JP2017084691A - Method of manufacturing electrode sheet, and electrode sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of active material layers, being fused due to thermal effect of laser, on the front and rear surfaces of a coating sheet.SOLUTION: A method of manufacturing an electrode sheet for cutting out an electrode sheet from a coating sheet 50, where a front active material layer 54 and a rear active material layer 56 are formed, respectively, on a strip metal foil 52 has a front coating area cutting step for irradiating the coating sheet from the front side 60, with front upstream side laser 180L (front side laser) with an intensity capable of cutting at least the front active material layer, and a rear coating area cutting step for irradiating the coating sheet from the rear side 70, with rear upstream side laser 190L (rear side laser) with an intensity capable of cutting at least the rear active material layer.SELECTED DRAWING: Figure 18

Description

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

  The power generation element of the secondary battery disclosed in Patent Document 1 is configured by alternately stacking a positive electrode unit in which a rectangular positive electrode sheet is covered with a separator and a rectangular negative electrode sheet. The power generation element of the secondary battery disclosed in Patent Document 2 includes these four sheets in a state where a belt-like positive electrode sheet, a first separator sheet, a negative electrode sheet, and a second separator sheet are superposed in this order. It is constructed by winding several times.

  In Patent Documents 1 and 2, each of the positive electrode sheet and the negative electrode sheet has an active material layer on both surfaces of the metal foil. These positive electrode sheet and negative electrode sheet are produced as follows. First, a positive electrode coating sheet and a negative electrode coating sheet in which active material layers are formed on both surfaces of a metal foil having a larger area than the positive electrode sheet and the negative electrode sheet, which are the final products, are prepared. Then, each of these coated sheets is irradiated with a laser to cut out the positive electrode sheet and the negative electrode sheet into a predetermined shape.

Japanese Patent Laid-Open No. 9-120836 JP 2007-273182 A

  Conventionally, each coating sheet is irradiated with a laser from either the front side or the back side to cut the metal foil and the active material layers on both sides together. However, strong laser intensity is required to cut the metal foil and the active material layers on both sides together. Further, when the metal foil and the active material layers on both sides are cut together, the two active material layers are melted at a time in addition to the metal foil, so that the cutting takes time. As a result, the amount by which both active material layers are melted due to the thermal effect of the laser increases, the capacity of the active material is reduced, and the scattering of foreign materials accompanying the melting of both active material layers is increased.

  The subject of this invention is reducing the quantity by which the active material layer of the front and back both surfaces of a coating sheet is fuse | melted by the thermal influence of a laser.

  In order to solve the above problems, the present invention takes the following means.

  1st invention of this invention is a manufacturing method of the electrode sheet which cuts out an electrode sheet using a laser from the coating sheet in which the active material layer was formed in the strip | belt-shaped metal foil, Comprising: The surface on the front side of a coating sheet is The front side active material layer is a region formed continuously in the longitudinal direction of the metal foil, and the metal foil is provided adjacent to the front side coating region in the width direction of the metal foil. And a front side non-coating region that is a region continuous in the longitudinal direction with the surface exposed. The back side surface of the coated sheet is a region facing the front side coating region with the metal foil interposed therebetween, and a region where the back side active material layer is formed, and a non-front side coating with the metal foil interposed therebetween. A back side non-coating region that is a region facing the work region and continuous in the longitudinal direction with the metal foil exposed. The electrode sheet has a rectangular current collecting portion and a tab portion protruding from a tab forming side which is one side of the current collecting portion, and the rectangular current collecting portion includes a tab forming side and a tab forming side. And a tab parallel side that is two sides excluding the tab forming side and the tab opposing side. The front side coating region and the back side coating region have a width corresponding to at least the length of the tab parallel side. A front side non-coating area | region and a back side non-coating area | region have the width | variety corresponding to the length of the protrusion direction of a tab part at least. The electrode sheet manufacturing method includes a front side laser having a strength capable of cutting at least the front side active material layer when the virtual outline of the electrode sheet is virtually set on the coated sheet. There is a front side coating region cutting step of irradiating the irradiated front side laser from the front side of the coating sheet along the portion of the front side coating region in the virtual contour on the coating sheet. Further, at least the back side laser that has a strength capable of cutting the back side active material layer and is focused, from the back side of the coating sheet, along the location of the back side coating region in the virtual contour on the coating sheet Irradiating, has a back side coating area cutting step. In addition, a laser for metal foil that is at least strong enough to cut the metal foil, and the focused laser for metal foil is applied from the front side of the coating sheet to a portion of the front side non-coating region in the virtual contour on the coating sheet. Or a non-coating region cutting step of irradiating the metal foil laser from the back side of the coating sheet along the portion of the back side non-coating region in the virtual contour on the coating sheet. .

  In the above-described configuration, the front-side active material layer and the back-side active material layer are individually cut using the front-side laser and the back-side laser. Compared with the case of cutting together, the intensities of both lasers can be set weaker, and the front-side active material layer and the back-side active material layer can each be cut faster. Therefore, the amount of both active material layers melted due to the thermal effect of the front side laser and the back side laser can be reduced. As a result, in the cut-out electrode sheet, a decrease in the capacity of the active material can be suppressed, and the scattering of foreign matters accompanying the melting of the active material layer when the front side laser and the back side laser are irradiated onto the coating sheet can be suppressed. .

  2nd invention of this invention is a manufacturing method of the electrode sheet as described in 1st invention, Comprising: While performing a front side coating area | region cutting process and a back side coating area | region cutting process simultaneously, front side coating area | region cutting process And the front side laser and the back side laser are simultaneously irradiated to the respective positions of the virtual contour to be cut in the back side coating region cutting step.

  In the above-described configuration, the front side laser and the back side laser are simultaneously irradiated to the same position on the virtual contour of the electrode sheet. Compensation of heat can occur. Therefore, even if the intensity | strength of a front side laser and a back side laser is set weakly, both active material layers and metal foil can be cut | disconnected. Therefore, it is possible to reduce the amount of melting of both active material layers due to the thermal effect of the front side laser and the back side laser. As a result, in the cut electrode sheet, the capacity reduction of the active material is suppressed, and the front side laser and the back side laser are Scattering of foreign matters accompanying melting of the active material layer when the coating sheet is irradiated can be suppressed.

  A third invention of the present invention is the electrode sheet manufacturing method according to the first or second invention, wherein the optical axis of the front side laser is set to be orthogonal to the coating sheet, and the back side laser Is set so as to be orthogonal to the coated sheet.

  In the above-described configuration, since the optical axes of the front side laser and the back side laser are orthogonal to the coating sheet, these lasers are different from the case where each of these lasers is irradiated obliquely to the coating sheet. The linear distances through which the two lasers pass through the active material layer are the shortest, and accordingly, the intensity of both lasers can be set weak. Therefore, the amount of both active material layers melted due to the thermal effect of the front side laser and the back side laser can be reduced. As a result, in the cut-out electrode sheet, a decrease in the capacity of the active material can be suppressed, and the scattering of foreign matters accompanying the melting of the active material layer when the front side laser and the back side laser are irradiated onto the coating sheet can be suppressed. .

  4th invention of this invention is a manufacturing method of the electrode sheet as described in any one of 1st-3rd invention, Comprising: The intensity | strength of a front side laser is predetermined from the surface of a front side active material layer. The front side laser reaching position is set at a predetermined position within the range from the front side surface of the metal foil provided with the front side active material layer to the inside of the back side active material layer. Is set. The intensity of the back side laser is set to an intensity capable of cutting from the surface of the back side active material layer to a predetermined back side laser reaching position, and the back side laser reaching position is a surface on the back side of the metal foil provided with the back side active material layer To a predetermined position within a range from the inside of the front side active material layer.

  In the above-described configuration, the intensities of the front side laser and the back side laser are respectively lower than the intensity at which both the active material layers and the metal foil are cut together. Therefore, the amount of both active material layers melted due to the thermal effect of the front side laser and the back side laser can be reduced. As a result, in the cut-out electrode sheet, a decrease in the capacity of the active material can be suppressed, and the scattering of foreign matters accompanying the melting of the active material layer when the front side laser and the back side laser are irradiated onto the coating sheet can be suppressed. .

  According to a fifth aspect of the present invention, a surface on the front side of the current collector in a current collector foil is a metal foil having a rectangular current collector and a tab having a shape protruding from one side of the current collector. An electrode sheet having a front side active material layer and a back side active material layer on each of the front side surface and the back side surface, wherein the front side active material layer has an edge portion of the current collector portion on at least one side of the front side surface of the current collector portion The front side active material layer has a front side tapered portion that is aligned with the edge of the front side active material layer and is inclined from the one side to the inner side of the current collector in the thickness direction of the front side active material layer. The back side active material layer has a current collecting part in which the edge of the current collecting part coincides with the edge of the back side active material layer on at least one side of the back side surface of the current collecting part, and the current collecting is performed from the one side in the thickness direction of the back side active material layer. A back side taper portion inclined toward the inner side of the portion. And the front side taper part and the back side taper part are provided in the same edge | side in four sides of a rectangular current collection part.

