Sealing device, battery shell component and single battery

Abstract

The utility model provides a sealing device, a battery shell component and a single battery, and mainly solves the problem that the performance of a high-capacity battery is influenced due to the fact that an opening hole of an existing sealing assembly cannot be opened or the opening hole is not completely opened. The sealing device comprises a dissolving sheet and an isolating layer attached to the dissolving sheet, the dissolving sheet is made of an electrolyte soluble material; the isolating layer is made of solid alkane or solid halogenated alkane which is insoluble in electrolyte, and the solid alkane or the solid halogenated alkane is attached to the end face of the dissolving sheet and forms an integrated sheet structure with the dissolving sheet. The isolating layer is supported by the dissolving sheet, the isolating layer has no strength, the strength of the whole sealing device is realized by the dissolving sheet, the dissolving sheet is dissolved by an external electrolyte during unpacking, the isolating layer is very easy to break after the isolating layer loses the support of the dissolving sheet, and the open pore on the battery shell component is opened after the isolating layer is broken, so that the effectiveness of unpacking the single battery is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a sealing device, a battery casing component, and a single battery cell. Background Technology

[0002] Currently, large-capacity batteries (also known as battery modules or battery packs) are created by connecting multiple individual cells in parallel or series. However, the individual cells in existing large-capacity batteries have inherent differences. Due to the "weakest link" effect, the performance of the weakest cell often affects the overall capacity, significantly limiting the maximum capacity and cycle life of the large-capacity battery. Therefore, improving the uniformity of individual cells in large-capacity batteries has become a key focus and challenge in this field.

[0003] To address the aforementioned issues, Chinese patent CN220324596U discloses a high-capacity battery. This type of high-capacity battery includes a casing and multiple individual cells connected in parallel and arranged within the casing's inner cavity. The casing has a shared chamber (which is an electrolyte shared chamber and / or a gas shared chamber) that communicates with the inner cavities of each individual cell. The electrolyte and / or gas within each individual cell are connected through the electrolyte shared chamber and / or gas shared chamber, ensuring that the electrolyte and / or gas in all individual cells are within the same system. This reduces the differences between individual cells, improves the consistency between them to some extent, and thus enhances the cycle life of the high-capacity battery.

[0004] Typically, communication between the shared chamber and the internal cavities of all individual cells can be achieved by opening the sealing assembly located at the opening in the battery casing. Specifically, the sealing assembly can be opened using external force or external electrolyte to complete the unpacking. The sealing assembly can be a sealing membrane that is soluble in electrolyte, as disclosed in Chinese Patent CN218525645U.

[0005] While the aforementioned patent discloses that the sealing assembly consists of a dissolving sheet and a protective film, with the protective film located on the side of the dissolving sheet facing the inside of the battery casing, and that the protective film detaches after the dissolving sheet dissolves in the electrolyte, in actual use, after the dissolving sheet dissolves in the electrolyte, the protective film may remain at the opening position of the battery casing, making it difficult to detach. This can result in situations where the opening cannot be opened or is not fully opened, leading to a mismatch between the electrolyte environment of some individual cells and that of the others, affecting the sharing effect and ultimately impacting the performance of high-capacity batteries. Summary of the Invention

[0006] To address the problem that existing sealing components sometimes fail to open the opening or the opening is not fully opened during use, thus affecting the performance of high-capacity batteries, this utility model provides a sealing device, a battery casing component, and a single battery cell.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows:

[0008] A sealing device is provided for sealing openings in a battery casing component. The sealing device includes a dissolving sheet and an insulating layer attached to the dissolving sheet. The dissolving sheet is made of an electrolyte-soluble material. The insulating layer is made of a solid alkane or a solid haloalkane that is insoluble in the electrolyte. The solid alkane or solid haloalkane is attached to the end face of the dissolving sheet, forming an integral sheet structure with the dissolving sheet. When the dissolving sheet is dissolved by the electrolyte, the insulating layer loses its support and ruptures.

[0009] Furthermore, the end face of the dissolving sheet attached to the isolation layer has a groove or a protrusion, the height of which is less than the thickness of the isolation layer.

[0010] Furthermore, the end face of the dissolving sheet away from the isolation layer is provided with a first chamfer.

[0011] Furthermore, the insulating layer is a paraffin layer.

[0012] Furthermore, the material of the dissolving sheet is PS, PMMA, SMMA, TPU, ABS, PA6, PA12 or PVC.

[0013] Furthermore, an isolation layer is attached to the circumferential sidewall of the dissolving sheet.

[0014] Furthermore, the thickness of the isolation layer is 1 nm to 0.5 mm, and the thickness of the dissolution sheet is 1 to 3 mm.

