Cover plate and shell for square battery, square battery and battery module

Abstract

The utility model belongs to the field of batteries, and particularly relates to a cover plate and a shell for a square battery, the square battery and a battery module. The problem that an existing battery module sharing pipeline assembly is difficult to assemble is solved. The cover plate comprises a cover plate main body; a sub-pipe section is arranged on the cover plate main body; mutually communicated openings are formed in the cover plate main body and the sub pipe sections; the two ends of the sub-pipe section are closed ends; and the cover plate main body and the sub-pipe sections are plastic components and are integrated. The end part of the sub-pipe section can be hermetically connected with the sub-pipe section of the cover plate main body corresponding to another square battery in a hot melting manner to form a shared pipeline; the connecting process is simple, the requirement for precision is low, good sealing connection can be achieved through hot melting even under a certain degree of dimensional deviation, and the precision control cost in the production process is reduced. The shell and the square batteries both comprise the cover plate, and the battery module is composed of a plurality of square batteries.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically a cover plate, shell, square battery, and battery module for a square battery. Background Technology

[0002] Currently, many batteries on the market are made into large-capacity batteries by electrically connecting multiple square batteries (also known as battery modules or battery packs).

[0003] An existing high-capacity battery has the following structure: Figure 1 As shown, the battery pack includes a main body formed by several square batteries connected in parallel and a shared piping assembly located at the bottom of the main body. The shared piping assembly connects all the internal cavities of the square batteries, ensuring that all the square batteries in the pack are within a single electrolyte system. This shared piping assembly enhances the uniformity of the electrolyte in each square battery, improving cycle life. It also allows for the replenishment of electrolyte to the battery pack, extending its lifespan and improving its safety.

[0004] However, such shared pipeline components are made of metal, and multiple sub-pipes 01 and connecting pipes 02 are directly sealed and plugged together with an interference fit; at this time, multiple sub-pipes 01 are set one by one on the lower cover plate 03 of the square battery. The sub-pipes 01 extend along the arrangement direction of the square battery and are integrally extruded with the lower cover plate 03 and communicate with the opening of the lower cover plate 03.

[0005] During assembly, the two ends of the sub-pipe 01 are used as the connection ends to the connecting pipe 02. When connecting two square batteries, one end of the sub-pipe on each of the two square batteries is squeezed into the two ends of the connecting pipe 02 respectively.

[0006] The shared piping assembly requires all sub-pipes 01 and connecting pipes 02 to be coaxial during the insertion process in order to achieve an effective connection. However, the coaxiality of the sub-pipes and connecting pipes 02 is difficult to guarantee due to the following reasons:

[0007] 1) The sub-pipes and the lower cover plate are a single piece. If the position of the sub-pipes on the lower cover plate is slightly off, or the dimensions of the sub-pipes themselves are slightly off, it will cause the coaxiality of the sub-pipes to be off when they are plugged in.

[0008] 2) When welding the above-mentioned integral component to the cylinder, due to differences in the welding process, the position of the sub-pipes relative to the cylinder may be inconsistent, which may lead to deviations in the coaxiality of each sub-pipe during insertion.

[0009] 3) This solution requires the use of special tooling during the connection process. If the tooling is not used properly or if the construction personnel are not careful, the coaxiality of each sub-pipeline may be deviated.

[0010] In addition, during the insertion process, the deviation between the various sub-pipes will increase with the number of insertions, making it more difficult to ensure the coaxiality between the various sub-pipes as the number of insertions increases; thus, the yield rate decreases during the assembly process as the number of insertions increases.

[0011] In summary, this solution is problematic because the sub-tubes of two adjacent square batteries are difficult to be coaxial. Therefore, during insertion, the sub-tubes may shift relative to the lower cover plate, or the lower cover plate may shift relative to the cylinder, which could lead to battery damage. Summary of the Invention

[0012] The purpose of this utility model is to provide a cover plate, shell, square battery and battery module for square batteries, to overcome the problem that it is difficult to assemble the shared pipeline components of existing battery modules.

[0013] The concept of this utility model is:

[0014] As described in the background section, there are certain challenges in connecting the sub-channels of two adjacent square batteries. This is because ensuring coaxiality is difficult, which can cause displacement of the sub-channels relative to the lower cover plate, or displacement of the lower cover plate relative to the battery body, during the connection process. Such displacement can damage the battery, thereby affecting its normal use and performance stability.

[0015] The inventors tried various methods to address this problem, but none were entirely satisfactory. These attempts included adjusting the design of the sub-pipes and improving the connection process, among others.

