Battery swelling suppression structure and battery pack

Abstract

The utility model belongs to battery technical field discloses a kind of battery expansion inhibition structure and battery pack.Battery pack includes single cell being stacked along first direction;The structure includes inhibition substructure, inhibition substructure is arranged along first direction and is set one-to-one with single cell, single cell is square battery, single cell includes first surface and second surface, first surface is oppositely arranged along first direction, second surface is oppositely arranged along second direction, and the area of first surface is greater than the area of second surface, first direction is perpendicular to second direction;Each inhibition substructure includes shoulder and compression part, shoulder is abutted on corresponding first surface along first direction, compression part is pressed on corresponding second surface along second direction, and the end of compression part is connected to shoulder vertically.The structure breaks through the limitation of traditional linear pressing strip in mechanics distribution and stress concentration, improves the bending resistance of overall structure, energy absorption capacity and the protection effect of battery.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a battery expansion suppression structure and battery pack. Background Technology

[0002] During charging and discharging, lithium batteries expand due to the combined effects of multiple factors, including electrochemistry, materials, and the environment. Cell expansion can have many negative impacts. From a mechanical perspective, it can lead to casing deformation and sealing failure, causing casing bulges or weld cracks, resulting in electrolyte leakage or external short circuits.

[0003] Currently, the industry offers a variety of structures that can suppress battery swelling and bulging, but most of them are rigid linear structures. When subjected to pressure, they are prone to local stress concentration, leading to material fatigue or connection failure. As a result, existing suppression structures still have defects in terms of safety and stability in use.

[0004] Therefore, there is an urgent need for a battery expansion suppression structure and battery pack to overcome the shortcomings of existing related technologies. Utility Model Content

[0005] One objective of this invention is to provide a battery expansion suppression structure that overcomes the limitations of traditional straight pressure strips in terms of mechanical distribution and stress concentration, effectively improving the overall structure's bending resistance and energy absorption capacity, thereby enhancing battery protection.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A battery expansion suppression structure is connected to a battery pack, the battery pack comprising individual cells stacked along a first direction. The battery expansion suppression structure includes suppression substructures, which are arranged along the first direction and corresponding one-to-one with each of the individual cells, wherein:

[0008] The single cell is a square cell, and the single cell includes a first surface and a second surface. The two first surfaces are arranged opposite each other along a first direction, and the two second surfaces are arranged opposite each other along a second direction. The area of ​​the first surface is larger than the area of ​​the second surface, and the first direction is perpendicular to the second direction.

[0009] Each of the aforementioned suppression substructures includes a shoulder and a pressing portion, the shoulder abutting against a corresponding first surface along the first direction, the pressing portion pressing against a corresponding second surface along the second direction, and the end of the pressing portion being perpendicularly connected to the shoulder.

[0010] Preferably, of the two ends adjacent to the clamping portion and disposed close together along the first direction, only one end is perpendicularly connected to the shoulder.

[0011] Preferably, the single battery is erected vertically, the second direction is the height direction of the single battery, and the two second surfaces are distributed vertically.

[0012] In the adjacent clamping portions, one of the clamping portions is pressed against the lower second surface of the corresponding single cell, and the other clamping portion is pressed against the upper second surface of the corresponding single cell, so that the adjacent clamping portions are staggered along the second direction.

[0013] Preferably, the first direction is the thickness direction of the single cell; two battery expansion suppression structures are provided, and the two battery expansion suppression structures are spaced apart at both ends of the battery pack along a third direction, which is the length direction of the single cell, and the first direction, the second direction and the third direction are perpendicular to each other.

[0014] Preferably, a chamfered portion is provided at the connection between the shoulder and the pressing portion;

[0015] The radius R of the chamfered portion is in the range of 0.5T≤R≤1.0T; where T is the dimension of the pressing portion along the second direction and the dimension of the shoulder portion along the first direction.

[0016] Preferably, the value of T is in the range of 1 / 20 Ct ≤ T ≤ 1 / 8 Ct; where Ct is the dimension of the single cell along the first direction.

[0017] Preferably, the dimensions of the pressing part along the third direction and the dimensions of the shoulder part along the third direction, W, are in the range of 1 / 5Ct≤W≤1 / 1.5Ct; where Ct is the dimension of the single battery (21) along the first direction.

[0018] Preferably, an elastic pad is sandwiched between the pressing part and the first surface; and / or, an elastic pad is sandwiched between the shoulder and the second surface.

