Housing for single battery, single battery, and large capacity battery

Abstract

The present application belongs to the field of battery, specifically a kind of shell for single battery, single battery and large capacity battery.Overcome the technical problems of higher cost and larger weight of existing large capacity battery.The shell is plastic shell, and the shell region corresponding to the electrode assembly support area is provided with recess and protrusion;Wherein the recess is used for the protrusion on the shell of another single battery to be embedded, and fixedly connected;Under the action of external force, a channel can be opened in the protrusion and recess, and the channel is communicated with the electrolyte area in the single battery shell cavity;Weak part is integrally arranged on the upper cover plate;The strength of weak part is less than the strength of the rest of upper cover plate.Single battery uses the above-mentioned shell, and large capacity battery includes a plurality of such single batteries, and single battery and battery pack have the advantages of low cost and light weight.The integrally arranged weak part greatly improves the stability and reliability of the structure, and can always maintain good explosion venting performance.

Description

Technical Field

[0001] This invention belongs to the field of batteries, specifically a casing for a single battery, a single battery cell, and a high-capacity battery. Background Technology

[0002] Chinese patent CN219658914U discloses a high-capacity battery, the structure of which is as follows: Figure 1 As shown, the battery includes a large-capacity battery body formed by several individual cells connected in parallel and a shared conduit located on the large-capacity battery. This shared conduit connects all the internal cavities of the individual cells, ensuring that all individual cells in the large-capacity battery are within a single system. This shared conduit enhances the uniformity of the individual cells within the large-capacity battery and improves cycle life.

[0003] The single-cell high-capacity battery in the aforementioned patent includes a housing, a sealing assembly, and a finished battery. The finished battery is installed inside the housing, and the finished battery housing has an opening. The housing is provided with a first through hole communicating with the opening, and a pipe 01 extending along the width or length direction of the housing. The side wall of the pipe is provided with a second through hole communicating with the first through hole. The sealing assembly is provided on the opening, the first through hole, or the second through hole.

[0004] By setting a first through hole and a pipe with a second through hole on the outer casing of a single cell, a shared pipeline 02 can be formed through the pipe when assembling a large-capacity battery; moreover, by adding an outer casing to the finished battery, existing finished battery production lines can be used to put the finished battery into production with slight modifications.

[0005] However, this design has some drawbacks. Typically, both the finished battery casing and the outer shell are made of aluminum, which makes the overall cost of large-capacity batteries higher and their weight heavier.

[0006] From a cost perspective, aluminum is a relatively expensive metal. Furthermore, the manufacturing process for aluminum casings is complex, requiring multiple steps such as cutting, stamping, and welding, and demanding advanced equipment and techniques. These factors combined inevitably lead to a significant increase in the manufacturing cost of large-capacity batteries.

[0007] From a weight perspective, the stacking of two aluminum components significantly increases the overall weight of a large-capacity battery. This is extremely disadvantageous for the use, storage, and transportation of large-capacity batteries. Summary of the Invention

[0008] The purpose of this invention is to provide a casing for a single battery, a single battery cell, and a high-capacity battery, overcoming the technical difficulties of high cost and heavy weight of existing high-capacity batteries.

[0009] The concept of this invention is:

[0010] This invention addresses the aforementioned technical challenges primarily by focusing on both the structure of the individual battery cell itself and its packaging structure.

[0011] Firstly, starting from the structure of the individual battery itself, reduce the cost and weight of large-capacity batteries;

[0012] Given that plastic materials have a lower density than aluminum materials and are relatively cheaper, this invention aims to replace the finished batteries in the prior art with finished batteries using plastic casings (finished batteries can also be called single-cell batteries).

[0013] Compared to traditional aluminum casings, plastic casings are significantly lighter. Furthermore, plastic materials are less expensive, and the manufacturing process is relatively simple, requiring no complex equipment or technology. This effectively reduces manufacturing costs, increases production efficiency, and provides a cost advantage in large-scale production.

[0014] Secondly, starting from the packaging structure of individual cells, we can reduce the weight and cost of large-capacity batteries.

[0015] This invention proposes placing multiple individual battery cells with plastic casings within a single pressure-bearing casing, which can simultaneously protect multiple individual battery cells. Compared to the prior art structure where each individual battery cell is individually encased in a casing, this reduces individual packaging and protection costs, resulting in lower overall cost. Furthermore, given the same number of individual battery cells, the weight of a single pressure-bearing casing is necessarily less than the weight of multiple smaller casings; therefore, the design of the pressure-bearing casing can further reduce the weight of large-capacity batteries.

[0016] Based on the above inventive concept, the first aspect of the present invention provides a housing for a single battery, which is characterized in that: it is formed by an upper cover plate, a cylindrical body and a lower cover plate; the upper cover plate, the cylindrical body and the lower cover plate are all made of plastic.

[0017] Along the height direction of the shell, from bottom to top, the inner cavity of the shell is divided into an electrode assembly support area and an electrode assembly receiving area;

[0018] The housing area corresponding to the electrode assembly support area is provided with a recess and a protrusion; the recess is used for the protrusion on the housing of another single cell to be embedded and fixedly connected; under the action of external force, a channel can be opened in the protrusion and the recess, which communicates with the electrolyte area inside the single cell housing.

[0019] The top cover plate has an integrally formed weak section; the strength of the weak section is less than the strength of the rest of the top cover plate. When a single cell experiences thermal runaway, the thermal runaway smoke breaks through the weak section and is discharged.

[0020] After the individual cells are connected by recesses and protrusions, the present invention uses tools to create channels in the recesses and protrusions that penetrate the inner cavity of the individual cell casing. In this way, the electrolyte between the individual cells is connected, so that the individual cells are in the same electrolyte system. The differences that may have existed can be effectively improved, ensuring the consistency of the individual cells during charging and discharging, extending the overall service life, and improving the performance of large-capacity batteries.

[0021] The battery casing provided by this invention is made of plastic, which offers advantages in terms of lower cost and lighter weight compared to finished batteries used in the prior art. Furthermore, by fully utilizing the electrode assembly support area within the casing, recesses and protrusions are positioned in this area. These recesses and protrusions do not affect the vertical dimensions of the individual battery, ensuring both connection stability and overall compactness and space utilization efficiency within a large-capacity battery. Simultaneously, when assembling a large-capacity battery, the protrusion of one individual battery is inserted into the recess of another individual battery for a secure connection, improving the stability between the individual batteries and making the entire large-capacity battery structure more robust and durable.

