Sealing device, battery case component, battery cell and high-capacity battery

Abstract

Provided in the present application are a sealing device, a battery case component, a battery cell and a high-capacity battery. The sealing device comprises a dissolvable layer and an isolation layer attached to the dissolvable layer, wherein the dissolvable layer is made of an electrolyte-soluble material; the material of the isolation layer is insoluble in an electrolyte; and when the battery cell is unsealed, the dissolvable layer is dissolved in the electrolyte, the isolation layer loses the support from the dissolvable layer and then breaks, and an opening in the battery case component is opened. The sealing device is reliably mounted on the battery case component, and has better sealing performance. Moreover, using the electrolyte can achieve smooth opening, thereby ensuring the effectiveness of unsealing of the battery cell.

Description

Sealing device, battery shell component, single battery and large-capacity battery Technical Field

[0001] The present application belongs to the field of batteries, and specifically relates to a sealing device, a battery shell component, a single cell and a large-capacity battery. Background Art

[0002] Currently, large-capacity batteries (also known as battery modules or battery packs) are created by connecting multiple cells in parallel or series. However, individual cells in existing large-capacity batteries vary, and 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.

[0003] To solve this problem, existing large-capacity batteries connect the electrolyte area and gas area of ​​each single cell through a shared chamber, so that each single cell is in a unified shared electrolyte and gas system, which to a certain extent reduces the differences between each single cell and improves the cycle life of large-capacity batteries.

[0004] Usually, the shared chamber can be connected to the inner cavities of all single cells by opening the sealing assembly sealed at the opening of the battery shell. Specifically, the sealing assembly can be opened by external force or external electrolyte to complete the unpacking. Among them, the sealing assembly can use the sealing film that is soluble in electrolyte disclosed in Chinese patent CN218525645U. Although the above patent discloses that the sealing assembly is composed of a dissolving film and a protective film, and the protective film is located on the side of the dissolving film facing the inside of the single cell shell; when the dissolving film is dissolved in the electrolyte, the protective film falls off. However, there is no detailed introduction to the dissolving film and the protective film and the specific installation method of the dissolving film and the protective film and the single cell shell. Therefore, how to ensure the reliable installation, sealing performance and smooth opening of the sealing assembly is a technical problem that is urgently needed to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a sealing device, a battery shell component, a single cell and a large-capacity battery. The sealing device and the battery shell component can be reliably installed and have good sealing performance. At the same time, the electrolyte can be used to open the package smoothly, ensuring the effectiveness of unpacking the single cell.

[0006] In order to solve the problem that the opening cannot be opened or the opening is not fully opened when the existing sealing device is used, thereby affecting the performance of large-capacity batteries, the present application provides a sealing device, which is used to seal the opening on the battery shell component. The sealing device includes a dissolving layer and an isolation layer attached to the dissolving layer; the material of the dissolving layer is an electrolyte-soluble material; the material of the isolation layer is a solid alkane or solid halogenated alkane that is insoluble in the electrolyte. The solid alkane or solid halogenated alkane is attached to the end face of the dissolving layer to form an integral sheet structure with the dissolving layer. After the dissolving layer is dissolved by the electrolyte, the isolation layer loses support and breaks.

[0007] The sealing device provided by the present application includes a dissolving layer and an isolation layer attached to the dissolving layer. The present application uses solid alkanes or solid halogenated alkanes that are chemically stable and insoluble in the electrolyte to make the isolation layer, so that the isolation layer can effectively isolate the electrolyte in the battery shell from the dissolving layer. At the same time, the solid alkanes or solid halogenated alkanes that form the isolation layer themselves have no chemical connection strength, and rely on intermolecular forces to form strength. They are brittle and hard. After being attached to the dissolving layer, the isolation layer is supported by the dissolving layer, and the isolation layer itself has no strength. When unpacking, the dissolving layer is dissolved by the external electrolyte. After the isolation layer loses the support of the dissolving layer, it directly breaks. After the isolation layer breaks into multiple pieces, it falls into the electrolyte. At this time, the opening on the battery shell component is opened. Therefore, the sealing device can open the opening in a timely and reliable manner when unpacking, ensuring the effectiveness of unpacking the single battery.

[0008] Furthermore, the end surface of the dissolving layer attached to the isolation layer has a groove or protrusion, and the height of the protrusion is less than the thickness of the isolation layer. In the sealing device of the present application, the end surface of the dissolving layer coated with the isolation layer has a groove or protrusion, which improves the bonding strength between the dissolving layer and the isolation layer, further enhancing the reliability of the entire sealing device.

[0009] Furthermore, a first chamfer is provided on the end surface of the dissolving layer away from the isolation layer. In the sealing device of the present application, the first chamfer is processed on the end surface of the dissolving layer away from the isolation layer, and the second chamfer is processed on the large hole of the battery casing member. The first chamfer and the second chamfer can form an annular groove filled with sealant. This annular groove not only facilitates the application of sealant, but also makes the connection between the dissolving layer and the battery casing member more reliable, and the dissolving layer also has better sealing performance on the opening.

[0010] Furthermore, the isolation layer is a paraffin layer. In the sealing device of the present application, the solid alkane is one of alkanes, cycloalkanes, and aromatic hydrocarbons, specifically paraffin. The paraffin layer is relatively simple to make and is very easy to break after the dissolving layer is dissolved, and the breakage has no effect on the electrolyte.

[0011] Furthermore, the material of the dissolving layer is PS, PMMA, SMMA, TPU, ABS, PA6, PA12 or PVC.

[0012] Furthermore, an isolation layer is attached to the circumferential sidewalls of the dissolving layer. In the sealing device of the present application, an isolation layer is also provided on the circumferential sidewalls of the dissolving layer. This arrangement can prevent the electrolyte in the battery housing from seeping into the gap between the dissolving layer and the opening, thereby improving the safety of the sealing device during use.

[0013] Furthermore, the thickness of the isolation layer is 1nm to 0.5mm, and the thickness of the dissolving layer is 1 to 3mm. The isolation layer and dissolving layer of this thickness can reliably seal the single battery before unpacking, and at the same time, ensure that the sealing device can reliably open the opening when unpacking.

[0014] Furthermore, the thickness of the isolation layer is 0.1 mm to 2 mm, the melting point is 45 to 80° C., and the thickness of the dissolving layer is 1 to 3 mm.

[0015] The present application also provides a battery shell component, which has an opening that penetrates the inner cavity of the battery shell. The above-mentioned sealing device is provided at the opening, which seals the opening, and the end surface of the dissolving layer having the isolation layer faces the inner cavity of the battery shell.

[0016] Furthermore, the opening is a stepped through hole, the large hole is located on the outer surface of the battery housing component, and the sealing device is embedded in the large hole of the stepped through hole. The inner wall of the large hole is provided with a second chamfer, and the first chamfer and the second chamfer form an annular groove for applying sealant. In the battery housing component of the present application, the opening is a stepped through hole, the large hole is located on the outer surface of the battery housing component, and the sealing device is embedded in the large hole of the stepped through hole. This arrangement can facilitate the sealing installation of the sealing device in the opening of the battery housing. At the same time, after the sealing device is embedded in the large hole of the stepped through hole, the outer surface of the housing of the single battery cell can be made relatively flat, improving the structural regularity of the single battery cell and facilitating the storage and transportation of the single battery cell.

[0017] The present application also provides a single battery, comprising the above-mentioned battery casing component.

[0018] The present application provides another battery housing component, a single cell, and a high-capacity battery, primarily addressing the problem of electrolyte leakage in single cells due to damage or rupture of the dissolution structure before assembly into a high-capacity battery. The battery housing component provided in the present application is provided with a first opening, on which is provided a dissolution layer capable of dissolving in the electrolyte. The battery housing component is unique in that the first opening is also provided with a protective protrusion protruding outward from the battery housing component. The protective protrusion is fixedly connected to the battery housing component and is used to protect the dissolution layer within the first opening. The protective protrusion also has a plurality of second openings extending therethrough.

[0019] The present application provides a protective protrusion on the outside of the dissolving layer of the battery shell component. The protective protrusion protects the dissolving layer and prevents the dissolving layer from being damaged or broken before the single cells are assembled into a large-capacity battery, thereby improving the reliability of the single cells. At the same time, the protective protrusion is provided with a plurality of second openings, which form electrolyte channels so that the electrolyte in the shared chamber can smoothly pass through the protective protrusion to dissolve the dissolving layer in the first opening. In addition, after the single cells are assembled into a large-capacity battery, the protective protrusion with the second opening forms a filter layer between the single cells and the shared chamber. The filter layer can prevent the molten material in the single cell from being discharged from the single cell when thermal runaway occurs in the single cell, thereby blocking the explosion venting channel of the large-capacity battery at the rear.

[0020] Furthermore, the second opening is provided with a dissolving layer that is soluble in the electrolyte. The addition of the dissolving layer to the second opening increases the storage life of the battery cells. Furthermore, after the dissolving layer in the first opening dissolves, the dissolving layer in the second opening can continue to seal the battery cells, improving the sealing performance of the battery cells. Furthermore, the dissolving layer in the second opening protects the space between the first and second openings, preventing impurities with an external particle size smaller than that of the second opening from entering the space.

[0021] Furthermore, the dissolving layer is disposed in the first opening and the second opening by nano-injection molding. This method has the advantage of providing a stronger connection between the battery housing component and the dissolving layer, and the dissolving layer can be reliably connected to the battery housing component during placement, transportation, and assembly of each battery cell.

[0022] Furthermore, the dissolving layers within the first and second openings are made of the same material. Using the same material facilitates the integrated fabrication of the dissolving layer and the battery housing. Furthermore, the thickness of the dissolving layer on the second opening is less than that on the first opening, facilitating the rapid dissolution of the dissolving layer within the second opening by subsequent electrolyte. This allows the electrolyte within the shared chamber and the single cell to work together to rapidly dissolve the dissolving layer within the first opening.

[0023] Furthermore, the thickness of the dissolving layer on the second opening is smaller than the thickness of the dissolving layer on the first opening.

[0024] Furthermore, the protective protrusion is stamped integrally with the battery housing member. This structure of the battery housing member is easy to manufacture, requiring no subsequent processing or assembly, and is therefore low in cost. Furthermore, the stamped protective protrusion does not require further assembly with the battery housing member, thereby improving the sealing performance of the battery housing member.

[0025] Furthermore, the size of the second opening is 1 to 5 mm, which can ensure that the electrolyte can pass through the second opening while minimizing the entry of external impurities into the single cell.

[0026] Furthermore, the battery housing component is mainly composed of an upper cover plate and a cylinder with an open top, the protective protrusion is arranged at the bottom of the cylinder, and the upper cover plate is provided with polarity terminals for drawing out the current of the single battery.

[0027] The present application also provides another single battery, which includes the above-mentioned battery casing member and an electrode assembly disposed in the battery casing member, wherein the electrode assembly is immersed in the electrolyte of the battery casing member.

[0028] The present application also provides a large-capacity battery, which includes an outer shell and multiple single cells as described above. The multiple single cells are placed side by side in the outer shell. A through hole is opened at the top of the outer shell at the position corresponding to the polarity terminal of each single cell. After the polarity terminal of each single cell passes through the through hole, the single cells are connected in parallel; the top and bottom of the outer shell are respectively provided with a shared chamber, and the multiple single cells realize the interconnection of the gas zone and the electrolyte zone through the shared chamber.

[0029] The present application also provides another battery shell component, single cell and large-capacity battery, which overcomes the problem that the sharing effect of existing large-capacity batteries is easily affected by the size of the through-holes of the single cells. At the same time, it can avoid the risk of damage to the electrode assembly during the through-hole opening process while ensuring sharing reliability.

[0030] The battery shell structure provided in the present application includes a cylinder and an end plate assembly sealed and fixed at any open end of the cylinder; through the action of external electrolyte, the end plate assembly can fall off from the cylinder, or an opening penetrating the inner cavity of the cylinder can be formed in the end plate assembly.

[0031] This application utilizes an end plate assembly to replace the lower cover of an existing single-cell battery housing. When the end plate assembly of this application is completely removed, the entire bottom of the single-cell battery and the electrolyte sharing chamber are connected. Compared to a structure that only shares through a through hole, the electrolyte in the inner cavity of the single-cell battery can be fully mixed with the electrolyte in the inner cavity of the electrolyte sharing chamber, achieving a better sharing effect. At the same time, this application does not require a through hole to be opened in the single-cell battery housing, and the preparation process has no effect on the electrode assembly. When preparing a single cell, the preparation of the battery housing component can be completed first, and then the electrode assembly can be installed into the battery housing component, and finally the cover plate can be installed.

[0032] This technical solution can adopt dissolving components with different structures, specifically taking the following two solutions as examples:

[0033] Option 1: The end plate assembly includes a first dissolving layer, both of which are in sheet form, and a first isolating layer attached to the inner surface of the first dissolving layer, wherein the inner surface of the first dissolving layer is located within the inner cavity of the cylinder; the first isolating layer is used to isolate the electrolyte in the inner cavity of the single cell from the first dissolving layer; the area of ​​the first dissolving layer to which the first isolating layer is not attached is sealed and fixed to the open end of the cylinder; the material of the first dissolving layer is an electrolyte-soluble material, and the material of the first isolating layer is an electrolyte-insoluble material.

[0034] Furthermore, the first dissolving layer cooperates with the stopper on the open end of the cylinder, which can improve the degree of integration between the entire end plate assembly and the cylinder.

[0035] Option 2: The end plate assembly includes a second isolation layer and a second dissolving layer; the second isolation layer is in sheet form and covers any open end of the cylinder; the second dissolving layer is annular, and its inner edge is sealed and fixed to the outer surface of the second isolation layer, and its outer edge is sealed and fixed to the outer surface of the open end of the cylinder; wherein, the outer surface of the second isolation layer is the surface of the second isolation layer located outside the inner cavity of the cylinder; the material of the second dissolving layer is an electrolyte-soluble material, and the material of the second isolation layer is an electrolyte-insoluble material. In this solution, the second isolation layer is fixed to the open end of the cylinder by using an annular second dissolving layer. The second dissolving layer can well seal the gap between the second isolation layer and the open end of the cylinder. At the same time, the electrolyte in the inner cavity of the single cell shell is in direct contact with the second isolation layer, but cannot contact the second dissolving layer. Therefore, during the assembly process of the large-capacity battery (before unpacking), the bottom of each single cell has good sealing. During the unpacking process, electrolyte is injected into the electrolyte shared chamber. Under the action of the electrolyte, the second dissolving layer dissolves and the second isolation layer falls off from the single cell shell, thereby connecting the inner cavity of each single cell shell with the inner cavity of the electrolyte shared chamber. Because the present application adopts an annular second dissolving layer, under the condition of the same outer diameter, the annular second dissolving layer has a smaller area than the sheet-shaped first dissolving layer (the first dissolving layer in solution one). Therefore, compared with the first dissolving layer in solution one, the dissolution time of this solution is shorter, which can shorten the preparation time of large-capacity batteries and improve production efficiency. In addition, the second dissolving layer of the present invention serves as both a sealing component and a fixing mechanism, and there is no need to introduce an additional fixing mechanism for the end plate assembly, thereby simplifying the overall structure of the end plate assembly and reducing the manufacturing cost.

