Battery assembly

Abstract

The utility model belongs to the field of batteries, particularly relates to a battery assembly, and solves the technical problems that the existing plastic shell battery is lower in mechanical strength and poor in safety during thermal runaway and the existing metal aluminum shell battery is high in thermal runaway risk. The battery assembly comprises a pressure-bearing shell and a battery unit positioned in the pressure-bearing shell; the battery unit comprises a sealing shell and n electrode assemblies positioned in the sealing shell; the sealing shell is a plastic shell; the strength of the pressure-bearing shell meets the strength requirement for the shell in the thermal runaway stage, and a second explosion venting part is arranged on the pressure-bearing shell. A first explosion venting part is arranged on the sealing shell, an explosion venting channel is arranged between the pressure-bearing shell and the first explosion venting part of the sealing shell, and the explosion venting channel is communicated with the second explosion venting part. According to the utility model, the explosion venting channel is arranged between the two shells in a matched manner, so that the safety and the reliability of the battery assembly are remarkably improved while the advantages of the plastic shell are reserved.

Description

Technical Field

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

[0002] Currently, the common battery casings on the market are made of plastic and aluminum.

[0003] Compared to aluminum casings, plastic casings are lighter, making batteries more portable. Furthermore, plastic is relatively inexpensive and its manufacturing process is simpler, requiring no complex processing equipment or technology. This effectively reduces battery manufacturing costs, increases production efficiency, and provides a cost advantage for large-scale production.

[0004] However, batteries with plastic casings also have some problems:

[0005] Firstly, the plastic casing has low mechanical strength and is easily deformed or broken when dropped, squeezed, or vibrated, leading to internal short circuits or electrolyte leakage in the battery.

[0006] Secondly, the plastic casing has poor thermal conductivity, which hinders the dissipation of heat generated during charging and discharging. This can easily lead to increased internal battery temperature, accelerating battery aging and reducing battery life and performance. The heat dissipation problem may become even more pronounced under high-power charging and discharging or prolonged use.

[0007] Due to the aforementioned issues, plastic casings have gradually been replaced by aluminum casings. Batteries with aluminum casings are widely used because of their advantages such as high mechanical strength and good heat dissipation.

[0008] However, with the continued growth in market demand, the energy density of batteries is expected to increase continuously for the same size. This means that the battery needs to accommodate more active materials and withstand more intense electrochemical reactions, which in turn requires higher casing strength.

[0009] However, the reality is far from optimistic, as the strength of the casing has not kept pace with the times. Taking a certain cell manufacturer as an example, the casing dimensions of its 280Ah and 314Ah cells are almost identical. The direct consequence of this mismatch is a sharp increase in the risk of thermal runaway, posing a significant safety hazard. Summary of the Invention

[0010] The purpose of this invention is to provide a battery assembly that overcomes the technical problems of existing plastic-cased batteries, such as low mechanical strength and poor safety during thermal runaway, as well as existing aluminum-cased batteries, such as high risk of thermal runaway.

[0011] The technical solution of this utility model is to provide a battery assembly, which is characterized by including a pressure-bearing housing and a battery cell located inside the pressure-bearing housing;

[0012] The battery cell includes a sealed housing and n electrode assemblies located inside the sealed housing, where n is an integer greater than 1; a polar terminal is provided on the first top plate of the sealed housing, and the polar terminal is electrically connected to the tabs of the electrode assemblies; the sealed housing is a plastic housing.

[0013] The strength of the aforementioned pressure-bearing shell meets the strength requirements for the shell during the thermal runaway stage, and a second explosion vent is provided on the pressure-bearing shell;

[0014] The aforementioned sealing housing is provided with a first explosion venting part, and an explosion venting channel is provided between the aforementioned pressure-bearing housing and the first explosion venting part of the sealing housing, and the aforementioned explosion venting channel is connected to the second explosion venting part.

[0015] This invention significantly improves the safety and reliability of the battery assembly by using a double-layer shell with an explosion venting channel between them, while retaining the advantages of a plastic shell.

[0016] The pressure-bearing shell can reinforce the plastic shell: the external pressure-bearing shell bears the mechanical load and thermal runaway pressure, making up for the plastic shell's weak impact / compression resistance, and avoiding the risk of short circuits caused by deformation or breakage of the internal plastic shell due to external forces.

[0017] Based on the venting channel, pressure can be released in a directional manner: In the early stages of thermal runaway, the runaway fumes can be discharged in an orderly manner through the venting channel between the pressure-bearing shell and the sealed shell, effectively preventing the fumes from spreading into the pressure-bearing shell and preventing the thermal runaway from worsening. In the middle and later stages of thermal runaway, even if the plastic sealed shell melts, the pressure-bearing shell can still form a robust barrier, isolating the high-temperature flames and harmful gases, preventing the further spread of thermal runaway, and greatly improving the safety of the battery after thermal runaway.

