High-capacity battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a high-capacity battery. The problems of high cost, large weight and low energy density of the existing high-capacity battery due to thicker shell thickness are solved. Comprising a shell and a battery pack assembly located in the shell. The wall thickness of the shell is 1-5mm; the battery pack assembly comprises a battery pack, an end part fixing plate and a fixing belt; the battery pack comprises a plurality of single batteries with mutually communicated inner cavities; the two end fixing plates abut against the two ends of the battery pack respectively. And the fixing band is sleeved on the peripheries of the two end part fixing plates and the battery pack so as to fix the battery pack between the two end part fixing plates. According to the utility model, the thin-wall shell is combined with the end part fixing plate and the fixing belt, so that the cost is reduced, the light weight is realized, and the overall structural strength is ensured.

Description

Technical Field

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

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

[0003] However, existing high-capacity batteries have inherent differences among their individual cells. Due to the "weakest link" effect, the performance of the weakest cell often affects the overall capacity, significantly limiting the battery's maximum capacity and cycle life. Therefore, improving the uniformity of individual cells in high-capacity batteries has become a key focus and challenge in this field.

[0004] Chinese patent CN 117977079 A discloses a high-capacity battery, including a casing and multiple individual cells connected in parallel and arranged inside the casing cavity. Each individual cell cavity includes an electrolyte region and a gas region. An electrolyte sharing channel is provided at the bottom of the casing, communicating with the electrolyte regions of each individual cell cavity. This high-capacity battery, through the electrolyte sharing channel, can enhance the uniformity of the electrolyte in each individual cell and improve cycle life.

[0005] The casing thickness of the aforementioned high-capacity batteries is greater than 7mm. The thicker casing not only consumes a lot of materials and increases the cost of raw materials, but also increases the weight significantly, reducing the portability of the battery. At the same time, the excessive weight and thickness of the casing reduce the overall energy density of the battery. Utility Model Content

[0006] The purpose of this invention is to provide a high-capacity battery that overcomes the problems of high cost, heavy weight, and low energy density of existing high-capacity batteries due to their thick outer casing.

[0007] This utility model of a high-capacity battery includes a casing and a battery pack assembly located inside the casing;

[0008] The wall thickness of the aforementioned outer casing is 1-5 mm;

[0009] The aforementioned battery pack assembly includes a battery pack, an end mounting plate, and a mounting strap;

[0010] The battery pack includes n individual cells arranged along a first direction, and the internal cavities of the n individual cells are interconnected; where n is an integer greater than 1; the top plate of the outer casing is provided with clearance holes corresponding to the polarity terminals of each individual cell; each polarity terminal extends out of the corresponding clearance hole; the clearance hole is fixedly sealed to the top plate area of ​​the outer casing and the individual cell casing.

[0011] There are two end fixing plates, which abut against both ends of the battery pack respectively;

[0012] The aforementioned fixing straps are fitted onto the two end fixing plates and the outer periphery of the battery pack to fix the battery pack between the two end fixing plates.

[0013] This invention sets the casing thickness of a large-capacity battery between 1-5mm, which is thinner than that of large-capacity batteries in the prior art. The thinner casing directly reduces the amount of material used. While meeting the basic structural strength requirements of the battery, this thinner casing design significantly reduces material costs. More importantly, the overall cost advantage will be very prominent during mass production.

[0014] At the same time, with the reduction in the amount of materials used, the overall weight of the battery is significantly reduced, which not only improves the portability of the battery, but also makes it convenient for users to carry and use it in various scenarios.

[0015] Furthermore, by reducing the thickness of the outer casing, the volume ratio of the energy storage section (individual cells) in the battery pack can be relatively increased while maintaining the same overall battery volume. This optimized volume ratio significantly improves the battery's energy density. Simultaneously, due to the weight reduction, the weight ratio of the energy storage section (individual cells) in the battery pack can be relatively increased while maintaining the same overall battery weight. This optimized weight ratio also contributes to a significant increase in the battery's energy density.

[0016] Because the casing of this invention is relatively thin, its strength is relatively weak. To overcome this problem, this invention utilizes fixing straps and two end fixing plates to secure the battery pack, improving the overall structural stability. By enhancing overall stability, the excessively high requirements for the strength of the battery casing are reduced. In this way, while ensuring the safe and reliable operation of the battery, the advantages of the thinner casing design in terms of cost control can be fully utilized.

[0017] Furthermore, the wall thickness of the aforementioned casing is 1.5-2mm, which, while meeting the basic requirements for battery structural strength, can further reduce battery cost, decrease battery weight, and increase battery energy density.

[0018] Furthermore, the aforementioned battery pack assembly also includes at least one separator; the separator is disposed between adjacent individual cells.

[0019] In high-capacity batteries, multiple individual cells generate heat during operation. Separators, placed between adjacent cells, effectively increase the heat dissipation area within the battery pack. When heat is generated, the separators act as a heat conduction medium, rapidly transferring heat from individual cells to all parts of the battery pack, accelerating heat dissipation. This effectively reduces the overall temperature of the battery pack, preventing performance degradation or shortened lifespan due to overheating, and ensuring the stability and reliability of the battery under high load operation.

[0020] In addition, as the battery charges and discharges, chemical reactions occur inside the individual cells, causing the battery volume to expand to a certain extent. When the individual cells expand, the separator can deform within a certain range to buffer this expansion force, preventing the individual cells from being damaged by mutual compression, thus improving the safety and durability of the battery pack.