[0036] Furthermore, the second dissolving layer is fixed to the outer surface of the second insulating layer and the outer surface of the open end of the cylinder by casting. Generally, a hot-melt slurry soluble in the electrolyte is cast on the edge of the second insulating layer and the outer surface of the open end of the cylinder. After cooling, the second dissolving layer is formed, achieving a seal and fixing the second insulating layer to the cylinder.

[0037] Furthermore, a second step structure is provided along the circumference of the second isolation layer at its edge; this allows the second dissolving layer to be fixed to it by means of a stopper, which can increase the bonding strength between the two and further improve the sealing reliability of this part. A first step structure is provided along the circumference of the open end surface of the cylinder; the inner surface edge of the second isolation layer contacts the step surface of the first step structure, forming a second dissolving layer installation space between the second step structure and the step surface and vertical surface of the first step structure; the second dissolving layer is fixed in the second dissolving layer installation space. Through this arrangement, the bottom of the single cell can be made relatively flat, the structural regularity of the single cell can be improved, and the storage and transportation of the single cell can be facilitated.

[0038] Furthermore, a plurality of blind holes are provided along the circumference of the stepped surface area of ​​the first step structure located within the second dissolving layer installation space. When hot melt slurry is poured into the second dissolving layer installation space, columns are formed within the blind holes, thereby increasing the bonding strength between the second dissolving layer and the cylinder, and further strengthening the bonding strength between the entire end plate assembly and the cylinder.

[0039] The present application also provides another single cell battery, which is special in that it includes a shell and an electrode assembly and electrolyte located inside the shell. The shell is composed of the above-mentioned battery shell component and an upper cover plate sealed and fixed to the open end of the battery shell component.

[0040] The present application provides a large-capacity battery, which is unique in that it includes a housing and multiple single cell components arranged within the housing; an electrolyte sharing chamber is provided between the bottom of each single cell component and the bottom plate of the housing; wherein the single cell component is a component in which the end plate assembly of the single cell is detached from the barrel or a hole is formed in the end plate assembly through the inner cavity of the barrel. When the end plate assembly of the single cell is completely detached from the barrel, the entire bottom of the single cell component is connected to the electrolyte sharing chamber. Compared to a structure in which the electrolyte is shared only through a through hole, the electrolyte in the inner cavity of the single cell component can be fully mixed with the electrolyte in the inner cavity of the electrolyte sharing chamber, achieving a better sharing effect.

[0041] Furthermore, avoidance holes are provided on the top plate of the large-capacity battery housing corresponding to the polarity terminals of each single battery component; the polarity terminals of each single battery component extend out of the avoidance holes, and the area of ​​the housing top plate corresponding to the avoidance holes is fixedly sealed to the upper cover plate of the single battery component; a heat transfer tube clamping portion is provided at the portion where each polarity terminal extends out of the avoidance hole; and the heat transfer tube is fixed to the heat transfer tube clamping portion of each polarity terminal.

[0042] This application fixes heat transfer tubes at the locations where the polarity terminals of each cell component extend out of the avoidance holes. The heat transfer tubes are in direct contact with each cell component. When the temperature of the large-capacity battery exceeds a set threshold, a lower-temperature heat transfer medium is introduced into the heat transfer tubes to promptly dissipate the heat. This heat dissipation method achieves balanced heat dissipation for each cell within the large-capacity battery, improving the safety of the large-capacity battery. Furthermore, when the temperature of the large-capacity battery falls below a set threshold, a higher-temperature heat transfer medium is introduced into the heat transfer tubes to raise the temperature of the large-capacity battery. By controlling the temperature of the heat transfer medium, the large-capacity battery can always operate at its normal operating temperature.

[0043] The present application also provides another single cell battery, which mainly solves the problem that the single cell battery needs to be unpacked twice during the existing large-capacity battery assembly process, making the production process of large-capacity batteries cumbersome and the assembly efficiency low.

[0044] The single cell includes a battery shell, an electrode assembly and a sealing device; a one-way breathable membrane is provided on the battery shell; the electrode assembly is located in the battery shell and connected to the polarity terminal on the top of the battery shell; a mounting portion for mounting a heat transfer tube is provided on the polarity terminal; a sealing device is provided on the battery shell, and the sealing device includes a dissolving structure formed by an electrolyte additive soluble in the electrolyte.

[0045] First, the single cell of the present application is provided with a one-way breathable membrane, which can discharge the gas generated within the single cell out of the battery housing of the single cell. When the single cell is assembled into a large-capacity battery, the gas pressure in the gas zone of each single cell can be kept basically consistent. Compared with the related art solution of achieving consistent gas pressure in the gas zone of each single cell by performing a second unpacking of the single cell, this saves manufacturing process and improves assembly efficiency. Secondly, because the one-way breathable membrane is installed on the battery housing of the single cell during the manufacturing process of the battery housing of the single cell, when the single cell undergoes the formation process during the manufacturing process, the one-way breathable membrane can directly discharge the gas generated during the formation process out of the battery housing. Compared with existing single cells, the steps of opening and sealing the single cell during the formation process are saved, thereby improving the manufacturing efficiency of the single cell. Thirdly, the polarity terminals of the single cells of the present application have mounting portions for heat transfer tubes. When multiple single cells are assembled into a large-capacity battery, the temperature of the electrode assemblies in each single cell can be transferred from the polarity terminals to an external temperature control device through the heat transfer tubes, reducing the problem of overheating of the electrode assemblies affecting the performance of the large-capacity battery. More importantly, direct temperature control of each electrode assembly reduces the probability of thermal runaway, thereby improving safety. Finally, a sealing device that can dissolve in the electrolyte is installed on the outer shell of the single cell. When electrolyte is injected into the large-capacity battery during the process of assembling a large-capacity battery with a shared electrolyte system, the sealing device is dissolved, and a through hole is formed in the single cell, thereby achieving interconnection between the electrolyte zones of each single cell in the large-capacity battery. This process does not require special tooling, is simple to operate, and reduces production costs. At the same time, because the sealing mechanism is solidified using electrolyte additives, it can improve the performance of the large-capacity battery to a certain extent after dissolving in the electrolyte.

[0046] Furthermore, a convex ring is provided on the battery housing, and the dissolving structure is installed in the convex ring; the dissolving structure includes a columnar body formed by an additive soluble in the electrolyte and an isolation layer; at least the first end face of the columnar body has an isolation layer, which is insoluble in the electrolyte.

[0047] Furthermore, the columnar body is made of propylene sulfate, ethylene carbonate or diphenyl carbonate.

[0048] Furthermore, in order to enable the sealing mechanism 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 coated with an isolation layer, and a blind hole is provided in the columnar body from the second end face to the first end face.

[0049] Furthermore, in order to achieve both a fast opening speed and a slow decomposition of the sealing mechanism in the electrolyte, the depth of the blind hole accounts for 90% of the length of the columnar body.

[0050] Furthermore, in order to enhance the sealing reliability of the sealing mechanism for the single battery, a sealing ring is provided between the columnar body and the convex ring.

[0051] Based on the above single battery, this application also provides two large-capacity batteries:

[0052] The first large-capacity battery includes a first hollow tube, a second hollow tube and a plurality of the above-mentioned single cells; the multiple single cells are placed side by side, and the positive polarity terminals of all the single cells are connected as a total positive pole, and the negative polarity terminals of all the single cells are connected as a total negative pole; the first hollow tube is provided with a plurality of first through holes, the first hollow tube is connected to the battery shell of each single cell, and the plurality of first through holes of the first hollow tube corresponds one-to-one to the one-way breathable membrane of the single cell, and the gas generated in each single cell overflows into the first hollow tube through the one-way breathable membrane, so that the air pressure in each single cell remains consistent; the second hollow tube is provided with a plurality of second through holes, the second hollow tube is connected to the battery shell of each single cell, and the second hollow tube is connected to the electrolyte area in each single cell, so that the electrolyte area of ​​each single cell is connected.

[0053] Furthermore, the large-capacity battery further includes a heat transfer tube; the heat transfer tube cooperates with the mounting portion of the polarity terminal of each single battery.

[0054] A second large-capacity battery comprises a housing and a plurality of cells described in the first aspect. The cells are arranged in the same direction within the housing, and the electrolyte regions of the cells are interconnected. A clearance hole is formed on the top plate of the housing, corresponding to the polarity terminals of each cell. Each cell terminal extends through the clearance hole, and the region of the housing top plate corresponding to the clearance hole is securely sealed to the battery casing of the cell. The positive terminals of all cells are connected to form a common positive electrode, and the negative terminals of all cells are connected to form a common negative electrode. A gas chamber is provided on the housing, extending along the direction in which the cells are arranged, and the gas chamber covers the one-way gas permeable membrane of each cell. Gas generated within each cell escapes through the one-way gas permeable membrane into the gas chamber, maintaining a consistent gas pressure within each cell.

[0055] Furthermore, the large-capacity battery further comprises an electrolyte sharing chamber provided on the box body and extending along the arrangement direction of the single cells; the electrolyte sharing chamber is in communication with the electrolyte area of ​​each single cell.

[0056] Furthermore, the large-capacity battery further includes a heat transfer tube; the heat transfer tube cooperates with the mounting portion of the polarity terminal of each single battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a schematic structural diagram of a lower cover plate of a single cell with a sealing device in Example 1;

[0058] FIG2 is an exploded view of the lower cover plate of the single cell with a sealing device in Example 1;

[0059] FIG3 is a schematic structural diagram of the sealing device in Example 1;

[0060] FIG4 is a schematic structural diagram of a sealing device (with a groove) in Example 1;

[0061] FIG5 is a schematic structural diagram of the sealing device (with a protrusion) in Example 1;

[0062] FIG6 is a schematic diagram of the sealing device on the upper cover plate in Example 2;

[0063] FIG7 is a schematic diagram of a lower cover plate having multiple sealing devices in Example 2;

[0064] FIG8 is a cross-sectional view of the sealing device on the lower cover plate in Example 2;

[0065] FIG9 is a schematic structural diagram of a dissolving layer having a first chamfer in Example 2;

[0066] FIG10 is a schematic diagram of the structure of a single cell assembled into a large-capacity battery in Example 3;

[0067] FIG11 is a schematic structural diagram of a battery housing member in Example 4;

[0068] FIG12 is a cross-sectional view of a battery housing member in Example 4;

[0069] FIG13 is an exploded schematic diagram of a battery housing member in Example 4;

[0070] FIG14 is a schematic diagram of the structure of a single cell in Example 5;

[0071] FIG15 is a schematic structural diagram of a large-capacity battery in Example 6;

[0072] FIG16 is an exploded view of a large-capacity battery in Example 6;

[0073] FIG17 is a schematic structural diagram of a large-capacity battery in the background art;

[0074] FIG18 is a schematic structural diagram of a battery housing member in Example 8;

[0075] FIG19 is an exploded schematic diagram of the battery housing member in Example 8;

[0076] FIG20 is a partial cross-sectional view 1 of the battery housing member in Example 8;

[0077] FIG21 is a second partial cross-sectional view of the battery housing member in Example 8;

[0078] FIG22 is a third partial cross-sectional view of the battery housing member in Example 8;

[0079] FIG23 is a schematic structural diagram of a single cell cylinder in Example 8;

[0080] FIG24 is a schematic structural diagram of another single cell cylinder in Example 8;

[0081] FIG25 is a partial cross-sectional view of a single cell cylinder in Example 8;

[0082] FIG26 is a partial cross-sectional view of another single cell cylinder in Example 8;

[0083] FIG27 is a partial cross-sectional view of a battery housing member in Example 8;

[0084] FIG28 is an exploded view of a battery housing member in Example 8;

[0085] FIG29 is an exploded view of a single cell in Example 8;

[0086] FIG30 is a schematic structural diagram of a single cell in Example 8;

[0087] FIG31 is a schematic structural diagram of a large-capacity battery in Example 8;

[0088] FIG32 is a schematic diagram of a partial structure of a large-capacity battery in Example 8;

[0089] FIG33 is a schematic structural diagram of a battery housing member in Example 9;

[0090] FIG34 is an exploded view of the battery housing member in Example 9;

[0091] Figure 35 is a schematic structural diagram of the cylinder in Example 9;

[0092] FIG36 is a cross-sectional view of a cylinder in Example 9;

[0093] FIG37 is a cross-sectional view of another cylinder in Example 9;

[0094] FIG38 is a partial cross-sectional view of a battery housing member in Example 9;

[0095] FIG39 is a partial cross-sectional view of another battery housing member in Example 9;

[0096] FIG40 is an exploded view of the battery housing member in Example 9;

[0097] FIG41 is a schematic diagram of the assembly process of the battery housing member in Example 9;

[0098] FIG42 is a schematic diagram of the structure of a single cell in Example 9;

[0099] FIG43 is a schematic diagram of the structure of a single cell in Example 10;

[0100] FIG44 is a second schematic diagram of the structure of a single cell in Example 10;

[0101] FIG45 is a cross-sectional view of a single cell in Example 10;

[0102] FIG46 is a cross-sectional view of the sealing device;

[0103] Figure 47 is a schematic diagram of the structure of a large-capacity battery in Example 11;

[0104] Figure 48 is a schematic diagram of the large-capacity battery structure in Example 12.

[0105] Reference numerals: 11-single cell, 12-sealing device, 13-housing, 14-electrolyte shared chamber, 15-gas shared chamber, 111-upper cover, 112-lower cover, 113-cylinder, 114-opening, 115-polarity terminal, 116-second chamfer, 121-dissolving layer, 122-isolating layer, 123-groove, 124-protrusion, 125-first chamfer, 21-single cell, 22-housing, 211-battery housing , 212-first opening, 213-dissolving layer, 214-protective protrusion, 215-second opening, 2111-cylinder, 2112-upper cover, 2113-polarity terminal, 221-shared chamber, 222-liquid injection port, 301-housing, 3001-single cell, 302-electrolyte shared chamber, 31-cylinder, 311-first step structure, 3111-step surface of the first step structure, 312-annular groove, 32-end plate assembly , 321-first isolation layer, 322-first dissolving layer, 3221-annular protrusion, 323-second isolation layer, 324-second dissolving layer, 33-U-shaped sealing ring, 34-battery core assembly, 351-single battery polarity terminal, 36-housing, 361-housing bottom plate, 362-housing top plate, 38-heat transfer tube, 39-electrolyte sharing chamber, 41-battery housing, 411-top cover, 412-housing, 413-bottom cover, 42-one-way transparent Air film, 43-polarity terminal, 44-mounting part, 45-sealing device, 46-convex ring, 47-column, 471-first end face, 472-second end face, 473-blind hole, 474-first cylindrical section, 475-second cylindrical section, 48-sealing ring, 401-single battery, 402-first hollow tube, 403-second hollow tube, 404-box, 405-gas chamber, 406-electrolyte shared chamber, 407-heat transfer tube. DETAILED DESCRIPTION

[0106] To make the above-mentioned purposes, features, and advantages of this application more clearly understood, the following detailed description of the specific embodiments of this application is given in conjunction with the accompanying drawings. It is obvious that the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary persons in this field without creative work should fall within the scope of protection of this application.

