Single battery, battery module and semi-finished single battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a single battery, a battery module and a semi-finished single battery. And the problem of high thermal runaway risk of the existing metal aluminum shell battery is solved. The single battery comprises a semi-finished single battery and a pressure-bearing shell; the semi-finished single battery comprises a sealing shell and an electrode assembly positioned in the sealing shell; the sealing shell is a plastic shell and has the strength P, and P is greater than or equal to P1 and less than or equal to P2; wherein P1 is the strength requirement of the formation stage and the normal charging and discharging stage of the battery on the shell; p2 is the strength requirement on the shell in the thermal runaway stage; the semi-finished single battery is mounted in the pressure-bearing shell, and a polarity terminal of the semi-finished single battery extends out of the pressure-bearing shell; wherein the strength of the pressure-bearing shell meets the requirement on the strength of the shell in a thermal runaway stage. The sealing shell on the inner layer of the single battery has certain strength, and compared with a single-layer shell in the prior art, the sealing shell is combined with the pressure-bearing shell on the outer layer, so that the strength is higher, and the safety performance is higher.

Description

Technical Field

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

[0002] Currently, the common casings for single-cell batteries 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, single-cell batteries with plastic casings also have certain problems:

[0005] Firstly, the mechanical strength of the plastic casing is relatively low. In order to make the casing have better protective performance, the plastic casing of existing single batteries is relatively thick, which increases the volume of the battery. The space inside the battery that can be used to store energy is relatively reduced, which in turn reduces the energy density of the battery.

[0006] Secondly, the thicker 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] The above problems become particularly prominent when it is used to construct battery modules.

[0008] Due to the aforementioned issues, plastic casings have gradually been replaced by aluminum casings. Aluminum-cased cells are widely used due to their advantages such as high mechanical strength and good heat dissipation.

[0009] 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.

[0010] 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. Utility Model Content

[0011] The purpose of this invention is to provide a single battery cell, a battery module, and a semi-finished single battery cell to overcome the technical problem of high thermal runaway risk in existing aluminum-cased batteries.

[0012] The first aspect of this utility model provides a single-cell battery, which is characterized in that it includes a semi-finished single-cell battery and a pressure-bearing casing.

[0013] The semi-finished single cell includes a sealed casing and an electrode assembly located inside the sealed casing; the sealed casing is a plastic casing, and the strength of the sealed 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.

[0014] The semi-finished single cell is installed inside the pressure-bearing housing, and the polarity terminal of the semi-finished single cell extends out of the pressure-bearing housing and is sealed to the pressure-bearing housing.

[0015] The strength of the pressure-bearing shell meets the strength requirements for the shell during the thermal runaway stage.

[0016] The inner shell of this utility model is a sealed shell made of plastic, which serves as a cavity for containing electrode components and electrolyte, and has a sealing function. At the same time, the strength of the sealed shell needs to meet the strength requirements of the shell during the formation stage and the normal charging and discharging stage of the battery; that is, the sealed shell is required to have a certain strength to ensure that the sealed shell will not break during the formation stage and the normal charging and discharging stage of the battery, as the internal environment of the battery changes, such as temperature and pressure.

[0017] The outer shell of this utility model is a pressure-bearing shell, and its strength needs to meet the strength requirements of the shell during the thermal runaway stage; that is, the pressure-bearing shell is required to have good strength to ensure that during the thermal runaway stage, the pressure-bearing shell can form a solid thermal barrier, effectively isolate high-temperature flames and harmful gases, and prevent the spread of thermal runaway.

[0018] The single-cell battery of this utility model adopts a double-layer shell. The inner sealed shell has a certain strength, and combined with the outer pressure-bearing shell, the double-layer shell has higher strength and higher safety performance compared with the single-layer shell in the prior art.

[0019] Furthermore, the thickness of the sealed housing is h, where h is less than h0, and h0 is the thickness of the existing single-cell plastic housing.

[0020] This invention features a sealed plastic casing with a relatively small thickness. While meeting the requirements for the casing during the formation and normal charge / discharge stages, the thickness of the plastic casing is minimized. A thinner plastic casing provides better thermal conductivity, allowing heat generated during charging and discharging to dissipate more quickly into the external environment. This helps reduce the internal temperature of the battery, minimizing battery aging and performance degradation caused by high temperatures.

