Battery module and battery pack
By designing a gradually decreasing separator stiffness scheme in the battery module, the uniformity of the cell expansion binding force is adjusted, solving the problem of uneven cell expansion and improving the service life of the cells and the module.
Patent Information
- Application Number
- CN202423068390.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-11
AI Technical Summary
In traditional battery modules, the binding forces on the cells during expansion are inconsistent, affecting cell consistency and lifespan.
The stiffness of different separators is designed to gradually decrease from the center of the battery module outwards. By adjusting the thickness, material, area, and structural shape of the separators, the binding force of the cell expansion is adjusted so that the binding force experienced by each cell during expansion is nearly uniform.
This improved the consistency of cell lifespan and extended the lifespan of the battery module.
Smart Images
Figure CN223625101U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and more particularly to a battery module and a battery pack. Background Technology
[0002] In traditional battery modules, multiple cells are stacked along their thickness. During actual operation, each cell expands, resulting in the cells near the center being subjected to pressure from multiple cells on the left and right sides. This causes the cells near the center to experience greater pressure, while the cells near the outer edges experience less pressure. Consequently, the constraint forces on the expansion of different cells are inconsistent, affecting the cell consistency of the entire battery module and its lifespan. Utility Model Content
[0003] One objective of this application is to provide a battery module that aims to improve the consistency of the binding force experienced by each cell during expansion, thereby improving the consistency of the lifespan of each cell.
[0004] To achieve the above objectives, this application provides a solution: a battery module comprising multiple separators and multiple battery cells. The separators are arranged along their thickness direction, and any one battery cell is disposed between two adjacent separators and connected to the two adjacent separators. In the thickness direction, the stiffness of the different separators is configured to gradually decrease from the center of the battery module outwards.
[0005] Optionally, in the thickness direction, the thickness of the different separators is configured to gradually decrease from the center of the battery module outwards.
[0006] Optionally, the plurality of separators includes a first separator and a second separator, wherein the first separator is located between the center of the battery module and the second separator; the thickness of the first separator is d1, the thickness of the second separator is d2, and 1.1≤d1 / d2≤1.2.
[0007] Optionally, in the thickness direction, the areas of the different separators are configured to gradually decrease from the center of the battery module outwards; the area of the separator is the planar area of the separator perpendicular to the thickness direction.
[0008] Optionally, the battery cell includes a main body and electrode terminals, at least a portion of which extends out of the main body. The cross-sectional area of the main body perpendicular to the thickness direction is S1. In the thickness direction, the area of the separator closest to the center of the battery module is S2, and the area of the separator furthest from the center of gravity of the battery module is S3, where S2 / S1≤1 and S3 / S1≥0.3.
[0009] Optionally, the plurality of separators includes a first separator and a second separator, wherein the first separator is located between the center of the battery module and the second separator; the area of the first separator is M1, the area of the second separator is M2, and 1.1≤M1 / M2≤1.2.
[0010] Optionally, the plurality of separators are made of different materials; in the thickness direction, the separator near the center of the battery module is made of metal, and the separator away from the center of the battery module is made of plastic.
[0011] Optionally, the separator includes a first plate, a second plate, and a plurality of ribs. The first plate and the second plate are respectively located on both sides of the separator along its thickness direction. The first plate and the second plate are spaced apart along the thickness direction. The plurality of ribs are disposed between the first plate and the second plate and are connected to the first plate and the second plate. In the thickness direction, the number of different ribs in the separator gradually decreases from the center of the battery module toward the outside.
[0012] Optionally, the partition further includes a through hole located between the first plate and the second plate, and penetrating the partition in a direction perpendicular to the thickness direction.
[0013] This application also provides a solution: a battery pack, the battery pack comprising the battery module described in any of the foregoing embodiments.
[0014] The beneficial effects of this application are as follows:
[0015] In the battery module of this application, by designing different stiffnesses of the separators, the separators closer to the center of the battery module (along the stacking direction of the cells) have greater stiffness, while the separators farther from the center of the battery module have less stiffness. The stiffness of each separator gradually decreases from the center outwards. When the cells in the battery module expand, it helps to make the binding force on each cell more consistent, thereby improving the consistency of the lifespan of each cell and increasing the lifespan of the battery module. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0017] Figure 1This is a schematic diagram of the assembly structure of the battery module provided in the embodiments of this application;
[0018] Figure 2 This is provided by the embodiments of this application. Figure 1 The exploded structure diagram of the battery module shown.
