Sealing mechanism for single battery and single battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a sealing mechanism for a single battery and the single battery. The sealing mechanism is used for being fixed on a single battery shell and sealing an opening in the single battery shell; comprising a sealing plate and sealing assemblies. The sealing plate is used for being fixedly connected with a single battery shell, and at least two first through holes communicated with the opening are formed in the sealing plate; the sealing assembly is fixed on the sealing plate and seals the first through hole; through external force or external electrolyte, the sealing assembly can fall off from the sealing plate or form an open hole penetrating through the first through hole and the opening in the sealing assembly. According to the utility model, only one opening needs to be formed in the shell of the single battery, and the sealing mechanism is used as a whole to seal the opening. On the premise of ensuring reliable sharing, the risk of damage to the electrode assembly in the opening process is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, in particular to a sealing mechanism for a single cell battery and a single cell battery. Background Art

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

[0003] However, the individual cells in existing large-capacity batteries are different from each other. Due to the existence of the barrel effect, they are often affected by the cell with the worst performance, which greatly limits the capacity limit and cycle times of the entire large-capacity battery. Therefore, how to improve the uniformity of each cell in a large-capacity battery has become the focus and difficulty of research in this field.

[0004] In order to solve the above problems, Chinese patent CN117477186A discloses a large-capacity battery, such as Figure 1 As shown, the electrolyte areas of all single cells 03 are connected by a first hollow component 01 fixed at the bottom of each single cell to achieve electrolyte sharing; the gas areas of all single cells 03 are connected by a second hollow component 02 fixed at the top of each single cell to achieve gas sharing, and the gas of each single cell 03 is balanced, thereby improving the performance and charge and discharge cycle life of large-capacity batteries.

[0005] After the assembly of the above-mentioned large-capacity battery is completed, the first hollow member 01 can be connected to the electrolyte area of ​​all the single cells by opening the sealing assembly sealed at the through hole position of the lower cover plate of the single cell 03. The sealing assembly sealed at the through hole position of the upper cover plate of the single cell 03 is opened to connect the second hollow member 02 with the gas area of ​​all the single cells.

[0006] Based on the functions of the first hollow member and the second hollow member, they can be collectively referred to as a shared chamber. Since the first hollow member is connected to the electrolyte areas of all the single cells, it can be further referred to as an electrolyte shared chamber, and correspondingly, the second hollow member can be referred to as a gas shared chamber.

[0007] In order to improve the reliability of the above-mentioned sharing effect, at least two through holes can be opened on the single cell cover plate. When the sealing assembly at one of the through holes cannot be opened smoothly, the sealing assembly at the remaining through holes can be opened to make the inner cavity of the single cell and the inner cavity of the shared chamber connected, thereby improving the sharing success rate.

[0008] To prepare the above-mentioned single cell battery, it is first necessary to open a through hole in the single cell battery cover (upper cover or lower cover), and then install the sealing assembly on the cover to seal the through hole; however, in the process of opening the through hole, there is a risk that the hole-opening tool will damage the electrode assembly inside the shell. The more through holes there are, the greater the risk. If one is not careful, the entire single cell battery may be scrapped due to damage to the electrode assembly. Utility Model Content

[0009] The utility model aims to provide a sealing mechanism for a single cell and a single cell, which can reduce the risk of damaging an electrode assembly during the process of opening a through hole while ensuring shared reliability.

[0010] The technical solution of the utility model is to provide a sealing mechanism for a single cell battery, which is special in that it is used to be fixed on a single cell battery housing and seal the opening on the single cell battery housing; it includes a sealing plate and a sealing assembly;

[0011] The sealing plate is used to be fixedly connected to the single battery housing, and the sealing plate is provided with at least two first through holes that penetrate the opening;

[0012] The sealing assembly is fixed on the sealing plate and seals the first through hole;

[0013] The sealing component can be detached from the sealing plate or an opening penetrating the first through hole and the opening can be formed in the sealing component by external force or external electrolyte.

[0014] The utility model additionally introduces a sealing mechanism, and at least two first through holes are opened on the sealing plate of the sealing mechanism, and the sealing assembly is used for sealing; accordingly, only one opening needs to be opened on the single cell housing (the single cell housing described herein includes at least one of the single cell upper cover plate, the single cell lower cover plate or the single cell cylinder), and the sealing mechanism is used as a whole to seal the opening. By increasing the number of first through holes on the sealing plate, the reliability of sharing can be ensured, and there is no need to open multiple openings on the single cell housing, thereby reducing the risk of damage to the electrode assembly during the opening process.

