Battery pack

Abstract

The utility model discloses a battery pack, and belongs to the technical field of batteries. The battery pack comprises single batteries; the liquid cooling plate is arranged on one side of the single battery and connected with the single battery, and the liquid cooling plate is provided with a flow channel; the plurality of reinforcing ribs are arranged in the flow channel and are arranged at intervals in the first direction, each reinforcing rib is connected with the liquid cooling plate, a spacing size is formed between every two adjacent reinforcing ribs, and in the first direction, the spacing sizes are gradually reduced from the middle to the two sides, and in the second direction, the spacing sizes are gradually reduced from the middle to the two sides; the reinforcing ribs are configured to generate elastic deformation when the liquid cooling plate is subjected to expansion force of the single batteries; the liquid cooling plate disclosed by the utility model can generate certain deformation under the action of expansion force of the single battery through the matching of the reinforcing ribs, and a certain space is reserved for the single battery, so that rigid extrusion between the single battery and the liquid cooling plate is avoided, the stress borne by a pole group in the single battery is reduced, and the effect of protecting the cycle life of the single battery is further achieved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a battery pack. Background Technology

[0002] With the rapid development of the new energy industry, the market demand for battery pack charge and discharge rates is gradually increasing. This increase in charge and discharge rates leads to a rise in the heat generation capacity of the battery cells. To improve the heat exchange rate of the liquid cooling plate, it is typically bonded to the large surface area of ​​the battery cell for heat exchange. Traditional liquid cooling plates, due to their high structural strength along the direction perpendicular to the large surface area, are prone to subjecting the thermally expanded battery cells to rigid compression in highly integrated cell layouts, resulting in a reduction in the cell's cycle life. Utility Model Content

[0003] Purpose of the utility model: This application provides a battery pack that aims to solve the technical problem that the liquid cooling plate, due to its high structural strength along the vertical direction, is prone to hard compression with the thermally expanded battery cell, resulting in a reduction in the cycle life of the battery cell.

[0004] Technical solution: The battery pack described in the embodiments of this application includes:

[0005] Single cell battery;

[0006] A liquid cooling plate is disposed on one side of the single cell and connected to the single cell; the liquid cooling plate has flow channels.

[0007] Multiple reinforcing ribs are disposed within the flow channel and arranged at intervals along a first direction. Each reinforcing rib is connected to the liquid cooling plate. There is a spacing dimension between two adjacent reinforcing ribs. In the first direction, the spacing dimension gradually decreases from the middle to both sides. The reinforcing ribs are configured to undergo elastic deformation when the liquid cooling plate is subjected to the expansion force of a single battery cell.

[0008] In some embodiments, at least a portion of the reinforcing rib extends in an arc shape;

[0009] The curvature of the arc-shaped portion of the reinforcing rib is K, satisfying: 20m -1 ≤K≤1000m -1 .

[0010] In some embodiments, the reinforcing rib includes a first straight segment and a second straight segment, both of which are inclined in the first direction and are disposed opposite to each other, and the first straight segment and the second straight segment are connected to each other.

[0011] In some embodiments, the reinforcing rib further includes a third segment disposed between the first straight segment and the second straight segment, wherein the first straight segment is connected to the second straight segment via the third segment.

[0012] In some embodiments, the third segment extends in a straight line along a second direction, which intersects with the first direction.

[0013] In some embodiments, the third segment is arc-shaped, and in the first direction, the third segment protrudes toward the side away from the first straight segment and the second straight segment, or is recessed toward the side close to the first straight segment and the second straight segment.

[0014] In some embodiments, the angle between the reinforcing rib and the inner wall of the flow channel is β, satisfying: 15°≤β≤60°.

[0015] In some embodiments, the battery pack further includes reinforcing blocks connected to the reinforcing ribs and the inner wall of the flow channel, respectively.

[0016] In some embodiments, the liquid cooling plate includes two first side plates and two second side plates. The two first side plates are spaced apart along a second direction, and the two second side plates are disposed between the two first side plates and spaced apart along the first direction. Each second side plate is connected to a first side plate. The two first side plates and the two second side plates form the flow channel. The reinforcing ribs are respectively connected to the two first side plates. The first side plates are connected to the single battery cell.

[0017] At least a portion of the second side panel extends in an arc shape, or the second side panel is V-shaped.

