Battery module and battery pack
By designing the receptacle of the fixture in the battery module, the specific length relationship is met, the problem of steel belt deformation under the action of expansion force is solved, and effective constraints and normal operation of the battery module are achieved.
Patent Information
- Application Number
- CN202421486913.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-26
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-06-26
AI Technical Summary
Under the action of expansion force, the steel belt may deform more than the reserved amount, resulting in the inability to effectively bind the battery module, increasing the risk of deformation and affecting normal operation.
A battery module is designed, and the battery cell group and end plate are fixed using the accommodating part of the fixing part. The length relationship of the accommodating part in the initial state and the preloading state satisfies L1=L2-2*K, ensuring that the fixing part has sufficient deformation in the preloading state and satisfies the binding effect of the module.
Through the design of the fixture, the battery cell group and end plate can be effectively fixed, prevent the module from deforming, and ensure the normal operation and stability of the battery module.
Smart Images
Figure CN222940108U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of batteries, and particularly to a battery module and a battery pack. Background Art
[0002] With the development of the economy and the progress of technology, lithium batteries, as one of the cleanest secondary energy sources, are widely favored by people. Lithium batteries have the advantages of light weight, large energy storage, high power, no pollution, long life, small self-discharge coefficient, wide temperature adaptation range, etc., so they are gradually favored by people and have gradually replaced other traditional batteries in the fields of energy storage and power batteries. When assembling the battery cells and the end plates, steel belts are usually used to fix the battery cells and absorb expansion. The steel belt will produce a certain deformation under the action of the expansion force of the battery module. Steel belts of different specifications have different bearing capacities and deformation amounts under the action of the expansion force of the battery module. When the expansion force of the battery module exceeds the maximum bearing capacity of the steel belt, the deformation amount of the steel belt will exceed the reserved deformation amount of the battery module. When the steel belt is under this expansion force, its structure will be damaged, resulting in the steel belt being unable to restrain the battery module, and the risk of deformation of the battery module increases, thus unable to ensure the normal operation of the battery module. Utility Model Content
[0003] This application provides a battery module and a battery pack, which can avoid the situation in the related art where the steel belt cannot effectively restrain the module.
[0004] In a first aspect, this application provides a battery module, which includes: a battery cell group including a plurality of battery cells arranged at intervals in a first direction; two end plates respectively arranged at both ends of the battery cell group in the first direction; a fixing member having a receiving portion, the fixing member is wound around the battery cell group and the two end plates, so that the battery cell group and the two end plates are both located in the receiving portion, and the fixing member fixes the battery cell group and the two end plates through the receiving portion; wherein, the battery module has an initial state and a pre-tightening state. When the battery module is in the initial state, the length of the receiving portion in the first direction is L1, and when the battery module is in the pre-tightening state, the total length of the two end plates and the battery cell group in the first direction is L2, and the deformation amount of the fixing member in the first direction in the pre-tightening state is K, and L1 = L2 - 2*K.
[0005] Optionally, the length range of the receiving portion in the first direction is: 990mm ≤ L1 ≤ 1000mm.
[0006] Optionally, the fixing member includes a first side wall, a second side wall, a third side wall, and a fourth side wall that are sequentially connected end to end. The first side wall, the second side wall, the third side wall, and the fourth side wall jointly enclose to form a receiving portion. The first side wall and the third side wall are oppositely arranged in a first direction, the second side wall and the fourth side wall are oppositely arranged in a second direction, the first side wall and the third side wall are respectively connected to the outer side walls of two end plates, the second side wall and the fourth side wall are respectively connected to the side walls of the battery cell group in the second direction, and the first direction and the second direction are perpendicular to each other.
[0007] Optionally, the extension length of the first side wall and the third side wall in the first direction is L3, and the extension length of the second side wall and the fourth side wall in the second direction is L4, and L3 = L4.
[0008] Optionally, 0.9 mm ≤ L3 ≤ 1.1 mm.
[0009] Optionally, the extension length of the first side wall, the second side wall, the third side wall, and the fourth side wall in a third direction is L5, 29.7 mm ≤ L5 ≤ 30.3 mm, and the first direction, the second direction, and the third direction are perpendicular to each other.
