A single battery upper cover plate, a single battery and a large capacity battery

Abstract

The application belongs to the field of batteries, and particularly relates to a single battery upper cover plate, a single battery and a large-capacity battery. The technical problems of high cost and large weight of the existing large-capacity battery are overcome. The upper cover plate is provided with a recess and a protrusion on opposite side walls; the recess is used for inserting and fixedly connecting the protrusion of another single battery; under the action of external force, a channel can be opened in the protrusion and the recess, and the channel is communicated with the inner cavity of the single battery shell. The single battery shell comprises the upper cover plate, and the shell is made of plastic material. The large-capacity battery comprises a plurality of single batteries. The plastic shell has the advantages of low cost and light weight compared with finished batteries. In addition, the recess and the protrusion are arranged on the opposite side walls of the upper cover plate by fully utilizing the structure of the upper cover plate, and the recess and the protrusion do not affect the size of the single battery in the height direction, and the compactness and space utilization efficiency of the large-capacity battery are considered.

Description

Technical Field

[0001] This invention belongs to the field of batteries, specifically a cover plate for a single cell battery, 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 cover plate for a single battery, a single 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 top cover plate for a single battery, characterized in that: the top cover plate is made of plastic material, and the opposite sidewalls of the top cover plate are provided with recesses and protrusions; wherein the recesses are used for the protrusions of another single battery to be inserted and fixedly connected; under the action of external force, a channel can be opened in the protrusions and recesses, and the channel communicates with the inner cavity of the single battery casing.

[0017] When individual cells are connected by recesses and protrusions, this invention uses tools to create channels in the recesses and protrusions that penetrate the inner cavity of the individual cell casing. In this way, the gas between the individual cells is connected, achieving gas balance. The differences that may have existed can be effectively improved, ensuring the consistency of the individual cells during charging and discharging, extending the overall service life, and improving the performance of large-capacity batteries.

[0018] The single-cell battery cover plate provided by this invention is made of plastic, which has the advantages of lower cost and lighter weight compared to the finished battery cover plates used in the prior art. Furthermore, by fully utilizing the cover plate's own structure, the recesses and protrusions are located on opposite sidewalls of the cover plate. These recesses and protrusions do not affect the dimensions of the single-cell battery in the height direction, thus balancing the overall compactness and space utilization efficiency of the large-capacity battery. Simultaneously, when assembling the large-capacity battery, the protrusion of one single-cell battery is inserted into the recess of another single-cell battery and fixedly connected, which improves the stability between the individual single-cell batteries, making the entire large-capacity battery structure more robust and durable.

[0019] Furthermore, the recess is a blind hole formed 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 blind hole of another single battery cell and to fix it in place; the first side wall and the second side wall are parallel to each other.

[0020] 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.

[0021] In addition, the blind holes and connectors do not affect the sealing performance of the individual battery casing.

[0022] 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 of the 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.

[0023] Under the action of external force, the separator and the bottom of the 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 blind hole are all connected to the inner cavity of the single cell.

[0024] By creating a channel in the top 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 later. At the same time, the inner cavity of this channel is connected to the inner cavity of the individual battery through a through hole in the top 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. When it is necessary to connect the inner cavities of each individual battery later, the partition and the bottom end of the 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 blind hole are all connected to the inner cavity of the individual battery.

[0025] Furthermore, both the recess and the protrusion are integral with the top cover plate; the recess is used for the protrusion of the top cover plate of another single battery cell to be inserted and fixedly connected by heat fusion.

[0026] This invention can use injection molding to integrally form the recesses and protrusions on the top cover plate. The processing is simple. Since the recesses and protrusions are formed at the same time as the top cover plate, there is no problem of dimensional deviation caused by subsequent assembly. The precision is high, which can ensure that the recesses and protrusions of each individual battery can be precisely matched, which is beneficial to the mass production and quality control of large-capacity batteries.

