Method and apparatus for manufacturing laminates

Abstract

The present invention provides a manufacturing apparatus for laminates that can reliably laminate a coating material onto a thin substrate. [Solution] An apparatus for manufacturing a laminate 70 in which a coating material 60 is laminated on a base material 50, comprising: a micro-groove forming apparatus 10 having a transfer roll 11 with a roll groove 11a formed on its outer circumference surface, which transfers the roll groove 11a to the surface of the base material 50 to form a micro-groove; a lamination apparatus 20 for laminating the coating material 60 onto the surface of the base material 50 on which the micro-groove has been formed; and a pressing apparatus 30 for pressing the base material 50 and the coating material 60 together, wherein the micro-groove is composed of a plurality of intersecting first grooves and second grooves arranged at predetermined intervals in a predetermined direction, respectively, in an apparatus for manufacturing a laminate 1.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a laminate.

Background Art

[0002] As an apparatus for manufacturing a laminate in which a coating material such as an electrode active material is laminated on the surface of a base material made of a current collector made of metal or the like, an electrode manufacturing apparatus disclosed in Patent Document 1 is known. This electrode manufacturing apparatus includes a film forming unit that supplies a wet powder to the surface of a sheet-shaped current collector to form a coating film, a coating film processing unit that presses the coating film in the thickness direction to perform a surface unevenness forming process, and a drying unit that dries the coating film after the surface unevenness forming process to form an electrode active material layer. The coating film processing unit includes a first unevenness processing roll and a second unevenness processing roll for performing unevenness transfer on the surface of the coating film, and each forms a first groove and a second groove.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For the current collector used in the above electrode manufacturing apparatus, it is required to reduce the thickness in order to increase the capacity of the battery. However, when the current collector is thinned, warping and distortion are likely to occur after the formation of the electrode active material layer, and there is a problem that peeling occurs between the current collector and the electrode active material layer.

[0005] That is, as shown in FIG. 8(a), since the electrode active material layer C is laminated on the surface of the current collector E so that both sides in the width direction of the current collector E are exposed, when the electrode active material layer C is pressed in the thickness direction, the elongation of the current collector E is restricted, and there is a possibility that the edges of the current collector E may warp upward starting from both side edges C1 and C2 of the electrode active material layer C.

[0006] Furthermore, if, from this state in which residual stress has been generated in the current collector E, one edge of the current collector E is partially cut off to form a tab E1, as shown in Figure 8(b), there is a risk that the current collector E will bend and become distorted due to the release of the residual stress.

[0007] Therefore, the present invention aims to provide a method and apparatus for manufacturing a laminate that can reliably laminate a coating material onto a thin substrate. [Means for solving the problem]

[0008] The object of the present invention is a method for manufacturing a laminate in which a coating material is laminated on a substrate, comprising a lamination step of laminating a coating material onto the surface of a substrate made of metal foil having fine grooves formed on its surface, and a pressing step of pressing the substrate and the coating material together, wherein the fine grooves are formed by a method for manufacturing a laminate in which a plurality of intersecting first grooves and second grooves are arranged at predetermined intervals in a predetermined direction.

[0009] In the method for manufacturing this laminate, the fine grooves are preferably formed in a rhombic lattice pattern on the surface of the strip-shaped substrate, and it is preferable that one diagonal of the rhombic lattice pattern extends in the longitudinal direction of the substrate, and the other diagonal of the rhombic lattice pattern extends in the width direction of the substrate. It is more preferable that one diagonal is shorter than the other diagonal.

[0010] The aforementioned fine grooves are preferably 1.5 to 3 μm deep and 15 to 30 μm wide.

[0011] The coating material can be an electrode active material.

[0012] The fine grooves may be formed on both the front and back surfaces of the substrate, in which case the lamination process may include a step of laminating a coating material on both the front and back surfaces of the substrate.

