JP2016219330A - Method and device for manufacturing electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for manufacturing an electrode, in which positioning can be performed simply.SOLUTION: A method for manufacturing an electrode includes the step of cutting out a positive electrode 21 with a predetermined shape by cutting an electrode intermediate 50 which includes a sheet-like metal foil 53 having a first surface 53a and a second surface 53b opposite to the first surface 53a and active material layers 54a, 54b covering a part of the metal foil 53. The step of cutting out the positive electrode 21 includes the steps of: forming a slit 58 at least in a part of a planned cutting line 50a; and breaking a slit 58 formed in the step of forming a slit 58.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electrode manufacturing method and an electrode manufacturing apparatus.

  2. Description of the Related Art Conventionally, vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with power storage devices for storing electric power used in electrical components. As such a power storage device, for example, a secondary battery such as a lithium ion secondary battery or a nickel hydride secondary battery is known. The secondary battery includes an electrode, and the electrode includes a metal foil and an active material layer containing an active material.

  For example, Patent Document 1 discloses an apparatus provided with a rotary die cutter that cuts out a predetermined shape of an electrode by cutting a belt-shaped electrode intermediate as an apparatus used in an electrode manufacturing process.

JP 2009-66676 A

  However, when the electrode is cut out from the belt-shaped electrode intermediate, the electrode cut out from the electrode intermediate is expected to be in a posture different from the posture planned in the conveyance surface or in the conveyance surface due to vibration during conveyance. There is a possibility of displacement to a position different from the position.

  This invention was made paying attention to the problem which exists in the prior art mentioned above. An object of the present invention is to provide an electrode manufacturing method and an electrode manufacturing apparatus capable of easily positioning.

  An electrode manufacturing method that solves the above-described problem is an electrode manufacturing method, and includes a sheet-like current collector having a first surface and a second surface opposite to the first surface, the first surface, and the first surface. A step of cutting out the electrode having a predetermined shape by cutting an electrode intermediate body including an active material layer covering at least one of the two surfaces, and the step of cutting out the electrode comprises: A step of forming a fragile portion in at least a part of a portion scheduled to be cut along the predetermined shape, and a step of breaking the fragile portion formed in the step of forming the fragile portion; The gist is that

  According to this, a weak part is first formed in at least one part of the site | part by which cutting | disconnection is planned in an electrode intermediate body. “Vulnerable part” means a part that is not completely cut but is weaker than a part of the electrode intermediate that is different from the fragile part. The fragile portion is an intermittent cut such as a perforation or a cut that does not penetrate in the thickness direction of the electrode intermediate.

  The electrode intermediate is not completely cut at least in the fragile portion among the portions scheduled to be cut. For this reason, the displacement of the part cut out as an electrode is suppressed. And the electrode intermediate body is finally cut | disconnected in this weak part by fracture | rupturing a weak part. Therefore, positioning can be performed easily.

  In the electrode manufacturing method, in the fragile portion, the current collector is cut, and a portion cut out as the electrode from the electrode intermediate is different from a portion cut out as the electrode. It is preferable that the first surface and the second surface are connected only by a portion of the active material layer covering one surface.

  According to this, in the fragile portion, the current collector is cut, and the portion cut out as an electrode is connected to the other portion only by the active material layer covering one surface of the current collector. . For this reason, in a process of cutting out an electrode, a weak part can be easily fractured.

  In the electrode manufacturing method, the electrode intermediate includes a covering portion in which at least one of the first surface and the second surface is covered with the active material layer, the first surface, and the second surface. An uncovered portion whose surfaces are not covered with the active material layer, and the step of cutting out the electrode is a portion of the portion scheduled to be cut before the step of breaking the fragile portion is completed. A step of cutting a portion in the uncovered portion, and in the step of forming the weakened portion, the weakened portion may be formed in a portion in the covered portion among the portions scheduled to be cut. preferable.

  According to this, in the uncovered portion where the current collector is not covered with the active material layer, the electrode intermediate is completely cut before the step of breaking the fragile portion is completed, that is, prior to the breakage of the fragile portion. Therefore, the process of breaking the fragile portion can be easily performed as compared with the case where the fragile portion is formed in the entire site where cutting is planned. Moreover, even if the site | part in an uncovered part is cut | disconnected, since at least one part of a weak part remains at that time, the displacement of the part cut out as an electrode can be suppressed.

  In the electrode manufacturing method, in the step of breaking the fragile portion, a portion of the electrode intermediate that is cut out as the electrode is guided in the first direction, while a portion different from the portion cut out as the electrode is provided. It is preferable that the fragile portion is broken by guiding in a second direction different from the first direction.

