Large battery

Abstract

The utility model discloses a large battery. The large battery comprises a box body, n single batteries, 2n sealing washers and 2n compression nuts, an explosion venting opening is formed in the box body, and the box body comprises a barrel body and a first top plate; the n single batteries are arranged in the barrel body, and the first top plate is hermetically fixed at the open end of the top of the barrel body; the first top plate is provided with avoiding holes corresponding to the polar terminals of the single batteries; the polarity terminal of each single battery extends out of the corresponding avoiding hole; the 2n sealing washers are arranged on the polar terminals of the single batteries in a sleeving manner one by one; each compression nut is in threaded connection with the polar terminal of the single battery and corresponds to the compression nut, so that the sealing gasket is tightly pressed on the first top plate, the gap between the avoiding hole and the polar terminal of the single battery is sealed after the sealing gasket generates radial deformation, the sealing performance between the polar terminal and the box body is ensured, the risk of thermal runaway is reduced to the greatest extent, and the service life of the box body is prolonged. And safe and stable operation of the large battery is ensured.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a large battery. Background Technology

[0002] In lithium-ion batteries, the seal between the terminals and the casing is crucial. From the perspective of mitigating thermal runaway risks, when a lithium-ion battery experiences thermal runaway, the large amount of harmful fumes generated must be discharged through the vent along a predetermined path. If the seal is defective, the fumes are likely to leak from the gap between the terminals and the casing. This not only further damages the structural integrity of the battery itself, exacerbating the severity of thermal runaway, but also rapidly fills the surrounding environment with harmful fumes, posing a significant safety hazard to operators and surrounding facilities, and threatening life and property. Utility Model Content

[0003] The purpose of this invention is to provide a large battery, mainly to solve the sealing problem between the terminals and the casing.

[0004] This utility model provides a large battery, which is special in that it includes a box, n individual batteries, 2n sealing gaskets and 2n clamping nuts, where n is an integer greater than 1;

[0005] The enclosure is equipped with an explosion vent and includes a barrel and a first top plate. n individual batteries are arranged inside the barrel, and the first top plate is sealed and fixed to the open end of the top of the barrel. The first top plate has clearance holes corresponding to the polarity terminals of each individual battery. The polarity terminals of each individual battery extend out of the corresponding clearance holes.

[0006] 2n sealing gaskets are installed one by one on the polarity terminal of each individual cell;

[0007] Each clamping nut is threaded to the polarity terminal of the individual battery and, in turn, presses the sealing washer tightly against the first top plate, causing radial deformation to seal the gap between the clearance hole and the polarity terminal of the individual battery.

[0008] This invention specifically incorporates a sealing washer and a clamping nut on the polarity terminal. The clamping nut is threaded to the polarity terminal and applies downward pressure to the sealing washer, causing radial deformation and sealing the gap between the clearance hole and the individual battery polarity terminal, ensuring the seal between the polarity terminal and the clearance hole. Even when the battery is subjected to external impact, vibration, or thermal expansion and contraction of the casing due to temperature changes, it can effectively prevent gaps from appearing between the clearance hole and the individual battery polarity terminal, minimizing the risk of thermal runaway and ensuring the safe and stable operation of the large battery. Furthermore, the sealing washer and clamping nut have a simple structure for sealing the clearance hole and the individual battery polarity terminal, making them easy to assemble.

[0009] Furthermore, in order to ensure that thermal runaway flue gas can be discharged in an orderly manner from the explosion vent of the enclosure in the early stage of thermal runaway, and to slow down or even avoid more severe thermal runaway, an explosion venting channel is formed between the first top plate and the top of each individual battery cell, covering the explosion venting part of each individual battery cell, and the explosion venting channel is connected to the explosion vent.

[0010] Furthermore, a first insulating sealant layer is filled between each individual battery cell, between each individual battery cell and the first top plate, and between each individual battery cell and the casing. This first insulating sealant layer not only fills the gaps between each individual battery cell and the first top plate and the casing, preventing thermal runaway fumes from flowing through these gaps to the area between the clearance hole and the polarity terminal of the individual battery cell and causing impact, thus further ensuring safety, but also, based on the adhesive and sealing properties of the first insulating sealant layer, further enhances the stability of the individual batteries within the casing, preventing displacement of the individual batteries under vibration, impact, and other operating conditions, comprehensively improving the reliability and safety of the large battery.

[0011] Furthermore, the aforementioned large battery also includes 2n heat exchange sleeves;

[0012] It also includes 2n heat exchange sleeves;

[0013] Each heat exchange sleeve corresponds 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 part of the polarity terminal extends out of the heat exchange sleeve; and the open end at the top of the heat exchange sleeve is sealed to the side wall of the polarity terminal, and the open end at the bottom of the heat exchange sleeve is sealed to the clamping nut.

[0014] The heat exchange sleeves are interconnected, thus forming a heat exchange channel.

[0015] By adopting a direct heat exchange method, part of the polar terminal structure is placed directly inside the heat exchange medium flow chamber, allowing the polar terminal to directly contact the heat exchange medium and achieve 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.

[0016] 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.

[0017] Furthermore, to facilitate the assembly of the heat exchange sleeve and ensure the sealing between the open end of the heat exchange sleeve and the upper surface of the clamping nut, a sealing groove is provided on the upper surface of the clamping nut. The open end of the heat exchange sleeve is inserted into the sealing groove filled with sealant, thereby achieving a seal between the open end of the heat exchange sleeve and the clamping nut.

