Mixture sheet molding device and molding method

Abstract

A device (1) for molding a mixture sheet (6) is provided with: a support roller (2) for supporting the mixture sheet (6) comprising a dry electrode mixture on the peripheral surface (2a); and a forming roller (4) having a frame-shaped cutting jig (8) and a removal pad (10) disposed in the frame of the cutting jig (8) on a peripheral surface (4a) facing the peripheral surface (2a) of the support roller (2) at a predetermined interval and rotating together with the support roller (2). The forming roller (4) makes the cutting jig (8) abut against the mixture sheet (6), partially cuts the mixture sheet (6), and makes the cutting part (6a) attached to the surface of the removal pad (10) and separated from the mixture sheet (6).

Description

Technical Field

[0001] The present invention relates to a forming device and a forming method for a composite tablet. Background Art

[0002] Patent document 1 describes a device for supplying granules to the gap between a pair of compression rollers, compressing them into sheets and forming a coating film, and laminating the coating film on a substrate. The device is provided with a stepped roller with a blade on the circumference, and a portion of the coating film is removed by the stepped roller. In addition, Patent document 1 also describes the use of the device to manufacture functional sheets used in power storage devices such as secondary batteries or capacitors. In addition, as a substrate, a collector plate is exemplified, and as a coating, an electrode mixture is exemplified.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-017962 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] When the electrode sheet is manufactured by laminating the electrode mixture sheet on the current collector plate using the above apparatus, an exposed portion of the current collector plate can be formed by removing a portion of the electrode mixture sheet. The exposed portion can be used as a connection portion of a current collector lead or the like.

[0008] There is a general demand for increasing the capacity of power storage devices. The inventors of the present invention have conducted intensive studies and have finally found that conventional devices still have room for improvement in terms of increasing the capacity of power storage devices.

[0009] The present disclosure has been made in view of such circumstances, and an object of the present disclosure is to provide a technology for increasing the capacity of a power storage device.

[0010] Methods used to solve technical problems

[0011] One scheme disclosed herein is a device for forming a composite sheet. The device includes: a support roller, which supports a composite sheet composed of a dry electrode composite with its circumferential surface; and a forming roller, which has a frame-shaped cutting fixture on its circumferential surface, and a removal pad arranged in the frame of the cutting fixture, the circumferential surface of which is opposite to the circumferential surface of the support roller at a predetermined interval and rotates together with the support roller. The forming roller presses the cutting fixture against the composite sheet and partially cuts the composite sheet, so that the cut portion adheres to the surface of the removal pad and is separated from the composite sheet.

[0012] Another scheme of the present disclosure is a method for forming a composite sheet. The method includes: supporting a composite sheet composed of a dry electrode composite with the circumferential surface of a support roller; rotating a forming roller together with the support roller, wherein the forming roller has a frame-shaped cutting fixture on the circumferential surface and a removal pad arranged in the frame of the cutting fixture, and the circumferential surface is opposite to the circumferential surface of the support roller at a predetermined interval; pressing the cutting fixture against the composite sheet and partially cutting the composite sheet, so that the cut portion adheres to the surface of the removal pad and is separated from the composite sheet.

[0013] Optional combinations of the above-described constituent elements and modes in which the expressions of the present disclosure are converted into methods, apparatuses, systems, etc. may also be effective as modes of the present disclosure.

[0014] Effects of the Invention

[0015] According to the present disclosure, it is possible to increase the capacity of the power storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a molding device for a mixed drug sheet according to an embodiment.

[0017] Figure 2 This is an exploded perspective view of the molding unit.

[0018] Figure 3 It is a cross-sectional view of the molding unit.

[0019] Figure 4 (A) is a top view of the electrode sheet. Figure 4 (B) is along Figure 4 (A) is a cross-sectional view along the line AA.

[0020] Figure 5 (A) is a top view of the electrode sheet joined to the current collecting lead sheet. Figure 5 (B) is an enlarged cross-sectional view of the window portion. DETAILED DESCRIPTION

[0021] Below, the present disclosure is described with reference to the accompanying drawings based on preferred embodiments. The embodiments do not limit the present disclosure but are exemplified, and all the features or combinations thereof described in the embodiments do not necessarily represent the essential content of the present disclosure. The same or equivalent components, parts, and processes shown in the drawings are marked with the same figure marks, and repeated descriptions are appropriately omitted. In addition, the scales or shapes of the various parts shown in the drawings are conveniently set for easy description, and are not interpreted restrictively unless otherwise mentioned. In addition, when the terms "first", "second", etc. are used in this specification or claims, unless otherwise mentioned, the terms do not indicate any order or importance, but are used to distinguish one structure from other structures. In addition, in each of the drawings, a part of unimportant parts is omitted for display when describing the embodiments.