  In a power storage device, positive electrode sheets (electrode sheets) and negative electrode sheets (electrode sheets) are alternately stacked with separators therebetween. The stacked positive electrode sheet and negative electrode sheet are subject to load on the outer edge portions of each other. Therefore, the positive electrode sheet and the negative electrode sheet may be in contact with each other (internal short circuit) because the separator is broken between the outer edge portions. In the above-described configuration, the front side taper portion and the back side taper portion are provided on the outer edges of the positive electrode sheet and the negative electrode sheet. Therefore, a gap is formed between the outer edge portions of the positive electrode sheet and the negative electrode sheet by the both taper portions, and even if the separator is torn, an internal short circuit is avoided.

It is a perspective view of a power storage device. It is sectional drawing of an electrode assembly. It is a perspective view of a positive electrode sheet, a separator, and a negative electrode sheet. It is a perspective view of a positive electrode sheet. It is a perspective view of a negative electrode sheet. It is a flowchart showing the manufacturing process of an electrode sheet. It is a schematic side view of a coating dryer. It is a top view of the front side of a coating sheet. It is a top view of the back side of a coating sheet. It is a side view of an electrode sheet manufacturing apparatus. It is a perspective view of an electrode sheet manufacturing apparatus. It is a top view of an electrode sheet manufacturing apparatus. It is a perspective view of a conveying apparatus. It is a top view of a conveying apparatus. It is a top view of a belt. It is a perspective view of the laser apparatus in the front side of a coating sheet. It is a perspective view of the laser apparatus in the back side of a coating sheet. It is sectional drawing of the coating sheet of the cut | disconnected state. It is a top view showing the example of a change of a coating sheet. It is a perspective view showing the example of a change of an electrode sheet manufacturing apparatus. It is a top view showing the example of a change of a coating sheet. It is sectional drawing showing the example which the outer edge of the negative electrode sheet approached the positive electrode sheet side. FIG. 17 is a perspective view illustrating a modification example of the laser device in correspondence with FIG. 16. FIG. 18 is a perspective view illustrating a modification example of the laser device in correspondence with FIG. 17.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The power storage device 1 shown in FIG. 1 is, for example, a lithium ion secondary battery. A case 10 of the power storage device 1 includes a bottomed rectangular parallelepiped case body 12 and a flat lid 11 that closes an opening of the case body 12. The lid 11 has external connection terminals 14 and 16. The external connection terminals 14 and 16 penetrate the lid 11 in the thickness direction.

  As shown in FIG. 1, the power storage device 1 includes an electrode assembly 20 and an electrolytic solution (not shown) inside a case 10. The electrode assembly 20 is connected to the external connection terminals 14 and 16 via a positive electrode tab portion 32b and a negative electrode tab portion 42b described later. The electrode assembly 20 supplies power to the outside of the power storage device 1 through the external connection terminals 14 and 16 (discharge), and power is supplied from the outside of the power storage device 1 (charging).

  As shown in FIGS. 2 and 3, the electrode assembly 20 is configured by alternately stacking positive electrode sheets 30 (electrode sheets) and negative electrode sheets 40 (electrode sheets). A separator 28 is provided between the positive electrode sheet 30 and the negative electrode sheet 40. The separator 28 is made of a thin film-like porous resin. The area of the separator 28 is larger than the area of a negative electrode current collector 42a described later.

  As shown in FIGS. 2, 3, and 4, the positive electrode sheet 30 has a positive electrode current collector foil 32 (current collector foil) as a base. The positive electrode current collector foil 32 is a metal foil, for example, an aluminum foil. The positive electrode current collector foil 32 includes a rectangular positive electrode current collector part 32a (current collector part) and a positive electrode tab part 32b (tab part) having a shape protruding from one side of the positive electrode current collector part 32a. The positive electrode current collector 32a has a front-side positive electrode active material layer 34 (front-side active material layer) on the surface of the front side 32c (see FIG. 2). The positive electrode current collector 32a has a back-side positive electrode active material layer 36 (back-side active material layer) on the surface of the back side 32d. The positive electrode active material layers 34 and 36 cover, for example, substantially the entire area of the positive electrode current collector 32a. Both the positive electrode active material layers 34 and 36 are made of, for example, a lithium-containing metal oxide. As shown in FIG. 4, the positive electrode current collector 32 a and both positive electrode active material layers 34 and 36 constitute a positive electrode base 38.

  The positive electrode tab portion 32b does not have the front-side positive electrode active material layer 34 and the back-side positive electrode active material layer 36, and the positive electrode current collector foil 32 is exposed. The positive electrode tab portions 32b of the positive electrode sheets 30 are overlapped with each other and welded to one external connection terminal 14 (see FIG. 1), for example. In this specification, the side provided with the positive electrode tab portion 32b in the positive electrode current collector 32a is referred to as a positive electrode tab forming side 38a (tab forming side). Further, a side facing the positive electrode tab forming side 38a is referred to as a positive electrode tab opposing side 38b. The two sides excluding the positive electrode tab forming side 38a and the positive electrode tab opposing side 38b are referred to as a first positive electrode tab parallel side 38c (tab parallel side) and a second positive electrode tab parallel side 38d (tab parallel side).

  The front-side positive electrode active material layer 34 has a positive-electrode front-side taper portion 34a (front-side taper portion), as shown in FIGS. The positive electrode front taper portion 34a is provided along each of the positive electrode tab opposing side 38b, the first positive electrode tab parallel side 38c, and the second positive electrode tab parallel side 38d. Each positive electrode front taper portion 34a is inclined from the corresponding side 38b, 38c, 38d to the inner side of the positive electrode current collector 32a on the surface 32c of the positive electrode current collector 32a, for example, linearly inclined. Yes. The position of each edge part 34EG (refer FIG. 2) of each positive electrode front side taper part 34a is substantially corresponded with the position of the edge part of the positive electrode current collection part 32a. Each positive electrode front side taper portion 34a has a positive electrode front side inclination angle θ1A (see FIG. 2).

  As shown in FIGS. 2 and 4, the back-side positive electrode active material layer 36 has a positive-electrode back-side taper portion 36 a (back-side taper portion). The positive electrode back side taper portion 36a is provided along each of the positive electrode tab opposing side 38b, the first positive electrode tab parallel side 38c, and the second positive electrode tab parallel side 38d. Each positive electrode back side taper portion 36a is inclined from the corresponding side 38b, 38c, 38d to the inward side of the positive electrode current collector portion 32a on the surface of the back side 32d of the positive electrode current collector portion 32a, for example, linearly inclined. Yes. The position of each edge portion 36EG (see FIG. 2) of each positive electrode back side taper portion 36a substantially coincides with the position of the edge portion of the positive electrode current collector portion 32a. Each positive electrode back side taper portion 36a has a positive electrode back side inclination angle θ1B (see FIG. 2).

  The negative electrode sheet 40 has a negative electrode current collector foil 42 (current collector foil) as a base, as shown in FIGS. The negative electrode current collector foil 42 is a metal foil, for example, a copper foil. The negative electrode current collector foil 42 has a rectangular negative electrode current collector part 42a (current collector part) and a negative electrode tab part 42b (tab part) having a shape protruding from one side of the negative electrode current collector part 42a. The area of the negative electrode current collector 42a is larger than the area of the positive electrode current collector 32a described above. The negative electrode current collector 42a has a front negative electrode active material layer 44 (front side active material layer) on the surface 42c (see FIG. 2). The negative electrode current collector 42a has a back-side negative electrode active material layer 46 (back-side active material layer) on the surface of the back side 42d. The negative electrode active material layers 44 and 46 cover, for example, substantially the entire area of the negative electrode current collector 42a. Both negative electrode active material layers 44 and 46 are made of, for example, carbon. As shown in FIG. 5, the negative electrode current collector 42 a and both negative electrode active material layers 44 and 46 constitute a negative electrode base 48.

  The negative electrode tab part 42b does not have the front side negative electrode active material layer 44 and the back side negative electrode active material layer 46, and the negative electrode current collector foil 42 is exposed. The negative electrode tab portions 42b of the negative electrode sheets 40 are overlapped with each other and welded, for example, to one external connection terminal 16 (see FIG. 1). In this specification, the side where the negative electrode tab portion 42b in the negative electrode current collector 42a is provided is referred to as a negative electrode tab forming side 48a (tab forming side). The side facing the negative electrode tab forming side 48a is referred to as a negative electrode tab opposing side 48b. The two sides excluding the negative electrode tab forming side 48a and the negative electrode tab opposing side 48b are referred to as a first negative electrode tab parallel side 48c (tab parallel side) and a second negative electrode tab parallel side 48d (tab parallel side).

  As shown in FIGS. 2, 3, and 5, the front-side negative electrode active material layer 44 has a negative-electrode front-side taper portion 44 a (front-side taper portion). The negative electrode front side taper portion 44a is provided along each of the negative electrode tab opposing side 48b, the first negative electrode tab parallel side 48c, and the second negative electrode tab parallel side 48d. Each negative electrode front side taper portion 44a is inclined from the corresponding side 48b, 48c, 48d to the inner side of the negative electrode current collector portion 42a on the surface 42c of the negative electrode current collector portion 42a, for example, linearly inclined. Yes. The position of each edge portion 44EG (see FIG. 2) of each negative electrode front side taper portion 44a substantially coincides with the position of the edge portion of the negative electrode current collector portion 42a. Each negative electrode front side taper portion 44a has a negative electrode front side inclination angle θ2A (see FIG. 2).