[0018] Meanwhile, in traditional battery design, the casing needs to simultaneously meet the requirements of sealing, mechanical strength and chemical stability, which limits the choice of materials; however, due to the insulation and sealing effect of the inner sealed casing, the pressure-bearing casing does not need to be in direct contact with the electrolyte, which greatly improves the freedom of material selection, and materials with lower cost or better mechanical properties can be selected.

[0019] Furthermore, the strength of the aforementioned sealed housing is P, where 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.

[0020] The strength of the aforementioned sealed casing only needs to meet the strength requirements of the casing during the formation stage and the normal charging and discharging stage of the battery; that is, the sealed casing is required to have a certain strength to ensure that it will not break during the formation stage and the normal charging and discharging stage of the battery cell, as the internal environment of the battery cell changes, such as temperature and pressure; compared with existing plastic-cased batteries, it has lower cost and lighter weight, thereby making the entire battery assembly also have lower cost and weight.

[0021] Furthermore, the thickness of the aforementioned sealed housing is h, where h is less than h0, and h0 is the thickness of the existing plastic-cased battery housing.

[0022] The sealing shell of this invention is a plastic shell with a relatively small thickness. While meeting the requirements for the shell during the formation and normal charge / discharge stages, this invention minimizes the thickness of the plastic shell. A thinner plastic shell has relatively better thermal conductivity, which helps dissipate the heat generated by the battery cell during charging and discharging more quickly to the external environment. This helps reduce the internal temperature of the battery cell and minimizes battery cell aging and performance degradation caused by high temperatures.

[0023] Reducing the thickness of the plastic casing decreases the volume of the battery cell, allowing more active material to be accommodated within the same cell size. This increases the energy density of the battery cell and, consequently, the energy density of the battery assembly. 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.

[0024] Furthermore, the sealed housing is provided with m partitions, which divide the inner cavity of the sealed housing into m+1 interconnected electrode assembly receiving cavities; each electrode assembly receiving cavity contains at least one set of the above-mentioned electrode assemblies; where m is an integer greater than or equal to 1.

[0025] At least one partition plate disposed within the sealed housing divides the inner cavity into at least two interconnected electrode assembly receiving cavities, each containing at least one set of electrode assemblies. When thermal runaway occurs in an electrode assembly within one of the receiving cavities, the partition plate can, to a certain extent, block heat transfer and heat diffusion, delaying the spread of thermal runaway to other electrode assembly receiving cavities.

[0026] Meanwhile, the presence of the separator also improves the overall stability of the battery cell structure. When subjected to external impact or internal pressure changes, the separator can play a supporting and buffering role, ensuring the normal positional relationship of the internal components, avoiding additional failures caused by electrode component displacement, and further improving the reliability of the battery cell operation.

[0027] In addition, the design of multiple electrode assembly cavities makes battery cell management more convenient. Each electrode assembly cavity can be regarded as a relatively independent unit, which facilitates the individual monitoring and management of the electrode assemblies in each cavity. It allows for the timely detection and handling of abnormalities in a single electrode assembly cavity without affecting the normal operation of other electrode assembly cavities. This helps to achieve a more refined battery cell management strategy and improve the overall performance and lifespan of the battery pack.

[0028] Furthermore, the first top plate of the aforementioned sealed housing includes m+1 sub-top plates; each sub-top plate corresponds to an electrode assembly receiving cavity and serves as the top plate of the corresponding electrode assembly receiving cavity;

[0029] Each sub-cover plate is equipped with positive and negative polarity terminals, which are electrically connected to the positive and negative terminals of the corresponding electrode assembly in the cavity.

[0030] The adjacent sub-cover plates are sealed together.

[0031] The first top plate is designed as a split structure, with each sub-top plate capable of independently sealing the corresponding electrode assembly cavity, which has significant advantages over a one-piece top plate:

[0032] Low processing difficulty, high precision and yield: The small size of the top cover plate makes it easier to operate and control the processing equipment, effectively improving processing precision and yield.

[0033] The requirements for the flatness of the top of the electrode assembly cavity are low: the integrated top plate requires the top of the cavity to have extremely high flatness, otherwise it will cause difficulties in installation and affect the overall performance. However, the sub-top plate corresponds to only one cavity. Even if there is unevenness at the top of each cavity, it can be compensated by adjusting the installation method or using a sealing gasket, without the need for high-precision flatness treatment.

[0034] High structural stability and long service life: In actual use, the sealing shell may expand or contract due to factors such as temperature and pressure. The integrated top plate, due to the limitations of its overall structure, suffers from uneven stress distribution, making it prone to deformation or even damage. The sub-top plates adopt a split design, allowing each sub-top plate to expand or contract independently, effectively reducing internal stress and improving the stability and service life of the sealing shell.

[0035] Furthermore, the sealed housing is provided with a liquid storage chamber, which stores free electrolyte and can flow to each electrode assembly.

[0036] This invention features a liquid storage chamber within a sealed housing, storing free electrolyte. The electrolyte possesses thermal conductivity; during battery cell operation, if the temperature rises, the stored free electrolyte rapidly absorbs heat through heat transfer, dispersing the absorbed heat throughout the housing and dissipating it through the sealed housing surface. This effectively prevents battery cell overheating, reduces the risk of thermal runaway, precisely regulates temperature, and maintains battery cell performance.

