JP2019046743A - Method for manufacturing bipolar electrode and device for manufacturing bipolar electrode - Google Patents

Abstract

To provide a method for manufacturing a bipolar electrode and a device for manufacturing a bipolar electrode which can suppress the occurrence of poor cutting of a conductive sheet.SOLUTION: A method for manufacturing a bipolar electrode comprises the steps of: conveying a work W having a belt-shaped conductive sheet S, and positive electrodes 36 and negative electrodes 38 intermittently arrayed on each of a lower face Sc and an upper face Sd of the conductive sheet S in a longitudinal direction of the conductive sheet S by circulating a loop-like carrier film 116 supporting the work W in the longitudinal direction; then, partially cutting the conductive sheet S and the carrier film 116 between adjacent negative electrodes 38 by moving a blade 124 of a die cutting roller 120 having the blade 124 downward (first cutting step); then, moving a bottom dead point of the blade 124 downward; and then, cutting the conductive sheet S at a position of a notch 116a formed in the carrier film 116 by the first cutting step (second cutting step).SELECTED DRAWING: Figure 7

Description

  One aspect of the present invention relates to a method of manufacturing a bipolar electrode and an apparatus for manufacturing a bipolar electrode.

  A bipolar battery is known in which a plurality of bipolar electrodes are stacked via a separator (see Patent Document 1). Each bipolar electrode has an electrode plate, a positive electrode provided on the first surface of the electrode plate, and a negative electrode provided on the second surface of the electrode plate.

JP 2005-135764 A

  As a method of manufacturing the bipolar electrode, for example, the following method can be considered. First, a plurality of positive electrodes are intermittently coated on the first surface of the strip-shaped conductive sheet in the longitudinal direction of the conductive sheet, and a plurality of the positive electrodes on the second surface of the strip-shaped conductive sheet in the longitudinal direction Is applied intermittently. Next, while conveying the conductive sheet in the longitudinal direction by the carrier film, the conductive sheet and a part of the carrier film are cut between the adjacent positive electrodes and between the adjacent negative electrodes. Thereby, a singulated bipolar electrode is obtained.

  If the conductive sheet is transported by circulating a looped carrier film, cutting may occur at the same location of the carrier film. In that case, since the cut is made in the carrier film by the cutting already performed, when the blade of the cutting device is pressed against the conductive sheet, the conductive sheet is pushed into the cut. As a result, for example, cutting defects of the conductive sheet, such as the generation of burrs, may occur.

  An object of the present invention is to provide a method of manufacturing a bipolar electrode and an apparatus for manufacturing a bipolar electrode that can suppress the occurrence of cutting defects of a conductive sheet.

  In the method of manufacturing a bipolar electrode according to one aspect of the present invention, a strip-shaped conductive sheet, and a plurality of active material layers arranged intermittently in the longitudinal direction of the conductive sheet on each of both surfaces of the conductive sheet A conveying step of conveying the work having the material in the longitudinal direction by circulating a loop-like carrier film supporting the work, and moving the blade of the cutting device having the blade downward, the adjacent active A second cutting step of cutting the conductive sheet and a part of the carrier film between material layers, and a second cutting step of cutting the conductive sheet at a position of a cut formed in the carrier film by the first cutting step A cutting step, and a moving step of moving the lower dead point of the blade downward between the first cutting step and the second cutting step; Including.

  According to the manufacturing method of this bipolar electrode, when the conductive sheet is cut in the second cutting step, even if the conductive sheet is pushed into the cut formed in the carrier film in the first cutting step, the lower side of the blade Since the dead point moves downward, the occurrence of cutting defects of the conductive sheet can be suppressed.

  The carrier film may be a PET film, and the depth of the cuts may be 80% or less of the thickness of the carrier film after the second cutting step. In this case, the possibility of breakage of the carrier film can be reduced.

  The cutting device may be a cutting roll having a rotation axis along the lateral direction of the conductive sheet. In this case, the conductive sheet can be cut while conveying the work by the carrier film by rotating the cutting roll around the rotation axis. Therefore, when cutting the conductive sheet, it is not necessary to stop the carrier film and the work, so that the production efficiency of the bipolar electrode can be enhanced. Furthermore, the force applied to the carrier film by acceleration and deceleration of the carrier film can be suppressed. Therefore, damage to the carrier film can be reduced.

