JPH09330707A - Roller for closely contacting lithium foil and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To impart a sufficient close contact strength to a lithium foil with a small pressure contacting force by knurling the outer circumferential surface of a resin-made roller for closely adhering the lithium foil to an electrode plate. SOLUTION: This roller 10 has a metallic shaft core 14 having a knurling 12 on the outer circumferential surface and a cylindrical body 16 made of a resin such as super-high density polyethylene or polypropylene to which the shaft core 14 is press fitted. The outer circumferential surface of the cylindrical body 16 has a knurling 18, and a plurality of hole part 19 are also formed thereon according to requirement. The roller 10 is arranged on one surface 26a side of a lengthy electrode plate 26 continuously carried in an arrowed direction A in order to intermittently apply an active material to a hoop-like copper foil support body at fixed intervals and stick a lithium foil 28 which is a thin metal foil adhesive to metal to the surface of 26a at a prescribed pitch. A nip roller 40 is arranged on the other surface 26b of the electrode plate 26 in such a manner as to approach to and retreat from the surface 26b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium foil contact roller for contacting a lithium foil with an electrode plate and a method for manufacturing the same.

[0002]

2. Description of the Related Art For example, a lithium battery incorporating a lithium electrode as a battery electrode has been adopted for various purposes. This lithium electrode is usually manufactured by cutting a long hoop-shaped or sheet-shaped lithium foil at each desired cutting site and then fixing the strip-shaped lithium foil to the current collector surface.

In this case, in order to transfer the cut lithium foil to the current collector surface, it is conceivable to adopt a transfer structure having a contact roller and a nip roller. That is, a contact roller is disposed on the lithium foil transfer surface side of the current collector, and a nip roller is disposed on the opposite surface side of the current collector, and a pressing force is applied between the contact roller and the nip roller. The lithium foil is transferred onto the current collector.

By the way, since the lithium foil has a property of easily adhering to a metal material, a roller having an outer peripheral surface made of metal cannot be used as a contact roller. Therefore, in the above-mentioned contact roller, it is considered to provide a material on which the lithium foil is hard to adhere, for example, a resin material such as ultra-high density polyethylene, on the outer periphery of the metal shaft core.

[0005]

However, resin materials such as ultra-high-density polyethylene are often not firmly bonded to the metal shaft core because of poor adhesion to metal. In addition, this type of resin material is a material that easily thermally expands, and the relative position between the metal shaft core and the resin material may shift due to the heat generated during processing.

Further, in order to press the lithium foil onto the current collector and obtain sufficient adhesion strength, a considerably large load, for example, a pressure of 4 to 5 kgf / mm ² is required. However, in order to obtain such a large load using the equipment including the above-mentioned contact roller and nip roller,
It has been pointed out that it is difficult to realize the strength design.

The present invention is intended to solve this type of problem. It is possible to firmly fix a resin cylinder on the outer periphery of a metal shaft core and to impart desired adhesion strength to a lithium foil. It is an object of the present invention to provide a possible lithium foil contact roller and a method for manufacturing the same.

[0008]

In order to solve the above-mentioned problems, the present invention provides a method in which the metal core is cooled and the resin core is heated while the metal core is heated. After being press-fitted into the cylinder, the outer peripheral surface of the cylinder is knurled.

Therefore, the shaft core and the cylindrical body can be reliably integrated with each other by a simple operation without being affected by the adhesive force between the shaft core and the cylindrical body. Here, the outer peripheral surface of the shaft core press-fitted into the cylindrical body is knurled, and the shaft core is cooled to a temperature of −15 ° C. to 5 ° C. It is heated to a temperature of 60 ° C. As a result, the shaft core and the tubular body are more firmly integrated, and problems such as separation do not occur.

Further, by subjecting the tubular body to knurling, the contact area between the tubular body and the lithium foil is significantly reduced, and the relatively small pressure-bonding force of the tubular body is sufficient for the lithium foil. Adhesion strength can be surely imparted. Further, if the cylindrical body is perforated, it can also have a suction function.