[0021] Reducing the thickness of the plastic casing decreases the volume of a single battery cell, allowing more active material to be accommodated within the same cell size. This increases the battery's energy density and consequently, the energy density of high-capacity battery modules. 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.

[0022] Furthermore, the pressure-bearing shell is an iron shell, a steel shell, or a stainless steel shell.

[0023] Metal shells offer advantages in terms of strength and cost, making them a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent.

[0024] The steel casing has relatively high strength, providing more reliable protection for the battery and making it suitable for applications with high requirements for safety and structural strength.

[0025] Stainless steel casings not only possess excellent strength properties but also outstanding corrosion resistance, making them perform exceptionally well in battery applications that may face humid or corrosive environments. This effectively extends battery life and ensures stable battery operation in complex environments.

[0026] By offering a variety of metal casing options, this invention can better adapt to the usage requirements of lithium-ion batteries in different fields and under different working conditions, enabling individual cells and battery modules to achieve a more optimized balance in terms of safety, performance, and cost, thus providing strong support for the wider application of lithium-ion battery technology.

[0027] Furthermore, in order to improve the heat dissipation performance of individual cells, through slots or through holes for installing heat transfer tubes are provided on the polar terminals.

[0028] This invention addresses the issue of heat exchange at the battery's polarity terminals, where heat is concentrated, thereby improving the battery's heat dissipation. Specifically, this invention provides through slots or holes on the polarity terminals for mounting heat transfer pipes. After constructing a battery module based on this type of battery, the heat generated inside the battery is conducted through the heat transfer pipes on the polarity terminals to the heat transfer pipes, which then dissipate the heat, thus achieving heat dissipation for the battery.

[0029] The design of through slots or holes allows for a larger contact area between the heat transfer tube and the polarity terminal. Compared to planar contact, this embedded contact method enables more efficient heat transfer between the heat transfer tube and the polarity terminal, improving heat exchange efficiency. Furthermore, the shape of the through slots or holes provides a certain degree of locking and fixing for the heat transfer tube, preventing displacement or loosening during use. Especially in vibrating or shaking operating environments, this fixing method ensures that the heat transfer tube and the polarity terminal maintain good contact at all times, guaranteeing the stability of heat exchange.

[0030] Furthermore, each polarity terminal is provided with a functional structure, which is used to increase the heat exchange area of ​​that part of the polarity terminal.

[0031] Furthermore, an anti-seepage membrane is provided between the semi-finished single cell and the pressure-bearing casing to prevent the electrolyte inside the semi-finished single cell from seeping outward.

[0032] This geomembrane plays a crucial protective role, firmly locking in the electrolyte. This not only prevents potential battery performance degradation caused by electrolyte leakage but also prevents corrosion of the pressure-bearing casing, effectively ensuring the safety and stability of the entire battery, extending its lifespan, and ensuring stable operation under various working conditions.

[0033] The second aspect of this utility model provides a battery module, which is characterized in that it includes n of the above-mentioned single cells.

[0034] Furthermore, the battery module also includes a heat exchange component that exchanges heat with the polarity terminals.

[0035] As a crucial component connecting the battery's internal structure to the external environment, the polarity terminals allow current to flow in and out of the battery during charging and discharging. When heat is generated inside the battery, the polarity terminals provide a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery to the polarity terminals, and then dissipated into the external environment from there.

[0036] Furthermore, since the polarity terminals are typically located at the positive and negative terminals of the battery, these areas are often where heat is concentrated during charging and discharging. By dissipating heat from the polarity terminals, the temperature of these critical components can be reduced more effectively.

[0037] Furthermore, the heat exchange component is a heat transfer tube; the heat transfer tube is fixed in the through slot or through hole of the polarity terminal of each individual cell. By utilizing the heat transfer tube on the polarity terminal, the heat generated inside the cell is conducted to the heat transfer tube through the polarity terminal, and then the heat transfer tube dissipates the heat to achieve heat dissipation of the cell.

[0038] Furthermore, the heat exchange component is a heat exchange device, which is located on top of each individual cell; the polar terminal penetrates the heat exchange device, and at least a part of the structure of the polar terminal is located inside the heat exchange device and is in direct contact with the heat exchange medium; another part of the structure of the polar terminal is located outside the heat exchange device and serves as an electrical connection part; the sidewall of the polar terminal is sealed to the heat exchange device.

