A single cell and a battery pack

Abstract

The utility model belongs to the battery field, concretely is a kind of single battery and battery pack.Overcome the technical problem of poor installation stability of each single battery in the existing battery pack.Single battery, including shell, shell is enclosed by upper cover plate, cylinder and lower cover plate;At least one of upper cover plate, cylinder and lower cover plate is provided with connecting piece.Battery pack is constituted by multiple single batteries, and connecting piece at corresponding position in adjacent single battery is connected each other.The utility model sets up connecting piece on single battery shell, in battery pack, two adjacent single batteries can be connected by connecting piece, improve the stability of single battery in box, make the structure of whole battery pack more stable and durable.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a single cell battery and a battery pack. Background Technology

[0002] In a battery pack, individual cells are typically arranged close together. In everyday use, battery packs are inevitably subjected to vibrations or impacts. If the individual cells lack reliable connections, they will collide with each other inside the battery pack.

[0003] In the event of a collision, the most direct consequence is damage to the casing of a single battery cell, breaking its original good seal and allowing external moisture, dust, and other impurities to enter. Once inside the battery, these impurities gradually corrode key components such as the electrolyte and electrodes, disrupting the originally stable chemical reaction environment inside the battery and directly interfering with its electrical performance.

[0004] Meanwhile, collisions can also trigger more serious internal problems. Due to the vibration and impact, the electrode materials and separators inside a single battery cell are highly susceptible to displacement or damage. Key parameters that play a decisive role in the electrochemical reaction, such as the contact area and spacing between electrodes, change accordingly, causing a sharp decline in the efficiency of the electrochemical reaction and making the battery's charge and discharge performance extremely unstable. As a result, individual batteries cannot operate collaboratively as they would under normal conditions, ultimately affecting the stability and reliability of the entire battery pack, causing numerous inconveniences and even potential safety hazards for users. Summary of the Invention

[0005] The purpose of this invention is to provide a single battery cell and a battery pack that overcomes the technical problem of poor installation stability of individual battery cells within existing battery packs.

[0006] The first aspect of this utility model provides a single battery cell, characterized in that: it includes a housing, which 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 connector, which is used to connect with a connector at a corresponding position of an adjacent single battery cell.

[0007] This invention provides a connector on the casing of a single battery cell. In the battery pack, two adjacent single batteries can be connected by the connector, which improves the stability of the single battery cells in the casing and makes the entire battery pack structure more stable and durable.

[0008] Furthermore, the upper cover, cylinder, and lower cover are all made of plastic; the connector is integrally set on the lower cover, cylinder, and lower cover; the two ends of the connector are used to connect to the connector at the corresponding position of another single battery cell via thermal capacitance connection.

[0009] This invention places multiple individual batteries into a pressure-bearing enclosure. The strength of the pressure-bearing enclosure needs to meet the strength requirements of the casing during the thermal runaway stage; that is, the pressure-bearing enclosure is required to have good strength to ensure that during the thermal runaway stage, the pressure-bearing enclosure can form a solid barrier, effectively isolate high-temperature flames and harmful gases, prevent the spread of thermal runaway, and improve the safety of the battery pack after thermal runaway.

[0010] The aforementioned individual battery casing is made of plastic, which has a lower cost compared to existing aluminum-cased individual batteries, thus making the entire battery pack also have a lower cost.

[0011] Meanwhile, the integrated design makes the overall structure of the single battery cell more compact and stable. It can be molded in one piece through injection molding, reducing the complexity of the manufacturing process and simplifying the process. Furthermore, the two ends of the connector are used to connect to the corresponding connector of another single battery cell through hot-melt connection. Utilizing the high efficiency and stability of hot-melt connection, the connection process is simplified while ensuring connection strength. Even if there are certain dimensional deviations during the production process, a precise connection can be successfully achieved, which greatly improves production efficiency.

[0012] In addition, the material of the connector can be the same as that of the upper cover plate, the cylinder and the lower cover plate, which has a certain strength and flexibility. It can not only adapt to the slight deformation of the single cell during use, but also provide reliable tension and support for adjacent single cells when subjected to force.

[0013] Furthermore, one end of the connector is a closed end, and a blind hole extending axially is formed at the closed end; the blind hole is used for the insertion and connection of a connector at the corresponding position of another single cell.

[0014] By incorporating blind holes, the precision of the connection is ensured. During assembly, the two connectors fit tightly together, preventing misalignment and other connection defects. Furthermore, the insertion-type connection increases stability. Even when the battery pack is subjected to vibration, impact, or other external forces, the connectors are less likely to separate, further guaranteeing the overall structural stability of the battery pack and enabling it to better adapt to complex and changing operating environments. Additionally, the bottom of the blind hole also acts as an axial limit. When the inserted connector reaches the bottom of the blind hole, it reaches its maximum insertion depth and is thus confined axially, further preventing axial movement and adding another layer of protection to the stability of the battery pack structure.

[0015] Furthermore, the other end of the connector is a closed end, and a connecting pipe is provided at the closed end; the connecting pipe is used to insert into the blind hole at the corresponding position of another single battery cell and connect.

[0016] The connecting pipe works in conjunction with the aforementioned blind holes. During battery pack assembly, the connecting pipe is precisely inserted into the corresponding blind holes, which not only further improves the accuracy of the connection, but also greatly enhances the stability of the connector in all directions due to the tight fit between the connecting pipe and the blind holes, similar to a mortise and tenon structure. Even if the battery pack encounters extreme situations such as severe vibration or collision, the connection between the individual cells remains stable and reliable.

[0017] The design of this sealing end provides radial limiting support for the connector, making it less prone to deformation in the radial direction and ensuring the reliability of the connection in all aspects.

[0018] Furthermore, the connector is a hollow tube; both ends of the hollow tube are closed ends; the upper cover plate, the cylinder, the lower cover plate, and the connector located thereon have interconnected openings; under the action of external force, the two closed ends of the connector can be opened.

[0019] The connector of this utility model adopts a hollow tube structure, with both ends made as closed ends. At the same time, openings that are precisely connected to each other are made on the upper cover plate, the cylinder body, and the lower cover plate at positions corresponding to the connector.

[0020] On the one hand, when multiple individual cells are assembled, adjacent individual cells can be stably connected with the help of connectors, which greatly improves the stability of the individual cells in the box, and thus makes the structure of the entire battery pack exhibit better stability and durability.

[0021] On the other hand, although the connector is normally closed at both ends, it can be opened smoothly under specific external forces. Once the closed ends are opened, the internal cavities of all connectors are immediately connected, and further connected to the internal cavities of all individual battery cells. In this way, the differences that may exist between individual battery cells can be effectively improved, ensuring the consistency of each individual battery cell during charging and discharging, extending the overall service life, and improving the performance of the battery pack.

[0022] Furthermore, a blind hole extending axially is formed at one closed end of the connector; the blind hole is used for inserting and connecting a connector at the corresponding position of another single cell.

[0023] Furthermore, the other closed end of the connector is provided with a connecting tube; the connecting tube is used to insert into the blind hole at the corresponding position of another single cell and connect.