[0107] Existing sealing devices consist of a dissolving layer and an isolation layer, with the isolation layer located on the side of the dissolving layer facing the interior of the battery case. Once the dissolving layer dissolves in the electrolyte, the isolation layer subsequently falls off. However, in actual use, after the dissolving layer dissolves in the electrolyte, the isolation layer may remain in the opening of the battery case and is difficult to fall off. This can result in the opening being unable to open or not fully opening. This can lead to the electrolyte environment in some cells being inconsistent with that in the rest of the cells, affecting the sharing effect and ultimately the performance of large-capacity batteries.

[0108] The present application provides a sealing device, which is used to be fixed on a battery shell component to seal an opening that passes through the inner cavity of the battery shell. At the same time, the sealing device can also open the opening under the action of external electrolyte to realize the unpacking of a single battery.

[0109] It should be noted that: 1. The single cell described here is a square shell battery, which includes an upper cover, a lower cover, a cylinder, a cell assembly and an electrolyte; the upper cover or the lower cover and the cylinder can be formed as one piece. The upper cover, the cylinder and the lower cover constitute the battery shell, and the cell assembly and the electrolyte are located inside the battery shell. The cell assembly here can be called an electrode assembly, which is arranged in sequence by a positive electrode, a diaphragm and a negative electrode, and is assembled by a lamination or winding process. The cell assembly here can also be a commercially available square shell battery with a through hole. 2. The battery shell component here can be the battery shell of a single cell, or it can be a partial structure of the battery shell, such as at least one of the upper cover, the lower cover or the cylinder.

[0110] The present application also provides a battery housing component having the above-mentioned sealing device.

[0111] The present application also discloses a single cell battery having the above-mentioned battery shell component, wherein an opening penetrating the inner cavity of the battery shell is opened on the battery shell component, and a sealing device is fixed at the opening to seal the opening; under the action of an external electrolyte (an electrolyte located outside the battery shell), the sealing device dissolves and falls off, opening the opening, thereby realizing unpacking of the single cell battery.

[0112] It should be noted here that: if the above-mentioned 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.

[0113] The single cells provided in this application are primarily used to construct large-capacity batteries, such as those described in the background art Chinese patent CN220324596U, or as disclosed in Chinese patents CN117477063A, CN117477186A, and CN115275453A. Such large-capacity batteries include at least a plurality of single cells and at least one shared chamber; the shared chamber referred to herein is defined as the shared chamber described in CN220324596U, the hollow member described in CN117477063A, the first and second hollow members described in CN117477186A, and the shared electrolyte channel described in CN115275453A.

[0114] When the battery shell component is the lower cover of a 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 device 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 the single cells to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0115] When the battery shell component is the upper cover of a single cell, the shared chamber can also be used as a gas sharing chamber. By using an external electrolyte (which can be understood as the electrolyte in the gas sharing chamber), part of the structure of the sealing device is dissolved 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.

[0116] When the battery 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 device 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.

[0117] Example 1

[0118] As shown in Figures 1 and 2, this embodiment provides a sealing device 12 for sealing an opening 114 on a battery housing member. This embodiment is described using the lower cover plate 112 of a single battery 11 as an example. The lower cover plate 112 of the single battery 11 is provided with an opening 114 extending through the lower cover plate 112. The shape of the opening 114 is not limited. In this embodiment, the opening 114 is a circular through-hole. In other embodiments, the shape of the opening 114 can be adjusted according to actual needs, such as a rectangular hole, an elliptical hole, etc.

[0119] As shown in Figure 3, the sealing device 12 provided in this embodiment is used to seal the opening 114 on the lower cover plate 112. The sealing device 12 includes a dissolving layer 121 and an isolation layer 122 attached to the dissolving layer 121; the material of the dissolving layer 121 is an electrolyte-soluble material; the material of the isolation layer 122 is an electrolyte-insoluble material, and the electrolyte-insoluble material is attached to the dissolving layer 121 to form an integrated sheet structure with the dissolving layer 121.

[0120] The dissolving layer 121 is a sheet-like structure. The shape of the dissolving layer 121 matches the shape of the opening 114, and the size of the dissolving layer 121 is not less than the size of the opening 114, so that the dissolving layer 121 can seal the opening 114. The dissolving layer 121 mainly has the following two functions: 1. It seals the opening 114 on the lower cover 112 and isolates the electrolyte inside the battery shell from the external environment; 2. It supports the isolation layer 122 before the single battery 11 is unpacked, so that the isolation layer 122 can isolate the dissolving layer 121 from the electrolyte inside the battery shell. When the single battery 11 is unpacked, the dissolving layer 121 can dissolve under the action of the external electrolyte, and the isolation layer loses support and breaks and falls off, thereby opening the opening 114 on the lower cover 112.

[0121] Based on the above two functions, this embodiment uses an electrolyte-soluble material to prepare the dissolution layer. The material of the dissolution layer is specifically PS (polystyrene), PMMA (polymethyl methacrylate), SMMA (styrene dimethyl methacrylate copolymer), TPU (thermoplastic polyurethane), ABS (acrylonitrile / butadiene / styrene copolymer), POM (polyoxymethylene), PA6 (nylon 6), PA12 (nylon 12) or PVC (polyvinyl chloride), etc.

[0122] At the same time, the dissolving layer 121 has a certain strength and hardness. Based on the dissolving layer 121, the sealing device 12 is sealed and fixed to the opening 114 of the lower cover plate 112, thereby preventing the single battery 11 from being scrapped due to the poor strength of the sealing device 12 before the single battery 11 is unpacked. During specific production, the strength can be improved by selecting materials and increasing the thickness of the dissolving layer 121. However, the thickness of the dissolving layer 121 should not be too thick to avoid prolonged unpacking and reduced production efficiency of large-capacity batteries. In actual use, the thickness of the dissolving layer 121 is generally 1 to 3 mm, which is the optimal thickness.

[0123] In this embodiment, the isolation layer 122 is attached to the inner surface of the dissolving layer 121 and forms an integral structure with the dissolving layer 121. The inner surface of the dissolving layer 121 is the surface of the dissolving layer 121 located within the inner cavity of the battery housing. The main function of the isolation layer 122 is to isolate the electrolyte in the inner cavity of the single cell 11 from the dissolving layer 121, preventing the electrolyte in the inner cavity of the single cell 11 from contacting the dissolving layer 121 before the single cell 11 is unpacked, thereby destroying the integrity of the dissolving layer 121, causing the sealing device 12 to fail and the single cell 11 to be scrapped. Therefore, in this embodiment, the isolation layer 122 is made of an electrolyte-insoluble material, and the size of the isolation layer 122 is not less than the size of the opening 114 to ensure complete isolation of the electrolyte in the inner cavity of the single cell 11 from the dissolving layer 121. The electrolyte-insoluble material is coated on one end surface of the dissolving layer 121 in a molten state and adheres to the end surface of the dissolving layer 121 after solidification, forming an integral sheet structure with the dissolving layer. When the single battery is unpacked, the dissolution layer 121 is dissolved by the electrolyte, and the isolation layer 122 loses support and breaks.

[0124] The material of the above-mentioned isolation layer 122 is a solid alkane or solid halogenated alkane that is insoluble in the electrolyte. The solid alkane or solid halogenated alkane is coated on the dissolving layer 121 in a molten state, and adheres to the end face of the dissolving layer 121 after solidification to form the isolation layer 122. The isolation layer 122 and the dissolving layer 121 are an integral sheet structure. The solid alkane or solid halogenated alkane itself has no chemical connection strength and relies on intermolecular forces to form strength. It is brittle and hard, so it is very easy to break. After it is attached to the dissolving layer, the isolation layer 122 is supported by the dissolving layer 121. The isolation layer itself has no strength. The strength of the entire sealing device is achieved by the dissolving layer. After the dissolving layer 121 is dissolved by the electrolyte, the isolation layer 122 that has lost the dissolving layer 121 can automatically break open, thereby opening the opening in a timely and reliable manner.

[0125] When the material of the isolation layer 122 is a solid alkane, a solid alkane with stable chemical properties is selected so that after the solid alkane falls into the electrolyte, it does not react with the electrolyte and does not affect the electrolyte. The isolation layer 122 is made of the following solid alkanes: C X H Y,10≤x≤n,20≤y≤2n+2,n≤100, the solid alkane can be a mixture or a single substance component, the main component of the mixture is a straight-chain alkane, or a small amount of alkanes with individual branches and monocyclic cycloalkanes with long side chains, specifically long-chain alkanes, cycloalkanes, etc., for example, n-pentacosane, n-triacontane, n-pentatriacontane, n-tetracontane, n-pentacontane, etc., and the cycloalkanes can specifically be nonadecylcyclohexane, etc.

[0126] When the material of the isolation layer 122 is a solid halogenated alkane, a chemically stable solid halogenated alkane is selected so that after the solid halogenated alkane falls into the electrolyte, it does not react with the electrolyte and does not affect the electrolyte. The solid halogenated alkane can be a long-chain halogenated alkane or a long-chain alkane completely substituted with fluorine atoms. For example, 1-chlorotriacontane (62016-82-4), 1-bromopentacosane (62108-45-6), perfluoropentadecane (2264-03-1), perfluorotetracosane (1766-41-2), perfluoroeicosane (37589-57-4), 1-iodo-5-octadecyltricosane (1639798-43-8), etc. can be used.

[0127] The isolation layer 122 in this embodiment is specifically made of paraffin wax. After the paraffin wax is melted, it is coated on one end surface of the dissolving layer 121 . After the paraffin wax is solidified, it forms an integrated sheet structure with the dissolving layer 121 . During specific coating, if the coating thickness is too thin, the isolation layer 122 is prone to rupture. If the coating thickness is too thick, the isolation layer 122 is not easy to rupture after the dissolving layer 121 dissolves. Experiments have confirmed that when the thickness of the isolation layer 122 is between 1nm and 0.5mm, it can better isolate the electrolyte inside the battery shell from the dissolving layer 121. At the same time, since the thickness of the isolation layer 122 is between 1nm and 0.5mm, the isolation layer 122 of this thickness has a certain brittleness. When the single battery 11 is unpacked, when the dissolving layer 121 is dissolved by the external electrolyte, the isolation layer 122 that has lost its supporting carrier is very easy to rupture, and the opening 114 is no longer sealed, so that the electrolyte in the inner cavity of each single battery 11 is connected through the electrolyte sharing chamber 14, thereby achieving the purpose of the electrolyte inside each single battery 11 being in the same electrolyte system.

[0128] As shown in Figures 4 and 5, in order to improve the bonding strength between the dissolving layer 121 and the isolation layer 122, the end surface of the dissolving layer 121 coated with the isolation layer 122 has a groove 123 or a protrusion 124. The depth of the groove 123 is less than the thickness of the dissolving layer 121, and the height of the protrusion 124 is less than the thickness of the isolation layer 122. The shape of the groove 123 or the protrusion 124 can be circular or strip-shaped, etc. Under the action of the groove 123 or the protrusion 124, the isolation layer 122 can be better attached to the dissolving layer 121.

[0129] Taking the paraffin layer as an example of the isolation layer 122, the manufacturing process of the above-mentioned sealing device 12 is as follows: S1, the electrolyte soluble material is made into a dissolving layer 121 with a sheet structure; in this step, in order to increase the bonding strength between the dissolving layer 121 and the isolation layer 122, a groove 123 or a protrusion 124 can also be processed on the end face of the dissolving layer 121 coated with the isolation layer 122. For example, the dissolving layer 121 can be roughened or corona treated to increase the adsorption fastness of the dissolving layer 121; S2, the solid alkane is heated to a molten state; during the specific operation, the paraffin is placed in an oven to ensure that the paraffin has good leveling properties when applied and can be evenly applied; S3, the molten state material heated in step S2 is applied to one end face of the dissolving layer 121 in step S1. After the molten state material solidifies, it adheres to the end face of the dissolving layer 121 to form the sealing device 12. In a specific operation, paraffin wax melted into wax water is coated on the surface of the dissolving layer 121 and evenly cured at room temperature; S4, the cured dissolving layer 121 is cut into corresponding sizes for use.

[0130] In other embodiments, after the dissolving layer 121 is formed, the isolation layer 122 may be prepared by waxing the end surface of the dissolving layer 121 to form the sealing device 12 .

[0131] After the sealing device 12 is manufactured, the sealing device 12 can be fixed to the lower cover plate 112 of the single cell 11 using the following process. This process is carried out in a set environment. Generally, the set environment is preferably an environment with a dew point standard between -25°C and -40°C, a temperature of 23°C±2°C, and a cleanliness level of 100,000. First, an opening 114 is machined on the lower cover plate 112 of the existing finished single cell 11. Second, the sealing device 12 is placed on the opening 114 on the lower cover plate 112. Finally, sealant is applied to the edge of the sealing device 12 and the area around the opening 114 of the lower cover plate 112.

[0132] The sealant not only fixes the sealing device 12 on the lower cover plate 112 , but also seals the edge of the sealing device 12 and the area surrounding the opening 114 of the lower cover plate 112 .

[0133] In addition, after the sealing device 12 is installed in the opening 114 of the battery housing member, if the sealing device is not installed reliably, the electrolyte in the battery housing may penetrate into the gap between the dissolution layer 121 and the opening 114, affecting the dissolution layer 121. In this case, this problem can be solved by the following methods:

[0134] First, a sealant is applied to the gap between the dissolving layer 121 and the opening 114 to fill the gap and prevent the electrolyte in the battery housing from penetrating into the gap and affecting the dissolving layer 121.

[0135] Second, an isolation layer 122 is also attached to the circumferential side wall of the dissolving layer 121, wherein the circumferential side wall of the dissolving layer 121 refers to the side wall of the dissolving layer in contact with the opening; at this time, the isolation layer 122 on the inner surface of the dissolving layer 121 and the isolation layer on the circumferential side wall of the dissolving layer 121 fully cover the dissolving layer 121, preventing the electrolyte in the battery shell from affecting the dissolving layer 121, thereby improving the reliability of the sealing device during use.

[0136] The sealing device 12 is installed on the single cell 11. The sealing device 12 only needs to ensure that the inner cavity of the single cell 11 is isolated from the external environment. When the single cells 11 are assembled into a large-capacity battery and each single cell 11 is unpacked, electrolyte is injected into the electrolyte sharing chamber 14. Under the action of the electrolyte, the dissolving layer 121 dissolves, the isolation layer 122 loses support and ruptures, and the opening 114 on the lower cover plate 112 opens, thereby allowing the electrolyte sharing pipeline to penetrate the inner cavity of the single cell 11, so that the electrolyte of all single cells is in the same system, achieving the electrolyte sharing effect.

[0137] Example 2

[0138] The sealing device 12 in this embodiment is similar to the sealing device 12 in Example 1, except that the sealing device 12 in this embodiment is manufactured together with the battery case of the single cell 11 when the single cell 11 is manufactured, and then the electrolyte and electrode assembly are installed.

[0139] The battery housing with the sealing device 12 forms a single cell 11, and the single cell 11 needs to be formed. The formation process is mainly the process of charging the single cell 11 in a suitable environment to form an SEI film. During the formation process of the single cell 11, the temperature and internal pressure are relatively high. At this time, the sealing device 12 is required to meet the temperature and pressure of the formation stage.