Since the cylinder is made of polyethylene resin or polypropylene resin, it is possible to effectively prevent the cylinder and the lithium foil from adhering to each other.

[0012]

1 is a perspective view of a lithium foil contact roller 10 according to a first embodiment of the present invention. The roller 10 includes a metal shaft core 14 provided with knurls 12 on the outer peripheral surface thereof, and a resin cylindrical body 1 such as ultra-high density polyethylene or polypropylene into which the shaft core 14 is press fitted.
6 is provided. On the outer peripheral surface of the cylindrical body 16, a knurl 18
And a plurality of holes 19 are formed as needed.

The roller 10 is made of a metal on one surface 26a of a long electrode plate 26 in which an active material is intermittently applied at regular intervals on a hoop-shaped copper foil support and continuously conveyed in the direction of arrow A. On the other hand, since the lithium foil 28, which is a thin metal foil having adhesiveness, is attached at a predetermined attachment pitch, this surface 26a
Placed on the side. A nip roller 30 is disposed on the other surface 26b side of the electrode plate 26 so as to be movable back and forth with respect to the surface 26b.

Next, an operation for manufacturing the roller 10 according to the first embodiment having the above structure will be described.
First, as shown in FIG. 2A, a shaft core 14 provided with a knurl 12 on its outer peripheral surface and a cylindrical body 16 are prepared. At that time, a fitting margin of 0.1 mm to 0.3 mm is set between the outer peripheral surface of the shaft core 14 and the inner peripheral surface of the cylindrical body 16.

Next, while the shaft core 14 is cooled to a temperature of -15 ° C. to 5 ° C. and the cylindrical body 16 is heated to 30 ° C. to 60 ° C., for example, about 50 ° C. It is pressed into the cylindrical body 16 (see (b) in FIG. 2). Then, proceeding to (c) in FIG. 2, knurling is applied to the outer peripheral surface of the cylindrical body 16 into which the shaft core 14 is press fitted. For example,
The knurling 18 is provided on the outer peripheral surface of the cylindrical body 16 by pressing 0.3 mm in the mesh line 50 of the mesh.

After that, a plurality of holes 19 are formed from the outer peripheral portion of the cylindrical body 16 as needed, and further, on the outer peripheral surface thereof,
In order to obtain a desired parallelism, turning processing of about 0.1 mm is performed.

In this case, in the first embodiment, the shaft core 14
While the cylinder 16 is cooled, the shaft core 14 is pressed into the cylinder 16 while the cylinder 16 is heated. Therefore, even if the tubular body 16 is formed of a material having poor adhesion to a metal such as ultra-high density polyethylene or polypropylene, the tubular body 16 and the shaft core 1 can be formed with a simple configuration and work.
4 can be reliably integrated.

Here, the knurl 1 is attached to the outer peripheral surface of the shaft core 14.
2 is formed, and it becomes possible to more firmly integrate the shaft core 14 and the cylindrical body 16. As a result, it is possible to obtain an effect that it is possible to reliably prevent a defect such as the tubular body 16 being separated from the shaft core 14. The shaft core 14
An adhesive may be used when press-fitting into the cylindrical body 16.

The cooling temperature of the shaft core 14 (-15 ° C to 5 ° C)
C.) and the heating temperature (30.degree. C. to 60.degree. C.) of the cylindrical body 16 are set. Therefore, there is an advantage that the close contact state between the shaft core 14 and the cylindrical body 16 becomes stronger.

The operation of the roller 10 thus constructed will be described. As shown in FIG.
Rotates intermittently in the arrow direction, and the electrode plate 26 is quantitatively conveyed in the arrow A direction. And the nip roller 30
Moves toward the surface 26b of the electrode plate 26 in synchronism with the rotation of the roller 10, and the lithium foil 28 fed to the outer peripheral surface of the roller 10 is connected to the surface 26a of the electrode plate 26 by the roller 10 and the nip roller 30. Is crimped to.

Next, the nip roller 30 is separated from the electrode plate 26 and the rotation of the roller 10 is stopped, whereby the lithium foil 28 is transferred onto the surface 26a of the electrode plate 26.