[0024] Furthermore, the connector is integrally mounted on the lower cover plate, and the connector has a rectangular cross-section; the first pair of connectors has a circular cross-section. Designing the connector's cross-section 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 first pair of connectors as circular makes it easier to insert them into the first blind hole, reducing resistance and friction during connection and improving connection smoothness. Additionally, the circular cross-section of the first pair of connectors also provides relatively better sealing performance, making it easier to achieve a tight fit with the first blind hole and prevent leakage.

[0025] Furthermore, there are two connectors, each extending along the width of the lower cover plate, and the two connectors are arranged along the length of the lower cover plate.

[0026] The two connectors allow for more stable placement of these individual battery cells during use, transportation, or storage. Furthermore, the design of the two connectors increases the overall strength and stability of the lower cover. The connectors 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.

[0027] 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 single battery cell, and the thermal runaway smoke breaks through the venting part and is discharged from the venting sub-pipe section.

[0028] Furthermore, the strength of the casing is P, where 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.

[0029] 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 battery pack.

[0030] Furthermore, the thickness of the casing is h, which is less than h0, where h0 is the casing thickness of a traditional single-cell battery with a plastic casing.

[0031] The upper cover, cylindrical body, and lower cover of this invention are made of plastic and are relatively thin. While meeting the requirements for the casing during the formation and normal charge / discharge stages, the thickness of the plastic casing (described here as being formed by the aforementioned upper cover, cylindrical body, and lower cover) is minimized. A thinner plastic casing has better thermal conductivity, which helps dissipate 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.

[0032] Reducing the thickness of the plastic casing decreases the volume of a single battery cell, allowing more active material to be accommodated within the same size cell, thus increasing the battery's energy density. Thinning the plastic casing also means using less plastic material, contributing to cost savings and providing an economic advantage for large-scale production and application.

[0033] Furthermore, in order to improve the heat dissipation performance of the battery, the top cover is provided with two polar terminals; each of the two polar terminals is provided with a through groove or through hole for installing heat transfer tubes.

[0034] This invention addresses the issue of heat exchange at the battery's polarity terminals, where heat is concentrated, thereby improving the battery's heat dissipation. Specifically, this invention provides through slots or holes on the polarity terminals for mounting heat transfer tubes. After constructing a battery pack based on this type of battery, the heat generated inside the battery is conducted through the heat transfer tubes on the polarity terminals to the heat transfer tubes, which then dissipate the heat, thus achieving heat dissipation for the battery.

[0035] 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.

[0036] Furthermore, since the polarity terminals are 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 terminals, the temperature of these critical components can be reduced more effectively.

[0037] The design of through slots or holes allows for a larger contact area between the heat transfer tube and the polarity terminal. Compared to planar contact, this embedded contact method enables more efficient heat transfer between the heat transfer tube and the polarity terminal, improving heat exchange efficiency. Furthermore, the shape of the through slots or holes provides a certain degree of locking and fixing for the heat transfer tube, preventing displacement or loosening during use. Especially in vibrating or shaking operating environments, this fixing method ensures that the heat transfer tube and the polarity terminal maintain good contact at all times, guaranteeing the stability of heat exchange.

[0038] Furthermore, the upper cover plate is provided with two polar terminals; each polar terminal is provided with a functional structure to increase the heat exchange area of ​​the polar terminals.

[0039] The second aspect of this utility model provides a battery pack, which is characterized in that it includes n individual batteries as described above, where n is an integer greater than 1; the connectors at corresponding positions in adjacent individual batteries are interconnected.

[0040] Furthermore, the aforementioned battery pack also includes a pressure-bearing housing; n individual cells are arranged inside the pressure-bearing housing;

[0041] The pressure tank has the strength required for the shell during thermal runaway, and it is equipped with a vent.

[0042] The outer casing of this battery pack is a pressure-bearing casing, and its strength must meet the requirements for the casing during thermal runaway. That is, the pressure-bearing casing must have good strength to ensure that during thermal runaway, it 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 battery pack after thermal runaway. Inside the pressure-bearing casing, adjacent individual cells are connected by connectors, providing reliable tension and support for adjacent individual cells, further improving the stability of the individual cells within the pressure-bearing casing, and making the entire battery pack structure more robust and durable.

[0043] Furthermore, the connector is a hollow tube; both ends of the hollow tube are closed ends;

[0044] Each individual battery cell has an interconnected opening on its top cover, cylinder, bottom cover, and connecting parts. Under external force, the two closed ends of each connecting part can be opened, allowing the inner cavities of each connecting part to connect and form a channel. The inner cavity of this channel is connected to the inner cavity of each individual battery cell to optimize the differences between individual batteries.

[0045] Furthermore, the pressure-bearing box is made of iron, steel, or stainless steel.

[0046] 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.

[0047] 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.

[0048] Stainless steel casings not only possess excellent strength properties but also outstanding corrosion resistance, making them perform exceptionally well in battery applications that may face humid or corrosive environments. This effectively extends battery life and ensures stable battery operation in complex environments.

[0049] Furthermore, the battery pack also includes a heat exchange component that exchanges heat with the polarity terminals.

[0050] 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.

[0051] Furthermore, since the polarity terminals are 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 terminals, the temperature of these critical components can be reduced more effectively.

[0052] Furthermore, the heat exchange component is a heat transfer tube; each individual cell has a through groove or through hole on its polarity terminal for installing the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole of each individual cell's polarity terminal.

[0053] By utilizing the heat transfer tube on the polarity terminal, the heat generated inside the battery is conducted through the polarity terminal to the heat transfer tube, and then the heat transfer tube dissipates the heat, thereby achieving heat dissipation for the battery.

[0054] Furthermore, the heat exchange component is a heat exchange device, which is located on top of each individual cell; the polar terminal penetrates the heat exchange device, and at least a part of the structure of the polar terminal is located inside the heat exchange device and is in direct contact with the heat exchange medium; another part of the structure of the polar terminal is located outside the heat exchange device and serves as an electrical connection part; the sidewall of the polar terminal is sealed to the heat exchange device.

[0055] By adopting a direct heat exchange method, part of the polar terminal structure is placed directly inside the heat exchange medium flow cavity (the inner cavity of the heat exchange device), so that the polar terminal is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal. Compared with the indirect heat exchange method, it has a shorter heat exchange path. 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.

[0056] Furthermore, the part of the polar terminal with a functional structure is located inside the heat exchange device to further optimize the heat exchange effect.

[0057] Furthermore, insulating sealant layers are provided between each individual cell and between each individual cell and the pressure tank; the heat exchange components are located within the insulating sealant layers.

[0058] The insulating sealant layer can prevent condensation and further improve the stability of individual cells within the pressure tank.

[0059] Furthermore, the top plate of the pressure tank has clearance holes corresponding to the polarity terminals of each individual battery; the area of ​​the top plate of the pressure tank corresponding to the clearance hole is fixedly sealed with the sealing shell of the individual battery; the polarity terminals of each individual battery extend out of the clearance hole.

[0060] Furthermore, an insulating sealant layer is laid on the top plate of the pressure tank, and the heat exchange components are located within the insulating sealant layer. By laying an insulating sealant layer only on the top plate of the pressure tank, the amount of insulating sealant used can be reduced, thereby lowering the cost of the battery pack.

