Electrode sheet manufacturing device

Abstract

To make an unformed portion of an electrode sheet easily and uniformly stretchable.SOLUTION: An electrode sheet manufacturing device 1 includes: a support roll 61 for supporting an electrode sheet 10; a pressing roll 62 disposed to face the support roll 61 with the electrode sheet 10 interposed therebetween, at least the outer peripheral surface of the pressing roll 62 being formed of rubber; and a control device 100. In the control device 100, a movement control unit 105 moves a pressing roll 62 from a first position P1 away from the electrode sheet 10 toward a second position P2 at which the pressing roll 62 contacts the electrode sheet 10 before conveyance of the electrode sheet 10 is started, a conveyance control unit 107 conveys the electrode sheet 10 after the pressing roll 62 has moved to the second position P2, and a pressing control unit 109 presses the pressing roll 62 against the electrode sheet 10 from the second position P2 when conveyance of the electrode sheet 10 is started or when a reference time T2 has elapsed after conveyance of the electrode sheet 10 is started.SELECTED DRAWING: Figure 9

Description

[Technical Field]

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

[0002] For example, Japanese Patent Application Laid-Open No. 2023-36089 discloses a method for manufacturing an electrode in a precursor sheet (in other words, an electrode sheet) having a metal foil, a coated portion on the metal foil where an electrode material is coated, and an uncoated portion on the metal foil where the electrode material is not coated, in which the uncoated portion is pressed with a pair of elastic rolls (in other words, rubber rolls).

[0003] For example, when an uncoated portion is pressed with a roll other than an elastic roll, tensile force or the like can cause voids to form inside the uncoated portion. These voids can cause the uncoated portion to break. By pressing the uncoated portion with a pair of elastic rolls, it is possible to apply a compressive force and a deforming force to the same location on the uncoated portion. This compressive force is a force that occurs when the pair of elastic rolls come into contact with each other and deform the elastic rolls. This allows the uncoated portion to be stretched while preventing breakage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-36089 Summary of the Invention [Problem to be solved by the invention]

[0005] In the electrode manufacturing method disclosed in JP 2023-36089 A, if the elastic roll is kept pressed against the precursor sheet, the pressed portion of the elastic roll may be locally deformed. If the locally deformed elastic roll rotates and presses the uncoated portion, there is a risk that the degree of stretching of the uncoated portion may differ. [Means for solving the problem]

[0006] The electrode sheet manufacturing apparatus disclosed herein is a manufacturing apparatus for manufacturing an electrode sheet having a current collector made of a long metal foil, an unformed portion set along the length of the current collector at a predetermined position in the width direction, and an electrode active material layer containing an electrode active material formed on the current collector at a portion excluding the unformed portion. The electrode sheet manufacturing apparatus includes a conveying device that conveys the electrode sheet along a predetermined conveying path, a support roll disposed on the conveying path and supporting a first surface of the electrode sheet conveyed along the conveying path along the width direction, a pressing roll disposed opposite the support roll on the second surface of the electrode sheet, a driving device that presses the pressing roll against the support roll while sandwiching the electrode sheet, and a control device. The pressing roll is a rubber roll having at least an outer peripheral surface formed of rubber, and is disposed so as to sandwich the unformed portion of the electrode sheet excluding the electrode active material layer between itself and the support roll. The driving device includes a moving mechanism and a pressing mechanism. The movement mechanism moves the pressure roll between a first position where the pressure roll is separated from the electrode sheet and a second position where the pressure roll is brought into contact with the electrode sheet. The press mechanism presses the pressure roll against the electrode sheet from the second position. The control device includes a movement control unit, a transport control unit, and a pressure control unit. The movement control unit moves the pressure roll from the first position toward the second position before the transport device starts transporting the electrode sheet. The transport control unit transports the electrode sheet along the support roll after the movement control unit moves the pressure roll to the second position. The pressure control unit presses the pressure roll against the electrode sheet from the second position when the transport control unit starts transporting the electrode sheet or when a predetermined reference time has elapsed since the transport control unit started transporting the electrode sheet.

[0007] According to the electrode sheet manufacturing apparatus disclosed herein, conveyance of the electrode sheet is initiated after the pressing roll is positioned at the second position. Then, when conveyance of the electrode sheet is initiated, or when a reference time has elapsed since conveyance of the electrode sheet was initiated, the pressing roll is pressed against the electrode sheet from the second position. This delays the timing at which the pressing roll is pressed against the electrode sheet from the second position, making it difficult for the pressing roll to deform locally. Therefore, the unformed portion of the electrode sheet can be pressed using the pressing roll and support roll, which are difficult to deform locally, making it easier to uniformly stretch the unformed portion. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a flow diagram of production using an electrode sheet production apparatus. [Figure 2] FIG. 2 is a schematic diagram of an electrode sheet. [Figure 3] FIG. 3 is a schematic side view of an electrode sheet manufacturing apparatus. [Figure 4] FIG. 4 is a front view of the roll press machine. [Figure 5] FIG. 5 is a cross-sectional view taken along the line AA in FIG. [Figure 6] FIG. 6 is a view equivalent to FIG. 5, showing a state in which the pressing roll is disposed at the first position. [Figure 7] FIG. 7 is a view equivalent to FIG. 5, showing a state in which the pressing roll is disposed at the second position and the press cylinder is OFF. [Figure 8] FIG. 8 is a block diagram of an electrode sheet manufacturing device. [Figure 9] FIG. 9 is a flowchart showing the procedure of the preprocessing. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of the technology disclosed herein will be described with reference to the drawings. It should be noted that the embodiment described here is not intended to limit the present invention in any way. Each drawing is a schematic diagram and does not necessarily faithfully reflect an 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.

[0010] 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 a conveying step S1, a measuring step S2, a kneading step S3, a coating step S4, a drying step S5, and a roll press step S6. However, production using the electrode sheet manufacturing apparatus 1 may also include other steps.