[0013] Furthermore, the present invention provides an apparatus for manufacturing a laminate in which a coating material is laminated on a substrate, comprising: a microgroove forming apparatus having a transfer roll with a roll groove formed on its outer circumference, which transfers the roll groove to the surface of the substrate to form a microgroove; a lamination apparatus for laminating a coating material onto the surface of the substrate on which the microgroove is formed; and a pressing apparatus for pressing the substrate and the coating material together, wherein the microgroove is formed by a laminate manufacturing apparatus in which a plurality of intersecting first grooves and second grooves are arranged at predetermined intervals in a predetermined direction. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a method for manufacturing a laminate and a manufacturing apparatus that can reliably laminate a coating material onto a thin substrate. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram of a laminate manufacturing apparatus according to one embodiment of the present invention. [Figure 2] A cross-sectional view showing the state of the laminate during the manufacturing process. [Figure 3] Figure 1 is a plan view showing an example of a substrate used in the manufacturing apparatus for the laminate. [Figure 4] This is a magnified view of a portion of Figure 2. [Figure 5] This figure shows a modified example of Figure 4. [Figure 6] This is a schematic diagram of a laminate manufacturing apparatus according to another embodiment of the present invention. [Figure 7] Figure 6 is a cross-sectional view of a laminate manufactured using the laminate manufacturing apparatus. [Figure 8] This is a plan view of a conventional laminate. [Modes for carrying out the invention]

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a laminate manufacturing apparatus according to an embodiment of the present invention. The laminate manufacturing apparatus 1 shown in FIG. 1 includes a microgroove forming apparatus 10, a laminating apparatus 20, and a pressure bonding apparatus 30, and can manufacture a laminate 70 in which a coating material 60 is laminated on a strip-shaped base material 50 by transporting the base material 50 along the longitudinal direction. In the present embodiment, as the base material 50, a current collector made of a metal foil having good conductivity such as an aluminum foil or a copper foil is used, and as the coating material 60, a material containing a binder, a conductive material, etc. as appropriate with an electrode active material (positive electrode active material or negative electrode active material) as the main component is used, whereby an electrode sheet (positive electrode sheet or negative electrode sheet) as the laminate 70 can be manufactured.

[0017] The microgroove forming apparatus 10 is an apparatus for forming microgrooves on the surface of the thin base material 50, and includes a transfer roll 11 and a support roll 12. The transfer roll 11 and the support roll 12 are arranged to face each other with a gap slightly smaller than the thickness of the base material 50 (for example, 6 to 15 μm).

[0018] The transfer roll 11 has roll grooves 11a for transfer formed on the outer peripheral surface, while the support roll 12 has a smooth outer peripheral surface. The transfer roll 11 and the support roll 12 are preferably rubber rolls having appropriate flexibility (for example, a Shore A hardness of about 70). By appropriately adjusting the pinch pressure, the reproducibility of the transfer of the roll grooves 11a can be improved, and microgrooves with a minute depth (for example, about 1.5 μm) can be accurately formed on the base material 50, and damage to the base material 50 due to pressing can be suppressed to prevent breakage of the base material 50.

[0019] The surface roughness Ra of the transfer roll 11 and the support roll 12 is not particularly limited. However, by generating an appropriate frictional force between the transfer roll 11 and the support roll 12 and the base material 50, smooth transfer can be achieved while maintaining good adhesion to the base material 50, and the transfer accuracy can be maintained well. As a preferable example of the surface roughness Ra, it is about 0.5 μm. When static electricity due to friction between the transfer roll 11 and the support roll 12 and the base material 50 becomes a problem, an electrostatic eliminator such as an ionizer may be provided.

[0020] The laminating device 20 includes a feeder 21 that supplies granulated bodies of a coating material containing an electrode active material, a binder, a solvent, etc., a first roll 22 and a second roll 23 that are arranged with a slight gap between them below the feeder 21, and a third roll 24 that is arranged adjacent to the second roll 23 with a slight gap. The base material 50 is stretched over the third roll 24 such that the fine grooves formed by the fine groove forming device 10 are on the outer surface side.

[0021] The first roll 22 and the second roll 23 compress and mold the granular coating material supplied from the feeder 21 into a sheet shape. When the third roll 24 conveys the base material 50 and passes it through the gap with the second roll 23, the formed coating material is overlaid on the surface of the base material 50. As a result, as shown in FIG. 2, the coating material 60 is laminated on the surface of the base material 50 in which the fine grooves 51 are formed.

