Manufacturing method for power storage device

Abstract

To provide a manufacturing method capable of improving easy detachability of an adhesive tape after temporary sealing.SOLUTION: There is provided a manufacturing method for a power storage device comprising an electrode body, electrolyte, a case body that has an aperture and houses the electrode body and the electrolyte, and a lid that has a liquid injection hole and closes the aperture of the case body. The manufacturing method includes: a temporary sealing step (S2) of pasting an adhesive tape on the lid so as to cover the liquid injection hole; and an opening step (S4) of peeling the adhesive tape pasted on the lid. In the temporary sealing step (S2), the adhesive tape and the lid are made to adhere closely at the periphery of the liquid injection hole and at least part of the adhesive tape is made to be in a state floated from the lid at a part apart from the liquid injection hole.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] An electricity storage device typically includes an electrode body, an electrolyte, a case body having an opening for accommodating the electrode body and the electrolyte, and a lid body having an injection hole for closing the opening of the case body (see Patent Documents 1 and 2).

[0003] For example, Patent Document 1 discloses a method for manufacturing an electricity storage device, including the following steps: temporarily sealing the liquid injection hole with a first sealing member (breathable film); impregnating the electrode body with electrolyte while the liquid injection hole is temporarily sealed with the first sealing member; removing the first sealing member to open the liquid injection hole; and permanently sealing the liquid injection hole with a second sealing member (sealing plug). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-139497 A [Patent Document 2] JP 2017-117657 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the inventor's study, if the first sealing member used in temporary sealing is an adhesive tape having adhesiveness, and the adhesive tape is firmly attached to the lid, it may be difficult to peel off the adhesive tape in a later process. Also, as described in Patent Document 1, adhesive matter may remain on the lid after the adhesive tape is peeled off. As a result, it may be difficult to fit the second sealing member into the liquid injection hole during main sealing.

[0006] 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 producing an electricity storage device that can improve the ease of peeling of an adhesive tape after temporary sealing. [Means for solving the problem]

[0007] According to the present invention, there is provided a method for manufacturing an electricity storage device including an electrode body, an electrolyte, a case body having an opening and accommodating the electrode body and the electrolyte, and a lid body having a liquid injection hole and closing the opening of the case body. The manufacturing method includes a temporary sealing step of attaching an adhesive tape to the lid body so as to close the liquid injection hole, and an unsealing step of peeling off the adhesive tape attached to the lid body, in which the adhesive tape is attached to the peripheral portion of the liquid injection hole, while at least a part of the adhesive tape is raised from the lid body in a portion away from the liquid injection hole.

[0008] As a result of intensive research by the present inventors, the following new fact was discovered. That is, when peeling off an adhesive tape from a lid, a gripping tool such as a fingernail or tweezers is often hooked on the edge of the adhesive tape and turned it up. However, if the adhesive tape is tightly attached to the lid up to the edge, it is difficult to hook the fingernail or the like on the edge of the adhesive tape. As a result, a large external force is required at the beginning of peeling, and adhesive matter is particularly likely to remain (so-called glue residue is likely to occur).

[0009] Therefore, in the present invention, in the temporary sealing step, the adhesive tape at a portion away from the liquid injection hole is raised from the lid. This makes it easier to peel the adhesive tape from the portion raised from the lid in the unsealing step. This reduces the external force required at the start of peeling. As a result, after the adhesive tape is peeled off, adhesive is less likely to remain around the liquid injection hole, making it easier to fit the sealing member into the liquid injection hole. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a perspective view that illustrates a schematic diagram of an electricity accumulation device according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing a schematic view of an electrode body. [Diagram 3] FIG. 3 is a schematic diagram showing the configuration of the electrode body. [Figure 4] FIG. 4 is a flow chart of a manufacturing method according to one embodiment. [Diagram 5] FIG. 5 is a side view that illustrates a schematic view of a main part of the tape application device. [Figure 6] 6(A) to 6(F) are schematic views illustrating the temporary sealing step. [Figure 7] FIG. 7(A) is a plan view showing a schematic view of the lid after the temporary sealing step, and FIG. 7(B) is a schematic vertical cross-sectional view taken along line IIV(B)-IIV(B) in FIG. 7(A). [Figure 8] FIG. 8 is a schematic diagram illustrating the opening process. [Figure 9] FIG. 9 is a view corresponding to FIG. 8 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, some preferred embodiments of the technology disclosed herein will be described with reference to the drawings. Matters other than those specifically mentioned in this specification and necessary for carrying out the present invention (for example, the general configuration and manufacturing process of an electricity storage device that does not characterize the technology disclosed herein) can be understood as design matters of a person skilled in the art based on the prior art in the field. The technology disclosed herein can be carried out based on the contents disclosed in this specification and the technical common sense in the field.

[0012] In this specification, the term "electricity storage device" refers to a general device that can be repeatedly charged and discharged, and is a concept that encompasses not only storage batteries such as lithium ion secondary batteries and nickel-metal hydride batteries, but also capacitors such as lithium ion capacitors and electric double layer capacitors. In addition, in this specification, the notation "A to B" indicating a numerical range not only means "A or more and B or less," but also includes the meanings of "greater than A" and "below B."

[0013] <Electricity storage device 100> First, an energy storage device 100 manufactured by the manufacturing method disclosed herein will be described. FIG. 1 is a perspective view of the energy storage device 100. In the following description, the symbol X indicates the "short side direction" of the energy storage device 100, the symbol Y indicates the "long side direction" perpendicular to the short side direction, and the symbol Z indicates the "height direction" perpendicular to the short side direction and the long side direction. In addition, F in the short side direction X indicates "front" and Rr indicates "rear". In the long side direction Y, L indicates "left" and R indicates "right". In the height direction Z, U indicates "up" and D indicates "down". However, these are merely directions for convenience of description and do not limit the installation form of the energy storage device 100 in any way.

