Single battery upper cover assembly, single battery and high-capacity battery

Abstract

The invention belongs to the field of batteries, and relates to a single battery upper cover assembly, a single battery and a high-capacity battery. The technical problems that an existing high-capacity battery is high in cost and large in weight are solved. The upper cover assembly comprises an upper cover plate, the upper cover plate is provided with a connecting piece and is used for being connected with the connecting piece on the adjacent single battery, a channel can be formed in the connecting piece under the action of external force, and the channel is communicated with the gas area of the inner cavity of the single battery shell; a weak part is integrally arranged on the upper cover plate; the strength of the weak part is smaller than that of other parts of the upper cover plate, and when the single battery is in thermal runaway, thermal runaway flue gas bursts the weak part to be discharged; wherein the upper cover plate, the weak part, the concave part and the bulge are all made of plastic materials. The single battery comprises the upper cover assembly, the large-capacity battery comprises a plurality of single batteries, and the shell of the single battery is a plastic shell, so that the large-capacity battery has the advantages of low cost and light weight. Due to the integrally-arranged weak part, the stability and reliability of the structure are greatly improved, and good explosion venting performance can be kept all the time.

Description

Technical Field

[0001] This invention belongs to the field of batteries, specifically a single-cell battery cover assembly, a single-cell battery, and a high-capacity battery. Background Technology

[0002] Chinese patent CN219658914U discloses a high-capacity battery, the structure of which is as follows: Figure 1 As shown, the battery includes a large-capacity battery body formed by several individual cells connected in parallel and a shared conduit located on the large-capacity battery. This shared conduit connects all the internal cavities of the individual cells, ensuring that all individual cells in the large-capacity battery are within a single system. This shared conduit enhances the uniformity of the individual cells within the large-capacity battery and improves cycle life.

[0003] The single battery in the aforementioned patent includes a housing, a sealing assembly, and a finished battery. The finished battery is installed inside the housing, and the finished battery housing has an opening. The housing has a first through hole communicating with the opening, and a pipe 01 extending along the width or length direction of the housing. The side wall of the pipe has a second through hole communicating with the first through hole. The sealing assembly is disposed on the opening, the first through hole, or the second through hole.

[0004] By setting a first through hole and a pipe with a second through hole on the outer casing of a single cell, a shared pipeline 02 can be formed through the pipe when assembling a large-capacity battery; moreover, by adding an outer casing to the finished battery, existing finished battery production lines can be used to put the finished battery into production with slight modifications.

[0005] However, this design has some drawbacks. Typically, both the finished battery casing and the outer shell are made of aluminum, which makes the overall cost of large-capacity batteries higher and their weight heavier.

[0006] From a cost perspective, aluminum is a relatively expensive metal. Furthermore, the manufacturing process for aluminum casings is complex, requiring multiple steps such as cutting, stamping, and welding, and demanding advanced equipment and techniques. These factors combined inevitably lead to a significant increase in the manufacturing cost of large-capacity batteries.

[0007] From a weight perspective, the stacking of two aluminum components significantly increases the overall weight of a large-capacity battery. This is extremely disadvantageous for the use, storage, and transportation of large-capacity batteries. Summary of the Invention

[0008] The purpose of this invention is to provide a single-cell battery cover assembly, a single-cell battery, and a large-capacity battery, overcoming the technical difficulties of high cost and heavy weight of existing large-capacity batteries.

[0009] The concept of this invention is:

[0010] This invention addresses the aforementioned technical challenges primarily by focusing on both the structure of the individual battery cell itself and its packaging structure.

[0011] Firstly, starting from the structure of the individual battery itself, reduce the cost and weight of large-capacity batteries;

[0012] Given that plastic materials have a lower density than aluminum materials and are relatively cheaper, this invention aims to replace the finished batteries in the prior art with finished batteries using plastic casings (finished batteries can also be called single-cell batteries).

[0013] Compared to traditional aluminum casings, plastic casings are significantly lighter. Furthermore, plastic materials are less expensive, and the manufacturing process is relatively simple, requiring no complex equipment or technology. This effectively reduces manufacturing costs, increases production efficiency, and provides a cost advantage in large-scale production.

[0014] Secondly, starting from the packaging structure of individual cells, we can reduce the weight and cost of large-capacity batteries.

[0015] This invention proposes placing multiple individual battery cells with plastic casings within a single pressure-bearing casing, which can simultaneously protect multiple individual battery cells. Compared to the prior art structure where each individual battery cell is individually encased in a casing, this reduces individual packaging and protection costs, resulting in lower overall cost. Furthermore, given the same number of individual battery cells, the weight of a single pressure-bearing casing is necessarily less than the weight of multiple smaller casings; therefore, the design of the pressure-bearing casing can further reduce the weight of large-capacity batteries.

[0016] Based on the above inventive concept, the first aspect of the present invention provides a single-cell battery cover assembly, which is characterized in that: it includes a cover plate, the cover plate is provided with a connector for connecting with a connector on an adjacent single-cell battery, and under the action of external force, a channel can be opened in the connector, the channel communicating with the gas area inside the cavity of the single-cell battery casing.

[0017] The top cover plate is integrally provided with a weak part; the strength of the weak part is less than the strength of the rest of the top cover plate. When a single cell experiences thermal runaway, the thermal runaway smoke breaks through the weak part and is discharged.

[0018] The top cover, weak points, recesses, and protrusions are all made of plastic.

[0019] When individual battery cells are connected by connectors, this invention uses a tool to create a channel in the connector that runs through the inner cavity of the individual battery cell casing. In this way, the gas between the individual battery cells is connected, achieving gas balance. The differences that may have existed can be effectively improved, ensuring the consistency of each individual battery cell during the charging and discharging process, extending the overall service life, and improving the performance of large-capacity batteries.

[0020] The single-cell battery cover plate provided by the present invention is made of plastic, which has the advantages of low cost and light weight compared with the finished battery cover plates used in the prior art.

[0021] In addition, the present invention also integrally forms a weak part as a venting part on the upper cover plate, which has at least the following advantages:

[0022] From a structural stability perspective, existing explosion-proof membranes are typically attached to the battery cover plate via adhesive or other methods. During long-term use, factors such as corrosion from internal battery chemicals, temperature changes, and mechanical vibrations can cause the connection between the explosion-proof membrane and the cover plate to loosen or detach, leading to a failure of its explosion-proof function. In contrast, the integrated weak point in this invention is a single unit with the cover plate, eliminating the risk of loosening or detachment at the connection point. This significantly improves structural stability and reliability, ensuring consistently excellent explosion-proof performance.

[0023] In terms of sealing, achieving an absolute seal at the junction of the existing explosion-proof membrane and the top cover faces numerous challenges. However, the seamless integration of the integrated weak point with the top cover effectively ensures the internal sealing of the battery under normal conditions, preventing the intrusion of external substances and providing a better environment for stable battery operation.

[0024] From a cost and manufacturing process perspective, existing explosion-proof membranes require additional materials and complex installation processes, which not only increases production costs but may also lead to inconsistent product quality due to human factors during manufacturing. In contrast, the integrated design of the weak point eliminates the need for additional installation steps during manufacturing, simplifying the production process, reducing production costs, and improving product consistency and quality stability.

[0025] Furthermore, the connector consists of a recess and a protrusion on opposite sidewalls of the upper cover plate; wherein the recess is used for the protrusion of another single battery cell to be embedded and fixedly connected, and under the action of external force, a channel can be opened in the protrusion and the recess, which communicates with the gas area inside the cavity of the single battery cell.

[0026] This invention fully utilizes the structure of the top cover plate itself, placing the recesses and protrusions on opposite sidewalls of the top cover plate. These recesses and protrusions do not affect the dimensions of individual cells in the height direction, thus balancing the overall compactness and space utilization efficiency of the large-capacity battery. Furthermore, when assembling the large-capacity battery, the protrusion of one individual cell is inserted into the recess of another individual cell and fixedly connected, improving the stability between the individual cells and making the entire large-capacity battery structure more robust and durable.

[0027] Furthermore, the recess is a first blind hole opened on the first side wall of the upper cover plate; the protrusion is a connecting pipe provided on the outer wall of the second side wall of the upper cover plate; the connecting pipe is used to insert into the first blind hole of another single cell and to fix it in place; the first side wall and the second side wall are parallel to each other.

