JP2002343344A - Device and method for manufacturing zonal electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a zonal electrode which can manufacture a zonal electrode in a way it neither undulates nor curves. SOLUTION: A belt 36 stretched between at least two rolls (15, 16) is made contacted to one face of zonal raw material 44 with an electrode active material layer formed on both sides of a zonal metal foil. And on the other face, a mobile body 14 is made contacted opposite to the belt 36 for moving along the face whose distance from the belt 36 is gradually decreasing from the upstream side 4 toward the downstream side 6. As a result, the zonal material 44 is gradually compressed within the distance 2 where the belt 36 faces the mobile body 14, to turn to be a zonal electrode. Thus, compression distance is secured for a long distance by using the belt 36, and that, the device is structured compact in size as compared with the roll made larger in caliber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing a strip electrode. In particular, the present invention relates to a method and an apparatus for manufacturing a strip electrode from a strip material.

[0002]

2. Description of the Related Art An electrode used in a lithium battery or the like is manufactured by winding a strip-shaped electrode into a paper-like shape. As shown in FIG. 6, the strip-shaped electrode used for this purpose has electrode active material layers 10 on both sides of a strip-shaped metal foil 102.
4 are formed. An uncoated area 105 on which the electrode active material is not applied is provided on both side ends of the strip-shaped electrode, and a connection terminal is often attached to the uncoated area 105. When manufacturing this strip-shaped electrode, a strip-shaped material is first manufactured by applying a paste-shaped electrode active material to both sides of the strip-shaped metal foil 102 and then drying it in a drying furnace. Since the compression degree or specific gravity of the electrode active material layer is low as it is, the compression and the specific gravity of the electrode active material layer 104 are increased by compressing both sides of the manufactured band-shaped material to manufacture the band-shaped electrode.

Conventionally, a belt-shaped electrode is manufactured by passing a belt-shaped material between a pair of rolls and performing roll pressing on both sides of the belt-shaped material. In this case, when the band-shaped material passes between the pair of rolls, the band-shaped material is not only compressed, but also stretched mainly in the longitudinal direction. No particular problem arises if the strip material is stretched uniformly, but in practice it is not stretched uniformly and the compressed strip electrode often undulates. In particular, as shown in FIG. 6, when manufacturing a strip-shaped electrode in which the uncoated region 105 is provided on both left and right ends of the strip-shaped electrode, the strip is stretched at the center in the width direction of the strip,
Since it is not stretched at both left and right ends, it is difficult to obtain a clean and flat finished strip-shaped electrode. If the manufactured strip-shaped electrode is not clean and flat, the strip-shaped electrode cannot be wound into a wrapping paper without any gap.

To solve this problem, Japanese Patent Laid-Open No.
The technology described in Japanese Patent No. 92726 is proposed. In this technique, by providing a large number of linear cuts in a strip-shaped metal foil, a strip-shaped electrode roll-pressed by a pair of rolls is prevented from waving.

[0005] Uncoated areas 1 provided on both left and right ends
In some cases, a band electrode 05 is manufactured to be asymmetrical on the left and right.
For example, there is a case where a strip-shaped electrode having no uncoated region 105 at the right edge and an uncoated region 105 only at the left edge is manufactured. In this case, since the right edge of the belt-shaped material is not stretched, it is likely to be curved in an arc shape with the right edge inside. If the strip-shaped electrode is curved, the end faces of the electrode in which the strip-shaped electrode is wound in a wrapping paper cannot be made flat.

To solve this problem, Japanese Patent Application Laid-Open No.
The technology described in 185736 is proposed. In this technique, a curved strip-shaped electrode is heated while applying tension to the curved strip-shaped electrode compressed from both sides, thereby correcting the curved strip-shaped electrode.

[0007]

The technique described in Japanese Patent Application Laid-Open No. 7-192726, in which a number of linear cuts are formed in a strip-shaped metal foil, requires a step of forming cuts in the metal foil, and productivity is reduced. bad. Further, cracks are generated from the cuts provided in the metal foil, and the electrode is likely to be deteriorated. In the technique described in Japanese Patent Application Laid-Open No. H11-185736, in which the bending is corrected by heating the belt-shaped electrode while applying tension, the electrode active material may be deteriorated by heating, which may adversely affect battery characteristics.

The present invention has been made in order to solve such a problem, and provides a method and apparatus capable of manufacturing a strip electrode while preventing the strip electrode from waving or curving. That is the task.