According to this, since the guide directions are different, a load is applied to the fragile portion. This load breaks the fragile portion. For this reason, the process of fracture | rupturing a weak part can be performed by simple structure.
Preferably, the electrode manufacturing method further includes a step of holding a portion to be cut out as the electrode before the step of cutting out the electrode is completed. According to this, by holding the portion cut out as an electrode, positioning can be easily performed even after the fragile portion is broken.

  In the electrode manufacturing method, in the step of holding the portion cut out as the electrode, the portion cut out as the electrode is preferably sandwiched and held between two separators.

  According to this, it is suppressed that the portion cut out as an electrode is displaced until immediately before being sandwiched and held between the two separators. Therefore, it can convey, maintaining the positioned state.

  An electrode manufacturing apparatus that solves the above-described problem is an electrode manufacturing apparatus, comprising: a sheet-like current collector having a first surface and a second surface opposite to the first surface; the first surface; A mechanism for cutting out the electrode having a predetermined shape by cutting an electrode intermediate body including an active material layer covering at least one of the second surfaces; and cutting out the electrode The mechanism includes a forming part that forms a weak part at least a part of a site that is scheduled to be cut along the predetermined shape, and a break part that breaks the weak part formed by the forming part. The gist is that

  According to this, in the forming part, the electrode intermediate is not completely cut at least in the weak part among the parts scheduled to be cut. For this reason, the displacement of the part cut out as an electrode is suppressed. And in a fracture | rupture part, an electrode intermediate body is finally cut | disconnected in this weak part by breaking a weak part. Therefore, positioning can be performed easily.

  According to the present invention, positioning can be simplified.

The perspective view which shows a secondary battery typically. The perspective view which shows an electrode assembly typically. The front view which shows a manufacturing apparatus typically. The perspective view which shows a cutting | disconnection mechanism typically. FIG. 5 is a sectional view taken along line 5-5 shown in FIG. 4. FIG. 6 is a sectional view taken along line 6-6 shown in FIG. The schematic diagram for demonstrating the fracture | rupture of a notch part. (A) is a front view which shows typically the manufacturing apparatus in 2nd Embodiment, (b) is an enlarged view of (a). The schematic diagram which expand | deployed the outer peripheral surface of the rotary die in 2nd Embodiment. (A) is a front view which shows typically the manufacturing apparatus in 3rd Embodiment, (b) is an enlarged view of (a). The schematic diagram which shows typically the die | dye in 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of an electrode manufacturing method and an electrode manufacturing apparatus will be described.
First, a secondary battery as a power storage device will be described.

  As shown in FIG. 1, the secondary battery 10 is, for example, a lithium ion secondary battery. The secondary battery 10 includes an electrode assembly 20, an electrolyte solution (not shown), a case 30 containing the electrode assembly 20 and the electrolyte solution, and two terminals 40 for transferring electricity to and from the electrode assembly 20. It is equipped with.

  As shown in FIG. 2, the electrode assembly 20 includes a plurality of positive electrodes 21, a plurality of negative electrodes 22, and a plurality of bag-like separators 26. The electrode assembly 20 has a structure in which the electrodes 21 and 22 are stacked in layers in a state where the electrodes 21 and 22 are insulated from each other by the bag-shaped separator 26.

  The electrodes 21 and 22 are provided with a metal foil 23 as a sheet-like current collector. The metal foil 23 includes a first surface 23a and a second surface 23b opposite to the first surface 23a. The metal foil 23 for the positive electrode is, for example, an aluminum foil. The metal foil 23 for the negative electrode is, for example, a copper foil. Note that the malleability of copper and aluminum is relatively high among metal materials.

  The metal foil 23 includes a rectangular main body part 23c and a tab part 25 protruding from the edge of the main body part 23c. The electrodes 21 and 22 include a first active material layer 24a covering the first surface 23a of the metal foil 23, and a second active material layer 24b covering the second surface 23b of the metal foil 23. .

  The active material layers 24 a and 24 b cover the entire main body portion 23 c and the base end portion of the tab portion 25. The tab portion 25 is not covered with the active material layers 24a and 24b except for the base end portion. That is, in the tab part 25, the metal foil 23 is exposed except for the base end part.

  The active material layers 24a and 24b contain respective polar active materials, binders, conductive assistants, and the like. The active material layers 24 a and 24 b have an increased active material density for the purpose of improving the output density of the secondary battery 10. For this reason, the active material layers 24a and 24b have a lower spreadability than the metal foil 23 and are brittle.

  The positive electrode 21 is accommodated in the bag-like separator 26. The bag-shaped separator 26 includes a first separator piece 26a and a second separator piece 26b. Separator pieces 26a and 26b are porous insulators. The respective peripheral portions of the separator pieces 26a and 26b are thermally welded to each other. The tab portion 25 protrudes from the edge portion of the bag-like separator 26.

