Electrode sheet manufacturing apparatus and method for manufacturing electrode sheet

Abstract

To improve the quality of an electrode sheet.SOLUTION: An electrode sheet manufacturing apparatus 1 manufactures an electrode sheet 10 including: a current collector 12 formed of a long metal foil; an unformed part 12a; an electrode active material layer 14; and a protective layer 16. An electrode sheet manufacturing apparatus 1 includes a transport device 17, a support roll 60, a pressing roll 70, and a driving device. The support roll 60 supports a first surface of the electrode sheet 10 along a width direction. The pressing roll 70 is disposed on a second surface of the electrode sheet 10 so as to face the support roll 60. The pressing roll 70 includes a shaft part 72 and a rubber part 73. The rubber part 73 is wound around an outer peripheral surface 72d of the shaft part 72 at least in a region contacting the unformed part 12a. The thickness of the rubber part 73 at a position overlapping with an inner end 12a2 of the unformed part 12a is thinner than the thickness of the rubber part 73 in a region located outward of the position overlapping with the inner end 12a2.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electrode sheet manufacturing apparatus and an electrode sheet manufacturing method. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2023-36089 discloses a method for manufacturing an electrode sheet, including a preparation step for preparing an electrode sheet, a coated portion pressing step for pressing the coated portion in the thickness direction, and an uncoated portion pressing step for pressing the uncoated portion in the thickness direction. The uncoated portion pressing step includes a shaft body and an elastic body covering the shaft body. In the uncoated portion pressing step, the uncoated portion is roll-pressed while being pressed in the thickness direction using a pair of elastic rolls. This manufacturing method is said to be able to stretch the uncoated portion while suppressing breakage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-36089 Summary of the Invention [Problem to be solved by the invention]

[0004] The ease of stretching of the current collector of the electrode sheet may vary depending on the position, and if the current collector stretches unevenly, this may affect the quality of the electrode sheet. [Means for solving the problem]

[0005] In the electrode sheet manufacturing apparatus disclosed herein, the electrode sheet has a current collector, an unformed portion, an electrode active material layer, and a protective layer. The current collector is made of a long metal foil. The unformed portion is set along the length of the current collector at a predetermined position in the width direction. The electrode active material layer is formed on the current collector in a portion excluding the unformed portion. The protective layer is formed along the length of the electrode active material layer. The apparatus is equipped with a conveying device, a support roll, a pressing roll, and a driving device. The conveying device conveys the long electrode sheet along a predetermined conveying path. The support roll is arranged in the conveying path. The support roll supports a first surface of the electrode sheet conveyed along the conveying path along the width direction. The pressing roll is arranged to face the support roll on the second surface of the electrode sheet. The driving device presses the pressing roll against the support roll, sandwiching the electrode sheet. The electrode sheet has a current collector, an electrode active material layer, and a protective layer. The current collector is made of metal foil. The electrode active material layer is formed on the current collector. The protective layer is formed along the longitudinal direction of the electrode active material layer. An uncoated portion where the electrode active material layer and the protective layer are not coated is provided at the end of the electrode sheet. The pressing roll has a shaft portion and a rubber portion. The rubber portion is wound around the outer surface of the shaft portion at least in the area that contacts the uncoated portion. The thickness of the rubber portion at the position overlapping with the inner end of the uncoated portion is thinner than the thickness of the rubber portion in the area outside the position overlapping with the inner end. With this electrode sheet manufacturing device, the current collector of the electrode sheet is likely to stretch uniformly, and the quality of the electrode sheet is likely to improve. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a flow diagram of manufacturing using an electrode sheet manufacturing apparatus 1. [Figure 2] FIG. 2 is a schematic diagram of the electrode sheet 10. [Figure 3] FIG. 3 is a schematic side view of the electrode sheet manufacturing apparatus 1. As shown in FIG. [Figure 4] FIG. 4 is a front view of the roll press machine 50. As shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along the line AA shown in FIG. [Figure 6] FIG. 6 is a schematic diagram showing the positional relationship between the electrode sheet 10, the support roll 60, and the pressure roll 70. [Figure 7] FIG. 7 is a schematic diagram showing the relationship between the thickness of the rubber and the amount of deformation. [Figure 8] FIG. 8 is a schematic diagram of a roll press machine 150 according to another embodiment. [Figure 9] FIG. 9 is a schematic diagram of a roll press machine 250 according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] An embodiment of the technology disclosed herein will be described below with reference to the drawings. The embodiment described here is, of course, not intended to limit the present invention. The drawings are schematic and do not necessarily reflect the actual product. Furthermore, the same reference numerals are appropriately used for components and parts that perform the same function, and redundant explanations will be omitted where appropriate.

[0008] Fig. 1 is a flow diagram of production using an electrode sheet manufacturing apparatus 1. As shown in Fig. 1, production using the electrode sheet manufacturing apparatus 1 includes preparation steps S1 to S5, a roll press step S6, and a main press step S7. In this embodiment, the preparation steps include a conveying step S1, a measuring step S2, a kneading step S3, a coating step S4, and a drying step S5. However, production using the electrode sheet manufacturing apparatus 1 may also include other steps.

[0009] <Electrode sheet manufacturing equipment 1> An electrode sheet 10 (see FIG. 2) that constitutes an electricity storage device is manufactured in an electrode sheet manufacturing apparatus 1. The electrode sheet 10 constitutes the positive electrode sheet or negative electrode sheet of an electrode body housed inside the electricity storage device. An electricity storage device refers to a device that can be repeatedly charged and discharged, and is a concept that encompasses so-called storage batteries (i.e., chemical batteries) such as lithium ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, as well as capacitors (i.e., physical batteries) such as electric double layer capacitors. Below, as an example, the configuration of an electrode sheet 10 used in a lithium ion secondary battery will be described, along with the electrode sheet manufacturing apparatus 1 that manufactures the electrode sheet 10.

[0010] <Electrode sheet 10> FIG. 2 is a schematic diagram of an electrode sheet 10. As shown in FIG. 2, the electrode sheet 10 includes a current collector 12, an electrode active material layer 14, and a protective layer 16. The current collector 12 is a member made of metal foil. The current collector 12 is a long, strip-shaped metal member. A metal material having a required conductivity can be used for the current collector 12. For example, aluminum or an aluminum alloy can be used for the positive electrode current collector. For example, copper or a copper alloy can be used for the negative electrode current collector. The electrode active material layer 14 is applied to a predetermined position on the current collector 12. The electrode active material layer 14 is formed on at least one surface of the strip-shaped current collector 12. In this embodiment, the electrode active material layer 14 is formed on both surfaces of the current collector 12. The electrode active material layer 14 is a layer containing an electrode active material. For example, a lithium transition metal composite oxide can be used as the positive electrode active material. Examples of the negative electrode active material that can be used include carbon materials, silicon-based materials, and mixed oxides thereof. The electrode active material layer may contain additives other than the electrode active material, such as a binder and a conductive material.

[0011] The electrode sheet 10 is formed by applying an electrode mixture slurry that will become the electrode active material layer 14 to a current collector 12 and drying the applied slurry. The current collector 12 has an uncoated portion 12a and a coated portion 12b. The uncoated portion 12a is a portion of the current collector 12 that is not coated with the electrode active material layer 14 and the protective layer 16. The uncoated portion 12a is set along the length of the electrode sheet 10 at a predetermined position in the width direction. The uncoated portion 12a is an example of an unformed portion set along the length of the current collector 12 at a predetermined position in the width direction, where the electrode active material layer 14 and the protective layer 16 are not formed. The electrode active material layer 14 is formed on a portion of the current collector 12 excluding the uncoated portion 12a. Here, the electrode active material layer 14 is formed by coating the portion of the current collector 12 excluding the uncoated portion 12a. In this embodiment, the uncoated portions 12a are set at both ends of the electrode sheet 10 in the width direction. The coated portions 12b are arranged between the uncoated portions 12a at both ends of the electrode sheet 10. The electrode mixture slurry is applied to the coated portions 12b. As a result, an electrode active material layer 14 is formed in the coated portions 12b of the current collector 12. In other words, the electrode active material layer 14 is arranged between the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction.

