High-capacity battery assembly

Abstract

The utility model belongs to the field of batteries, and particularly relates to a high-capacity battery assembly. The technical problems that an existing high-capacity battery is high in cost and large in weight are solved. Comprising a pressure-bearing shell as well as a high-capacity battery and a heat exchange device which are positioned in the pressure-bearing shell, the large-capacity battery comprises a shared pipeline and n single batteries arranged in the x direction, and inner cavities of the n single batteries are communicated through the shared pipeline; the shell of each single battery is a plastic shell; the strength P of the plastic shell is greater than or equal to P1 and less than or equal to P2; wherein P1 is the strength requirement of the formation stage and the normal charging and discharging stage of the battery on the shell; p2 is the strength requirement on the shell in the thermal runaway stage; an explosion venting opening communicated with the shared pipeline is formed in the pressure-bearing shell; the heat exchange device is positioned at the top of the high-capacity battery; and each single battery polar terminal penetrates through the heat exchange device. Compared with a finished battery cell, the single battery disclosed by the utility model has the advantages of light weight and low cost.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a high-capacity battery module. 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 an electrolyte sharing pipeline located at the bottom of the large-capacity battery body. The electrolyte sharing pipeline is used to completely connect the internal cavities of the individual cells, so that all individual cells in the large-capacity battery are under a single electrolyte system. This large-capacity battery, through the electrolyte sharing pipeline, can enhance the uniformity of the electrolyte in each individual cell, improve cycle life, and also replenish the electrolyte for the large-capacity battery, extending its service life and improving its safety during use.

[0003] The single battery in the above patent includes a casing, a sealing assembly, and a finished battery cell. The finished battery cell is installed inside the casing, and the casing of the finished battery cell has an opening. The casing is provided with a first through hole communicating with the opening, and a pipe 01 extending along the width or length direction of the casing. The side wall of the pipe is provided with a second through hole communicating with the first through hole. The sealing assembly is provided 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 casing of a single cell, an electrolyte sharing pipeline can be formed through the pipe when assembling a large-capacity battery; moreover, by adding a casing to the finished cell, existing finished cell production lines can be used, and the finished cells can be put into production with slight modifications.

[0005] However, this design has some drawbacks. Typically, both the finished cell casing and the outer casing 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] In terms of weight, aluminum has a relatively high density, and stacking two aluminum components will inevitably increase the overall weight of a large-capacity battery significantly. 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 high-capacity battery assembly that overcomes the technical difficulties of high cost and heavy weight in existing high-capacity batteries.

[0009] The concept of this utility model is:

[0010] This utility model mainly addresses the above-mentioned technical challenges from two aspects: the structure of the individual battery cell itself and the packaging structure of the individual battery cell.

[0011] Firstly, starting from the structure of the individual battery cells themselves, we can reduce the weight and cost of large-capacity battery modules.

[0012] Given that plastic materials have a lower density than metal materials and are relatively cheaper, this invention aims to replace the finished battery cells in the prior art with single-cell batteries using plastic casings.

[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] However, traditional plastic-cased single-cell batteries also have certain problems:

[0015] Firstly, plastic casings have relatively low mechanical strength. To improve the casing's protection during thermal runaway, the pressure resistance of traditional plastic-cased individual batteries is typically increased by optimizing the plastic material or thickening the casing. However, optimizing the plastic material increases the cost of the casing. Thicker plastic casings have poor thermal conductivity, hindering heat dissipation during charging and discharging, which can lead to increased internal battery temperature, accelerated battery aging, and reduced battery life and performance. Heat dissipation issues may become even more pronounced under high-power charging and discharging or prolonged use.

[0016] Secondly, a thicker plastic casing increases the size of the battery, while reducing the space inside the battery available for energy storage, thus lowering the battery's energy density.

[0017] Due to the aforementioned problems, plastic-cased batteries have limited practicality.

[0018] However, unlike traditional single-cell batteries with plastic casings, the single-cell battery of this invention is merely an intermediate product. It does not require the plastic casing to have high strength during the thermal runaway stage. It only needs to meet the strength requirements of the casing during the formation stage and the normal charging and discharging stage of the battery. The requirements for the plastic material are low, so there is no need to optimize the plastic material or make it thicker.

[0019] Specifically, this utility model can overcome the problems of heat dissipation and reduced energy density through the following two points:

[0020] First, this invention, while meeting the strength requirements of the casing during the formation stage, minimizes the thickness of the plastic casing. A thinner plastic casing has better thermal conductivity, which helps dissipate the heat generated by the battery during charging and discharging more quickly to the external environment. This helps reduce the internal temperature of the battery and minimizes battery aging and performance degradation caused by high temperatures.

[0021] Reducing the thickness of the plastic casing decreases the volume of individual cells, allowing more active materials to be accommodated in cells of the same size, thus increasing the energy density of the cells and consequently the energy density of large-capacity battery modules.

[0022] Furthermore, reducing the thickness of the plastic casing means using less plastic material, which helps save on material costs and provides an economic advantage for large-scale production and application.

[0023] Secondly, this utility model also improves the heat dissipation performance of large-capacity battery modules by setting up a heat exchange device.

[0024] Secondly, starting from the packaging structure of individual cells, we can reduce the weight and cost of large-capacity battery modules.

[0025] This invention proposes placing multiple individual battery cells with thin plastic casings within a single pressure-bearing casing, which can simultaneously protect multiple individual cells. Compared to the prior art structure where each individual cell is individually casinged, this reduces individual packaging and protection costs, resulting in lower overall cost. Furthermore, given 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 can further reduce the weight of large-capacity battery modules.

[0026] Based on the above analysis, this utility model provides a large-capacity battery assembly, which is characterized by including a pressure-bearing housing and a large-capacity battery and a heat exchange device located inside the pressure-bearing housing.

[0027] The high-capacity battery consists of a shared conduit and n individual cells arranged along the x-direction, with the inner cavities of the n individual cells connected by the shared conduit; where n is an integer greater than 1; the casing of each individual cell is a plastic casing; the strength of the plastic casing is P, P1≤P≤P2; where P1 is the strength requirement of the casing during the formation stage and the normal charge and discharge stage of the battery; P2 is the strength requirement of the casing during the thermal runaway stage;

[0028] The pressure-bearing shell is equipped with a vent that connects to the shared pipeline;

[0029] The heat exchange device is located at the top of the large-capacity battery, and the inner cavity of the heat exchange device serves as a cavity for the insulating heat exchange medium. In the z-direction, the polar terminals of each individual battery pass through the heat exchange device. Part of the structure of the polar terminal is located inside the heat exchange device and is in direct contact with the insulating heat exchange medium. The other part of the structure of the polar terminal is located outside the heat exchange device and serves as an electrical connection part.

[0030] First, the single battery provided by this utility model can be considered as an intermediate transitional product. Its casing is made of plastic, and its strength only needs to meet the strength requirements of the single battery casing during the formation stage and the normal charging and discharging stage of the battery. Compared with the traditional single battery casing with plastic casing, its strength is lower.

[0031] Because it is made of plastic, the single battery provided by this invention has the advantages of being lightweight and low-cost compared to the finished battery cells used in the prior art.

[0032] Secondly, this invention places multiple individual battery cells within a single pressure-bearing casing, the strength of which must meet the strength requirements of the casing during thermal runaway; that is, the pressure-bearing casing must have good strength to protect multiple individual battery cells simultaneously. In the extreme case of thermal runaway of a single battery cell and melting of the plastic casing, the pressure-bearing casing can form a robust thermal barrier, effectively isolating high-temperature flames and harmful gases, and preventing the spread of thermal runaway. Compared with the prior art structure where each individual battery cell is individually encased, this reduces individual packaging and protection costs, resulting in lower overall cost. Furthermore, given the same number of individual battery cells and the same material and thickness of the pressure-bearing casing as the individual battery casings in the prior art, the weight of a single pressure-bearing casing will inevitably be 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.