[0009]

Means for Solving the Problems, Functions and Effects According to the present invention, if the band-shaped material can be compressed while not expanding, the band-shaped electrode may be wavy or curved. Leverage the knowledge that there is nothing. Actually, when a short material is compressed by a flat plate press in order to manufacture a short electrode, the material hardly expands, and the compressed electrode does not undulate or curve. When continuously manufacturing a long strip-shaped electrode, a flat plate press cannot be used, and a pair of rolls is usually used. At this time, as the radius of the roll increases, the phenomenon in which the band-shaped material is stretched during compression is suppressed, and the state approaches that of being compressed by a flat plate press. However, a large roll is required to effectively suppress the stretching of the strip material, which is not practical. In the present invention, a belt is used. Utilizing the knowledge that the use of a belt enables compacting the device size and compressing it as large as a large roll.

In the method according to the first aspect of the present invention, a belt stretched between at least two rolls is applied to one surface of a strip material having an electrode active material layer formed on both surfaces of a strip metal foil. Contact Then, a moving body that moves along a surface that faces the belt and whose separation distance from the belt gradually decreases from the upstream side to the downstream side is brought into contact with the other surface. As a result, the belt-shaped material is gradually compressed within the distance between the belt and the moving body to produce a belt-shaped electrode.
The above-mentioned moving body may be constituted by a roll or a belt.

By using the belt, the compression distance can be ensured over a clearly longer distance than the compression distance when the compression is performed between the pair of rolls. In addition, the apparatus can be configured much more compactly than when the diameter of the roll is increased. The method of the present invention can be performed in a compact device, can be gradually compressed over a long distance, and can be compressed while suppressing elongation of the strip material. As a result, it is possible to continuously manufacture a strip-shaped electrode that does not undulate or curve with a compact device.

[0012] The device according to claim 2 of the present invention has at least two components.
The belt stretched between the two rolls, the moving body facing the belt and moving along the surface where the separation distance from the belt gradually changes, and the separation distance of the facing portion of the belt and the moving body Means for introducing a band-shaped material into the end on the larger side. The moving body here may be a roll or a belt. The means for introducing the belt-like material may be a means for positively introducing the belt-like material into the gap between the belt and the moving body, or a passive method that allows the belt-like material to be introduced into the gap between the belt and the moving body. It may be something.

Although this manufacturing apparatus is compact,
It is possible to continuously manufacture a strip-shaped electrode that does not undulate or curve.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment An apparatus for manufacturing a strip-shaped electrode according to a first embodiment will be described with reference to FIGS. The belt-shaped electrode manufacturing apparatus 10 includes a frame 12, an upper rotating roll 14, a lower rotating roll 15, a belt tension roll 16, a belt 36 stretched between the lower rotating roll 15 and the belt tension roll 16, It is composed of an electric motor 22 for rotating the roll and the like.
As shown in FIG. 3, the lower rotating roll 15 is disposed below the upper rotating roll 14, and the axis of the belt tension roll 16 is disposed slightly lower than the axis of the upper rotating roll 14. Have been.

As shown in FIG. 1, the upper rotating roll 14 has shaft cores 14a formed at both ends, and the shaft core 1a is located between the shaft cores 14a.
A compression portion 14b having a diameter larger than 4a is formed.
A gear 14c is fixed to one shaft core 14a of the upper rotating roll 14. And the upper rotating roll 14
Is mounted in a rotatable state with its shaft core 14a attached to the frame 12 via a pair of bearings 26.

The lower rotating roll 15 has shaft cores 15a formed at both ends, and a compression portion 15b having a larger diameter than the shaft core 15a is formed therebetween. A gear 15c is fixed to one shaft core 15a of the lower rotating roll 15, and the gear 15c
c is meshed with the gear 14c of the upper rotating roll 14. The shaft core 15a of the lower rotating roll 15 is a pair of bearings 2
8, and the bearing 28 is vertically movable along a guide (not shown) formed on the frame 12. The bearing 28 is fixed to a hydraulic cylinder 29 to which a piston 29a extends when hydraulic pressure is applied. With this configuration, the lower rotating roll 15 moves upward (in the direction of the arrow 42 in FIG. 3) with the extension of the piston 29a of the hydraulic cylinder 29. When the hydraulic pressure applied to the hydraulic cylinder 29 is reduced, the piston 29a contracts, and accordingly, the lower rotating roll 15 moves downward.

