Flexible isostatic pressing jig for pouch cell and method for isostatically pressing pouch cell using same

Abstract

The present invention provides an isostatic pressing jig for a pouch cell and a method for isostatically pressing a pouch cell using same, the isostatic pressing jig comprising: a flexible lower sheet located below the pouch cell and covering the entire surface area of the pouch cell; a flexible upper sheet located above the pouch cell and covering the entire surface area of the pouch cell; and a ring-shaped plate disposed between the lower sheet and the upper sheet, wherein the ring-shaped plate accommodates a cup portion of the pouch cell in a ring inner hole and fixes the pouch cell by positioning a sealing portion of the pouch cell on one surface of a ring-shaped plate.

Description

Jig for isotropic pressurizing a flexible pouch cell and method for isotropic pressurizing a pouch cell using the same

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0127981 dated September 23, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to a jig for isotropically pressurizing a flexible pouch cell and a method for isotropically pressurizing a pouch cell using the same.

[0003] Lithium-ion secondary batteries are classified into can-type secondary batteries, in which an electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which an electrode assembly is embedded in a pouch. The pouch-type secondary battery comprises an electrode assembly, an electrode lead coupled to the electrode assembly, and a pouch that accommodates the electrode assembly with the tip of the electrode lead drawn out to the outside.

[0004] Pouch-type secondary batteries are commercialized by housing an electrode assembly having a structure in which one or more unit cells, including a positive electrode, a negative electrode, and a separator interposed between them, are stacked in the cup portion of a pouch and then injecting an electrolyte, or by housing an electrode assembly equipped with a solid electrolyte from the beginning in the cup portion of a pouch and then sealing the sealing portion of the pouch.

[0005] Among these, all-solid-state batteries have the advantage of being superior in terms of safety. In the manufacturing process of all-solid-state batteries, a warm isostatic pressing (WIP) process is generally applied to bond the interface between the electrode and the solid electrolyte. This isostatic pressing is essential because if the interface between the electrode and the solid electrolyte is not properly formed, the movement of lithium (Li) ions becomes difficult, making battery operation impossible.

[0006] FIG. 1 is an exploded perspective view showing the form of a conventional open-type pouch cell isotropic pressurization jig. That is, the conventional pouch cell isotropic pressurization jig (1) is composed of an upper plate (1a) and a lower plate (1b), and the upper plate (1a) and the lower plate (1b) include an opening in the center that can accommodate a cup portion (2b) of a pouch cell (2).

[0007] The open-type pouch cell isotropic pressurization jig (1) described above has a large volume and weight, and since it takes a long time to accommodate the pouch cell (2) in the jig and mechanically combine the upper plate (1a) and the lower plate (1b), it has the disadvantage of low isotropic pressurization process efficiency.

[0008] [Prior Art Literature]

[0009] [Patent Literature]

[0010] Republic of Korea Published Patent No. 10-2024-0012798

[0011]

[0012] The present invention has been devised to resolve the above-mentioned problems of the prior art, and

[0013] The purpose is to provide a flexible pouch cell isotropic pressurizing jig that has a simple structure, excellent isotropic pressurizing process efficiency, and can minimize deformation of the pouch cell during isotropic pressurization, and a method for isotropic pressurizing a pouch cell using the same.

[0014]

[0015] To achieve the above objective, the present invention

[0016] A flexible bottom sheet located at the bottom of the pouch cell and covering the entire surface area of ​​the pouch cell,

[0017] A flexible upper sheet positioned on the upper part of the pouch cell and covering the entire surface area of ​​the pouch cell, and

[0018] A jig for isotropically pressurizing a pouch cell is provided, comprising a ring-shaped plate that accommodates a cup portion of a pouch cell in an inner hole of the ring, positions a sealing portion of a pouch cell on one surface of the ring-shaped plate to fix the pouch cell, and includes a ring-shaped plate disposed between a lower sheet and an upper sheet.