[0033] In addition, this utility model also sets up a heat exchange device on the large-capacity battery, adopting a direct heat exchange method, placing part of the polar terminal structure directly in the heat exchange medium flow cavity, so that the polar terminal is in direct contact with the heat exchange medium, realizing heat exchange of the polar terminal. 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, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0034] As a crucial component connecting the battery's internal structure to the external environment, the polarity terminals allow current to flow in and out of the battery during charging and discharging. When heat is generated inside the battery, the polarity terminals provide a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery to the polarity terminals, and then dissipated into the external environment from there.

[0035] Furthermore, the thickness of the plastic casing is h, where h is less than h0, and h0 is the casing thickness of a traditional single-cell battery with a plastic casing.

[0036] This single-cell battery is thinner than traditional finished plastic-cased batteries, thus reducing its volume and increasing its energy density. Simultaneously, the thinner plastic casing offers better thermal conductivity, allowing heat generated during charging and discharging to dissipate more quickly into the external environment. Furthermore, reducing the thickness of the plastic casing means using less plastic material, contributing to cost savings and providing an economic advantage for large-scale production and application.

[0037] Furthermore, the plastic shell is formed by an upper cover plate, a cylindrical body, and a lower cover plate; at least one of the upper cover plate, the cylindrical body, and the lower cover plate is provided with a sub-tube segment, the inner cavity of the sub-tube segment is connected to the inner cavity of the shell; the corresponding sub-tube segments in adjacent single cells are sealed and connected to form a shared pipeline.

[0038] Furthermore, the sub-pipe section is integrally mounted on the lower cover plate; the lower cover plate and the sub-pipe section have a first opening that is interconnected; both ends of the sub-pipe section are closed ends.

[0039] This invention uses a plastic lower cover plate and sub-tube segments, which can be integrally molded through injection molding, reducing the complexity of the manufacturing process and simplifying the process. In addition, the ends of the sub-tube segments can be sealed and connected to the corresponding sub-tube segments of another single battery cell through heat fusion to form an electrolyte sharing pipeline. The connection process is simple and has low precision requirements. Even with a certain degree of dimensional deviation, a good sealing connection can be achieved through heat fusion, reducing the precision control cost in the production process. At the same time, compared with traditional connection methods, heat fusion connection has higher strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the shared pipeline during use.

[0040] In addition, both ends of the sub-tube section are closed ends. Before the individual cells are unpacked, the closed ends can ensure that the inside of the individual cells is not affected by the external environment.

[0041] Furthermore, the two ends of the sub-tube segment are defined as the first closed end and the second closed end, respectively; a first connecting tube is provided on the end face of the first closed end, and a first blind hole extending axially along the first sub-tube segment is opened at the second closed end; the first blind hole is used for the insertion of the first connecting tube on the lower cover plate of another single cell, and the connection is made by heat fusion.

[0042] Before the individual cells are unpacked, the first and second sealed ends ensure that the interior of the individual cells is not affected by the external environment. When a large-capacity battery is constructed based on such individual cells, in adjacent individual cells, the first connecting tube of one individual cell is inserted into the first blind hole of another individual cell and connected by heat fusion sealing to form an electrolyte sharing pipeline on the large-capacity battery. By inserting the unpacking tool into the sharing pipeline and opening the sealed ends of each first sub-tube segment, the inner cavities of all individual cells can be connected through the electrolyte sharing pipeline.

[0043] A first connecting tube is provided on the end face of one closed end, and a first blind hole extending axially along the sub-tube segment is opened at the other closed end. This design provides a precise interface for the connection between two individual cells. The cooperation between the first connecting tube and the first blind hole enables a fast and accurate connection, improving the reliability and stability of the connection.

[0044] Furthermore, the outer wall cross-section of the sub-tube segment is rectangular, while the outer wall cross-section of the first connecting tube is circular. Designing the outer wall cross-section of the sub-tube segment as rectangular provides a larger contact area on the plane compared to a circular cross-section, ensuring stable placement of this type of single-cell battery during use, transportation, or storage. Designing the outer wall cross-section of the first connecting tube as circular makes it easier to insert the connecting tube into the first blind hole, reducing resistance and friction during connection and improving connection smoothness. In addition, the circular cross-section of the first connecting tube also provides relatively better sealing performance, making it easier to achieve a tight fit with the first blind hole and prevent leakage.

[0045] Furthermore, there are two sub-pipe sections, each extending along the width of the lower cover plate, and the two sub-pipe sections are arranged along the length of the lower cover plate.

[0046] Corresponding to the two sub-tube segments, when the closed end of one sub-tube segment cannot be opened, the closed end of the other sub-tube segment can be opened to connect the inner cavity of the single cell and the inner cavity of the electrolyte sharing pipeline, thereby improving the sharing success rate. In addition, when the closed ends of both sub-tube segments are opened, compared to the structure that shares only one sub-tube segment, the electrolyte in the inner cavity of the single cell can be fully mixed with the electrolyte in the inner cavity of the electrolyte sharing pipeline, resulting in a better sharing effect.

[0047] Meanwhile, the two sub-tube segments allow for better stability during use, transportation, and storage of these individual batteries. Furthermore, the two sub-tube segments increase the overall strength and stability of the lower cover. These sub-tube segments act as reinforcing ribs, enabling them to withstand greater external forces and pressures, thus reducing the risk of deformation and damage to the lower cover during use.

[0048] Furthermore, the sub-pipe section is integrally installed on the upper cover plate; a second opening is opened on the upper cover plate and the sub-pipe section to communicate with each other; both ends of the sub-pipe section are closed ends.

[0049] This invention uses a plastic top cover and sub-tube segments, which can be integrally molded through injection molding, reducing the complexity of the manufacturing process and simplifying the process. In addition, the end of the sub-tube segment can be sealed to a sub-tube segment on another single battery cell through heat fusion to form a gas-sharing pipeline. The connection process is simple and has low precision requirements. Even with a certain degree of dimensional deviation, a good sealing connection can be achieved through heat fusion, reducing the precision control cost in the production process. At the same time, compared with traditional connection methods, heat fusion connection has higher strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the battery during use.

[0050] Furthermore, the two closed ends of the sub-tube segment are defined as the third closed end and the fourth closed end, respectively; a second connecting tube is provided on the end face of the third closed end, and a second blind hole extending along the axial direction of the sub-tube segment is opened at the fourth closed end; the second blind hole is used for the insertion of the second connecting tube of the cover plate of another single cell, and the connection is made by heat fusion.

[0051] Before the individual cells are unpacked, the third and fourth sealed ends ensure that the interior of the individual cells is not affected by the external environment. When a large-capacity battery is constructed based on such individual cells, in adjacent individual cells, the second connecting tube of one individual cell is inserted into the second blind hole of another individual cell and connected by heat fusion sealing to form a gas sharing pipeline on the top of the large-capacity battery. By inserting the unpacking tool into the gas sharing pipeline and opening the third and fourth sealed ends of each second sub-tube, the internal cavities of all individual cells can be connected through the gas sharing pipeline.

[0052] A second connecting tube is provided on the end face of the third closed end, and a second blind hole extending axially along the second sub-tube is opened at the fourth closed end. This design provides a precise interface for the connection between the two individual cells. The cooperation between the second connecting tube and the second blind hole enables a fast and accurate connection, improving the reliability and stability of the connection.