[0015] Furthermore, the thickness of the isolation layer is 0.1 mm to 2 mm, the melting point is 45 to 80 °C, and the thickness of the melting sheet is 1 to 3 mm.

[0016] This utility model also provides a battery housing component, on which an opening is formed that penetrates the inner cavity of the battery housing. The opening is provided with the aforementioned sealing device, which seals the opening, and the end face of the dissolving sheet with the isolation layer faces the inner cavity of the battery housing.

[0017] Furthermore, the opening is a stepped through hole, with the large hole located on the outer surface of the battery casing component. The sealing device is embedded in the large hole of the stepped through hole, and the inner wall of the large hole is provided with a second chamfer. The first chamfer and the second chamfer form an annular groove coated with sealant.

[0018] This utility model also provides a single battery cell, including the aforementioned battery casing component.

[0019] Compared with the prior art, the beneficial effects of this utility model's technical solution are as follows:

[0020] 1. The sealing device provided by this utility model includes a dissolving sheet and an insulating layer attached to the dissolving sheet. This utility model uses a chemically stable solid alkane or solid haloalkane that is insoluble in the electrolyte to make the insulating layer, enabling the insulating layer to effectively isolate the electrolyte inside the battery casing from the dissolving sheet. Simultaneously, the solid alkane or solid haloalkane forming the insulating layer itself lacks chemical bonding strength, relying on intermolecular forces for strength; it is brittle and hard. After being attached to the dissolving sheet, the insulating layer is supported by the dissolving sheet, and the insulating layer itself has no strength. Upon opening the package, the dissolving sheet dissolves in the external electrolyte. The insulating layer, losing the support of the dissolving sheet, breaks directly, shattering into multiple pieces that fall into the electrolyte. At this time, the opening on the battery casing component is opened. Therefore, this sealing device can reliably and promptly open the opening upon opening the package, ensuring the effectiveness of opening the individual battery.

[0021] 2. In the sealing device of this utility model, the end face of the dissolving sheet coated with the isolation layer has a groove or a protrusion. The groove or protrusion improves the bonding strength between the dissolving sheet and the isolation layer, and further enhances the reliability of the entire sealing device.

[0022] 3. In the sealing device of this utility model, a first chamfer is processed on the end face of the dissolving sheet away from the isolation layer, and a second chamfer is processed on the large hole of the battery housing component. The first chamfer and the second chamfer can form an annular groove for filling with sealant. This annular groove not only facilitates the application of sealant, but also makes the connection between the dissolving sheet and the battery housing component more reliable, and the sealing performance of the dissolving sheet for the opening is also better.

[0023] 4. In the sealing device of this utility model, the solid alkane is one of alkane, cycloalkanes, and aromatic hydrocarbons. Specifically, paraffin wax can be used. The paraffin wax layer is relatively simple to make, and the paraffin wax layer is very easy to break after the dissolving sheet is dissolved, and the breakage has no effect on the electrolyte.

[0024] 5. In the sealing device of this utility model, an isolation layer is also provided on the circumferential sidewall of the dissolving sheet. This arrangement can prevent the electrolyte in the battery casing from seeping into the gap between the dissolving sheet and the opening, thereby improving the safety of the sealing device during use.

[0025] 6. In the sealing device of this utility model, the thickness of the isolation layer is 1nm to 0.5mm, and the thickness of the dissolving sheet is 1 to 3mm. The isolation layer and dissolving sheet of this thickness can reliably seal the individual battery before opening the package, and at the same time, can also ensure that the sealing device can reliably open the opening when opening the package.

[0026] 7. In the battery casing component of this utility model, the opening is a stepped through hole, with the large hole located on the outer surface of the battery casing component. The sealing device is embedded in the large hole of the stepped through hole. This arrangement can facilitate the sealing device to be sealed and installed in the opening of the battery casing. At the same time, after the sealing device is embedded in the large hole of the stepped through hole, the outer surface of the casing of the single battery can be made relatively flat, improving the structural regularity of the single battery and facilitating the storage and transportation of the single battery.

[0027] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the sealing device on the lower cover of a single battery cell in Example 1;

[0029] Figure 2 This is an exploded view of the sealing device on the lower cover of the single battery cell in Example 1;

[0030] Figure 3 This is a schematic diagram of the sealing device in Example 1;

[0031] Figure 4 This is a schematic diagram of the sealing device (with a groove) in Example 1;

[0032] Figure 5 This is a schematic diagram of the sealing device (with protrusions) in Example 1;

[0033] Figure 6 This is a schematic diagram of the sealing device on the upper cover plate in Example 2;

[0034] Figure 7 This is a schematic diagram of the lower cover plate having multiple sealing devices in Example 2;

[0035] Figure 8 This is a cross-sectional view of the sealing device on the lower cover plate in Example 2;

[0036] Figure 9 This is a schematic diagram of the structure of the dissolving sheet with the first chamfer in Example 2;

[0037] Figure 10 This is a schematic diagram of the assembly of a single cell into a large-capacity battery in Example 3.