[0022] Figure 1 It is a schematic diagram of a molding device 1 for a composite sheet 6 of an embodiment. The molding device 1 for the composite sheet 6 includes a supporting roller 2 and a molding roller 4. The supporting roller 2 supports the composite sheet 6 by a peripheral surface 2a. As an example, the composite sheet 6 is in the shape of a strip that is long in the conveying direction, and after being stacked on a collector plate, it is monolithically formed into a plurality of electrode sheets, and is used in a storage device such as a secondary battery or a capacitor. The composite sheet 6 is formed, for example, in the following manner. That is, a powder of a dry electrode mixture that is a raw material of the composite sheet 6 is supplied from a known storage portion such as a storage tank to a gap between a pair of compression rollers. The pair of compression rollers rotate in opposite directions to each other, and compress the dry electrode mixture supplied to the gap into a sheet. Thus, the composite sheet 6 is formed.

[0023] The composite sheet 6 is continuously fed out from the gap between the pair of compression rollers. The support roller 2 is located on the downstream side of the pair of compression rollers, and supports the composite sheet 6 through the circumferential surface 2a while transmitting the composite sheet 6 to the downstream side through its own rotation. In addition, the composite sheet 6 can also be stretched to a target thickness during the transmission process.

[0024] The dry electrode mixture includes an electrode active material, and a conductive agent and an adhesive material (adhesive) as needed. In the case of a general lithium-ion secondary battery, the positive electrode of the electrode active material is lithium cobaltate or lithium iron phosphate, etc., and the negative electrode is graphite, etc. In addition, the conductive agent is graphite, carbon black, acetylene black, etc. The adhesive material is polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), etc. In addition, in the dry electrode mixture, the content of the solvent is less than 5% by mass, or less than 3% by mass, and further 0% by mass relative to the total mass of the dry electrode mixture. Therefore, the drying furnace of the mixture sheet 6 can be omitted. In addition, the dry electrode mixture can also contain a very small amount of solvent to the extent that the drying furnace can be omitted.

[0025] The shaping roller 4 is positioned so that the rotation axis is parallel to the rotation axis of the support roller 2. The peripheral surface 4a is opposite to the peripheral surface 2a of the support roller 2 at a predetermined interval. The shaping roller 4 rotates together with the support roller 2. The support roller 2 and the shaping roller 4 rotate in opposite directions. As an example, the support roller 2 and the shaping roller 4 rotate at the same rotation speed.

[0026] The forming roller 4 has a forming unit 7 composed of a cutting clamp 8, a removal pad 10 and an elastic body 12 on the circumferential surface 4a. The forming roller 4 rotates together with the supporting roller 2, and presses the cutting clamp 8 to the composite sheet 6 supported by the supporting roller 2. As a result, the composite sheet 6 is partially cut. In addition, the forming roller 4 makes the cut portion 6a of the composite sheet 6 adhere to the surface of the removal pad 10 and separate from the composite sheet 6. The cut portion 6a is removed, thereby forming a through hole on the composite sheet 6 that penetrates the composite sheet 6 in the thickness direction. The through hole constitutes the window portion 6b.

[0027] Figure 2 It is an exploded perspective view of the molding unit 7. Figure 3 is a cross-sectional view of the molding unit 7. It should be noted that Figure 3 The illustration of the compound tablet 6 is omitted. Figure 2 As shown, the cutting fixture 8 is frame-shaped. The cutting fixture 8 of this embodiment is a rectangular frame, and has a first cutting knife 14a to a fourth cutting knife 14d combined into a rectangular shape. The first cutting knife 14a and the second cutting knife 14b are arranged at a predetermined interval in the circumferential direction of the forming roller 4, and extend in the axial direction of the forming roller 4. In the rotation direction A of the forming roller 4, the first cutting knife 14a is located at the front end side, and the second cutting knife 14b is located at the rear end side. The third cutting knife 14c and the fourth cutting knife 14d are arranged at a predetermined interval in the axial direction of the forming roller 4, and extend in the circumferential direction of the forming roller 4. The blade tips of the first cutting knife 14a and the second cutting knife 14b extend in a straight line. The blade tips of the third cutting knife 14c and the fourth cutting knife 14d extend in a curved line parallel to the peripheral surface 4a. Each knife faces the radial outer side of the forming roller 4. In addition, the cutting fixture 8 can also be a frame-shaped rectangle, a perfect circle, an ellipse, etc. with rounded corners.