[0018] Furthermore, the polar terminal located inside the heat exchange sleeve is provided with a functional structure. This functional structure is used to increase the heat exchange area of ​​this part, which can further improve the heat exchange efficiency and ensure that the heat of the single cell can be quickly and effectively dissipated under complex operating conditions such as high load operation, thus maintaining the stable performance of the large battery.

[0019] Furthermore, the aforementioned first top plate includes a horizontal plate and vertical plates fixedly disposed around the horizontal plate, with the vertical plates sealed and fixed to the open end of the barrel; the space formed by the horizontal plate and the surrounding vertical plates is filled with a second insulating sealant layer, and at least a portion of the structure of each heat exchange sleeve is located within the second insulating sealant layer.

[0020] The second insulating sealant layer can prevent short circuits caused by condensation on the heat exchange sleeve. On the other hand, it can provide a secondary seal at the connection between the heat exchange sleeve and the polarity terminal. It can also provide a seal at the connection between the polarity terminal and the clearance hole, reinforcing the original sealing structure.

[0021] Furthermore, the casing of each individual battery 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.

[0022] The strength of the enclosure meets the strength requirements for the shell during the thermal runaway stage.

[0023] The housing of this utility model is a pressure-bearing housing, and its strength needs to meet the strength requirements of the shell during the thermal runaway stage; that is, the pressure-bearing housing is required to have good strength to ensure that during the thermal runaway stage, the pressure-bearing housing can form a solid barrier, effectively isolate high-temperature flames and harmful gases, prevent the spread of thermal runaway, and improve the safety of large batteries after thermal runaway.

[0024] Furthermore, the individual cells within the large battery of this invention can be considered semi-finished individual cells. Their casings are sealed plastic casings, serving as containment cavities for the electrode components and electrolyte, and providing a sealing function. Simultaneously, the strength of the sealed casing must meet the strength requirements of the formation stage and the normal charge / discharge stage of the battery; that is, the sealed casing must possess a certain strength to ensure that it will not crack during the formation stage and the normal charge / discharge stage, despite changes in the internal environment of the battery, such as temperature and pressure. Compared to existing finished individual cells, this semi-finished individual cell has a lower cost, thereby reducing the overall cost of the large battery.

[0025] 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 and the inner cavity of the shell are connected; the corresponding sub-tube segments in adjacent single cells are sealed and connected to form a shared channel.

[0026] Furthermore, the sub-pipe section is integrally installed on the upper cover plate, the cylinder, and the lower cover plate; interconnected openings are provided on the upper cover plate, the cylinder, the lower cover plate, and the sub-pipe section; both ends of the sub-pipe section are closed ends.

[0027] This invention uses a plastic shell 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 to the corresponding sub-tube segments of another single battery cell through heat fusion, forming a shared electrolyte channel. 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 channel during use.

[0028] 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.

[0029] A connecting pipe is provided on the end face of a closed end, and a blind hole extending axially along the sub-tube segment is opened at the other closed end; in adjacent single cells, the connecting pipe of one single cell is inserted into the blind hole of another single cell and sealed by heat fusion.

[0030] Before a single cell is unpacked, the sealed end ensures that the inside of the single cell is not affected by the external environment. When a large battery is constructed based on such a single cell, the connecting pipe of one single cell is inserted into the blind hole of another single cell and connected by heat fusion sealing to form a shared channel on the large battery. When the unpacking tool is inserted into the shared channel and the sealed end of each sub-tube segment is opened, the inner cavity of all single cells can be connected through the shared channel.

[0031] The beneficial effects of this utility model are:

[0032] This invention specifically incorporates a sealing washer and a clamping nut on the polarity terminal. The clamping nut is threaded to the polarity terminal and applies downward pressure to the sealing washer, causing radial deformation and sealing the gap between the clearance hole and the individual battery polarity terminal, ensuring the seal between the polarity terminal and the clearance hole. Even when the battery is subjected to external impact, vibration, or thermal expansion and contraction of the casing due to temperature changes, it can effectively prevent gaps from appearing between the clearance hole and the individual battery polarity terminal, minimizing the risk of thermal runaway and ensuring the safe and stable operation of the large battery. Furthermore, the sealing washer and clamping nut have a simple structure for sealing the clearance hole and the individual battery polarity terminal, making them easy to assemble. Attached Figure Description

[0033] Figure 1 These are schematic diagrams of the exploded structures of the large batteries in Examples 1 to 3;

[0034] Figure 2 These are cross-sectional views of the large batteries in Examples 1 to 3;

[0035] Figure 3 These are partial cross-sectional views of the large batteries in Examples 1 to 3;

[0036] Figure 4 Cross-sectional views of the large battery in Examples 4 and 5;

[0037] Figure 5 These are partial cross-sectional views of the large batteries in Examples 4 and 5;

[0038] Figure 6 This is a schematic diagram of the structure of a heat exchange sleeve in Examples 4 and 5;

[0039] Figure 7 This is a schematic diagram of another heat exchange sleeve in Examples 4 and 5;

[0040] Figure 8 This is a cross-sectional view of the large battery in Example 6;

[0041] Figure 9 This is a structural diagram of a single cell in Example 7;

[0042] Figure 10 This is a schematic diagram of the lower cover plate in Example 7;

[0043] Figure 11 This is a first sectional view of the lower cover plate in Embodiment 7;

[0044] Figure 12 This is a second sectional view of the lower cover plate in Embodiment 7;

[0045] Figure 13 This is a partial cross-sectional view of the connection between the various first sub-pipe segments in Example 7.

