Pressurized and airtight device for all-solid-state secondary batteries

Abstract

To provide an all-solid secondary battery pressure airtight device.SOLUTION: The present invention provides an all-solid secondary battery airtight device (1). In the secondary battery pressure airtight device (1), a secondary battery (9) is compressed under an isotropic pressure condition in a high-temperature pressurizing step for the secondary battery (9) by forming an internal space for transmitting a compression force to the secondary battery (9) while sealing the all-solid secondary battery (9) by absorbing one side in vacuum. The object of the present invention is to provide the all-solid secondary battery pressure airtight device, in which one side is vacuum-adsorbed to seal the all-solid secondary battery, and an internal space for transmitting a pressurizing force to the secondary battery is formed, so that the secondary battery is pressurized under the isotropic pressure condition during a high-temperature pressurizing process.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pressurization and airtight device for a secondary battery for all-solid-state use. More specifically, an internal space is formed on one side where vacuum adsorption is performed to seal the secondary battery for all-solid-state use while transmitting a pressing force to the secondary battery, so that the secondary battery is pressurized under isotropic pressure conditions during the high-temperature pressurization process. The present invention relates to a pressurization and airtight device for a secondary battery for all-solid-state use of a secondary battery.

Background Art

[0002] Recently, as the development of electric vehicles, energy storage batteries, robots, satellites, etc. has become full-scale, research on secondary batteries, which are high-performance batteries capable of repeated charging and discharging, has been actively conducted. Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries have attracted attention due to the advantages that they hardly cause memory effects compared to nickel-based secondary batteries, can be freely charged and discharged, have a very low self-discharge rate, and have a high energy density.

[0003] Such lithium secondary batteries mainly use a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with a positive electrode active material and a negative electrode active material, are arranged with a separator interposed therebetween, and a pouch, which is an exterior material that seals and houses the electrode assembly together with an electrolytic solution.

[0004] Among them, a secondary battery for all-solid-state use is a secondary battery in which all main materials are made of solids. By using a solid electrolyte, the risks of fire and explosion are significantly reduced, the scope of utilization is widened, and although the performance is extremely excellent, lithium metal, which could not be utilized due to the risks of fire and explosion, can be used as a negative electrode material, so that the energy density can be dramatically increased. Due to these advantages, development of secondary batteries for all-solid-state use is currently actively underway.

[0005] In such all-solid-state secondary batteries, the solid electrolyte must minimize interfacial resistance while maximizing the contact interface between the active material and the electrolyte, as ions move between the solid lattice. To achieve this, after stacking the solid electrolyte layers, a high-temperature pressurization process under isotropic conditions must be carried out via a fluid acting as a pressure transfer medium. During this process, equipment configurations such as jigs are required to ensure airtightness in order to protect the all-solid-state secondary battery from the fluid acting as a pressure transfer medium during isotropic pressurization of the secondary battery.

[0006] For this purpose, the inventors of the present invention present a novel configuration for a pressurized and airtight device for all-solid-state secondary batteries, the details of which will be described later. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Korean Published Patent No. 10-2015-0069523, "All-solid-state secondary battery and method for manufacturing an all-solid-state secondary battery" [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention was devised to solve the problems of the prior art described above, and its purpose is to provide an all-solid-state secondary battery pressurizing airtight device that seals the all-solid-state secondary battery by vacuum adsorption on one side, while simultaneously forming an internal space that transmits pressurizing force to the secondary battery, thereby ensuring that the secondary battery is pressurized under isotropic conditions during the high-temperature pressurizing process.

[0009] Furthermore, the present invention aims to provide a pressurized and airtight device for all-solid-state secondary batteries that prevents fluid inflow into the internal space by forming an adsorption portion on one side of the upper cover and the lower cover.

[0010] Furthermore, the present invention aims to provide a pressurized and airtight device for all-solid-state secondary batteries, wherein the internal space is vacuum-sealed by, for example, silicone vacuum adsorption between the upper and lower covers.

[0011] Furthermore, the present invention aims to provide a pressurized and airtight device for all-solid-state secondary batteries, which prevents overall shape deformation to the greatest extent possible when pressurized by a heat transfer oil, by forming a shape-fixing portion on one side of the upper cover and the lower cover.

[0012] Furthermore, the present invention aims to provide an all-solid-state secondary battery pressurizing and airtight device that enables contact and pressurization of both the upper and lower surfaces of a secondary battery located between them, by forming pressurizing surfaces on one side of the upper cover and the lower cover so that they face each other.

[0013] Furthermore, the present invention aims to provide a pressurized and airtight device for all-solid-state secondary batteries that has excellent heat resistance and elongation characteristics by forming a pressurized surface of silicone material. [Means for solving the problem]

[0014] To achieve the above objectives, the present invention can be realized by embodiments having the following configurations.

[0015] According to one embodiment of the present invention, the airtight pressurizing device for a solid-state secondary battery according to the present invention includes an airtight section comprising: a lower cover and an upper cover that is vacuum-adsorbed to one side of the lower cover and forms an internal space in which a solid-state secondary battery is arranged; wherein the upper cover includes a first pressurizing section that pressurizes the upper side of the secondary battery in the internal space of the airtight section; the first pressurizing section includes a first pressurizing surface that is pressurized by a fluid during the pressurizing process to pressurize the upper surface of the secondary battery in the internal space of the airtight section; and the lower cover includes a second pressurizing section that pressurizes the lower side of the secondary battery in the internal space of the airtight section; the second pressurizing section includes a second pressurizing surface that is pressurized by a fluid during the pressurizing process to pressurize the bottom surface of the secondary battery in the internal space of the airtight section.

