Sealing assembly, cover plate assembly, cylinder, battery cell casing member, and battery cell

Abstract

A sealing assembly (2), a cover plate assembly, a cylinder, a battery cell casing member, and a battery cell. The sealing assembly (2) comprises a protection mechanism (6) and a dissolving mechanism (7). The protection mechanism (6) is used for isolating the dissolving mechanism from an electrolyte in the inner cavity of the battery cell, and the dissolving mechanism (7) is used for dissolving under the action of an external electrolyte, and enabling the protection mechanism (6) to fall off from the battery cell casing; and the dissolving mechanism (7) is made of a material soluble in the electrolyte, and the protection mechanism (6) is made of a material insoluble in the electrolyte. The cover plate assembly (2), the cylinder, the battery cell casing member, and the battery cell are all provided with the sealing assembly (2). The sealing assembly (2) can be reliably mounted to the battery cell casing, has good sealing performance, and can be smoothly opened by using the electrolyte.

Description

Sealing assembly, cover assembly, cylinder, single cell shell component and single cell Technical Field

[0001] The present invention belongs to the field of batteries, and in particular relates to a sealing assembly, a cover assembly, a cylinder, a single cell shell component and a single cell. Background Art

[0002] Currently, many batteries on the market are connected in parallel or in series to form large-capacity batteries (also known as battery modules or battery packs).

[0003] However, existing large-capacity batteries have inherent differences among individual cells. Due to the "barrel effect," the performance of the worst cell is often affected, significantly limiting the upper capacity and cycle life of the entire large-capacity battery. Therefore, improving the uniformity of individual cells in large-capacity batteries has become a key and challenging area of ​​research in this field.

[0004] To address the above-mentioned problems, Chinese patent CN219892382U discloses a large-capacity battery, as shown in FIG1 . The electrolyte areas of all single cells 03 are connected by a first hollow component 01 fixed at the bottom of each single cell, and the gas areas of all single cells 03 are connected by a second hollow component 02 fixed at the top of each single cell. The first hollow component 01 allows each single cell 03 to be placed in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell 03. The second hollow component 02 achieves gas balance in each single cell 03, thereby improving the performance and charge-discharge cycle life of the large-capacity battery.

[0005] Usually, the first hollow member 01 can be connected to the electrolyte area of ​​all the single cells, and the second hollow member 02 can be connected to the gas area of ​​all the single cells 03 by opening the sealing components sealed at the bottom and top openings of the single cells 03.

[0006] Specifically, the electrolyte itself may be used to open the sealing component, and the sealing component disclosed in Chinese patent CN218525645U may be used.

[0007] For example, Chinese patent CN220324596U discloses a large-capacity battery, the structure of which is shown in FIG2 . This type of large-capacity battery includes a housing 301 and multiple single cells 3001 . The multiple single cells 3001 are connected in parallel and arranged in the inner cavity of the housing 301 . The housing 301 is provided with a shared chamber (the shared chamber described herein is an electrolyte shared chamber 302 and / or a gas shared chamber 303 ), which is connected to the inner cavity of each single cell. The electrolyte and / or gas in the inner cavity of each single cell is connected through the electrolyte shared chamber and / or the gas shared chamber, so that the electrolyte and / or gas of all single cells are in the same system, reducing the differences between the single cells and improving the consistency between the single cells to a certain extent, thereby improving the cycle life of the large-capacity battery to a certain extent.

[0008] Typically, the shared chamber is connected to the internal cavities of all the cells by opening the sealing assembly located at the opening of the cell housing. Specifically, the sealing assembly can be opened by external force or by the electrolyte itself. Alternatively, the sealing assembly can be made of a sealing film that dissolves in electrolyte, as disclosed in Chinese Patent CN218525645U.

[0009] While the aforementioned patent discloses that the sealing assembly comprises a dissolving membrane and a protective film, with the protective film located on the side of the dissolving membrane facing the interior of the battery housing; and that the protective film falls off after the dissolving membrane dissolves in the electrolyte, it does not provide detailed information on the specific installation of the dissolving membrane and the protective film, or how they are mounted on the battery housing. Therefore, ensuring reliable installation, sealing performance, and smooth opening of the sealing assembly is a pressing technical issue. Summary of the Invention

[0010] The present invention aims to provide a sealing assembly, a cover assembly, a barrel, a single cell housing component and a single cell, wherein the sealing assembly and the single cell housing can be reliably assembled and have good sealing performance, and can be opened smoothly using electrolyte.

[0011] A first aspect of the present invention provides a sealing assembly for sealing an opening on a single cell housing, comprising a protection mechanism and a dissolving mechanism;

[0012] The protection mechanism is used to isolate the dissolution mechanism from the electrolyte in the inner cavity of the single cell;

[0013] The dissolving mechanism is used to dissolve under the action of external electrolyte and make the protective mechanism fall off from the single battery shell;

[0014] The material of the dissolving mechanism is a material soluble in the electrolyte, and the material of the protecting mechanism is a material insoluble in the electrolyte.

[0015] Specifically, the present invention provides the following three types of sealing assemblies:

[0016] The first type of sealing components:

[0017] The protective mechanism is a protective film;

[0018] The dissolving mechanism is a dissolving membrane;

[0019] The protective film is in sheet form and is used to cover the opening; the dissolving film is in ring form and is used to be fixed on the outer surface area of ​​the shell around the edge of the protective film and the opening, thereby fixing the protective film on the shell.

[0020] This type of sealing assembly uses an annular dissolving film to fix the protective film on the battery shell. The dissolving film can well seal the gap between the protective film and the shell area around the opening; at the same time, the electrolyte in the inner cavity of the single cell shell is in direct contact with the protective film, but cannot contact the dissolving film located on the outer surface of the shell. Therefore, during the assembly process of the large-capacity battery (before unpacking), the opening of each single cell has good sealing performance; during the unpacking process, the electrolyte is injected into the shared pipeline assembly. Under the action of the electrolyte, the dissolving film melts and the protective film falls off from the single cell shell, thereby connecting the inner cavity of each single cell shell with the inner cavity of the shared pipeline assembly. Due to the use of an annular dissolving film, when the outer diameter is the same, the annular dissolving film has a smaller area than the circular dissolving film (the dissolving film in the background technology). Therefore, compared with the dissolving film in the background technology, the dissolving time of the present invention is shorter, which can shorten the preparation time of large-capacity batteries and improve production efficiency. In addition, the dissolving film acts as a sealing component and a fixing mechanism at the same time. There is no need to introduce an additional fixing mechanism of the sealing assembly, which makes the overall structure of the sealing assembly simple and the manufacturing cost low.

[0021] Furthermore, the dissolving film in the present invention is fixed to the outer surface of the housing around the edge of the protective film and the opening by casting. Generally, a hot-melt slurry soluble in the electrolyte is cast on the outer surface of the housing around the edge of the protective film and the opening. After cooling, a dissolving film is formed, which simultaneously achieves sealing and fixes the protective film to the battery cell housing.

[0022] Furthermore, a second step structure is provided along the circumference of the protective film at its edge, so that the dissolving film can be fixed to it by using a stopper, which can increase the bonding strength between the two and further improve the sealing reliability of this part.

