Electrode sheet manufacturing apparatus

Abstract

To suppress variation in the elongation ratio of an unformed part of an electrode sheet.SOLUTION: In an electrode sheet manufacturing apparatus 1 according to the present embodiment, an uncoated part 12a (an unformed part) of an electrode sheet 10 is elongated while being sandwiched between a support roll 61 and a pressing roll 62. The pressing roll 62 is a rubber roll including a rubber part 62ab. A conductive member 68 is attached to the pressing roll 62. The conductive member 68 includes an insertion part 68a and a heat conduction plate 68b. The insertion part 68a extends in the axial direction of the pressing roll 62, and a part of the insertion part 68a is inserted into the inside of the rubber part 62ab. The heat conduction plate 68b is connected to a connection part 68aa of the insertion part 68a, the connection part 68aa being positioned outside the rubber part 62ab.SELECTED DRAWING: Figure 6

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, and 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 drive device that presses the pressure roll against the support roll with the electrode sheet sandwiched between them, and a conductive material. 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 conductive material is attached to the axial end of the pressure roll, and includes an insertion portion that extends in the axial direction of the pressure roll and has a part inserted inside the rubber, and a plate-shaped heat conduction plate connected to the part of the insertion portion that is located outside the rubber.

[0006] In this electrode sheet manufacturing device, even if the rubber elastically deforms and generates heat when the pressure roll presses the unformed portion, the heat is transferred to the conductive material. This makes it possible to suppress an increase in the surface temperature of the pressure roll. As a result, it is possible to suppress variation in the elongation of the unformed portion 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] FIG. 6 is a cross-sectional view taken along the line BB in FIG. [Figure 7] FIG. 7 is a partial cross-sectional view of a pressure roll 62A according to a first modified example. [Figure 8] FIG. 8 is a view corresponding to FIG. 5 and relating to a second modified example. 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 conductive material 68, a heat conductive sheet 63, a heat sink 64, and a press pressure adjusting mechanism .

[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 shows a 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 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.

[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 either pressing roll 62L or 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] FIG. 6 is a cross-sectional view of the cross section BB in FIG. 5. As shown in FIG. 6, the pressing roll 62 has chamfered portions 62ac that are chamfered in the circumferential direction. More specifically, the chamfered portions 62ac are formed at both widthwise ends of the rubber portion 62ab. The chamfered portions 62ac have a C-chamfered shape in which the corners of the rubber portion 62ab are cut off in a substantially straight line. The shape of the chamfered portions 62ac is not particularly limited, and may be, for example, an R-chamfered shape. The chamfered portions 62ac are formed continuously in the circumferential direction. Although not particularly limited, the chamfered portions 62ac may be formed inward from a position slightly away from the end of the electrode active material layer 14 in the widthwise direction of the electrode sheet 10 (see FIG. 2) so as to prevent excessive compression of the electrode active material layer 14 (see FIG. 2) during roll pressing.

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

[0026] As shown in FIG. 5, when the support roll 61 and the pressing roll 62 sandwich the electrode sheet 10 and the support roll 61 rotates in the direction of arrow R1, the pressing 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 pressing roll 62 are in contact, the pressing roll 62 receives a force rotating in the direction of arrow R2 due to the force of the rotation of the support roll 61 (see also FIG. 8). As a result, the pressing roll 62 rotates in the direction of arrow R2. In other words, the pressing roll 62 is a driven roll that rotates following the rotation of the support roll 61.

[0027] As shown in FIG. 4, the conductive material 68 is attached to the axial end of the pressing roll 62. In this embodiment, a conductive material 68 is attached to each of the pressing rolls 62L and 62R. The conductive material 68 attached to the outer side of the pressing roll 62L and the conductive material 68 attached to the outer side of the pressing roll 62R are arranged symmetrically in the width direction of the electrode sheet 10. The material forming the conductive material 68 is not particularly limited, but may be aluminum, an aluminum alloy, stainless steel, or the like. It is preferable that the material forming the conductive material 68 has a relatively high thermal conductivity. As shown in FIG. 6, the conductive material 68 includes an insert 68a and a heat conduction plate 68b.