[0012] The protective layer 16 is a layer formed along the electrode active material layer 14. The protective layer 16 is provided along the electrode active material layer 14 on the positive electrode side. The protective layer 16 is, for example, a layer having a higher resistance than the electrode active material layer 14. The protective layer 16 contains, for example, inorganic particles and a resin (binder). Examples of the inorganic particles include inorganic oxides such as alumina, boehmite, magnesia, silica, and titania. Examples of the resin (binder) include polyvinylidene fluoride (PVdF). Alternatively, the protective layer 16 may be a layer made of a resin. The protective layer 16 may contain a conductive material such as a carbon material, if necessary. By providing the protective layer 16, the short-circuit suppression effect in the electrode body can be improved.

[0013] For example, the thickness of the protective layer 16 is smaller than the thickness of the electrode active material layer 14. If the thickness of the protective layer 16 is smaller than the thickness of the electrode active material layer 14, flexibility of the corners at the longitudinal ends of the current collector 12 can be improved. The thickness of the protective layer 16 is not particularly limited, but can be, for example, about 0.3 to 0.7 (e.g., about 0.4 to 0.6) times the thickness of the electrode active material layer 14.

[0014] <Conveyor device 17> In the conveying step S1 shown in FIG. 1, the electrode sheet 10 is conveyed. FIG. 3 is a schematic side view of the electrode sheet manufacturing apparatus 1. The conveying step S1 can be achieved by a conveying device 17. As shown in FIG. 3, the conveying device 17 conveys the long electrode sheet 10. For example, a motor is used for the conveying device 17. The conveying device 17 includes an unwinding roll 17a and a take-up roll 17b so as to convey the electrode sheet 10 at a predetermined conveying speed. The unwinding roll 17a is disposed upstream of the roll press machine 50 in the conveying direction. The take-up roll 17b is disposed downstream of the roll press machine 50 in the conveying direction. However, the conveying device 17 is not limited to the unwinding roll 17a and the take-up roll 17b. For example, the conveying device 17 may include rolls in addition to the unwinding roll 17a and the take-up roll 17b. The electrode sheet 10 is conveyed by the conveying device 17 along a predetermined conveying path 18.

[0015] <Measuring process S2, kneading process S3, coating process S4, drying process S5> In the measuring step S2 shown in FIG. 1, raw materials for the electrode active material layer 14 (see FIG. 2) are measured. The measuring can be achieved, for example, by a measuring device (not shown) having a balance, a load cell, or the like. The measured raw materials for the electrode active material layer 14 are mixed in the kneading step S3. The kneading step S3 can be achieved by a kneading device (not shown). The raw materials for the electrode active material layer 14, which have been made into a slurry by the kneading device, are applied to the current collector 12 (see FIG. 2) in the coating step S4. The coating step S4 can be achieved, for example, by a coating device (not shown) such as a slit coater, gravure coater, die coater, or comma coater. In the drying step S5, the applied raw materials for the electrode active material layer 14 in a slurry state are dried. The drying step S5 can be achieved, for example, by a drying device (not shown) that emits hot air or infrared rays.

[0016] <Roll press process S6> In the roll press step S6, the electrode sheet 10 is pressed. The roll press step S6 can be achieved by a roll press machine 50 shown in FIG. 3. As shown in FIG. 3, the electrode sheet 10 is pressed by the roll press machine 50 midway along the conveying path 18. The electrode sheet 10 is supplied by an unwinding roll 17a. The electrode sheet 10 pressed by the roll press machine 50 is taken up by a take-up roll 17b. The electrode sheet manufacturing apparatus 1 includes a control device 100 that controls the unwinding roll 17a, the take-up roll 17b, and the roll press machine 50.

[0017] <Roll Press Machine 50> FIG. 4 is a front view of a roll press machine 50. The roll press machine 50 according to this embodiment is a device that presses the uncoated portion 12a of the electrode sheet 10 with a rubber roll before or after pressing the coated portion 12b. When the uncoated portion 12a is pressed by the rubber roll, the uncoated portion 12a receives a reaction force from the elastic deformation and compressive deformation of the rubber roll, and the portion pressed by the roll is pressed and stretched. As a result, the uncoated portion 12a can be stretched while preventing breakage of the uncoated portion 12a. In view of this function, a device that presses the uncoated portion 12a of the electrode sheet 10 with a rubber roll may be appropriately referred to as an EPS (Elasticity Powered Stretching) device. In addition to the roll press machine 50, the electrode sheet manufacturing apparatus 1 may also include a device that presses the coated portion 12b.

[0018] The roll press machine 50 includes a support roll 60, a pressing roll 70, and a pressing pressure adjusting mechanism 80.

[0019] <Support Roll 60> The support roll 60 is disposed on the conveying path 18 (see FIG. 3). The support roll 60 supports the lower surface 10D of the electrode sheet 10 conveyed along the conveying path 18 in the width direction of the electrode sheet 10. The lower surface 10D is an example of the first surface in the present invention. The support roll 60 is disposed below the pressing roll 70. The support roll 60 is a rubber roll that presses the uncoated portion 12a of the electrode sheet 10 together with the pressing roll 70. The support roll 60 includes a main body portion 61 and two shaft portions 66.

[0020] FIG. 5 is a cross-sectional view of the AA cross section shown in FIG. 4. However, FIG. 5 illustrates a state in which the uncoated portion 12a is pressed by the support roll 60 and the pressure roll 70. As shown in FIG. 5, the main body 61 of the support roll 60 includes a shaft portion 62 and a rubber portion 63. The shaft portion 62 is made of metal. The material forming the shaft portion 62 is not particularly limited, but is, for example, a material with relatively high hardness such as SUS304 (stainless steel). The rubber portion 63 is arranged so as to cover at least the outer peripheral surface of the shaft portion 62. The material forming the rubber portion 63 is, for example, nitrile rubber (NBR). The support roll 60 presses the uncoated portion 12a of the electrode sheet 10 with the rubber portion 63.

[0021] The support roll 60 is rotated in a predetermined direction by a roll drive device 84 (see FIG. 4), which will be described later. In this embodiment, the support roll 60 rotates in the direction of arrow R1 shown in FIG. 5. At this time, the electrode sheet 10 is transported from left to right as viewed in the drawing. That is, the left side in FIG. 5 is the upstream side in the transport direction, and the right side in FIG. 5 is the downstream side in the transport direction.

[0022] As shown in Fig. 4, both shaft portions 66 are inserted into the main body portion 61. Both shaft portions 66 are inserted into the shaft portions 62 (see Fig. 5) of the main body portion 61. Both shaft portions 66 extend to the outside in the axial direction of the support roll 60. Although not shown in the figure, both shaft portions 66 are fitted with bearings, gap screws for adjusting the gap between the support roll 60 and the pressure roll 70, and the like.