[0028] The removal pad 10 is arranged in the frame of the cutting jig 8. Therefore, when viewed from the radial direction of the forming roller 4, the removal pad 10 is surrounded by the first to fourth cutting blades 14a to 14d. The surface roughness of the surface 10a of the removal pad 10 facing the support roller 2 is greater than that of the peripheral surface 2a of the support roller 2. For example, the arithmetic mean roughness Ra of the surface 10a is greater than the arithmetic mean roughness Ra of the peripheral surface 2a. The surface roughness of the surface 10a can be increased by a known roughening treatment such as sandblasting.

[0029] The elastic body 12 supports the removal pad 10. The elastic body 12 can be composed of a known spring or sponge. The elastic body 12 of the present embodiment is composed of a coil spring as an example, and is arranged between the cutting fixture 8 and the removal pad 10. The cutting fixture 8 has a base 16 in the frame. The end of the elastic body 12 on the cutting fixture 8 side is fixed to the base 16. The end of the elastic body 12 on the removal pad 10 side is fixed to the back of the removal pad 10. When the removal pad 10 is opposite to the support roller 2, the elastic body 12 applies force to the removal pad 10 toward the cutting portion 6a side by its own elastic force. In addition, when the removal pad 10 is separated from the support roller 2 by the rotation of the support roller 2 and the forming roller 4, the removal pad 10 is attracted to the forming roller 4 side by its own elastic force. The elastic body 12 performs the same action as the pop-up component of the blanking die. In addition, the removal pad 10 itself may also have elasticity. In this case, the removal pad 10 also serves as the elastic body 12.

[0030] like Figure 3As shown, the front end of the cutting jig 8 in the rotation direction A of the forming roller 4 protrudes further toward the support roller 2 side than the front end of the removal pad 10. In addition, the rear end of the cutting jig 8 in the rotation direction A protrudes further toward the support roller 2 side than the rear end of the removal pad 10. That is, the blade tips of the first cutting blade 14a and the second cutting blade 14b protrude further toward the support roller 2 side than the surface 10a of the removal pad 10. On the other hand, the middle portion of the removal pad 10 in the rotation direction A protrudes further toward the support roller 2 side than the middle portion of the cutting jig 8. That is, in at least a portion of the removal pad 10 in the rotation direction A including the middle point, the surface 10a of the removal pad 10 protrudes further toward the support roller 2 side than the third cutting blade 14c and the fourth cutting blade 14d. As an example, the surface 10a of the removal pad 10 has a curved surface shape with a greater curvature than the peripheral surface 4a of the forming roller 4.

[0031] The molding unit 7 approaches the peripheral surface 2a of the support roller 2 as the molding roller 4 rotates. And, first, the first cutting blade 14a is pressed against the composite sheet 6. Since the front end of the cutting jig 8 in the rotation direction A protrudes more than the removal pad 10, the first cutting blade 14a can be pressed against the composite sheet 6 more reliably. The first cutting blade 14a cuts the composite sheet 6, thereby forming the starting point of the cutting portion 6a.

[0032] When the forming roller 4 rotates further, the surface 10a of the removal pad 10 abuts against the composite sheet 6, and the surface 10a is pressed against the composite sheet 6 by the force of the elastic body 12. In addition, the removal pad 10 receives the reaction force of the composite sheet 6 and sinks into the frame of the cutting fixture 8. As a result, the third cutting blade 14c and the fourth cutting blade 14d are pressed against the composite sheet 6. The third cutting blade 14c and the fourth cutting blade 14d cut the composite sheet 6, so that the cutting portion 6a extends backward in the rotation direction A.

[0033] The cut portion 6a is transferred to the surface 10a of the removal pad 10 from the front end side in the rotation direction A. By making the surface roughness of the surface 10a of the removal pad 10 greater than the surface roughness of the peripheral surface 2a of the backup roller 2, the cut portion 6a can be easily transferred to the removal pad 10. In addition, by pressing the surface 10a to the cut portion 6a with the elastic body 12, the cut portion 6a can also be easily transferred to the removal pad 10.

