Electrode sheet manufacturing device

Abstract

To suppress variation in the elongation ratio of an unformed portion of an electrode sheet.SOLUTION: In an electrode sheet manufacturing device 1, an uncoated portion 12a (an unformed portion) of an electrode sheet 10 is stretched while being sandwiched between a support roll 61 and a pressure roll 62. The pressure roll 62 is a rubber roll including a rubber portion 62ab, the pressure roll 62 having a heat sink 64 attached thereto.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2023-36089 discloses a method for manufacturing an electrode sheet having a coated portion on a metal foil where an active material layer containing an electrode material is coated, and an uncoated portion is set at the end of the coated portion. The manufacturing method disclosed in this publication discloses that the uncoated portion is pressed with a pair of elastic rolls (rubber rolls). By pressing the uncoated portion with the 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 is said to enable the uncoated portion to be stretched while suppressing breakage of the uncoated portion. [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] Incidentally, the inventors of the present application wish to suppress variations in the stretching of uncoated portions (unformed portions). [Means for solving the problem]

[0005] 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 formed on the current collector except for the unformed portion. The manufacturing apparatus includes: a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll that is arranged on the conveying path and supports a first surface of the electrode sheet conveyed along the conveying path along the width direction; a pressure roll that is arranged to face the support roll on the second surface of the electrode sheet; a driving device that presses the pressure roll against the support roll with the electrode sheet sandwiched between the pressure roll and the support roll; and a heat sink. The pressure roll is arranged so as to sandwich the unformed portion of the electrode sheet between itself and the support roll. The pressure roll is a rubber roll having at least an outer peripheral surface made of rubber. The heat sink is attached to an axial end of the pressure roll.

[0006] According to this electrode sheet manufacturing device, it is possible to suppress variations in the stretching of the uncoated portions of the electrode sheet. [Brief explanation of the drawings]

[0007] [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 60. As shown in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along the line AA in FIG. [Figure 6] 6(a) and 6(b) are diagrams showing modified examples of the heat sink 64. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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.

[0009] 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.

[0010] <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.

[0011] <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 and an electrode active material layer 14. The current collector 12 is a member made of a long metal foil. The current collector 12 is a 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 foil. For example, copper or a copper alloy can be used for the negative electrode current collector foil. 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.

[0012] 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. The uncoated portion 12a is set along the length of the current collector 12 at a predetermined position in the width direction. In this embodiment, the uncoated portion 12a is set at both ends of the electrode sheet 10 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 is 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. The coated portions 12b are disposed between the uncoated portions 12a on 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 on the coated portions 12b of the current collector 12. In other words, the electrode active material layer 14 is disposed between the uncoated portions 12a on both ends of the electrode sheet 10 in the width direction.

[0013] <Conveyor device 15> 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 15. The conveying device 15 conveys the electrode sheet 10. For example, a motor 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 unwinding roll 15a is disposed upstream of the roll press machine 60 in the conveying direction. The take-up roll 15b is disposed downstream of the roll press machine 60 in the conveying direction. However, the conveying device 15 is not limited to the unwinding roll 15a and the take-up roll 15b. For example, the conveying device 15 may include rolls in addition to the unwinding roll 15a and the take-up roll 15b. The electrode sheet 10 is conveyed by the conveying device 15 along a predetermined conveying path 18.

[0014] <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.

[0015] <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 60 shown in FIG. 3. As shown in FIG. 3, the electrode sheet 10 is pressed by the roll press machine 60 midway along the conveying path 18. The electrode sheet 10 is supplied by an unwinding roll 15a. The electrode sheet 10 pressed by the roll press machine 60 is taken up by a take-up roll 15b. The electrode sheet manufacturing apparatus 1 includes a control device 100 that controls the unwinding roll 15a, the take-up roll 15b, and the roll press machine 60.

[0016] 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. 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 60, the electrode sheet manufacturing apparatus 1 may also include a device that presses the coated portion 12b of the electrode sheet 10.

[0017] As shown in FIG. 4, the roll press machine 60 includes a support roll 61, a pressure roll 62, a heat conductive sheet 63, a heat sink 64, a cover 65, an air blower 66, a suction device 67 (see FIG. 4), and a press pressure adjustment mechanism 70.