[0014] The electricity storage device 100 includes a battery case 10, an electrode assembly 20 (not shown in FIG. 1, see FIGS. 2 and 3), and an electrolyte (not shown). The electricity storage device 100 here is a lithium ion secondary battery.

[0015] The battery case 10 includes a case body 12 having an opening, and a lid (sealing plate) 14 that closes the opening. The battery case 10 is integrated by joining the lid 14 to the periphery of the opening of the case body 12, and is hermetically sealed (closed). Here, the battery case 10 has a flat, bottomed rectangular parallelepiped (angled) shape. However, in other embodiments, the battery case 10 may have, for example, a cubic or cylindrical shape.

[0016] The case body 12 is a housing that contains the electrode assembly 20 and the electrolyte. The case 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 two long sides of the bottom surface 12a, respectively. The pair of narrow surfaces 12c rise from two short sides of the bottom surface 12a, respectively. The lid body 14 is a flat plate-shaped member. The lid body 14 faces the bottom surface 12a of the case body 12. The lid body 14 has an upper surface 14u. The upper surface 14u is the surface on the side away from the case body 12, and constitutes the outer surface of the battery case 10. The lid body 14 is substantially rectangular here. In this specification, the term "approximately rectangular" refers not only to a perfect rectangular shape (rectangular shape), but also to shapes such as a shape in which the corners connecting the long and short sides of the rectangle are rounded or a shape having a notch at the corner.

[0017] The lid 14 is provided with a liquid injection hole 15, a safety valve 17, a positive electrode external terminal 30, and a negative electrode external terminal 40. The liquid injection hole 15 is a through hole for injecting an electrolyte into the battery case 10 after the lid 14 is assembled to the case main body 12. Here, the liquid injection hole 15 is formed in a circular shape in a plan view. The liquid injection hole 15 is sealed with a sealing member 16. The sealing member 16 is preferably a sealing plug having a portion that can be inserted into the sealing member 16. The safety valve 17 is a thin-walled portion that is configured to break when the pressure inside the battery case 10 reaches a predetermined value or more, and to discharge the gas inside the battery case 10 to the outside. The positive electrode external terminal 30 and the negative electrode external terminal 40 are electrically connected to the electrode body accommodated in the battery case 10.

[0018] Although not particularly limited, the battery case 10 is made of, for example, a metal. 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.

[0019] The electrode body 20 (see FIGS. 2 and 3) is housed inside the battery case 10 (more specifically, inside the case body 12). The number of electrode bodies 20 arranged inside one battery case 10 is not particularly limited, and may be one or two or more (plural).

[0020] Fig. 2 is a perspective view of the electrode body 20. Fig. 3 is a schematic diagram showing the configuration of the electrode body 20. As shown in Figs. 2 and 3, a positive electrode internal terminal 50 and a negative electrode internal terminal 60 are attached to the electrode body 20. The positive electrode internal terminal 50 is connected to the positive electrode external terminal 30 (see Fig. 1). The negative electrode internal terminal 60 is connected to the negative electrode external terminal 40 (see Fig. 1).

[0021] As shown in FIG. 3, the electrode body 20 has a positive electrode 22 and a negative electrode 24. Here, the electrode body 20 is a flat-shaped 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. As shown in FIG. 2, the electrode body 20 has a pair of flat parts 20a whose outer surfaces are flat, and a pair of curved parts 20b whose outer surfaces are curved. However, in other embodiments, the electrode body 20 may be a laminated electrode body in which a square-shaped (typically rectangular) positive electrode and a square-shaped (typically rectangular) negative electrode are stacked in an insulated state.

[0022] Although detailed illustration is omitted, the electrode body 20 is disposed inside the case body 12 with the winding axis WL oriented parallel to the long side direction Y. When housed in the battery case 10 of Fig. 1, a pair of flat portions 20a of the electrode body 20 face the wide surface 12b of the battery case 10, and a pair of curved portions 20b face the narrow surface 12c.

[0023] The positive electrode 22 has a strip-shaped positive electrode current 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 current collector foil 22c. Although not particularly limited, a positive electrode protective layer 22p may be provided on one side edge portion in the long side direction Y of the positive electrode 22 as necessary. Note that, as the materials constituting the positive electrode active material layer 22a and the positive electrode protective layer 22p, those used in this type of electricity storage device (in this embodiment, a lithium ion secondary battery) can be used without particular limitation, and detailed description thereof will be omitted since they do not characterize the technology disclosed herein.

[0024] A plurality of positive electrode tabs 22t are provided at one end (left end in FIG. 3) in the long side direction Y of the positive electrode current collector foil 22c. The plurality of positive electrode tabs 22t each protrude toward one side (left side in FIG. 3) in the long side direction Y. The plurality of positive electrode tabs 22t are provided at intervals (intermittently) along the longitudinal direction of the positive electrode 22. The positive electrode tabs 22t are part of the positive electrode current collector foil 22c, and are a portion (current collector foil exposed portion) of the positive electrode current collector foil 22c where the positive electrode active material layer 22a and the positive electrode protective layer 22p are not formed. The plurality of positive electrode tabs 22t are stacked at one end (left end in FIG. 3) in the long side direction Y to form a positive electrode tab group 23. A positive electrode internal terminal 50 is joined to the positive electrode tab group 23 (see FIG. 2).