[0022] Meanwhile, the present invention integrates a weak section as a deflation vent on the upper cover plate, which has at least the following advantages:

[0023] From a structural stability perspective, existing explosion-proof membranes are typically attached to the battery cover plate via adhesive or other methods. During long-term use, factors such as corrosion from internal battery chemicals, temperature changes, and mechanical vibrations can cause the connection between the explosion-proof membrane and the cover plate to loosen or detach, leading to a failure of its explosion-proof function. In contrast, the integrated weak point in this invention is a single unit with the cover plate, eliminating the risk of loosening or detachment at the connection point. This significantly improves structural stability and reliability, ensuring consistently excellent explosion-proof performance.

[0024] In terms of sealing, achieving an absolute seal at the junction of the existing explosion-proof membrane and the top cover faces numerous challenges. However, the seamless integration of the integrated weak point with the top cover effectively ensures the internal sealing of the battery under normal conditions, preventing the intrusion of external substances and providing a better environment for stable battery operation.

[0025] From a cost and manufacturing process perspective, existing explosion-proof membranes require additional materials and complex installation processes, which not only increases production costs but may also lead to inconsistent product quality due to human factors during manufacturing. In contrast, the integrated design of the weak point eliminates the need for additional installation steps during manufacturing, simplifying the production process, reducing production costs, and improving product consistency and quality stability.

[0026] Furthermore, the recess is a blind hole opened on the first side wall of the lower cover plate; the protrusion is a connecting pipe provided on the outer wall of the second side wall of the lower cover plate; the connecting pipe is used to be embedded in the blind hole of another single battery cell and fixedly connected, and the first side wall of the lower cover plate and the second side wall of the lower cover plate are parallel to each other.

[0027] This invention employs blind holes and connecting pipes for a simple and convenient connection process, enabling quick and accurate connection of individual cells. This makes the assembly of the entire large-capacity battery more orderly and efficient. Once the cells are interlocked and secured, a reliable connection can be formed between adjacent cells. This ensures that the cells will not easily loosen or shift when subjected to vibration or impact, maintaining a stable electrical connection and structural state over a long period.

[0028] In addition, the blind holes and connectors do not affect the sealing performance of the individual battery casing.

[0029] Furthermore, the inner surface of the lower cover plate is provided with multiple protrusions arranged in an array. The top of the protrusions is used to support the electrode assembly, and the gap between the protrusions serves as an electrolyte flow channel.

[0030] The regularly arranged protrusions provide stable and evenly distributed support points for the electrode assembly, preventing deformation or damage caused by excessive localized stress. Furthermore, the gaps between the protrusions serve as electrolyte flow channels, allowing the electrolyte to be evenly distributed around the electrode assembly, ensuring that all electrodes are in full contact with the electrolyte.

[0031] Furthermore, under the action of external force, the bottom end of the blind hole and the second side wall area of ​​the lower cover plate defined by the connecting pipe can be opened to connect with the electrolyte flow channel.

[0032] The blind hole and connecting pipe of this invention are both hollow structures. On the one hand, when multiple individual cells are assembled, adjacent individual cells can be stably connected by means of the blind hole and connecting pipe, which greatly improves the stability between individual cells and makes the structure of the entire large-capacity battery exhibit better stability.

[0033] On the other hand, although the inner cavities of the blind holes and connecting pipes are normally isolated from the battery's inner cavity, under specific external forces, the bottom of the blind holes and the area on the second side wall of the lower cover plate defined by the connecting pipes can be opened smoothly. Once the sealed end is opened, the inner cavities of all blind holes and connecting pipes immediately connect with the electrolyte flow channels, and further connect with the inner cavities of all individual cells. In this way, the differences that may exist between individual cells can be effectively improved, ensuring the consistency of each individual cell during charging and discharging, extending the overall service life, and improving the performance of large-capacity batteries.

[0034] Furthermore, a recessed area is created on the upper cover plate to form a weak point. Compared to some methods that create weak points by changing material composition or microstructure, creating a recessed area is simpler and allows for more intuitive and precise control over the strength and opening pressure of the weak point. Specifically, by controlling parameters such as the depth, shape, and area of ​​the recessed area, the opening of the weak point under a specific pressure can be accurately set, greatly improving the reliability of the explosion venting function.

[0035] Furthermore, through holes are made in the top cover plate along its width or length to form a weak section. When through holes are made in the top cover plate along its width or length to form a weak section, the flatness of the battery top cover plate can be maintained better than a weak section formed by a recessed area.

[0036] Furthermore, both the recess and the protrusion are integral with the cylinder or the lower cover plate; the recess is used for the protrusion of another single battery cell to be inserted and is fixedly connected by heat fusion.

[0037] This invention can be manufactured using injection molding to integrally form the recesses and protrusions on the lower cover plate or cylinder. The processing is simple. Since the recesses, protrusions, second recesses and second protrusions are formed simultaneously with the shell, there are no dimensional deviations caused by subsequent assembly. The precision is high, which can ensure that the recesses and protrusions, second recesses and second protrusions of each individual battery can be precisely matched, which is beneficial to the mass production and quality control of large-capacity batteries.

[0038] Furthermore, the recesses and protrusions are connected via a heat-fusion process. During this process, the plastic material melts upon heating, and upon cooling and solidification, the materials of the recesses and protrusions fuse together to form a single, integrated structure, creating a very strong bond between them. This connection method can withstand significant tensile, compressive, and shear forces, effectively preventing loosening or separation of individual battery cells during use and ensuring the structural stability of high-capacity batteries. Simultaneously, heat-fusion connections have lower precision requirements; even with slight dimensional deviations between the recesses and corresponding protrusions during production, precise connection can still be achieved, greatly improving production efficiency.

[0039] A second aspect of the present invention provides a single-cell battery, characterized in that it includes the aforementioned casing for a single-cell battery.

[0040] Furthermore, the shell strength is P, P1≤P≤P2; where P1 is the strength requirement of the shell during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell during the thermal runaway stage.

[0041] The aforementioned single-cell battery casing is a sealed plastic casing that serves as a cavity for the electrode components and electrolyte, providing a sealing function. Simultaneously, the strength of the sealed casing must meet the strength requirements of the casing during the formation stage and the normal charge / discharge stages of the battery. That is, the sealed casing must possess sufficient strength to ensure that it will not crack under changes in the internal environment of the battery, such as temperature and pressure, during the formation stage and normal charge / discharge stages. Compared to existing finished plastic-cased single-cell batteries, this single-cell battery has a lower cost, thereby reducing the overall cost of the large-capacity battery.