[0018] In some embodiments, the liquid cooling plate further includes two water nozzles, each water nozzle being connected to a first side plate and communicating with the flow channel. The two water nozzles are respectively disposed at both ends of the liquid cooling plate along a third direction and are staggered in the first direction. The third direction intersects both the first direction and the second direction.

[0019] Beneficial effects: The battery pack of this application embodiment adjusts the arrangement of the reinforcing ribs so that the strength of the middle part of the liquid cooling plate is relatively low, which matches the difference in expansion force generated by the thermal expansion of the individual cells. At the same time, combined with the elastic deformation characteristic of the reinforcing ribs, the liquid cooling plate can deform to a certain extent under the expansion force of the individual cells, giving the individual cells a certain space to bulge outward, thereby avoiding the situation of hard compression between them, reducing the stress on the internal electrode group of the individual cells, and thus protecting the cycle life of the individual cells. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a three-dimensional structural diagram of the battery pack provided in an embodiment of this application;

[0022] Figure 2 A cross-sectional view of the liquid cooling plate provided in an embodiment of this application;

[0023] Figure 3 A schematic diagram of the reinforcing ribs provided in the embodiments of this application;

[0024] Figure 4 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0025] Figure 5 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0026] Figure 6 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0027] Figure 7 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0028] Figure 8 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0029] Figure 9 A schematic diagram of another structure of the reinforcing rib provided in the embodiments of this application;

[0030] Figure 10 for Figure 2 A partial enlarged view of point A in the middle;

[0031] Figure 11 A schematic diagram of the second side plate provided in an embodiment of this application;

[0032] Reference numerals: 1. Single cell; 2. Liquid cooling plate; 20. Flow channel; 21. First side plate; 22. Second side plate; 23. Water nozzle; 3. Reinforcing rib; 31. First straight section; 32. Second straight section; 33. Third section; 4. Reinforcing block. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0034] In the description of this application, it should be understood that the terms "height," "thickness," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application 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 on this application. In the description of this application, "a plurality of" means two or more, and "at least one" can mean one, two, or more, unless otherwise expressly specified.

[0035] It should also be noted that in the accompanying drawings of the embodiments of this application, the arrow marked X represents the first direction X of the liquid cooling plate, the arrow marked Y represents the second direction Y of the liquid cooling plate, and the arrow marked Z represents the third direction Z of the liquid cooling plate. The first direction X, the second direction Y, and the third direction Z are introduced to more clearly illustrate the structure and relative positional relationship of each component in the liquid cooling plate. In practical applications, the first direction X, the second direction Y, and the third direction Z may change depending on the placement of the battery pack. In the description of this application, "vertical" means completely perpendicular to 90° or almost completely perpendicular, for example, an angle within the range of 85°-95° ​​is considered vertical.

[0036] In related technologies, when battery cells are arranged in a concentrated manner, a liquid cooling plate is placed between two adjacent rows of cells. Reinforcing ribs are installed inside the flow channels of the liquid cooling plate to improve its hydrodynamic characteristics. Simultaneously, because the reinforcing ribs are perpendicular to the inner wall of the flow channels, the structural strength and rigidity of the liquid cooling plate are increased. Therefore, when a large area of ​​the battery cell is attached to the liquid cooling plate, the plate has high structural strength perpendicular to the large area. However, the lack of expansion space for the battery cell leads to a reduction in the battery pack's cycle life.

[0037] Please combine them together Figure 1 and Figure 2The battery pack of this embodiment includes a single battery cell 1, a liquid cooling plate 2, and multiple reinforcing ribs 3. The single battery cell 1 is a prismatic battery. The liquid cooling plate 2 is disposed on one side of the single battery cell 1 and connected to the single battery cell 1, that is, the liquid cooling plate 2 and the side of the single battery cell 1 are in contact with each other or can be thermally connected through thermally conductive adhesive. The liquid cooling plate 2 has a flow channel 20 for fluid flow, and cooling is achieved through heat exchange between the fluid and the single battery cell 1. Multiple reinforcing ribs 3 are disposed in the flow channel 20 and are arranged at intervals along a first direction X, which is the height direction of the liquid cooling plate 2. There is a spacing L between two adjacent reinforcing ribs 3. Along the first direction X, the spacing L gradually decreases from the middle to both sides. The reinforcing ribs 3 are configured to undergo elastic deformation when the liquid cooling plate 2 is subjected to the expansion force of the single battery cell 1. Along the first direction X, the midpoint P between the two ends of the liquid cooling plate 2 corresponds to the middle spacing L. That is, each reinforcing rib 3 is relatively distributed on both sides of the midpoint P along the first direction X.