  A manufacturing apparatus of a bipolar electrode according to one aspect of the present invention includes a strip-shaped conductive sheet, and a plurality of active material layers intermittently arranged in the longitudinal direction of the conductive sheet on each of both surfaces of the conductive sheet. And a cutting device having a blade moving downward so as to cut the conductive sheet between the adjacent active material layers, and moving the lower dead point of the blade downward And the transport device transports the work in the longitudinal direction by circulating a loop-like carrier film supporting the work, and the drive includes the conductive sheet and the carrier. The conductive sheet at a position of a cut formed on the carrier film by a first cutting step of cutting a part of the film and the first cutting step In between the second cutting step of cutting, moving the bottom dead center of the blade downward.

  According to the manufacturing apparatus of this bipolar electrode, when the conductive sheet is cut in the second cutting step, the conductive sheet is moved under the blade even if the conductive sheet is moved into the cut formed in the carrier film in the first cutting step. Since the dead point moves downward, the occurrence of cutting defects of the conductive sheet can be suppressed.

  According to one aspect of the present invention, a method of manufacturing a bipolar electrode and an apparatus for manufacturing a bipolar electrode can be provided that can suppress the occurrence of cutting defects of a conductive sheet.

It is a schematic sectional drawing which shows embodiment of an electrical storage apparatus provided with an electrical storage module. It is a schematic sectional drawing which shows the electrical storage module which comprises the electrical storage apparatus of FIG. It is a front view which shows typically the manufacturing apparatus of the bipolar electrode which concerns on embodiment. It is a top view which shows a part of manufacturing apparatus of the bipolar electrode of FIG. It is a front view which shows a part of manufacturing apparatus of the bipolar electrode in a 1st cutting process. It is a front view which shows a part of manufacturing apparatus of the bipolar electrode in a transfer process. It is a front view which shows a part of manufacturing apparatus of the bipolar electrode in a 2nd cutting process. It is a front view which shows a part of manufacturing apparatus of the bipolar electrode of FIG. It is a flowchart which shows an example of the control procedure of the manufacturing apparatus of the bipolar electrode of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and the overlapping description is omitted. In the drawings, an XYZ orthogonal coordinate system is shown as needed. For example, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction.

  An embodiment of a power storage device will be described with reference to FIG. Power storage device 10 shown in FIG. 1 is used, for example, as a battery of various vehicles such as a forklift, a hybrid car, and an electric car. The storage device 10 includes a plurality of (three in the present embodiment) storage modules 12, but may include a single storage module 12. The storage module 12 is a bipolar battery. The storage module 12 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, but may be an electric double layer capacitor. The following description exemplifies a nickel-hydrogen secondary battery.

  The plurality of storage modules 12 may be stacked via a conductive plate 14 such as a metal plate, for example. As viewed from the stacking direction, the storage module 12 and the conductive plate 14 have, for example, a rectangular shape. Details of each storage module 12 will be described later. The conductive plates 14 are also disposed outside the storage modules 12 positioned at both ends in the stacking direction (Z direction) of the storage modules 12. Conductive plate 14 is electrically connected to adjacent power storage module 12. Thereby, the plurality of power storage modules 12 are connected in series in the stacking direction. In the stacking direction, the positive electrode terminal 24 is connected to the conductive plate 14 located at one end, and the negative electrode terminal 26 is connected to the conductive plate 14 located at the other end. The positive electrode terminal 24 may be integral with the conductive plate 14 to be connected. The negative electrode terminal 26 may be integral with the conductive plate 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in the direction (X direction) intersecting the stacking direction. The charge and discharge of the power storage device 10 can be performed by the positive electrode terminal 24 and the negative electrode terminal 26.

  Conductive plate 14 can also function as a heat sink for releasing the heat generated in storage module 12. By passing a refrigerant such as air through the plurality of air gaps 14 a provided inside the conductive plate 14, the heat from the storage module 12 can be efficiently released to the outside. Each void 14a extends, for example, in a direction (Y direction) intersecting the stacking direction. When viewed in the stacking direction, conductive plate 14 is smaller than storage module 12, but may be the same as or larger than storage module 12.