[0016] According to another embodiment of the present invention, the upper cover in the pressurized airtight device for all-solid-state secondary batteries according to the present invention further comprises a first adsorption portion formed on the end or edge of the upper cover and adsorbed to one side of the lower cover.

[0017] According to another embodiment of the present invention, the upper cover in the pressurized airtight device for all-solid-state secondary batteries according to the present invention further comprises a first shape-fixing portion that maintains the shape of the upper cover during the pressurization process.

[0018] According to another embodiment of the present invention, the first shape fixing portion in the pressurized airtight device for all-solid-state secondary batteries according to the present invention is characterized by having a greater upper and lower thickness than the first pressurized surface.

[0019] According to another embodiment of the present invention, the pressurized airtight device for all-solid-state secondary batteries according to the present invention is characterized in that a vacuum is formed inside the airtight part by adsorption of the first adsorption part.

[0020] According to another embodiment of the present invention, the upper cover in the pressurized airtight device for all-solid-state secondary batteries according to the present invention further comprises a first detachable portion formed on one side of the upper cover, which allows the upper cover to be detached from the lower cover when pressurization is completed.

[0021] According to another embodiment of the present invention, in the first desorption part of the all-solid-state secondary battery pressurization airtight device according to the present invention, a first desorption hole extending in one direction is formed.

[0022] According to another embodiment of the present invention, the first pressurization part in the all-solid-state secondary battery pressurization airtight device according to the present invention is a groove shape formed on the upper surface of the upper cover, and further includes a first pressurization groove for pressing the first pressurization surface and the upper surface of the secondary battery in close contact.

[0023] According to another embodiment of the present invention, the first adsorption part in the all-solid-state secondary battery pressurization airtight device according to the present invention is formed in a shape with rounded edges on each side.

[0024] According to another embodiment of the present invention, the lower cover in the all-solid-state secondary battery pressurization airtight device according to the present invention further includes a second shape fixing part for maintaining the shape of the lower cover during the pressurization process, and a second adsorption part formed at the end or edge side of the lower cover and adsorbed to the first adsorption part.

[0025] According to another embodiment of the present invention, the lower cover in the all-solid-state secondary battery pressurization airtight device according to the present invention further includes a second desorption part formed at the end side of the lower cover for allowing the lower cover to be desorbed from the upper cover at the end of pressurization.

[0026] According to another embodiment of the present invention, the second pressurization part in the all-solid-state secondary battery pressurization airtight device according to the present invention is a groove shape formed on the bottom surface of the lower cover, and further includes a second pressurization groove for pressing one side of the second pressurization part and the bottom surface of the secondary battery in close contact.

[0027] According to another embodiment of the present invention, the first pressurization surface and / or the second pressurization surface in the all-solid-state secondary battery pressurization airtight device according to the present invention contains a silicone material.

[0028] According to another embodiment of the present invention, the first pressing surface and / or the second pressing surface in the all-solid-state secondary battery pressurization and airtightness device according to the present invention contain a silicone material.

[0029] According to another embodiment of the present invention, the first pressing surface and / or the second pressing surface in the all-solid-state secondary battery pressurization and airtightness device according to the present invention have a thickness of 0.5T or more and less than 1T, respectively.

Effects of the Invention

[0030] The present invention has the following effects by the above-described configuration.

[0031] The present invention has the effect of pressurizing the secondary battery under isotropic pressure conditions during the high-temperature pressurization process by forming an internal space on one side of which vacuum adsorption is performed and through which pressure is transmitted to the secondary battery while sealing the all-solid-state secondary battery.

[0032] In addition, the present invention has the effect of preventing the inflow of fluid into the internal space by forming adsorption portions on one side of the upper cover and the lower cover.

[0033] In addition, the present invention has the effect of forming a vacuum in the internal space by causing the upper cover and the lower cover to be vacuum-adsorbed, for example, with silicone.

[0034] In addition, the present invention has the effect of preventing overall shape deformation to the maximum extent when a pressing force by a heat transfer medium oil is applied by forming shape fixing portions on one side of the upper cover and the lower cover.

[0035] In addition, the present invention has the effect of making it possible to contact and pressurize both the upper surface and the bottom surface of the secondary battery located therebetween by forming the pressing surfaces on one side of the upper cover and the lower cover so as to face each other.

[0036] Furthermore, the present invention has the effect of providing excellent heat resistance and elongation characteristics by forming a pressure surface on the silicone material.

[0037] On the other hand, even effects not explicitly mentioned herein, as well as the effects described below in the specification and their provisional effects that are expected by the technical features of the present invention, shall be treated as described in the specification of the present invention. [Brief explanation of the drawing]

[0038] [Figure 1] This is a perspective view showing a pressurized and airtight device for all-solid-state secondary batteries according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view showing a pressurized and airtight device for all-solid-state secondary batteries. [Figure 3] Figure 1 is a plan view showing a pressurized and airtight device for all-solid-state secondary batteries. [Figure 4] Figure 1 is a cross-sectional view showing a pressurized and airtight device for all-solid-state secondary batteries. [Figure 5] Figure 1 is a bottom view showing the upper cover of the pressurized and airtight device for all-solid-state secondary batteries. [Figure 6] This is a reference diagram showing the results of pressurizing a secondary battery pressurized airtight device under reduced pressure when the internal space is not vacuum-sealed. [Figure 7] This table shows the physical properties of the pressure surface of a silicone material. [Figure 8] This is a cross-sectional view showing a pressurized and airtight device for all-solid-state secondary batteries according to a second embodiment of the present invention. [Figure 9] This is a reference diagram showing the pressurization results based on the hardness of the pressurized surface according to one embodiment of the present invention. [Figure 10] This is a reference diagram showing the pressurization results based on the thickness of the pressurized surface according to one embodiment of the present invention. [Modes for carrying out the invention]

[0039] Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to these embodiments, but rather as being construed in terms of the matters described in the claims. Furthermore, these embodiments are provided only as reference to further fully explain the present invention to those who are ordinary skill in the art.