[0023] <Pressing Roll 70> As shown in FIG. 5, the pressing roll 70 is disposed on the upper surface 10U of the electrode sheet 10 so as to face the support roll 60. The pressing roll 70 is disposed so as to sandwich the uncoated portion 12a of the electrode sheet 10 between itself and the support roll 60, excluding the coated portion 12b (see FIG. 2) of the electrode sheet 10. The upper surface 10U is an example of the second surface of the present invention. The axial center of the pressing roll 70 and the axial center of the support roll 60 are aligned in the vertical direction. As shown in FIG. 4, the pressing roll 70 is a rubber roll that presses the uncoated portion 12a of the electrode sheet 10 together with the support roll 60. The pressing roll 70 is not disposed above the coated portion 12b of the electrode sheet 10. In this embodiment, as described above, the uncoated portions 12a of the electrode sheet 10 are provided at both ends in the width direction of the electrode sheet 10. Therefore, as shown in FIG. 4, the pressing rolls 70 are disposed above the uncoated portions 12a at both ends in the width direction of the electrode sheet 10. However, when there is one uncoated portion 12a, there may be only one pressing roll 70. Of the two pressing rolls 70, the one located on the left will also be referred to as pressing roll 70L, and the one located on the right will also be referred to as pressing roll 70R. However, the name pressing roll 70 will be used appropriately in descriptions that apply to both pressing rolls 70L and 70R. The pressing roll 70 includes a main body portion 71 (see FIG. 5) and two shaft portions 76.

[0024] As shown in FIG. 5, the main body 71 of the pressing roll 70 includes a shaft 72 and a rubber portion 73. The shaft 72 is made of metal. The material forming the shaft 72 is not particularly limited, but is, for example, a material with a relatively high hardness such as SUS304 (stainless steel). The rubber portion 73 is arranged so as to cover at least the outer peripheral surface of the shaft 72. The material forming the rubber portion 73 is not particularly limited, but is, for example, nitrile rubber (NBR). The pressing roll 70 presses the uncoated portion 12a of the electrode sheet 10 with the rubber portion 73.

[0025] As shown in Fig. 4, both shaft portions 76 are inserted into the main body portion 71. Both shaft portions 76 are inserted into the shaft portions 72 (see Fig. 5) of the main body portion 71. Both shaft portions 76 extend to the outside in the axial direction of the two pressing rolls 70. Although not shown in the figure, both shaft portions 76 are fitted with bearings, gap screws for adjusting the gap between the support roll 60 and the pressing roll 70, and the like.

[0026] As shown in FIG. 5 , when the support roll 60 and the pressure roll 70 sandwich the electrode sheet 10 and the support roll 60 rotates in the direction of arrow R1, the pressure roll 70 receives a force rotating in the direction of arrow R2 via the electrode sheet 10. Alternatively, when the electrode sheet 10 is not disposed and the support roll 60 and the pressure roll 70 are in contact with each other, the pressure roll 70 receives a force rotating in the direction of arrow R2 due to the force of the rotation of the support roll 60. As a result, the pressure roll 70 rotates in the direction of arrow R2. In other words, the pressure roll 70 rotates in conjunction with the rotation of the support roll 60.

[0027] As shown in FIG. 4, the press pressure adjusting mechanism 80 includes a press cylinder 81, a roll chock 82, a cylinder driving device 83, a roll driving device 84, and a support portion 85.

[0028] The press cylinders 81 press the pressure roll 70 against the support roll 60. The press cylinders 81 are arranged one on each end of the pressure roll 70, one on the outside. Here, in FIG. 4 , the press cylinder 81 arranged to the left of the electrode sheet 10 is referred to as press cylinder 81L, and the press cylinder 81 arranged to the right of the electrode sheet 10 is also referred to as press cylinder 81R. However, when describing matters common to the press cylinders 81L and 81R, they will also be referred to as press cylinder 81. In this embodiment, the press cylinder 81 is a pneumatic cylinder. The press cylinder 81 includes a rod 81a. The rod 81a is connected to a roll chock 82. The roll chock 82 is a member that rotatably supports both shaft portions 76 of the pressure roll 70. When the press cylinder 81 is driven and the rod 81a descends, the pressure roll 70 descends. When the press cylinder 81 is driven and the rod 81a rises, the pressure roll 70 rises.

[0029] The cylinder driving device 83 is a device that sandwiches the electrode sheet 10 and presses the pressure roll 70 against the support roll 60. The cylinder driving device 83 is an example of a driving device in the present invention. The cylinder driving device 83 is connected to the press cylinder 81. The cylinder driving device 83 drives the press cylinder 81, thereby raising and lowering the rod 81a of the press cylinder 81. In this embodiment, the cylinder driving device 83 is configured to be able to independently drive the press cylinder 81L and the press cylinder 81R. In other words, the cylinder driving device 83 independently drives the press rolls 70 arranged above the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction. The cylinder driving device 83 is connected to a control device 100 (see FIG. 3).

[0030] The roll driving device 84 is connected to the support roll 60. The roll driving device 84 is a device that rotates the support roll 60. In this embodiment, the roll driving device 84 rotates the support roll 60 in the direction of arrow R1 shown in FIG. 5. The configuration of the roll driving device 84 is not particularly limited, but may be configured by, for example, an electric motor, gears, etc. The roll driving device 84 is connected to a control device 100 (see FIG. 3). Note that the roll driving device 84 may also rotate the pressing roll 70.

[0031] The support portion 85 is a member that supports the support roll 60. The support portion 85 supports both shaft portions 66 of the support roll 60.

[0032] Below, the support roll 60 and the pressing roll 70 that constitute the roll press machine 50 will be described together with the electrode sheet 10 to be pressed.

[0033] FIG. 6 is a schematic diagram showing the positional relationship between the electrode sheet 10, the support roll 60, and the pressure roll 70. In FIG. 6, the electrode sheet 10, the support roll 60, and the pressure roll 70 are shown as if they were virtually separated. In FIG. 6, cross sections of the electrode sheet 10, the support roll 60, and the right-side pressure roll 70R are shown. The configuration of the left-side pressure roll 70L can be the same as the configuration of the right-side pressure roll 70R, so a detailed description will be omitted.

[0034] <Support Roll 60> 6, the support roll 60 (in this embodiment, a main body portion 61) includes a shaft portion 62 and a rubber portion 63. The outer diameter of the support roll 60 is approximately constant.

[0035] <Shaft 62> The shaft portion 62 is a substantially cylindrical member extending in the width direction of the electrode sheet 10. In this embodiment, the diameter of the shaft portion 62 is substantially constant. A rubber portion 63 is wound around the outer peripheral surface 62d of the shaft portion 62. The thickness of the rubber portion 63 is substantially constant except for both end portions along the axis of the support roll 60.

[0036] <Rubber part 63> The rubber portion 63 is formed in a substantially cylindrical shape. An inner peripheral surface 63d of the rubber portion 63 corresponds to an outer peripheral surface 62d of the shaft portion 62. The inner diameter of the rubber portion 63 is the same as the outer diameter of the shaft portion 62. In this embodiment, the inner diameter of the rubber portion 63 is substantially constant, similar to the outer diameter of the shaft portion 62. The electrode sheet 10 is supported on the outer peripheral surface 63f of the rubber portion 63. The uncoated portion 12a of the electrode sheet 10 is pressed by the pressing roll 70. The thickness of the rubber portion 63 is not particularly limited. In this embodiment, the thickness of the rubber portion 63 is set to be approximately the same as the thickness of the thick portion 73a, which will be described later. The thickness of the rubber portion 63 can be set to be, for example, 0.9 to 1.1 times the thickness of the thick portion 73a.

[0037] <Pressing Roll 70> The pressing roll 70 (in this embodiment, a main body 71) includes a shaft 72 and a rubber portion 73. The length (dimension along the axis) of the pressing roll 70 is shorter than the length of the support roll 60. Therefore, the electrode sheet 10 is partially sandwiched between the support roll 60 and the pressing roll 70 and pressed. The pressing roll 70 is set to a dimension that enables it to press the uncoated portion 12a of the electrode sheet 10. The length of the pressing roll 70 is longer than the width of the uncoated portion 12a. In this embodiment, the length of the pressing roll 70 is approximately twice the width of the uncoated portion 12a. Although not particularly limited, the length of the pressing roll 70 is preferably approximately 1.5 to 2.5 times the width of the uncoated portion 12a, and more preferably approximately 1.8 to 2.2 times. In the roll pressing step S6, the position overlapping the inner end 12a2 of the uncoated portion 12a is pressed by the center portion 73f1 of the rubber portion 73.

