Manufacturing method and manufacturing apparatus for an electricity storage device

Abstract

To provide a method for manufacturing a power storage device, with which improvements in manufacturing efficiency and manufacturing quality can be achieved.SOLUTION: A method for manufacturing a power storage device 100 includes a mounting step S2, a first roll pressing step S3, and a second roll pressing step S4. In the mounting step S2, a pre-doping target electrode 10 that is at least one of a positive electrode and a negative electrode and a pre-doping metal foil 15 are made to overlap each other and are mounted on a crimp table 2. In the first roll pressing step S3, part of an overlapping area 15a of the pre-doping target electrode 10 and the pre-doping metal foil 15 is roll-pressed by a first roller 31 having a roller width 31a smaller than a size 10a of the pre-doping target electrode 10 in a width direction X. In the second roll pressing step S4, after the start of the first roll pressing step S3, an area that is not roll-pressed at least in the first roll pressing step S3 in the overlapping area 15a of the pre-doping target electrode 10 and the pre-doping metal foil 15 is roll-pressed by a second roller 32.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] Conventionally, in a manufacturing process of an electricity storage device formed by laminating sheet-shaped positive and negative electrodes together with a separator and enclosing a laminate in a film-shaped exterior body together with an electrolyte solution, a pre-doped metal foil is provided on the laminate, and metal ions are dissolved from the pre-doped metal foil into the electrolyte solution at the same time as the electrolyte solution is injected, thereby pre-doping the electrodes. For example, Patent Document 1 discloses a method of performing pre-doping by press-bonding the pre-doped metal foil to a part of the negative electrodes constituting the laminate by roll pressing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6871676 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the method disclosed in Patent Document 1, the press surface of the roll press is larger than the entire width of the negative electrode, and the pre-doped metal foil is placed on the negative electrode and roll-pressed once from one end of the negative electrode to the other end, thereby pressing the entire area of ​​the pre-doped metal foil to the negative electrode. Therefore, bubbles are likely to form between the pre-doped metal foil and the negative electrode, which is particularly noticeable in the central region of the pre-doped metal foil. If bubbles form between the pre-doped metal foil and the negative electrode, the bubbles inhibit the pre-doping of metal ions into the electrode during the pre-doping process, which can result in insufficient pre-doping or require a long pre-doping process, resulting in reduced manufacturing efficiency. Furthermore, in areas where such bubbles occur, the adhesion between the pre-doped metal foil and the negative electrode is low, which can lead to peeling or falling off of the pre-doped metal foil before the pre-doping process, thereby reducing manufacturing quality.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide a method and apparatus for manufacturing an electricity storage device that can improve manufacturing efficiency and manufacturing quality. [Means for solving the problem]

[0006] One aspect of the present invention is a method for manufacturing an electricity storage device, which includes laminating sheet-like positive and negative electrodes together with a separator and sealing the laminate in a film-like exterior body, comprising: A placing step of superimposing a pre-doped target electrode, which is at least one of the positive electrode and the negative electrode, on a pre-doped metal foil and placing them on a crimping table; A first roll press process in which a part of the overlapping area between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table is roll-pressed by a first roller having a roller width smaller than the width direction size of the pre-doped target electrode; After the start of the first roll press process, a second roller is used to roll press at least an area of ​​the overlapping area between the pre-doped target electrode placed on the pressure bonding table and the pre-doped metal foil that has not been roll pressed in the first roll press process.fruit, In the placing step, the pre-doped metal foil is placed on the pressure-bonding table, and then the pre-doped target electrode is placed on the pressure-bonding table so as to overlap the pre-doped metal foil. The present invention relates to a method for manufacturing an electricity storage device.

[0007] Another aspect of the present invention is a manufacturing apparatus for an electricity storage device, in which a laminate formed by laminating sheet-like positive electrodes and negative electrodes together with a separator is encapsulated in a film-like exterior body, A crimping table on which a pre-doped target electrode, which is at least one of the positive electrode and the negative electrode, and a pre-doped metal foil are placed in a superposed state; A first roller having a roller width smaller than the width direction size of the pre-doped target electrode and configured to roll press a part of the overlapping area between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table; a second roller configured to roll-press at least a region of the overlapping region between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table that has not been roll-pressed by the first roller; 、 a transfer unit that is reciprocally movable in a forward direction and a reverse direction from one end to the other end in a direction perpendicular to the width direction of the pre-doping target electrode, and that holds the first roller and the second roller at a position on the reverse side of the first roller; Equipped with 、 The roll pressing is performed sequentially by the first roller and the second roller by moving the transfer unit in the forward direction. It is found in manufacturing equipment for electricity storage devices. [Effects of the Invention]

[0008] In the manufacturing method for an electricity storage device according to the above aspect, when the pre-doped electrode and the pre-doped metal foil are pressure-bonded together, a first roller having a roller width smaller than the width of the pre-doped electrode is first roll-pressed to a portion of the overlapping region between the pre-doped electrode and the pre-doped metal foil. After the roll-pressing by the first roller begins, a second roller is used to roll-press at least the region of the overlapping region between the pre-doped electrode and the pre-doped metal foil that was not roll-pressed by the first roller. In this way, as the first-stage roll-pressing, a portion of the overlapping region is first roll-pressed by the first roller having a small roller width, which facilitates pressure-bonding while pushing out air present between the pre-doped electrode and the pre-doped metal foil. Then, as the second-stage roll-pressing, at least the region of the overlapping region that has not been pressure-bonded is roll-pressed to pressure-bond the entire overlapping region. This makes it easier to push out the gas present between the pre-doped target electrode and the pre-doped metal foil, compared to conventional methods in which the entire overlapping region is pressed together in a single roll press operation, thereby suppressing the generation of bubbles between them. As a result, the number of bubbles that inhibit metal ions eluted from the pre-doped metal foil into the electrolyte from being pre-doped into the pre-doped target electrode in the subsequent pre-doping process is reduced, allowing the pre-doping process to be carried out efficiently and improving manufacturing efficiency. Furthermore, suppressing the generation of bubbles increases the adhesive strength between the pre-doped target electrode and the pre-doped metal foil, suppressing peeling or falling off of the pre-doped metal foil before the pre-doping process, thereby improving manufacturing quality.