[0028] This invention employs blind holes and connecting pipes, simplifying the connection process and enabling quick and accurate connection of individual battery cells. This makes the assembly of the entire large-capacity battery more orderly and efficient. Furthermore, once inserted and secured, they form a mortise-and-tenon joint-like connection, ensuring a reliable connection between adjacent battery cells. This prevents loosening or displacement of individual cells when subjected to vibration or impact, thus guaranteeing the stability of the large-capacity battery's performance and its lifespan.

[0029] In addition, the blind holes and connectors do not affect the sealing performance of the individual battery casing.

[0030] Furthermore, a channel communicating with the inner cavity of the connector is provided on the upper cover plate; a partition is provided in the channel, and a cavity is formed between the partition and the bottom end of the first blind hole. A through hole is provided in the upper cover plate area corresponding to the cavity for communicating with the inner cavity of the single cell.

[0031] Under the action of external force, the separator and the bottom of the first blind hole can be opened, so that the inner cavity of the connecting pipe, the inner cavity of the channel, and the inner cavity of the first blind hole are all connected to the inner cavity of the single cell.

[0032] By creating a channel in the upper cover plate that connects to the inner cavity of the connector, it is easy to connect the inner cavity of the connector and the inner cavity of the individual battery through external force in the later stage. At the same time, the inner cavity of the channel is connected to the inner cavity of the individual battery through a through hole in the upper cover plate. In order to ensure that the internal environment of the individual battery is not affected by the external environment, a partition is required to isolate the through hole from the inner cavity of the connector. In the later stage, when it is necessary to connect the inner cavities of each individual battery, the partition and the bottom end of the first blind hole are opened under the action of external force, so that the inner cavity of the connector, the inner cavity of the channel, and the inner cavity of the first blind hole are all connected to the inner cavity of the individual battery.

[0033] The aforementioned connector can also be a sub-pipe segment set on the upper surface of the cover plate; the sub-pipe segment is a hollow pipe fitting; the hollow pipe fitting and the cover plate have interconnected openings, and both ends of the hollow pipe fitting are closed ends.

[0034] Define the two closed ends as the first closed end and the second closed end, respectively;

[0035] A third blind hole extending axially is provided at the first closed end; the third blind hole is used for the insertion and fixed connection of the second closed end of another single cell hollow tube.

[0036] Under the action of external force, the first and second closed ends of the hollow tube can be opened.

[0037] The sub-pipe section of this invention adopts a hollow pipe structure, with both ends made as closed ends. At the same time, on the upper cover plate, openings are precisely made at positions corresponding to the sub-pipe section, communicating with each other.

[0038] On the one hand, when multiple individual cells are assembled, adjacent individual cells can be stably connected with the help of sub-tubes, which greatly improves the stability of the individual cells in the box, and thus makes the structure of the entire large-capacity battery exhibit better stability and durability.

[0039] On the other hand, although the two ends of this sub-tube segment are normally closed, they can be opened smoothly under specific external forces. Once the closed ends are opened, the inner cavities of all sub-tube segments are immediately connected, and further connected with the inner cavities of all individual cells. In this way, the differences that may exist between individual cells can be effectively improved, ensuring the consistency of each individual cell during charging and discharging, extending the overall service life, and improving the performance of large-capacity batteries.

[0040] Furthermore, a recessed area is created on the upper cover plate to form a weak point. Compared to some methods that create weak points by changing material composition or microstructure, creating a recessed area is simpler and allows for more intuitive and precise control over the strength and opening pressure of the weak point. Specifically, by controlling parameters such as the depth, shape, and area of ​​the recessed area, the opening of the weak point under a specific pressure can be accurately set, greatly improving the reliability of the explosion venting function.

[0041] The recessed area can be located on the upper surface of the top cover plate, recessed towards the lower surface, forming a weak point. Alternatively, it can be located on the lower surface of the top cover plate, recessed towards the upper surface, also forming a weak point. Creating recessed areas on either the upper or lower surface of the top cover plate can be achieved using conventional stamping, injection molding, or other processing methods, resulting in relatively low processing costs.

[0042] Furthermore, through holes can be made in the top cover plate along its width or length to form a weak section. When through holes are made in the top cover plate along its width or length to form a weak section, the flatness of the battery top cover plate can be maintained better than that formed by a recessed area.

[0043] The weak point is located between the two polarity terminals of the top cover, which can dissipate the heat generated by thermal runaway in a timely manner and effectively alleviate local high temperature. In addition, compared with placing the weak point in other locations, it reduces interference with other functional areas of the battery and achieves a more efficient layout in a limited space.

[0044] Furthermore, the connector and the top cover are integrated; the connectors of adjacent individual cells are fixedly connected by heat fusion.

[0045] In terms of weight, plastic has a lower density than metal, which can significantly reduce the overall weight of the battery. In terms of cost, plastic raw materials are cheaper, and the molding process is simpler; for example, injection molding can be used to create complex structures in a single step, reducing processing steps and lowering production costs.

[0046] From a molding process perspective, plastics are highly malleable, making it easy to manufacture various complex shapes of top covers and weak structural components with connectors. Whether it's recessed areas on the upper or lower surface, or through holes along the width or length, they can all be precisely molded. Furthermore, since the connectors are molded simultaneously with the top cover, there are no dimensional deviations caused by subsequent assembly. This high precision ensures that the connectors for each individual battery cell fit precisely, which is beneficial for mass production and quality control of high-capacity batteries.

[0047] Furthermore, the connectors are joined via thermofusion. During the thermofusion process, the plastic material melts upon heating, and upon cooling and solidification, the materials of the connectors fuse together to form a single, integrated structure, resulting in a very strong bond between the connectors. This connection method can withstand significant tensile, compressive, and shear forces, effectively preventing loosening or separation of individual battery cells during use and ensuring the structural stability of large-capacity batteries. Simultaneously, thermofusion connections have lower precision requirements; even with slight dimensional deviations in the connectors during production, precise connections can be achieved smoothly, greatly improving production efficiency.

[0048] A second aspect of the present invention provides a single-cell battery, characterized in that it includes a housing, which is formed by an upper cover assembly, a cylindrical body and a lower cover plate; wherein the upper cover assembly is the aforementioned single-cell battery upper cover assembly.

[0049] Furthermore, the shell strength is P, P1≤P≤P2; where P1 is the strength requirement of the shell during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell during the thermal runaway stage.

[0050] The aforementioned single-cell battery casing is a sealed plastic casing that serves as a cavity for the electrode components and electrolyte, providing a sealing function. Simultaneously, the strength of the sealed casing must meet the strength requirements of the casing during the formation stage and the normal charge / discharge stages of the battery. That is, the sealed casing must possess sufficient strength to ensure that it will not crack under changes in the internal environment of the battery, such as temperature and pressure, during the formation stage and normal charge / discharge stages. Compared to existing finished plastic-cased single-cell batteries, this single-cell battery has a lower cost, thereby reducing the overall cost of the large-capacity battery.

[0051] A third aspect of the present invention provides a high-capacity battery, characterized in that it includes a pressure-bearing housing and n of the above-mentioned single cells arranged within the pressure-bearing housing, wherein n is an integer greater than 1;

[0052] The connectors of adjacent individual cells are connected to each other, and a channel is opened in the connector to penetrate the inner cavity of the individual cell housing; a venting channel is formed between the weak part of each individual cell and the pressure-bearing housing.

[0053] The pressure-bearing shell has the strength required for the shell during the thermal runaway stage. The pressure-bearing shell is equipped with a venting section corresponding to the venting channel. When a single cell experiences thermal runaway, the thermal runaway flue gas breaks through the weak part, passes through the venting channel, and then breaks through the venting section to exit the pressure-bearing shell.

[0054] The outer casing of the high-capacity battery of this invention is a pressure-bearing shell, whose strength must meet the requirements for shell strength during thermal runaway; that is, the pressure-bearing shell must have good strength to protect multiple individual cells simultaneously. In the extreme case of thermal runaway of a single cell and melting of the plastic shell, the pressure-bearing shell can form a robust barrier, effectively isolating high-temperature flames and harmful gases, preventing the spread of thermal runaway, and improving the safety of the high-capacity battery after thermal runaway. Compared with the structure of individual cell casings in the prior art, this reduces the cost of individual packaging and protection, resulting in lower costs. Furthermore, given the same number of individual cells and the same material and thickness of the pressure-bearing shell as the individual cell casings in the prior art, the weight of a single pressure-bearing shell is necessarily less than the weight of multiple smaller casings. Therefore, the design of the pressure-bearing shell can further reduce the weight of the high-capacity battery.