[0010] Optionally, the battery module further includes an insulating member, and an insulating member is provided at the connection between the fixing member and the battery cell group.
[0011] Optionally, the material of the fixing member includes SUS201 stainless steel or LH stainless steel.
[0012] Optionally, the connection between the first side wall, the second side wall, the third side wall, and the fourth side wall is a rounded corner structure.
[0013] In a second aspect, an embodiment of the present application provides a battery pack, and the battery pack includes the above-mentioned battery module.
[0014] Applying the technical solution of the present application, the battery cell group and two end plates are fixed by using the receiving portion of the fixing member. At the same time, the length of the receiving portion in the first direction in the initial state satisfies L1 = L2 - 2*K. Such a setting can not only fix the battery cell group and the end plates by the fixing member, but also enable the fixing member to have sufficient deformation to meet the binding effect on the module and prevent the module from deforming, thereby ensuring the normal operation of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.
[0016] Figure 1 is a three-dimensional schematic diagram of a battery module provided by an embodiment of the present application;
[0017] Figure 2 is a three-dimensional schematic diagram of a fixing member provided by an embodiment of the present application;
[0018] Figure 3 is a top view schematic diagram of a fixing member provided by an embodiment of the present application;
[0019] Figure 4 is Figure 3 an enlarged view of part A in
[0020] Figure 5 is Figure 3 an enlarged view of part B in
[0021] Figure 6 is a side view schematic diagram of a fixing member provided by an embodiment of the present application.
[0022] Among them, the above-mentioned drawings include the following reference numerals:
[0023] 10, battery cell group; 11, battery cell;
[0024] 20, end plate;
[0025] 30, fixing member; 31, first side wall; 32, second side wall; 33, third side wall; 34, fourth side wall; 35, rounded corner structure;
[0026] 40, insulating member;
[0027] X, first direction; Y, second direction; Z, third direction. Detailed implementation manners
[0028] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.
[0029] As Figures 1 - 6As shown in the figure, in a first aspect, an embodiment of the present application provides a battery module. The battery module includes: a battery cell group 10, including a plurality of battery cells 11 arranged at intervals in a first direction; two end plates 20, respectively arranged at both ends of the battery cell group 10 in the first direction, and the plurality of battery cells 11 are located between the two end plates 20; a fixing member 30, having a receiving portion, the fixing member 30 is wound around the battery cell group 10 and the two end plates 20, so that the battery cell group 10 and the two end plates 20 are both located in the receiving portion, and the fixing member 30 fixes the battery cell group 10 and the two end plates 20 through the receiving portion; wherein, the battery module has an initial state and a pre-tightening state. When the battery module is in the initial state, the length of the receiving portion in the first direction is L1. When the battery module is in the pre-tightening state, the total length of the two end plates 20 and the battery cell group 10 in the first direction is L2, and the deformation amount of the fixing member 30 in the first direction in the pre-tightening state is K, and L1 = L2 - 2*K.
[0030] In the present application, the initial state is the uninstalled state, and the fixing member 30 is not assembled with the end plate 20 and the battery cell group 10. At this time, the length L1 of the receiving portion in the first direction is the length in the natural state. During the installation process of the battery module of the present application, first place the battery cell group 10 between the two end plates 20, and then use an external member to squeeze and clamp the two end plates 20 to fix them, so that the length of the two end plates 20 and the battery cell group 10 in the first direction is less than the length L1 of the receiving portion in the first direction. Due to the mutual action of forces, the two end plates 20 and the battery cell group 10 also exert extrusion forces on the external member. Then, sleeved the fixing member 30 on the two end plates 20 and the battery cell group 10. Then, loosen the external member, and the state at this time is the pre-tightening state. In the pre-tightening state, the extrusion force originally exerted by the two end plates 20 and the battery cell group 10 on the external member is borne by the fixing member 30, and the receiving portion will produce an expandable deformation within the expected range and the deformation amount is K. That is to say, in the pre-tightening state, there will be a mutual acting force between the fixing member 30 and the two end plates 20 and the battery cell group 10, and this acting force is the pre-tightening acting force. Due to reasons such as processing errors, L2 and K will randomly fluctuate under different working conditions. Therefore, L1 under different working conditions is not a fixed value, but may randomly fall on a certain point value within an interval range. However, no matter what the value of L1 of the fixing member 30 is, it should satisfy L1 = L2 - 2*K.