[0016] After some exploration, the inventors discovered that thermofusion bonding has relatively lower precision requirements. Thermofusion bonding primarily involves heating the connection points of the tubing and fittings, melting them together. During this process, the molten plastic possesses a certain degree of fluidity and filling capacity. Therefore, even if the coaxiality of the two sub-tubings is not very high before connection, once heated to a molten state, the plastic will flow under pressure and fill the gap at the connection point, thus achieving a relatively reliable connection. This means that in the connection process of square battery sub-tubings, thermofusion bonding can reduce the stringent requirements for coaxiality, thereby reducing displacement problems caused by improper insertion.

[0017] Based on the advantages of heat fusion bonding, the inventors considered replacing the sub-tubes with plastic material, connecting the sub-tubes of adjacent square batteries via heat fusion. Furthermore, the plastic material possesses a certain degree of flexibility and plasticity, making it easier to achieve a tight connection during the heat fusion bonding process, thereby improving the stability of the connection.

[0018] However, it is difficult to connect the plastic sub-channels to the metal casing of the square battery. To solve this problem, the inventors considered using plastic for the entire square battery casing. The advantages of this approach are that the manufacturing process is simpler; the plastic casing with sub-channels can be integrally molded using injection molding, enabling mass production and improving efficiency. Simultaneously, it also better ensures the consistency and quality stability of the battery casing.

[0019] Based on the above analysis, the first aspect of this utility model provides a square battery cover, which is characterized in that: it includes a cover body; a sub-tube segment is provided on the cover body; an opening is provided on the cover body and the sub-tube segment; both ends of the sub-tube segment are closed ends; the cover body and the sub-tube segment are both plastic components and are integral pieces.

[0020] This invention uses a plastic cover plate body (which can be either a lower or upper cover plate) and sub-tube segments, which can be integrally molded using injection molding, reducing the complexity of the manufacturing process and simplifying the process. Furthermore, the ends of the sub-tube segments can be sealed to the corresponding sub-tube segments of another square battery cover plate body via heat fusion, forming a shared pipeline. The connection process is simple and requires low precision; even with a certain degree of dimensional deviation, a good sealing connection can be achieved through heat fusion, reducing the cost of precision control during production. At the same time, compared to traditional connection methods, heat fusion connections have higher strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the shared pipeline during use.

[0021] In addition, compared to the metal cover body, the plastic cover body is significantly lighter, making the battery more portable.

[0022] Meanwhile, both ends of the sub-tube section are closed ends, which ensures that the inside of the square battery is not affected by the external environment before the square battery is unpacked.

[0023] Furthermore, a connecting tube is provided on the end face of one closed end, and a blind hole extending axially along the sub-tube segment is opened at the other closed end; the blind hole is used for the insertion of a connecting tube on the corresponding cover body of another square battery, and the connection is made by heat fusion.

[0024] Before the square battery is unpacked, the closed end ensures that the inside of the square battery is not affected by the external environment. When a battery module is built based on this type of square battery, the connecting tube of one square battery is inserted into the blind hole of another square battery and connected by heat fusion sealing to form a shared pipeline on the battery module. When the unpacking tool is inserted into the shared pipeline and the closed end of each sub-pipe is opened, the inner cavity of all square batteries can be connected through the shared pipeline.

[0025] A connecting tube is provided on one closed end face, and a blind hole extending axially along the sub-tube segment is opened at the other closed end. This design provides a precise interface for connecting two square batteries. The cooperation between the connecting tube and the blind hole enables a fast and accurate connection, improving the reliability and stability of the connection.

[0026] Furthermore, when the main body of the cover plate is the lower cover plate, the outer wall cross-section of the sub-tube segment is rectangular; the outer wall cross-section of the connecting tube is circular. Designing the outer wall cross-section of the sub-tube segment as rectangular, compared to a circular cross-section, provides a larger contact area on the plane, ensuring stable placement of such square batteries during use, transportation, or storage. Designing the outer wall cross-section of the connecting tube as circular makes it easier to insert the connecting tube into the blind hole, reducing resistance and friction during connection and improving connection smoothness. In addition, the circular cross-section of the connecting tube also offers relatively better sealing performance, making it easier to achieve a tight fit with the blind hole and prevent leakage.

[0027] Furthermore, when the main body of the cover plate is the lower cover plate, there are two sub-pipe sections, each extending along the width direction of the lower cover plate, and the two sub-pipe sections are arranged along the length direction of the lower cover plate.

[0028] Corresponding to the two sub-tube segments, if the closed end of one sub-tube segment cannot be opened, the closed end of the other sub-tube segment can be opened to connect the inner cavity of the square battery and the inner cavity of the shared pipeline, thereby improving the success rate of sharing. In addition, when the closed ends of both sub-tube segments are opened, compared to the structure that shares only one sub-tube segment, the electrolyte in the inner cavity of the square battery can be fully mixed with the electrolyte in the inner cavity of the shared pipeline, resulting in a better sharing effect.