[0037] In addition, when the electrode assembly is working, the electrolyte consumption can be replenished in a timely manner to avoid local drying out, ensure stable internal reactions of the battery cell, and improve charge and discharge performance.

[0038] Furthermore, the battery assembly also includes a heat exchange component that exchanges heat with the polarity terminals.

[0039] As a crucial component connecting the internal and external parts of a battery cell, the polarity terminal allows current to flow in and out of the cell during charging and discharging. When heat is generated inside the battery cell, the polarity terminal provides a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery cell to the polarity terminal, and then dissipated from the terminal into the external environment.

[0040] Furthermore, since the polarity terminals are typically located at the positive and negative terminals of the battery cell, 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.

[0041] Furthermore, the heat exchange component is a heat transfer tube; each polarity terminal is provided with a through groove or through hole for installing the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole of the polarity terminal.

[0042] By utilizing the heat transfer tube on the polarity terminal, the heat generated inside the battery cell is conducted through the polarity terminal to the heat transfer tube, and then the heat transfer tube dissipates the heat, thereby achieving heat dissipation of the battery cell.

[0043] The design of through slots or holes allows for a larger contact area between the heat transfer tube and the polarity terminal. 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 polarity terminal maintain good contact at all times, guaranteeing the stability of heat exchange.

[0044] Furthermore, the aforementioned heat exchange component is a heat exchange device, which is disposed on the top of the battery cell; the polar terminal penetrates the heat exchange device, and at least a portion of the structure of the polar terminal is located in the inner cavity of the heat exchange device and is in direct contact with the heat exchange medium; another portion 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 with the heat exchange device.

[0045] 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 cell.

[0046] Furthermore, the second top plate of the aforementioned pressure-bearing housing has a clearance hole corresponding to the polarity terminal of the battery unit; the area of ​​the second top plate of the pressure-bearing housing corresponding to the clearance hole is fixedly sealed with the battery unit sealing housing; the polarity terminal of the battery unit extends out of the clearance hole.

[0047] Furthermore, an insulating sealant layer is laid on the second top plate of the pressure-bearing housing, and at least a portion of the heat exchange components are located within the insulating sealant layer. This insulating sealant layer not only prevents condensation but also improves the stability of the battery within the pressure-bearing housing.

[0048] Furthermore, an impermeable membrane is provided between the sealing shell and the pressure-bearing shell to prevent the electrolyte inside the sealing shell from seeping out.

[0049] The beneficial effects of this utility model are:

[0050] This utility model adopts a double-layer shell structure with an explosion relief channel in between. While fully leveraging the advantages of the plastic shell, it greatly improves the safety and reliability of the battery assembly, specifically in the following key aspects:

[0051] 1. High structural strength of the casing: The external pressure-bearing casing bears the mechanical load and thermal runaway pressure, effectively making up for the inherent deficiency of the plastic casing in terms of impact and pressure resistance. It also prevents the internal plastic casing from deforming or cracking due to external forces, thereby reducing the risk of short circuits from the root and laying a solid foundation for the stable operation of the battery.

[0052] 2. High safety performance after thermal runaway: In the initial stage of thermal runaway, the flue gas generated can be discharged in an orderly manner through the explosion venting channel between the pressure-bearing shell and the sealed shell. This effectively prevents the flue gas from spreading into the pressure-bearing shell and curbs the deterioration of the thermal runaway. Even in the middle and later stages of thermal runaway, when the plastic sealed shell melts due to high temperature, the pressure-bearing shell can still form a robust barrier, isolating the high-temperature flames and harmful gases, greatly improving the safety of the battery assembly after thermal runaway.

[0053] 3. Expanded material selection and economic advantages: In traditional battery design, the casing needs to simultaneously meet multiple requirements such as sealing, mechanical strength, and chemical stability, which greatly limits material selection. However, in this invention, because the inner sealed casing provides excellent insulation and sealing, the pressure-bearing casing does not need to directly contact the electrolyte, thus providing a wider range of material choices. Not only can lower-cost materials be used, effectively reducing production costs, but materials with superior mechanical properties can also be selected to further improve product performance. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the battery assembly of this utility model;

[0055] Figure 2 This is an exploded view of the battery assembly of this utility model;

[0056] Figure 3 This is a cross-sectional view of the battery assembly of this utility model;

[0057] Figure 4 This is a partial enlarged cross-sectional view of the battery assembly of this utility model;

[0058] Figure 5 This is an exploded structural diagram of another battery component of this utility model;

[0059] Figure 6 This is a schematic diagram of another battery assembly of the present invention;

[0060] Figure 7 This is an exploded structural diagram of the sealed shell of this utility model.

[0061] The attached figures are labeled as follows:

[0062] 1. Battery unit; 11. Sealed housing; 111. First top plate; 1111. Sub-top cover; 112. Barrel body; 113. Polar terminal; 114. Electrode assembly; 115. Separator; 116. Electrode assembly receiving cavity; 12. Weak part; 2. Pressure bearing housing; 21. Second top plate; 22. Clearance hole; 23. Second explosion vent; 3. Heat exchange component; 4. Explosion venting channel; 5. Groove. Detailed Implementation

[0063] 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.