[0140] To meet this requirement, it can be achieved by selecting materials and increasing thickness. In this embodiment, the thickness of the isolation layer 122 is 0.1mm to 2mm. The isolation layer 122 of this thickness can meet the formation requirements of the single cell 11. At the same time, the melting point of alkanes increases with the increase of molecular weight (ie, the number of carbon atoms). The isolation layer 122 is selected from the following solid alkanes: C X H Y, 18≤x≤n, 36≤y≤2n+2, n≤100, according to the formation or aging conditions of the single cell 11, a solid alkane with a melting point of 45 to 80°C is used to make the isolation layer 122. The isolation layer 122 in this melting point range can meet the temperature of the formation stage of the single cell 11 (less than 90°C. The formation temperature exceeding 90°C may cause problems such as electrolyte decomposition, increased internal pressure of the battery, and instability of the SEI film, thereby affecting the performance and safety of the battery). At the same time, if the isolation layer 122 does not rupture when unpacking, at this time, the temperature of the single cell 11 can be adjusted to melt the isolation layer 122 to achieve opening. Since the melting point range of the isolation layer 122 is between 45 and 80°C, it will not affect the performance and safety of the battery.

[0141] The sealing device 12 with the above-mentioned isolation layer 122 is installed on the battery shell. When the single cells are unpacked and assembled into a large-capacity battery, electrolyte is injected into the electrolyte sharing chamber 14. Under the action of the electrolyte, the dissolving layer 121 dissolves, and the isolation layer 122 loses support and breaks. If the isolation layer 122 does not break, at this time, the temperature of the single cell is adjusted to melt the isolation layer 122, and the opening 114 on the lower cover plate 112 is opened, thereby allowing the electrolyte sharing pipeline to penetrate the inner cavity of the single cell 11, so that the electrolyte of all single cells is in the same system, achieving the electrolyte sharing effect.

[0142] Example 3

[0143] As shown in FIG6 , this embodiment provides a single cell battery. The single cell battery 11 includes a battery housing member having the aforementioned sealing device 12. The battery housing member is at least one of an upper cover plate 111, a lower cover plate 112, or a cylindrical body 113. An opening 114 is provided in the battery housing member. The location of opening 114 corresponds to the shared chamber in the large-capacity battery. Opening 114 can be circular, square, or other polygonal, depending on actual needs. The size of opening 114 must meet the following requirements: 1. Opening 114 must not be too large to ensure sufficient strength of the battery housing member, thus preventing the single cell battery 11 from being scrapped due to insufficient strength before the sealing device 12 at the opening 114 is opened; 2. Opening 114 must not be too small to ensure that after the sealing device 12 at the opening 114 is opened, the electrolyte region within each single cell battery 11 is smoothly connected to the shared chamber, ensuring a good sharing effect.

[0144] As shown in FIG7 , in some other embodiments, multiple openings 114 may be provided on the battery housing member. Generally, the multiple openings 114 are arranged along the length or height of the battery housing member. When all openings 114 are opened, the electrolyte and / or gas within the inner cavity of the single battery 11 can be fully mixed with the electrolyte and / or gas within the inner cavity of the shared piping assembly, compared to a structure where only one opening 114 is used for sharing, resulting in a better sharing effect.

[0145] As shown in FIG8 , in this embodiment, to facilitate the installation of the sealing device 12, the opening 114 is configured as a stepped through hole. The large hole of the stepped through hole is located on the outer surface of the battery shell component, and the small hole is located on the inner surface of the battery shell component. At the same time, the size of the large hole is slightly larger than the size of the dissolving layer 121 in the sealing device 12, so that the sealing device 12 can be embedded in the large hole of the stepped through hole. The size of the small hole is smaller than the size of the isolation layer 122, so that the isolation layer 122 can isolate the electrolyte in the battery shell from the dissolving layer 121. The provision of such a stepped hole can facilitate the sealed installation of the sealing device 12 in the opening 114 of the battery shell. At the same time, after the sealing device 12 is embedded in the large hole of the stepped through hole, the outer surface of the shell of the single battery 11 can be made relatively flat, thereby improving the structural regularity of the single battery 11 and facilitating the storage and transportation of the single battery 11.

[0146] After the sealing device 12 is embedded in the above-mentioned opening 114, a sealant is applied to the edge of the dissolving layer 121 and the surrounding area of ​​the opening 114. The sealant fixes the dissolving layer 121 on the battery shell component. At the same time, the sealant also seals the edge of the dissolving layer and the surrounding area of ​​the opening 114.

[0147] As shown in Figure 9, in order to facilitate the application of glue and the reliable connection when the sealing device 12 is connected to the battery shell component, a first chamfer 125 is processed on the end face of the dissolving layer 121 away from the isolation layer 122, and a second chamfer 116 is provided on the inner wall of the large hole of the battery shell component, which is consistent with the position of the first chamfer 125. The first chamfer 125 and the second chamfer 116 can form an annular groove with a rectangular or triangular cross-section. The annular groove is not only convenient for applying sealant, but also fills the annular groove with sealant, so that the connection between the dissolving layer 121 and the battery shell component is more reliable, and the dissolving layer 121 has better sealing performance for the opening.

[0148] As shown in FIG10 , a high-capacity battery constructed using the above-described single cells 11 includes a housing 13 and multiple single cells 11 arranged within the housing 13. An electrolyte sharing chamber 14 is provided between the bottom of each single cell 11 and the bottom plate of the housing 13, and a gas sharing chamber 15 is provided between the top of each single cell 11 and the top plate of the housing 13. The electrolyte sharing chamber 14 is a liquid channel extending along the length (x-direction) of the housing 13, located between the bottom plate of the housing 13 and each single cell 11. This liquid channel can be integrally formed with the bottom plate of the housing 13, or formed by providing a support member between the lower cover plate 112 of the single cell 11 and the bottom plate of the housing 13. The gas sharing chamber 15 is a gas channel extending along the length (x-direction) of the housing 13, located between the top plate of the housing 13 and each single cell 11. This gas channel can be integrally formed with the top plate of the housing 13.

[0149] In addition, in order to improve the heat dissipation performance of such large-capacity batteries, an avoidance hole can be opened on the top plate of the shell 13 to allow the polarity terminal 115 of each single battery 11 to extend out; the polarity terminal 115 of each single battery 11 extends out of the avoidance hole and the top plate area of ​​the shell 13 around the avoidance hole is fixedly sealed with the shell of the single battery 11.

[0150] It should be noted that the polarity terminal 115 of the single cell 11 component here can be the pole of the single cell 11. In order to avoid the pole of the single cell 11 from being unable to smoothly extend out of the avoidance hole as the polarity terminal 115, a pole adapter can also be connected to the pole of the single cell 11, and the overall structure of the pole of the single cell 11 and the pole adapter can be used as the polarity terminal 115 of the single cell 11.

[0151] In the process of constructing the above-mentioned large-capacity battery, each single battery 11 can be unpacked through the following process (each single battery 11 is unpacked to form a large-capacity battery):

[0152] If the battery shell component is the lower cover plate 112 of the single battery 11, the liquid circuit can be unpacked through the following process: after the assembly of the large-capacity battery is completed (the individual single batteries 11 are not unpacked), the electrolyte is injected into the electrolyte sharing chamber 14. Under the action of the electrolyte, the dissolving layer 121 dissolves, the isolation layer 122 loses support and breaks, and the opening 114 on the lower cover plate 112 is opened, thereby allowing the electrolyte sharing chamber 14 to penetrate the inner cavity of the single battery 11, so that the electrolytes of all single batteries 11 are in the same system, achieving the electrolyte sharing effect.

[0153] If the battery shell component is the upper cover plate 111 of the single battery 11, the gas circuit can be opened through the following process: after completing the assembly of the large-capacity battery, the electrolyte is injected into the gas sharing chamber 15 to automatically dissolve the dissolving layer 121 from the outside. Under the action of the electrolyte, the dissolving layer 121 dissolves, the isolation layer 122 loses support and breaks, and the opening 114 on the upper cover plate 111 is opened, thereby allowing the gas sharing chamber 15 to communicate with the inner cavity of the single battery 11, so that all single batteries 11 reach gas balance.

[0154] Existing large-capacity batteries include multiple single cells arranged in sequence. The electrolyte area and gas area of ​​each single cell are connected through a shared chamber, so that each single cell is in a unified shared electrolyte and gas system, which reduces the differences between the single cells to a certain extent and improves the cycle life of the large-capacity battery. Before the above-mentioned single cells are assembled into a large-capacity battery, a through hole is set on the battery shell of the single cell, and the through hole is sealed with a dissolving layer. The dissolving layer isolates the electrolyte in the single cell from the outside world. When multiple single cells are assembled into a large-capacity battery, the inner cavities of the multiple single cells need to be connected to the shared chamber. At this time, electrolyte is injected into the shared chamber, and the dissolving layer on the single cell is dissolved by the electrolyte in the single cell and the shared chamber, so that the inner cavity of the single cell and the shared chamber are connected, and the multiple single cells are in a shared electrolyte system and gas system.

[0155] The above-mentioned single cell with a dissolving layer has a simple structure, and the electrolyte, gas zone and shared chamber of each single cell can be connected without mechanical operation. However, before the single cells are assembled into a large-capacity battery, the dissolving layer on each single cell is in an external state. During the transportation, movement or assembly of each single cell, the dissolving structure is easily damaged or accidentally ruptured, resulting in leakage of the electrolyte in the single cell, and in severe cases, causing the single cell to be damaged and scrapped. Based on this, the present application provides a protective protrusion for protecting the dissolving layer on the outside of the above-mentioned dissolving layer, and a plurality of second openings are provided on the protective protrusion. The protective protrusion can not only protect the dissolving layer, but also form a filter layer between the single cell and the shared chamber after the single cell is assembled into a large-capacity battery. The filter layer can prevent the molten material in the single cell from discharging from the single cell when thermal runaway occurs in the single cell, and block the explosion venting channel of the large-capacity battery at the rear.

[0156] Example 4

[0157] As shown in Figures 11 and 12, this embodiment provides a battery shell component, which is the entire battery shell, or the battery shell component is a part of the battery shell. The following description takes the battery shell component as the entire battery shell as an example. The battery shell 211 includes the following structural forms: First, the battery shell mainly consists of a cylinder with open ends and an upper cover plate and a lower cover plate respectively arranged at the open ends. The battery shell structure of this structure is simple and the processing of each component is relatively simple; Second, the battery shell 211 mainly consists of a cylinder 2111 with an open top and an upper cover plate 2112 arranged at the open end. When the battery shell 211 of this structure is assembled to form a single battery 21, it is only necessary to ensure the sealing performance of the connection between the upper cover plate 2112 and the cylinder 2111, and the structure is relatively reliable.

[0158] The battery housing 211 is provided with a first opening 212. The first opening 212 can be located on the upper cover 2112 of the battery housing 211, the upper or lower cover of the sidewall of the cylindrical body 2111, or the bottom of the cylindrical body 2111, depending on the specific structure of the high-capacity battery. Furthermore, a dissolving layer 213 capable of dissolving in electrolyte is provided on the first opening 212. The dissolving layer 213 can seal each individual battery 21 before the individual batteries 21 are assembled into a high-capacity battery. When the individual batteries 21 are assembled into a high-capacity battery, electrolyte is injected into the shared chamber 221 of the high-capacity battery. The electrolyte in the shared chamber 221 and the individual batteries 21 dissolves the dissolving layer 213 in the first opening 212. After the dissolving layer 213 dissolves, the inner cavity of each individual battery 21 communicates with the shared chamber 221, forming a high-capacity battery. After the dissolving layer 213 dissolves, no residual electrolyte remains in the electrolyte system.

[0159] The battery case 211 in this embodiment is unique in that, as shown in Figures 11 and 12, a protective protrusion 214 is provided on the first opening 212, protruding outward from the battery case 211. The protective protrusion 214 is fixed to the battery case 211 and has a plurality of second openings 215. Before the individual cells 21 are assembled into a large-capacity battery, the protective protrusion 214 protects the dissolution layer 213 within the first opening 212, thereby preventing the dissolution layer 213 within the first opening 212 from being damaged or ruptured during the handling, movement, or assembly of the individual cells 21, which could lead to leakage of electrolyte in the individual cells 21, or even damage and scrapping of the individual cells 21.

[0160] The above-mentioned protective protrusion 214 is a hollow tubular structure with one end open and the other end closed. The open end is fixedly connected to the battery shell 211 and communicates with the first opening 212. The second opening 215 is provided at the closed end. The protective protrusion 214 can be fixed to the battery shell 211 in a variety of ways. It can be processed separately from the battery shell 211, and then the protective protrusion 214 is fixed to the battery shell 211. Alternatively, the protective protrusion 214 can also be formed integrally with the battery shell 211. When the protective protrusion 214 and the battery shell 211 are processed separately, different materials can be used. At this time, it should be noted that the material of the protective protrusion 214 is insoluble in the electrolyte and will not affect the electrolyte. Specifically, the following methods can be used to set the protective protrusion 214 on the battery shell 211;

[0161] First, the protective protrusion 214 is provided with an external thread, and the first opening 212 of the battery housing 211 is provided with an internal thread, and the protective protrusion 214 and the battery housing 211 are connected by threads;

[0162] Second, the protective protrusion 214 is fixed to the battery housing 211 by gluing;

[0163] Third, the protective protrusion 214 is fixed to the first opening 212 by welding;

[0164] Fourth, the protective protrusion 214 and the battery housing 211 are integrally stamped;

[0165] The first, second, and third installation methods are relatively simple, but all require installation, and special attention must be paid to the sealing of the connection between the protective protrusion 214 and the battery housing 211. The fourth method is an integrated molding structure. The battery housing 211 of this structure is easy to manufacture and does not require any subsequent installation. At the same time, the stamped protective protrusion 214 can improve the sealing performance of the battery housing 211.

[0166] As shown in Figure 12, the protective protrusion 214 is provided with a plurality of second openings 215. The second openings 215 form electrolyte channels, allowing the electrolyte in the shared chamber to pass through the battery housing 211 and correspondingly dissolve the dissolving layer 213 in the first openings 212. In addition, after the individual cells 21 are assembled into a large-capacity battery, the second openings 215 form a filter layer between the individual cells 21 and the shared chamber 221. This filter layer prevents the molten material in the individual cells 21 from discharging from the individual cells and blocking the explosion venting channel of the subsequent large-capacity battery when thermal runaway occurs.

[0167] In this embodiment, the following requirements apply to the size of the second opening 215. If the second opening 215 is too small, the electrolyte cannot pass through the second opening 215 to dissolve the dissolving layer 213 within the first opening 212. If the second opening 215 is too large, external impurities can easily enter the single cell 21 through the second opening 215. In this case, it is necessary to ensure that the electrolyte can pass through the second opening 215 while preventing external impurities from entering the single cell 21. Therefore, in this embodiment, the size of the second opening 215 is 1 to 5 mm. This size allows the electrolyte to pass freely and smoothly, while preventing impurities such as solid particles from passing through the second opening 215. This prevents solid matter such as metal fragments in the shared chamber 221 from entering the battery and affecting the performance of the single cell.