As shown in FIGS. 1 and 2, the electric motor 22 and the gear box 23 are connected by a shaft 22a. The gear box 23 has a plurality of built-in reduction gears therein, and reduces the rotation speed of the electric motor 22. A gear 38 is fixed to the shaft 23a of the gear box 23, and the gear 38 meshes with a gear 15c fixed to the shaft core 15a of the lower rotating roll 15.

As shown in FIG. 2, the belt tension roll 16 has shaft cores 16a formed at both ends.
In the meantime, the tension portion 16 having a larger diameter than the shaft core 16a
b is formed. The belt tension roll 16 is mounted on the frame 12 via a pair of bearings 32. The belt tension roll 16 is freely rotatable about the frame 12. Bearing 32 of belt tension roll 16
Is movable up and down along a guide (not shown) formed on the frame 12, and is fixed to a hydraulic cylinder 34 in which a piston 34a extends when hydraulic pressure is applied. Therefore, when the piston 34a of the hydraulic cylinder 34 extends, the belt tension roll 16 moves upward (in the direction of the arrow 43 in FIG. 3). When the hydraulic pressure applied to the hydraulic cylinder 34 is reduced, the piston 34
a contracts, and the belt tension roll 16 moves downward accordingly.

The belt 36 is formed of a belt-like flexible material (for example, a rubber sheet) with a closed circumference. FIG.
, The belt 36 is stretched between the belt tension roll 16 and the lower rotating roll 15. The belt 36 includes the upper rotating roll 14 and the lower rotating roll 1.
5 and is wound around a part of the circumference of the upper rotating roll 14. A part of the circumference of the upper rotating roll 14 (indicated by reference numeral 2 in FIG. 3) has a positional relationship facing the belt 36.

The operation of the strip electrode manufacturing apparatus 10 configured as described above will be described. When the electric motor 22 is rotationally driven, the shaft 22a rotates to rotate the reduction gear built in the gear box 23. Since the reduction gear of the gear box 23 reduces the rotation speed of the electric motor 22, the rotation torque output to the shaft 23a of the gear box 23 is increased. When the gear 38 rotates together with the shaft 23a, the gear 15c of the lower rotating roll 15 meshed with the gear 38 rotates, and the gear 14c of the upper rotating roll 14 meshed with the gear 15c also rotates. In this way, the upper rotating roll 14 and the lower rotating roll 15 are driven to rotate by the electric motor 22, and rotate in opposite directions (directions of arrows 45 and 46), respectively, as well shown in FIG. At the same time, the rotational force of the lower rotating roll 15 is transmitted to the belt tension roll 16 via the belt 36, and the belt tension roll 16 also rotates in the direction of arrow 49.

When hydraulic pressure is applied to the hydraulic cylinder 29,
The piston 29a extends, and the lower rotating roll 15 moves upward. When hydraulic pressure is applied to the hydraulic cylinder 34, the piston 34a extends, and the belt tension roll 16a moves upward. The amount of movement of the lower rotating roll 15 and the belt tension roll 16 depends on the hydraulic cylinder 2
9 and a hydraulic pressure adjusting means (not shown) of the hydraulic cylinder 34 can be adjusted. When the lower rotating roll 15 moves upward, the belt 36 moves to the upper rotating roll 1.
It is pressed to the 4 side. When the belt tension roll 16 moves upward, tension is applied to the belt 36.

During operation, the belt-shaped material 44 is introduced into the space between the belt 36 and the upper rotating roll 14. The position of the lower rotating roll 15 and the belt tension roll 16 is such that when the belt-shaped material 44 is introduced into the gap between the belt 36 and the upper rotating roll 14, the separation distance between the belt 36 and the upper rotating roll 14 is on the upstream side (see FIG. 3). The positional relationship is adjusted so as to be large at the position indicated by reference numeral 4, gradually decrease toward the downstream, and minimized at the most downstream position (indicated by reference numeral 6 in FIG. 3). The belt 36 and the upper rotating roll 14 keep running or rotating while maintaining this positional relationship. The upper rotating roll 14 can be said to be a moving body that moves along a surface where the separation distance from the belt 36 gradually changes.

When the belt 36 runs and the upper rotating roll 14 rotates, the belt-shaped material 44 is attached to the end (4) of the side (4) where the separation distance between the belt 36 and the opposing portion (2) of the moving body (upper rotating roll) 14 is large. be introduced.