[0055] Meanwhile, a venting channel is provided on the pressure-bearing shell. In the initial stage of thermal runaway, the thermal runaway flue gas can be discharged in an orderly manner through the venting channel, effectively preventing it from spreading to the large-capacity battery shell and thus preventing further deterioration of the thermal runaway situation.

[0056] Furthermore, the top plate of the pressure-bearing housing has clearance holes corresponding to the polarity terminals of each individual battery; the polarity terminals of each individual battery extend out of the clearance holes; the area of ​​the top plate of the pressure-bearing housing corresponding to the clearance holes is fixedly sealed to the individual battery housing.

[0057] Furthermore, the aforementioned high-capacity battery also includes a heat exchange component that exchanges heat with the polarity terminals.

[0058] During the operation of a large-capacity battery, heat can easily accumulate at the polarity terminals due to current conduction. Heat exchange components can promptly remove this heat, ensuring the polarity terminals remain within a suitable operating temperature range. This not only helps maintain the performance stability of individual cells within the large-capacity battery and reduces performance degradation caused by excessive temperature, but also further enhances the overall safety and reliability of the large-capacity battery, preventing potential malfunctions caused by localized overheating.

[0059] The beneficial effects of this invention are:

[0060] The single-cell battery of this invention uses a plastic casing, which enables the construction of large-capacity batteries with lower cost and lighter weight.

[0061] Meanwhile, to improve the safety performance of the high-capacity battery constructed from the aforementioned individual cells, this invention places multiple individual cells within a pressure-bearing casing. In extreme cases where a single cell experiences thermal runaway and the plastic casing melts, this pressure-bearing casing forms a robust thermal barrier, effectively isolating high-temperature flames and harmful gases, and preventing the spread of thermal runaway. Furthermore, protecting multiple individual cells with a pressure-bearing casing reduces external impacts and damage during transportation and use, extending battery life. Compared to the prior art structure where each individual cell is individually encased, this reduces individual packaging and protection costs, resulting in lower overall cost. Moreover, with the same number of individual cells, the weight of a single pressure-bearing casing is necessarily less than the weight of multiple smaller casings; therefore, the design of the pressure-bearing casing further reduces the weight of the high-capacity battery.

[0062] Meanwhile, this invention also integrates a weak section into the upper cover plate, serving as a venting section for individual batteries. Compared to existing structures that use venting membranes as venting sections, this offers advantages such as high structural stability, good sealing performance, and low manufacturing cost. Correspondingly, in a large-capacity battery, a venting channel is formed between the weak section of each individual battery and the pressure-bearing casing, with a corresponding venting section on the pressure-bearing casing. In the event of thermal runaway of an individual battery, the runaway gas ruptures through the weak section, passes through the venting channel, and then ruptures the venting section before exiting the pressure-bearing casing. In the initial stage of thermal runaway, the runaway gas can be discharged in an orderly manner through the venting channel, effectively preventing its spread to the large-capacity battery casing and thus preventing further deterioration of the thermal runaway situation.

[0063] The above analysis shows that the high-capacity battery of the present invention has advantages over the high-capacity batteries in the prior art, such as low cost, light weight, and high safety performance. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the structure of a large-capacity battery in the background art;

[0065] Figure 2This is a first-view structural schematic diagram of the single-cell battery cover assembly in Example 1;

[0066] Figure 3 This is a structural schematic diagram of the single-cell battery cover assembly from a second perspective in Example 1;

[0067] Figure 4 This is a cross-sectional view of the single-cell battery cover assembly of Example 1;

[0068] Figure 5 This is a schematic diagram of the structure of a single cell in Example 1;

[0069] Figure 6 This is a first-view structural schematic diagram of the single-cell battery cover assembly in Example 2;

[0070] Figure 7 This is a structural schematic diagram of the single-cell battery cover assembly from a second perspective in Example 2;

[0071] Figure 8 This is a structural schematic diagram of the single-cell battery cover assembly from a third-view perspective in Example 2;

[0072] Figure 9 This is a schematic diagram of the structure of a single cell in Example 2;

[0073] Figure 10 This is a schematic diagram of the structure of a single-cell battery cover assembly in Example 3;

[0074] Figure 11 This is a schematic diagram of another single-cell battery cover assembly in Example 3;

[0075] Figure 12 This is a schematic diagram of the structure of a single cell in Example 3;

[0076] Figure 13 This is a schematic diagram of the structure of a single-cell battery cover assembly in Example 4;

[0077] Figure 14 This is a first-view structural schematic diagram of another single-cell battery cover assembly in Embodiment 4;

[0078] Figure 15 This is a schematic diagram of the structure of another single-cell battery cover assembly from a second perspective in Example 4;

[0079] Figure 16 This is a schematic diagram of the structure of a single cell in Example 4;

[0080] Figure 17 This is a schematic diagram of another single-cell battery in Example 4;

[0081] Figure 18 This is a schematic diagram of the structure of the high-capacity battery in Example 5;

[0082] Figure 19 This is a schematic diagram of the exploded structure of a high-capacity battery in Example 5;

[0083] Figure 20 This is a schematic diagram of a partial explosion structure of a large-capacity battery in Example 5;

[0084] Figure 21 This is a schematic diagram of a partial explosion structure of another high-capacity battery in Example 5;

[0085] Figure 22 This is a schematic diagram of the partial explosion structure of the third type of high-capacity battery in Example 5;

[0086] Figure 23 This is a schematic diagram of the partial explosion structure of the fourth type of large-capacity battery in Example 5;

[0087] Figure 24 This is a schematic diagram of the exploded structure of the fifth type of high-capacity battery in Example 5;

[0088] Figure 25 This is a schematic diagram of the structure of the fifth type of high-capacity battery in Example 5.

[0089] The attached figures are labeled as follows:

[0090] 01. Pipeline; 02. Shared pipeline;

[0091] 1. Top cover plate; 2. Recess; 3. Protrusion; 4. First side wall; 5. Second side wall; 6. First blind hole; 61. Stepped surface of countersunk hole; 62. Bottom end of first blind hole; 7. Connecting pipe; 8. Channel; 9. Through hole; 10. Partition plate; 11. Polar terminal; 12. Sub-pipe section; 13. Third blind hole; 14. Pressure-bearing shell; 15. Individual battery; 16. Heat exchange component; 17. Explosion vent; 18. Clearance hole; 19. Opening; 22. Through groove; 23. Cylinder; 24. Bottom cover plate; 25. Groove; 26. Through hole. Detailed Implementation

[0092] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0093] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0094] In the description of this invention, it should be noted that the terms "top," "bottom," "upper," or "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0095] Example 1

[0096] like Figure 2 and Figure 3 The diagram shown is a structural schematic of the single-cell battery cover assembly in this embodiment.

[0097] For ease of description, in this embodiment, the width direction of the single battery cover assembly is defined as the x-direction, the length direction as the y-direction, and the height direction as the z-direction.

[0098] In this embodiment, a recess 2 and a protrusion 3 are provided on the opposite sidewalls of the upper cover plate 1 as connecting parts. When assembling a large-capacity battery, the protrusion 3 of one single cell 15 can be inserted into the recess 2 of another single cell 15 and fixedly connected. Under the action of external force, a channel can be opened between the protrusion 3 and the recess 2, and the channel communicates with the gas area inside the cavity of the single cell casing.

[0099] At the same time, it can also improve the stability of the single cell 15 in the large-capacity battery, making the structure of the entire large-capacity battery more compact and stable, effectively resisting interference under various working conditions, and ensuring the continuous, efficient and safe operation of the large-capacity battery.

