JP2024038864A - Fixing jig with rigid film - Google Patents

Abstract

[Problem] To provide a fixing jig capable of suppressing the occurrence of defective products and the deterioration of battery performance in the manufacturing process of lithium ion secondary batteries. [Solution] One embodiment of the fixing jig includes a first jig including a first frame and a first flexible sheet suspended across the first frame, a second jig including a second frame and a second flexible sheet suspended across the second frame, a first rigid sheet joined to the first flexible sheet, a second rigid sheet joined to the second flexible sheet, and a transport jig for supporting a pressure target. The first jig and the second jig form a storage space between them in which the pressure target is placed, the first rigid sheet and the second rigid sheet face each other between the first flexible sheet and the second flexible sheet with the storage space interposed therebetween, and at least one of the first jig and the second jig is formed with an exhaust hole communicating with the storage space. [Selected Figure] Figure 1

Description

The present disclosure relates to a fixture.

BACKGROUND ART In the manufacturing process of electronic devices, a roll press technique is used in which a pressurized object is passed between a pair of rolls and pressed. If the object to be pressurized is a laminate or powder, passing the object between a pair of rolls may cause the laminate to shift or the powder to scatter, causing the object to be pressurized to It is difficult to apply sufficient pressure to objects. Therefore, roll pressing may be performed after fixing the object to be pressed using a fixing jig.

As this type of fixing jig, for example, fixing jigs described in Patent Documents 1 and 2 below are known. The fixing jigs described in Patent Documents 1 and 2 are for fixing and holding a pressurized object such as a laminate for a semiconductor chip or a battery, and include a first pressure reducing member and a device facing the first pressure reducing member. It has a second pressure reducing member, a sealing member that seals the accommodation space formed between the first pressure reduction member and the second pressure reduction member, and an exhaust path that exhausts air from the accommodation space. The first pressure reducing member and the second pressure reducing member include a frame member and a flexible resin sheet stretched over the frame member. In this fixture, the housing space is depressurized by exhausting air through the exhaust passages formed in the frame-like members of the first and second pressure reducing members, and the pressure is increased using the resin sheets of the first and second pressure reducing members. By sandwiching the object, the pressurized object placed in the accommodation space is fixed. Then, by passing this fixing jig between the pair of rolls, the object to be pressurized fixed in the accommodation space is pressurized.

Patent No. 5182451 Patent No. 6269496

By the way, pressure treatment using a pressure device such as a roll press device is also used for manufacturing lithium ion secondary batteries. For example, in the production of lithium ion secondary batteries, powdered active materials are pressed using a pressurizing device to densify them according to the required functions. producing a material layer; Then, the produced electrode active material layers are stacked to produce a lithium ion secondary battery having a plurality of cell structures.

When the fixing jigs described in Patent Documents 1 and 2 are applied to the production of lithium ion secondary batteries, when pressure is applied to the pressurized object through the resin sheet, the There is a risk that the powdered active material contained will pierce the resin sheet. When the active material penetrates the resin sheet, unevenness may be formed on the surface of the electrode active material layer, or the electrode active material layer may collapse, resulting in non-uniformity in the thickness of the electrode active material layer. There is. Non-uniformity in the thickness of the electrode active material layer leads to the production of defective products and deterioration of battery performance.

Therefore, an object of the present disclosure is to provide a fixing jig that can suppress the occurrence of defective products and a decrease in battery performance.

In one embodiment, a fixing jig is provided that fixes a pressurized object containing an active material in order to manufacture an electrode active material layer for a lithium ion secondary battery. This fixing jig includes a first jig including a first frame and a first flexible sheet spanned over the first frame, a second frame and a second flexible sheet spanned over the second frame. a second jig including a flexible sheet, a first rigid sheet joined to the first flexible sheet, a second rigid sheet joined to the second flexible sheet, and supporting a pressurized object. and a conveying jig. The first jig and the second jig form a storage space between which a pressurized object is placed, and the first rigid sheet and the second rigid sheet form a first flexible sheet and a second flexible sheet. The first jig and the second jig face each other via a housing space, and an exhaust hole communicating with the housing space is formed in at least one of the first jig and the second jig.

In this fixing jig, a first rigid sheet and a second rigid sheet are arranged between a first flexible sheet and a second flexible sheet, and the object to be pressed is a It is placed in the storage space between the seat and the seat. That is, the object to be pressed is sandwiched between the first rigid sheet and the second rigid sheet, and the first flexible sheet and the second flexible sheet do not directly contact the object to be pressed, so the first flexible sheet The active material is prevented from penetrating the sheet and the second flexible sheet. Therefore, non-uniformity in the thickness of the electrode active material layer is suppressed, and as a result, generation of defective products and deterioration of battery performance can be suppressed.

In one embodiment, the first flexible sheet and the second flexible sheet may be resin sheets, and the first rigid sheet and the second rigid sheet may be metal sheets. Note that the first rigid sheet and the second rigid sheet may be made of stainless steel. By making the first rigid sheet and the second rigid sheet metal sheets, it is possible to more reliably prevent the active material from penetrating the first flexible sheet and the second flexible sheet. Furthermore, by using resin sheets as the first flexible sheet and the second flexible sheet, damage may occur to the rolls of the pressurizing device when pressurizing the pressurized object via the fixing jig. can be suppressed.

