Battery cell and battery pack

Abstract

The utility model discloses a battery cell and a battery pack, and belongs to the technical field of battery packs. Comprising a shell and a battery cell, the shell comprises a first large face, a second large face and a bent face, the first large face and the second large face are oppositely arranged in the first direction, and the bent face is connected with the first large face and the second large face to define a containing space; the roll core is arranged in the containing space and comprises a straight part and a bent part, the bent part is connected to the end, in the second direction, of the straight part, and the bent part and the bent face are at least partially overlapped in the first direction. The peripheral surfaces of the battery cells are limited to be polygonal through the arrangement of the bending surfaces, the effects of improving the torsional rigidity and rhombus-shaped and ship-shaped deformation resistance of the battery cell group are achieved, the overall supporting strength of the battery cells can be further improved through the arrangement of the mutually overlapped bending parts and the bending surfaces, and the overall deformation resistance of the battery cells is further improved; and therefore, the beneficial effect of improving the stability and the safety of the battery cell when the battery cell is impacted by external force is achieved.

Description

Technical Field

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

[0002] With the continuous development and progress of new energy technologies, the capacity requirements for battery packs are increasing, and the space occupied by battery packs in new energy vehicles is becoming larger and larger.

[0003] In existing technologies, battery packs are usually installed in the chassis. However, the battery pack itself has low structural strength and cannot provide strength to the vehicle body as a structural component. It occupies most of the chassis space but cannot provide a corresponding proportion of support strength to the vehicle. Utility Model Content

[0004] The purpose of this application is to provide a battery cell and battery pack that can solve the problem of low structural strength of battery packs in the prior art.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application provide a battery cell having a first direction, a second direction, and a third direction that intersect each other. The battery cell includes a housing and a core. The housing includes a first large surface, a second large surface, and a bending surface. The first large surface and the second large surface are disposed opposite each other along the first direction. The bending surface connects the first large surface and the second large surface to define an accommodating space. The core is disposed in the accommodating space. The core includes a straight portion and a curved portion. The curved portion is connected to the end of the straight portion along the second direction. Along the first direction, the curved portion and the bending surface at least partially overlap.

[0007] In this embodiment, the housing has a bent surface. Compared to a straight surface, the bent surface enhances the supporting strength of the housing, and the core has a curved portion. Furthermore, when the core is disposed within the receiving space, the curved portion and the bent surface at least partially overlap along the first direction. In practical applications, the core is disposed within the receiving space, and the curved portion and the bent surface at least partially overlap. It is understood that defining the outer periphery of the core as a polygon by the bent surface improves the torsional stiffness and resistance to rhomboid and boat-shaped deformations. The overlapping curved portion and bent surface further enhance the overall supporting strength of the core, thereby improving its overall resistance to deformation and enhancing its stability and safety under external impact.

[0008] Optionally, in this embodiment of the application, the cross-section of the battery cell perpendicular to the third direction is octagonal.

[0009] Optionally, in an embodiment of this application, the bent surface includes a first sub-surface, a second sub-surface, and a third sub-surface. The second sub-surface is perpendicular to the first large surface. The first sub-surface connects the second sub-surface and the first large surface. The third sub-surface connects the second sub-surface and the second large surface. The angle between the first sub-surface and the second sub-surface and the first large surface is greater than 90°. The angle between the third sub-surface and the second sub-surface and the second large surface is also greater than 90°.

[0010] Optionally, in this embodiment of the application, the distance between the first large surface and the second large surface is L, and the first large surface, the second large surface, the first sub-surface, the second sub-surface and the third sub-surface are inscribed in a circle with a diameter of L.

[0011] Secondly, in this application embodiment, a battery pack is also provided, including a plurality of battery cells as described above. The plurality of battery cells are arranged along the first direction to form a plurality of first battery cell groups and a plurality of second battery cell groups. The first battery cell groups and the second battery cell groups are arranged alternately along the second direction. The first battery cell groups and the second battery cell groups are staggered along the first direction, and the battery cells in the first battery cell groups and the battery cells in the second battery cell groups are staggered along the first direction.

[0012] Optionally, in this embodiment of the application, the two bending surfaces of two adjacent cells in the first cell group enclose a first clearance space; the cells in the second cell group are opposite to the first clearance space along the second direction, and the first clearance space is provided with functional components.

[0013] Optionally, in an embodiment of this application, at least a portion of the cells in the second cell group are accommodated within the first clearance space.

[0014] Optionally, in this embodiment of the application, the cross-sectional shape of the first clearance space along the plane containing the first direction and the second direction is triangular.