[0064] 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.

[0065] In the description of this utility model, it should be noted that the terms "top," "bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] Example 1

[0067] like Figures 1 to 3 As shown, the battery assembly in this embodiment mainly consists of two parts: battery cell 1 and pressure-bearing housing 2.

[0068] The battery unit 1 includes a sealed housing 11 and 12 electrode assemblies 114 arranged within the sealed housing 11. In other embodiments, the number of electrode assemblies 114 can be adjusted according to actual needs.

[0069] The sealed housing 11 serves as a cavity for containing the electrode assembly 114 and the electrolyte, providing a closed space for the electrode assembly 114 and the electrolyte, and has both sealing and insulation functions.

[0070] from Figure 2 As can be seen from the figure, the sealing shell 11 in this embodiment is a rectangular shell. For ease of description, the length direction of the sealing shell 11 can be defined as the x direction, the width of the sealing shell 11 as the y direction, and the height of the sealing shell 11 as the z direction.

[0071] The sealed housing 11 is composed of a barrel 112 (a rectangular box with one open end) and a first top plate 111; a polarized terminal 113 is provided on the first top plate 111, which is electrically connected to the tabs of the electrode assembly 114 located inside the sealed housing 11. Figure 2 Electrode assembly 114 is not shown in the image.

[0072] The sealing shell 11 is made of plastic and can be molded into the aforementioned barrel 112 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 during the molding process, making the battery barrel 112 more robust and with higher overall structural strength. Additionally, reinforcing ribs can be integrally molded onto the barrel 112, effectively increasing its resistance to bending, compression, and torsion.

[0073] In this embodiment, since both the first top plate 111 and the barrel 112 are made of plastic, a heat-sealing connection can be used. Heat-sealing ensures a continuous, uniform, and tight connection between the first top plate 111 and the barrel 112, resulting in extremely high stability. Compared to other sealing methods, it does not loosen or leak over time, maintaining excellent sealing performance at all times. External water, dust, and other impurities cannot enter the battery, effectively protecting the electrode assembly 114 and ensuring battery performance and lifespan. Furthermore, the heat-sealing process is simple, and the parameters are easy to control.

[0074] It should be noted that the plastic material selected in this utility model should have the following properties:

[0075] 1. It has sufficient strength to ensure the stability of the battery cell 1 structure;

[0076] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0077] 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 the battery unit 1 and the pressure-bearing shell 2 to prevent the electrolyte inside the battery unit 1 from seeping out.

[0078] Fourth, it exhibits good 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 or decompose due to high temperatures.

[0079] The plastic material used can be the material used in existing plastic casing batteries, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0080] Combination Figure 3 and Figure 4 The aforementioned battery unit 1 is installed inside the pressure-bearing housing 2. The sealing housing 11 is provided with a first explosion vent. An explosion venting channel 4 is provided between the pressure-bearing housing 2 and the first explosion vent. The pressure-bearing housing 2 is provided with a second explosion vent 23 corresponding to the explosion venting channel 4 (the second explosion vent 23 here can also be called an explosion-proof part, explosion-proof port, or explosion vent, etc., and is usually provided with a pressure relief valve or explosion venting membrane, etc.). When the battery unit 1 experiences thermal runaway, the thermal runaway flue gas breaks through the first explosion vent on the sealing housing 11, passes through the explosion venting channel 4, breaks through the second explosion vent 23, and exits the pressure-bearing housing 2.

[0081] In the initial stage of thermal runaway, the thermal runaway flue gas can be discharged in an orderly manner through the explosion relief channel 4, effectively preventing it from spreading to the pressure-bearing shell 2, thereby preventing further deterioration of the thermal runaway situation.

[0082] Specifically, a weak part 12 can be provided on the sealing shell 11 as a first explosion venting part, and a certain gap is left between the pressure-bearing shell 2 and the weak part 12, which is used as an explosion venting channel 4; the strength of the weak part 12 is less than the strength of the rest of the sealing shell 11.

[0083] from Figure 3 and Figure 4 As can be seen from the figure, in this embodiment, a weak part 12 is provided on the first top plate 111 of the sealing housing 11. The weak part 12 is located between the two polar terminals 113 and extends along the length direction of the sealing housing 11. A channel is provided on the second top plate 21 of the pressure-bearing housing 2. The channel covers the weak part 12 and forms a large cavity explosion relief channel 4 between the channel and the sealing housing 11.

[0084] The strength of the aforementioned pressure-bearing shell 2 needs to meet the strength requirements of the shell during the thermal runaway stage, that is, the pressure-bearing shell 2 needs to have good strength. This design not only enables the reinforced pressure-bearing shell 2 to effectively resist the high pressure impact during thermal runaway, greatly improving the overall safety of the battery module; especially in the middle and later stages of thermal runaway, the pressure-bearing shell 2 can form a solid thermal barrier. Even in the extreme case where the sealing shell 11 of the battery 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 module after thermal runaway.