[0018] <Support Roll 61> 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. In this embodiment, the electrode sheet 10 has a first surface 10D and a second surface 10U. Here, 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. The support roll 61 is an example of another rubber roll defined in the present invention. In this embodiment, the support roll 61 has a main body portion 61a and two shaft portions 61b.

[0019] FIG. 5 is a cross-sectional view of the AA section in FIG. 4. FIG. 5 illustrates the state in which the uncoated portion 12a is pressed by the support roll 61 and the pressing roll 62. 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 for 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 for 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.

[0020] The support roll 61 is rotated in a predetermined direction by a roll driving device 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 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.

[0021] 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, bearings, gap screws for adjusting the gap between the support roll 61 and the pressure roll 62, and the like are attached to both shaft portions 61b.

[0022] <Pressing Roll 62> As shown in FIG. 5, the pressing roll 62 is disposed opposite the support roll 61 on the second surface 10U (here, the upper surface) of the electrode sheet 10. The pressing roll 62 is disposed 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) of the electrode sheet 10. Here, the axial center of the pressing roll 62 and the axial center of the support roll 61 are aligned in the vertical direction. As shown in FIG. 4, the pressing roll 62, together with the support roll 61, presses the uncoated portion 12a of the electrode sheet 10. The pressing roll 62 is an example of a rubber roll. In this embodiment, a roll whose outer peripheral surface is at least made of rubber is referred to as a rubber roll. The pressing roll 62 is not disposed above the coated portion 12b (see FIG. 2) of the electrode sheet 10. In this embodiment, as described above, the uncoated portion 12a of the electrode sheet 10 is provided at both ends in the width direction of the electrode sheet 10. Therefore, as shown in FIG. 4, the pressing rolls 62 are respectively arranged above the uncoated portions 12a at both ends in the width direction of the electrode sheet 10. The number of pressing rolls 62 is two. However, the number of uncoated portions 12a may be one, and when there is one uncoated portion 12a, there may be one pressing roll 62. Of the two pressing rolls 62, the one arranged on the left will be referred to as pressing roll 62L, and the one arranged on the right will be referred to as pressing roll 62R. However, when describing both pressing rolls 62L and 62R, the name pressing roll 62 will be used appropriately. The pressing rolls 62 (here, pressing rolls 62L and 62R) are replaceable and removable from the roll press machine 60. In this embodiment, the pressing roll 62 includes a main body portion 62a and two shaft portions 62b.

[0023] As shown in FIG. 5, the main body 62a includes a shaft portion 62aa and a rubber portion 62ab. The shaft portion 62aa is made of metal. The material for forming the shaft portion 62aa is not particularly limited, but is, for example, a material with relatively high hardness such as SUS304 (stainless steel). The rubber portion 62ab is arranged so as to cover at least the outer peripheral surface of the shaft portion 62aa. The material for forming the rubber portion 62ab is not particularly limited, but is, for example, nitrile rubber (NBR). The rubber portion 62ab is an example of rubber in the present invention. The pressing roll 62 presses the uncoated portion 12a of the electrode sheet 10 with the rubber portion 62ab.

[0024] 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 may be fitted with bearings, gap screws for adjusting the gap between the support roll 61 and the pressing roll 62, or the like.

[0025] 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.

[0026] <Thermal Conduction Sheet 63> As shown in FIG. 4, the thermally conductive sheet 63 is disposed between the pressing roll 62 and the heat sink 64. In this embodiment, the thermally conductive sheet 63 has a circular shape when viewed in the axial direction of the pressing roll 62. The thermally conductive sheet 63 is formed to have an outer diameter slightly smaller than that of the pressing roll 62. Therefore, when the support roll 61 and the pressing roll 62 press the electrode sheet 10, the thermally conductive sheet 63 does not come into contact with the support roll 61. However, the shape of the thermally conductive sheet 63 is not limited thereto. The thermally conductive sheet 63, together with the heat sink 64, is fixed to the pressing roll 62 with screws 76 shown in FIG. 5. The material from which the thermally conductive sheet 63 is formed is not particularly limited. For example, the thermally conductive sheet 63 is formed from a resin material such as acrylic, silicone, polypropylene (PP), or polyphenylene sulfide (PPS).