[0038] Reference numerals: 1-Single cell, 2-Sealing device, 3-Outer shell, 4-Electrolyte sharing chamber, 5-Gas sharing chamber, 11-Upper cover plate, 12-Lower cover plate, 13-Cylinder body, 14-Opening, 15-Polar terminal, 16-Second chamfer, 21-Dissolving sheet, 22-Separating layer, 23-Groove, 24-Protrusion, 25-First chamfer. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] In the description of this utility model, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] This utility model provides a sealing device for fixing to a battery housing component and sealing an opening that communicates with the inner cavity of the battery housing. At the same time, the sealing device can also open the opening under the action of external electrolyte to realize the opening of a single battery cell.

[0043] It should be noted that:

[0044] 1. The single-cell battery described herein is a prismatic battery, which includes an upper cover plate, a lower cover plate, a cylindrical body, a cell assembly, and an electrolyte; the upper or lower cover plate and the cylindrical body can be integrally formed. The upper cover plate, the cylindrical body, and the lower cover plate constitute the battery casing, and the cell assembly and electrolyte are located inside the battery casing. The cell assembly here can be referred to as an electrode assembly, which consists of a positive electrode, a separator, and a negative electrode arranged in sequence, assembled using a stacking or winding process. The cell assembly here can also be a commercially available prismatic battery with through holes.

[0045] 2. The battery casing component here can be the battery casing of a single battery cell, or it can be a part of the battery casing structure, such as at least one of the upper cover plate, lower cover plate, or cylinder.

[0046] This utility model also provides a battery casing component having the above-mentioned sealing device.

[0047] This utility model also discloses a single battery having the above-mentioned battery casing component. An opening penetrating the inner cavity of the battery casing is made on the battery casing component, and a sealing device is fixed at the opening to seal the opening. Under the action of the external electrolyte (the electrolyte located outside the battery casing), the sealing device dissolves and falls off, opening the opening and realizing the opening of the single battery.

[0048] It should be noted here that if the above-mentioned cell assembly is a commercially available square-shell battery with a through hole, then the opening is connected to the through hole on the commercially available square-shell battery.

[0049] The single-cell battery provided by this utility model is mainly used to construct large-capacity batteries, such as the large-capacity battery described in Chinese patent CN220324596U in the background art, and can also be used to construct large-capacity batteries disclosed in Chinese patents CN117477063A, CN117477186A, and CN115275453A. Such large-capacity batteries include at least multiple single-cell batteries and at least one shared chamber; the shared chamber mentioned here refers to the shared chamber described in CN220324596U, the hollow component described in CN117477063A, the first hollow component and the second hollow component described in CN117477186A, and the electrolyte sharing channel described in CN115275453A.

[0050] When the battery casing component is a bottom cover plate for a single cell, the shared chamber can serve as an electrolyte sharing chamber. By using external electrolyte (which can be understood as the electrolyte in the electrolyte sharing chamber), part of the sealing device structure is dissolved, forming an opening in the bottom cover plate. The electrolytes in the cavities of each single cell are connected through the electrolyte sharing chamber, so that the electrolytes of all single cells are in the same system. This reduces the differences between the electrolytes of each single cell and improves the consistency between each single cell to a certain extent, thereby improving the cycle life of the large-capacity battery to a certain extent.

[0051] When the battery casing component is a cover plate for a single cell, the shared chamber can also serve as a gas-sharing chamber. By using external electrolyte (which can be understood as the electrolyte in the gas-sharing chamber), part of the sealing device structure is dissolved, forming an opening in the cover plate. The gas in the cavity of each single cell is connected through the gas-sharing chamber, which balances the gas in the entire large-capacity battery cavity and improves the cycle life of the large-capacity battery to a certain extent.

[0052] When the battery casing is a single-cell battery cylinder, the shared chamber can serve as a gas-liquid shared chamber. By using external electrolyte (which can be understood as the electrolyte within the gas-liquid shared chamber), a portion of the sealing device structure is dissolved, forming an opening in the side wall of the cylinder. The electrolyte and gas within each individual cell can then be connected through the gas-liquid shared chamber, ensuring that the electrolyte and gas of all individual cells are in the same system. This reduces the differences between individual cells and improves the consistency between them to some extent, thereby enhancing the cycle life of the large-capacity battery.