[0100] In this embodiment, both the recess 2 and the protrusion 3 are located on opposite sidewalls of the upper cover plate 1, ensuring that the recess 2 and the protrusion 3 do not introduce additional dimensional increases in the height direction of the individual battery cell 15. For large-capacity batteries, especially in applications with stringent space requirements, this connection structure that does not increase height dimensions is particularly important. It allows a large-capacity battery to accommodate more individual battery cells 15 within a limited space, or, while meeting the same battery capacity requirements, makes the overall large-capacity battery more compact and lightweight, facilitating device portability, installation, and layout optimization.

[0101] from Figure 2 and Figure 3As can be seen from the image, in this embodiment, the recess 2 and the protrusion 3 are respectively provided on the first sidewall 4 and the second sidewall 5, which are parallel to each other, on the upper cover plate 1. In addition, two recesses 2 can be provided on the first sidewall 4, and two protrusions 3 are correspondingly provided on the second sidewall 5.

[0102] In some other embodiments, a recess 2 and a protrusion 3 may be provided on the first sidewall 4, and a corresponding protrusion 3 and a recess 2 may be provided on the second sidewall 5.

[0103] In this embodiment, when assembling a large-capacity battery, the operator can easily distinguish the correspondence between the recess 2 and the protrusion 3, and can quickly and accurately connect each individual battery cell 15. However, if there are both recesses 2 and protrusions 3 on the same side wall, the operator needs to be more careful in distinguishing which recess 2 corresponds to which protrusion 3 during assembly. If the operator is not careful, a mismatch may occur, resulting in reduced assembly efficiency.

[0104] It should be noted that the first sidewall 4 and the second sidewall 5 mentioned above are parallel to each other and can both be parallel to the xz plane. When they are parallel to the xz plane, both the protrusion 3 and the recess 2 extend along the y direction. Alternatively, the first sidewall 4 and the second sidewall 5 mentioned above can both be parallel to the yz plane. When they are parallel to the yz plane, both the protrusion 3 and the recess 2 extend along the x direction.

[0105] The following example mainly focuses on the parallelism between the first sidewall 4 and the second sidewall 5 and the yz plane.

[0106] like Figure 4 As shown, in this embodiment, the recess 2 is a first blind hole 6 formed on the first side wall 4 of the upper cover plate 1, that is, the opening end of the first blind hole 6 is located on the first side wall 4 of the upper cover plate 1. The inner cavity of the first blind hole 6 is used to accommodate the protrusion 3 of another single cell 15, and is fixedly connected to the protrusion 3 by means of heat fusion.

[0107] In some other embodiments, the recess 2 may also be a groove or other structure formed in the first side wall 4 of the upper cover plate 1.

[0108] from Figure 3 As can be seen from the diagram, the first blind hole 6 in this embodiment adopts a countersunk hole structure. The stepped surface 61 of the countersunk hole is used to mate with the end face of the protrusion 3. When the protrusion 3 is inserted into the first blind hole 6, the stepped surface fits tightly with the end face of the protrusion 3, limiting the protrusion 3 in the axial direction. This effectively prevents unnecessary displacement of the protrusion 3 in the axial direction, thereby avoiding problems such as loose connection and poor contact caused by displacement, and ensuring that the individual cells 15 maintain a stable connection state during long-term use of the large-capacity battery.

[0109] The protrusion 3 is a connecting tube 7 located on the second side wall 5 of the upper cover plate 1; the connecting tube 7 is used to insert into the first blind hole 6 of another single cell 15 and is fixedly connected by heat fusion. The connecting tube 7 adopts a hollow structure, which effectively reduces the overall weight while ensuring the connection function.

[0110] In some other embodiments, the protrusion 3 can also be a solid column. A solid column has higher strength than the hollow connecting pipe 7 and can withstand greater tensile and compressive forces. However, compared to this embodiment, it is more difficult to create a through-channel with the inner cavity of the single battery casing on it.

[0111] from Figure 3 It can also be seen that in this embodiment, there are two first blind holes 6, each extending along the x-direction, and the two first blind holes 6 are arranged along the y-direction and located on the outer side of the two polarity terminals 11 respectively; correspondingly, as Figure 2 As shown, there are also two connecting pipes 7, which correspond one-to-one with the two first blind holes 6. Each connecting pipe 7 extends along the x-direction, and the two connecting pipes 7 are arranged along the y-direction, and are located on the outside of the two polarity terminals 11 respectively.

[0112] From a stress perspective, the above arrangement ensures that when adjacent individual cells 15 are connected, the force can be distributed relatively evenly to the corresponding parts of the battery through the two connecting pipes 7 and the first blind hole 6 when the large-capacity battery is subjected to complex external forces from different directions. This avoids excessive local stress that could damage the connection structure or cause displacement of the individual cells 15.

[0113] Furthermore, in this embodiment, both the first blind hole 6 and the connecting pipe 7 are hollow structures. After being constructed into a high-capacity battery, under external force, the inner cavities of the first blind hole 6 and the connecting pipe 7 can be interconnected. By opening through holes 9 at the corresponding positions on the cover plate 1 along the interconnected path, all the inner cavities of the first blind holes 6 and the connecting pipe 7 are immediately connected, and further connected to the gas regions of all individual battery cells 15, achieving gas balance. In this way, the differences that may have existed between individual battery cells 15 can be effectively improved, ensuring the consistency of each individual battery cell 15 during charging and discharging, extending the overall service life, and improving the performance of the high-capacity battery.

[0114] Specifically, in order to facilitate the connection between the inner cavity of the first blind hole 6 and the inner cavity of the connecting pipe 7, such as Figure 4 As shown, in this embodiment, a channel 8 is provided on the upper cover plate 1, communicating with the inner cavity of the connecting pipe 7. The channel 8 is isolated from the inner cavity of the first blind hole 6 through the bottom end 62 of the first blind hole. At the same time, a through hole 9 is provided on the upper cover plate 1, communicating with the inner cavity of the channel 8. A partition 10 is also required to be provided in the channel 8 to isolate the inner cavity of the single battery 15 from the external environment.

[0115] The aforementioned partition 10 and the bottom end 62 of the first blind hole have at least the following functions:

[0116] First, the function of preventing external substances from entering the interior of the single cell 15 before or during the construction of a large-capacity battery.

[0117] The separator 10 and the bottom of the first blind hole 62 play a crucial role in the use of the single cell 15. Before and during the construction of a large-capacity battery, the single cell 15 is in an independent state. If the internal environment of the battery is affected by external factors, its performance will be impaired. For example, if air from the external environment enters the battery through the connector 7, channel 8, through hole 9, or the bottom of the first blind hole 62 and through hole 9, it may trigger an oxidation reaction, affecting the chemical reaction balance inside the battery; the entry of moisture may cause problems such as short circuits or electrode corrosion; the intrusion of other impurities will also damage the electrochemical system inside the battery.

[0118] In this embodiment, a partition 10 and a first blind hole 6 are specially provided to build a solid barrier to ensure that air, water and other impurities in the external environment cannot enter the interior of the single cell 15 through the through hole 9 via the connecting pipe 7 and the opening of the first blind hole 6.

[0119] To achieve this function, certain requirements are placed on the strength of the separator 10. It needs to have a certain structural strength and sealing performance to resist various external pressures and corrosion, thereby creating a stable and clean environment inside the individual battery 15 and ensuring that the battery performance is not adversely affected by external factors.

[0120] Second, the partition 10 and the bottom end 62 of the first blind hole can be opened by a package opening tool to achieve the function of gas communication;

[0121] After the large-capacity battery is assembled, a special unpacking tool is needed to open the separator 10 and the bottom of the first blind hole 62, so that the gas regions inside all the individual cells 15 can be connected, thus completing the assembly of the large-capacity battery.

[0122] To meet this functional requirement, the separator 10 and the bottom of the first blind hole 62 must be able to be opened by an unpacking tool. This requires that the separator 10 and the bottom of the first blind hole 62 be designed to be able to be opened smoothly by an unpacking tool, and that the opening process will not damage other parts of the high-capacity battery, ensuring that the integrity and functionality of the high-capacity battery are not affected.

[0123] In addition, such as Figure 2 and Figure 3As shown, in this embodiment, a through groove 22 is also formed on the upper surface of the upper cover plate 1, and the area of ​​the upper cover plate 1 corresponding to the bottom of the through groove 22 is regarded as a weak part. When thermal runaway occurs inside the single cell 15 and the internal pressure reaches a certain requirement, the thermal runaway flue gas breaks through the weak part to form an opening and is discharged from the opening of the weak part.