[0053] Furthermore, at least one of the upper cover plate, the cylinder body, and the lower cover plate is provided with a venting sub-pipe section, which covers the venting part of the individual battery. The corresponding venting sub-pipe sections in adjacent individual batteries are sealed and connected to form a venting manifold, and the thermal runaway flue gas breaks through the venting part and is discharged from the venting manifold.

[0054] Furthermore, this utility model can employ a variety of heat exchange devices with different structures. For example, the heat exchange device may include multiple heat exchange sleeves, each corresponding to a polarity terminal. Each heat exchange sleeve is fitted around the corresponding polarity terminal, and an annular cavity is formed between the inner wall of the heat exchange sleeve and the side wall of the polarity terminal, which serves as a flow cavity for the heat exchange medium. The electrical connection portion of the polarity terminal extends out of the heat exchange sleeve, and the top and bottom open ends of the heat exchange sleeve are sealed to the side wall of the polarity terminal. Each heat exchange sleeve is interconnected, forming a heat exchange channel at the top of the large-capacity battery.

[0055] The heat exchange device may also include two heat exchange tubes; each heat exchange tube has n through holes; the n through holes are arranged along the x direction and correspond one-to-one with the polarity terminals of the n individual cells on the same side; each through hole extends along the z direction and penetrates the heat exchange tube; the inner cavity of the heat exchange tube serves as the flow cavity for the heat exchange medium.

[0056] Two heat exchange tubes are fixed to the polarity terminals on different sides of n individual cells. Each polarity terminal is inserted into the corresponding through hole, and in the z direction, the electrical connection part of the polarity terminal extends out of the through hole; the side wall of the polarity terminal is sealed with the wall of the corresponding through hole.

[0057] Furthermore, the pressure-bearing shell is made of iron, steel, or stainless steel.

[0058] Metal shells offer advantages in terms of strength and cost, making them a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent.

[0059] The steel casing has relatively high strength, providing more reliable protection for the battery and making it suitable for applications with high requirements for safety and structural strength.

[0060] Stainless steel casings not only possess excellent strength properties but also outstanding corrosion resistance, making them suitable for battery applications that may face humid or corrosive environments.

[0061] Furthermore, the aforementioned high-capacity battery assembly also includes at least one liquid storage tank, with a third sub-tube section provided on the bottom plate and / or top plate of the liquid storage tank; the third sub-tube section is sealed to the sub-tube section on the adjacent single cell.

[0062] This invention integrates a electrolyte storage chamber into a large-capacity battery. The electrolyte is stored in the storage chamber. As the large-capacity battery is used, the electrolyte may decrease due to evaporation, consumption, or other reasons. The electrolyte stored in the storage chamber can be replenished to the large-capacity battery in a timely manner through a shared pipeline to maintain the amount of electrolyte inside the large-capacity battery and ensure the stable performance of the large-capacity battery.

[0063] Furthermore, insulating sealant layers are provided between each individual cell and between each individual cell and the pressure-bearing casing; the heat exchange device is located within the insulating sealant layers. These insulating sealant layers prevent condensation and also improve the stability of the individual cells within the pressure-bearing casing.

[0064] 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.

[0065] Furthermore, an insulating sealant layer is laid on the top plate of the pressure shell, and the heat exchange device is located inside the insulating sealant layer.

[0066] Furthermore, an impermeable membrane is installed between the high-capacity battery and the pressure-bearing casing to prevent the electrolyte inside the battery from seeping out. This membrane plays a crucial protective role, firmly locking in the electrolyte. This not only prevents battery performance degradation that could be caused by electrolyte leakage, but also prevents it from corroding the pressure-bearing casing, effectively ensuring the safety and stability of the entire battery, extending its lifespan, and ensuring stable operation under various working conditions.

[0067] The beneficial effects of this utility model are:

[0068] 1. As an intermediate transitional product, the single cell of this utility model can reduce the strength of the plastic shell while meeting the requirements for shell strength during the formation stage and the normal charging and discharging stage of the battery. This results in lower requirements for the plastic shell, thus enabling it to have lower cost and lighter weight.

[0069] 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. This casing acts as a pressure-bearing barrier, effectively isolating high-temperature flames and harmful gases in extreme situations where a single cell experiences thermal runaway and the plastic casing melts, thus preventing the spread of thermal runaway. Furthermore, protecting multiple individual cells with the 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.

[0070] In addition, this utility model also sets up a heat exchange device on the large-capacity battery, adopting a direct heat exchange method, placing part of the polar terminal structure directly in the heat exchange medium flow cavity, so that the polar terminal is in direct contact with the heat exchange medium, realizing heat exchange of the polar terminal. 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, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0071] The above analysis shows that the large-capacity battery of this invention has advantages over the large-capacity batteries in the background art, such as light weight, easy processing, low cost, and good heat dissipation.

[0072] 2. This utility model reduces the volume of a single battery by thinning the plastic casing of existing single batteries. This allows more active materials to be accommodated in a battery of the same size, increasing the energy density of the battery and thus improving the energy density of large-capacity batteries.

[0073] Meanwhile, the thinner plastic casing has relatively good thermal conductivity, which helps dissipate the heat generated by the battery during charging and discharging more quickly to the external environment. This helps reduce the internal temperature of the battery and minimizes battery aging and performance degradation caused by high temperatures.

[0074] In addition, reducing the thickness of the plastic casing means using less plastic material, which helps save material costs and provides an economic advantage for large-scale production and application. Attached Figure Description

[0075] Figure 1 This is a schematic diagram of the structure of a large-capacity battery in the background art;

[0076] Figure 2 This is a schematic diagram of the structure of a single cell in Example 1;

[0077] Figure 3 This is a schematic diagram of the exploded structure of a single cell in Example 1;

[0078] Figure 4 This is a schematic diagram of the lower cover plate in Example 1;

[0079] Figure 5 This is a first-view sectional view of the lower cover plate in Embodiment 1;

[0080] Figure 6 This is a second-view sectional view of the lower cover plate in Embodiment 1;

[0081] Figure 7 This is a schematic diagram of the structure of a single cell in Example 2;

[0082] Figure 8 This is a cross-sectional view of the upper cover plate in Example 2;

[0083] Figure 9 This is a schematic diagram of the structure of the large-capacity battery module in Example 4;

[0084] Figure 10 This is a schematic diagram of the exploded structure of the large-capacity battery module in Example 4;

[0085] Figure 11 This is a partial exploded view of the high-capacity battery in Example 4;

[0086] Figure 12 This is a schematic diagram of the structure of a heat exchange sleeve in Example 4;

[0087] Figure 13 This is a schematic diagram of another heat exchange sleeve in Example 4;

[0088] Figure 14 This is a cross-sectional view of another heat exchange sleeve in Example 4;

[0089] Figure 15 This is a schematic diagram of an assembly process of the heat exchange device in Example 4;

[0090] Figure 16 This is a partial structural diagram of the high-capacity battery module in Example 5;

[0091] Figure 17 This is a schematic diagram of the heat exchange tubes in Example 5;

[0092] Figure 18 This is a cross-sectional view of the heat exchanger tubes in Example 5;

[0093] Figure 19 This is a schematic diagram of the structure of the large-capacity battery module in Example 7;

[0094] Figure 20 This is a schematic diagram of the exploded structure of the large-capacity battery module in Example 7.