[0027] Furthermore, the recesses and protrusions are connected via a heat-fusion process. During this process, the plastic material melts upon heating, and upon cooling and solidification, the materials of the recesses and protrusions fuse together to form a single, integrated structure, creating a very strong bond between them. 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 high-capacity batteries. Simultaneously, heat-fusion connections have lower precision requirements; even with slight dimensional deviations in the recesses and protrusions during production, precise connections can still be achieved, greatly improving production efficiency.

[0028] 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 plate, a cylindrical body and a lower cover plate; wherein the upper cover plate is the aforementioned single-cell battery upper cover plate.

[0029] 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.

[0030] 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.

[0031] 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;

[0032] In adjacent individual cells, the protrusion of one individual cell is inserted into the recess of another individual cell and fixedly connected. The protrusion and the recess form a channel that penetrates the inner cavity of the individual cell casing.

[0033] The pressure-bearing shell has the strength required for the shell during the thermal runaway stage, and the pressure-bearing shell is equipped with a vent.

[0034] 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.

[0035] Furthermore, in adjacent individual cells, the connector of one individual cell is inserted into the blind hole of another individual cell and thermally fused together; and the separator is opened, and the inner cavity of the connector is connected to the inner cavity of the individual cell housing; the bottom end of the blind hole is opened, and the inner cavity of the blind hole is connected to the inner cavity of the individual cell housing.

[0036] 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.

[0037] Furthermore, the aforementioned high-capacity battery also includes a heat exchange component that exchanges heat with the polarity terminals.

[0038] 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.

[0039] The beneficial effects of this invention are:

[0040] The single-cell battery of this invention uses a plastic casing, which enables the large-capacity battery constructed from it to have lower cost and lighter weight.

[0041] 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.

[0042] Meanwhile, the present invention makes full use of the structure of the top cover plate itself, setting the recesses and protrusions on the opposite sidewalls of the top cover plate. The recesses and protrusions do not affect the dimensions of the individual cells in the height direction, thus taking into account the overall compactness and space utilization efficiency of the large-capacity battery.

[0043] 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 compact structure. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of a large-capacity battery in the background art;

[0045] Figure 2 This is a schematic diagram of the structure of the top cover of a single battery cell in Example 1 from a first-view perspective;

[0046] Figure 3 This is a schematic diagram of the structure of the top cover plate of a single battery cell in Example 1 from a second perspective;

[0047] Figure 4 This is a cross-sectional view of the top cover of a single battery cell in Example 1;

[0048] Figure 5 This is a schematic diagram of the structure of a single cell in Example 2;

[0049] Figure 6 This is a schematic diagram of the exploded structure of a single cell in Example 2;

[0050] Figure 7 This is a schematic diagram of the structure of a high-capacity battery in Example 3;

[0051] Figure 8 This is a schematic diagram of the exploded structure of a high-capacity battery in Example 3;

[0052] Figure 9 This is a schematic diagram of a partial explosion structure of the large-capacity battery in Example 3;

[0053] Figure 10 This is a schematic diagram of the exploded structure of another high-capacity battery in Example 3;

[0054] Figure 11 This is a schematic diagram of another high-capacity battery in Example 3;

[0055] The attached figures are labeled as follows:

[0056] 01. Pipeline; 02. Shared pipeline;

[0057] 1. Top cover plate; 2. Recess; 3. Protrusion; 4. First side wall; 5. Second side wall; 6. Blind hole; 61. Stepped surface of countersunk hole; 62. Bottom end of blind hole; 7. Connecting pipe; 8. Channel; 9. Through hole; 10. Partition plate; 11. Bottom cover plate; 12. Pressure-bearing shell; 13. Heat exchange component; 14. Individual cell; 15. Clearance hole; 16. Polar terminal; 17. Cylinder. Detailed Implementation

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Example 1

[0062] like Figure 2 and Figure 3The diagram shown is a structural schematic of the top cover plate 1 of the single cell in this embodiment.

[0063] For ease of description, in this embodiment, the width direction of the single cell 14 is defined as the x-direction, the length direction as the y-direction, and the height direction as the z-direction.

[0064] In this embodiment, a recess 2 and a protrusion 3 are provided on the opposite sidewalls of the upper cover plate 1. When assembling a large-capacity battery, the protrusion 3 of one single cell 14 can be inserted into the recess 2 of another single cell 14 and fixedly connected. 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 single cell housing.