[0039] 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.

[0040] Furthermore, the functional structure of the polar terminal is located inside the heat exchanger, which can further improve the heat exchange effect.

[0041] The third aspect of this utility model provides a semi-finished single-cell battery, which is characterized in that it includes a sealed housing and an electrode assembly located inside the sealed housing; the sealed housing is a plastic housing, and its strength meets the strength requirements of the housing during the formation stage and the normal charging and discharging stage of the battery.

[0042] Furthermore, the thickness of the sealed housing is h, where h is less than h0, and h0 is the thickness of the existing single-cell plastic housing.

[0043] The beneficial effects of this utility model are:

[0044] 1. The inner shell of this utility model is a sealed shell made of plastic. As a cavity for containing electrode components and electrolyte, it has a sealing function. At the same time, the strength of the sealed shell needs to meet the strength requirements of the shell during the formation stage and the normal charging and discharging stage of the battery. That is, the sealed shell is required to have a certain strength to ensure that the sealed shell will not break during the formation stage and the normal charging and discharging stage of the battery, as the internal environment of the battery changes, such as temperature and pressure.

[0045] The outer shell of this utility model is a pressure-bearing shell, and its strength needs to meet the strength requirements of the shell during the thermal runaway stage; that is, the pressure-bearing shell is required to have good strength to ensure that during the thermal runaway stage, the pressure-bearing shell can form a solid thermal barrier, effectively isolate high-temperature flames and harmful gases, and prevent the spread of thermal runaway.

[0046] This utility model's single-cell battery adopts a double-layer shell. The inner sealed shell has a certain strength, and combined with the outer pressure-bearing shell, the double-layer shell has higher strength and higher safety performance compared with the single-layer shell in the prior art. In addition, compared with metal materials, the plastic sealed shell is relatively lighter and has a lower cost.

[0047] 2. The sealing shell of this utility model is a plastic shell with a relatively small thickness. While meeting the shell strength requirements during the formation stage, this utility model 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 during charging and discharging more quickly to the external environment. This helps reduce the internal temperature of the battery and minimizes battery aging and performance degradation caused by high temperatures.

[0048] Reducing the thickness of the plastic casing decreases the volume of a single battery cell, allowing more active material to be accommodated within the same cell size. This increases the battery's energy density and consequently, the energy density of high-capacity battery modules. 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.

[0049] The pressure-bearing casing is made of iron, steel, or stainless steel, which has higher pressure resistance than aluminum casing, improves battery safety, and allows for larger capacity single cells. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of a single cell in Example 1;

[0051] Figure 2 This is a schematic diagram of the exploded structure of a single cell in Example 1;

[0052] Figure 3 This is a schematic diagram of the structure of a single cell in Example 2;

[0053] Figure 4 This is a schematic diagram of the battery module structure in Example 3;

[0054] Figure 5 This is an exploded view of the battery module in Example 3;

[0055] Figure 6 This is a schematic diagram of the battery module structure in Example 4;

[0056] Figure 7 This is a schematic diagram of the heat exchange tubes in Example 4;

[0057] Figure 8 This is a cross-sectional view of the heat exchanger tubes in Example 4;

[0058] Figure 9 This is a schematic diagram of the first exploded structure of the battery module in Example 5;

[0059] Figure 10 This is a schematic diagram of the second exploded structure of the battery module in Example 5;

[0060] Figure 11 This is a schematic diagram of the heat exchange sleeve in Example 5;

[0061] Figure 12 This is a schematic diagram of the structure of another heat exchange sleeve in Example 5;

[0062] The attached figures are labeled as follows:

[0063] 1. Single cell; 2. Semi-finished single cell; 21. Polar terminal; 22. Sealed shell; 221. Lower cover plate; 222. Cylinder; 223. Upper cover plate; 224. Through groove; 225. Annular groove; 3. Pressure-bearing shell; 4. Heat transfer tube; 5. Heat exchange fittings; 51. Through hole; 512. Bottom port; 513. Top port; 6. Heat exchange sleeve; 311. Hollow component; 312. Annular sealing plate; 313. First through hole; 314. Liquid inlet pipe; 315. Liquid outlet pipe; Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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.