[0015] Furthermore, there are two first through holes, which are symmetrically arranged on the sealing plate along the length direction of the sealing plate, so as to ensure the overall strength of the sealing plate before unpacking and improve the sharing reliability of each single battery.

[0016] Furthermore, the sealing assembly includes a protective layer and a dissolving layer; the protective layer is in sheet form and covers the first through hole; the dissolving layer is in annular form and is fixed to the outer surface area of ​​the sealing plate between the edge of the protective layer and the periphery of the first through hole, and the protective layer is fixed to the sealing plate;

[0017] The material of the dissolving layer is a material soluble in the electrolyte, and the material of the protective layer is a material insoluble in the electrolyte.

[0018] The protective layer is fixed on the sealing plate by using an annular dissolving layer, and the dissolving layer can well seal the gap between the protective layer and the sealing plate area around the first through hole; after the sealing mechanism is fixed on the single cell shell, the electrolyte in the inner cavity of the single cell shell is in direct contact with the protective layer, but cannot contact with the dissolving layer located on the outer surface of the shell, so that during the assembly process of the large-capacity battery (before unpacking), the first through hole of each single cell has good sealing performance; during the unpacking process, the electrolyte is injected into the shared chamber, and under the action of the electrolyte, the dissolving layer melts, and the protective layer falls off the sealing plate, thereby connecting the inner cavity of each single cell shell with the inner cavity of the shared chamber. Because the utility model adopts an annular dissolving layer, under the condition of the same outer diameter, the annular dissolving layer has a smaller area than the circular dissolving layer (the dissolving layer in the background technology), so compared with the dissolving layer in the background technology, the dissolving time of the utility model is shorter, which can shorten the preparation time of large-capacity batteries and improve production efficiency. In addition, the dissolving layer of the utility model serves as a sealing component and a fixing mechanism at the same time, and there is no need to introduce an additional fixing mechanism of the sealing component, so that the overall structure of the sealing component is simple and the manufacturing cost is low.

[0019] Furthermore, the dissolving layer is fixed on the outer surface area of ​​the sealing plate around the edge of the protective layer and the first through hole by pouring. Generally, a hot-melt slurry soluble in electrolyte can be poured on the outer surface area of ​​the sealing plate around the edge of the protective layer and the first through hole. After cooling, a dissolving layer can be formed, and the protective layer can be fixed on the sealing plate while achieving sealing.

[0020] Furthermore, the first through hole is a stepped through hole, and a large hole of the stepped through hole is close to the outer surface of the sealing plate;

[0021] The protective layer is located in the large hole of the step through hole, and a second step structure is provided at the edge of the protective layer along its circumference, so that the dissolving layer can be fixed to it by means of stopper matching, which can improve the bonding strength between the two and further improve the sealing reliability of this part. A dissolving layer installation space is formed between the protective layer, the step surface of the step through hole, and the wall of the large hole of the step through hole; the dissolving layer is fixed in the dissolving layer installation space. Through such an arrangement, the outer surface of the sealing mechanism can be made into the same plane, and after it is fixed on the housing of the single cell, the structural regularity of the single cell can be improved.

[0022] Furthermore, when the sealing plate is thin, a protrusion may be provided on the inner surface of the sealing plate, and a stepped through hole penetrating the sealing plate is provided on the protrusion as the first through hole.

[0023] 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 layer and the sealing plate.

[0024] Furthermore, the material of the dissolving layer 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).

[0025] Furthermore, the material of the protective layer is aluminum, copper, zinc, nickel, silver, epoxy resin, PE (polyethylene), PP (polypropylene), polytetrafluoroethylene or EPDM rubber.

[0026] The utility model also provides a single cell battery, including a housing, which is special in that it also includes the above-mentioned sealing mechanism for the single cell battery;

[0027] An opening is provided on the shell;

[0028] The single cell is fixed to the single cell housing by welding using a sealing mechanism, and the opening on the single cell housing is sealed.