[0065] At the same time, it can also improve the stability of the single cell 14 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.

[0066] 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 14. 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 14 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.

[0067] In this embodiment, the top cover 1 is made of plastic and can be integrally molded using injection molding, forming a top cover 1 with recesses 2 and protrusions 3. During injection molding, the dimensions of the mold cavity can be precisely controlled, ensuring high dimensional accuracy of the recesses 2 and protrusions 3 during molding, guaranteeing precise fit with other individual battery cells 14. 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 connection between the individual battery cells 14. 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. Simultaneously, in adjacent individual battery cells 14, when the protrusion 3 of one cell 14 is inserted into the recess 2 of another cell 14, the two can be fixedly connected by heat fusion. After the plastic cools and solidifies after heat fusion, the two become integrated, forming a stable connection structure capable of withstanding significant mechanical stress. For example, when the large-capacity battery is subjected to external forces such as vibration, impact, or compression, it effectively prevents the connection between the individual battery cells 14 from loosening or detaching, ensuring the structural integrity and electrical connection stability of the large-capacity battery under complex operating conditions, thereby improving the safety and reliability of the large-capacity battery and extending its service life. In addition, 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-melt, which reduces the precision control cost in the production process.

[0068] from Figure 2 and Figure 3 As 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.

[0069] 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.

[0070] 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 14. 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.

[0071] 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.

[0072] The following example mainly focuses on the parallelism between the first sidewall 4 and the second sidewall 5 and the yz plane.

[0073] like Figure 4 As shown, in this embodiment, the recess 2 is a blind hole 6 formed on the first side wall 4 of the upper cover plate 1, that is, the opening end of the blind hole 6 is located on the first side wall 4 of the upper cover plate 1. The inner cavity of the blind hole 6 is used to accommodate the protrusion 3 of another single cell 14, and is fixedly connected to the protrusion 3 by means of heat fusion.

[0074] 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.

[0075] from Figure 4 As can be seen from the diagram, the 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 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 14 maintain a stable connection state during long-term use of the large-capacity battery.

[0076] 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 blind hole 6 of another single cell 14 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.

[0077] 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.

[0078] from Figure 3 It can also be seen that in this embodiment, there are two blind holes 6, each extending along the x-direction, and the two blind holes 6 are arranged along the y-direction, respectively located outside the two polarity terminals 16; correspondingly, as Figure 2 As shown, there are also two connecting pipes 7, which correspond one-to-one with the two 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 16 respectively.

[0079] From a stress perspective, the above arrangement ensures that when adjacent individual cells 14 are connected, the force can be distributed relatively evenly to the corresponding parts of the battery through the two connecting pipes 7 and the 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 14.

[0080] Furthermore, in this embodiment, both the 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 blind hole 6 and the connecting pipe 7 can easily communicate with each other. By opening through holes 9 at the positions corresponding to the upper cover plate 1 in the communication path, all the inner cavities of the blind holes 6 and the connecting pipe 7 are immediately connected, and further connected with the gas regions of all the individual battery cells 14, achieving gas balance. In this way, the differences that may have existed between the individual battery cells 14 can be effectively improved, ensuring the consistency of each individual battery cell 14 during the charging and discharging process, extending the overall service life, and improving the performance of the high-capacity battery.

[0081] Specifically, to facilitate the connection between the inner cavity of blind hole 6 and the inner cavity of connecting pipe 7, such as Figure 4 As shown, in this embodiment, a channel 8 is provided on the upper cover plate 1, which communicates with the inner cavity of the connecting pipe 7. The channel 8 is isolated from the inner cavity of the blind hole 6 by the bottom end 62 of the blind hole. At the same time, a through hole 9 is provided on the upper cover plate 1, which communicates 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 cell 14 from the external environment.

[0082] The aforementioned partition 10 and the bottom end 62 of the blind hole have at least the following functions:

[0083] First, the function of preventing external substances from entering the interior of the single cell 14 before or during the construction of a large-capacity battery.