[0061] Furthermore, an impermeable membrane is installed between each individual battery cell and the pressure tank to prevent the electrolyte inside each battery cell 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 corrosion of the pressure tank, effectively ensuring the safety and stability of the entire battery, extending its lifespan, and ensuring stable operation under various working conditions.

[0062] The capacity of a single battery cell is 280Ah or 314Ah, and n equals 13. By limiting the capacity and number of single batteries contained in the pressure tank, the safety performance of this battery pack can be optimized.

[0063] The beneficial effects of this utility model are:

[0064] 1. This utility model provides a connector on the casing of a single battery cell. In the battery pack, two adjacent single batteries can be connected by the connector, which improves the stability of the single battery cell in the pressure box and makes the structure of the entire battery pack more stable and durable.

[0065] 2. This utility model places multiple plastic-cased individual batteries into a pressure-bearing box. The strength of the pressure-bearing box needs to meet the strength requirements of the casing during the thermal runaway stage; that is, the pressure-bearing box needs to have good strength to ensure that during the thermal runaway stage, the pressure-bearing box can form a solid barrier, effectively isolate high-temperature flames and harmful gases, prevent the spread of thermal runaway, and improve the safety of the battery pack after thermal runaway.

[0066] Meanwhile, the cost of a single cell with a plastic casing is lower than that of an existing single cell with an aluminum casing, which in turn makes the overall battery pack less expensive.

[0067] In addition, the connector can also be made of plastic and integrated with the casing, making the overall structure of the single battery more compact and stable. It can be integrally molded through injection molding, reducing the complexity of the manufacturing process and simplifying the process. Furthermore, the two ends of the connector are used to connect to the corresponding connector of another single battery through hot-melt connection. Utilizing the high efficiency and stability of hot-melt connection, the connection process is simplified while ensuring connection strength. Even if there are certain dimensional deviations during the production process, a precise connection can be achieved smoothly, which greatly improves production efficiency. Attached Figure Description

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

[0069] Figure 2 This is a schematic diagram of the exploded structure of a single cell in Example 1;

[0070] Figure 3 This is a schematic diagram of another single-cell battery in Example 1;

[0071] Figure 4 This is a schematic diagram of the lower cover plate in Example 1;

[0072] Figure 5 This is a cross-sectional view of the lower cover plate in Example 1;

[0073] Figure 6 This is a cross-sectional view of another type of lower cover plate in Embodiment 1;

[0074] Figure 7 This is a cross-sectional view of the third type of lower cover plate in Example 1;

[0075] Figure 8 This is a schematic diagram of the structure of a single cell in Example 2;

[0076] Figure 9 This is a cross-sectional view of the upper cover plate in Example 2;

[0077] Figure 10 This is a schematic diagram of the battery pack structure in Example 6;

[0078] Figure 11 This is a schematic diagram of the exploded structure of the battery pack in Example 6. Figure 1 ;

[0079] Figure 12 This is a schematic diagram of the exploded structure of the battery pack in Example 6;

[0080] Figure 13 This is a schematic diagram of the battery pack structure in Example 7;

[0081] Figure 14 This is a schematic diagram of the exploded structure of the battery pack in Example 7;

[0082] Figure 15 This is a partial exploded view of the battery pack structure in Example 7;

[0083] Figure 16 This is a partial structural diagram of the battery pack in Example 8;

[0084] Figure 17 This is a schematic diagram of the heat exchange tubes in Example 8;

[0085] Figure 18 This is a cross-sectional view of the heat exchanger tubes in Example 8;

[0086] Figure 19 This is a partial exploded view of the battery pack in Example 9. Figure 1 ;

[0087] Figure 20 This is a partial exploded view of the battery pack in Example 9. Figure 2 ;

[0088] Figure 21 This is a schematic diagram of the structure of the first type of heat exchange sleeve in Example 9;

[0089] Figure 22 This is a schematic diagram of the structure of the second type of heat exchange sleeve in Example 9;

[0090] Figure 23 This is an exploded view of the battery pack in Example 11;

[0091] Figure 24 This is a schematic diagram of the battery pack structure in Example 11.

[0092] The attached figures are labeled as follows:

[0093] 1. Single cell; 2. Casing; 21. Cylinder; 22. Top cover; 23. Bottom cover; 3. Polar terminal; 31. Through slot; 32. Annular groove; 4. First connector; 41. Second closed end; 42. First closed end; 43. First connecting pipe; 44. First blind hole; 45. Opening; 5. Second connector; 51. Third closed end; 52. Fourth closed end; 53. Second connecting pipe; 54. Second blind hole; 6. Pressure bearing Box body; 61. Explosion vent; 62. Top plate of pressure box; 63. Clearance hole; 7. Bottom connecting rib; 8. Top connecting rib; 9. Heat transfer tube; 91. Liquid inlet end; 92. Liquid outlet end; 11. Heat exchange fittings; 110. Through hole; 111. Bottom port; 112. Top port; 12. Heat exchange sleeve; 311. Hollow component; 312. Annular sealing plate; 313. First through hole; 314. Liquid inlet pipe; 315. Liquid outlet pipe. Detailed Implementation

[0094] 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.

[0095] 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.

[0096] 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," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0097] Example 1

[0098] like Figure 1 The diagram shown is a structural schematic of a single battery cell 1 in this embodiment, including a housing 2 and an electrode assembly located inside the housing 2.

[0099] In this embodiment, to reduce cost and battery weight, a plastic casing is used as casing 2. For example... Figure 2 The diagram shown is an exploded view of the housing 2 of the single battery 1 in this embodiment. It is formed by a cylindrical body 21, an upper cover plate 22 and a lower cover plate 23. The cylindrical body 21, the upper cover plate 22 and the lower cover plate 23 are all made of plastic.

[0100] The lower cover plate 23 and the cylinder body 21 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 23 and the cylinder body 21, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder body 21, effectively increasing its resistance to bending, compression, and torsion.

[0101] In this embodiment, since both the upper cover plate 22 and the cylindrical body 21 are made of plastic, a heat-sealing connection can be used. Heat-sealing ensures a continuous, uniform, and tight connection between the upper cover plate 22 and the cylindrical body 21, resulting in extremely high stability. External water, dust, and other impurities cannot enter the battery, providing excellent protection for the electrode components and ensuring the battery's performance and lifespan. Furthermore, the heat-sealing process is simple, and the parameters are easy to control.

[0102] It should be noted that the plastic material selected in this utility model should have the following properties:

[0103] First, it must have sufficient strength to ensure the stability of the battery structure;

[0104] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0105] 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.

[0106] 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.

[0107] The plastic material used can be the material used in the existing plastic casing 2 single battery 1, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0108] This utility model has a connector on at least one of the upper cover plate 22, the cylinder 21 and the lower cover plate 23. By connecting the multiple individual batteries 1 with the corresponding connectors, the stability of the individual batteries 1 in the battery pack can be further improved, making the structure of the entire battery pack more compact and stable, effectively resisting interference under various working conditions, and ensuring the continuous, efficient and safe operation of the battery pack.