In one embodiment, the area of the first rigid sheet and the second rigid sheet may be smaller than the area of the first flexible sheet and the second flexible sheet. The first rigid sheet and the second rigid sheet are less likely to deform than the first flexible sheet or the second flexible sheet, so the area of the first rigid sheet and the second rigid sheet is smaller than that of the first flexible sheet. If the area is about the same as that of the second flexible sheet, the first jig and the second jig will not be in sufficient close contact when the pressure of the accommodation space is reduced, which will cause trouble in fixing the object to be pressurized. By making the area of the first rigid sheet and the second rigid sheet smaller than the area of the first flexible sheet and the second flexible sheet, there is a gap between the first flexible sheet and the second flexible sheet. The pressurized object can be securely fixed by sealing the accommodation space. Furthermore, by configuring the first flexible sheet and the second flexible sheet with a highly flexible material, it is possible to absorb the error between the pressure roll of the pressure device and the loading height of the fixing jig. It is possible to suppress lifting of the jig and plastic deformation of the first rigid sheet and the second rigid sheet.

In one embodiment, the thickness of the first rigid sheet and the second rigid sheet may be 50 μm or more and 400 μm or less. By setting the thickness of the first rigid sheet and the second rigid sheet to 50 μm or more, sufficient strength can be ensured. If the thickness of the first rigid sheet and the second rigid sheet is too large, the rigidity of the first rigid sheet and the second rigid sheet may depend on the first flexible sheet, the second flexible sheet, the first rigid sheet, or the first rigid sheet. 2. The rigid sheet may not be sufficiently deformed, and the first jig and the second jig may not be able to be brought into close contact with the object to be pressurized. If the first jig and the second jig are not in close contact with the object to be pressurized, the powdered active material may be ejected out of the predetermined installation position. On the other hand, by setting the thickness of the first rigid sheet and the second rigid sheet to 400 μm or less, the object to be pressed can be securely fixed.

In one embodiment, the first rigid sheet and the second rigid sheet may be attached to the first flexible sheet and the second flexible sheet using double-sided tape, respectively. In this case, the first rigid sheet and the second rigid sheet can be joined to the first flexible sheet and the second flexible sheet, respectively.

The fixing jig of one embodiment includes a rectangular frame-shaped pressing member arranged on the second frame, and a rectangular frame-shaped sealing member arranged along the outer edge of the pressing member and sealing the accommodation space. Further, it may be provided. By sealing the accommodation space with the seal member, the pressure in the accommodation space can be reliably reduced.

In one embodiment, the fixing jig is arranged to face the first rigid sheet with the first flexible sheet interposed therebetween, and the first preliminary decompression chamber is formed between the first preliminary decompression chamber and the first flexible sheet. a second preliminary pressure reducing member, which is disposed opposite to the second rigid sheet via the second flexible sheet and forms a second preliminary pressure reducing chamber between the second flexible sheet and the second flexible sheet; Further provision may be made. When the accommodation space is depressurized without depressurizing the first preliminary decompression chamber and the second preliminary decompression chamber, the first rigid sheet and the first flexible sheet are applied with respect to the second rigid sheet and the second flexible sheet. They will come into close contact with the object being pressed between them. At this time, the region (outer edge) between the exhaust hole and the pressurized object is in a sealed state, so that depressurization of the accommodation space is inhibited. In that case, the pressurized object may not be sufficiently fixed, and defects such as cracks, active material spouting, and voids may occur in the pressurized object after processing. In this embodiment, a pre-decompression chamber is formed between the first pre-decompression member and the first flexible sheet and between the second pre-decompression member and the second flexible sheet. By depressurizing these preliminary decompression chambers and then depressurizing the accommodation space, the outer edge portion is sealed after the accommodation space has been sufficiently depressurized, so that the object to be pressurized can be reliably fixed. Therefore, it is possible to suppress defects from occurring in the pressurized object.

One embodiment further includes a plurality of spacers disposed in the first preliminary decompression chamber, and the plurality of spacers are disposed at positions that do not overlap the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet. You can. By arranging the plurality of spacers at positions that do not overlap the first rigid sheet of the first preliminary decompression chamber, it is possible to suppress excessive bending of the outer edge of the first flexible sheet.

In one embodiment, the first rigid sheet may have a substantially rectangular shape, and the plurality of spacers may be arranged on a diagonal extension of the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet. . By arranging the plurality of spacers on a diagonal extension of the first rigid sheet, excessive bending of the first rigid sheet is suppressed when the accommodation space is depressurized. As a result, the first rigid sheet is less likely to undergo plastic deformation.

According to the present disclosure, it is possible to suppress the occurrence of defective products and a decrease in battery performance.

FIG. 2 is a schematic cross-sectional view of a fixing jig according to an embodiment. FIG. 3 is a bottom view of the upper jig. It is a top view of a lower jig. FIG. 3 is an enlarged cross-sectional perspective view showing the vicinity of the exhaust hole of the lower jig. FIG. 3 is a top view of the upper jig. It is a schematic perspective view of a fixing jig. It is a figure which shows the method of pressurizing a pressurization object using a fixing jig. It is a figure which shows the method of pressurizing a pressurization object using a fixing jig. It is a figure which shows the method of pressurizing a pressurization object using a fixing jig. It is a figure which shows the method of pressurizing a pressurization object using a fixing jig.