[0015] Optionally, in an embodiment of this application, the functional component is a first adhesive component, which fills the first clearance space and connects the cells in the adjacent first cell group and second cell group.

[0016] Optionally, in this embodiment of the application, the battery pack further includes a housing and a second adhesive member. The housing has an inner cavity, in which a plurality of first cell groups and a plurality of second cell groups are disposed. Along the first direction and / or along the second direction, the plurality of first cell groups and the plurality of second cell groups are spaced apart from the housing. The second adhesive member fills the space and is bonded to the first cell groups and the housing. Alternatively, the second adhesive member is bonded to the second cell groups and the housing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the battery cell structure in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of a battery cell at another angle in an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of the battery pack structure in an embodiment of this application;

[0020] Figure 4 This is an embodiment of the present application. Figure 1 Enlarged structural diagram at point A;

[0021] Figure 5 This is a schematic diagram of the cross-sectional structure of the shell and the core in the embodiments of this application.

[0022] Explanation of reference numerals in the attached figures:

[0023] 101. First cell assembly; 102. Second cell assembly; 11. Cell; 111. First large surface; 112. Second large surface; 113. Bending surface; 114. Straight section; 115. Bending section; 1131. First sub-surface; 1132. Second sub-surface; 1133. Third sub-surface; 20. Housing; 30. First clearance space; X. First direction; Y. Second direction; Z. Third direction. Detailed Implementation

[0024] 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0026] The battery cells and battery packs provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0027] See Figures 1 to 5 An embodiment of this application provides a battery cell 11 having a first direction X, a second direction Y, and a third direction Z that intersect each other. The battery cell 11 includes a housing and a core. The housing includes a first large surface 111, a second large surface 112, and a bending surface 113. The first large surface 111 and the second large surface 112 are disposed opposite each other along the first direction X. The bending surface 113 connects the first large surface 111 and the second large surface 112 to define an accommodating space. The battery cell 11 also includes a core, which includes a straight portion 114 and a bent portion 115. The bent portion 115 is connected to the end of the straight portion 114 along the second direction Y. Along the first direction X, the bent portion 115 and the bending surface 113 at least partially overlap.

[0028] In this embodiment, the housing has a bent surface 113. Compared to a straight surface, the bent surface 113 enhances the support strength of the housing. The core has a bent portion 115. Furthermore, when the core is disposed within the receiving space, the bent portion 115 and the bent surface 113 at least partially overlap along the first direction. In practical applications, the core is disposed within the receiving space, and the bent portion 115 and the bent surface 113 at least partially overlap. It is understood that by defining the outer periphery of the battery cell 11 as a polygon through the bent surface 113, the torsional stiffness and resistance to rhomboid and boat-shaped deformations of the battery cell 11 are improved. The overlapping bent portion 115 and the bent surface 113 further enhance the overall support strength of the battery cell, thereby also improving the overall resistance to deformation. This has the beneficial effect of improving the stability and safety of the battery cell under external impact.

[0029] It should be noted that the first direction X is the thickness direction of the battery cell 11, the second direction Y is the length direction of the battery cell 11, and the third direction Z is the height direction of the battery cell.

[0030] Optionally, in this embodiment, the cross section of the battery cell 11 perpendicular to the third direction Z is octagonal.

[0031] In this embodiment, it is understood that the number of octagonal cross-section battery cells 11 on their outer surfaces is relatively large, which has the advantage of facilitating heat dissipation compared to the rectangular and hexagonal battery cells 11 commonly used in related technologies. In practical applications, the battery cells 11 in this embodiment, after being arranged in groups, have equal spacing between adjacent battery cells 11. This spacing can simultaneously reduce the heat transfer efficiency between the battery cells 11 and their sides, thus enhancing the heat dissipation efficiency of the battery cells 11.

[0032] Optionally, in this embodiment of the application, the bent surface 113 includes a first sub-surface 1131, a second sub-surface 1132, and a third sub-surface 1133. The second sub-surface 1132 is perpendicular to the first large surface 111. The first sub-surface 1131 connects the second sub-surface 1132 and the first large surface 111. The third sub-surface 1133 connects the second sub-surface 1132 and the second large surface 112. The angle between the first sub-surface 1131 and the second sub-surface 1132 and the first large surface 111 is greater than 90°. The angle between the third sub-surface 1133 and the second sub-surface 1132 and the second large surface 112 is also greater than 90°.