[0084] The separator 10 and the bottom of the blind hole 62 play a crucial role in the use of the single cell 14. Before and during the construction of a large-capacity battery, the single cell 14 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 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.

[0085] In this embodiment, the partition 10 and the 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 14 through the through hole 9 via the connecting pipe 7 and the opening of the blind hole 6.

[0086] 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 pure environment inside the individual battery 14 and ensuring that the battery performance is not adversely affected by external factors.

[0087] Secondly, the partition 10 and the bottom of the blind hole 62 can be opened with a package opening tool to achieve the function of gas communication;

[0088] After the large-capacity battery is assembled, a special unpacking tool is needed to open the separator 10 and the bottom of the blind hole 62, so that the gas regions inside all the individual cells 14 can be connected, thus completing the assembly of the large-capacity battery.

[0089] To meet this functional requirement, the separator 10 and the bottom of the blind hole 62 must be able to be opened by an unpacking tool. This requires that the separator 10 and the bottom of the 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.

[0090] Example 2

[0091] like Figure 5 and Figure 6 The diagram shown is a schematic diagram of the structure of a single battery cell 14 in this embodiment, including a housing, which is formed by an upper cover plate 1, a cylindrical body 17 and a lower cover plate 11; wherein, the upper cover plate 1 is the upper cover plate 1 in embodiment 1.

[0092] To reduce costs and battery weight, this embodiment uses a plastic casing. The lower cover 11 and the cylinder 17 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 ensures uniform material distribution and tight bonding, resulting in a stronger connection between the battery lower cover 11 and the cylinder 17, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder 17, effectively increasing its resistance to bending, compression, and torsion.

[0093] In this embodiment, the upper cover plate 1 and the cylinder 17 can be connected by a heat-fusion seal. The heat-fusion seal ensures a continuous, uniform, and tight connection between the upper cover plate 1 and the cylinder 17, 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-fusion sealing process is simple, and the parameters are easy to control.

[0094] It should be noted that the plastic material selected in this invention should have the following properties:

[0095] First, it must have sufficient strength to ensure the stability of the battery structure;

[0096] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0097] 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.

[0098] 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.

[0099] The plastic material used can be the same material used in existing plastic-cased single-cell batteries 14, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0100] To further reduce costs, the strength of each individual battery cell 14 casing 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. 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.

[0101] 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.

[0102] Under the premise of meeting the above strength requirements, in this embodiment, the thickness of the shell (cylinder 17, upper cover plate 1, and lower cover plate 11) is h, where h is less than h0, and h0 is the thickness of the plastic shell of the conventional single-cell battery 14; the thickness of the plastic shell of the conventional single-cell battery 14 is typically 5-8 mm. In this embodiment, the thickness of the shell can be between 1-4 mm. By reducing the thickness of the shell of the conventional single-cell battery 14 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.

[0103] Example 3

[0104] This embodiment is a high-capacity battery, including a pressure-bearing casing 12 and 12 individual battery cells 14 as described in the above embodiment. In other embodiments, the number of individual battery cells 14 can be adjusted according to actual needs.

[0105] Its structure is as follows Figure 7 and Figure 8 As shown, 12 individual battery cells 14 from the above embodiments are arranged inside the pressure-bearing housing 12. The pressure-bearing housing 12 is provided with an explosion vent. This explosion vent can also be referred to as an explosion vent section, explosion-proof vent, etc.

[0106] like Figure 9 As shown, inside the pressure-bearing housing 12, among adjacent individual cells 14, the connecting pipe 7 of one individual cell 14 is inserted into the blind hole 6 of another individual cell 14 and connected by heat fusion.

[0107] In this embodiment, appropriate tools are used to open the bottom 62 of the blind holes 6 and the separator 10 of each individual battery cell 14, making the inner cavities of all blind holes 6 and the connecting pipe 7 interconnected, and further connecting them with the gas regions inside the inner cavities of all individual battery cells 14. This allows the gas in the inner cavities of all individual battery cells 14 to reach equilibrium, thereby obtaining a large-capacity battery. Based on gas connectivity, the potential differences between individual battery cells 14 are improved, ensuring consistency of each individual battery cell 14 during charging and discharging, extending the overall service life, and improving the performance of the large-capacity battery.