[0038] The pressing roll 70 is provided at a position where it can press the uncoated portion 12a. The position of the pressing roll 70 can be set according to the dimensions of the coated portion 12b of the electrode sheet 10. In this embodiment, the inner end face 70a (left side in the embodiment shown in FIG. 6) of the pressing roll 70 is located slightly inside the outer end 14a (right side in the embodiment shown in FIG. 6) of the electrode active material layer 14 in the coated portion 12b of the electrode sheet 10. The outer end face 70b of the pressing roll 70 is located outside the outer end 12a1 of the uncoated portion 12a of the electrode sheet 10. In this embodiment, the pressing roll 70 is positioned so that the center portion 73f1 of the rubber portion 73 overlaps the outer end 12a1 of the uncoated portion 12a.

[0039] <Shaft 72> The shaft portion 72 has a cylindrical portion 72a, a stepped portion 72b, and an inclined portion 72c.

[0040] The cylindrical portion 72a is a generally cylindrical portion whose rotation axis is set to be generally parallel to the rotation axis of the pressing roll 70. The diameter of the cylindrical portion 72a is generally constant. The cylindrical portion 72a is provided from the outside (end surface 70b side) of the shaft portion 72 toward the inside.

[0041] The stepped portion 72b is a portion having a larger diameter than the cylindrical portion 72a. The stepped portion 72b is provided on the inner side (the end surface 70a side) of the shaft portion 72. The stepped portion 72b is provided at a position where at least a portion thereof overlaps with the inner end 12a2 of the uncoated portion 12a of the electrode sheet 10. In this embodiment, the outer end of the stepped portion 72b approximately coincides with the inner end 12a2 of the uncoated portion 12a. The stepped portion 72b may extend outward beyond the inner end 12a2. The stepped portion 72b is provided at a position where it overlaps with the protective layer 16.

[0042] The inclined portion 72c is a portion that connects the cylindrical portion 72a and the stepped portion 72b. The inclined portion 72c is a portion that is inclined from the cylindrical portion 72a toward the stepped portion 72b. In this embodiment, the inclined portion 72c is inclined so that the diameter increases from the cylindrical portion 72a toward the stepped portion 72b. Note that the inclined portion 72c does not necessarily have to be provided on the shaft portion 72. A rubber portion 73 is wrapped around the outer peripheral surface 72d of the shaft portion 72.

[0043] <Rubber part 73> The rubber portion 73 is wound around the outer peripheral surface 72d of the shaft portion 72 at least in the region that contacts the uncoated portion 12a. The inner diameter of the rubber portion 73 corresponds to the outer diameter of the shaft portion 72. In this embodiment, the rubber portion 73 covers the entire outer peripheral surface (side peripheral surface) 72d of the shaft portion 72. In other words, the inner peripheral surface 73d of the rubber portion 73 is aligned with the outer peripheral surface 72d of the shaft portion 72. The length of the rubber portion 73 and the length of the shaft portion 72 are approximately the same. The rubber portion 73 is formed in a substantially cylindrical shape. The outer diameter of the rubber portion 73 is approximately constant. In this embodiment, the rubber portion 73 has a thick portion 73a, a thin portion 73b, and an inclined portion 73c. ​​The thick portion 73a is wound around the cylindrical portion 72a of the shaft portion 72. The thin portion 73b is wound around the stepped portion 72b of the shaft portion 72. The inclined portion 73c is wound around the inclined portion 72c of the shaft portion 72.

[0044] The thick portion 73a is thicker than the thin portion 73b. Although not particularly limited, the thickness of the thin portion 73b can be set to approximately 1 mm or more and 30 mm or less. The thickness of the thick portion 73a can be set to approximately two to three times the thickness of the thin portion 73b. The inclined portion 73c is inclined so as to become thinner from the thick portion 73a toward the thin portion 73b. The sum of the outer diameter of the cylindrical portion 72a and the thickness of the thick portion 73a is approximately the same as the sum of the outer diameter of the stepped portion 72b and the thickness of the thin portion 73b. The sum of the outer diameter of the inclined portion 72c and the thickness of the inclined portion 73c is approximately constant in the axial direction of the pressing roll 70. Therefore, the diameter of the pressing roll 70 is approximately constant.

[0045] As described above, the stepped portion 72b overlaps the inner end 12a2 of the uncoated portion 12a. The thin portion 73b of the rubber portion 73 is wrapped around the outer peripheral surface of the stepped portion 72b. As a result, the thickness of the rubber portion at the position overlapping the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion in the region outside the position overlapping with the protective layer 16.

[0046] In this embodiment, the widthwise end of the rubber portion 73 is chamfered, forming a chamfered portion 73e at the end. The chamfered portion 73e is a portion at the end that is recessed from the outer peripheral surface 73f. The chamfered portion 73e has a C-chamfered shape in which the corner of the rubber portion 73 is cut in a substantially straight line. The shape of the chamfered portion 73e is not particularly limited and may be, for example, a rounded chamfered shape. The chamfered portion 73e is continuously formed in the circumferential direction. The chamfered portion 73e is provided at a position that overlaps the boundary between the electrode active material layer 14 and the protective layer 16 of the electrode sheet 10. Although not particularly limited, the chamfered portion 73e can be formed inward from a position slightly away from the end 14a of the electrode active material layer 14 to prevent excessive compression of the electrode active material layer 14 during roll pressing. In this embodiment, the chamfered portion 73e is formed inward from a position approximately 2 mm outside the end 14a of the electrode active material layer 14.

[0047] The electrode sheet manufacturing apparatus 1 according to this embodiment has been described above. Next, the operation when the uncoated portion 12a of the electrode sheet 10 is pressed by the roll press machine 50 will be described.

[0048] First, as shown in FIG. 4, the control device 100 (see FIG. 3) controls the cylinder drive device 83 and the roll drive device 84. The cylinder drive device 83 lowers the rod 81a of the press cylinder 81. The cylinder drive device 83 lowers the rod 81a to a predetermined position. This causes the pressing roll 70 to lower. At this time, the roll drive device 84 also rotates the support roll 60. In this embodiment, as shown in FIG. 5, the roll drive device 84 rotates the support roll 60 in the direction of arrow R1. When the pressing roll 70 lowers, the portion of the uncoated portion 12a sandwiched between the support roll 60 and the pressing roll 70 is compressed.

[0049] At this time, as shown in FIG. 6 , the electrode sheet 10 is pressed by the outer peripheral surface 63f of the rubber portion 63 of the support roll 60 and the outer peripheral surface 73f of the rubber portion 73 of the pressing roll 70. The rubber portion 73 is formed on the pressing roll 70 from the inner end surface 70a to the outer end surface 70b. Because the rubber portion 73 is provided in an area that contacts the uncoated portion 12a, the uncoated portion 12a is pressed across its entire width. As a result, the uncoated portion 12a is stretched as it passes between the support roll 60 and the pressing roll 70. At this time, the outer peripheral surface 73f of the rubber portion 73 is also pressed against the protective layer 16. Because a chamfered portion 73e is formed on the rubber portion 73 at a position overlapping the end portion 14a of the electrode active material layer 14, the lower surface 14f is less likely to interfere with the electrode active material layer 14 even when the protective layer 16 and the uncoated portion 12a are compressed.

[0050] After the uncoated portion 12a is pressed and stretched in the roll press step S6, the coated portion 12b is subsequently rolled in the main press step S7.