[0042] A third aspect of the present invention provides a high-capacity battery, comprising a pressure-bearing housing and n of the above-mentioned single cells arranged within the pressure-bearing housing, wherein n is an integer greater than 1;

[0043] In adjacent individual cells, the protrusion of one individual cell is inserted into the recess of another individual cell and fixedly connected; the protrusion and the recess form a channel that penetrates the electrolyte area inside the individual cell housing; a venting channel is formed between the weak part of each individual cell and the pressure-bearing housing.

[0044] The pressure-bearing shell has the strength required for the shell during the thermal runaway stage. The pressure-bearing shell is equipped with a venting section corresponding to the venting channel. When a single cell experiences thermal runaway, the thermal runaway flue gas breaks through the weak part, passes through the venting channel, and then breaks through the venting section to exit the pressure-bearing shell.

[0045] In the initial stage of thermal runaway, the thermal runaway fumes can be discharged in an orderly manner through the explosion venting channel, effectively preventing them from spreading to the large-capacity battery casing and thus preventing further deterioration of the thermal runaway situation.

[0046] The outer casing of the high-capacity battery of this invention is a pressure-bearing casing, whose strength must meet the requirements for casing strength during thermal runaway; that is, the pressure-bearing casing must have good strength to protect multiple individual cells simultaneously. In the extreme case of thermal runaway of a single cell and melting of the plastic casing, the pressure-bearing casing can form a robust barrier, effectively isolating high-temperature flames and harmful gases, preventing the spread of thermal runaway, and improving the safety of the high-capacity battery after thermal runaway. Compared with the structure of individual casings for each individual cell in the prior art, this reduces the cost of individual packaging and protection, resulting in lower costs. Furthermore, given the same number of individual cells and the same material and thickness of the pressure-bearing casing as the individual cell casings in the prior art, the weight of a single pressure-bearing casing will inevitably be less than the weight of multiple smaller casings. Therefore, the design of the pressure-bearing casing can further reduce the weight of the high-capacity battery.

[0047] Furthermore, the top plate of the pressure-bearing housing has clearance holes corresponding to the polarity terminals of each individual battery; the polarity terminals of each individual battery extend out of the clearance holes; the area of ​​the top plate of the pressure-bearing housing corresponding to the clearance holes is fixedly sealed to the individual battery housing.

[0048] Furthermore, the aforementioned high-capacity battery also includes a heat exchange component that exchanges heat with the polarity terminals.

[0049] During the operation of a large-capacity battery, heat can easily accumulate at the polarity terminals due to current conduction. Heat exchange components can promptly remove this heat, ensuring the polarity terminals remain within a suitable operating temperature range. This not only helps maintain the performance stability of individual cells within the large-capacity battery and reduces performance degradation caused by excessive temperature, but also further enhances the overall safety and reliability of the large-capacity battery, preventing potential malfunctions caused by localized overheating.

[0050] The beneficial effects of this invention are:

[0051] The single-cell battery of this invention uses a plastic casing, which enables the large-capacity battery constructed from it to have lower cost and lighter weight.

[0052] Meanwhile, to improve the safety performance of the high-capacity battery constructed from the aforementioned individual cells, this invention places multiple individual cells within a pressure-bearing casing. In extreme cases where a single cell experiences thermal runaway and the plastic casing melts, this pressure-bearing casing forms a robust thermal barrier, effectively isolating high-temperature flames and harmful gases, and preventing the spread of thermal runaway. Furthermore, protecting multiple individual cells with a pressure-bearing casing reduces external impacts and damage during transportation and use, extending battery life. Compared to the prior art structure where each individual cell is individually encased, this reduces individual packaging and protection costs, resulting in lower overall cost. Moreover, with the same number of individual cells, the weight of a single pressure-bearing casing is necessarily less than the weight of multiple smaller casings; therefore, the design of the pressure-bearing casing further reduces the weight of the high-capacity battery.

[0053] Meanwhile, the present invention makes full use of the electrode assembly support area inside the casing, and sets the recesses and protrusions in this area. The recesses and protrusions do not affect the size of the individual battery in the height direction, thus taking into account the overall compactness and space utilization efficiency of the large-capacity battery.

[0054] Furthermore, this invention also integrates a weak section into the upper cover plate, serving as a single-cell explosion vent. Compared to existing structures that use explosion vent membranes as the explosion vent, this offers advantages such as high structural stability, good sealing performance, and low manufacturing cost. Correspondingly, in a large-capacity battery, an explosion venting channel is formed between the weak section of each single-cell and the pressure-bearing casing; a corresponding explosion venting section is provided on the pressure-bearing casing; in the event of thermal runaway of a single-cell, the runaway gas ruptures through the weak section, passes through the explosion venting channel, and then ruptures the explosion venting section before exiting the pressure-bearing casing. In the initial stage of thermal runaway, the runaway gas can be discharged in an orderly manner through the explosion venting channel, effectively preventing its spread to the large-capacity battery casing and thus preventing further deterioration of the thermal runaway situation.

[0055] The above analysis shows that the high-capacity battery of the present invention has advantages over the high-capacity batteries in the prior art, such as low cost, light weight, compact structure, and high safety performance. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the structure of a large-capacity battery in the background art;

[0057] Figure 2 This is a schematic diagram of the structure of a single cell in Example 1 from a first-view perspective;

[0058] Figure 3 This is a schematic diagram of the structure of a single cell in Example 1 from a second perspective;

[0059] Figure 4 This is a partial structural diagram of the single battery casing in Example 1;

[0060] Figure 5 This is a partial cross-sectional view of the single battery casing in Example 1;

[0061] Figure 6 This is a partial cross-sectional view of the single-cell battery casing in other embodiments;

[0062] Figure 7 This is a schematic diagram of the upper cover plate in Example 3;

[0063] Figure 8 This is a schematic diagram of the upper cover plate in Example 4;

[0064] Figure 9 This is a schematic diagram of the structure of a single cell in Example 4;

[0065] Figure 10 This is a schematic diagram of the structure of a high-capacity battery in Example 5;

[0066] Figure 11 This is a schematic diagram of the exploded structure of a high-capacity battery in Example 5;

[0067] Figure 12 This is a schematic diagram of a partial explosion structure of a large-capacity battery in Example 5;

[0068] Figure 13 This is a schematic diagram of the exploded structure of the second type of high-capacity battery in Example 5;

[0069] Figure 14 This is a schematic diagram of the partial explosion structure of the second type of large-capacity battery in Example 5;

[0070] Figure 15 This is a schematic diagram of the partial explosion structure of the third type of high-capacity battery in Example 5;

[0071] Figure 16 This is a schematic diagram of the exploded structure of the fourth type of high-capacity battery in Example 5;

[0072] Figure 17 This is a schematic diagram of the structure of the fourth type of high-capacity battery in Example 5.