[0019] In one embodiment of the present invention, the flexible upper sheet and lower sheet further include an outer circumference coupling means, and the outer circumferences of the upper sheet and lower sheet can be coupled to each other by the coupling means while accommodating the pouch cell and the ring-shaped plate between them.

[0020] In one embodiment of the present invention, the flexible upper sheet and lower sheet may be sheets of a polymer material.

[0021] In one embodiment of the present invention, the polymer material may be a rubber material, a silicone material, or a mixture thereof.

[0022] In one embodiment of the present invention, the ring-shaped plate may be a plate of metal, wood, or polymer material.

[0023] In one embodiment of the present invention, the thickness of the ring-shaped plate may be the same as the height of the cup portion of the pouch cell or thinner than the height of the cup portion of the pouch cell.

[0024] In one embodiment of the present invention, the isotropic pressing jig is used for isotropic pressing of a pouch cell in which cup portions are formed on both sides centered on a sealing portion, and may be equipped with two ring-shaped plates applied to each of the cup portions.

[0025]

[0026] In addition, the present invention

[0027] A method of isotropically pressurizing a pouch cell using the above-mentioned isotropically pressurizing jig,

[0028] a) A step of positioning the cup portion of the pouch cell on the upper surface of a flexible lower sheet so that it faces upward;

[0029] b) a step of inserting the cup portion of the pouch cell into the hole of the ring-shaped plate and positioning the ring-shaped plate such that the lower surface of the ring-shaped plate is positioned on the upper surface of the sealing portion of the pouch cell;

[0030] c) a step of covering the pouch cell on which the above-mentioned ring-shaped plate is placed with a flexible upper sheet;

[0031] d) a step of applying pressure to an isotropic pressurizing jig containing the above pouch cell by hydraulic pressure; the present invention provides a method for isotropically pressurizing a pouch cell.

[0032] In one embodiment of the present invention, the isotropic pressing method may further include a step of joining the outer periphery of a flexible upper sheet and a lower sheet after step c).

[0033] In one embodiment of the present invention, the isotropic pressurization method may further include the step of inserting the isotropic pressurization jig containing the pouch cell into a flexible sealing container and sealing the sealing container after step c).

[0034] In one embodiment of the present invention, the isotropic pressing method further includes the step of joining the outer periphery of a flexible upper sheet and a lower sheet, and after this step, may further include the step of inserting the isotropic pressing jig containing the pouch cell into a flexible sealing container and sealing the sealing container.

[0035] In one embodiment of the present invention, in the isotropic pressurization method, the pouch cell is a pouch cell in which cup portions are formed on both sides with respect to a sealing portion, and

[0036] Step a) above is a step of placing a first ring-shaped plate on the upper surface of a flexible lower sheet and inserting and positioning the lower cup portion of a pouch cell into the hole of the first ring-shaped plate.

[0037] Step b) above may be a step of inserting the upper cup portion of the pouch cell into the hole of the second ring-shaped plate and positioning the second ring-shaped plate such that the lower surface of the second ring-shaped plate is positioned on the upper surface of the sealing portion of the pouch cell.

[0038]

[0039] The flexible pouch cell isotropic pressurization jig of the present invention has a simple structure, provides excellent isotropic pressurization process efficiency, and provides the effect of minimizing deformation of the pouch cell during isotropic pressurization.

[0040] In addition, according to the isotropic pressurization method of the pouch cell of the present invention, the isotropic pressurization process is efficiently carried out, and the effect of minimizing deformation of the pouch cell during isotropic pressurization is provided.

[0041]

[0042] FIG. 1 is an exploded perspective view showing the form of a conventional open-type pouch cell isotropic pressurization jig.