[0051] <Main press process S7> In the main pressing step S7, the coated portion 12b of the electrode sheet 10 is pressed. In this embodiment, the coated portion 12b is rolled in the main pressing step S7. The main pressing step S7 can be achieved by a roll press machine 90 shown in FIG. 3. As shown in FIG. 3, the roll press machine 90 is provided downstream of the roll press machine 50 on the conveying path 18. The roll press machine 90 includes a pair of rolling rolls 91 and 92. The rolling rolls 91 and 92 are each a substantially cylindrical roll extending in the width direction of the coated portion 12b (see FIG. 4) of the electrode sheet 10. The rolling rolls 91 and 92 are each longer than the width of the coated portion 12b.

[0052] The pair of rolling rolls 91, 92 face each other vertically with a required gap therebetween. The gap between the pair of rolling rolls 91, 92 may be adjusted by a driving device (e.g., a cylinder device, etc.) not shown. The gap between the pair of rolling rolls 91, 92 may be set to be narrower than the thickness of the electrode sheet 10 (see FIG. 2 ) (in this embodiment, the total thickness of the current collector 12 and the electrode active material layers 14 formed on both sides). For example, the pair of rolling rolls 91, 92 may be driven in a state of contact with each other.

[0053] The pair of rolling rolls 91, 92 can be rotated by a driving device (e.g., an electric motor, etc.) not shown. The pair of rolling rolls 91, 92 can be rotated in accordance with the transport of the electrode sheet 10. For example, the pair of rolling rolls 91, 92 can be rotated so that the peripheral speed of the outer circumferential surface matches the transport speed of the electrode sheet 10. As a result, the electrode sheet 10 passes between the pair of rolling rolls 91, 92 while being transported. At this time, the electrode active material layer 14, which is the thickest part of the electrode sheet 10, is compressed by the pair of rolling rolls 91, 92 while being transported. When the electrode active material layer 14 is compressed, the portion of the current collector 12 coated with the electrode active material layer 14 is also pressed, and accordingly, that portion of the current collector 12 is stretched. At this time, the protective layer 16 and the uncoated portion 12a, which are thinner than the current collector 12, are not compressed by the pair of rolling rolls 91, 92.

[0054] Note that the main pressing step S7 is not limited to the above-described embodiment as long as it can compress the electrode active material layer 14. Furthermore, the main pressing step S7 may be performed before the roll pressing step S6. In this case, a roll pressing machine 90 may be provided upstream of the conveying path 18, and a roll pressing machine 50 may be provided downstream.

[0055] After passing through the roll press machine 90, the electrode sheet 10 is taken up on the take-up roll 17b. In this way, the current collector 12 in the uncoated portion 12a of the electrode sheet 10 is stretched by the roll press machine 50, and the current collector 12 in the coated portion 12b is stretched by the roll press machine 90. This stretches the current collector 12 in both the uncoated portion 12a and the coated portion 12b, making it less likely that the current collector 12 will be stretched unevenly. As a result, it is less likely that the stretched current collector 12 will deform unevenly when it shrinks. This reduces the likelihood of defects such as wrinkles forming in the uncoated portion 12a or breakage of the uncoated portion 12a, improving the quality of the electrode sheet 10.

[0056] According to the inventors' findings, the ease of stretching the current collector of an electrode sheet can vary depending on the position. In the roll press process, the uncoated portion of the current collector is stretched, but the deformation of the rubber portion becomes smaller toward the end of the pressing roller. As a result, the portion closer to the electrode active material layer is less compressed than the portion farther from the electrode active material layer. Therefore, the current collector is less likely to stretch toward the electrode active material layer. Furthermore, in the main press process, the electrode active material layer is pressed, so the coated portion of the current collector stretches, while the portion of the current collector outside the coated portion is less likely to stretch. For these reasons, even after the roll press process and the main press process, the uncoated portion of the current collector near the electrode active material layer tends to be less likely to stretch. In particular, if a protective layer is formed on the current collector, the protective layer is thinner than the electrode active material layer and is less likely to stretch even in the main press process. As a result, the portion of the current collector where the protective layer is formed tends to be less likely to stretch than the other portions. As a result, the current collector tends to stretch unevenly.

[0057] In the embodiment described above, the electrode sheet manufacturing apparatus 1 includes a conveying device 17, a support roll 60, a pressure roll 70, and a driving device (a cylinder driving device 83 in this embodiment) (see FIGS. 3 and 4). The conveying device 17 conveys the long electrode sheet 10 along a predetermined conveying path 18. The support roll 60 is disposed on the conveying path 18 and supports the first surface (lower surface 10D) of the electrode sheet 10 conveyed along the conveying path 18 in the width direction. The pressure roll 70 is disposed so as to face the support roll 60 on the second surface (upper surface 10U) of the electrode sheet 10. The cylinder driving device 83 presses the pressure roll 70 against the support roll 60 with the electrode sheet 10 sandwiched between them. The electrode sheet 10 includes a current collector 12, an electrode active material layer 14, and a protective layer 16. The current collector 12 is made of metal foil. The electrode active material layer 14 is formed on the current collector 12. The protective layer 16 is formed along the longitudinal direction of the electrode active material layer 14. An uncoated portion 12a, which is not coated with the electrode active material layer 14 or the protective layer 16, is provided at the end of the electrode sheet 10. The pressing roll 70 includes a shaft portion 72 and a rubber portion 73. The rubber portion 73 is wound around the outer circumferential surface 72d of the shaft portion 72 at least in the region that contacts the uncoated portion 12a. The thickness of the rubber portion 73 at a position overlapping with the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion 73 in a region outside the position overlapping with the inner end 12a2.

[0058] FIG. 7 is a schematic diagram showing the relationship between rubber thickness and deformation amount. Note that FIG. 7 is a diagram that schematically illustrates that the amount of deformation of rubber in the planar direction varies depending on the rubber thickness, and does not necessarily reflect the actual situation. According to the inventor's findings, as shown in FIG. 7, even if the compression amount x is the same, the deformation amount y1 in the planar direction (the direction perpendicular to the compression direction) of the thin rubber A1 is larger than the displacement amount y2 of the thick rubber A2. With the electrode sheet manufacturing apparatus 1 described above, the thickness of the rubber portion 73 at the position overlapping with the protective layer 16 is thinner than the thickness of the rubber portion 73 in the region outside the position overlapping with the inner end 12a2 of the uncoated portion 12a. The uncoated portion 12a is pressed by the thick portion of the rubber portion 73, and the protective layer 16 inside the inner end 12a2 of the uncoated portion 12a can be pressed by the thin portion of the rubber portion 73. As a result, the widthwise deformation of the rubber portion 73 at the position overlapping with the protective layer 16 is greater than the widthwise deformation of the rubber portion 73 outside the position overlapping with the protective layer 16. Therefore, in the roll press step S6, the current collector 12 is more likely to be stretched at the current collector 12 on which the protective layer 16 is formed and in its vicinity. As a result, the difference in elongation of the current collector 12 between the portion stretched in the roll press step S6 (the uncoated portion 12a) and the portion stretched in the main press step S7 (the portion of the coated portion 12b on which the electrode active material layer 14 is formed) is likely to be smaller. By reducing the variation in the elongation of the current collector 12, defects such as wrinkles and breakage are less likely to occur in the current collector 12 after pressing. This can improve the quality of the electrode sheet 10.