[0034] Then, when the forming roller 4 rotates further, the second cutting blade 14b is pressed against the composite sheet 6. The rear end of the cutting jig 8 in the rotation direction A protrudes further than the removal pad 10, so the second cutting blade 14b can be pressed against the composite sheet 6 more reliably. The second cutting blade 14b cuts the composite sheet 6, thereby forming the end point of the cut portion 6a. As a result, the cut portion 6a becomes rectangular.

[0035] When the forming roller 4 rotates further, the removal pad 10 is separated from the peripheral surface 2a of the support roller 2. As a result, the cut portion 6a transferred to the removal pad 10 is separated from the composite sheet 6. When the removal pad 10 is separated from the peripheral surface 2a, the removal pad 10 is pulled tight on the support roller 2 side via the cut portion 6a. However, the removal pad 10 is attracted to the forming roller 4 side by the elastic body 12 with a force stronger than the force pulled tight on the support roller 2 side. As a result, the cut portion 6a can be pulled away from the composite sheet 6 more reliably.

[0036] The cutting jig 8 is fixed to the forming roller 4. Therefore, compared with a structure in which the cutting jig 8 is displaced in the radial direction of the forming roller 4, the structure of the forming unit 7 can be simplified. In addition, the maintenance of the forming roller 4 becomes easy. In addition, in the present embodiment, a window portion 6b is formed before the composite sheet 6 is stacked on the collector plate. Thus, the collector plate can be prevented from being notched by the cutting jig 8. Therefore, the quality of the power storage device can be improved.

[0037] The cut portion 6a cut from the composite sheet 6 is peeled off and removed from the removal pad 10 at a predetermined position by a peeling structure not shown in the figure. After the cut portion 6a is removed, the molding unit 7 advances again to a position opposite to the support roller 2 by the rotation of the molding roller 4, and is used for the cutting process of the composite sheet 6. Thus, a plurality of window portions 6b arranged at predetermined intervals in the conveying direction are formed on the composite sheet 6. As an example, each window portion 6b is arranged at the center of the width direction (direction orthogonal to the conveying direction) of the composite sheet 6.

[0038] Figure 1 The molding roller 4 shown has only one molding unit 7, but the number of molding units 7 is not limited to one. The molding roller 4 may also have a plurality of molding units 7 according to the intervals of the windows 6b formed in the compound sheet 6. In addition, the intervals of the windows 6b may be adjusted according to the intervals of the plurality of molding units 7, or may be adjusted according to the radius of the molding roller 4.

[0039] Figure 4 (A) is a top view of the electrode sheet 20 . Figure 4 (B) is along Figure 4 A cross-sectional view of the line AA of (A). The composite sheet 6 having the window portion 6b is transported to the downstream side by the support roller 2. Moreover, the composite sheet 6 is stacked on the surface of the collector plate 18 to obtain the electrode sheet 20. The electrode sheet 20 is a continuum of a plurality of dry electrode sheets. As an example, the composite sheet 6 is stacked on both sides of the collector plate 18. In the case of a conventional lithium-ion secondary battery, the positive electrode of the collector plate 18 is composed of aluminum foil or the like, and the negative electrode is composed of copper foil or the like. The collector plate 18 is exposed in the window portion 6b.

[0040] Each window portion 6b is surrounded by a dry electrode mixture on its entire circumference. Therefore, the collector plate 18 is exposed in a dot shape. In the previous electrode sheet, the exposed portion of the collector plate 18, that is, the uncoated portion of the electrode mixture, extends as a whole in the width direction of the electrode sheet. In contrast, in the electrode sheet 20 of the present embodiment, the exposed portion of the collector plate 18 extends only in a portion of the width direction of the electrode sheet 20. Thus, the amount of dry electrode mixture in each electrode sheet can be increased. Thus, a high capacity of the storage device can be achieved. In addition, since the exposed portion of the collector plate 18 can be reduced, the safety of the storage device can also be improved.

[0041] Figure 5 (A) is a plan view of the electrode sheet 20 joined to the current collecting lead sheet 22 . Figure 5 (B) is an enlarged cross-sectional view of the window portion 6b. It should be noted that, Figure 5 The cross section shown in (B) is a cross section of the electrode sheet 20 that is perpendicular to the extending direction of the collector plate 18 and the composite sheet 6, in other words, a cross section that is parallel to the normal line of the collector plate 18 and the composite sheet 6. Figure 5 In (B), one compound tablet 6 is omitted from illustration.