[0022] The crimping device 30 includes a pair of crimping rolls 31 and 32 that are arranged vertically with a slight gap between them. When the pair of crimping rolls 31 and 32 press and crimp the base material 50 and the coating material 60 shown in FIG. 2 in the thickness direction, the fine grooves 51 relieve the residual stress of the base material 50 due to pressing, and a part of the coating material 60 enters the fine grooves 51, so that the base material 50 and the coating material 60 adhere to each other. As the crimping rolls 31 and 32, a rubber roll, a metal roll, or the like can be used. The laminate 70 manufactured through the crimping device 30 is supplied to the battery manufacturing line after tabs are formed and cutting or the like is performed.

[0023] A method for manufacturing a laminate using the laminate manufacturing apparatus 1 having the above configuration comprises a micro-groove forming step of forming micro-grooves on the surface of a substrate 50 using a micro-groove forming apparatus 10, a lamination step of laminating a coating material 60 on the surface of a substrate 50 using a lamination apparatus 20, and a crimping step of crimping the substrate 50 and the coating material 60 using a crimping apparatus 30.

[0024] Figure 3 is a plan view of the substrate 50 on which microgrooves 51 have been formed by the microgroove formation process, and Figure 4 is a partially enlarged view of Figure 3. As shown in Figure 3, the microgrooves 51 formed on the surface of the strip-shaped substrate 50 include first grooves 52 and second grooves 53 that extend in an inclined linear manner with respect to the transport direction T, which is the longitudinal direction of the substrate 50. The first grooves 52 and second grooves 53 are arranged to intersect each other, and multiple grooves are formed in each direction T at regular intervals (for example, 100 to 150 μm). As a result, the microgrooves 51 are formed in a rhombic lattice pattern in which a large number of rhombic shapes are continuous.

[0025] The depth of the first groove 52 and the second groove 53 is preferably 1.5 to 3 μm for a substrate 50 thickness of 6 to 15 μm, for example, because if the depth is too large relative to the thickness of the substrate 50, the substrate 50 will be easily damaged, while if it is too small, it will be difficult to obtain adhesion with the coating material 60 that will be laminated in the lamination process. Furthermore, the width of the first groove 52 and the second groove 53 is preferably 15 to 30 μm, for example, from the viewpoint of promoting the fixation of the laminated coating material 60 and ensuring uniformity of thickness. By setting the depth and width of the first groove 52 and the second groove 53 in this way, a laminate 70 with a stable shape and minimal distortion can be manufactured.

[0026] Each rhombic shape of the rhombic grid-like micro-grooves 51 has one diagonal extending in the transport direction (longitudinal direction) T of the base material 50, and the other diagonal extending in the width direction of the base material 50. This allows for the reduction of stress accumulated in the base material 50 when it is pressed in the thickness direction during the crimping process by the crimping device 30, thereby reducing the risk of the coating material 60 peeling off from the base material 50. Furthermore, by strengthening the adhesion between the base material 50 and the coating material 60, the cycle life and electrical characteristics when the laminate 70 is used as an electrode sheet can be improved.

[0027] To reliably relieve the residual stress on the base material 50 generated during the crimping process, as shown in Figure 3, it is preferable that the rhombic shape formed inside the micro-grooves 51 has a diagonal length L1 extending in the transport direction T that is smaller than the other diagonal length L2 perpendicular to it. More specifically, it is preferable to set L2 to 0.6 mm or less and then make L1 smaller than L2 (for example, to 0.1 to 0.3 mm). However, the first groove 52 and the second groove 53 may be inclined at 45 degrees with respect to the transport direction T to be perpendicular to each other, thereby forming the micro-grooves 51 in a rhombic lattice shape of continuous squares.

[0028] Furthermore, as shown in Figure 5(a), the first groove 52 and the second groove 53 may be formed in a sine curve shape with their inversions to each other, at regular intervals along the transport direction T. In this case as well, a roughly rhombic shape can be formed by intersecting the first groove 52 and the second groove 53. Alternatively, as shown in Figure 5(b), the linear first groove 52 and the second groove 53 may be intersected, with the first groove 52 arranged at regular intervals along the transport direction T, while the second groove 53 is arranged at regular intervals along a direction perpendicular to the transport direction T, thereby forming a grid-like fine groove 51.