[0067] Example 1

[0068] like Figure 1 and Figure 2 The diagram shown is a structural schematic of a single cell 1 in this embodiment, including a semi-finished single cell 2 and a pressure-bearing casing 3.

[0069] The semi-finished single cell 2 includes a sealed housing 22 and an electrode assembly located within the sealed housing 22.

[0070] The sealed housing 22 serves as a cavity for the electrode assembly and electrolyte, providing a sealed space for these components. The strength of the sealed housing 22 must meet certain requirements. In this embodiment, the strength of the sealed housing 22 is not required to meet the strength requirements during the thermal runaway stage; it only needs to meet the strength requirements during the formation stage and normal charge / discharge processes. During the formation stage and normal charge / discharge processes, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressure and heat are generated inside the battery. The sealed housing 22 needs to have sufficient strength to withstand this pressure and heat to ensure the smooth progress of the formation process and the normal use of the battery. To reduce cost and battery weight while meeting the aforementioned strength requirements, this embodiment uses a plastic housing as the sealed housing 22.

[0071] It can be assumed that the strength of the aforementioned sealed housing 22 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.

[0072] In this embodiment, the thickness of the sealing shell 22 is h, where h is less than h0, and h0 is the thickness of the existing plastic shell of the single-cell battery 1; the thickness of the existing plastic shell of the single-cell battery 1 is typically 5-8 mm. In this embodiment, the thickness of the sealing shell 22 can be between 1-4 mm. By reducing the thickness of the shell of the conventional single-cell battery 1 with a plastic shell, better heat dissipation can be achieved, while also increasing the battery energy density. Furthermore, reducing the thickness of the plastic shell means using less plastic material, which helps save material costs and provides an economic advantage for large-scale production and application.

[0073] from Figure 2 As can be seen from the image, the sealing shell 22 in this embodiment is formed by a cylinder 222, an upper cover plate 223, and a lower cover plate 221.

[0074] The lower cover plate 221 and the cylinder body 222 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 221 and the cylinder body 222, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder body 222, effectively increasing its resistance to bending, compression, and torsion.

[0075] In this embodiment, since both the upper cover plate 223 and the cylindrical body 222 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 223 and the cylindrical body 222, exhibiting 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, providing good protection for the electrode components and ensuring battery performance and lifespan. Furthermore, the heat-fusion sealing process is simple, and the parameters are easy to control.

[0076] It should be noted that the plastic material selected in this utility model should have the following properties:

[0077] First, it must have sufficient strength to ensure the stability of the battery structure;

[0078] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0079] Third, it has barrier properties, which can effectively prevent the electrolyte, gas and other substances inside the battery from leaking out, while also preventing external impurities such as moisture and oxygen from entering the battery; in addition, a seepage-proof membrane can be installed between the semi-finished single cell and the pressure-bearing shell to prevent the electrolyte inside the semi-finished single cell from seeping out.

[0080] 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.

[0081] The plastic material used can be the material used in existing plastic-cased single-cell batteries, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0082] The semi-finished single cell 2 is installed inside the pressure-bearing housing 3, and the polarity terminal 21 of the semi-finished single cell 2 extends out of the pressure-bearing housing 3 and is sealed to the pressure-bearing housing 3. The strength of the pressure-bearing housing 3 meets the strength requirements of the housing during the thermal runaway stage.

[0083] Thermal runaway is a major safety hazard for batteries. When abnormal conditions occur inside the battery, such as overcharging, short circuits, or high temperatures, thermal runaway may occur. During thermal runaway, a large amount of heat and harmful gases are rapidly released from the battery, with temperatures potentially reaching hundreds of degrees Celsius. The pressure-bearing casing 3 needs to have sufficient strength to withstand the high temperatures and pressures generated by thermal runaway, preventing the outward spread of high-temperature flames and harmful gases. This buys time for personnel evacuation and emergency response, reducing the severity of the accident.

[0084] Meanwhile, in the extreme case where the sealed housing 22 melts, the pressure-bearing housing 3 can also form a robust thermal barrier, effectively isolating high-temperature flames and harmful gases, and preventing the spread of thermal runaway.

[0085] Compared to other materials, the metal pressure-bearing casing 3 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 3 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.