[0040] As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, as used herein, “comprise” and / or “comprising” identify the presence of the shape, figure, step, action, member, element, and / or group thereof mentioned, and do not exclude the presence or addition of one or more other shapes, figures, actions, members, elements, and / or groups thereof.

[0041] In the following, when it is stated that one component (or layer) is placed on another component (or layer), it should be noted that the component may also be placed directly on the other component, or another component or layer may be interposed between them. Also, when it is stated that one component is placed directly on another component, there is no other component located between them. Furthermore, being located "on top," "above," "below," "upper side," "lower side," "one side," or "side" of a component refers to a relative positional relationship.

[0042] In the following, with reference to the attached drawings, a pressurized and airtight device 1 for all-solid-state secondary batteries according to one embodiment of the present invention will be described in detail.

[0043] Figure 1 is a perspective view showing a pressurized airtight device for all-solid-state secondary batteries, Figure 2 is an exploded perspective view showing the pressurized airtight device for all-solid-state secondary batteries according to Figure 1, Figure 3 is a plan view showing the pressurized airtight device for all-solid-state secondary batteries according to Figure 1, Figure 4 is a cross-sectional view showing the pressurized airtight device for all-solid-state secondary batteries according to Figure 1, and Figure 5 is a bottom view showing the upper cover of the pressurized airtight device for all-solid-state secondary batteries according to Figure 1.

[0044] Referring to Figures 1 to 5, the present invention relates to a pressurized airtight device 1 for all-solid-state secondary batteries, and more particularly to a secondary battery pressurized airtight device 1 that ensures that the secondary battery 9 is pressurized under isotropic conditions during a high-temperature pressurization process, by forming an internal space that transmits pressurizing force to the secondary battery 9 while sealing the all-solid-state secondary battery 9 by vacuum adsorption on one side. Such a pressurized airtight device 1 is preferably made of, for example, a silicone material, and further details therebefore will be described later.

[0045] For this purpose, the pressurized airtight device 1 may include an airtight section 10.

[0046] Referring to Figures 1 to 5, the airtight section 10 forms the outer surface of the pressurized airtight device 1. Such an airtight section 10 can be designed to ensure airtightness within its internal space, for example, a unit cell or bi-cell, but there are no other restrictions. There are also no restrictions on the shape of the airtight section 10, but as an example, it may have a polygonal planar shape with rounded edges. Furthermore, the airtight section 10 can be formed from a material having high elongation characteristics on at least one side, so that the internal secondary battery 9 can be pressurized. As an example, the airtight section 10 can be formed from a silicone material.

[0047] This configuration of the airtight section 10 prevents fluids such as heat transfer oil from penetrating the internal space of the airtight section 10 and coming into contact with the secondary battery 9 during the pressurization process. Specifically, when a fluid such as heat transfer oil flows into the vessel and a pressure above a predetermined level is transmitted to the airtight section 10, at least one side of the airtight section 10 can pressurize the secondary battery 9 located in its internal space. Therefore, the airtight section 10 can protect the secondary battery 9 from direct contact with the fluid while the high-temperature pressurization process is performed.

[0048] For this purpose, the airtight section 10 may include an upper cover 110 and a lower cover 130. For example, it is preferable that the upper cover 110 and the lower cover 130 are formed in corresponding shapes to each other to protect the secondary battery 9 from fluid. The term "internal space" refers to the fact that the upper cover 110 and the lower cover 130 can create a vacuum environment in the sealed space where the secondary battery 9 is placed. That is, the upper cover 110 and the lower cover 130 can be configured to be vacuum-adhered to each other.

[0049] The upper cover 110 is configured to be coupled to the lower cover 130 so that the all-solid-state secondary battery 9 is placed between them. For example, the upper cover 110 can cover the secondary battery 9 by coupling to or vacuum-suctioning one side of the lower cover 130. To this end, the upper cover 110 may include a first pressurizing portion 111, a first shape fixing portion 113, a first suction portion 115, and a first attachment / detachment portion 117.

[0050] The first pressurizing section 111 is configured to pressurize the upper surface of the all-solid-state secondary battery 9 within the internal space of the airtight section 10. Such a first pressurizing section 111 can be formed on one side of the upper cover 110 so as to pressurize the upper surface of the secondary battery 9. For example, the first pressurizing section 111 may be formed in a predetermined shape approximately in the center of the upper cover 110. As an example, the first pressurizing section 111 may be formed in a rectangular planar shape approximately in the center of the upper cover 110, but the scope of the present invention is not limited thereto. For this purpose, the first pressurizing section 111 may include a first pressurizing groove 1111 and a first pressurizing surface 1113.