The strip-shaped electrode manufacturing apparatus 10 operating as described above
A method for manufacturing a strip-shaped electrode using will be described. The band-shaped material 44 has an electrode active material layer (for example, on both sides of a metal foil).
(A lithium cobalt composite oxide, a lithium manganese composite oxide, etc.). As shown in FIG. 3, the belt material 44 before the processing is introduced into the space between the belt 36 and the upper rotating roll 14 by the rotation of the upper rotating roll 14 by the movement of the belt 36. At this time, the belt-shaped material 44 is introduced from the end (4) on the side where the interval between the belt 36 and the upper rotating roll 14 is large. The belt-shaped material 44 introduced into the gap between the belt 36 and the upper rotating roll 14 is gradually compressed in response to the narrowing of the gap between the belt 36 and the upper rotating roll 14. The thickness of the electrode active material layers formed on both surfaces of the metal foil is controlled by adjusting the amount of movement of the lower rotating roll 15 and changing the compressive force between the upper rotating roll 14 and the lower rotating roll 15. be able to.

The belt-shaped material 44 is first compressed while passing between the compression section 14b of the upper rotation roll 14 and the belt 36, and finally is compressed by the compression section 14b of the upper rotation roll 14 and the belt 3
6, and is compressed by the compression section 15b of the lower rotating roll 15. Since the electrode active material layer of the band-shaped material 44 is gradually compressed, the elongation of the band-shaped material is suppressed. Although the manufacturing apparatus 10 is compact, the electrode active material layer of the band-shaped material 44 can be gradually compressed, and can be compressed while suppressing the elongation of the band-shaped material. For this,
The manufactured strip-shaped electrodes do not undulate or bend, and are of very good quality.

Second Embodiment Next, a second embodiment will be described with reference to FIG. The description of the same configuration and operation as in the first embodiment will be omitted. The strip-shaped electrode manufacturing apparatus according to the second embodiment is configured by adding a belt roll 62 to the strip-shaped electrode manufacturing apparatus 10 according to the first embodiment. The belt roll 62 has a columnar outer shape, and as shown in FIG. 4, the belt-shaped material 44 is interposed between the belt tension roll 16 and the lower rotation roll 15 via the belt 36. It is arranged at a position sandwiched between the rotating roll 14. The belt roll 62 is mounted on the frame 12 so as to be movable in the vertical direction, and is connected to a hydraulic cylinder (not shown). When hydraulic pressure is applied to the hydraulic cylinder, the belt roll 62 moves upward. The belt roll 62 is rotationally driven by the motor 22 via a rotation transmission mechanism (not shown).

When the electric motor 22 rotates, the belt roll 62 is driven to rotate together with the upper rotating roll 14 and the lower rotating roll 15 in the direction of arrow 63. When hydraulic pressure is applied to a hydraulic cylinder connected to the belt roll 62, the belt roll 62 moves upward (in the direction of the arrow 64) and moves via the belt 36 to the compression unit 1 of the upper rotary roll 14.
4b, the band-shaped material 44 is compressed. For this reason, the belt 36 is securely stretched over the portion between the belt roll 62 and the lower rotating roll 15, and the belt 36 is prevented from being bent. When the deflection of the belt 36 is prevented, a strip-shaped electrode having a more uniform thickness of the electrode active material layer can be obtained. Further, the belt-shaped electrode manufacturing apparatus according to the second embodiment can adjust the compression force of the belt roll 62 in addition to the adjustment of the compression force between the upper rotation roll 14 and the lower rotation roll 15. The thickness of the active material layer formed on the substrate can be more finely controlled.

In the case of this apparatus, the upper rotating roll 1 is moved from the position (4) where the belt roll 62 faces the upper rotating roll 14.
In a range (2) up to the position (6) where the lower rotating roll 15 faces 4, the belt 36 and the upper rotating roll 14 face each other.
At the upstream side in the moving direction of the belt-shaped material 44 (the position (4) where the belt roll 62 faces the upper rotating roll 14), the belt 3
The distance between the upper rotating roll 6 and the upper rotating roll 14 is large, and decreases toward the downstream side, and becomes the smallest at the most downstream portion (the position (6) where the lower rotating roll 15 faces the upper rotating roll 14).
The maximum separation distance can be adjusted by adjusting the position of the belt roll 62, and the minimum separation distance can be adjusted by adjusting the position of the lower rotating roll 15. According to this device, it is possible to freely adjust the progress of the degree of compression when the strip material is gradually compressed.