[0021] Furthermore, the aforementioned battery pack assembly also includes at least two fixing stiffeners;

[0022] The aforementioned fixing stiffeners are fixed perpendicularly to the plane of the partition and to the opposite sides of the partition. In the first direction, the partition extends out from both sides of the fixing stiffeners.

[0023] The fixing ribs extend out of both sides of the separator and abut against the sides of the individual cells on both sides of the separator, and the fixing ribs are welded to the outer casing.

[0024] The aforementioned fixing ribs are tightly connected to the separator and the outer shell, which to a certain extent strengthens the rigidity of the entire large-capacity battery, comprehensively improves the strength of the outer shell structure, and effectively ensures the safe operation of the battery.

[0025] In addition, the fixing ribs extend out from both sides of the partition and abut against the sides of the individual cells, which plays a limiting role, preventing the individual cells from shaking or shifting within the battery pack, avoiding collisions, and ensuring that the battery pack can operate stably even under vibration and bumpy conditions.

[0026] In addition, the fixing ribs are in close contact with the individual cells, which can efficiently conduct the heat generated by the charging and discharging of the battery, and dissipate the heat through the connection with the outer casing, maintain the internal temperature balance of the battery pack, extend the battery life, and improve the battery performance in all aspects.

[0027] Furthermore, the aforementioned outer casing includes a box body with an open end and a top plate for sealing the open end of the box body;

[0028] One of the open-ended boxes is formed in one piece using a stamping process.

[0029] Stamping enables efficient mass production, reducing splicing and welding processes, lowering costs and errors, and improving product consistency and yield. The unibody casing structure is more robust, with no seams, better able to withstand internal and external forces, strengthening the outer shell and providing reliable protection for the battery pack.

[0030] Furthermore, the casing material can be either steel or aluminum. Steel casings offer high strength, but the inner wall needs to be lined with an electrolyte-repellent film to prevent reaction with the electrolyte and its impact on battery performance. Aluminum, on the other hand, has low density, is lightweight, does not react with the electrolyte, and has high thermal conductivity, facilitating heat dissipation and ensuring long-term stable and reliable battery operation.

[0031] Furthermore, the aforementioned high-capacity battery also includes an annular pad located inside the casing; the annular pad is disposed between the lower cover plate of each individual cell and the bottom plate of the casing.

[0032] Each individual cell has a first through hole on its lower cover plate. The inner hole of the annular pad is located directly below each first through hole, forming an electrolyte sharing channel between the lower cover plate of each individual cell and the bottom plate of the casing. This allows each individual cell to be in the same electrolyte system, improving the performance of the high-capacity battery.

[0033] Furthermore, a liquid storage cavity is provided on the aforementioned end fixing plate to store free electrolyte, and the liquid storage cavity and the electrolyte share a channel for communication.

[0034] This invention features a liquid storage chamber on the end fixing plate, which stores free electrolyte. The electrolyte possesses a certain thermal conductivity; during battery cell operation, if the temperature rises, the free electrolyte stored in the chamber 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.

[0035] In addition, when a single battery cell is working, the electrolyte can be replenished in a timely manner to avoid local drying out, ensure stable internal reactions, and improve charge and discharge performance.

[0036] Furthermore, the aforementioned high-capacity battery also includes a heat exchange component; the heat exchange component exchanges heat with the polarity terminals.

[0037] As a crucial component connecting the internal and external parts of a battery cell, the polarity terminal allows current to flow in and out of the cell during charging and discharging. When heat is generated inside the battery cell, the polarity terminal provides a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery cell to the polarity terminal, and then dissipated from the terminal into the external environment.

[0038] Furthermore, since the polarity terminals are typically located at the positive and negative terminals of the battery cell, these areas are often where heat is concentrated during charging and discharging. By dissipating heat from the polarity terminals, the temperature of these critical components can be reduced more effectively.

[0039] Furthermore, a cavity is provided at the portion of the polarity terminal that extends out of the clearance hole, the cavity penetrating the polarity terminal along the first direction, and the cross-section of the cavity is an open cross-section.

[0040] The heat exchange component is a heat transfer tube, and the cross-section of the heat transfer tube is adapted to the cross-section of the cavity.

[0041] The aforementioned heat transfer tubes are inserted into the cavities of the polarity terminals located on the same side along the first direction;

[0042] The top plate of the aforementioned outer casing is provided with a first insulating sealant layer, which seals the open port of the heat transfer tube; a heat exchange channel is formed on the top plate of the outer casing.

[0043] This invention inserts heat transfer tubes into the cavities of the polar terminals of each individual battery cell located on the same side, forming a heat transfer channel at the top of the large-capacity battery for heat exchange. A portion of the battery polar terminal structure is directly placed within the heat transfer medium flow cavity, allowing direct contact between the polar terminals and the heat transfer medium, thus achieving heat exchange at the polar terminals. This provides a shorter heat exchange path, and the heat transfer medium acts directly on the polar terminals, improving the utilization efficiency of the heat transfer medium and enhancing the heat exchange efficiency of the large-capacity battery.

[0044] The beneficial effects of this utility model are:

[0045] This invention combines a thin-walled outer shell with an end fixing plate and a fixing strap, which reduces costs and achieves lightweight while ensuring overall structural strength. Its advantages are specifically reflected in the following aspects:

[0046] 1. Lower cost;

[0047] By setting the casing wall thickness to 1-5mm, compared with conventional large-capacity batteries with a wall thickness greater than 5mm, the amount of material used is significantly reduced, greatly lowering material costs. Especially in mass production, the overall cost advantage is extremely prominent.