[0029] The beneficial effects of the utility model are:

[0030] The utility model transfers the through hole sealed with the sealing assembly in the background technology (corresponding to the first through hole of the utility model) from the single cell housing (the single cell housing described herein includes at least one of the single cell upper cover plate, the single cell lower cover plate or the single cell cylinder) to an independent component, namely the sealing mechanism described in the utility model (at least two first through holes are opened on the sealing plate of the sealing mechanism, and the sealing assembly is used for sealing); accordingly, only one opening needs to be opened on the single cell housing, and the sealing mechanism is used as a whole to seal the opening. When it is necessary to improve the shared reliability, it is only necessary to increase the number of first through holes on the sealing plate, seal the first through hole with the sealing assembly, fix the sealing mechanism at the opening position, and seal the opening, without opening multiple openings on the single cell housing, thereby reducing the risk of damage to the electrode assembly during the opening process.

[0031] In addition, the utility model opens a first through hole on an independent sealing plate and fixes a sealing component at the first through hole position. Compared with the solution of opening a through hole in a single battery housing and fixing the sealing component at the through hole position, the opening of the first through hole and the fixing of the sealing component are relatively simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a large-capacity battery in the background technology;

[0033] Figure 2This is a schematic structural diagram of a sealing mechanism for a single cell in Example 1;

[0034] Figure 3 This is an exploded schematic diagram of the sealing mechanism for a single cell in Example 1;

[0035] Figure 4 This is a schematic diagram of an explosion of a single cell in Example 1;

[0036] Figure 5 This is a schematic diagram of the structure of a single cell in Example 1;

[0037] Figure 6 This is a schematic structural diagram of a single cell in Example 1 from another perspective;

[0038] Figure 7 It is a partial cross-sectional view of a single cell of Example 1;

[0039] Figure 8 This is a schematic diagram of a partial explosion of a single cell in Example 1;

[0040] Fig. 9 is a cross-sectional view of a sealing plate in Example 2;

[0041] Fig.10 is a cross-sectional view of another sealing plate in Example 2;

[0042] Fig.11 is a schematic structural diagram of the sealing mechanism in Example 2;

[0043] Fig.12 This is an exploded schematic diagram of the sealing mechanism in Example 2;

[0044] Fig.13 is a cross-sectional view of a sealing mechanism in Example 2;

[0045] Fig.14 is a cross-sectional view of another sealing mechanism of Example 2;

[0046] Fig.15 This is an exploded schematic diagram of the sealing assembly in Example 2;

[0047] The accompanying drawings in the figure are marked as follows:

[0048] 01. first hollow member; 02. second hollow member; 03. single cell;

[0049] 1. Sealing plate; 11. First through hole; 12. Outer surface of sealing plate; 13. Protrusion; 14. Blind hole; 15. Step surface; 2. Sealing assembly; 21. Protective layer; 22. Dissolving layer; 221. Sealing part; 222. Fixing part; 23. O-ring; 24. Annular groove; 3. Single cell housing; 31. Opening; 32. Electrode assembly; 33. Lower cover plate; 4. Pole; 41. Heat transfer tube clamping part; 42. Second end face; 43. Side wall. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and 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.

[0052] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom, upper, lower" etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0053] The utility model provides a sealing mechanism for a single cell, which is used for being fixed on a single cell shell and sealing an opening on the single cell shell and communicating with an inner cavity of the single cell shell; the sealing mechanism comprises a sealing plate and a sealing component; the sealing plate is fixedly connected with the single cell shell, a first through hole communicating with the opening is provided on the sealing plate, and the sealing component is fixed on the sealing plate and seals the first through hole; such a sealing component can fall off from the sealing plate by external force or external electrolyte, or an opening communicating with the first through hole and the opening is formed in the sealing component.

[0054] It should be noted that:

[0055] 1. The single cell battery described herein is a square shell battery, including an upper cover plate, a lower cover plate, a cylinder, a battery cell assembly and an electrolyte; the upper cover plate or the lower cover plate and the cylinder can be integrally formed;

[0056] In the present invention, the battery cell assembly described here can be referred to as an electrode assembly, which is composed of a positive electrode, a separator, and a negative electrode arranged in sequence and assembled by a lamination or winding process. The upper cover plate, the cylinder, and the lower cover plate constitute a single battery shell, and the battery cell assembly and the electrolyte are located in the single battery shell;

[0057] In the present invention, the battery cell assembly described herein may also be a commercially available square shell battery having a second through hole, and the second through hole is connected to the opening.