[0009] The electricity storage device manufacturing apparatus according to the other aspect described above can realize the manufacturing of an electricity storage device by the electricity storage device manufacturing method according to the aspect described above, thereby improving manufacturing efficiency and manufacturing quality.

[0010] As described above, according to the above aspect, it is possible to provide a method and apparatus for manufacturing an electricity storage device that can improve manufacturing efficiency and manufacturing quality. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2A is a perspective view of an electricity storage device according to a first embodiment, and FIG. 2B is a cross-sectional conceptual diagram taken along line Ib-Ib in FIG. 2A. [Figure 2] 1 is a conceptual side view of an apparatus for manufacturing an electricity storage device according to a first embodiment. [Figure 3] 1 is a conceptual top view of an apparatus for manufacturing an electricity storage device according to a first embodiment. [Figure 4] 3 is a flowchart of a method for manufacturing an electricity storage device according to the first embodiment. [Figure 5] 3(a) to 3(d) are conceptual side views illustrating a method for manufacturing an electricity storage device according to the first embodiment. [Figure 6] 5(a) to 5(c) are other conceptual side views illustrating the method for manufacturing the electricity storage device according to the first embodiment. [Figure 7] 3(a) to 3(c) are conceptual side views illustrating a method for manufacturing an electricity storage device according to the first embodiment. [Figure 8] 5(a) to 5(c) are conceptual top views of a pressure bonding table for illustrating a method for manufacturing an electricity accumulation device according to the first embodiment. [Figure 9] 5(a) to 5(c) are other conceptual side views illustrating the method for manufacturing the electricity storage device according to the first embodiment. [Figure 10] 6(a) to 6(c) are other conceptual top views of the pressure bonding table for illustrating the method for manufacturing an electricity accumulation device in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment 1) An embodiment of a method and apparatus for manufacturing an electricity storage device will be described with reference to FIGS. First, as shown in FIGS. 1(a) and 1(b), the electricity storage device 100 of this embodiment is configured by enclosing a laminate 101 in a film-like outer casing 102. The laminate 101 is configured by stacking sheet-like positive and negative electrodes (not shown) together with separators. In this embodiment, the electricity storage device 100 includes a capacitor, a secondary battery, or the like. The electricity storage device 100 is configured as a lithium ion capacitor. The laminate 101 is configured by alternately stacking multiple positive electrodes and multiple negative electrodes, each made of a metal current collector foil coated with an active material, with separators interposed between them. The negative electrode is pre-doped with lithium ions. The laminate 101 is then sealed in an outer casing 102 together with an electrolyte solution containing a lithium salt as an electrolyte. As shown in FIG. 1(a), the electricity storage device 100 has a flat rectangular outer shape and includes a pair of current collector tabs 103 at its upper end. The pair of current collector tabs 103 are connected to the positive and negative electrodes (not shown) constituting the laminate 101, respectively.

[0013] Next, the manufacturing apparatus 1 for the electricity storage device 100 of this embodiment will be described. As shown in FIGS. 2 and 3, a manufacturing apparatus 1 for an electricity storage device 100 (hereinafter also referred to as “manufacturing apparatus 1”) includes a crimping table 2, a transfer unit 3, a pre-doped metal foil supply unit 4, and a pre-doped target electrode supply unit 5.

[0014] As shown in FIGS. 7(a) and 8(a), a pre-doped target electrode 10 and a pre-doped metal foil 15 are placed on the pressure bonding table 2 in a stacked state. The pre-doped target electrode 10 is at least one of a plurality of positive electrodes and negative electrodes stacked in the laminate 101. In this embodiment, one out of six of the plurality of negative electrodes is the pre-doped target electrode 10. The pre-doped target electrode 10 has a rectangular sheet shape in a plan view, as shown in FIG. 8(a). In this embodiment, the pre-doped metal foil 15 is a lithium foil (Li foil), and as shown in FIG. 8(a), has a sheet shape having an outer shape slightly smaller than that of the pre-doped target electrode 10. In each figure, the thicknesses of the pre-doped target electrode 10 and the pre-doped metal foil 15 are shown larger than they actually are, and in reality, the thicknesses of both the pre-doped target electrode 10 and the pre-doped metal foil 15 are much smaller than those shown in each figure.

[0015] As shown in Figures 2 and 3, the crimping table 2 has a rectangular plate shape in a plan view, and the upper and lower surfaces are flat. As shown in Figure 2, the crimping table 2 is provided on a crimping table installation part 20, and an elastic member 21 is provided between the crimping table 2 and the crimping table installation part 20. The crimping table installation part 20 has an L-shaped angle shape, and as shown in Figure 3, it is fixed to a vertical wall 1a, which is part of the housing of the manufacturing apparatus 1. The material of the crimping table 2 is not limited, but it is preferably made of a hard resin. When the pre-doped metal foil 15 is placed directly on the upper surface of the crimping table 2, the roll pressing in each of the roll pressing steps S3 and S4 described below prevents the pre-doped metal foil 15 from sticking to the upper surface of the crimping table 2, and prevents the pre-doped metal foil 15 from peeling off from the pre-doped target electrode 10. Examples of the material of the hard resin include polypropylene, polyethylene, elastomer, natural rubber, synthetic rubber, etc., and among them, polypropylene, which has relatively low adhesion to the Li foil as the pre-doped metal foil 15, is more preferable.