[0011] 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 has a positive electrode sheet or a negative electrode sheet of an electrode body that is 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.

[0012] FIG. 2 is a schematic diagram of an electrode sheet 10. As shown in FIG. 2, the electrode sheet 10 is in the form of a long strip. The electrode sheet 10 includes a current collector 12 and an electrode active material layer 14. 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. As an example of the current collector 12, a positive electrode current collector foil can be used, for example, aluminum or an aluminum alloy. As another example of the current collector 12, a negative electrode current collector foil can be used, for example, copper or a copper alloy. The electrode active material layer 14 is coated at 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. As an example of the electrode active material, a lithium transition metal composite oxide can be used as the positive electrode active material. As another example of the electrode active material, a negative electrode active material can be used as the negative electrode active material. For example, a carbon material, a silicon-based material, or a mixed oxide thereof can be used. The electrode active material layer may contain additives other than the electrode active material, such as a binder or a conductive material.

[0013] The electrode sheet 10 is formed by applying an electrode composite 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 an example of an unformed portion. The uncoated portion 12a is a portion of the current collector 12 that is not coated with the electrode active material layer 14. The uncoated portion 12a is set along the length of the current collector 12 at a predetermined position in the width direction. The uncoated portion 12a is set along the length of the electrode sheet 10 at an end in the width direction. In this embodiment, the uncoated portion 12a is set at both ends in the width direction of the electrode sheet 10. The coated portion 12b is located between the uncoated portions 12a at both ends of the electrode sheet 10. The coated portion 12b is a portion of the current collector 12 that is coated with the electrode active material layer 14. The electrode mixture slurry is applied to the coated portion 12b. As a result, an electrode active material layer 14 is formed in the coated portion 12b of the current collector 12. That is, the electrode active material layer 14 is disposed between the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction. The electrode active material layer 14 is formed in the current collector 12 except for the uncoated portion 12a. Although not shown, a protective layer containing an inorganic filler may be provided at the boundary between the uncoated portion 12a and the coated portion 12b. If a protective layer is formed, when an EPS rubber roll is pressed against the electrode sheet, the elongation percentage may not be the same between the portion where the protective layer is formed and the portion where the protective layer is not formed.

[0014] In the conveying step S1 shown in FIG. 1, an electrode sheet 10 is conveyed. FIG. 3 is a schematic side view of the electrode sheet manufacturing apparatus 1. In this embodiment, the electrode sheet manufacturing apparatus 1 includes a conveying device 15. The conveying step S1 can be achieved by the conveying device 15. The conveying device 15 conveys the electrode sheet 10. A motor, for example, is used for the conveying device 15. The conveying device 15 includes an unwinding roll 15a and a take-up roll 15b so as to convey the electrode sheet 10 at a predetermined conveying speed. The electrode sheet 10 is wound around the unwinding roll 15a and the take-up roll 15b. The unwinding roll 15a is arranged upstream of a roll press machine 60, which will be described later, in the conveying direction. The take-up roll 15b is arranged downstream of the roll press machine 60 in the conveying direction. However, the conveying device 15 is not limited to a configuration including the unwinding roll 15a and the take-up roll 15b. For example, the transport device 15 may be provided with rolls in addition to the unwinding roll 15a and the winding roll 15b. The transport device 15 transports the electrode sheet 10 along a predetermined transport path 18.

[0015] 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 by a measuring device (not shown) having, for example, 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 by a coating device (not shown) such as a slit coater, gravure coater, die coater, or comma coater. In the drying step S5 shown in FIG. 1, the applied raw materials for the electrode active material layer 14 in a slurry state are dried. The drying step S5 can be achieved by a drying device (not shown) that emits, for example, hot air or infrared rays.

[0016] In the roll press step S6 shown in FIG. 1, the electrode sheet 10 is pressed. The electrode sheet 10 is stretched by being pressed. The roll press step S6 can be achieved by a roll press machine 60 shown in FIG. 3. The electrode sheet manufacturing apparatus 1 is equipped with the roll press machine 60. As shown in FIG. 3, the electrode sheet 10 is pressed by the roll press machine 60 midway along the conveyance path 18. The electrode sheet 10 is supplied to the roll press machine 60 by an unwinding roll 15a. The electrode sheet 10 pressed by the roll press machine 60 is conveyed toward the take-up roll 15b and taken up by the take-up roll 15b. The electrode sheet manufacturing apparatus 1 is equipped with a control device 100 that controls the unwinding roll 15a, the take-up roll 15b, and the roll press machine 60.

[0017] FIG. 4 is a front view of a roll press machine 60. The roll press machine 60 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 of the electrode sheet 10. When the uncoated portion 12a is pressed by the rubber roll, the portion pressed by the rubber roll is pressed and stretched due to the reaction force of the elastic deformation and compressive deformation of the rubber roll. As a result, the uncoated portion 12a can be stretched while preventing breakage of the uncoated portion 12a. Due to 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. The electrode sheet manufacturing apparatus 1 may also include a device that presses the coated portion 12b in addition to the roll press machine 60.

[0018] As shown in FIG. 4, the roll press machine 60 includes a support roll 61 , a pressing roll 62 , and a driving device 65 .

[0019] The support roll 61 is disposed on the conveying path 18 (see FIG. 3). The support roll 61 supports the first surface 10D of the electrode sheet 10 conveyed along the conveying path 18 in the width direction of the electrode sheet 10. The electrode sheet 10 has a first surface 10D and a second surface 10U. In this embodiment, the first surface 10D forms the lower surface of the electrode sheet 10. The second surface 10U is the surface of the electrode sheet 10 opposite to the first surface 10D. Here, the second surface 10U forms the upper surface of the electrode sheet 10. The support roll 61 is disposed below the pressing roll 62. The support roll 61 is a rubber roll that presses the uncoated portion 12a of the electrode sheet 10 together with the pressing roll 62. In this embodiment, the support roll 61 has a main body portion 61a and two shaft portions 61b.