[0023] Furthermore, the material of the dissolving film is 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).

[0024] Furthermore, the material of the protective film is aluminum, copper, zinc, nickel, silver, epoxy resin, PE (polyethylene), PP (polypropylene), polytetrafluoroethylene or EPDM rubber.

[0025] Second type of sealing components:

[0026] The dissolving mechanism is a columnar body formed by an additive soluble in the electrolyte; the protecting mechanism is an isolation membrane arranged on at least the first end surface of the columnar body.

[0027] This type of sealing component is installed on the outer shell of the single cell, which can be reliably installed and has good sealing performance. When the electrolyte is injected, the sealing component is dissolved, and a through hole is formed on the single cell, which enables the single cell to be unpacked. This process does not require special tooling, is simple to operate, and reduces production costs. In addition, since the sealing component is solidified using electrolyte additives, it can improve the performance of large-capacity batteries to a certain extent after dissolving in the electrolyte.

[0028] Furthermore, the columnar body is made of propylene sulfate, ethylene carbonate or diphenyl carbonate.

[0029] Furthermore, in order to enable the sealing component to slowly dissolve in the electrolyte and thus continuously improve the electrolyte performance, the first end face, the second end face and the side face of the above-mentioned columnar body are covered with an isolation film, and a blind hole is provided in the columnar body from the second end face to the first end face.

[0030] Furthermore, in order to achieve both a fast opening speed and a slow decomposition of the sealing component in the electrolyte, the depth of the blind hole accounts for 90% of the length of the columnar body.

[0031] Furthermore, in order to enhance the sealing reliability of the sealing assembly to the single battery, a circle of grooves for installing the sealing ring is engraved on the side wall of the columnar body.

[0032] Furthermore, the columnar body includes a first cylindrical segment and a second cylindrical segment, the outer diameter of the first cylindrical segment is larger than that of the second cylindrical segment, and the groove is provided on the side surface of the second cylindrical segment.

[0033] Furthermore, the first end surface, the second end surface and the side surface of the columnar body are covered with an isolation film, and the second end surface is provided with a blind hole.

[0034] Furthermore, the above-mentioned isolation film is a PP film.

[0035] The third type of sealing components:

[0036] The protection mechanism is a protection cap; the dissolving mechanism is a dissolving film layer;

[0037] The protective cap includes an annular side wall and a bottom plate; the annular side wall is used to be fixed to the single cell housing component area around the opening, the bottom plate is located in the inner cavity of the single cell housing, and the cavity of the protective cap serves as a dissolving film layer accommodating cavity;

[0038] The dissolving film layer is fixed in the dissolving film layer accommodating cavity, so that the dissolving film layer accommodating cavity is expanded, and the annular side wall of the protective cap is squeezed to fit the area of ​​the single cell housing component around the opening, thereby sealing the opening;

[0039] The material of the protective cap is elastic.

[0040] This type of sealing assembly fixes an elastic protective cap to the single cell shell component area around the opening, and fills the protective cap cavity with a dissolving film layer. Based on the support of the dissolving film layer, the protective cap is deformed and fits tightly with the single cell shell component area around the opening to seal the opening. At the same time, the electrolyte in the inner cavity of the single cell shell is in direct contact with the protective cap, but cannot contact the dissolving film located in the protective cap cavity. Therefore, during the assembly process of large-capacity batteries (before unpacking), the opening parts of each single cell have better sealing performance. Before the dissolving film layer dissolves, the protective cap is not easy to fall off, which makes the installation reliability of the entire sealing assembly higher. During the unpacking process, electrolyte is injected into the shared chamber. Under the action of the electrolyte, the dissolving film layer dissolves, and the protective cap falls off from the single cell shell component, thereby connecting the inner cavity of each single cell shell with the inner cavity of the shared chamber, making the unpacking process simple and reliable. In addition, the dissolving film layer is used as a mechanism for fixing the protective cap, and there is no need to introduce an additional fixing mechanism for the sealing assembly, which makes the overall structure of the sealing assembly simple and the manufacturing cost low.

[0041] Furthermore, a first annular groove is formed on the outer surface of the annular side wall of the protective cap along its circumference. The first annular groove cooperates with the single cell housing component area around the opening to further improve the sealing performance of the protective cap on the opening.

[0042] Furthermore, a second annular groove is provided along its circumference on the inner surface of the annular side wall of the protective cap; the dissolving film layer is provided with an annular protrusion embedded in the second annular groove, and based on the cooperation between the second annular groove and the annular protrusion, the dissolving film layer can be stably fixed in the inner cavity of the protective cap.

[0043] Furthermore, the material of the dissolving film layer is PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12 or PVC.

[0044] Furthermore, the material of the protective cap is PP or EPDM rubber.

[0045] A second aspect of the present invention provides a cover plate assembly, comprising a cover plate body, wherein an opening is formed on the cover plate body, and the above-mentioned first type sealing assembly is disposed at the opening.

[0046] The protective film is located within the macropore, and a dissolving film installation space is formed between the protective film, the stepped surface, and the macropore wall. The dissolving film is fixed within the dissolving film installation space. This arrangement allows the outer surfaces of the cover plate assembly of the single cell to be flat, improving the structural regularity of the single cell.

[0047] Furthermore, when the thickness of the cover plate body is relatively thin, a protrusion may be provided on the inner surface of the cover plate body, and a stepped through hole penetrating the cover plate body may be provided on the protrusion as the opening.

[0048] Furthermore, a plurality of blind holes are provided on the step surface along its circumference. When hot melt slurry is poured at this position, columns can be formed in the blind holes, thereby further improving the bonding strength between the dissolving film and the shell.

[0049] Furthermore, when the cover plate assembly is used as a lower cover plate, two openings can be symmetrically opened along the length direction of the cover plate body, which can improve the electrolyte sharing effect of each single cell compared to one opening.

[0050] A third aspect of the present invention provides a cylinder, comprising a cylinder body, wherein an opening is provided on the cylinder body, and the above-mentioned first type sealing component is provided at the opening.

[0051] A fourth aspect of the present invention provides a single cell battery, comprising a housing, wherein the housing defines an opening penetrating an inner cavity of the single cell battery; the above-mentioned first type sealing assembly is disposed at the opening.

[0052] A fifth aspect of the present invention provides another single cell battery, comprising a battery housing and the second type of sealing assembly described above; the battery housing is provided with a convex ring, and the sealing assembly is fixedly sealed in the convex ring.

[0053] Furthermore, the protruding direction of the convex ring is toward the inner cavity of the battery.

[0054] Furthermore, a clamping portion for clamping a heat transfer tube is provided on the pole of the single battery.

[0055] A sixth aspect of the present invention provides a single cell housing component, wherein an opening penetrating the inner cavity of the single cell housing is provided on the single cell housing component, and the above-mentioned third type sealing assembly is fixed to the region of the single cell housing component around the opening.