[0086] By offering a variety of metal casing options, this invention can better adapt to the usage requirements of lithium-ion batteries in different fields and under different working conditions, enabling individual cells and battery modules to achieve a more optimized balance in terms of safety, performance, and cost, thus providing strong support for the wider application of lithium-ion battery technology.

[0087] Example 2

[0088] Based on Example 1, this embodiment provides through slots 224 or through holes for installing heat transfer tubes 4 on the two polar terminals 21.

[0089] For details, please refer to [link / reference]. Figure 3 As shown in the figure, the polar terminal 21 in this embodiment is a cylindrical body, including a second end face, a first end face, and a side face (the second end face and the first end face are parallel to each other). The second end face is provided with an electrical connection area for connection with an external electrical connector, and the first end face is used for electrical connection with the electrode assembly inside the battery casing. A through groove 224 is provided on the side face (i.e., the opening of the through groove 224 is located on the side face), which serves as a mounting part for the heat transfer tube 4 to be installed.

[0090] In some other embodiments, a through hole may be provided on the side, that is, the opening of the through hole is located on the side.

[0091] In some other embodiments, the through groove 224 may also be formed on the second end face, that is, the opening of the through groove 224 is located on the second end face.

[0092] By creating through slots 224 and through holes on the side, compared to creating through slots 224 on the second end face, the heat transfer tube 4 has a larger contact area with the inner wall of the through slot 224, resulting in higher heat exchange efficiency. Furthermore, when the through slots 224 and through holes are located on the side, the entire area of ​​the second end face can be used as an electrical connection area. Two through slots 224 or through holes can also be provided on the side of the polarity terminal 21 simultaneously to increase the number of heat transfer tubes 4 and further improve heat exchange efficiency.

[0093] Furthermore, the through-slot 224 structure makes the heat transfer tube 4 easier to install compared to the through-hole structure. To further improve the ease of installation of the heat transfer tube 4, such as... Figure 3 As shown, in this embodiment, the openings of the through slots 224 on the two polarity terminals 21 face the same direction. This unidirectional orientation allows the heat transfer tube 4 to be installed along one direction, eliminating the need for complex adjustments and alignments by the operator in different directions. This significantly improves installation efficiency and accuracy, reducing the possibility of installation errors.

[0094] The cross-section of the through-slot 224 is C-shaped or U-shaped. The opening width of the C-shaped through-slot 224 is smaller than the widest part of the through-slot 224. This design is conducive to the interference fit of the heat transfer tube 4 in the through-slot 224. The arc formed by the two ends of the C-shaped through-slot 224 has natural tension, which is conducive to the tight fit of the heat transfer tube 4 in the through-slot 224. The cross-section of the U-shaped through-slot 224 is rectangular at the opening and semi-circular near the bottom of the slot. The size of the opening is slightly smaller than the widest part of the through-slot 224 and also slightly smaller than the outer diameter of the heat transfer tube 4. This design is also conducive to the interference fit of the heat transfer tube 4 in the through-slot 224 and to fixing the heat transfer tube 4 in the through-slot 224. The interference fit is mainly in the bottom area of ​​the slot with a semi-circular cross-section.

[0095] The horizontal cross-section of the polarity terminal 21 can be circular, rectangular, or racetrack-shaped. Different shapes of polarity terminals 21 can be selected according to different battery models, or other different shapes. These will not be listed exhaustively in this embodiment.

[0096] In this embodiment, the first end face of the polarity terminal 21 is close to the electrode assembly. Therefore, the first end face is closer to the internal electrode assembly of the battery, and the heat transfer pipe 4 should be positioned as close as possible to the first end face. This arrangement allows the heat transfer pipe 4 to be as close as possible to the inside of the battery for heat transfer.

[0097] Example 3

[0098] This embodiment is a battery module, which includes multiple individual battery cells 1 as described in the above embodiments.

[0099] Figure 4Taking the 12 individual battery cells 1 in Embodiment 2 as an example, in other embodiments, the number of individual battery cells 1 can be adjusted according to actual needs. As can be seen from the figure, this embodiment also includes a heat transfer pipe 4. The heat generated inside the battery module can be conducted to the heat transfer pipe 4 through the polarity terminal 21, and then the heat transfer pipe 4 dissipates the heat, thereby achieving heat dissipation of the battery module.