[0020] FIG. 5 is a cross-sectional view of the AA section in FIG. 4. FIG. 5 shows a state in which the uncoated portion 12a is pressed by the support roll 61 and the pressing roll 62. FIG. 5 also shows a state in which the pressing roll 62 is disposed at the second position P2 and a press cylinder 71 (see FIG. 4), which will be described later, is ON. As shown in FIG. 5, the main body 61a includes a shaft portion 61aa and a rubber portion 61ab. The shaft portion 61aa is made of metal. The material forming the shaft portion 61aa is not particularly limited, but is, for example, a material with relatively high hardness such as SUS304 (stainless steel). The rubber portion 61ab is arranged to cover at least the outer peripheral surface of the shaft portion 61aa. The material forming the rubber portion 61ab is, for example, nitrile rubber (NBR). The support roll 61 presses the uncoated portion 12a of the electrode sheet 10 with the rubber portion 61ab.

[0021] The support roll 61 is rotated in a predetermined direction by a rotation mechanism 74 (see FIG. 4), which will be described later. In this embodiment, the support roll 61 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 FIG. 5. That is, in FIG. 5, the left side is the upstream side in the transport direction, and the right side is the downstream side in the transport direction.

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

[0023] As shown in FIG. 5, the pressing roll 62 is a member that presses (in other words, presses) the electrode sheet 10 against the support roll 61. The pressing roll 62 is arranged so as to face the support roll 61 on the second surface 10U (here, the upper surface) of the electrode sheet 10. The pressing roll 62 is arranged so as to sandwich the uncoated portion 12a of the electrode sheet 10 between itself and the support roll 61, excluding the coated portion 12b (see FIG. 2). Here, the axial center position of the pressing roll 62 and the axial center position of the support roll 61 are aligned in the vertical direction. As shown in FIG. 4, the pressing roll 62 is a rubber roll having at least an outer peripheral surface made of rubber. The pressing roll 62 is a rubber roll that presses the uncoated portion 12a of the electrode sheet 10 together with the support roll 61. The pressing roll 62 is not arranged 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 set at both ends in the width direction of the electrode sheet 10, and there are two of them. Therefore, as shown in FIG. 4, a pressing roll 62 is disposed above each uncoated portion 12a at both ends in the width direction of the electrode sheet 10. There are two pressing rolls 62. However, the number of uncoated portions 12a may be one, and when there is one uncoated portion 12a, there may be only one pressing roll 62. Of the two pressing rolls 62, the one located on the left will be referred to as pressing roll 62L, and the one located on the right will be referred to as pressing roll 62R. However, when describing either pressing roll 62L or 62R, the term pressing roll 62 will be used as appropriate. In this embodiment, the pressing roll 62 includes a main body portion 62a and two shaft portions 62b.

[0024] As shown in FIG. 5, the main body 62a includes a shaft 62aa and a rubber portion 62ab. The shaft 62aa is made of metal. The material for the shaft 62aa is not particularly limited, but may be, for example, a material with a relatively high hardness such as SUS304 (stainless steel). The rubber portion 62ab is disposed so as to cover at least the outer peripheral surface of the shaft 62aa. The material for the rubber portion 62ab is not particularly limited, but may be, for example, nitrile rubber (NBR). The pressing roll 62 presses the uncoated portion 12a of the electrode sheet 10 with the rubber portion 62ab.

[0025] As shown in Fig. 4, both shaft portions 62b are inserted into the main body portion 62a. Both shaft portions 62b are inserted into shaft portions 62aa (see Fig. 5) of the main body portion 62a. Both shaft portions 62b extend to the outside in the axial direction of the two pressing rolls 62. Although not shown, both shaft portions 62b are fitted with bearings, gap screws for adjusting the gap between the support roll 61 and the pressing roll 62, and the like.

[0026] As shown in Fig. 5, when the support roll 61 and the pressure roll 62 sandwich the electrode sheet 10 and the support roll 61 rotates in the direction of arrow R1, the pressure roll 62 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 61 and the pressure roll 62 are in contact, the pressure roll 62 receives a force rotating in the direction of arrow R2 due to the force of the rotation of the support roll 61. As a result, the pressure roll 62 rotates in the direction of arrow R2. In other words, the pressure roll 62 is a driven roll that rotates in conjunction with the rotation of the support roll 61.

[0027] The driving device 65 is a device that presses the pressure roll 62 against the support roll 61 with the electrode sheet 10 sandwiched between them. Here, as shown in FIG. 4, the driving device 65 includes a moving mechanism 68 and a pressing mechanism 70.

[0028] FIG. 6 is a view equivalent to FIG. 5 showing the state in which the pressing roll 62 is disposed at the first position P1. The movement mechanism 68 is a mechanism that moves the pressing roll 62 between the first position P1 (see FIG. 6) and the second position P2 (see FIG. 5). Here, the first position P1 and the second position P2 refer to the positions of the pressing roll 62 relative to the support roll 61 (e.g., the electrode sheet 10 supported by the support roll 61). The first position P1 refers to the position of the pressing roll 62 when it is separated from the electrode sheet 10 supported by the support roll 61, as shown in FIG. 6. At the first position P1, the pressing roll 62 is disposed above the support roll 61 and is spaced apart from the support roll 61. The second position P2 refers to the position of the pressing roll 62 when it contacts the electrode sheet 10 supported by the support roll 61, as shown in FIG. 5. At the second position P2, the pressing roll 62 contacts the second surface 10U of the electrode sheet 10. The second position P2 is located below the first position P1. At the second position P2, the pressing roll 62 rests on the electrode sheet 10 due to its own weight. When the electrode sheet 10 is not supported on the support roll 61 and the pressing roll 62 is at the second position P2, the pressing roll 62 comes into contact with the support roll 61. In this embodiment, the movement mechanism 68 is a mechanism that moves the pressing roll 62 between the first position P1 and the second position P2. The movement mechanism 68 is a mechanism that moves the pressing roll 62 in the vertical direction. The configuration of the movement mechanism 68 is not particularly limited, and it may be configured integrally with a press cylinder 71 (see FIG. 4 ) described later, or may be realized by the press cylinder 71. For example, the movement mechanism 68 may be configured so that the pressing roll 62 moves along a rod 71a (described later) of the press cylinder 71.