[0059] In the above-described embodiment, the shaft portion 72 has a cylindrical portion 72a and a stepped portion 72b. The cylindrical portion 72a is cylindrical. The stepped portion 72b has a larger diameter than the cylindrical portion 72a. The rubber portion 73 has a thick portion 73a and a thin portion 73b. The thick portion 73a is wrapped around the outer peripheral surface of the cylindrical portion 72a. The thin portion 73b is wrapped around the outer peripheral surface of the stepped portion 72b. The stepped portion 72b is located at a position overlapping the protective layer 16. This configuration makes it easier to locally stretch the portion of the current collector 12 where the protective layer 16 is formed, which is difficult to stretch. This effect is more pronounced when the thickness of the thick portion 73a is set to be approximately two to three times the thickness of the thin portion 73b. This effect is more pronounced when the thickness of the rubber portion 63 and the thickness of the thick portion 73a are approximately the same (for example, the thickness of the rubber portion 63 is 0.9 to 1.1 times the thickness of the thick portion 73a).

[0060] In the above-described embodiment, the shaft portion 72 has an inclined portion 72c that inclines from the cylindrical portion 72a toward the stepped portion 72b. By gradually changing the thickness of the rubber portion 73 on the outer peripheral surface of the stepped portion 72b, it is possible to adjust the change in elongation of the current collector 12 at the position corresponding to the inclined portion 72c. The angle of inclination of the inclined portion 72c is not particularly limited. When it is desired to locally stretch the portion of the current collector 12 where the protective layer 16 is formed, the angle of inclination of the inclined portion 72c can be increased. When it is not necessary to locally stretch the portion of the current collector 12 where the protective layer 16 is formed, the angle of inclination of the inclined portion 72c can be decreased. The angle of inclination of the inclined portion 72c can be appropriately set depending on the widths of the protective layer 16 and the uncoated portion 12a, the thicknesses of the protective layer 16 and the current collector 12, the thickness configuration of the rubber portion 73 corresponding to the cylindrical portion 72a and the stepped portion 72b, and the like.

[0061] In the above-described embodiment, the end of the rubber portion 73 is chamfered. This makes it difficult for the electrode active material layer 14 to be compressed by the rubber portion 73. As a result, the load on the electrode active material layer 14 can be reduced.

[0062] In the above-described embodiment, the length of the pressure roll 70 is longer than the width of the uncoated portion 12a. Therefore, the length of the rubber portion 73 is longer than the width of the uncoated portion 12a. The central portion 73f1 of the rubber portion 73 overlaps with the outer end 12a1 of the uncoated portion 12a. As a result, the uncoated portion 12a is compressed by the central portion 73f1 of the rubber portion 73. According to the inventor's findings, the amount of deformation in the surface direction (the direction perpendicular to the compression direction) increases as the central portion 73f1 of the rubber portion 73 increases. Therefore, the uncoated portion 12a is more likely to be stretched even at the outer end 12a1. As a result, the variation in elongation in the uncoated portion 12a is likely to be significant.

[0063] The configuration of the electrode sheet manufacturing apparatus 1 is not limited to the above-described embodiment. Fig. 8 is a schematic diagram of a roll press machine 150 according to another embodiment. Fig. 9 is a schematic diagram of a roll press machine 250 according to another embodiment. The roll press machines 150 and 250 can be used in the electrode sheet manufacturing apparatus 1 instead of the roll press machine 50. The roll press machines 150 and 250 differ in the configuration of the support roll and pressing roll of the roll press machine, but the other configurations may be the same.

[0064] <Roll Press Machine 150> 8, the roll press machine 150 includes a support roll 160 and a pressure roll 170. The support roll 160 and the pressure roll 170 can be driven by a press pressure adjusting mechanism 80 (see FIG. 4).

[0065] <Support Roll 160> As shown in FIG. 6, the support roll 160 (in this embodiment, a main body portion 161) includes a shaft portion 162 and a rubber portion 163.

[0066] <Shaft 162> The shaft portion 162 has a cylindrical portion 162a, a stepped portion 162b, and an inclined portion 162c. Although not shown, the cylindrical portions 162a are provided at both ends of the support roll 160. The stepped portions 162b are sandwiched between the cylindrical portions 162a provided at both ends.

[0067] The cylindrical portion 162a is a generally cylindrical portion whose rotation axis is set to be generally parallel to the rotation axis of the support roll 160. The diameter of the cylindrical portion 162a is generally constant. The cylindrical portion 162a is provided from the outside (end face 160b side) of the shaft portion 162 toward the inside. The cylindrical portion 162a is provided at a position where at least a portion thereof overlaps with the uncoated portion 12a. The cylindrical portion 162a extends outward beyond the outer end 12a1 of the uncoated portion 12a.

[0068] The stepped portion 162b is a portion having a larger diameter than the cylindrical portion 162a. The stepped portion 162b is provided in the shaft portion 162, more inward than the cylindrical portion 162a. The stepped portion 162b is provided at a position where at least a portion thereof overlaps with the inner end 12a2 of the uncoated portion 12a of the electrode sheet 10. In this embodiment, the outer end of the stepped portion 162b approximately coincides with the inner end 12a2 of the uncoated portion 12a. The stepped portion 162b may extend outward beyond the inner end 12a2. The stepped portion 162b is provided at a position where it overlaps with the protective layer 16.

[0069] The inclined portion 162c is a portion that connects the cylindrical portion 162a and the stepped portion 162b. The inclined portion 162c is a portion that is inclined from the cylindrical portion 162a toward the stepped portion 162b. In this embodiment, the inclined portion 162c is inclined so that the diameter increases from the cylindrical portion 162a toward the stepped portion 162b. Note that the inclined portion 162c does not necessarily have to be provided on the shaft portion 162. A rubber portion 163 is wound around the outer circumferential surface 162d of the shaft portion 162.

[0070] <Rubber part 163> The rubber portion 163 is wound around the outer peripheral surface 162d of the shaft portion 162 at least in the region that contacts the uncoated portion 12a. The inner diameter of the rubber portion 163 corresponds to the outer diameter of the shaft portion 162. In this embodiment, the rubber portion 163 covers the entire outer peripheral surface (side peripheral surface) 162d of the shaft portion 162. In other words, the inner peripheral surface 163d of the rubber portion 163 is aligned with the outer peripheral surface 162d of the shaft portion 162. The length of the rubber portion 163 and the length of the shaft portion 162 are approximately the same. The rubber portion 163 is formed in a substantially cylindrical shape. The outer diameter of the rubber portion 163 is approximately constant. In this embodiment, the rubber portion 163 has a thick portion 163a, a thin portion 163b, and an inclined portion 163c. The thick portion 163a is wound around the cylindrical portion 162a of the shaft portion 162. The thin portion 163b is wound around the stepped portion 162b of the shaft portion 162. The inclined portion 163c is wound around the inclined portion 162c of the shaft portion 162.

[0071] The thick portion 163a is thicker than the thin portion 163b. The inclined portion 163c is inclined so as to become thinner from the thick portion 163a toward the thin portion 163b. The sum of the outer diameter of the cylindrical portion 162a and the thickness of the thick portion 163a is approximately the same as the sum of the outer diameter of the stepped portion 162b and the thickness of the thin portion 163b. The sum of the outer diameter of the inclined portion 162c and the thickness of the inclined portion 163c is approximately constant in the axial direction of the support roll 160. Therefore, the diameter of the support roll 160 is approximately constant.

[0072] As described above, the stepped portion 162b overlaps the inner end 12a2 of the uncoated portion 12a. The thin portion 163b of the rubber portion 163 is wrapped around the outer peripheral surface of the stepped portion 162b. As a result, the thickness of the rubber portion at the position overlapping with the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion in an area outside the position overlapping with the protective layer 16. The electrode sheet 10 is supported on the outer peripheral surface 163f of the rubber portion 163. The uncoated portion 12a of the electrode sheet 10 is pressed by the pressing roll 170.

[0073] <Pressing Roll 170> The pressure roll 170 (in this embodiment, a main body 171) includes a shaft 172 and a rubber part 173. The dimensions of the pressure roll 170 and its position relative to the electrode sheet 10 can be the same as those of the pressure roll 70 (see FIG. 6), and therefore detailed description thereof will be omitted.