[0046] The attached figures are labeled as follows:

[0047] 1. Box body; 11. Barrel body; 12. First top plate; 121. Horizontal plate; 122. Vertical plate; 13. Clearance hole; 14. Sealing gasket; 15. Compression nut; 151. Sealing groove; 16. First sub-pipe section; 161. First connecting pipe; 162. First blind hole; 17. First opening; 18. First closed end; 19. Second closed end; 2. Single cell; 21. Polar terminal; 22. Cylinder body; 23. Top cover plate; 24. Lower cover plate; 3. First insulating sealant layer; 4. Heat exchange sleeve; 41. Hollow component; 42. Second annular sealing plate; 43. First through hole; 44. Liquid inlet pipe; 45. Liquid outlet pipe; 5. Annular groove; 6. Second insulating sealant layer; 7. Explosion vent; 8. Explosion vent channel. Detailed Implementation

[0048] 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.

[0049] 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.

[0050] 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.

[0051] This utility model discloses a large battery, including a housing, n individual batteries, 2n sealing gaskets and 2n clamping nuts, where n is an integer greater than 1;

[0052] The enclosure is equipped with an explosion vent;

[0053] A rectangular box is typically used. For ease of description, the length direction of the box is defined as the x-direction, the width direction as the y-direction, and the height direction as the z-direction.

[0054] This utility model does not specifically limit the structure of the box, but at least the following two structures can be adopted:

[0055] The first structure includes a first cylinder with open ends (i.e., the port parallel to the yz plane is an open end) and end plates fixed to the two open ends of the first cylinder (i.e., the end plates are parallel to the yz plane).

[0056] The second structure includes a second cylinder with open ends at the top and bottom (i.e., the port parallel to the xy plane is the open end) and a first top plate and a bottom plate respectively fixed to the open ends at the top and bottom of the second cylinder (i.e., the first top plate and the bottom plate are both parallel to the xy plane, and the first top plate or bottom plate can be an integral structure with the second cylinder).

[0057] The following example uses the second structure of the box body, in which the bottom plate and the second cylinder are integrated. The structure composed of the bottom plate and the second cylinder is called the barrel body.

[0058] n individual batteries are arranged in the body of the barrel along the x-direction. The first top plate is sealed and fixed to the open end of the top of the barrel. The first top plate has clearance holes for the polarity terminals of each individual battery. The polarity terminals of each individual battery extend out of the corresponding clearance holes.

[0059] 2n sealing gaskets are installed one by one on the polarity terminal of each individual cell;

[0060] Each clamping nut is threaded to the polarity terminal of the individual cell and applies downward pressure to the corresponding sealing gasket, pressing the sealing gasket tightly against the first top plate and causing it to deform radially, thereby sealing the gap between the clearance hole and the polarity terminal of the individual cell.

[0061] It should be noted that:

[0062] 1. The polarity terminal of the above-mentioned single battery can be the single battery post. In order to avoid the single battery post height not meeting the set requirements, a post adapter can be connected to the single battery post, and the overall structure of the single battery post and the post adapter can be used as the single battery polarity terminal.

[0063] 2. The polarity terminals of each individual cell in the above-mentioned large battery need to extend out of the casing to facilitate electrical connection and help dissipate heat.

[0064] The large battery described in this utility model can also be of another battery structure form, in which the inner cavities of each individual battery are connected through a shared pipeline inside the box. Such a large battery includes at least multiple individual batteries and at least one shared pipeline. The shared pipeline mentioned here is the shared chamber described in CN220324596U, the hollow component described in CN117477063A, the first hollow component and the second hollow component described in CN117477186A, and the electrolyte sharing channel described in CN115275453A, which realizes electrolyte sharing and / or gas balance, reduces the differences between individual batteries inside the box, and improves the performance of the large battery.

[0065] However, regardless of the type of large battery mentioned above, the sealing between the polarity terminals and the enclosure is crucial. If this sealing fails, especially in the event of thermal runaway, the fumes will most likely leak through the gap between the polarity terminals and the clearance holes on the enclosure, rather than being vented through the designated explosion vents. This will not only further damage the structural integrity of the large battery and exacerbate the severity of thermal runaway, but will also rapidly fill the surrounding environment with harmful fumes, posing a significant safety hazard to operators and surrounding facilities, and threatening life and property.

[0066] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0067] Example 1

[0068] like Figure 1 As shown, the large battery in this embodiment includes a housing 1 and multiple individual battery cells 2 inside the housing 1.

[0069] In this embodiment, the box body 1 includes a barrel body 11 and a first top plate 12;

[0070] Multiple reinforcing ribs can be provided on the side wall of the barrel 11 to improve the strength of the barrel 11 and further improve the protection performance of the box 1 for each individual battery 2. At the same time, an explosion vent 7 is provided on the side wall of the barrel 11. This explosion vent can also be called an explosion-proof vent, explosion-proof part, explosion venting part, etc., and is used to allow thermal runaway fumes inside the box 1 to be discharged from here.