In this case, in the first embodiment, the roller 1
The knurling 18 is provided on the outer peripheral surface of the cylindrical body 16 that constitutes 0. Therefore, the contact area with the lithium foil 28 on the outer peripheral surface of the cylindrical body 16 is reduced, and the pressure required to give sufficient adhesion strength to the lithium foil 28 is 4 to 5 kgf / mm ² of the related art. Compared with 0.5-0.6kgf /
It is greatly reduced to mm ² . Therefore, it is possible to obtain an effect that it is possible to surely provide the lithium foil 28 with sufficient adhesion strength with a simple configuration.

Experiments were conducted to inspect the state of adhesion to the lithium foil 28 using various materials for the cylindrical body 16. The results are shown in Table 1.

[0024]

[Table 1]

From this, it was found that the use of polyethylene resin or polypropylene resin for the cylinder 16 can effectively prevent the cylinder 16 and the lithium foil 28 from adhering to each other.

FIG. 3 is a schematic configuration diagram of a sticking device 24 incorporating a transfer roller 20 which is a lithium foil contacting roller according to the second embodiment of the present invention. This pasting device 24
Is a long electrode plate 2 in which an active material is intermittently applied at regular intervals to a hoop-shaped copper foil support and continuously conveyed in the direction of arrow A.
6 has a function of attaching a hoop-shaped lithium foil 28, which is a thin metal foil having adhesiveness to a metal, to one surface 26a of the metal sheet 6 at a predetermined cutting pitch and attachment pitch.

The sticking device 24 holds a partially separated lithium foil 28 (hereinafter referred to as a partially cut lithium foil 28a) and intermittently rotates on one surface 26a side of the electrode plate 26. Form transfer roller 20 and the electrode plate 2
6, a nip roller 30 for pressing the peripheral surface of the transfer roller 20 in synchronization with the transfer roller 20 from the other surface 26b.
And a cutting roller 22 arranged in parallel with the transfer roller 20.

The peripheral surface of the transfer roller 20 and the peripheral surface of the cutting roller 22 are separated from each other with a space of 0.2 mm to 0.5 mm, and in the vicinity of the peripheral surface of the cutting roller 22, the cutting roller 22 is provided. In synchronization with the above, the lithium foil 28 is intermittently provided with openings, for example, perforations 28b at predetermined intervals and along a cutting site provided orthogonally to the transport direction (direction of arrow E) of the lithium foil 28. A processing means 32 for forming is provided.

As shown in FIGS. 3 and 4, the cutting roller 22 is rotatably disposed on the outer peripheral portion of the fixed shaft body 34 via a bearing 36. The fixed shaft body 34 has a suction opening 38 that communicates with a negative pressure source (not shown) (for example, a ring blower) and has a lower side cut out in a predetermined angle range to be opened to the outside.

The cutting roller 22 has a metal shaft core 23,
The shaft core 23 is press-fitted and a material capable of avoiding adhesion of the lithium foil 28, for example, a cylinder 25 made of ultra-high density polyethylene is provided.

A plurality of suction holes 27 are formed so as to penetrate the cutting roller 22 in the diameter direction. The suction hole 27 has a diameter of 1.
A plurality of rectangular cross sections having a width of 1 mm in the circumferential direction and 5 mm in the depth direction are provided between the suction holes 27 at 5 mm and are provided on the entire circumference at intervals of L as a cutting pitch in the circumferential direction. Grooves 42 are formed on the entire circumference at intervals of a distance L in the circumferential direction.

As shown in FIG. 3, the processing means 32 is provided with a support member 44 which is connected to a driving means (not shown) such as a cylinder and is movable back and forth in the direction of arrow B. The support member 44 includes
A plurality of needle members 46 are provided at predetermined intervals in the width direction of the lithium foil 28, and pressing members 48 are movably supported on both sides of the needle members 46 via springs (not shown). When the cutting roller 22 is intermittently fed, the needle member 46 is provided with each groove 42 at the stop position of the cutting roller 22.
Are positioned to face each other.