[0048] 2. Lighter weight;

[0049] With the reduction in the amount of casing material used, the overall weight of the battery is significantly reduced. This is of great significance for weight-sensitive applications.

[0050] 3. High energy density;

[0051] While keeping the total battery volume constant, reducing the thickness of the outer casing allows for a relative increase in the volume ratio of the energy storage section (individual cells) in the battery pack, thereby improving the battery's energy density.

[0052] At the same time, due to the weight reduction, the weight ratio of the energy storage component (individual cells) in the battery pack can be relatively increased while keeping the total battery weight unchanged. This optimized weight ratio can also lead to a significant increase in the battery's energy density.

[0053] 4. Stable structure;

[0054] The battery pack is secured using a fixing strap and two end fixing plates, forming a stable overall structure. The two end fixing plates abut against both ends of the battery pack along a first direction, and the fixing strap is fitted around the two end fixing plates and the outer perimeter of the battery pack, firmly fixing the battery pack between the two end fixing plates. This effectively prevents displacement or collision of individual battery cells during use, reducing the strength requirements on the casing.

[0055] The retaining straps encircle the battery pack assembly, which not only secure the battery pack assembly but also evenly distribute any external pressure, reducing the risk of damage to the casing due to concentrated pressure. Overall, this significantly improves the structural strength and reliability of the battery. Attached Figure Description

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

[0057] Figure 2 This is a schematic diagram of the exploded structure of the large-capacity battery in Example 1;

[0058] Figure 3 This is a schematic diagram of the battery pack assembly in Example 1;

[0059] Figure 4 This is a schematic diagram of the battery pack assembly in Example 2;

[0060] Figure 5 This is a partial exploded view of the battery pack assembly in Example 2;

[0061] Figure 6 This is a schematic diagram of the end fixing plate in Example 3;

[0062] Figure 7 This is a schematic diagram of the structure of the high-capacity battery in Example 4;

[0063] Figure 8 This is a cross-sectional view of the high-capacity battery in Example 4;

[0064] Figure 9 This is a partial enlarged cross-sectional view of the large-capacity battery in Example 4;

[0065] Figure 10 This is a schematic diagram of the partial explosion structure of the large-capacity battery in Example 4.

[0066] The attached figures are labeled as follows:

[0067] 1. Outer shell; 11. Housing; 12. Top plate; 13. Clearance hole; 2. Battery pack assembly; 21. Battery pack; 211. Individual cell; 212. Polar terminal; 213. First through hole; 214. Cavity; 22. End fixing plate; 221. Liquid storage chamber; 222. Supporting rib; 223. Limiting groove; 23. Fixing strap; 3. Annular pad; 31. Inner hole; 4. Partition plate; 5. Fixing rib; 6. Heat transfer tube; 7. Blind hole; 8. Second through hole. 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," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] Example 1

[0072] like Figure 1 and Figure 2 The figures show a schematic diagram and an exploded view of the high-capacity battery of this embodiment, respectively. As can be seen from the figures, the high-capacity battery of this embodiment includes a casing 1 and a battery pack assembly 2 arranged within the casing 1. The battery pack assembly 2 mainly consists of a battery pack 21, an end fixing plate 22, and a fixing strap 23. The battery pack 21 includes 12 individual battery cells 211 arranged along a first direction. In other embodiments, the number of individual battery cells 211 can be adjusted according to actual needs.

[0073] from Figure 1As can be seen from the figure, the outer shell 1 in this embodiment is a rectangular shell. For ease of description, the length direction of the outer shell 1 can be defined as the x direction (the x direction is the same as the first direction mentioned above), the width of the outer shell 1 can be defined as the y direction, and the height of the outer shell 1 can be defined as the z direction.

[0074] This embodiment aims to reduce the cost of high-capacity batteries, focusing on optimizing the thickness of the outer casing 1. The wall thickness of the outer casing 1 is set within the range of 1-5mm. While meeting the basic structural strength requirements of the battery, the wall thickness can be further limited to the range of 1.5-2mm.

[0075] Compared to traditional high-capacity batteries, the outer casing 1 of this invention is significantly thinner. While ensuring the battery structure meets basic strength requirements, it significantly reduces material costs. This cost advantage is particularly pronounced during mass production. Simultaneously, with reduced material usage, the overall battery weight is significantly reduced. This not only improves portability, making it more convenient for users to carry and use in various scenarios, but also, with a thinner outer casing 1, the volume ratio of the energy storage section (individual cells 211) in the battery pack 21 can be relatively increased while maintaining the same total battery volume. This optimized volume ratio significantly improves the energy density of the battery pack. At the same time, due to the reduced weight, the weight ratio of the energy storage section (individual cells 211) in the battery pack 21 can also be relatively increased while maintaining the same total battery pack weight. This optimized weight ratio also contributes to a significant increase in the energy density of the battery pack.

[0076] On the top plate 12 of the outer casing 1 (the top plate 12 here is the plate that is parallel to the xy plane and close to the polarity terminal 212), there are clearance holes 13 corresponding to the polarity terminals 212 of each individual battery 211; each polarity terminal 212 extends out of the corresponding clearance hole 13; the clearance hole 13 is fixedly sealed to the housing of the individual battery 211 in the area of ​​the top plate 12 of the outer casing 1.