[0095] The attached figures are labeled as follows:

[0096] 01. Pipeline; 02. Shared electrolyte pipeline;

[0097] 1. First sub-tube segment; 11. First closed end; 12. First connecting tube; 13. Second closed end; 14. First blind hole; 2. First opening; 3. Cylinder body; 4. Lower cover plate; 41. Upper cover plate; 42. Polar terminal; 43. Second sub-tube segment; 44. Second opening; 45. Third closed end; 46. Fourth closed end; 47. Second connecting tube; 48. Second blind hole; 5. Single cell; 6. Liquid storage tank; 61. Third sub-tube 7. Pressure-bearing shell; 71. Explosion vent; 72. Top plate of pressure-bearing shell; 73. Clearance hole; 8. Heat exchange device; 81. Liquid inlet end; 82. Liquid outlet end; 9. Annular groove; 31. Heat exchange sleeve; 311. Hollow component; 312. Annular sealing plate; 313. First through hole; 314. Liquid inlet pipe; 315. Liquid outlet pipe; 32. Heat exchange fitting; 321. Through hole; 322. Bottom port; 323. Top port. Detailed Implementation

[0098] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0099] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0100] In the description of this utility model, it should be noted that the terms "top," "bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0101] Example 1

[0102] This embodiment is a single-cell battery 5, the structure of which is as follows: Figure 2 As shown, it includes a housing and an electrode assembly located within the housing.

[0103] The casing serves as a containment cavity for the electrode assembly and electrolyte, providing a sealed space for these components. Simultaneously, the casing needs to meet certain strength requirements. In this embodiment, the casing strength is not required to meet the strength requirements during the thermal runaway phase; it only needs to meet the strength requirements during the formation phase and normal charge / discharge processes. During the formation and normal charge / discharge phases, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressures and heat are generated inside the battery. The casing needs sufficient strength to withstand these pressures and heat to ensure the smooth progress of the formation process and the normal operation of the battery.

[0104] 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.

[0105] To meet the aforementioned strength requirements, and in order to reduce cost and battery weight, this embodiment uses a plastic casing. For example... Figure 3 The diagram shown is an exploded view of the casing of the single battery 5 in this embodiment. It is composed of a cylindrical body 3, an upper cover plate 41, and a lower cover plate 4. All three components, including the cylindrical body 3, the upper cover plate 41, and the lower cover plate 4, are made of plastic.

[0106] In this embodiment, the thickness of the casing (cylinder 3, upper cover plate 41, and lower cover plate 4) is h, where h is less than h0, and h0 is the thickness of a traditional single-cell battery plastic casing; the thickness of a traditional single-cell battery plastic casing is typically 5-8 mm. In this embodiment, the casing thickness can be between 1-4 mm. By reducing the casing thickness of a traditional single-cell battery with a plastic casing, better heat dissipation can be achieved, while also increasing the battery energy density. Furthermore, reducing the thickness of the plastic casing means using less plastic material, which helps save material costs and provides an economic advantage for large-scale production and application.

[0107] The lower cover plate 4 and the cylinder body 3 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 plate 4 and the cylinder body 3, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder body 3, effectively increasing its resistance to bending, compression, and torsion.

[0108] In this embodiment, both the upper cover plate 41 and the cylindrical body 3 are made of plastic and are connected using a heat-fusion seal. The heat-fusion seal ensures a continuous, uniform, and tight connection between the upper cover plate 41 and the cylindrical body 3, exhibiting extremely high stability. Compared to other sealing methods, it does not loosen or leak over time, maintaining an excellent sealing effect at all times. 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.

[0109] It should be noted that the plastic material selected in this utility model should have the following properties:

[0110] First, it must have sufficient strength to ensure the stability of the battery structure;

[0111] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0112] Third, it has barrier properties, which can effectively prevent the electrolyte, gas and other substances inside the battery from leaking out, while also preventing external impurities such as moisture and oxygen from entering the battery; in addition, a seepage-proof membrane can be installed between the large-capacity battery and the pressure-bearing shell to prevent the electrolyte inside the large-capacity battery from seeping out.

[0113] 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.

[0114] The plastic material used can be the material used in existing plastic-cased single-cell batteries, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0115] This invention features sub-tube segments on at least one of the upper cover plate 41, the cylindrical body 3, and the lower cover plate 4. The inner cavity of each sub-tube segment communicates with the inner cavity of the casing. By connecting the corresponding sub-tube segments of multiple individual batteries 5, a shared pipeline can be formed. For example, connecting the sub-tube segments located on the lower cover plate 4 forms an electrolyte shared pipeline, and connecting the sub-tube segments located on the upper cover plate 41 forms a gas shared pipeline. Connecting the sub-tube segments located on the cylindrical body 3 forms both an electrolyte and a gas shared pipeline (the electrolyte and gas regions in each individual battery 5 are connected through this pipeline).

[0116] This embodiment takes setting a sub-pipe section on the lower cover plate 4 as an example.

[0117] In this embodiment, for ease of description, the sub-pipe segment on the lower cover plate 4 is defined as the first sub-pipe segment 1; the outer wall cross-section of the first sub-pipe segment 1 can be circular or rectangular, from... Figure 3 As can be seen from the diagram, this embodiment preferably uses a rectangular cross-section, allowing the bottom surface of the first sub-tube segment 1 to serve as the supporting surface for the individual battery 5. Compared to the first sub-tube segment 1 with a circular outer tube wall cross-section, the rectangular cross-section provides a larger contact area on the plane. This feature makes the individual battery 5 with this type of lower cover plate 4 more stable during use and less prone to rolling or shaking.

[0118] In this embodiment, the first sub-tube segment 1 extends along the width direction of the lower cover plate 4. From the perspective of improving the stability of the individual battery 5 during use, the size of the first sub-tube segment 1 in the width direction of the lower cover plate 4 can be increased to create a larger bottom surface area, as a larger bottom surface area results in a more stable placement of the individual battery 5. However, this introduces a new problem: as the size of the first sub-tube segment 1 increases, the size of the electrolyte sharing pipeline it forms also increases. A larger electrolyte sharing pipeline means more electrolyte is required, which undoubtedly leads to an increase in the cost of the individual battery 5 or a large-capacity battery.

[0119] To resolve the contradiction of ensuring stable placement of the individual battery cell 5 while minimizing electrolyte usage, this embodiment employs a clever design. For example... Figure 3 As shown, two narrow first sub-tube segments 1 are provided on the lower cover plate 4. These two first sub-tube segments 1 can simultaneously provide support, ensuring that the individual battery cells 5 can be placed stably. At the same time, due to their narrow width, compared to designing a larger single first sub-tube segment 1, the size of the resulting electrolyte sharing pipeline is relatively smaller, thereby reducing the amount of electrolyte used. This effectively controls battery costs while meeting the requirement for stable battery placement, achieving a win-win effect.

[0120] from Figure 4 , Figure 5 neutralization Figure 6 As can be seen, interconnected openings are formed in the lower cover plate 4 and the first sub-tube segment 1. In this embodiment, for ease of description, the openings in the lower cover plate 4 and the first sub-tube segment 1 are defined as the first opening 2; the shape of the first opening 2 is not limited in this embodiment, but the size of the first opening 2 needs to be ensured so that the electrolyte inside the single cell 5 can enter the first sub-tube segment 1 through the opening.

[0121] from Figure 6As can be seen from the diagram, the two ends of the first sub-pipe segment 1 in this embodiment are closed ends. This can be achieved in several ways. One feasible method is to set a sealing gasket or sealing plug inside the first sub-pipe segment 1, thereby effectively blocking the channels at both ends of the first sub-pipe segment 1 and forming a closed end. Alternatively, a sealing plate can be integrally molded inside the first sub-pipe segment 1, which can also achieve the purpose of sealing both ends of the first sub-pipe segment 1. Since this embodiment uses injection molding, the second method is preferred.

[0122] This sealing end mainly has the following two functions:

[0123] First, the function of preventing external substances from entering the interior of the individual cell before or during the construction of a large-capacity battery.