The transfer roller 20 includes a metal shaft core 14a.
The shaft core 14a is press-fitted and is provided with, for example, a cylinder body 16a made of ultra-high density polyethylene. Cylinder 1
On the outer peripheral surface of 6a, for example, a knurl 18a is provided by being pressed with a mesh mesh number 50 by 0.3 mm.

A plurality of holes 19a opened outward from the outer peripheral surface of the transfer roller 20 are formed. Each hole 19a is
The diameter of the transfer roller 20 is 1.5 mm, and the transfer roller 20 is spaced apart by a distance L in the circumferential direction and is disposed on the entire circumference, and extends in the axial direction of the transfer roller 20 and is opened outward from one side portion of the transfer roller 20. To the passage 54.

At the side portion of the transfer roller 20, a transfer position S where the transfer roller 20 and the cutting roller 22 are slidably contacted with each other so that the partially cut lithium foil 28a is adsorbed and held on the peripheral surface.
A suction opening 56 is provided that connects the hole 52 arranged from 1 to just before the attachment position S2 where the transfer roller 20 and the nip roller 30 are in sliding contact with a negative pressure generation source (for example, a ring blower). The side of the transfer roller 20 is provided with a blower opening 58 that connects the hole 52 immediately after passing through the attachment position S2 to an air blower (not shown).

The transfer roller 20 and the cutting roller 22 are rotationally driven in synchronization in opposite directions (directions of arrow C and arrow D) by a single servo motor (not shown) or individual servo motors, and the nip roller 30 is The driving is controlled by the cam mechanism 60 in synchronization with the transfer roller 20.

The operation of the sticking device 24 thus constructed will be described below in connection with the transfer roller 20 according to the second embodiment. The transfer roller 20 is the first
Since it is manufactured in the same manner as the roller 10 according to the embodiment,
Detailed description thereof will be omitted.

As shown in FIG. 3, in the cutting roller 22,
Under the action of a negative pressure generating source (not shown), the inside of the fixed shaft body 34 of the cutting roller 22 is sucked and the cutting roller 2
2 and the transfer roller 20 are synchronously rotated in opposite directions (see arrow C direction and arrow D direction). Therefore, the lithium foil 28 is suction-held on the outer peripheral surface of the cutting roller 22 under the suction action of the plurality of suction holes 27, and is suction-conveyed within the range where the suction opening 38 of the fixed shaft body 34 is provided. It

Here, the cutting pitch of the lithium foil 28 is set to the interval L (for example, 4 mm), the cutting roller 22 is intermittently rotated, and the lithium foil 28 is separated to the interval L.
They are transported intermittently. Then, when the cutting portion of the lithium foil 28 is stopped at a position corresponding to the processing means 32, the support member 44 moves to the peripheral surface side of the cutting roller 22 under the action of a drive source (not shown) forming the processing means 32. To do. As a result, the plurality of needle members 46 enter the groove 42 and form the perforations 28b in the lithium foil 28 in a state in which the pressing member 48 presses the outer peripheral surface of the cutting roller 22 before and after the cutting portion of the lithium foil 28.

By intermittently rotating the cutting roller 22 and the transfer roller 20 in the directions of arrow C and arrow D, respectively, in perfect synchronization, the lithium foil 28 having the perforations 28b, that is, a partial cut is formed. Lithium foil 28
The a is transferred from the outer peripheral surface of the cutting roller 22 to the outer peripheral surface side of the transfer roller 20.

At this time, the suction opening 38 of the cutting roller 22 is closed at the delivery position S1 of the partially cut lithium foil 28a, while the suction opening 56 of the transfer roller 20 is opened from the delivery position S1. Therefore, the suction of the partially cut lithium foil 28a by the cutting roller 22 is released, and at the same time, the suction of the partially cut lithium foil 28a by the transfer roller 20 is started, so that the partially cut lithium foil 28a is smoothly moved to the transfer roller 20 side. And it is delivered reliably.