[0029] 4, the press mechanism 70 is a mechanism that presses, i.e., presses, the pressure roll 62 against the electrode sheet 10. The press mechanism 70 is a mechanism that adjusts the force (i.e., the press pressure) with which the pressure roll 62 presses the electrode sheet 10. The press mechanism 70 includes a press cylinder 71, a roll chock 72, and a cylinder drive device 73.

[0030] The press cylinders 71 press the pressure roll 62 against the support roll 61. One press cylinder 71 is arranged on each end of the pressure roll 62, one on the outside. Here, in FIG. 4, the press cylinder 71 arranged to the left of the electrode sheet 10 will be referred to as the press cylinder 71L, and the press cylinder 71 arranged to the right of the electrode sheet 10 will also be referred to as the press cylinder 71R. However, when describing matters common to the press cylinders 71L and 71R, they will also be referred to as the press cylinder 71. In this embodiment, the press cylinder 71 is a pneumatic cylinder. The press cylinder 71 includes a rod 71a. The rod 71a is connected to a roll chock 72. The roll chock 72 is a member that rotatably supports both shaft portions 62b of the pressure roll 62. When the press cylinder 71 is driven and the rod 71a descends, the pressure roll 62 descends. As the pressing roll 62 descends, the pressing roll 62 is pressed against the support roll 61, increasing the pressing pressure. When the press cylinder 71 is driven and the rod 71a rises, the pressing roll 62 rises. As the pressing roll 62 rises, the pressing pressure decreases.

[0031] The cylinder driving device 73 is a device that presses the pressing roll 62 against the support roll 61. The cylinder driving device 73 is connected to the press cylinder 71. The cylinder driving device 73 drives the press cylinder 71, thereby raising and lowering the rod 71a of the press cylinder 71. In this embodiment, the cylinder driving device 73 is configured to be able to independently drive the press cylinder 71L and the press cylinder 71R. In other words, the cylinder driving device 73 independently drives the pressing rolls 62 arranged above the uncoated portions 12a at both ends of the electrode sheet 10 in the width direction. The cylinder driving device 73 is connected to a control device 100 (see FIG. 3).

[0032] In this embodiment, the press cylinder 71 is configured to be switchable between ON and OFF by a cylinder drive device 73. When the press cylinder 71 is OFF, the cylinder drive device 73 is not driven, and the press cylinder 71 is not pressing the press roll 62 against the electrode sheet 10. When the press cylinder 71 is ON, the cylinder drive device 73 is driven, and the cylinder drive device 73 and the press cylinder 71 press the press roll 62 against the electrode sheet 10.

[0033] FIG. 7 is a diagram equivalent to FIG. 5 , illustrating a state in which the press roll 62 is disposed at the second position P2 and the press cylinder 71 is OFF. Here, when the press roll 62 is at the second position P2, the press cylinder 71 is switched ON and OFF. As shown in FIG. 7 , for example, when the press roll 62 is at the second position P2 and the press cylinder 71 is OFF, the press roll 62 is not pressed against the electrode sheet 10 by the press cylinder 71, but is placed on the electrode sheet 10 supported by the support roll 61. At this time, the press roll 62 may be pressed somewhat against the electrode sheet 10 due to its own weight. Here, when the press roll 62 is at the second position P2 and the press cylinder 71 is OFF, the press roll 62 presses against the electrode sheet 10 with a predetermined first load value V1. The specific value of this first load value V1 is not particularly limited, but for example, the first load value is 800 N or less.

[0034] As shown in FIG. 5 , for example, when the pressure roll 62 is at the second position P2 and the press cylinder 71 is ON, the cylinder drive device 73 drives the pressure roll 62, causing the press cylinder 71 to press the pressure roll 62 against the electrode sheet 10. Here, when the pressure roll 62 is at the second position P2 and the press cylinder 71 is ON, the pressure roll 62 presses the electrode sheet 10 with a predetermined second load value V2. This second load value V2 is greater than the first load value V1. The specific value of the second load value V2 is not particularly limited, but may be, for example, 1000 N to 4000 N, or 2000 N to 3000 N. The second load value V2 is approximately 10 to 80 times the first load value V1, for example, approximately 10 to 30 times the first load value V1. The relationship between the magnitude of the first load value V1 and the magnitude of the second load value V2 may vary depending on the specific value of the first load value V1.

[0035] In this embodiment, as shown in FIG. 4, the electrode sheet manufacturing apparatus 1 includes a rotation mechanism 74 and a support unit 75. The rotation mechanism 74 is a mechanism for rotating the support roll 61. The rotation mechanism 74 is connected to the support roll 61. In this embodiment, the rotation mechanism 74 rotates the support roll 61 in the direction of arrow R1 shown in FIG. 5. However, the rotation mechanism 74 can also rotate the support roll 61 in the direction opposite to the arrow R1. The configuration of the rotation mechanism 74 is not particularly limited, and may include, for example, an electric motor, gears, etc. The rotation mechanism 74 is connected to a control device 100 (see FIG. 3).

[0036] The support portion 75 is a member that supports the support roll 61. The support portion 75 supports both shaft portions 61b of the support roll 61.