[0073] The attached figures are labeled as follows:

[0074] 01 - Pipelines; 02 - Shared piping;

[0075] 1. Top cover plate; 11. Polar terminal; 2. Cylinder; 3. Bottom cover plate; 31. Blind hole; 32. Bottom of blind hole; 33. Connecting pipe; 4. Electrode assembly support area; 5. Electrode assembly receiving area; 6. Recess; 7. Protrusion; 10. First sub-pipe section; 12. Boss; 13. Pressure-bearing shell; 14. Explosion relief section; 15. Individual battery; 16. Heat exchange component; 17. Clearance hole; 18. Second channel; 42. Through groove; 45. Groove; 46. Through hole. Detailed Implementation

[0076] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0077] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0078] In the description of this invention, it should be noted that the terms "top," "bottom," etc., indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention 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 the invention. 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.

[0079] Example 1

[0080] like Figure 2 and Figure 3 The diagram shown is a structural schematic of a single battery cell 15 in this embodiment. The single battery cell 15 includes a housing, an electrode assembly located in the inner cavity of the housing, and an electrolyte. The housing is formed by an upper cover plate 1, a cylindrical body 2, and a lower cover plate 3.

[0081] To reduce costs and battery weight, this embodiment uses a plastic casing. The lower cover plate 3 and the cylinder 2 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 3 and the cylinder 2, and higher overall structural strength. Additionally, reinforcing ribs can be integrally molded on the cylinder 2, effectively increasing its resistance to bending, compression, and torsion.

[0082] In this embodiment, the upper cover plate 1 and the cylinder 2 can be sealed together by heat fusion or welding. This ensures a continuous, uniform, and tight connection between the upper cover plate 1 and the cylinder 2, resulting in extremely high stability. External water, dust, and other impurities cannot enter the battery, thus providing excellent protection for the electrode components and ensuring the battery's performance and lifespan.

[0083] It should be noted that the plastic material selected in this invention should have the following properties:

[0084] First, it must have sufficient strength to ensure the stability of the battery structure;

[0085] Second, it has chemical corrosion resistance and can resist the corrosion of electrolytes;

[0086] 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.

[0087] 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.

[0088] The plastic material used can be the same material used in existing plastic-cased single-cell batteries 15, or the plastic material disclosed in Chinese patents CN106543551A and CN106977894A.

[0089] For ease of description, in this embodiment, the width direction of the casing of the single battery 15 is defined as the x-direction, the length direction as the y-direction, and the height direction as the z-direction.

[0090] In this embodiment, along the z-direction from bottom to top, the inner cavity of the housing is divided into an electrode assembly support area 4 and an electrode assembly receiving area 5.

[0091] Combination Figure 4 and Figure 5 As can be seen, in this embodiment, the electrode assembly support area 4 is mainly located on the lower cover plate 3; the electrode assembly receiving area 5 is located above the electrode assembly support area 4.

[0092] In some other embodiments, such as Figure 6 As shown, the electrode assembly support area 4 can be enclosed by the lower cover plate 3 and a portion of the cylinder 2 connected thereto; the electrode assembly receiving area 5 is located above the electrode assembly support area 4.

[0093] The present invention provides a recess 6 and a protrusion 7 on the housing area corresponding to the electrode assembly support area 4; wherein the recess 6 is used for another single battery cell 15 to be embedded in and fixedly connected to the protrusion 7 on the housing. Under the action of external force, a channel can be opened in the protrusion 7 and the recess 6, and the channel communicates with the inner cavity of the housing of the single battery cell 15.

[0094] The recess 6 and protrusion 7 of this invention are interlocked to connect multiple individual battery cells 15, which can also improve the stability of the individual battery cells 15 in the large-capacity battery, making the structure of the entire large-capacity battery more compact and stable, effectively resisting interference under various working conditions, and ensuring the continuous, efficient and safe operation of the large-capacity battery.

[0095] This invention places both the recess 6 and the protrusion 7 on the housing corresponding to the electrode assembly support area 4, ensuring that the recess 6 and protrusion 7 do not generate additional dimensional increments in the height direction of the individual battery cell 15. For high-capacity batteries, especially in applications with stringent space requirements, this connection structure that does not increase height dimensions is particularly important. It allows a large-capacity battery to accommodate more individual batteries 15 within a limited space, or, while meeting the same battery capacity requirements, makes the overall large-capacity battery more compact and lightweight, facilitating device portability, installation, and layout optimization.

[0096] Since the shell in this embodiment is made of plastic, it can be integrally molded using injection molding, forming a shell with recesses 6 and protrusions 7 (the shell here consists of a lower cover plate 3 and a cylindrical body 2). During injection molding, the dimensions of the mold cavity can be precisely controlled, ensuring high dimensional accuracy of the recesses 6 and protrusions 7 during molding, guaranteeing precise fit with other individual battery cells 15. Furthermore, because it is integrally molded, there is no issue of accumulated dimensional deviations due to the assembly process, ensuring the stability and consistency of the individual battery cell connections. This is beneficial for improving the overall performance and quality stability of the large-capacity battery, reducing problems such as poor connection and abnormal battery operation caused by dimensional mismatch. Simultaneously, in adjacent individual battery cells 15, after the protrusion 7 of one individual battery cell 15 is embedded into the recess 6 of another individual battery cell 15, the two can be fixedly connected by heat fusion. After the plastic is melted and cooled, it solidifies, fusing the two together to form a stable connection structure capable of withstanding significant mechanical stress. For example, when a large-capacity battery is subjected to external forces such as vibration, impact, or compression, it effectively prevents the connections between individual cells from loosening or detaching. This ensures the structural integrity and electrical connection stability of the large-capacity battery under complex operating conditions, thereby improving its safety and reliability and extending its lifespan. Furthermore, the hot-melt connection method has lower precision requirements; even with a certain degree of dimensional deviation, a good connection can be achieved through hot melting, reducing the cost of precision control during the production process.

[0097] from Figure 2 and Figure 3 As can be seen from the image, in this embodiment, the recess 6 and the protrusion 7 are respectively provided on the first sidewall and the second sidewall, which are parallel to each other on the housing. In addition, two recesses 6 can be provided on the first sidewall, and two protrusions 7 can be provided on the second sidewall.