[0071] The first top plate 12 is used to seal and fix the top open end of the barrel 11, and a clearance hole 13 is provided on it corresponding to the polarity terminal 21 of each individual battery 2.

[0072] In this embodiment, the single battery cell 2 is a square-shell battery, and there are 12 of them. In other embodiments, the number and shape of the single battery cell 2 can be adjusted according to actual needs.

[0073] like Figure 1As shown, 12 individual batteries 2 are arranged in the barrel 11 along the x direction. The first top plate 12 is sealed and fixed to the open end of the top of the barrel 11. At the same time, the polarity terminals 21 of the 12 individual batteries 2 extend out of the corresponding clearance holes 13 on the first top plate 12.

[0074] In order for the polar terminal 21 to extend smoothly out of the corresponding clearance hole 13, the opening size of the clearance hole 13 must be slightly larger than the cross-sectional size of the corresponding polar terminal 21; in this way, after the polar terminal 21 extends out, there will be a certain gap between the two.

[0075] The existence of this gap may cause thermal runaway fumes to be unable to be vented from the explosion vent of housing 1 for treatment when thermal runaway occurs, but instead to be discharged through this gap. This will not only further damage the structural integrity of the large battery itself and exacerbate the degree of harm of thermal runaway, but will also cause the surrounding environment to be quickly filled with harmful fumes, posing a huge safety hazard to operators and surrounding facilities, and threatening life and property safety.

[0076] Combination Figure 2 and Figure 3 As can be seen, in this embodiment, a sealing washer 14 is fitted on each polarity terminal 21, and each clamping nut 15 is threadedly connected to the polarity terminal 21 of the individual battery and provides downward pressure to the corresponding sealing washer 14, so that the sealing washer 14 is pressed tightly on the first top plate 12, and after the radial deformation of the sealing washer 14, the gap between the clearance hole 13 and the polarity terminal 21 of the individual battery is sealed, thus ensuring the sealing between the polarity terminal 21 and the clearance hole 13. When thermal runaway occurs, the thermal runaway flue gas is led out from the explosion vent of the housing 1 for treatment, thereby minimizing the risk of thermal runaway and ensuring the safe and stable operation of the battery pack.

[0077] In this embodiment, the single cell 2 can also be referred to as a semi-finished single cell, which includes a sealed casing and an electrode assembly located inside the sealed casing.

[0078] The sealed housing serves as a containment cavity for the electrode assembly and electrolyte, providing a sealed space for these components. Simultaneously, the strength of the sealed housing needs to meet certain requirements. In this embodiment, the strength requirement for the housing during thermal runaway is not required; it only needs to meet the strength requirements during the formation stage and normal charge / discharge processes. During the formation and normal charge / discharge stages, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressures and heat are generated inside the battery. The sealed housing needs sufficient strength to withstand these pressures and heat to ensure the smooth progress of the formation process and the normal use of the battery. While meeting the aforementioned strength requirements, this embodiment uses a plastic housing as the sealed housing to reduce cost and battery weight.

[0079] We can assume that the strength of the sealed housing is P, P1≤P≤P2; where P1 is the strength requirement of the housing during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the housing during the thermal runaway stage.

[0080] In this embodiment, the thickness of the sealed casing is h, where h is less than h0, and h0 is the thickness of a conventional plastic-cased battery cell; the thickness of a conventional plastic-cased battery cell is typically 5-8 mm. In this embodiment, the thickness of the sealed casing can be between 1-4 mm. By reducing the thickness of the plastic casing, better heat dissipation can be achieved, while also increasing the battery's 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.

[0081] from Figure 2 As can be seen from the image, the sealing shell in this embodiment is formed by the cylinder 22, the upper cover plate 23, and the lower cover plate 24.

[0082] The lower cover plate 24 and the cylinder body 22 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 24 and the cylinder body 22, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder body 22, effectively increasing its resistance to bending, compression, and torsion.

[0083] In this embodiment, since both the upper cover plate 23 and the cylindrical body 22 are made of plastic, a heat-fusion sealing connection can be used. Heat-fusion sealing ensures a continuous, uniform, and tight connection between the upper cover plate 23 and the cylindrical body 22, resulting in extremely high stability. Compared to other sealing methods, it will 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 good 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.

[0084] It should be noted that the plastic material selected in this utility model should have the following properties:

[0085] First, it must have sufficient strength to ensure the stability of the battery structure;

[0086] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0087] 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; in addition, a seepage-proof membrane can be provided between each semi-finished single cell and the casing 1 to prevent the electrolyte inside the semi-finished single cell from seeping out.

[0088] 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.

[0089] The plastic material used can be the material used in existing plastic casing semi-finished single-cell batteries, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0090] The semi-finished single cell is installed inside the housing 1. The strength of housing 1 needs to meet the strength requirements of the casing during the thermal runaway stage; that is, the housing needs to have good strength to ensure that during the thermal runaway stage, the housing can form a solid thermal barrier. Even in the extreme case of the sealed casing melting, it can effectively isolate high-temperature flames and harmful gases, prevent the spread of thermal runaway, and improve the safety of the large battery after thermal runaway.