[0029] Meanwhile, the two sub-tube segments allow for better stability during use, transportation, and storage of these square batteries. Furthermore, the two sub-tube segments increase the overall strength and stability of the lower cover. These sub-tube segments act as reinforcing ribs, enabling them to withstand greater external forces and pressures, thus reducing the risk of deformation and damage to the lower cover during use.

[0030] The second aspect of this utility model provides a housing for a square battery, including a cylindrical body and the aforementioned square battery cover plate; the cylindrical body is a plastic component, and the square battery cover plate is sealed and fixed to the open end of the cylindrical body.

[0031] Using a plastic cylinder reduces the overall weight of the square battery. Furthermore, the plastic cylinder and the plastic cover are highly compatible, facilitating connection and reducing processing costs.

[0032] Furthermore, when the main body of the cover plate is the lower cover plate, the lower cover plate and the cylinder are integral parts. This utility model allows for the one-time molding of the battery lower cover plate and cylinder using injection molding, eliminating the need for separate processing and assembly. This significantly reduces production steps and shortens the production cycle. Additionally, during the molding process, the material is evenly distributed and tightly bonded in the injection-molded integral part. This makes the connection between the battery lower cover plate and the cylinder more robust, resulting in higher overall structural strength. Reinforcing ribs can also be provided on the cylinder, with the reinforcing ribs integrally formed with the cylinder. The presence of reinforcing ribs effectively increases the cylinder's resistance to bending, compression, and torsion. During battery storage, transportation, and use, the cylinder may be subjected to various external forces, such as compression, collision, and vibration. The reinforcing ribs can disperse these external forces, allowing the cylinder to better withstand these loads, thereby protecting the internal electrode components. The injection molding process allows for the integral molding of the reinforcing ribs and cylinder, simplifying the production process, improving production efficiency, and reducing production costs.

[0033] Furthermore, when the main body of the cover plate is the upper cover plate, the upper cover plate is heat-sealed and fixed to the open end of the cylinder.

[0034] The top cover and the cylinder are fixed together by a heat-fusion seal, forming a continuous, uniform, and tight bond. This seal offers high stability and, compared to other sealing methods, is less prone to loosening or leakage over time, maintaining a good seal for a long period. This effectively prevents external moisture, dust, and other impurities from entering the battery, protecting its internal components and ensuring its performance and lifespan. Furthermore, the heat-fusion sealing process is relatively simple, and the parameters are easy to control.

[0035] The third aspect of this utility model provides a square battery, which is characterized in that it includes the above-mentioned square battery casing.

[0036] The fourth aspect of this utility model provides a battery module, which is characterized in that: it includes n square batteries arranged in the same direction; where n is an integer greater than 1; the sub-tube segments on the corresponding cover body of adjacent square batteries are sealed and connected by heat fusion to form a shared pipeline on the battery module.

[0037] Furthermore, the battery module also includes at least one liquid storage tank, and the bottom plate and / or top plate of the liquid storage tank are provided with a third sub-pipe section. Both the liquid storage tank and the third sub-pipe section are plastic components and are integral pieces.

[0038] The third sub-tube segment is sealed to the sub-tube segment on the adjacent square battery by heat fusion.

[0039] This invention integrates a electrolyte storage tank into the battery module, which stores electrolyte. As the battery module is used, the electrolyte may decrease due to evaporation, consumption, or other reasons. The electrolyte stored in the storage tank can be replenished to the battery module in a timely manner through a shared pipeline to maintain the amount of electrolyte inside the battery module and ensure the stable performance of the battery module.

[0040] The beneficial effects of this utility model are:

[0041] This invention uses a plastic cover plate body and sub-tube segments, which can be integrally molded through injection molding, reducing the complexity of the manufacturing process and simplifying the process. In addition, the end of the sub-tube segment can be sealed and connected to the corresponding sub-tube segment of the cover plate body on another square battery through heat fusion, forming a shared pipeline. The connection process is simple and has low precision requirements. Even with a certain degree of dimensional deviation, a good sealing connection can be achieved through heat fusion, reducing the precision control cost in the production process. At the same time, compared with traditional connection methods, heat fusion connection has higher strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the battery during use.

[0042] In addition, the use of a plastic cylinder in this invention can reduce the weight of the entire square battery, making it more portable. Furthermore, the plastic cylinder and the plastic cover have good material compatibility, making them easy to connect and reducing processing costs.