(Third Embodiment) Next, a third embodiment will be described with reference to FIG. As shown in FIG. 5, the apparatus for manufacturing a strip-shaped electrode according to the third embodiment has an upper belt 8.
6 and the lower belt 87 are respectively upper belt rolls (82,
83) and the lower belt roll (84, 85). The interval between the upper belt 86 and the lower belt 87 is
The portion between the upper belt roll 82 and the lower belt roll 84 is set to be narrower than the portion between the upper belt roll 83 and the lower belt roll 85. Upper belt roll 82
Between the upper belt roll 83 and the upper belt 86
An upper holding roll 91 is provided. A lower belt 87 is also provided between the lower belt roll 84 and the lower belt roll 85.
, Two lower holding rolls 92 are provided.
The upper holding roll 91 and the lower holding roll 92 have a function of preventing the upper belt 86 and the lower belt 87 from bending inward. The upper belt rolls (82, 83) and the lower belt rolls (84, 85) are indicated by arrows (82a, 83).
a, 84a, 85a), whereby the upper belt 86 and the lower belt 87 are moved in the directions of arrows (86a, 86a, 85a).
Travel in the direction of 87a).

In this case, with respect to the belt 86 stretched between the rolls 82 and 83, the belt 87 stretched between the rolls 84 and 85 faces the belt 86 and gradually separates from the belt 86. It can be said that the moving body moves along a plane that changes in the direction. In addition, the running belts 86 and 87 serve as a means for introducing the belt-shaped material 44 to the end on the side where the separation distance of the facing portion is large.

The belt-shaped material 44 is taken into the space between the upper belt 86 and the lower belt 87, and is gradually compressed while passing through the space. Since the compression of the band-shaped material 44 is performed gradually in this manner, the elongation of the band-shaped material 44 is suppressed,
The manufactured strip-shaped electrodes do not undulate or bend, and are of very good quality.

Although the embodiment of the present invention has been described in detail, this is merely an example, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. . For example, the case where a metal foil having no holes is used as the metal foil has been illustrated, but a metal foil or a lath metal in which a large number of holes are punched can also be used. Although an example using a rubber belt has been described, a metal belt can also be used.

[Brief description of the drawings]

FIG. 1 is a front view of a strip-shaped electrode manufacturing apparatus according to a first embodiment.

FIG. 2 is a rear view of the strip electrode manufacturing apparatus of FIG. 1;

FIG. 3 is a schematic view of a belt, a roll, and a strip material of the strip electrode manufacturing apparatus of FIG.

FIG. 4 is a schematic view of a belt, a roll, and a strip material of a strip electrode manufacturing apparatus according to a second embodiment.

FIG. 5 is a schematic view of a belt, a roll, and a strip material of a strip electrode manufacturing apparatus according to a third embodiment.

FIG. 6 is a perspective view of a strip electrode.

[Explanation of symbols]

10: Strip electrode manufacturing apparatus 14: Upper rotating roll, 14a: Shaft core, 14b: Compression section,
14c: Gear 15: Lower rotating roll, 15a: Shaft core, 15b: Compressor,
15c: Gear 16: Belt tension roll, 16a: Shaft core, 16
b: tension part 22: electric motor 26: bearing 28: bearing 29: hydraulic cylinder 32: bearing 34: hydraulic cylinder 36: belt 44: belt-like material 62: belt roll 86: upper belt 87: lower belt

Continued on the front page F term (reference) 4E090 AA04 AB04 HA10 5H017 AA03 AS02 BB06 BB08 CC01 EE01 5H050 BA06 DA04 EA02 FA02 GA03

Claims (2)

[Claims] 1. A method of manufacturing a band-shaped electrode by compressing from both sides of a band-shaped material in which electrode active material layers are formed on both sides of a band-shaped metal foil, wherein one side of the band-shaped material is provided between at least two rolls. The moving belt moves along a surface that faces the belt on the other surface and moves away from the belt gradually from the upstream side to the downstream side. A method of manufacturing a strip electrode by gradually compressing the strip material within a distance between the belt and the moving body. 2. An apparatus for manufacturing a strip electrode from a strip material having electrode active material layers formed on both surfaces of a strip metal foil, comprising: a belt stretched between at least two rolls; and a belt facing the belt. And a moving body moving along a surface where a separation distance from the belt gradually changes, and a means for introducing a band-shaped material to an end on a side where a separation distance between the belt and the moving body is large. apparatus.