Next, the electrode manufacturing apparatus 100 will be described.
As shown in FIG. 3, the manufacturing apparatus 100 cuts the belt-shaped electrode intermediate 50 to cut out the positive electrode 21 having a predetermined shape, and stores the positive electrode 21 in the bag-shaped separator 26. It is a device for performing. The manufacturing apparatus 100 is supplied with an electrode intermediate 50 and two separators 60a and 60b.

  The transport direction D1 indicates the direction in which the electrode intermediate body 50 and the separators 60a and 60b are transported in the manufacturing apparatus 100. The transport direction D1 coincides with the longitudinal direction of the electrode intermediate 50 and the separators 60a and 60b. Moreover, the width direction D2 has shown the direction orthogonal to the conveyance direction D1 among the surface directions of the electrode intermediate body 50 and the separators 60a and 60b. Moreover, the surface direction of the electrode intermediate body 50 and the separators 60a and 60b is a direction along these conveyance surfaces.

Here, the electrode intermediate 50 will be described.
As shown in FIG. 4, the belt-shaped electrode intermediate 50 includes a metal foil 53 as a belt-shaped sheet-shaped current collector. The metal foil 53 includes a first surface 53a and a second surface 53b opposite to the first surface 53a. The metal foil 53 includes a first edge E1 in the width direction D2 and a second edge E2 opposite to the first edge E1.

  The electrode intermediate body 50 includes a first active material layer 54 a that covers the first surface 53 a of the metal foil 53, and a second active material layer 54 b that covers the second surface 53 b of the metal foil 53. . The active material layers 54 a and 54 b extend with a certain width like a band along the longitudinal direction of the electrode intermediate 50.

  The active material layers 54 a and 54 b are in the same position and the same range on both surfaces 53 a and 53 b of the metal foil 53. As described above, the electrode intermediate body 50 includes the covering portion 55 that is a region in which both surfaces 53a and 53b of the metal foil 53 are covered with the active material layer. In the electrode intermediate 50, the active material layers 54 a and 54 b cover a part of the metal foil 53.

  Both edge portions E1 and E2 of the metal foil 53 are not covered with the active material layers 54a and 54b. That is, the electrode intermediate body 50 includes uncovered portions 56a and 56b that are regions in which both surfaces 53a and 53b of the metal foil 53 are not covered with the active material layer. The non-covering part 56a extends along the first edge E1 with a certain width like a band. The non-covering portion 56b extends along the second edge portion E2 with a certain width like a band.

Next, the manufacturing apparatus 100 will be described in detail.
As shown in FIG. 3, the manufacturing apparatus 100 includes an intermediate supply unit 110 that supplies the electrode intermediate 50. The intermediate body supply unit 110 includes a holder 111 that supports the electrode intermediate body 50 wound in a roll shape. The holder 111 sends the electrode intermediate 50 in accordance with the conveyance speed of the electrode intermediate 50.

  The manufacturing apparatus 100 includes a cylindrical transport roll 120 that transports the electrode intermediate 50. The axis of the transport roll 120 extends along the width direction D2. The conveyance roll 120 is supported so that it can rotate around an axis.

  As shown in FIG. 4, the manufacturing apparatus 100 includes a cutting mechanism 130 as a mechanism for cutting out the positive electrode 21 having a predetermined shape by cutting the electrode intermediate 50. The cutting mechanism 130 includes a laser irradiation device 131.

  The laser irradiation device 131 includes a laser generator, and irradiates the electrode intermediate 50 being conveyed from the first surface 53a side of the metal foil 53 with a processing laser 131a. Further, the laser irradiation device 131 includes, for example, a galvano scanner as a mechanism for moving the irradiation position of the laser 131a. The laser irradiation device 131 scans the laser 131a along a predetermined scheduled cutting line 50a.

  The planned cutting line 50 a is a part of the electrode intermediate 50 that is scheduled to be cut. In this embodiment, the planned cutting line 50a has the same shape as the contour of the positive electrode 21 having a predetermined shape. That is, the planned cutting line 50a in this embodiment is a closed ring. The planned cutting line 50a is repeatedly set at a predetermined interval along the transport direction D1. A portion inside the planned cutting line 50 a corresponds to a portion cut out as the positive electrode 21.

  A portion corresponding to the main body portion 23 c of the planned cutting line 50 a is set to the covering portion 55. A portion of the planned cutting line 50 a corresponding to the base end portion of the tab portion 25 is set at an edge portion of the covering portion 55. The part corresponding to the front-end | tip part of the tab part 25 among the cutting scheduled lines 50a is set to the non-coating part 56a.

  As shown in FIG. 5, in this embodiment, the intensity of the laser 131a is such that when the laser 131a is irradiated to the non-covering portion 56a, the laser 131a penetrates the metal foil 53 in the thickness direction, thereby The strength is set so that 50 can be completely cut.