  The storage device 10 may include a restraint member 16 for restraining the storage modules 12 and the conductive plates 14 stacked alternately in the stacking direction. The constraining member 16 includes a pair of constraining plates 16A and 16B and a connecting member (bolt 18 and nut 20) that interconnects the constraining plates 16A and 16B. An insulating film 22 such as a resin film, for example, is disposed between the restraint plates 16A and 16B and the conductive plate 14. Each restraint plate 16A, 16B is made of, for example, a metal such as iron. When viewed from the stacking direction, each of the restraint plates 16A, 16B and the insulating film 22 has, for example, a rectangular shape. The insulating film 22 is larger than the conductive plate 14, and the restraint plates 16 </ b> A and 16 </ b> B are larger than the storage module 12. As viewed in the stacking direction, an insertion hole 16A1 for inserting the shaft of the bolt 18 is provided at a position outside the storage module 12 at the edge of the restraint plate 16A. Similarly, as viewed in the stacking direction, an insertion hole 16B1 for inserting the shaft of the bolt 18 is provided at a position outside the storage module 12 at the edge of the restraint plate 16B. When the restraint plates 16A and 16B have a rectangular shape when viewed from the stacking direction, the insertion holes 16A1 and the insertion holes 16B1 are located at the corners of the restraint plates 16A and 16B.

  One restraint plate 16A is abutted against the conductive plate 14 connected to the negative electrode terminal 26 via the insulating film 22, and the other restraint plate 16B is attached to the conductive plate 14 connected to the positive electrode terminal 24. It is hit through. The bolt 18 is passed through the insertion hole 16A1 and the insertion hole 16B1 from, for example, one restraint plate 16A to the other restraint plate 16B. A nut 20 is screwed into the tip of a bolt 18 projecting from the other restraint plate 16B. Thus, the insulating film 22, the conductive plate 14, and the storage module 12 are sandwiched to form a unit, and a restraint load is applied in the stacking direction.

  With reference to FIG. 2, a power storage module constituting the power storage device will be described. The storage module 12 shown in FIG. 2 includes a stacked body 30 in which a plurality of bipolar electrodes 32 are stacked. As viewed from the stacking direction of the bipolar electrodes 32, the stacked body 30 has, for example, a rectangular shape. A separator 40 may be disposed between adjacent bipolar electrodes 32.

  Each bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on a first surface 34c of the electrode plate 34, and a negative electrode 38 provided on a second surface 34d of the electrode plate 34. In the laminated body 30, the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one bipolar electrode 32 adjacent in the stacking direction with the separator 40 interposed therebetween, and the negative electrode 38 of one bipolar electrode 32 It opposes the positive electrode 36 of the other bipolar electrode 32 which adjoins in the lamination direction on both sides.

  In the stacking direction, at one end of the stacked body 30, an electrode plate 34 in which the negative electrode 38 is disposed on the inner side surface (the lower surface in the drawing) is disposed. The electrode plate 34 corresponds to a negative electrode side terminal electrode. In the stacking direction, at the other end of the stacked body 30, an electrode plate 34 in which the positive electrode 36 is disposed on the inner side surface (upper surface in the drawing) is disposed. The electrode plate 34 corresponds to a positive electrode side terminal electrode. The negative electrode 38 of the negative electrode side termination electrode faces the positive electrode 36 of the uppermost bipolar electrode 32 via the separator 40. The positive electrode 36 of the positive electrode side termination electrode faces the negative electrode 38 of the lowermost bipolar electrode 32 via the separator 40. The electrode plates 34 of these terminal electrodes are connected to the adjacent conductive plates 14 (see FIG. 1).

  The storage module 12 includes a cylindrical resin portion 50 that extends in the stacking direction of the bipolar electrode 32 and accommodates the stacked body 30. The resin portion 50 holds the peripheral portions 34 a of the plurality of electrode plates 34. The resin portion 50 is configured to surround the stacked body 30. The resin portion 50 has, for example, a rectangular shape when viewed from the stacking direction of the bipolar electrode 32. That is, the resin part 50 is, for example, a square tube.