Embodiments of the present disclosure will be described below with reference to the drawings. In addition, in explaining based on the drawings, the same elements or elements having the same function are given the same reference numerals, and redundant explanation will be omitted. In some drawings, some parts may be simplified or exaggerated for ease of understanding, and dimensional ratios, angles, etc. are not limited to those shown in the drawings. In this specification, the terms "upper", "lower", "left", and "right" are used for convenience and are based on the illustrated state.

FIG. 1 is a cross-sectional view schematically showing a fixing jig according to an embodiment. A fixing jig 1 shown in FIG. 1 fixes a pressurized object 100 that is pressurized by a pressurizing device such as a roll press device. The pressurizing object 100 includes, for example, an active material for manufacturing an electrode active material layer for a lithium ion secondary battery. The electrode active material layer is a component (electrode) that constitutes a lithium ion secondary battery, such as a positive electrode layer and a negative electrode layer. The pressurizing object 100 includes a powdered active material made of a compound depending on the function of the electrode active material layer. For example, an electrode active material layer for a lithium ion secondary battery is manufactured by pressing the pressurized object 100 using a pressurizing device to increase the density.

As shown in FIG. 1, the fixing jig 1 includes an upper jig (first jig) 10, a lower jig (second jig) 20, a first rigid sheet 31, and a second rigid sheet 32. . The upper jig 10 and the lower jig 20 are arranged to face each other and fix and hold the pressurized object 100 therebetween. In the following description, the direction in which the upper jig 10 and the lower jig 20 face each other will be referred to as the Z direction, and the two directions perpendicular to the Z direction and orthogonal to each other will be referred to as the X direction and the Y direction. For example, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction.

FIG. 2 is a bottom view of the upper jig 10. As shown in FIGS. 1 and 2, the upper jig 10 includes a first frame 11 and a first flexible sheet 12 spanning the first frame 11. The first frame 11 is made of metal such as aluminum, and has a rectangular frame shape. In one embodiment, the first flexible sheet 12 is a flexible, substantially rectangular resin sheet. For example, the first flexible sheet 12 is made of polyimide film. When the upper jig 10 and the lower jig 20 are overlapped, the first flexible sheet 12 comes into contact with a substantially rectangular frame-shaped sealing member 24 installed on the lower jig 20, and the upper jig 10 and the lower jig The space between the jig 20 and the jig 20 is hermetically sealed.

The lower jig 20 is arranged to face the upper jig 10. As shown in FIG. 1, a space S is formed between the upper jig 10 and the lower jig 20. The space S includes a central portion S1 and an outer edge portion S2. The central portion S1 is a part of the space S between the upper jig 10 and the lower jig 20, and constitutes a space that accommodates the pressurized object 100. That is, the upper jig 10 and the lower jig 20 form a housing space for the pressurized object 100 therebetween. The outer edge portion S2 is arranged to surround the center portion S1 when viewed from the Z direction, and functions as a flow path for exhausting air from the center portion S1.

FIG. 3 is a top view of the lower jig 20. As shown in FIG. 3, the lower jig 20 includes a second frame 21 and a second flexible sheet 22 spanning the second frame 21. The second frame 21 is made of metal such as aluminum, and has a rectangular frame shape. In one embodiment, the second flexible sheet 22 is a flexible, substantially rectangular resin sheet. For example, the second flexible sheet 22 is made of polyimide film.

A rectangular frame-shaped pressing member 23 is provided on the upper surface of the second frame 21 . The holding member 23 is made of metal such as stainless steel, for example. For example, the holding member 23 is fixed to the second frame 21 with bolts or the like, with the outer edge of the second flexible sheet 22 being sandwiched between the second frame 21 and the holding member 23. Note that the second flexible sheet 22 may be adhered to the second frame 21.

A rectangular frame-shaped sealing member 24 extending along the outer edge of the pressing member 23 is provided on the upper surface of the second frame 21 . The seal member 24 is made of a heat-resistant elastic body such as silicone rubber. For example, the sealing member 24 may be an L-shaped packing, and may be adhered to a groove formed in the second frame 21 using double-sided tape and silicone sealant. The sealing member 24 hermetically seals the space S between the upper jig 10 and the lower jig 20 together with the first flexible sheet 12 of the upper jig 10 .

The second frame 21 has one or more exhaust holes 25 formed therein. As shown in FIG. 3, a plurality of exhaust holes 25 may be formed in the second frame 21. FIG. 4 is an enlarged cross-sectional perspective view showing the vicinity of the exhaust hole 25. As shown in FIG. As shown in FIG. 4, the exhaust hole 25 is a through hole that penetrates the second frame 21 in the thickness direction. In one embodiment, the exhaust hole 25 is formed at a position overlapping the pressing member 23 when viewed from the Z direction. The holding member 23 may be formed with a cutout portion 28 that cuts out a part of the holding member 23 at a position close to the exhaust hole 25 . The cutout portion 28 provides a flow path that communicates the exhaust hole 25 formed in the second frame 21 with the space S.