  As shown in FIG. 6, when the laser 131a is irradiated on the covering portion 55, the laser 131a penetrates the first active material layer 54a and the metal foil 53 in the thickness direction. By not penetrating up to the second active material layer 54b in the thickness direction, the strength is set such that the electrode intermediate body 50 cannot be completely cut.

  That is, the intensity of the laser 131a is such that when the laser 131a is irradiated on the covering portion 55, the electrode intermediate 50 can be cut in half so that a cut 58a that does not penetrate in the thickness direction of the electrode intermediate 50 is formed. It is set to strength.

  In the electrode intermediate 50, the notch 58a is open to the surface of the first active material layer 54a, and penetrates the first active material layer 54a and the metal foil 53 to reach the second active material layer 54b. It is the groove of the mold.

  That is, the metal foil 23 is cut at the cut portion 58 having the cut 58a. In the cut portion 58, the inner side and the outer side of the planned cutting line 50a, that is, a portion cut out as the positive electrode 21 in the electrode intermediate 50 and a portion different from the portion cut out as the positive electrode 21 are the second active material. They are connected only by the layer 54b. In other words, the metal foil 53 is cut over the entire planned cutting line 50a. In this embodiment, the laser irradiation device 131 corresponds to a forming portion that forms the cut portion 58 in at least a part of the planned cutting line 50a.

  As shown in FIG. 4, the cutting mechanism 130 includes a cylindrical separation roll 132. The axis of the separation roll 132 extends along the width direction D2. The separation roll 132 is supported so as to be able to rotate around an axis.

  The separation roll 132 guides the positive electrode 21 separated from the electrode intermediate body 50 in the transport direction D1 as the first direction. The transport direction D1 of the positive electrode 21 coincides with the transport direction D1 of the electrode intermediate 50.

  On the other hand, the separation roll 132 guides the waste intermediate body 52, which is the remaining part of the electrode intermediate body 50 from which the positive electrode 21 has been separated, in the transport direction D3 as a second direction different from the transport direction D1. In this embodiment, the discard intermediate 52 corresponds to a portion outside the planned cutting line 50a.

  As shown in FIG. 3, the manufacturing apparatus 100 includes a first separator supply unit 140 that supplies the separator 60a and a second separator supply unit 150 that supplies the separator 60b.

  The 1st separator supply part 140 is provided with the holder 141 which supports the separator 60a wound by roll shape. The holder 141 sends out the separator 60a in accordance with the conveying speed of the separator 60a.

  The second separator supply unit 150 includes a holder 151 that supports the separator 60b wound in a roll shape. The holder 151 sends out the separator 60b in accordance with the transport speed of the separator 60b.

  The manufacturing apparatus 100 includes a holding unit 160 that holds the positive electrode 21 cut out from the electrode intermediate 50 in the cutting mechanism 130. The holding unit 160 includes a columnar first holding roll 161 that conveys the separator 60a, and a columnar second holding roll 162 that conveys the separator 60b.

  The axial centers of the holding rolls 161 and 162 extend in parallel with each other along the width direction D2. The holding rolls 161 and 162 are supported so as to be rotatable around the axis. The separators 60a and 60b are transported in the transport direction D1 by the holding unit 160 in an overlapped state.

  In addition, the holding unit 160 is disposed on an extension line in the traveling direction of the electrode intermediate 50 and the positive electrode 21. When the leading end of the positive electrode 21 guided in the transport direction D1 by the separation roll 132 reaches between the holding rolls 161 and 162, the holding unit 160 moves the positive electrode 21 between the two separators 60a and 60b. With the sandwiched and held state, the sheet is pulled in the transport direction D1.

  The manufacturing apparatus 100 includes a welding portion 170 that thermally welds the two separators 60 a and 60 b around the positive electrode 21. For example, the welding part 170 includes a cylindrical welding roll 171. The welding roll 171 includes a quadrangular convex portion 172 having a size surrounding the positive electrode 21 when it is assumed that the outer peripheral surface is developed. In addition, the welded portion 170 may be a press-type welded portion.

  The manufacturing apparatus 100 includes a cutting unit 180 that cuts the separators 60a and 60b between the adjacent positive electrodes 21 and 21 in the transport direction D1. For example, the cutting portion 180 includes a blade 181 that extends along the width direction D2 and has a sharp shape. In the cutting part 180, the blades 181 reciprocate, whereby the separators 60a and 60b are cut. In addition, the cutting unit 180 may be, for example, a rotary type cutting unit or a press type cutting unit.

Next, a method for manufacturing an electrode will be described together with its operation.
The electrode manufacturing method includes a step of cutting the positive electrode 21 having a predetermined shape by cutting the electrode intermediate 50 by the cutting mechanism 130. Details will be described below.