[0019] Preferably, the battery swelling suppression structure further includes a fixing member connected to the outermost shoulder and used to fix the battery swelling suppression structure so that the battery swelling suppression structure can be fixed relative to the battery pack.

[0020] Another objective of this invention is to provide a battery pack that can more stably constrain battery pack expansion, thereby extending the service life of the entire battery pack and ensuring the long-term reliability of the battery pack's operation.

[0021] To achieve this objective, the present invention adopts the following technical solution:

[0022] The battery pack includes the battery assembly and the aforementioned battery swelling suppression structure.

[0023] The beneficial effects of this utility model are:

[0024] In the battery expansion suppression structure provided by this utility model, by replacing the pressure bar of the traditional rigid straight structure with multiple suppression substructures, the single suppression substructure can transform the single-point force into multi-unit distributed force when subjected to pressure, so that multiple suppression substructures are subjected to force evenly, avoiding local stress concentration and stress peaks, thereby preventing fatigue of the battery expansion suppression structure material or failure of connection with the single battery, and significantly improving the bending resistance and energy absorption capacity of the overall structure.

[0025] The battery pack provided by this utility model, by setting the above-mentioned battery expansion suppression structure, can more stably restrain the expansion of the battery pack, extend the service life of the entire battery pack, and ensure the long-term reliability of the battery pack operation. Attached Figure Description

[0026] Figure 1 This is an isometric view of the connection between the battery expansion suppression structure and the battery pack provided by this utility model;

[0027] Figure 2 This is a front view of the connection between the battery expansion suppression structure and the battery pack provided by this utility model;

[0028] Figure 3 This is a front view of the battery expansion suppression structure provided by this utility model;

[0029] Figure 4 This is a top view of the battery expansion suppression structure provided by this utility model.

[0030] In the picture:

[0031] 1. Battery swelling suppression structure; 11. Suppression substructure; 111. Shoulder; 112. Pressing part; 113. Chamfered part; 12. Fixing component;

[0032] 2. Battery pack; 21. Single cell; 211. First surface; 212. Second surface. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0034] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0037] The technical solution provided by this utility model will be described below with reference to the accompanying drawings and specific embodiments.

[0038] Combination Figures 1 to 4 As shown, this utility model provides a battery expansion suppression structure 1 for connection with a battery pack 2. The battery pack 2 includes single cells 21 stacked along a first direction. The battery expansion suppression structure 1 includes suppression substructures 11, which are arranged along the first direction and correspond one-to-one with the single cells 21. The single cell 21 is a square cell, and each single cell 21 includes a first surface 211 and a second surface 212. The two first surfaces 211 are arranged opposite each other along the first direction, and the two second surfaces 212 are arranged opposite each other along the second direction. The area of ​​the first surface 211 is larger than the area of ​​the second surface 212. Each suppression substructure 11 includes a shoulder 111 and a pressing part 112. The shoulder 111 abuts against the corresponding first surface 211 along the first direction, and the pressing part 112 presses against the corresponding second surface 212 along the second direction. The end of the pressing part 112 is perpendicularly connected to the shoulder 111.

[0039] Specifically, refer to Figure 1 As shown, in this embodiment, the second surface 212 of the single battery 21 is the outer surface of the top cover assembly. The pressing part 112 is pressed onto the outer surface of the top cover assembly, which can restrain the top cover assembly from warping and edge movement due to the internal pressure of the single battery 21 (e.g., the gas pressure generated during charging and discharging of the single battery 21). By setting the pressing part 112 and the shoulder 111, the risk of casing deformation and sealing failure of each single battery 21, leading to casing bulging or weld cracking, resulting in electrolyte leakage or external short circuit is significantly reduced. Moreover, since adjacent single batteries 21 are separated by the shoulder 111, the mutual chain effects of heat transfer, physical collision and deformation conduction between adjacent single batteries 21 can be effectively reduced, which helps to improve the overall operational stability and safety protection capability of the battery pack 2. Furthermore, in this embodiment, the pressure bar of the traditional rigid straight structure is replaced with multiple suppression substructures 11, so that when a single suppression substructure 11 is subjected to pressure, it can transform the single-point force into a multi-unit distributed force, so that multiple suppression substructures 11 are subjected to force evenly, avoiding local stress concentration and stress peaks, thereby preventing material fatigue of the battery expansion suppression structure 1 or failure of connection with the single battery 21, and significantly improving the bending resistance and energy absorption capacity of the overall structure.