[0100] In this embodiment, the heat transfer tube 4 is U-shaped and includes a first tube, a second tube, and a connecting tube. The first tube is fixed in the through groove 224 of the polar terminal 21 of each individual battery 1 on one side of the battery module. The second tube is fixed in the through groove 224 of the polar terminal 21 of each individual battery 1 on the other side of the battery module. The two ends of the connecting tube are respectively connected to the ports of the first tube and the second tube on the same side.

[0101] like Figure 5 As shown, when installing heat transfer tube 4, the first tube, the second tube, and the connecting tube can be pre-assembled into one unit. Then, the first tube and the second tube are inserted into the corresponding through slot 224 in the direction indicated by the arrow in the figure. The installation process is simple and convenient, which improves the efficiency and accuracy of the installation.

[0102] Example 4

[0103] This embodiment is another type of battery module. Unlike embodiment 3, it uses a different heat exchange component to exchange heat on the polar terminal 21.

[0104] from Figure 6 As can be seen from the diagram, the heat exchange component in this embodiment includes two heat exchange tubes 5. The two heat exchange tubes 5 are respectively disposed on the polarity terminals 21 on different sides of the battery module. In order to improve the safety performance of the battery module, the heat exchange tubes 5 should not be energized. In this embodiment, heat exchange tubes 5 made of insulating material can be selected. In some other embodiments, the walls of the non-insulated heat exchange tubes 5 can be insulated, such as by spraying insulating paint or wrapping with insulating film. An insulating sealing gasket can also be added between the polarity terminal 21 and the heat exchange tubes 5 to achieve the above purpose.

[0105] The structure of heat exchanger tube 5 is as follows Figure 7 and Figure 8 As shown in the figure, the heat exchange tube 5 in this embodiment has 12 through holes 51. The 12 through holes 51 are arranged along the x-direction and correspond one-to-one with the polarity terminals 21 of each individual battery 1. In some other embodiments, the number of through holes 51 can be adjusted according to the number of individual batteries 1 in the battery module, and the arrangement of the through holes 51 can be adjusted according to the arrangement of the individual batteries 1.

[0106] The aforementioned through hole 51 is a through hole 51 that penetrates the top plate and bottom plate of the heat exchange tube 5 and communicates with the inner cavity of the heat exchange tube 5. In this embodiment, after the heat exchange tube 5 is fixed to the top of the single cell 1, the extension direction of the through hole 51 is consistent with the height direction (i.e., the z direction) of the single cell 1. Therefore, it can be considered that the through hole 51 extends along the z direction.

[0107] In addition, when the heat exchange tube 5 is fixed on the top of the single cell 1, the electrical connection part of the polarity terminal 21 of each single cell 1 passes through the bottom port 512 of the corresponding through hole 51 and extends out from the top port 513, and the polarity terminal 21 is sealed with the hole wall of the through hole 51. The top port 513 here is the port near the electrical connection part of the polarity terminal 21.

[0108] from Figure 6 As can be seen from the diagram, in this embodiment, the two heat exchange tubes 5 are respectively sleeved on the polarity terminals 21 on different sides of the battery module based on the through holes 51, and the two heat exchange tubes 5 are connected in series through connecting pipes. In some other embodiments, the two heat exchange tubes 5 can also be connected in parallel.

[0109] In addition, this embodiment can also provide a functional structure on the polarity terminal 21 to increase the heat exchange area of ​​that part of the polarity terminal 21.

[0110] For details, please refer to [link / reference]. Figure 1 In this embodiment, at least two annular grooves 225 are formed on the sidewall of the polarity terminal 21. The two annular grooves 225 are arranged along the height direction of the polarity terminal 21, and each annular groove 225 extends circumferentially along the sidewall of the polarity terminal 21. The heat exchange area of ​​this part of the polarity terminal 21 can be increased by the two annular grooves 225. Placing the part with the functional structure in the heat exchange medium flow cavity can further improve the heat exchange effect.

[0111] In some other embodiments, the number of annular grooves 225, as well as the dimensions such as groove width and groove depth, can be adjusted as needed, specifically without affecting the conductivity of the polarity terminal 21.