[0019] Figure 3 This is provided by the embodiments of this application. Figure 1 The front view of the battery module shown;
[0020] Figure 4 This is a schematic diagram of the assembly structure of the battery module provided in the embodiments of this application;
[0021] Figure 5 This is provided by the embodiments of this application. Figure 4 The exploded structure diagram of the battery module shown.
[0022] Figure 6 This is provided by the embodiments of this application. Figure 4 The front view of the battery module shown;
[0023] Figure 7 This is a cross-sectional view of the partition provided in an embodiment of this application;
[0024] Figure 8 This is a schematic diagram of the battery pack provided in the embodiments of this application.
[0025] Explanation of reference numerals in the attached figures: Battery pack 100, Battery module 10, Cell 11, Main body 111, Cell housing 1111, Electrode terminal 112, Separator 12, First separator 121, Second separator 122, Rib 123, First plate 124, Second plate 125, Through hole 126, Bisecting surface 13, Thickness direction X, Width direction Y, Height direction Z. Detailed Implementation
[0026] 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 the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0027] like Figure 1 and Figure 2As shown, this application provides a battery module 10, which includes a plurality of battery cells 11 stacked along its thickness direction X. In one embodiment, the plurality of battery cells 11 are electrically connected by parallel connection. In another embodiment, the plurality of battery cells 11 are electrically connected by series connection. In yet another embodiment, the plurality of battery cells 11 are electrically connected by a combination of parallel and series connection.
[0028] In one embodiment, the battery module 10 further includes a plurality of separators 12, which are arranged along their thickness direction X. The thickness direction X of the separators 12 is parallel to the thickness direction X of the battery cell 11. For ease of description, the thickness direction X of the separators 12 and the thickness direction X of the battery cell 11 are referred to as the thickness direction X.
[0029] In some embodiments, any one of the battery cells 11 is disposed between two adjacent separators 12 along the thickness direction X, and the two adjacent separators 12 are connected. This arrangement ensures that the separators 12 and battery cells 11 are alternately connected in the thickness direction X. When any of the battery cells 11 expands, the multiple separators 12 can provide binding force to the different battery cells 11, thereby suppressing the expansion of the battery cells 11 and extending their service life.
[0030] In one embodiment, the battery cell 11 includes a main body 111 and electrode terminals 112. The main body 111 includes a battery cell housing 1111 and an electrode assembly (not shown). The electrode assembly is disposed within the battery cell housing 1111. A portion of the electrode terminals 112 is connected to the electrode assembly, and a portion of the electrode terminals extends out of the main body 111. The main body 111 is connected to an adjacent separator 12. When the battery cell 11 expands, the dimension of the main body 111 changes along its thickness direction X. At this time, there is an interactive compressive force between the main body 111 and the separator 12.
[0031] In one embodiment, electrode terminal 112 includes a positive terminal and a negative terminal, which serve as output terminals of cell 11.
[0032] In one embodiment, the stiffness of different separators 12 is configured to gradually decrease from the center of the battery module 10 outward in the thickness direction X. The center of the battery module 10 is located on its bisecting plane 13 along the thickness direction X, which is perpendicular to the thickness direction X. Since multiple cells 11 and multiple separators 12 are stacked along the thickness direction X, when each cell 11 expands, the cell 11 closer to the center of the battery module 10 is subjected to greater expansion pressure from the cells 11 on the left and right sides, making it more difficult for the cell 11 closer to the center of the battery module 10 to expand. Similarly, the cell 11 farther from the center of the battery module 10 expands more easily. That is, the expansion restraint force on cells 11 at different distances from the center of the battery module 10 is inconsistent. This difference in expansion restraint force will cause different cells 11 to expand to different degrees, thereby affecting the consistency of the lifespan of different cells 11. In this embodiment, different separators 12 are designed with different stiffnesses, and the stiffness of different separators 12 decreases from the center of the battery module 10 outwards. This makes the separators 12 closer to the center of the battery module 10 have a stronger ability to resist deformation, which helps to reduce the impact of the expansion of multiple cells 11 on the cells 11 closer to the center. It also helps to make the binding force on each cell 11 during expansion more consistent, thereby improving the consistency of the service life of each cell 11 and improving the service life of the battery module 10.