[0109] The aforementioned connector can be integrated with the upper cover plate 22, the cylinder 21, and the lower cover plate 23 as a single unit, formed using injection molding. Specifically, the connector can be a hollow tube, whose internal hollow structure helps reduce overall weight and provides a certain degree of cushioning. Furthermore, both ends of the hollow tube can be sealed, and through holes can be opened in both the hollow tube and the shell, providing more practical functions. For example, when the hollow tube is placed on the lower cover plate, its inner cavity can serve as an electrolyte storage chamber. During battery operation, if the temperature rises, the stored electrolyte can absorb heat through heat transfer, thus playing a certain role in temperature control. If the hollow tube is placed on the upper cover plate, its inner cavity can serve as a gas storage chamber, where gas generated inside the battery can be stored to prevent bulging.

[0110] Furthermore, when the connectors use hollow tubular components with closed ends, and interconnected through holes are formed in both the hollow tubular component and the casing (when the hollow tubular component is mounted on the lower cover plate, interconnected openings are formed in both the hollow tubular component and the lower cover plate; when the hollow tubular component is mounted on the upper cover plate, interconnected openings are formed in both the hollow tubular component and the upper cover plate; when the hollow tubular component is mounted on the cylinder, interconnected openings are formed in both the hollow tubular component and the cylinder), under external force, the two closed ends of the hollow tubular component can be opened, instantly connecting the inner cavities of all connectors, and further connecting them with the inner cavities of all individual battery cells. In this way, the potential differences between individual battery cells can be effectively mitigated, ensuring consistency of each individual battery cell during charging and discharging, extending the overall lifespan, and improving the performance of the battery pack.

[0111] The above-mentioned external force generally refers to using appropriate tools to apply a certain force to the closed end and the closed end, causing it to break and form an opening.

[0112] The connector can also be a solid column, which has higher strength and can withstand greater tensile and compressive forces.

[0113] This embodiment takes the example of setting a connector on the lower cover plate 23.

[0114] In this embodiment, for ease of description, the connector on the lower cover plate 23 is defined as the first connector 4; from Figure 1 , Figure 2 and Figure 3 As can be seen from the diagram, the first connector 4 in this embodiment is generally cylindrical, and its cross-sectional outer contour can be circular or rectangular. This embodiment preferably uses a rectangular cross-section, so that the bottom surface of the first connector 4 can serve as the supporting surface of the single battery 1. Compared with the first connector 4 with a circular cross-section, the rectangular cross-section has a larger contact area on the plane. This feature makes the single battery 1 with this type of lower cover 23 more stable during use and less prone to rolling or shaking.

[0115] In this embodiment, the first connector 4 extends along the width direction of the lower cover plate 23. From the perspective of improving the stability of the single battery 1 during use, the size of the first connector 4 in the width direction of the lower cover plate 23 can be increased. Alternatively, multiple first connectors 4 can be provided to form a larger bottom area, because the larger the bottom area, the more stable the single battery 1 will be when placed.

[0116] like Figure 3 and Figure 4 As shown, in this embodiment, two first connectors 4 are provided on the lower cover plate 23. These two first connectors 4 can simultaneously play a supporting role to ensure that the single battery 1 can be placed stably.

[0117] from Figure 5 As can be seen from the above, the first connector 4 in this embodiment is a hollow tube, and both ends of the first connector 4 are closed ends; for ease of description, in this embodiment, the closed ends of the first connector 4 are defined as the second closed end 41 and the first closed end 42, respectively; from Figure 5 As can be seen from the diagram, this embodiment adopts a structure combining a butt-fitting tube and a blind hole. In two adjacent first connectors 4, the butt-fitting tube of one first connector 4 is inserted into the blind hole of the other first connector 4 and fixed by heat fusion, thereby connecting the two first connectors 4. The butt-fitting tube provided on the end face of the second closed end 41 is defined as the first butt-fitting tube 43, and the blind hole opened in the first closed end 42 is defined as the first blind hole 44.

[0118] like Figure 6 The figure shows a cross-sectional view of the hollow tube and the lower cover plate with interconnected openings 45. When the connector with this structure is used, on the one hand, when multiple individual cells are assembled, the connector can be used to connect adjacent individual cells stably, which greatly improves the stability of the individual cells in the box, and thus makes the structure of the entire battery pack present better stability and durability.

[0119] On the other hand, although the connector is normally closed at both ends, it can be opened smoothly under specific external forces. Once the closed ends are opened, the internal cavities of all connectors are immediately connected, and further connected to the electrolyte areas of all individual cells. In this way, the differences that may exist between individual cells can be effectively improved, ensuring the consistency of each individual cell during charging and discharging, extending the overall service life, and improving the performance of the battery pack.

[0120] In some other embodiments, the first connector 4 may have only one closed end with a blind hole. In two adjacent first connectors 4, one end of one first connector 4 is inserted into the blind hole of the other first connector 4 and heat-fused together to achieve the connection of the two first connectors 4.

[0121] Combination Figure 3 and Figure 4 As can be seen, in this embodiment, the first pair of connecting pipes 43 has a circular cross-section, and the corresponding first blind hole 44 that mates with it is also a circular hole. Using a first pair of connecting pipes 43 with a circular cross-section makes it easier for the first pair of connecting pipes 43 to be inserted into the first blind hole 44. The circular shape has good guiding properties, which can reduce resistance and friction during connection and improve the smoothness of connection.

[0122] In some other embodiments, the first connector 4 may be a solid column, with the structure as follows: Figure 7 As shown, the connection of the two first connectors 4 can also be achieved by using a structure that combines a butt joint and a blind hole.

[0123] In some other embodiments, the first connector 4 of one single cell 1 can be abutted against the end face of the first connector 4 of another single cell 1 (i.e., blind holes and connecting pipes may not be provided on the end face of the closed end of the connector), and the connection between the two can be achieved by heat fusion at the abutment.

[0124] In some other embodiments, a metal housing and connectors may also be used, and adjacent connectors may be connected by welding, interference fit, or other methods.

[0125] Example 2

[0126] This embodiment also refers to a single-cell battery 1. Unlike the single-cell battery 1 in Embodiment 1, this embodiment also integrates a connector onto the upper cover plate 22, the structure of which is as follows: Figure 8 As shown.

[0127] As shown in the figure, in this embodiment, the upper cover plate 22 is provided with two terminals 3 of opposite polarity, and a connector is provided between the two terminals 3, which extends along the width direction of the upper cover plate 22. In this embodiment, for ease of description, the connector on the upper cover plate 22 is defined as the second connector 5.

[0128] It should be noted that the polarity terminal 3 mentioned here can be the terminal of a single cell 1. If the height of the terminal of the single cell 1 as the polarity terminal 3 does not meet the set requirements, a terminal adapter can be connected to the terminal of the single cell 1, and the overall structure of the single cell 1 terminal and the terminal adapter can be used as the polarity terminal 3.