[0124] In some other embodiments, an annular groove may be formed on the top cover plate, and the area enclosed by the annular groove may be used as a weak point.

[0125] from Figure 2 As can be seen from the image, in this embodiment, the through groove 22 penetrates the upper cover plate 1 along the x direction and is located between the two polarity terminals 11 of the upper cover plate 1.

[0126] From a thermal management perspective, the polar terminals 11 are usually the concentrated areas of heat generation in the battery. By placing the weak points near the two polar terminals 11, the heat generated by thermal runaway can be dissipated in a timely manner, effectively alleviating local high temperatures and optimizing the internal heat distribution of the battery.

[0127] In terms of structural layout, this arrangement makes the battery top cover 1 more compact and rational. Compared to placing the weakest part in other locations, it reduces interference with other functional areas of the battery, achieving a more efficient layout within a limited space.

[0128] In some other embodiments, the through slot 22 can also extend through the upper cover plate 1 along the length of the upper cover plate 1, avoiding the location of the polarity terminal 11.

[0129] The depth and width of the through groove 22 can be set according to specific needs to ensure that the area of ​​the upper cover plate 1 where the bottom of the through groove 22 is located can be opened under the set pressure.

[0130] However, it is important to note that the depth and width of the through-slot 22 should not be excessive. If the dimensions exceed a reasonable range, the through-slot 22 may deform due to insufficient strength when the battery has not experienced thermal runaway, thereby affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the through-slot 22, while ensuring the structural stability of the top cover 1 under normal operating conditions, it is also ensured that the through-slot 22 can reliably perform its explosion-venting function in the event of thermal runaway.

[0131] In this embodiment, the top cover 1 is made of plastic and can be integrally molded using injection molding to form a top cover 1 with recesses 2, protrusions 3, and through grooves 22. The low density of plastic material significantly reduces the overall weight of the battery. Simultaneously, thanks to the good plasticity of plastic, the injection molding process allows for precise control of the mold cavity dimensions, ensuring high dimensional accuracy of the recesses 2 and protrusions 3 during molding, guaranteeing precise fit with other individual battery cells 15. Furthermore, because it is integrally molded, there is no issue of accumulated dimensional deviations due to the assembly process, ensuring the stability and consistency of the individual battery cell connections. This is beneficial for improving the overall performance and quality stability of the large-capacity battery, reducing problems such as poor connection and abnormal battery operation caused by dimensional mismatch. Additionally, in adjacent individual battery cells 15, when the protrusion 3 of one individual battery cell 15 is inserted into the recess 2 of another individual battery cell 15, the two can be fixedly connected by heat fusion. After the plastic is melted and cooled, it solidifies, fusing the two together to form a stable connection structure capable of withstanding significant mechanical stress. For example, when a large-capacity battery is subjected to external forces such as vibration, impact, or compression, it effectively prevents the connections between individual cells from loosening or detaching. This ensures the structural integrity and electrical connection stability of the large-capacity battery under complex operating conditions, thereby improving its safety and reliability and extending its lifespan. Furthermore, the hot-melt connection method has lower precision requirements; even with a certain degree of dimensional deviation, a good connection can be achieved through hot melting, reducing the cost of precision control during the production process.

[0132] The one-piece molded through-slot 22 also avoids additional splicing gaps, ensuring the overall sealing of the top cover 1 and effectively preventing the intrusion of external impurities. In addition, the injection molding process is low-cost and highly efficient, reducing processing steps and production costs, resulting in significant economic benefits in large-scale production.

[0133] like Figure 5 As shown, a single battery 15 with the top cover assembly of this embodiment includes a housing, which is formed by a cylindrical body 23, a lower cover plate 24 and the aforementioned top cover assembly.

[0134] Corresponding to the aforementioned upper cover assembly, both the cylindrical body 23 and the lower cover plate 24 in this embodiment are made of plastic. The lower cover plate 24 and the cylindrical body 23 can be molded in one piece using injection molding, eliminating the need for separate processing and assembly. This significantly reduces production steps and shortens the production cycle. Furthermore, the injection-molded integral part exhibits uniform material distribution and tight bonding during the molding process, resulting in a more robust connection between the battery lower cover plate 24 and the cylindrical body 23, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylindrical body 23, effectively increasing its resistance to bending, compression, and torsion.

[0135] In this embodiment, since both the upper cover plate 1 and the cylindrical body 23 are made of plastic, a heat-sealing connection can be used. Heat-sealing ensures a continuous, uniform, and tight connection between the upper cover plate 1 and the cylindrical body 23, resulting in extremely high stability. External water, dust, and other impurities cannot enter the battery, providing excellent protection for the electrode components and ensuring the battery's performance and lifespan. Furthermore, the heat-sealing process is simple, and the parameters are easy to control.

[0136] It should be noted that the plastic material selected in this invention should have the following properties:

[0137] First, it must have sufficient strength to ensure the stability of the battery structure;

[0138] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0139] Third, it has barrier properties, which can effectively prevent the electrolyte, gas and other substances inside the battery from leaking out, and at the same time prevent external impurities such as moisture and oxygen from entering the battery.

[0140] Fourth, it possesses excellent thermal stability. Batteries generate heat during charging and discharging, especially at high rates. This plastic material needs to maintain stable performance within a certain temperature range and will not soften, deform, or decompose due to high temperatures.

[0141] The plastic material used can be the same material used in existing plastic-cased single-cell batteries 15, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0142] To further reduce costs, the strength of the cell casing 15 in this embodiment meets certain requirements. However, this embodiment does not require the casing to meet the strength requirements during the thermal runaway stage; it only needs to meet the strength requirements during the formation stage and normal charge / discharge processes. (Correspondingly, the strength of any weak points on the casing should also meet the strength requirements during the formation stage and normal charge / discharge processes.) During the formation stage and normal charge / discharge processes, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressure and heat are generated inside the battery. The casing needs to have sufficient strength to withstand this pressure and heat to ensure the smooth progress of the formation process and the normal use of the battery.

[0143] We can assume that the strength of the casing is P, P1≤P≤P2; where P1 is the strength requirement of the casing during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the casing during the thermal runaway stage.

[0144] Under the premise of meeting the above strength requirements, in this embodiment, the thickness of the shell (cylinder 23, upper cover plate 1, and lower cover plate 24) is h, where h is less than h0, and h0 is the thickness of the plastic shell of a conventional single-cell battery 15; the thickness of the plastic shell of a conventional single-cell battery 15 is typically 5-8 mm. In this embodiment, the thickness of the shell can be between 1-4 mm, and the thickness of the upper cover plate 1 corresponding to the bottom of the through groove 22 is less than the thickness of the rest of the upper cover plate 1. By reducing the thickness of the shell of a conventional single-cell battery 15 with a plastic shell, better heat dissipation can be achieved, and the battery energy density can also be increased. In addition, reducing the thickness of the plastic shell means using less plastic material, which helps to save material costs and provides an economic advantage for large-scale production and application.

[0145] Example 2

[0146] Unlike Example 1, as Figure 6 As shown, in this embodiment, a sub-tube segment 12 is provided on the upper surface of the upper cover plate 1 as a connector; the inner cavity of the sub-tube segment 12 is used to communicate with the inner cavity of the single cell 15 housing. By connecting the corresponding sub-tube segments 12 of multiple single cells 15, a shared pipeline can be formed. In addition, connecting the sub-tube segments 12 of multiple single cells 15 can also improve the stability of the single cell 15 in the large-capacity battery, making the structure of the entire large-capacity battery more compact and stable, effectively resisting interference under various operating conditions, and ensuring the continuous, efficient and safe operation of the large-capacity battery.

[0147] In this embodiment, the sub-pipe segment is located on the weak point. In other embodiments, the sub-pipe segment may be located at other positions on the upper cover plate.

[0148] The aforementioned sub-pipe segment 12 preferably uses a hollow pipe fitting, whose internal hollow structure helps to reduce the overall weight and can also serve as a shared passage; and, as Figure 8 As shown, the two ends of the hollow tube can also be sealed, and through openings 19 can be made on the hollow tube and the upper cover plate 1. In this way, the inner cavity of the hollow tube can be used as a gas storage cavity, and the gas generated inside the battery can be stored in this space to prevent bulging.