[0025] 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. Note that the material constituting the negative electrode active material layer 24a can be any material used in this type of electricity storage device (in this embodiment, a lithium ion secondary battery) without any particular limitation, and is not a feature of the technology disclosed herein, so detailed description will be omitted.

[0026] A plurality of negative electrode tabs 24t are provided at one end (right end in FIG. 3) in the long side direction Y of the negative electrode current collector foil 24c. The plurality of negative electrode tabs 24t protrude toward one side (right side in FIG. 3) in the long side direction Y. The plurality of negative electrode tabs 24t are provided at intervals (intermittently) along the longitudinal direction of the negative electrode 24. The negative electrode tabs 24t are part of the negative electrode current collector foil 24c here, and are a portion (current collector foil exposed portion) of the negative electrode current collector foil 24c where the negative electrode active material layer 24a is not formed. The plurality of negative electrode tabs 24t are stacked at one end (right end in FIG. 3) in the long side direction Y to form a negative electrode tab group 25. A negative electrode internal terminal 60 is joined to the negative electrode tab group 25 (see FIG. 2).

[0027] The electrolyte is typically a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. As the non-aqueous solvent and the supporting salt, various solvents used in electrolytes for this type of power storage device (here, lithium ion secondary battery) can be used without any particular limitation. As the non-aqueous solvent, for example, carbonates such as ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and the like can be mentioned. As the supporting salt, for example, lithium salts such as LiPF6 and the like can be mentioned. The electrolyte may contain conventionally known additives such as a film forming agent, a thickener, a dispersant, and the like, as necessary.

[0028] <Method of Manufacturing Electricity Storage Device 100> FIG. 4 is a flow chart of a manufacturing method according to one embodiment. The manufacturing method shown in FIG. 4 includes the following steps: an electrode assembly housing step (step S1); a temporary sealing step (step S2); a case joining step (step S3); an opening step (step S4); a leak inspection step (step S5); a liquid injection step (step S6); and a full sealing step (step S7), in this order. However, this is merely an example of the technique disclosed herein. The temporary sealing step (step S2) and the opening step (step S4) can also be performed at other times. In addition, the order of the temporary sealing step (step S2) and the electrode assembly housing step (step S1) can be reversed. In addition, the inspection step (step S5) is optional and can be omitted. In addition, other steps can be further included at any stage.

[0029] The electrode assembly accommodation step (step S1) is a step of preparing the electrode assembly 20 and accommodating it in the battery case 10. In a preferred embodiment, this step includes an electrode fabrication step (step S11), an electrode assembly fabrication step (step S12), and an accommodation step (step S13). Furthermore, other steps may be included at any stage.

[0030] First, in the electrode preparation step (step S11), the positive electrode 22 and the negative electrode 24 are each prepared by a conventionally known method. The positive electrode 22 can be prepared, for example, by mixing a positive electrode active material, a conductive material, a binder, and a dispersion solvent to prepare a positive electrode composite slurry, applying the prepared positive electrode composite slurry on the positive electrode current collector foil 22c by a conventionally known method, drying, and appropriately pressing. The negative electrode 24 can be prepared, for example, by mixing a negative electrode active material, a binder, a dispersant, and a dispersion solvent to prepare a negative electrode composite slurry, applying the prepared negative electrode composite slurry on the negative electrode current collector foil 24c by a conventionally known method, drying, and appropriately pressing. Note that, although the electrodes (positive electrode 22 and / or negative electrode 24) are prepared in this embodiment, in other embodiments, the electrodes may be prepared by purchasing commercially available products.

[0031] Next, in the electrode body preparation step (step S12), the positive electrode 22 and the negative electrode 24 prepared above are opposed to each other with the separator 26 interposed therebetween to prepare the electrode body 20. When preparing 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 interposed therebetween, and then wound into a cylindrical shape around the winding axis WL (winding step). Next, the cylindrically wound electrode body (cylindrical body) is press-molded into a flat shape (pressing step). Next, the positive electrode internal terminal 50 is attached to the positive electrode tab group 23 of the electrode body 20, and the negative electrode internal terminal 60 is attached to the negative electrode tab group 25. Next, the positive electrode external terminal 30 and the negative electrode external terminal 40 are attached to the lid body 14. Then, internal terminals of the same polarity (positive electrode internal terminal 50 and negative electrode internal terminal 60) are joined to these external terminals (positive electrode external terminal 30 and negative electrode external terminal 40) by a conventionally known method (current collecting joining step). In this manner, the electrode body 20 and the lid body 14 are integrated together.

[0032] Next, in the accommodation step (step S13), the lid 14 with the electrode body 20 integrated therewith is fitted into the opening of the case body 12. As a result, the electrode body 20 is accommodated inside the case body 12.

[0033] The temporary sealing step (step S2) is a step of attaching an adhesive tape 90 (see FIG. 5) to the lid body 14 so as to close the liquid injection hole 15 of the lid body 14. The adhesive tape 90 is wider than the liquid injection hole 15. The adhesive tape 90 is typically wound in a roll. 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 prevents spatter from entering the inside of the case body 12 through the liquid injection hole 15 when spatter is generated in the subsequent case joining step (step S3).

[0034] The adhesive tape 90 typically has a base layer and an adhesive layer provided on the surface of the base layer facing the lid 14 and having adhesive properties with respect to the lid 14. Although not particularly limited, the base layer is preferably made 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 these, resin materials are preferred, and polyimide resin and fluororesin are particularly preferred because they have high heat resistance to sputtering (are less likely to burn).

[0035] 5 is a side view showing a schematic diagram of a main part of the tape application device 200 used in this step. The tape application device 200 is disposed above the lid body 14, and configured to apply an adhesive tape 90 to the periphery of the liquid injection hole 15 of the lid body 14. In the following, an embodiment in which the tape application device 200 is used will be described with reference to the drawings as appropriate. However, in other embodiments, the adhesive tape 90 can be applied to the lid body 14 by hand (manually) without using the tape application device 200.