[0031] In the present application, a tensile test device is used to perform a tensile test on a single fixing member in the present application. From the initial state to the broken state of the fixing member, the device will display the curve relationship diagram of the deformation amount and the force of the fixing member. At the same time, the battery cell group 10 and the end plate 20 in the present application are subjected to simulation analysis through finite element to obtain the acting forces in different situations, and the deformation amount of the fixing member can be obtained under different acting forces, and this deformation amount is the above-mentioned K value.
[0032] The fixing member 30 is specifically an annular steel strip. In other embodiments, the fixing member 30 can also be made of other metals or plastics, which can be set according to specific circumstances.
[0033] Applying the technical solution of the present application, the accommodating portion of the fixing member 30 is used to fix the battery cell group 10 and the two end plates 20. At the same time, the length of the accommodating portion in the first direction in the initial state satisfies L1 = L2 - 2*K. Such a setting can not only enable the fixing member 30 to fix the battery cell group 10 and the end plates 20, but also enable the fixing member 30 to have sufficient deformation to meet the binding effect on the module, prevent the module from deforming, and thus ensure the normal operation of the battery module.
[0034] In the present application, X is the length direction of the battery module, Y is the width direction of the battery module, and Z is the height direction of the battery module.
[0035] In the embodiment of the present application, the battery cell 11 is in a cuboid shape. A foam board is provided between two adjacent battery cells 11, and the foam board is made of foam. The foam has a series of characteristics such as elasticity, light weight, fast pressure-sensitive fixation, easy use, flexible bending, ultra-thin volume, and reliable performance. Providing a foam board between two adjacent battery cells 11 can buffer the extrusion between the battery cells 11 and prevent static electricity, etc.
[0036] Among them, the battery module in the present application is specifically 1 parallel and 13 series-connected battery cells.
[0037] Further, in the present application, the length range of the accommodating portion in the first direction is: 990 mm ≤ L1 ≤ 1000 mm. When L1 > 1000 mm, the length of the accommodating portion of the fixing member 30 is too large. When the battery cell group 10 does not expand, the pre-tightening force between the accommodating portion of the fixing member 30 and the end plate 20 and the battery cell group 10 will be too small, thus reducing the fixing effect of the fixing member 30. At the same time, it will also increase the production cost of the device, which is not conducive to the mass production of the battery module. When L1 < 990 mm, the length of the accommodating portion of the fixing member 30 is too small. Thus, during the operation of the battery module, when the battery cell group 10 expands, the accommodating portion may be overstretched and damaged, reducing the stability of the battery module during use. In extreme cases, the fixing member 30 may be overstretched and unable to effectively restrain the battery cell group 10, causing the module to deform. Furthermore, the connecting aluminum busbar on the battery cell group 10 may be deformed and broken, resulting in the failure of the battery module. Therefore, 990 mm ≤ L1 ≤ 1000 mm can not only ensure the fixing effect of the fixing member 30, reduce the production cost of the battery module, but also effectively restrain the battery cell group 10 as much as possible, avoid the deformation of the battery cell group 10, and ensure the stability of the battery module during use. Optionally, L1 can be set to values such as 990 mm, 995 mm, or 1000 mm. The specific setting should be selected according to the use environment of the battery module and is not specifically limited here.
[0038] Specifically, in the present application, 0.9 mm ≤ L3 ≤ 1.1 mm. When L3 > 1.1 mm, the thickness of the fixing member 30 is too large, which will lead to an overweight of the fixing member 30 and increase the production cost of the device, thus being not conducive to the mass production of the battery module. When L3 < 0.9 mm, the thickness of the fixing member 30 is too small, which will reduce the structural strength of the fixing member 30. Thus, during the operation of the battery module, when the battery cell group 10 expands, the accommodating portion cannot effectively restrain the battery cell group 10, causing the module to deform. Furthermore, the connecting aluminum busbar on the battery cell group 10 may be deformed and broken, reducing the stability of the battery module during use. Therefore, 0.9 mm ≤ L3 ≤ 1.1 mm can not only reduce the weight of the fixing member 30, reduce the production cost of the battery module, but also effectively restrain the battery cell group 10 as much as possible, avoid the deformation of the battery cell group 10, and ensure the stability of the component during use. Optionally, L3 can be set to values such as 0.9 mm, 1.0 mm, or 1.1 mm. The specific setting should be selected according to the use environment of the battery module and is not specifically limited here.