[0027] <Heat Sink 64> As shown in FIG. 4, the heat sink 64 is attached to the axial end of the pressing roll 62. In this embodiment, a heat sink 64 is attached to each of the pressing rolls 62L and 62R. The heat sink 64 attached to the outer side of the pressing roll 62L and the heat sink 64 attached to the outer side of the pressing roll 62R are arranged symmetrically in the width direction of the electrode sheet 10. As shown in FIG. 5, the heat sink 64 is attached to the shaft portion 62aa and the rubber portion 62ab of the pressing roll 62. In this embodiment, the heat sink 64 is attached to the pressing roll 62 via a thermally conductive sheet 63. The material for the heat sink 64 is not particularly limited, but may be, for example, aluminum, an aluminum alloy, or stainless steel. The material for the heat sink 64 is preferably a material with relatively high thermal conductivity. As shown in FIG. 4, the heat sink 64 includes a base portion 64a and a protrusion 64b.

[0028] The base portion 64a is located on the inner side of the heat sink 64 in the width direction of the electrode sheet 10. As shown in FIG. 5, the base portion 64a has a circular shape when viewed from the axial direction of the pressing roll 62. In this embodiment, the base portion 64a has substantially the same shape as the heat conduction sheet 63 (see FIG. 4). That is, the outer diameter of the base portion 64a is slightly smaller than the outer diameter of the pressing roll 62. A screw 76 is attached to the base portion 64a. This attaches the heat sink 64 to the pressing roll 62.

[0029] The protrusions 64b have a plate-like shape extending from the base 64a outward in the width direction of the electrode sheet 10. As shown in FIG. 5, the protrusions 64b are a plurality of plate-like members extending in one direction when viewed from the axial direction of the pressing roll 62. In this embodiment, the plurality of protrusions 64b are approximately parallel to one another when viewed from the axial direction of the pressing roll 62. The base 64a and the protrusions 64b may be formed integrally or may be separate bodies. The shape of the protrusions 64b is not limited to this.

[0030] <Cover 65> The cover 65 is arranged to cover a portion of the heat sink 64 and a portion of the pressure roll 62. In this embodiment, approximately the upper half of the heat sink 64 and the pressure roll 62 is covered by the cover 65. As shown in FIG. 4, in this embodiment, the covers 65 are arranged to cover each of the two pressure rolls 62. The material from which the covers 65 are formed is not particularly limited, but for example, the cover 65 is formed of acrylic. In this embodiment, as shown in FIG. 5, the cover 65 includes a front wall 65F, an upper wall 65U, a rear wall 65B, a lower wall 65D, and a side wall 65S (see also FIG. 4). The front wall 65F is arranged downstream of the pressure roll 62 in the conveying direction of the electrode sheet 10. The upper wall 65U is arranged above the pressure roll 62. The upper wall 65U extends in the circumferential direction of the pressure roll 62. The rear wall 65B is arranged upstream of the pressure roll 62 in the conveying direction of the electrode sheet 10. The front wall 65F and the rear wall 65B extend downward, approaching the pressing roll 62. The lower wall 65D is connected to the lower ends of the front wall 65F, the rear wall 65B, and the side walls 65S. Although not shown, the lower wall 65D has a hollowed-out area slightly larger than the area that overlaps with the pressing roll 62 in a plan view. Therefore, the pressing roll 62 does not contact the lower wall 65D. The lower end of the pressing roll 62 is located below the lower wall 65D. The side walls 65S are connected to both ends of the front wall 65F, the upper wall 65U, the lower wall 65D, and the rear wall 65B. The side walls 65S have a generally fan-shaped shape. Although not shown, the side walls 65S are fixed to both shaft portions 62b, thereby fixing the cover 65. However, the method of fixing the cover 65 is not particularly limited. As shown in FIG. 5, the cover 65 includes an air inlet 65a, an air flow path 65b, and an air outlet 65c.

[0031] The inlet 65a is formed in the front wall 65F. The inlet 65a opens toward the heat sink 64. The shape of the inlet 65a is not particularly limited, but is, for example, circular. A blower 66, which will be described later, is connected to the inlet 65a. As shown in FIG. 4, in this embodiment, two blowers 66 are connected to one cover 65. Therefore, two inlets 65a are formed for one cover 65. However, the number of inlets 65a is not particularly limited.