[0037] The control device 100 shown in FIG. 3 controls the roll press machine 60 as described above. The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but may include, for example, an I / F, a CPU, a ROM, a RAM, and a storage device. FIG. 8 is a block diagram of the electrode sheet manufacturing apparatus 1. As shown in FIG. 8, the control device 100 is communicatively connected to, for example, the conveying device 15, the moving mechanism 68, the press mechanism 70 (more specifically, the cylinder driving device 73), and the rotation mechanism 74. The control device 100 controls the conveying device 15, the moving mechanism 68, the press mechanism 70, and the rotation mechanism 74.

[0038] The electrode sheet manufacturing apparatus 1 according to this embodiment has been described above. As described above, the pressure roll 62 is a rubber roll having at least its outer peripheral surface made of rubber. Therefore, as shown in FIG. 5 , when the pressure roll 62 is pressed against the electrode sheet 10, the outer peripheral surface of the pressure roll 62 is easily deformed. In particular, the portion of the outer peripheral surface of the pressure roll 62 that is pressed against the electrode sheet 10 may deform. This deformed portion of the pressure roll 62 may become flat to conform to the shape of the electrode sheet 10. If the pressure roll 62 is kept pressed against the electrode sheet 10 for a long period of time without rotating, the deformed portion of the pressure roll 62 may become permanently deformed. If a pressure roll 62 in this partially deformed state (e.g., a permanently deformed state) rotates and presses the electrode sheet 10 to stretch the uncoated portion 12 a of the electrode sheet 10, uniform stretching may not be achieved. For example, the portion of the uncoated section 12a pressed by the deformed portion of the pressing roll 62 may be stretched less than the portion of the uncoated section 12a pressed by the non-deformed portion of the pressing roll 62. As a result, it may be difficult to stretch the uncoated section 12a uniformly.

[0039] Furthermore, if the pressure roll 62 is not rotated and is kept pressed against the electrode sheet 10 for a long period of time, the pressed portion of the pressure roll 62 may be permanently deformed, which may result in excessive stretching of the uncoated portion 12a of the electrode sheet 10. As a result, the excessively stretched uncoated portion 12a of the electrode sheet 10 may break.

[0040] Furthermore, if the support roll 61 is rotated by the rotation mechanism 74 and the pressure roll 62 is placed against the electrode sheet 10 to sandwich the electrode sheet 10, the difference in rotation speed between the support roll 61 and the pressure roll 62 may prevent the uncoated portion 12a from being properly stretched (for example, causing breakage).

[0041] Therefore, in this embodiment, in order to stretch the uncoated portion 12a as uniformly as possible, a predetermined pre-processing is controlled by the control device 100 before stretching the uncoated portion 12a of the electrode sheet 10. In this embodiment, as shown in Fig. 8, the control device 100 includes a memory unit 101, a tension adjustment unit 103, a movement control unit 105, a conveyance control unit 107, a pressing control unit 109, and a stretching control unit 111. Note that each unit of the control device 100 may be realized by one or more processors or may be realized by a circuit.

[0042] Next, the pretreatment that is performed before the uncoated portion 12a of the electrode sheet 10 is pressed and stretched by the roll press machine 60 will be described with reference to the flowchart in Fig. 9. As shown in Fig. 6, this pretreatment is started when the electrode sheet 10 is supported by the support roll 61 and the pressing roll 62 is at the first position P1. When the pretreatment is started, the pressing roll 62 is not in contact with the electrode sheet 10 supported by the support roll 61 and is spaced upward from the electrode sheet 10. Furthermore, when the pretreatment is started, the conveying device 15 is not driven and the electrode sheet 10 is not being conveyed.

[0043] In the pretreatment, first, in step S101 of FIG. 9, the tension adjustment unit 103 of FIG. 8 adjusts the tension of the electrode sheet 10. Here, the tension adjustment unit 103 adjusts the tension of the electrode sheet 10 supported by the support roll 61. As shown in FIG. 3, the electrode sheet 10 supported by the support roll 61 is stretched across the unwinding roll 15a and the winding roll 15b of the conveying device 15. Therefore, the tension adjustment unit 103 adjusts the tension of the electrode sheet 10 between the unwinding roll 15a and the winding roll 15b. Here, the tension adjustment unit 103 controls the conveying device 15 (for example, the rotation of the unwinding roll 15a or the winding roll 15b) so that the tension of the electrode sheet 10 becomes a predetermined reference tension. This reference tension is the tension of the electrode sheet 10 when the uncoated portion 12a is pressed by the roll press machine 60. The reference tension is a value stored in advance in the memory unit 101 of FIG. 8. When the tension of the electrode sheet 10 is adjusted by the tension adjusting unit 103, the electrode sheet 10 is not sandwiched between the support roll 61 and the pressing roll 62. At this time, the pressing roll 62 is disposed above the electrode sheet 10 and is spaced apart from the electrode sheet 10.

[0044] Next, in step S102 of FIG. 9, the movement control unit 105 of FIG. 8 moves the pressing rolls 62 (here, both pressing rolls 62L and 62R) to the second position P2 (see FIG. 7). In step S102, the tension of the electrode sheet 10 supported by the support rolls 61 is set to the reference tension but the electrode sheet 10 is not being conveyed. Before step S102 is executed, the pressing roll 62 is disposed at the first position P1 as shown in FIG. 6. Before the conveyance device 15 starts conveying the electrode sheet 10, the movement control unit 105 moves the pressing roll 62 from the first position P1 to the second position P2. Here, as shown in FIG. 7, the movement control unit 105 controls the movement mechanism 68 to lower the pressing roll 62 to move it to the second position P2. Note that when moving the pressing roll 62 to the second position P2, the movement control unit 105 turns off the press cylinder 71, i.e., does not drive the cylinder drive device 73. When the pressing roll 62 is moved to the second position P2, the movement control unit 105 turns off the press cylinder 71. Furthermore, the movement control unit 105 moves the pressing roll 62 to the second position P2 so that the pressing roll 62 is pressed against the electrode sheet 10 with a first load value V1 (see FIG. 7) at the second position P2.