[0038] The spacing dimension L is the distance between the connection ends of two adjacent reinforcing ribs 3 and the inner wall of the flow channel 20 on the same side. The spacing dimension L can be measured using tools such as vernier calipers, digital calipers, and rulers. Taking vernier calipers as an example, when measuring the spacing dimension L, align the two measuring jaws of the vernier calipers with the connection ends of the two adjacent reinforcing ribs 3 and the inner wall of the flow channel 20 respectively, keep the calipers parallel in the first direction X, observe the scale line on the vernier calipers, and read the dimension value corresponding to the position of the measuring jaws, which is the spacing dimension, represented by L in the attached figure.

[0039] When a single battery cell 1 undergoes thermal expansion, the deformation at the center of its casing is greater than that at the periphery. By limiting the arrangement of the reinforcing ribs 3, the spacing L gradually decreases from the center to both sides. This change in spacing L corresponds to a gradual decrease in the strength of the liquid cooling plate 2 from the center to both sides. This strength distribution pattern matches the deformation distribution pattern of the single battery cell 1. Simultaneously, the reinforcing ribs 3 possess the characteristic of elastic deformation. Therefore, when the single battery cell 1 undergoes thermal expansion, the liquid cooling plate 2 can deform under stress, providing sufficient space for the expansion of the single battery cell 1 and preventing rigid compression between them. This protects the single battery cell 1 and helps ensure its cycle life. Furthermore, because the strength distribution pattern of the liquid cooling plate 2 matches the deformation distribution pattern of the single battery cell 1, the liquid cooling plate 2 can minimize deformation to accommodate the expansion of the single battery cell 1 under stress, while maintaining the contact surface as much as possible, thus achieving high-efficiency cooling of the single battery cell 1. After thermal expansion, the casing of the single cell 1 shrinks, and the liquid cooling plate 2 returns to its original shape under the elastic force of the reinforcing rib 3.

[0040] Please refer to Figure 2In some embodiments, at least a portion of the reinforcing rib 3 extends in an arc shape. The arc-shaped reinforcing rib 3 ensures uniform stress distribution. When the reinforcing rib 3 is subjected to external force, it can deform relatively uniformly, reducing stress concentration and thus achieving stable contraction of the liquid cooling plate 2. This reduces the possibility of excessive local or instantaneous load on the liquid cooling plate 2, which could lead to plastic deformation.

[0041] Please refer to Figures 2 to 5 In some embodiments, the curvature of the arc-shaped portion of the reinforcing rib 3 is K, satisfying: 20m -1 ≤K≤1000m -1 Specifically, the curvature K can be any value from 20, 160, 300, 440, 580, 720, 860, and 1000, or a range between any two values. The smaller the curvature of the reinforcing rib 3, the less it bends, and the reinforcing rib 3 gradually becomes perpendicular to the inner wall of the flow channel 20, thus increasing the strength of the liquid cooling plate 2 at this point. Conversely, the larger the curvature of the reinforcing rib 3, the greater its bending, and the more easily it deforms under external force. The spacing of the reinforcing ribs 3 can be combined with the curvature, meaning the curvature of each reinforcing rib 3 gradually decreases from the center to both sides along the first direction X, to accommodate the different degrees of outward bulging deformation of the casing when the single battery cell 1 undergoes thermal expansion.

[0042] The curvature of the arc-shaped portion of the reinforcing rib 3 can be measured using a radius of curvature measuring instrument or a coordinate measuring machine. For example, the reinforcing rib 3 is placed on the worktable of the measuring machine, and the shape of the curved surface is measured using a probe or laser scanner, and the curvature is calculated.

[0043] Please refer to Figure 6 In some embodiments, the reinforcing rib 3 includes a first straight segment 31 and a second straight segment 32. Both the first straight segment 31 and the second straight segment 32 are inclined in the first direction X and are arranged opposite to each other. The first straight segment 31 and the second straight segment 32 form an angle and are distributed in a V-shape. The V-shaped reinforcing rib 3 can simultaneously meet the requirements of stiffness and deformation of the liquid cooling plate 2 and provide relatively more deformation space.