[0129] It is worth noting that, since the second connector 5 is located on the upper cover plate 22, unlike the first connector 4 located on the lower cover plate 23, its cross-sectional shape does not affect the stable placement of the single battery cell 1. This characteristic gives the second connector 5 greater flexibility in shape design. In this embodiment, the shape of the second connector 5 is not strictly limited; it can be either circular or square. Furthermore, due to the limitation of the polarity terminal 3, this embodiment only provides one second connector 5 on the upper cover plate 22.

[0130] Similar to the first connector 4 in Embodiment 1, the two ends of the second connector 5 are closed ends, and the closed ends of the two ends of the second connector 5 are defined as the third closed end 51 and the fourth closed end 52, respectively.

[0131] like Figure 9 As shown, this embodiment also employs a structure combining a connecting pipe and a blind hole to connect the two second connectors 5. The connecting pipe disposed on the end face of the third closed end 51 is defined as the second connecting pipe 53, and the blind hole opened on the fourth closed end 52 is defined as the second blind hole 54. In this embodiment, the cross-section of the second connecting pipe 53 is circular, and the corresponding second blind hole 54 that mates with it is also circular. Using a second connecting pipe 53 with a circular cross-section makes it easier for the second connecting pipe 53 to be inserted into the second blind hole 54. The circular shape has good guiding properties, which can reduce resistance and friction during connection and improve the smoothness of connection.

[0132] Example 3

[0133] Unlike Embodiment 1, this embodiment may also have a venting sub-pipe section on at least one of the upper cover plate 22, the cylinder 21 and the lower cover plate 23. The venting sub-pipe section covers the venting part of the single battery cell, and the thermal runaway smoke breaks through the venting part and is discharged from the venting sub-pipe section, thereby improving safety performance.

[0134] Preferably, in this embodiment, the explosion vent of the single battery cell is located on the upper cover plate 22, and the explosion vent sub-tube section is disposed on the upper cover plate 22. The explosion vent can also be referred to as an explosion-proof port, explosion-proof section, etc.

[0135] Example 4

[0136] Unlike the embodiments described above, this embodiment aims to further reduce the cost of the battery pack. The strength of each individual battery casing 2 must meet certain requirements. However, this embodiment does not require the casing 2 to meet the strength requirements during the thermal runaway stage; it only needs to meet the strength requirements during the formation stage and the normal charge / discharge process. During the formation stage and the normal charge / discharge process, 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 2 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.

[0137] It can be assumed that the strength of the shell 2 is P, P1≤P≤P2; where P1 is the strength requirement of the shell 2 during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell 2 during the thermal runaway stage.

[0138] Under the premise of meeting the above strength requirements, in this embodiment, the thickness of the shell 2 (cylinder 21, upper cover plate 22, and lower cover plate 23) is h, where h is less than h0, and h0 is the thickness of a traditional single-cell plastic shell; the thickness of a traditional single-cell plastic shell 2 is typically 5-8 mm. In this embodiment, the thickness of the shell 2 can be between 1-4 mm. By reducing the thickness of the shell 2 of a traditional single-cell battery with a plastic shell 2, better heat dissipation can be achieved, and the battery energy density can also be increased. In addition, reducing the thickness of the plastic shell 2 means using less plastic material, which helps to save material costs and provides an economic advantage for large-scale production and application.

[0139] Example 5

[0140] This embodiment is also a single cell 1. Unlike the above embodiments, this embodiment has a through groove 31 or through hole on the polar terminal 3 for installing the heat transfer tube 9.

[0141] For details, please refer to [link / reference]. Figure 7 As shown in the figure, the polar terminal 3 in this embodiment is a cylindrical body, including a second end face, a first end face, and a side face (the second end face and the first end face are parallel to each other). The second end face is provided with an electrical connection area for connection with an external electrical connector, and the first end face is used for electrical connection with the electrode assembly inside the battery housing 2. A through groove 31 is provided on the side face (i.e., the opening of the through groove 31 is located on the side face), which serves as a mounting part for the heat transfer tube 9 to be installed.

[0142] In some other embodiments, a through hole may be provided on the side, that is, the opening of the through hole is located on the side.

[0143] In some other embodiments, the through groove 31 may also be formed on the second end face, that is, the opening of the through groove 31 is located on the second end face.

[0144] By creating through slots 31 and through holes on the side, compared to creating through slots 31 on the second end face, the heat transfer tube 9 has a larger contact area with the inner wall of the through slot 31, resulting in higher heat exchange efficiency. Furthermore, when the through slots 31 and through holes are located on the side, the entire area of ​​the second end face can be used as an electrical connection area. Two through slots 31 or through holes can also be provided on the side of the polarity terminal 3 simultaneously to increase the number of heat transfer tubes 9 and further improve heat exchange efficiency.

[0145] Furthermore, the through-slot structure 31 makes the heat transfer tube 9 easier to install compared to the through-hole structure. To further improve the ease of installation of the heat transfer tube 9, such as... Figure 7 As shown, in this embodiment, the openings of the through slots 31 on the two polarity terminals 3 face the same direction. This unidirectional orientation allows the heat transfer tube 9 to be installed along one direction, eliminating the need for complex adjustments and alignments by the operator in different directions. This significantly improves installation efficiency and accuracy, reducing the possibility of installation errors.

[0146] The cross-section of the through groove 31 is C-shaped or U-shaped. The opening width of the C-shaped through groove 31 is smaller than the widest part of the through groove 31. This design is conducive to the interference fit of the heat transfer tube 9 in the through groove 31. The arc formed at both ends of the C-shaped through groove 31 has natural tension, which is conducive to the tight fit of the heat transfer tube 9 in the through groove 31. The cross-section of the U-shaped through groove 31 is rectangular at the opening and semi-circular near the bottom of the groove. The size of the opening is slightly smaller than the widest part of the through groove 31 and also slightly smaller than the outer diameter of the heat transfer tube 9. This design is also conducive to the interference fit of the heat transfer tube 9 in the through groove 31 and to fixing the heat transfer tube 9 in the through groove 31. The interference fit is mainly in the bottom area of ​​the groove with a semi-circular cross-section.

[0147] The horizontal cross-section of the polarity terminal 3 can be circular, rectangular, or racetrack-shaped. Different shapes of polarity terminals 3 can be selected according to different battery models, or other different shapes. These will not be listed exhaustively in this embodiment.

[0148] In this embodiment, the first end face of the polar terminal 3 is close to the electrode assembly. Therefore, the first end face is closer to the internal electrode assembly of the battery, and the heat transfer pipe 9 should be positioned as close as possible to the first end face. This arrangement allows the heat transfer pipe 9 to be as close as possible to the inside of the battery for heat transfer.

[0149] Example 6

[0150] This embodiment is a battery pack comprising 12 individual battery cells 1 as described in the above embodiments. In other embodiments, the number of individual battery cells 1 can be adjusted according to actual needs.

[0151] Figure 10 , Figure 11 and Figure 12 Taking the single cell 1 in Example 2 as an example.

[0152] The first connector 4 of adjacent individual cells 1 is sealed and connected, forming two bottom connecting ribs 7 at the bottom of each individual cell 1; the second connector 5 of adjacent individual cells 1 is sealed and connected, forming a top connecting rib 8 at the top of each individual cell 1.