[0040] It should be further explained that in the battery expansion suppression structure 1, the suppression substructure 11 is strip-shaped. Compared with columnar or other shaped structures, this allows the pressing part 112 and the shoulder 111 to better fit and press against the single battery 21. By increasing the force-bearing area with the single battery 21, damage to the outer surface of the single battery 21 can be reduced, thus maintaining the stable performance of the single battery 21. In this embodiment, multiple single batteries 21 in the battery pack 2 can be stacked in series or in parallel along the first direction. Moreover, the position of the pressing part 112 on the second surface 212 can be the location area of ​​the electrodeless column and the explosion-proof valve. For example, the pressing part 112 can be pressed against one end of the second surface 212 along a third direction. This embodiment is not limited to this. Among them, the third direction, the first direction, and the second direction are all perpendicular to each other.

[0041] Furthermore, in this embodiment, two battery expansion suppression structures 1 are provided. The two battery expansion suppression structures 1 are spaced apart at both ends of the battery pack 2 along the third direction, which can form a bidirectional constraint from both ends of the battery pack 2 along the third direction. This can strengthen the control of the battery expansion suppression structure 1 over the overall expansion, avoid the suppression of unilateral deviation caused by single-end suppression, and effectively suppress the expansion force of the single battery 21 along the first direction, the second direction and the third direction.

[0042] In this embodiment, reference Figure 2As shown, among the two ends of the adjacent pressing part 112 that are close together along the first direction, only one end is vertically connected to the shoulder 111. This arrangement reduces the number of shoulders 111 between adjacent single cells 21 from two to one. The reduced number of shoulders 111 means a decrease in the space occupied by the battery expansion structure in the first direction. By rationally designing the thickness of the shoulders 111, while ensuring the bending resistance of the shoulders 111 meets the requirements of actual working conditions, the distance between the single cells 21 is reduced, thereby shortening the length of the battery pack 2 along the first direction. This results in higher energy density, smaller size, and more flexible and convenient installation and use of the battery pack 2.

[0043] It should be further noted that in the accompanying drawings of this application, a double-headed arrow labeled X represents the first direction, a double-headed arrow labeled Y represents the second direction, and a double-headed arrow labeled Z represents the third direction. In this embodiment, the first direction X corresponds to the thickness direction of the single battery 21. For a prismatic cell, the direction corresponding to its two main surfaces is the thickness direction; the second direction Y corresponds to the height direction of the single battery 21; and the third direction corresponds to the length direction of the single battery 21. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0044] As can be seen from the above, reference Figure 2 As shown, the single battery 21 is erected, and two second surfaces 212 are distributed vertically (i.e., along the second direction) at both ends of the single battery 21. In addition, among the adjacent pressing parts 112, one pressing part 112 is pressed onto the lower second surface 212 of the corresponding single battery 21, and the other pressing part 112 is pressed onto the upper second surface 212 of the corresponding single battery 21, so that the adjacent pressing parts 112 are staggered along the second direction. With the above configuration, the battery expansion suppression structure 1 presents an S-shaped bending structure. One part of the pressing part 112 is pressed onto the surface of the top cover assembly of the single battery 21, and the other part of the pressing part 112 is pressed onto the bottom surface of the casing of the single battery 21. When the battery pack 2 is placed in the box, the other part of the pressing part 112 separates the bottom plate of the box from the corresponding single battery 21. In this way, when the bottom surface of the casing of the single battery 21 bulges and expands due to air pressure during charging and discharging, the pressing part 112 can absorb the expansion force, thereby preventing the bottom plate of the box from being deformed by the force. The S-shaped battery expansion suppression structure 1 provided in this embodiment can maintain high bending resistance and energy absorption capacity, ensure high energy density and space utilization of battery pack 2, and reduce damage to the bottom plate of the box when assembled and installed with the box. Especially when the bottom plate of the box integrates the function of liquid cooling plate, it can reduce the damage rate of the bottom plate of the box, increase the stability of use, and maintain a good heat dissipation and cooling effect on battery pack 2.