[0043] FIG. 2 is a perspective view illustrating the usage form of a simple type of flexible pouch cell isotropic pressurization jig, and

[0044] FIG. 3 is a plan view illustrating the state of a pouch cell isotropically pressurized using the flexible pouch cell isotropic pressurization jig of FIG. 2, and

[0045] FIG. 4 is a perspective view showing one embodiment of a jig for isotropic pressing of a flexible pouch cell according to the present invention, and

[0046] FIG. 5 is a plan view illustrating the state of a pouch cell isotropically pressurized using the flexible pouch cell isotropic pressurization jig of FIG. 4, and

[0047] FIG. 6 is a plan view sequentially illustrating one embodiment of the method for isotropically pressurizing a pouch cell according to the present invention, and

[0048] FIG. 7 is a plan view sequentially illustrating another embodiment of the method for isotropically pressurizing a pouch cell according to the present invention, and

[0049] FIG. 8 is a cross-sectional view illustrating the shape of a pouch cell that isotropically pressurizes using the pouch cell isotropic pressurizing jig of the present invention.

[0050]

[0051] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Throughout the specification, similar parts are denoted by the same reference numerals.

[0052] When it is stated that one component is "connected, equipped, or installed" on another component, it should be understood that it may be directly connected or installed on that other component, or that there may be other components in between. Conversely, when it is stated that one component is "directly connected, equipped, or installed" on another component, it should be understood that there are no other components in between. Meanwhile, other expressions describing the relationships between components, such as "on top of" and "directly on top," "between" and "exactly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0053] The present invention will be described in detail below with reference to the drawings.

[0054] FIG. 4 is a perspective view showing one embodiment of a flexible pouch cell isotropic pressurizing jig of the present invention, and FIG. 5 is a plan view showing the state of a pouch cell isotropically pressurized using the flexible pouch cell isotropic pressurizing jig of FIG. 4.

[0055] As illustrated in FIGS. 4 and 5 above, the pouch cell isotropic pressurizing jig (100) of the present invention comprises a flexible lower sheet (20) positioned at the bottom of the pouch cell (40) to cover the entire surface area of ​​the pouch cell,

[0056] A flexible upper sheet (10) positioned on top of the pouch cell (40) and covering the entire surface area of ​​the pouch cell, and

[0057] It is characterized by including a ring-shaped plate, which accommodates the cup portion (42) of a pouch cell in the inner hole of the ring, and fixes the pouch cell by positioning the sealing portion (42) of the pouch cell on one surface of the ring-shaped plate, and a ring-shaped plate (30) disposed between the lower sheet (20) and the upper sheet (10).

[0058] The open-type pouch cell isotropic pressurization jig (1) as shown in FIG. 1 has a large volume and weight, and since it takes a long time to accommodate the pouch cell (2) in the jig and mechanically combine the upper plate (1a) and the lower plate (1b), it has the disadvantage of low isotropic pressurization process efficiency.

[0059] FIGS. 2 and 3 are plan views illustrating the usage of a simple type of flexible pouch cell isotropic pressurizing jig and the state of a pouch cell isotropically pressurized using such a jig. Although this type of flexible pouch cell isotropic pressurizing jig can overcome the disadvantages of the open type pouch cell isotropic pressurizing jig to some extent, as shown in FIG. 3, it has the disadvantage that deformation occurs in the sealing part as well as the cup part of the pouch cell due to the pressure applied during isotropic pressurization.

[0060] The present invention is characterized by having a structure capable of resolving such problems. That is, the pouch cell isotropic pressurizing jig (100) of the present invention effectively prevents deformation occurring in the cup portion and sealing portion of the pouch cell by further comprising a ring-shaped plate (30).

[0061]

[0062] The thickness of the flexible upper sheet (10) and lower sheet (20) is not particularly limited and may be a thickness such that the sheet can be flexibly deformed by the pressure applied by the fluid during isotropic pressing. For example, the thickness of the upper sheet (10) and lower sheet (20) may be 0.05 mm to 10 mm, 0.05 mm to 5 mm, 0.05 mm to 3 mm, 0.05 mm to 1 mm, or 0.05 mm to 0.5 mm.