[0029] The method for manufacturing a laminate of the present invention is particularly effective for manufacturing electrode sheets, as in this embodiment. When the manufactured electrode sheets are combined with an electrolyte and a separator to form a battery, the adhesion of the electrode sheets and the permeability of the electrolyte can be improved. This can lead to improved product reliability, improved energy efficiency, and improved production efficiency. However, the method for manufacturing a laminate of the present invention can also be used for laminating various coating materials such as paints and films onto a substrate, and can be suitably used for purposes other than manufacturing electrode sheets.

[0030] In this embodiment, the method for manufacturing the laminate involves laminating the coating material 60 only on the surface of the base material 50 to form the laminate 70. However, using the laminate manufacturing apparatus 1' shown in Figure 6, the coating material 60 and 61 can also be laminated on both the front and back surfaces of the base material 50 to form the laminate 70', as shown in Figure 7.

[0031] The laminate manufacturing apparatus 1' shown in Figure 6 is configured as shown in Figure 1 of the laminate manufacturing apparatus 1, with the fine groove forming apparatus 10' being equipped with a pair of transfer rolls 11 and 13, and further, another laminate apparatus 40 being positioned between the laminate apparatus 20 and the crimping apparatus 30. The configuration of the laminate apparatus 40 is the same as that of the laminate apparatus 20, and is equipped with a feeder 41, a first roll 42, a second roll 43, and a third roll 44.

[0032] A pair of transfer rolls 11 and 13 are positioned adjacent to each other so that the substrate 50 passes through the gap between them. By transferring the roll grooves 11a and 13a formed on the outer surfaces of each roll to the substrate 50, fine grooves are formed on both the front and back surfaces of the substrate 50. Coating materials 60 and 61 supplied from lamination devices 20 and 40, respectively, are laminated onto both the front and back surfaces of the substrate 50 on which the fine grooves have been formed.

[0033] The coating materials 60 and 61 laminated on the base material 50 are pressed by the pressing device 30, and as shown in Figure 7, they adhere closely to the base material 50, with the coating materials 60 and 61 respectively embedded in the fine grooves 51 and 52 on the front and back surfaces of the base material 50. This makes it possible to obtain a laminate 70' in which the coating materials 60 and 61 are reliably laminated on the base material 50. [Explanation of Symbols]

[0034] 1. Laminate manufacturing apparatus 10 Fine groove forming device 11,13 Transfer Roll 11a, 13a Roll groove 20,40 Stacking equipment 30 Crimping device 50 Base material 51 Micro-grooves 52 First groove 53 Second groove 60 Coating materials 70-layer structure

Claims

1. A method for manufacturing a laminate in which a coating material is laminated onto a strip-shaped substrate, A lamination process in which a coating material is laminated onto the surface of a substrate made of metal foil having fine grooves formed on its surface, The system includes a pressing step for pressing the substrate and the coating material together, The method for manufacturing a laminate is characterized in that the fine grooves are composed of a plurality of intersecting first grooves and second grooves arranged at predetermined intervals in a predetermined direction.

2. The aforementioned fine grooves are formed in a diamond-shaped grid pattern on the surface of the strip-shaped substrate, The method for manufacturing a laminate according to claim 1, wherein one diagonal of the rhombus shape extends in the longitudinal direction of the base material, and the other diagonal of the rhombus grid extends in the width direction of the base material.

3. The method for manufacturing a laminate according to claim 2, wherein one of the diagonals is shorter than the other diagonal.

4. The method for manufacturing a laminate according to claim 1, wherein the fine grooves have a depth of 1.5 to 3 μm and a width of 15 to 30 μm.

5. The method for manufacturing a laminate according to claim 1, wherein the coating material is an electrode active material.

6. The aforementioned fine grooves are formed on both the front and back surfaces of the substrate. The method for manufacturing a laminate according to claim 1, further comprising a step of laminating a coating material on both the front and back surfaces of the substrate.

7. An apparatus for manufacturing a laminate in which a coating material is laminated onto a strip-shaped substrate, A microgroove forming apparatus having a transfer roll with a roll groove formed on its outer surface, and transferring the roll groove to the surface of a substrate to form a microgroove, A lamination apparatus for laminating a coating material onto the surface of a substrate on which fine grooves are formed, The system includes a crimping device for pressing the substrate and the coating material together. The aforementioned fine grooves are formed by a manufacturing apparatus for a laminate, in which multiple first grooves and second grooves intersecting each other are arranged at predetermined intervals in a predetermined direction.

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