[0051] The first pressure groove 1111 is a groove-shaped structure formed on the upper surface of the upper cover 110, allowing the upper surface of the secondary battery 9 and the first pressure surface 1113 to be in close contact and pressurized. For example, the first pressure groove 1111 may be a groove-shaped structure formed with a step downward on one side of the upper cover 110, and the scope of the present invention is not limited by specific examples. Furthermore, the first pressure groove 1111 may be formed with a step downward, for example, so that when a pressure above a predetermined level is applied to the upper cover 110, the pressure can be easily transmitted to the upper surface of the secondary battery 9, and the first pressure surface 1113 may be formed to be relatively thinner than the surrounding structure such as the first shape fixing part 113. Therefore, the first pressure surface 1113 can be in close contact with the secondary battery 9 located in the internal space of the airtight part 10 and easily transmit the applied pressure.

[0052] The first pressurizing surface 1113 is pressurized by a fluid such as a heat transfer oil during the process, so that the upper surface of the secondary battery 9 in the internal space of the airtight part 10 is pressurized. For example, the first pressurizing surface 1113 is formed to face the second pressurizing surface 1313 of the lower cover 130, which will be described later, so that the upper and bottom surfaces of the secondary battery 9 located between them can be pressurized. Furthermore, it is preferable that the opposing surfaces of the pair of pressurizing surfaces 1113 and 1313 are formed substantially flat so that the secondary battery 9 is pressed in close contact with the upper and lower parts under isotropic pressurization conditions. As mentioned above, it is preferable that the first pressurizing surface 1113 has a thinner upper and lower thickness than the first shape fixing part 113. A specific explanation of the upper and lower thickness of the first pressurizing surface 113 will be given later.

[0053] The first shape-fixing portion 113 is formed between the first pressurizing portion 111 and the first suction portion 115, and can maintain the shape of the upper cover 110 during the pressurizing process. There are no restrictions on the shape of such a first shape-fixing portion 113, but as an example, it may have a rectangular frame-like planar shape with rounded edges. For example, the first shape-fixing portion 113 is formed to face the second shape-fixing portion 133 of the lower cover 130, and can maintain the shape of the airtight portion 10 during the pressurizing process. More specifically, the pair of shape-fixing portions 113 and 133 are formed in a frame shape along the outside of the pressurizing portions 111 and 131 in order to maintain the shape of the airtight portion 10, and even if the pressurizing portions 111 and 131 deform during vacuum suction of the upper cover 110 and the lower cover 130 or during the high-temperature pressurizing process, deformation of the outer structure of the pressurizing portions 111 and 131 can be prevented as much as possible. Therefore, it is preferable that the first shape fixing portion 113 has a larger vertical thickness than the first pressurizing portion 111 and / or the first suction portion 115 described later.

[0054] The first suction portion 115 is formed on one side of the upper cover 110, for example, on the end or edge side, and is configured to create a vacuum in the internal space of the airtight portion 10 by vacuum suction with the second suction portion 135, or conversely, to release the vacuum. Such a first suction portion 115 is formed in a polygonal planar shape with rounded edges along the outside of the first shape fixing portion 113, and can be vacuum-suctioned with the second suction portion 135 during the pressurization process for the secondary battery 9 so that a vacuum environment is created in the internal space of the airtight portion 10. In this case, it is preferable that the first suction portion 115 is formed with rounded edges in order to ensure maximum airtightness to the internal space of the airtight portion 10 under isotropic pressurization conditions using a heat transfer oil.

[0055] For example, if the first adsorption portion 115 and the second adsorption portion 135 are formed in a polygonal frame shape such as a square frame, even if the adsorption portions 115 and 135 are vacuum-adsorbed to each other, the airtightness will inevitably be lower compared to the embodiment of the present invention. It is preferable that the first adsorption portion 115 is formed of a silicone material and is vacuum-adsorbed to the first adsorption portion 135 by silicone. The above-mentioned "vacuum environment" can mean an environment having a pressure value lower than atmospheric pressure.

[0056] Furthermore, the first suction portion 115 is preferably formed to be inclined toward the end side of the adjacent upper cover 110, and more preferably formed to be inclined downward toward the end side of the upper cover 110. For example, the first suction portion 115 can be formed with a cross-sectional shape that becomes more inclined from the end side of the adjacent first shape fixing portion 113 toward the end side of the adjacent upper cover 110. More specifically, the pair of suction portions 115 and 135 can be inclined to converge toward each other toward the end side of the adjacent airtight portion 10 in order to ensure airtightness of the internal space of the airtight portion 10 and to facilitate vacuum suction between them. Such a first suction portion 115 is vacuum-adsorbed with the second suction portion 135. At this time, the upper and bottom surfaces of the secondary battery 9 placed in the internal space of the airtight portion 10 can be in contact with the respective pressure surfaces 1113 and 1313, or at least partially in contact with them, but there are no other restrictions.

[0057] The first detachable portion 117 is formed on one side of the upper cover 110 and is configured to allow the upper cover 110 to be detached from the lower cover 130 at the end of the pressurizing process. For example, the first detachable portion 117 can be formed on both ends of the upper cover 110 and used together with the second detachable portion 137 at the end of the pressurizing process to separate both covers 110 and 130. Specifically, the first detachable portion 117 can be formed on the side of the lower cover 130 that overlaps vertically with the second detachable portion 137.