[0056] A seventh aspect of the present invention provides a third unit battery, comprising the above-mentioned unit battery casing member. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a schematic structural diagram of a large-capacity battery in the background art;

[0058] FIG2 is a schematic diagram of the structure of a large-capacity battery in the background art;

[0059] FIG3 is a schematic structural diagram of the cover plate assembly of Example 1;

[0060] FIG4 is a schematic structural diagram of the cover plate body in Example 1;

[0061] FIG5 is a cross-sectional view of the cover plate body in Example 1;

[0062] FIG6 is a partial cross-sectional view of the cover plate assembly of Example 1;

[0063] FIG7 is a schematic structural diagram of the protective film in Example 1;

[0064] FIG8 is a schematic diagram of the main structure of the cover plate provided with a protective film in Example 1;

[0065] FIG9 is a schematic structural diagram of the sealing assembly in Example 1;

[0066] FIG10 is an exploded schematic diagram of the sealing assembly in Example 1;

[0067] FIG11 is a cross-sectional view of the sealing assembly in Example 1;

[0068] FIG12 is a schematic diagram of the assembly process of the cover plate assembly in Example 1;

[0069] FIG13 is a schematic structural diagram of the cover plate assembly in Example 2;

[0070] FIG14 is a schematic structural diagram of the cover plate assembly in Example 2;

[0071] FIG15 is a schematic structural diagram of a single cell according to Example 3 from one perspective;

[0072] FIG16 is a structural diagram of a single cell according to Example 3 from another perspective;

[0073] FIG17 is a schematic structural diagram of a first large-capacity battery in Example 4;

[0074] FIG18 is a schematic structural diagram of a second large-capacity battery in Example 4;

[0075] FIG19 is a cross-sectional view of the sealing assembly in Example 4;

[0076] FIG20 is a schematic diagram of the structure of a single cell in Example 4;

[0077] FIG21 is a cross-sectional view of a single cell in Example 4;

[0078] FIG22 is a schematic structural diagram of the lower cover plate of a single cell in Example 5;

[0079] FIG23 is a schematic diagram of the partial structure of the lower cover plate of the single cell in Example 5;

[0080] FIG24 is a partial cross-sectional view of the lower cover plate of the single cell (without the sealing assembly fixed thereto) in Example 5;

[0081] FIG25 is an exploded view of the lower cover of a single cell in Example 5;

[0082] FIG26 is a schematic structural diagram of the protective cap in Example 5;

[0083] FIG27 is a cross-sectional view of the protective cap in Example 5;

[0084] FIG28 is a partial cross-sectional view of the protective cap and the lower cover of the single cell in Example 5;

[0085] FIG29 is a partial cross-sectional view of the lower cover of a single cell in Example 5;

[0086] FIG30 is a schematic structural diagram of a single cell in Example 5;

[0087] FIG31 is a schematic diagram of the structure of a single cell after the dissolving film layer is dissolved in Example 5;

[0088] FIG32 is a partial cross-sectional view of a single cell after the dissolving film layer is dissolved in Example 5;

[0089] FIG33 is a partial cross-sectional view of the upper cover plate of a single cell in Example 6;

[0090] FIG34 is a schematic diagram of the structure of a single cell in Example 6;

[0091] The accompanying drawings are marked as follows: 01, first hollow member; 02, second hollow member; 03, single cell; 1, cover plate body; 11, opening; 12, blind hole; 2, sealing assembly; 3, outer surface of cover plate body; 4, protrusion; 5, sealing assembly installation space; 6, protective film; 7, dissolving film; 8, step surface; 9, second step structure; 10, dissolving film installation space; 13, sealing portion; 14, fixing portion; 15, pole; 100, housing; 200, single cell; 300, hollow member; 400, sealing assembly; 21, columnar body; 211, first cylindrical segment; 212, second cylindrical segment; 22, first end face; 23, second end face; 24, blind hole; 25, groove; 26, convex ring; 27, sealing ring; 500, heat transfer tube; 301. Housing; 302. Electrolyte sharing chamber; 303. Gas sharing chamber; 3001. Single cell; 31. Cover plate body; 311. Opening; 32. Sealing assembly; 321. Protective cap; 3211. Annular side wall; 3212. Bottom plate; 3213. First annular groove; 3214. Second annular groove; 3215. Dissolving film layer accommodating chamber; 322. Dissolving film layer; 33. Pole. DETAILED DESCRIPTION

[0092] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. It is obvious that the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of the present invention.

[0093] In the following description, many specific details are set forth to facilitate 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 may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0094] In the description of the present invention, it should be noted that the terms "top," "bottom," and so on, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and so on, are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0095] The following embodiments 1 to 3 provide a sealing assembly for sealing an opening on a single cell housing.

[0096] The single cell described here is a square shell battery, which includes an upper cover plate, a lower cover plate, a cylinder, a battery cell assembly and an electrolyte; the battery cell assembly described here can be called an electrode assembly, which is arranged in sequence by a positive electrode, a diaphragm and a negative electrode and assembled by a lamination or winding process.

[0097] The opening may be located on the upper cover plate, the lower cover plate and / or the cylinder of the single cell.

[0098] Examples 1 to 3 also provide a cover plate assembly, a cylinder, and a single battery provided with the above-mentioned sealing assembly.

[0099] The single cells provided in Examples 1 to 3 are primarily used to construct large-capacity batteries (also known as battery packs or battery modules). Such large-capacity batteries include multiple single cells arranged side by side and at least one shared conduit assembly (the shared conduit assembly herein is the first hollow member and the second hollow member described in the background art); the shared conduit assembly communicates with the inner cavity of the single cell through the opening of the single cell.

[0100] If the opening is opened on the lower cover of the single cell, the shared pipeline assembly can be used as an electrolyte shared pipeline. The sealing assembly sealed on the opening of the lower cover of each single cell is opened by external force, and the electrolyte in the inner cavity of each single cell is connected through the electrolyte shared pipeline, so that the electrolyte of all single cells is in the same system, reducing the difference between the electrolytes of each single cell, improving the consistency between each single cell to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0101] If the opening is opened on the upper cover of the single cell, the shared pipeline assembly serves as a gas sharing pipeline, and uses external force to open the sealing assembly sealed on the through-hole of the upper cover of each single cell. The gas in the inner cavity of each single cell is connected through the gas sharing pipeline, so that the gas in the inner cavity of the entire large-capacity battery is balanced, which improves the cycle life of the large-capacity battery to a certain extent.

[0102] If the opening is opened on the side wall of the single cell cylinder, the shared pipeline assembly can serve as both an electrolyte shared pipeline and a gas shared pipeline. External force is used to open the sealing assembly sealed on the side wall of each single cell cylinder, so that the gas and electrolyte in each single cell can enter the shared pipeline assembly at the same time. At this time, the gas is distributed in the upper half of the shared pipeline assembly, and the electrolyte is distributed in the lower half of the shared pipeline assembly; gas and liquid sharing can be achieved through a shared pipeline assembly.

[0103] The following further describes Examples 1 to 3 with reference to the accompanying drawings.

[0104] Example 1

[0105] This embodiment is mainly described by taking the example of fixing the sealing assembly 2 to the lower cover plate of a single battery.

[0106] As shown in Figure 3, which is a schematic structural diagram of the cover assembly of this embodiment, it can be seen that the cover assembly of this embodiment includes a cover body 1 and a sealing assembly 2 fixed on the cover body 1.

[0107] For the convenience of description below, the length direction of the cover plate body 1 may be defined as the x direction, the width direction as the y direction, and the thickness direction as the z direction.