[0036] The tape application device 200 includes an application unit 290. The application unit 290 is directly or indirectly supported by a support member (not shown). The application unit 290 is located at a predetermined home position (not shown) during standby, i.e., when not performing application operation. The application unit 290 includes a tape supply section 210, a tape application section 220, and a tape cut section 230. The application unit 290 is configured to be movable from the home position to a downward application position by a vertical movement mechanism (not shown). The application unit 290 is configured to be movable in the long side direction Y by a long side direction movement mechanism (not shown). The long side direction Y is an example of the "first direction along the surface of the lid body".

[0037] The configurations of the vertical movement mechanism and the long side movement mechanism may be the same as those of the conventional mechanism. The vertical movement mechanism is, for example, a lifting cylinder. The vertical movement mechanism is electrically connected to a control unit (not shown). The joining unit 290, i.e., the tape supply unit 210, the tape joining unit 220, and the tape cutting unit 230, are moved integrally to the side approaching the lid body 14 (the joining position) by driving the lifting cylinder.

[0038] The long side direction 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 via, for example, a ball screw or the like. 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, move integrally on the guide rail in the long side direction Y by the drive motor rotating. In FIG. 5, the right side is the front side in the traveling direction of the pasting unit 290, and the left side is the rear side in the traveling direction of the pasting unit 290.

[0039] The tape supply unit 210 is configured to supply the adhesive tape 90 to the joining roller 221, which will be described later. The tape supply unit 210 is disposed to the right of the joining roller 221 (front side in the traveling direction). 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 support member 212 that supports the guide roller 211, a tape supply path 213, a tape chuck 214, and a supply unit movement mechanism (not shown). The supply unit movement mechanism moves the tape supply unit 210 alone (in other words, separately from the tape joining unit 220 and the tape cutting unit 230) upward from the joining position. The configuration of the supply unit movement mechanism is not particularly limited, but is, for example, a drive motor. The supply unit movement mechanism moves the roller support member 212 in the vertical direction by driving the drive motor. This causes the guide roller 211 to move in the vertical direction.

[0040] The guide roller 211 is a member that pulls out the adhesive tape 90 from the supply reel and guides it to the vicinity of the joining roller 221. The guide roller 211 has a long cylindrical shape. The guide roller 211 is arranged such that the cylindrical axis is along the short side direction X. The guide roller 211 is supported by the roller support member 212 so as to be rotatable about an axis extending in the short side direction X. The guide roller 211 may be configured to rotate by, for example, a connected motor or the like. 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 may be shorter than the cover body 14.

[0041] The tape supply path 213 constitutes a running path for the adhesive tape 90, which passes the adhesive tape 90 pulled out from the supply reel over 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. As shown in Fig. 5, at the attachment position, the angle θ between the tape supply path 213 and the upper surface 14u of the lid 14 is preferably 20 to 50°. This makes it easier to attach the adhesive tape 90 to the upper surface 14u of the lid 14.

[0042] The tape supply path 213 is provided with a suction mechanism. Here, a plurality of suction holes are provided on the guide rail for suctioning the adhesive tape 90. The plurality of suction 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 suction holes. As a result, the adhesive tape 90 is fixed to the tape supply path 213 by suction.

[0043] A tape chuck 214 is provided in the middle of the tape supply path 213. The tape chuck 214 is normally in a closed state and supports, from below, the adhesive tape 90 that is fixed by suction to the tape supply path 213. The tape chuck 214 is configured to move downward during the joining operation and to be automatically opened by an appropriate mechanism (not shown).

[0044] The tape application unit 220 is configured to apply the adhesive tape 90 to the upper surface 14u of the lid body 14. The tape application unit 220 includes an application roller 221, a roller support member 222 that supports the application roller 221, and an application unit movement mechanism (not shown). The application unit movement mechanism moves the application roller 221 upward from the application position. The configuration of the supply unit movement mechanism is not particularly limited, but is, for example, a drive motor. The application unit movement mechanism moves the roller support member 222 in the vertical direction by driving the drive motor. This causes the application roller 221 to move in the vertical direction.

[0045] The pasting roller 221 is a member that presses the adhesive tape 90 against the upper surface 14u of the lid body 14. The pasting roller 221 is arranged alongside the tape supply unit 210 (specifically, the guide roller 211) in the long side direction Y. The pasting roller 221 is arranged to the left of the tape supply unit 210 (rear side in the traveling direction). The pasting roller 221 has a long cylindrical shape. The pasting roller 221 is arranged so that the cylindrical axis is along the short side direction X. The pasting roller 221 is supported by the roller support member 222 so as to be rotatable about an axis extending in the short side direction X. The pasting roller 221 may 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 may be shorter than the lid body 14. The pasting roller 221 may be configured to press the upper surface 14u of the lid body 14 more strongly than the guide roller 211 by a biasing mechanism such as a spring.

[0046] The tape cutting section 230 includes a cutter 231, a cutter support member 232 that supports the cutter 231, a cutter movement mechanism (not shown), and a cutting mechanism (not shown). The cutter movement mechanism moves the cutter 231 upward from the attachment position. The configuration of the cutter movement mechanism is not particularly limited, but is, for example, a drive motor. The cutter movement mechanism moves the cutter support member 232 in the up-down direction by driving the drive motor. The cutting mechanism moves the cutter 231 from the attachment position to a cutting position diagonally downward. The configuration of the cutting mechanism is not particularly limited, but is, for example, a piston cylinder. The cutting mechanism is configured to move reciprocally diagonally downward by driving the piston cylinder, and cut the adhesive tape 90.