[0058] Furthermore, the first detachment section 117 has a first detachment hole 1171 on one side, and the upper cover 110 and the lower cover 130 can be separated from each other by utilizing the first detachment hole 1171 when pressurization ends. For example, the upper cover 110 and the lower cover 130 can be separated when pressurization ends by utilizing the first detachment hole 1171 of the first detachment section 117 and the second detachment hole 1371 of the second detachment section 137. As an example, the upper cover 110 and the lower cover 130 can be vacuum-suctioned by inserting a detachment means into the first detachment hole 1171 and the second detachment hole 1371. Here, "detachment means" refers to a means such as a pin or bolt configuration that is inserted into a detachment hole to release the vacuum from an airtight device. Alternatively, the worker can manually separate both covers 110 and 130 using the first and second detachment holes 1171 and 1371, and the present invention is not limited by any particular example. The first and second detachment holes 1171 and 1371 described above may both extend horizontally or vertically, but the scope of the present invention is not limited thereto, and they may be through holes of any shape, and in some cases may be formed in a groove shape.

[0059] Referring to Figures 1 to 5, the lower cover 130 is configured to be coupled with the upper cover 110 so that the all-solid-state secondary battery 9 is positioned between them. For example, the lower cover 130 can be coupled to one side of the upper cover 110 to cover the secondary battery 9. The lower cover 130 is symmetrical to the upper cover 110 along the x-axis (or horizontal plane) and includes substantially the same configuration, however, it should be noted that at least one of the second pressurizing portion 131, the second shape fixing portion 133, the second adsorption portion 135, and the second detachment portion 137 may be omitted in some cases.

[0060] For this purpose, the lower cover 130 may include a second pressurizing portion 131, a second shape fixing portion 133, a second suction portion 135, and a second detachable portion 137.

[0061] The second pressurizing section 131 is configured to pressurize the bottom surface of the all-solid-state secondary battery 9 within the internal space of the airtight section 10. Such a second pressurizing section 131 can be formed on one side of the lower cover 130 so as to pressurize the bottom surface of the secondary battery 9. For example, it is preferable that the second pressurizing section 131 is formed in a predetermined shape approximately in the center of the lower cover 130 and is formed in a shape corresponding to the first pressurizing section 111. Such a second pressurizing section 131 may include a second pressurizing groove 1311 and a second pressurizing surface 1313.

[0062] The second pressure groove 1311 is a groove-shaped structure formed on the bottom surface of the lower cover 110, allowing the bottom surface of the secondary battery 9 and the second pressure surface 1113 to be in close contact and pressurized. For example, the second pressure groove 1311 may be a groove-shaped structure formed with a step on one side of the lower cover 130, and the scope of the present invention is not limited by specific examples. Furthermore, when a pressure above a predetermined level is applied to the lower cover 130, the second pressure groove 1311 can be formed with a step upward, for example, so that the pressure is easily transmitted to the bottom surface of the secondary battery 9, thereby allowing the second pressure surface 1313 to be formed relatively thinner than the surrounding structure such as the second shape fixing part 133. Thus, the second pressure surface 1313 can be in close contact with the secondary battery 9 located in the internal space of the airtight part 10 and easily transmit the applied pressure.

[0063] The second pressurizing surface 1313 is a planar structure that is pressurized by a fluid such as a heat transfer oil during the process, so that the bottom surface of the secondary battery 9 in the internal space of the airtight part 10 is pressurized. For example, the second pressurizing part 1313 can be formed to face the first pressurizing surface 1113 of the upper cover 110 described above, and can be configured to contact and pressurize both the top and bottom surfaces of the secondary battery 9. It is preferable that such a second pressurizing surface 1313 has a thinner vertical thickness compared to the second shape fixing part 133.

[0064] The second shape-fixing portion 133 is formed between the second pressurizing portion 131 and the second suction portion 135, and can maintain the shape of the lower cover 130 during the pressurizing process. There are no restrictions on the shape of such a second shape-fixing portion 133, but as an example, it may have a rectangular frame-like planar shape. The second shape-fixing portion 133 is formed to face the first shape-fixing portion 113 of the upper cover 110, and can maintain the shape of the lower cover 130 during the pressurizing process. With such a second shape-fixing portion 133, even if the shape of the second pressurizing portion 131 is slightly deformed by the pressurizing force from a fluid such as a heat transfer oil, deformation of the shape of its outer structure can be prevented. Therefore, it is preferable that the second shape-fixing portion 133 has a larger vertical thickness than the second pressurizing portion 131 and / or the second suction portion 135 described later. It is preferable that the second shape-fixing portion 133 is formed to be substantially the same shape as the first shape-fixing portion 113, but the scope of the present invention is not limited thereto.

[0065] The second suction portion 135 is formed on one side of the lower cover 130, for example, on the end or edge side, and is configured to create a vacuum in the internal space of the airtight portion 10 or, conversely, release the vacuum by being vacuum-adsorbed together with the first suction portion 115. Such a second suction portion 135 can be formed in a polygonal planar shape with each edge side rounded along the outside of the second shape fixing portion 133. In this case, it is preferable that the second suction portion 135 is formed with each edge side rounded in order to ensure maximum airtightness to the internal space of the airtight portion 10 under isotropic pressure conditions with heat transfer oil.

[0066] Furthermore, the second suction portion 135 is preferably formed to be inclined toward the end side of the lower cover 130, and more preferably formed to be inclined upward toward the end side of the lower cover 130. For example, the second suction portion 135 can be formed with a cross-sectional shape that is inclined toward the end side of the lower cover 130 from the outside of the second shape fixing portion 133. Such a second suction portion 135 is vacuum-adsorbed to the first suction portion 115, and at this time, the upper and bottom surfaces of the secondary battery 9 placed in the internal space of the airtight portion 10 can maintain a state of contact with the respective pressurized surfaces 1113 and 1313, or at least partially in contact with them. Furthermore, the second suction portion 135 is preferably formed of a silicone material.