[0108] As shown in Figure 4, the cover plate body 1 of this embodiment is a rectangular plate with an area slightly larger than the area of ​​the open end of the cylinder. It is fixed to the open end of the cylinder by welding. Alternatively, a first step structure can be provided around the cover plate body 1 to achieve fixation by welding. The stepped surface of the first step structure can also be used as a positioning surface. The cover plate can be positioned on the open end of the cylinder using this positioning surface and then fixed by welding. The area of ​​the cover plate body 1 can also be slightly smaller than the area of ​​the open end of the cylinder and fixed to the open end of the cylinder by embedding welding. In other embodiments, the cover plate body 1 and the cylinder are integral.

[0109] Two openings 11 are defined on the cover body 1 . The two openings 11 are arranged along the x direction and are symmetrical to each other.

[0110] The size of the opening 11 needs to meet the following conditions:

[0111] 1. The opening 11 cannot be too large to ensure that the entire cover body 1 has a certain strength, so as to avoid the cover body 1 from being scrapped due to poor strength before the sealing component 2 at the opening 11 is opened;

[0112] 2. The opening 11 cannot be too small to ensure that after the sealing assembly 2 at the opening 11 is opened, the electrolyte area of ​​each single battery cavity and the cavity of the shared pipeline assembly are smoothly connected to ensure a good sharing effect.

[0113] In some other embodiments, an opening 11 may be provided on the cover body 1 . Generally, the opening 11 may be located at the exact center of the cover body 1 .

[0114] As can be seen from Figure 5, the opening 11 of this embodiment is a circular stepped through hole. The large hole of the stepped through hole is opened near the side of the outer surface 3 of the cover body. The surface of the cover body 1 away from the electrode assembly is defined as the outer surface. When the thickness of the cover body 1 is relatively thin, a protrusion 4 can be provided on the inner surface of the cover body 1, and a stepped through hole can be opened on the protrusion 4 as the opening 11. When the thickness of the cover body 1 is relatively thick, the stepped through hole can be directly opened. The large hole of the stepped through hole serves as the installation space 5 of the sealing component. When the sealing component 2 is fixed in the large hole, the flatness of the outer surface 3 of the cover body can be ensured.

[0115] In some other embodiments, the opening 11 can be a circular straight-through hole, but relative to this embodiment, when the sealing assembly 2 is fixed at the position of the opening 11, the protective film 6 and the dissolving film 7 will protrude from the outer surface 3 of the cover body, making it difficult to ensure the flatness of the outer surface 3 of the cover body.

[0116] To improve the stability of the sealing assembly 2 at the opening 11, this embodiment further provides multiple fastening structures on the stepped surface 8 of the stepped through-hole. These fastening structures can securely secure the sealing assembly 2 to the cover plate body 1. In this embodiment, the fastening structures are multiple blind holes 12 (see FIG. 4 ) formed on the stepped surface 8. The multiple blind holes 12 are evenly arranged along the circumference of the stepped surface 8. In other embodiments, an annular groove can be formed along the circumference of the stepped surface 8 as the fastening structure.

[0117] As shown in FIG6 , the sealing assembly 2 of this embodiment includes a protection mechanism and a dissolving mechanism; the protection mechanism is a protection film 6 , and the dissolving mechanism is a dissolving film 7 .

[0118] The protective film 6, shown in Figure 7, is a sheet-like structure with a circular shape that matches the shape of the opening 11. Its edge is secured to the stepped surface 8 of the stepped through-hole by a dissolving film 7, sealing the opening 11. The protective film 6 is made of a material that is insoluble in the electrolyte and possesses a certain strength to prevent the protective film 6 from being damaged by the pressure of the electrolyte within the individual cells before the sealing assembly 2 at the opening 11 is opened, thereby rendering the individual cells useless. Typical materials include aluminum, copper, zinc, nickel, silver, epoxy resin, PE, PP, polytetrafluoroethylene, or EPDM rubber.

[0119] In order to improve the bonding strength between the dissolving film and the protective film 6, it can be seen from Figures 7 and 8 that in this embodiment, a second step structure 9 is provided along the circumference of the edge of the protective film 6, and a dissolving film installation space 10 is formed between the second step structure 9, the step surface 8 of the step through hole and the wall of the large hole of the step through hole.

[0120] In this embodiment, the dissolving membrane 7 is annular and fixed in the dissolving membrane installation space 10 , with its inner ring pressed against the edge of the protective membrane 6 and its outer ring fixed to the shell, thereby fixing the protective membrane 6 on the step surface 8 .

[0121] In this embodiment, the dissolving membrane 7 is fixed within the dissolving membrane installation space 10 by casting. Generally, a hot-melt slurry soluble in the electrolyte is poured into the dissolving membrane installation space 10. After cooling, the dissolving membrane 7 is formed, achieving a seal while securing the protective film 6 to the battery cell housing. The dissolving membrane 7 is made of at least one of PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12, and PVC.

[0122] In some other embodiments, a sealant that is soluble in the electrolyte may be poured into the dissolving membrane installation space 10 and formed into the dissolving membrane 7 after solidification.

[0123] The sealing assembly 2 is isolated from the cover plate body 1, and its structure is shown in Figures 9 to 11. For ease of description, the dissolving membrane 7 is divided into a sealing portion 13 and a fixing portion 14 according to different functions. The sealing portion 13 is annular, with the inner ring surface mating with the stopper of the protective membrane 6 and the outer ring surface being fixed to the inner wall of the opening 11. The fixing portion 14 is a column adapted to fit the blind holes 12 and is used to strengthen the bonding strength between the sealing assembly 2 and the cover plate body 1. As can be seen from Figure 8, in this embodiment, there are multiple blind holes 12, evenly distributed on the step surface 8. In other embodiments, there can also be one blind hole 12, which is simpler in structure than in this embodiment. However, the bonding strength between the sealing assembly 2 and the cover plate body 1 is weaker. When there is a slight pressure in the cavity of the single cell, the entire sealing assembly 2 may fall off the cover plate body 1, or cracks may form between the dissolving membrane 7 and the protective membrane 6, thereby impairing the performance of the single cell.

[0124] 12 , in this embodiment, the sealing assembly 2 can be fixed to the cover plate body 1 using the following process:

[0125] First, the protective film 6 is covered on the opening 11;

[0126] Next, hot melt material is poured into the dissolvable film installation space 10 . After the hot melt material cools down, a dissolvable film 7 is formed to achieve sealing while fixing the protective film 6 on the cover plate body 1 .

[0127] The liquid circuit can be opened by the following process:

[0128] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the electrolyte sharing pipeline to automatically dissolve the dissolving film 7 from the outside. Since the protective film 6 and the cover body 1 are not fixed in any way, when the dissolving film 7 dissolves, the protective film 6 will automatically fall off from the cover body 1, thereby allowing the electrolyte sharing pipeline to penetrate the inner cavity of the single battery, achieving the effect of the electrolyte of all single batteries being in the same system.

[0129] Example 2

[0130] As shown in FIG. 13 and FIG. 14 , this embodiment is described by taking the example of fixing the sealing assembly 2 to the upper cover plate of a single battery.