[0077] It should be noted that the polarity terminal 212 of the single cell 211 mentioned here can be the terminal post of the single cell 211. To prevent the terminal post of the single cell 211 from not extending smoothly out of the clearance hole 13 or from not meeting the required height when extending out of the clearance hole 13, a terminal post adapter can be connected to the terminal post of the single cell 211, and the overall structure of the terminal post of the single cell 211 and the terminal post adapter can be used as the polarity terminal 212 of the single cell 211. A corresponding connection structure can be provided on the terminal post adapter. For example, a folded edge structure can be provided on the terminal post adapter, and the terminal post can be welded or bolted to it through the folded edge structure; alternatively, a blind hole 7 extending along the z-direction can be opened on the terminal post adapter, and the terminal post can be welded or bolted to it through the bottom of the blind hole 7 (see details). Figure 8 and Figure 9 (Structure shown).

[0078] Inside the outer casing 1, the internal cavities of each individual battery cell 211 are interconnected, specifically through a shared channel set inside the outer casing 1.

[0079] The aforementioned shared channel can be an electrolyte sharing channel. This channel ensures that each individual battery cell 211 is in a uniform electrolyte environment, guaranteeing the homogeneity of the electrolyte within each cell and improving the performance and charge-discharge cycle life of the high-capacity battery. The electrolyte sharing channel described here is a liquid channel extending along the length of the outer casing 1 between the bottom plate of the outer casing 1 (which is a plate parallel to the top plate 12) and each individual battery cell 211. This liquid channel can be integrally formed with the bottom plate of the outer casing 1, or it can be formed by providing a support member between the lower cover plate of the individual battery cell 211 and the bottom plate of the outer casing 1.

[0080] The aforementioned shared channel can also be a gas shared channel. This channel achieves gas balance among the individual battery cells 211, thereby improving the performance and charge / discharge cycle life of the large-capacity battery. Here, the gas shared channel is a gas channel extending along the length of the casing 1 between the top plate 12 of the casing 1 and each individual battery cell 211.

[0081] The aforementioned shared channel can also be a gas-liquid shared channel. A gas-liquid shared channel allows each individual battery cell 211 to be in a unified electrolyte and gas environment, improving the performance and charge-discharge cycle life of the large-capacity battery. The gas-sharing channel described here is a channel extending along the length of the casing 1 between the side plate of the casing 1 (a plate parallel to the xz plane) and each individual battery cell 211.

[0082] This embodiment mainly uses an electrolyte sharing channel as an example for explanation. An electrolyte sharing channel is formed by setting a support between the lower cover plate of the single cell 211 and the bottom plate of the outer casing 1. Specifically, as shown below... Figure 2 As shown, an annular pad 3 is provided as a support between the lower cover plate of each individual battery 211 and the bottom plate of the outer casing 1, and a first through hole 213 is opened on the lower cover plate of each individual battery 211 (see reference). Figure 5 The inner hole 31 of the annular pad 3 is located directly below each of the first through holes 213, forming an electrolyte sharing channel between the lower cover plate of each individual cell 211 and the bottom plate of the outer casing 1, so that each individual cell 211 is under the same electrolyte system, thereby improving the performance of the large-capacity battery.

[0083] This embodiment does not specifically limit the structure of the outer shell 1, but at least the following two structures can be adopted:

[0084] The first structure includes a cylindrical body with open ends (i.e., the port parallel to the yz plane is the open end) and end plates fixed to the two open ends of the cylindrical body (i.e., the end plates are parallel to the yz plane).

[0085] The second structure includes a cylinder with open ends at the top and bottom (i.e., the port parallel to the xy plane is the open end) and a top plate 12 and a bottom plate respectively fixed to the open ends at the top and bottom of the cylinder (i.e., both the top plate 12 and the bottom plate are parallel to the xy plane, and the top plate 12 or the bottom plate can be an integral structure with the cylinder).

[0086] like Figure 2 As shown, this embodiment uses the second structure, where the base plate and the cylinder are integral parts. Specifically, in this embodiment, the outer shell 1 consists of a box 11 with one open end and a top plate 12 for sealing the open end of the box 11. The box 11 with one open end can be integrally formed using a stamping process. In terms of manufacturing, integrally forming the box 11 with one open end using a stamping process has significant advantages. The stamping process enables efficient and mass production, greatly improving production efficiency. Integral forming means reducing complex processes such as splicing and welding, reducing labor and time costs in the production process, and also reducing errors that may occur due to the assembly of multiple parts, improving product consistency and yield. From a structural performance perspective, the integrally formed box 11 is more stable. Compared to a box 11 composed of multiple spliced ​​parts, integral forming eliminates splicing gaps, avoiding the problem of overall structural weakness caused by insufficient strength at the gaps. This allows the housing 11 to better maintain its structural integrity when subjected to the pressure of the internal battery pack 21 and possible external impacts and compressions, further enhancing the structural strength of the battery casing 1 and providing more reliable protection for the battery pack 21.

[0087] The box 11, formed by stamping, has an open end and a certain draft angle. In this embodiment, the draft angle can be corrected by using the end fixing plates 22 on both sides, allowing for more precise assembly of the battery pack assembly 2 and the outer casing 1. The end fixing plates 22 can be designed as inclined surfaces that complement the draft angle of the box 11. During assembly, the end fixing plates 22 apply appropriate pressure to fine-tune the sides of the box 11, compensating for dimensional deviations caused by the draft angle. This not only improves the flatness of the outer casing 1 but also enhances the sealing when installing the top plate 12, effectively preventing dust, moisture, and other impurities from entering and affecting battery performance.