[0091] Compared to other materials, the metal casing 1 is more reliable in emergency situations such as thermal runaway. It can withstand greater impact and destructive forces, reducing the likelihood of accidents and protecting the safety of personnel and surrounding equipment. In this embodiment, the casing 1 does not directly contact the electrolyte, so an iron, steel, or stainless steel casing can be used. An iron casing 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 casing 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 casing not only possesses good strength properties but also excellent corrosion resistance, making it perform exceptionally well in battery applications that may face humid or corrosive environments. This effectively extends battery life and ensures stable operation in complex environments.

[0092] Example 2

[0093] See Figure 2 and Figure 3This embodiment is another type of large battery. Unlike embodiment 1, this embodiment, based on embodiment 1, forms a venting channel 8 between the first top plate 12 and the top of each individual battery 2, covering the venting part of each individual battery. The venting channel 8 is connected to the venting port 7. The purpose of setting the venting channel 8 is to ensure that, in the early stage of thermal runaway, the thermal runaway smoke from the individual battery can be discharged to the venting port of the housing 1 in a sufficient space and in an orderly manner, and to open the venting port in time to slow down or even avoid the occurrence of more violent thermal runaway events.

[0094] Example 3

[0095] See Figure 2 and Figure 3 This embodiment is another type of large battery. The difference is that, based on embodiment 2, this embodiment has a first insulating sealant layer 3 between the first top plate 12 and each individual battery 2 (specifically, between the lower surface of the first top plate and the top surface of the individual battery, excluding the explosion relief channel), between the barrel 11 and each individual battery 2 (between the side wall of the barrel and the side wall of each individual battery, and between the bottom surface of the barrel and the bottom surface of each individual battery), and between each individual battery 2.

[0096] In this embodiment, the first insulating sealant layer 3 has at least the following advantages:

[0097] 1. Further improve the sealing performance between the clearance hole 13 and the corresponding polarity terminal 21;

[0098] Specifically, the insulating sealant liquid constituting the first insulating sealant layer 3 penetrates into the tiny gap between the clearance hole 13 and the corresponding polarity terminal 21, thereby further sealing the gap.

[0099] II. Further improve the stability of each individual battery cell 2 within the housing 11;

[0100] The insulating sealant penetrates into the gaps between each individual battery cell 2 and between each individual battery cell 2 and the casing 11. Based on its adhesive and sealing properties, it can further improve the stability of each individual battery cell 2 within the casing 1.

[0101] Example 4

[0102] This embodiment is another type of large battery. Unlike the above embodiments, this embodiment adds a heat exchange sleeve 4 to optimize the heat dissipation effect of this type of large battery.

[0103] like Figure 4 and 5 As shown, this embodiment includes 24 heat exchange sleeves 4, which are respectively mounted on the periphery of 24 polar terminals 21.

[0104] The structure of heat exchange sleeve 4 is as follows Figure 6 As shown, it includes a hollow component 41 and a second annular sealing plate 42; two first through holes 43 are opened on the side wall of the hollow component 41 to penetrate its inner cavity, which serve as liquid inlet and liquid outlet respectively; the second annular sealing plate 42 is coaxial with the hollow component 41 and is sealed and fixed to the top of the hollow component 41.

[0105] Combination Figure 4 and Figure 5 As can be seen, the heat exchange sleeve 4 is sleeved around the polar terminal 21, forming an annular cavity between it and the side wall of the polar terminal 21. This annular cavity serves as a flow cavity for the heat exchange medium. The bottom end of the hollow component 41 is sealed and fixed with the compression nut. The inner ring surface of the second annular sealing plate 42 is sealed and fixed with the side wall of the polar terminal 21. At the same time, part of the structure of the polar terminal 21 extends out of the inner hole of the second annular sealing plate 42, serving as the electrical connection part of the polar terminal 21.

[0106] This utility model does not specifically limit the cross-sectional shape of the hollow component 41. Generally, the cross-sectional shape of the hollow component 41 is adapted to the cross-sectional shape of the polar terminal 21. For example, when the cross-section of the polar terminal 21 is circular, the cross-section of the corresponding hollow component 41 is annular; when the cross-section of the polar terminal 21 is square, the cross-section of the corresponding hollow component 41 is square annular.

[0107] In this embodiment, the hollow component 41 and the second annular sealing plate 42 are integrated. In some other embodiments, the hollow component 41 and the second annular sealing plate 42 can be separate components, but the processing is more complicated than in this embodiment.

[0108] The heat exchange sleeve 4 is made of rubber, which has a certain degree of elastic deformation. The bottom end of the hollow component 41 and the upper surface of the clamping nut are tightly fitted together to achieve a sealed fixation. To improve sealing reliability, insulating sealant can also be used for bonding. In this embodiment, to make the bonding between the bottom end of the hollow component and the clamping nut even tighter and to achieve a better sealing effect, such as... Figure 5 As shown, a sealing groove 151 is provided on the upper surface of the clamping nut 15, and the open end of the bottom of the heat exchange sleeve 4 is inserted into the sealing groove 151 filled with sealant.

[0109] A seal can be achieved between the inner ring surface of the second annular sealing plate 42 and the side wall of the polar terminal 21 through a tight fit. In some other embodiments, an annular sealing ring can be added between the inner ring surface of the second annular sealing plate 42 and the side wall of the polar terminal 21 to further improve the sealing performance between the two.