[0045] In this embodiment, the battery expansion suppression structure 1 further includes a fixing member 12, which is connected to the outermost shoulder 111 and used to fix the battery expansion suppression structure 1 so that the battery expansion suppression structure 1 can be fixed relative to the battery pack 2. Specifically, refer to Figure 3 As shown, the fixing member 12 is a pressure plate integrally formed at the end of the outermost shoulder 111, and the pressure plate is perpendicularly connected to the shoulder 111. It should be noted that when the number of single batteries 21 is even, the orientation of the ends of the outermost shoulders 111 is opposite. In this case, the two fixing members 12 are staggered vertically along the second direction. The lower fixing member 12 can be relatively fixed to the battery pack 2 by fixing it to the bottom plate of the casing, and the upper fixing member 12 can be relatively fixed to the battery pack 2 by fixing it to the top cover of the casing. (Reference) Figure 2 As shown, when the number of single batteries 21 is odd, the ends of the shoulders 111 at the outermost two ends face the same direction. At this time, the two fasteners 12 are aligned along the second direction, and the two fasteners 12 can be fixed to the bottom plate of the box at the same time. This achieves the relative fixation of the battery expansion suppression structure 1 and the battery pack 2, ensuring that the battery expansion suppression structure 1 will not be shifted under force, and maintaining a stable constraint on the battery pack 2.

[0046] It should be noted that this embodiment does not limit the fixing connection method between the fastener 12 and the box. The fastener 12 and the box can be detachably connected by purely mechanical structures such as threaded connection and snap-fit ​​connection. The connection is highly stable, safe and reliable, and easy to disassemble.

[0047] In this embodiment, a chamfered portion 113 is provided at the connection between the shoulder 111 and the pressing portion 112; the radius R of the chamfered portion 113 is in the range of 0.5T ≤ R < 1.0T; where T is the dimension of the pressing portion 112 along the second direction and the dimension of the shoulder 111 along the first direction. Specifically, refer to... Figure 3 As shown, the chamfer 113 is preferably a rounded corner, which has the advantage of ensuring that the suppression substructure 11 does not experience fatigue failure under the long-term cyclic expansion force of the single cell 21. In addition, if a chamfer 113 with a small radius (R < 0.5T) is used, the stress at that point will theoretically tend to infinity under stress, becoming the origin point of fatigue cracks; if a chamfer 113 with a large radius (R ≥ 1.0T) is used, the stress distribution will be uneven, and the maximum stress value will increase significantly, leading to an increased probability of structural fracture and greatly reducing the structural reliability of the suppression substructure 11 in long-term use.

[0048] In this embodiment, the value of T ranges from 1 / 20 Ct ≤ T ≤ 1 / 8 Ct; where Ct is the dimension of the single cell 21 along the first direction. (Reference) Figure 3As shown, the dimensions of the clamping part 112 along the second direction and the shoulder part 111 along the first direction are controlled between 1 / 20 Ct and 1 / 8 Ct, ensuring that the suppression substructure 11 has sufficient rigidity. It should be noted that if T < 1 / 20 Ct, the suppression substructure 11 will be too thin, and it will easily yield or deform excessively under strong expansion force, losing its restraining effect; if T > 1 / 8 Ct, the suppression substructure 11 will be too bulky, increasing material costs and hindering the improvement of the energy density of the battery pack 2.

[0049] In this embodiment, the dimensions of the pressing part 112 along the third direction and the dimension W of the shoulder 111 along the third direction are in the range of 1 / 5Ct ≤ W ≤ 1 / 1.5Ct. (Reference) Figure 4 As shown, controlling W within this range allows for reasonable control of the contact area between the suppression substructure 11 and the single cell 21, especially the contact area between the shoulder 111 and the first surface 211 of the single cell 21. This helps to disperse pressure, avoid stress concentration, and also slightly improves the bending stiffness of the suppression substructure 11. W ≥ 1 / 5Ct provides sufficient contact area for the suppression substructure 11, ensuring that the constraint force acts uniformly on the outer surface of the single cell 21. W ≤ 1 / 1.5Ct avoids the suppression substructure 11 from being too wide and encroaching on too much internal module space, leaving room for thermal management components (such as liquid cooling plates) and bus layout.

[0050] Optionally, in this embodiment, an elastic gasket (not shown in the figure) is sandwiched between the pressing part 112 and the first surface 211, and an elastic gasket is also sandwiched between the shoulder part 111 and the second surface 212. By using the suppression substructure 11 in conjunction with the elastic gasket, the elastic gasket can absorb minor inconsistencies on the outer surface of the battery pack 2, while the suppression substructure 11 can provide macroscopic rigid constraints. Thus, the rigid constraints of the suppression substructure 11 are retained, and the surface errors are compensated by the elastic gasket, thereby making the pressing of the suppression substructure 11 onto the single battery 21 more closely and the constraint performance more reliable.