[0067] Generally, when performing a high-temperature pressurization process on an all-solid-state secondary battery 9, if air remains inside the airtight section 10, defects are inevitable in the resulting product. In other words, the residual air prevents the isotropic pressure conditions from being met for the internal secondary battery 9. For this reason, the pressurized airtight device 1 according to one embodiment of the present invention can create a vacuum in the internal space through upper and lower vacuum suction between the upper cover 110 and the lower cover 130.

[0068] Figure 6 is a reference diagram showing the results of pressurizing a secondary battery pressurized airtight device under reduced pressure when the internal space is not vacuum-sealed.

[0069] Vacuum adsorption Referring to Figures 1 to 5, the first adsorption portion 115 and the second adsorption portion 135 have corresponding shapes that adsorb from above and below, and vacuum adsorption is performed on the end side and / or internal space of the airtight portion 10 so that the secondary battery 9 is pressurized. More specifically, the pair of adsorption portions 115 and 135 can be formed so that they converge towards the end side of the first adsorption portion 115 or the end side of the upper cover 110 as they move from the outside of the second shape fixing portion 133 towards the end side of the lower cover 130, in order to ensure the airtightness of the internal space of the airtight portion 10. Such a pair of adsorption portions 115 and 135 are formed in a polygonal planar shape with rounded edges along the outside of the shape fixing portions 113 and 135, and a vacuum environment can be created in the internal space of the airtight portion 10 during the pressurization process for the secondary battery 9. At this time, the top and bottom surfaces of the secondary battery 9 placed in the internal space of the airtight portion 10 can maintain a state of contact with or at least partial contact with the respective pressurized surfaces 1113 and 1313.

[0070] Referring to Figure 6, after placing the secondary battery 9 in the internal space of the airtight section 10, a pressurization process is performed using a heat transfer oil or water under conditions of maintaining a pressure of 2000 bar for 1 minute in a room temperature environment. As mentioned above, Figure 6 shows the results of pressurized paper under reduced pressure when the internal space is not vacuum-formed.

[0071] At this time, pressurization of the secondary battery 9 can be confirmed, but air bubbles are generated due to the inflow of air into the internal space, which inevitably causes deformation of the pressurized surfaces 1113 and 1313. Furthermore, it can be seen that the uniformity of the pressurization results is low.Therefore, in order to prevent such problems, a separate vacuum means that communicates with the outside can be provided, but the pressurized airtight device 1 according to one embodiment of the present invention performs the pressurization process via upper and lower vacuum suction between the upper cover 110 and the lower cover 130.

[0072] Figure 7 is a table showing the physical properties of the pressure surface of the silicone material.

[0073] Material of pressure surfaces 1113 and 1313 Generally, when applying high temperature and pressure to a solid-state secondary battery 9, the process is carried out in an environment with a pressure of 7000 bar, preferably at a temperature of approximately 100°C or higher, and more preferably at a maximum of approximately 200°C or higher. Furthermore, since the pressurization process according to one embodiment of the present invention is carried out in an environment of approximately 200°C, it is preferable to use a heat transfer oil rather than water, but the process is not limited to this.

[0074] Therefore, the pressurizing surfaces 1113 and 1313, which contact the top and bottom surfaces of the secondary battery 9 and are subjected to pressure, require a material with high elongation characteristics so that pressure is applied to all surfaces of the secondary battery 9, due to the isotropic pressure characteristics in which pressure is applied to the secondary battery 9 in all directions. Generally, film materials such as PTFE (Polytetrafuoroethylene), PEEK (Polyether ether ketone), and PI (Polyimides), which are used in the pressurizing process, have high heat resistance and oil resistance, but their elongation characteristics are relatively low, and there is no way to compensate for this, making them difficult to use as pressurizing materials. In this case, elongation characteristics refer to the stretched state, and in one embodiment of the present invention, it refers to the property of the pressurizing material to adhere closely to the outer shape of the object to be pressed, as well as the property of having restorative force for repeated use.

[0075] The pressure surfaces 1113 and 1313 in one embodiment of the present invention are preferably made of a silicone material having high elongation characteristics. Here, the "silicone" material refers to a pressure material selected to satisfy the elongation characteristics and heat resistance of rubber material, while supplementing its weakness in oil resistance with a specially specified silicone.

[0076] Referring to Figure 7, the comparison table is a reference diagram showing the physical properties of steam-resistant silicone (KCC SILICONE; SH6070U), heat-resistant silicone (KCC SILICONE; SH9161U), and fluorosilicone (KCC SILICONE; FQE205) from left to right. The pressurized surfaces 1113 and 1313 according to one embodiment of the present invention can be made of steam-resistant silicone, heat-resistant silicone, or fluorosilicone, and among these, fluorosilicone is preferred, but the scope of the present invention is not limited thereto. Details regarding the selection of the fluorosilicone pressurized material are described below.

[0077] The test is conducted under the conditions of 150°C, a holding time of 70 hours, and IRM 903 oil (ASTM Oil TEST Reference Oil). Based on the test results, the fluorosilicone that exhibits the best performance in terms of oil resistance, which is a weakness of silicone materials, is selected, taking into account properties such as volume change, hardness change, tensile strength change, and elongation change of the special specification silicone material. However, if water or other fluids other than heat transfer oil are used as the pressure transmission medium during the pressurization process, it is not necessary to limit the pressurized surfaces 1113 and 1313 in the embodiment of the present invention to fluorosilicone.