  As shown in FIG. 4, in the laser irradiation device 131 of the cutting mechanism 130, the laser 131 a is scanned along the planned cutting line 50 a with respect to the electrode intermediate 50. As a result, as shown by a thick line in the figure, the electrode intermediate body 50 (metal foil 53) is completely cut at a portion in the uncovered portion 56a in the planned cutting line 50a. As described above, the step of cutting out the positive electrode 21 includes a step of cutting a portion in the uncovered portion 56a of the planned cutting line 50a.

  Further, as indicated by the middle thick line in the drawing, the electrode intermediate 50 is semi-cut at a portion of the planned cutting line 50a in the covering portion 55. That is, the step of cutting out the positive electrode 21 includes the step of forming the cut portion 58 having the cut 58a in at least a part of the planned cutting line 50a by the laser irradiation device 131 of the cutting mechanism 130. In the step of forming the cut portion 58, the cut portion 58 is formed at a portion of the planned cutting line 50a in the covering portion 55.

  Thus, in this embodiment, the cut portion 58 is formed in at least a part of the planned cutting line 50a. Of the planned cutting line 50a, at least in the cut portion 58, the electrode intermediate 50 is not completely cut. For this reason, the displacement of the positive electrode 21 which is a portion to be separated from the electrode intermediate 50 is suppressed. The displacement of the positive electrode 21 includes, for example, a change in posture and a change in position of the positive electrode 21 in the transport surface.

  In the separation roll 132 of the cutting mechanism 130, the portion inside the planned cutting line 50a and cut out as the positive electrode 21 is guided in the transport direction D1. On the other hand, in the separation roll 132, the waste intermediate body 52, which is a portion outside the planned cutting line 50a and different from the portion cut out as the positive electrode 21, is guided in the transport direction D3. The transport direction D1 of the positive electrode 21 and the transport direction D3 of the discard intermediate 52 are different directions. For this reason, a load is applied to the cut portion 58.

  As shown in FIG. 7, since the second active material layer 54b has a brittle property, the breaking position P1 in the transporting direction of the positive electrode 21 and the disposal intermediate 52 in the separation roll 132 is different. It cuts so that it may break in order from the passing part. Therefore, the separation roll 132 corresponds to a break portion that breaks the cut portion 58.

  The cut surface in the first active material layer 54a is smoother than the cut surface in the second active material layer 54b. That is, the shape of the cut surface in the first active material layer 54a is different from the shape of the cut surface in the second active material layer 54b.

  Thus, in this embodiment, the step of cutting out the positive electrode 21 includes a step of breaking the cut portion 58 with the separation roll 132. By breaking the cut portion 58, the entire cut line 50a is finally cut. That is, in this embodiment, before the step of breaking the cut portion 58 is completed, a step of cutting a portion in the uncovered portion 56a of the planned cutting line 50a is performed. Therefore, the positive electrode 21 can be easily positioned in the process including cutting.

  Moreover, in the manufacturing apparatus 100, the front-end | tip part of the positive electrode 21 in the advancing direction reaches | attains the holding | maintenance part 160 before the whole positive electrode 21 passes the fracture | rupture position P1. That is, the positive electrode 21 is held by the holding unit 160 before the positive electrode 21 is completely separated from the electrode intermediate 50.

  Thus, the electrode manufacturing method includes the step of holding the positive electrode 21 before the step of cutting out the positive electrode 21 by the holding unit is completed, that is, before all the cut portions 58 are broken. Yes. The “all cut portions 58” means all the cut portions 58 formed along one planned cutting line 50a. For this reason, the positive electrode 21 is prevented from being unintentionally displaced with the breakage of the cut portion 58.

  In the holding unit 160, the positive electrode 21 is sandwiched and held between the two separators 60a and 60b. For this reason, the step of sandwiching the positive electrode 21 between the two separators 60 a and 60 b and the step of holding the positive electrode 21 can be performed simultaneously. Therefore, the electrode manufacturing method is simplified. Further, the positive electrode 21 is prevented from being displaced until just before being sandwiched and held between the two separators 60a and 60b. Further, it is not necessary to provide a dedicated positioning mechanism for positioning the positive electrode 21.

Therefore, this embodiment has the effects described below.
(1) The electrode intermediate body 50 is not completely cut at least in the cut portion 58 of the planned cutting line 50a. For this reason, the displacement of the positive electrode 21 which is going to be separated from the electrode intermediate body 50 is suppressed. Then, by breaking the cut portion 58, the electrode intermediate body 50 is finally cut at the cut portion 58. Therefore, positioning can be performed easily.

  (2) In the cut portion 58, the portion cut out as the positive electrode 21 and the other portion (the discard intermediate 52) are connected only by the second active material layer 54b. For this reason, in the process of cutting out the positive electrode 21, the cut portion 58 can be easily broken.