[0033] In this embodiment, the shell has an octagonal cross-section, with the angle between the first sub-face 1131 and the first large face 111 greater than 90°, the angle between the first sub-face 1131 and the second sub-face 1132 greater than 90°, the angle between the third sub-face 1133 and the second sub-face 1132 greater than 90°, and the angle between the third sub-face 1133 and the second large face 112 greater than 90°. It is understood that the first large face 111 and the second large face 112 are arranged opposite each other, and the two bending surfaces are also arranged opposite each other. Furthermore, the angle between the surfaces being greater than 90° enhances the deformation resistance of the bending surfaces, thereby improving the supporting strength of the shell and having the beneficial effect of improving the stability and safety of the battery cell under external impact.

[0034] Optionally, in this embodiment of the application, the distance between the first large surface 111 and the second large surface 112 is L, and the first large surface 111, the second large surface 112, the first sub-surface 1131, the second sub-surface 1132 and the third sub-surface 1133 are inscribed in a circle with a diameter of L.

[0035] In the embodiments of this application, such as Figure 2As shown, the five sides at both ends of the battery cell 11, namely the first large surface 111, the first sub-surface 1131, the second sub-surface 1132, the third sub-surface 1133, and the second large surface 112 connected in sequence, are simultaneously tangent to a circle with a diameter (L) equal to the thickness of the battery cell 11 in a cross-section perpendicular to the third direction Z. It is understandable that when the side length of a square and the diameter of a circle are the same, the area of ​​the circle is larger. Therefore, the above arrangement can maximize the utilization of the internal space of the battery cell 11, increasing the volumetric energy density of the battery cell 11. The structural design of the battery cell 11 has the beneficial effect of effectively improving system strength and system volume utilization during system arrangement.

[0036] Furthermore, the lengths of the first large surface 111, the second large surface 112, the first sub-surface 1131, the second sub-surface 1132, and the third sub-surface 1133 can be determined according to the actual situation. For example, the lengths of the first large surface 111 and the second large surface 112 along the second direction Y can be 165.9 mm, the length of the second sub-surface 1132 along the first direction X can be 18.2 mm, and the lengths of the first sub-surface 1131 and the third sub-surface 1133 can be 17.4 mm.

[0037] Optionally, in this embodiment of the application, a battery pack is also provided, including a plurality of cells 11 as described above. The plurality of cells 11 are arranged along a first direction X to form a plurality of first cell groups 101 and a plurality of second cell groups 102. The first cell groups 101 and the second cell groups 102 are arranged alternately along a second direction Y. The first cell groups 101 and the second cell groups 102 are staggered along the first direction X, and the cells 11 in the first cell group 101 and the cells 11 in the second cell group 102 are staggered along the first direction X.

[0038] In this embodiment, multiple battery cells 11 are arranged in an array within the battery pack. When the first battery cell group 101 and the second battery cell group 102 are staggered along the first direction X, the first battery cell group 101 and the second battery cell group 102 mutually reinforce each other, which can greatly improve the force intensity under top pressure. At the same time, it can stagger the weak points of the battery cells 11 during the force application process, which plays a role in uniformly distributing external force, enhances the protection of the battery cells 11 from uneven force distribution caused by lateral compression, and also avoids the formation of weak points when the middle of the side of the battery cell 11 is compressed.

[0039] It should be noted that, in the above case, the area enclosed by the three cells 11 creates gaps between adjacent cells 11, which reduces the heat transfer efficiency between cells 11 and has the beneficial effect of reducing the probability of heat spread within the battery pack.

[0040] Furthermore, in the same first cell group 101 or the same second cell group 102, the gap between the first large surface 111 of one cell 11 and the second large surface 112 of the other cell 11 is about 0.1mm to 5mm. The above gap can be used to select heat insulation pads of different thicknesses for different systems and different thermal runaway heat-generating cells 11, thereby improving the adaptability of the solution.

[0041] Furthermore, in two adjacent cells 11 along the second direction Y, the gap between the bending surface 113 of one cell 11 and the bending surface 113 of the other cell 11 is about 0.1~5mm. The gap can be adjusted according to different systems and different thermal runaway heat generation energies of the cells 11. The gap can be filled with a low thermal conductivity insulating adhesive, which has a certain thermal insulation performance while ensuring strength.

[0042] It should also be noted that the first cell group 101 and the second cell group 102 in this application are arranged in an alternating manner, which has lower requirements for the strength of structural components compared with the existing common battery pack designs, and has the beneficial effect of reducing the cost of structural components to a certain extent.

[0043] Optionally, in this embodiment of the application, the two bending surfaces 113 of two adjacent cells 11 in the first cell group 101 enclose a first clearance space 30; the cells 11 in the second cell group 102 are opposite to the first clearance space 30 along the second direction Y, and the first clearance space is provided with functional components.

