a tape supply path for feeding the adhesive tape to the guide roller; An adsorption mechanism, which is disposed on the tape supply path and adsorbs the adhesive tape; as well as a tape clamp disposed in the tape supply path and supporting the adhesive tape from below, In the sticking operation, the sticking unit is moved in the first direction in a state where the suction mechanism is stopped and the tape holder is opened.

7. The method for manufacturing an electric storage device according to claim 6, wherein: In the sticking operation, an angle formed by the tape supply path and the cover is set to be greater than or equal to 20° and less than or equal to 50°.

8. The method for manufacturing an electrical storage device according to claim 1 or 2, wherein: In the unsealing step, the portion of the adhesive tape that floats from the cover body in the temporary sealing step is sucked by a suction device, and the adhesive tape is peeled off starting from the floated portion.

9. The method for manufacturing an electric storage device according to claim 1 or 2, wherein: In the unsealing step, the portion of the adhesive tape that floats from the lid in the temporary sealing step is gripped, and the adhesive tape is peeled off starting from the floated portion.

10. The method for manufacturing an electric storage device according to claim 9, wherein: In the unsealing step, the adhesive tape is peeled off by moving the adhesive tape along the cover body.

11. The method for manufacturing an electrical storage device according to claim 1 or 2, wherein: The method further includes a case joining step of welding the cover body to the periphery of the opening of the case body between the temporary sealing step and the unsealing step.

12. The method for manufacturing an electric storage device according to claim 11, wherein: Also includes: After the unsealing step, a liquid injection step of injecting the electrolyte into the interior of the case body from the liquid injection hole; and After the liquid injection step, a final sealing step of sealing the liquid injection hole with a sealing member is performed.

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