  The resin portion 50 is joined to the peripheral portion 34a of the electrode plate 34, and the first seal portion 52 which holds the peripheral portion 34a, and the first seal portion 52 in the direction (X direction and Y direction) intersecting the laminating direction. And a second seal portion 54 provided on the outside of the

  The first seal portion 52 constituting the inner wall of the resin portion 50 is provided over the entire circumference of the peripheral portion 34 a of the electrode plate 34 in the plurality of bipolar electrodes 32 (that is, the stacked body 30). The first seal portion 52 is welded, for example, to the peripheral portion 34 a of the electrode plate 34, and seals the peripheral portion 34 a. That is, the first seal portion 52 is joined to the peripheral portion 34 a of the electrode plate 34. The peripheral portion 34 a of the electrode plate 34 of each bipolar electrode 32 is held in a state of being buried in the first seal portion 52. The peripheral portions 34 a of the electrode plates 34 disposed at both ends of the stacked body 30 are also held in a state of being buried in the first seal portion 52. As a result, an internal space is airtightly partitioned between the electrode plates 34 and 34 and the first seal portion 52 between the electrode plates 34 and 34 adjacent in the stacking direction. In the internal space, an electrolytic solution (not shown) made of an alkaline solution such as a potassium hydroxide aqueous solution is accommodated.

  The second seal portion 54 constituting the outer wall of the resin portion 50 covers the outer peripheral surface 52 a of the first seal portion 52 extending in the stacking direction of the bipolar electrode 32. The inner peripheral surface 54a of the second seal portion 54 is welded, for example, to the outer peripheral surface 52a of the first seal portion 52, and seals the outer peripheral surface 52a. That is, the second seal portion 54 is joined to the outer peripheral surface 52 a of the first seal portion 52. The welding surface (bonding surface) of the second seal portion 54 with respect to the first seal portion 52 has, for example, four rectangular flat surfaces.

  The electrode plate 34 is a rectangular metal foil made of, for example, nickel. The peripheral portion 34 a of the electrode plate 34 is an uncoated region where the positive electrode active material and the negative electrode active material are not coated. The electrode plate 34 is exposed in the uncoated area. The uncoated area is embedded in and held by the first seal portion 52 that constitutes the inner wall of the resin portion 50. As a positive electrode active material which comprises the positive electrode 36, nickel hydroxide is mentioned, for example. As a negative electrode active material which comprises the negative electrode 38, a hydrogen storage alloy is mentioned, for example. The formation region of the negative electrode 38 in the second surface 34 d of the electrode plate 34 may be one size larger than the formation region of the positive electrode 36 in the first surface 34 c of the electrode plate 34.

  The separator 40 is formed, for example, in a sheet shape. The separator 40 has, for example, a rectangular shape. Examples of materials for forming the separator 40 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or non-woven fabrics made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like. . The separator 40 may be reinforced with a vinylidene fluoride resin compound. The separator 40 is not limited to a sheet but may be a bag.

  The resin portion 50 (the first seal portion 52 and the second seal portion 54) is formed in a rectangular cylindrical shape, for example, by injection molding using an insulating resin. As a resin material which constitutes resin part 50, polypropylene (PP), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE) etc. are mentioned, for example.

  Next, an apparatus for manufacturing the bipolar electrode 32 of the storage module 12 will be described with reference to FIGS. 3 to 7. FIG. 3 is a front view schematically showing the manufacturing apparatus 100 of the bipolar electrode 32. As shown in FIG. FIG. 4 is a plan view showing a part of the manufacturing apparatus 100 of FIG. 5 to 7 are front views showing a part of the manufacturing apparatus 100 of FIG.

  As shown in FIGS. 3 and 4, the manufacturing apparatus 100 of the bipolar electrode 32 includes a conveying device 110, a die cutting roll 120 as a cutting device or a cutting roll, and a driving device 140.

  The transport device 110 transports the strip-shaped workpiece W in the longitudinal direction (X direction). The work W has a plurality of active material layers (positive electrode 36) intermittently arranged in the longitudinal direction of the conductive sheet S on each of the strip-like conductive sheet S and both surfaces (the lower surface Sc and the upper surface Sd) of the conductive sheet S. And the negative electrode 38). The positive electrode 36 and the negative electrode 38 are, for example, active material layers having a rectangular shape when viewed from the thickness direction (Z direction) of the conductive sheet S. The upper surface Sd of the conductive sheet S is exposed between the plurality of positive electrodes 36. The lower surface Sc of the conductive sheet S is exposed between the plurality of negative electrodes 38. The upper surface Sd is also exposed on both sides of the positive electrode 36 in the lateral direction. The lower surface Sc is also exposed on both sides of the negative electrode 38 in the lateral direction.