A duct portion 26 is attached to the lower jig 20. The duct portion 26 has an inlet 26a facing the end of the exhaust hole 25 and a plurality of outlets 26b. An exhaust path 27 is formed between the inlet 26a and the plurality of outlets 26b, which guides exhaust from the space S from the inlet 26a to the plurality of outlets 26b. That is, the exhaust path 27 communicates with the space S via the exhaust hole 25. In one embodiment, the inlet 26a and the plurality of outlets 26b may be provided with check valves that prevent outside air from flowing back into the space S. These check valves may be connected to springs that bias the check valves in a direction that closes the opening. The plurality of outlets 26b are connected to an exhaust device such as a vacuum pump. When the exhaust device operates, the air in the space S is exhausted to the outside of the fixing jig 1 through the exhaust hole 25 and the exhaust path 27. As a result, the pressure in the space S is reduced.

The first rigid sheet 31 and the second rigid sheet 32 are arranged between the first flexible sheet 12 of the upper jig 10 and the second flexible sheet 22 of the lower jig 20. The first rigid sheet 31 and the second rigid sheet 32 have higher rigidity than the first flexible sheet 12 and the second flexible sheet 22. For example, the first rigid sheet 31 and the second rigid sheet 32 are substantially rectangular metal sheets. In one embodiment, the first rigid sheet 31 and the second rigid sheet 32 may be made of stainless steel.

In one embodiment, the first rigid sheet 31 and the second rigid sheet 32 have a thickness of 50 μm or more and 400 μm or less. By setting the thickness of the first rigid sheet 31 and the second rigid sheet 32 to 50 μm, sufficient rigidity can be ensured. Further, by setting the thickness of the first rigid sheet 31 and the second rigid sheet 32 to 400 μm or less, the first rigid sheet 31 and the second rigid sheet 32 are easily elastically deformed, and the upper jig 10 and the lower jig 2 The pressurized object 100 can be reliably fixed between the two.

The area of the first rigid sheet 31 may be smaller than the area of the first flexible sheet 12. Similarly, the area of the second rigid sheet 32 may be smaller than the area of the second flexible sheet 22. For example, the areas of the first rigid sheet 31 and the second rigid sheet 32 are slightly larger than the area of the electrode active material layer on which the pressurized object 100 is pressed. Note that the areas of the first flexible sheet 12, the second flexible sheet 22, the first rigid sheet 31, and the second rigid sheet 32 are the areas of the first flexible sheet 12, the second flexible sheet 22, It represents the area of the main surfaces of the first rigid sheet 31 and the second rigid sheet 32.

As shown in FIG. 2, the first rigid sheet 31 is joined to the center portion of the lower surface of the first flexible sheet 12 of the upper jig 10. As shown in FIG. Therefore, when viewed from the Z direction, the first rigid sheet 31 overlaps the central portion S1. As shown in FIG. 3, the second rigid sheet 32 is joined to the center of the upper surface of the second flexible sheet 22 of the lower jig 20. As shown in FIG. Therefore, the first rigid sheet 31 and the second rigid sheet 32 face each other via the central portion S1. A pressurized object 100 is placed in a central portion S1 formed between the first rigid sheet 31 and the second rigid sheet 32. Note that a plurality of pressurizing objects 100 may be arranged in the central portion S1.

Note that the first rigid sheet 31 and the second rigid sheet 32 may be attached to the first flexible sheet 12 and the second flexible sheet 22 using double-sided tape 33. In the embodiment shown in FIGS. 2 and 3, the double-sided tape 33 is placed between the first rigid sheet 31 and the first flexible sheet 12 and between the second rigid sheet 32 and the second flexible sheet 22. placed in between. As shown in FIGS. 2 and 3, the double-sided tape 33 extends along the outer edges of the first flexible sheet 12 and the second flexible sheet 22, and also extends along the outer edges of the first flexible sheet 12 and the second flexible sheet 22. 2 extends along the center line of the flexible sheet 22 in the X direction. In one embodiment, two pressurized objects 100 may be arranged side by side in the X direction. In this case, the double-sided tape 33 is arranged in a figure 8 shape at a position that does not overlap the pressurized object 100 when viewed from the Z direction.

In one embodiment, as shown in FIG. 1, the fixture 1 may further include an upper preliminary pressure reducing member (first preliminary pressure reducing member) 41 and a lower preliminary pressure reducing member (second preliminary pressure reducing member) 42. The upper preliminary pressure reducing member 41 is made of a material with high rigidity, such as hard plastic or metal, and is arranged above the upper jig 10 so as to face the upper jig 10 . That is, the upper preliminary pressure reducing member 41 faces the first rigid sheet 31 with the first flexible sheet 12 in between.

A first preliminary decompression chamber 43 is formed between the first flexible sheet 12 of the upper jig 10 and the upper preliminary decompression member 41 . The upper preliminary pressure reducing member 41 is configured to be detachable from the upper jig 10. A substantially rectangular frame-shaped sealing member 46 is arranged in the upper preliminary pressure reducing member 41 at a position facing the first flexible sheet 12, and when the first frame 11 and the upper preliminary pressure reducing member 41 come into contact with each other, The first flexible sheet 12 and the sealing member 46 come into contact with each other, and the first preliminary decompression chamber 43 is hermetically sealed.