[0045] In this way, when the movement control unit 105 moves the pressing roll 62 to the second position P2, the pressing roll 62 is in contact with the second surface 10U of the electrode sheet 10, but is placed on the electrode sheet 10 due to its own weight. At this time, the pressing roll 62 is in a state of pressing the electrode sheet 10 with a first load value V1 due to its own weight.

[0046] Next, in step S103 of FIG. 9, the conveyance control unit 107 of FIG. 8 conveys the electrode sheet 10 along the support rolls 61. Here, as shown in FIG. 7, the pressing rolls 62 are disposed at the second position P2, and the press cylinder 71 is OFF. The conveyance control unit 107 starts conveying the electrode sheet 10 downstream on the conveyance path 18. Here, the conveyance control unit 107 controls the conveyance device 15 (see FIG. 3) to convey the electrode sheet 10, and also controls the rotation mechanism 74 to rotate the support rolls 61 in the direction of arrow R1 to convey the electrode sheet 10. In this embodiment, in step S103, the pressing rolls 62 are pressed against the electrode sheet 10 by their own weight. Therefore, when the electrode sheet 10 is conveyed, the pressing rolls 62 rotate in the direction of arrow R2 following the rotation of the support rolls 61. At this time, the rotation speed of the support rolls 61 and the rotation speed of the pressing rolls 62 are the same.

[0047] In this embodiment, the transport control unit 107 transports the electrode sheet 10 along the support roll 61 when a predetermined waiting time T1 (see FIG. 8) has elapsed after the movement control unit 105 has moved the pressing roll 62 to the second position P2. This waiting time T1 is a value stored in advance in the storage unit 101 (see FIG. 8). The specific value of the waiting time T1 is not particularly limited, but is, for example, 0.1 to 10 seconds.

[0048] After the conveyance of the electrode sheet 10 has started in this way, step S104 in FIG. 9 is then executed. In step S104, the pressing control unit 109 in FIG. 8 presses the pressing roll 62 against the electrode sheet 10, as shown in FIG. 5. Here, the pressing control unit 109 presses the pressing roll 62 against the electrode sheet 10 from the second position P2. More specifically, the pressing control unit 109 drives the cylinder driving device 73 to change the press cylinder 71 from OFF to ON. This causes the pressing roll 62 to descend, and the pressing roll 62 can be pressed against the electrode sheet 10 with a second load value V2.

[0049] In this embodiment, the pressing control unit 109 controls the pressing roll 62 to press against the electrode sheet 10 from the second position P2 when a predetermined reference time T2 (see FIG. 8) has elapsed since the conveyance control unit 107 started conveying the electrode sheet 10. This reference time T2 is pre-stored in the memory unit 101 of FIG. 8. The specific value of the reference time T2 is not particularly limited, but the reference time T2 is, for example, 3 seconds or less, preferably 1 second or less. The reference time T2 is, for example, 0.1 seconds. The reference time T2 may be set according to the rotation speed of the pressing roll 62. For example, the reference time T2 may be the time it takes for the pressing roll 62 to make one rotation when the electrode sheet 10 is conveyed by the conveyance device 15.

[0050] Note that the reference time T2 may be 0. When the reference time T2 is 0, the pressing control unit 109 presses the pressing roll 62 against the electrode sheet 10 from the second position P2 when the transport control unit 107 starts transporting the electrode sheet 10. In this way, the timing when the transport control unit 107 starts transporting the electrode sheet 10 and the timing when the pressing control unit 109 starts pressing the pressing roll 62 against the electrode sheet 10 may be the same.

[0051] Pretreatment is performed as described above. After pretreatment is performed, the stretching control unit 111 in FIG. 8 presses and stretches the uncoated portion 12a of the electrode sheet 10 using the roll press machine 60. Here, as shown in FIG. 5, the stretching control unit 111 turns on the press cylinder 71 to press the pressure roll 62 against the electrode sheet 10 at the second load value V2, while controlling the conveying device 15 (see FIG. 3) and the rotation mechanism 74 to convey the electrode sheet 10 downstream of the conveying path 18 (see FIG. 3). As a result, the uncoated portion 12a of the electrode sheet 10 is pressed at the second load value V2 while sandwiched between the support roll 61 and the pressure roll 62, and is thereby stretched.