[0028] The insertion portion 68a extends in the axial direction of the pressing roll 62, and a portion thereof is inserted inside the rubber portion 62ab. The insertion portion 68a is arranged radially inward of the pressing roll 62 relative to the chamfered portion. In this embodiment, as shown in FIG. 5, eight insertion portions 68a are provided along the circumferential direction of the pressing roll 62. However, the number and arrangement of the insertion portions 68a are not limited to this. As shown in FIG. 6, a connection portion 68aa is formed at one end of the insertion portion 68a. A needle portion 68ab is formed at the other end of the insertion portion 68a. The connection portion 68aa is an example of one end of the insertion portion in the present invention. The needle portion 68ab is an example of the other end of the insertion portion in the present invention.

[0029] The connecting portion 68aa is arranged on one axial end face side of the pressing roll 62. In this embodiment, the connecting portion 68aa is arranged on the outer surface 62U side of the pressing roll 62. As shown in FIG. 4, the outer surface 62U is the surface of the pressing roll 62 in the axial direction that is farther from the coated portion 12b of the electrode sheet 10. Of the surfaces of the pressing roll 62 in the axial direction, the surface closer to the coated portion 12b of the electrode sheet 10 is referred to as the inner surface 62N.

[0030] As shown in FIG. 6 , the needle portion 68ab is disposed inside the rubber portion 62ab at a position closer to the other axial end face of the pressing roll 62 than to one axial end face of the pressing roll 62. The needle portion 68ab is a needle-shaped portion that protrudes in the axial direction of the pressing roll 62. The needle portion 68ab is inserted inside the rubber portion 62ab of the pressing roll 62. In this embodiment, the needle portion 68ab is disposed inside the rubber portion 62ab at a position closer to the inner surface 62N than to the outer surface 62U in the axial direction of the pressing roll 62. That is, the needle portion 68ab is inserted into the rubber portion 62ab from the outer surface 62U side, and is inserted until the needle portion 68ab reaches a position closer to the inner surface 62N than to the center of the rubber portion 62ab in the axial direction of the pressing roll 62, whereby the insertion portion 68a is attached to the pressing roll 62.

[0031] The heat conduction plate 68b is a plate-shaped member connected to a portion of the insertion portion 68a located outside the rubber portion 62ab. The heat conduction plate 68b is connected to an end of the insertion portion 68a that is outside the rubber portion 62ab. In this embodiment, the heat conduction plate 68b is connected to the connection portion 68aa of the insertion portion 68a. When viewed from the axial direction of the pressing roll 62, the heat conduction plate 68b has a circular ring shape with the shapes of both shaft portions 62b hollowed out. The position of the outer peripheral edge of the heat conduction plate 68b is located inside the chamfered portion 62ac of the pressing roll 62 in the radial direction of the pressing roll 62. In other words, the outer diameter of the heat conduction plate 68b is smaller than the outer diameter of the pressing roll 62. Therefore, when the support roll 61 (see FIG. 4) and the pressing roll 62 press the electrode sheet 10 (see FIG. 4), the heat conduction plate 68b does not come into contact with the support roll 61. The heat conduction plate 68b and the insertion portion 68a may be formed integrally or separately. Although not shown, the heat conduction plate 68b has a screw hole formed on the surface opposite to the surface to which the insertion portion 68a is connected, into which a screw 76 (see FIG. 5) described later is attached.

[0032] <Thermal Conduction Sheet 63> As shown in FIG. 4, the thermally conductive sheet 63 is disposed between the conductive material 68 and the heat sink 64. In this embodiment, the thermally conductive sheet 63 has a circular ring shape with the shapes of both shaft portions 62b hollowed out when viewed from the axial direction of the pressure roll 62. The thermally conductive sheet 63 is formed to have an outer diameter slightly smaller than that of the pressure roll 62. Therefore, when the support roll 61 and the pressure roll 62 press the electrode sheet 10, the thermally conductive sheet 63 does not contact 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 thermally conductive plate 68b (see FIG. 6) with screws 76 shown in FIG. 5. The material forming the thermally conductive sheet 63 is not particularly limited. For example, the thermally conductive sheet 63 is formed of a resin material such as polypropylene (PP) or polyphenylene sulfide (PPS). The thermally conductive sheet 63 does not have to be attached.