[0063] In the above, the meaning of “covering the entire area of ​​the pouch cell” is that the flexible upper sheet (10) or lower sheet (20) has an area capable of covering the entire area of ​​the pressure direction side or the opposite direction side of the pouch cell (40). If the flexible upper sheet (10) and lower sheet (20) include a coupling means for coupling with each other, it means that the flexible upper sheet (10) and lower sheet (20) have an area capable of forming a coupling with their outer peripheries while accommodating the pouch cell (40).

[0064] In one embodiment of the present invention, the flexible upper sheet (10) and lower sheet (20) may be sheets of a polymer material. For example, the polymer material may be a rubber material, a silicone material, or a mixture thereof, but is not limited thereto.

[0065] In one embodiment of the present invention, the flexible upper sheet (10) and lower sheet (20) may further include an outer periphery coupling means. The coupling means is not particularly limited as long as it is a means capable of coupling the upper sheet (10) and lower sheet (20) to each other. For example, a clip coupling means, a button coupling means, a magnetic coupling means, a zipper coupling means, etc., may be applied. Among these, the zipper coupling means may be selected for sealing the upper sheet (10) and lower sheet (20).

[0066] The above flexible upper sheet (10) and lower sheet (20) can have their outer peripheries joined together by the coupling means while accommodating the pouch cell (40) and ring-shaped plate (30) between them.

[0067]

[0068] In one embodiment of the present invention, the ring-shaped plate may be a plate made of metal, wood, or a polymer material. The ring-shaped plate has a hardness that does not deform under isotropic pressure and may be manufactured from a material having, for example, a hardness of 100 HV according to the measurement standard of Vickers hardness.

[0069] In one embodiment of the present invention, the thickness of the ring-shaped plate may be equal to the height of the cup portion of the pouch cell or thinner than the height of the cup portion of the pouch cell, but is not limited thereto. For example, the ring-shaped plate may have a thickness of 1.5T (1.5mm) or more.

[0070] In one embodiment of the present invention, the isotropic pressing jig (100) can be used for isotropic pressing of a pouch cell (Fig. 8, (a)) in which a cup portion is formed on one side centered on a sealing portion (44), as shown in FIG. 8. It can also be used for isotropic pressing of a pouch cell (Fig. 8, (b)) in which cup portions are formed on both sides centered on a sealing portion (44). In this case, two ring-shaped plates (30) may be provided so that they can be applied to each cup portion (see FIG. 7).

[0071] In one embodiment of the present invention, the pouch cell isotropic pressurizing jig (100) may further include a sealing container capable of housing and sealing the jig while the pouch cell (40) is housed in the jig. The sealing container may be a flexible container and may be made of a material that is more flexible than the upper sheet (10) and the lower sheet (20). A container commonly used in the field may be used as such a sealing container.

[0072] Although the pouch cell isotropic pressurization jig (100) of the present invention has been described above focusing on essential components, descriptions of components generally used in this field have been omitted. However, it should be understood that the pouch cell isotropic pressurization jig (100) of the present invention may include, without limitation, additional components or devices known in this field, in addition to the components or devices described above.

[0073]

[0074] The isotropic pressurization method of the pouch cell of the present invention can be performed, for example, in the manner shown in FIGS. 6 and FIGS. 7.

[0075] The following description refers to the drawing illustrated in FIG. 6. The isotropic pressurization method of the pouch cell of the present invention is a method of isotropically pressurizing a pouch cell (40) using the isotropic pressurization jig (100), wherein

[0076] a) A step of positioning the cup portion (42) of the pouch cell on the upper surface of the flexible lower sheet (20) so that it faces upward;

[0077] b) a step of inserting the cup portion (42) of the pouch cell (40) into the hole of the ring-shaped plate (30), and positioning the ring-shaped plate (30) such that the lower surface of the ring-shaped plate (30) is positioned on the upper surface of the sealing portion (44) of the pouch cell;

[0078] c) a step of covering the pouch cell (40) on which the above-mentioned ring-shaped plate (30) is placed with a flexible upper sheet (10);

[0079] d) a step of applying pressure by hydraulic pressure to the isotropic pressurizing jig (100) containing the above pouch cell; the feature is included.