[0124] This sealed end plays a crucial role in the use of the single cell 5. Before and during the construction of a large-capacity battery, the single cell 5 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 both ends of the first sub-tube segment 1 and the first opening 2, 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.

[0125] In this embodiment, the two ends of the first sub-tube segment 1 are designed as closed ends. The purpose is to build a solid barrier to ensure that air, water and other impurities in the external environment cannot enter the single cell 5 through the openings at both ends of the first sub-tube segment 1.

[0126] To achieve this function, certain requirements are placed on the strength of the sealing end. 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 single cell and ensuring that the battery performance is not adversely affected by external factors.

[0127] Secondly, the sealed end can be opened with a packaging tool to form an electrolyte sharing pipeline;

[0128] Once a large-capacity battery is assembled, specialized unpacking tools are needed to open the sealed ends of each first sub-pipeline, thereby forming an electrolyte-sharing pipeline.

[0129] To meet this functional requirement, the sealed end must be able to be opened by an unpacking tool. This necessitates that the sealed end be designed to open smoothly with the tool without damaging other parts of the high-capacity battery during the opening process, ensuring the integrity and functionality of the battery remain unaffected.

[0130] For ease of description, in this embodiment, the closed ends at both ends of the first sub-pipe segment 1 are defined as the first closed end 11 and the second closed end 13, respectively; from Figure 6 As can be seen from the figure, this embodiment adopts a structure that combines a connecting pipe and a blind hole to achieve the connection of two first sub-pipe segments 1. The connecting pipe set on the end face of the first closed end 11 is defined as the first connecting pipe 12, and the blind hole opened on the second closed end 13 is defined as the first blind hole 14.

[0131] In some other embodiments, the first sub-tube segment 1 of one of the single cell batteries 5 can be abutted against the end face of the first sub-tube segment 1 of another single cell battery 5, and the connection between the two can be achieved by heat fusion at the abutment.

[0132] Combination Figure 4 As can be seen, in this embodiment, the outer wall cross-section of the first connecting pipe 12 is circular, and the corresponding first blind hole 14 that mates with it is also circular. Using a circular cross-section for the first connecting pipe 12 makes it easier to insert it into the first blind hole 14. The circular shape provides good guidance, reducing resistance and friction during connection and improving smoothness. Furthermore, due to the uniform stress distribution of the circular shape, a tight fit with the first blind hole 14 is more easily achieved. After the circular cross-section first connecting pipe 12 is heat-fused within the first blind hole 14, its sealing performance is relatively good, effectively preventing electrolyte leakage.

[0133] Example 2

[0134] This embodiment also refers to a single-cell battery 5. Unlike the single-cell battery 5 in Embodiment 1, this embodiment also integrally forms a sub-tube segment on the upper cover plate 41, with the structure as follows: Figure 7 As shown.

[0135] As shown in the figure, in this embodiment, the upper cover plate 41 is provided with two terminals 42 of opposite polarity, and a sub-tube segment is provided between the two terminals 42, which extends along the width direction of the upper cover plate 41. In this embodiment, for ease of description, the sub-tube segment on the upper cover plate 41 is defined as the second sub-tube segment 43.

[0136] It should be noted that the polarity terminal 42 mentioned here can be the 5-terminal of a single battery. If the height of the 5-terminal of the single battery as the polarity terminal 42 does not meet the set requirements, a terminal adapter can be connected to the 5-terminal of the single battery, and the overall structure of the 5-terminal of the single battery and the terminal adapter can be used as the polarity terminal 42.

[0137] It is worth noting that, since the second sub-segment 43 is located on the upper cover plate 41, unlike the first sub-segment 1 located on the lower cover plate 4, its cross-sectional shape does not affect the stable placement of the single battery cell 5. This characteristic gives the second sub-segment 43 greater flexibility in shape design. In this embodiment, the shape of the second sub-segment 43 is not strictly limited; it can be either circular or square. Furthermore, due to the limitation imposed by the polarity terminal 42, this embodiment only provides one second sub-segment 43 on the upper cover plate 41.

[0138] from Figure 8 As can be seen from the diagram, in this embodiment, interconnected openings are formed in the upper cover plate 41 and the second sub-tube segment 43. In this embodiment, the openings in the upper cover plate 41 and the second sub-tube segment 43 are defined as the second opening 44. This embodiment does not limit the shape of the second opening 44, but the size of the second opening 44 needs to be ensured so that the gas inside the single cell 5 can enter the second sub-tube segment 43 through this opening.

[0139] Similar to the first sub-pipe segment 1 in Embodiment 1, the two ends of the second sub-pipe segment 43 are closed ends. The closed ends of the two ends of the second sub-pipe segment 43 are defined as the third closed end 45 and the fourth closed end 46, respectively. This embodiment also adopts an integrally formed sealing plate inside the second sub-pipe segment 43 to close both ends of the second sub-pipe segment 43.

[0140] The closed end has a similar function to the closed end in Example 1. The only difference is that after a large-capacity battery is constructed, a special unpacking tool is needed to open the closed ends of each second sub-pipe to form a gas sharing pipeline.

[0141] from Figure 8As can be seen, this embodiment also adopts a structure combining a connecting pipe and a blind hole to connect the two second sub-pipe segments 43. The connecting pipe set on the end face of the third closed end 45 is defined as the second connecting pipe 47, and the blind hole opened at the fourth closed end 46 is defined as the second blind hole 48. In this embodiment, the outer wall cross-section of the second connecting pipe 47 is circular, and the corresponding second blind hole 48 that matches it is also a circular hole. Using a second connecting pipe 47 with a circular cross-section makes it easier for the second connecting pipe 47 to be inserted into the second blind hole 48. The circular shape has good guiding properties, which can reduce resistance and friction during connection and improve the smoothness of connection. In addition, since the circular shape has a uniform stress distribution, it is easier to achieve a tight fit with the second blind hole 48. After the circular cross-section second connecting pipe 47 is heat-fused in the second blind hole 48, the sealing performance is also relatively good, which can effectively prevent gas leakage.

[0142] Example 3

[0143] Unlike Embodiment 1, this embodiment may also have a venting sub-pipe section on at least one of the upper cover plate, the cylinder and the lower cover plate. The venting sub-pipe section covers the venting part of the single battery cell. Thermal runaway smoke breaks through the venting part and is discharged from the venting sub-pipe section, thereby improving safety performance.

[0144] Preferably, in this embodiment, the explosion vent of the single battery cell is located on the upper cover plate, and the explosion vent sub-tube section is disposed on the upper cover plate. The explosion vent can also be referred to as an explosion-proof port, explosion-proof section, etc.

[0145] Example 4

[0146] This embodiment is a high-capacity battery assembly, the structure of which is as follows: Figure 9 and Figure 10 As shown, it includes a pressure-bearing housing 7 and a large-capacity battery and heat exchange device 8 located inside the pressure-bearing housing 7;

[0147] The high-capacity battery includes 12 individual battery cells 5 as described in the above embodiments. In other embodiments, the number of individual battery cells 5 can be adjusted according to actual needs.

[0148] Figure 9 and Figure 10 Taking the single cell 5 from Example 2 as an example.

[0149] The first sub-tube segment 1 of adjacent single cells 5 is sealed and connected, forming two electrolyte sharing pipelines at the bottom of the large-capacity battery; the second sub-tube segment 43 of adjacent single cells 5 is sealed and connected, forming a gas sharing pipeline at the top of the large-capacity battery.