[0085] Compared to other materials, the metal pressure-bearing casing 2 is more reliable in emergency situations such as thermal runaway. It can withstand greater impact and destructive forces, reducing the likelihood of accidents and protecting the safety of personnel and surrounding equipment. In this embodiment, the pressure-bearing casing 2 does not directly contact the electrolyte, so an iron, steel, or stainless steel casing can be used. Iron casings offer advantages in strength and cost, making them a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent. Steel casings offer relatively high strength, providing more reliable protection for the battery and are suitable for applications with high safety and structural strength requirements. Stainless steel casings not only possess good strength properties but also excellent corrosion resistance, making them ideal for battery applications facing humid or corrosive environments. This effectively extends battery life and ensures stable operation in complex environments.

[0086] from Figures 1 to 4 As can be seen from the diagram, in this embodiment, a clearance hole 22 can also be provided on the second top plate 21 of the pressure-bearing housing 2 corresponding to the polarity terminal 113 of each battery unit 1; the polarity terminal 113 of the battery unit 1 extends out of the corresponding clearance hole 22; the area of ​​the second top plate 21 of the pressure-bearing housing 2 corresponding to the clearance hole 22 is fixedly sealed with the sealing housing 11 of the battery unit 1. The area of ​​the second top plate 21 of the pressure-bearing housing 2 corresponding to the clearance hole 22 can be the area of ​​the second top plate 21 surrounding the clearance hole 22, or it can be the wall of the clearance hole 22.

[0087] In some other embodiments, such as Figure 5 and Figure 6 As shown, the second top plate 21 of the pressure-bearing housing 2 may not have an avoidance hole 22. The battery unit 1 is entirely located inside the pressure-bearing housing 2, but the electrical connectors used for connecting to external equipment need to extend out of the pressure-bearing housing 2.

[0088] To optimize the heat dissipation performance of the battery assembly, this embodiment further includes a heat exchange component 3 to exchange heat with the polarity terminal 113. The polarity terminal 113 is a crucial component connecting the battery's internal and external components; during charging and discharging, current flows through the polarity terminal 113 into and out of the battery. When heat is generated inside the battery, heat dissipation through the polarity terminal 113 provides a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery to the polarity terminal 113, and then dissipated from the polarity terminal 113 to the external environment. Furthermore, since the polarity terminal 113 is typically located at the positive and negative terminals of the battery, these areas are often where heat is concentrated during charging and discharging. By dissipating heat from the polarity terminal 113, the temperature of these critical components can be reduced more effectively.

[0089] The heat exchange component 3 can be a heat transfer tube; each polarity terminal 113 of the battery unit 1 is provided with a through groove or through hole for installing the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole of the polarity terminal 113 of the battery unit 1. By using the heat transfer tube on the polarity terminal 113, the heat generated inside the battery is conducted to the heat transfer tube through the polarity terminal 113, and then the heat transfer tube dissipates the heat to achieve heat dissipation of the battery.

[0090] The heat exchange component 3 can also be a heat exchange device, which is disposed on top of the battery cell 1. At least a portion of the structure of the polar terminal 113 is located inside the heat exchange device and is in direct contact with the heat exchange medium. Another portion of the structure of the polar terminal 113 is located outside the heat exchange device and serves as an electrical connection. By placing a portion of the structure of the polar terminal 113 directly inside the heat exchange medium flow cavity (the inner cavity of the heat exchange device), the polar terminal 113 is in direct contact with the heat exchange medium, thereby achieving heat exchange of the polar terminal 113. This provides a shorter heat exchange path, and the heat exchange medium acts directly on the polar terminal 113, improving the utilization efficiency of the heat exchange medium and enhancing the heat exchange efficiency of the battery.

[0091] In this embodiment, an insulating sealant layer can also be laid on the second top plate 21 of the pressure-bearing shell 2 to wrap at least part of the structure of the heat exchange component 3 within the insulating sealant layer.

[0092] When there is a small gap between the sealing housing 11 and the pressure-bearing housing 2, this embodiment can also provide an insulating sealant layer between the sealing housing 11 and the pressure-bearing housing 2. When the polar terminal 113 is located inside the pressure-bearing housing 2, the heat exchange components 3 inside the pressure-bearing housing 2 are all located within the insulating sealant layer.

[0093] It should be noted that no insulating sealant layer is installed inside the explosion venting channel 4.

[0094] In this embodiment, the insulating sealant layer has at least the following advantages:

[0095] 1. Prevent condensation;

[0096] During long-term use, due to the temperature difference between the inside and outside of the heat exchange component 3, condensation will form on the surface. When the condensation accumulates to a certain amount, it may cause a short circuit. By laying an insulating sealant layer to wrap the heat exchange component 3, when condensation forms on the surface of the heat exchange component 3, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0097] II. Further improve the stability of battery cell 1 within the pressure-bearing housing 2;

[0098] The insulating sealant penetrates into the gaps between the sealing housing 11 and the pressure-bearing housing 2, which can further improve the stability of the battery cell 1 within the pressure-bearing housing 2.