[0153] In other embodiments, when using the single cell 1 in Embodiment 3, the first connector 4 in adjacent single cells 1 is sealed and connected, and two bottom connecting ribs 7 are formed at the bottom of each single cell 1; the corresponding explosion relief sub-pipe sections in adjacent single cells 1 are sealed and connected, and an explosion relief manifold is formed at the top of each single cell 1, and the thermal runaway flue gas breaks through the explosion relief part and is discharged from the explosion relief manifold into the pressure box 6.

[0154] Furthermore, with the continued growth in market demand, there is a growing expectation for increasing battery energy density within the same size context. This means that the battery needs to accommodate more active materials and withstand more intense electrochemical reactions, which in turn places higher demands on the strength of the casing.

[0155] However, the actual situation is not optimistic; currently, the strength of the battery casing is not keeping pace with demand. For example, the casing dimensions of a certain battery manufacturer's 280Ah and 314Ah batteries are almost identical. This mismatch directly results in a sharp increase in the risk of thermal runaway.

[0156] Once these batteries are assembled into a battery pack, thermal runaway can occur. Due to insufficient shell strength and poor pressure resistance of the outer packaging, high-temperature and high-pressure gas can quickly break through the battery pack's protection and spread outwards, causing a serious safety accident.

[0157] In view of the above problems, this embodiment uses the outer packaging casing of the battery pack as the core pressure-bearing casing. Meanwhile, plastic material is used as the inner casing for each individual battery cell. This design not only effectively resists the high-pressure impact during thermal runaway thanks to the reinforced outer packaging casing, greatly improving the overall safety of the battery pack, but also reasonably reduces the production cost of the battery casing through the plastic casing, achieving a balance between safety and economy. Furthermore, an anti-seepage membrane can be installed between each individual battery cell and the pressure-bearing casing to prevent the electrolyte inside each individual battery cell from seeping out.

[0158] like Figure 10 and Figure 12As shown, in this embodiment, 12 individual battery cells 1 from the above embodiments are arranged inside a pressure-bearing housing 6. The pressure-bearing housing 6 is provided with an explosion vent 61. This explosion vent 61 can also be referred to as an explosion vent, explosion-proof vent, etc.

[0159] The strength of the pressure-bearing box 6 needs to meet the strength requirements of the shell 2 during the thermal runaway stage; that is, the pressure-bearing box 6 needs to have good strength to ensure that during the thermal runaway stage, the pressure-bearing box 6 can form a solid thermal barrier, and even in the extreme case where the shell 2 of the single cell 1 melts, it can effectively isolate high-temperature flames and harmful gases, prevent the spread of thermal runaway, and improve the safety of the battery pack after thermal runaway.

[0160] Compared to other materials, the metal pressure tank 6 is more reliable in emergency situations such as thermal runaway. It can withstand greater impact and destructive forces, reducing the likelihood of accidents and protecting personnel and surrounding equipment. In this embodiment, the pressure tank 6 does not directly contact the electrolyte, so an iron, steel, or stainless steel shell can be used. An iron shell offers advantages in strength and cost, making it a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent. A steel shell provides relatively high strength, offering more reliable protection for the battery and is suitable for applications with high safety and structural strength requirements. A stainless steel shell not only possesses good strength properties but also excellent corrosion resistance, making it perform well in battery applications that may face humid or corrosive environments. This effectively extends battery life and ensures stable operation in complex environments.

[0161] Example 7

[0162] This embodiment is also a battery pack. Unlike embodiment 6, this embodiment adds a heat exchange component to dissipate heat from the polarity terminal 3.

[0163] like Figure 13 and Figure 14 As shown in the figure, the heat exchange component in this embodiment is a heat transfer tube 9. The heat generated inside each individual cell 1 can be conducted to the heat transfer tube 9 through the polar terminal 3, and then the heat transfer tube 9 dissipates the heat, thereby achieving heat dissipation for each individual cell 1.

[0164] This embodiment uses the single cell 1 described in Embodiment 4, that is, through grooves 31 or through holes for installing heat transfer tubes 9 are provided on the two polar terminals 3.

[0165] from Figure 14As can be seen from the figure, the heat transfer tube 9 in this embodiment is U-shaped in general, including a first tube, a second tube and a connector; the first tube is fixed in the through groove 31 of the polar terminal 3 on one side of each individual cell 1; the second tube is fixed in the through groove 31 of the polar terminal 3 on the other side of each individual cell 1; the two ends of the connector are respectively connected to the ports of the first tube and the second tube on the same side.

[0166] In addition, the inlet end 91 and outlet end 92 of the heat transfer tube 9 can extend out of the pressure tank 6.

[0167] like Figure 15 As shown, when installing the heat transfer tube 9, the first tube, the second tube, and the connector can be pre-assembled into one piece. Then, the first tube and the second tube are inserted into the corresponding through slot 31 in the direction indicated by the arrow in the figure. The installation process is simple and convenient, which improves the installation efficiency.

[0168] The battery pack may also include electrical connections. Figure 13 and Figure 14 (Not shown in the image), the electrical connector includes a first electrical connector that enables electrical connection between individual battery cells 1, and a second electrical connector that enables electrical connection between battery packs or between a battery pack and an external load, wherein one end of the second electrical connector needs to extend out of the pressure-bearing housing 6.

[0169] Example 8

[0170] This embodiment is another type of battery pack, which differs from embodiment 7 in that it uses a different heat exchange component to exchange heat on the polarity terminal 3.

[0171] Figure 16 This is a partial structural diagram of the battery pack in this embodiment. The pressure tank is not shown in the diagram, and the single cell from Embodiment 1 is used as an example.

[0172] from Figure 16 As can be seen from the diagram, the heat exchange component in this embodiment includes two heat exchange tubes 11. The two heat exchange tubes 11 are respectively disposed on the polarity terminals 3 on different sides of each individual battery 1. In order to improve the safety performance of each individual battery 1, the heat exchange tubes 11 should not be energized. In this embodiment, heat exchange tubes 11 made of insulating material can be selected. In some other embodiments, the non-insulated heat exchange tubes 11 can be insulated, for example, by spraying insulating paint or wrapping with an insulating film. An insulating sealing gasket can also be added between the polarity terminal 3 and the heat exchange tube 11 to achieve the above purpose.

[0173] The structure of heat exchanger tube 11 is as follows Figure 17 and Figure 18As shown in the figure, the heat exchange tube 11 in this embodiment has 12 through holes 110. The 12 through holes 110 are arranged along the x-direction and correspond one-to-one with the polarity terminals 3 of each individual cell 1. In some other embodiments, the number of through holes 110 can be adjusted according to the number of individual cells 1 in each individual cell 1, and the arrangement of the through holes 110 can be adjusted according to the arrangement of the individual cells 1.

[0174] The aforementioned through hole 110 is a through hole 110 that penetrates the top plate and bottom plate of the heat exchange tube 11 and communicates with the inner cavity of the heat exchange tube 11. In this embodiment, after the heat exchange tube 11 is fixed to the top of the single cell 1, the extension direction of the through hole 110 is consistent with the height direction (i.e., the z direction) of the single cell 1. Therefore, it can be considered that the through hole 110 extends along the z direction.