[0078] Figure 8 is a cross-sectional view showing a pressurized and airtight device for all-solid-state secondary batteries according to a second embodiment of the present invention.

[0079] As a second embodiment, referring to Figure 8, the shape-fixing parts 213 and 233 are formed between the pressurizing parts 211 and 231 and the adsorption parts 215 and 235, which will be described later, and the shape of the airtight part 20 can be maintained during the pressurizing process. There are no restrictions on the shape of such shape-fixing parts 213 and 233, but as an example, they can have a rectangular frame-like planar shape. For example, the first shape-fixing part 213 is formed to face the second shape-fixing part 233 of the lower cover 230, and the shape of the upper cover 210 can be maintained during the pressurizing process. More specifically, the pair of shape-fixing parts 213 and 233 are formed in a frame shape along the outside of the pressurizing parts 211 and 231 in order to maintain the shape of the upper cover 210 and the lower cover 230, and the outer structure of the pressurizing parts 211 and 231 can be prevented from deforming during the high-temperature pressurizing process.

[0080] Furthermore, the shape-fixing portions 213 and 233 can be formed to overlap vertically with the adsorption portions 215 and 235 in order to enhance the maintenance of the shape of the airtight portion 20. For example, the shape-fixing portions 213 and 233 can extend to the end side of the adsorption portions 215 and 235 with substantially the same vertical thickness, thereby enhancing the prevention of deformation of the airtight portion 20 due to surface pressure during the pressurizing process. With such shape-fixing portions 213 and 233, the shape of the pressurizing portions 211 and 231 will deform due to the pressure applied by the heat transfer oil, but deformation of the shape of their outer structure can be prevented. Therefore, it is preferable that the shape-fixing portions 213 and 233 and the adsorption portions 215 and 235 have a larger vertical thickness than the pressurizing portions 211 and 231.

[0081] The suction parts 215 and 235 are suction pads formed on one side of the airtight part 20 when the upper cover 210 and the lower cover 230 are joined together. This configuration allows for the formation or release of a vacuum in the internal space of the airtight part 20 by blocking not only the end side of the airtight part 20 but also the internal space communicating with the shape fixing parts 213 and 233.

[0082] More specifically, the pair of suction parts 215 and 235 can be formed so that they converge towards each other from the outside of the shape-fixing parts 213 and 233 towards the end of the upper cover 210 in order to create a vacuum in the internal space of the airtight part 20. At this time, the opposing surfaces of the suction parts 215 and 235 are pressed together so that they come into contact with each other, and the end sides of the upper cover 210 and the lower cover 230 can be vacuum-adsorbed.

[0083] Furthermore, the adsorption portions 215 and 235 are formed with a flat central side of their internal space, and one side of the adsorption portions 215 and 235 has a cross-sectional shape that slopes from the central side towards the end of the airtight portion 10, thereby blocking the inflow of fluid (e.g., water) during the pressurizing process and ensuring the airtightness of the airtight portion 20. Also, the other side of the adsorption portions 215 and 235 has a cross-sectional shape that slopes from the central side towards the shape-fixing portions 213 and 233, thereby strengthening the airtightness of the airtight portion 20 when the upper cover 210 and the lower cover 230 are adsorbed vertically.

[0084] Therefore, when performing the pressurization process, it is possible to prevent fluids such as heat transfer oil from penetrating into the internal space of the airtight section 20 and coming into contact with the secondary battery 9. For example, by vacuum adsorption between the upper cover 210 and the lower cover 230, which are made of silicone material, it is possible to prevent heat transfer oil and the like from flowing into the internal space of the adsorption sections 215, 235, the shape fixing sections 213, 233 and the pressurization sections 211, 231 and coming into contact with the secondary battery 9.

[0085] Specifically, when a fluid such as heat transfer oil flows into the vessel and a pressure above a predetermined level is transmitted to the airtight section 20, the pressurizing sections 211 and 231 of the airtight section 20 can pressurize the secondary battery 9 located in the internal space. At this time, the airtight section 20 can perform the high-temperature pressurizing process while protecting the secondary battery 9 from direct contact with the heat transfer oil in the internal space.

[0086] Figure 9 is a reference diagram showing the pressurization results based on the hardness of the pressurized surface according to one embodiment of the present invention.

[0087] Hardness of pressure surfaces 1113 and 1313 Referring to Figure 9, in a pressurizing device with pressurizing surfaces having different hardnesses, vacuum paper 3EA is placed in the internal space of the airtight section 10, and graphite-treated copper foil is placed on the uppermost and lowermost sides of the vacuum paper. The molding silicone constituting the pressurizing surfaces 1113 and 1313 is formed in two types: hardness 5 (Comparative Example 1, Figure 9(a)) and hardness 20 (Comparative Example 2, Figure 9(b)).

[0088] Subsequently, a pressurization process was performed using water under conditions of maintaining a pressure of 2000 bar for 1 minute at room temperature. Upon examination of the results, a significantly increased pressurization rate was observed compared to Comparative Examples 1 and 2. Therefore, it can be seen that a lower silicone hardness value on the pressurized surface is advantageous for the pressurization process.

[0089] Figure 10 is a reference diagram showing the pressurization results based on the thickness of the pressurized surface according to one embodiment of the present invention.