[0042] As an example, the electrode sheet 20, such as Figure 5 As shown in (A), it is cut in the center in the width direction and divided into two. As a result, each window portion 6b is also divided into two. As a result, each rectangular window portion 6b is in a state where three of them are surrounded by the dry electrode mixture. In addition, the portion of the collector plate 18 exposed from each divided window portion 6b is joined to the collector lead piece 22 (collector ear) by welding or the like. The exposed portion of the collector plate 18 to which the collector lead piece 22 is joined is covered by an insulating protective tape (not shown). Thereafter, the electrode sheet 20 is cut between the collector lead pieces 22 adjacent to each other and is singulated into a plurality of dry electrode sheets.

[0043] like Figure 5As shown in (B), in a cross section orthogonal to the extension direction of the collector plate 18 and the mixture sheet 6, the angle θ1 formed by the side wall 6c (the side connecting the two main surfaces) of the mixture sheet 6 in the window portion 6b and the surface 18a of the collector plate 18 is greater than 75° and less than 105°. Preferably, the angle θ1 is 75° to 105° throughout the entire circumference of the window portion 6b. In addition, preferably, the angle θ1 is greater than 85° and less than 95°. By setting the angle θ1 formed by the side wall 6c and the surface 18a of the collector plate 18 to be greater than 75° and less than 105°, which is approximately a right angle, it is possible to easily suppress poor bonding of the collector plate 18 and the collector lead sheet 22 caused by interference with the dry electrode mixture. In addition, it is possible to easily suppress contact between the collector lead sheet 22 and the dry electrode mixture. Thereby, the quality of the storage device can be improved. In particular, when the uncoated portion of the dry electrode mixture is in the form of dots, it becomes difficult to join the current collecting lead piece 22. Therefore, the quality improvement effect of the power storage device brought about by setting the angle θ1 to be substantially a right angle is more easily exerted.

[0044] In addition, in the case where the mixture sheet is composed of a wet electrode mixture, the boundary between the uncoated portion and the coated portion of the wet electrode mixture may be deformed due to the sagging of the wet electrode mixture. In addition, when the uncoated portion is formed by intermittently coating the wet electrode mixture, the edge of the coated portion may become jagged. At this time, the separator may be damaged when the electrode sheet repeatedly expands and contracts due to the charging and discharging of the power storage device. Damage to the separator may cause an internal short circuit.

[0045] In this regard, in the present embodiment, the mixture sheet 6 composed of the dry electrode mixture is cut with a cutting fixture 8 to form a window portion 6b. Therefore, the boundary between the uncoated portion and the coated portion of the dry electrode mixture is difficult to deform, and the above-mentioned angle θ1 can be maintained at a substantially right angle. In addition, the edge of the coated portion is formed into a straight line in accordance with the shape of the cutting knife. Therefore, damage to the partition can also be suppressed. In addition, since the window portion 6b is formed by cutting with the cutting fixture 8, the edge of the coated portion can be suppressed from swelling in the thickness direction of the mixture sheet 6. Thus, damage to the partition can be suppressed when the electrode sheet repeatedly expands and contracts due to charging and discharging of the storage device.

[0046] The above is a detailed description of the embodiments of the present disclosure. The aforementioned embodiments only show specific examples when the present disclosure is implemented. The content of the embodiments does not limit the technical scope of the present disclosure, and various design changes such as changes, additions, and deletions of constituent elements can be made without departing from the scope of the idea of ​​the present disclosure specified in the claims. The new embodiment with design changes has the effects of the combined embodiment and the deformation. In the aforementioned embodiments, the content that can make such design changes is emphasized by giving expressions such as "this embodiment", "in this embodiment", etc., and design changes are allowed even if there is no such expression. Any combination of the constituent elements included in each embodiment is also valid as a scheme of the present disclosure. The hatching marked on the cross section of the accompanying drawings does not limit the material of the object marked with the hatching.

[0047] The embodiment can also be determined by the items described below.

[0048] [First item]

[0049] A device (1) for forming a composite tablet (6), comprising:

[0050] A support roller (2) supports a mixture sheet (6) composed of a dry electrode mixture with a peripheral surface (2a), and

[0051] A forming roller (4) having a frame-shaped cutting fixture (8) and a removal pad (10) arranged in the frame of the cutting fixture (8) on its circumferential surface (4a), the circumferential surface (4a) being opposite to the circumferential surface (2a) of the support roller (2) at a predetermined interval and rotating together with the rotation of the support roller (2);

[0052] The forming roller (4) presses the cutting jig (8) against the composite sheet (6) and partially cuts the composite sheet (6), so that the cut portion (6a) adheres to the surface (10a) of the removal pad (10) and is separated from the composite sheet (6).