[0052] As described above, in this embodiment, the electrode sheet manufacturing apparatus 1 is a manufacturing apparatus that manufactures an electrode sheet 10. As shown in FIG. 2, the electrode sheet 10 includes a current collector 12 made of a long metal foil, uncoated portions 12a set along the length of the current collector 12 at predetermined positions in the width direction, and an electrode active material layer 14 containing an electrode active material formed on the current collector 12 except for the uncoated portions 12a. As shown in FIGS. 3 and 4, the electrode sheet manufacturing apparatus 1 includes a conveying device 15, a support roll 61, a pressing roll 62, a driving device 65, and a control device 100. The conveying device 15 conveys the long electrode sheet 10 along a predetermined conveying path 18. The support roll 61 is disposed on the conveying path 18 and supports the first surface 10D of the electrode sheet 10 conveyed along the conveying path 18 in the width direction. The pressing roll 62 is disposed so as to face the support roll 61 on the second surface 10U of the electrode sheet 10. The driving device 65 presses the pressure roll 62 against the support roll 61 with the electrode sheet 10 sandwiched between them. As shown in FIG. 5, the pressure roll 62 is a rubber roll having at least an outer peripheral surface made of rubber, and is disposed so as to sandwich the uncoated portion 12a of the electrode sheet 10, excluding the electrode active material layer 14, between the pressure roll 62 and the support roll 61. As shown in FIG. 4, the driving device 65 includes a movement mechanism 68 and a press mechanism 70. The movement mechanism 68 moves the pressure roll 62 between a first position P1 (see FIG. 6) where the pressure roll 62 is separated from the electrode sheet 10 and a second position P2 (see FIG. 7) where the pressure roll 62 is brought into contact with the electrode sheet 10. As shown in FIG. 5, the press mechanism 70 presses the pressure roll 62 against the electrode sheet 10 from the second position P2. As shown in FIG. 8, the control device 100 includes a movement control unit 105, a conveyance control unit 107, and a press control unit 109. 9, the movement control unit 105 moves the pressing roll 62 from the first position P1 toward the second position P2 before the conveyance device 15 starts conveying the electrode sheet 10. After the movement control unit 105 moves the pressing roll 62 to the second position P2, the conveyance control unit 107 conveys the electrode sheet 10 along the support roll 61 as in step S103 in FIG.When a predetermined reference time T2 (see FIG. 8) has elapsed since the transport control unit 107 started transporting the electrode sheet 10, the pressing control unit 109 presses the pressing roll 62 against the electrode sheet 10 from the second position P2, as in step S104 in FIG. 9. Alternatively, the pressing control unit 109 may press the pressing roll 62 against the electrode sheet 10 from the second position P2 when the transport control unit 107 started transporting the electrode sheet 10.

[0053] According to this embodiment, as shown in Fig. 7, after the pressing roll 62 is positioned at the second position P2, conveyance of the electrode sheet 10 begins. Then, when conveyance of the electrode sheet 10 begins, or when a reference time T2 has elapsed since conveyance of the electrode sheet 10 began, the pressing roll 62 is pressed against the electrode sheet 10 from the second position P2, as shown in Fig. 5. This delays the timing at which the pressing roll 62 is pressed against the electrode sheet 10 from the second position P2, making it difficult for the pressing roll 62 to deform locally. Therefore, the uncoated portion 12a of the electrode sheet 10 can be pressed using the pressing roll 62 and the support roll 61, which are difficult to deform locally, making it easy to uniformly stretch the uncoated portion 12a.

[0054] In this embodiment, as shown in Fig. 7, the movement control unit 105 moves the pressing roll 62 to the second position P2 so that the pressing roll 62 is pressed against the electrode sheet 10 with a predetermined first load value V1 at the second position P2. The pressing control unit 109 presses the pressing roll 62 against the electrode sheet 10 with a second load value V2 (see Fig. 5) that is greater than the first load value V1. This reduces the pressure with which the pressing roll 62 is pressed against the electrode sheet 10 when the movement control unit 105 moves the pressing roll 62 from the first position P1 to the second position P2. This makes it difficult for the pressing roll 62 to deform locally at the second position P2.

[0055] In this embodiment, as shown in Fig. 4, the press mechanism 70 has a press cylinder 71 that, when turned on, presses the press roll 62 against the electrode sheet 10. The movement control unit 105 turns the press cylinder 71 off when the press roll 62 has moved to the second position P2. The pressing control unit 109 turns the press cylinder 71 on, thereby pressing the press roll 62 against the electrode sheet 10 from the second position P2, as shown in Fig. 5. In this way, by switching the press cylinder 71 from off to on, it is possible to control the timing at which the press roll 62 is pressed against the electrode sheet 10 from the second position P2.

[0056] In this embodiment, as shown in Fig. 4, the electrode sheet manufacturing apparatus 1 includes a rotation mechanism 74 that rotates the support roll 61. As shown in Fig. 7, the conveyance control unit 107 rotates the support roll 61 to start conveying the electrode sheet 10 along the support roll 61. In this way, when conveying the electrode sheet 10, by rotating the support roll 61, the pressing roll 62 is easily rotated in response to the rotation of the support roll 61. Therefore, the portion pressed against the electrode sheet 10 by the pressing roll 62 can be changed by the rotation of the pressing roll 62, making it difficult for the pressing roll 62 to deform locally.

[0057] In this embodiment, the conveyance control unit 107 conveys the electrode sheet 10 along the support roll 61 when a predetermined waiting time T1 (see FIG. 8 ) has elapsed after the movement control unit 105 moves the pressing roll 62 to the second position P2. For example, if the electrode sheet 10 is conveyed simultaneously with the movement of the pressing roll 62 to the second position P2 or before the pressing roll 62 moves to the second position P2, when the pressing roll 62 contacts the uncoated portion 12a of the electrode sheet 10, pressure is likely to be applied to the current collector 12 exposed in the uncoated portion 12a, which may cause wrinkles or deformation. However, as in this embodiment, by conveying the electrode sheet 10 after the waiting time T1 has elapsed since the pressing roll 62 moved to the second position P2, conveyance of the electrode sheet 10 can begin after the pressing roll 62 contacts the uncoated portion 12a. Therefore, pressure is applied to the uncoated portion 12a from the pressure roll 62 relatively less, and the uncoated portion 12a is less likely to be deformed.

[0058] In the above embodiment, the pressing roll 62 is disposed above the support roll 61. However, the pressing roll 62 may be disposed below the support roll 61. In this case, the pressing roll 62 may be configured to sandwich the electrode sheet 10 together with the support roll 61 by rising. In this case, the first surface of the electrode sheet 10 supported by the support roll 61 becomes the upper surface of the electrode sheet 10. The second surface of the electrode sheet 10 that comes into contact with the pressing roll 62 becomes the lower surface of the electrode sheet 10.

[0059] The invention disclosed herein has been described in various ways. Unless otherwise specified, the embodiments described herein do not limit the present invention. Furthermore, the embodiments of the invention disclosed herein can be modified in various ways, and each component and each process described herein can be omitted or combined as appropriate, unless a particular problem arises.