[0016] The elastic member 21 may be made of any elastic material, and in this embodiment, silicone rubber is used. The pre-doping target electrode 10 may have poor planarity due to thickness variations. Even in such cases, the elastic member 21 can be elastically deformed via the crimping table 2 to conform to the planarity of the pre-doping target electrode 10 based on the pressure of the first roller 31 and the second roller 32 during roll pressing by the first roller 31 and the second roller 32, as described below. As a result, high contact accuracy between the first roller 31 and the second roller 32 and the pre-doping target electrode 10 can be maintained. Although not shown, the crimping table 2 has a plurality of suction portions that open onto the upper surface of the crimping table 2 at predetermined intervals. The suction portions adsorb the pre-doped metal foil 15 placed on the upper surface of the crimping table 2, thereby fixing the pre-doped metal foil 15 to the upper surface of the crimping table 2. In this embodiment, the width direction of the pre-doped target electrode 10 placed on the pressure bonding table 2 is designated as X as shown in FIG. 8(a), the thickness direction is designated as Y as shown in FIG. 7(a), and the direction perpendicular to the X and Y directions is designated as Z as shown in FIG. 8(a).

[0017] 2 and 3, the transfer unit 3 has a first roller 31, a second roller 32, a first gripping portion 33, and a second gripping portion 34. The transfer unit 3 is capable of reciprocating in both directions Z1 and Z2 in the Z direction along a guide rail 35. Note that the guide rail 35 is fixed to a vertical wall 1a that is part of the housing of the manufacturing apparatus 1, as shown in FIG.

[0018] As shown in FIGS. 2 and 3, the first roller 31 is a cylindrical roller. As shown in FIG. 8(a), the roller width 31a of the first roller 31 is smaller than the size 10a of the pre-doping target electrode 10 in the width direction X. The roller width 31a of the first roller 31 can be, for example, 10 to 30% of the size 10a of the pre-doping target electrode 10 in the width direction X. In this embodiment, the size 10a of the pre-doping target electrode 10 in the width direction X is 120 mm, and the roller width 31a of the first roller 31 is 20 mm. The diameter of the first roller 31 is not limited, but is set to 40 mm in this embodiment. The axis 31b of the first roller 31 is configured to be parallel to the width direction X of the pre-doping target electrode 10. The first roller 31 is configured to be located at a central position 10b in the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2, and in this embodiment, a central position 31c of the first roller 31 is located at the central position 10b. The material of the first roller 31 is not limited, and can be the same as the material of the pressure bonding table 2.

[0019] As shown in FIGS. 2 and 3, the second roller 32 is a cylindrical roller. As shown in FIG. 8(a), the roller width 32a of the second roller 32 is larger than the roller width 31a of the first roller 31. In this embodiment, the roller width 32a of the second roller 32 is 130 mm, which is equal to or larger than the size 10a in the width direction X of the pre-doping target electrode 10. The diameter of the second roller 32 is not limited, but in this embodiment, it is 40 mm, similar to the first roller 31. The axis 32b of the second roller 32 is parallel to the width direction X of the pre-doping target electrode 10, and the center position 32c of the second roller 32 is located on the center position 10b of the pre-doping target electrode 10. The material of the second roller 32 is also not limited, and can be the same as the material of the pressure bonding table 2, similar to the first roller 31.

[0020] The first roller 31 and the second roller 32 are configured to be able to apply pressure toward the crimping table 2 by a pressure mechanism (not shown). The pressure load of the first roller 31 and the pressure load of the second roller 32 can be set separately, and the pressure loads of the two rollers may be different or the same. In this embodiment, the pressure load of the first roller 31 is set smaller than the pressure load of the second roller 32, and specifically, the unit area load of the first roller 31 is set to 0.125 to 1.2 N / mm 2 The unit area load on the second roller 32 is 1.4 to 1.85 N / mm 2 7(b) and 7(c), the first roller 31 and the second roller 32 are configured to be movable in both directions Z1 and Z2 in the Z direction while being pressed toward the crimping table 2 by a pressure mechanism (not shown). In the Z direction, the Z1 direction is referred to as the forward direction, and the Z2 direction opposite to the Z1 direction is referred to as the reverse direction. In this embodiment, the second roller 32 is located closer to the forward direction Z1 than the first roller 31.

[0021] 2 and 3, the first gripping portion 33 is provided at a position closer to the positive direction Z1 than the first roller 31 and the second roller 32. The first gripping portion 33 is configured to be able to grip the pre-doped metal foil 15. In this embodiment, the first gripping portion 33 is configured to adsorb and grip the pre-doped metal foil 15 using a suction portion.

[0022] 2 and 3, the second gripping portion 34 is provided at a position on the reverse direction Z2 side of the first roller 31 and the second roller 32. The second gripping portion 34 is configured to be able to grip the pre-doping target electrode 10. In this embodiment, similar to the first gripping portion 33, the second gripping portion 34 is configured to adsorb and grip the pre-doping target electrode 10 using a suction portion.

[0023] As shown in FIGS. 2 and 3, the pre-doped metal foil supply unit 4, which supplies the pre-doped metal foil 15, is located closer to the forward direction Z1 than the pressure bonding table 2. The pre-doped metal foil supply unit 4 includes a Li foil roll 41, a draw-out unit 42, a cutting unit 43, and an intermediate table 44. The Li foil roll 41 is a roll of Li foil wound up. The draw-out unit 42 is composed of a pair of rollers that are driven and controlled, and can draw out a predetermined length of Li foil from the Li foil roll 41. The cutting unit 43 cuts the drawn Li foil. The cut Li foil is placed on the intermediate table 44 as the pre-doped metal foil 15. The intermediate table 44 is located on an intermediate table installation unit 40. The intermediate table installation unit 40 has an L-shaped angled shape and is fixed to a vertical wall 1a, which is part of the housing of the manufacturing apparatus 1, as shown in FIG. 3.

[0024] 2 and 3, the pre-doping target electrode supply unit 5 that supplies the pre-doping target electrode 10 is provided on the reverse direction Z2 side of the crimping table 2. In this embodiment, the pre-doping target electrode supply unit 5 is configured as an index table having a disk-shaped stage 52 on which a mounting unit 51 is mounted and an axis 53 connected to the center of the stage 52, and the stage 52 is configured to be rotatable around the axis 53. As shown in FIG. 3, the pre-doping target electrode supply unit 5 has a first mounting unit 51a and a second mounting unit 51b as the mounting unit 51, and by rotating the stage 52 180 degrees, it is possible to switch between a first position in which the first mounting unit 51a is located on the forward direction Z1 side and the second mounting unit 51b is located on the reverse direction Z2 side with respect to the axis 53, and a second position in which the second mounting unit 51b is located on the forward direction Z1 side and the first mounting unit 51a is located on the reverse direction Z2 side with respect to the axis 53. The placement sections 51 a and 51 b are both in the form of a magazine that can be attached to and detached from the stage 52 .