[0108] The aforementioned tool should have a sharp head and a certain strength, such as a long steel needle. Specifically, the following process can be used to open the bottom 62 of the blind hole of each individual cell 14 and the separator 10: Insert the tool into the blind hole 6 of one of the outermost individual cells 14 along the x-direction, apply a pushing force, and open the bottom 62 of the blind hole of each individual cell 14 and the separator 10.

[0109] It should be noted that:

[0110] 1. To ensure that the inner cavity of each individual cell 14 in the large-capacity battery is not affected by the external environment, one of the two outermost individual cells 14 of the large-capacity battery does not need to be opened, and the blind hole 6 opening of the other outermost individual cell 14 also needs to be sealed.

[0111] 2. In order to improve the regularity of the entire large-capacity battery structure, this embodiment can cut off the outermost single cell 14 to expose the unconnected connecting pipe 7. After cutting off, it is necessary to ensure the sealing of the casing of the single cell 14.

[0112] The strength of the pressure-bearing enclosure needs to meet the strength requirements of the casing during thermal runaway, meaning the pressure-bearing enclosure must have good strength. This design not only effectively resists the high-pressure impact during thermal runaway with the reinforced outer 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 14, the pressure-bearing enclosure can form a robust thermal barrier. Even in the extreme case where the casing of the individual cells 14 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 14, an anti-seepage membrane can be installed between each individual cell 14 and the pressure-bearing enclosure to prevent the electrolyte inside each individual cell 14 from seeping out.

[0113] Compared to other materials, metal pressure tanks are more reliable in emergencies such as thermal runaway. They 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 tank does not directly contact the electrolyte, so an iron, steel, or stainless steel shell can be used. Iron shells 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 shells 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 shells 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.

[0114] like Figure 10 and Figure 11 As shown, in this embodiment, a clearance hole 15 is provided on the top plate of the pressure-bearing housing 12 corresponding to the polarity terminal 16 of each individual battery 14; the polarity terminal 16 of each individual battery 14 extends out of the clearance hole 15; the top plate area of ​​the pressure-bearing housing 12 corresponding to the clearance hole 15 is fixedly sealed with the housing of the individual battery 14.

[0115] To optimize the heat dissipation performance of the aforementioned high-capacity battery, this embodiment adds a heat exchange component 13 to the existing high-capacity battery to exchange heat with the polarity terminal 16. The polarity terminal 16 is a key component connecting the battery's internal and external components; during charging and discharging, current flows through the polarity terminal 16 into and out of the battery. When heat is generated inside the battery, heat dissipation through the polarity terminal 16 provides a relatively direct heat conduction path. Heat can be quickly conducted from inside the battery to the polarity terminal 16, and then dissipated from the polarity terminal 16 into the external environment. Furthermore, since the polarity terminal 16 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 16, the temperature of these critical components can be reduced more effectively.

[0116] The heat exchange component 13 can be a heat transfer tube; each polarity terminal 16 of the individual cell 14 is provided with a through groove or through hole 9 for installing the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole 9 of the polarity terminal 16 of each individual cell 14. By using the heat transfer tube on the polarity terminal 16, the heat generated inside the battery is conducted to the heat transfer tube through the polarity terminal 16, and then the heat transfer tube dissipates the heat to achieve heat dissipation of the battery.

[0117] The heat exchange component 13 can also be a heat exchange device, which is disposed on top of each individual battery cell 14. A polar terminal 16 penetrates the heat exchange device, with at least a portion of its structure located within the heat exchange device's inner cavity and in direct contact with the heat exchange medium. Another portion of the polar terminal 16 is located outside the heat exchange device, serving as an electrical connection. The sidewall of the polar terminal 16 is sealed to the heat exchange device. By employing a direct heat exchange method, a portion of the polar terminal 16 is directly placed within the heat exchange medium flow cavity (the inner cavity of the heat exchange device), allowing direct contact between the polar terminal 16 and the heat exchange medium. This achieves heat exchange at the polar terminal 16, resulting in a shorter heat exchange path. The heat exchange medium directly acts on the polar terminal 16, improving the utilization efficiency of the heat exchange medium and enhancing the battery's heat exchange efficiency.