[0098] In some other embodiments, a recess 6 and a protrusion 7 may be provided on the first sidewall, and a corresponding protrusion 7 and a recess 6 may be provided on the second sidewall.

[0099] In this embodiment, when assembling a large-capacity battery, the operator can easily distinguish the correspondence between the recess 6 and the protrusion 7, and can quickly and accurately connect the individual battery cells 15. However, if there are both recesses 6 and protrusions 7 on the same side wall, the operator needs to be more careful in distinguishing which recess 6 corresponds to which protrusion 7 during assembly. If the operator is not careful, a mismatch may occur, resulting in reduced assembly efficiency.

[0100] It should be noted that:

[0101] 1. The first sidewall mentioned above is composed of the first sidewall of the cylinder 2 and the first sidewall of the lower cover plate; the second sidewall mentioned above is composed of the second sidewall of the cylinder 2 and the second sidewall of the lower cover plate.

[0102] 2. The first and second sidewalls described above are parallel to each other and can both be parallel to the xz plane. When parallel to the xz plane, both the protrusion 7 and the recess 6 extend along the y direction. Alternatively, both the first and second sidewalls described above can be parallel to the yz plane. When parallel to the yz plane, both the protrusion 7 and the recess 6 extend along the x direction.

[0103] The following example mainly focuses on the first and second sidewalls being parallel to the yz plane.

[0104] from Figure 5 As can be seen, in this embodiment, the recess 6 is a blind hole 31 formed on the first side wall of the lower cover plate, that is, the opening end of the blind hole 31 is located on the first side wall of the lower cover plate, and the bottom end 32 of the blind hole is located in the electrode assembly support area 4. The protrusion 7 is a connecting tube 33 provided on the outer wall of the second side wall of the lower cover plate; the connecting tube 33 is used to be embedded in the blind hole 31 of another single cell 15 and fixedly connected.

[0105] In some other embodiments, the recess 6 may also employ... Figure 6 The structure shown, namely the recess 6, can be a first sub-tube segment 10 disposed on the first side wall of the cylinder 2; the first sub-tube segment 10 extends along the x-direction, one end of the first sub-tube segment 10 is closed, and the other end is open; the closed end is located in the electrode assembly support area 4, and the open end penetrates through the first side wall and is located on the first side wall. The protrusion 7 is a connecting tube 33 disposed on the outer wall of the second side wall of the cylinder 2; the connecting tube 33 is used to embed into the blind hole 31 of another single cell 15 and to fix it in place.

[0106] In some other embodiments, the protrusion 7 can also be a solid column. Solid columns have higher strength and can withstand greater tensile and compressive forces. However, compared to this embodiment, it is more difficult to open a channel through the cavity of a single cell on it.

[0107] from Figure 5It can also be seen that this embodiment has multiple protrusions 12 arranged in an array on the inner surface of the lower cover plate 3. The tops of the protrusions 12 are used to support the electrode assembly, and the gaps between the protrusions 12 serve as electrolyte flow channels. The aforementioned multiple protrusions 12 can be arranged in a rectangular array or a ring array, etc.; the regularly arranged multiple protrusions 12 can provide stable and uniformly distributed support points for the electrode assembly, avoiding the situation where excessive local stress leads to deformation or damage of the electrode assembly. In addition, using the gaps between the protrusions 12 as electrolyte flow channels allows the electrolyte to be evenly distributed around the electrode assembly, ensuring that the electrodes in each part can fully contact the electrolyte.

[0108] Furthermore, during battery operation, if the temperature rises, the electrolyte stored in the electrolyte flow channels can rapidly absorb heat through heat transfer, dispersing the absorbed heat throughout the casing and dissipating it through the casing surface. This effectively prevents battery overheating, reduces the risk of thermal runaway, precisely regulates temperature, and maintains battery performance.

[0109] In this embodiment, both the blind hole 31 and the connecting pipe 33 are hollow structures. After being constructed into a high-capacity battery, under the action of external force, the bottom end 32 of the blind hole and the second side wall area of ​​the lower cover plate enclosed by the connecting pipe 33 will be hollow. Figure 5 The area shown in the middle circle (a) can be opened, immediately connecting the inner cavities of all blind holes 31 and the connecting pipe 33, and further connecting them with the electrolyte areas of all individual cell 15, achieving electrolyte sharing. In this way, the differences that may have existed between individual cells 15 can be effectively improved, ensuring the consistency of each individual cell 15 during charging and discharging, extending the overall service life, and improving battery performance.

[0110] If adopted Figure 6 The structure shown, after being constructed into a high-capacity battery, under the action of external force, the closed end of the first sub-tube segment 10 and the second side wall area of ​​the lower cover plate enclosed by the connecting tube 33 ( Figure 6 The area shown in the middle circle (a) can be opened, immediately connecting the inner cavities of all first sub-tube segments 10 and the connecting tube 33, and further connecting them with the inner cavities of all individual cells 15. This can also improve the differences that may exist between individual cells 15, ensure the consistency of each individual cell 15 during charging and discharging, extend the overall service life, and improve battery performance.

[0111] The above-mentioned external force generally refers to using appropriate tools to apply a certain force to the bottom end 32 of the blind hole (or the closed end of the first sub-pipe section 10) and the second side wall area of ​​the lower cover plate enclosed by the connecting pipe 33, so as to break it and form an opening.

[0112] In addition, such as Figure 2 and Figure 3As shown, in this embodiment, a through groove 42 can also be formed on the upper surface of the upper cover plate 1, and the area of ​​the upper cover plate 1 corresponding to the bottom of the through groove 42 is regarded as a weak part. When thermal runaway occurs inside the single cell 15 and the internal pressure reaches a certain requirement, the thermal runaway flue gas breaks through the weak part to form an opening and is discharged from the opening of the weak part.

[0113] In some other embodiments, an annular groove may be formed on the top cover plate, and the area enclosed by the annular groove may be used as a weak point.

[0114] from Figure 2 As can be seen from the image, in this embodiment, the through groove 42 penetrates the upper cover plate 1 along the x direction and is located between the two polarity terminals 11 of the upper cover plate 1.

[0115] From a thermal management perspective, the polar terminals 11 are usually the concentrated areas of heat generation in the battery. By placing the weak points near the two polar terminals 11, the heat generated by thermal runaway can be dissipated in a timely manner, effectively alleviating local high temperatures and optimizing the internal heat distribution of the battery.