[0110] In this embodiment, the heat exchange sleeves 4 of each individual battery 2 located on the same side are connected to form two heat exchange channels on the top of the 12 individual batteries 2. 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.

[0111] In this embodiment, as Figure 7 As shown, the heat exchange sleeve 4 may also include an inlet pipe 44 and an outlet pipe 45; the inlet pipe 44 and the outlet pipe 45 are both fixed on the side wall of the hollow component 41 and are respectively connected to the inlet and the outlet.

[0112] The hollow component 41, the second annular sealing plate 42, the liquid inlet pipe 44 and the liquid outlet pipe 45 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.

[0113] It should be noted that the inlet pipe 44 of one heat exchanger 4 and the outlet pipe 45 of the other heat exchanger 4 can be connected to each other to achieve communication between the two adjacent heat exchanger 4. Alternatively, a connecting section can be used to connect the inlet pipe 44 of one heat exchanger 4 and the outlet pipe 45 of the other heat exchanger 4 to achieve communication between the two adjacent heat exchanger 4.

[0114] By adopting a direct heat exchange method, part of the structure of the polar terminal 21 is placed directly in the inner cavity of the heat exchange sleeve 4, so that the polar terminal 21 is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal 21. It has a shorter heat exchange path, and the heat exchange medium acts directly on the polar terminal 21, improving the utilization efficiency of the heat exchange medium and improving the heat exchange efficiency of the battery.

[0115] Example 5

[0116] Based on Example 4, this embodiment adds a functional structure to the polar terminal 21 of each individual battery cell 2 to increase the heat exchange area of ​​that part of the polar terminal 21; placing the part with the functional structure in the heat exchange medium flow cavity can further improve the heat exchange effect.

[0117] For the specific structure of polarity terminal 21, please refer to Figure 5 In this embodiment, at least two annular grooves 5 are formed on the sidewall of the polarity terminal 21. The two annular grooves 5 are arranged along the height direction of the polarity terminal 21, and each annular groove 5 extends circumferentially along the sidewall of the polarity terminal 21. Since the two annular grooves 5 can increase the heat exchange area of ​​this part of the polarity terminal 21, after placing this part in the heat exchange medium flow cavity, a better heat exchange effect can be obtained compared with the polarity terminal 21 with smooth sidewalls.

[0118] In some other embodiments, the number of annular grooves 5 and the dimensions such as groove width and groove depth can be adjusted as needed, specifically without affecting the conductivity of the polarity terminal 21.

[0119] In other embodiments, other structures can be processed on the polar terminal 21 to increase the heat exchange area of ​​the polar terminal 21. Such functional structures may include dot-shaped pits or protrusions on the sidewall of the polar terminal 21, and may also include through holes on the polar terminal 21 (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 5 structure in this embodiment is easier to process and has a lower processing cost.

[0120] Example 6

[0121] This embodiment is an improvement based on the above embodiments, such as... Figure 8 As shown, annular baffles are provided around the first top plate 12. That is, the first top plate 12 includes a horizontal plate 121 and vertical plates 122 fixedly arranged around the horizontal plate 121. The vertical plates 122 are sealed and fixed to the open end of the barrel 11 or around the first top plate 12 (usually by welding, sealant bonding, etc.). The space formed by the horizontal plate 121 and the surrounding vertical plates 122 is filled with a second insulating sealant layer 6. At least part of the structure of each heat exchange sleeve 4 is located in the second insulating sealant layer 6.

[0122] The battery pack of this utility model also includes electrical connectors. The electrical connectors include a first electrical connector for realizing electrical connection between each individual battery cell 2, and a second electrical connector for realizing electrical connection between battery packs or between the battery pack and an external load. The first electrical connector and part of the second electrical connector may also be located within the second insulating sealant layer 6. One end of the second electrical connector needs to extend out of the second insulating sealant layer 6 (not shown in the figure).

[0123] In this embodiment, the second insulating sealant layer 6 has at least the following advantages:

[0124] I. Further improve the sealing performance of all parts of the heat exchange device;

[0125] Specifically, the insulating sealant liquid constituting the second insulating sealant layer 6 penetrates into the gap between the heat exchange sleeve 4 and the side wall of the polar terminal 21, 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 4 and the side wall of the polar terminal 21).

[0126] II. Preventing condensation;

[0127] During prolonged use, condensation will form on the surface of the heat exchanger due to the temperature difference between the inside and outside of the heat exchanger. When the condensation accumulates to a certain amount, it may cause a short circuit. By laying a second insulating sealant layer 6 to completely wrap the heat exchanger, the condensation on the surface of the heat exchanger can be protected by the insulating sealant layer to prevent the battery from short-circuiting.

[0128] Example 7

[0129] This embodiment takes another battery structure as an example. Unlike the above embodiment, in the case 1, the inner cavities of each individual battery cell 2 are connected through at least one shared pipeline to achieve electrolyte sharing and / or gas communication, thereby reducing the differences between the individual battery cells 2 in the case 1 and improving the performance of the large battery.

[0130] In this embodiment, two electrolyte sharing channels are formed at the bottom of the large battery to achieve electrolyte sharing, and a gas sharing channel is formed at the top of the large battery to connect the gases in the internal cavities of each individual cell 2 and achieve balance.