  (3) In the uncovered portion 56a, the electrode intermediate body 50 is completely cut before the step of breaking the cut portion 58 is completed, that is, before the cut portion 58 is broken. Compared with the case where the cut portion 58 is formed, the step of breaking the cut portion 58 can be easily performed. Even if the portion in the non-covering portion 56a is cut, at that time, at least a part of the cut portion 58 remains, so that the displacement of the portion cut out as the positive electrode 21 can be suppressed.

  (4) Since the guide directions of the positive electrode 21 and the disposal intermediate 52 are different, a load is applied to the cut portion 58. The cut portion 58 is broken by this load. For this reason, the process of breaking the notch 58 can be performed with a simple configuration.

(5) By holding the positive electrode 21, positioning can be easily performed even after the cut portion 58 is broken.
(6) Displacement of the positive electrode 21 is suppressed until just before being sandwiched and held between the two separators 60a and 60b. Therefore, it can convey, maintaining the positioned state.

  (7) In order to position the positive electrode 21 cut out from the electrode intermediate body 50, a dedicated positioning mechanism is not provided. Therefore, the possibility that foreign matter generated by the positioning mechanism is mixed and the possibility that a load is applied to the positive electrode 21 due to the positioning of the positive electrode 21 is reduced. Thereby, the quality of the positive electrode 21 is improved.

(Second Embodiment)
Next, a second embodiment of an electrode manufacturing method and an electrode manufacturing apparatus will be described. In the following description, the same configuration and the same control as those of the above-described embodiments are denoted by the same reference numerals, and redundant description is omitted or simplified.

  As shown in FIGS. 8A and 8B, the cutting mechanism 130 of this embodiment includes a columnar rotary die 133 and an electrode intermediate 50 in addition to the laser irradiation device 131 and the separation roll 132. And a columnar anvil roll 134 opposite to each other. The axis of the rotary die 133 and the axis of the anvil roll 134 extend along the width direction D2.

  The rotary die 133 and the anvil roll 134 are supported so as to be rotatable around the axis. The cutting mechanism 130 includes a driving device such as a motor (not shown). By this drive device, the rotary die 133 and the anvil roll 134 are rotated.

  As shown in FIG. 9, the rotary die 133 includes a blade 133a for forming a cut portion 58 at a portion of the planned cutting line 50a in the covering portion 55 on the outer peripheral surface thereof. The blade 133a has the same shape as the portion of the planned cutting line 50a in the covering portion 55 when it is assumed that the outer peripheral surface of the rotary die 133 has been cut and developed along the reference line CP.

  The rotary die 133 and the anvil roll 134 are supported at a position where the blade 133a penetrates the first active material layer 54a and the metal foil 53 of the electrode intermediate 50 but does not penetrate the second active material layer 54b. Therefore, the rotary die 133 corresponds to a forming portion that forms the cut portion 58 in at least a part of the planned cutting line 50a by rotating.

  Further, the laser irradiation device 131 of this embodiment is downstream of the rotary die 133 in the transport direction D1. The laser irradiation device 131 irradiates the laser 131a only to a portion in the uncovered portion 56a of the planned cutting line 50a. In other words, the laser irradiation device 131 cuts a portion in the uncovered portion 56a of the planned cutting line 50a. For this reason, in this embodiment, the process of forming the cut | notch part 58 and the process of cut | disconnecting the site | part in the non-coating part 56a among the planned cutting lines 50a are performed independently.

Therefore, this embodiment has the following effects in addition to the effects (1) to (7) already described.
(8) By using the rotary die 133, the cut portion 58 can be easily formed. And since the blade 133a does not contact the anvil roll 134, wear of the blade 133a can be reduced and damage to the anvil roll 134 can be prevented.

  (9) After the step of forming the cut portion 58, a step of cutting a portion in the uncovered portion 56a of the planned cutting line 50a is performed. For this reason, the portion corresponding to the tab portion 25 is separated from the electrode intermediate body 50, so that the portion is prevented from being cut by the rotary die 133.

(Third embodiment)
Next, a third embodiment of an electrode manufacturing method and an electrode manufacturing apparatus will be described.
As shown in FIGS. 10A and 10B, the cutting mechanism 130 of this embodiment sandwiches the press die 135 and the electrode intermediate body 50 in addition to the laser irradiation device 131 and the separation roll 132. And a support stand 136 on the opposite side. The cutting mechanism 130 includes a driving device such as a hydraulic cylinder (not shown). With this driving device, the die 135 reciprocates.

  As shown in FIG. 11, the die 135 includes a blade 135 a for forming a cut portion 58 in a portion of the planned cutting line 50 a in the covering portion 55 on the surface facing the electrode intermediate body 50. The blade 135a has the same shape as the part in the covering portion 55 of the planned cutting line 50a.