  The back side negative electrode active material layer 46 has a negative electrode back side taper portion 46a (back side taper portion) as shown in FIGS. The negative electrode back side taper portion 46a is provided along each of the negative electrode tab opposing side 48b, the first negative electrode tab parallel side 48c, and the second negative electrode tab parallel side 48d. Each negative electrode back side taper portion 46a is inclined from the corresponding sides 48b, 48c, 48d to the inner side of the negative electrode current collector portion 42a on the surface of the back side 42d of the negative electrode current collector portion 42a, for example, linearly inclined. Yes. The position of each edge portion 46EG (see FIG. 2) of each negative electrode back side taper portion 46a substantially coincides with the position of the edge portion of the negative electrode current collector portion 42a. Each negative electrode back side taper portion 46a has a negative electrode back side inclination angle θ2B (see FIG. 2).

  In general, in the electrode assembly 20, a load is easily applied to the outer edge portions of the positive electrode sheet 30 and the negative electrode sheet 40. Therefore, the positive electrode sheet 30 and the negative electrode sheet 40 may be in contact with each other (internal short circuit) because the separator 28 is broken between the outer edge portions. As shown in FIG. 2, in the electrode assembly 20, a positive electrode front side taper portion 34 a and a positive electrode back side taper portion 36 a are provided on the outer edge portion of the positive electrode sheet 30. Further, a negative electrode front side taper portion 44 a and a negative electrode back side taper portion 46 a are provided on the outer edge portion of the negative electrode sheet 40. Therefore, a gap is formed between the outer edge portions of the positive electrode sheet 30 and the negative electrode sheet 40 by the amount of each of these taper portions 34a, 36a, 44a, 46a, and even if the separator 28 is torn, Short circuit is avoided. For example, as shown in FIG. 22, even when the separator 28 is torn and the outer edge of the negative electrode sheet 40 approaches the positive electrode sheet 30 side, the inner space is increased by the gap S corresponding to the positive electrode front side taper portion 34a. Short circuit is avoided.

  It continues and the manufacturing method of the positive electrode sheet 30 and the negative electrode sheet 40 is demonstrated. The manufacturing method of both the sheets 30 and 40 is the same. Therefore, below, both the sheets 30 and 40 are called the electrode sheet 80, and the manufacturing method of the said electrode sheet 80 is demonstrated. In addition, the material of the metal foil 52 and each active material layer 54 and 56 of the coating sheet 50 mentioned later is changed corresponding to the positive electrode sheet 30 and the negative electrode sheet 40, respectively.

  Each tab portion 82, 82AT, 82BT, 382b, and 482b to be described later corresponds to the positive electrode tab portion 32b and the negative electrode tab portion 42b. Each tab forming side 88a, 388a, 488a described later corresponds to the positive electrode tab forming side 38a and the negative electrode tab forming side 48a. Each tab facing side 88b, 388b, 488b described later corresponds to the positive tab facing side 38b and the negative tab facing side 48b. The first tab parallel sides 88c, 388c, and 488c described later correspond to the first positive electrode tab parallel side 38c and the first negative electrode tab parallel side 48c. Each of the second tab parallel sides 88d, 388d, and 488d described later corresponds to the second positive electrode tab parallel side 38d and the first negative electrode tab parallel side 48d. A later-described front taper portion 54a corresponds to a positive electrode front taper portion 34a and a negative electrode front taper portion 44a. The back side taper portion 56a described later corresponds to the positive electrode back side taper portion 36a and the negative electrode back side taper portion 46a. The base portion 88 corresponds to the positive electrode base portion 38 and the negative electrode base portion 48.

  As shown in FIG. 6, the manufacturing method of the electrode sheet 80 includes a coating sheet preparation step S1 and an electrode sheet cutting step S2. In the coating sheet preparation step S <b> 1, a coating sheet 50 in which active material layers 54 and 56 are formed on both surfaces of a strip-shaped metal foil 52 is prepared. In the electrode sheet cutting step S2, the electrode sheet 80 is cut out from the coating sheet 50 using a laser.

  In the coating sheet preparation step S1, a coating dryer 170 is used as shown in FIG. The coating dryer 170 includes a supply roller 171, a coating machine 172, a dryer 173, a press roller 174, and a winding roller 176. The metal foil 52 is unwound from the supply roller 171 and passes through the coating machine 172, the dryer 173, and the press roller 174 in order. The metal foil 52 is coated with an active material on both surfaces of the metal foil 52 by the coating machine 172. As a result, the front side active material layer 54 is formed on the surface 60 of the metal foil 52, and the back side active material layer 56 is formed on the back side 70. Both active material layers 54 and 56 are dried by a dryer 173 and compressed in the thickness direction by a press roller 174. In this way, the coated sheet 50 in which the active material layers 54 and 56 are formed on both the front and back surfaces of the metal foil 52 is produced. The coating sheet 50 is taken up by the take-up roller 176 while being stretched by the rollers 177.

  The coating sheet 50 will be described in detail. In the following description, the longitudinal direction of the metal foil 52 is referred to as the X direction, and the width direction of the metal foil 52 is referred to as the Y direction. The coating sheet 50 has a front side coating region 62 and a front side non-coating region 64 on the surface of the front side 60 (see FIG. 8). The front side coating region 62 is a region where the front side active material layer 54 is continuously formed in the X direction. The width | variety of the front side coating area | region 62 is corresponded in the length of the double of the 1st tab parallel side 388c in 1st virtual outline R1 mentioned later. The front side non-coating region 64 is provided adjacent to the front side coating region 62 in the Y direction, and is continuous in the X direction with the metal foil 52 exposed without forming the front side active material layer 54. It is an area to do.

  The front side non-coating region 64 has a first front side non-coating region 66 and a second front side non-coating region 68 on both sides of the front side coating region 62 in the Y direction. The first front side non-coating region 66 has an inner first front side non-coating region 66a and an outer first front side non-coating region 66b. The inner first front-side non-coating region 66a is a region adjacent to the front-side coating region 62 in the Y direction and continuous in the X direction. The width of the inner first front-side non-coating region 66a substantially coincides with the length in the protruding direction of the tab portion 382b in the first virtual contour R1 described later. The outer first front-side non-coating region 66b is a region that is located on the opposite side of the inner first front-side non-coating region 66a in the Y direction from the front-side coating region 62 and that is continuous in the X direction.

  The second front side non-coating region 68 has an inner second front side non-coating region 68a and an outer second front side non-coating region 68b. The inner second front side non-coating region 68a is a region adjacent to the front side coating region 62 in the Y direction and continuous in the X direction. The width of the inner second front-side non-coating region 68a is substantially equal to the length in the protruding direction of the tab portion 482b in the second virtual contour R2 described later. The outer second front-side non-coating region 68b is a region located on the opposite side of the front-side coating region 62 with respect to the inner second front-side non-coating region 68a in the Y direction and continuous in the X direction.

  The coating sheet 50 has the back side coating area | region 72 and the back side non-coating area | region 74 in the surface of the back side 70 (refer FIG. 9). The back side coating region 72 is a region facing the front side coating region 62 (see FIG. 8) across the metal foil 52, and is a region where the back side active material layer 56 (see FIG. 9) is formed. The back side non-coating region 74 is a region facing the front side non-coating region 64 (see FIG. 8) across the metal foil 52, and the metal foil is formed without forming the back side active material layer 56 (see FIG. 9). An area 52 is exposed.

  As shown in FIG. 9, the back side non-coating region 74 has a first back side non-coating region 76 and a second back side non-coating region 78 on both sides of the back side coating region 72 in the Y direction. The first back side non-coating region 76 has an inner first back side non-coating region 76a and an outer first back side non-coating region 76b. The inner first back side non-coating region 76a is a region facing the inner first front side non-coating region 66a with the metal foil 52 interposed therebetween. The outer first back side non-coating region 76b is a region facing the outer first front side non-coating region 66b with the metal foil 52 interposed therebetween.

  The second back side non-coating region 78 has an inner second back side non-coating region 78a and an outer second back side non-coating region 78b. The inner second back side non-coating region 78a is a region facing the inner second front side non-coating region 68a with the metal foil 52 interposed therebetween. The outer second back side non-coating region 78b is a region facing the outer second front side non-coating region 68b with the metal foil 52 interposed therebetween.

  In addition, electrode sheet cutting-out process S2 mentioned later is implemented as what prescribe | regulated the virtual outline R shown to FIG. The virtual contour R is obtained by virtually setting the contour of the electrode sheet 80 on the coating sheet 50. 8 and 9, the first virtual contour R1 is indicated by a one-dot chain line, and the second virtual contour R2 is indicated by a two-dot difference line. Both virtual contours R1 and R2 have the same shape. The first virtual contour R1 is set on the first front side non-coating region 66 side from the center in the Y direction on the coating sheet 50. The second virtual contour R2 is set on the side of the second front side non-coating region 68 from the center in the Y direction on the coating sheet 50. A plurality of both virtual contours R1, R2 are set continuously in the X direction.

  As shown in FIG. 8, the first virtual contour R1 has its tab facing side 388b and both tab parallel sides 388c and 388d set on the front side coating region 62, and the tab forming side 388a and the tab portion 382b are inside. It is set on the first front side non-coating area 66a. Note that a part of each of the tab parallel sides 388c and 388d protrudes toward the inner first non-coating region 66a. The first tab parallel side 388c and the second tab parallel side 388d of the first virtual contour R1 adjacent in the X direction coincide with each other.