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0054] Example 1

[0055] like Figure 1 and Figure 2 As shown, this embodiment provides a sealing device 2 for sealing the opening 14 on a battery casing component. This embodiment uses the lower cover plate 12 of a single battery cell 1 as an example. The lower cover plate 12 of the single battery cell 1 has an opening 14 that penetrates through it. The shape of the opening 14 is not limited; in this embodiment, the opening 14 is a circular through-hole. In other embodiments, the shape of the opening 14 can be adjusted according to actual needs, such as using a rectangular hole or an elliptical hole.

[0056] like Figure 3 As shown, the sealing device 2 provided in this embodiment is used to seal the opening 14 on the lower cover plate 12. The sealing device 2 includes a dissolving sheet 21 and an isolation layer 22 attached to the dissolving sheet 21. The dissolving sheet 21 is made of an electrolyte-soluble material. The isolation layer 22 is made of an electrolyte-insoluble material. The electrolyte-insoluble material is attached to the dissolving sheet 21 and forms an integral sheet structure with the dissolving sheet 21.

[0057] The aforementioned dissolving sheet 21 has a sheet-like structure. The shape of the dissolving sheet 21 matches the shape of the opening 14, and the size of the dissolving sheet 21 is not smaller than the size of the opening 14, so that the dissolving sheet 21 can seal the opening 14. The dissolving sheet 21 mainly has the following two functions: 1. To seal the opening 14 on the lower cover plate 12 and isolate the electrolyte inside the battery casing from the external environment; 2. To support the separator layer 22 before the single battery 1 is unpacked, so that the separator layer 22 can isolate the dissolving sheet 21 and the electrolyte inside the battery casing. When the single battery 1 is unpacked, the dissolving sheet 21 can dissolve under the action of the external electrolyte, and the separator layer 22 loses its support, breaks and falls off, thereby opening the opening 14 on the lower cover plate 12.

[0058] Based on the above two functions, this embodiment uses an electrolyte-soluble material to prepare the dissolving sheet 21. The material of the dissolving sheet 21 is specifically PS (polystyrene), PMMA (polymethyl methacrylate), SMMA (styrene-dimethyl methacrylate copolymer), TPU (thermoplastic polyurethane), ABS (acrylonitrile / butadiene / styrene copolymer), POM (polyoxymethylene), PA6 (nylon 6), PA12 (nylon 12) or PVC (polyvinyl chloride), etc.

[0059] Meanwhile, the dissolving sheet 21 possesses a certain strength and hardness. Based on the dissolving sheet 21, the sealing device 2 and the opening 14 of the lower cover plate 12 are sealed and fixed, preventing the single battery 1 from being scrapped due to poor strength of the sealing device 2 before unpacking. In specific manufacturing, strength can be improved by selecting materials and increasing the thickness of the dissolving sheet 21. However, the thickness of the dissolving sheet 21 should not be too thick to avoid excessively long unpacking time and reduced production efficiency of large-capacity batteries. In practical use, a thickness of 1–3 mm is generally optimal for the dissolving sheet 21.

[0060] In this embodiment, the insulating layer 22 is attached to the inner surface of the dissolving sheet 21 and is an integral structure with the dissolving sheet 21. The inner surface of the dissolving sheet 21 is the surface of the dissolving sheet 21 located inside the cavity of the battery casing. The main function of the insulating layer 22 is to isolate the electrolyte inside the cavity of the single battery cell 1 from the dissolving sheet 21, preventing the electrolyte inside the single battery cell 1 from contacting the dissolving sheet 21 before the single battery cell 1 is opened, which would damage the integrity of the dissolving sheet 21, causing the sealing device 2 to fail and the single battery cell 1 to be scrapped. Therefore, in this embodiment, the material of the insulating layer 22 is an electrolyte-insoluble material, and the size of the insulating layer 22 is not smaller than the size of the opening 14, so as to ensure complete isolation between the electrolyte inside the cavity of the single battery cell 1 and the dissolving sheet 21. The electrolyte-insoluble material is coated on one end face of the dissolving sheet 21 in a molten state, and after solidification, it is attached to the end face of the dissolving sheet 21, forming an integral sheet structure with the dissolving sheet. When the single battery cell is opened, the dissolving sheet 21 is dissolved by the electrolyte, and the insulating layer 22 loses its support and breaks.