[0168] Furthermore, as shown in FIG13 , the second opening 215 in this embodiment may also be provided with a dissolving layer 213 that is soluble in the electrolyte. Before each battery cell is assembled, after the dissolving layer 213 in the first opening 212 is dissolved, the dissolving layer 213 in the second opening 215 can continue to seal the battery cell 21, thereby improving the sealing performance of the battery cell 21 and correspondingly increasing the storage life of the battery cell 21. Furthermore, the dissolving layer 213 in the second opening 215 can also protect the space between the first opening 212 and the second opening 215, preventing impurities with an external particle size smaller than that of the second opening 215 from entering the space and affecting the performance of subsequent battery cells.

[0169] If it is necessary to connect the inner cavities of each single cell 21 with the shared chamber 221 in a short time, there is no need to set the dissolving layer 213 in the second opening 215, or the dissolving layer 213 in the second opening 215 can be actively removed before the single cells 21 are assembled to form a large-capacity battery.

[0170] Experiments have confirmed that materials such as polystyrene (PS), polymethyl methacrylate (PMMA), thermoplastic polyurethane elastomer rubber (TPU), styrene dimethyl methacrylate copolymer (SMMA), acrylic rubber-acrylonitrile-styrene graft copolymer (ASA), polyamide 6 (PA6), imide (PAI), and polylaurylamide (PA12) gradually dissolve in the electrolyte after being immersed in the electrolyte for a period of time without contaminating the electrolyte. Among the above materials, materials such as PS, PMMA, TPU, SMMA, and ASA dissolve relatively quickly, while materials such as PA6, PA12, and PAI dissolve relatively slowly. Because different materials have different dissolution times in the electrolyte, different materials are selected as the dissolution layer based on actual usage needs. The thickness of the dissolution layer is also one of the more critical parameters. As the thickness of the dissolution layer increases, the time it takes to dissolve in the electrolyte increases. In order to ensure that the dissolution time of the dissolution layer of each single cell 21 after being immersed in the electrolyte meets the design requirements, different dissolution layers are used based on actual usage needs.

[0171] As shown in FIG13 , the dissolving layer 213 can be installed in various ways when it is disposed in the first opening 212 and the second opening 215. For example, the dissolving layer can be fixed to the first opening and the second opening by gluing or other methods after the battery housing 211 is manufactured.

[0172] Since the battery shell 211 is generally made of metal, such as an aluminum shell, and the dissolving layer 213 is made of a plastic that can dissolve slowly, in this embodiment, the dissolving layer 213 is formed by injection molding at the same time as the aluminum shell. Specifically, the dissolving layer 213 is formed on the first opening 212 and the second opening 215 by nano injection molding. Nano injection molding is a method for connecting metal and plastic, that is, the metal surface is first nano-processed, and then the plastic is directly injection molded on the metal surface, so that the metal and plastic can be integrally molded and finally combined into a whole. The advantages of this connection method are: improving the connection strength, the connection strength between the battery shell 211 and the dissolving layer 213 is better, and during the placement, transportation and assembly of each single battery 21, the dissolving layer 213 can be reliably connected to the battery shell 211.

[0173] The dissolving layer 213 within the first opening 212 and the second opening 215 can be made of the same material or different materials. In this embodiment, the dissolving layer 213 within the first opening 212 and the second opening 215 is made of the same material, which facilitates the integrated processing of the dissolving layer 213 and the battery housing 211. In addition, the thickness of the dissolving layer 213 on the second opening 215 is less than that on the first opening 212, which facilitates the subsequent electrolyte to quickly dissolve the dissolving layer 213 on the second opening 215. This allows the electrolyte in the shared chamber 221 and the single battery 21 to work together to quickly dissolve the dissolving layer 213 within the first opening 212.

[0174] Example 5

[0175] As shown in FIG14 , this embodiment provides a single cell. The single cell 21 includes a battery housing 211 and an electrode assembly disposed in the battery housing 211 . The battery housing is the battery housing 211 in Embodiment 4. The electrode assembly is immersed in the electrolyte of the battery housing 211 .

[0176] When manufacturing the above-mentioned single battery 21, the battery shell 211 of each single battery 21 is first manufactured. At this time, the dissolution layer 213 in the first opening 212 and the second opening 215 is simultaneously formed on the battery shell 211. Then, the electrode assembly is placed in the battery shell 211, and the upper cover plate 2112 is sealed and set on the open end of the cylinder 2111.

[0177] When each single cell 21 forms a large-capacity battery, electrolyte is injected from the outside to the inside of the shared chamber 221, and the electrolyte in the shared chamber 221 dissolves the dissolved layer 213 in the second opening 215. Then, the electrolyte and the electrolyte in the single cell 21 work together to dissolve the dissolved layer 213 in the first opening 212. The first opening 212 is opened, so that the electrolyte area and the gas area of ​​each single cell 21 are interconnected, thereby realizing gas sharing, electrolyte sharing, or sharing of both gas and electrolyte of each single cell 21 in the large-capacity battery.

[0178] Example 6

[0179] As shown in Figures 15 and 16, the large-capacity battery in this embodiment includes an outer shell 22 and multiple single cells 21; the single cells are the single cells 21 in Example 5, and the number of single cells 21 can be adjusted according to actual capacity requirements. Multiple single cells 21 are placed side by side in the outer shell 22, and the top and bottom of the outer shell 22 are respectively provided with shared chambers 221, wherein the shared chamber 221 at the top is a gas shared chamber, and the shared chamber 221 at the bottom is an electrolyte shared chamber, so that the gas area and the electrolyte area of ​​each single cell 21 can be interconnected. A through hole is opened at the top of the outer shell 22 corresponding to the position of the polarity terminal 2113 of each single cell 21; after the polarity terminal 2113 of each single cell 21 passes through the through hole, each single cell 21 is connected in parallel. The specific structure of the outer shell 22 of the above-mentioned large-capacity battery is as follows:

[0180] 1) The outer shell includes an outer cylinder, an upper cover, and a lower cover. The top and bottom of the outer cylinder are both open. The upper cover is sealed and fixed (welded) to the top of the outer cylinder. The upper cover has through-holes that allow the polarity terminals 2113 of each single battery 21 to extend. The lower cover is sealed and fixed (welded) to the bottom of the outer cylinder. The upper cover is provided with a gas sharing chamber, and the lower cover is provided with an electrolyte sharing chamber.

[0181] 2) The outer shell includes a U-shaped shell, a first cover plate, a third cover plate, and a second cover plate; the first cover plate and the third cover plate respectively cover the two opposite open ends of the U-shaped shell; the second cover plate covers the top open end of the U-shaped shell and is sealed to the open end, and the second cover plate has through holes that allow the polarity terminals of each single cell to extend out. At the same time, the second cover plate is provided with a gas sharing chamber, and the bottom of the U-shaped shell is provided with an electrolyte sharing chamber;

[0182] 3) As shown in FIG16 , the outer shell 22 includes an outer cylinder, a front side plate, and a rear side plate; the front and rear portions of the outer cylinder are open, the front side plate is sealed and fixed (welded) to the front portion of the outer cylinder, and the rear side plate is sealed and fixed (welded) to the rear portion of the outer cylinder. A through hole is provided at the top of the outer cylinder through which the polarity terminals 2113 of each single battery 21 can extend. A gas sharing chamber is provided at the top of the outer cylinder, and an electrolyte sharing chamber is provided at the bottom.

[0183] The outer shell 22 is provided with a liquid injection port 222, through which electrolyte can be injected into the inner cavity of each single cell 21 and the outer shell 22, thereby performing liquid injection, liquid replenishment, or liquid replacement for large-capacity batteries. It should be noted that when liquid is not injected, the liquid injection port 222 needs to be sealed with a plug or valve.

[0184] In the process of manufacturing a large-capacity battery, the single cell 21 having the above-mentioned battery shell 211 is placed in the outer shell 22, and then under a specific environment, the electrolyte is injected into the outer shell 22 through the injection port 222. The electrolyte in the outer shell 22 first dissolves the dissolving layer 213 in the second opening 215, and then gradually dissolves the dissolving layer 213 in the first opening 212. When the dissolving layer 213 is partially or completely dissolved, the inner cavity of each single cell 21 is connected to the shared chamber 221, thereby achieving the purpose of the electrolyte inside each single cell 21 being in the same electrolyte system.

[0185] Example 7

[0186] This embodiment provides a high-capacity battery comprising a battery pack body and a hollow member. The battery pack body comprises a plurality of sequentially arranged single cells, the number of which can be adjusted based on actual capacity requirements, and the single cells are connected in parallel via electrical connectors. The single cells may be the single cells described in Example 5. The hollow member is a split structure, primarily consisting of a hollow box with one end open and a cover plate for covering the open end.

[0187] The number of hollow members is determined based on demand. When there is only one hollow member, it is fixedly connected to the side wall of the battery pack body, allowing the electrolyte and gas areas of each cell to communicate with each other. The detailed structure of this hollow member is detailed in Chinese Patent CN117477063A. When there are multiple hollow members, one of them is fixedly connected to the upper cover of the cell, allowing the gas areas of each cell to communicate with each other. The inner cavity of this hollow member serves as a shared gas chamber. Another hollow member is connected to the lower cover of the cell, allowing the electrolyte areas of each cell to communicate with each other. The inner cavity of this hollow member serves as a shared electrolyte chamber. The detailed structure of this hollow member is detailed in Chinese Patent CN219892382U.

[0188] The hollow member is provided with a liquid injection port, through which electrolyte can be injected into the inner cavity of each single cell and the hollow member, thereby filling, replenishing, or replacing the electrolyte in large-capacity batteries. It should be noted that when liquid is not being injected, the liquid injection port needs to be sealed with a plug or valve.

[0189] In the process of making large-capacity batteries, the single cells are connected to the hollow component, and then under specific conditions, the electrolyte is injected into the hollow component through the injection port. The electrolyte in the hollow component first dissolves the dissolving layer in the second opening, and then gradually dissolves the dissolving layer in the first opening. When the dissolving layer is partially or completely dissolved, the inner cavity of each single cell is connected to the shared chamber, thereby achieving the purpose of the electrolyte inside each single cell being in the same electrolyte system.

[0190] Chinese patent CN220324596U discloses a large-capacity battery, the structure of which is shown in Figure 17. This large-capacity battery includes a housing 301 and multiple single cells 3001, which are connected in parallel within the interior of the housing 301. The housing 301 is provided with a shared electrolyte chamber 302, which communicates with the interiors of each single cell. The electrolytes in the individual cells are connected through the shared electrolyte chamber, so that the electrolytes in all cells are in the same system, reducing differences between the individual cells and improving their consistency to a certain extent, thereby improving the cycle life of the large-capacity battery to a certain extent.

[0191] Usually, the electrolyte sharing chamber can be connected to the inner cavities of all single cells by opening the sealing assembly sealed at the through-hole position of the lower cover plate of the single cell. The sealing assembly can be selected from the sealing film disclosed in Chinese patent CN218525645U. The above patent only provides one through-hole in the lower cover plate of the single cell, and the electrolyte sharing chamber is connected to the inner cavities of all single cells through the through-hole. When the through-hole is small, it is difficult to fully mix the electrolyte in the inner cavity of the single cell and the electrolyte in the inner cavity of the electrolyte sharing chamber, which makes it difficult to ensure that the electrolyte environment of the single cell is consistent with that of the other single cells, affecting the sharing effect and ultimately affecting the performance of the large-capacity battery. In addition, the preparation of the above-mentioned single cell first requires opening a through-hole in the lower cover plate of the single cell, and then installing the sealing assembly on the lower cover plate to seal the through-hole. 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. If you are not careful, the entire single cell may be scrapped due to damage to the electrode assembly.

[0192] The present application provides a battery shell component, including a cylinder and an end plate assembly sealed and fixed at any open end of the cylinder; such an end plate assembly can fall off from the cylinder through external electrolyte or form an opening through the inner cavity of the cylinder in the end plate assembly.

[0193] It should be noted here that:

[0194] 1. The above-mentioned single battery is a square shell battery, which includes a shell and a battery cell assembly and electrolyte located inside the shell; the battery cell assembly herein 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;

[0195] 2. The above-mentioned shell member is a part of the shell of the single cell, including a cylinder with two open ends and an end plate assembly sealed and fixed to either open end of the cylinder, and the end plate assembly serves as the lower cover of the single cell;

[0196] 3. The above-mentioned external electrolyte refers to the electrolyte located outside the single cell shell, rather than the electrolyte in the inner cavity of the single cell. In other words, the electrolyte in the inner cavity of the single cell cannot cause the above-mentioned end plate assembly to fall off from the cylinder or form an opening through the inner cavity of the cylinder in the end plate assembly.

[0197] The present application can adopt end plate assemblies of various different structures. For example, the dissolution mechanism disclosed in Chinese patent CN217823012U can be used as the end plate assembly; an end plate assembly including a first dissolution layer in sheet form and a first isolation layer attached to the inner surface of the first dissolution layer can also be used; an end plate assembly including a sheet-shaped second isolation layer and an annular second dissolution layer; and an end plate assembly in which the inner edge of the annular second dissolution layer is sealed and fixed to the outer surface of the second isolation layer can also be used. In the following embodiments, the battery casing components are mainly described in detail in combination with the latter two end plate assemblies.

[0198] The present application also provides a single battery, including a shell and an electrode assembly and an electrolyte located in the shell. The shell is composed of the above-mentioned battery shell component and an upper cover plate sealed and fixed to the open end of the battery shell component.

[0199] This type of single cell is mainly used to build large-capacity batteries (also known as battery packs or battery modules). This type of large-capacity battery includes a housing and multiple single cell components arranged in the housing, with an electrolyte sharing chamber provided between the bottom of each single cell component and the bottom plate of the housing;

[0200] The single cell component here is a component after the end plate assembly of the above-mentioned single cell falls off from the cylinder or an opening is formed in the end plate assembly through the inner cavity of the cylinder. Specifically, it can be formed by injecting electrolyte into the electrolyte sharing chamber to make the end plate assembly of the above-mentioned single cell fall off from the cylinder or an opening is formed in the end plate assembly through the inner cavity of the cylinder.

[0201] In this high-capacity battery, the inner cavity of each cell component and the shared electrolyte chamber are interconnected. This allows the electrolytes of all cells to be in the same system, reducing differences between the electrolytes of each cell and improving the consistency between the cells to a certain extent, thereby improving the cycle life of the high-capacity battery to a certain extent.

[0202] When the end plate assembly of the above-mentioned single cell is completely detached from the cylinder, the entire bottom of the single cell component and the electrolyte sharing chamber are connected. Compared with the structure that shares only through one through hole, the electrolyte in the inner cavity of the single cell component can be fully mixed with the electrolyte in the inner cavity of the electrolyte sharing chamber, which has a better sharing effect.

[0203] Example 8

[0204] As shown in Figures 18 and 19, the battery case structure of this embodiment includes a cylindrical body 31 with open ends at both ends and an end plate assembly 32 fixed to either open end of the cylindrical body 31. Before the single battery 3001 is unpacked (before the end plate assembly 32 is opened), the end plate assembly 32 directly serves as the lower cover of such single battery 3001. During the unpacking process, the end plate assembly 32 can fall off the cylindrical body 31 due to the action of external electrolyte, or an opening can be formed in the end plate assembly 32 that penetrates the inner cavity of the cylindrical body 31.