[0116] In terms of structural layout, this arrangement makes the battery top cover 1 more compact and rational. Compared to placing the weakest part in other locations, it reduces interference with other functional areas of the battery, achieving a more efficient layout within a limited space.

[0117] In some other embodiments, the through slot 42 can also extend through the upper cover plate 1 along the length of the upper cover plate 1, avoiding the location of the polarity terminal 11.

[0118] The depth and width of the through groove 42 can be set according to specific needs to ensure that the area of ​​the upper cover plate 1 where the bottom of the through groove 42 is located can be opened under the set pressure.

[0119] However, it is important to note that the depth and width of the through-slot 42 should not be excessive. If the dimensions exceed a reasonable range, the through-slot 42 may deform due to insufficient strength when the battery has not experienced thermal runaway, thereby affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the through-slot 42, while ensuring the structural stability of the top cover 1 under normal operating conditions, it is also ensured that the through-slot 42 can reliably perform its explosion-venting function in the event of thermal runaway.

[0120] In this embodiment, the top cover plate 1 with the through groove 42 can be integrally molded using injection molding. The integrally molded through groove 42 avoids additional splicing gaps, ensuring the overall sealing of the top cover plate 1 and effectively preventing the intrusion of external impurities. In addition, the injection molding process is low-cost and highly efficient, reducing processing steps and production costs, resulting in significant economic benefits in large-scale production.

[0121] Example 2

[0122] Unlike the embodiments described above, this embodiment, in order to further reduce costs, requires that the strength of each individual battery cell 15 casing meets certain requirements. In this embodiment, the casing strength 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 the normal charge / discharge process. (Correspondingly, the strength of the weak points provided on it should also meet the strength requirements during the formation stage and the normal charge / discharge process.) During the formation stage and the normal charge / discharge stage, the battery undergoes a series of chemical reactions and physical changes. During this process, certain pressure and heat are generated inside the battery. The casing 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.

[0123] We can assume that the strength of the casing is P, P1≤P≤P2; where P1 is the strength requirement of the casing during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the casing during the thermal runaway stage.

[0124] Under the premise of meeting the above strength requirements, in this embodiment, the thickness of the shell (cylinder 2, upper cover plate 1, and lower cover plate 3) is h, where h is less than h0, and h0 is the thickness of the plastic shell of a conventional single-cell battery 15; the thickness of the plastic shell of a conventional single-cell battery 15 is typically 5-8 mm. In this embodiment, the thickness of the shell can be between 1-4 mm. By reducing the thickness of the shell of a conventional single-cell battery 15 with a plastic shell, better heat dissipation can be achieved, while also increasing the battery energy density. In addition, 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.

[0125] Example 3

[0126] Unlike the above embodiments, this embodiment has a groove 45 formed on the lower surface of the upper cover plate 1, and the area of ​​the upper cover plate 1 corresponding to the bottom of the groove 45 is a weak part.

[0127] Specifically, such as Figure 7 As shown, in this embodiment, the groove 45 extends along the x-direction. Similar to Embodiment 1, the groove 45 is located between the two polar terminals 11.

[0128] The depth and width of the groove 45 can be set according to specific needs to ensure that the area of ​​the upper cover plate 1 where the bottom of the groove 45 is located can be opened under the set pressure.

[0129] However, it is also important to note that the depth and width of the groove 45 should not be too large. If the dimensions exceed a reasonable range, the groove 45 may deform due to insufficient strength when the battery has not experienced thermal runaway, thereby affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the groove 45, while ensuring the structural stability of the top cover 1 under normal operating conditions, it is also necessary to ensure that the groove 45 can reliably perform its explosion-proof function in the event of thermal runaway.

[0130] Compared to the example of opening a through groove 42 on the upper surface of the upper cover plate 1 in Example 1, this example can better maintain the flatness of the battery upper cover plate 1.

[0131] In addition, during normal operation of the single cell 15, the inner cavity of the groove 45 can serve as a gas storage cavity, where the gas generated inside the single cell 15 can be stored, thus reducing the degree of bulging of the single cell 15 casing.

[0132] Example 4

[0133] Unlike the above embodiments, this embodiment has a through hole 46 in the upper cover plate 1 along its width direction, forming a weak part.

[0134] Specifically, such as Figure 8 and Figure 9 As shown, this embodiment also uses a plastic cover plate 1, which can be integrally molded with a through hole 46 using an injection molding process.

[0135] As can be seen from the figure, in this embodiment, the through hole 46 extends through the upper cover plate 1 along the width direction of the upper cover plate 1 and is located between the two polarity terminals 11 of the upper cover plate 1.

[0136] In some other embodiments, a through hole 46 along the length of the upper cover plate 1 may be formed to create a weak point.

[0137] The cross-sectional shape and size of the through hole 46 can be set according to specific requirements to ensure that the area of ​​the upper cover plate 1 where the bottom of the through hole 46 is located can be opened under the set pressure.

[0138] However, it is also important to note that the through hole 46 should not be too large. If it exceeds a reasonable range, the through hole 46 may deform due to insufficient strength when the battery has not experienced thermal runaway, thus affecting battery performance. Therefore, during the design phase, it is necessary to comprehensively consider the various stresses that the top cover 1 will bear during normal battery operation, including internal pressure and external vibration. By rationally planning the corresponding dimensions of the through hole 46, while ensuring the structural stability of the top cover 1 under normal operating conditions, it is also necessary to ensure that the through hole 46 can reliably perform its explosion-venting function in the event of thermal runaway.

[0139] Compared to the weak point in Embodiment 1, this embodiment can also better maintain the flatness of the battery cover plate 1.

[0140] Example 5

[0141] This embodiment is a high-capacity battery, including a pressure-bearing casing 13 and 12 individual battery cells 15 as described in the above embodiment. In other embodiments, the number of individual battery cells 15 can be adjusted according to actual needs.

[0142] Its structure is as follows Figures 10 to 15 As shown, Figure 11 and Figure 12 To adopt Figure 2 The single-cell battery shown is an example; Figure 13 and Figure 14 To adopt Figure 7 Taking the single battery cell corresponding to the top cover assembly as an example; Figure 15 To adopt Figure 9 The single-cell battery shown is an example;

[0143] Twelve individual cells 15 from the above embodiments are arranged inside the pressure-bearing housing 13.

[0144] from Figure 12 , Figure 14 and Figure 15 It can be seen that, inside the pressure-bearing housing 13, among the adjacent single cells 15, the connecting pipe 33 of one single cell 15 is embedded in the blind hole 31 of another single cell 15 and connected by heat fusion.