The upper preliminary decompression member 41 is formed with one or more through holes 41 a that communicate with the first preliminary decompression chamber 43 . In the embodiment shown in FIG. 1 , a plurality of through holes 41 a are formed in the upper preliminary pressure reducing member 41 . These multiple through holes 41a are connected to an exhaust device such as a vacuum pump. When the exhaust device operates, the air in the first preliminary decompression chamber 43 is exhausted to the outside of the fixture 1 through the through hole 41a. As a result, the first preliminary decompression chamber 43 is depressurized.

Similarly, the lower preliminary pressure reducing member 42 is made of a highly rigid material such as hard plastic or metal, and is disposed below the lower jig 20 so as to face the lower jig 20. That is, the lower preliminary pressure reducing member 42 faces the second rigid sheet 32 with the second flexible sheet 22 in between.

A second preliminary decompression chamber 44 is formed between the second flexible sheet 22 of the lower jig 20 and the lower preliminary decompression member 42 . The lower preliminary pressure reducing member 42 is configured to be detachable from the lower jig 20. A substantially rectangular frame-shaped sealing member 47 is arranged in the lower preliminary pressure reducing member 42 at a position facing the second flexible sheet 22, and when the lower jig 20 and the lower preliminary pressure reducing member 42 come into contact with each other, The second preliminary decompression chamber 44 is hermetically sealed by the contact between the second flexible sheet 22 and the sealing member 47 . The lower preliminary decompression member 42 is formed with one or more through holes 42 a that communicate with the second preliminary decompression chamber 44 . In the embodiment shown in FIG. 1, a plurality of through holes 42a are formed in the lower preliminary pressure reducing member 42. These multiple through holes 42a are connected to an exhaust device such as a vacuum pump. When the exhaust device operates, the air in the second preliminary decompression chamber 44 is exhausted to the outside of the fixture 1 through the through hole 42a. As a result, the second preliminary decompression chamber 44 is depressurized.

In one embodiment, the first preliminary decompression chamber 43 is provided with a spacer 45 . As shown in FIG. 1, the fixture 1 may include a plurality of spacers 45. The plurality of spacers 45 are arranged at positions that do not overlap the first rigid sheet 31 when viewed from the Z direction. That is, the plurality of spacers 45 are arranged on the outer edge of the first flexible sheet 12. In this embodiment, a plurality of spacers 45 are interposed between the first flexible sheet 12 and the upper preliminary pressure reducing member 41.

FIG. 5 is a top view of the upper jig 10. The plurality of spacers 45 arranged on the upper preliminary decompression member 41 may be arranged on an extension of the diagonal line of the first rigid sheet 31. In the embodiment shown in FIG. 5, the fixing jig 1 includes four rectangular parallelepiped spacers 45 spaced apart from each other. Two spacers 45 among these four spacers 45 are arranged on an extension line of one of the two diagonal lines of the first rigid sheet 31, and the other two spacers 45 are arranged on the extension line of one of the two diagonal lines of the first rigid sheet 31. It is placed on an extension of the other diagonal of the book.

More specifically, the four spacers 45 are arranged at positions that do not overlap the first rigid sheet 31 when viewed from the X direction and the Y direction. By arranging the plurality of spacers 45 on the extension of the diagonal line of the first rigid sheet 31, the first rigid sheet 31 is prevented from excessively bending toward the upper preliminary decompression member 41 when the first preliminary decompression chamber 43 is depressurized. It is suppressed. As a result, the first rigid sheet 31 becomes less likely to undergo plastic deformation, and a stable flow path can be formed in the space S.

In the example shown in FIG. 1, the plurality of spacers 45 are provided only in the first preliminary decompression chamber 43, but the spacers 45 may also be provided in the second preliminary decompression chamber 44. For example, the plurality of spacers 45 are interposed between the second flexible sheet 22 and the lower preliminary decompression member 42, and are arranged on a diagonal extension of the second rigid sheet 32 when viewed from the Z direction. You can.

In one embodiment, the fixing jig 1 may further include a conveying jig 50 that supports the pressurized object 100. FIG. 6 is a schematic perspective view of the fixing jig 1 including the transport jig 50. In addition, in FIG. 6, for convenience of explanation, the first rigid sheet 31 and the second rigid sheet 32 are omitted.

As shown in FIG. 6, the conveyance jig 50 includes a third frame 51 and a support sheet 52 that spans the third frame 51. The third frame 51 has a rectangular frame shape, for example. The support sheet 52 is a flexible, substantially rectangular resin sheet. A pressurized object 100 is supported on the upper surface of the support sheet 52 .

The length of the support sheet 52 substantially matches the length of the third frame 51 in the X direction, and the width of the support sheet 52 may be shorter than the width of the third frame 51 in the Y direction. In the embodiment shown in FIG. 6, both ends of the support sheet 52 in the X direction are connected to the third frame 51, and both ends of the support sheet 52 in the Y direction are not connected to the third frame 51. By placing the electrode active material on this support sheet 52, a pressurized object 100 is formed on the support sheet 52. The conveyance jig 50 is arranged between the upper jig 10 and the lower jig 20 with the pressurized object 100 placed on the support sheet 52 . As a result, the pressurized object 100 is placed in the center S1 of the space S formed between the first rigid sheet 31 and the second rigid sheet 32.