[0205] As can be seen from Figures 20, 21, and 22, the end plate assembly 32 of this embodiment includes a first dissolving layer 322 and a first isolation layer 321. Both the first dissolving layer 322 and the first isolation layer 321 are in sheet form, where sheet form can also be understood as plate form. The first isolation layer 321 is attached to the inner surface of the first dissolving layer 322, which is the surface of the first dissolving layer 322 located within the inner cavity of the cylinder 31. The primary function of the first isolation layer 321 is to isolate the electrolyte in the inner cavity of the single cell 3001 from the first dissolving layer 322, preventing the electrolyte in the inner cavity of the single cell 3001 from contacting the first dissolving layer 322 before the single cell 3001 is unpacked, thereby preventing the integrity of the first dissolving layer 322 from being destroyed, causing the end plate assembly 32 to fail and the single cell 3001 to be scrapped. Therefore, in this embodiment, the first isolation layer 321 is made of an electrolyte-insoluble material, has a shape that matches the shape of the open end of the cylinder 31, and has an area no less than that of the open end (in FIG. 20 , the area of ​​the first isolation layer 321 is equal to the area of ​​the open end of the cylinder 31; in FIG. 21 , the area of ​​the first isolation layer 321 is slightly larger than that of the open end of the cylinder 31). This ensures complete isolation of the electrolyte in the inner cavity of the single cell 3001 from the first dissolving layer 322. The first isolation layer 321 can be made of aluminum, copper, zinc, nickel, silver, epoxy resin, PE (polyethylene), PP (polypropylene), polytetrafluoroethylene, or EPDM rubber.

[0206] The first dissolving layer 322 has the following two main functions: 1. Before the single battery 3001 is unpacked, the first dissolving layer 322 seals and secures the end plate assembly 32 to the open end of the cylinder 31; 2. When the single battery 3001 is unpacked, the first dissolving layer 322 dissolves under the action of the external electrolyte, thereby opening the end plate assembly 32.

[0207] Based on the above two functions, this embodiment uses an electrolyte-soluble material to prepare the first dissolving layer 322, and the area of ​​the first dissolving layer 322 not attached to the first isolation layer 321 is sealed and fixed to the open end of the cylinder 31; when the area of ​​the first dissolving layer 322 not attached to the first isolation layer 321 contacts the electrolyte and dissolves, because the first isolation layer 321 and the cylinder 31 are not fixed in any way, after the area of ​​the first dissolving layer 322 not attached to the first isolation layer 321 dissolves, the entire end plate assembly 32 will fall off from the cylinder 31.

[0208] The material of the first dissolving layer 322 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).

[0209] It should be noted that since the end plate assembly 32 serves as the lower cover before unpacking and needs to be opened when unpacking, the end plate assembly 32 needs to meet the following conditions:

[0210] 1. This type of end plate assembly 32 should also have a certain strength. Since the end plate assembly 32 and the open end of the cylinder 31 are sealed and fixed based on the first dissolving layer 322, the strength of the first dissolving layer 322 should be ensured to avoid the problem of the single battery 3001 being scrapped due to poor strength before the end plate assembly 32 is opened. The strength can be improved by selecting materials and increasing the thickness of the first dissolving layer 322. However, the thickness of the first dissolving layer 322 should not be too thick to avoid the unpacking process taking too long and reducing the production efficiency of large-capacity batteries.

[0211] 2. The connection strength between the first dissolving layer 322 and the open end of the cylinder 31 should be ensured to avoid the problem of cracking of the connection part due to poor connection strength under the pressure of the electrode assembly and the electrolyte before opening the end plate assembly 32, or even the detachment of the end plate assembly 32, which would lead to the scrapping of the single battery 3001. Such problems can be improved by designing the connection structure between the two.

[0212] In this embodiment, in order to improve the connection strength between the first dissolving layer 322 and the open end of the cylinder 31, it can be seen from Figures 23 to 26 that in this embodiment, a first step structure 311 is provided on the end surface of the open end of the cylinder 31 along its circumference.

[0213] When the thickness of the cylinder wall is relatively thin, an annular plate parallel to the xy plane can be provided along the circumference of the open end of the cylinder 31; a first step structure 311 can be provided on the annular plate, as shown in Figures 20, 21, 23 and 25; when the thickness of the cylinder wall is relatively thick, the first step structure 311 can be directly provided, as shown in Figures 22, 24 and 26. A step structure that cooperates with the first step structure 311 is provided on the outer circumference of the first dissolving layer, and the first dissolving layer 322 is fixed to the open end of the cylinder 31 in a stop-fit ​​manner. In addition, an annular groove 312 can be provided on the vertical wall of the first step structure 311 along its circumference, and an annular protrusion 3221 that cooperates with the annular groove 312 is provided on the outer circumference of the first dissolving layer. The annular protrusion 3221 is embedded in the annular groove 312 to further improve the connection strength between the first dissolving layer 322 and the open end of the cylinder 31.

[0214] In order to further improve the sealing performance of the end plate assembly 32 to the open end of the cylinder 31, with respect to the structure shown in Figure 21, this embodiment can also add a U-shaped sealing ring 33 between the end plate assembly and the open end of the cylinder, wherein the U-shaped sealing ring 33 refers to a sealing ring with a U-shaped cross-section, and the inner edge of the annular plate is embedded in the U-shaped sealing ring 33, as shown in Figures 27 and 28.

[0215] As shown in Figures 29 and 30, it is a schematic structural diagram of a single battery 3001 of this embodiment, which includes the above-mentioned battery shell member, the battery cell assembly 34 located in the battery shell member, the electrolyte, and the upper cover plate sealed and fixed to the open end of the battery shell member.

[0216] The single battery 3001 in this embodiment can be specifically prepared through the following process: when preparing the single battery 3001, the above-mentioned battery shell component can be prepared first, then the battery cell assembly 34 can be installed into the battery shell component, and finally the cover plate can be installed.

[0217] In this embodiment, there is no need to open the shell of the single battery 3001, which can avoid the risk of damaging the electrode assembly during the opening process.

[0218] As shown in FIG31 and FIG32 , a large-capacity battery constructed using the above-mentioned single cell 3001 includes a housing 36 and a plurality of single cells 3001 arranged within the housing 36 ; an electrolyte sharing chamber 39 is provided between the bottom of each single cell 3001 and the housing bottom plate 361 ;

[0219] The electrolyte sharing chamber 39 described here is a liquid channel extending along the length direction (x direction) of the shell 36 and located between the shell bottom plate 361 and each single cell 3001. The liquid channel can be integrally formed with the shell bottom plate 361, or it can be formed by setting a support member between the lower cover plate of the single cell 3001 and the shell bottom plate 361.

[0220] In the process of constructing the above-mentioned large-capacity battery, each single cell 3001 can be unpacked (each single cell 3001 is unpacked to form a single cell 3001 component): After the assembly of the large-capacity battery is completed (each single cell 3001 is not unpacked), the electrolyte is injected into the electrolyte sharing chamber 39 to automatically dissolve the first dissolving layer 322 from the outside; because the first isolation layer 321 and the cylinder 31 are not fixed in any way, when the part where the first dissolving layer 322 is fixed to the cylinder 31 dissolves, the first isolation layer 321 falls off with the first dissolving layer 322, thereby making the electrolyte sharing chamber 39 and the inner cavity of the single cell 3001 connected, so that the electrolyte of all single cells is in the same system, achieving the electrolyte sharing effect.

[0221] In addition, in order to improve the heat dissipation performance of such large-capacity batteries, an avoidance hole can be opened on the top plate 362 of the outer shell to allow the polarity terminal 351 of each single cell to extend out; the polarity terminal 351 of each single cell extends out of the avoidance hole and the area of ​​the top plate 362 of the outer shell around the avoidance hole is fixedly sealed with the shell of the single cell 3001.

[0222] It should be noted that the polarity terminal of the single cell battery 3001 component described here can be the single cell battery 3001 pole. In order to avoid the single cell battery 3001 pole from being unable to smoothly extend out of the avoidance hole as a polarity terminal, a pole adapter can also be connected to the single cell battery 3001 pole, and the overall structure of the single cell battery 3001 pole and the pole adapter can be used as the single cell battery polarity terminal 351.

[0223] To further enhance the heat dissipation performance of the large-capacity battery in the aforementioned embodiment, this embodiment also includes a heat transfer tube 38. This embodiment incorporates a heat transfer tube clamping portion located where the polarity terminals extend from the relief holes. Heat transfer tube 38 is secured within the clamping portion, directly connecting the heat transfer tube to the large-capacity battery's polarity terminals. This allows for the timely removal of heat from the polarity terminals, where heat is most concentrated, improving the heat dissipation performance of the large-capacity battery. Furthermore, when the temperature of the large-capacity battery falls below a set threshold, a higher-temperature heat transfer medium is introduced into the heat transfer tube to raise the temperature of the large-capacity battery. By controlling the temperature of the heat transfer medium, the large-capacity battery is ensured to maintain its normal operating temperature.

[0224] Example 9

[0225] As shown in FIG. 33 and FIG. 34 , unlike the eighth embodiment, this embodiment adopts a different end plate assembly 32 .

[0226] 35 to 37 , it can be seen that in this embodiment, a first step structure 311 is also provided on the open end surface of the cylinder 31 along its circumference.

[0227] When the thickness of the cylinder wall is relatively thin, an annular plate parallel to the xy plane can be provided along the circumference of the open end of the cylinder 31; a first step structure 311 is provided on the annular plate, as shown in Figure 36; when the thickness of the cylinder wall is relatively thick, the first step structure 311 can be directly provided, as shown in Figure 37.

[0228] The step surface 3111 of the first step structure serves as the mounting surface of the end plate assembly 32 . When the end plate assembly 32 is fixed on the step surface 3111 of the first step structure, the flatness of the lower cover of the single cell 3001 can be ensured by adjusting the overall thickness of the end plate assembly 32 .

[0229] To enhance the connection strength between the end plate assembly 32 and the cylinder 31, this embodiment further provides multiple fastening structures on the step surface 3111 of the first step structure. These fastening structures securely secure the end plate assembly 32 to the cylinder 31. In this embodiment, the fastening structures comprise multiple blind holes formed on the step surface, which are evenly spaced along the circumference of the step surface. In other embodiments, an annular groove may be formed along the circumference of the step surface as the fastening structure.

[0230] As shown in Figures 38, 39, and 40, the end plate assembly 32 of this embodiment includes a second isolation layer 323 and a second dissolving layer 324. The second isolation layer 323 is a sheet-like structure, and its shape is rectangular, matching the shape of the open end of the cylinder 31. The edge is fixed to the step surface 3111 of the first step structure through the second dissolving layer 324, thereby sealing the open end of the cylinder 31.

[0231] The second isolation layer 323 is made of a material that is insoluble in the electrolyte and has a certain strength to prevent the second isolation layer 323 from being damaged by the pressure of the electrolyte inside the single cell before the end plate assembly 32 at the open end of the cylinder 31 is opened, thereby causing the single cell 3001 to be scrapped. Typical materials include aluminum, copper, zinc, nickel, silver, epoxy resin, PE, PP, polytetrafluoroethylene, or EPDM rubber.

[0232] In order to improve the bonding strength between the second dissolving layer 324 and the second isolation layer 323, it can be seen from Figures 38 and 39 that in this embodiment, a second step structure is provided along the circumference of the edge of the second isolation layer 323, and an installation space for the second dissolving layer 324 is formed between the second step structure, the step surface 3111 of the first step structure and the vertical surface.

[0233] In this embodiment, the second dissolving layer 324 is annular and fixed in the installation space of the second dissolving layer 324. Its inner edge is pressed against the second step structure of the second isolation layer 323, and its outer edge is fixed on the cylinder 31, thereby fixing the second isolation layer on the step surface 3111 of the first step structure.

[0234] In this embodiment, the second dissolving layer 324 is fixed within the installation space of the second dissolving layer 324 by casting. Generally, a hot-melt slurry soluble in the electrolyte is cast into the installation space of the second dissolving layer 324. After cooling, the second dissolving layer 324 is formed, achieving a seal while fixing the second isolation layer 323 to the cylinder 31. The material of the second dissolving layer 324 is at least one of PS, PMMA, SMMA, TPU, ABS, POM, PA6, PA12, and PVC.

[0235] In some other embodiments, a sealant that is soluble in the electrolyte may be poured into the installation space of the second dissolving layer 324 , and after solidification, the second dissolving layer 324 may be formed.

[0236] 41 , in this embodiment, the end plate assembly 32 can be fixed to the cylinder 31 using the following process: first, the second isolation layer 323 is covered on the open end of the cylinder 31; secondly, hot-melt material is poured into the installation space of the second dissolving layer 324. After the hot-melt material cools, the second dissolving layer 324 is formed, thereby achieving sealing and fixing the second isolation layer 323 to the cylinder 31.

[0237] FIG42 is a schematic structural diagram of a single cell 3001 according to this embodiment, which includes the battery housing member, the battery cell assembly 34 located inside the battery housing member, the electrolyte, and an upper cover plate sealed and fixed to the open end of the battery housing member.

[0238] A large-capacity battery is constructed using the above-mentioned single cell 3001, including a shell 36 and multiple single cell 3001 components arranged in the shell 36; an electrolyte sharing chamber 39 is provided between the bottom of each single cell 3001 component and the shell bottom plate 361, as shown in Figures 31 and 32 for details.

[0239] The electrolyte sharing chamber 39 described here is a liquid channel extending along the length direction (x direction) of the shell 36 and located between the shell bottom plate 361 and each single cell 3001. The liquid channel can be integrally formed with the shell bottom plate 361, or it can be formed by setting a support member between the lower cover plate of the single cell 3001 and the shell bottom plate 361.

[0240] In the process of constructing the above-mentioned large-capacity battery, each single cell 3001 can be unpacked through the following process (each single cell 3001 is unpacked to form the above-mentioned single cell 3001 components):

[0241] After the assembly of the large-capacity battery is completed (the individual single cells 3001 are not unpacked), the electrolyte is injected into the electrolyte shared chamber 39, which allows the second dissolving layer 324 to automatically dissolve from the outside. Since the second isolation layer 323 and the cylinder 31 are not fixed in any way, when the second dissolving layer 324 dissolves, the second isolation layer 323 will automatically fall off from the cylinder 31, thereby allowing the electrolyte shared chamber 39 to communicate with the inner cavity of the single cell 3001, thereby achieving the effect of the electrolyte of all single cells 3001 being in the same system.

[0242] This embodiment uses an annular second dissolving layer 324 instead of the solid sheet-shaped first dissolving layer 322 used in Example 8, which has at least the following advantages:

[0243] 1. The end plate assembly 32 has high installation reliability. The present application utilizes an annular second dissolving layer 324 to fix the second isolation layer 323 on the battery housing. The annular second dissolving layer 324 can ensure that the edge of the second isolation layer 323 is firmly bonded to the housing of the single battery 3001. Before the second dissolving layer 324 dissolves, the second isolation layer 323 is not easy to fall off, thereby making the installation reliability of the entire end plate assembly 32 high.