[0145] In this embodiment, appropriate tools are used to open the second sidewall area of ​​the lower cover plate defined by the bottom end 32 of the blind holes 31 and the connecting pipe 33 of each individual battery cell 15, so that the inner cavities of all blind holes 31 and connecting pipe 33 are connected, and further connected to the inner cavities of all individual battery cells 15, allowing the electrolyte in the inner cavities of all individual battery cells 15 to be shared, thereby obtaining a large-capacity battery. Based on electrolyte sharing, the potential differences between individual battery cells 15 are improved, ensuring the consistency of each individual battery cell 15 during charging and discharging, extending the overall service life, and improving the performance of the large-capacity battery.

[0146] The aforementioned tool should have a sharp head and a certain strength, such as a long steel needle. Specifically, the following process can be used to open the second side wall area of ​​the lower cover plate enclosed by the blind hole bottom 32 of each individual battery cell 15 and the connecting pipe 33: Insert the tool into the blind hole 31 of one of the outermost individual battery cells 15 along the x-direction, apply a pushing force, and open the second side wall area of ​​the lower cover plate enclosed by the blind hole bottom 32 of each individual battery cell 15 and the connecting pipe 33.

[0147] It should be noted that:

[0148] 1. To ensure that the inner cavity of each individual cell 15 in the large-capacity battery is not affected by the external environment, the second side wall area of ​​the lower cover plate enclosed by the connecting pipe 33 of one of the two outermost individual cells 15 of the large-capacity battery does not need to be opened, and the blind hole 31 opening of the other outermost individual cell 15 also needs to be sealed.

[0149] 2. In order to improve the regularity of the entire large-capacity battery structure, this embodiment can cut off the outermost single cell 15 to expose the unconnected connecting pipe 33. After cutting off, it is necessary to ensure the sealing of the casing of the single cell 15.

[0150] Figure 11 and Figure 12 In this design, the weakest point is a through-slot. When the through-slots of each individual battery cell are connected, a venting channel is formed. This venting channel is located between the weakest point of each individual battery cell and the pressure-bearing casing. Alternatively, a channel can be provided on the pressure-bearing casing, covering the through-slots of each individual battery cell and forming a larger cavity venting channel.

[0151] Figure 13 and Figure 14 In the middle, the weak part is a groove opened on the lower surface of the upper cover plate. A second channel 18 needs to be set on the pressure-bearing housing. The second channel 18 covers the weak part of each individual battery cell and forms a venting channel between the two.

[0152] Figure 15 In the middle, the weak part is the through hole opened on the upper cover plate. The through holes of each individual battery are connected to form a venting channel. This venting channel is also located between the weak part (the bottom of the through hole) and the pressure-bearing shell.

[0153] The pressure-bearing housing 13 is provided with an explosion relief part 14 corresponding to the explosion relief channel (the explosion relief part 14 here can also be called an explosion-proof part, explosion-proof port or explosion relief port, etc., and is usually provided with a pressure relief valve or explosion relief membrane, etc.). When the single cell 15 thermally runs away, the thermal runaway flue gas breaks through the weak part, passes through the explosion relief channel, breaks through the explosion relief part 14 and is discharged from the pressure-bearing housing 13.

[0154] In the initial stage of thermal runaway, the thermal runaway fumes can be discharged in an orderly manner through the explosion venting channel, effectively preventing them from spreading to the large-capacity battery casing and thus preventing further deterioration of the thermal runaway situation.

[0155] The strength of the aforementioned pressure-bearing casing 13 needs to meet the strength requirements of the casing during thermal runaway, meaning that the pressure-bearing casing 13 needs to have good strength. This design not only effectively resists the high-pressure impact during thermal runaway with the reinforced outer casing, greatly improving the overall safety of the large-capacity battery; especially when a lower-strength plastic casing is used as the casing for the internal individual cells 15, the pressure-bearing casing 13 can form a robust thermal barrier. Even in the extreme case where the casing of the individual cell 15 melts, it can effectively isolate high-temperature flames and harmful gases, preventing the spread of thermal runaway and improving the safety of the large-capacity battery after thermal runaway. In addition, when plastic material is used as the casing for the internal individual cells 15, an anti-permeability membrane can be provided between each individual cell 15 and the pressure-bearing casing 13 to prevent the electrolyte inside each individual cell 15 from permeating outward.

[0156] Compared to other materials, the metal pressure-bearing housing 13 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 housing 13 does not directly contact the electrolyte, so an iron, steel, or stainless steel housing can be used. Iron housings offer advantages in strength and cost, making them a viable option in scenarios where cost is a primary concern and strength requirements are not particularly stringent. Steel housings offer relatively high strength, providing more reliable protection for the battery and are suitable for applications with high safety and structural strength requirements. Stainless steel housings not only possess good strength properties but also excellent corrosion resistance, making them ideal for battery applications facing humid or corrosive environments. This effectively extends battery life and ensures stable operation in complex environments.

[0157] like Figure 15 and Figure 16 As shown, in this embodiment, a clearance hole 17 is provided on the top plate of the pressure-bearing housing 13 corresponding to the polarity terminal 11 of each individual battery 15; the polarity terminal 11 of each individual battery 15 extends out of the clearance hole 17; the top plate area of ​​the pressure-bearing housing 13 corresponding to the clearance hole 17 is fixedly sealed with the housing of the individual battery 15.

[0158] To optimize the heat dissipation performance of the aforementioned high-capacity battery, this embodiment adds a heat exchange component 16 to the high-capacity battery to exchange heat with the polarity terminal 11. The polarity terminal 11 is a key component connecting the battery's internal and external components; during charging and discharging, current flows through the polarity terminal 11 into and out of the battery. When heat is generated inside the battery, heat dissipation through the polarity terminal 11 provides a relatively direct heat conduction path. Heat can be quickly conducted from inside the battery to the polarity terminal 11, and then dissipated from the polarity terminal 11 to the external environment. Furthermore, since the polarity terminal 11 is typically located at the positive and negative terminals of the battery, these areas are often where heat is concentrated during charging and discharging. By dissipating heat from the polarity terminal 11, the temperature of these key components can be reduced more effectively.

[0159] The heat exchange component 16 can be a heat transfer tube; each polarity terminal 11 of the individual cell 15 is provided with a through groove 42 or through hole for installing the heat transfer tube; the heat transfer tube is fixed in the through groove 42 or through hole of each polarity terminal 11 of the individual cell 15. By using the heat transfer tube on the polarity terminal 11, the heat generated inside the battery is conducted to the heat transfer tube through the polarity terminal 11, and then the heat transfer tube dissipates the heat to achieve heat dissipation of the battery.