[0043] In summary, this utility model, starting from the problem of connecting the sub-tubes of square batteries, has discovered the advantages of thermofusion connection through continuous attempts and explorations, and has gradually advanced to considering a solution that uses plastic material for the entire casing, providing a new idea and method for solving the problem of connecting the sub-tubes of square batteries. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of a large-capacity battery in the background art;

[0045] Figure 2 This is a schematic diagram of the structure of the cover plate for the square battery in Example 1;

[0046] Figure 3 This is a first-direction sectional view of the cover plate for the square battery in Embodiment 1;

[0047] Figure 4 This is a cross-sectional view of the cover plate for the square battery in Embodiment 1 from a second direction, where the second direction is perpendicular to the first direction;

[0048] Figure 5This is a schematic diagram of the cover plate for the square battery in Example 2 from a first-view perspective;

[0049] Figure 6 This is a schematic diagram of the cover plate for the square battery in Example 2 from a second perspective.

[0050] Figure 7 This is a cross-sectional view of the cover plate for the square battery in Example 2;

[0051] Figure 8 This is an exploded structural diagram of the square battery casing in Example 3;

[0052] Figure 9 This is a partial structural diagram of the square battery casing in Example 3;

[0053] Figure 10 This is a partial cross-sectional view of the square battery casing in Example 3;

[0054] Figure 11 This is a schematic diagram of the square battery structure in Example 3;

[0055] Figure 12 This is a cross-sectional view of the square battery in Example 3;

[0056] Figure 13 This is an exploded structural diagram of the square battery casing in Example 4;

[0057] Figure 14 This is a schematic diagram of the square battery structure in Example 4;

[0058] Figure 15 This is an exploded structural diagram of the square battery casing in Example 5;

[0059] Figure 16 This is a schematic diagram of the square battery structure in Example 5;

[0060] Figure 17 This is a schematic diagram of the battery module structure in Example 6;

[0061] Figure 18 This is an exploded view of the battery module in Example 6;

[0062] Figure 19 This is a partial exploded cross-sectional view of the battery module in Example 6. Figure 1 ;

[0063] Figure 20 This is a partial exploded cross-sectional view of the battery module in Example 6. Figure 2 ;

[0064] Figure 21 This is a partial cross-sectional view of the battery module in Example 6.

[0065] The attached figures are labeled as follows:

[0066] 01. Sub-pipeline; 02. Connecting pipe; 03. Lower cover plate;

[0067] 1. First sub-tube segment; 11. First closed end; 12. First connecting pipe; 13. Second closed end; 14. First blind hole; 2. First opening; 3. Cylinder body; 41. Top cover plate; 42. Polar terminal; 43. Second sub-tube segment; 44. Second opening; 45. Third closed end; 46. Fourth closed end; 47. Second connecting pipe; 48. Second blind hole; 5. Square battery; 51. Electrode assembly; 6. Liquid storage tank; 61. Third sub-tube segment; 62. Top plate; 63. Bottom plate; 64. Non-connecting end of the third sub-tube segment; 65. Connecting end of the third sub-tube segment. Detailed Implementation

[0068] 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.

[0069] 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.

[0070] 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.

[0071] This utility model discloses a cover plate for a square battery, comprising a housing of the cover plate, a square battery having the housing, and a battery module constructed based on the square battery.

[0072] The cover plate includes a main body and sub-tube segments disposed on the main body, with interconnected openings in both the main body and the sub-tube segments. To prevent the internal environment of the square battery with this type of cover plate from being affected by the external environment before or during the construction of the battery module, thus causing performance degradation, this invention designs both ends of the sub-tube segments as closed ends, ensuring that air, water, and other impurities from the external environment cannot enter the square battery through the openings at both ends of the sub-tube segments.

[0073] The aforementioned cover plate can be either the upper or lower cover plate of a square battery. Connecting the sub-tube segments of multiple square batteries corresponding to the cover plate body and opening the sealed ends of each sub-tube creates a shared pipeline. For example, connecting the sub-tube segments on the lower cover plate and opening the sealed ends of each sub-tube creates an electrolyte shared pipeline, while connecting the sub-tube segments on the upper cover plate and opening the sealed ends of each sub-tube creates a gas shared pipeline.

[0074] In this embodiment, both the main body of the cover plate and the sub-pipe section are made of plastic and are integral parts, which can be integrally molded using injection molding.

[0075] Compared to traditional aluminum, plastic batteries are significantly lighter, making them more portable. Furthermore, plastic is relatively inexpensive, and the injection molding process is simple, requiring no complex equipment or technology, effectively reducing manufacturing costs and increasing production efficiency, giving it a cost advantage in large-scale production. Additionally, the integrated design of the cover body and sub-tube segments ensures a stronger connection between them, improving the overall structural strength.