[0150] In other embodiments, when using the single cell in Embodiment 3, the first sub-tube segment 1 of adjacent single cells 5 is sealed and connected, forming two electrolyte shared pipelines 02 at the bottom of the large-capacity battery; the corresponding explosion-venting sub-tube segments of adjacent single cells are sealed and connected, forming an explosion-venting manifold at the top of the large-capacity battery, and the thermal runaway flue gas breaks through the explosion-venting part and is discharged from the pressure-bearing shell through the explosion-venting manifold.

[0151] The pressure-bearing housing 7 is provided with a vent 71 that communicates with the shared pipeline. In this embodiment, the vent 71 is connected to the shared gas pipeline. The vent 71 here can also be referred to as a venting section, an explosion-proof port, etc.

[0152] This embodiment uses hot-melt connection to achieve a sealed connection of each sub-pipe segment, forming a shared pipeline. The connection process is simple and has low precision requirements. Even with a certain degree of dimensional deviation, a good sealed connection can be achieved through hot-melt connection, reducing the precision control cost in the production process. At the same time, compared with traditional connection methods, hot-melt connection has higher strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the large-capacity battery during use.

[0153] The high-capacity battery also includes electrical connectors, which include a first electrical connector for electrical connection between individual cells 5, and a second electrical connector for electrical connection between high-capacity batteries or between a high-capacity battery and an external load, wherein one end of the second electrical connector needs to extend out of the pressure-bearing housing 7. Figure 9 and Figure 10 (Not shown in the image).

[0154] In addition, such as Figure 11 As shown, this embodiment also includes two liquid storage chambers 6, located outside the two outermost individual cells 5 of the large-capacity battery; and a third sub-tube segment 61 is provided on both the bottom plate and the top plate of the liquid storage chamber 6, the third sub-tube segment 61 being sealed to the sub-tube segment on the corresponding cover plate of the adjacent individual cell 5. For example, the third sub-tube segment 61 on the bottom plate of the liquid storage chamber 6 is sealed to the first sub-tube segment 1 of the lower cover plate 4 of the adjacent individual cell 5. The third sub-tube segment 61 on the top plate of the liquid storage chamber 6 is sealed to the second sub-tube segment 43 of the upper cover plate 41 of the adjacent individual cell 5.

[0155] In some other embodiments, the number and position of the liquid storage tanks 6 can be adjusted. The liquid storage tanks 6 can be located in the middle of the large-capacity battery, between two individual cells 5.

[0156] Electrolyte is stored in the storage tank 6. As the large-capacity battery is used, the electrolyte may decrease due to evaporation, consumption, or other reasons. The electrolyte stored in the storage tank 6 can be replenished to the large-capacity battery in a timely manner through a shared pipeline to maintain the amount of electrolyte inside the large-capacity battery and ensure the stable performance of the large-capacity battery.

[0157] In this embodiment, both the electrolyte storage tank 6 and the third sub-pipe segment 61 are plastic components and are integral pieces. The third sub-pipe segment 61 is sealed to the sub-pipe segment on the adjacent single cell 5 via heat fusion. The non-connecting end of the third sub-pipe segment 61 is a closed end. The connecting end of the third sub-pipe segment 61 can be directly inserted into the blind hole in the sub-pipe of the single cell 5 for heat fusion connection, or the connecting pipe of the sub-pipe of the single cell 5 can be inserted into the connecting end of the third sub-pipe segment 61 for heat fusion connection. Heat fusion connection achieves a good sealing effect, preventing electrolyte or gas leakage. Furthermore, the connection strength is high, capable of withstanding certain pressure and vibration, ensuring the stability of the shared pipeline during the operation of large-capacity batteries.

[0158] Combination Figure 10 and Figure 11 As can be seen, the heat exchange device 8 in this embodiment includes 24 heat exchange sleeves 31, which are respectively set around the 24 polar terminals 42.

[0159] The structure of heat exchange sleeve 31 is as follows Figure 12 As shown, it includes a hollow component 311 and an annular sealing plate 312; two first through holes 313 are opened on the side wall of the hollow component 311 to penetrate its inner cavity, which serve as liquid inlet and liquid outlet respectively; the annular sealing plate 312 is coaxial with the hollow component 311 and is sealed and fixed at the top of the hollow component 311.

[0160] Combination Figure 10 As can be seen, the heat exchange sleeve 31 is sleeved around the polar terminal 42, forming an annular cavity between it and the side wall of the polar terminal 42. This annular cavity serves as a flow cavity for the heat exchange medium. The bottom end of the hollow component 311 is sealed and fixed to the polar terminal 42 of the single cell 5. The inner ring surface of the annular sealing plate 312 is sealed and fixed to the side wall of the polar terminal 42. At the same time, part of the structure of the polar terminal 42 extends out of the inner hole of the annular sealing plate 312, serving as the electrical connection part of the polar terminal 42.

[0161] This utility model does not specifically limit the cross-sectional shape of the hollow component 311. Generally, the cross-sectional shape of the hollow component 311 is adapted to the cross-sectional shape of the polar terminal 42. For example, when the cross-section of the polar terminal 42 is circular, the cross-section of the corresponding hollow component 311 is annular; when the cross-section of the polar terminal 42 is square, the cross-section of the corresponding hollow component 311 is square annular.

[0162] In this embodiment, the hollow component 311 and the annular sealing plate 312 are an integral part. In some other embodiments, the hollow component 311 and the annular sealing plate 312 can be separate parts, but the processing is more complicated than in this embodiment.

[0163] In this embodiment, the heat exchange sleeve 31 is made of rubber, which has a certain elastic deformation. The bottom end of the hollow component 311 and the polar terminal 42 are tightly fitted together to achieve a sealed fixation. To improve the sealing reliability, insulating sealant can also be used for bonding. The inner ring surface of the annular sealing plate 312 and the side wall of the polar terminal 42 are sealed by a tight fit. In some other embodiments, an annular sealing ring can be added between the inner ring surface of the annular sealing plate 312 and the side wall of the polar terminal 42 to further improve the sealing performance.

[0164] In some other embodiments, the bottom end of the heat exchange sleeve 31 can also be sealed and fixed to the upper cover plate 41 of the single cell 5 to ensure the seal between the hollow component 311 and the side wall of the polar terminal 42; the inner ring surface of the annular sealing plate 312 and the side wall of the polar terminal 42 are sealed by insulating sealant.

[0165] like Figure 10 and Figure 11 As shown, in this embodiment, the heat exchange sleeves 31 of each individual battery 5 located on the same side are connected, forming two heat exchange channels on the top of the 12 individual batteries 5. The two heat exchange channels can be connected in parallel or in series, and heat exchange is achieved based on the two heat exchange channels. The liquid inlet end 81 and the liquid outlet end 82 of the heat exchange channels extend out of the pressure-bearing shell. This extension is in the usage state; it can be extended later by connecting an external pipe section.

[0166] In addition, in this embodiment, a functional structure can be provided on the polar terminal 42 to increase the heat exchange area of ​​that part of the polar terminal 42; placing the part with the functional structure in the heat exchange medium flow cavity can further improve the heat exchange effect.

[0167] For details, please refer to [link / reference]. Figure 7 In this embodiment, at least two annular grooves 9 are formed on the sidewall of the polarity terminal 42. The two annular grooves 9 are arranged along the height direction of the polarity terminal 42, and each annular groove 9 extends circumferentially along the sidewall of the polarity terminal 42. Since the two annular grooves 9 can increase the heat exchange area of ​​this part of the polarity terminal 42, after this part is placed in the inner cavity of the heat exchange device 8, a better heat exchange effect can be obtained compared with the polarity terminal 42 with smooth sidewalls.

[0168] In some other embodiments, the number of annular grooves 9 and the dimensions such as groove width and groove depth can be adjusted as needed, specifically without affecting the conductivity of the polarity terminal 42.