[0088] In this embodiment, the outer shell 1 can be made of steel or aluminum.

[0089] The steel casing 1 has relatively high strength, providing robust physical protection for the battery pack 21. However, under certain circumstances, it may react chemically with the electrolyte, negatively impacting battery performance. To overcome this problem, this embodiment provides an electrolyte-repellent film on the inner wall of the steel casing 1, acting as a barrier to effectively isolate the steel casing 1 from the electrolyte and prevent direct contact and reaction between the two.

[0090] The electrolyte-repellent membrane should have at least two characteristics: firstly, it should not react with the electrolyte; secondly, it should have good mechanical properties and be able to firmly adhere to the inner wall of the steel shell 1, thus playing a stable role in isolation over a long period of time. In this embodiment, the electrolyte-repellent membrane can be a metallic nickel layer coated on the inner wall of the steel shell 1, or it can be a polytetrafluoroethylene (PTFE) coating, etc.

[0091] The aluminum casing 1 has a low density, making it significantly lighter than traditional steel. Furthermore, unlike steel, aluminum does not react with the electrolyte, ensuring the battery's long-term stability and reliability. In addition, aluminum has high thermal conductivity, enabling it to quickly dissipate heat generated inside the battery.

[0092] In some other embodiments, the outer shell 1 of the first structure can also be used, and the cylindrical body with open ends can be prepared by aluminum extrusion process.

[0093] Given that the outer casing 1 in this embodiment is relatively thin, its strength is somewhat weakened. To effectively solve this problem, this embodiment adopts a design combining a fixing strap 23 and two end fixing plates 22 in the battery pack assembly 2, thereby firmly fixing the battery pack 21 and significantly improving the overall structural stability. By strengthening the overall stability of the battery pack 21, the reliance on the high strength of the battery casing 1 is reduced, ensuring battery performance while fully leveraging the advantages of the thin-casing design in terms of cost control, etc.

[0094] Specifically, such as Figure 3 As shown, the battery pack assembly 2 in this embodiment includes two end fixing plates 22, which are arranged along the x-direction (the same direction as the arrangement of the individual battery cells 211) and abut against both ends of the battery pack 21. Two fixing straps 23 are also present, arranged along the z-direction, and respectively fitted onto the two end fixing plates 22 and the outer periphery of the battery pack 21 to fix the battery pack 21 between the two end fixing plates 22. One fixing strap 23 is closer to the top of the battery pack 21; the other is closer to the bottom, forming a symmetrical constraint structure around the battery pack 21. In practical applications, the number and installation position of the fixing straps 23 can be flexibly adjusted according to the specific size of the battery pack 21, the usage environment, and the stress conditions. For example, for a larger battery pack 21 subjected to complex stresses, the number of fixing straps 23 can be appropriately increased to provide stronger fixation and protection.

[0095] To limit the movement of the fixing band 23, a limiting groove 223 can be provided on the end fixing plate 22, and the fixing band 23 can be embedded in the limiting groove 223. In terms of the forming method, on the one hand, part of the structure of the end fixing plate 22 can be removed to form the limiting groove 223; on the other hand, ribs can be added to the end fixing plate 22, and the limiting groove 223 can be formed between adjacent ribs.

[0096] The shape of the end fixing plate 22 is generally adapted to the side shape of the adjacent single battery cell 211. In this embodiment, it is a rectangular flat plate, and its thickness needs to ensure that it has sufficient strength to support the battery pack 21 and withstand the tension of the fixing strap 23. The limiting groove 223 can be formed on the two sides of the end fixing plate 22 parallel to the xz plane, or it can be formed on the side of the end fixing plate 22 parallel to the yz plane. The depth and width of the limiting groove need to ensure that the fixing strap 23 can be tightly embedded, but also has a certain amount of room to move within the limiting groove, so as to facilitate installation and adjustment.

[0097] The fixing strap 23 has a continuous ring structure. The length of the fixing strap 23 needs to be accurately calculated based on the actual dimensions of the battery pack 21 and the end fixing plate 22 to ensure that it can fit tightly after wrapping around the battery pack 21 and the end fixing plate 22.

[0098] The fixing strap 23 in this invention not only serves to secure the battery pack assembly 2, but more importantly, it effectively compensates for the weakness of the thin outer casing 1. The fixing strap 23 tightly wraps around the outer periphery of the battery pack assembly 2, evenly distributing any external pressure. In practical applications, external forces such as compression and impact are evenly transmitted to the entire battery pack 21 by the fixing strap 23, preventing pressure concentration in a specific area of ​​the battery casing 1. This reduces the risk of damage to the casing 1 due to pressure concentration, comprehensively improving the structural strength and reliability of the battery.

[0099] Example 2

[0100] The large-capacity battery in this embodiment differs from that in Embodiment 1. Based on the battery pack assembly 2 in Embodiment 1, this embodiment adds a separator 4 between adjacent individual cells 211 to further improve the structural stability of the battery pack assembly 2 and optimize its heat dissipation performance.

[0101] The structure of battery pack component 2 in this embodiment is as follows: Figure 4 and Figure 5 As shown in the figure, this embodiment has a separator 4 between every three individual cells 211, and a total of 3 separators 4 are provided.