[0175] In addition, when the heat exchange tube 11 is fixed to the top of the single cell 1, the electrical connection part of the polar terminal 3 of each single cell 1 passes through the bottom port 111 of the corresponding through hole 110 and extends out from the top port 112, and the polar terminal 3 is sealed with the hole wall of the through hole 110. The top port 112 here is the port near the electrical connection part of the polar terminal 3.

[0176] from Figure 16 As can be seen from the diagram, in this embodiment, the two heat exchange tubes 11 are respectively sleeved on the polarity terminals 3 on different sides of each individual battery cell 1 based on the through holes 110, and the two heat exchange tubes 11 are connected in series through a connector. In some other embodiments, the two heat exchange tubes 11 can also be connected in parallel.

[0177] In addition, in this embodiment, a functional structure can be provided on the polar terminal 3 to increase the heat exchange area of ​​the polar terminal 3 at that part. The part with the functional structure is located in the inner cavity of the heat exchange tube 11.

[0178] For details, please refer to [link / reference]. Figure 3 In this embodiment, at least two annular grooves 32 are formed on the sidewall of the polarity terminal 3. The two annular grooves 32 are arranged along the height direction of the polarity terminal 3, and each annular groove 32 extends circumferentially along the sidewall of the polarity terminal 3. The heat exchange area of ​​this part of the polarity terminal 3 can be increased by the two annular grooves 32. Placing the part with the functional structure in the heat exchange medium flow cavity can further improve the heat exchange effect.

[0179] In some other embodiments, the number of annular grooves 32, as well as the dimensions such as groove width and groove depth, can be adjusted as needed, provided that the conductivity of the polar terminal 3 is not affected.

[0180] In other embodiments, other structures can be processed on the polar terminal 3 to increase the heat exchange area of ​​the polar terminal 3. Such functional structures may include dot-shaped pits or protrusions on the sidewall of the polar terminal 3, and may also include through holes on the polar terminal 3 (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 32 structure in this embodiment is easier to process and has a lower processing cost.

[0181] This embodiment adopts a direct heat exchange method, in which part of the structure of the polar terminal 3 is placed directly in the inner cavity of the heat exchange tube 11, so that the polar terminal 3 is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal 3. Compared with the indirect heat exchange method (the heat exchange method of embodiment 6), it has a shorter heat exchange path. The heat exchange medium acts directly on the polar terminal 3, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0182] Example 9

[0183] This embodiment is another type of battery pack, which differs from embodiment 8 in that it uses a different heat exchange component to exchange heat on the polarity terminal 3.

[0184] Figure 19 and Figure 20 This is a partial exploded view of the battery pack in this embodiment. The pressure tank is not shown in the figure, and the single cell from Embodiment 2 is used as an example.

[0185] Combination Figure 19 and Figure 20 As can be seen, the heat exchange component in this embodiment includes 24 heat exchange sleeves 12, which are respectively set around the 24 polar terminals 3.

[0186] The structure of heat exchange sleeve 12 is as follows Figure 21 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.

[0187] Combination Figure 19 As can be seen, the heat exchange sleeve 12 is sleeved around the polar terminal 3, forming an annular cavity between it and the side wall of the polar terminal 3 (which may have an annular groove 32). 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 3 of the single cell 1. The inner ring surface of the annular sealing plate 312 is sealed and fixed to the side wall of the polar terminal 3. At the same time, part of the structure of the polar terminal 3 extends out of the inner hole of the annular sealing plate 312, serving as the electrical connection part of the polar terminal 3.

[0188] 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 3. For example, when the cross-section of the polar terminal 3 is circular, the cross-section of the corresponding hollow component 311 is annular; when the cross-section of the polar terminal 3 is square, the cross-section of the corresponding hollow component 311 is square annular.

[0189] 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.

[0190] In this embodiment, the heat exchange sleeve 12 is made of rubber, which has a certain elastic deformation. The bottom end of the hollow component 311 and the polar terminal 3 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 3 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 3 to further improve the sealing performance.

[0191] In some other embodiments, the bottom end of the heat exchange sleeve 12 can also be sealed and fixed to the upper cover plate 22 of the single cell 1 to ensure the seal between the hollow component 311 and the side wall of the polar terminal 3.

[0192] like Figure 19 As shown, in this embodiment, the heat exchange sleeves 12 on the same side of each individual battery 1 are connected to form two heat exchange channels on the top of the 12 individual batteries 1. 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.

[0193] In this embodiment, as Figure 22 As shown, the heat exchange sleeve 12 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.

[0194] 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.

[0195] It should be noted that the inlet pipe 314 of one heat exchanger 12 and the outlet pipe 315 of the other heat exchanger 12 can be connected to each other to achieve communication between the two adjacent heat exchanger 12. Alternatively, a connecting section can be used to connect the inlet pipe 314 of one heat exchanger 12 and the outlet pipe 315 of the other heat exchanger 12 to achieve communication between the two adjacent heat exchanger 12.

[0196] This embodiment can adopt the following two installation methods to fix the heat exchange component to each individual battery cell 1:

[0197] Installation Method 1:

[0198] like Figure 19 As shown, each heat exchange sleeve 12 is fitted onto the corresponding polarity terminal 3 one by one. During the fitting process, adjacent heat exchange sleeves 12 are connected, and the top and bottom open ends of the heat exchange sleeve 12 are sealed to the side wall of the polarity terminal 3; finally, two heat exchange channels are formed.

[0199] Installation Method Two:

[0200] like Figure 20 As shown, firstly, the heat exchange sleeves 12 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 1. During the installation process, each heat exchange sleeve 12 of each heat exchange channel is fitted onto the corresponding polarity terminal 3 to complete the sealing between the open top end and the open bottom end of the heat exchange sleeve 12 and the side wall of the polarity terminal 3; finally, two heat exchange channels are formed.

[0201] By adopting a direct heat exchange method, part of the structure of the polar terminal 3 is placed directly in the inner cavity of the heat exchange sleeve 12, so that the polar terminal 3 is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal 3. Compared with the indirect heat exchange method (the heat exchange method of Example 6), it has a shorter heat exchange path. The heat exchange medium acts directly on the polar terminal 3, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0202] Example 10

[0203] Based on Embodiments 7, 8 and 9, this embodiment adds an insulating and sealing layer between each individual battery cell 1 and between each individual battery cell 1 and the pressure-bearing housing 6.

[0204] The insulating sealant layer is mainly laid in the space between each individual cell 1 and the pressure tank 6. The heat exchange components inside the pressure tank 6 are all located within the insulating sealant layer. At the same time, the electrical connectors connected to the polar terminals 3 inside the pressure tank 6 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 cell 1, the insulating sealant liquid can also seep into the gap to form an insulating sealant layer.

[0205] In this embodiment, the insulating sealant layer has at least the following advantages:

[0206] 1. Prevent condensation;

[0207] During prolonged use, condensation will form on the surface of the heat exchange components due to the temperature difference between the inside and outside. 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 components, the condensation on the surface of the heat exchange components can be protected from short circuits.