[0112] In other embodiments, other structures can be processed on the polarity terminal 21 to increase the heat exchange area of ​​the polarity terminal 21. Such functional structures may include dot-shaped pits or protrusions on the sidewall of the polarity terminal 21, and may also include through holes on the polarity 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 225 structure in this embodiment is easier to process and has a lower processing cost.

[0113] This embodiment adopts a direct heat exchange method, in which part of the structure of the polar terminal 21 is placed directly in the inner cavity of the heat exchange tube 5, so that the polar terminal 21 is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal 21. Compared with the indirect heat exchange method (the heat exchange method of embodiment 4), it has a shorter heat exchange path. 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.

[0114] Example 5

[0115] This embodiment is another type of battery module. Unlike embodiment 3, it uses a different heat exchange component to exchange heat on the polar terminal 21.

[0116] Combination Figure 9 and Figure 10 As can be seen, the heat exchange component in this embodiment includes 24 heat exchange sleeves 6, which are respectively set around the 24 polar terminals 21.

[0117] The structure of heat exchange sleeve 6 is as follows Figure 11 As shown, it includes a hollow component 311 and an annular sealing plate 312; two first through holes 313 are opened on the side wall of the hollow component 311 to penetrate its inner cavity, which serve as liquid inlet and liquid outlet respectively; the annular sealing plate 312 is coaxial with the hollow component 311 and is sealed and fixed at the top of the hollow component 311.

[0118] Combination Figure 9 As can be seen, the heat exchange sleeve 6 is sleeved around the polar terminal 21, forming an annular cavity between it and the side wall of the polar terminal 21 (which may have an annular groove 225). This annular cavity serves as a flow cavity for the heat exchange medium. The bottom end of the hollow component 311 is sealed and fixed to the polar terminal 21 of the single cell 1. The inner ring surface of the annular sealing plate 312 is sealed and fixed to the side wall of the polar terminal 21. At the same time, part of the structure of the polar terminal 21 extends out of the inner hole of the annular sealing plate 312, serving as the electrical connection part of the polar terminal 21.

[0119] This utility model does not specifically limit the cross-sectional shape of the hollow component 311. Generally, the cross-sectional shape of the hollow component 311 is adapted to the cross-sectional shape of the polar terminal 21. For example, when the cross-section of the polar terminal 21 is circular, the cross-section of the corresponding hollow component 311 is annular; when the cross-section of the polar terminal 21 is square, the cross-section of the corresponding hollow component 311 is square annular.

[0120] In this embodiment, the hollow component 311 and the annular sealing plate 312 are an integral part. In some other embodiments, the hollow component 311 and the annular sealing plate 312 can be separate parts, but the processing is more complicated than in this embodiment.

[0121] In this embodiment, the heat exchange sleeve 6 is made of rubber, which has a certain degree of elastic deformation. The bottom end of the hollow component 311 and the polar terminal 21 are tightly fitted together to achieve a sealed fixation. To improve the sealing reliability, insulating sealant can also be used for bonding. The inner ring surface of the annular sealing plate 312 and the side wall of the polar terminal 21 are sealed by a tight fit. In some other embodiments, an annular sealing ring can be added between the inner ring surface of the annular sealing plate 312 and the side wall of the polar terminal 21 to further improve the sealing performance.

[0122] In some other embodiments, the bottom end of the heat exchange sleeve 6 can also be sealed and fixed to the upper cover plate 223 of the single cell 1 to ensure the seal between the hollow component 311 and the side wall of the polar terminal 21.

[0123] like Figure 9 As shown, in this embodiment, the heat exchange sleeves 6 of each individual battery 1 located on the same side are connected to form two heat exchange channels on the top of the 12 individual batteries 1. The two heat exchange channels can be connected in parallel or in series, and heat exchange is achieved based on the two heat exchange channels.

[0124] In this embodiment, as Figure 12 As shown, the heat exchange sleeve 6 also includes an inlet pipe 314 and an outlet pipe 315; the inlet pipe 314 and the outlet pipe 315 are both fixed on the side wall of the hollow component 311 and are respectively connected to the inlet and the outlet.

[0125] The hollow component 311, the annular sealing plate 312, the liquid inlet pipe 314 and the liquid outlet pipe 315 are integrated into one piece, and all of them are made of insulating material, preferably an insulating material with a certain degree of elastic deformation.