[0039] Further, in the present application, the extension lengths of the first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34 in the third direction are L5, where 29.7 mm ≤ L5 ≤ 30.3 mm, and the first direction, the second direction, and the third direction are perpendicular to each other. When L5 > 30.3 mm, the extension length of the fixing member 30 is too large, which will increase the production cost of the device and thus is not conducive to the mass production of the battery module. When L5 < 29.7 mm, the extension length of the fixing member 30 is too small, which will reduce the structural strength of the fixing member 30. Thus, during the operation of the battery module, when the battery cell group 10 expands, the accommodating portion cannot effectively restrain the battery cell group 10, which will cause the module to deform, and further cause the connecting aluminum bars on the battery cell group 10 to deform and break, reducing the stability of the battery module during use. Therefore, setting 29.7 mm ≤ L5 ≤ 30.3 mm can not only reduce the production cost of the battery module but also effectively restrain the battery cell group 10 as much as possible, avoiding the deformation of the battery cell group 10 and ensuring the stability of the battery module during use. Optionally, L5 can be set to values such as 29.7 mm, 30 mm, or 30.3 mm, and the specific setting should be selected according to the use environment of the battery module, which is not specifically limited here.
[0040] Specifically, the fixing member 30 includes the first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34 connected in sequence end to end. The first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34 jointly enclose to form an accommodating portion. More precisely, the inner sidewalls of the first sidewall 31, the second sidewall 32, the third sidewall 33, and the fourth sidewall 34 jointly enclose to form an accommodating portion. The first sidewall 31 and the third sidewall 33 are oppositely arranged along the first direction, and the second sidewall 32 and the fourth sidewall 34 are oppositely arranged along the second direction. In the initial state, the sum of the dimensions of the inner sidewalls of the first sidewall 31 and the third sidewall 33 in the first direction is L1. The first sidewall 31 and the third sidewall 33 are respectively connected to the outer sidewalls of the two end plates 20, and the second sidewall 32 and the fourth sidewall 34 are respectively connected to the sidewalls of the battery cell group 10 in the second direction. The first direction and the second direction are perpendicular to each other. Such a setting can make the fixing member 30 more tightly connected to the two end plates 20 and the battery cell group 10, thereby improving the fixing effect of the fixing member 30 on the end plates 20 and the battery cell group 10.
[0041] In the present application, two fixing members 30 are provided, and the two fixing members 30 are arranged at intervals along the height direction of the battery module, which can improve the fixing effect of the fixing members 30 on the end plates 20 and the battery cell group 10 to ensure the normal operation of the battery module as much as possible. Optionally, the fixing member 30 can also be set to other numbers as long as it can meet the use requirements of the battery module.
[0042] Further, the extension length of the first side wall 31 and the third side wall 33 in the first direction is L3, and the extension length of the second side wall 32 and the fourth side wall 34 in the second direction is L4, and L3 = L4. This can make the thicknesses of the four side walls of the fixing member consistent. Such a setting not only facilitates the processing of the fixing member 30, reduces the production cost of the fixing member 30, but also can ensure the structural stability, thus being beneficial to the fixing effect on the end plate 20 and the battery cell group 10.
[0043] Specifically, the battery module further includes an insulating member 40, and the insulating member 40 is provided at the connection between the fixing member 30 and the battery cell group 10. In this application, the insulating member 40 is sleeved on the fixing member 30. Such a setting can prevent the risk of conductive contact between the fixing member 30 and the battery cell 11, thereby further improving the use stability of the device. In this embodiment, the insulating member 40 is a heat shrinkable tube. After the heat shrinkable tube is sleeved on the fixing member 30, heating can fix the heat shrinkable tube on the fixing member 30. This not only facilitates assembly, is beneficial to improving the installation effect of the device, but also has a simple structure and is easy to process, so it can also reduce the use cost of the device.