[0160] The heat exchange component 16 can also be a heat exchange device, which is disposed on top of each individual battery cell 15. A polar terminal 11 penetrates the heat exchange device, with at least a portion of its structure located within the heat exchange device's inner cavity and in direct contact with the heat exchange medium. Another portion of the polar terminal 11 is located outside the heat exchange device, serving as an electrical connection. The sidewall of the polar terminal 11 is sealed to the heat exchange device. By employing a direct heat exchange method, a portion of the polar terminal 11 is directly placed within the heat exchange medium flow cavity (the inner cavity of the heat exchange device), allowing direct contact between the polar terminal 11 and the heat exchange medium. This achieves heat exchange for the polar terminal 11, resulting in a shorter heat exchange path. The heat exchange medium directly acts on the polar terminal 11, improving the utilization efficiency of the heat exchange medium and enhancing the battery's heat exchange efficiency.

[0161] In this embodiment, an insulating sealant layer can also be provided between each individual battery cell 15 and between each individual battery cell 15 and the pressure-bearing housing 13. The insulating sealant layer is mainly laid in the space between each individual battery cell 15 and the pressure-bearing housing 13, and the heat exchange components 16 inside the pressure-bearing housing 13 are all located within the insulating sealant layer; when there is a gap between each individual battery cell 15, the insulating sealant liquid can also penetrate into the gap to form an insulating sealant layer.

[0162] It should be noted that no insulating sealant layer is installed inside the explosion venting channel.

[0163] In this embodiment, the insulating sealant layer has at least the following advantages:

[0164] 1. Prevent condensation;

[0165] During long-term use, due to the temperature difference between the inside and outside of the heat exchange component 16, condensation will form on the surface. When the condensation accumulates to a certain amount, it may cause a short circuit. By laying an insulating sealant layer to completely wrap the heat exchange component 16, when condensation forms on the surface of the heat exchange component 16, the battery short circuit can be prevented under the protection of the insulating sealant layer.

[0166] II. Further improve the stability of each individual battery cell 15 within the pressure-bearing casing 13;

[0167] The insulating sealant penetrates into the gaps between each individual cell 15 and between each individual cell 15 and the pressure-bearing housing 13, which can further improve the stability of each individual cell 15 within the pressure-bearing housing 13.

[0168] use Figure 15 and Figure 16 In the structure shown, an insulating sealant layer can also be laid on the top plate of the pressure-bearing shell 13, and the heat exchange component 16 is located inside the insulating sealant layer. When condensation occurs on the surface of the heat exchange component 16, the battery short circuit can be prevented under the protection of the insulating sealant layer.

Claims

1. A casing for a single battery cell, characterized in that: It is composed of an upper cover plate, a cylindrical body, and a lower cover plate; the upper cover plate, the cylindrical body, and the lower cover plate are all made of plastic. Along the height direction, from bottom to top, the inner cavity of the housing is divided into an electrode assembly support area and an electrode assembly receiving area; The housing area corresponding to the electrode assembly support area is provided with a recess and a protrusion; wherein the recess is used for the protrusion on the housing of another single cell to be embedded and fixedly connected; under the action of external force, a channel can be opened in the protrusion and the recess, and the channel communicates with the electrolyte area inside the single cell housing. The top cover plate has an integrally formed weak section; the strength of the weak section is less than the strength of the rest of the top cover plate. When a single cell experiences thermal runaway, the thermal runaway smoke breaks through the weak section and is discharged.

2. The housing for a single battery cell according to claim 1, characterized in that: The recess is a blind hole formed on the first side wall of the lower cover plate; the protrusion is a connecting tube provided on the outer wall of the second side wall of the lower cover plate; the connecting tube is used to be embedded in the blind hole of another single battery cell and fixedly connected; the first side wall of the lower cover plate and the second side wall of the lower cover plate are parallel to each other.

3. The housing for a single battery cell according to claim 2, characterized in that: The inner surface of the lower cover plate has multiple protrusions arranged in an array. The top of the protrusions is used to support the electrode assembly, and the gap between the protrusions serves as an electrolyte flow channel.

4. The housing for a single battery cell according to claim 3, characterized in that: Under the action of external force, the bottom end of the blind hole and the second side wall area of ​​the lower cover plate defined by the connecting pipe can be opened and connected to the electrolyte flow channel.

5. The housing for a single battery cell according to claim 1, characterized in that: A recessed area is provided on the top cover plate to form a weak part; or, a through hole is opened on the top cover plate along its width or length to form a weak part.

6. The housing for a single battery cell according to claim 1, characterized in that: Both the recess and the protrusion are integral with the cylinder or the lower cover plate; the recess is used for the protrusion of another single battery cell to be inserted and fixedly connected by heat fusion.

7. A single-cell battery, characterized in that: Includes the casing for a single-cell battery as described in any one of claims 1 to 6.

8. The single-cell battery according to claim 7, characterized in that: The shell strength is P, where P1≤P≤P2; where P1 is the strength requirement of the shell during the formation stage and the normal charging and discharging stage of the battery; and P2 is the strength requirement of the shell during the thermal runaway stage.

9. A high-capacity battery, characterized in that: It includes a pressure-bearing housing and n individual battery cells as described in claim 7 or 8 arranged within the pressure-bearing housing, where n is an integer greater than 1; In adjacent individual cells, the protrusion of one individual cell is inserted into the recess of another individual cell and fixedly connected; the protrusion and the recess form a channel that penetrates the electrolyte area inside the individual cell housing; a venting channel is formed between the weak part of each individual cell and the pressure-bearing housing. The pressure-bearing shell has the strength required for the shell during the thermal runaway stage. The pressure-bearing shell is equipped with a venting section corresponding to the venting channel. When a single cell experiences thermal runaway, the thermal runaway flue gas breaks through the weak part, passes through the venting channel, and then breaks through the venting section to exit the pressure-bearing shell.

10. The high-capacity battery according to claim 9, characterized in that: The top plate of the pressure-bearing housing has clearance holes corresponding to the polarity terminals of each individual battery; the polarity terminals of each individual battery extend out of the clearance holes; the area of ​​the top plate of the pressure-bearing housing corresponding to the clearance holes is fixedly sealed to the individual battery housing.

11. The high-capacity battery according to claim 9, characterized in that: It also includes heat exchange components that exchange heat with the polarity terminals.

Images