[0060] As described above, this specification includes the disclosures set forth in the following sections. Section 1: 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, and an electrode active material layer formed on a portion of the current collector excluding the unformed portion, the electrode active material layer including an electrode active material, 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 toward the support roll with the electrode sheet sandwiched therebetween; a control device; Equipped with the pressing roll is a rubber roll having at least an outer peripheral surface formed of rubber, and is disposed so as to sandwich the unformed portion of the electrode sheet excluding the electrode active material layer between itself and the support roll; The drive device is a movement mechanism that moves the pressure roll between a first position where the pressure roll is separated from the electrode sheet and a second position where the pressure roll is brought into contact with the electrode sheet; a press mechanism that presses the press roll against the electrode sheet from the second position; Equipped with The control device a movement control unit that moves the pressing roll from the first position toward the second position before the conveyance device starts conveying the electrode sheet; a transport control unit that transports the electrode sheet along the support roll after the pressing roll is moved to the second position by the movement control unit; and a pressing control unit that presses the pressing roll against the electrode sheet from the second position when the conveyance control unit starts conveying the electrode sheet or when a predetermined reference time has elapsed since the conveyance control unit started conveying the electrode sheet; An electrode sheet manufacturing device comprising:

[0061] Section 2: the movement control unit moves the pressing roll to the second position so that the pressing roll presses the electrode sheet with a predetermined first load value at the second position; Item 2. The electrode sheet manufacturing apparatus according to item 1, wherein the pressing control unit presses the pressing roll against the electrode sheet with a second load value that is greater than the first load value.

[0062] Section 3: the press mechanism has a press cylinder that presses the press roll against the electrode sheet when turned on; the movement control unit turns off the press cylinder when the pressing roll is moved to the second position, 3. The electrode sheet manufacturing apparatus according to item 1 or 2, wherein the pressing control unit presses the pressing roll against the electrode sheet from the second position by turning on the press cylinder.

[0063] Section 4: 4. The electrode sheet manufacturing apparatus according to any one of items 1 to 3, wherein the pressing control unit presses the pressing roll against the electrode sheet from the second position when the reference time has elapsed since the conveyance control unit started conveying the electrode sheet.

[0064] Section 5: a rotation mechanism for rotating the support roll, 5. The electrode sheet manufacturing apparatus according to any one of items 1 to 4, wherein the transport control unit starts transporting the electrode sheet along the support roll by rotating the support roll.

[0065] Item 6: 6. The electrode sheet manufacturing apparatus according to any one of items 1 to 5, wherein the transport control unit transports the electrode sheet along the support roll when a predetermined waiting time has elapsed after the movement control unit moves the pressing roll to the second position. [Explanation of symbols]

[0066] 1. Electrode sheet manufacturing equipment 10 Electrode sheet 10D 1st page 10U 2nd side 12 Current collector 12a Uncoated area (unformed area) 14 Electrode active material layer 15. Conveying equipment 18 Transport Route 61 Support Roll 62 Pressing roll 65 Drive unit 68 Moving mechanism 70 Press mechanism 71 Press Cylinder 74 Rotation mechanism 100 control device 105 Movement control unit 107 Transport control unit 109 Pressing control section P1 1st position P2 Second position T1 Waiting Time T2 Reference time V1 First load value V2 Second load value

Claims

1. 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, and an electrode active material layer formed on a portion of the current collector excluding the unformed portion, the electrode active material layer including an electrode active material, 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 toward the support roll with the electrode sheet sandwiched therebetween; a control device; Equipped with the pressing roll is a rubber roll having at least an outer peripheral surface formed of rubber, and is disposed so as to sandwich the unformed portion of the electrode sheet excluding the electrode active material layer between itself and the support roll; The drive device is a moving mechanism that moves the pressing roll between a first position where the pressing roll is separated from the electrode sheet and a second position where the pressing roll is brought into contact with the electrode sheet; a press mechanism that presses the press roll against the electrode sheet from the second position; Equipped with The control device a movement control unit that moves the pressing roll from the first position toward the second position before the conveyance device starts conveying the electrode sheet; a transport control unit that transports the electrode sheet along the support roll after the pressing roll is moved to the second position by the movement control unit; and a pressing control unit that presses the pressing roll against the electrode sheet from the second position when the conveyance control unit starts conveying the electrode sheet or when a predetermined reference time has elapsed since the conveyance control unit started conveying the electrode sheet; An electrode sheet manufacturing device comprising:

2. the movement control unit moves the pressing roll to the second position so that the pressing roll presses the electrode sheet with a predetermined first load value at the second position; The electrode sheet manufacturing apparatus according to claim 1 , wherein the pressing control unit presses the pressing roll against the electrode sheet with a second load value that is greater than the first load value.

3. the press mechanism has a press cylinder that presses the press roll against the electrode sheet when turned on; the movement control unit turns off the press cylinder when the pressing roll is moved to the second position, The electrode sheet manufacturing apparatus according to claim 1 , wherein the pressing control unit presses the pressing roll against the electrode sheet from the second position by turning on the press cylinder.

4. 2. The electrode sheet manufacturing apparatus according to claim 1, wherein the pressing control unit presses the pressing roll against the electrode sheet from the second position when the reference time has elapsed since the conveying control unit started conveying the electrode sheet.

5. a rotation mechanism for rotating the support roll, The electrode sheet manufacturing apparatus according to claim 1 , wherein the transport control unit starts transporting the electrode sheet along the support roll by rotating the support roll.

6. 2. The electrode sheet manufacturing apparatus according to claim 1, wherein the transport control unit transports the electrode sheet along the support roll when a predetermined waiting time has elapsed after the movement control unit moves the pressing roll to the second position.

Images