  The transport device 110 transports the workpiece W in the longitudinal direction by circulating a looped carrier film 116 supporting the workpiece W. The carrier film 116 is, for example, a resin film such as a PET film. The thickness 116D (see FIG. 7) of the carrier film 116 is, for example, 10 to 200 μm. The transport apparatus 110 includes a pair of transport rolls 112a and 112b that transport the work W therebetween, and a transport unit 114 disposed downstream of the transport rolls 112a and 112b in the transport direction (X direction) of the work W. Can be provided. The transport rolls 112a and 112b are, for example, nip rolls. The transport unit 114 has a plurality of (four in the present embodiment) rolls 114 a, 114 b, 114 c, and 114 d for circulating the carrier film 116. The carrier film 116 returns from the roll 114a through the rolls 114b, 114c, 114d to the roll 114a. Thus, the carrier film 116 can be used repeatedly.

  The die-cut roll 120 is disposed between the roll 114 b and the roll 114 c which transport the carrier film 116 in the transport direction (X direction) of the workpiece W. The die cut roll 120 is an example of a cutting roll having a rotation axis Ax along the lateral direction (Y direction) of the conductive sheet S. The die cut roll 120 has a roll body 122 and a blade 124 provided on the outer peripheral surface 122 s of the roll body 122 and extending in the short direction. The die-cut roll 120 cuts the conductive sheet S between the adjacent positive electrodes 36 and between the adjacent negative electrodes 38 by rotating around the rotation axis Ax. As a result, a cutting line along the short direction is formed on the conductive sheet S. The rotational speed of the die cutting roll 120 is synchronized with the transport speed of the work W and the carrier film 116, and is constant, for example. The length of the blade 124 in the short direction is larger than the width of the conductive sheet S. Although the die-cut roll 120 of this embodiment has a single blade 124, it may have a plurality of blades 124 arranged at equal intervals in the circumferential direction.

  A support roll 126 is disposed on the opposite side of the die cut roll 120 with the work W interposed therebetween. The support roll 126 is disposed between the roll 114 b and the roll 114 c which transport the carrier film 116 in the transport direction (X direction) of the work W. Between the support roll 126 and the die cut roll 120, the carrier film 116 and the work W are interposed. As shown in FIG. 3, when the blade 124 does not hit the workpiece W, the outer peripheral surface 122 s of the die cut roll 120 contacts the negative electrode 38 of the workpiece W. As shown in FIG. 5, when the blade 124 hits the workpiece W, the conductive sheet S is cut. At this time, a part of the carrier film 116 is also cut so that the conductive sheet S is completely cut. As a result, notches 116 a having a depth T 1 are formed in the carrier film 116.

  The drive device 140 can be connected to the shaft portion 121 (see FIG. 4) along the rotation axis Ax of the die cut roll 120. The drive device 140 moves the bottom dead center of the blade 124 downward by a distance K (direction Z1 in FIG. 6), as shown in FIGS. The distance K may be, for example, 1 mm or less, or 0.5 mm or less. The movement of the bottom dead center of the blade 124 is controlled as follows by the controller 150 (see FIGS. 3 and 4) connected to the drive device 140. First, as shown in FIG. 5, the conductive sheet S and a part of the carrier film 116 are cut (first cutting step). Next, as shown in FIG. 6, the position of the die-cut roll 120 in the thickness direction (Z direction) of the conductive sheet S is shifted downward by the distance K. As a result, the bottom dead center of the blade 124 moves downward by the distance K. The downward movement of the die cutting roll 120 is performed while rotating the die cutting roll 120 when the blade 124 does not hit the workpiece W. Next, as shown in FIG. 7, the conductive sheet S is cut at a position of the notch 116 a formed in the carrier film 116 in the first cutting step (second cutting step). In the second cutting step, the bottom dead center of the blade 124 is moved downward by the distance K as compared to the first cutting step, so the depth T2 of the cut 116a after the second cutting step is the first cutting step The distance K is deeper than the depth T1 of the rear notch 116a. That is, T2 = T1 + K. The depth T2 of the cut 116a is, for example, 80% or less of the thickness 116D of the carrier film 116.

  The manufacturing apparatus 100 of the bipolar electrode 32 may include a conveyer 160 that conveys the singulated bipolar electrode 32. Each bipolar electrode 32 has a size D in the longitudinal direction. The conveyer 160 receives the bipolar electrode 32 peeled off from the carrier film 116 and conveys it to the next process.