[0149] Furthermore, when a high-capacity battery is constructed using individual cells 15 with this sub-tube segment 12 structure, the two closed ends of the hollow tube can be opened under external force, instantly connecting the inner cavities of all sub-tube segments 12 and further connecting them with the gas regions within the inner cavities of all individual cells 15, achieving gas balance within each individual cell 15. This effectively mitigates potential differences between individual cells 15, ensuring consistency during charging and discharging, extending overall lifespan, and improving the performance of the high-capacity battery.

[0150] The above-mentioned external force generally refers to using appropriate tools to apply a certain force to the closed end, causing it to break and form an opening.

[0151] from Figures 6 to 8 As can be seen from the figure, the sub-pipe section 12 in this embodiment adopts a hollow pipe fitting. The hollow pipe fitting and the lower cover plate 24 are provided with interconnecting openings 19, and both ends of the hollow pipe fitting are closed ends (in this embodiment, the two sides of the hollow pipe fitting located at the opening in the axial direction of the hollow pipe fitting are referred to as the two ends of the hollow pipe fitting); for ease of description, in this embodiment, the closed ends of the two ends of the hollow pipe fitting are defined as the first closed end and the second closed end, respectively.

[0152] This can be achieved in several ways. One feasible method is to set a sealing gasket or sealing plug inside or at the end of the hollow tube, thereby effectively blocking the channels at both ends of the hollow tube and forming a closed end. Alternatively, a sealing plate can be integrally formed inside the hollow tube, which can also achieve the purpose of sealing both ends of the hollow tube.

[0153] To facilitate the connection of adjacent hollow pipes, this embodiment uses a circular reducing pipe. The outer diameter of the first closed end of the reducing pipe is larger than the outer diameter of the second closed end. A third blind hole 13 extending axially is opened at the first closed end, and an upper cover plate 1 extends from the second closed end.

[0154] In a pair of adjacent hollow tubes, the second closed end of one hollow tube is inserted into the third blind hole 13 of the other hollow tube and fixed by heat fusion, thus connecting the two hollow tubes. The length of the second closed end extending out of the upper cover plate 1 and the depth of the third blind hole 13 can be adjusted to ensure that the two individual cells 15 are close together after connection.

[0155] Preferably, in this embodiment, the third blind hole 13 adopts a countersunk hole structure. The stepped surface 61 of the countersunk hole is used to mate with the end face of the second closed end of the hollow tube. When the second closed end of the hollow tube is inserted into the third blind hole 13, the stepped surface fits tightly with the end face of the second closed end, limiting the hollow tube in the axial direction. This effectively prevents unnecessary displacement of the hollow tube in the axial direction, thereby avoiding problems such as loose connection and poor contact caused by displacement, and ensuring that the individual cells 15 maintain a stable connection state during long-term use of the large-capacity battery.

[0156] When the sub-tube segment 12 of this structure is used, on the one hand, when multiple individual cells 15 are assembled, adjacent individual cells 15 can be stably connected with the help of the sub-tube segment 12, which greatly improves the stability of the individual cells 15 in the box, thereby making the structure of the entire large-capacity battery exhibit better stability and durability.

[0157] On the other hand, although the two ends of the sub-tube segment 12 are normally closed, under the specific action of external force, its two closed ends can be opened smoothly. Once the closed ends are opened, the inner cavities of all sub-tube segments 12 are immediately connected, and further connected with the gas regions inside the cavities of all individual cells 15.

[0158] Similar to Embodiment 1, the top cover 1 in this embodiment is also made of plastic and can be integrally molded using injection molding to form the top cover 1 with the sub-tube segment 12 and the through groove 22. The low density of the plastic material significantly reduces the overall weight of the battery. Simultaneously, thanks to the good plasticity of the plastic, the injection molding process allows for precise control of the mold cavity dimensions, ensuring high dimensional accuracy of the sub-tube segment 12 during molding and guaranteeing precise fit with other individual battery cells 15. Furthermore, since it is integrally molded, there is no issue of accumulated dimensional deviations due to the assembly process, ensuring the stability and consistency of the connection between the individual battery cells 15. This is beneficial for improving the overall performance and quality stability of the large-capacity battery and reducing problems such as poor connection and abnormal battery operation caused by dimensional mismatch. Additionally, in adjacent individual battery cells 15, after the sub-tube segment 12 of one individual battery cell 15 is inserted into the third blind hole 13 of the sub-tube segment 12 of another individual battery cell 15, the two can be fixedly connected by heat fusion. After the plastic is melted and cooled, it solidifies, fusing the two together to form a stable connection structure capable of withstanding significant mechanical stress. For example, when a large-capacity battery is subjected to external forces such as vibration, impact, or compression, it effectively prevents the connections between individual cells from loosening or detaching. This ensures the structural integrity and electrical connection stability of the large-capacity battery under complex operating conditions, thereby improving its safety and reliability and extending its lifespan. Furthermore, the hot-melt connection method has lower precision requirements; even with a certain degree of dimensional deviation, a good connection can be achieved through hot melting, reducing the cost of precision control during the production process.

[0159] The one-piece molded through-slot 22 also avoids additional splicing gaps, ensuring the overall sealing of the top cover 1 and effectively preventing the intrusion of external impurities. In addition, the injection molding process is low-cost and highly efficient, reducing processing steps and production costs, resulting in significant economic benefits in large-scale production.

[0160] like Figure 9 As shown, the single battery 15 with the top cover assembly of this embodiment includes a housing, which is formed by a cylindrical body 23, a lower cover plate 24, and the aforementioned top cover assembly. Except for the top cover assembly, which differs from that of Embodiment 1, the rest of the structure is the same as that of Embodiment 1, and will not be described again here.

[0161] Example 3

[0162] Unlike the above embodiments, this embodiment has a groove 25 formed on the lower surface of the upper cover plate 1, and the area of ​​the upper cover plate 1 corresponding to the bottom of the groove 25 is a weak part.

[0163] Specifically, such as Figure 10 and Figure 11 As shown, Figure 10 Taking the connector structure in Embodiment 1 as an example, Figure 11 Taking the connector structure in Embodiment 2 as an example.

[0164] In this embodiment, the groove 25 extends along the x-direction, similar to the through groove in embodiment 1, and the groove 25 is located between the two polar terminals 11.

[0165] The depth and width of the groove 25 can be set according to specific needs to ensure that the area of ​​the upper cover plate 1 where the bottom of the groove 25 is located can be opened under the set pressure.

[0166] However, it is also important to note that the depth and width of the groove 25 should not be too large. If the dimensions exceed a reasonable range, the groove 25 may deform due to insufficient strength when the battery has not experienced thermal runaway, thereby affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the groove 25, while ensuring the structural stability of the top cover 1 under normal operating conditions, it is also necessary to ensure that the groove 25 can reliably perform its explosion-proof function in the event of thermal runaway.

[0167] Compared to the example of opening a through groove 22 on the upper surface of the upper cover plate 1 in embodiment 1, this embodiment can better maintain the flatness of the battery upper cover plate 1.

[0168] In addition, during normal operation of the single cell 15, the inner cavity of the groove 25 can serve as a gas storage cavity, where the gas generated inside the single cell 15 can be stored, thus reducing the degree of bulging of the single cell 15 casing.

[0169] like Figure 12 As shown, it has Figure 10 The single battery 15 of the upper cover assembly shown includes a housing, which is formed by the cylindrical body 23, the lower cover plate 24, and the aforementioned upper cover assembly. Except for the upper cover assembly, which differs from Embodiment 1, the rest of the structure is the same as that of Embodiment 1, and will not be described again here.

[0170] Example 4

[0171] Unlike the above embodiments, this embodiment has a through hole 26 in the upper cover plate 1 along its width direction, forming a weak part.

[0172] Specifically, such as Figures 13 to 15 As shown, Figure 13 Taking the connector structure in Embodiment 1 as an example, Figure 14 and Figure 15 Taking the connector structure in Embodiment 2 as an example, the sub-pipe segment is set inside the through hole.

[0173] This embodiment also uses a plastic cover plate 1, which can be integrally molded using injection molding process. The cover plate 1 has a through hole 26 and corresponding connecting parts.