  As shown in FIG. 10, the reciprocation of the die 135 is performed only to a position where the blade 135a penetrates the first active material layer 54a and the metal foil 53 of the electrode intermediate 50 but does not penetrate the second active material layer 54b. In addition, it is restricted so as not to move to the support stand 136 side. Therefore, the die 135 corresponds to a forming portion that forms the cut portion 58 in at least a part of the planned cutting line 50a by repeatedly reciprocating.

  Further, the laser irradiation device 131 of this embodiment is downstream of the die 135 in the transport direction D1. The laser irradiation device 131 irradiates the laser 131a only to a portion in the uncovered portion 56a of the planned cutting line 50a. In other words, the laser irradiation device 131 cuts a portion in the uncovered portion 56a of the planned cutting line 50a. For this reason, in this embodiment, the process of forming the cut | notch part 58 and the process of cut | disconnecting the site | part in the non-coating part 56a among the planned cutting lines 50a are performed independently.

Accordingly, this embodiment has the following effects in addition to the effects (1) to (7) and (9) already described.
(10) By using the die 135, the cut portion 58 can be easily formed. And since the blade 135a does not contact the support stand 136, wear of the blade 135a and the support stand 136 can be reduced.

In addition, you may change embodiment as follows.
In the second embodiment, a portion of the planned cutting line 50a that is in the uncovered portion 56a may be cut by the rotary die 133.

(Circle) in 2nd Embodiment, the anvil roll 134 may be provided with the buffer layer which has covered the outer peripheral surface. The buffer layer is made of a synthetic resin material such as silicone.
In the third embodiment, a portion of the planned cutting line 50a that is in the non-covered portion 56a may be cut by the press die 135.

  In the second embodiment and the third embodiment, the laser irradiation device 131 may be located upstream of the dies 133 and 135 in the transport direction D1. That is, before the step of forming the cut portion 58, a step of cutting a portion in the uncovered portion 56a of the planned cutting line 50a may be performed.

  In each embodiment, before the process of breaking the cut portion 58 is completed, the process of cutting the portion in the uncovered portion 56a of the planned cutting line 50a may be completed, and both processes are performed in parallel. There may be a period.

  In each embodiment, the discard intermediate 52 is maintained in a continuous state, but the discard intermediate 52 may be divided into individual pieces. In this case, the manufacturing apparatus 100 may be provided with a mechanism for holding the waste intermediate body 52 that is a piece.

  In each embodiment, the planned cutting lines 50a may be adjacent to each other in the transport direction D1. According to this, the yield of raw materials is improved.

In each embodiment, the planned cutting line 50 a may be set so that one or both of the edge portions E <b> 1 and E <b> 2 of the electrode intermediate body 50 are part of the edge portion of the positive electrode 21.
In each embodiment, the part to be completely cut out of the planned cutting line 50a may be changed. For example, the part ahead of the advancing direction along the conveyance direction D1 among the planned cutting lines 50a may be completely cut. According to this, when passing through the breaking position P <b> 1 of the separation roll 132, the cut portion 58 is easily broken.

In each embodiment, in the cutting mechanism 130, the cut portion 58 may be formed in the entire planned cutting line 50a.
In each embodiment, in the separation roll 132, the transport direction of the positive electrode 21 and the transport direction of the discard intermediate 52 need only be different from each other, and may be changed as appropriate. For example, the conveyance direction D1 of the electrode intermediate body 50 and the conveyance direction of the positive electrode 21 may be different.

  In each embodiment, the fragile portion penetrates the electrode intermediate body 50 in the thickness direction, and may have intermittent notches such as perforations, such as notches 58a and perforations. Notches may be mixed. That is, the fragile portion is not completely cut, but may be fragile as compared with a portion of the electrode intermediate 50 that is different from the fragile portion.

  In each embodiment, the manufacturing apparatus 100 may include a different type of breakage portion instead of the separation roll 132. For example, a method of breaking the cut portion 58 with ultrasonic waves may be employed for the break portion.

In each embodiment, the cut 58a may not penetrate the metal foil 53.
In each embodiment, there may be a plurality of transport rolls.
In each embodiment, an accumulator mechanism for adjusting the tension when the electrode intermediate body 50 is conveyed may be provided.

  In each embodiment, the manufacturing apparatus 100 may include a transport mechanism such as another transport roll or a transport belt, or a mechanism that transports the electrode intermediate 50 using ultrasonic waves, in addition to or instead of the transport roll 120. Good.

  In each embodiment, the manufacturing apparatus 100 may not include the separator supply units 140 and 150, the holding unit 160, the welding unit 170, and the cutting unit 180. The manufacturing apparatus 100 may include an inspection unit that inspects the positive electrode 21, for example. The manufacturing apparatus 100 may include a defective product discharging apparatus. The manufacturing apparatus 100 may include a stacked portion that forms the electrode assembly 20 by stacking the positive electrode 21 and the negative electrode 22 that are covered with the bag-shaped separator 26. Further, the manufacturing apparatus 100 may include an assembly unit that houses the electrode assembly 20 in the case 30 and assembles the secondary battery 10 by injecting an electrolytic solution therein.