[0076] Meanwhile, the sub-tube segment can be sealed and connected to the corresponding sub-tube segment of the cover plate of another square battery through heat fusion, forming a shared pipeline. The connection process is simple and has low precision requirements. Even with a certain degree of dimensional deviation, a good sealing connection can be achieved through heat fusion, reducing the precision control cost in the production process. Moreover, the heat fusion connection has high strength and can withstand greater external forces and internal pressures, ensuring the structural stability of the shared pipeline during use.

[0077] Specifically, in this invention, a connecting tube can be provided on the end face of one closed end of the sub-tube segment, and a blind hole extending axially along the sub-tube segment can be opened at the other closed end; the blind hole is used for the insertion of the connecting tube of the corresponding cover body of another square battery, and the connection is made by heat fusion. The cooperation between the connecting tube and the blind hole provides a precise interface for the connection between the two square batteries, which can achieve a fast and accurate connection, and improve the reliability and stability of the connection.

[0078] In this invention, one of the square battery first sub-tube segments can be abutted against the end face of another square battery first sub-tube segment, and the connection between the two can be achieved by heat fusion at the abutment part.

[0079] It should be noted that the plastic material selected in this utility model should have the following properties:

[0080] First, it must have sufficient strength to ensure the stability of the battery structure;

[0081] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0082] 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.

[0083] Fourth, it possesses excellent thermal stability. Batteries generate heat during charging and discharging, especially at high rates. This plastic material needs to maintain stable performance within a certain temperature range and will not soften, deform, or decompose due to high temperatures.

[0084] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0085] Example 1

[0086] This embodiment is a cover plate for a square battery 5, the structure of which is as follows: Figure 2 , Figure 3 and Figure 4 As shown, this embodiment takes the lower cover plate as the main body of the cover plate as an example.

[0087] In this embodiment, for ease of description, the sub-pipe segment on the lower cover plate is defined as the first sub-pipe segment 1; from Figure 2 As can be seen from the diagram, the outer wall cross-section of the first sub-tube segment 1 in this embodiment is rectangular. The bottom surface of the first sub-tube segment 1 can be used as the supporting surface of the square battery 5. Compared with the first sub-tube segment 1, which has a circular outer wall cross-section, the rectangular cross-section has a larger contact area on the plane. This feature makes the square battery 5 with this type of lower cover plate more stable during use and less prone to rolling or shaking.

[0088] In this embodiment, the first sub-tube segment 1 extends along the width direction of the lower cover plate. From the perspective of improving the stability of the square battery 5 during use, the size of the first sub-tube segment 1 in the width direction of the lower cover plate can be increased to create a larger bottom surface area, as a larger bottom surface area results in a more stable placement of the square battery 5. However, this introduces a new problem: as the size of the first sub-tube segment 1 increases, the size of the electrolyte sharing pipeline it forms also increases. A larger electrolyte sharing pipeline means more electrolyte is required, which undoubtedly leads to an increase in the cost of the square battery 5 or the battery module.

[0089] To resolve the contradiction of ensuring the stable placement of the square battery 5 while minimizing electrolyte usage, this embodiment employs a clever design. For example... Figure 2 As shown, two narrow first sub-tube segments 1 are provided on the lower cover plate. These two first sub-tube segments 1 can simultaneously provide support, ensuring that the square battery 5 can be placed stably. At the same time, due to their narrow width, compared to designing a larger single first sub-tube segment 1, the size of the electrolyte sharing pipeline is relatively smaller, thereby reducing the amount of electrolyte used. This effectively controls battery costs while meeting the requirement for stable battery placement, achieving a win-win effect.

[0090] from Figure 3 As can be seen, interconnected openings are made in the lower cover plate and the first sub-tube segment 1. In this embodiment, for ease of description, the openings in the lower cover plate and the first sub-tube segment 1 are defined as the first opening 2; the shape of the first opening 2 is not limited in this embodiment, but the size of the first opening 2 needs to be ensured so that the electrolyte inside the square battery 5 can enter the first sub-tube segment 1 through the opening.

[0091] from Figure 4 As can be seen from the diagram, the two ends of the first sub-pipe segment 1 in this embodiment are closed ends. This can be achieved in several ways. One feasible method is to set a sealing gasket or sealing plug inside the first sub-pipe segment 1, thereby effectively blocking the channels at both ends of the first sub-pipe segment 1 and forming a closed end. Alternatively, a sealing plate can be integrally molded inside the first sub-pipe segment 1, which can also achieve the purpose of sealing both ends of the first sub-pipe segment 1. Since this embodiment uses injection molding, the second method is preferred.