[0126] It should be noted that the inlet pipe 314 of one heat exchanger 6 and the outlet pipe 315 of the other heat exchanger 6 can be connected to each other to achieve communication between the two adjacent heat exchanger 6. Alternatively, a connecting pipe section can be used to connect the inlet pipe 314 of one heat exchanger 6 and the outlet pipe 315 of the other heat exchanger 6 to achieve communication between the two adjacent heat exchanger 6.

[0127] This embodiment can adopt the following two installation methods to fix the heat exchange component to each individual battery cell 1:

[0128] Installation Method 1:

[0129] like Figure 9 As shown, each heat exchange sleeve 6 is fitted onto the corresponding polarity terminal 21 one by one. During the fitting process, adjacent heat exchange sleeves 6 are connected, and the top and bottom open ends of the heat exchange sleeve 6 are sealed to the side wall of the polarity terminal 21; finally, two heat exchange channels are formed.

[0130] Installation Method Two:

[0131] like Figure 10 As shown, firstly, the heat exchange sleeves 6 are connected to form two heat exchange channels. Then, each heat exchange channel is installed as a whole on top of the 12 individual cells 1. During the installation process, each heat exchange sleeve 6 of each heat exchange channel is fitted onto the corresponding polarity terminal 21 to complete the sealing between the open top end and the open bottom end of the heat exchange sleeve 6 and the side wall of the polarity terminal 21; finally, two heat exchange channels are formed.

[0132] 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 6, so that the polar terminal 21 is in direct contact with the heat exchange medium, thereby realizing heat exchange of the polar terminal 21. Compared with the indirect heat exchange method (the heat exchange method of Example 4), it has a shorter heat exchange path. 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.

Claims

1. A single-cell battery, characterized in that: This includes semi-finished individual battery cells and pressure-bearing casings; The semi-finished single cell includes a sealed casing and an electrode assembly located inside the sealed casing; the sealed casing is a plastic casing, and the strength of the sealed 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 semi-finished single cell is installed inside the pressure-bearing housing, and the polarity terminal of the semi-finished single cell extends out of the pressure-bearing housing and is sealed to the pressure-bearing housing. The strength of the pressure-bearing shell meets the strength requirements for the shell during the thermal runaway stage.

2. The single-cell battery according to claim 1, 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 single-cell plastic housing.

3. The single-cell battery according to claim 2, characterized in that: The pressure-bearing shell is made of iron, steel, or stainless steel.

4. The single-cell battery according to any one of claims 1 to 3, characterized in that: The polar terminals of the semi-finished single cells are provided with through slots or through holes for installing heat transfer tubes.

5. The single-cell battery according to any one of claims 1 to 3, characterized in that: The polar terminals of the semi-finished single-cell batteries are provided with functional structures, which are used to increase the heat exchange area of ​​the polar terminals.

6. The single-cell battery according to any one of claims 1 to 3, characterized in that: An anti-seepage membrane is installed between the semi-finished single cell and the pressure-bearing casing to prevent the electrolyte inside the semi-finished single cell from seeping out.

7. A battery module, characterized in that: It includes n single-cell batteries as described in any one of claims 1 to 6.

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

9. The battery module according to claim 8, characterized in that: The heat exchange component is a heat transfer tube; the heat transfer tube is fixed in the through slot or through hole of each individual cell polarity terminal.

10. The battery module according to claim 8, characterized in that: The heat exchange component is a heat exchange device, which is located on top of each individual cell; the polar terminal penetrates the heat exchange device, and at least a part of the structure of the polar terminal is located inside the heat exchange device and is in direct contact with the heat exchange medium; another part of the structure of the polar terminal is located outside the heat exchange device and serves as an electrical connection part; the side wall of the polar terminal is sealed with the heat exchange device.

11. The battery module according to claim 10, characterized in that: The part of the polarity terminal with a functional structure is located inside the heat exchanger.

12. A semi-finished single-cell battery, characterized in that: It includes a sealed housing and an electrode assembly located within the sealed housing; the sealed housing is a plastic housing, and its strength meets the strength requirements of the housing during the formation stage and the normal charging and discharging stage of the battery.

13. The semi-finished single-cell battery according to claim 12, 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 single-cell plastic housing.

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