[0131] Different from the first embodiment, this embodiment has only one opening 11 , and its position on the cover body 1 is not limited. However, for the sake of structural symmetry, the opening 11 can be opened at the center of the cover body 1 .

[0132] The size of the opening 11 needs to ensure that the gas in the inner cavity of the single battery housing can escape and allow external electrolyte to enter the inner cavity of the single battery housing through the opening 11.

[0133] It should be noted that when the cover assembly is an upper cover, poles 15 need to be added to the cover body 1, and the opening 11 is located between the two poles 15. The opening 11 can be a round hole, a square hole or other polygonal hole, which can be selected according to actual needs.

[0134] The sealing assembly 2 can be fixed to the cover plate body 1 using the same method as in Example 1.

[0135] The gas line can be opened through the following process:

[0136] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the gas sharing pipeline assembly to automatically dissolve the dissolving film 7 from the outside. Since the protective film 6 and the cover plate body 1 are not fixed in any way, when the dissolving film 7 dissolves, the protective film 6 will automatically fall off from the cover plate body 1, thereby allowing the gas sharing pipeline assembly to penetrate the inner cavity of the single battery, achieving the effect of gas balance in all single batteries.

[0137] It should be noted that, in this embodiment, after the large-capacity battery is assembled, it can be turned upside down and the above-mentioned gas path unpacking process can be performed to ensure that the protective film 6 is completely detached from the cover plate body 1 .

[0138] Example 3

[0139] As shown in FIG15 and FIG16 , this embodiment is a single battery, the lower cover plate of which adopts the cover plate assembly in Example 1, and the upper cover plate adopts the cover plate assembly in Example 2.

[0140] Example 4

[0141] The large-capacity battery structures applicable to this embodiment include the following two types:

[0142] The first structure:

[0143] As shown in Figure 17, the large-capacity battery includes a box body 100 and N single cells 200; N ≥ 2; the N single cells 200 are connected in parallel in sequence and arranged in the inner cavity of the box body 100; the inner cavity of each single cell 200 includes an electrolyte area and a gas area, and the electrolyte areas of the inner cavity of each single cell 200 are interconnected, so that each single cell is in an electrolyte system; a pole avoidance hole is opened on the top of the box body 100 to enable the pole of each single cell 200 to extend out; the pole of each single cell 200 extends out of the pole avoidance hole and the box body area corresponding to the pole avoidance hole is fixedly sealed with the outer shell of the single cell 200.

[0144] In order to ensure the connectivity of the electrolyte in each single cell, an electrolyte channel is provided at the sealing component position of each single cell shell of the box body (the electrolyte channel is provided at the bottom of the box body). The electrolyte in each single cell is connected through the electrolyte channel, so that the continuity of the electrolyte liquid level is better.

[0145] The second structure:

[0146] As shown in Figure 18, the large-capacity battery includes a hollow component 300 and N single cells 200; N ≥ 2; the N single cells 200 are connected in parallel in sequence, and the inner cavity of each single cell 200 includes an electrolyte area and a gas area, and the electrolyte areas in the inner cavity of each single cell 200 are interconnected through the hollow component 300 (the hollow component is an electrolyte channel), thereby placing each single cell in an electrolyte system.

[0147] The hollow component 300 can be a complete circular or rectangular tube; the hollow component can also be formed by extruding and splicing the sub-pipelines on each single battery.

[0148] In both types of high-capacity batteries, interconnecting the electrolyte zones of the individual cells requires opening the sealing assembly 400 on the individual cells. As shown in Figure 19 , in this embodiment, the sealing assembly 400 includes a protective mechanism and a dissolving mechanism. The dissolving mechanism utilizes a columnar body 21 formed from an additive soluble in the electrolyte. At least the first end surface 22 of the columnar body 21 includes a separator, which acts as a protective mechanism and is insoluble in the electrolyte. The first end surface 22 is the surface closest to the cell's inner cavity. The separator is provided to prevent the electrolyte within the cell from dissolving the columnar body before the cell is opened.

[0149] The sealing assembly 400 is installed on the outer shell of the single battery 200. When the electrolyte is injected into the electrolyte channel, the sealing assembly 400 is dissolved, and a through hole is formed on the single battery 200, which enables the single battery to be unpacked. This process does not require special tooling, is simple to operate, and reduces production costs. At the same time, since the sealing assembly is formed using an electrolyte additive, it can improve the performance of large-capacity batteries to a certain extent after dissolving in the electrolyte.

[0150] Specifically, the columnar body is made of propylene sulfate, ethylene carbonate, or diphenyl carbonate as an electrolyte additive. The production process is as follows:

[0151] First, grind propylene sulfate crystals, ethylene carbonate crystals, or diphenyl carbonate crystals into powder;

[0152] The powder is then heated to convert it into a liquid additive;

[0153] Then pour the liquid additive into the mold prepared in advance, and form a column after natural cooling;

[0154] Finally, remove the column.

[0155] Among them, propylene sulfate as an electrolyte additive can improve the low-temperature performance of the electrolyte and prevent PC molecules from being embedded in the graphite electrode;

[0156] As an electrolyte additive, ethylene carbonate has the following functions:

[0157] 1. Transferring ions in battery reactions: In a battery, when the positive and negative electrodes react, ions need to move in the battery to complete the reaction. Ethylene carbonate acts as an electrolyte to transfer ions and promote the reaction.

[0158] 2. Maintaining Charge Balance: During battery reactions, the positive and negative electrodes consume or release charge. This charge balance must be maintained, otherwise battery performance and lifespan will be affected. Ethylene carbonate can maintain charge balance in the battery by transferring ions, ensuring proper functioning.

[0159] 3. Improve battery performance: improve battery conductivity, enhance battery stability and safety.

[0160] As an electrolyte additive, diphenyl carbonate has good redox stability and thermal stability, can provide high conductivity and extend battery life.

[0161] Therefore, in actual use, any one of the above three substances can be selected as the material to make the columnar body according to the needs, and then the performance of the battery can be improved and enhanced from different aspects.

[0162] The isolation film only needs to be non-reactive and insoluble in the electrolyte. While there are many such film materials, for safety and reliability reasons, the isolation film in this embodiment is preferably a PP film. When making the sealing assembly, the isolation film can be applied to the columnar body by heat sealing, coating, or gluing.

[0163] Preferably, as shown in FIG19 , since an electrolyte additive is used as a sealing component 400 in this embodiment, in order to allow the sealing component to slowly dissolve in the electrolyte and thus continuously improve electrolyte performance, the first end face 22, the second end face 23, and the side faces of the columnar body 21 are coated with a separator (the second end face 23 is the surface away from the inner cavity of the single cell), and a blind hole 24 is provided in the columnar body from the second end face 23 to the first end face 22. When electrolyte is injected into the electrolyte channel, due to the presence of the separator, the electrolyte can only contact the wall and bottom of the blind hole. First, the bottom of the blind hole is penetrated, and the single cell is opened. Since the rest of the columnar body is coated with the separator, the electrolyte only contacts the wall at all times, and the electrolyte continuously and slowly dissolves the columnar body.