[0092] This sealing end mainly has the following two functions:

[0093] First, the function of preventing external substances from entering the interior of the square battery 5 before or during the construction of the battery module;

[0094] This sealed end plays a crucial role in the use of the square battery 5. Before and during the construction of the battery module, the square battery 5 is in an independent state. If the internal environment of the battery is affected by external factors, its performance will be impaired. For example, if air from the external environment enters the battery through both ends of the first sub-tube segment 1 and the first opening 2, it may trigger an oxidation reaction, affecting the chemical reaction balance inside the battery; the entry of moisture may cause problems such as short circuits or corrosion of the electrodes; the intrusion of other impurities will also damage the electrochemical system inside the battery.

[0095] In this embodiment, the two ends of the first sub-tube segment 1 are designed as closed ends. The purpose is to build a solid barrier to ensure that air, water and other impurities in the external environment cannot enter the square battery 5 through the openings at both ends of the first sub-tube segment 1.

[0096] To achieve this function, certain requirements are placed on the strength of the sealed end. It needs to have a certain structural strength and sealing performance to resist various external pressures and corrosion, thereby creating a stable and pure environment inside the square battery 5 and ensuring that the battery performance is not adversely affected by external factors.

[0097] Secondly, the sealed end can be opened with a packaging tool to form an electrolyte sharing pipeline;

[0098] Once the battery module is assembled, specialized unpacking tools are needed to open the sealed ends of each first sub-pipe, thereby forming a shared electrolyte pipeline.

[0099] To meet this functional requirement, the sealed end must be able to be opened by an unpacking tool. This necessitates that the sealed end be designed to open smoothly with the tool without damaging other parts of the battery module during the opening process, ensuring the integrity and functionality of the battery module remain unaffected.

[0100] For ease of description, in this embodiment, the closed ends at both ends of the first sub-pipe segment 1 are defined as the first closed end 11 and the second closed end 13, respectively; from Figure 4 As can be seen from the figure, this embodiment adopts a structure that combines a connecting pipe and a blind hole to achieve the connection of two first sub-pipe segments 1. The connecting pipe set on the end face of the first closed end 11 is defined as the first connecting pipe 12, and the blind hole opened on the second closed end 13 is defined as the first blind hole 14.

[0101] Combination Figure 2As can be seen, in this embodiment, the outer wall cross-section of the first connecting pipe 12 is circular, and the corresponding first blind hole 14 that mates with it is also circular. Using a circular cross-section for the first connecting pipe 12 makes it easier to insert it into the first blind hole 14. The circular shape provides good guidance, reducing resistance and friction during connection and improving smoothness. Furthermore, due to the uniform stress distribution of the circular shape, a tight fit with the first blind hole 14 is more easily achieved. After the circular cross-section first connecting pipe 12 is heat-fused within the first blind hole 14, its sealing performance is relatively good, effectively preventing electrolyte leakage.

[0102] Example 2

[0103] This embodiment is also a cover plate for a square battery 5, and its structure is as follows: Figure 5 and Figure 6 As shown, this embodiment takes the upper cover plate 41 as the main body of the cover plate.

[0104] As shown in the figure, in this embodiment, the upper cover plate 41 is provided with two terminals 42 of opposite polarity, and a sub-tube segment is provided between the two terminals 42, which extends along the width direction of the upper cover plate 41. In this embodiment, for ease of description, the sub-tube segment on the upper cover plate 41 is defined as the second sub-tube segment 43.

[0105] It is worth noting that, since the second sub-segment 43 is located on the upper cover plate 41, unlike the first sub-segment 1 located on the lower cover plate, its cross-sectional shape does not affect the stable placement of the square battery 5. This characteristic gives the second sub-segment 43 greater flexibility in shape design. In this embodiment, the shape of the second sub-segment 43 is not strictly limited; it can be either circular or square. Furthermore, due to the limitation imposed by the polarity terminal 42, this embodiment only provides one second sub-segment 43 on the upper cover plate 41.

[0106] from Figure 5 and Figure 7 As can be seen from the diagram, this embodiment has interconnected openings on the upper cover plate 41 and the second sub-tube segment 43. In this embodiment, the openings on the upper cover plate 41 and the second sub-tube segment 43 are defined as the second opening 44. This embodiment does not limit the shape of the second opening 44, but the size of the second opening 44 needs to be ensured so that the gas inside the square battery 5 can enter the second sub-tube segment 43 through this opening.

[0107] Similar to the first sub-pipe segment 1 in Embodiment 1, the two ends of the second sub-pipe segment 43 are closed ends. The closed ends of the two ends of the second sub-pipe segment 43 are defined as the third closed end 45 and the fourth closed end 46, respectively. This embodiment also adopts an integrally formed sealing plate inside the second sub-pipe segment 43 to close both ends of the second sub-pipe segment 43.