[0174] As can be seen from the figure, in this embodiment, the through hole 26 extends through the upper cover plate 1 along the width direction of the upper cover plate 1 and is located between the two polarity terminals 11 of the upper cover plate 1.

[0175] In some other embodiments, a through hole 26 along the length of the upper cover plate 1 may be formed to create a weak point.

[0176] The cross-sectional shape and size of the through hole 26 can be set according to specific requirements to ensure that the area of ​​the upper cover plate 1 where the bottom of the through hole 26 is located can be opened under the set pressure.

[0177] However, it is also important to note that the through hole 26 should not be too large. If it exceeds a reasonable range, the through hole 26 may deform due to insufficient strength when the battery has not experienced thermal runaway, thus affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the through hole 26, it is possible to ensure the structural stability of the top cover 1 under normal operating conditions while ensuring that the through hole 26 can reliably perform its explosion-proof function in the event of thermal runaway.

[0178] Compared to the weak point in Embodiment 1, this embodiment can also better maintain the flatness of the battery cover plate 1.

[0179] like Figure 16 and Figure 17 As shown, the single battery 15 has the top cover assembly of this embodiment. Except for the top cover assembly, which is different from that of Embodiment 1, the rest of the structure is the same as that of Embodiment 1, and will not be described again here.

[0180] Example 5

[0181] This embodiment is a high-capacity battery, including a pressure-bearing housing 14 and 12 individual battery cells 15 arranged within the pressure-bearing housing 14 as described in the above embodiment. In other embodiments, the number of individual battery cells 15 can be adjusted according to actual needs.

[0182] Its structure is as follows Figures 18 to 22 As shown, Figure 19 and Figure 20 China and Israel adopt Figure 9 Taking the single cell 15 shown as an example, in adjacent single cells 15, one end of the sub-tube segment 12 of one single cell 15 is inserted into the third blind hole 13 on the sub-tube segment 12 of another single cell 15 and connected by heat fusion.

[0183] Figure 21To adopt Figure 5 Taking the single cell 15 shown as an example, in adjacent single cells 15, the connector 7 of one single cell 15 is inserted into the first blind hole 6 of another single cell 15 and connected by heat fusion.

[0184] Figure 22 China and Israel adopt Figure 17 Taking the single cell 15 shown as an example, in adjacent single cells 15, one end of the sub-tube segment 12 of one single cell 15 is inserted into the third blind hole 13 on the sub-tube segment 12 of another single cell 15 and connected by heat fusion.

[0185] Figure 23 To adopt Figure 12 Taking the single cell 15 shown as an example, in adjacent single cells 15, the connector 7 of one single cell 15 is inserted into the first blind hole 6 of another single cell 15 and connected by heat fusion.

[0186] In this embodiment, appropriate tools are used to open the bottom 62 of the first blind hole of each individual battery cell 15 and the separator 10 (or the closed end of the sub-tube segment), so that the inner cavity of all the first blind holes 6 and the inner cavity of the connecting pipe 7 are connected (or the inner cavity of all the sub-tube segments are connected), and further connected with the gas region inside the cavity of all individual batteries 15, so that the gas in the inner cavity of all individual batteries 15 is balanced, thereby obtaining a large-capacity battery. Based on the gas connection, the differences that may originally exist between individual batteries 15 are improved, ensuring the consistency of each individual battery 15 during the charging and discharging process, extending the overall service life, and improving the performance of the large-capacity battery.

[0187] The tools mentioned above should have sharp heads and a certain degree of strength, such as long steel needles.

[0188] Specifically, the following process can be used to open the bottom 62 of the first blind hole of each individual cell 15 and the separator 10: Insert a tool into the first blind hole 6 of one of the outermost individual cells 15 along the x direction, apply a pushing force, and open the bottom 62 of the first blind hole of each individual cell 15 and the separator 10.

[0189] It should be noted that:

[0190] 1. To ensure that the inner cavity of each individual cell 15 in the large-capacity battery is not affected by the external environment, one of the two outermost individual cells 15 of the large-capacity battery does not need to be opened, and the opening of the first blind hole 6 of the other outermost individual cell 15 also needs to be sealed.

[0191] 2. In order to improve the regularity of the entire large-capacity battery structure, this embodiment can cut off the outermost single cell 15 to expose the unconnected connecting pipe 7. After cutting off, it is necessary to ensure the sealing of the casing of the single cell 15.

[0192] against Figure 22 The structure shown can be opened by the following process: insert a tool into the third blind hole of one of the outermost single cells along the x-direction and apply a pushing force to open the closed end of each single cell's sub-tube segment.

[0193] It should be noted that:

[0194] To ensure that the internal cavity of each individual cell in the large-capacity battery is not affected by the external environment, the closed end of one of the two outermost individual cells does not need to be opened, and the third blind hole opening of the other outermost individual cell also needs to be sealed.

[0195] Figure 19 , Figure 20 and Figure 21 In this design, the weakest point is a through-slot. When the through-slots of each individual battery cell are connected, a venting channel is formed. This venting channel is located between the weakest point of each individual battery cell and the pressure-bearing casing. Alternatively, a channel can be provided on the pressure-bearing casing, covering the through-slots of each individual battery cell and forming a larger cavity venting channel.

[0196] Figure 22 In the middle, the weak part is the through hole opened on the upper cover plate. The through holes of each individual battery are connected to form a venting channel. This venting channel is also located between the weak part (the bottom of the through hole) and the pressure-bearing shell.

[0197] Figure 23 In the middle, the weak part is a groove opened on the lower surface of the upper cover plate. A channel needs to be set on the pressure-bearing shell. This channel covers the weak part of each individual battery cell and forms a venting channel between the channel and the weak part of the individual battery cell.

[0198] The pressure-bearing housing 14 is provided with an explosion relief part 17 corresponding to the explosion relief channel (the explosion relief part 17 here can also be called an explosion-proof part, explosion-proof port or explosion relief port, etc., and is usually provided with a pressure relief valve or explosion relief membrane, etc.). When the single cell 15 thermally runs away, the thermal runaway flue gas breaks through the weak part, passes through the explosion relief channel, breaks through the explosion relief part 17 and is discharged from the pressure-bearing housing 14.

[0199] In the initial stage of thermal runaway, the thermal runaway fumes can be discharged in an orderly manner through the explosion venting channel, effectively preventing them from spreading to the large-capacity battery casing and thus preventing further deterioration of the thermal runaway situation.

[0200] The strength of the pressure-bearing casing 14 needs to meet the strength requirements of the casing during thermal runaway, meaning that the pressure-bearing casing 14 needs to have good strength. This design not only effectively resists the high-pressure impact during thermal runaway with the reinforced outer encapsulation casing, greatly improving the overall safety of the large-capacity battery; especially when a lower-strength plastic casing is used as the casing for the internal individual cells 15, the pressure-bearing casing 14 can form a robust thermal barrier. Even in the extreme case where the casing of the individual cell 15 melts, it can effectively isolate high-temperature flames and harmful gases, preventing the spread of thermal runaway and improving the safety of the large-capacity battery after thermal runaway. In addition, when plastic material is used as the casing for the internal individual cells 15, an anti-permeability membrane can be provided between each individual cell 15 and the pressure-bearing casing 14 to prevent the electrolyte inside each individual cell 15 from seeping outward.

[0201] Compared to other materials, the metal pressure-bearing housing 14 is more reliable in emergency situations such as thermal runaway. It can withstand greater impact and destructive forces, reducing the likelihood of accidents and protecting the safety of personnel and surrounding equipment. In this embodiment, the pressure-bearing housing 14 does not directly contact the electrolyte, so an iron, steel, or stainless steel housing can be used. Iron housings offer advantages in strength and cost, making them a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent. Steel housings offer relatively high strength, providing more reliable protection for the battery and are suitable for applications with high safety and structural strength requirements. Stainless steel housings not only possess good strength properties but also excellent corrosion resistance, making them ideal for battery applications facing humid or corrosive environments. This effectively extends battery life and ensures stable operation in complex environments.

[0202] like Figure 24 and Figure 25 As shown, to adopt Figure 9 Taking the single battery shown as an example, in this embodiment, a clearance hole 18 is provided on the top plate of the pressure-bearing housing 14 corresponding to the polarity terminal 11 of each single battery 15; the polarity terminal 11 of each single battery 15 extends out of the clearance hole 18; the top plate area of ​​the pressure-bearing housing 14 corresponding to the clearance hole 18 is fixedly sealed with the housing of the single battery 15.