[0118] In this embodiment, an insulating sealant layer can also be provided between each individual battery cell 14 and between each individual battery cell 14 and the pressure-bearing housing 12. The insulating sealant layer is mainly laid in the space between each individual battery cell 14 and the pressure-bearing housing 12, and the heat exchange components 13 inside the pressure-bearing housing 12 are all located within the insulating sealant layer; when there are gaps between each individual battery cell 14, the insulating sealant liquid can also penetrate into the gaps to form an insulating sealant layer. In this embodiment, the insulating sealant layer has at least the following advantages:

[0119] 1. Prevent condensation;

[0120] During long-term use, due to the temperature difference between the inside and outside of the heat exchange component 13, 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 13, when condensation forms on the surface of the heat exchange component 13, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0121] II. Further improve the stability of each individual battery cell 14 within the pressure-bearing casing 12;

[0122] The insulating sealant penetrates into the gaps between each individual cell 14 and between each individual cell 14 and the pressure-bearing housing 12, which can further improve the stability of each individual cell 14 within the pressure-bearing housing 12.

[0123] use Figure 10 and Figure 11 In the structure shown, an insulating sealant layer can also be laid on the top plate of the pressure-bearing shell 12, and the heat exchange component 13 is located inside the insulating sealant layer. When condensation occurs on the surface of the heat exchange component 13, the battery short circuit can be prevented under the protection of the insulating sealant layer.

Claims

1. A cover plate for a single battery cell, characterized in that: The top cover is made of plastic, and there are recesses and protrusions on the opposite side walls of the top cover; the recesses are used for the protrusions of another single battery to be inserted and fixedly connected; under the action of external force, a channel can be opened in the protrusions and recesses, and the channel communicates with the inner cavity of the single battery casing.

2. The single-cell battery cover plate according to claim 1, characterized in that: The recess is a blind hole formed on the first side wall of the upper cover plate; the protrusion is a connecting tube set on the outer wall of the second side wall of the upper cover plate; the connecting tube is used to insert into the blind hole of another single battery cell and to fix it in place; the first side wall and the second side wall are parallel to each other.

3. The single-cell battery cover plate according to claim 2, characterized in that: The top 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 blind hole. A through hole is provided in the area of ​​the top cover plate 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 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 blind hole are all connected to the inner cavity of the single cell.

4. The single-cell battery cover plate according to claim 1, characterized in that: Both the recess and the protrusion are integral with the top cover; the recess is used for the protrusion of the top cover of another single battery cell to be inserted and fixedly connected by heat fusion.

5. A single-cell battery, characterized in that: It includes a housing, which is formed by an upper cover plate, a cylindrical body and a lower cover plate; wherein the upper cover plate is the single cell upper cover plate as described in any one of claims 1 to 4.

6. The single-cell battery according to claim 5, 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.

7. A high-capacity battery, characterized in that: It includes a pressure-bearing housing and n individual battery cells as described in claim 5 or 6 arranged within the pressure-bearing housing, where n is an integer greater than 1; In adjacent individual cells, the protrusion of one individual cell is inserted into the recess of another individual cell and fixedly connected. The protrusion and the recess form a channel that penetrates the inner cavity of the individual cell casing. The pressure-bearing shell has the strength required for the shell during the thermal runaway stage, and the pressure-bearing shell is equipped with a vent.

8. The high-capacity battery according to claim 7, characterized in that: In adjacent cells, the connector of one cell is inserted into the blind hole of another cell and thermally fused together; the separator is opened, and the inner cavity of the connector is connected to the inner cavity of the cell housing; the bottom of the blind hole is opened, and the inner cavity of the blind hole is connected to the inner cavity of the cell housing.

9. The high-capacity battery according to claim 7 or 8, 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.

10. The high-capacity battery according to claim 7, characterized in that: It also includes heat exchange components that exchange heat with the polarity terminals.

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