[0080] The details regarding the pouch cell isotropic pressurization jig (100) described above can be applied equally to the isotropic pressurization method of the present invention. Therefore, the description of overlapping details is omitted.

[0081] In one embodiment of the present invention, the isotropic pressurization method may further include a step of joining the outer periphery of the flexible upper sheet (10) and the lower sheet (20) after step c). At this time, the joining may be a joining between the outer periphery of the upper sheet (10) and the lower sheet (20) protruding out of the pouch cell (40).

[0082] In one embodiment of the present invention, the isotropic pressurization method may further include the step of inserting the isotropic pressurization jig (100) containing the pouch cell into a flexible sealing container (not shown) and sealing the sealing container after step c).

[0083] In one embodiment of the present invention, the isotropic pressing method further includes the step of joining the outer periphery of a flexible upper sheet (10) and a lower sheet (20), and after this step, may further include the step of inserting the isotropic pressing jig (100) containing the pouch cell (40) into a flexible sealing container and sealing the sealing container.

[0084] The isotropic pressurization method of the present invention can be applied to a pouch cell (Fig. 8, (b)) in which cup portions are formed on both sides centered on the sealing portion, as shown in Fig. 7.

[0085] In the above isotropic pressurization method, the pouch cell (40) is a pouch cell in which cup portions (42) are formed on both sides centered on the sealing portion (44).

[0086] Step a) above is a step of placing a first ring-shaped plate (30a) on the upper surface of a flexible lower sheet (20) and inserting and positioning the lower cup portion of a pouch cell (40) into the hole of the first ring-shaped plate (30a).

[0087] Step b) above may be a step of fitting the upper cup portion of the pouch cell into the hole of the second ring-shaped plate (30b) and positioning the second ring-shaped plate so that the lower surface of the second ring-shaped plate (30b) is positioned on the upper surface of the sealing portion of the pouch cell (40).

[0088]

[0089] In one embodiment of the present invention, the pouch cell (40) may be a mono-cell in which a cathode, a solid electrolyte, and an anode are sequentially stacked, as shown in FIG. 8, with a conventional pouch covering it. Alternatively, the pouch cell (40) may be a bi-cell in which a solid electrolyte and an anode are sequentially stacked on both sides of a cathode, as shown in FIG. 8, with a conventional pouch covering it. Furthermore, the pouch cell (40) may include a structure greater than that of a bi-cell. Additionally, the pouch cell (40) may be a cell in which the electrodes and electrolyte are stacked in a structure different from the above. The cathode and the anode may be in a form including an active material layer and a current collector, and may also be freestanding electrodes that do not require a separate current collector.

[0090] In the present invention, the isostatic pressing can be performed as any one of warm isostatic pressing (WIP), hot isostatic pressing (HIP), and cold isostatic pressing (CIP). These isostatic pressings can be performed under pressure where good interfacial contact is achieved between the solid electrolyte and the electrode. Additionally, they can be performed under a temperature within an appropriate range where the electrode constituent material is thermally stable. For example, the warm isostatic pressing (WIP) can be performed at 45 to 100°C.

[0091]

[0092] Although the present invention has been described in relation to the preferred embodiments mentioned above, various modifications and variations are possible without departing from the essence and scope of the invention. Accordingly, the appended claims will include such modifications and variations insofar as they fall within the essence of the invention.