[0058] 2. The shell described herein includes at least one of a single cell barrel, a single cell lower cover plate or a single cell upper cover plate, that is, the above-mentioned opening can be opened on at least one of the single cell barrel, the single cell lower cover plate or the single cell upper cover plate.

[0059] 3. The external electrolyte mentioned above refers to the electrolyte outside the housing of the single cell, not the electrolyte in the inner cavity of the single cell. That is to say, the sealing assembly cannot be opened through the electrolyte in the inner cavity of the single cell.

[0060] The utility model also provides a single cell with the above sealing mechanism. An opening penetrating the inner cavity of the single cell shell is provided on the single cell shell, and the sealing mechanism is fixed at the opening to seal the opening; the sealing assembly can be caused to fall off from the sealing plate by external force or external electrolyte, or an opening penetrating the first through hole and the opening can be formed in the sealing assembly.

[0061] The single cell provided by the utility model is mainly used to construct a large-capacity battery, such as the large-capacity battery described in the background technology Chinese patent CN117477186A, and can also be used to construct a large-capacity battery disclosed in Chinese patents CN117477063A, CN220324596U, and CN115275453A.

[0062] Such a large-capacity battery comprises at least a plurality of single cells and at least one shared chamber;

[0063] The shared chamber described here is the first hollow member and the second hollow member described in CN117477186A, the hollow member described in CN117477063A, the shared chamber described in CN220324596U, and the electrolyte shared channel described in CN115275453A.

[0064] When the opening is opened in 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 to 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 each single cell to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0065] When an opening is opened on the upper cover of a single cell, the shared chamber can also be used as a gas sharing chamber. An 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 gases in the inner cavities of each single cell are 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.

[0066] When the opening is opened in the 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 sharing 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 sharing chamber, so that the electrolyte and gas of all single cells are in the same system, which reduces the differences between 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.

[0067] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0068] Example 1

[0069] like Figure 2 and Figure 3 As shown in the figure, the structural schematic diagram and the exploded diagram of the sealing mechanism of this embodiment are shown respectively. As can be seen from the figure, the sealing mechanism for the single cell of this embodiment comprises a sealing plate 1 and a sealing assembly 2 fixed on the sealing plate 1.

[0070] The sealing plate 1 is used to be fixed on the single battery housing 3. Its shape is adapted to the shape of the opening 31 on the single battery housing 3. This embodiment is described by taking the rectangular opening 31 as an example. Figure 4 , as shown in FIG4 , the opening 31 is opened on the lower cover plate of the single cell as an example.

[0071] Corresponding to the rectangular opening 31, this embodiment adopts a rectangular sealing plate 1. For the convenience of description, the length direction of the sealing plate 1 can be defined as the x direction, the width direction as the y direction, and the thickness direction as the z direction.

[0072] The area of ​​the sealing plate 1 can be slightly larger than the area of ​​the opening 31, and it can be fixed to the opening 31 of the single battery housing 3 by welding; the first step structure can also be arranged around the sealing plate 1, and fixed by welding. The step surface 15 of the first step structure can also be used as a positioning surface, and the sealing plate 1 can be positioned at the housing opening 31 by using the positioning surface, and then fixed by welding. The area of ​​the sealing plate 1 can also be slightly smaller than the area of ​​the opening 31, and it can be fixed to the housing opening 31 by embedding welding.

[0073] Two first through holes 11 are provided on the sealing plate 1. The two first through holes 11 are arranged along the x direction and are symmetrical to each other. As can be seen from the figure, the two first through holes 11 are provided near the edge in the width direction of the sealing plate 1. When the battery cell inside the single cell adopts a winding core formed by winding, there is a large space between the side wall 43 in the width direction of the single cell housing 3 and the winding core. When the first through hole 11 is provided near the edge in the width direction of the sealing plate 1, after the sealing assembly 2 at this position is opened, the electrolyte in the inner cavity of the electrolyte sharing chamber can better enter the inner cavity of the single cell.

[0074] The size of the first through hole 11 needs to meet the following conditions:

[0075] 1. The first through hole 11 cannot be too large to ensure that the entire sealing plate 1 has a certain strength, so as to avoid the sealing plate 1 from being scrapped due to poor strength before the sealing assembly 2 at the first through hole 11 is opened;

[0076] 2. The first through hole 11 cannot be too small to ensure that after the sealing assembly 2 at the first through hole 11 is opened, the electrolyte area in the inner cavity of each single battery and the inner cavity of the electrolyte sharing chamber are smoothly connected to ensure a good sharing effect.