[0044] Further, the material of the fixing member 30 can be SUS201 stainless steel or LH stainless steel. Among them, the composition of SUS201 stainless steel is 17Cr - 4.5Ni - 6Mn - N, and the nickel content is low and the manganese content is high. Therefore, it has good corrosion resistance and heat treatment performance. Such a setting not only facilitates the processing of the fixing member 30, but also can extend the service life of the fixing member 30, thereby further ensuring the stability during the operation of the battery module.
[0045] Specifically, the connections between the first side wall 31, the second side wall 32, the third side wall 33 and the fourth side wall 34 are arc transitions, preferably a rounded corner structure 35. Such a setting can reduce the stress concentration between adjacent side walls, thereby improving the structural strength of the fixing member 30.
[0046] In a second aspect, an embodiment of the present application provides a battery pack, and the battery pack includes the above-mentioned battery module.
[0047] Applying the technical solution of the present application, the accommodating part of the fixing member 30 is used to fix the battery cell group 10 and the two end plates 20. At the same time, the length of the accommodating part in the first direction in the initial state satisfies L1 = L2 - 2*K. Such a setting can not only enable the fixing member 30 to fix the battery cell group 10 and the end plate 20, but also enable the fixing member 30 to have sufficient deformation to meet the binding effect on the module and prevent the module from deforming, thereby ensuring the normal operation of the battery module.
[0048] Note that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and / or combinations thereof.
[0049] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.
[0050] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.
[0051] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used herein will be made accordingly.
[0052] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without further statement, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present application.
[0053] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. A battery module, characterized in that: The battery module comprises: A battery cell group, comprising a plurality of battery cells arranged at intervals along a first direction; Two end plates, respectively arranged at two ends of the battery cell group along the first direction; A fixing member having a receiving portion, wherein the fixing member is wound around the battery cell group and the two end plates so that the battery cell group and the two end plates are both located in the receiving portion, and the fixing member fixes the battery cell group and the two end plates through the receiving portion; Wherein, the battery module has an initial state and a pre-tightened state. When the battery module is in the initial state, the length of the accommodating portion in the first direction is L1. When the battery module is in the pre-tightened state, the total length of the two end plates and the battery cell group in the first direction is L2. The deformation of the fixing member along the first direction in the pre-tightened state is K, and L1=L2-2*K.
2. The battery module according to claim 1, characterized in that: The length range of the accommodating portion in the first direction is: 990 mm ≤ L1 ≤ 1000 mm.
3. The battery module according to claim 1, characterized in that: The fixing member includes a first side wall, a second side wall, a third side wall and a fourth side wall connected in sequence from end to end, the first side wall, the second side wall, the third side wall and the fourth side wall are jointly arranged to form the accommodating portion, the first side wall and the third side wall are arranged opposite to each other along the first direction, the second side wall and the fourth side wall are arranged opposite to each other along the second direction, the first side wall and the third side wall are respectively connected to the outer side walls of the two end plates, the second side wall and the fourth side wall are respectively connected to the side walls of the battery cell group in the second direction, and the first direction and the second direction are perpendicular to each other.
4. The battery module according to claim 3, characterized in that: In the initial state, an extension length of the first side wall and the third side wall along the first direction is L3, an extension length of the second side wall and the fourth side wall along the second direction is L4, and L3=L4.
5. The battery module according to claim 4, characterized in that: 0.9mm≤L3≤1.1mm.
6. The battery module according to claim 3, characterized in that: An extension length of the first side wall, the second side wall, the third side wall and the fourth side wall in the third direction is L5, 29.7 mm≤L5≤30.3 mm, and the first direction, the second direction and the third direction are perpendicular to each other.
7. The battery module according to any one of claims 1 to 6, characterized in that: The battery module further comprises an insulating member, and the insulating member is disposed at the connection between the fixing member and the battery cell group.
8. The battery module according to claim 1, characterized in that: The material of the fixing member includes SUS201 stainless steel or LH stainless steel.
9. The battery module according to claim 3, characterized in that: The connection between the first side wall, the second side wall, the third side wall and the fourth side wall is an arc structure.
10. A battery pack, characterized in that: include: A box body having a containing cavity; The battery module according to any one of claims 1 to 9, wherein the battery module is arranged in the accommodating cavity.