[0033] <Heat Sink 64> As shown in FIG. 6, the heat sink 64 is connected to a thermally conductive plate 68b and is connected to the opposite side of the insertion portion 68a from the thermally conductive plate 68b. As shown in FIG. 4, the heat sink 64 is attached to the pressing roll 62 via a conductive material 68 and a thermally conductive sheet 63. 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. The material for forming the heat sink 64 is not particularly limited, but may be aluminum, an aluminum alloy, stainless steel, or the like. Preferably, the material for forming the heat sink 64 has a relatively high thermal conductivity. As shown in FIG. 5, in this embodiment, the heat sink 64 has a plurality of plate-shaped protrusions 64b. The plate-shaped protrusions 64b are approximately parallel to each other when viewed from the axial direction of the pressing roll 62. However, the shape of the heat sink 64 is not limited thereto. 5, screws 76 are attached to the heat sink 64. In this way, the heat sink 64 is attached to the thermally conductive plate 68b.

[0034] 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.

[0035] 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.

[0036] The cylinder driving device 73 is a device that sandwiches the electrode sheet 10 and 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).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] As shown in FIG. 6 , a conductive material 68, a heat-conducting sheet 63, and a heat sink 64 are attached to the pressing roll 62. The needles 68ab of the conductive material 68 are inserted into the rubber portion 62ab of the pressing roll 62. Therefore, heat generated from the rubber portion 62ab of the pressing roll 62 is gradually transferred from the needles 68ab to the entire conductive material 68. The heat transferred to the conductive material 68 is then transferred to the heat-conducting sheet 63 and the heat sink 64. When the pressing roll 62 rotates, the convex portions 64b of the heat sink 64 come into contact with the air surrounding the heat sink 64. At this time, heat is exchanged between the convex portions 64b and the air. That is, heat is released from the heat sink 64 into the air. Therefore, the heat generated from the rubber portion 62ab of the pressing roll 62 is released into the air through the conductive material 68, the heat-conducting sheet 63, and the heat sink 64.

[0044] After the uncoated portion 12a of the electrode sheet 10 shown in FIG. 2 is pressed, the electrode active material layer 14 (here, the coated portion 12b) of the electrode sheet 10 is pressed. As described above, the coated portion 12b is pressed, for example, using a dedicated device for pressing the coated portion 12b. This allows the coated portion 12b to be stretched. The electrode sheet 10 passes through a roll press 60 and is then taken up by a take-up roll 15b shown in FIG. 3. In this way, the current collectors of the uncoated portion 12a and the coated portion 12b of the electrode sheet 10 are stretched. This makes it less likely that the current collector 12 will stretch non-uniformly. As a result, it is less likely that the stretched current collector 12 will deform non-uniformly when it shrinks. This reduces the likelihood of defects such as wrinkles forming in the uncoated portion 12a or breakage of the uncoated portion 12a, thereby improving the quality of the electrode sheet 10.

[0045] 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.

[0046] 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 pressure roll 62 against the support roll 61, sandwiching the uncoated portion 12a of the electrode sheet 10 between them. The pressure roll 62 is a rubber roll including a rubber portion 62ab. A conductive material 68 is attached to the pressure roll 62. The support roll 61 and the pressure 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 compresses and deforms, causing the pressure roll 62 to generate heat. The heat generated by the pressure roll 62 is transferred to the conductive material 68. This makes it possible to suppress a temperature rise in the pressure roll 62. Therefore, in the production of the electrode sheet 10, a temperature rise in the electrode sheet 10 can be suppressed, and variation in the stretching of the uncoated portion 12a can be suppressed.