[0203] To optimize the heat dissipation performance of the aforementioned high-capacity battery, this embodiment may further include a heat exchange component 16 to exchange heat with the polarity terminal 11. As a crucial component connecting the battery's internal structure to the external environment, the polarity terminal 11 allows current to flow in and out of the battery during charging and discharging. When heat is generated inside the battery, heat dissipation through the polarity terminal 11 provides a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery to the polarity terminal 11, and then dissipated from the polarity terminal 11 to the external environment. Furthermore, since the polarity terminal 11 is typically located at the positive and negative terminals of the battery, these areas are often where heat is concentrated during charging and discharging. By dissipating heat from the polarity terminal 11, the temperature of these critical components can be reduced more effectively.

[0204] The heat exchange component 16 is a heat transfer tube; each polarity terminal 11 of the individual cell 15 is provided with a through groove or through hole for installing the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole of each polarity terminal 11 of the individual cell 15. By using the heat transfer tube on the polarity terminal 11, the heat generated inside the battery is conducted to the heat transfer tube through the polarity terminal 11, and then the heat transfer tube dissipates the heat to achieve heat dissipation of the battery.

[0205] The heat exchange component 16 can also be a heat exchange device, which is disposed on top of each individual battery cell 15. The polar terminal 11 passes through the heat exchange device, and at least a portion of the structure of the polar terminal 11 is located inside the heat exchange device and is in direct contact with the heat exchange medium. Another portion of the structure of the polar terminal 11 is located outside the heat exchange device and serves as an electrical connection. The sidewall of the polar terminal 11 is sealed to the heat exchange device. By adopting a direct heat exchange method, a portion of the structure of the polar terminal 11 is directly placed inside the heat exchange medium flow cavity (the inner cavity of the heat exchange device), so that the polar terminal 11 is in direct contact with the heat exchange medium, thereby achieving heat exchange of the polar terminal 11. Compared with the indirect heat exchange method, it has a shorter heat exchange path, and the heat exchange medium acts directly on the polar terminal 11, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0206] In this embodiment, an insulating sealant layer can also be provided between each individual battery cell 15 and between each individual battery cell 15 and the pressure-bearing housing 14. The insulating sealant layer is mainly laid in the space between each individual battery cell 15 and the pressure-bearing housing 14, and the heat exchange components 16 inside the pressure-bearing housing 14 are all located within the insulating sealant layer; when there is a gap between each individual battery cell 15, the insulating sealant liquid can also penetrate into the gap to form an insulating sealant layer.

[0207] It should be noted that no insulating sealant layer is installed inside the explosion venting channel.

[0208] In this embodiment, the insulating sealant layer has at least the following advantages:

[0209] 1. Prevent condensation;

[0210] During long-term use, due to the temperature difference between the inside and outside of the heat exchange component 16, condensation will form on the surface. When the condensation accumulates to a certain amount, it may cause a short circuit. By laying an insulating sealant layer to completely wrap the heat exchange component 16, when condensation forms on the surface of the heat exchange component 16, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0211] II. Further improve the stability of each individual battery cell 15 within the pressure-bearing casing 14;

[0212] The insulating sealant penetrates into the gaps between each individual cell 15 and between each individual cell 15 and the pressure-bearing housing 14, which can further improve the stability of each individual cell 15 within the pressure-bearing housing 14.

[0213] use Figure 24 and Figure 25 In the structure shown, an insulating sealant layer can also be laid on the top plate of the pressure-bearing housing 14, and the heat exchange component 16 is located inside the insulating sealant layer. When condensation occurs on the surface of the heat exchange component 16, the battery short circuit can be prevented under the protection of the insulating sealant layer.

Claims

1. A single-cell battery cover assembly, characterized in that: It includes a top cover plate, which is equipped with a connector for connecting to the connector on the adjacent single cell. Under the action of external force, a channel can be opened in the connector, which communicates with the gas area inside the cavity of the single cell casing. The top cover plate is integrally provided with a weak part; the strength of the weak part is less than the strength of the rest of the top cover plate. When a single cell experiences thermal runaway, the thermal runaway smoke breaks through the weak part and is discharged. The top cover, weak points, recesses, and protrusions are all made of plastic.

2. The single-cell battery cover assembly according to claim 1, characterized in that: The connector consists of a recess and a protrusion on opposite sidewalls of the upper cover plate; the recess is used for the protrusion of another single battery cell to be embedded and fixedly connected, and under the action of external force, a channel can be opened in the protrusion and the recess, which communicates with the gas area inside the cavity of the single battery cell.

3. The single-cell battery cover assembly according to claim 2, characterized in that: The recess is a first blind hole opened on the first side wall of the upper cover plate; the protrusion is a connecting pipe provided on the outer wall of the second side wall of the upper cover plate; the connecting pipe is used to be embedded in the first blind hole of another single cell and fixedly connected; the first side wall of the upper cover plate and the second side wall of the upper cover plate are parallel to each other.

4. The single-cell battery cover assembly according to claim 3, characterized in that: The upper cover plate has a channel that communicates with the inner cavity of the connector; a partition is provided in the channel, and a cavity is formed between the partition and the bottom of the first blind hole. A through hole is provided in the upper cover plate area corresponding to the cavity for communicating with the inner cavity of the single cell. Under the action of external force, the separator and the bottom of the first blind hole can be opened, so that the inner cavity of the connecting pipe, the inner cavity of the channel, and the inner cavity of the first blind hole are all connected to the inner cavity of the single cell.

5. The single-cell battery cover assembly according to claim 1, characterized in that: The connector is a sub-pipe segment set on the upper surface of the upper cover plate; the sub-pipe segment is a hollow pipe; the hollow pipe and the upper cover plate have interconnected openings, and the two ends of the hollow pipe are closed ends. Define the two closed ends as the first closed end and the second closed end, respectively; A third blind hole extending axially is provided at the first closed end; the third blind hole is used for the insertion and fixed connection of the second closed end of another single cell hollow tube. Under the action of external force, the first and second closed ends of the hollow tube can be opened.

6. The single-cell battery cover assembly according to any one of claims 1 to 5, characterized in that: A recessed area is created on the top cover plate to form a weak point.

7. The single-cell battery cover assembly according to any one of claims 1 to 5, characterized in that: A through hole is made in the top cover plate along its width or length to form a weak point.

8. The single-cell battery cover assembly according to claim 1, characterized in that: The connector and the top cover are integrated, and the connectors of adjacent individual cells are fixedly connected by heat fusion.

9. A single-cell battery, characterized in that: The device includes a housing, which is formed by an upper cover assembly, a cylindrical body, and a lower cover plate; wherein the upper cover assembly is the single-cell battery upper cover assembly as described in any one of claims 1 to 8.

10. The single-cell battery according to claim 9, characterized in that: The shell strength is P, where P1≤P≤P2; where P1 is the strength requirement of the shell during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell during the thermal runaway stage.

11. A high-capacity battery, characterized in that: It includes a pressure-bearing housing and n individual battery cells as described in claim 9 or 10 arranged within the pressure-bearing housing, where n is an integer greater than 1; The connectors of adjacent individual cells are connected to each other, and a channel is opened in the connector to penetrate the inner cavity of the individual cell housing; a venting channel is formed between the weak part of each individual cell and the pressure-bearing housing. The pressure-bearing shell has the strength required for the shell during the thermal runaway stage. The pressure-bearing shell is equipped with a venting section corresponding to the venting channel. When a single cell experiences thermal runaway, the thermal runaway flue gas breaks through the weak part, passes through the venting channel, and then breaks through the venting section to exit the pressure-bearing shell.

12. The high-capacity battery according to claim 11, characterized in that: The top plate of the pressure-bearing housing has clearance holes corresponding to the polarity terminals of each individual battery; the polarity terminals of each individual battery extend out of the clearance holes; the area of ​​the top plate of the pressure-bearing housing corresponding to the clearance holes is fixedly sealed to the individual battery housing.

13. The high-capacity battery according to claim 11, characterized in that: It also includes heat exchange components that exchange heat with the polarity terminals.

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