[0032] 5, the air flow path 65b is connected to the inlet 65a. The air flow path 65b is a flow path formed by the front wall 65F, the upper wall 65U, the rear wall 65B, the lower wall 65D, and the side wall 65S. Therefore, the air flow path 65b extends in the circumferential direction of the pressing roll 62. The air flowing in from the inlet 65a passes through the air flow path 65b and heads toward the outlet 65c.

[0033] The outlet 65c is connected to the air flow path 65b and opens downstream of the inlet 65a in a predetermined rotation direction of the pressing roll 62. In this embodiment, the outlet 65c is formed in the rear wall 65B. In this embodiment, the pressing roll 62 rotates in the direction of arrow R2 shown in FIG. 5. Therefore, the rear wall 65B is located downstream in the rotation direction of the pressing roll 62. The shape of the outlet 65c is not particularly limited, but may be, for example, a rectangular shape. A suction device 67, which will be described later, is connected to the outlet 65c.

[0034] The air blower 66 is attached to the inlet 65a. In this embodiment, as shown in FIG. 4, two air blowers 66 are attached to one cover 65. The air blower 66 is a device that blows air toward the heat sink 64. As shown in FIG. 5, the air blower 66 includes an air outlet 66a and a passage 66b. The air outlet 66a faces the heat sink 64. The passage 66b is formed, for example, by a pressure-resistant hose or a joint connected to the pressure-resistant hose. The air outlet 66a is located at one end of the passage 66b. The other end of the passage 66b is connected, for example, to a compressor (not shown). When the compressor is driven, compressed air passes through the passage 66b and is sent from the air outlet 66a to the air flow path 65b.

[0035] The suction device 67 is attached to the outlet 65c. The suction device 67 is a device that sucks air from inside the cover 65. The suction device 67 has an air intake port 67a and a passage portion 67b. The air intake port 67a faces the inside of the cover 65. The passage portion 67b is configured, for example, by a pressure-resistant hose and a joint connected to the pressure-resistant hose. The air intake port 67a is located at one end of the passage portion 67b. The other end of the passage portion 67b is connected, for example, to a vacuum pump (not shown). When the vacuum pump is driven, air inside the cover 65 is sucked through the air intake port 67a, passes through the passage portion 67b, and flows out to the outside of the cover 65. In this embodiment, the amount of air sucked by the suction device 67 is set to be greater than the amount of air blown by the blower 66. For example, the rotational speeds of the compressor and the vacuum pump are set so that the amount of suction by the vacuum pump provided in the suction device 67 is greater than the amount of air blown by the compressor of the air blowing device 66.

[0036] As shown in FIG. 4, the press pressure adjusting mechanism 70 includes a press cylinder 71, a roll chock 72, a cylinder driving device 73, a roll driving device 74, and a support portion 75.

[0037] The press cylinders 71 press the pressure roll 62 against the support roll 61. One press cylinder 71 is disposed on each end of the pressure roll 62, one on the outside. Here, in FIG. 4 , the press cylinder 71 disposed to the left of the electrode sheet 10 is referred to as press cylinder 71L, and the press cylinder 71 disposed to the right of the electrode sheet 10 is also referred to as press cylinder 71R. However, when describing matters common to the press cylinders 71L and 71R, they will also be referred to as 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. When the press cylinder 71 is driven and the rod 71a rises, the pressure roll 62 rises.

[0038] The cylinder driving device 73 is a device that sandwiches the electrode sheet 10 and presses the pressure roll 62 against the support roll 61. The cylinder driving device 73 is an example of a driving device in the present invention. 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 press 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).

[0039] The roll driving device 74 is connected to the support roll 61. The roll driving device 74 is a device that rotates the support roll 61. In this embodiment, the roll driving device 74 rotates the support roll 61 in the direction of arrow R1 shown in FIG. 5. The configuration of the roll driving device 74 is not particularly limited, but may be configured by, for example, an electric motor, gears, etc. The roll driving device 74 is connected to a control device 100 (see FIG. 3). Note that the roll driving device 74 may also rotate the pressing roll 62.