[0025] Next, a method for manufacturing the electricity storage device 100 according to this embodiment will be described in detail below. As shown in FIG. 4, the method for manufacturing the electricity storage device 100 in this embodiment includes a pre-process S1, a placement process S2, a first roll press process S3, a second roll press process S4, a stack arrangement process S5, a determination process S6, and a post-process S7.

[0026] 4, a pre-doped target electrode 10 and a pre-doped metal foil 15 are prepared. As shown in FIG. 5(a), the pre-doped metal foil 15 is placed on the intermediate table 44 by the pre-doped metal foil supply unit 4. The pre-doped target electrode 10 is placed on the second placement unit 51b located at the first position in the pre-doped target electrode supply unit 5.

[0027] 4, the process proceeds to the placing step S2, and as shown in FIG. 5(b), the transfer unit 3 grips the pre-doped metal foil 15 placed on the intermediate table 44 with the first gripping portion 33 at the end position on the forward direction Z1 side. At the same time, the pressure-bonded body 16 of the pre-doped target electrode 10 and the pre-doped metal foil 15 formed in the previous first roll press step S3 and second roll press step S4 and placed on the pressure-bonding table 2 is gripped with the second gripping portion 34. Thereafter, the transfer unit 3 is moved in the reverse direction Z2 as shown by the arrow P1.

[0028] 5(c), the transfer unit 3 places the pre-doped metal foil 15 held by the first gripping portion 33 on the crimping table 2 at the end position on the reverse direction Z2 side, and the crimped body 16 held by the second gripping portion 34 is placed on the first mounting portion 51a of the pre-doped target electrode supply unit 5. Then, as the stage 52 of the pre-doped target electrode supply unit 5 rotates, the first mounting portion 51a and the second mounting portion 51b are changed from the first position shown in FIG. 5(c) to the second position shown in FIG. 5(d), and the pre-doped target electrode 10 moves in the forward direction Z1 and the crimped body 16 moves in the reverse direction Z2. At the same time, as shown in FIG. 5(d), the pre-doped metal foil supply unit 4 supplies the pre-doped metal foil 151 to be used next and places it on the intermediate table 44.

[0029] 6(a), the second gripping part 34 grips the pre-doping target electrode 10 on the second mounting part 51b that has moved in the forward direction Z1, and moves the transfer unit 3 in the forward direction Z1 as shown by the arrow P2, until the transfer unit 3 is positioned at the end on the forward direction Z1 side, as shown in FIG. 6(b). At the same time, the first mounting part 51a on which the pressure-bonded body 16 that has been moved in the reverse direction Z2 in the pre-doping target electrode supply part 5 is mounted is removed from the pre-doping target electrode supply part 5.

[0030] On the other hand, as shown in FIG. 6(b), the pre-doped target electrode 10 held by the second holding unit 34 is placed on top of the pre-doped metal foil 15 placed on the crimping table 2 as shown in FIG. 6(c). Then, as shown in FIG. 8(a), in this embodiment, when the pre-doped metal foil 15 and the pre-doped target electrode 10 are placed on the crimping table 2, the entire pre-doped metal foil 15 is covered by the pre-doped target electrode 10. Therefore, the entire pre-doped metal foil 15 forms an overlapping region 15a between the pre-doped metal foil 15 and the pre-doped target electrode 10. Furthermore, as shown in FIG. 6(c), in the pre-doped target electrode supply unit 5, a first placing unit 51a on which the pre-doped target electrode 110 to be used next is placed is attached to the stage 52. This completes the placing step S2.

[0031] After the placement step S2 is completed, the process proceeds to the first roll pressing step S3, which is the first parallel process shown in Fig. 4, and then to the second roll pressing step S4. First, an outline of the first roll pressing step S3 and the second roll pressing step S4 will be described. In the first roll pressing step S3, as shown in Fig. 7(a), first, the first roller 31 and the second roller 32 are lowered toward the pressure bonding table 2 at a position on the forward direction Z1 side of the pre-doping target electrode 10 placed on the pressure bonding table 2. Then, with the first roller 31 and the second roller 32 each pressed toward the pressure bonding table 2 with a predetermined pressure load, the transfer unit 3 is moved in the reverse direction Z2 as shown by arrow P3. As a result, as shown in Figure 7(b), the first roller 31 roll-presses the pre-doped target electrode 10 and the pre-doped metal foil 15 placed on the pressure-bonding table 2 to bond them together, thereby performing the first roll-pressing process S3, and the second roller 32 roll-presses the pre-doped target electrode 10 and the pre-doped metal foil 15 to bond them together, thereby performing the second roll-pressing process S4.

[0032] The first roll pressing step S3 and the second roll pressing step S4 will be described in detail with reference to FIGS. 7 to 10. First, as shown in FIGS. 7(a) and 7(b), the transfer unit 3 is moved in the reverse direction Z2 as indicated by the arrow P3, and the first roller 31 pressed toward the pressure bonding table 2 comes into contact with the end 11 of the pre-doping target electrode 10 in the forward direction Z1, as shown in FIG. 8(a), thereby starting the first roll pressing step S3. That is, the position where the transfer unit 3 is moved so that the first roller 31 comes into contact with the end 11 is the start position of the roll pressing by the first roller 31. By further moving the transfer unit 3 in the reverse direction Z2, the central region of the pre-doping target electrode 10, including the central position 10b, is sequentially roll pressed by the first roller 31 from the end 11 of the pre-doping target electrode 10 toward the opposite end 12, as shown in FIGS. 8(a) to 8(c). 8(c), the first roller 31 reaches the end 12 on the reverse direction Z2 side of the pre-doping target electrode 10, thereby completing the first roll press step S3. In other words, the position where the transfer unit 3 is moved so that the first roller 31 abuts against the end 12 is the end position of the roll press by the first roller 31.