[0044] Please refer to Figure 7 In some embodiments, the reinforcing rib 3 further includes a third segment 33, which is disposed between the first straight segment 31 and the second straight segment 32. The first straight segment 31 is connected to the second straight segment 32 through the third segment 33. The combination of the first straight segment 31, the second straight segment 32 and the third segment 33 increases the possible shapes. The elasticity and strength of the reinforcing rib 3 under different shapes are also different, which can meet the usage requirements under different conditions.

[0045] Please refer to Figure 7In some embodiments, the third segment 33 extends linearly along the second direction Y, which intersects with the first direction X. The second direction Y is the thickness direction of the liquid cooling plate 2. The third segment 33 is linear, and the first straight segment 31 and the second straight segment 32 are arranged opposite to the third segment 33, and the third segment 33 forms an angle with the first straight segment 31 and the second straight segment 32, with the angle being greater than 90°. When the reinforcing rib 3 is subjected to external force, the first straight segment 31 and the second straight segment 32 can deform to a certain extent with the third segment 33 to meet the needs of liquid cooling plate shrinkage.

[0046] Please combine them together Figure 8 and Figure 9 In some embodiments, the third segment 33 is arc-shaped. In the first direction X, the third segment 33 protrudes towards the side away from the first straight segment 31 and the second straight segment 32, or the third segment 33 is recessed towards the side closer to the first straight segment 31 and the second straight segment 32. The arc-shaped third segment 33 ensures uniform stress distribution, and since the third segment 33 is part of the reinforcing rib 3, it can meet the arrangement requirements of the liquid cooling plate 2 for relatively small shrinkage in local locations. The protruding or recessed direction of the third segment 33 can change the cross-sectional shape of the cavity between two adjacent reinforcing ribs 3 to meet different design requirements of the flow channel 20.

[0047] Please combine them together Figures 2 to 9 In some embodiments, the included angle β between the reinforcing rib 3 and the inner wall of the flow channel 20 satisfies: 15°≤β≤60°. Specifically, the included angle β can be any value among 15°, 30°, 45°, and 60°, or a range between any two values. The included angle β can be measured using an angle measuring instrument, a coordinate measuring machine, or an optical measuring instrument.

[0048] The smaller the included angle β, the greater the degree of bending or protrusion of the reinforcing rib 3 in the first direction X, and the more easily the reinforcing rib 3 is subjected to external forces and deforms. The larger the included angle β, the closer the reinforcing rib 3 is to the shape of being perpendicular to the inner wall of the flow channel 20, and thus the supporting strength provided by the reinforcing rib 3 also increases. The load area can be divided according to the magnitude of the expansion force of the single cell 1, and the reinforcing rib 3 in the liquid cooling plate 2 can be arranged in different load areas, and the included angle β of the reinforcing rib 3 can be designed. In areas with large loads, the included angle β of the reinforcing rib 3 is relatively small so that the liquid cooling plate 2 can fully contract and give the single cell 1 enough expansion space. In areas with small loads, the included angle β of the reinforcing rib 3 is relatively large to maintain the strength of the liquid cooling plate 2.

[0049] Please combine them together Figure 2 and Figure 10In some embodiments, the battery pack further includes reinforcing blocks 4, which are respectively connected to the reinforcing rib 3 and the inner wall of the flow channel 20. The reinforcing blocks 4 are located on the side of the reinforcing rib 3 protruding along the first direction X. The reinforcing blocks 4 increase the stability of the connection of the reinforcing rib 3 and increase the thickness of the reinforcing rib 3 at the connection end. When the liquid cooling plate 2 contracts under extreme external force, the reinforcing blocks 4 on both sides of the flow channel 20 abut against each other, maintaining the minimum space of the flow channel 20, allowing the medium within the flow channel 20 to circulate and carry away heat, thereby maintaining the basic function of the liquid cooling plate 2. The reinforcing blocks 4 can be connected to the reinforcing rib 3 and the inner wall of the flow channel 20 by welding, i.e., welding between the reinforcing rib 3 and the inner wall of the flow channel 20 to thicken the connection end of the reinforcing rib 3; or they can be manufactured using a process that integrally forms with the reinforcing rib 3.