[0077] In some other embodiments, three or more first through holes 11 may be provided on the sealing plate 1, and the first through holes 11 may be evenly distributed on the sealing plate 1. The size of the first through holes 11 still needs to meet the above two conditions.

[0078] In this embodiment, the sealing component 2 can adopt the sealing film disclosed in Chinese patent CN218525645U; the patent discloses two types of sealing films, one type of sealing film can be dissolved when encountering electrolyte; the other type of sealing film can be opened under the action of external force.

[0079] When a sealing film that is soluble in electrolyte is used, a protective layer that is insoluble in electrolyte is generally provided on the side of the sealing film that faces the inside of the single battery housing 3. When the sealing film is dissolved in the electrolyte, the protective layer falls off.

[0080] Figure 5 and Figure 6Schematic diagram of the structure of the single cell of this embodiment from different perspectives. This embodiment mainly takes the single cell with the opening 31 opened in the lower cover plate 33 as an example. Figure 4 , Figure 5 and Figure 6 It can be seen that in this embodiment, a rectangular opening 31 is opened on the lower cover plate 33 of the single cell, and the single cell is welded and fixed on the lower cover plate 33 of the single cell by a sealing mechanism, and the opening 31 on the lower cover plate 33 of the single cell is sealed.

[0081] like Figure 7 , which is a partial cross-sectional view of a single cell in this embodiment. In this embodiment, the area of ​​the sealing plate 1 is slightly smaller than the area of ​​the opening 31 , and the sealing plate 1 is fixed at the shell opening 31 by embedding welding.

[0082] from Figure 6 It can be seen that in this embodiment, a through groove is provided in the single cell pole 4 as a heat transfer tube clamping portion 41; in this embodiment, the single cell pole 4 is a cylinder, including a first end face, a second end face 42 and a side wall 43 (the first end face and the second end face 42 are parallel to each other), and the through groove is provided in the polarity terminal side wall 43, that is, the opening of the through groove is located on the side wall 43.

[0083] In some other embodiments, a through hole may be further provided on the side wall 43 , that is, the opening of the through hole is located on the side wall 43 .

[0084] In some other embodiments, a through groove may be further provided on the second end surface 42 , that is, the opening of the through groove is located on the second end surface 42 .

[0085] The second end face 42 serves as the electrical connection portion of the pole 4 and is used to connect to an electrical connector to achieve electrical connection between individual cells and / or two large-capacity batteries; the first end face is used to electrically connect to the electrode assembly 32 in the cell housing 3 .

[0086] The through grooves and through holes are provided on the side wall 43. Compared with the through grooves provided on the second end face 42, the contact area between the heat transfer tube and the inner wall of the through groove or through hole is larger, and the heat exchange efficiency is higher. In addition, when the through grooves and through holes are located on the side wall 43, the entire area of ​​the second end face 42 can be used as an electrical connection area. Two through grooves or through holes can also be provided on the side wall 43 of the polarity terminal at the same time to increase the number of heat transfer tubes placed and further improve the heat exchange efficiency. Compared with the through hole structure, the through groove makes the heat transfer tube easier to install.

[0087] The cross section of the through groove is C-shaped. The opening width of the through groove with a C-shaped cross section is smaller than the widest part of the through groove. Such a design is conducive to the interference fit of the heat transfer tube in the through groove. The arcs formed at both ends of the C-shaped through groove have natural tension, which is conducive to the tight fit of the heat transfer tube in the through groove.

[0088] The heat transfer tube is fixed in the through groove or through hole (the heat transfer tube is insulated from the single battery). When the temperature of the large-capacity battery is higher than the set threshold, a heat transfer medium with a lower temperature is introduced into the heat transfer tube to cool the large-capacity battery; when the temperature of the large-capacity battery is lower than the set threshold, a heat transfer medium with a higher temperature is introduced into the heat transfer tube to heat the large-capacity battery; by controlling the temperature of the heat transfer medium, it can be ensured that the large-capacity battery always operates at a normal operating temperature.