[0047] According to the embodiment described above, the pressing roll 62 has a chamfered portion 62ac. The insertion portion 68a is disposed radially inward of the chamfered portion 62ac in the pressing roll 62. If the insertion portion 68a is disposed radially inward of the pressing roll 62, i.e., near the outer diameter of the rubber portion 62ab, there is a possibility that the portion of the rubber portion 62ab that is compressed when the uncoated portion 12a is stretched and the insertion portion 68a will be disposed relatively close to each other. The insertion portion 68a also extends in the axial direction of the pressing roll 62. The rubber portion 62ab elastically deforms radially of the pressing roll 62. Therefore, if the insertion portion 68a is disposed radially in the vicinity of the outer diameter of the rubber portion 62ab, there is a possibility that the elastic deformation of the rubber portion 62ab will be hindered by the insertion portion 68a. However, in this embodiment, since the insertion portion 68a is positioned more inward than the chamfered portion 62ac in the radial direction of the pressing roll 62, it is possible to prevent the insertion portion 68a from hindering the elastic deformation of the rubber portion 62ab.

[0048] According to the embodiment described above, the connection portion 68aa of the conductive material 68 is disposed on the outer surface 62U side of the pressing roll 62. The needle portion 68ab is inserted until it reaches a position closer to the inner surface 62N than the outer surface 62U in the axial direction of the pressing roll 62. Therefore, the insertion portion 68a is inserted to a relatively deep position as viewed from the outer surface 62U of the pressing roll 62. In other words, a relatively large portion of the insertion portion 68a is disposed inside the rubber portion 62ab. As a result, when the pressing roll 62 generates heat, the heat is relatively easily transferred to the insertion portion 68a, and therefore, a structure is provided in which heat generation by the pressing roll 62 is relatively easily suppressed.

[0049] According to the embodiment described above, the heat conduction plate 68b is connected to the connecting portion 68aa of the insertion portion 68a. That is, the heat conduction plate 68b is connected to the end of the insertion portion 68a that is on the outer side of the rubber portion 62ab. The heat sink 64 is connected to the heat conduction plate 68b and is connected to the opposite side of the insertion portion 68a with respect to the heat conduction plate 68b. As a result, heat transferred to the insertion portion 68a is transferred to the heat conduction plate 68b and further to the heat sink 64. Therefore, heat generated by the pressing roll 62 is transferred to the heat sink 64 via the insertion portion 68a of the conductive material 68 and the heat conduction plate 68b. The heat sink 64 releases heat into the surrounding air. Therefore, heat generated by the pressing roll 62 is more easily released.

[0050] In the above-described embodiment, the conductive material 68 is provided with one heat conductive plate 68b for each of the multiple insertion portions 68a, but this is not limited to this. FIG. 7 is a partial cross-sectional view of a pressing roll 62A according to a first modified example. As shown in FIG. 7, a roll press 60A according to this modified example includes multiple conductive materials 68A. That is, as shown in FIG. 7, one heat conductive plate 68bA is attached to each of the insertion portions 68aA. Note that the pressing roll 62 shown in FIG. 7 does not have a heat conductive sheet 63 or a heat sink 64 attached thereto.

[0051] In the above-described embodiment, the conductive material 68, the heat conductive sheet 63, and the heat sink 64 are attached to the pressing roll 62, but this is not limiting. The electrode sheet manufacturing apparatus may further include a cover that covers the heat sink, a blower that blows air to the heat sink, and a suction device that sucks air from inside the cover. FIG. 8 is a view corresponding to FIG. 5 according to a second modified example. As shown in FIG. 8, a roll press machine 60B according to this modified example includes a cover 65, a blower 66, and a suction device 67. The cover 65 is disposed so as to cover the heat sink 64 and the pressing roll 62 from above. The blower 66 is attached to the cover 65. An air outlet 66a of the blower 66 faces the heat sink 64. The blower 66 is connected to, for example, a compressor (not shown). When the compressor is driven, air is blown from the air outlet 66a. The suction device 67 is disposed on the opposite side of the blower 66 from the pressing roll 62 and is attached to the cover 65. The suction device 67 is connected to, for example, a vacuum pump (not shown) and sucks the air inside the cover 65 .