[0102] During the operation of a large-capacity battery, as the charging and discharging process proceeds, a chemical reaction occurs inside the individual battery cell 211, causing a certain degree of volume expansion. Compared to Example 1, in this example, when the individual battery cell 211 expands, the separator 4 can deform within a certain range to buffer this expansion force, thus maintaining the overall stability of the battery pack assembly 2 and preventing the application of additional stress to the outer casing 1 that could potentially damage it.

[0103] Furthermore, when heat is generated, the separator 4 acts as a heat conduction medium, rapidly transferring the heat generated by the individual battery cell 211 to all parts of the battery pack 21, accelerating heat dissipation. This effectively reduces the overall temperature of the battery pack 21, preventing battery performance degradation or shortened lifespan due to overheating, and ensuring the stability and reliability of the battery under high load operation.

[0104] In other embodiments, the number of separators 4 can be flexibly adjusted based on factors such as the capacity of the battery pack 21, the number of individual cells 211, and the expected usage environment. For example, if the capacity of the battery pack 21 is large and the individual cells 211 generate a lot of heat, the number of separators 4 can be appropriately increased to enhance the heat dissipation effect; if the number of individual cells 211 is large, the number of separators 4 can also be increased to ensure structural stability.

[0105] To further improve the overall structural stability of the battery pack assembly 2, this embodiment can also provide a fixing rib 5 on the separator 4 (the fixing rib 5 and the separator 4 can be an integral part or separate parts), specifically as follows: Figure 4 and Figure 5 As shown, in this embodiment, three fixing ribs 5 are respectively provided on opposite sides of each partition 4. The three fixing ribs 5 are evenly distributed along the z-direction, and each fixing rib 5 is parallel to the xz plane. In the thickness direction (x-direction) of the partition 4, the size of the fixing rib 5 is larger than the thickness of the partition 4. It extends out of the partition 4 on both sides and abuts against the sides of the individual battery cells 211 on both sides of the partition 4, so as to limit the individual battery cells 211 on both sides from the y-direction.

[0106] In other embodiments, the number of fixing ribs 5 can be flexibly adjusted according to various factors such as the specific specifications of the battery pack 21, the expected external forces it will withstand, and the arrangement of the individual cells 211. For example, if the battery pack 21 is used in an environment with frequent vibration, the number of fixing ribs 5 can be appropriately increased, and they can be installed in key parts of the battery pack 21 that are susceptible to vibration.

[0107] In some other embodiments, fixing ribs 5 can also be provided on the other two opposite sides of the partition 4, that is, the fixing ribs 5 are parallel to the xy plane and can limit the single cell 211 from the z direction.

[0108] After the battery pack assembly 2 is installed inside the housing 1, the fixing stiffener 5 can be welded to the housing 1 by through welding to ensure that a strong and durable connection is formed between the fixing stiffener 5 and the housing 1, so that the two are tightly integrated into a whole structure.

[0109] In this embodiment, the fixing rib 5 is tightly connected to the partition 4 and the outer shell 1, which has at least the following advantages:

[0110] From a structural strength perspective, this design enhances the rigidity of the entire large-capacity battery to a certain extent. The fixing rib 5, working in conjunction with the separator 4 and the outer casing 1, comprehensively improves the structural strength of the outer casing 1. In practical applications, when the battery is subjected to external impact or compression, the fixing rib 5 effectively disperses the external force, preventing the outer casing 1 from deforming or cracking due to excessive localized stress, thus strongly ensuring the safe operation of the battery. Furthermore, the fixing rib 5 extends beyond the sides of the separator 4 and tightly abuts against the sides of the individual battery cell 211, thus limiting the position of the individual battery cell 211. During daily use of the battery pack 21, especially under complex conditions such as vibration and bumps, it can prevent the displacement of the individual battery cells 211.

[0111] In terms of heat dissipation, since the fixing rib 5 is in close contact with the individual battery cell 211, it can effectively conduct the heat generated by the battery during charging and discharging, and dissipate the heat to the outside through the connection with the outer casing 1. This helps to maintain the temperature balance inside the battery pack 21, prevent local overheating, thereby extending the battery's lifespan and improving the overall performance of the battery.

[0112] Example 3

[0113] Unlike the above embodiments, this embodiment, based on the above embodiments, provides a liquid storage chamber 221 on the end fixing plate 22, stores free electrolyte in the liquid storage chamber 221, and the liquid storage chamber 221 is connected to the electrolyte through a shared channel.

[0114] The electrolyte has excellent thermal conductivity. During battery operation, especially during charging and discharging, individual cells 211 generate heat due to electrochemical reactions. When the battery temperature rises, the electrolyte can quickly absorb this heat. Because the storage chamber 221 and the electrolyte share a common channel and are interconnected, the absorbed heat can be evenly distributed. Subsequently, the heat is dissipated to the surrounding environment through the surface of the casing 1, effectively preventing the battery from overheating. This process precisely regulates the battery temperature and maintains stable battery performance. In addition, the electrolyte in the storage chamber 221 can replenish the electrolyte consumed by the individual cells 211 during operation, preventing localized drying and thus improving the battery's charging and discharging performance.

[0115] The specific structure of the end fixing plate 22 in this embodiment is as follows: Figure 6As shown, the liquid storage cavity 221 extends through the end fixing plate 22 in the z direction. In order to enhance the strength of the end fixing plate 22, multiple supporting ribs 222 are provided in the liquid storage cavity 221. The multiple supporting ribs 222 are arranged along the y direction, and each supporting rib 222 extends along the z direction.