[0131] In some other embodiments, only an electrolyte sharing channel or a gas sharing channel may be provided.

[0132] In some other embodiments, a shared channel may also be formed on the side of the large battery.

[0133] like Figure 9 As shown, in this embodiment, sub-tube segments are respectively provided on the upper cover plate 23 and the lower cover plate 24 of each individual battery. Connecting the sub-tube segments located on the lower cover plate 24 can form an electrolyte sharing channel, and connecting the sub-tube segments located on the upper cover plate 23 can form a gas sharing channel.

[0134] Taking the setting of sub-pipe segments on the lower cover plate 24 as an example, the shared channel structure will be described in detail.

[0135] In this embodiment, for ease of description, the sub-pipe segment on the lower cover plate 24 is defined as the first sub-pipe segment 16; the outer wall cross-section of the first sub-pipe segment 16 can be circular or rectangular, from... Figure 5 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 16 to serve as the supporting surface for the individual battery 2. Compared to the first sub-tube segment 16 with a circular outer wall cross-section, the rectangular cross-section provides a larger contact area on the plane. This feature makes the individual battery 2 with this type of lower cover plate 24 more stable during use, less prone to rolling or shaking. Furthermore, in the large battery, the connection between two adjacent individual batteries 2 via the first sub-tube segment 16 further enhances the stability of the individual batteries 2 within the encapsulation housing 1, making the entire large battery structure more robust and durable.

[0136] In this embodiment, the first sub-tube segment 16 extends along the width direction of the lower cover plate 24. From the perspective of improving the stability of the single-cell battery 2 during use, the size of the first sub-tube segment 16 in the width direction of the lower cover plate 24 can be increased to create a larger bottom surface area, as a larger bottom surface area results in greater stability when the single-cell battery 2 is placed. However, this introduces a new problem: as the size of the first sub-tube segment 16 increases, the size of the electrolyte sharing channel it forms also increases. A larger electrolyte sharing channel means more electrolyte is required, which undoubtedly leads to an increase in the cost of the single-cell battery 2 or the larger battery.

[0137] To resolve the contradiction of ensuring stable placement of the individual battery cell 2 while minimizing electrolyte usage, this embodiment employs a clever design. For example... Figure 9 and Figure 10 As shown, two narrow first sub-tube segments 16 are provided on the lower cover plate 24. These two first sub-tube segments 16 can simultaneously provide support, ensuring that the individual battery cells 2 can be placed stably. At the same time, due to their narrow width, compared to a design that increases the size of a single first sub-tube segment 16, the size of the electrolyte sharing channel formed is relatively small, 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.

[0138] from Figure 11 neutralization Figure 12 As can be seen, interconnected openings are formed in the lower cover plate 24 and the first sub-tube segment 16. In this embodiment, for ease of description, the openings in the lower cover plate 24 and the first sub-tube segment 16 are defined as the first opening 17; the shape of the first opening 17 is not limited in this embodiment, but the size of the first opening 17 needs to be ensured so that the electrolyte inside the single cell 2 can enter the first sub-tube segment 16 through the opening.

[0139] from Figure 12 As can be seen from the diagram, the two ends of the first sub-pipe segment 16 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 16, thereby effectively blocking the channels at both ends of the first sub-pipe segment 16 and forming a closed end. Alternatively, a sealing plate can be integrally molded inside the first sub-pipe segment 16, which can also achieve the purpose of sealing both ends of the first sub-pipe segment 16. Since this embodiment uses injection molding, the second method is preferred.

[0140] This sealing end mainly has the following two functions:

[0141] First, the function of preventing external substances from entering the interior of the single cell 2 before or during the construction of a large battery.

[0142] This sealed end plays a crucial role in the use of the single cell 2. Before and during the construction of the large battery, the single cell 2 is in an independent state. If the internal environment of the battery is affected by external factors, its performance will be impaired. For example, if air from the external environment enters the battery through the two ends of the first sub-tube section 16 and the first opening 17, 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 corrosion of the electrodes; the intrusion of other impurities will also damage the electrochemical system inside the battery.

[0143] In this embodiment, the two ends of the first sub-tube segment 16 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 2 through the openings at both ends of the first sub-tube segment 16.

[0144] 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.

[0145] Secondly, the sealed end can be opened by a packaging tool to form a shared electrolyte channel;

[0146] Once the large battery is assembled, specialized unpacking tools are needed to open the sealed ends of each first sub-tube, thereby forming a shared electrolyte channel.

[0147] 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 battery during the opening process, ensuring the integrity and functionality of the battery remain unaffected.

[0148] For ease of description, in this embodiment, the closed ends at both ends of the first sub-pipe segment 16 are defined as the first closed end 18 and the second closed end 19, respectively; from Figure 11 and Figure 12As can be seen from the figure, this embodiment adopts a structure of matching the connecting pipe and the blind hole to realize the connection of the two first sub-pipe segments 16. The connecting pipe set on the end face of the first closed end 18 is defined as the first connecting pipe 161, and the blind hole opened in the second closed end 19 is defined as the first blind hole 162. In two adjacent single cells, the first connecting pipe 161 of one single cell is inserted into the first blind hole 162 of the other single cell to achieve a sealed connection.

[0149] In some other embodiments, the first sub-tube segment 16 of one of the single cell batteries 2 can be abutted against the end face of the first sub-tube segment 16 of the other single cell battery 2, and the connection between the two can be achieved at the abutment location.