[0052] In the roll press machine 60B shown in FIG. 8, when the air blower 66 is driven, air is sent from the air outlet 66a toward the heat sink 64. The sent air travels inside the cover 65 toward the suction device 67. At this time, part of the sent air comes into contact with the heat sink 64, and heat is released from the heat sink 64. The air from which heat has been released is sucked by the suction device 67. Therefore, by providing the cover 65, the air blower 66, and the suction device 67, the heat generated by the pressing roll 62 is more easily released.

[0053] 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.

[0054] As described above, this specification includes the disclosures set forth in the following sections.

[0055] 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; Conductive material 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 conductive material is attached to an end of the pressure roll in the axial direction, The conductive material is an insertion portion extending in the axial direction of the pressing roll and a part of which is inserted into the rubber; a plate-shaped heat conduction plate connected to a portion of the insertion portion located outside the rubber; An electrode sheet manufacturing apparatus comprising:

[0056] Section 2: The pressing roll has a chamfered portion that is chamfered in the circumferential direction, Item 2. The electrode sheet manufacturing apparatus according to item 1, wherein the insertion section is disposed on the inside of the chamfered section in the radial direction of the pressing roll.

[0057] Section 3: Item 3. The electrode sheet manufacturing apparatus according to item 1 or 2, wherein one end of the insertion portion is arranged on one end face side of the pressing roll in the axial direction, and the other end of the insertion portion is arranged at a position inside the rubber closer to the other end face in the axial direction of the pressing roll than to the one end face in the axial direction of the pressing roll.

[0058] Section 4: the heat conduction plate is connected to an end of the insertion portion on an outer side of the rubber, 4. The electrode sheet manufacturing apparatus according to claim 1, further comprising a heat sink connected to the heat conduction plate and connected to the opposite side of the insertion portion with respect to the heat conduction plate. [Explanation of symbols]

[0059] 1. Electrode sheet manufacturing equipment 10 Electrode sheet 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, 60A, 60B Roll Press Machine 61 Support Roll 61a Main body 61aa Shaft 61ab, 62ab Rubber part (rubber) 61b, 62b Both shafts 62, 62L, 62R Pressing roll 62N inner surface 62U exterior 62a Main body 62aa shaft 62ab rubber part 62ac chamfered part 63 Thermal Conduction Sheet 64 Heatsink 64b Convex part 65 Cover 66 Blower 66a Air outlet 67 Suction device 68,68A Conductive material 68a, 68aA Insertion part 68aa connection 68ab needle part 68b Heat conduction plate 68b, 68bA Heat conduction plate 70 Press pressure adjustment mechanism 71, 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 R1 Arrow R2 Arrow 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; Conductive material 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 conductive material is attached to an end of the pressure roll in the axial direction, The conductive material is an insertion portion extending in the axial direction of the pressing roll and a part of which is inserted into the rubber; a plate-shaped heat conduction plate connected to a portion of the insertion portion located outside the rubber; An electrode sheet manufacturing apparatus comprising:

2. The pressing roll has a chamfered portion that is chamfered in the circumferential direction, The electrode sheet manufacturing apparatus according to claim 1 , wherein the insertion portion is disposed more inward than the chamfered portion in the radial direction of the pressing roll.

3. 2. The electrode sheet manufacturing apparatus according to claim 1, wherein one end of the insertion portion is arranged on one axial end face side of the pressing roll, and the other end of the insertion portion is arranged at a position inside the rubber closer to the other axial end face of the pressing roll than to the one axial end face of the pressing roll.

4. the heat conduction plate is connected to an end of the insertion portion on an outer side of the rubber, The electrode sheet manufacturing apparatus according to claim 1 , further comprising a heat sink connected to the thermally conductive plate and connected on an opposite side of the insertion portion with respect to the thermally conductive plate.

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