[0044] In this embodiment, the first clearance space 30 is provided as a space for functional components. The functional components can be used to further strengthen the connection and tightness between the cells in the first cell group 101 and the second cell group 102, and can also be used to space between cells 11 to achieve heat insulation between cells 11. Specifically, the functional components can be adhesive components or heat insulation components; this embodiment does not limit this and can be determined according to the actual situation.

[0045] In practical applications, the corresponding arrangement of the cells 11 in the second cell group 102 and the first clearance space 30 can improve the support strength of the first cell group 10, thereby enhancing the overall support strength of multiple cells 11 in the battery pack. This can enhance the overall structural strength of the battery pack to a certain extent, thereby reducing the strength requirements of the battery pack's top cover, which is in line with the current CTB (Cell to Body, battery top cover and vehicle floor are integrated) design requirements.

[0046] Correspondingly, since the first cell group 101 and the second cell group 102 are staggered, the two bending surfaces 113 of two adjacent cells 11 in the second cell group 102 enclose a second clearance space. Similarly, the second clearance space is provided to provide space for functional components. The corresponding arrangement of the cells 11 in the first cell group 101 and the second clearance space can improve the support strength of the second cell group 102, thereby enhancing the overall support strength of multiple cells 11 in the battery pack. This can enhance the overall structural strength of the battery pack to a certain extent, thereby reducing the strength requirements of the battery pack's top cover, which well meets the requirements of the current CTB (Cell to Body, battery top cover and vehicle floor integrated) design.

[0047] It should be noted that among the adjacent cells 11 along the second direction Y, the sides of cells 11 are in contact with each other through the first clearance space 30 or the second clearance space. The sharp corner design of the end structure of the cell 11 and the structural design of the first clearance space 30 or the second clearance space can play a good supporting role, so that the winding core inside the cell 11 can be protected when the battery pack is subjected to side collision and compression.

[0048] Optionally, in this embodiment of the application, the battery cells 11 in the second battery cell group 102 are at least partially housed in the first clearance space 30.

[0049] In this embodiment of the application, the arrangement of at least partially accommodating the cells 11 in the second cell group 102 in the first clearance space 30 can form an interleaved structure between the cells in the second cell group 102 and the first cell group 101. The projections of the above structure along the first direction X overlap each other, which has the beneficial effect of improving the structural strength of the first cell group 101.

[0050] Correspondingly, the arrangement of at least partially accommodating the cells 11 in the first cell group 101 in the second clearance space can form an interleaved structure between the cells in the first cell group 102 and the second cell group 102. The projections of the above structure along the first direction X overlap each other, which has the beneficial effect of improving the structural strength of the second cell group 101.

[0051] Optionally, in this embodiment of the application, the cross-sectional shape of the first clearance space 30 along the plane containing the first direction X and the second direction Y is triangular.

[0052] In the embodiments of this application, it can be understood that, due to the strong stability of the triangular region, the first clearance space 30 formed by the three battery cells 11 with a triangular cross-sectional shape can provide good support for the multiple battery cells 11 in the battery pack. In addition, under the impact of external force on the battery pack, the triangular region formed by the three battery cells 11 also has the effect of uniform external force, which enhances the effect of the battery cells 11 being squeezed from the side, resulting in uneven force on the battery cells 11 as a whole, and also avoids the beneficial effect of forming a weak point when the middle of the side of the battery cells 11 is squeezed.

[0053] Optionally, in this embodiment of the application, the functional component is a first adhesive component, which fills the first clearance space 30 and connects the battery cells 11 in the adjacent first battery cell group 101 and second battery cell group 102.

[0054] In this embodiment, since the first clearance space 30 is used to fill the first adhesive, it is understood that the first adhesive is constrained by the structure of the first clearance space 30. The cross-section of the first adhesive formed along the plane containing the first direction X and the second direction Y is also triangular. Furthermore, the first adhesive increases the adhesive area between the sides of adjacent cells 11, while reducing the heat transfer efficiency between cells 11. This has the beneficial effect of reducing the probability of heat spread in the system and improving the overall structural strength of multiple cells 11.

[0055] It should be noted that the first adhesive component can be a structural adhesive with low thermal conductivity.

[0056] Optionally, in this embodiment of the application, the battery pack further includes a housing 20 and a second adhesive member. The housing 20 has an inner cavity, in which a plurality of first cell groups 101 and a plurality of second cell groups 102 are disposed. Along the first direction X and / or along the second direction Y, the plurality of first cell groups 101 and the plurality of second cell groups 102 are spaced apart from the housing 20. The second adhesive member fills the space and is bonded to the first cell groups 101 and the housing 20, or the second adhesive member is bonded to the second cell groups 102 and the housing 20.