(Circle) in each embodiment, the manufacturing apparatus 100 may be provided with the apparatus which removes the fine cuttings generated at the time of the cutting | disconnection of the electrode intermediate body 50. FIG.
In each embodiment, the manufacturing apparatus 100 may be an apparatus that manufactures the negative electrode 22 by cutting the negative electrode intermediate 50.

  (Circle) in each embodiment, the electrode intermediate body 50 does not need to be provided with the non-coating part 56b. The covering portion 55 and the non-covering portions 56a and 56b may not coincide on both surfaces 53a and 53b of the metal foil 53. The covering portion 55 and the non-covering portions 56a and 56b may meander along the transport direction D1.

  In each embodiment, the electrode intermediate body 50 includes at least one of the first active material layer 54a covering the first surface 53a and the second active material layer 54b covering the second surface 53b. It only has to be.

○ In each embodiment, each step included in the electrode manufacturing method may be performed by an operator.
○ It can also be applied to power storage devices other than secondary batteries, such as capacitors.

○ The secondary battery is not limited to being mounted on a vehicle, but may be a stationary battery used in a house or the like.
The technical idea shown below can be understood from the above embodiment.
(A) The current collector includes a first surface and a second surface opposite to the first surface, and the active material layer includes a first active material layer covering the first surface; And a second active material layer covering the second surface.

  (B) The shape of the cut surface in the first active material layer may be different from the shape of the cut surface in the second active material layer.

  D1 ... transport direction (first direction), D3 ... transport direction (second direction), 21 ... positive electrode (electrode), 22 ... negative electrode (electrode), 50 ... intermediate electrode, 50a ... planned cutting line (cut is (Planned part), 52 ... waste intermediate, 53 ... metal foil (current collector), 53a ... first surface, 53b ... second surface, 54a ... first active material layer, 54b ... second active material layer 55 ... covering part, 56a ... non-covering part, 56b ... non-covering part, 58 ... cutting part (fragile part), 58a ... cutting, 60a ... separator, 60b ... separator, 100 ... manufacturing apparatus, 130 ... cutting mechanism, 131 ... laser irradiation device (formation part), 132 ... separation roll (breaking part), 133 ... rotary die (formation part), 135 ... die (formation part).

Claims (7)

An electrode manufacturing method comprising:
A sheet-like current collector having a first surface and a second surface opposite to the first surface;
A step of cutting out the electrode having a predetermined shape by cutting an electrode intermediate body including an active material layer covering at least one of the first surface and the second surface. ,
The step of cutting out the electrode includes:
Forming a fragile portion in at least a part of a portion scheduled to be cut along the predetermined shape;
A step of breaking the fragile portion formed in the step of forming the fragile portion.   In the fragile portion, the current collector is cut, a portion cut out from the electrode intermediate as the electrode, and a portion different from the portion cut out as the electrode are the first surface and the The manufacturing method of the electrode of Claim 1 connected only by the active material layer of the part which has covered 1 surface among 2nd surfaces. The electrode intermediate includes a covering portion in which at least one of the first surface and the second surface is covered with the active material layer, and the first surface and the second surface are both the active material layer. An uncovered portion that is not covered with,
The step of cutting out the electrode comprises a step of cutting a portion in the uncovered portion among the portions scheduled to be cut before the step of breaking the fragile portion is completed,
The method for manufacturing an electrode according to claim 1, wherein, in the step of forming the fragile portion, the fragile portion is formed in a portion of the covering portion among the portions scheduled to be cut.   In the step of breaking the fragile portion, a portion of the electrode intermediate that is cut out as the electrode is guided in the first direction, while a portion different from the portion cut out as the electrode is defined as the first direction. The manufacturing method of the electrode as described in any one of Claims 1-3 which fractures | ruptures the said weak part by guiding to a different 2nd direction.   The manufacturing method of the electrode as described in any one of Claims 1-4 provided with the process of hold | maintaining the part cut out as the said electrode before the process of cutting out the said electrode is complete | finished.   6. The method for manufacturing an electrode according to claim 5, wherein in the step of holding the portion cut out as the electrode, the portion cut out as the electrode is sandwiched and held between two separators. An electrode manufacturing apparatus,
A sheet-like current collector having a first surface and a second surface opposite to the first surface;
A mechanism for cutting out the electrode having a predetermined shape by cutting an electrode intermediate body including an active material layer covering at least one of the first surface and the second surface; ,
The mechanism for cutting out the electrode is:
A forming part that forms a fragile part in at least a part of the part scheduled to be cut along the predetermined shape,
An electrode manufacturing apparatus comprising: a breaking portion that breaks the fragile portion formed by the forming portion.