[0040] 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.

[0041] The control device 100 shown in Fig. 3 controls the roll press machine 60. 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.

[0042] 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 60 will be described.

[0043] First, the control device 100 controls the cylinder drive device 73 and the roll drive device 74 shown in FIG. 4. The cylinder drive device 73 lowers the rod 71a of the press cylinder 71. The cylinder drive device 73 lowers the rod 71a to a predetermined position. This causes the pressing roll 62 to lower. At this time, the roll drive device 74 rotates the support roll 61. In this embodiment, as shown in FIG. 5, the roll drive device 74 rotates the support roll 61 in the direction of arrow R1. When the pressing roll 62 lowers, the portion of the uncoated portion 12a sandwiched between the support roll 61 and the pressing roll 62 is compressed.

[0044] As shown in FIG. 5 , the rubber portion 61ab of the support roll 61 and the rubber portion 62ab of the pressing roll 62 are compressed and deformed near the uncoated portion 12a. When the support roll 61 and the pressing roll 62 rotate, the compressed portions of the rubber portions 61ab, 62ab return to their original shapes due to elasticity. At this time, the portions of the rubber portions 61ab, 62ab that have moved near the uncoated portion 12a are compressed. Therefore, when the support roll 61 and the pressing roll 62 rotate and the electrode sheet 10 is transported, the rubber portions 61ab, 62ab elastically deform in the radial direction of the support roll 61 and the pressing roll 62 near the uncoated portion 12a. This elastic deformation is repeated along the circumferential direction of the support roll 61 and the pressing roll 62. As the rubber portions 61ab, 62ab are repeatedly elastically deformed, they generate heat.

[0045] A heat conductive sheet 63 and a heat sink 64 are attached to the pressing roll 62. Therefore, heat generated by the pressing roll 62 is transferred to the heat sink 64 via the heat conductive sheet 63. When the pressing roll 62 rotates, the heat sink 64 attached to the pressing roll 62 also rotates. At this time, the heat sink 64 comes into contact with the air AR inside the cover 65. At this time, part of the heat held by the heat sink 64 is released into the air AR.

[0046] The control device 100 (see FIG. 3 ) controls the blower 66 and the suction device 67. As described above, the control device 100 sets the amount of air suctioned by the suction device 67 to be greater than the amount of air blown by the blower 66. At this time, air sent from the air outlet 66a of the blower 66 to the inside of the cover 65 passes through the air flow path 65b and is sucked through the air intake 67a. Therefore, the air AR inside the cover 65 forms a flow from the air inlet 65a through the air flow path 65b toward the air outlet 65c. When the air AR passes through the air flow path 65b, the air AR comes into contact with the heat sink 64. At this time, heat possessed by the heat sink 64 is released to the air AR. The air AR that has released heat from the heat sink 64 is sucked through the air intake 67a of the suction device 67. Therefore, the heat generated by the pressing roll 62 is discharged to the outside of the roll press machine 60 via the suction device 67.

[0047] According to the findings of the present inventors, the elongation rate of the uncoated portion of the electrode sheet varies depending on the temperature of the pressure roll (rubber roll) that presses the current collector. That is, the higher the temperature of the pressure roll, the higher the elongation rate of the uncoated portion. Meanwhile, the pressure roll elastically deforms when stretching the uncoated portion. Therefore, when the pressure roll stretches the electrode sheet, the pressure roll generates heat, and the surface temperature of the pressure roll increases. When the uncoated portion is stretched, the surface temperature of the pressure roll increases, which tends to cause the elongation rate of the uncoated portion to become non-uniform.

[0048] In the electrode sheet manufacturing apparatus 1 of this embodiment, the electrode sheet 10 is conveyed along the conveying path 18. A cylinder drive device 73 of the roll press machine 60 presses the press roll 62 against the support roll 61, sandwiching the uncoated portion 12a of the electrode sheet 10 between them. The press roll 62 is a rubber roll including a rubber portion 62ab. A heat sink 64 is attached to the press roll 62. The support roll 61 and the press roll 62 rotate with the uncoated portion 12a sandwiched between them, thereby stretching the uncoated portion 12a. At this time, the rubber portion 62ab repeatedly undergoes compressive deformation, causing the press roll 62 to generate heat. The heat generated by the press roll 62 is transferred to the heat sink 64, and the heat is released from the heat sink 64 into the air AR. This cools the press roll 62, suppressing a rise in temperature of the press roll 62. Therefore, in the production of the electrode, the temperature rise of the electrode sheet 10 can be suppressed, and the variation in the stretching of the uncoated portion 12a can be suppressed.