[0051] Preferably, the elastic gasket can be any one of silicone sheet or PU foam.

[0052] This embodiment also provides a battery pack, including a battery group 2 and the battery expansion suppression structure 1 described above. In this battery expansion suppression structure 1, by replacing the traditional rigid linear pressure bar with multiple suppression substructures 11, the single-point force on each suppression substructure 11 can be transformed into a multi-unit distributed force when subjected to pressure. This ensures that the multiple suppression substructures 11 are evenly stressed, avoiding local stress concentration and stress peaks. This prevents material fatigue of the battery expansion suppression structure 1 or failure of its connection with the single battery 21, significantly improving the overall structure's bending resistance and energy absorption capacity. Furthermore, it can more stably constrain the expansion of the battery group 2, extending the service life of the entire battery pack and ensuring the long-term reliability of the battery pack's operation.

[0053] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery swelling suppression structure, characterized in that, Connected to a battery pack (2), the battery pack (2) includes single cells (21) stacked along a first direction, and the battery expansion suppression structure (1) includes a suppression substructure (11), the suppression substructure (11) being arranged along the first direction and corresponding one-to-one with the single cells (21), wherein: The single cell (21) is a square cell. The single cell (21) includes a first surface (211) and a second surface (212). The two first surfaces (211) are arranged opposite to each other along the first direction, and the two second surfaces (212) are arranged opposite to each other along the second direction. The area of ​​the first surface (211) is larger than the area of ​​the second surface (212). The first direction is perpendicular to the second direction. Each of the aforementioned suppression substructures (11) includes a shoulder (111) and a pressing part (112), wherein the shoulder (111) abuts against the corresponding first surface (211) along the first direction, and the pressing part (112) presses against the corresponding second surface (212) along the second direction, and the end of the pressing part (112) is perpendicularly connected to the shoulder (111).

2. The battery expansion suppression structure according to claim 1, characterized in that, Of the two ends adjacent to the clamping portion (112) and disposed close together along the first direction, only one of the ends is perpendicularly connected to the shoulder portion (111).

3. The battery expansion suppression structure according to claim 1, characterized in that, The single battery (21) is set upright, the second direction is the height direction of the single battery (21), and the two second surfaces (212) are distributed vertically. In the adjacent clamping portions (112), one of the clamping portions (112) is pressed against the lower second surface (212) of the corresponding single cell (21), and the other clamping portion (112) is pressed against the upper second surface (212) of the corresponding single cell (21), so that the adjacent clamping portions (112) are staggered along the second direction.

4. The battery expansion suppression structure according to claim 3, characterized in that, The first direction is the thickness direction of the single cell (21); two battery expansion suppression structures (1) are provided, and the two battery expansion suppression structures (1) are spaced apart at both ends of the battery pack (2) along a third direction, which is the length direction of the single cell (21), and the first direction, the second direction and the third direction are perpendicular to each other.

5. The battery expansion suppression structure according to claim 4, characterized in that, A chamfered portion (113) is provided at the connection between the shoulder (111) and the pressing portion (112); The radius R of the chamfered portion (113) is in the range of 0.5T≤R≤1.0T; where T is the dimension of the pressing portion (112) along the second direction and the dimension of the shoulder portion (111) along the first direction.

6. The battery expansion suppression structure according to claim 5, characterized in that, The value of T is in the range of 1 / 20 Ct ≤ T ≤ 1 / 8 Ct; where Ct is the dimension of the single cell (21) along the first direction.

7. The battery expansion suppression structure according to claim 4, characterized in that, The dimensions of the pressing part (112) along the third direction and the dimensions of the shoulder part (111) along the third direction, W, are in the range of 1 / 5Ct≤W≤1 / 1.5Ct; where Ct is the dimension of the single battery (21) along the first direction.

8. The battery swelling suppression structure according to claim 1, characterized in that, An elastic pad is sandwiched between the pressing part (112) and the first surface (211); and / or, an elastic pad is sandwiched between the shoulder part (111) and the second surface (212).

9. The battery swelling suppression structure according to claim 1, characterized in that, The battery expansion suppression structure (1) further includes a fixing member (12), which is connected to the outermost shoulder (111) and is used to fix the battery expansion suppression structure (1) so that the battery expansion suppression structure (1) can be fixed relative to the battery pack (2).

10. A battery pack, characterized in that, It includes a battery pack (2) and a battery expansion suppression structure (1) as described in any one of claims 1-9.

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