  In the second virtual contour R2, the tab facing side 488b and the tab parallel sides 488c and 488d are set on the front side coating region 62, and the tab forming side 488a and the tab portion 482b are inside the second front side non-coating region. 68a is set. The tab parallel sides 488c and 488d partially protrude from the inner second non-coating region 68a. The first tab parallel side 488c and the second tab parallel side 488d of the second virtual contour R2 adjacent in the X direction coincide with each other. The tab facing sides 388b and 488b of both virtual contours R1 and R2 coincide with each other. Note that the positions of both virtual contours R1 and R2 face each other on the front side 60 (see FIG. 8) and the back side 70 (see FIG. 9) of the coating sheet 50.

  The electrode sheet cutting-out step S2 is performed after the coating sheet preparing step S1, as shown in FIG. The electrode sheet cutting step S2 includes a coating region cutting step T1, a non-coating region cutting step T2, and a recovery step T3. The coating region cutting step T1 includes a front side coating region cutting step T1a and a back side coating region cutting step T1b.

  In the electrode sheet cutting step S2, an electrode sheet manufacturing apparatus 280 shown in FIGS. 10 and 11 is used. The electrode sheet manufacturing apparatus 280 is an apparatus that cuts out the electrode sheet 80 from the coating sheet 50 while transporting the coating sheet 50 in the transport direction M along the X direction at the transport height HT. The coating sheet 50 is unwound from the supply roller 81. The electrode sheet manufacturing apparatus 280 includes a transport device 282, a laser device 284, a collection device 286, and a controller 288. All operations of the electrode sheet manufacturing apparatus 280 are controlled by the controller 288. In FIG. 11, the collection device 286 (see FIG. 10) is omitted. 8 to 17 and 19 to 21, the direction indicated by the X axis coincides with the transport direction M.

  As shown in FIGS. 13 and 14, the transport device 282 includes an upstream transport device 90, a downstream transport device 92, an auxiliary downstream transport device 94, a guide member 96, an upstream suction device 98, a downstream suction device 100, and an auxiliary device. And a downstream suction device 102.

  As shown in FIGS. 13 and 14, the upstream-side transport device 90 includes a first upstream-side transport device 90 a and a second upstream-side transport device 90 b. Both upstream side conveyance devices 90a and 90b are configured such that a belt BT is stretched between two rollers RL1 and RL2. The first upstream transport device 90a includes a first upstream suction device 98a in the inner peripheral area of the belt BT. The second upstream suction device 98b has a second upstream suction device 98b in the inner peripheral area of the belt BT. As shown in FIG. 15, the belt BT has a plurality of holes BH. Each hole BH is circular and penetrates the belt BT in the thickness direction.

  As shown in FIG. 12, the first upstream conveyance device 90a has a width equal to or smaller than the width of the inner first back side non-coating region 76a of the coating sheet 50, and is opposed to the inner first back side non-coating region 76a. And it arrange | positions so that the inner 1st back side non-coating area | region 76a may be contact | connected. The first upstream transport device 90a is configured such that the inner first back side non-coating region 76a is sucked to the upper surface of the first upstream transport device 90a by the suction force of the first upstream suction device 98a. The non-coating region 76a is transported in the transport direction M. In FIG. 12, the laser device 284 and the recovery device 286 shown in FIG. 10 are omitted.

  As shown in FIG. 12, the second upstream-side transport device 90b has a width equal to or smaller than the width of the inner second back-side non-coating region 78a, is opposed to the inner second back-side non-coating region 78a, and It arrange | positions so that the 2nd back side non-coating area | region 78a may be contact | connected. Further, the second upstream transfer device 90b is arranged in parallel with the first upstream transfer device 90a. The second upstream transport device 90b is configured such that the inner second back side non-coating region 78a is sucked to the upper surface of the second upstream transport device 90b by the suction force of the second upstream suction device 98b. The non-coating region 78a is transported in the transport direction M. An upstream laser space 104 is formed between the first upstream transfer device 90a and the second upstream transfer device 90b.

  As shown in FIG. 13, the downstream-side transport device 92 has a configuration in which a belt BT is stretched between two rollers RL1 and RL2. The downstream transport device 92 includes a downstream suction device 100 in the inner peripheral region of the belt BT. As shown in FIG. 15, the belt BT has a plurality of holes BH. Each hole BH is circular and penetrates the belt BT in the thickness direction.

  As shown in FIG. 12, the downstream side conveyance device 92 has a width equal to or smaller than the width of the back side coating region 72 of the coating sheet 50. The downstream transfer device 92 is disposed on the downstream side in the transfer direction M with respect to the upstream transfer device 90. The coated sheet conveying unit 92 a that is the upstream portion of the downstream conveying device 92 is disposed so as to face the back side coating region 72 and to be in contact with the back side coating region 72. The electrode sheet transport unit 92b, which is the middle stream portion and the downstream portion of the downstream transport device 92, is disposed so as to face the back surface of the cut electrode sheet 80 and to be in contact with the back surface. The coating sheet conveyance unit 92a conveys the back side coating region 72 in a state where the back side coating region 72 of the coating sheet 50 is sucked to the upper surface of the coating sheet conveyance unit 92a by the suction force of the downstream suction device 100. Transport in direction M. The electrode sheet transport unit 92b transports the electrode sheet 80 in the transport direction M in a state where the back surface of the electrode sheet 80 is sucked to the upper surface of the electrode sheet transport unit 92b by the suction force of the downstream suction device 100. The downstream side laser space 106 is formed on both sides in the Y direction with respect to the coated sheet conveying unit 92a.

  As shown in FIGS. 13 and 14, the auxiliary downstream transport device 94 includes a first auxiliary downstream transport device 94 a and a second auxiliary downstream transport device 94 b. Both auxiliary downstream-side transport devices 94a and 94b have a configuration in which a belt BT is stretched between two rollers RL1 and RL2. The first auxiliary downstream transport device 94a includes a first auxiliary downstream suction device 102a in the inner peripheral area of the belt BT. The second auxiliary downstream transport device 94b has a second auxiliary downstream suction device 102b in the inner peripheral area of the belt BT. As shown in FIG. 15, the belt BT has a plurality of holes BH. Each hole BH is circular and penetrates the belt BT in the thickness direction.

  As shown in FIG. 12, the first auxiliary downstream transport device 94a has a width equal to or less than the width of the outer first back side non-coating region 76b of the coating sheet 50, and the outer first back side non-coating region 76b. It arrange | positions so that it may oppose and may contact | connect the outer 1st back side non-coating area | region 76b. Further, the first auxiliary downstream side transport device 94 a is arranged in parallel with the coated sheet transport portion 92 a of the downstream side transport device 92. The first auxiliary downstream transport device 94a is in a state where the outer first back side non-coating region 76b is sucked to the upper surface of the first auxiliary downstream transport device 94a by the suction force of the first auxiliary downstream suction device 102a. The first back side non-coating region 76b is transported in the transport direction M.

  As shown in FIG. 12, the second auxiliary downstream transport device 94b has a width equal to or smaller than the width of the outer second back side non-coating region 78b, is opposed to the outer second back side non-coating region 78b, and It arrange | positions so that the outer 2nd back side non-coating area | region 78b may be contact | connected. Further, the second auxiliary downstream side conveyance device 94 b is arranged in parallel with the coated sheet conveyance unit 92 a of the downstream side conveyance device 92. The second auxiliary downstream transport device 94b is in the state where the outer second back side non-coating region 78b is sucked to the upper surface of the second auxiliary downstream transport device 94b by the suction force of the second auxiliary downstream suction device 102b. The 2nd back side non-coating area | region 78b is conveyed in the conveyance direction M. FIG.

  As shown in FIGS. 13 and 14, the upstream laser space 104 is a space that is adjacent to the upstream transport device 90 in the Y direction and that is in series with the downstream transport device 92 in the transport direction M. is there. The upstream laser space 104 is a space sandwiched between the first upstream transfer device 90a and the second upstream transfer device 90b. The upstream laser space 104 is composed of a first upstream laser space 104a and a second upstream laser space 104b. The first upstream laser space 104a is a space close to the first upstream transfer device 90a. The second upstream laser space 104b is a space close to the second upstream conveyance device 90b. As shown in FIG. 12, the front side coating region 62 and the back side coating region 72 of the coating sheet 50 pass through the upstream laser space 104.

  As shown in FIGS. 13 and 14, the downstream laser space 106 is a space adjacent to the downstream transport device 92 in the Y direction, and in the transport direction M with respect to each of the upstream transport devices 90 a and 90 b. It is a space that is in series. The downstream laser space 106 includes a first downstream laser space 106a and a second downstream laser space 106b. The first downstream laser space 106a is a space sandwiched between the downstream transport device 92 and the first auxiliary downstream transport device 94a. The second downstream laser space 106b is a space sandwiched between the downstream transport device 92 and the second auxiliary downstream transport device 94b. As shown in FIG. 12, an inner first front side non-coating region 66a and an inner first back side non-coating region 76a of the coating sheet 50 pass through the first downstream laser space 106a. The inner second front side non-coating region 68a and the inner second back side non-coating region 78a pass through the second downstream laser space 106b.