[0089] The single cell in this embodiment can be prepared by the following process:

[0090] like Figure 8 As shown, an opening 31 is provided on the lower cover plate 33 of the single battery;

[0091] The sealing mechanism is welded and fixed as a whole to the peripheral area of ​​the opening 31 of the lower cover plate 33 to seal the opening 31 .

[0092] In this embodiment, only one opening is required on the single battery housing, and the sealing mechanism is used as a whole to seal the opening, without the need to provide multiple openings on the single battery housing, thereby reducing the risk of damaging the electrode assembly during the opening process.

[0093] Using a sealing film that is soluble in electrolyte, the liquid circuit can be opened through the following process:

[0094] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the electrolyte sharing chamber, and the sealing films at the two first through holes 11 are automatically dissolved from the outside; because the protective layer and the sealing plate 1 are not fixed in any way, when the sealing film is dissolved, the protective layer will automatically fall off the sealing plate 1, thereby making the electrolyte sharing chamber and the inner cavity of the single battery connected, so that the electrolytes of all single batteries are in the same system, achieving the electrolyte sharing effect. In this embodiment, during the unpacking process, even if the sealing film at one first through hole 11 is not completely dissolved, the electrolyte sharing effect can be achieved through another first through hole 11 (the sealing film of the first through hole 11 is dissolved).

[0095] A sealing film that can be opened under the action of an external force is used. Generally, a traction ring can be provided on the sealing film. The traction ring is pulled by an external force to form an opening at the sealing film.

[0096] The liquid circuit can be opened through the following process:

[0097] After the assembly of the large-capacity battery is completed, the traction ring is pulled by a traction tool, and each sealing film is torn or falls off from the first through hole 11, so that the electrolyte sharing chamber is connected with the inner cavity of the single battery, so that the electrolyte of all single batteries is in the same system, achieving the electrolyte sharing effect. During the unpacking process, even if the sealing film at one first through hole 11 is not torn or falls off, it can also pass through another first through hole 11 (the sealing film of the first through hole 11 is torn or completely falls off) to achieve the electrolyte sharing effect.

[0098] Example 2

[0099] Different from the first embodiment, the present embodiment adopts a different sealing assembly 2 , and in order to cooperate with the sealing assembly 2 , the structure of the first through hole 11 is also adjusted.

[0100] like Fig. 9 and Fig.10 As shown, in this embodiment, the first through hole 11 is a circular step through hole, and the large hole of the step through hole is opened near the side of the outer surface 12 of the sealing plate, and the surface of the sealing plate 1 away from the electrode assembly 32 is defined as the outer surface 12 of the sealing plate. When the thickness of the sealing plate 1 is relatively thin, a protrusion 13 can be provided on the inner surface of the sealing plate 1, and a step through hole can be opened on the protrusion 13 as the first through hole 11 (as shown in FIG. Fig.10 When the sealing plate 1 is thicker, a stepped through hole can be directly opened as the first through hole 11 (as shown in FIG. Fig. 9 The large hole of the step through hole serves as the installation space of the sealing component 2. When the sealing component 2 is fixed in the large hole of the step through hole, the flatness of the outer surface 12 of the sealing plate can be ensured.

[0101] In some other embodiments, the first through hole 11 can be a circular straight through hole, but relative to this embodiment, when the sealing component 2 is fixed at the position of the first through hole 11, part of the structure of the sealing component 2 will protrude from the outer surface 12 of the sealing plate, making it difficult to ensure the flatness of the outer surface 12 of the sealing plate.

[0102] In order to improve the stability of the sealing assembly 2 at the position of the first through hole 11, the present embodiment further provides a plurality of fastening structures on the step surface 15 of the step through hole, through which the sealing assembly 2 can be firmly fixed on the sealing plate 1. The fastening structures of the present embodiment are a plurality of blind holes 14 provided on the step surface 15, and the plurality of blind holes 14 are evenly arranged along the circumference of the step surface 15. In some other embodiments, an annular groove 24 can be provided on the step surface 15 along its circumference as a fastening structure.

[0103] like Figures 11 to 14 As shown, the sealing component 2 of this embodiment includes a protective layer 21 and a dissolving layer 22 .