[0033] On the other hand, as shown in FIG. 8(b), the second roller 32 pressed toward the pressure bonding table 2 comes into contact with the end 11 of the pre-doping target electrode 10, thereby starting the second roll pressing step S4. That is, the position where the transfer unit 3 is moved so that the second roller 32 comes into contact with the end 11 is the start position of the roll pressing by the second roller 32. Therefore, at the timing when the transfer unit 3 is moved to the start position of the roll pressing by the second roller 32, the first roller 31 has not yet reached the end 12. Therefore, the second roll pressing step S4 starts after the start of the first roll pressing step S3 but before the end of the first roll pressing step S3. Then, by further moving the transfer unit 3 in the reverse direction Z2, as shown in FIGS. 8(b) and 8(c), the entire area of ​​the pre-doping target electrode 10, including the area of ​​the overlapping region 15a that was not roll pressed by the first roller 31, is sequentially roll pressed by the second roller 32 from the end 11 of the pre-doping target electrode 10 toward the opposite end 12. After the first roller 31 reaches the end 12 of the pre-doped electrode 10 as shown in Figure 8(c), the transport unit 3 moves further in the reverse direction Z2 and is raised as shown in Figure 7(c) until the second roller 32 reaches the end 12 as shown in Figure 10(a).

[0034] 10(a), when the second roller 32 reaches the end 12 of the pre-doping target electrode 10, the transfer unit 3 moves in the opposite positive direction Z1 as shown by arrow P4 while maintaining the second roller 32 pressed against the pressure table 2 as shown in FIG. 7(c). As a result, as shown in FIGS. 9(a) and (b) and 10(a) to (c), the entire area of ​​the pre-doping target electrode 10 is sequentially roll-pressed by the second roller 32 from the end 12 of the pre-doping target electrode 10 to the opposite end 11. Then, as shown in FIG. 10(c), the second roller 32 reaches the end 11 of the pre-doping target electrode 10 again, thereby completing the second roll-pressing step S4. That is, the position where the second roller 32 moves back and forth between the end 11 and the opposite end 12 of the pre-doping target electrode 10 and returns to abut against the end 11 again is the end position of the roll-pressing by the second roller 32. As a result, in this embodiment, in the second roll pressing step S4, the second roller 32 roll presses the entire area of ​​the pre-doping target electrode 10 from the end 11 to the opposite end 12 in one round trip, i.e., twice.

[0035] As shown in Fig. 7(c), in the first roll pressing step S3 and the second roll pressing step S4, the first roller 31 and the second roller 32 and the pre-doped target electrode 10 are in line contact with each other. Therefore, compared to when pressure is applied in a surface contact state using plates instead of the first roller 31 and the second roller 32, even if the pressure load on the first roller 31 and the second roller 32 is relatively small, a pressure force sufficient to press the pre-doped target electrode 10 and the pre-doped metal foil 15 can be obtained. Then, as shown in Fig. 9(b), when the second roll pressing step S4 is completed, a pressure-bonded body 16 of the pre-doped target electrode 10 and the pre-doped metal foil 15 is formed on the pressure-bonding table 2.

[0036] 9(b) and 9(c), after the second roll pressing step S4 is completed, the transfer unit 3 is moved to the end position on the forward direction Z1 side and the second roller 32 is raised, resulting in the state shown in FIG. 5(a). As a result, the transfer unit 3 operates to position the first gripping portion 33 above the intermediate table 44 so that it can grip the pre-doped metal foil 151 to be used next time placed on the intermediate table 44. That is, in the first roll pressing step S3 and the second roll pressing step S4, in parallel with the roll pressing by the first roller 31 and the second roller 32, the first gripping portion 33 is moved toward a gripping position where it will grip the pre-doped metal foil 151 to be used next time. This completes the first parallel processing consisting of the first roll pressing step S3 and the second roll pressing step S4.

[0037] On the other hand, after completing the placement process S2, in the second parallel process, stacking arrangement process S5 shown in Figure 4, the pressure-bonded body 16 placed on the first placement section 51a removed from the pre-doped target electrode supply section 5, a separator and positive electrode not shown, and a negative electrode to which the pre-doped metal foil 15 is not pressure-bonded are sequentially stacked, and the process is completed.

[0038] After the first and second parallel processes, the process proceeds to a determination step S6 shown in Fig. 4, where it is determined whether or not the necessary number of pressure-bonded bodies 16, separators, positive electrodes, and negative electrodes to constitute the laminate 101 shown in Fig. 1 have been laminated. This determination can be made by counting and obtaining the number of layers using a counter (not shown), and comparing this number of layers with a predetermined necessary number of layers using a determination unit (not shown). If it is determined in the determination step S6 that the necessary number of pressure-bonded bodies 16, separators, positive electrodes, and negative electrodes have not been laminated, the process proceeds to No in the determination step S6, and the placing step S2 and subsequent steps are performed again.

[0039] On the other hand, if it is determined in the determination step S6 shown in FIG. 4 that the required number of laminated pressure bodies 16, separators, positive electrodes, and negative electrodes have been stacked, the process proceeds to Yes in the determination step S6, and the post-step S7 is performed. In the post-step S7, a laminate 101 is created from the required number of laminated pressure bodies 16, separators, positive electrodes, and negative electrodes, and sealed in an outer casing 102 together with an electrolyte solution containing a lithium salt as an electrolyte. Thereafter, a pre-doping process is performed, and lithium ions are eluted from the Li foil as the pre-doped metal foil 15 compressed to the pre-doping target electrode 10 into the electrolyte solution in the outer casing 102, and pre-doped into the negative electrode as the pre-doping target electrode 10. After the pre-doping process, an initial charge and discharge is performed, and the exterior casing 102 is degassed, and then resealed and quality checked to complete the lithium ion capacitor as the electricity storage device 100, and the flow ends.