[0074] <Shaft 172> The shaft portion 172 is a substantially cylindrical member that extends along the width direction of the electrode sheet 10. In this embodiment, the diameter of the shaft portion 172 is substantially constant. A rubber portion 173 is wound around an outer circumferential surface 172d of the shaft portion 172.

[0075] <Rubber part 173> The rubber portion 173 is formed in a substantially cylindrical shape. An inner peripheral surface 173d of the rubber portion 173 corresponds to an outer peripheral surface 172d of the shaft portion 172. The inner diameter of the rubber portion 173 is the same as the outer diameter of the shaft portion 172. In this embodiment, the inner diameter of the rubber portion 173 is substantially constant, just like the outer diameter of the shaft portion 172. The thickness of the rubber portion 173 is substantially constant except for both end portions along the axis of the pressing roll 170. The ends of the rubber portion 173 in the width direction are chamfered, and chamfered portions 173e are formed at the ends. The configuration of the chamfered portions 173e can be the same as the chamfered portion 73e (see FIG. 6), so a detailed description will be omitted.

[0076] As described above, the support roll 160 includes a shaft portion 162 and a rubber portion 163. The rubber portion 163 is wound around the outer peripheral surface 162d of the shaft portion 162 at least in the region that contacts the uncoated portion 12a. The thickness of the rubber portion 163 at the position overlapping the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion 163 in the region outside the position overlapping the inner end 12a2. In this way, the relatively thin portion of the rubber portion may be provided on the support roll side. Even in this case, the uncoated portion 12a is pressed by the thick portion of the rubber portion 163, and the protective layer 16 inside the inner end 12a2 of the uncoated portion 12a can be pressed by the thin portion of the rubber portion 163. This makes it easier to stretch the current collector 12 on which the protective layer 16 is formed and in its vicinity, as in the embodiment shown in FIG. 6. As a result, the variation in elongation of the current collector 12 tends to be small. The current collector 12 after pressing is less likely to suffer from defects such as wrinkles and breakage. This can improve the quality of the electrode sheet 10.

[0077] <Roll Press Machine 250> As shown in Fig. 9, the roll press machine 250 includes a support roll 160 and a pressing roll 70. The support roll 160 and the pressing roll 70 can be driven by a press pressure adjusting mechanism 80 (see Fig. 4). The support roll 160 has a similar configuration to the support roll 160 shown in Fig. 8, and the pressing roll 70 has a similar configuration to the pressing roll 70 shown in Fig. 6, so detailed explanations will be omitted.

[0078] In this embodiment, the thickness of the rubber portion 163 of the support roll 160 at the position overlapping with the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion 163 in the region outside the position overlapping with the inner end 12a2. Furthermore, the thickness of the rubber portion 73 of the pressing roll 70 at the position overlapping with the inner end 12a2 of the uncoated portion 12a is thinner than the thickness of the rubber portion 73 in the region outside the position overlapping with the inner end 12a2. As a result, the region inside the inner end 12a2 of the uncoated portion 12a (protective layer 16) is compressed by the relatively thin rubber portions 73, 163 of both the support roll 160 and the pressing roll 70. This allows the total amount of deformation of the rubber portions 73, 163 to be increased. The increased deformation of the rubber portions 73, 163 makes it easier for the current collector 12 on which the protective layer 16 is formed and the vicinity thereof to be stretched.

[0079] In the roll press machine 250 shown in FIG. 9, the outer end of the thin portion 163b of the rubber portion 163 of the support roll 160 and the outer end of the thin portion 73b of the rubber portion 73 of the pressing roll 70 are set at approximately the same position. However, this is not limited to this configuration. In at least one of the rubber portion 163 of the support roll 160 and the rubber portion 73 of the pressing roll 70, the thickness of the rubber portion at a position overlapping with the inner end 12a2 of the uncoated portion 12a may be thinner than the thickness of the rubber portion in a region outside the position overlapping with the inner end 12a2. In this embodiment, the shaft portion 162 of the support roll 160 is the second shaft portion, and the rubber portion 163 is the second rubber portion.

[0080] The technology disclosed herein has been described in various ways. Unless otherwise specified, the embodiments and the like described herein do not limit the present invention. Furthermore, the technology disclosed herein can be modified in various ways, and as long as no particular problems arise, each component and each process described herein can be omitted or combined as appropriate. Furthermore, this specification includes the disclosures described in the following sections.

[0081] Section 1: A manufacturing apparatus for manufacturing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along a length direction of the current collector at a predetermined position in a width direction thereof, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer, a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll disposed on the transport path and configured to support, along a width direction, a first surface of the electrode sheet transported along the transport path; a pressing roll disposed on the second surface of the electrode sheet so as to face the support roll; a driving device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Equipped with the pressing roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end; Electrode sheet manufacturing equipment.

[0082] Section 2: the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, Item 1. The electrode sheet manufacturing apparatus according to item 1, wherein the thickness of the second rubber portion at a position overlapping the inner end of the unformed portion is thinner than the thickness of the second rubber portion in an area outside the position overlapping the inner end.

[0083] Section 3: A manufacturing apparatus for manufacturing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along a length direction of the current collector at a predetermined position in a width direction thereof, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer, a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll disposed on the transport path and configured to support, along a width direction, a first surface of the electrode sheet transported along the transport path; a pressing roll disposed on the second surface of the electrode sheet so as to face the support roll; a driving device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Equipped with the support roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end; Electrode sheet manufacturing equipment.

[0084] Section 4: The shaft portion has a cylindrical column portion and a step portion having a diameter larger than that of the cylindrical column portion, the rubber portion has a thick portion wound around an outer circumferential surface of the cylindrical portion and a thin portion wound around an outer circumferential surface of the stepped portion, 4. The electrode sheet manufacturing apparatus according to any one of items 1 to 3, wherein the step portion is provided at a position overlapping the protective layer.

[0085] Section 5: Item 5. The electrode sheet manufacturing apparatus according to item 4, wherein the shaft portion has an inclined portion that inclines from the cylindrical portion toward the step portion.

[0086] Item 6: Item 6. The electrode sheet manufacturing apparatus according to item 4 or 5, wherein the thickness of the thick portion is two to three times the thickness of the thin portion.

[0087] Section 7: the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, 7. The electrode sheet manufacturing apparatus according to any one of items 4 to 6, wherein the thickness of the second rubber portion is 0.9 to 1.1 times the thickness of the thick portion.

[0088] Section 8: 8. The electrode sheet manufacturing apparatus according to any one of items 1 to 7, wherein the end of the rubber portion is chamfered.

[0089] Section 9: The length of the rubber portion is longer than the width of the unformed portion, Item 9. The electrode sheet manufacturing apparatus according to any one of items 1 to 8, wherein a center portion of the rubber portion overlaps an outer end of the unformed portion.

[0090] Section 10: a preparation step of preparing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along the length direction of the current collector at a predetermined position in the width direction, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer; a roll press process in which the electrode sheet is sandwiched and pressed between a support roll and a press roll while being transported along a predetermined transport path; Including, the pressing roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end, In the roll press step, the electrode sheet is pressed using the pressing roll. Manufacturing method of electrode sheet.

[0091] Section 11: the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, Item 11. The method for manufacturing an electrode sheet according to item 10, wherein the thickness of the second rubber portion at a position overlapping the inner end of the unformed portion is thinner than the thickness of the second rubber portion in an area outside the position overlapping the inner end.

[0092] Section 12: a preparation step of preparing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along the length direction of the current collector at a predetermined position in the width direction, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer; a roll press process in which the electrode sheet is sandwiched and pressed between a support roll and a press roll while being transported along a predetermined transport path; Including, the support roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end, In the roll pressing step, the electrode sheet is pressed using the support roll. Manufacturing method of electrode sheet.