[0061] The aforementioned isolation layer 22 is made of solid alkanes or solid haloalkanes that are insoluble in the electrolyte. The solid alkanes or solid haloalkanes are coated onto the dissolving sheet 21 in a molten state, and after solidification, they adhere to the end face of the dissolving sheet 21, forming the isolation layer 22. The isolation layer 22 and the dissolving sheet 21 form an integral sheet structure. Solid alkanes or solid haloalkanes themselves lack chemical bonding strength; their strength is achieved through intermolecular forces. They are brittle and hard, making them extremely prone to breakage. After being attached to the dissolving sheet, the isolation layer 22 is supported by the dissolving sheet 21. The isolation layer itself has no strength; the strength of the entire sealing device is achieved through the dissolving sheet. After the dissolving sheet 21 is dissolved by the electrolyte, the isolation layer 22, having lost the dissolving sheet 21, can automatically break and open, thus reliably and promptly opening the opening.

[0062] When the material of the isolation layer 22 is solid alkane, a chemically stable solid alkane is selected so that after the solid alkane falls into the electrolyte, it does not react with the electrolyte and has no effect on the electrolyte. The isolation layer 22 is selected from the following solid alkane: C X H Y ,10≤x≤n,20≤y≤2n+2,n≤100,The solid alkane can be a mixture or a single substance component. The main component of the mixture is a straight-chain alkane, or a small amount of alkanes with individual branches and monocyclic cycloalkanes with long side chains. Specifically, long-chain alkanes and cycloalkanes are used, such as n-pentane, n-triane, n-pentadecane, n-tetradecane, n-pentane, etc. The cycloalkanes can specifically be nonadecanylcyclohexane, etc.

[0063] When the material of the isolation layer 22 is a solid haloalkane, a chemically stable solid haloalkane is selected so that after the solid haloalkane falls into the electrolyte, it does not react with the electrolyte and has no effect on the electrolyte. The solid haloalkane can be a long-chain haloalkane or a long-chain alkanes completely replaced by fluorine atoms, such as 1-chlorotriane (62016-82-4), 1-bromopentane (62108-45-6), perfluoropentadecane (2264-03-1), perfluorotetracosane (1766-41-2), perfluoroeicosane (37589-57-4), and 1-iodo-5-octadecyltriane (1639798-43-8).

[0064] In this embodiment, the insulating layer 22 is made of paraffin wax. After melting, the paraffin wax is coated onto one end face of the dissolving sheet 21. After solidification, the paraffin wax and the dissolving sheet 21 form a sheet-like structure. Specifically, if the coating thickness is too thin, the insulating layer 22 is prone to cracking; if the coating thickness is too thick, the insulating layer 22 is less likely to crack after the dissolving sheet 21 dissolves. Experiments have shown that when the thickness of the insulating layer 22 is between 1 nm and 0.5 mm, it can effectively isolate the electrolyte inside the battery casing from the dissolving sheet 21. However, because the insulating layer 22 is between 1 nm and 0.5 mm thick, it has a certain degree of brittleness. When the individual battery 1 is opened, if the dissolving sheet 21 is dissolved by the external electrolyte, the insulating layer 22, having lost its supporting carrier, is very prone to cracking. The opening 14 is no longer sealed, allowing the electrolyte inside each individual battery 1 to be connected through the electrolyte sharing chamber 4, thus achieving the goal of having the electrolyte inside each individual battery 1 in the same electrolyte system.

[0065] like Figure 4 and Figure 5As shown, in order to improve the bonding strength between the dissolving sheet 21 and the isolation layer 22, the end face of the dissolving sheet 21 coated with the isolation layer 22 has a groove 23 or a protrusion 24. The groove depth of the groove 23 is less than the thickness of the dissolving sheet 21, and the height of the protrusion 24 is less than the thickness of the isolation layer 22. The shape of the groove 23 or the protrusion 24 can be circular or strip-shaped, etc. Under the action of the groove 23 or the protrusion 24, the isolation layer 22 can adhere to the dissolving sheet 21 better.

[0066] Taking the paraffin layer as an example, the manufacturing process of the sealing device 2 is as follows:

[0067] S1. A dissolving sheet 21 with a sheet-like structure is made from an electrolyte-soluble material;

[0068] In this step, in order to increase the bonding strength between the dissolving sheet 21 and the isolation layer 22, a groove 23 or a protrusion 24 can be processed on the end face of the dissolving sheet 21 coated with the isolation layer 22. For example, the dissolving sheet 21 can be roughened or corona treated to increase the adsorption strength of the dissolving sheet 21.

[0069] S2. Heat solid alkane to a molten state;

[0070] In practice, the paraffin wax is placed in an oven to ensure good leveling properties and even coating.

[0071] S3. The molten material heated in step S2 is coated onto one end face of the dissolved sheet 21 in step S1. After the molten material solidifies, it adheres to the end face of the dissolved sheet 21 to form a sealing device 2.