  As shown in FIGS. 12, 13, and 14, the guide member 96 includes a first guide member 96a and a second guide member 96b. The first guide member 96a is a position adjacent to the electrode sheet conveyance portion 92b of the downstream side conveyance device 92 in the Y direction, and extends the first back side non-coating region 76a of the coating sheet 50 in the conveyance direction M. It is arranged at the position. The first guide member 96a extends linearly along the transport direction M. The first guide member 96 a has an inclined surface 95 and a tab holding surface 97. As shown in FIG. 10, the inclined surface 95 is inclined along the transport direction M from a position lower than the transport height HT to a position close to the transport height HT. The tab holding surface 97 extends in the transport direction M at a position substantially coincident with the transport height HT. As shown in FIG. 11, the inclined surface 95 scoops up the tab portion 82AT of the first electrode sheet 80A cut out from the coating sheet 50 to bring it close to the transport height HT. The tab holding surface 97 guides the tab portion 82AT at the conveyance height HT.

  As shown in FIG. 12, the second guide member 96 b is a position adjacent to the electrode sheet conveyance unit 92 b of the downstream conveyance device 92 in the Y direction, and the second back side non-coating region 78 a of the coating sheet 50. Is extended in the transport direction M. The second guide member 96b extends linearly along the transport direction M. The second guide member 96 b has an inclined surface 95 and a tab holding surface 97. Since the structures and functions of the inclined surface 95 and the tab holding surface 97 are the same as those of the first guide member 96a, a duplicate description is omitted.

  As shown in FIG. 11, the laser device 284 includes a front upstream laser device 180, a back upstream laser device 190, a first downstream laser device 210, and a second downstream laser device 220. The front upstream laser device 180 and the back upstream laser device 190 constitute an upstream laser device. The first downstream laser device 210 and the second downstream laser device 220 constitute a downstream laser device.

  As shown in FIG. 10, the front upstream laser device 180 is disposed above the coating sheet 50 (the front side 60 of the coating sheet 50). The back upstream laser device 190 is disposed below the coating sheet 50 (the back side 70 of the coating sheet 50). As shown in FIG. 11, the front upstream laser device 180 irradiates the front upstream laser 180 </ b> L (front laser) toward the first virtual contour R <b> 1 and the second virtual contour R <b> 2 in the upstream laser space 104. The back upstream laser device 190 irradiates the back upstream laser 190L (back laser) toward the first virtual contour R1 and the second virtual contour R2 in the upstream laser space 104. In FIG. 11, the first virtual contour R1 is indicated by a one-dot chain line, and the second virtual contour R2 is indicated by a two-dot chain line.

  As shown in FIG. 16, the front upstream laser device 180 has a laser head 182 and an XY axis robot 184. The laser head 182 is supplied with a laser beam from a laser oscillator (not shown). Then, the laser head 182 irradiates the front upstream laser 180L toward the first virtual contour R1 and the second virtual contour R2 in the front side coating region 62. In FIG. 16, the first virtual contour R1 is indicated by a one-dot chain line, and the second virtual contour R2 is indicated by a two-dot chain line. The laser head 182 is attached to an XY axis robot 184. The XY axis robot 184 moves the laser head 182 in the X direction and the Y direction. The XY axis robot 184 includes, for example, a Y axis member 184a that supports the laser head 182 to be movable in the Y direction, and an X axis member 184b that supports the Y axis member 184a to be movable in the X direction. The XY axis robot 184 moves the laser head 182 in accordance with a program stored in the controller 288. In FIG. 11, the XY axis robot 184 (see FIG. 16) is omitted.

  As shown in FIG. 17, the back upstream laser device 190 includes a laser head 192 and an XY axis robot 194. The XY axis robot 194 includes a Y axis member 194a and an X axis member 194b. The laser head 192 and the XY axis robot 194 function in the same manner as the devices 182 and 184 of the front upstream laser device 180, and thus a duplicate description is omitted. The laser head 192 irradiates the back upstream laser 190L toward the first virtual contour R and the second virtual contour R2 of the back side coating region 72. In FIG. 17, the first virtual contour R1 is indicated by a one-dot chain line, and the second virtual contour R2 is indicated by a two-dot chain line. In FIG. 11, the XY axis robot 194 (see FIG. 17) is omitted.

  Both laser heads 182 and 192 have lenses 182a and 192a as shown in FIG. By these lenses 182a and 192a, the upstream lasers 180L and 190L are condensed toward the focal points P1 and P2 set at predetermined positions on the coating sheet 50, respectively. Each focal point P <b> 1, P <b> 2 is located near the thickness center of the metal foil 52, for example, within the thickness of the metal foil 52. Alternatively, the focal points P <b> 1 and P <b> 2 are located in the front side active material layer 54 in the vicinity of the metal foil 52 or in the back side active material layer 56 in the vicinity of the metal foil 52. The focal points P1 and P2 may be set at the same position or may be set at different positions.

  The front upstream laser 180L has an output intensity capable of cutting at least the front active material layer 54 in the thickness direction. The back upstream laser 190L has an output intensity capable of cutting at least the back side active material layer 56 in the thickness direction. At least one of the upstream lasers 180L and 190L has an output intensity capable of cutting the metal foil 52 in addition to the front side active material layer 54 or the back side active material layer 56. That is, the front upstream laser 180L has an output intensity capable of cutting the front active material layer 54 and the metal foil 52 in the thickness direction, and the back upstream laser 190L can output only the back active material layer 56. It may have strength. Further, the front upstream laser 180L has an output intensity capable of cutting only the front side active material layer 54, and the back upstream laser 190L can output the back side active material layer 56 and the metal foil 52 in the thickness direction. It may have strength. Further, the front upstream laser 180L has an output intensity capable of cutting the front active material layer 54 and the metal foil 52 in the thickness direction, and the back upstream laser 190L provides the back active material layer 56 and the metal foil 52. You may have the output intensity | strength which can be cut | disconnected over the thickness direction. For example, the front upstream laser 180L has an output intensity capable of cutting the front active material layer 54 and a part in the thickness direction of the metal foil 52, and the back upstream laser 190L is connected to the remaining part of the metal foil 52 and the back active You may have the output intensity | strength which can cut | disconnect the material layer 56. FIG. As described above, the upstream lasers 180L and 190L have an output intensity capable of cutting the front-side active material layer 54, the metal foil 52, and the back-side active material layer 56 by combining the two lasers 180L and 190L.

  The output intensity of both upstream lasers 180L and 190L will be described in further detail. The output intensity of the front upstream laser 180L is set to an intensity capable of cutting from the surface of the front active material layer 54 to a predetermined front laser arrival position. The front side laser reaching position is set to a predetermined position within a range from the surface of the front side 52 a of the metal foil 52 to the inside of the back side active material layer 56. The output intensity of the back upstream side laser 190L is set to an intensity capable of cutting from the surface of the back side active material layer 56 to a predetermined back side laser arrival position. This back side laser reaching position is set to a predetermined position within a range from the surface of the back side 52 b of the metal foil 52 to the inside of the front side active material layer 54.

  As described above, the output intensity of each of the upstream lasers 180L and 190L is weaker than the intensity of cutting both the active material layers 54 and 56 and the metal foil 52 together. Therefore, the amounts of both the active material layers 54 and 56 that are melted by the thermal effects of the upstream lasers 180L and 190L are reduced. As a result, in the electrode sheet 80 after being cut out, the capacity reduction of the active material can be suppressed. In addition, when both the upstream lasers 180L and 190L are irradiated onto the coating sheet 50, the scattering of foreign matters accompanying the melting of the active material layers 54 and 56 is suppressed.

  As shown in FIG. 18, the two upstream lasers 180 </ b> L and 190 </ b> L are irradiated so that the optical axes J <b> 1 and J <b> 2 are perpendicular to the coating sheet 50. Accordingly, the two upstream lasers 180L and 190L are different from the case where each of the lasers 180L and 190L is irradiated obliquely with respect to the coating sheet 50, and the shortest linear distance through which each of them passes through the coating sheet 50 in the thickness direction is the shortest. Become. Therefore, the output intensity of each of the upstream lasers 180L and 190L can be set weak. As a result, it is possible to reduce the amount of melting of the active material layers 54 and 56 due to the thermal effects of the two upstream lasers 180L and 190L, and to suppress a decrease in the capacity of the active material in the electrode sheet 80 after being cut out. When the laser beams 180L and 190L are applied to the coating sheet 50, the scattering of foreign matters accompanying the melting of the active material layers 54 and 56 is suppressed. The optical axis J1 is a straight line passing through the center of the lens 182a and the focal point P1. Similarly, the optical axis J2 is a straight line passing through the center of the lens 192a and the focal point P2.

  As shown in FIG. 18, when the front-side upstream laser 180L cuts the front-side active material layer 54, the front-side tapered portions 54a are formed on both sides of the laser 180L. When the back-side active material layer 56 is cut, the back-upstream laser 190L forms back-side tapered portions 56a on both sides of the laser 190L.

  Both upstream lasers 180L and 190L are continuous wave lasers. The wavelengths of both upstream lasers 180L and 190L are preferably set within a range of 300 to 1100 nm. The spot diameters of both upstream lasers 180L and 190L are preferably set within a range of 10 to 100 μm. It is preferable that the cutting speed of the coating sheet 50 by both the upstream lasers 180L and 190L is set within a range of 1 to 3 m / s. The output intensity of both upstream lasers 180L and 190L is preferably set within a range of 0.005 to 1.0 kW.