Next, a method of pressurizing the pressurizing object 100 using the fixing jig 1 will be described with reference to FIGS. 7 to 10.

In this method, first, as shown in FIG. 7(a), an upper preliminary decompression member 41 is arranged on the upper jig 10, and a first preliminary decompression chamber is placed between the upper jig 10 and the upper preliminary decompression member 41. 43 is formed. Further, a lower preliminary pressure reducing member 42 is arranged under the lower jig 20, and a second preliminary pressure reducing chamber 44 is formed between the lower jig 20 and the lower preliminary pressure reducing member 42.

Next, preliminary depressurization of the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 is performed. That is, the exhaust device connected to the through hole 41a of the upper preliminary decompression member 41 and the through hole 42a of the lower preliminary decompression member 42 is activated, and the air in the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 is supplied to the fixing jig. Exhausted to the outside of 1. As a result, the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 are depressurized. At this time, the pressure in the space S between the upper jig 10 and the lower jig 20 is set to atmospheric pressure.

As shown in FIG. 7(b), when the first preliminary decompression chamber 43 is depressurized, the first flexible sheet 12 of the upper jig 10 is It is drawn toward the upper preliminary pressure reducing member 41 and bends toward the upper preliminary pressure reducing member 41. Here, since the first preliminary decompression chamber 43 is provided with a spacer 45, the first flexible sheet 12 is bent along the shape of the spacer 45.

Similarly, when the second preliminary decompression chamber 44 is depressurized, the second flexible sheet 22 of the lower jig 20 moves toward the lower preliminary decompression member 42 due to the pressure difference between the space S and the second preliminary decompression chamber 44. It is pulled in and bent toward the lower preliminary decompression member 42. By bending the first flexible sheet 12 and the second flexible sheet 22, the volume of the space S increases.

Next, the pressurized object 100 is formed on the support sheet 52 of the conveying jig 50. Then, as shown in FIG. 8(a), the transport jig 50 is placed on the lower jig 20. At this time, a portion of the seal member 24 of the lower jig 20 modestly contacts the support sheet 52.

Next, as shown in FIG. 8(b), the upper jig 10 is placed on the lower jig 20. At this time, the first flexible sheet 12 of the upper jig 10 is in close contact with the seal member 24 of the lower jig 20. As a result, the space S between the upper jig 10 and the lower jig 20 is sealed. In the center S1 of the space S, a pressurized object 100 supported on a transport jig 50 is arranged.

Next, the exhaust device connected to the exhaust hole 25 of the lower jig 20 is activated, and the air in the space S is exhausted from the exhaust hole 25. At this time, at the initial stage of evacuation of the space S, the pressures in the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 are lower than the pressure in the space S, so the first flexible sheet 12 and the second flexible sheet 22 is maintained in a bent state toward the upper preliminary pressure reducing member 41 and the lower preliminary pressure reducing member 42. Further, although a force is applied to the space S to close it, the spacer 45 acts as an intermediate support, and the space S is maintained by the thickness of the spacer 45 in consideration of shrinkage due to pressure. Note that although the upper preliminary pressure reducing member 41 and the lower preliminary pressure reducing member 42 are in close contact with each other via the spacer 45, an air flow path from the space S to the exhaust hole 25 is ensured at a location where the spacer 45 is not provided. Therefore, the reduced pressure in the space S is maintained. Therefore, the first flexible sheet 12 is prevented from coming into close contact with the pressurized object 100 and pressure is applied to the pressurized object 100 in a state where the pressure in the space S is insufficiently reduced. Therefore, the occurrence of defects such as voids in the pressurized object 100 is suppressed.

Then, when the pressure in the space S continues to be reduced to a predetermined pressure, the pressures in the first preliminary pressure reduction chamber 43 and the second preliminary pressure reduction chamber 44 are gradually returned to atmospheric pressure. In the process where the pressure in the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 return to atmospheric pressure, when the pressure in the space S falls below the pressure in the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44, as shown in FIG. 9(a), the first flexible sheet 12 and the second flexible sheet 22 are deformed to wrap around the pressurized object 100 by a weak force corresponding to the pressure difference, and the first rigid sheet 31 and comes into close contact with the pressurized object 100 via the second rigid sheet 32. Finally, the pressures in the first preliminary decompression chamber 43 and the second preliminary decompression chamber 44 are returned to atmospheric pressure. As a result, the pressurized object 100 is compressed and fixed between the first rigid sheet 31 and the second rigid sheet 32.

Next, as shown in FIG. 9(b), the upper preliminary pressure reducing member 41 and the lower preliminary pressure reducing member 42 are removed from the upper jig 10 and the lower jig 20. Next, the fixing jig 1 is transported to a pressurizing device, and the pressurizing object 100 is subjected to a pressurizing process via the upper jig 10 and the lower jig 20. For example, as shown in FIG. 10(a), the fixing jig 1 passes between a pair of rolls R of a roll press apparatus with the pressurized object 100 accommodated in the center part S1, Receives pressure. By being pressurized by the pair of rolls R, the pressurized object 100 is pressed within the central portion S1, and its density is increased. As a result, an electrode active material layer 101 for a lithium ion secondary battery is formed (see FIG. 10(b)).