[0104] The protective layer 21 is a sheet structure, and its shape is adapted to the shape of the first through hole 11, and is circular. The edge is fixed on the step surface 15 of the step through hole through the dissolving layer 22, and the first through hole 11 is sealed. The material of the protective layer 21 is a material that is insoluble in the electrolyte and has a certain strength, so as to avoid the protective layer 21 from being damaged due to the pressure of the electrolyte inside the single cell due to poor strength before the sealing component 2 at the first through hole 11 is opened, thereby causing the single cell to be scrapped. Generally, aluminum, copper, zinc, nickel, silver, epoxy resin, PE, PP, polytetrafluoroethylene or EPDM rubber and other materials can be selected.

[0105] In order to improve the bonding strength between the dissolving layer 22 and the protective layer 21, Fig.13 and Fig.14 It can be seen that in this embodiment, a second step structure is provided at the edge of the protective layer 21 along the circumference thereof, and an installation space for the dissolving layer 22 is formed between the second step structure, the step surface 15 of the step through hole and the large hole wall of the step through hole.

[0106] In this embodiment, the dissolving layer 22 is annular and fixed in the installation space of the dissolving layer 22 , with its inner ring pressed against the edge of the protective layer 21 and its outer ring fixed on the shell, thereby fixing the protective layer 21 on the step surface 15 .

[0107] In this embodiment, the dissolving layer 22 is fixed in the installation space of the dissolving layer 22 by casting. Generally, a hot-melt slurry soluble in electrolyte can be cast in the installation space of the dissolving layer 22, and after cooling, the dissolving layer 22 can be formed, and the sealing is achieved while fixing the protective layer 21 on the single battery housing 3. The material of the dissolving layer 22 is at least one of PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12, and PVC.

[0108] In some other embodiments, a sealant that is soluble in the electrolyte may be poured into the installation space of the dissolvable layer 22, and after solidification, the dissolvable layer 22 may be formed.

[0109] In this embodiment, an annular groove 24 is also provided along the circumference of the surface of the protective layer 21 in contact with the step surface 15 (see FIG. Fig.15 ), an O-ring 23 is fixed in the annular groove 24, and the O-ring 23 can further improve the sealing performance of the sealing component 2 to the first through hole 11.

[0110] The sealing assembly 2 is isolated from the sealing plate 1, and its structure is as follows Fig.15As shown, for the convenience of description, the dissolving layer 22 is divided into a sealing portion 221 and a fixing portion 222 according to different functions. The sealing portion 221 is annular, the inner ring surface cooperates with the stopper of the protective layer 21, and the outer ring surface is used to be fixed to the inner wall of the first through hole 11. The fixing portion 222 is a column adapted to the blind hole 14, which is used to strengthen the bonding strength between the sealing assembly 2 and the sealing plate 1. In this embodiment, there are multiple fixing portions 222, which are evenly distributed on the sealing portion 221. In some other embodiments, there may be one fixing portion 222, which is simpler in structure than the present embodiment, but the bonding strength between the sealing assembly 2 and the sealing plate 1 is weaker. When there is a slight pressure in the inner cavity of the single cell, the entire sealing assembly 2 may fall off the sealing plate 1, or cracks may be formed between the dissolving layer 22 and the protective layer 21, thereby damaging the performance of the single cell.

[0111] In this embodiment, the sealing assembly 2 can be fixed on the sealing plate 1 by the following process:

[0112] First, the protective layer 21 is covered on the first through hole 11;

[0113] Secondly, hot melt material is poured into the installation space of the dissolving layer 22 . After the hot melt material is cooled, the dissolving layer 22 is formed, and the sealing is achieved while fixing the protective layer 21 on the sealing plate 1 .

[0114] The liquid circuit can be opened through the following process:

[0115] After the assembly of the large-capacity battery is completed, the electrolyte is injected into the electrolyte sharing chamber to allow the dissolving layer 22 to automatically dissolve from the outside. Since the protective layer 21 and the sealing plate 1 are not fixed in any way, when the dissolving layer 22 is dissolved, the protective layer 21 will automatically fall off the sealing plate 1, thereby allowing the electrolyte sharing chamber to communicate with the inner cavity of the single battery, thereby achieving the effect that the electrolytes of all single batteries are in the same system.

[0116] This embodiment uses an annular dissolving layer 22 instead of the solid sheet-shaped sealing film (soluble in electrolyte, also referred to as the dissolving layer) used in Embodiment 1, which has at least the following advantages:

[0117] 1. The sealing component 2 has high installation reliability;

[0118] The utility model utilizes the annular dissolving layer 22 to fix the protective layer 21 on the battery shell. The annular dissolving layer 22 can make the edge of the protective layer 21 firmly bonded to the single battery shell 3. Before the dissolving layer 22 is dissolved, the protective layer 21 is not easy to fall off, so that the installation reliability of the entire sealing assembly 2 is high.