[0164] Preferably, in order to achieve both fast unpacking speed and slow decomposition of the sealing component in the electrolyte, the depth of the blind hole 24 in this embodiment accounts for 90% of the length of the columnar body 21. In other words, the bottom of the blind hole is relatively thin, and the bottom of the blind hole will be penetrated in a short time, thereby achieving unpacking of the single battery.

[0165] Preferably, in order to enhance the sealing reliability of the sealing assembly to the single battery, a groove 25 for mounting a sealing ring is provided on the side wall of the columnar body 21 of this embodiment. The groove can be provided in the following manner:

[0166] 1. A circle of annular protrusions is set on the inner wall of the mold. After the liquid additive is poured into the mold and cooled, a groove can be formed on the columnar body.

[0167] 2. After the column is formed, a groove is formed on the column by machining.

[0168] Preferably, as shown in Figure 19, in order to facilitate the matching installation of the sealing assembly and the single cell housing, the columnar body 21 includes a first cylindrical section 211 and a second cylindrical section 212, the outer diameter of the first cylindrical section 211 is larger than the second cylindrical section 212, and the groove 25 is set on the side of the second cylindrical section 212.

[0169] As shown in Figures 20 and 21, this embodiment also provides a single cell 200, comprising a housing and a cell assembly. The cell assembly, also referred to herein as an electrode assembly, comprises a positive electrode, a separator, and a negative electrode arranged in sequence, assembled using a lamination or winding process. The housing comprises an upper cover, a lower cover, and a cylindrical body. In some cases, the lower cover and cylindrical body can also be integrally formed. The housing has a raised ring 26 (in this embodiment, the raised ring 26 is located at the bottom, i.e., on the lower cover), and a sealing assembly 400 is fixedly sealed within the raised ring 26.

[0170] There are several ways to fix the seal assembly to the convex ring:

[0171] 1. Apply adhesive to the outer wall of the sealing structure 400 or the inner wall of the protruding ring 26 to seal and fix them by bonding;

[0172] 2. The sealing assembly 400 is directly fixed in the raised ring 26 by means of interference fit;

[0173] 3. The sealing assembly 400 is fixed in the convex ring 26 by means of interference fit with the sealing ring 27.

[0174] Since method 3 is easy to operate and has stronger sealing reliability, method 3 is preferred in this embodiment.

[0175] Preferably, in order to ensure the flatness of the outer shape of the single battery, the protruding direction of the convex ring 26 in this embodiment is toward the inner cavity of the battery.

[0176] Since the most concentrated heat in the single cell 200 is at the pole, in this embodiment, each single cell pole is provided with a heat transfer tube clamping portion. Referring to Figures 17 and 18 , a heat transfer tube 500 is fixed to the heat transfer tube clamping portion of each single cell pole, and the heat transfer tube 500 is insulated from the heat transfer tube clamping portion of each single cell. This heat transfer tube not only achieves balanced heat dissipation for each single cell, improving the safety of large-capacity batteries, but also has a simple structure, is easy to manufacture and assemble, and has a low production cost. The heat transfer tube clamping portion can be a groove or a through-hole provided on the polarity terminal.

[0177] In other embodiments, the sealing component can also be set in a sheet shape and fixedly sealed on the through hole of the single cell shell by bonding. If a sheet-shaped sealing component is used, the sealing component can dissolve in a relatively short time. Therefore, it can only improve the electrolyte performance in the initial operation of the large-capacity battery, and the cycle life of the large-capacity battery is not significantly improved.

[0178] Examples 5 to 6 provide a sealing assembly; wherein the sealing assembly is used to be fixed on the single cell shell component to seal the opening on the single cell shell component and communicate with the inner cavity of the single cell shell. At the same time, the sealing assembly can also fall off from the single cell shell component under the action of external electrolyte to open the opening.

[0179] It should be noted that:

[0180] 1. The single cell battery described herein is a prismatic battery, comprising an upper cover, a lower cover, a barrel, a cell assembly, and an electrolyte. The upper or lower cover and the barrel can be integrally formed. The cell assembly, which can be referred to as an electrode assembly, consists of a positive electrode, a separator, and a negative electrode arranged in sequence, assembled using a lamination or winding process. The upper cover, barrel, and lower cover form the cell housing, within which the cell assembly and electrolyte are located.

[0181] 2. In Examples 5 and 6, the battery cell assembly described herein may also be a commercially available square-shell battery with through holes.

[0182] 3. The single cell housing member described herein may be a single cell housing, or may be a partial structure of a single cell housing, such as at least one of a single cell upper cover plate, a single cell lower cover plate, or a single cell cylinder.

[0183] 4. The external electrolyte mentioned above refers to the electrolyte outside the single cell shell, not the electrolyte in the inner cavity of the single cell. In other words, the sealing component cannot be opened through the electrolyte in the inner cavity of the single cell.

[0184] Embodiments 5 and 6 also provide a single cell housing member having the above-mentioned sealing assembly.

[0185] Examples 5 to 6 also disclose a single cell battery having the above-mentioned single cell battery shell component, wherein an opening penetrating the inner cavity of the single cell battery shell is provided on the single cell battery shell component, and a sealing assembly is fixed at the opening to seal the opening; under the action of an external electrolyte (an electrolyte located outside the single cell battery shell), part of the structure of the sealing assembly is dissolved, causing it to fall off from the single cell battery shell component, thereby opening the opening.

[0186] It should be noted here that:

[0187] If the battery cell assembly is a commercially available square-shell battery with a through hole, the opening is connected to the through hole on the commercially available square-shell battery.

[0188] The single cells provided in Examples 5 and 6 are mainly used to construct large-capacity batteries, such as the large-capacity batteries described in the background art Chinese patent CN220324596U, and can also be used to construct large-capacity batteries as disclosed in Chinese patents CN117477063A, CN117477186A, and CN115275453A.

[0189] Such a large-capacity battery comprises at least a plurality of single cells and at least one shared chamber;

[0190] The shared chamber described here is 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 shared channel described in CN115275453A.

[0191] When the single cell shell component is the lower cover of the single cell, the shared chamber can be used as an electrolyte sharing chamber. The external electrolyte (which can be understood as the electrolyte in the electrolyte sharing chamber) is used to dissolve part of the structure of the sealing component and form an opening in the lower cover. The electrolytes in the inner 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, reducing the differences between the electrolytes of each single cell, improving the consistency between the single cells to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0192] When the single cell shell component is the single cell upper cover, the shared chamber can also be used as a gas sharing chamber. The external electrolyte (which can be understood as the electrolyte in the gas sharing chamber) is used to dissolve part of the structure of the sealing component to form an opening in the upper cover. The gas in the inner cavity of each single cell is connected through the gas sharing chamber, so that the gas in the inner cavity of the entire large-capacity battery is balanced, which improves the cycle life of the large-capacity battery to a certain extent.

[0193] When the single cell shell component is a single cell cylinder, the shared chamber can be used as a gas-liquid shared chamber. The external electrolyte (which can be understood as the electrolyte in the gas-liquid shared chamber) is used to dissolve part of the structure of the sealing component to form an opening on the side wall of the cylinder. The electrolyte and gas in the inner cavity of each single cell can be connected through the gas-liquid shared chamber, so that the electrolyte and gas of all single cells are in the same system, reducing the differences between the single cells, and improving the consistency between the single cells to a certain extent, thereby improving the cycle life of the large-capacity battery to a certain extent.