When pressurizing the pressurized object 100 between the pair of rolls R, since the pressurized object 100 is fixed inside the fixing jig 1, air bubbles may get mixed inside the pressurized object 100. Thus, the occurrence of defects in the pressurized object 100 is suppressed. Moreover, since the pressurization target 100 is fixed, the active material of the pressurization target 100 is prevented from collapsing during pressurization, and pressure is appropriately applied to the pressurization target 100.

In addition, when the pressurized object 100 contains powdered active material, pressure is applied to the pressurized object 100 via the first flexible sheet 12 and the second flexible sheet 22. At times, the active material material may pierce the first flexible sheet 12 and the second flexible sheet 22. When the active material penetrates the first flexible sheet 12 and the second flexible sheet 22, unevenness may be formed on the surface of the electrode active material layer 101, or collapse may occur in the electrode active material layer 101. , non-uniformity may occur in the thickness of the electrode active material layer 101. In this way, non-uniformity in the thickness of the electrode active material layer 101 leads to the production of defective products and a decrease in battery performance. On the other hand, in the fixing jig 1, since the pressurizing object 100 is held between the first rigid sheet 31 and the second rigid sheet 32, the first flexible sheet 12 and the second flexible sheet 22 does not come into direct contact with the pressurized object 100. Therefore, the active material becomes difficult to penetrate into the first flexible sheet 12 and the second flexible sheet 22. On the other hand, since the outer surfaces of the first rigid sheet 31 and the second rigid sheet 32 are covered with the first flexible sheet 12 and the second flexible sheet 22, the pair of rolls R of the roll press device have high rigidity. It does not contact the first rigid sheet 31 and the second rigid sheet 32. Therefore, the pair of rolls R is less likely to be damaged.

When the electrode active material layer 101 is formed by pressurizing the pressurizing object 100, the upper jig 10 and the lower jig 20 are removed from the electrode active material layer 101, as shown in FIG. 10(b). At this time, since the active material contained in the pressurizing object 100 is prevented from penetrating the first flexible sheet 12 and the second flexible sheet 22, the upper jig 10 and the lower jig 20 can be easily removed from the electrode active material layer 101. By stacking the electrode active material layers 101 manufactured as described above, a lithium ion secondary battery having a plurality of cell structures is assembled.

As explained above, in the fixing jig 1 according to the above embodiment, the first rigid sheet 31 and the second rigid sheet 32 are arranged between the first flexible sheet 12 and the second flexible sheet 22. , the pressurizing object 100 is arranged between the first rigid sheet 31 and the second rigid sheet 32. Therefore, since the first flexible sheet 12 and the second flexible sheet 22 do not directly contact the pressurized object 100, the first flexible sheet 12 and the second flexible sheet 22 do not touch the pressurized object 100. This prevents the active material contained in the material from being pierced. Therefore, the occurrence of defective products is suppressed, and the productivity of lithium ion secondary batteries can be improved.

Although fixing jigs according to various embodiments have been described above, various modifications can be made without being limited to the embodiments described above and without changing the gist of the invention.

For example, in the above embodiment, an example has been described in which the exhaust hole 25 is formed in the lower jig 20 of the fixing jig 1, but an exhaust hole is formed in the first frame 11 of the upper jig 10, and the exhaust hole is formed through the exhaust hole. The air in the space S may be exhausted. Note that the exhaust hole may be formed in both the first frame 11 of the upper jig 10 and the second frame 21 of the lower jig 20.

Moreover, the material of the first flexible sheet 12 and the second flexible sheet 22 is not limited to polyimide film as long as it has flexibility. For example, as the constituent material of the first flexible sheet 12 and the second flexible sheet 22, a fiber-reinforced rubber sheet or Teflon (registered trademark) having rubber as a base material and containing fibers may be used.

Further, in the above embodiment, an example was described in which the pressurizing object 100 is pressurized by a roll press device including a pair of rolls R, but the pressurizing device that pressurizes the pressurizing object 100 is not limited to the roll press device. . For example, the pressurized object 100 may be pressurized by a uniaxial press device.

Furthermore, in the embodiment described above, an example has been described in which the pressurized object 100 containing an electrode active material is rolled to produce an electrode active material layer of a lithium ion secondary battery. The pressurizing object 100 is not necessarily limited to an electrode active material for a lithium ion secondary battery. Note that the various embodiments described above can be combined within a consistent range.

The invention will be described with reference to the provisions listed below. Note that the present invention may include the following clauses in any combination without specific enumeration.

1. A fixing jig for fixing a pressurized object containing an active material material for manufacturing an electrode active material layer for a lithium ion secondary battery,
a first jig including a first frame and a first flexible sheet spanning the first frame;
a second jig including a second frame and a second flexible sheet spanning the second frame;
a first rigid sheet joined to the first flexible sheet;
a second rigid sheet joined to the second flexible sheet;
a conveying jig that supports the pressurized object;
Equipped with
The first jig and the second jig form a housing space between which the pressurized object is placed,
The first rigid sheet and the second rigid sheet face each other via the accommodation space between the first flexible sheet and the second flexible sheet,
A fixing jig, wherein at least one of the first jig and the second jig is formed with an exhaust hole communicating with the accommodation space.