[0169] In other embodiments, other structures can be processed on the polarity terminal 42 to increase the heat exchange area of ​​the polarity terminal 42. Such functional structures may include dot-shaped pits or protrusions on the sidewall of the polarity terminal 42, and may also include through holes on the polarity terminal 42 (heat dissipation teeth can be added along its axial direction in the through hole to further increase the heat exchange area in the through hole). Compared with the above functional structures, the annular groove 9 structure in this embodiment is easier to process and has a lower processing cost.

[0170] In this embodiment, as Figure 13 and Figure 14 As shown, the heat exchange sleeve 31 also includes an inlet pipe 314 and an outlet pipe 315; the inlet pipe 314 and the outlet pipe 315 are both fixed on the side wall of the hollow component 311 and are respectively connected to the inlet and outlet.

[0171] The hollow component 311, the annular sealing plate 312, the liquid inlet pipe 314 and the liquid outlet pipe 315 are integrated into one piece, and all of them are made of insulating material, preferably an insulating material with a certain degree of elastic deformation.

[0172] It should be noted that the inlet pipe 314 of one heat exchanger 31 and the outlet pipe 315 of the other heat exchanger 31 can be connected to each other to achieve communication between the two adjacent heat exchanger 31s. Alternatively, a connecting pipe section can be used to connect the inlet pipe 314 of one heat exchanger 31 and the outlet pipe 315 of the other heat exchanger 31 to achieve communication between the two adjacent heat exchanger 31s.

[0173] This embodiment can adopt the following two installation methods to fix the heat exchange device 8 to each individual battery cell 5:

[0174] Installation Method 1:

[0175] like Figure 15 As shown, each heat exchange sleeve 31 is fitted onto the corresponding polarity terminal 42 one by one. During the fitting process, adjacent heat exchange sleeves 31 are connected, and the top and bottom open ends of the heat exchange sleeves 31 are sealed to the side wall of the polarity terminal 42; finally, two heat exchange channels are formed.

[0176] Installation Method Two:

[0177] like Figure 11 As shown, firstly, the heat exchange sleeves 31 are connected to form two heat exchange channels. Then, each heat exchange channel is installed as a whole on top of the 12 individual cells 5. During the installation process, each heat exchange sleeve 31 of each heat exchange channel is fitted onto the corresponding polarity terminal 42 to complete the sealing between the open top and bottom ends of the heat exchange sleeve 31 and the side wall of the polarity terminal 42; finally, two heat exchange channels are formed.

[0178] Example 5

[0179] Unlike Embodiment 4, this embodiment uses a heat exchange device 8 with a different structure.

[0180] like Figure 16 As shown ( Figure 16 This is a partial structure of the large-capacity battery module in this embodiment (the pressure-bearing housing 7 is not shown in the figure). In this embodiment, two heat exchange tubes 32 are used as heat exchange devices 8, and the two heat exchange tubes 32 are respectively set on the polarity terminals 42 on different sides of the large-capacity battery (the heat exchange tubes 32 may or may not be in contact with the cover plate 41 of the individual battery 5). In order to improve the safety performance of the large-capacity battery module, the heat exchange tubes 32 should not be energized. In this embodiment, heat exchange tubes 32 made of insulating material can be selected; in some other embodiments, the walls of the non-insulated heat exchange tubes 32 can be insulated, such as by spraying insulating paint or wrapping with insulating film; an insulating sealing gasket can also be added between the polarity terminals 42 and the heat exchange tubes 32 to achieve the above purpose.

[0181] The structure of heat exchange tube 32 is as follows Figure 17 and Figure 18 As shown in the figure, the heat exchange tube 32 in this embodiment has 12 through holes 321. The 12 through holes 321 are arranged along the x-direction and correspond one-to-one with the polarity terminals 42 of each individual cell 5. In some other embodiments, the number of through holes 321 can be adjusted according to the number of individual cells 5 in the large-capacity battery, and the arrangement of the through holes 321 can be adjusted according to the arrangement of the individual cells 5.

[0182] This invention does not specifically limit the cross-sectional shape of the tube body. Since the heat exchange tube 32 in this embodiment is placed on the planar single cell 5 cover plate 41, considering the structural regularity, it can be seen from the figure that the tube body in this embodiment is a rectangular tube. In some other embodiments, a circular tube or other structural forms of tube can also be used.

[0183] The aforementioned through hole 321 is a through hole 321 that passes through the top plate and bottom plate of the heat exchange tube 32 and communicates with the inner cavity of the heat exchange tube 32. In this embodiment, after the heat exchange tube 32 is fixed to the top of the single cell 5, the extension direction of the through hole 321 is consistent with the height direction of the shell 1 (the height direction of the shell 1 is the z direction). Therefore, it can be considered that the through hole 321 extends along the z direction.

[0184] In addition, when the heat exchange tube 32 is fixed to the top of the individual cell 5, the electrical connection part of the polarity terminal 42 of each individual cell 5 passes through the bottom port 322 of the corresponding through hole 321 and extends out from the top port 323. The top port 323 here is the port near the electrical connection part of the polarity terminal 42.

[0185] In this embodiment, the shapes of the two ports of the through hole 321 are adapted to the cross-sectional shape of the polar terminal 42. The two ports of the through hole 321 are circular, and the cross-section of the polar terminal 42 is also circular. The diameter of the two ports of the through hole 321 is slightly larger than the outer diameter of the polar terminal 42. In other embodiments, the shapes of the two ports of the through hole 321 and the cross-sectional shape of the polar terminal 42 may be different, as long as it is ensured that the polar terminal 42 can be inserted into the through hole 321.

[0186] from Figure 16 As can be seen from the diagram, in this embodiment, the two heat exchange tubes 32 are respectively sleeved on the polarity terminals 42 on different sides of the large-capacity battery based on the through hole 321, and the two heat exchange tubes 32 are connected in series through a connecting pipe. In some other embodiments, the two heat exchange tubes 32 can also be connected in parallel.

[0187] Example 6

[0188] Based on Examples 4 and 5, this embodiment adds an insulating sealant layer between each individual battery cell 5 and between each individual battery cell and the pressure-bearing housing 7.

[0189] The insulating sealant layer is mainly laid in the space between each individual battery cell 5 and the pressure-bearing housing 7. The heat exchange device 8 inside the pressure-bearing housing 7 is located within the insulating sealant layer. At the same time, the electrical connectors connected to the polarity terminal 42 inside the pressure-bearing housing 7 can also be located within the insulating sealant layer (when it is necessary to collect signals from the electrical connectors, the electrical connectors need to be exposed within the insulating sealant layer). When there is a gap between each individual battery cell 5, the insulating sealant liquid can also penetrate into the gap to form an insulating sealant layer.

[0190] In this embodiment, the insulating sealant layer has at least the following advantages:

[0191] 1. Prevent condensation;

[0192] During long-term use, due to the temperature difference between the inside and outside of the heat exchange device 8, 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 device 8, when condensation forms on the surface of the heat exchange device 8, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0193] II. Further improve the stability of each individual battery cell 5 within the pressure-bearing casing 7;

[0194] The insulating sealant penetrates into the gaps between each individual cell 5 and between each individual cell 5 and the pressure-bearing housing 7, which can further improve the stability of each individual cell 5 within the pressure-bearing housing 7.

[0195] III. Further improve the sealing performance of each part of the heat exchange device;

[0196] Specifically, the insulating sealant liquid constituting the insulating sealant layer penetrates into the gap between the heat exchange sleeve 31 and the side wall of the polar terminal 42 or the gap between the through hole 321 and the side wall of the polar terminal 42, further sealing the gap radially (the insulating sealant liquid cannot flow into the heat exchange medium flow cavity through the gap between the heat exchange sleeve 31 and the side wall of the polar terminal 42 or the gap between the through hole 321 and the side wall of the polar terminal 42).