[0108] This closed end has a similar function to the closed end in Example 1. The only difference is that after the battery module is constructed, a special unpacking tool is needed to open the closed ends of each second sub-pipe to form a gas sharing pipeline.

[0109] from Figure 7 As can be seen, this embodiment also adopts a structure combining a connecting pipe and a blind hole to connect the two second sub-pipe segments 43. The connecting pipe set on the end face of the third closed end 45 is defined as the second connecting pipe 47, and the blind hole opened at the fourth closed end 46 is defined as the second blind hole 48. In this embodiment, the outer wall cross-section of the second connecting pipe 47 is circular, and the corresponding second blind hole 48 that matches it is also a circular hole. Using a second connecting pipe 47 with a circular cross-section makes it easier for the second connecting pipe 47 to be inserted into the second blind hole 48. The circular shape has good guiding properties, which can reduce resistance and friction during connection and improve the smoothness of connection. In addition, since the circular shape has a uniform stress distribution, it is easier to achieve a tight fit with the second blind hole 48. After the circular cross-section second connecting pipe 47 is heat-fused in the second blind hole 48, the sealing performance is also relatively good, which can effectively prevent gas leakage.

[0110] Example 3

[0111] This embodiment is a square battery casing, the structure of which is as follows: Figures 8 to 10 As shown.

[0112] like Figure 8 The diagram shown is an exploded view of the casing of the square battery 5 in this embodiment, which is formed by the cylindrical body 3, the upper cover plate 41 in embodiment 2 and the lower cover plate in embodiment 1.

[0113] In this embodiment, the cylinder 3 is also made of plastic material, such as Figure 9 and Figure 10 As shown, the lower cover plate and the cylinder 3 can be molded in one piece using injection molding, eliminating the need for separate processing and assembly. This significantly reduces production steps and shortens the production cycle. Furthermore, the injection-molded integral part exhibits uniform material distribution and tight bonding during the molding process, resulting in a stronger connection between the battery lower cover plate and the cylinder 3, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder 3, effectively increasing its resistance to bending, compression, and torsion.

[0114] In this embodiment, since both the top cover plate 41 and the cylinder 3 are made of plastic, heat fusion sealing becomes an ideal method for connecting them. Heat fusion sealing ensures a continuous, uniform, and tight connection between the top cover plate 41 and the cylinder 3, 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, effectively protecting the electrode assembly 51 and ensuring the battery's performance and lifespan. Furthermore, the heat fusion sealing process is simple, and the parameters are easy to control.

[0115] like Figure 11 and Figure 12 The diagram shows the structure and cross-sectional view of the square battery 5 in this embodiment, including the aforementioned housing and the electrode assembly 51 located inside the housing. When processing the square battery 5, the electrode assembly 51 is installed into the barrel formed by the cylindrical body 3 and the lower cover plate, and then the upper cover plate 41 is fixed to the open end of the barrel.

[0116] Example 4

[0117] This embodiment is a square battery casing, the structure of which is as follows: Figure 13 As shown, it is formed by the enclosure of the cylinder 3, the lower cover plate from Embodiment 1, and the conventional upper cover plate 41 made of plastic. That is, unlike Embodiment 3, this embodiment does not have a second sub-pipeline on the upper cover plate 41.

[0118] like Figure 14 The diagram below shows the structure of the square battery 5 in this embodiment, which includes the aforementioned housing and the electrode assembly 51 located inside the housing. When processing the square battery 5, the electrode assembly 51 is installed into the barrel formed by the cylindrical body 3 and the lower cover plate, and then the upper cover plate 41 is fixed to the opening end of the barrel.

[0119] Example 5

[0120] This embodiment is a square battery casing, the structure of which is as follows: Figure 15 As shown, it is formed by the enclosure of the cylinder 3, the upper cover plate 41 in Embodiment 2, and a conventional lower cover plate made of plastic. That is, unlike Embodiment 3, this embodiment does not have a first sub-pipeline on the lower cover plate.

[0121] like Figure 16 The diagram shows the structure and cross-sectional view of the square battery 5 in this embodiment, including the aforementioned housing and the electrode assembly 51 located inside the housing. When processing the square battery 5, the electrode assembly 51 is installed into the barrel formed by the cylindrical body 3 and the lower cover plate, and then the upper cover plate 41 is fixed to the open end of the barrel.

[0122] Example 6

[0123] This embodiment is a battery module, the structure of which is as follows: Figures 17 to 20 As shown, this includes 12 square batteries 5 from Embodiment 3 arranged in the same direction; in other embodiments, the number of square batteries 5 can be adjusted according to actual needs. Additionally, in other embodiments, the square batteries 5 from Embodiments 4 and 5 can also be used.