Next, when the partially cut lithium foil 28a adsorbed and held on the outer peripheral surface of the transfer roller 20 reaches the attaching position S2, the nip roller 3 is passed through the cam mechanism 60.
0 moves in the direction of arrow F (on the other surface 26b side of the electrode plate 26) in synchronization with the rotation of the transfer roller 20. As a result, the nip roller 30 presses the electrode plate 26 toward the transfer roller 20 side with a predetermined nip pressure.

Then, 1 / of the strip area of the partially cut lithium foil 28a adsorbed and held on the peripheral surface of the transfer roller 20.
The nip operation by the nip roller 30 is performed until the area of 2 to 4/5 comes into close contact with the electrode plate 26, and then the cam mechanism 60.
The nip roller 30 is separated from the electrode plate 26 via the, and the rotation of the transfer roller 20 is stopped. Therefore, there is a speed difference between the electrode plate 26 that is quantitatively conveyed in the direction of the arrow A and the partially cut lithium foil 28a that is partially attached to the electrode plate 26 and is held on the peripheral surface of the transfer roller 20. The partially cut lithium foil 28a is easily and surely separated from the perforations 28b, and reliably transferred onto the electrode plate 26 as the strip-shaped lithium foil 28c.

In this case, in the second embodiment, the transfer roller 20 is manufactured in the same manner as the roller 10 according to the first embodiment. Therefore, the transfer roller 20 can be manufactured efficiently and reliably by a simple process. can do. Moreover, the roller 1 according to the first embodiment has a simple structure and can reliably provide sufficient adhesion strength to the lithium foil 28.
The same effect as 0 can be obtained.

[0045]

According to the lithium foil contact roller and the method for manufacturing the same according to the present invention, the shaft core and the cylindrical body can be easily operated without being affected by the adhesive force between the shaft core and the cylindrical body. Can be reliably integrated. Here, since the outer peripheral surface of the cylindrical body is knurled, it is possible to reliably impart sufficient adhesion strength to the lithium foil with a relatively small pressure bonding force of the cylindrical body.

[Brief description of drawings]

FIG. 1 is a perspective explanatory view of a roller according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a manufacturing process of the roller according to the first embodiment.

FIG. 3 is a partially cutaway explanatory view of a sticking device incorporating a roller according to a second embodiment of the present invention.

FIG. 4 is an explanatory longitudinal cross-sectional view of a transfer roller and a cutting roller that constitute the pasting device.

[Explanation of symbols]

10 ... rollers 12, 18, 1
8a ... Knurl 14, 14a ... Shaft core 16, 16a ...
Cylindrical body 19, 19a ... Hole portion 20 ... Transfer roller 22 ... Cutting roller 24 ... Sticking device 26 ... Electrode plate 28, 28a,
28c ... Lithium foil 30 ... Nip roller

Claims (8)

[Claims] 1. A roller for adhering a lithium foil to an electrode plate, comprising a metal shaft core and a resin cylinder body into which the shaft core is press-fitted and whose outer peripheral surface is knurled. A roller for contacting a lithium foil, comprising: 2. The lithium foil contacting roller according to claim 1, wherein the outer peripheral surface of the shaft core is knurled. 3. The lithium foil contacting roller according to claim 1, wherein the outer peripheral surface of the cylindrical body is perforated. 4. The lithium foil contacting roller according to claim 1, wherein the cylindrical body is made of polyethylene resin or polypropylene resin. 5. A method for manufacturing a roller for bringing a lithium foil into close contact with an electrode plate, the method comprising: cooling a metal shaft core and heating a resin cylinder, and then rotating the shaft core into the cylinder. And a step of knurling the outer peripheral surface of the cylindrical body after the shaft core is press-fitted. 6. The manufacturing method according to claim 5, wherein the shaft core is cooled to a temperature of −15 ° C. to 5 ° C., and the cylindrical body is heated to a temperature of 30 ° C. to 60 ° C. Manufacturing method of roller for adhesion of lithium foil. 7. The method for manufacturing a lithium foil contact roller according to claim 5, wherein the outer peripheral surface of the shaft core is knurled in advance. 8. The lithium foil contacting method according to claim 5, further comprising a step of piercing the cylindrical body after knurling the outer peripheral surface of the cylindrical body. Roller manufacturing method.