  As shown in FIG. 11, both downstream laser devices 210 and 220 are disposed above the coating sheet 50 (the front side 60 of the coating sheet 50). The first downstream laser device 210 irradiates the first downstream laser 210L (metal foil laser) toward the first virtual contour R1 in the first downstream laser space 106a. The second downstream laser device 220 irradiates the second downstream laser 220L (metal foil laser) toward the second virtual contour R2 in the second downstream laser space 106b.

  As shown in FIG. 16, the first downstream laser device 210 includes a laser head 212 and an XY axis robot 214. The XY axis robot 214 includes a Y axis member 214a and an X axis member 214b. The second downstream laser device 220 includes a laser head 222 and an XY axis robot 224. The XY axis robot 224 includes a Y axis member 224a and an X axis member 224b. Both the laser heads 212 and 222 and the two XY axis robots 214 and 224 function in the same manner as the devices 182 and 184 of the front upstream laser device 180, respectively. The laser head 212 irradiates the first downstream laser 210L toward the first virtual contour R1 in the inner first front side non-coating region 66a. The laser head 222 irradiates the second downstream laser 220L toward the second virtual contour R2 in the inner second front side non-coating region 68a. In FIG. 11, both XY axis robots 214 and 224 (see FIG. 16) are omitted.

  Both the laser heads 212 and 222 have lenses (not shown) as in the laser head 182. Both downstream lasers 210 </ b> L and 220 </ b> L are condensed toward the respective focal points set at predetermined positions of the coating sheet 50 by the lens. The focal points of the downstream lasers 210 </ b> L and 220 </ b> L are located near the thickness center of the metal foil 52, for example, within the thickness of the metal foil 52. The two downstream lasers 210 </ b> L and 220 </ b> L are irradiated so that their optical axes are perpendicular to the coating sheet 50, for example. As already described, the optical axis is a straight line passing through the center and the focal point of the lens.

  Both downstream lasers 210L and 220L are pulse wave lasers. The wavelengths of the two downstream lasers 210L and 220L are preferably set within a range of 500 to 1100 nm. The spot diameters of both downstream lasers 210L and 220L are preferably set within a range of 25 to 100 μm. It is preferable that the cutting speed of the coating sheet 50 by both downstream side lasers 210L and 220L is set within a range of 1 to 3 m / s. The output intensities of the downstream lasers 210L and 220L are each preferably set within a range of 10 to 100W. The output intensity of both downstream lasers 210L and 220L is set to an intensity at which the metal foil 52 can be cut. The pulse widths of both downstream lasers 210L and 220L are preferably set to be smaller than 20 ps (picoseconds). The repetition frequencies of both downstream lasers 210L and 220L are preferably set in the range of 0.1 to 1 MHz.

  In the electrode sheet manufacturing apparatus 280 described above, the electrode sheet cutting step S2 is performed. As shown in FIG. 6, the electrode sheet cutting step S2 includes a coating region cutting step T1, a non-coating region cutting step T2, and a recovery step T3. The non-coating region cutting step T2 is performed after the coating region cutting step T1. The collection step T3 is performed after the non-coating region cutting step T2. As already described, the electrode sheet cutting step S <b> 2 is performed on the assumption that the virtual contour R of the electrode sheet 80 is defined on the coating sheet 50.

  In the coating area cutting step T1, as shown in FIG. 11, both upstream lasers 180L and 190L are applied to the front side coating area 62 and the back side coating area 72 of the coating sheet 50 being conveyed in the conveyance direction M. Irradiation is performed to cut out portions of the first virtual contour R1 and the second virtual contour R2 on both coating regions 62 and 72. The coating sheet 50 has an inner first back side non-coating region 76a and an inner second back side non-coating region 78a supported by the first upstream conveying device 90a and the second upstream conveying device 90b, respectively. In the conveying direction M.

  The coating region cutting step T1 includes a front side coating region cutting step T1a and a back side coating region cutting step T1b (see FIG. 6). In the front side coating region cutting step T1a, the front upstream laser 180L is irradiated from the front side 60 of the coating sheet 50 as shown in FIGS. The front upstream laser 180L has a portion of the first virtual contour R1 on the front side coating region 62 that passes through the first upstream laser space 104a and a front side coating region that passes through the second upstream laser space 104b. The light is irradiated along the second virtual contour R <b> 2 on 62. That is, the front upstream laser 180L is irradiated along both the first tab parallel sides 388c and 488c and the tab opposing sides 388b and 488b. The front upstream laser 180L is continuously irradiated to the first tab parallel sides 388c and 488c. As already described, the first tab parallel side 388c is also the second tab parallel side 388d. Similarly, the second tab parallel side 488c is also the second tab parallel side 488d.

  In the back side coating region cutting step T <b> 1 b, the back upstream laser 190 </ b> L is irradiated from the back side 70 of the coating sheet 50 as shown in FIGS. The back upstream laser 190L includes a portion of the first virtual contour R1 on the back side coating region 72 passing through the first upstream laser space 104a and a back side coating region passing through the second upstream laser space 104b. 72 is irradiated along the location of the second virtual contour R <b> 2 on 72. Similarly to the case of the front upstream laser 180L, the back upstream laser 190L is irradiated along both the first tab parallel sides 388c and 488c and the tab opposing sides 388b and 488b. The back upstream laser 190L is continuously irradiated to both first tab parallel sides 388c and 488c.

  The front side coating region cutting step T1a and the back side coating region cutting step T1b are performed simultaneously. Both upstream lasers 180L and 190L are simultaneously irradiated to the positions of both virtual contours R1 and R2. As a result, at the irradiation positions of the two upstream lasers 180L and 190L, the mutual heat compensation of the two upstream lasers 180L and 190L can occur. Therefore, both the upstream lasers 180L and 190L can cut both the active material layers 54 and 56 and the metal foil 52 of the coating sheet 50 even if these output intensities are set to be weak. Therefore, both upstream lasers 180L and 190L are reduced in the amount of melting of both active material layers 54 and 56 due to their thermal effects, and as a result, capacity reduction of the active material is suppressed in the cut electrode sheet 80. At the same time, when the two upstream lasers 180L and 190L are irradiated onto the coating sheet 50, the scattering of foreign matters accompanying the melting of the active material layers 54 and 56 is suppressed.

  By performing the front side coating region cutting step T1a and the back side coating region cutting step T1b, both first tab parallel sides 388c, 488c, both second tab parallel sides 388d, 488d, and both tab opposing sides 388b, 488b Is cut out. Thereafter, the coating sheet 50 reaches the downstream side conveyance device 92 without being drooped downward, and is conveyed in the conveyance direction M by the downstream side conveyance device 92. In addition, in each tab parallel side 388c, 388d, 488c, 488d, the part which protrudes from the front side coating area | region 62 and the back side coating area | region 72 is cut out by the non-coating area | region cutting process T2 demonstrated after this.

  In the non-coating region cutting step T2, as shown in FIG. 11, the first downstream laser 210L and the second downstream laser 220L are irradiated to the coating sheet 50 conveyed in the conveying direction M, and both The uncut portions in the virtual contours R1 and R2 are cut. The first downstream laser 210L cuts an uncut portion of the first virtual contour R1. The second downstream laser 220L cuts an uncut portion of the second virtual contour R2. The first downstream-side laser 210L includes a back-side coating region 72 and an outer first back-side non-coating region formed by the coating sheet conveyance unit 92a (see FIG. 13) of the downstream-side conveyance device 92 and the first auxiliary downstream-side conveyance device 94a. 76b is irradiated toward the coating sheet 50 supported respectively. The second downstream laser 220L is a coating sheet in which the back side coating region 72 and the outer second back side non-coating region 78b are supported by the coating sheet transport unit 92a and the second auxiliary downstream transport device 94b, respectively. 50 is irradiated.

  The first downstream laser 210L is irradiated from the front side 60 of the coating sheet 50 as shown in FIGS. The first downstream laser 210L is irradiated along the portion of the first virtual contour R1 on the first front-side uncoated region 66a that passes through the first downstream laser space 106a. That is, the first downstream laser 210L includes the tab forming side 388a, the tab portion 382b, and a part of the first tab parallel side 388c (second tab parallel side 388d) of the first virtual contour R1 (first tab parallel side 388c). In the first front side non-coating region 66a. As a result, the sides 388a, 388b, 388c, 388d and the tab portion 382b of the first virtual contour R1 are all cut out to produce the first electrode sheet 80A. In addition, the part which did not become the 1st electrode sheet 80A in the 1st front side non-coating area | region 66 (1st back side non-coating area | region 76) is cut | disconnected from the said electrode sheet 80A.

  The second downstream laser 220L is irradiated from the front side 60 of the coating sheet 50 as shown in FIGS. The second downstream laser 220L is irradiated along the second virtual contour R2 on the second front-side non-coating region 68a that passes through the second downstream laser space 106b. In other words, the second downstream laser 220L includes the tab forming side 488a, the tab portion 482b, and a part of the first tab parallel side 488c (second tab parallel side 488d) (first tab parallel side 488c) of the second virtual contour R2. The projection is irradiated toward the second front side non-coating area 68a. As a result, the sides 488a, 488b, 488c, 488d and the tab portion 482b of the second virtual contour R2 are all cut out to produce the second electrode sheet 80B. In addition, the part which did not become the 2nd electrode sheet 80B in the 2nd front side non-coating area | region 68 (2nd back side non-coating area | region 78) is cut | disconnected from the said electrode sheet 80B.