[0208] II. Further improve the stability of each individual battery cell 1 within the pressure-bearing housing 6;

[0209] The insulating sealant penetrates into the gaps between individual cells 1 and between individual cells 1 and the pressure tank 6, which can further improve the stability of each individual cell 1 within the pressure tank 6.

[0210] Third, further improve the sealing performance of each part of the heat exchange components;

[0211] Specifically, the insulating sealant that forms the insulating sealant layer penetrates into the gap between the heat exchange sleeve 12 and the side wall of the polar terminal 3 or the gap between the through hole 110 and the side wall of the polar terminal 3, further sealing the gap radially (the insulating sealant cannot flow into the heat exchange medium flow cavity through the gap between the heat exchange sleeve 12 and the side wall of the polar terminal 3 or the gap between the through hole 110 and the side wall of the polar terminal 3).

[0212] Example 11

[0213] This embodiment is also a high-capacity battery, but it differs from embodiment 10 in that... Figure 23 and Figure 24 As shown, in this embodiment, clearance holes 63 are provided on the top plate 62 of the pressure-bearing box corresponding to the polarity terminals 3 of each individual battery 1; the polarity terminals 3 of each individual battery 1 extend out of the clearance holes 63; the area of ​​the top plate 62 of the pressure-bearing box corresponding to the clearance holes 63 is fixedly sealed to the housing 2 of the individual battery 1. The heat exchange component is fixed on the part where the polarity terminals 3 extend out of the clearance holes 63.

[0214] In this embodiment, an insulating sealant layer can be laid only on the top plate 62 of the pressure tank, and the heat exchange component is located inside the insulating sealant layer. When condensation occurs on the surface of the heat exchange component, the battery short circuit can also be prevented under the protection of the insulating sealant layer.

[0215] Compared to Example 10, this example can significantly reduce the amount of insulating sealant used, thereby reducing battery costs.

Claims

1. A single-cell battery, characterized in that: The device includes a housing, which 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 connector; the connector is used to connect with a connector at a corresponding position of an adjacent single cell.

2. The single-cell battery according to claim 1, characterized in that: The upper cover, cylinder, and lower cover are all made of plastic; the connector is integrally set on the lower cover, cylinder, and lower cover; the two ends of the connector are used to connect to the corresponding connector of another single battery cell via thermal capacitance connection.

3. The single-cell battery according to claim 2, characterized in that: One end of the connector is a closed end, and a blind hole extending axially is formed at the closed end; the blind hole is used for the insertion and connection of a connector at the corresponding position of another single cell.

4. The single-cell battery according to claim 3, characterized in that: The other end of the connector is a closed end, and a connecting pipe is provided on the closed end; the connecting pipe is used to insert into the blind hole at the corresponding position of another single cell and connect.

5. The single-cell battery according to claim 2, characterized in that: The connector is a hollow tube; both ends of the hollow tube are closed. The upper cover plate, the cylinder, the lower cover plate, and the connecting parts located thereon have interconnected openings; under the action of external force, the two closed ends of the connecting parts can be opened.

6. The single-cell battery according to claim 5, characterized in that: A blind hole extending axially is provided at one closed end of the connector; a connecting tube is provided at the other closed end of the connector; the connecting tube is used to insert into the blind hole at the corresponding position of another single cell and connect.

7. The single-cell battery according to claim 4, characterized in that: The connector is integrally mounted on the lower cover plate, and the cross-section of the connector is rectangular; the cross-section of the first pair of pipes is circular.

8. The single-cell battery according to claim 7, characterized in that: There are two connectors, each extending along the width of the lower cover plate, and the two connectors are arranged along the length of the lower cover plate.

9. The single-cell battery according to any one of claims 1 to 8, characterized in that: At least one of the upper cover plate, the cylinder and the lower cover plate is provided with a venting sub-pipe section, which covers the venting part of the single cell battery. Thermal runaway smoke breaks through the venting part and is discharged from the venting sub-pipe section.

10. The single-cell battery according to any one of claims 1 to 8, characterized in that: The strength of the casing is P, where 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.

11. The single-cell battery according to claim 10, characterized in that: The thickness of the casing is h, which is less than h0, where h0 is the casing thickness of a traditional single-cell battery with a plastic casing.

12. The single-cell battery according to any one of claims 1 to 8, characterized in that: The top cover plate has two polarized terminals; each polarized terminal has a through groove or through hole for installing heat transfer tubes.

13. The single-cell battery according to any one of claims 1 to 8, characterized in that: The top cover plate has two polarized terminals; each polarized terminal has a functional structure to increase the heat exchange area of ​​the polarized terminal.

14. A battery pack, characterized in that: It includes n single-cell batteries as described in any one of claims 1 to 13, where n is an integer greater than 1; The connectors at corresponding positions in adjacent individual cells are connected to each other.

15. The battery pack according to claim 14, characterized in that: It also includes a pressure tank; n individual cells are arranged inside the pressure tank; The pressure tank has the strength required for the shell during thermal runaway, and it is equipped with a vent.

16. The battery pack according to claim 14 or 15, characterized in that: The connector is a hollow tube; both ends of the hollow tube are closed. Each individual battery cell has an interconnected opening on its top cover, cylinder, bottom cover, and connecting parts. Under external force, the two closed ends of each connecting part can be opened, allowing the inner cavities of each connecting part to connect and form a channel, and the inner cavity of this channel is connected to the inner cavity of each individual battery cell.

17. The battery pack according to claim 15, characterized in that: The pressure-bearing box is made of iron, steel, or stainless steel.

18. The battery pack according to claim 15, characterized in that: It also includes heat exchange components that exchange heat with the polarity terminals.

19. The battery pack according to claim 18, characterized in that: The heat exchange component is a heat transfer tube; the heat transfer tube is fixed in the through slot or through hole of each individual cell polarity terminal.

20. The battery pack according to claim 18, characterized in that: The heat exchange component is a heat exchange device, which is located on top of each individual cell; the polar terminal penetrates the heat exchange device, and at least a part of the structure of the polar terminal is located inside the heat exchange device and is in direct contact with the heat exchange medium; another part of the structure of the polar terminal is located outside the heat exchange device and serves as an electrical connection part; the side wall of the polar terminal is sealed with the heat exchange device.

21. The battery pack according to claim 20, characterized in that: The part of the polar terminal with a functional structure is located inside the heat exchanger.

22. The battery pack according to claim 15, characterized in that: Insulating sealant layers are provided between each individual cell and between each individual cell and the pressure tank; the heat exchange components are located within the insulating sealant layers.

23. The battery pack according to claim 15, characterized in that: The top plate of the pressure tank has clearance holes corresponding to the polarity terminals of each individual battery; the area of ​​the top plate of the pressure tank corresponding to the clearance hole is fixedly sealed with the sealing shell of the individual battery; the polarity terminals of each individual battery extend out of the clearance hole.

24. The battery pack according to claim 23, characterized in that: An insulating sealant layer is laid on the top plate of the pressure tank, and the heat exchange components are located inside the insulating sealant layer.

25. The battery pack according to claim 15, characterized in that: An impermeable membrane is installed between each individual cell and the pressure tank to prevent the electrolyte inside each individual cell from seeping out.

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