[0072] In practice, the paraffin wax, which has been melted into wax water, is applied to the surface of the dissolution sheet 21, and then cured at room temperature after being evenly distributed.

[0073] S4. Cut the solidified dissolving sheet 21 into appropriate sizes for use.

[0074] In other embodiments, after the dissolution sheet 21 is fabricated, an isolation layer 22 can be prepared on the end face of the dissolution sheet 21 by waxing to form a sealing device 2.

[0075] After the sealing device 2 is manufactured, the sealing device 2 can be fixed on the lower cover plate 12 of the single cell 1 by the following process. This process is carried out in a set environment. Generally, the set environment is preferably an environment with a dew point standard between -25°C and -40°C, a temperature of 23°C ± 2°C, and a cleanliness level of 100,000.

[0076] First, a hole 14 is machined on the lower cover plate 12 of the existing finished single cell 1;

[0077] Next, the sealing device 2 is placed on the opening 14 on the lower cover plate 12;

[0078] Finally, sealant is applied to the edge of the sealing device 2 and the area around the opening 14 of the lower cover plate 12.

[0079] The sealant not only fixes the sealing device 2 to the lower cover plate 12, but also seals the edge of the sealing device 2 with the area around the opening 14 of the lower cover plate 12.

[0080] Furthermore, if the sealing device 2 is not installed reliably after installation within the opening 14 of the battery casing component, electrolyte from inside the battery casing may seep into the gap between the dissolving plate 21 and the opening 14, affecting the dissolving plate 21. This problem can be solved in the following way:

[0081] First, sealant is applied to the gap between the dissolution sheet 21 and the opening 14. The sealant fills the gap to prevent the electrolyte in the battery casing from seeping into the gap and affecting the dissolution sheet 21.

[0082] Secondly, an isolation layer 22 is also attached to the circumferential sidewall of the dissolving sheet 21. The circumferential sidewall of the dissolving sheet 21 refers to the sidewall that contacts the opening. At this time, the isolation layer 22 on the inner surface of the dissolving sheet 21 and the isolation layer on the circumferential sidewall of the dissolving sheet 21 fully cover the dissolving sheet 21, so as to avoid the electrolyte in the battery casing from affecting the dissolving sheet 21 and improve the reliability of the sealing device during use.

[0083] The sealing device 2 is installed on the individual battery cell 1. The sealing device 2 only needs to ensure that the inner cavity of the individual battery cell 1 is isolated from the external environment. When the individual batteries cell 1 are assembled into a large-capacity battery, when the individual batteries cell 1 are unpacked, electrolyte is injected into the electrolyte sharing chamber 4. Under the action of the electrolyte, the dissolving sheet 21 dissolves, the isolation layer 22 loses its support and ruptures, and the opening 14 on the lower cover plate 12 opens, thereby allowing the electrolyte sharing pipeline to be connected to the inner cavity of the individual battery cell 1, so that the electrolyte of all individual batteries cell 1 is in the same system, achieving the electrolyte sharing effect.

[0084] Example 2

[0085] The sealing device 2 in this embodiment is similar to the sealing device 2 in embodiment 1. The difference is that the sealing device 2 in this embodiment is manufactured together with the battery casing of the single cell 1 during the manufacturing process, and then the electrolyte and electrode assembly are installed.

[0086] The battery casing with the sealing device 2 forms a single cell 1. The single cell 1 needs to be formed. The formation process is mainly the process of charging the single cell 1 in a suitable environment to form an SEI film. During the formation process, the temperature and internal pressure of the single cell 1 are relatively high. At this time, the sealing device 2 needs to meet the temperature and pressure of the formation stage.

[0087] To meet this requirement, it can be achieved by selecting appropriate materials and increasing the thickness. In this embodiment, the thickness of the separator 22 is 0.1 mm to 2 mm, which is sufficient to meet the formation requirements of the single cell 1. Furthermore, the melting point of alkanes increases with increasing molecular weight (i.e., the number of carbon atoms), and the separator 22 is selected from the following solid alkanes: C X H Y 18≤x≤n, 36≤y≤2n+2, n≤100. Based on the formation or aging conditions of the single cell 1, a solid alkane with a melting point of 45~80℃ is used to make the separator layer 22. The separator layer 22 with this melting point range can meet the temperature requirements of the single cell 1 formation stage (<90℃, as a formation temperature exceeding 90℃ may lead to electrolyte decomposition, increased internal pressure of the battery, and instability of the SEI film, thereby affecting the performance and safety of the battery). At the same time, if the separator layer 22 does not break when the package is opened, the temperature of the single cell 1 can be adjusted to melt the separator layer 22 to achieve the opening. Since the melting point range of the separator layer 22 is between 45 and 80℃, it will not affect the performance and safety of the battery.