  After the non-coating region cutting step T2, a collecting step T3 is performed. The first electrode sheet 80A and the second electrode sheet 80B are transported in the transport direction M through the electrode sheet transport unit 92b of the downstream transport device 92. As shown in FIG. 11, the tab portion 82AT of the first electrode sheet 80A is scooped up by the inclined surface 95 of the first guide member 96a. Thereafter, the tab portion 82AT is guided by the inclined surface 95 to a position close to the conveyance height HT shown in FIG. Similarly, the tab portion 82BT of the second electrode sheet 80B is scooped up by the inclined surface 95 of the second guide member 96b, and then conveyed on the tab holding surface 97. Thus, the tab portions 82AT and 82BT are scooped up by the inclined surfaces 95 of the guide members 96a and 96b, thereby preventing the tab portions 82AT and 82BT from hanging down. Therefore, it is possible to prevent the two tab portions 82AT and 82BT from being broken from the respective electrode sheets 80A and 80B due to a burden applied to both the tab portions 82AT and 82BT.

  Both electrode sheets 80A and 80B are collected by the collection device 286 when they reach the downstream portion of the downstream side conveyance device 92. As shown in FIG. 10, the collection device 286 includes, for example, a suction hand 286a and a collection box 286b. The suction hand 286a sucks the second electrode sheet 80B and moves it to the collection box 286b. The suction hand 286a releases the suction of the second electrode sheet 80B above the collection box 286b, and collects the second electrode sheet 80B in the collection box 286b. The collection device 286 similarly collects the first electrode sheet 80A in the collection box 286b. In addition, you may provide two collection | recovery apparatuses 286 corresponding to each of both electrode sheet 80A, 80B. Further, both electrode sheets 80A and 80B may be dropped directly from the downstream end of the downstream side conveyance device 92 and collected in the collection box 286b without using the suction hand 286a. The above is the manufacturing method of the electrode sheet in this embodiment.

  In the above-described configuration, the upstream laser space 104 serving as a passing space for the front side coating region 62 and the back side coating region 72 of the coating sheet 50 is provided at a position adjacent to the upstream side conveyance device 90 in the Y direction. (See FIG. 11). Further, the front side non-coating region of the coating sheet 50 at a position that is in series downstream of the upstream conveying device 90 in the conveying direction M and that is adjacent to the downstream conveying device 92 in the Y direction. 64 and a downstream laser space 106 serving as a passage space for the back side non-coating region 74 is provided. Therefore, first, in the upstream laser space 104, the front side coating region 62 and the back side coating region 72 are irradiated with the upstream lasers 180L and 190L, and the tab facing sides 388b and 488b and the tab parallel sides 388c, 388d, 488c, Cut out 488d, and then irradiate the front side non-coated region 64 and the back side non-coated region 74 with the downstream lasers 210L, 220L in the downstream laser space 106 to cut out the tab portions 382b, 482b and tab forming sides 388a, 488a. Thus, in the coating sheet 50 in which the front-side coating region 62 and the back-side coating region 72 are continuously formed in the longitudinal direction, the coating sheet 50 is continuously formed without stopping the conveyance of the coating sheet 50. The electrode sheet 80 can be cut out from.

  In the above-described configuration, when both the upstream lasers 180L and 190L are irradiated toward the first virtual contour R1 and the second virtual contour R2 of the upstream laser space 104, the coating sheet 50 is transported to the first upstream side. Both sides are supported by the device 90a and the second upstream side transfer device 90b. In addition, when the first downstream laser 210L is irradiated toward the first virtual contour R1 of the first downstream laser space 106a, the coating sheet 50 includes the downstream conveying device 92 and the first auxiliary downstream conveying device 94a. And both sides are supported. In addition, when the second downstream laser 220L is irradiated toward the second virtual contour R2 of the second downstream laser space 106b, the coating sheet 50 includes the downstream conveying device 92 and the second auxiliary downstream conveying device 94b. And both sides are supported. Therefore, the coating sheet 50 is irradiated with the lasers 180L, 190L, 210L, and 220L in a stable position. As a result, each of the lasers 180L, 190L, 210L, and 220L is suppressed from being irradiated to positions that are out of the first virtual contour R1 and the second virtual contour R2.

  In the above-described configuration, individual laser devices are provided corresponding to the upstream laser space 104 that cuts the metal foil 52 and the active material layers 54 and 56 and the downstream laser space 106 that cuts only the metal foil 52. Is provided. Therefore, the type of laser (for example, continuous wave or pulse wave) and output intensity can be individually set in correspondence with the respective laser spaces 104 and 106.

  In the above-described configuration, the front side active material layer 54 and the back side active material layer 56 are individually cut using the front upstream laser 180L and the back upstream laser 190L. From this, the output intensity of both the upstream lasers 180L and 190L is higher than that of the case where both the active material layers 54 and 56 are cut together by either one of these two upstream lasers 180L and 190L, respectively. Can be set to be weak, and both active material layers 54 and 56 can be cut quickly. Therefore, it is possible to reduce the amount of melting of both active material layers 54 and 56 due to the thermal influence of both upstream lasers 180L and 190L. As a result, the capacity reduction of the active material is suppressed in the electrode sheet 80 after cutting. In addition, when both the upstream lasers 180L and 190L are irradiated onto the coating sheet 50, the scattering of foreign matters accompanying the melting of the active material layers 54 and 56 is suppressed.

  Although one embodiment for carrying out the present invention has been described above with reference to the drawings, the present invention can be implemented in other embodiments. The tab forming sides 388a and 488a of both virtual contours R1 and R2 may be set on the front side coating region 62 and the back side coating region 72. In this case, both tab forming sides 388 a and 488 a are cut out in the upstream laser space 104.

  Only one virtual contour R may be set in the Y direction on the coating sheet 50 by eliminating one of the virtual contours R1 and R2. FIG. 19 shows an example of the coating sheet 50a when the virtual contour R is only the first virtual contour R1. When this coating sheet 50a is employed, for example, the electrode sheet 80A is cut out from the coating sheet 50a by the electrode sheet manufacturing apparatus 280a shown in FIG. In the electrode sheet manufacturing apparatus 280a, the second downstream laser apparatus 220 shown in FIG. 11 is eliminated. Further, in the transport device 282a, the second auxiliary downstream transport device 94b, the second auxiliary downstream suction device 102b, and the second guide member 96b shown in FIG. 11 are eliminated. The width of the downstream transport device 92 is set to a width obtained by combining the width of the front side coating region 62 and the width of the second front side non-coating region 68. In addition, the width | variety of the 2nd front side non-coating area | region 68 shown in FIG. 20 is substantially corresponded to the width | variety of the 2nd front side coating area | region 68a shown in FIG. The first upstream transfer device 90a and the first auxiliary downstream transfer device 94a have a first upstream suction device 98a (see FIG. 13) and a first auxiliary downstream suction device 102a (see FIG. 13), respectively, not shown. 19 and 20, parts having the same or substantially the same configurations and functions as those in FIGS. 1 to 18 are denoted by the same reference numerals as those in FIGS.

  As in the coating sheet 50b shown in FIG. 21, the position of the tab portion 382b of the first virtual contour R1 and the position of the tab portion 482b of the second virtual contour R2 may be shifted in the longitudinal direction. In FIG. 21, portions having the same or substantially the same configuration / function as those in FIG. 8 are denoted by the same reference numerals as those in FIG.

  The front side coating region cutting step T1a and the back side coating region cutting step T1b may be performed separately. That is, both upstream lasers 180L and 190L (see FIG. 11) may be irradiated separately to the respective positions of the virtual contour R without simultaneously irradiating.

  Both downstream lasers 210 </ b> L and 220 </ b> L may be irradiated from the back side 70 of the coating sheet 50. In this case, both downstream laser devices 210 and 220 are disposed below the coating sheet 50 (the back side 70 of the coating sheet 50). Note that either one of the two downstream laser devices 210 and 220 may be abolished, and laser irradiation may be performed from the single downstream laser device toward the virtual contour R in the two downstream laser spaces 106a and 106b. Good.

  The laser axes of the lasers 180L, 190L, 210L, and 220L may not be perpendicular to the coating sheet 50.

  The laser device 284 may be a scanner type as shown in the examples of FIGS. The front upstream laser device 180a shown in FIG. 23 includes a support member 186 fixed at a predetermined position and a scanner 187 fixed at a predetermined position of the support member 186. The scanner 187 has a mirror 188. The angle of the mirror 188 can be freely changed. A laser beam is supplied to the scanner from a laser oscillator (not shown). The mirror 188 reflects the supplied laser beam. This reflected laser beam is a laser 180L. The mirror 188 can change the irradiation position of the laser 180 </ b> L three-dimensionally by changing the angle of the mirror 188. The laser beam reflected by the mirror 188 is condensed by a lens (not shown). The angle of the mirror 188 is controlled by the controller 288, for example.