[0093] Section 13: The shaft portion has a cylindrical column portion and a step portion having a diameter larger than that of the cylindrical column portion, the rubber portion has a thick portion wound around an outer circumferential surface of the cylindrical portion and a thin portion wound around an outer circumferential surface of the stepped portion, Item 13. The method for manufacturing an electrode sheet according to any one of items 10 to 12, wherein the step portion is provided at a position overlapping the protective layer.

[0094] Section 14: Item 14. The method for manufacturing an electrode sheet according to item 13, wherein the shaft portion has an inclined surface that slopes from the columnar portion toward the step portion.

[0095] Section 15: Item 15. The method for producing an electrode sheet according to Item 13 or 14, wherein the thickness of the thick portion is two to three times the thickness of the thin portion.

[0096] Section 16: the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, Item 16. The method for manufacturing an electrode sheet according to any one of items 13 to 15, wherein the thickness of the second rubber portion is 0.9 to 1.1 times the thickness of the thick portion.

[0097] Section 17: Item 17. The method for producing an electrode sheet according to any one of items 10 to 16, wherein the end of the rubber part is chamfered.

[0098] Section 18: The length of the rubber portion is longer than the width of the unformed portion, Item 18. The method for producing an electrode sheet according to any one of Items 10 to 17, wherein in the roll pressing step, a position where a center part of the rubber part overlaps with an outer end of the unformed part is pressed. [Explanation of symbols]

[0099] 1. Electrode sheet manufacturing equipment 10 Electrode sheet 10D Bottom 10U top 12 Current collector 12a Uncoated area (unformed area) 12a1 outer edge 12a2 inner edge 12b Coating Department 14 Electrode active material layer 14a End 14f Bottom 16 Protective layer 17. Conveying equipment 17a Unwinding roll 17b Winding roll 18 Transport Route 50,150,250 Roll press machine 60,160 support rolls 61,161 Main body 62,162 Shaft 62d Outer surface 63,163 Rubber part 63d,163d Inner surface 63f,163f Outer surface 66 Both shafts 70, 70L, 70R, 170 pressure roll 70a,70b end face 71,171 Main body 72,172 Shaft 72a Cylindrical part 72b Step 72c Slope 72d,172d Outer surface 73,173 Rubber part 73a Thick part 73b Thin section 73c Slope 73d,173d Inner surface 73e,173e Chamfered part 73f Outer surface 73f1 central part 76 Both shafts 80 Press pressure adjustment mechanism 81, 81L, 81R Press Cylinder 81a Rod 82 Roll Chock 83 Cylinder drive unit 84 Roll drive unit 85 Support part 90 Roll press machine 91,92 Rolling mill 100 control device 160b end face 162a Cylinder 162b Step 162c Slope 162d Outer surface 163a thick part 163b Thin section 163c Slope A1, A2 Rubber

Claims

1. A manufacturing apparatus for manufacturing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along a length direction of the current collector at a predetermined position in a width direction thereof, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer, a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll disposed on the transport path and configured to support, along a width direction, a first surface of the electrode sheet transported along the transport path; a pressing roll disposed on the second surface of the electrode sheet so as to face the support roll; a driving device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Equipped with the pressing roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end; Electrode sheet manufacturing equipment.

2. the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, 2. The electrode sheet manufacturing apparatus according to claim 1, wherein the thickness of the second rubber portion at a position overlapping the inner end of the unformed portion is thinner than the thickness of the second rubber portion in an area outside the position overlapping the inner end.

3. A manufacturing apparatus for manufacturing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along a length direction of the current collector at a predetermined position in a width direction thereof, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer, a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll disposed on the transport path and configured to support, along a width direction, a first surface of the electrode sheet transported along the transport path; a pressing roll disposed on the second surface of the electrode sheet so as to face the support roll; a driving device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Equipped with the support roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end; Electrode sheet manufacturing equipment.

4. The shaft portion has a cylindrical column portion and a step portion having a diameter larger than that of the cylindrical column portion, the rubber portion has a thick portion wound around an outer circumferential surface of the cylindrical portion and a thin portion wound around an outer circumferential surface of the stepped portion, The electrode sheet manufacturing apparatus according to any one of claims 1 to 3, wherein the step portion is provided at a position overlapping the protective layer.

5. The electrode sheet manufacturing device according to claim 4 , wherein the shaft portion has an inclined portion that is inclined from the cylindrical portion toward the step portion.

6. The electrode sheet manufacturing device according to claim 4 , wherein the thickness of the thick portion is between two and three times the thickness of the thin portion.

7. the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, The electrode sheet manufacturing device according to claim 4 , wherein the thickness of the second rubber portion is 0.9 to 1.1 times the thickness of the thick portion.

8. 4. The electrode sheet manufacturing apparatus according to claim 1, wherein an end of the rubber portion is chamfered.

9. The length of the rubber portion is longer than the width of the unformed portion, 4. The electrode sheet manufacturing device according to claim 1, wherein a central portion of the rubber portion overlaps an outer end of the unformed portion.

10. a preparation step of preparing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along the length direction of the current collector at a predetermined position in the width direction, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer; a roll press process in which the electrode sheet is sandwiched and pressed between a support roll and a press roll while being transported along a predetermined transport path; Including, the pressing roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end, In the roll press step, the electrode sheet is pressed using the pressing roll. Manufacturing method of electrode sheet.

11. the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, The method for manufacturing an electrode sheet according to claim 10, wherein the thickness of the second rubber portion at a position overlapping the inner end of the unformed portion is thinner than the thickness of the second rubber portion in an area outside the position overlapping the inner end.

12. a preparation step of preparing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along the length direction of the current collector at a predetermined position in the width direction, an electrode active material layer formed on a portion of the current collector excluding the unformed portion, and a protective layer formed along the length direction of the electrode active material layer; a roll press process in which the electrode sheet is sandwiched and pressed between a support roll and a press roll while being transported along a predetermined transport path; Including, the support roll includes a shaft portion and a rubber portion wound around an outer circumferential surface of the shaft portion at least in a region that contacts the unformed portion, a thickness of the rubber portion at a position overlapping with an inner end of the unformed portion is thinner than a thickness of the rubber portion in a region outside the position overlapping with the inner end, In the roll pressing step, the electrode sheet is pressed using the support roll. Manufacturing method of electrode sheet.

13. The shaft portion has a cylindrical column portion and a step portion having a diameter larger than that of the cylindrical column portion, the rubber portion has a thick portion wound around an outer circumferential surface of the cylindrical portion and a thin portion wound around an outer circumferential surface of the stepped portion, The method for manufacturing an electrode sheet according to any one of claims 10 to 12, wherein the step portion is provided at a position overlapping the protective layer.

14. The method for manufacturing an electrode sheet according to claim 13 , wherein the shaft portion has an inclined surface that is inclined from the columnar portion toward the step portion.

15. The method for manufacturing an electrode sheet according to claim 13 , wherein the thickness of the thick portion is between two and three times the thickness of the thin portion.

16. the support roll includes a second shaft portion and a second rubber portion wound around an outer circumferential surface of the second shaft portion at least in a region that contacts the unformed portion, The method for manufacturing an electrode sheet according to claim 13 , wherein the thickness of the second rubber portion is 0.9 to 1.1 times the thickness of the thick portion.

17. The method for manufacturing an electrode sheet according to any one of claims 10 to 12, wherein the end of the rubber portion is chamfered.

18. The length of the rubber portion is longer than the width of the unformed portion, The method for manufacturing an electrode sheet according to any one of claims 10 to 12, wherein in the roll press step, a position where a center part of the rubber part overlaps an outer end of the unformed part is pressed.

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