[0049] In the above-described embodiment, uncoated portions 12a are arranged on both widthwise ends of the electrode sheet 10. Furthermore, the electrode active material layer 14 is formed between the uncoated portions 12a on both widthwise ends of the electrode sheet 10. The pressing roll 62 is arranged above the uncoated portions 12a on both ends. This allows each of the uncoated portions 12a to be stretched even when the electrode sheet 10 has uncoated portions 12a on both widthwise ends.

[0050] In the above-described embodiment, the pressing rolls 62L, 62R each include a heat sink 64. As a result, when the uncoated portions 12a are arranged at both ends in the width direction of the electrode sheet 10, heat is released from each heat sink 64. Therefore, when the uncoated portions 12a are arranged at both ends in the width direction of the electrode sheet 10, the pressing roll 62 can be cooled more efficiently.

[0051] In the above-described embodiment, the support roll 61 includes a shaft portion 61aa and a rubber portion 61ab. Therefore, the support roll 61 is a rubber roll. Even when all of the rolls that sandwich and stretch the uncoated portion 12a of the electrode sheet 10 are rubber rolls, as in the present embodiment, heat can be dissipated by the heat sink 64.

[0052] In the above-described embodiment, the pressure roll 62 is a rubber roll including a shaft portion 62aa and a rubber portion 62ab. The heat sink 64 is attached to the shaft portion 62aa and the rubber portion 62ab. Here, the shaft portion 62aa is made of metal and has relatively high thermal conductivity. Therefore, a portion of the heat generated from the rubber portion 62ab is also transferred to the shaft portion 62aa. The heat transferred to the shaft portion 62aa is also dissipated from the heat sink 64. Therefore, by attaching the heat sink 64 to the metal shaft portion 62aa, the heat generated by the pressure roll 62 is more easily transferred to the heat sink 64 than when the heat sink 64 is attached only to the rubber portion 62ab. Therefore, the pressure roll 62 can be cooled more efficiently.

[0053] In the above-described embodiment, the heat conductive sheet 63 is disposed between the pressing roll 62 and the heat sink 64. By disposing the heat conductive sheet 63, it is relatively unlikely that a gap will occur between the pressing roll 62 and the heat sink 64. This results in a structure in which heat generated from the pressing roll 62 is relatively easily transferred to the heat sink 64. Therefore, the pressing roll 62 can be cooled more efficiently.

[0054] In the above-described embodiment, the electrode sheet manufacturing apparatus 1 is equipped with an air blower 66 that blows air to the heat sink 64. By blowing air toward the heat sink 64, heat exchange with the air surrounding the heat sink 64 is further promoted. Therefore, the pressing roll 62 can be cooled more efficiently.

[0055] In the above-described embodiment, the cover 65 covers a portion of the heat sink 64 and a portion of the pressure roll 62. The cover 65 includes an inlet 65a, an air flow path 65b, and an outlet 65c. Therefore, air blown from the blower 66 passes through the air flow path 65b and flows out from the outlet 65c. This stabilizes the flow of air passing near the heat sink 64 in the direction from the inlet 65a toward the outlet 65c. Therefore, the air supplied from the blower 66 is more likely to flow out from the outlet 65c after releasing heat from the heat sink 64. This suppresses the rise in temperature of the air AR inside the cover 65. This enhances the cooling effect of the heat sink 64.

[0056] In the embodiment described above, the suction device 67 is connected to the outlet 65c. The suction device 67 sucks in the air AR inside the cover 65. Therefore, the air AR from which heat has been released from the heat sink 64 is more likely to flow out through the outlet 65c. This increases the cooling effect of the heat sink 64.