[0040] Next, the effects of the method for manufacturing the electricity storage device 100 of this embodiment will be described in detail. In the manufacturing method of the electricity storage device 100 of this embodiment, when the pre-doping target electrode 10 and the pre-doped metal foil 15 are pressure-bonded together, first, a first roller 31 having a roller width 31a smaller than the size 10a of the pre-doping target electrode 10 in the width direction X is used to roll-press a portion of the overlapping region 15a of the pre-doping target electrode 10 and the pre-doped metal foil 15. Then, after the roll-pressing by the first roller 31 begins, a second roller 32 is used to roll-press at least the region of the overlapping region 15a of the pre-doping target electrode 10 and the pre-doped metal foil 15 that was not roll-pressed by the first roller 31. In this way, as the first stage of roll-pressing, first, a portion of the overlapping region 15a of the pre-doping target electrode 10 and the pre-doped metal foil 15 is roll-pressed by the first roller 31 having the small roller width 31a, thereby making it easier to pressure-bond the pre-doping target electrode 10 and the pre-doped metal foil 15 together while pushing out any air present between them. Then, in the second roll pressing step, at least the unbonded region of the overlapping region 15a is roll pressed, thereby bonding the entire overlapping region 15a. This makes it easier to push outward any gas present between the pre-doping target electrode 10 and the pre-doped metal foil 15, thereby suppressing the formation of bubbles between them, compared to conventional methods in which the entire overlapping region 15a is bonded in a single roll pressing operation. As a result, bubbles that inhibit the pre-doping of metal ions eluted from the pre-doped metal foil 15 into the electrolyte solution in the subsequent pre-doping process are reduced, allowing the pre-doping process to be performed efficiently and improving manufacturing efficiency. Furthermore, suppressing the formation of bubbles improves adhesion between the pre-doping target electrode 10 and the pre-doped metal foil 15, suppressing peeling or falling off of the pre-doping metal foil 15 before the pre-doping process, thereby improving manufacturing quality.

[0041] Furthermore, in the manufacturing method of the electricity storage device 100 in this embodiment, in the first roll press step S3, the first roller 31 roll presses a region including the central position 10b in the width direction X of the pre-doping target electrode 10, with the axis 31b of the first roller 31 parallel to the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2. As a result, air bubbles are likely to occur between the pre-doping target electrode 10 and the pre-doping metal foil 15 in the central region of the pre-doping target electrode 10, but by roll pressing with the first roller 31 as described above in the first roll press step S3, the pre-doping target electrode 10 and the pre-doping metal foil 15 can be pressed together while pushing out the air between them in the central region, so that the generation of air bubbles between the pre-doping target electrode 10 and the pre-doping metal foil 15 can be further suppressed, and manufacturing efficiency and manufacturing quality can be further improved.

[0042] Furthermore, in the manufacturing method of the electricity storage device 100 in this embodiment, in the second roll press step S4, the second roller 32 has a roller width 32a that is equal to or larger than the size 10a of the pre-doping target electrode 10 in the width direction X, and the entire region of the pre-doping target electrode 10 is roll-pressed with the axis 32b of the second roller 32 parallel to the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2. This allows the pre-doping target electrode 10 and the pre-doping metal foil 15 to be pressure-bonded together while pushing out any air between them over the entire region of the pre-doping target electrode 10, thereby further improving manufacturing efficiency and manufacturing quality.

[0043] Furthermore, in the manufacturing method of the electricity storage device 100 in this embodiment, in the placing step S2, the pre-doped metal foil 15 is placed on the pressure bonding table 2, and then the pre-doped target electrode 10 is placed on the pressure bonding table 2 so as to overlap the pre-doped metal foil 15. As a result, in the first roll pressing step S3 and the second roll pressing step S4, the pre-doped metal foil 15 does not come into direct contact with the first roller 31 and the second roller 32, so that the pre-doped metal foil 15 is prevented from adhering to the first roller 31 and the second roller 32 and peeling off from the pre-doped target electrode 10, thereby improving manufacturing quality.

[0044] Furthermore, in the manufacturing method of the electricity storage device 100 of this embodiment, in the first roll press step S3, one end 11 of the pre-doping target electrode 10 in a direction perpendicular to the width direction X is set as the start position of the roll press by the first roller, and the other end 12 is set as the end position of the roll press by the first roller 31, and the first roller 31 is advanced from the start position to the end position to perform the roll press. Then, in the second roll press step S4, the second roller 32 is advanced from the start position to the end position to perform the roll press at a position on the reverse direction Z2 side, which is behind the advancing direction of the first roller 31. As a result, the roll press in the second roll press step S4 can be started after the start of the roll press in the first roll press step S3 and before its end, so that parts of both steps S3 and S4 can be performed in parallel, improving manufacturing efficiency. Furthermore, since the first roller 31 and the second roller 32 roll press in the same direction, the partial pressure-bonded body of the pre-doped target electrode 10 and the pre-doped metal foil 15 formed in the first roll press step S3 can be prevented from being displaced on the pressure-bonding table 2 in the second roll press step S4, or from being released from adhesion to the pressure-bonding table 2. In this embodiment, in the second roll press step S4, the second roller 32 is advanced from the start position to the end position to perform roll pressing, and then the second roller 32 is further advanced from the end position back to the start position to perform roll pressing. This makes it possible to further remove air between the pre-doped target electrode 10 and the pre-doped metal foil 15, thereby further improving manufacturing quality.

[0045] Furthermore, in the manufacturing method of the electricity storage device 100 in this embodiment, the first roller 31 and the second roller 32 are provided in the transfer unit 3, and the transfer unit 3 has a first gripping portion 33 capable of gripping the pre-doped metal foil 15 and a second gripping portion 34 capable of gripping the pre-doped target electrode 10. Then, in the placing step S2, the pre-doped metal foil 15 held by the first gripping portion 33 is moved to the pressure bonding table 2 and placed thereon, and the pressure bonded body 16 of the pre-doped target electrode 10 and the pre-doped metal foil 15 formed in the previous first roll press step S3 and second roll press step S4 placed on the pressure bonding table 2 is held by the second gripping portion 34 and removed from the pressure bonding table 2. This improves the efficiency of the operation and further improves manufacturing efficiency.