[0047] The cutter 231 is a member that cuts the adhesive tape 90. The cutter 231 extends obliquely downward (toward the upper surface 14u of the lid 14). At the attachment position, the lower end 231d of the cutter 231 is disposed at approximately the same height as the upper end of the guide roller 211 and the upper end of the attachment roller 221. The lower end 231d of the cutter 231 is disposed between the guide roller 211 and the attachment roller 221 in the long side direction Y.

[0048] 6(A) to 6(F) are schematic diagrams for explaining this step. In FIG. 6, the lid body 14 is omitted. For the reference numerals of each part, please refer to FIG. 5. In this step, first, as shown in FIG. 5, the pasting unit 290 (i.e., the tape supplying part 210, the tape pasting part 220, and the tape cutting part 230) is moved from the home position to the pasting position by the vertical movement mechanism. When the pasting unit 290 is moved from the home position to the pasting position, the lower ends of the guide roller 211 and the pasting roller 221 come into contact with the upper surface 14u of the lid body 14. However, when the guide roller 211 is configured to rotate by a motor or the like, the guide roller 211 does not need to come into contact with the upper surface 14u of the lid body 14. At this time, the tape chuck 214 of the tape supplying part 210 is closed, and the suction pump is driven. Therefore, the adhesive tape 90 is fixed to the tape supply path 213.

[0049] Next, as shown in FIG. 6(A), the tape chuck 214 of the tape supply unit 210 is released, and the suction pump (not shown) is stopped. In this state, the pasting operation is performed. More specifically, as shown by an arrow in FIG. 6(B), the pasting unit 290 is moved a predetermined first distance in a first direction (here, from left to right in the long side direction Y) by the long side direction moving mechanism. The first distance is longer than the length of the liquid inlet 15 in the long side direction Y. As a result, when the guide roller 211 rotates, the adhesive tape 90 is pulled out from the supply reel by the first distance and sent to the vicinity of the pasting roller 221 through the tape supply path 213. As a result, the adhesive tape 90 is sequentially supplied to the pasting roller 221. The adhesive tape 90 is pressed against the upper surface 14u of the lid body 14 by the pasting roller 221, and pasted to the upper surface 14u so as to close the liquid inlet 15. In Fig. 6(B), during the joining operation, the angle θ between the tape supply path 213 and the lid 14 is 20 to 50°. This makes it possible to preferably achieve stable joining.

[0050] Next, as shown in FIG. 6(C), the tape chuck 214 of the tape supply unit 210 is closed, and the suction pump is driven. As a result, the adhesive tape 90 is fixed again to the tape supply path 213. Next, as shown by the arrow in FIG. 6(D), the roller support member 212 is moved upward from the attachment position by the supply unit moving mechanism. In FIG. 6(D), the roller support member 212 is moved upward so that the lower end of the guide roller 211 is higher than the upper end of the attachment roller 221. As a result, the adhesive tape 90 is lifted up from the tape supply path 213 between the tape supply unit 210 (specifically, the tape chuck 214) and the attachment roller 221. The lifted adhesive tape 90 is in a position extending obliquely upward. Therefore, the lifted adhesive tape 90 is given a tendency to curl upward with the attachment roller 221 as a fulcrum. As a result, it is possible to more reliably lift a part of the adhesive tape 90.

[0051] Next, as shown in FIG. 6(E), the cutter 231 is moved to a cutting position diagonally downward by the cutting mechanism. At the cutting position, the lower end 231d of the cutter 231 is disposed below the lower end of the guide roller 211. The lower end 231d of the cutter 231 is disposed at substantially the same height as the lower end of the joining roller 221. In the long side direction Y, the lower end 231d of the cutter 231 is disposed to the right (front side in the traveling direction) of the guide roller 211. Therefore, the adhesive tape 90 is cut between the tape supply unit 210 (specifically, the tape chuck 214) and the joining roller 221. In FIG. 6(E), the roller support member 212 is moved upward, so that the angle between the cutter 231 and the adhesive tape 90 is substantially perpendicular (90°±5°) in a side view. This allows stable cutting to be achieved.

[0052] Next, as shown by an arrow in FIG. 6(F), the pasting unit 290 is moved by the long side direction moving mechanism in the first direction (here, from left to right in the long side direction Y) a predetermined second distance. As a result, the adhesive tape 90 near the cut pasting roller 221 is pasted to the upper surface 14u of the lid body 14 by the pasting roller 221. The second distance is shorter than the entire length of the lifted part of the cut adhesive tape 90. The second distance is typically shorter than the first distance. By pressing the end of the pasted part after cutting the adhesive tape 90, the adhesive tape 90 can be better adhered to the upper surface 14u of the lid body 14. When the above-mentioned operation is completed, the cutter 231 is moved upward by the cutter moving mechanism. The pasting roller 221 is moved upward from the pasting position by the pasting unit moving mechanism. Therefore, a part of the cut adhesive tape 90 is maintained in a state of being lifted from the upper surface 14u of the lid body 14.

[0053] FIG. 7(A) is a plan view showing the top surface 14u of the lid 14 after this step. FIG. 7(B) is a schematic longitudinal sectional view taken along line IIV(B)-IIV(B) in FIG. 7(A). As shown in FIG. 7(A), the adhesive tape 90 arranged on the top surface 14u of the lid 14 is substantially rectangular here. The adhesive tape 90 is arranged on the top surface 14u in such a direction that the long side of the rectangle coincides with the long side direction Y of the lid 14. However, the planar shape of the adhesive tape 90 is not particularly limited. The adhesive tape 90 is a portion divided into two in the long side direction Y, and has a peripheral portion 90a surrounding the liquid injection hole 15 and an extension portion 90b extending from the peripheral portion 90a to one side in the long side direction Y (the front side in the traveling direction, the right side in FIG. 7(A)). The extension portion 90b is an example of a "portion away from the liquid injection hole".