  According to the manufacturing apparatus 100 of the bipolar electrode 32, when cutting the conductive sheet S in the second cutting process (FIG. 7), the inside of the notch 116a formed in the carrier film 116 in the first cutting process (FIG. 5) Even if the conductive sheet S moves, since the bottom dead center of the blade 124 moves downward, it is possible to suppress the occurrence of the cutting failure of the conductive sheet S.

  Next, a method of manufacturing the bipolar electrode 32 will be described with reference to FIGS. The bipolar electrode 32 can be manufactured using the manufacturing apparatus 100 as follows.

(Preparation process)
First, the work W and the carrier film 116 are prepared. For example, on the lower surface Sc of the conductive sheet S, the plurality of positive electrodes 36 are applied intermittently in the longitudinal direction. Similarly, a plurality of negative electrodes 38 are applied intermittently in the longitudinal direction on the upper surface Sd of the conductive sheet S. The workpiece W obtained in this manner is wound around, for example, a supply roll. The positive electrode 36 is provided on the lower surface Sc of the conductive sheet S, and the negative electrode 38 is provided on the upper surface Sd of the conductive sheet S. The size of the negative electrode 38 in the longitudinal direction is larger than the size of the positive electrode 36 in the longitudinal direction.

(Transporting process)
Next, the workpiece W is transported by the transport device 110 in the longitudinal direction. For example, first, the work W supplied from the supply roll is nipped and conveyed between the pair of conveyance rolls 112a and 112b. Thereafter, the work W is transported in the longitudinal direction by circulating the carrier film 116 in the transport unit 114.

(First cutting step)
As shown in FIG. 5, while conveying the work W in the longitudinal direction, the die-cut roll 120 is rotated about the rotation axis Ax, and a part of the conductive sheet S and the carrier film 116 between the adjacent negative electrodes 38 Disconnect. The blade 124 is rotated around the rotation axis Ax, and the blade 124 is moved downward, whereby the conductive sheet S and a part of the carrier film 116 are cut. Thereby, the notch 116a having the depth T1 is formed in the carrier film 116. The first cutting process is performed at least until the carrier film 116 makes one rotation. The singulated bipolar electrodes 32 are transported by the transport conveyor 160 to the next process.

(Movement process)
Next, as shown in FIG. 6, the position of the die-cut roll 120 in the thickness direction (Z direction) of the conductive sheet S is shifted downward by the distance K. As a result, the bottom dead center of the blade 124 moves downward by the distance K. The downward movement of the die cutting roll 120 is performed while rotating the die cutting roll 120 when the blade 124 does not hit the workpiece W.

(2nd cutting process)
Next, as shown in FIG. 7, the conductive sheet S is cut at the position of the cut 116 a formed in the carrier film 116 by the first cutting process. The second cutting process is started when the conductive sheet S is cut for the first time at the same position as the cut 116a formed in the carrier film 116 by the first cutting process. In the second cutting step, the bottom dead center of the blade 124 is moved downward by the distance K as compared to the first cutting step, so the depth T2 of the cut 116a after the second cutting step is the first cutting step The distance K is deeper than the depth T1 of the rear notch 116a. That is, T2 = T1 + K. The second cutting process is performed at least until the carrier film 116 makes one rotation. The depth T2 of the notch 116a after the second cutting step is, for example, 80% or less of the thickness 116D of the carrier film 116.

  After the second cutting step, the moving step and the second cutting step are repeated until the depth of the cut 116a after cutting exceeds a predetermined value (80% of the thickness 116D of the carrier film 116). It is also good.

  According to the method of manufacturing the bipolar electrode of the present embodiment, when the conductive sheet S is cut in the second cutting step, the conductive sheet S is pushed into the notch 116a formed in the carrier film 116 in the first cutting step. Even if it is, since the lower dead point of the blade 124 is moved downward by the moving step, the generation of the cutting defect of the conductive sheet S can be suppressed.

  In addition, when the carrier film 116 is a PET film and the depth T2 of the cut 116a is 80% or less of the thickness 116D of the carrier film 116 after the second cutting process, the possibility of the carrier film 116 being broken can be reduced. .