[0099] Unlike Example 1, Example 2, in order to further reduce costs, ensures that the strength of the sealed housing 11 of the battery cell 1 meets certain requirements. In this example, the strength of the sealed housing 11 is not required to meet the strength requirements of the housing during the thermal runaway stage; it only needs to meet the strength requirements of the housing during the formation stage and the normal charge / discharge process of the battery (correspondingly, the strength of the weak point 12 provided thereon should also meet the strength requirements of the housing during the formation stage and the normal charge / discharge process of the battery). During the formation stage and the normal charge / discharge stage of the battery, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressure and heat are generated inside the battery. The housing needs to have sufficient strength to withstand these pressures and heat to ensure the smooth progress of the formation process and the normal use of the battery.

[0100] It can be assumed that the strength of the sealed housing 11 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.

[0101] Under the premise of meeting the above strength requirements, in this embodiment, the thickness of the sealing shell 11 is h, where h is less than h0, and h0 is the thickness of the plastic shell of a traditional plastic-cased battery; the thickness of the plastic shell of a traditional plastic-cased battery is typically 5-8 mm. In this embodiment, the thickness of the sealing shell 11 can be between 1-4 mm. By reducing the thickness of the sealing shell 11, better heat dissipation can be achieved, and the battery energy density can also be increased. In addition, reducing the thickness of the plastic shell means using less plastic material, which helps to save material costs and provides an economic advantage for large-scale production and application.

[0102] Example 3

[0103] The battery assembly in this embodiment differs from the previous embodiment in that a partition 115 is provided inside the sealed housing 11 to divide the inner cavity of the sealed housing 11 into multiple electrode assembly receiving cavities 116, so that multiple electrode assemblies 114 are located in different electrode assembly receiving cavities 116.

[0104] from Figure 7 As can be seen from the diagram, in this embodiment, 11 partitions 115 are provided inside the sealed housing 11, dividing the inner cavity of the sealed housing 11 into 12 electrode assembly receiving cavities 116, and an electrode assembly 114 is installed in each electrode assembly receiving cavity 116. Figure 7Electrode assembly 114 (not shown) is interconnected with adjacent electrode assembly receiving cavities 116. This interconnected design can be achieved by creating a perforated area on the partition 115 (e.g., through holes or slots). The size and shape of the perforated area can be adjusted according to actual needs to ensure smooth flow of electrolyte between the electrode assembly receiving cavities 116 without affecting the heat insulation and support performance of the partition 115. Alternatively, the size of the partition 115 in the z-direction can be reduced. While ensuring the basic function of the partition 115, a certain gap is left to allow the electrode assembly receiving cavities 116 to communicate with each other, ensuring smooth flow of electrolyte between the electrode assembly receiving cavities 116.

[0105] In some other embodiments, the number of partitions 115 can be adjusted according to the number of electrode assemblies 114. In addition, two or more electrode assemblies 114 can be installed in each electrode assembly receiving cavity 116.

[0106] The partition 115 is typically made of thermal insulation material. From a safety perspective, when thermal runaway occurs in an electrode assembly 114 within an electrode assembly housing 116, the partition 115 can, to a certain extent, block heat transfer and heat diffusion, delaying the spread of thermal runaway to other electrode assembly housings 116.

[0107] From a structural stability perspective, the separator 115 provides support and cushioning when the battery is subjected to external impacts or internal pressure changes. For example, when the battery is hit, the separator 115 can disperse the impact force, ensure the normal positional relationship of the components inside the battery, avoid additional failures caused by component displacement, and improve the overall structural stability of the battery.

[0108] In this embodiment, the separator 115 and the sealing shell 11 can be a single piece manufactured using injection molding, resulting in a seamless connection between the separator 115 and the sealing shell 11. This provides high overall structural strength, effectively reducing the risk of internal battery leakage due to assembly gaps and improving the battery's sealing performance and reliability. The integrated molding also reduces the number of parts, lowers assembly costs and complexity, and improves production efficiency, facilitating large-scale production. When the battery is subjected to vibration or impact, the integrated separator 115 and the shell work together to bear the force, better protecting the internal electrode assembly 114 and ensuring normal battery operation.

[0109] In some other embodiments, the separator 115 can also be a separate component, which facilitates replacement and maintenance. When an electrode assembly 114 or separator 115 in an electrode assembly receiving cavity 116 fails, it is not necessary to replace the entire battery casing; only the damaged separator 115 needs to be replaced, thus reducing maintenance costs and time costs.

[0110] from Figure 7As can be seen from the diagram, the first top plate 111 in this embodiment adopts a split design, consisting of 12 sub-top plates 1111. Each sub-top plate 1111 corresponds to an electrode assembly receiving cavity 116 and serves as the top plate of the corresponding electrode assembly receiving cavity 116. Each sub-top plate 1111 is provided with positive and negative polarity terminals 113, which are electrically connected to the positive and negative electrodes of the electrode assembly 114 in the corresponding electrode assembly receiving cavity 116. Adjacent sub-top plates 1111 are sealed together. In this embodiment, they can be sealed together by heat fusion, which not only ensures good sealing performance but also effectively improves the firmness of the connection.