[0093] [Explanation of the symbol]

[0094] 10: Flexible upper sheet 20: Flexible lower sheet

[0095] 30, 30a, 30b: Ring-shaped plate 40: Pouch cell

[0096] 42: Pouch cell cup section 44: Pouch cell sealing section

[0097] 100: Jig for isotropic pressure application to pouch cells

Claims

1. A flexible bottom sheet located at the bottom of the pouch cell and covering the entire surface area of ​​the pouch cell, A flexible upper sheet positioned on the upper part of the pouch cell and covering the entire surface area of ​​the pouch cell, and A jig for isotropically pressurizing a pouch cell, comprising a ring-shaped plate that accommodates a cup portion of a pouch cell in an inner hole of the ring, positions a sealing portion of a pouch cell on one surface of the ring-shaped plate to fix the pouch cell, and is disposed between a lower sheet and an upper sheet.

2. In Paragraph 1, A pouch cell isotropic pressurizing jig characterized in that the flexible upper sheet and lower sheet further include an outer circumference coupling means, and the outer circumferences of the upper sheet and lower sheet are coupled to each other by the coupling means while accommodating the pouch cell and the ring-shaped plate between them.

3. In Paragraph 1, A pouch cell isotropic pressurizing jig characterized in that the above flexible upper sheet and lower sheet are sheets of a polymer material.

4. In Paragraph 3, A pouch cell isotropic pressurizing jig characterized in that the polymer material is a rubber material, a silicone material, or a mixture thereof.

5. In Paragraph 1, A pouch cell isotropic pressurizing jig characterized in that the above-mentioned ring-shaped plate is a plate made of metal, wood, or polymer material.

6. In Paragraph 1, A jig for isotropic pressure of a pouch cell, characterized in that the thickness of the above-mentioned ring-shaped plate is equal to the height of the cup portion of the pouch cell or thinner than the height of the cup portion of the pouch cell.

7. In Paragraph 1, A jig for isotropically pressurizing a pouch cell, characterized by being used for isotropically pressurizing a pouch cell in which cup portions are formed on both sides centered on a sealing portion, and having two ring-shaped plates applied to each of the cup portions.

8. A method of isotropically pressurizing a pouch cell using the jig of claim 1, a) A step of positioning the cup portion of the pouch cell on the upper surface of a flexible lower sheet so that it faces upward; b) a step of inserting the cup portion of the pouch cell into the hole of the ring-shaped plate and positioning the ring-shaped plate such that the lower surface of the ring-shaped plate is positioned on the upper surface of the sealing portion of the pouch cell; c) a step of covering the pouch cell on which the above-mentioned ring-shaped plate is placed with a flexible upper sheet; d) a step of applying pressure to an isotropic pressurizing jig containing the pouch cell by hydraulic pressure; a method for isotropically pressurizing a pouch cell.

9. In Paragraph 8, A method for isotropically pressurizing a pouch cell, characterized by further including a step of joining the outer periphery of a flexible upper sheet and a lower sheet after step c) above.

10. In Paragraph 8, c) A method for isotropically pressurizing a pouch cell, characterized by further including the step of inserting the isotropically pressurizing jig containing the pouch cell into a flexible sealing container and sealing the sealing container after the step.

11. In Paragraph 9, A method for isotropically pressurizing a pouch cell, characterized by further including the step of inserting an isotropically pressurizing jig containing the pouch cell into a flexible sealing container and sealing the sealing container after the step of combining the outer periphery of a flexible upper sheet and a lower sheet.

12. In Paragraph 8, The above pouch cell is a pouch cell in which cup portions are formed on both sides with the sealing portion at the center. Step a) above is a step of placing a first ring-shaped plate on the upper surface of a flexible lower sheet and inserting and positioning the lower cup portion of a pouch cell into the hole of the first ring-shaped plate. A method for isotropically pressurizing a pouch cell, characterized in that step b) above is a step of inserting the upper cup portion of the pouch cell into the hole of the second ring-shaped plate and positioning the second ring-shaped plate such that the lower surface of the second ring-shaped plate is positioned on the upper surface of the sealing portion of the pouch cell.

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