[0046] Furthermore, in the manufacturing method of the electricity storage device 100 in this embodiment, the operation of roll pressing with the first roller 31 and the second roller 32 in the first roll pressing step S3 and the second roll pressing step S4 is performed in parallel with the operation of positioning the first gripping part 33 above the pre-doped metal foil 151 to be used in the next placing step S2 so that the pre-doped metal foil 151 can be gripped. This improves the efficiency of the operation and further improves the manufacturing efficiency.

[0047] According to the manufacturing apparatus 1 for the electricity storage device 100 of this embodiment, it is possible to realize the manufacturing of the electricity storage device 100 by the manufacturing method described above, and as described above, it is possible to improve the manufacturing efficiency and manufacturing quality.

[0048] In the manufacturing apparatus 1 for the electricity storage device 100 in this embodiment, the first roller 31 is positioned at a central position 10b in the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2, and is configured so that the axis 31b of the first roller 31 is parallel to the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2. This allows the central region of the pre-doping target electrode 10, where bubbles are likely to occur, to be compressed by roll pressing with the first roller 31, thereby further suppressing the occurrence of bubbles between the pre-doping target electrode 10 and the pre-doped metal foil 15, and further improving manufacturing efficiency and manufacturing quality.

[0049] Furthermore, according to the manufacturing apparatus 1 for the electricity storage device 100 in this embodiment, the second roller 32 has a roller width 32a that is equal to or larger than the size 10a of the pre-doping target electrode 10 in the width direction X, and is configured so that the axis 32b of the second roller 32 is parallel to the width direction X of the pre-doping target electrode 10 placed on the pressure bonding table 2. As a result, by roll pressing with the second roller 32, the pre-doping target electrode 10 and the pre-doping metal foil 15 can be pressure-bonded together over the entire area of ​​the pre-doping target electrode 10 while pushing outward any air between them, thereby further improving manufacturing efficiency and manufacturing quality.

[0050] Furthermore, the manufacturing apparatus 1 for the power storage device 100 according to this embodiment includes a transport unit 3 that can reciprocate in a forward direction Z1 and a reverse direction Z2 from one end 11 to the other end 12 in a direction Z perpendicular to the width direction X of the pre-doping target electrode 10, and that holds a first roller 31 and a second roller 32 at a position on the forward direction Z1 side of the first roller 31. The transport unit 3 is configured to move in the reverse direction Z2 and then in the forward direction Z1, thereby sequentially performing roll pressing by the first roller 31 and the second roller 32. This allows the roll pressing by the second roller 32 to start after the start of the roll pressing by the first roller 31 and before its completion, thereby allowing parts of the roll pressing by both rollers to be performed in parallel, improving manufacturing efficiency. Furthermore, when the transfer unit 3 is moved in the reverse direction Z2, the first roller 31 and the second roller 32 can roll press in the same direction, so that the partial pressure-bonded body of the pre-doped target electrode 10 and the pre-doped metal foil 15 formed by the roll press of the first roller 31 can be prevented from shifting position on the pressure-bonding table 2 during the roll press by the second roller 32, or from losing adhesion of the partial pressure-bonded body to the pressure-bonding table 2.

[0051] Furthermore, the manufacturing apparatus 1 for the power storage device 100 in this embodiment includes a pre-doped metal foil supply unit 4 that supplies the pre-doped metal foil 15 and is provided at a position on the forward direction Z1 side of the transfer unit 3, and a pre-doped target electrode supply unit 5 that supplies the pre-doped target electrode 10 and is provided at a position on the reverse direction Z2 side of the transfer unit 3. The transfer unit 3 includes a first gripping unit 33 that is configured to be able to grip the pre-doped metal foil 15 and is provided at a position on the forward direction Z1 side of the first roller 31 and the second roller 32, and a second gripping unit 34 that is configured to be able to grip the pre-doped target electrode 10 and is provided at a position on the reverse direction Z2 side of the first roller 31 and the second roller 32. As a result, from a state in which the pre-doped metal foil 15 is held by the first gripping portion 33, the transfer unit 3 is moved in the reverse direction Z2 to the crimping table 2 to place the pre-doped metal foil 15 on the crimping table 2, and the crimped body 16 of the previously formed pre-doped target electrode 10 and the pre-doped metal foil 15 placed on the crimping table 2 is gripped by the second gripping portion 34 and removed from the crimping table 2. This can be performed in parallel, improving the efficiency of the operation and further improving manufacturing efficiency. Furthermore, in the transfer unit 3, the operation of roll pressing with the first roller 31 and the second roller 32 and the operation of making the pre-doped metal foil 151 to be used next time available for gripping by the first gripping portion 33 can be performed in parallel, so the operation of the transfer unit 3 can be made more efficient, and manufacturing efficiency can be further improved.

[0052] Furthermore, in the manufacturing apparatus 1 for the electricity storage device 100 in this embodiment, the crimping table 2 is made of hard resin. This prevents the pre-doped metal foil 15 from adhering to the upper surface of the crimping table 2 during roll pressing by the first roller 31 and the second roller 32 when the pre-doped metal foil 15 is directly placed on the upper surface of the crimping table 2, and prevents the pre-doped metal foil 15 from peeling off from the pre-doping target electrode 10, thereby improving manufacturing quality.

[0053] Furthermore, in the manufacturing apparatus 1 for the electricity storage device 100 in this embodiment, an elastic member 21 is provided between the crimping table 2 and the crimping table installation section 20 on which the crimping table 2 is installed. This allows the elastic member 21 to be elastically deformed via the crimping table 2 in accordance with the shape (flatness) of the pre-doping target electrode 10 based on the pressure of the first roller 31 and the second roller 32 during roll pressing by the first roller 31 and the second roller 32. As a result, it is possible to maintain high contact accuracy between the first roller 31 and the second roller 32 and the pre-doping target electrode 10, thereby improving manufacturing quality.