[0194] The following describes Examples 5 and 6 in detail with reference to the accompanying drawings.

[0195] Example 5

[0196] This embodiment is mainly described by taking the single cell housing component as a single cell lower cover plate as an example.

[0197] FIG22 is a schematic structural diagram of the lower cover plate of a single cell according to this embodiment. As can be seen from the figure, the lower cover plate of the single cell according to this embodiment includes a cover plate body 31 and a sealing assembly 32 fixed on the cover plate body 31.

[0198] As shown in Figure 23, the cover plate body 31 of this embodiment is a rectangular plate with an area slightly larger than the open end of the cylinder. It is fixed to the open end of the cylinder by welding. Alternatively, a first step structure can be provided around the cover plate body 31 to achieve fixation by welding. The stepped surface of the first step structure can also be used as a positioning surface. This positioning surface can be used to first position the cover plate at the open end of the cylinder and then fix it by welding. The area of ​​the cover plate body 31 can also be slightly smaller than the open end of the cylinder and fixed to the open end of the cylinder by insert welding. In other embodiments, the cover plate body 31 and the cylinder are integral.

[0199] An opening 311 is provided on the cover body 31 . The position of the opening 311 should correspond to the shared cavity in the large-capacity battery. Generally, the opening 311 can be placed in the center of the cover body 31 .

[0200] The size of the opening 311 needs to meet the following conditions:

[0201] 1. The opening 311 cannot be too large to ensure that the entire cover body 31 has a certain strength, so as to avoid the cover body 31 from being damaged due to poor strength before the sealing component 32 at the opening 311 is opened, thus causing the single battery to be scrapped;

[0202] 2. The opening 311 cannot be too small to ensure that after the sealing assembly 32 at the opening 311 is opened, the electrolyte area of ​​each single cell cavity and the shared chamber cavity are smoothly connected to ensure a good sharing effect.

[0203] In other embodiments, two openings 311 may be provided in the cover plate body 31. Generally, the two openings 311 are arranged along the length of the cover plate body and are symmetrical with each other. When the electrode assembly within the single cell utilizes a wound core, there is a large space between the widthwise sidewalls of the cell housing and the core. Providing the through-hole close to the widthwise edge of the cover plate body 31 ensures, firstly, that the through-hole has no effect on the internal cell structure. Secondly, after opening the sealing assembly 32 in this area, the electrolyte in the shared chamber can better enter the cell cavity.

[0204] In embodiments 5 and 6, the shape of the opening 311 is not limited. As can be seen from Figure 24, the opening 311 in this embodiment is a circular straight-through hole. In other embodiments, the shape of the opening 311 can be adjusted according to actual needs, such as a rectangular hole, an elliptical hole, etc.

[0205] As shown in FIG. 25 , the sealing assembly 32 of this embodiment includes a protection mechanism and a dissolving mechanism. The protection mechanism is a protection cap 321 , and the dissolving mechanism is a dissolving film layer 322 .

[0206] The structure of the protective cap 321 is shown in Figures 26 and 27 , and includes an annular sidewall 3211 and a bottom plate 3212 fixed to one end of the annular sidewall 3211 and sealing the open end. Its shape matches the shape of the opening 311, and a first annular groove 3213 is defined along the outer surface of the annular sidewall 3211 along its circumference. This first annular groove 3213 allows the protective cap 321 to be secured to the cover body 31. The specific securing method is shown in Figure 28 : the area of ​​the cover body 31 surrounding the opening 311 is embedded in the first annular groove 3213, with the open end of the protective cap 321 located outside the inner cavity of the single cell housing, while the bottom plate 3212 of the protective cap 321 is located within the inner cavity of the single cell housing.

[0207] In this embodiment, the material of the protective cap 321 is an electrolyte-insoluble material and has a certain strength to prevent the protective cap 321 from being damaged by the pressure of the electrolyte inside the single cell due to poor strength before the sealing component 32 at the opening 311 is opened, thereby causing the single cell to be scrapped.

[0208] At the same time, the protective cap 321 of this embodiment also needs to have a certain degree of elasticity. On the one hand, it can be easily fixed to the opening of the cover body 31. On the other hand, when the inner cavity of the protective cap 321 is filled with the dissolving film layer 322, the protective cap 321 can be squeezed and deformed, so that its annular side wall 3211 fits tightly with the cover body 31, ensuring the sealing performance of the sealing component to the opening.

[0209] Therefore, in this embodiment, the protective cap 321 can generally be made of PP or rubber (such as EPDM rubber) with a certain elasticity.

[0210] As described above, in Examples 5 and 6, the inner cavity of the protective cap 321 is used as the dissolving film layer accommodating cavity 3215; in conjunction with Figure 29, the dissolving film layer 322 is fixed in the dissolving film layer accommodating cavity 3215, so that the dissolving film layer accommodating cavity 3215 is expanded, and the annular side wall 3211 of the protective cap 321 is squeezed to fit tightly with the cover plate body 31, and the protective cap 321 is fixed on the cover plate body 31, while the opening 311 is sealed.

[0211] In this embodiment, dissolving film layer 322 is made of an electrolyte-soluble material. Generally, the block-shaped dissolving film layer 322 can be inserted into dissolving film layer accommodating cavity 3215 to expand dissolving film layer accommodating cavity 3215. The material of dissolving film layer 322 is at least one of PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12, and PVC.

[0212] To enhance the bonding strength between the dissolving film layer 322 and the protective cap 321, as shown in Figures 28 and 29, a second annular groove 3214 is formed on the inner surface of the annular sidewall 3211 of the protective cap 321 along the circumference of the annular sidewall 3211. The dissolving film layer 322 forms an annular protrusion at this location that fits into the second annular groove 3214.

[0213] As shown in FIG30 , this is a single cell with the above-mentioned lower cover plate of this embodiment;

[0214] In this embodiment, the sealing assembly 32 can be fixed to the cover plate body 31 using the following process:

[0215] First, fix the protective cap 321 to the opening 311 of the cover body 31 so that the edge of the opening 311 is embedded in the first annular groove 3213 of the protective cap 321;

[0216] Secondly, hot melt material is poured into the dissolving film layer accommodating cavity 3215 to expand the dissolving film layer accommodating cavity 3215, and the annular side wall 3211 of the protective cap 321 is squeezed to fit tightly with the cover plate body 31, thereby sealing the opening 311; after the hot melt material cools, a dissolving film layer 322 is formed.

[0217] The liquid circuit can be opened by the following process:

[0218] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the electrolyte sharing chamber to automatically dissolve the dissolving film layer 322 from the outside. Since the protective cap 321 has a certain elasticity, it is assembled with the cover plate body 31 only in a manner similar to a stopper. Therefore, when the dissolving film layer 322 dissolves, the protective cap 321 will shrink to its original size and automatically fall off from the cover plate body 31 (see Figures 31 and 32), thereby allowing the electrolyte sharing chamber to communicate with the inner cavity of the single battery, achieving the effect that the electrolyte of all single batteries is in the same system.