[0054] 7(B), peripheral portion 90a closes liquid injection hole 15. In peripheral portion 90a, adhesive tape 90 is present above liquid injection hole 15 and around it. In peripheral portion 90a, adhesive tape 90 is attached to upper surface 14u of lid body 14 and is in close contact with upper surface 14u of lid body 14. This makes it possible to prevent spatter from entering inside case body 12 through liquid injection hole 15 when lid body 14 is welded to case body 12 in a case joining step (step S3) described later.

[0055] The extension portion 90b is spaced from the upper surface 14u of the lid body 14 and is in a state of floating from the upper surface 14u of the lid body 14. By having the extension portion 90b, the center position of the adhesive tape 90 is shifted to the left in the long side direction Y from the center position of the liquid injection hole 15. This configuration is maintained until the adhesive tape 90 is removed in the opening step (step S4) described later. By making a part of the adhesive tape 90 (extension portion 90b) in this way floating from the upper surface 14u of the lid body 14, it becomes easier to peel off the adhesive tape 90 in the opening step (step S4) by utilizing the part (extension portion 90b) floating from the lid body 14.

[0056] In addition, according to the inventor's study, when a reusable resin cap is washed and reused instead of the adhesive tape 90 as a means for temporarily sealing the liquid injection hole 15, as described in Patent Document 2, for example, foreign matter gradually becomes more likely to adhere to the surface of the cap due to wear, and there is a risk of foreign matter being mixed in. Furthermore, when the cap is washed or used repeatedly, it may become deformed and lose its adhesion to the liquid injection hole 15, or may become more likely to move within the liquid injection hole 15. By using a disposable adhesive tape 90, such a situation can be appropriately avoided.

[0057] The case joining step (step S3) is a step of welding the lid 14 to the periphery of the opening of the case body 12. In this step, for example, first, the lid 14 is placed on the opening of the case body 12. Next, the outer peripheral edge of the lid 14 is welded to the inner peripheral edge of the opening of the case body 12 over the entire circumference. The welding can be performed by a conventionally known method (for example, laser welding). This seals the opening of the case body 12, and integrates the case body 12 and the lid 14. During laser welding, high-temperature molten metal may be generated as fine particles (so-called spatter) from the welded portion. However, in the technology disclosed herein, since the liquid injection hole 15 is blocked with the adhesive tape 90, it is possible to prevent the spatter from entering the inside of the case body 12 through the liquid injection hole 15.

[0058] The unsealing step (step S4) is a step of peeling off the adhesive tape 90 attached to the lid 14. This opens the liquid injection hole 15. FIG. 8 is a schematic diagram illustrating this step. In this embodiment, first, a gripping tool 300 for gripping the adhesive tape 90 is prepared. By using the gripping tool 300, the productivity and workability of this step can be improved. The gripping tool 300 may have a configuration similar to that of a conventionally used tool, and is not particularly limited. Here, the gripping tool 300 includes a pair of thin plate-like blades 310. The blades 310 have a sharp end shape on the adhesive tape 90 side. This makes it easy to turn up the adhesive tape 90. However, in other embodiments, the adhesive tape 90 can be gripped with a person's fingertips or the like and peeled off from the lid 14 without using the gripping tool 300.

[0059] Next, as shown in FIG. 8, one blade 310 is inserted between the lid body 14 and the part (extension 90b) of the adhesive tape 90 that is lifted from the lid body 14, and the other blade 310 pinches the adhesive tape 90. As a result, the extension 90b of the adhesive tape 90 is gripped by the gripper 300. Then, while gripping the adhesive tape 90, the gripper 300 is moved in the horizontal direction as shown by the arrow in FIG. 8. As a result, the adhesive tape 90 moves along the lid body 14, and the adhesive tape 90 is peeled off from the lid body 14 starting from the extension 90b. As described above, gripping the extension 90b makes it easier to peel off the adhesive tape 90. Therefore, adhesive matter is less likely to remain around the injection hole 15. In addition, as the adhesive tape 90 moves along the lid body 14, peeling proceeds little by little in the long side direction Y, and the peeling area is stabilized, so that the occurrence of uneven peeling can be reduced.

[0060] The leak inspection process (step S5) is a process for evaluating the airtightness of the battery case 10. This process can be performed by a conventionally known procedure. For example, first, a test gas for leak inspection (e.g., helium gas) is filled into the battery case 10 through the open liquid filling hole 15. Then, leakage of the test gas from the battery case 10 is detected by an inspection device. This makes it possible to inspect the battery case 10 (e.g., the safety valve 17, the joint between the case body 12 and the lid 14, etc.) for the presence or absence of a leak and the location of the leak.

[0061] The liquid injection step (step S6) is a step of injecting the electrolyte into the battery case 10. Here, it is a step of injecting the electrolyte into the case body 12 from the liquid injection hole 15 of the lid 14. The liquid injection may be performed at atmospheric pressure, or may be performed with the pressure inside the battery case 10 reduced for the purpose of improving the impregnation of the electrolyte into the electrode body 20, for example. This results in the construction of an assembly (a combination of the battery case 10 and the electrode body 20). After the liquid injection, the assembly may be left (held) for a predetermined time. This allows the electrolyte to be distributed evenly, for example, in the long side direction Y of the electrode body 20.