[0033] like Figures 1 to 3 As shown, in one embodiment, the stiffness of different separators 12 is varied by designing different thicknesses. For example, in the thickness direction X, the thickness of different separators 12 is configured to gradually decrease from the center of the battery module 10 outwards. In this embodiment, the separator 12 closer to the center of the battery module 10 is thicker, which has a stronger resistance to deformation and can better withstand the expansion and compression forces from multiple outer cells 11. This reduces the impact of the expansion of multiple cells 11 on the cells 11 closer to the center, which helps to make the binding force on each cell 11 during expansion more consistent, thereby improving the consistency of the service life of each cell 11 and increasing the service life of the battery module 10. In this embodiment, the materials of each separator 12 can be the same or different.
[0034] In one embodiment, the plurality of separators 12 include a first separator 121 and a second separator 122. The first separator 121 is located between the center of the battery module 10 and the second separator 122, that is, the first separator 121 is closer to the center of the battery module 10 than the second separator 122. The thickness of the first separator 121 is defined as d1, and the thickness of the second separator 122 is defined as d2, where d1 > d2.
[0035] In one embodiment, 1.1≤d1 / d2≤1.2 is beneficial to make the thickness of the multiple separators 12 vary in a gradient, thereby making the binding force on the expansion of each cell 11 more consistent, improving the consistency of the service life of each cell 11, and improving the service life of the battery module 10.
[0036] In one embodiment, the value of d1 / d2 is any one of 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19 and 1.2, which is beneficial to make the thickness of the multiple separators 12 vary in a gradient, thereby making the binding force on the expansion of each cell 11 more consistent, improving the consistency of the service life of each cell 11, and improving the service life of the battery module 10.
[0037] In one embodiment, when the stiffness of different partitions 12 is different by designing different thicknesses of the partitions 12, the width and height of each partition 12 can be equal.
[0038] In one embodiment, multiple separators 12 are made of different materials, with separators 12 at different locations using different materials. The different material properties result in varying stiffness among the separators 12. For example, in the thickness direction X, the separator 12 near the center of the battery module 10 is made of metal, while the separator 12 away from the center is made of plastic. In this embodiment, the separator 12 near the center of the battery module 10 is made of a rigid metal material, which has a stronger resistance to deformation and can better withstand the expansion and compression forces from the multiple outer cells 11, reducing the impact of the expansion of the cells 11 on the cells near the center. Meanwhile, the separators 12 near the outer edges of the battery module 10 are made of a less rigid plastic material, which has a weaker resistance to deformation. This arrangement helps to make the binding force on each cell 11 during expansion more consistent, thereby improving the consistency of the lifespan of each cell 11 and extending the lifespan of the battery module 10.
[0039] In one embodiment, the metal partition 12 is integrally formed by casting, which not only helps to ensure its high rigidity, but also helps to improve its manufacturing efficiency and save costs.
[0040] In one embodiment, the plastic partition 12 is integrally molded by injection molding, which helps to improve its manufacturing efficiency and save costs.
[0041] like Figures 4 to 6As shown, in one embodiment, the binding force of different separators 12 on the expansion of the battery cell 11 is adjusted by designing different areas of the separators 12. For example, in the thickness direction X, the areas of different separators 12 are configured to gradually decrease from the center of the battery module 10 outwards, wherein the area of the separator 12 is the plane area of the separator 12 perpendicular to the thickness direction X. In this embodiment, the contact area between the separator 12 near the center of the battery module 10 and the battery cell 11 is larger, that is, the surface area for suppressing the expansion of the battery cell 11 is larger, which can better withstand the expansion pressure from multiple batteries 11 on the outside, and reduce the impact of the expansion of multiple batteries 11 on the battery cell 11 near the center. At the same time, the contact area between the separator 12 near the outside of the battery module 10 and the battery cell 11 is smaller, that is, the surface area for suppressing the expansion of the battery cell 11 is smaller. This setting helps to make the binding force on the expansion of each battery cell 11 more consistent, thereby improving the consistency of the service life of each battery cell 11 and improving the service life of the battery module 10.