[0111] In some other embodiments, an integral first top plate 111 may be used, and at least one pair of positive and negative polarity terminals may be provided on the first top plate.

[0112] The split design of this embodiment has at least the following advantages over the integrated design:

[0113] Superior sealing performance: Adjacent sub-cover plates 1111 are sealed together, allowing for individual sealing of each electrode assembly receiving cavity 116. Compared to the integrated first top plate 111, when a sealing problem occurs in a certain area, only the connection point of the corresponding sub-cover plate 1111 needs to be addressed, without requiring sealing maintenance of the entire top plate. This effectively reduces the difficulty and cost of sealing maintenance while improving overall sealing reliability.

[0114] Reduced processing difficulty and cost: In the design of the integrated first top plate 111, to achieve a tight fit with each electrode assembly receiving cavity 116, ensuring sealing effect and overall structural stability, the flatness requirements of the top of each cavity are almost stringent. Even the slightest unevenness at the top of a cavity can make the top plate installation difficult, thereby affecting sealing performance and overall structural strength. In contrast, in the split design, each sub-top cover 1111 corresponds to only one electrode assembly receiving cavity 116. Even if there is some unevenness at the top of a cavity, it can be compensated for by adjusting the installation angle and position of the sub-top cover 1111, or by using sealing gaskets, etc. Unlike the integrated top plate, there is no need to perform high-precision flatness treatment on the top of the entire cavity, which greatly reduces processing difficulty and cost.

[0115] Small size facilitates processing: The size of the sub-top cover 1111 is significantly smaller than that of the one-piece first top plate 111. During processing, the smaller size makes the operation and control of the processing equipment simpler, and the processing accuracy is easier to ensure.

[0116] Reducing overall structural internal stress: In actual use, the sealing shell 11 may expand or contract due to factors such as temperature changes and internal pressure fluctuations. The integrated first top plate 111 is constrained by the overall structure, resulting in extremely uneven internal stress distribution and a high risk of deformation or even damage. In contrast, the multiple sub-top plates 1111, designed as separate units, can each expand or contract independently. This effectively disperses and reduces the internal stress of the overall structure, significantly improving the stability and service life of the sealing shell 11 and reducing the risk of equipment damage due to structural problems.

[0117] Example 4

[0118] The battery assembly in this embodiment differs from the one described above in that it also includes a liquid storage chamber within the sealed housing 11, which stores free electrolyte.

[0119] The electrolyte has excellent thermal conductivity. During battery operation, especially during charging and discharging, the electrode assembly 114 generates heat due to electrochemical reactions. When the battery temperature rises, the electrolyte can quickly absorb this heat. Since the storage chamber and the electrode assembly housing 116 are interconnected, the electrolyte can flow freely throughout the entire battery cell 1, evenly dispersing the absorbed heat. Subsequently, the heat is dissipated to the surrounding environment through the surface of the casing (sealed casing 11 and pressure-bearing casing 2), effectively preventing the battery from overheating. This process precisely regulates the battery temperature and maintains stable battery performance. In addition, the electrolyte in the storage chamber can replenish the portion consumed by the electrode assembly 114 during operation, preventing localized drying and thus improving the battery's charging and discharging performance.

[0120] The specific structure of the liquid storage chamber is as follows: Figure 7 As shown, in this embodiment, multiple grooves 5 are provided on the inner wall of the sealed shell 11 barrel 112, and the inner cavity of the grooves 5 is used as a liquid storage cavity. Each groove 5 extends along the z-direction, and multiple grooves 5 are arranged along the x-direction.

[0121] In terms of the formation method, on the one hand, a portion of the structure in the thickness direction of the inner wall of the sealing housing 11 can be removed to form a groove; on the other hand, ribs can be added to the inner wall of the sealing housing 11, and a groove can be formed between adjacent ribs.

[0122] Multiple grooves extending along the z-direction form a liquid storage cavity, enabling rapid and uniform distribution of the electrolyte along the height direction. Since the electrode assembly 114 within each electrode assembly receiving cavity 116 is closely adjacent to its corresponding liquid storage cavity, this ensures that the electrode assembly 114 maintains sufficient contact with the electrolyte across the entire height range. During battery charging and discharging, this avoids reaction differences caused by uneven electrolyte distribution along the height, resulting in more consistent electrochemical reaction rates at different height positions of the electrode assembly 114, thereby improving the overall battery performance.

[0123] Furthermore, when the electrode assembly 114 generates heat due to electrochemical reactions, the electrolyte can rapidly absorb the heat. Since the grooves extend along the z-direction and are arranged along the x-direction, the electrolyte can form an effective heat transfer path within these grooves after absorbing heat.

[0124] Furthermore, the presence of grooves enhances the structural strength of the casing 112. When the battery is subjected to external pressure, vibration, or changes in internal pressure, these grooves can effectively disperse stress and resist bending and torsional deformation.