[0062] The main sealing step (step S7) is a step of sealing the liquid injection hole 15 with a sealing member 16. In a preferred embodiment, first, gas inside the battery case 10, such as air or gas generated by decomposition of the electrolyte, is exhausted to the outside of the battery case 10. The gas can be exhausted, for example, by reducing the pressure inside the battery case 10. Next, the sealing member 16 is fitted into the liquid injection hole 15 while the pressure inside the battery case 10 is kept at normal pressure or reduced. Next, the sealing member 16 and the liquid injection hole 15 are welded together to seal the liquid injection hole 15. This hermetically seals the battery case 10. In this manner, the electricity storage device 100 can be preferably manufactured.

[0063] The power storage device 100 can be used for various applications. Suitable applications 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 a battery electric vehicle (BEV). The power storage device 100 can also be used as a storage battery for a small power storage device or the like. The power storage device 100 can also be used in the form of a battery pack in which a plurality of the power storage devices 100 are typically connected in series and / or parallel.

[0064] Although the preferred embodiment of the present invention has been described above, the above embodiment is merely an example. The present invention can be implemented in various other forms. The present invention can be implemented based on the contents disclosed in this specification and the technical common sense in the field. The technology described in the claims includes various modifications and changes of the above-exemplified embodiment. For example, it is possible to replace a part of the above-mentioned embodiment with another modification, and it is also possible to add another modification to the above-mentioned embodiment. Furthermore, if a technical feature is not described as essential, it can be appropriately deleted.

[0065] For example, in the above embodiment, in the temporary sealing step (step S2), as shown in FIG. 6(D), the guide roller 211 is moved upward to give the adhesive tape 90 a shape, and a portion of the adhesive tape 90 (extended portion 90b) is raised. However, this is not limited to this. In a modified example, for example, a curve when wound on a supply reel may be used to raise a portion of the adhesive tape 90, or the adhesive tape 90 may be manually folded to raise a portion of the adhesive tape 90. In addition, an adhesive layer may not be provided on the extended portion 90b.

[0066] For example, in the above-described embodiment, in the opening step (step S4), the portion (extended portion 90b) of the adhesive tape 90 that is lifted from the lid 14 is gripped by the gripper 300, and the adhesive tape 90 is peeled off. However, the present invention is not limited to this.

[0067] FIG. 9 is a view corresponding to FIG. 8 according to a modified example. In this modified example, first, a suction device 400 is prepared instead of the gripping tool 300. By using the suction device 400, the risk of damaging the lid body 14 can be reduced. The suction device 400 may have a configuration similar to that of a conventionally used one, and is not particularly limited. The suction device 400 includes a suction unit 410 and a moving mechanism (not shown). The suction unit 410 is provided on a surface (lower surface in FIG. 9) facing the adhesive tape 90. The outer shape of the suction unit 410 is preferably smaller than the outer shape of the extension portion 90b. Although not shown, the suction unit 410 has a plurality of suction holes for suctioning the adhesive tape 90 (specifically, the extension portion 90b). The suction holes are connected to a suction pump (not shown). The suction device 400 is controlled to suction and release the suction by controlling the driving and stopping of the suction pump. The movement mechanism moves (here, lowers and raises) the suction section 410 toward the side approaching the adhesive tape 90 and toward the side moving away from the adhesive tape 90. The movement mechanism is, for example, a piston cylinder.

[0068] Next, the suction part 410 is lowered by the moving mechanism, and the suction part 410 is brought into contact with the part (extension part 90b) of the adhesive tape 90 that is lifted from the lid body 14. In this state, the suction pump is driven, so that the extension part 90b is sucked into the suction part 410 and adsorbed thereto, as shown by the arrow in FIG. 9. Next, as shown by the arrow in FIG. 9, the suction part 410 is moved upward or obliquely upward by the moving mechanism while the extension part 90b is being adsorbed. As a result, the extension part 90b is pulled up together with the suction part 410, and the adhesive tape 90 is peeled off from the lid body 14 starting from the extension part 90b. In this manner, the liquid injection hole 15 may be opened.