[0042] In one embodiment, the cross-sectional area of the main body 111 perpendicular to the thickness direction X is defined as S1, and the area of the partition 12 closest to the center of the battery module 10 in the thickness direction X is defined as S2, where S2 / S1≤1.
[0043] In one embodiment, S2 / S1 = 1, that is, the area of the separator 12 closest to the center of the battery module 10 is equal to the area of the main body 111. This is beneficial to reduce the weight of the separator 12 and reduce the impact of the gravity of the separator 12 on the battery module 10 while increasing the contact area between the separator 12 and the main body 111.
[0044] In one embodiment, the area of the separator 12 furthest from the center of gravity of the battery module 10 is defined as S3, where S3 < S2 and S3 / S1 ≥ 0.3. If S3 is too small, it will not be able to suppress the expansion of the cell 11. Designing S3 to be S3 / S1 ≥ 0.3 is beneficial to ensure that the separator 12 can suppress the expansion of the cell 11 while allowing the area of different cells 11 to form a gradient change. This makes the restraining force on the expansion of each cell 11 more consistent, thereby improving the consistency of the service life of each cell 11 and improving the service life of the battery module 10.
[0045] In one embodiment, the area of the first separator 121 is defined as M1, and the area of the second separator 122 is defined as M2, with 1.1≤M1 / M2≤1.2, so that the areas of different cells 11 form a gradient change, causing the binding force on each cell 11 to be closer to the same when it expands, thereby improving the consistency of the service life of each cell 11 and improving the service life of the battery module 10.
[0046] In one embodiment, the value of M1 / M2 is any one of 1.1, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19 and 1.2, which is beneficial to make the area of the multiple separators 12 vary in a gradient, thereby making the binding force on the expansion of each cell 11 more consistent, improving the consistency of the service life of each cell 11, and improving the service life of the battery module 10.
[0047] In one embodiment, each partition 12 has the same width, and the area ratio between each partition 12 is equal to its height ratio. Further, in one embodiment, the width of each partition 12 is equal to the width of the battery cell 11, and the end of the partition 12 along the width direction Y is flush with the end of the battery cell 11. This facilitates the partition 12 applying a restraining force to the main body 111 of the battery cell 11 to suppress expansion, thereby extending the service life of the battery cell 11. The width direction Y of the partition 12 is parallel to the width direction Y of the battery cell 11 and is perpendicular to the thickness direction X. Correspondingly, the height direction Z of the partition 12 is parallel to the height direction Z of the battery cell 11 and is perpendicular to both the thickness direction X and the width direction Y. Further, at least a portion of the structure of the electrode terminal 112 extends out of the main body 111 along the height direction Z.
[0048] like Figure 1 and Figure 7 As shown, in one embodiment, the stiffness of different separators 12 is adjusted by designing different structural shapes, so that the separators 12 closer to the center of the battery module 10 have a stronger resistance to deformation, while the separators 12 farther from the center of the battery module 10 have a weaker resistance to deformation, thereby improving the consistency of the service life of each cell 11 and increasing the service life of the battery module 10. For example, ribs 123 can be provided on the separators 12 closer to the center of the battery module 10 to improve their resistance to deformation. In this case, ribs 123 may not be provided on the separators 12 farther from the center of the battery module 10, or the ribs 123 may be fewer and thinner, so that the stiffness of the separator 12 is less than that of the middle separator 12.
[0049] In one embodiment, the rib 123 can be disposed on the surface of the partition 12 or inside the partition 12.
[0050] In one embodiment, the separator 12 includes a first plate 124 and a second plate 125, which are located on opposite sides of the separator 12 along its thickness direction X. The first plate 124 and the second plate 125 are spaced apart along the thickness direction X. A plurality of ribs 123 are disposed between the first plate 124 and the second plate 125 and connect the first plate 124 and the second plate 125. By placing the ribs 123 inside the separator 12, it is beneficial to improve the flatness of the surface of the separator 12 and reduce the adverse effects of the shape of the separator 12 on the battery cell 11.