[0197] Example 7

[0198] This embodiment is also a high-capacity battery, but it differs from embodiment 6 in that, as Figure 19 and Figure 20 As shown, in this embodiment, clearance holes 73 are provided on the top plate 72 of the pressure-bearing housing corresponding to the polarity terminals 42 of each individual battery 5; the polarity terminals 42 of each individual battery 5 extend out of the clearance holes 73; the area of ​​the top plate 72 of the pressure-bearing housing corresponding to the clearance holes is fixedly sealed to the individual battery housing; the heat exchange device 8 is fixed on the part where the polarity terminals 42 extend out of the clearance holes 73. In this embodiment, only an insulating sealant layer is laid on the top plate 72 of the pressure-bearing housing, and the heat exchange device 8 is located inside the insulating sealant layer. When condensation occurs on the surface of the heat exchange device 8, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0199] Compared to Example 6, this example can significantly reduce the amount of insulating sealant used, thereby lowering the cost of high-capacity battery modules.

Claims

1. A large capacity battery assembly characterized by: The application relates to a large-capacity battery, which comprises a pressure-bearing shell, a large-capacity battery and a heat exchange device in the pressure-bearing shell. The large-capacity battery comprises a shared pipeline and n single batteries arranged in the same direction, and the inner cavities of the n single batteries are communicated through the shared pipeline; wherein n is an integer greater than 1; the shell of each single battery is a plastic shell; the strength of the plastic shell is P, P1<=P<=P2; wherein P1 is the strength requirement of the shell in the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell in the thermal runaway stage. The strength of the pressure-bearing shell meets the strength requirement of the shell in the thermal runaway stage, and the pressure-bearing shell is provided with a blast venting opening communicated with the shared pipeline. The heat exchange device is located at the top of the large-capacity battery, the inner cavity of the heat exchange device serves as an insulation heat exchange medium accommodating cavity; the polarity terminals of the single batteries penetrate through the heat exchange device, and part of the structure of the polarity terminals is located in the heat exchange device and directly contacts with the insulation heat exchange medium; the other part of the structure of the polarity terminals is located outside the heat exchange device and serves as an electric connection part.

2. The large capacity battery assembly of claim 1, wherein: The thickness of the plastic shell is h, and h is less than h0, wherein h0 is the shell thickness of a traditional single battery with a plastic shell.

3. The large capacity battery assembly of claim 1, wherein: The plastic shell is enclosed by an upper cover plate, a cylinder and a lower cover plate; at least one of the upper cover plate, the cylinder and the lower cover plate is provided with a sub-pipe section, and the inner cavity of the sub-pipe section is communicated with the inner cavity of the shell; the corresponding sub-pipe sections of adjacent single batteries are sealingly connected to form a shared pipeline.

4. The large capacity battery assembly of claim 3, wherein: The sub-pipe section is integrally arranged on the lower cover plate; the lower cover plate and the sub-pipe section are provided with first openings communicated with each other; and the two ends of the sub-pipe section are closed ends.

5. The large capacity battery assembly of claim 4, wherein: The two ends of the sub-pipe section are defined as a first closed end and a second closed end respectively; a first connecting pipe is arranged on the end face of the first closed end, and a first blind hole extending in the axial direction of the first sub-pipe section is arranged on the second closed end; the first blind hole is used for inserting the first connecting pipe on the lower cover plate of another single battery and is connected through a hot melting mode.

6. The large capacity battery assembly of claim 5, wherein: The outer pipe wall section of the sub-pipe section is rectangular; and the outer pipe wall section of the first connecting pipe is circular.

7. The large capacity battery assembly of claim 6, wherein: The sub-pipe section is two, and each sub-pipe section extends in the width direction of the lower cover plate; and the two sub-pipe sections are arranged in the length direction of the lower cover plate.

8. The high capacity battery assembly of any one of claims 3 to 7, wherein: The sub-pipe section is integrally arranged on the upper cover plate; the upper cover plate and the sub-pipe section are provided with second openings communicated with each other; and the two ends of the sub-pipe section are closed ends.

9. The large capacity battery assembly of claim 8, wherein: The two ends of the sub-pipe section are defined as a third closed end and a fourth closed end respectively; a second connecting pipe is arranged on the end face of the third closed end, and a second blind hole extending in the axial direction of the sub-pipe section is arranged on the fourth closed end; the second blind hole is used for inserting the second connecting pipe on the upper cover plate of another single battery and is connected through a hot melting mode.

10. The high capacity battery assembly of any one of claims 3 to 7, wherein: At least one of the upper cover plate, the cylinder and the lower cover plate is provided with a blast sub-pipe section, the blast sub-pipe section covers the blast part of the single battery, the corresponding blast sub-pipe sections of adjacent single batteries are sealingly connected to form a blast manifold, and the thermal runaway flue gas is discharged from the blast manifold after breaking through the blast part.

11. The large capacity battery assembly of claim 1, wherein: The heat exchange device comprises a plurality of heat exchange sleeves corresponding to the polarity terminals one by one; each heat exchange sleeve is sleeved on the periphery of the corresponding polarity terminal, and an annular cavity is formed between the inner side wall of the heat exchange sleeve and the side wall of the polarity terminal, which serves as a heat exchange medium flow cavity; the electrical connection part of the polarity terminal extends out of the heat exchange sleeve; and the top open end and the bottom open end of the heat exchange sleeve are sealed with the side wall of the polarity terminal; The heat exchange sleeves are in communication with each other, and a heat exchange channel is formed on the top of the large-capacity battery.

12. The high capacity battery assembly of claim 1, wherein: The heat exchange device comprises two heat exchange pipes; n through holes are formed on each heat exchange pipe; the n through holes are arranged along the x direction and correspond to the polarity terminals on the same side of the n single batteries one by one; each through hole extends along the z direction and penetrates the heat exchange pipe; the inner cavity of the heat exchange pipe serves as a heat exchange medium flow cavity; The two heat exchange pipes are respectively fixed on the polarity terminals on different sides of the n single batteries, each polarity terminal is inserted into the corresponding through hole, and in the z direction, the electrical connection part of the polarity terminal extends out of the through hole; the side wall of the polarity terminal is sealed with the hole wall of the corresponding through hole.

13. The high capacity battery assembly of claim 1, wherein: The material of the pressure-bearing shell is iron, steel or stainless steel.

14. The high capacity battery assembly of claim 1, wherein: At least one liquid storage bin is further included, and a third sub-pipe section is arranged on the bottom plate and / or the top plate of the liquid storage bin; the third sub-pipe section is sealingly connected with the corresponding sub-pipe section on the adjacent single battery.

15. The high capacity battery assembly of claim 1, wherein: Insulating sealing adhesive layers are arranged between each single battery and between each single battery and the pressure-bearing shell; the heat exchange device is located in the insulating sealing adhesive layers.

16. The high capacity battery assembly of claim 1, wherein: An avoiding hole is formed on the top plate of the pressure-bearing shell corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the avoiding hole; the top plate region of the pressure-bearing shell corresponding to the avoiding hole is fixedly sealed with the single battery shell.

17. The large capacity battery assembly of claim 16, wherein: An insulating sealing adhesive layer is arranged on the top plate of the pressure-bearing shell, and the heat exchange device is located in the insulating sealing adhesive layer.

18. The high capacity battery assembly of claim 1, wherein: A permeation prevention film is arranged between the large-capacity battery and the pressure-bearing shell, for preventing the electrolyte inside the large-capacity battery from permeating outward.

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