[0057] In the above-described embodiment, the amount of air suctioned by the suction device 67 is set to be greater than the amount of air blown by the blower device 66. For example, if the amount of air suctioned by the suction device 67 is less than the amount of air blown by the blower device 66, the air AR may stagnate inside the cover 65. In this case, the air AR that has released heat from the heat sink 64 does not flow out through the outlet 65c, and the temperature inside the cover 65 rises. This reduces the cooling effect of the heat sink 64. However, in this embodiment, the amount of air suctioned by the suction device 67 is greater than the amount of air blown by the blower device 66, making it less likely that the air AR will stagnate inside the cover 65. This suppresses the rise in temperature of the air AR inside the cover 65. This improves the cooling effect of the heat sink 64.

[0058] 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.

[0059] In the above-described embodiment, the convex portions 64b of the heat sink 64 are multiple plate-like members extending in one direction when viewed from the axial direction of the pressing roll 62. However, this is not limiting. FIGS. 6(a) and 6(b) are diagrams showing modified examples of the heat sink 64. Similar to FIG. 5, FIGS. 6(a) and 6(b) show the heat sinks 64A and 64B, respectively, as seen from the cross section AA in FIG. 4. However, in FIGS. 6(a) and 6(b), only the pressing roll 62 and the heat sinks 64A and 64B are shown. As shown in FIG. 6(a), the heat sink 64A has slits 64c formed in a direction substantially perpendicular to the direction in which the convex portions 64bA extend. This prevents air that has released heat from the heat sink 64 from being trapped between the convex portions 64b and stagnating. As shown in FIG. 6(b), the convex portions 64bB of the heat sink 64B extend from the inside to the outside in the radial direction of the heat sink 64B when viewed from the axial direction of the pressing roll 62. The convex portions 64bB are curved in the direction of arrow R2. That is, the convex portions 64bB are curved in the rotation direction of the pressing roll 62. This allows air around the convex portions 64bB to pass between the convex portions 64bB and easily flow to the outside in the radial direction of the heat sink 64B when the pressing roll 62 rotates. This prevents the air that has released heat from the heat sink 64B from accumulating near the heat sink 64B.

[0060] In the above-described embodiment, the heat sink 64 is attached only to the pressing roll 62, but this is not limiting. The heat sink 64 may be attached to the support roll 61 in addition to the pressing roll 62.

[0061] As described above, this specification includes the disclosures set forth in the following sections.

[0062] 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, a conveying device that conveys the electrode sheet along a predetermined conveying path; a support roll that is disposed on the transport path and supports, along a width direction, a first surface of the electrode sheet that is 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 drive device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Heat sink and Equipped with the pressing roll is disposed so as to sandwich the unformed portion of the electrode sheet between the pressing roll and the support roll, the pressure roll is a rubber roll having at least an outer peripheral surface made of rubber, The heat sink is attached to an end portion of the pressing roll in the axial direction. Electrode sheet manufacturing equipment.

[0063] Section 2: the electrode sheet has the uncoated portions disposed on both ends in the width direction, and the electrode active material layer disposed between the uncoated portions on both ends in the width direction, Item 2. The electrode sheet manufacturing apparatus according to item 1, wherein the pressure rolls are arranged above the uncoated portions at both ends.

[0064] Section 3: Item 3. The electrode sheet manufacturing apparatus according to item 2, wherein the pressure rolls at both ends are each provided with the heat sink.

[0065] Section 4: Item 4. The electrode sheet manufacturing apparatus according to any one of Items 1 to 3, wherein the support roll is a rubber roll including a metal shaft portion and rubber arranged to cover at least the outer peripheral surface of the shaft portion.

[0066] Section 5: the pressure roll is a rubber roll including a metal shaft portion and rubber arranged to cover at least the outer peripheral surface of the shaft portion, 5. The electrode sheet manufacturing apparatus according to any one of items 1 to 4, wherein the heat sink is attached to the rubber and the shaft portion.

[0067] Item 6: Item 6. The electrode sheet manufacturing apparatus according to any one of items 1 to 5, further comprising a heat conductive sheet disposed between the pressing roll and the heat sink.

[0068] Section 7: Item 7. The electrode sheet manufacturing apparatus according to any one of items 1 to 6, further comprising an air blower that blows air toward the heat sink.