[0244] 2. The end plate assembly 32 has good sealing performance; the second dissolving layer 324 can effectively seal the gap between the second isolation layer 323 and the shell area around the opening. At the same time, the electrolyte in the inner cavity of the shell of the single battery 3001 is in direct contact with the second isolation layer 323, but cannot contact the second dissolving layer 324 located on the outer surface of the shell. Therefore, during the assembly process of the large-capacity battery (before unpacking), the opening part of each single battery 3001 has good sealing performance.

[0245] 3. The end plate assembly 32 is easy to open. During the unpacking process, electrolyte is injected into the shared pipe assembly. Under the action of the electrolyte, the second dissolving layer 324 dissolves, and the second isolation layer 323 falls off from the shell of the single battery 3001, thereby connecting the inner cavity of the shell of each single battery 3001 with the inner cavity of the shared pipe assembly. Because the present application uses an annular second dissolving layer 324, when the outer diameter is the same, the annular second dissolving layer 324 has a smaller area than the solid dissolving layer (the sealing film in Example 8). Therefore, compared with Example 8, the dissolution time of the present application is shorter, and the second isolation layer 323 can fall off in a short time, which can shorten the preparation time of large-capacity batteries and improve production efficiency.

[0246] A large-capacity battery is provided in the related art. The large-capacity battery includes multiple single cells. Each single cell is connected to the gas area in the inner cavity of each single cell through a gas chamber. After the gas area is connected, the internal pressure of each single cell can be kept basically consistent, reducing the problem of excessive internal pressure of a single cell causing the single cell to swell and fail or even produce thermal runaway.

[0247] During the manufacturing process of this high-capacity battery, a primary opening is first made in the battery casing of each single cell, and then a sealing mechanism is installed on this primary opening. The main function of this sealing mechanism is to seal the single cells and protect the electrolyte inside the single cells from contact with air. When the single cells are assembled to form a high-capacity battery, the sealing mechanism needs to be detached from the single cells, at which point a secondary opening is formed in the battery casing of the single cells. Finally, the internal cavities of the single cells are connected through this secondary opening. The above unpacking method requires unpacking the single cells twice, making the manufacturing process of large-capacity batteries cumbersome and low in assembly efficiency.

[0248] The present application provides a single cell battery, the basic concept of which is: a one-way breathable membrane is provided on the battery shell of the single cell battery. When the single cell battery is used to form a large-capacity battery, there is no need to unpack the single cell battery, thereby saving the production process of the large-capacity battery and improving the assembly efficiency of the large-capacity battery.

[0249] Example 10

[0250] As shown in Figures 43 and 44 , in this embodiment, a single cell 401 includes a battery housing 41, an electrode assembly, and a sealing device. A one-way breathable membrane 42 is provided on the battery housing 41 to discharge gases generated within the single cell out of the housing. The electrode assembly is located within the battery housing and connected to a polarity terminal 43 at the top of the battery housing 41, and the electrolyte is located within the battery housing. The polarity terminal 43 is provided with a mounting portion 44 for mounting a heat transfer tube. The battery housing 41 is a component used to create an internal environment for the single cell 401, wherein this internal environment can be used to accommodate the electrode assembly, electrolyte, and other components. The battery housing 41 can have a variety of shapes and sizes, such as a rectangular parallelepiped. Specifically, the shape of the battery housing 41 can be determined based on the specific shape and size of the electrode assembly.

[0251] The battery case 41 can have the following two forms: 1. The battery case 41 includes a top cover 411 and an outer shell 412 with an open top. The top cover 411 is provided with the positive and negative terminals of the individual cells. The top cover 411 is sealed and mounted on the outer shell 412 with an open top. 2. The battery case 41 includes a top cover 411, a bottom cover 413, and an outer shell 412 with open top and bottom. The top cover 411 is provided with the positive and negative terminals of the individual cells. The top cover 411 is sealed and mounted on the open top of the outer shell 412, and the bottom cover 413 is sealed and mounted on the open bottom of the outer shell 412.

[0252] The electrode assembly is the component within a single cell where the electrochemical reaction occurs. The battery housing may contain one or more electrode assemblies. The electrode assembly also includes tabs. During the battery's charge and discharge processes, the positive and negative active materials react with the electrolyte. The electrode assembly is made of multiple layers of electrode sheets, either wound or stacked. Each layer consists of a positive electrode sheet, a separator, and a negative electrode sheet.

[0253] The battery housing 41 is provided with a one-way breathable membrane 42, which is used to vent gases generated within the individual cells out of the battery housing. When these individual cells 401 are assembled into a high-capacity battery that connects the gas zones of each cell 401, there is no need to unpack the individual cells a second time, which saves time and improves assembly efficiency. Specifically, the one-way breathable membrane 42 can be installed on the top or side wall of the battery housing 41. Its location must correspond to the gas zone within the cavity of the individual cells 401, ensuring that gases within the individual cells can be discharged from the battery housing. In this embodiment, the one-way breathable membrane is installed on the top cover of the battery housing.

[0254] The one-way breathable membrane 42 can be installed on the single battery 401 in the following two ways:

[0255] 1. It can be fixed to the battery housing 41 of the single cell 401 by injection molding during the production process of the single cell 401, that is, the single cell 401 is a homemade battery, and no explosion relief mechanism is required on the single cell 401; 2. It can also be modified using a finished single cell, that is, first an opening is opened in the battery housing of the single cell, and then the one-way breathable membrane 42 is fixedly installed on the opening of the battery housing of the single cell 401 (the explosion relief membrane of the finished single cell can be removed first to form an opening, and then the one-way breathable membrane is used to seal the opening).

[0256] Compared with the second method, since the one-way breathable membrane 42 is installed in the battery shell during the manufacturing process of the battery shell of the single cell 401, when the single cell is subjected to a formation treatment, the one-way breathable membrane 42 can directly discharge the gas generated during the formation out of the battery shell 41. Compared with the existing single cell, the steps of opening and sealing the single cell when performing the formation treatment are saved, thereby improving the manufacturing efficiency of the single cell.

[0257] The electrode assembly is located inside the battery casing and is connected to the polarity terminal 43 on the top of the battery casing 41; a mounting portion 44 for mounting a heat transfer tube is provided on the polarity terminal 43; when multiple single cells 401 are assembled into a large-capacity battery, the temperature of the electrode assembly in each single cell 401 can be transferred from the polarity terminal to an external temperature control device through the heat transfer tube, thereby reducing the problem of overheating of the electrode assembly affecting the performance of the large-capacity battery. More importantly, direct temperature control of each electrode assembly reduces the probability of thermal runaway, thereby improving safety.

[0258] Specifically, the heat transfer tube mounting portion in this application has two forms: Method 1: A through-hole formed on the polarity terminal 43, perpendicular to the axial direction of the polarity terminal 43. The through-hole diameter must be sized to ensure that the heat transfer tube is tightly clamped therein, ensuring installation stability while also ensuring heat transfer between the heat transfer tube and the polarity terminal. Method 2: A groove formed on the top or side wall of the polarity terminal 43. The groove width must be sized to ensure that the heat transfer tube is tightly clamped therein, ensuring installation stability while also ensuring heat transfer between the heat transfer tube and the polarity terminal.

[0259] Since the polarity terminals 43 of the single battery are charged, to ensure safety, insulation must be maintained between the heat transfer tube and the polarity terminals of the single battery. The insulation can be maintained by oxidizing the heat transfer tube or providing an insulating layer in the area where the heat transfer tube contacts the polarity terminals.

[0260] The battery housing is provided with a sealing device 45, which utilizes a dissolving structure formed from an additive soluble in the electrolyte. The dissolving structure can be a sheet-like structure, affixed to the battery housing by injection molding. In this embodiment, the battery housing 41 is provided with a raised ring 46, within which the dissolving structure is mounted. The dissolving structure comprises a columnar body 47 formed from an additive soluble in the electrolyte, and an isolation layer. At least the first end surface of the columnar body 47 comprises an isolation layer that is insoluble in the electrolyte. The first end surface 471 is the surface adjacent to the inner cavity of the cell. This isolation layer is provided to prevent the electrolyte within the cell from dissolving the columnar body before the cell is unpacked.

[0261] There are several ways to secure the sealing device 45 to the raised ring: 1. Apply adhesive to the outer wall of the sealing device 45 or the inner wall of the raised ring 46 for sealing and securing by bonding; 2. Secure the sealing device 45 directly within the raised ring 46 by interference fit; 3. Secure the sealing device 45 within the raised ring 46 by interference fit with the sealing ring 48. Method 3 is preferred in this embodiment due to its ease of operation and greater sealing reliability.

[0262] Preferably, in order to ensure the flatness of the outer shape of the single battery, the protruding direction of the convex ring 46 in this embodiment is toward the inner cavity of the battery.

[0263] Specifically, the columnar body 47 is made of propylene sulfate, ethylene carbonate or diphenyl carbonate as an electrolyte additive, and the production process is as follows: first, the propylene sulfate crystals, ethylene carbonate crystals or diphenyl carbonate crystals are ground into powder; then the above powder is heated to convert it into a liquid additive; then the liquid additive is poured into a mold prepared in advance, and a columnar body is formed after natural cooling; finally, the columnar body is taken out.

[0264] Among them, propylene sulfate, as an electrolyte additive, can improve the low-temperature performance of the electrolyte and prevent PC molecules from embedding into the graphite electrode. Ethylene carbonate, as an electrolyte additive, has the following main functions: 1. Transferring ions during battery reactions: In a battery, when the positive and negative electrodes react, ions need to move within the battery to complete the reaction. Ethylene carbonate, as an electrolyte, plays the role of transferring ions and promoting the reaction. 2. Maintaining charge balance: During a battery reaction, the positive and negative electrodes consume or release charge. The charge needs to be balanced, otherwise it will affect battery performance and life. Ethylene carbonate can maintain charge balance in the battery by transferring ions, ensuring the normal operation of the battery. 3. Improving battery performance: It improves the battery's conductivity and enhances its stability and safety.

[0265] As an electrolyte additive, diphenyl carbonate has good redox stability and thermal stability, can provide high conductivity and extend battery life.

[0266] 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.

[0267] The isolation layer only needs to be non-reactive and insoluble in the electrolyte. While there are many such film materials, PP film is preferred for the isolation layer in this embodiment for safety and reliability considerations. When fabricating the sealing mechanism, the isolation layer can be applied to the columnar body by heat sealing, coating, or gluing.

[0268] Preferably, as shown in Figures 45 and 46, since an electrolyte additive is used as the sealing device 45 in this embodiment, in order to allow the sealing device 45 to slowly dissolve in the electrolyte and thus continuously improve the electrolyte performance, the first end face 471, the second end face 472, and the side of the columnar body 47 are coated with an isolation layer (the second end face 472 is the surface away from the inner cavity of the single cell), and the columnar body is provided with a blind hole 473 from the second end face 472 to the first end face 471. When the electrolyte is injected into the electrolyte channel, due to the presence of the isolation layer, the electrolyte can only contact the hole wall and the hole 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 covered by the isolation layer, the electrolyte is always in contact with the hole wall, and the electrolyte continuously and slowly dissolves the columnar body.

[0269] Preferably, in order to achieve both fast unpacking speed and slow decomposition of the sealing device in the electrolyte, the depth of the blind hole 473 in this embodiment accounts for 90% of the length of the columnar body 47. In other words, the bottom of the blind hole 473 is relatively thin, and the bottom of the blind hole will be penetrated in a short time, thereby achieving unpacking of the single battery.

[0270] Preferably, as shown in Figure 46, to facilitate the installation of the dissolving structure in conjunction with the battery housing of the single cell, the columnar body 47 includes a first cylindrical section 474 and a second cylindrical section 475. The outer diameter of the first cylindrical section 474 is larger than that of the second cylindrical section 475. A sealing ring 48 is disposed between the second cylindrical section 475 and the protruding ring 46. To facilitate the installation of the sealing ring, a groove for accommodating the sealing ring is provided on the sidewall of the columnar body in this embodiment.

[0271] Example 11

[0272] Based on the structure of the single cell in Example 10, this embodiment discloses a large-capacity battery, as shown in FIG47 , comprising a first hollow tube 402, a second hollow tube 403, and a plurality of single cells 401; the plurality of single cells 401 are placed side by side, and the positive terminals of all the single cells 401 are connected as a total positive electrode, and the negative terminals of all the single cells 401 are connected as a total negative electrode;

[0273] The first hollow tube 402 is provided with a plurality of first through holes. The first hollow tube 402 is fixed on the battery shell of each single battery 401, and the plurality of first through holes of the first hollow tube 402 correspond one by one to the one-way breathable membrane of the single battery. The gas generated in each single battery 401 overflows into the first hollow tube 402 through the one-way breathable membrane, so that the air pressure in each single battery remains consistent.

[0274] The second hollow tube 403 is provided with a plurality of second through holes. The second hollow tube 403 is fixed to the battery housing of each single cell, and the plurality of second through holes of the second hollow tube 403 correspond one-to-one to the sealing device 45 on the battery housing of the single cell. When the sealing device dissolves, the electrolyte areas of each single cell are connected.

[0275] The first hollow tube 402 is a rectangular tube, and the second hollow tube 403 is essentially the same shape as the first hollow tube 402. In this embodiment, the one-way breathable membrane is located at the top of the battery housing of the single cell, the first hollow tube 402 is located above the high-capacity battery, the sealing device is located at the bottom of the battery housing of the single cell, and the second hollow tube 403 is located below the high-capacity battery. The second hollow tube 403 can be used to connect to the injection equipment and the explosion relief mechanism.

[0276] Example 12

[0277] Based on the structure of the single cell in Example 10, this embodiment discloses a large-capacity battery, as shown in Figure 48, including a box body 404 and multiple single cells 401; the multiple single cells 401 are arranged in the box body 404 along the same direction, and the electrolyte areas of each single cell are interconnected; a pole avoidance hole is opened on the top plate of the box body 404 corresponding to the polarity terminal of each single cell; the polarity terminal of each single cell extends out of the pole avoidance hole, and the top plate area of ​​the box body corresponding to the pole avoidance hole is fixedly sealed with the battery shell of the single cell; the positive polarity terminals of all single cells are connected as a total positive electrode, and the negative polarity terminals of all single cells are connected as a total negative electrode; a gas chamber 405 extending along the arrangement direction of the single cells is provided on the box body 404, and the gas chamber 405 covers the one-way breathable membrane of each single cell, and the gas generated in each single cell overflows into the gas chamber through the one-way breathable membrane, so that the air pressure in each single cell remains consistent.

[0278] In order to ensure good continuity of the liquid level when the electrolyte areas of each single cell are connected (to avoid liquid interruption) and to ensure that there is a sufficient amount of electrolyte in the large-capacity battery, the large-capacity battery of this embodiment also includes an electrolyte sharing chamber 406 arranged on the box body 404 and extending along the arrangement direction of the single cells; the electrolyte sharing chamber 406 is connected to the electrolyte areas of each single cell.

[0279] The box has the following three forms:

[0280] 1. The box body 404 includes a cylinder, a first cover plate, and a second cover plate; the top and bottom of the cylinder are both open, the first cover plate is sealed and fixed (welded) to the top of the cylinder, and the second cover plate is sealed and fixed (welded) to the bottom of the cylinder;

[0281] The first cover plate is provided with a pole avoidance hole for the extension of the polarity terminals of multiple single cells. The first cover plate is integrally formed with an upwardly protruding groove body, which serves as a gas chamber; the second cover plate is integrally formed with a groove serving as an electrolyte shared chamber.