[0069] As described above, specific aspects of the technology disclosed herein include those described in the following sections. Item 1: A manufacturing method for an electricity storage device including an electrode body, an electrolyte, and a case body having an opening and containing the electrode body and the electrolyte, and a lid body having a liquid injection hole and closing the opening of the case body, the manufacturing method for an electricity storage device including a temporary sealing step of attaching an adhesive tape to the lid body so as to close the liquid injection hole, and an unsealing step of peeling off the adhesive tape attached to the lid body, wherein in the temporary sealing step, the adhesive tape is attached to a peripheral portion of the liquid injection hole, while at least a portion of the adhesive tape is raised from the lid body in a portion away from the liquid injection hole. Item 2: The manufacturing method according to item 1, wherein the adhesive tape is rectangular, and in the temporary sealing step, one end of the rectangular shape in a long side direction is raised above the lid body. Item 3: The manufacturing method according to item 1 or 2, wherein in the temporary sealing step, a tape application device is provided that includes an application unit that is movable in a first direction along a surface of the lid body, the application unit including an application roller that presses the adhesive tape against the surface of the lid body, and a tape supply unit that is disposed forward of the application roller in the first direction and supplies the adhesive tape to the application roller, and the adhesive tape is applied to the lid body by an application operation in which the adhesive tape is sequentially supplied from the tape supply unit and pressed by the application roller while moving the application unit in the first direction. Item 4: The manufacturing method described in item 3, wherein the tape supply unit is provided with a supply unit moving mechanism capable of moving upward, and after the joining operation, the tape supply unit is moved upward, causing the adhesive tape between the tape supply unit and the joining roller to have a tendency to curl upward. Item 5: The manufacturing method according to item 3 or 4, wherein the joining unit further includes a cutter for cutting the adhesive tape, and the adhesive tape between the tape supply unit and the joining roller is cut by the cutter. Item 6: A manufacturing method according to any one of items 3 to 5, wherein the tape supply section includes a guide roller that guides the adhesive tape to the vicinity of the application roller, a tape supply path that passes the adhesive tape over the guide roller, an adsorption mechanism provided in the tape supply path that adsorbs the adhesive tape, and a tape chuck provided in the tape supply path that supports the adhesive tape from below, and during the application operation, the adsorption mechanism is stopped and the tape chuck is opened while the application unit is moved in the first direction. Item 7: The manufacturing method according to item 6, wherein in the bonding operation, an angle between the tape supply path and the lid is set to be equal to or greater than 20° and equal to or less than 50°. Item 8: The manufacturing method according to any one of items 1 to 7, wherein in the unsealing step, the portion of the adhesive tape that is lifted from the lid body in the temporary sealing step is sucked by a suction device, and the adhesive tape is peeled off starting from the lifted portion. Item 9: The manufacturing method according to any one of items 1 to 7, wherein in the opening step, the portion of the adhesive tape that is lifted from the lid body in the temporary sealing step is gripped, and the adhesive tape is peeled off starting from the lifted portion. Item 10: The manufacturing method according to item 9, wherein in the unsealing step, the adhesive tape is peeled off by moving the adhesive tape along the lid body. Item 11: The manufacturing method according to any one of items 1 to 10, further comprising a case joining step of welding the lid body to the periphery of the opening of the case body between the temporary sealing step and the opening step. Item 12: The manufacturing method according to any one of items 1 to 11, further comprising: a liquid injection step of injecting the electrolyte into the inside of the case body through the liquid injection hole after the opening step; and a main sealing step of sealing the liquid injection hole with a sealing member after the liquid injection step. [Explanation of symbols]

[0070] 10 Battery case 12 Case body 14 Lid 15 Liquid injection hole 20 Electrode body 90 Adhesive Tape 90a Periphery 90b Extension part 100 Energy storage device 210 Tape supply section 211 Guide roller 213 Tape supply route 214 Tape zipper 220 Attachment part 221 Pasting roller 230 Ribbon Cutting Section 231 Cutter 290 units 300 Gripping tool 400 Adsorption device 410 Adsorption part

Claims

1. An electrode body; An electrolyte; A case body having an opening and accommodating the electrode assembly and the electrolyte; a lid having a liquid injection hole and closing the opening of the case body; A method for manufacturing an electricity storage device comprising: a temporary sealing step of attaching an adhesive tape to the lid body so as to close the liquid injection hole; an opening step of peeling off the adhesive tape attached to the lid; Including, In the temporary sealing step, the adhesive tape is attached to a peripheral portion of the liquid injection hole, while at least a portion of the adhesive tape is floated from the lid in a portion away from the liquid injection hole. A method for manufacturing an electricity storage device.

2. The adhesive tape has a rectangular shape, and in the temporary sealing step, one end of the rectangular shape in a long side direction is raised above the lid body. The method of claim 1 .

3. In the temporary sealing step, a tape application device including an application unit movable in a first direction along a surface of the lid body is provided; The bonding unit includes: a sticking roller for pressing the adhesive tape onto a surface of the lid; a tape supply unit that is disposed forward of the joining roller in the first direction and supplies the adhesive tape to the joining roller; Equipped with The adhesive tape is attached to the lid body by a bonding operation in which the adhesive tape is sequentially supplied from the tape supply unit and pressed by the bonding roller while the bonding unit is moved in the first direction. The method according to claim 1 or 2.

4. the tape supply unit includes a supply unit moving mechanism that is movable upward; After the joining operation, the tape supply unit is moved upward, and the adhesive tape between the tape supply unit and the joining roller is caused to curl upward. The method according to claim 3.

5. The joining unit further includes a cutter that cuts the adhesive tape, the adhesive tape between the tape supply unit and the joining roller is cut by the cutter; The method according to claim 3.

6. The tape supply unit includes: a guide roller that guides the adhesive tape to the vicinity of the joining roller; a tape supply path through which the adhesive tape is passed over the guide roller; a suction mechanism provided in the tape supply path and configured to suction the adhesive tape; a tape chuck provided in the tape supply path and configured to support the adhesive tape from below; Equipped with In the joining operation, the adhering unit is moved in the first direction while the suction mechanism is stopped and the tape chuck is opened. The method according to claim 3.

7. In the joining operation, an angle between the tape supply path and the lid is set to be equal to or greater than 20° and equal to or less than 50°. The method according to claim 6.

8. In the unsealing step, the portion of the adhesive tape that has been lifted from the lid body in the temporary sealing step is sucked by a suction device, and the adhesive tape is peeled off from the lifted portion as a starting point. The method according to claim 1 or 2.

9. In the unsealing step, the portion of the adhesive tape that has been lifted from the lid body in the temporary sealing step is gripped, and the adhesive tape is peeled off starting from the lifted portion. The method according to claim 1 or 2.

10. In the opening step, the adhesive tape moves along the lid body, thereby peeling off the adhesive tape. The method of claim 9.

11. The case further includes a case joining step of welding the lid to a periphery of the opening of the case body between the temporary sealing step and the opening step. The method according to claim 1 or 2.

12. a liquid injection step of injecting the electrolyte into the case body through the liquid injection hole after the opening step; a main sealing step of sealing the liquid injection hole with a sealing member after the liquid injection step; Further comprising: The method of claim 11.

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