[0069] Section 8: a cover that covers a part of the heat sink and a part of the pressing roll; The cover is an inlet opening that opens toward the heat sink and to which the blower device is attached; an air flow path connected to the inlet and extending in a circumferential direction of the pressing roll; Item 8. The electrode sheet manufacturing apparatus according to Item 7, further comprising: an outlet connected to the air flow path and opening downstream of the inlet in a predetermined rotation direction of the pressing roll.

[0070] Section 9: Item 9. The electrode sheet manufacturing apparatus according to item 8, further comprising a suction device connected to the outlet and configured to suck air from inside the cover.

[0071] Section 10: Item 10. The electrode sheet manufacturing apparatus according to item 9, wherein the amount of air sucked by the suction device is greater than the amount of air blown by the blower. [Explanation of symbols]

[0072] 1. Electrode sheet manufacturing equipment 10 Electrode sheet 10D 1st page 10U 2nd side 12 Current collector 12a Uncoated area (unformed area) 12b Coating Department 14 Electrode active material layer 15. Conveying equipment 15a Unwinding roll 15b Winding roll 18 Transport Route 60 Roll press machine 61 Support Roll 61a, 62a Main body 61aa, 62aa Shaft 61ab, 62ab Rubber part (rubber) 61b, 62b Both shafts 62, 62L, 62R Pressing roll 63 Thermal Conduction Sheet 64, 64A, 64B heat sink 64a Platform 64b, 64bA, 64bB convex part 64c slit 65 Cover 65B Back wall 65D lower wall 65F front wall 65S side wall 65U upper wall 65a Inlet 65b Air flow path 65c Outlet 66 Blower 66a Air outlet 66b Passage section 67 Suction device 67a Air intake 67b Passage section 70 Press pressure adjustment mechanism 71 Press Cylinder 71L, 71R Press Cylinder 71a Rod 72 Roll Chock 73 Cylinder drive unit 74 Roll drive unit 75 Support part 76 bis 100 control device AR Air R1,R2 arrows S1 Transport process S2 Weighing process S3 Mixing process S4 Coating process S5 Drying process S6 Roll press process

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, 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 drive device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them; Heat sink and Equipped with the pressing roll is disposed so as to sandwich the unformed portion of the electrode sheet between the pressing roll and the support roll, the pressure roll is a rubber roll having at least an outer peripheral surface made of rubber, The heat sink is attached to an end portion of the pressing roll in the axial direction. Electrode sheet manufacturing equipment.

2. the electrode sheet has the unformed portions disposed at both ends in the width direction, and the electrode active material layer disposed between the unformed portions at both ends in the width direction, The electrode sheet manufacturing apparatus according to claim 1 , wherein the pressing rolls are disposed above the unformed portions at both ends.

3. The electrode sheet manufacturing apparatus according to claim 2 , wherein the pressure rolls at both ends are each provided with the heat sink.

4. 2. The electrode sheet manufacturing apparatus according to claim 1, wherein the support roll is a rubber roll having a metal shaft portion and rubber arranged so as to cover at least an outer peripheral surface of the shaft portion.

5. the pressure roll is a rubber roll including a metal shaft portion and the rubber disposed so as to cover at least an outer peripheral surface of the shaft portion, The electrode sheet manufacturing apparatus according to claim 1 , wherein the heat sink is attached to the rubber and the shaft portion.

6. The electrode sheet manufacturing apparatus according to claim 1 , further comprising a thermally conductive sheet disposed between the pressing roll and the heat sink.

7. The electrode sheet manufacturing apparatus according to claim 1 , further comprising an air blower that blows air toward the heat sink.

8. a cover that covers a part of the heat sink and a part of the pressing roll; The cover is an inlet opening that opens toward the heat sink and to which the blower device is attached; an air flow path connected to the inlet and extending in a circumferential direction of the pressing roll; The electrode sheet manufacturing apparatus according to claim 7 , further comprising: an outlet connected to the air flow path and opening downstream of the inlet in a predetermined rotation direction of the pressing roll.

9. The electrode sheet manufacturing apparatus according to claim 8 , further comprising a suction device connected to the outlet and configured to suck air from inside the cover.

10. The electrode sheet manufacturing apparatus according to claim 9 , wherein an amount of air sucked by the suction device is greater than an amount of air blown by the air blower.

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