[0116] Example 4

[0117] To optimize the heat dissipation performance of the aforementioned high-capacity battery, unlike the previous embodiment, this embodiment incorporates a heat exchange component to exchange heat with the polarity terminal 212. The polarity terminal 212 is a crucial component connecting the battery's internal and external components; during charging and discharging, current flows through the terminal 212 into and out of the battery. When heat is generated inside the battery, heat dissipation through the polarity terminal 212 provides a relatively direct heat conduction path. Heat can be rapidly conducted from inside the battery to the polarity terminal 212, and then dissipated from the terminal 212 into the external environment. Furthermore, since the polarity terminal 212 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 212, the temperature of these critical components can be reduced more effectively.

[0118] like Figure 7 , Figure 8 and Figure 9 As shown, in this embodiment, a heat transfer tube 6 with a U-shaped cross-section (a cross-section perpendicular to the x-direction) is used as a heat exchange component; correspondingly, a cavity 214 with a U-shaped cross-section is opened at the part of each polarity terminal 212 that extends out of the avoidance hole 13, and the cavity 214 passes through the polarity terminal 212 in the x-direction.

[0119] Combination Figure 10 As can be seen, in this embodiment, the heat transfer tube 6 is inserted along the x-direction into the cavity 214 of each polarity terminal 212 located on the same side; combined with Figure 7 , Figure 8 and Figure 9As can be seen, at this time, there may be a small gap between the end face of the open port of the heat transfer tube 6 inserted into the cavity 214 of the polar terminal 212 (it should be noted here that the open port of the heat transfer tube 6 refers to the port parallel to the xy plane) and the inner wall of the cavity 214. There is also a certain gap between the end face of the open port of the heat transfer tube 6 not inserted into the cavity 214 of the polar terminal 212 and the top plate 12 of the outer shell 1. In order to ensure that the heat transfer medium does not overflow from the above gaps, this embodiment lays a first insulating sealant layer on the top plate 12 of the outer shell 1. In the z direction, the height of the first insulating sealant layer is higher than the end face of the open port of the heat transfer tube 6, thereby sealing the above gaps, effectively preventing the leakage of the heat transfer medium, ensuring the integrity and efficiency of the heat transfer channel, and enabling heat to be continuously and stably dissipated through the heat transfer tube 6 and the heat transfer medium, further improving the heat dissipation performance of the battery module.

[0120] In some other embodiments, the cross-section of the cavity 214 may be C-shaped, corresponding to the C-shaped cross-section of the heat transfer tube 6. In some other embodiments, the cross-section of the cavity 214 may be Ω-shaped, corresponding to the Ω-shaped cross-section of the heat transfer tube 6.

[0121] For ease of description, the cavity 214 having the aforementioned non-closed cross-section such as U-shape, C-shape, or Ω-shape is defined as an open cross-section cavity 214. That is, in this embodiment, a cavity 214 with an open cross-section is formed on the polar terminal 212. The heat transfer tube 6 also has an open cross-section, and its cross-section is adapted to the cross-section of the cavity 214 on the polar terminal 212.

[0122] In this embodiment, efficient heat exchange is achieved through ingenious structural design. Specifically, a heat transfer tube 6 is inserted into the cavity 214 of the polarity terminal 212 on the same side of each individual battery cell 211. The open port of the heat transfer tube 6 is sealed using a first insulating sealant layer, thereby constructing two heat exchange channels. A heat transfer medium is injected into the heat exchange channels to facilitate heat exchange for the large-capacity battery. Part of the structure of the battery polarity terminal 212 is directly placed inside the heat exchange channel, allowing direct contact between the polarity terminal 212 and the heat transfer medium. In conventional heat exchange methods, heat needs to pass through multiple levels of transfer to achieve exchange. However, in this embodiment, the polarity terminal 212 is directly connected to the heat transfer medium, allowing the heat transfer medium to act directly on the polarity terminal 212 without energy loss in other intermediate stages, significantly improving the utilization efficiency of the heat transfer medium. This means that the same amount of heat transfer medium can play a greater role in heat transfer, greatly improving the efficiency of heat transfer. While improving the utilization efficiency of the heat transfer medium, the overall heat exchange efficiency of the large-capacity battery is also greatly improved. The problem of battery performance degradation that might have been caused by untimely heat exchange is solved by this efficient heat exchange design, thus ensuring that the large-capacity battery is always in good working condition, extending its service life and improving its operational stability.

[0123] In addition, the open-section cavity 214 on the polar terminal 212 is matched with the open-section heat transfer tube 6 (which can be prepared by aluminum extrusion process), which has low requirements for the machining accuracy of the parts themselves, reducing the assembly difficulty and complexity when assembling large-capacity batteries, thereby reducing the processing cost and assembly cost of large-capacity battery parts.

[0124] To further improve the heat transfer performance of the aforementioned polarity terminal 212, such as Figure 8 and Figure 9 As shown, in this embodiment, two second through holes 8 can also be formed on the polarity terminal 212, with the second through holes 8 penetrating the polarity terminal 212 along the x-direction. In practical applications, the size and number of the second through holes 8 can be flexibly adjusted according to specific needs, provided that the conductivity of the polarity terminal 212 is not affected. The second through holes 8 increase the contact area between the polarity terminal 212 and the heat transfer medium, thereby significantly improving heat transfer efficiency. When the heat transfer medium flows through the polarity terminal 212, it can more fully surround the polarity terminal 212 through the second through holes 8. Previously, the heat transfer medium could only exchange heat with the surface of the polarity terminal 212 through contact; now, internal through-heat exchange can be achieved through the second through holes 8, which greatly increases the amount of heat transferred per unit time and accelerates the heat dissipation rate of the polarity terminal 212.