[0050] Please combine them together Figure 2 and Figure 11 In some embodiments, the liquid cooling plate 2 includes two first side plates 21 and two second side plates 22. The two first side plates 21 are spaced apart along a second direction Y and extend along a first direction X, where the second direction Y is perpendicular to the first direction X. The two second side plates 22 are disposed between the two first side plates 21 and spaced apart along the first direction X. Each second side plate 22 is connected to one of the two first side plates 21. The two first side plates 21 and the two second side plates 22 form a flow channel 20. Reinforcing ribs 3 are connected to the two first side plates 21. The first side plates 21 are connected to the individual battery cells 1. At least a portion of the second side plates 22 extends in an arc shape, or the second side plates 22 are V-shaped. The arc-shaped second side plates 22 can evenly distribute stress, reduce stress concentration, and provide a larger deformation space. This can increase the overall shrinkage of the liquid cooling plate 2 within a certain range, leaving sufficient expansion space for the individual battery cells 1 and avoiding hard compression of the individual battery cells 1. The V-shaped second side plate 22 gives it a certain amount of elastic compression, which can meet the requirements of liquid cooling plate 2 shrinkage and connection strength.

[0051] Please combine them together Figure 1 and Figure 2 In some embodiments, the liquid cooling plate 2 further includes two water nozzles 23, each water nozzle 23 connected to a first side plate 21 and communicating with the flow channel 20. The two water nozzles 23 are respectively disposed at both ends of the liquid cooling plate 2 along a third direction Z, and are staggered in a first direction X. The third direction Z is the length direction of the liquid cooling plate 2, and is perpendicular to both the first direction X and the second direction Y. The height difference between the two water nozzles 23 allows the cooling medium to form natural convection within the flow channel 20 due to gravity, covering more surface area and thus improving heat transfer efficiency. At the same time, heat flows from the high-temperature area to the low-temperature area, achieving effective heat transfer and dissipation.

[0052] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0053] The battery pack provided in the embodiments of this application has been described in detail above, and specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery pack, characterized in that, include: Single cell battery; A liquid cooling plate is disposed on one side of the single cell and connected to the single cell; the liquid cooling plate has flow channels. Multiple reinforcing ribs are disposed within the flow channel and arranged at intervals along a first direction. Each reinforcing rib is connected to the liquid cooling plate. There is a spacing dimension between two adjacent reinforcing ribs. In the first direction, the spacing dimension gradually decreases from the middle to both sides. The reinforcing ribs are configured to undergo elastic deformation when the liquid cooling plate is subjected to the expansion force of a single battery cell.

2. The battery pack according to claim 1, characterized in that, At least a portion of the reinforcing rib extends in an arc shape; The curvature of the arc-shaped portion of the reinforcing rib is K, satisfying: 20m -1 ≤K≤1000m -1 .

3. The battery pack according to claim 1, characterized in that, The reinforcing rib includes a first straight segment and a second straight segment, both of which are inclined in the first direction and are arranged opposite to each other, and the first straight segment and the second straight segment are connected to each other.

4. The battery pack according to claim 3, characterized in that, The reinforcing rib also includes a third segment, which is disposed between the first straight segment and the second straight segment, and the first straight segment is connected to the second straight segment through the third segment.

5. The battery pack according to claim 4, characterized in that, The third segment extends in a straight line along the second direction, which intersects with the first direction.

6. The battery pack according to claim 4, characterized in that, The third segment is arc-shaped. In the first direction, the third segment protrudes toward the side away from the first straight segment and the second straight segment, or is recessed toward the side close to the first straight segment and the second straight segment.

7. The battery pack according to claim 1, characterized in that, The angle between the reinforcing rib and the inner wall of the flow channel is β, which satisfies: 15°≤β≤60°.

8. The battery pack according to claim 1, characterized in that, The battery pack also includes reinforcing blocks, which are respectively connected to the reinforcing ribs and the inner wall of the flow channel.

9. The battery pack according to claim 1, characterized in that, The liquid cooling plate includes two first side plates and two second side plates. The two first side plates are spaced apart along a second direction, and the two second side plates are disposed between the two first side plates and spaced apart along the first direction. Each second side plate is connected to a first side plate. The two first side plates and the two second side plates form the flow channel. The reinforcing ribs are respectively connected to the two first side plates. The first side plates are connected to the single battery cell. At least a portion of the second side panel extends in an arc shape, or the second side panel is V-shaped.

10. The battery pack according to claim 9, characterized in that, The liquid cooling plate also includes two water nozzles, each of which is connected to a first side plate and communicates with the flow channel. The two water nozzles are respectively disposed at both ends of the liquid cooling plate along a third direction and are staggered in the first direction. The third direction intersects both the first direction and the second direction.

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