[0090] Thickness of pressure surfaces 1113, 1313 Referring to Figure 10, the pressure surfaces made of silicone were set to thicknesses of 0.5T, 1T, and 2T, and a pressurization process was carried out using water under conditions of maintaining a pressure of 2000 bar for 1 minute in a room temperature environment. At this time, the configuration of the pressure surfaces 1113 and 1313 was substantially the same as described above, and vacuum paper 5EA was placed in the internal space of the airtight section 10.

[0091] The pressurization process revealed that the pressurization results and pressurization uniformity were significantly increased at the 0.5T pressurization surfaces 1113 and 1313. Furthermore, while the pressurization results were similar at the 1T pressurization surfaces 1113 and 1313 and the 2T pressurization surfaces 1113 and 1313, the 1T pressurization surfaces 1113 and 1313 exhibited higher pressurization uniformity.

[0092] This shows that the thinner the thickness of the pressure surfaces 1113 and 1313, the more uniform the results of higher pressure application. Therefore, the pressure surfaces 1113 and 1313 in the present invention are preferably about 1T or less in thickness, and preferably 0.5T or more and less than 1T.

[0093] The above detailed description is illustrative of the present invention. Furthermore, the foregoing describes preferred embodiments of the present invention, and the present invention can be used in a variety of different combinations, modifications, and environments. That is, modifications and alterations are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the disclosed content, and / or within the scope of the art or knowledge of the art. The embodiments described herein describe the best possible state for realizing the technical idea of ​​the present invention, and various modifications are possible as required in the specific field of application and use of the present invention. Therefore, the above detailed description of the invention is not intended to limit the present invention to the disclosed embodiments. [Explanation of Symbols]

[0094] 1. Pressurized and airtight device for all-solid-state secondary batteries 10 Airtight parts 110 Top cover 111 First pressurization section 1111 First pressure groove 1113 First pressure surface 113 1st shape fixing part 115 1st suction part 117 1st detachment section 1171 1st detachment hole 130 Lower cover 131 Second pressurization section 1311 Second pressure groove 1313 Second pressure surface 133 Second shape fixing part 135 2nd suction part 137 Second detachment section 1371 2nd detachment hole 9 All-solid-state secondary battery

Claims

1. An airtight section comprising a lower cover and an upper cover that is vacuum-adhered to one side of the lower cover and forms an internal space in which an all-solid-state secondary battery is arranged; The aforementioned upper cover is It includes a first pressurizing section that pressurizes the upper side of the secondary battery in the internal space of the airtight section, The first pressurizing section is, A first pressurizing surface is included, which is pressurized by a fluid during the pressurizing process so that the upper surface of the secondary battery in the internal space of the airtight part is pressurized; The aforementioned lower cover is A second pressurizing section is included, which causes the lower side of the secondary battery in the internal space of the airtight section to be pressurized; The second pressurizing section is, A pressurized and airtight device for all-solid-state secondary batteries, characterized by including a second pressurizing surface which is pressurized by a fluid during the pressurizing process so that the bottom surface of the secondary battery in the internal space of the airtight section is pressurized.

2. The aforementioned upper cover is The all-solid-state secondary battery pressurized airtight device according to claim 1, further comprising: a first adsorption portion formed on the end or edge of the upper cover and adsorbed to one side of the lower cover.

3. The aforementioned upper cover is The all-solid-state secondary battery pressurized airtight device according to claim 2, further comprising a first shape fixing part for maintaining the shape of the upper cover during the pressurizing process.

4. The all-solid-state secondary battery pressurized airtight device according to claim 3, characterized in that the first shape fixing portion has a greater upper and lower thickness than the first pressurizing surface.

5. The all-solid-state secondary battery pressurized airtight device according to claim 2, characterized in that a vacuum is formed in the internal space of the airtight part by the adsorption of the first adsorption part.

6. The aforementioned upper cover is The all-solid-state secondary battery pressurized airtight device according to claim 2, further comprising: a first detachable portion formed on one side of the upper cover, which allows the upper cover to be detached from the lower cover when pressurization is completed;

7. The pressurized and airtight device for all-solid-state secondary batteries according to claim 6, characterized in that the first attachment / detachment portion has a first attachment / detachment hole extending in one direction.

8. The first pressurizing section is, The all-solid-state secondary battery pressurizing and airtight device according to claim 1, further comprising: a groove-shaped first pressurizing groove formed on the upper surface of the upper cover, which causes the first pressurizing surface and the upper surface of the secondary battery to be in close contact and pressurized.

9. The pressurized and airtight device for all-solid-state secondary batteries according to claim 2, characterized in that the first adsorption portion is formed with rounded edges.

10. The aforementioned lower cover is A second shape-fixing part that maintains the shape of the lower cover during the pressurizing process; The all-solid-state secondary battery pressurized airtight device according to claim 2, further comprising: a second adsorption portion formed on the end or edge side of the lower cover and adsorbed by the first adsorption portion;

11. The aforementioned lower cover is The all-solid-state secondary battery pressurized airtight device according to claim 6, further comprising: a second detachable portion formed on the end side of the lower cover, which allows the lower cover to be detached from the upper cover when pressurization is completed;

12. The second pressurizing section is, The all-solid-state secondary battery pressurizing airtight device according to claim 1, further comprising: a groove-shaped second pressurizing groove formed on the bottom surface of the lower cover, which causes one side of the second pressurizing section and the bottom surface of the secondary battery to be in close contact and pressurized.

13. The all-solid-state secondary battery pressurized airtight device according to claim 1, characterized in that the first pressurizing surface and / or the second pressurizing surface include a silicone material.

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