[0053] [Second item]

[0054] According to the molding device (1) described in the first item,

[0055] The surface (10a) of the removal pad (10) has a greater surface roughness than the peripheral surface (2a) of the support roller (2).

[0056] [Third Item]

[0057] The molding device (1) according to the first item or the second item,

[0058] The forming roller (4) has an elastic body (12) for supporting the removal pad (10).

[0059] [Fourth Item]

[0060] The molding device (1) according to any one of the first to third items,

[0061] The front end of the cutting jig (8) in the rotation direction (A) of the forming roller (4) protrudes further toward the supporting roller (2) than the front end of the removal pad (10).

[0062] The rear end of the cutting jig (8) in the rotation direction (A) protrudes further toward the support roller (2) than the rear end of the removal pad (10).

[0063] The middle portion of the removal pad (10) in the rotation direction (A) protrudes further toward the support roller (2) than the middle portion of the cutting jig (8).

[0064] [Fifth Item]

[0065] A method for forming a composite tablet (6), comprising:

[0066] The mixture sheet (6) composed of a dry electrode mixture is supported by the peripheral surface (2a) of the support roller (2).

[0067] A forming roller (4) is rotated together with a support roller (2), wherein the forming roller (4) has a frame-shaped cutting jig (8) on a peripheral surface (4a) and a removal pad (10) arranged in the frame of the cutting jig (8), and the peripheral surface (4a) is opposed to the peripheral surface (2a) of the support roller (2) at a predetermined interval.

[0068] The cutting jig (8) is pressed against the composite sheet (6) to partially cut the composite sheet (6), so that the cut portion (6a) adheres to the surface (10a) of the removal pad (10) and is separated from the composite sheet (6).

[0069] [Sixth Item]

[0070] An electrode sheet (20) comprises a current collector (18) and a mixture sheet (6) composed of a dry electrode mixture and stacked on the surface of the current collector (18).

[0071] The mixture sheet (6) has a window portion (6b) entirely surrounded by a dry electrode mixture, and the current collector (18) is exposed in the window portion (6b).

[0072] In a cross section perpendicular to the extension direction of the collector plate (18) and the composite sheet (6), an angle (θ1) formed by a side wall (6c) of the composite sheet (6) in the window portion (6b) and a surface (18a) of the collector plate (18) is greater than 75° and less than 105°.

[0073] Industrial Applicability

[0074] The present disclosure can be utilized in a molding device and a molding method for a composite tablet.

[0075] Description of Reference Numerals

[0076] 1 forming device, 2 supporting roller, 4 forming roller, 6 compound sheet, 6a cutting portion, 6b window portion, 6c side wall, 8 cutting jig, 10 removal pad, 12 elastic body, 18 collector plate, 20 electrode sheet.

Claims

1. A device for forming a composite tablet, comprising: A support roller supports a mixture sheet composed of a dry electrode mixture with a peripheral surface, and A forming roller having a frame-shaped cutting jig and a removal pad arranged in the frame of the cutting jig on its circumferential surface, the circumferential surface of the forming roller being opposed to the circumferential surface of the supporting roller at a predetermined interval and rotating together with the supporting roller; The forming roller causes the cutting jig to press against the mixture sheet and partially cuts the mixture sheet, so that the cut portion adheres to the surface of the removal pad and is separated from the mixture sheet.

2. The molding device according to claim 1, The surface of the removal pad has a greater surface roughness than the peripheral surface of the backup roller.

3. The molding device according to claim 1 or 2, The molding roller has an elastic body that supports the removal pad.

4. The molding device according to claim 1 or 2, The front end portion of the cutting jig in the rotation direction of the forming roller protrudes further toward the support roller than the front end portion of the removal pad. A rear end portion of the cutting jig in the rotation direction protrudes further toward the support roller than a rear end portion of the removal pad. A middle portion of the removal pad in the rotation direction protrudes toward the support roller more than the middle portion of the cutting jig.

5. A method for forming a composite tablet, comprising: The mixture sheet composed of the dry electrode mixture is supported by the peripheral surface of the support roller. The forming roller is rotated together with the support roller, wherein the forming roller has a frame-shaped cutting jig and a removal pad arranged in the frame of the cutting jig on its circumference, and the circumference of the forming roller faces the circumference of the support roller at a predetermined interval, The cutting jig is brought into pressure contact with the mixture sheet to partially cut the mixture sheet, so that the cut portion adheres to the surface of the removal pad and is separated from the mixture sheet.

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