[0051] In one embodiment, in the thickness direction X, the number of different inner ribs 123 of the separator 12 gradually decreases from the center of the battery module 10 outwards. This arrangement helps to make the stiffness of the different separators 12 vary in a gradient, causing the binding force on each cell 11 to be closer to uniform during expansion, thereby improving the consistency of the service life of each cell 11 and increasing the service life of the battery module 10.
[0052] In one embodiment, the separator 12 further includes a through hole 126, which is located between the first plate 124 and the second plate 125 and extends through the separator 12 in a direction perpendicular to the thickness direction X. By providing the through hole 126, it is not only beneficial to reduce the weight of the separator 12 and reduce the impact of the gravity of the separator 12 on the battery module 10, but also beneficial to increase the heat dissipation area of the separator 12 and improve the heat dissipation efficiency of the battery module 10.
[0053] In other embodiments, the rib 123 may also be provided on the surface of the partition 12 (not shown).
[0054] like Figure 8 As shown, embodiments of this application also provide a battery pack 100, which includes the battery module 10 of any of the foregoing embodiments.
[0055] In summary, in the battery module 10 of this application, by designing different stiffnesses of the separators 12, the separators 12 closer to the center of the battery module 10 (along the stacking direction of the cells 11) have greater stiffness, while the separators 12 farther from the center of the battery module 10 have less stiffness. The stiffness of each separator 12 gradually decreases from the center outwards. When each cell 11 in the battery module 10 expands, it helps to make the binding force on each cell 11 more consistent, thereby improving the consistency of the service life of each cell 11 and improving the service life of the battery module 10.
[0056] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0057] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.
[0058] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.
[0059] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the content of this application's specification and drawings under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.
Claims
1. A battery module, characterized in that, include: Multiple partitions, wherein the multiple partitions are arranged along their thickness direction; Multiple battery cells, wherein any one of the battery cells is disposed between two adjacent partitions and connected to the two adjacent partitions; In the thickness direction, the stiffness of the different separators is configured to gradually decrease from the center of the battery module toward the outside.
2. The battery module according to claim 1, characterized in that, In the thickness direction, the thickness of the different separators is configured to gradually decrease from the center of the battery module outwards.
3. The battery module according to claim 2, characterized in that, The plurality of separators includes a first separator and a second separator, wherein the first separator is located between the center of the battery module and the second separator; The thickness of the first partition is d1, the thickness of the second partition is d2, and 1.1≤d1 / d2≤1.
2.
4. The battery module according to claim 1, characterized in that, In the thickness direction, the areas of the different separators are configured to gradually decrease from the center of the battery module toward the outside. The area of the partition is the plane area of the partition perpendicular to the thickness direction.
5. The battery module according to claim 4, characterized in that, The battery cell includes a main body and electrode terminals, at least a portion of which extends out of the main body, and the cross-sectional area of the main body perpendicular to the thickness direction is S1; In the thickness direction, the area of the separator closest to the center of the battery module is S2, and the area of the separator furthest from the center of gravity of the battery module is S3, S2 / S1≤1, S3 / S1≥0.
3.
6. The battery module according to claim 4, characterized in that, The plurality of separators includes a first separator and a second separator, wherein the first separator is located between the center of the battery module and the second separator; The area of the first partition is M1, the area of the second partition is M2, and 1.1 ≤ M1 / M2 ≤ 1.
2.
7. The battery module according to claim 1, characterized in that, The multiple partitions are made of different materials; In the thickness direction, the separator near the center of the battery module is made of metal, and the separator away from the center of the battery module is made of plastic.
8. The battery module according to claim 1, characterized in that, The partition includes a first plate, a second plate, and a plurality of ribs. The first plate and the second plate are respectively located on both sides of the partition along its thickness direction. The first plate and the second plate are spaced apart along the thickness direction. The plurality of ribs are all disposed between the first plate and the second plate and are all connected to the first plate and the second plate. In the thickness direction, the number of different inner ribs of the separator gradually decreases from the center of the battery module toward the outside.
9. The battery module according to claim 8, characterized in that, The partition also includes a through hole located between the first plate and the second plate, and penetrating the partition in a direction perpendicular to the thickness direction.
10. A battery pack, characterized in that, The battery pack includes the battery module as described in any one of claims 1 to 9.