2. The first flexible sheet and the second flexible sheet are resin sheets,
The fixing jig according to clause 1, wherein the first rigid sheet and the second rigid sheet are metal sheets.

3. The fixing jig according to clause 2, wherein the first rigid sheet and the second rigid sheet are made of stainless steel.

4. The fixed fixture according to any one of clauses 1 to 3, wherein the first rigid sheet and the second rigid sheet have an area smaller than the first flexible sheet and the second flexible sheet. Ingredients.

5. The fixing jig according to any one of clauses 1 to 4, wherein the first rigid sheet and the second rigid sheet have a thickness of 50 μm or more and 400 μm or less.

6. The method according to any one of clauses 1 to 5, wherein the first rigid sheet and the second rigid sheet are respectively attached to the first flexible sheet and the second flexible sheet with double-sided tape. fixing jig.

7. a rectangular frame-shaped pressing member disposed on the second frame;
a rectangular frame-shaped sealing member disposed along the outer edge of the pressing member and sealing the accommodation space;
The fixing jig according to any one of Clauses 1 to 6, further comprising:

8. A first preliminary decompression member that is disposed opposite the first rigid sheet via the first flexible sheet and forms a first preliminary decompression chamber between the first flexible sheet and the first preliminary decompression member;
a second preliminary decompression member disposed opposite the second rigid sheet via the second flexible sheet and forming a second preliminary decompression chamber between the second flexible sheet and the second preliminary decompression member;
8. The fixture of any one of clauses 1-7, further comprising:

9. further comprising a plurality of spacers arranged in the first preliminary decompression chamber,
The fixing jig according to clause 8, wherein the plurality of spacers are arranged at positions that do not overlap the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet.

10. The first rigid sheet has a substantially rectangular shape,
The fixing jig according to clause 9, wherein the plurality of spacers are arranged on a diagonal extension of the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet.

DESCRIPTION OF SYMBOLS 1... Fixing jig, 10... Upper jig (first jig), 11... First frame, 12... First flexible sheet, 23... Holding member, 24, 46, 47... Seal member, 20... Lower Jig (second jig), 21... Second frame, 22... Second flexible sheet, 25... Exhaust hole, 28... Notch, 31... First rigid sheet, 32... Second rigid sheet, 33 ...Double-sided tape, 41...Upper preliminary pressure reducing member (first preliminary pressure reducing member), 42...Lower preliminary pressure reducing member (second preliminary pressure reducing member), 43...First preliminary pressure reducing chamber, 44...Second preliminary pressure reducing chamber, 45... Spacer, 50... Transport jig, 100... Pressurized object, 101... Electrode active material layer, S1... Center part (housing space), S2... Outer edge part.

Claims (10)

A fixing jig for fixing a pressurized object containing an active material material for manufacturing an electrode active material layer for a lithium ion secondary battery,
a first jig including a first frame and a first flexible sheet spanning the first frame;
a second jig including a second frame and a second flexible sheet spanning the second frame;
a first rigid sheet joined to the first flexible sheet;
a second rigid sheet joined to the second flexible sheet;
a conveying jig that supports the pressurized object;
Equipped with
The first jig and the second jig form a housing space between which the pressurized object is placed,
The first rigid sheet and the second rigid sheet face each other via the accommodation space between the first flexible sheet and the second flexible sheet,
A fixing jig, wherein at least one of the first jig and the second jig is formed with an exhaust hole communicating with the accommodation space. The first flexible sheet and the second flexible sheet are resin sheets,
The fixing jig according to claim 1, wherein the first rigid sheet and the second rigid sheet are metal sheets. The fixing jig according to claim 2, wherein the first rigid sheet and the second rigid sheet are made of stainless steel. The fixing according to any one of claims 1 to 3, wherein the first rigid sheet and the second rigid sheet have a smaller area than the first flexible sheet and the second flexible sheet. jig. The fixing jig according to any one of claims 1 to 3, wherein the first rigid sheet and the second rigid sheet have a thickness of 50 μm or more and 400 μm or less. The first rigid sheet and the second rigid sheet are attached to the first flexible sheet and the second flexible sheet with double-sided tape, respectively, according to any one of claims 1 to 3. Fixing jig. a rectangular frame-shaped pressing member disposed on the second frame;
a rectangular frame-shaped sealing member disposed along the outer edge of the pressing member and sealing the accommodation space;
The fixing jig according to any one of claims 1 to 3, further comprising: a first preliminary decompression member disposed opposite to the first rigid sheet via the first flexible sheet and forming a first preliminary decompression chamber between the first flexible sheet;
a second preliminary decompression member disposed opposite to the second rigid sheet via the second flexible sheet and forming a second preliminary decompression chamber between the second flexible sheet;
The fixing jig according to any one of claims 1 to 3, further comprising: further comprising a plurality of spacers arranged in the first preliminary decompression chamber,
The fixing jig according to claim 8, wherein the plurality of spacers are arranged at positions that do not overlap the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet. The first rigid sheet has a substantially rectangular shape,
The fixing jig according to claim 9, wherein the plurality of spacers are arranged on a diagonal extension of the first rigid sheet when viewed from a direction perpendicular to the first rigid sheet.

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