[0124] Combination Figure 17 , Figure 18 and Figure 19 It can be seen that the first sub-segment 1 of the adjacent square batteries 5 is sealed and connected by heat fusion, forming two electrolyte sharing pipelines at the bottom of the battery module; combined with Figure 17 , Figure 18 and Figure 20 It can be seen that the second sub-tube segment 43 in the adjacent square battery 5 is sealed and connected by heat fusion, forming a gas sharing pipeline on the top of the battery module.

[0125] In addition, from Figure 17 and Figure 18 It can also be seen that this embodiment includes two liquid storage tanks 6, located outside the two outermost square batteries 5 of the battery module; and a third sub-tube segment 61 is provided on both the bottom plate 63 and the top plate 62 of the liquid storage tank 6, the third sub-tube segment 61 being sealed to the sub-tube segment on the corresponding cover plate body of the adjacent square battery 5. For example, the third sub-tube segment 61 on the bottom plate 63 of the liquid storage tank 6 is sealed to the first sub-tube segment 1 of the lower cover plate of the adjacent square battery 5. The third sub-tube segment 61 on the top plate 62 of the liquid storage tank 6 is sealed to the second sub-tube segment 43 of the upper cover plate 41 of the adjacent square battery 5.

[0126] In some other embodiments, the number and position of the liquid storage tanks 6 can be adjusted. The liquid storage tanks 6 can be located in the middle of the battery module, between the two square batteries 5.

[0127] Electrolyte is stored in the storage tank 6. As the battery module is used, the electrolyte may decrease due to evaporation, consumption, or other reasons. The electrolyte stored in the storage tank 6 can be replenished to the battery module in a timely manner through a shared pipeline to maintain the amount of electrolyte inside the battery module and ensure the stable performance of the battery module.

[0128] In this embodiment, both the liquid storage tank 6 and the third sub-tube segment 61 are plastic components and are integral pieces. The third sub-tube segment 61 is sealed to the sub-tube segment on the adjacent square battery 5 by heat fusion. The non-connecting end 64 of the third sub-tube segment is a closed end, and the connecting end 65 of the third sub-tube segment can be directly inserted into the blind hole in the sub-tube of the square battery 5 for heat fusion connection (e.g., Figure 19 As shown), the connecting pipe of the 5th sub-tube of the square battery can also be inserted into the connecting end 65 of the third sub-tube segment for heat fusion connection (e.g. Figure 20 and Figure 21 (As shown). A good sealing effect is achieved through heat fusion connection, preventing electrolyte or gas leakage. Furthermore, the connection strength is high, capable of withstanding certain pressure and vibration, ensuring the stability of the shared pipeline during battery module operation.

Claims

1. A cover plate for a square battery, characterized by: The cover plate body and the sub-tube section are provided with openings penetrating each other; both the cover plate body and the sub-tube section are plastic components and are an integral piece.

2. The cover plate for a square battery according to claim 1, characterized by: A connecting pipe is arranged on the end face of one closed end, and a blind hole extending along the axial direction of the sub-tube section is arranged on the other closed end; the blind hole is used for inserting the connecting pipe of the other square battery and is connected by hot melting.

3. The cover plate for a square battery according to claim 2, characterized by: The cover plate body is a lower cover plate, and the outer tube wall section of the sub-tube section is rectangular; the outer tube wall section of the first connecting pipe is circular.

4. The cover plate for a square battery according to claim 3, characterized by: The sub-tube section is two, each of which extends along the width direction of the lower cover plate, and the two sub-tube sections are arranged along the length direction of the lower cover plate.

5. A case for a square battery, characterized by: The square battery cover plate is sealed and fixed in the open end of the cylinder. The cover plate body is a lower cover plate, and the lower cover plate and the cylinder are an integral piece.

6. The case for a square battery according to claim 5, characterized by: The cover plate body is an upper cover plate; the upper cover plate and the open end of the cylinder are hot melt sealed and fixed.

7. The case for a square battery according to claim 5, characterized by: The square battery shell comprises the square battery cover plate.

8. A square battery characterized by: The square batteries are arranged in the same direction; n is an integer greater than 1; the sub-tube sections on the corresponding cover plate bodies of adjacent square batteries are sealed and connected by hot melting.

9. A battery module, characterized by: The liquid storage bin is also provided with at least one third sub-tube section on the bottom plate and / or the top plate; the liquid storage bin and the third sub-tube section are plastic components and are an integral piece.

10. The battery module of claim 9, wherein: The third sub-tube section and the sub-tube section on the adjacent square battery are sealed and connected by hot melting. ​

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