[0150] Combination Figure 13 As can be seen, in this embodiment, the outer wall cross-section of the first connecting pipe 161 is circular, and the corresponding first blind hole 162 that mates with it is also circular. Using a circular cross-section for the first connecting pipe 161 makes it easier to insert it into the first blind hole 162. 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 162 is more easily achieved. After the circular-section first connecting pipe 161 is connected within the first blind hole 162, its sealing performance is relatively good, effectively preventing electrolyte leakage.

[0151] like Figure 9 As shown, the sub-tube segment on the top cover plate is located between the two polarity terminals, and this sub-tube segment extends along the width direction of the top cover plate. For ease of description, this sub-tube segment is defined as the second sub-tube segment. Similar to the first sub-tube segment, a second, interconnecting opening needs to be made on the top cover plate and the second sub-tube segment. The shape of the second opening is not limited, but the size of the second opening needs to ensure that the gas inside the single cell can enter the second sub-tube segment through this opening. The second sub-tube segment has a similar structure to the first sub-tube segment, and its two ends are also closed ends. These closed ends have similar functions to the aforementioned closed ends. The only difference is that when a large battery is constructed, a special unpacking tool is needed to open the closed ends of each second sub-tube, thereby forming a gas-sharing pipeline.

[0152] It should be noted that:

[0153] To ensure that the internal cavity of each individual cell in the large battery is not affected by the external environment, the sub-tubes of the two outermost individual cells of the large battery need to be sealed with the internal cavity of the packaging box.

[0154] It is worth noting that, since the second sub-segment is located on the upper cover plate, unlike the first sub-segment located on the lower cover plate, its cross-sectional shape does not affect the stable placement of the individual battery cells. This characteristic gives the second sub-segment greater flexibility in shape design. In this embodiment, the shape of the second sub-segment is not strictly limited; it can be either circular or square. Furthermore, due to the limitations of the polarity terminals, this embodiment only has one second sub-segment on the upper cover plate.

Claims

1. A large battery, characterized in that: It includes a housing, n individual batteries, 2n sealing gaskets, and 2n clamping nuts, where n is an integer greater than 1; The enclosure is equipped with an explosion vent and includes a barrel and a first top plate. n individual batteries are arranged inside the barrel, and the first top plate is sealed and fixed to the open end of the top of the barrel. The first top plate has clearance holes corresponding to the polarity terminals of each individual battery. The polarity terminals of each individual battery extend out of the corresponding clearance holes. 2n sealing gaskets are installed one by one on the polarity terminal of each individual cell; Each clamping nut is threaded to the polarity terminal of the individual battery and applies downward pressure to the corresponding sealing gasket, pressing the sealing gasket tightly against the first top plate. This causes radial deformation, sealing the gap between the clearance hole and the polarity terminal of the individual battery.

2. The large battery according to claim 1, characterized in that: An explosion venting channel is formed between the first top plate and the top of each individual battery cell, covering the explosion venting part of each individual battery cell, and the explosion venting channel is connected to the explosion venting port.

3. The large battery according to claim 1 or 2, characterized in that: A first insulating sealant layer is filled between each individual battery cell, between each individual battery cell and the first top plate, and between each individual battery cell and the barrel body.

4. The large battery according to claim 3, characterized in that: It also includes 2n heat exchange sleeves; Each heat exchange sleeve corresponds 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 part of the polarity terminal extends out of the heat exchange sleeve; and the open end at the top of the heat exchange sleeve is sealed to the side wall of the polarity terminal, and the open end at the bottom of the heat exchange sleeve is sealed to the clamping nut. The heat exchange sleeves are interconnected, thus forming a heat exchange channel.

5. The large battery according to claim 4, characterized in that: A sealing groove is provided on the upper surface of the clamping nut, and the open end of the heat exchange sleeve is inserted into the sealing groove filled with sealant, thereby achieving a seal between the open end of the heat exchange sleeve and the clamping nut.

6. The large battery according to claim 5, characterized in that: The polarity terminal located inside the heat exchange sleeve has a functional structure, which is used to increase the heat exchange area of ​​that part.

7. The large battery according to claim 4, characterized in that: The first top plate includes a horizontal plate and vertical plates fixed around the horizontal plate. The vertical plates are sealed and fixed to the open end of the barrel. The space formed by the horizontal plate and the surrounding vertical plates is filled with a second insulating sealant layer, and at least part of the structure of each heat exchange sleeve is located within the second insulating sealant layer.

8. The large battery according to claim 1, characterized in that: Each individual battery cell has 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. The strength of the enclosure meets the strength requirements for the shell during the thermal runaway stage.

9. The large battery according to claim 8, characterized in that: 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 channel.

10. The large battery according to claim 9, characterized in that: The sub-tube section is integrally set on the upper cover plate, the cylinder and the lower cover plate; the upper cover plate, the cylinder, the lower cover plate and the sub-tube section have interconnected openings; both ends of the sub-tube section are closed ends; a connecting pipe is provided on the end face of one closed end, and a blind hole extending along the axial direction of the sub-tube section is provided on the other closed end; in adjacent single cells, the connecting pipe of one single cell is inserted into the blind hole of another single cell and sealed by heat fusion.

Images