  Similar to the front upstream laser device 180 a, the first downstream laser device 210 a includes a support member 216 and a scanner 217 including a mirror 218. The second downstream laser device 220 a includes a support member 226 and a scanner 227 including a mirror 228. The back upstream laser device 190 a shown in FIG. 24 includes a support member 196 and a scanner 197 provided with a mirror 198. Since each laser device 190a, 210a, 220a functions in the same manner as the front upstream laser device 180a, a duplicate description is omitted. 23 and 24, the same reference numerals as those in FIGS. 16 and 17 are assigned to portions having the same or substantially the same configuration and function as those in FIGS.

  The inclined surface 95 of the first guide member 96a may be extended to below the first downstream laser space 106a so as to face the inner first back side non-coating region 76a. Similarly, the inclined surface 95 of the second guide member 96a may extend to the lower side of the second downstream laser space 106b so as to face the inner second back side non-coating region 78a.

  In the electrode sheet manufacturing apparatus 280, the collection device 286 may be eliminated. In this case, the collecting step T3 is abolished in the electrode sheet cutting step S2.

  The electrode sheet cut out from the coating sheet 50 may have a long rectangular shape in which the tab-forming side and the tab-facing side are longer than the positive electrode sheet 30 and the negative electrode sheet 40 shown in the example of FIG. This elongate electrode sheet comprises the winding type electric power generation element currently disclosed by patent document 2, for example.

  4 may be provided on all four sides 38a, 38b, 38c, and 38d of the positive electrode current collector 32a, or at least one side of these four sides 38a, 38b, 38c, and 38d. May be provided. Similarly, the positive electrode back side taper portion 36a may be provided on all four sides 38a, 38b, 38c, 38d of the positive electrode current collecting portion 32a, or on at least one side of these four sides 38a, 38b, 38c, 38d. It may be provided. 5 may be provided on all four sides 48a, 48b, 48c, 48d of the negative electrode current collector 42a, or at least one side of these four sides 48a, 48b, 48c, 48d. May be provided. Similarly, the negative electrode back side taper portion 46a may be provided on all four sides 48a, 48b, 48c, 48d of the negative electrode current collector 42a, or on at least one side of these four sides 48a, 48b, 48c, 48d. It may be provided.

  The positive electrode front side inclination angle θ1A and the positive electrode back side inclination angle θ1B shown in FIG. 2 can be freely set. The positive electrode front side inclination angle θ1A and the positive electrode back side inclination angle θ1B may be individually set for each of the sides 38a, 38b, 38c, and 38d of the positive electrode current collector 32a. The negative electrode front side inclination angle θ2A and the negative electrode back side inclination angle θ2B can be freely set. The negative electrode front side inclination angle θ2A and the negative electrode back side inclination angle θ2B may be individually set for each of the sides 48a, 48b, 48c, and 48d of the negative electrode current collector 42a.

30 Positive electrode sheet (electrode sheet)
32b Positive electrode tab part (tab part)
32 Positive electrode current collector foil (current collector foil)
32a Cathode current collector (current collector)
34 Front-side positive electrode active material layer (front-side active material layer)
34a Positive side taper portion (front side taper portion)
34EG Edge 36 Back side positive electrode active material layer (back side active material layer)
36a Positive side back taper part (back side taper part)
36EG edge 38a positive electrode tab formation side (tab formation side)
38b Opposite side of positive electrode tab (opposite side of tab)
38c 1st positive electrode tab parallel side (1st tab parallel side)
38d 2nd positive electrode tab parallel side (2nd tab parallel side)
40 Negative electrode sheet (electrode sheet)
42b Negative electrode tab (tab)
42 Negative electrode current collector foil (current collector foil)
42a Negative electrode current collector (current collector)
44 Front-side negative electrode active material layer (front-side active material layer)
44a Negative electrode front side taper part (front side taper part)
44EG Edge 46 Back side negative electrode active material layer (back side active material layer)
46a Negative side taper part (back side taper part)
46EG Edge 48a Negative electrode tab formation side (tab formation side)
48b Negative electrode tab facing side (tab facing side)
48c 1st negative electrode tab parallel side (1st tab parallel side)
48d 2nd negative electrode tab parallel side (2nd tab parallel side)
50, 50a Coating sheet 52 Metal foil 52a Front side 52b Back side 54 Front side active material layer 56 Back side active material layer 62 Front side coating region 64 Front side non-coating region 66 First front side non-coating region 68 Second front side non-coating region 72 Back side coating region 74 Back side non-coating region 76 First back side non-coating region 78 Second back side non-coating region 90 Upstream conveying device 92 Downstream conveying device 94 Auxiliary downstream conveying device 96 Guide member 95 Inclined surface 98 Upstream suction device 100 Downstream suction device 102 Auxiliary downstream suction device 104 Upstream laser space 106 Downstream laser space 180, 180a Front upstream laser device 180L Front upstream laser (front laser)
190, 190a Back upstream laser device 190L Back upstream laser (back laser)
210, 210a First downstream laser device 210L First downstream laser 220, 220a Second downstream laser device 220L Second downstream laser 280, 280a Electrode sheet manufacturing device 284 Laser device J1, J2 Optical axis M Conveying direction R Virtual Contour R1 First virtual contour R2 Second virtual contour T1 Coating region cutting step T1a Front side coating region cutting step T1b Back side coating region cutting step T2 Non-coating region cutting step

Claims (5)

A method for producing an electrode sheet by cutting out an electrode sheet using a laser from a coating sheet in which an active material layer is formed on a strip-shaped metal foil,
The front side surface of the coating sheet is a front side coating region that is a region in which a front side active material layer is continuously formed in the longitudinal direction of the metal foil, and the width of the metal foil with respect to the front side coating region. A front-side non-coating region that is a region continuous in the longitudinal direction with the metal foil exposed and provided adjacent to the direction,
The back side surface of the coating sheet is a region facing the front side coating region across the metal foil and a region where a back side active material layer is formed, and sandwiching the metal foil A back side non-coating region that is a region facing the front side non-coating region and continuous in the longitudinal direction with the metal foil exposed.
The electrode sheet has a rectangular current collecting part and a tab part protruding from a tab forming side that is one side of the current collecting part,
The rectangular current collecting portion includes the tab forming side, the tab facing side that is the side facing the tab forming side, and the tab parallel side that is two sides excluding the tab forming side and the tab facing side. And
The front side coating region and the back side coating region have a width corresponding to at least the length of the tab parallel sides,
The front side non-coating region and the back side non-coating region have at least a width corresponding to the length in the protruding direction of the tab portion,
On the coating sheet, when the virtual sheet outline is defined as a virtual outline of the electrode sheet,
The front side laser which is a front side laser having a strength capable of cutting at least the front side active material layer and is focused from the front side of the coating sheet to the front side coating region in the virtual contour on the coating sheet. Irradiating along the location, cutting process on the front side coating area,
At least the backside laser that has a strength capable of cutting the backside active material layer and is focused, from the backside of the coating sheet, in the backside coating region in the virtual contour on the coating sheet. Irradiation along the part, back side coating area cutting process,
At least the metal foil laser that has a strength capable of cutting the metal foil and is focused, the metal foil laser is focused from the front side of the coating sheet to the front side non-coating in the virtual contour on the coating sheet. Irradiate along the part of the work area,
Alternatively, the metal foil laser is irradiated from the back side of the coating sheet along the portion of the back side non-coating region in the virtual contour on the coating sheet, and a non-coating region cutting step, Have
A method for producing an electrode sheet. It is a manufacturing method of the electrode sheet according to claim 1,
While performing the said front side coating area cutting process and the said back side coating area cutting process simultaneously, with respect to each position of the said virtual outline cut | disconnected in the said front side coating area cutting process and the said back side coating area cutting process Irradiating the front side laser and the back side laser simultaneously,
A method for producing an electrode sheet. It is a manufacturing method of the electrode sheet according to claim 1 or 2,
The optical axis of the front side laser is set so as to be orthogonal to the coating sheet,
The optical axis of the back side laser is set so as to be orthogonal to the coating sheet,
A method for producing an electrode sheet. It is a manufacturing method of the electrode sheet according to any one of claims 1 to 3,
The intensity of the front side laser is set to an intensity capable of cutting from the surface of the front side active material layer to a predetermined front side laser arrival position,
The front side laser arrival position is set at a predetermined position within a range from the front side surface of the metal foil provided with the front side active material layer to the inside of the back side active material layer,
The intensity of the back side laser is set to an intensity capable of cutting from the surface of the back side active material layer to a predetermined back side laser arrival position,
The back side laser arrival position is set to a predetermined position within a range from the back side surface of the metal foil provided with the back side active material layer to the inside of the front side active material layer,
A method for producing an electrode sheet. Each of the front side surface and the back side surface of the current collector in a current collector foil that is a metal foil having a rectangular current collector and a tab that protrudes from one side of the current collector. An electrode sheet having a front side active material layer and a back side active material layer,
In the front side active material layer, at least one side of the front side surface of the current collector is such that the edge of the current collector matches the edge of the front side active material layer and the thickness of the front side active material layer from the one side A front taper portion inclined inward of the current collector in the direction,
In the back side active material layer, at least one side of the back side surface of the current collector is such that the edge of the current collector and the edge of the back side active material layer coincide with each other, and the thickness of the back side active material layer from the one side A back side taper portion inclined inward of the current collector in the direction,
The front side taper portion and the back side taper portion are provided on the same side of the four sides of the rectangular current collector,
Electrode sheet.

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