  Furthermore, when using the die cut roll 120, the conductive sheet S can be cut while the work W is being conveyed by the carrier film 116 by rotating the die cut roll 120 around the rotation axis Ax. Therefore, since it is not necessary to stop the carrier film 116 and the work W when cutting the conductive sheet S, the production efficiency of the bipolar electrode 32 can be enhanced. Furthermore, the force applied to the carrier film 116 by acceleration and deceleration of the carrier film 116 can be suppressed. Therefore, damage to the carrier film 116 can be reduced.

As shown in FIG. 8, the entire length L of the carrier film 116 along the circulation direction (the length when the looped carrier film 116 is broken and made linear) can be obtained by cutting the conductive sheet S. The size (maximum size) C in the longitudinal direction of the blade 124 may be deviated from the natural number times (n times n is a natural number) of the size (maximum size) D in the longitudinal direction of the bipolar electrode 32. Assuming that the amount of deviation is α, the following equations (1) and (2) hold.
L = D × n + α formula (1)
| Α | ≧ C equation (2)

  n may be 6 or more. α may be a positive value or a negative value. When α is a positive value, as shown in FIG. 8, the distance of the position of the blade 124 relative to the carrier film 116 to the downstream side in the conveyance direction (X direction) of the work W each time the carrier film 116 is rotated once. Shift by | α |. On the other hand, when α is a negative value, the position of the blade 124 relative to the carrier film 116 is shifted upstream by the distance | α | in the conveyance direction (X direction) of the workpiece W each time the carrier film 116 is rotated once. I will. The absolute value of α may be less than D, may be 1 mm or less, or may be 0.5 mm or less. For example, when D = 200 mm and | α | = 0.5 mm, the carrier film 116 can be rotated 400 (= 200 / 0.5) until cutting is performed at the same position of the carrier film 116.

  When the entire length L of the carrier film 116 deviates from the natural number times the size D of the bipolar electrode 32, after the carrier film 116 makes one rotation, the cut formed in the carrier film 116 at the first rotation at the next rotation. The cutting is performed at a position different from that of (see FIG. 8). Therefore, in each of the first cutting step and the second cutting step described above, it is possible to suppress the cutting at the same position of the carrier film 116 while circulating the carrier film 116. Therefore, generation | occurrence | production of the cutting defect of the electroconductive sheet S can be suppressed. Moreover, since the lifetime of the carrier film 116 can be extended, the manufacturing cost of the bipolar electrode 32 can be reduced.

  FIG. 9 is a flow chart showing an example of a control procedure of the manufacturing apparatus of the bipolar electrode of FIG. As shown in FIG. 9, the manufacturing apparatus 100 of the bipolar electrode 32 can be controlled as follows.

  First, the lowering frequency N of the bottom dead center of the blade 124 is set to 0 (step S1). Next, the number of rotations M of the carrier film 116 is set to 0 (step S2). Next, the workpiece W is cut while rotating the carrier film 116 once (step S3). Next, the rotation number M is incremented by 1 (step S4). Next, it is determined whether M × | α |> D is satisfied (step S5). D is the size in the longitudinal direction of the bipolar electrode 32. Is a deviation between the entire length L of the carrier film 116 and a natural number multiple of the size D in the longitudinal direction of the bipolar electrode 32, and corresponds to the pitch of the position where the blade 124 enters. If M × │α│> D is not satisfied, the process returns to step S3 and the workpiece W is cut while rotating the carrier film 116 once again. Steps S3 to S5 correspond to the above-mentioned first cutting step. If M × │α│> D is satisfied, the lower dead point of the blade 124 is moved downward by the distance K (step S6). Step S6 corresponds to the above-described transfer step. Next, the lowering number N is incremented by 1 (step S7). Next, it is determined whether T0 + N × K> G is satisfied (step S8). T0 is the initial depth of the notch 116a of the carrier film 116, and may be the same as the depth T1 described above. G is a limit depth of a predetermined cut depth (for example, 80% of the thickness 116D of the carrier film 116). If T0 + N × K> G is not satisfied, the process returns to step S2 and the number of revolutions M is set to zero. The subsequent steps S3 to S5 correspond to the above-mentioned second cutting step. If T0 + N × K> G is satisfied, the carrier film 116 is replaced with a new one (step S9). Next, it is determined whether or not the cutting of the workpiece W is finished (step S10). When the cutting of the work W is not completed, the process returns to step S1 and the lowering number N is set to zero. When the cutting of the work W is ended, the control is ended.