[0054] As described above, according to this embodiment, it is possible to provide a manufacturing method and manufacturing apparatus 1 for the electricity storage device 100 that can improve manufacturing efficiency and manufacturing quality.

[0055] The present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the spirit of the present invention. [Explanation of symbols]

[0056] 1: manufacturing apparatus for electricity storage device, 2: crimping table, 3: transfer unit, 4: pre-doped metal foil supply unit, 5: pre-doped target electrode supply unit, 10: pre-doped target electrode, 15: pre-doped metal foil, 15a: overlapping region, 20: crimping table installation unit, 21: elastic member, 31: first roller, 32: second roller, 33: first gripping unit, 34: second gripping unit, 100: electricity storage device, 101: laminate, 102: exterior body

Claims

1. A method for manufacturing an electricity storage device, comprising laminating sheet-like positive and negative electrodes together with a separator, and sealing the laminate in a film-like exterior body, A placing step of superposing a pre-doped target electrode, which is at least one of the positive electrode and the negative electrode, on a pre-doped metal foil and placing them on a crimping table; A first roll pressing process in which a part of the overlapping area between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table is roll pressed by a first roller having a roller width smaller than the width direction size of the pre-doped target electrode; After the start of the first roll press process, a second roller is used to roll press at least an area of ​​the overlapping area between the pre-doped target electrode placed on the pressure bonding table and the pre-doped metal foil that has not been roll pressed in the first roll press process. In the placing step, the pre-doped metal foil is placed on the pressure bonding table, and then the pre-doped target electrode is placed on the pressure bonding table so as to overlap the pre-doped metal foil.

2. 2. The method for manufacturing an electric storage device according to claim 1, wherein in the first roll press process, the first roller roll presses an area including the central position in the width direction of the pre-doped target electrode with the axis of the first roller parallel to the width direction of the pre-doped target electrode placed on the pressure bonding table.

3. 3. A method for manufacturing an electric storage device as described in claim 1 or 2, wherein in the second roll press process, the second roller has a roller width equal to or greater than the width direction of the pre-doped target electrode, and the axis of the second roller is parallel to the width direction of the pre-doped target electrode placed on the pressure bonding table, and the entire area of ​​the pre-doped target electrode is roll pressed.

4. In the first roll press step, one end of the pre-doped target electrode in a direction perpendicular to the width direction is set as a start position of the roll press by the first roller, and the other end is set as an end position of the roll press by the first roller, and the first roller is advanced from the start position to the end position to perform the roll press, 4. The method for manufacturing an electricity storage device according to claim 1, wherein in the second roll pressing step, the second roller is advanced from the start position to the end position at a position rearward of the first roller in a direction of advancement, thereby performing the roll pressing.

5. The first roller and the second roller are provided in a transfer unit, and the transfer unit has a first gripping portion capable of gripping the pre-doped metal foil and a second gripping portion capable of gripping the pre-doped target electrode, In the above-mentioned placing step, the pre-doped metal foil held by the first holding portion is moved to the crimping table and placed thereon, and the crimped body of the pre-doped target electrode and the pre-doped metal foil formed in the previous first roll press step and the second roll press step placed on the crimping table is held by the second holding portion and removed from the crimping table. A method for manufacturing an electric storage device as described in any one of claims 1 to 4, wherein the following operations are performed in parallel.

6. A method for manufacturing an electricity storage device as described in claim 5, wherein the operation of roll pressing with the first roller and the second roller in the first roll pressing process and the operation of positioning the first gripping portion above the pre-doped metal foil to be used in the next loading process to make the pre-doped metal foil in a grippable state are performed in parallel.

7. An apparatus for manufacturing an electricity storage device, comprising: a laminate formed by laminating sheet-like positive and negative electrodes together with a separator; and encapsulating the laminate in a film-like exterior body, A crimping table on which a pre-doped target electrode, which is at least one of the positive electrode and the negative electrode, and a pre-doped metal foil are placed in a superposed state; A first roller having a roller width smaller than the width direction size of the pre-doped target electrode and configured to roll press a part of the overlapping area between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table; A second roller configured to roll press at least the area not roll-pressed by the first roller in the overlapping area between the pre-doped target electrode and the pre-doped metal foil placed on the pressure bonding table; A transport unit is provided which can move back and forth in a forward direction and a reverse direction from one end to the other end in a direction perpendicular to the width direction of the pre-doping target electrode, holds the first roller, and holds the second roller at a position on the reverse side of the first roller, The manufacturing apparatus for an electricity storage device is configured to sequentially perform the roll pressing by the first roller and the second roller by moving the transfer unit in the forward direction.

8. The manufacturing apparatus for an electric storage device as described in claim 7, wherein the first roller is positioned at the center position in the width direction of the pre-doped target electrode placed on the crimping table, and the axis of the first roller is configured to be parallel to the width direction of the pre-doped target electrode placed on the crimping table.

9. The second roller has a roller width equal to or greater than the width of the pre-doped target electrode, and the axis of the second roller is configured to be parallel to the width of the pre-doped target electrode placed on the crimping table.

10. A pre-doped metal foil supply unit that supplies the pre-doped metal foil and is provided at a position on the positive side of the transfer unit; a pre-doping target electrode supply unit that supplies the pre-doping target electrode and is provided at a position on the opposite side of the transport unit; Equipped with The transport unit is provided with a first gripping portion configured to grip the pre-doped metal foil at a position on the positive side of the first roller and the second roller, and a second gripping portion configured to grip the pre-doped target electrode at a position on the opposite side of the first roller and the second roller, as described in any one of claims 7 to 9.

11. The electricity storage device manufacturing apparatus according to any one of claims 7 to 10, wherein the pressure bonding table is made of a hard resin.

12. The electricity storage device manufacturing apparatus according to any one of claims 7 to 11, wherein an elastic member is provided between the crimping table and a crimping table installation section on which the crimping table is installed.

Images