[0088] When the sealing device 2 with the above-mentioned isolation layer 22 is installed on the battery casing, and the individual cells 1 are unpacked and assembled into a large-capacity battery, electrolyte is injected into the electrolyte sharing chamber 4. Under the action of the electrolyte, the dissolving sheet 21 dissolves, and the isolation layer 22 loses its support and ruptures. If the isolation layer 22 does not rupture, the temperature of the individual cell 1 is adjusted to melt the isolation layer 22, and the opening 14 on the lower cover plate 12 is opened, thereby making the electrolyte sharing pipeline connected to the inner cavity of the individual cell 1, so that the electrolyte of all individual cells 1 is in the same system, achieving the electrolyte sharing effect.

[0089] Example 3

[0090] like Figure 6 As shown, this embodiment provides a single-cell battery 1, which includes a battery casing component having the aforementioned sealing device 2. The battery casing component is at least one of an upper cover plate 11, a lower cover plate 12, or a cylindrical body 13. An opening 14 is formed on the battery casing component, the position of which corresponds to the shared chamber in the high-capacity battery. The opening 14 can be a round hole, a square hole, or other polygonal holes, which can be selected according to actual needs. The size of the opening 14 needs to meet the following conditions:

[0091] 1. The opening 14 should not be too large to ensure that the battery casing components have a certain strength, so as to avoid the single cell 1 being scrapped due to poor strength before the sealing device 2 at the opening 14 is opened.

[0092] 2. The opening 14 should not be too small, so as to ensure that after the sealing device 2 at the opening 14 is opened, the electrolyte area of ​​each individual battery 1 and the shared cavity can be smoothly connected to ensure a good sharing effect.

[0093] like Figure 7 As shown, in some other embodiments, multiple openings 14 can be formed on the battery casing component. Generally, the multiple openings 14 are arranged along the length or height direction of the battery casing component. When all openings 14 are open, compared to a structure that shares resources through only one opening 14, the electrolyte and / or gas inside the individual battery 1 can be fully mixed with the electrolyte and / or gas inside the shared pipeline assembly, resulting in a better sharing effect.

[0094] like Figure 8 As shown, in this embodiment, to facilitate the installation of the sealing device 2, the opening 14 is designed as a stepped through hole. The larger hole of the stepped through hole is located on the outer surface of the battery casing component, and the smaller hole is located on the inner surface of the battery casing component. The size of the larger hole is slightly larger than the size of the dissolving sheet 21 in the sealing device 2, so that the sealing device 2 can be embedded into the larger hole of the stepped through hole. The size of the smaller hole is smaller than the size of the insulating layer 22, so that the insulating layer 22 isolates the electrolyte and the dissolving sheet 21 inside the battery casing. This stepped hole design facilitates the sealing installation of the sealing device 2 within the opening 14 of the battery casing. Furthermore, embedding the sealing device 2 into the larger hole of the stepped through hole makes the outer surface of the single-cell battery 1 relatively flat, improving the structural regularity of the single-cell battery 1 and facilitating its storage and transportation.

[0095] After the sealing device 2 is embedded in the opening 14, sealant is applied to the edge of the dissolving sheet 21 and the area around the opening 14. The sealant fixes the dissolving sheet 21 to the battery housing component. At the same time, the sealant also seals the edge of the dissolving sheet 21 and the area around the opening 14.

[0096] like Figure 9As shown, to facilitate adhesive application and ensure reliable connection when the sealing device 2 is connected to the battery housing component, a first chamfer 25 is machined on the end face of the dissolving sheet 21 away from the separator layer 22. A second chamfer 16 is provided on the inner wall of the large hole in the battery housing component, which corresponds to the position of the first chamfer 25. The first chamfer 25 and the second chamfer 16 can form an annular groove with a rectangular or triangular cross-section. This annular groove not only facilitates the application of sealant, but also, by filling the annular groove with sealant, the connection between the dissolving sheet 21 and the battery housing component becomes more reliable, and the sealing performance of the dissolving sheet 21 to the opening is also better.

[0097] like Figure 10 As shown, a high-capacity battery constructed using the aforementioned single-cell battery 1 includes a casing 3 and multiple single-cell batteries 1 arranged within the casing 3. An electrolyte sharing chamber 4 is provided between the bottom of each single-cell battery 1 and the bottom plate of the casing 3, and a gas sharing chamber 5 is provided between the top of each single-cell battery 1 and the top plate of the casing 3. The electrolyte sharing chamber 4 is a liquid channel extending along the length direction (x-direction) of the casing 3 between the bottom plate of the casing 3 and each single-cell battery 1. This liquid channel can be integrally formed with the bottom plate of the casing 3, or it can be formed by providing a support member between the lower cover plate 12 of the single-cell battery 1 and the bottom plate of the casing 3. The gas sharing chamber 5 is a gas channel extending along the length direction (x-direction) of the casing 3 between the top plate of the casing 3 and each single-cell battery 1. This gas channel can be integrally formed with the top plate of the casing 3.