[0282] 2. The box body 404 includes a U-shaped shell, a first cover plate, a third cover plate and a fourth cover plate; the top, front and rear of the U-shaped shell are all open, the first cover plate is sealed and fixed (welded) to the top of the U-shaped shell, and the third cover plate and the fourth cover plate are sealed and fixed (welded) to the front and rear of the U-shaped shell respectively.

[0283] The first cover plate is provided with 2N pole avoidance holes for the extension of the polarity terminals of multiple single cells. The first cover plate is integrally formed with an upwardly protruding groove body, which serves as a gas chamber; the bottom of the U-shaped shell is integrally formed with a groove serving as an electrolyte shared chamber.

[0284] 3. The box body 404 includes a cylinder, a third cover plate, and a fourth cover plate; the front and rear of the cylinder are open, the third cover plate is sealed and fixed (welded) to the front of the cylinder, and the fourth cover plate is sealed and fixed (welded) to the rear of the cylinder;

[0285] The top of the cylinder is provided with multiple pole avoidance holes for the extension of the polarity terminals of multiple single cells. The top of the cylinder is integrally formed with an upwardly protruding groove body, which serves as a gas chamber; the bottom of the cylinder is integrally formed with a groove as an electrolyte shared chamber.

[0286] In the above three types of shells, the cylinder and the U-shaped shell can be spliced ​​together by welding, or can be integrally formed by casting or stamping. In order to facilitate processing while ensuring sealing, the integral forming method is usually selected.

[0287] To ensure the tightness of the box, the box area corresponding to the terminal avoidance hole needs to be fixedly sealed with the battery shell of the single battery. The fixed sealing at this location can be achieved in the following three ways:

[0288] Method 1: The edge of the terminal avoidance hole can be welded to the top cover of the single battery to achieve sealing;

[0289] However, if the height dimensions of the individual cells are not completely equal, some of the cell covers with smaller height dimensions may have problems with poor welding or even no welding between them and the top of the box. In this case, the following method 2 or method 3 can be used.

[0290] Method 2: A weak portion is provided in the peripheral area of ​​the pole avoidance hole. During the welding process, the deformation of the weak portion compensates for the height difference of the top of the battery casing of each single cell, so that the polarity terminals of all single cells extend out of the pole avoidance hole. The weak portion in this embodiment can be an annular groove with the center of the pole avoidance hole as the center point and opened along the peripheral area of ​​the pole avoidance hole. In other embodiments, the weak portion can also be a long strip groove opened in the peripheral area of ​​the pole avoidance hole. In other embodiments, if a similar problem exists, that is, the polarity terminals of all single cells cannot fully extend out of the pole avoidance hole at the same time, the solution can be adopted to add a weak portion in the peripheral area of ​​the pole avoidance hole.

[0291] Method 3: Add a hollow connector between the pole avoidance hole and the polarity terminal; the bottom of the hollow connector is used to seal and connect with the first area of ​​the single cell, and the top of the hollow connector is sealed and connected with the second area of ​​the box; the first area is the area located around any polarity terminal in any single cell; the second area is the area corresponding to any pole avoidance hole on the box. The area corresponding to the pole avoidance hole is the area around any pole avoidance hole on the top outer surface of the box; or the area corresponding to the pole avoidance hole is the wall of the pole avoidance hole. The area around the pole avoidance hole is the area around the insulating gasket on the pole avoidance hole. The insulating gasket is a part on the single cell used to insulate between the pole avoidance hole and the top cover.

[0292] In the above embodiments 11 and 12, the large-capacity batteries are provided with heat transfer tubes 407 ; the heat transfer tubes 407 are matched with the mounting portions of the polarity terminals of each single battery.

[0293] The heat transfer tube can be made in the following ways:

[0294] 1. An aluminum tube is bent into a U-shaped structure, and two parallel tube sections are used to cooperate with the total positive electrode and the total negative electrode respectively, so as to realize heat exchange between each single battery and the external temperature control device, and the liquid inlet and outlet of the aluminum tube are located on the same side; the transmission medium in the aluminum tube can be water, insulating oil or fluorinated liquid; or two aluminum tubes can be used to cooperate with the total positive electrode and the total negative electrode respectively.

[0295] 2. Two cored heat pipes are used to cooperate with the total positive electrode and the total negative electrode respectively, so as to realize the heat exchange between each single battery and the external temperature control device. The cored heat pipe is an evaporation-condensation type heat exchange device, which realizes heat transfer by the state change of the working fluid in the pipe.

[0296] Since the heat transfer effect of a cored heat pipe is affected by its length, its use is limited when the number of cells in a large-capacity battery is large (i.e., the large-capacity battery is long). Therefore, in this embodiment, aluminum tubes are preferably used as heat transfer tubes. If insulation between the heat transfer tubes and the polarity terminals can be effectively ensured, water can be preferably used as the heat transfer medium flowing in the aluminum tubes in consideration of heat transfer efficiency and cost.

Claims

1. A sealing device for sealing an opening on a battery housing member, characterized in that: It includes a dissolving layer and an isolation layer attached to the dissolving layer; the material of the dissolving layer is an electrolyte-soluble material; the material of the isolation layer is a solid alkane or solid halogenated alkane that is insoluble in the electrolyte, the solid alkane or solid halogenated alkane is attached to the end face of the dissolving layer, and forms an integral sheet structure with the dissolving layer. After the dissolving layer is dissolved by the electrolyte, the isolation layer loses support and breaks.

2. The sealing device according to claim 1, characterized in that The end surface of the dissolving layer adhering to the isolation layer is provided with a groove or a protrusion, and the height of the protrusion is less than the thickness of the isolation layer.

3. The sealing device according to claim 1, characterized in that A first chamfer is provided on the end surface of the dissolving layer away from the isolation layer.

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

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

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

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

8. A battery housing component, characterized in that: An opening penetrating the inner cavity of the battery shell is provided on the battery shell component, and a sealing device according to any one of claims 1 to 7 is provided at the opening, the sealing device seals the opening, and the end surface of the dissolving layer having the isolation layer faces the inner cavity of the battery shell.

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

10. A battery housing member, the battery housing member being provided with a first opening, wherein a dissolvable layer capable of dissolving in an electrolyte is provided on the first opening; The first opening is also provided with a protective protrusion protruding outward from the battery shell component. The protective protrusion is fixedly connected to the battery shell component and is used to protect the dissolution layer in the first opening. The protective protrusion has a plurality of through second openings.

11. The battery housing member according to claim 10, wherein: The second opening is provided with a dissolving layer that can dissolve in the electrolyte.

12. The battery housing member according to claim 11, wherein: The dissolving layer is arranged in the first opening and the second opening by nano injection molding.

13. The battery housing member according to claim 12, wherein: The dissolving layers in the first opening and the second opening are made of the same material.

14. The battery housing member according to claim 12, wherein: The thickness of the dissolving layer on the second opening is less than the thickness of the dissolving layer on the first opening.

15. The battery housing member according to any one of claims 10 to 14, characterized in that: The protective protrusion is integrally formed by stamping with the battery housing component.

16. The battery housing member according to claim 15, characterized in that The size of the second opening is 1 to 5 mm.

17. The battery housing member according to claim 16, wherein: The battery shell component is mainly composed of an upper cover plate and a cylinder with an open top. The protective protrusion is arranged at the bottom of the cylinder. The upper cover plate is provided with polarity terminals for drawing out the current of the single battery.

18. A battery housing component, characterized in that: It includes a cylinder and an end plate assembly sealed and fixed at any open end of the cylinder; through the action of external electrolyte, the end plate assembly can fall off from the cylinder, or an opening penetrating the inner cavity of the cylinder can be formed in the end plate assembly.

19. The battery housing member according to claim 18, wherein: The end plate assembly includes a first dissolving layer and a first isolation layer attached to the inner surface of the first dissolving layer, both of which are in the form of a sheet. The inner surface of the first dissolving layer is the surface located in the inner cavity of the cylinder. The first isolation layer is used to isolate the electrolyte in the inner cavity of the single cell from the first dissolving layer; the area of ​​the first dissolving layer not attached to the first isolation layer is sealed and fixed to the open end of the cylinder; the material of the first dissolving layer is an electrolyte soluble material, and the material of the first isolation layer is an electrolyte insoluble material.

20. The battery housing member according to claim 19, wherein: The first dissolving layer is matched with the stopper on the end surface of the open end of the cylinder.

21. The battery housing member according to claim 18, wherein The end plate assembly includes a second isolation layer and a second dissolving layer; the second isolation layer is in sheet form and covers any open end of the cylinder; the second dissolving layer is annular, the inner edge is sealed and fixed to the outer surface of the second isolation layer, and the outer edge is sealed and fixed to the outer surface of the open end of the cylinder; wherein, the outer surface of the second isolation layer is the surface of the second isolation layer located outside the inner cavity of the cylinder; the material of the second dissolving layer is an electrolyte soluble material, and the material of the second isolation layer is an electrolyte insoluble material.

22. The battery housing member according to claim 21, wherein: The second dissolving layer is sealed and fixed on the outer surface of the second isolation layer and the outer surface of the open end of the cylinder in a pouring manner.

23. The battery housing member according to claim 22, wherein: A first step structure is provided along the circumference of the open end surface of the cylinder; a second step structure is provided along the circumference of the second isolation layer at its edge; the inner surface edge of the second isolation layer contacts the step surface of the first step structure, and a second dissolving layer installation space is formed between the second step structure and the step surface and vertical surface of the first step structure; The second dissolving layer is fixed in the second dissolving layer installation space.

24. The battery housing member according to claim 23, wherein: A plurality of blind holes are provided along the circumference of the step surface area of ​​the first step structure located in the second dissolution layer installation space.

25. A single cell battery, characterized in that: The battery comprises a shell and an electrode assembly and an electrolyte located in the shell, wherein the shell is composed of the battery shell component according to any one of claims 18 to 24 and an upper cover plate sealed and fixed to the open end of the battery shell component.

26. A single cell battery, characterized in that: The battery casing member comprises the battery casing member according to claim 8 or 9.

27. A single cell battery, characterized in that: The invention comprises the battery casing member according to any one of claims 10 to 17 and an electrode assembly provided in the battery casing member, wherein the electrode assembly is immersed in the electrolyte of the battery casing member.

28. A single cell battery, characterized in that: It includes a battery shell, an electrode assembly and a sealing device; a one-way breathable membrane is provided on the battery shell; the electrode assembly is located in the battery shell and connected to the polarity terminal on the top of the battery shell; a mounting portion for mounting a heat transfer tube is provided on the polarity terminal; a sealing device is provided on the battery shell, and the sealing device includes an electrolyte additive soluble in the electrolyte to form a dissolving structure.

29. The single cell according to claim 28, characterized in that: A convex ring is provided on the battery shell, and the dissolving structure is installed in the convex ring; the dissolving structure includes a columnar body formed by an additive soluble in the electrolyte and an isolation layer; at least the first end face of the columnar body has an isolation layer, which is insoluble in the electrolyte.

30. The single cell according to claim 29, characterized in that: The columnar body is made of propylene sulfate, ethylene carbonate or diphenyl carbonate.

31. The single cell according to claim 30, characterized in that: The first end surface, the second end surface and the side surface of the column are covered with an isolation layer, and a blind hole is provided on the column from the second end surface to the first end surface.

32. The single cell according to claim 31, characterized in that: The depth of the blind hole accounts for 90% of the length of the columnar body.

33. The single cell according to claim 32, characterized in that: A sealing ring is provided between the columnar body and the convex ring.

34. A large capacity battery, characterized in that: It includes a first hollow tube, a second hollow tube and a plurality of single cells as described in claim 28; the plurality of single cells are placed side by side, and the positive terminals of all the single cells are connected as a total positive pole, and the negative terminals of all the single cells are connected as a total negative pole; the first hollow tube is provided with a plurality of first through holes, the first hollow tube is connected to the battery shell of each single cell, and the plurality of first through holes of the first hollow tube corresponds to the one-way breathable membrane of the single cell one by one, and the gas generated in each single cell overflows into the first hollow tube through the one-way breathable membrane, so that the air pressure in each single cell remains consistent; the second hollow tube is provided with a plurality of second through holes, the second hollow tube is connected to the battery shell of each single cell, and the second hollow tube is connected to the electrolyte area in each single cell, so that the electrolyte area of ​​each single cell is connected.

35. A large capacity battery, characterized in that: It comprises a box body and a plurality of single cells as described in claim 28; the plurality of single cells are arranged in the box body in the same direction, and the electrolyte areas of the single cells are interconnected; avoidance holes are provided on the top plate of the box body corresponding to the polarity terminals of the single cells; the polarity terminals of the single cells extend out of the avoidance holes, and the area of ​​the top plate of the outer shell corresponding to the avoidance holes is fixedly sealed with the battery shell of each single cell; the positive polarity terminals of all the single cells are connected as a total positive electrode, and the negative polarity terminals of all the single cells are connected as a total negative electrode; a gas chamber extending along the arrangement direction of the single cells is provided on the box body, and the gas chamber covers the one-way breathable membrane of each single cell, and the gas generated in each single cell overflows into the gas chamber through the one-way breathable membrane, so that the air pressure in each single cell remains consistent.

36. The large-capacity battery according to claim 35, characterized in that: It also includes an electrolyte sharing chamber which is arranged on the box body and extends along the arrangement direction of the single cells; the electrolyte sharing chamber is communicated with the electrolyte area of ​​each single cell.

37. The large-capacity battery according to claim 35, characterized in that: It also includes a heat transfer tube; the heat transfer tube is matched with the mounting portion of the polarity terminal of each single battery.

38. A large capacity battery, characterized in that: The invention comprises an outer shell and a plurality of single cells as claimed in claim 27, wherein the plurality of single cells are placed side by side in the outer shell, a through hole is provided at the top of the outer shell at the position corresponding to the polarity terminal of each single cell, and the polarity terminal of each single cell passes through the through hole to realize parallel connection of each single cell; the top and bottom of the outer shell are respectively provided with a shared chamber, and the plurality of single cells realize interconnection between the gas zone and the electrolyte zone through the shared chamber.

39. A large capacity battery, characterized in that: It includes a shell and multiple single cell components arranged in the shell; an electrolyte sharing chamber is provided between the bottom of each single cell component and the bottom plate of the shell; the single cell component is a component in which the end plate assembly of the single cell in claim 25 falls off from the cylinder or an opening is formed in the end plate assembly that passes through the inner cavity of the cylinder.

40. The large-capacity battery according to claim 39, characterized in that: The top plate of the large-capacity battery housing is provided with avoidance holes corresponding to the polarity terminals of each single battery component; the polarity terminals of each single battery component extend through the avoidance holes, and the area of ​​the housing top plate corresponding to the avoidance holes is fixedly sealed to the upper cover plate of the single battery component; a heat transfer tube clamping portion is provided at the portion where each polarity terminal extends through the avoidance hole; and the heat transfer tube is fixed to the heat transfer tube clamping portion of each polarity terminal.

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