  Subsequently, a method of manufacturing power storage device 10 using bipolar electrode 32 will be described. After the bipolar electrode 32 is transported by the transport conveyor 160, the frame is joined to the peripheral portion 34 a of the electrode plate 34 of the bipolar electrode 32. At this time, the frame may be welded to the peripheral portion 34 a by performing heat pressing from the upper and lower surfaces of the bipolar electrode 32. Then, a plurality of bipolar electrodes 32 joined together with the frame are stacked via the separator 40 to obtain the stacked body 30 of FIG. The first seal portion 52 is configured by laminating a plurality of frames. Next, the second seal portion 54 is formed by, for example, injection molding. For example, the second seal portion 54 can be formed by pouring the resin material of the second seal portion 54 having fluidity into the mold.

  Next, an electrolytic solution is injected into the resin portion 50 through a liquid injection port or the like. After injecting the electrolytic solution, the storage port 12 is manufactured by sealing the liquid injection port. Thereafter, as shown in FIG. 1, the plurality of storage modules 12 are stacked via the conductive plate 14. The positive electrode terminal 24 and the negative electrode terminal 26 are connected in advance to the conductive plates 14 positioned at both ends in the stacking direction. Thereafter, a pair of restraint plates 16A and 16B are disposed at both ends in the stacking direction via the insulating film 22, and the restraint plates 16A and 16B are connected to each other using the bolts 18 and the nuts 20. Thus, power storage device 10 shown in FIG. 1 is manufactured.

  The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited to the above embodiments.

  For example, as a cutting device, a Thomson type or Thomson blade may be used instead of the die cutting roll 120. In this case, after the work W is transported in the longitudinal direction by circulating the carrier film 116, the work W and the carrier film 116 are stopped at a predetermined cutting position. Thereafter, by reciprocating a Thomson type or Thomson blade in the thickness direction (Z direction) of the conductive sheet S, the conductive sheet S is cut between the adjacent negative electrodes 38. After cutting, the work W is conveyed in the longitudinal direction by circulating the carrier film 116 again. Also in the Thomson type or Thomson blade, the lower dead point of the blade can be moved downward between the first cutting step and the second cutting step.

  32: bipolar electrode 36: positive electrode (active material layer) 38: negative electrode (active material layer) 100: manufacturing device 110: conveying device 116: carrier film 116a: notching 120: die cut roll (cutting device, Cutting roll), 124: blade, 140: driving device, Ax: rotating shaft, S: conductive sheet, Sc: lower surface, Sd: upper surface, W: work.

Claims (4)

A method of manufacturing a bipolar electrode, comprising
A loop-shaped carrier for supporting the work comprising a strip-like conductive sheet and a plurality of active material layers arranged intermittently in the longitudinal direction of the conductive sheet on each of both surfaces of the conductive sheet Conveying the film in the longitudinal direction by circulating the film;
A first cutting step of cutting part of the conductive sheet and the carrier film between the adjacent active material layers by moving the blade of the cutting device having the blade downward;
A second cutting step of cutting the conductive sheet at a position of a cut formed in the carrier film by the first cutting step;
Between the first cutting step and the second cutting step, a moving step of moving the lower dead center of the blade downward;
A method of manufacturing a bipolar electrode, including: The carrier film is a PET film,
The manufacturing method of the bipolar electrode according to claim 1 whose depth of said cut is 80% or less of thickness of said carrier film after said 2nd cutting process.   The manufacturing method of the bipolar electrode of Claim 1 or 2 whose said cutting device is a cutting roll which has a rotating shaft along the transversal direction of the said electroconductive sheet. An apparatus for manufacturing a bipolar electrode,
A conveying device for conveying in the longitudinal direction a workpiece having a strip-like conductive sheet and a plurality of active material layers intermittently arranged in the longitudinal direction of the conductive sheet on both surfaces of the conductive sheet;
A cutting device having a blade moving downward so as to cut the conductive sheet between the adjacent active material layers;
A driving device for moving the blade to the lower dead center downward;
Equipped with
The transport device transports the work in the longitudinal direction by circulating a looped carrier film supporting the work.
The driving device cuts the conductive sheet at a position of a cut formed in the carrier film in the first cutting step of cutting the conductive sheet and a part of the carrier film, and the first cutting step. The manufacturing apparatus of the bipolar electrode which moves the lower dead center of the said blade downward between 2 cutting processes.

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