[0057] In this embodiment of the application, a second adhesive is filled between the first cell group 101 and the housing 20 inside the battery pack, and a second adhesive is also filled between the second cell group 102 and the housing 20. The above-mentioned arrangement in the second direction Y can effectively resist the expansion of the cell 11 and absorb the expansion deformation, eliminating the need for additional expansion beam design. This has the beneficial effect of reducing the battery pack structure and lowering the battery pack cost. The above-mentioned arrangement in the second direction Y can also play an energy absorption role, effectively releasing external extrusion pressure and protecting the cell 11.

[0058] It should be noted that the second adhesive component can be expanding foam.

[0059] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0060] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A battery cell (11), characterized in that, Having a first direction (X), a second direction (Y), and a third direction (Z) that intersect each other, the battery cell (11) includes a housing and a core. The housing includes a first large surface (111), a second large surface (112), and a bending surface (113). The first large surface (111) and the second large surface (112) are arranged opposite to each other along the first direction (X). The bending surface (113) connects the first large surface (111) and the second large surface (112) to define an accommodating space. The core is disposed in the receiving space. The core includes a straight portion (114) and a curved portion (115). The curved portion (115) is connected to the end of the straight portion (114) along the second direction (Y). Along the first direction (X), the curved portion (115) and the bending surface (113) at least partially overlap.

2. The battery cell (11) according to claim 1, characterized in that, The cross section of the battery cell (11) perpendicular to the third direction (Z) is octagonal.

3. The battery cell (11) according to claim 1, characterized in that, The bent surface (113) includes a first sub-surface (1131), a second sub-surface (1132), and a third sub-surface (1133). The second sub-surface (1132) is perpendicular to the first large surface (111). The first sub-surface (1131) connects the second sub-surface (1132) and the first large surface (111). The third sub-surface (1133) connects the second sub-surface (1132) and the second large surface (112). The angle between the first sub-face (1131) and the second sub-face (1132) and the first large face (111) is greater than 90°, and the angle between the third sub-face (1133) and the second sub-face (1132) and the second large face (112) is greater than 90°.

4. The battery cell (11) according to claim 3, characterized in that, The distance between the first large surface (111) and the second large surface (112) is L. The first large surface (111), the second large surface (112), the first sub-surface (1131), the second sub-surface (1132) and the third sub-surface (1133) are inscribed in a circle with a diameter of L.

5. A battery pack, characterized in that, The battery includes a plurality of battery cells (11) as described in any one of claims 1-4, wherein the plurality of battery cells (11) are arranged along the first direction (X) to form a plurality of first battery cell groups (101) and a plurality of second battery cell groups (102), wherein the first battery cell groups (101) and the second battery cell groups (102) are arranged alternately along the second direction (Y); The first battery cell group (101) and the second battery cell group (102) are staggered along the first direction (X), and the battery cells (11) in the first battery cell group (101) and the battery cells (11) in the second battery cell group (102) are interleaved along the first direction (X).

6. The battery pack according to claim 5, characterized in that, The two bending surfaces (113) of two adjacent cells (11) in the first cell group (101) enclose a first clearance space (30). The cell (11) in the second cell group (102) is opposite to the first clearance space along the second direction (Y), and the first clearance space (30) is provided with functional components.

7. The battery pack according to claim 6, characterized in that, The cell (11) in the second cell group (102) is at least partially housed in the first clearance space (30).

8. The battery pack according to claim 7, characterized in that, Along the plane containing the first direction (X) and the second direction (Y), the cross-sectional shape of the first clearance space (30) is triangular.

9. The battery pack according to claim 7, characterized in that, The functional component is a first adhesive component, which fills the first clearance space (30) and connects the battery cells (11) in the adjacent first battery cell group (101) and second battery cell group (102).

10. The battery pack according to any one of claims 5-7, characterized in that, The battery pack also includes a housing (20) and a second adhesive component. The housing (20) has an inner cavity in which a plurality of first cell groups (101) and a plurality of second cell groups (102) are disposed. Along the first direction (X) and / or along the second direction (Y), a plurality of first cell groups (101) and a plurality of second cell groups (102) are spaced from the housing (20), and a second adhesive fills the space. The second adhesive is bonded to the first cell group (101) and the housing (20), or the second adhesive is bonded to the second cell group (102) and the housing (20).

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