[0098] In addition, in order to improve the heat dissipation performance of such high-capacity batteries, clearance holes can be opened on the top plate of the casing 3 to allow the polar terminals 15 of each individual battery 1 to extend out; the polar terminals 15 of each individual battery 1 extend out of the clearance holes and the area of ​​the top plate of the casing 3 around the clearance holes is fixedly sealed to the casing of the individual battery 1.

[0099] It should be noted that the polarity terminal 15 of the single cell 1 component here can be the terminal post of the single cell 1. In order to prevent the terminal post of the single cell 1 from not being able to extend smoothly out of the clearance hole as the polarity terminal 15, a terminal post adapter can be connected to the terminal post of the single cell 1, and the overall structure of the single cell 1 terminal post and the terminal post adapter can be used as the polarity terminal 15 of the single cell 1.

[0100] In the process of constructing the above-mentioned large-capacity battery, the individual cell 1 can be unpacked through the following process (the unpacking of individual cell 1 forms a large-capacity battery):

[0101] If the battery casing component is the lower cover plate 12 of a single cell 1, the liquid circuit can be opened through the following process:

[0102] After the large-capacity battery is assembled (without opening the individual cells 1), electrolyte is injected into the electrolyte sharing chamber 4. Under the action of the electrolyte, the dissolving sheet 21 dissolves, the insulating layer 22 loses its support and ruptures, and the opening 14 on the lower cover plate 12 opens, thereby making the electrolyte sharing chamber 4 connected to the inner cavity of the individual cells 1, so that the electrolyte of all individual cells 1 is in the same system, achieving the electrolyte sharing effect.

[0103] If the battery casing component is the top cover 11 of a single cell 1, the gas path can be opened through the following process:

[0104] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the gas sharing chamber 5, which allows the dissolving sheet 21 to automatically dissolve from the outside. Under the action of the electrolyte, the dissolving sheet 21 dissolves, the isolation layer 22 loses its support and cracks, and the opening 14 on the upper cover plate 11 opens, thereby allowing the gas sharing chamber 5 to be connected with the inner cavity of the single cell 1, so that all the single cells 1 can achieve the effect of gas balance.

Claims

1. A sealing device for sealing an opening on a battery casing component, characterized in that, This includes the dissolving tablet and the insulating layer attached to the dissolving tablet; The dissolving sheet is made of an electrolyte-soluble material; The insulating layer is made of solid alkanes or solid haloalkanes that are insoluble in the electrolyte. The solid alkanes or solid haloalkanes are attached to the end face of the dissolving sheet, forming an integral sheet structure with the dissolving sheet. After the dissolving sheet is dissolved by the electrolyte, the insulating layer loses its support and breaks.

2. The sealing device according to claim 1, characterized in that, The end face of the dissolving sheet attached to the isolation layer has a groove or a protrusion, the height of which is less than the thickness of the isolation layer.

3. The sealing device according to claim 1, characterized in that, The end face of the dissolving sheet away from the isolation layer has a first chamfer.

4. The sealing device according to claim 1, characterized in that, The insulating layer is a paraffin layer.

5. The sealing device according to claim 1, characterized in that, The material of the dissolving sheet is PS, PMMA, SMMA, TPU, ABS, PA6, PA12 or PVC.

6. The sealing device according to any one of claims 1 to 5, characterized in that, An isolation layer is attached to the circumferential sidewall of the dissolving sheet.

7. The sealing device according to claim 6, characterized in that, The thickness of the isolation layer is 1 nm to 0.5 mm, and the thickness of the dissolution sheet is 1 to 3 mm.

8. A battery casing component, characterized in that, An opening is formed in the battery housing component, penetrating the inner cavity of the battery housing. A sealing device according to any one of claims 1 to 7 is provided at the opening. The sealing device seals the opening, and the end face of the dissolving sheet with the insulating layer faces the inner cavity of the battery housing.

9. The battery casing component according to claim 8, characterized in that, The opening is a stepped through hole, with the large hole located on the outer surface of the battery casing component. The sealing device is embedded in the large hole of the stepped through hole. The inner wall of the large hole is provided with a second chamfer, and the first chamfer and the second chamfer form an annular groove coated with sealant.

10. A single-cell battery, characterized in that, Includes the battery casing component as described in claim 8 or 9.

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