[0219] Example 6

[0220] This embodiment is described by taking the single cell housing component as a single cell upper cover plate as an example.

[0221] As shown in Figures 33 and 34, the opening 311 in this embodiment is located between the two poles 33. The opening 311 can be a circular hole, a square hole, or other polygonal hole, and the specific selection can be based on actual needs. In other embodiments, there can also be two openings 311, one on each side of the two poles 33.

[0222] The size of the opening 311 needs to ensure that the gas in the inner cavity of the single cell housing can escape and allow external electrolyte to enter the inner cavity of the single cell housing through the opening 311 .

[0223] The sealing assembly 32 can be fixed to the cover plate body 31 using the same method as in Example 5.

[0224] The gas line can be opened through the following process:

[0225] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the gas sharing chamber to automatically dissolve the dissolving film layer 322 from the outside. Since the protective cap 321 has a certain elasticity, it is assembled with the cover plate body 31 only in a manner similar to a stopper. Therefore, when the dissolving film layer 322 dissolves, the protective cap 321 will shrink to its original size and automatically fall off from the cover plate body 31, thereby allowing the gas sharing chamber to communicate with the inner cavity of the single battery, achieving the effect of gas balance in all single batteries.

Claims

1. A sealing assembly, characterized in that: Used to seal the opening on the housing of a single cell, including a protection mechanism and a dissolving mechanism; The protection mechanism is used to isolate the dissolving mechanism from the electrolyte in the inner cavity of the single cell; The dissolving mechanism is used to dissolve under the action of external electrolyte and make the protective mechanism fall off from the single battery shell; the material of the dissolving mechanism is electrolyte soluble material, and the material of the protective mechanism is electrolyte insoluble material.

2. The sealing assembly according to claim 1, characterized in that: The protective mechanism is a protective film; the dissolving mechanism is a dissolving film; The protective film is in sheet form and is used to cover the opening; the dissolving film is in ring form and is used to be fixed on the outer surface area of ​​the shell around the edge of the protective film and the opening, so as to fix the protective film on the shell.

3. The sealing assembly according to claim 2, characterized in that: The dissolving film is fixed on the outer surface area of ​​the shell around the edge of the protective film and the opening in a casting manner.

4. The sealing assembly according to claim 3, characterized in that: A second step structure is provided at the edge of the protective film along the circumference thereof.

5. The sealing assembly according to any one of claims 2 to 4, characterized in that: The material of the dissolving film is PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12 or PVC.

6. The sealing assembly according to any one of claims 2 to 4, characterized in that: The material of the protective film is aluminum, copper, zinc, nickel, silver, epoxy resin, PE, PP, polytetrafluoroethylene or EPDM rubber.

7. The sealing assembly according to claim 1, characterized in that: The dissolving mechanism is a columnar body formed by an additive that can be dissolved in the electrolyte; the protecting mechanism is an isolation film arranged on at least the first end surface of the columnar body.

8. The sealing assembly according to claim 7, characterized in that: The columnar body is made of propylene sulfate, ethylene carbonate or diphenyl carbonate.

9. The sealing assembly according to claim 8, characterized in that: The first end surface, the second end surface and the side surface of the columnar body are covered with an isolation film, and a blind hole is arranged on the columnar body from the second end surface to the first end surface.

10. The sealing assembly according to claim 9, characterized in that: The hole depth of the blind hole accounts for 90% of the length of the columnar body.

11. The sealing assembly according to any one of claims 7 to 10, characterized in that: A circle of grooves for installing a sealing ring is engraved on the side wall of the columnar body.

12. The sealing assembly according to claim 11, characterized in that: The columnar body comprises a first cylindrical section and a second cylindrical section, the outer diameter of the first cylindrical section is larger than that of the second cylindrical section, and the groove is arranged on the side surface of the second cylindrical section.

13. The sealing assembly according to claim 12, characterized in that: The isolation film is a PP film.

14. The sealing assembly according to claim 1, characterized in that: The protection mechanism is a protection cap; the dissolving mechanism is a dissolving film layer; The protective cap includes an annular side wall and a bottom plate; the annular side wall is used to be fixed to the single cell housing component area around the opening, the bottom plate is located in the inner cavity of the single cell housing, and the cavity of the protective cap serves as a dissolving film layer accommodating cavity; The dissolving film layer is fixed in the dissolving film layer containing cavity, so that the dissolving film layer containing cavity is expanded, and the annular side wall of the extruded protective cap is fitted with the single cell housing component area around the opening, thereby sealing the opening; The material of the protective cap is elastic.

15. The sealing assembly according to claim 14, characterized in that: A first annular groove is formed on the outer surface of the annular side wall of the protection cap along the circumference thereof.

16. The sealing assembly according to claim 14 or 15, characterized in that: A second annular groove is provided on the inner surface of the annular side wall of the protective cap along its circumference; and the dissolving film layer is provided with an annular protrusion embedded in the second annular groove.

17. The sealing assembly according to claim 14, characterized in that: The material of the dissolving film layer is PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12 or PVC.

18. The sealing assembly according to claim 14, characterized in that: The material of the protective cap is PP or EPDM rubber.

19. A cover plate assembly, characterized in that: It comprises a cover plate body, an opening is formed on the cover plate body, and a sealing assembly according to any one of claims 1 to 6 is arranged at the opening.

20. The cover plate assembly according to claim 19, characterized in that: The opening is a stepped through hole, and the large hole is located on the outer surface of the cover plate body; The protective film is located in the macropore, and a dissolving film installation space is formed between the protective film, the step surface and the macropore wall; The dissolving membrane is fixed in the dissolving membrane installation space.

21. The cover plate assembly according to claim 20, characterized in that: A protrusion is arranged on the inner surface of the cover plate body, and a stepped through hole penetrating the cover plate body is opened on the protrusion as the opening.

22. The cover plate assembly according to claim 21, characterized in that: A plurality of blind holes are arranged on the step surface along its circumference.

23. The cover plate assembly according to claim 19, characterized in that: There are two openings, which are symmetrically arranged on the cover plate body along the length direction of the cover plate body.

24. A cylinder, characterized in that: It comprises a cylinder body, an opening is formed on the cylinder body, and a sealing assembly according to any one of claims 1 to 6 is arranged at the opening.

25. A single cell battery, characterized in that: It comprises a shell, wherein the shell has an opening penetrating the inner cavity of the single battery; the sealing assembly according to any one of claims 1 to 6 is arranged at the opening.

26. A single cell battery, characterized in that: It comprises a battery housing and a sealing assembly as claimed in any one of claims 7 to 13; the battery housing is provided with a convex ring, and the sealing assembly is fixedly sealed in the convex ring.

27. The single cell according to claim 26, characterized in that: The protruding direction of the convex ring faces the inner cavity of the battery.

28. The single cell according to claim 27, characterized in that: The pole of the single cell is provided with a clamping part for clamping the heat transfer tube.

29. A single cell housing component, characterized in that: An opening penetrating the inner cavity of the single cell housing is provided on the single cell housing component, and a sealing assembly according to any one of claims 14 to 18 is fixed to the single cell housing component region around the opening.

30. A single cell battery, characterized in that: The invention comprises a single cell casing member as claimed in claim 29.

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