[0125] Meanwhile, the regularly spaced grooves on the barrel 112 simplify mold design. Compared to complex irregular structures, this regularly arranged groove mold is easier to manufacture, and the machining accuracy is easier to control during production. This not only helps reduce production costs but also improves production efficiency, meeting the needs of large-scale production.

[0126] In other embodiments, the number, position, and arrangement of the grooves can be adjusted according to actual needs. For example, to further optimize the electrolyte distribution and improve the structural strength, multiple grooves can be provided on all four side walls of the barrel 112. This allows for the storage of more electrolyte while enabling the electrolyte to permeate evenly into the electrode assembly 114 from more directions, greatly improving the uniformity of electrolyte distribution and enhancing the ability of the sealed shell 11 to resist external forces in all directions.

[0127] Furthermore, the arrangement of the grooves on the barrel 112 can also be adjusted. In addition to the parallel arrangement mentioned above, the grooves can also be arranged in a spiral shape or in an interlaced grid pattern. This arrangement is like building a tight support network, which not only ensures the smooth flow of electrolyte but also significantly improves the overall structural strength of the shell and effectively copes with complex external force environments.

[0128] Furthermore, in this embodiment, multiple sets of grooves can be formed on the inner wall of the bottom plate of the barrel 112 as liquid storage chambers. The grooves on the bottom plate of the barrel 112 extend along the x-direction, and the multiple sets of grooves are arranged along the y-direction. From a heat dissipation perspective, the grooves on the bottom plate of the barrel 112 increase the contact area between the electrolyte and the sealed shell 11. After absorbing the heat generated by the electrode assembly 114, the heat can be transferred to the shell and dissipated more quickly. When the battery is under high load for a long time, the electrolyte in the grooves of the bottom plate of the barrel 112 can absorb heat in time and dissipate heat through the shell, preventing the battery temperature from becoming too high, thereby maintaining the stability of battery performance. In terms of structural strength, the grooves on the bottom plate of the barrel 112 cooperate with the structure of other parts of the shell to further enhance the overall pressure resistance of the battery. When the battery is squeezed from the bottom, the structure of the grooves can disperse the pressure, protect the electrode assembly 114 and other key components inside the battery, and reduce the risk of battery damage caused by external pressure.

Claims

1. A battery assembly, characterized in that: Includes a pressure-bearing housing and battery cells located within the pressure-bearing housing; The battery unit includes a sealed housing and n electrode assemblies located inside the sealed housing, where n is an integer greater than 1; a polar terminal is provided on the first top plate of the sealed housing, and the polar terminal is electrically connected to the electrode tabs of the electrode assemblies; the sealed housing is a plastic housing, and a first explosion vent is provided on the sealed housing; The strength of the pressure-bearing shell meets the strength requirements of the shell during the thermal runaway stage, and a second explosion vent is provided on the pressure-bearing shell; An explosion venting channel is provided between the pressure-bearing shell and the first explosion venting part of the sealing shell, and the explosion venting channel is connected to the second explosion venting part.

2. The battery assembly according to claim 1, characterized in that: The strength of the sealed housing is P, where 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.

3. The battery assembly according to claim 2, characterized in that: The thickness of the sealed housing is h, where h is less than h0, and h0 is the thickness of the existing plastic-cased battery housing.

4. The battery assembly according to any one of claims 1 to 3, characterized in that: The sealed housing is further provided with m partitions, which divide the inner cavity of the sealed housing into m+1 interconnected electrode assembly receiving cavities; each electrode assembly receiving cavity contains at least one set of the electrode assemblies; where m is an integer greater than or equal to 1.

5. The battery assembly according to claim 4, characterized in that: The first top plate of the sealed housing includes m+1 sub-top plates; each sub-top plate corresponds to an electrode assembly receiving cavity and serves as the top plate of the corresponding electrode assembly receiving cavity; Each sub-cover plate is equipped with positive and negative terminals, which are electrically connected to the positive and negative terminals of the corresponding electrode assembly in the cavity. The adjacent sub-cover plates are sealed together.

6. The battery assembly according to claim 1, characterized in that: The sealed housing is provided with a liquid storage chamber, which stores free electrolyte and can flow to each electrode assembly.

7. The battery assembly according to claim 1, characterized in that: It also includes heat exchange components that exchange heat with the polarity terminals.

8. The battery assembly according to claim 7, characterized in that: An avoidance hole is provided on the second top plate of the pressure-bearing housing corresponding to the polarity terminal of the battery unit; the area of ​​the second top plate of the pressure-bearing housing corresponding to the avoidance hole is fixedly sealed with the battery unit sealing housing; the polarity terminal of the battery unit extends out of the corresponding avoidance hole.

9. The battery assembly according to claim 8, characterized in that: An insulating sealant layer is laid on the second top plate of the pressure shell, and at least a portion of the structure of the heat exchange component is located within the insulating sealant layer.

10. The battery assembly according to claim 8, characterized in that: An impermeable membrane is provided between the sealed housing and the pressure-bearing housing to prevent the electrolyte inside the sealed housing from seeping out.

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