[0119] 2. The sealing component 2 has good sealing performance;

[0120] The dissolving layer 22 can effectively seal the gap between the protective layer 21 and the shell area around the opening 31. At the same time, the electrolyte in the inner cavity of the single cell shell 3 is in direct contact with the protective layer 21, but cannot contact the dissolving layer 22 located on the outer surface of the shell. Therefore, during the assembly process of the large-capacity battery (before unpacking), the opening 31 of each single cell has good sealing performance.

[0121] 3. The sealing component 2 is easy to open;

[0122] During the unpacking process, electrolyte is injected into the shared chamber. Under the action of the electrolyte, the dissolving layer 22 is dissolved, and the protective layer 21 falls off from the single battery shell 3, thereby connecting the inner cavity of each single battery shell 3 with the inner cavity of the shared chamber. Because the utility model adopts an annular dissolving layer 22, when the outer diameter is the same, the annular dissolving layer 22 has a smaller area than the solid dissolving layer (sealing film in Example 1). Therefore, compared with Example 1, the dissolving time of the utility model is shorter, and the protective layer 21 can fall off in a short time, which can shorten the preparation time of large-capacity batteries and improve production efficiency.

Claims

1. A sealing mechanism for a single cell, characterized in that: Used to be fixed on the housing of a single battery and seal the opening on the housing of the single battery; including a sealing plate and a sealing assembly; The sealing plate is used to be fixedly connected to the single battery housing, and the sealing plate is provided with at least two first through holes that penetrate the opening; The sealing assembly is fixed on the sealing plate and seals the first through hole; The sealing component can be detached from the sealing plate or an opening penetrating the first through hole and the opening can be formed in the sealing component by external force or external electrolyte.

2. The sealing mechanism for a single cell according to claim 1, characterized in that: There are two first through holes, which are symmetrically arranged on the sealing plate along the length direction of the sealing plate.

3. The sealing mechanism for a single cell according to claim 2, characterized in that: The sealing assembly includes a protective layer and a dissolving layer; the protective layer is in sheet form and covers the first through hole; the dissolving layer is in annular form and is fixed to the outer surface area of ​​the sealing plate between the edge of the protective layer and the periphery of the first through hole, and the protective layer is fixed to the sealing plate; The material of the dissolving layer is a material soluble in the electrolyte, and the material of the protective layer is a material insoluble in the electrolyte.

4. The sealing mechanism for a single cell according to claim 3, characterized in that: The dissolving layer is fixed on the outer surface area of ​​the sealing plate around the edge of the protection layer and the first through hole by casting.

5. The sealing mechanism for a single cell according to claim 4, characterized in that: The first through hole is a step through hole, and the large hole of the step through hole is close to the outer surface of the sealing plate; The protective layer is located in the large hole of the step through hole, and a second step structure is provided at the edge of the protective layer along the circumference thereof, and a dissolving layer installation space is formed between the protective layer, the step surface of the step through hole, and the large hole wall of the step through hole; The dissolving layer is fixed in the dissolving layer installation space.

6. The sealing mechanism for a single cell according to claim 5, characterized in that: A protrusion is arranged on the inner surface of the sealing plate, and a stepped through hole penetrating the sealing plate is opened on the protrusion as the first through hole.

7. The sealing mechanism for a single cell according to claim 6, characterized in that: A plurality of blind holes are arranged on the step surface of the step through hole along its circumference.

8. The sealing mechanism for a single cell according to any one of claims 3 to 7, characterized in that: The material of the dissolving layer is PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12 or PVC.

9. The sealing mechanism for a single cell according to any one of claims 3 to 7, characterized in that: The material of the protective layer is aluminum, copper, zinc, nickel, silver, epoxy resin, PE, PP, polytetrafluoroethylene or EPDM rubber.

10. A single battery, comprising a housing, characterized in that: Also includes the sealing mechanism for a single cell according to any one of claims 1 to 9; An opening is provided on the shell; The single cell is fixed to the single cell housing by welding using a sealing mechanism, and the opening on the single cell housing is sealed.

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