[0125] In other embodiments, other structures may be processed on the wall of cavity 214 and / or the inner wall of heat transfer tube 6 to increase the heat exchange area. For ease of description, in this utility model, the structures that can increase the heat exchange area are collectively referred to as functional structures. Such functional structures may include dot-shaped pits and protrusions located on the wall of cavity 214, and may also include annular grooves located on the wall of cavity 214; and may also include heat dissipation teeth provided on the inner wall of heat transfer tube 6.

[0126] In other embodiments, the heat exchange component may also be a heat transfer tube (round or square) with a closed cross-section; each polarity terminal 212 of the individual battery 211 is provided with a through groove or through hole for mounting the heat transfer tube; the heat transfer tube is fixed in the through groove or through hole of the polarity terminal 212 of the individual battery 211. Using the heat transfer tube on the polarity terminal 212, the heat generated inside the battery is conducted through the polarity terminal 212 to the heat transfer tube, and then the heat transfer tube dissipates the heat, thereby achieving heat dissipation of the battery.

[0127] In some other embodiments, the heat exchange component can also be a heat exchange device, which is disposed on the top of the outer casing top plate 12; at least a portion of the structure of the polar terminal 212 is located in the inner cavity of the heat exchange device and is in direct contact with the heat exchange medium; another portion of the structure of the polar terminal 212 is located outside the heat exchange device and serves as an electrical connection portion. By placing a portion of the structure of the polar terminal 212 directly in the heat exchange medium flow cavity (the inner cavity of the heat exchange device), the polar terminal 212 is in direct contact with the heat exchange medium, thereby achieving heat exchange of the polar terminal 212. This provides a shorter heat exchange path, and the heat exchange medium acts directly on the polar terminal 212, improving the utilization efficiency of the heat exchange medium and enhancing the heat exchange efficiency of the battery.

Claims

1. A high capacity battery, characterized by: The battery pack assembly comprises a shell and a battery pack located in the shell; The wall thickness of the shell is 1-5 mm; The battery pack assembly comprises a battery pack, end fixing plates and a fixing belt; The battery pack comprises n single cells arranged along a first direction, and the inner cavities of the n single cells are in communication with each other; wherein n is an integer greater than 1; the top plate of the shell is provided with avoiding holes corresponding to the polarity terminals of the single cells; each polarity terminal extends out of the corresponding avoiding hole; the area of the top plate of the shell corresponding to the avoiding hole is fixedly sealed with the shell of the single cell; The end fixing plates are two, and the two end fixing plates abut against the two ends of the battery pack, respectively; The fixing belt is sleeved on the two end fixing plates and the outer periphery of the battery pack to fix the battery pack between the two end fixing plates.

2. The high capacity battery of claim 1, wherein: The wall thickness of the shell is 1.5-2 mm.

3. The high capacity battery of claim 1, wherein: The battery pack assembly further comprises at least one partition plate; the partition plate is arranged between adjacent single cells.

4. The battery of claim 3, wherein: The battery pack assembly further comprises at least two fixing rib plates; The fixing rib plates are fixed to the opposite sides of the partition plate perpendicularly to the plane of the partition plate, and in the first direction, the two sides of the fixing rib plate extend out of the partition plate, respectively; The two sides of the fixing rib plate extending out of the partition plate abut against the side surfaces of the single cells on the two sides of the partition plate, respectively, and the fixing rib plate is welded with the shell.

5. The high capacity battery of any one of claims 1 to 4, wherein: The shell comprises a box with one open end and a top plate for sealing the open end of the box; The box with one open end is integrally formed by stamping process.

6. The battery of claim 5, wherein: The material of the shell is steel, and an electrolyte-diffusing film is arranged on the inner wall of the shell; or the material of the shell is aluminum.

7. The high capacity battery of claim 1, wherein: Further comprising a ring-shaped pad plate located in the shell; the ring-shaped pad plate is arranged between the lower cover plate of each single cell and the bottom plate of the shell; A first through hole is formed in each single cell lower cover plate, and the inner hole of the ring-shaped pad plate is located directly below each first through hole; an electrolyte sharing channel is formed between each single cell lower cover plate and the bottom plate of the shell.

8. The battery of claim 7, wherein: A liquid storage cavity is arranged on the end fixing plate, and free electrolyte is stored in the liquid storage cavity; the liquid storage cavity is in communication with the electrolyte sharing channel.

9. The high capacity battery of claim 1, wherein: Further comprising a heat exchange member; the heat exchange member exchanges heat with the polarity terminals.

10. The battery of claim 9, wherein: A cavity is arranged on the part of the polarity terminal extending out of the avoiding hole, the cavity penetrates through the polarity terminal along the first direction, and the cross section of the cavity is an open cross section; The heat exchange member is a heat transfer pipe, and the cross section of the heat transfer pipe is adapted to the cross section of the cavity; The heat transfer pipe is inserted into the cavity of each polarity terminal on the same side along the first direction; A first insulating sealing adhesive layer is arranged on the top plate of the shell, and the first insulating sealing adhesive layer seals the open port of the heat transfer pipe; a heat exchange channel is formed on the top plate of the shell.

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