Battery module and battery pack

Abstract

The embodiment of the utility model provides a battery module and a battery pack, the battery module comprises a frame body and a battery monomer, the battery monomer comprises a shell and a pole core accommodated in the shell, the shell is provided with a first side wall, the pole core comprises a body area and a thinned area connected to the body area, the frame body comprises a plurality of borders, a plurality of first electrodes and a plurality of second electrodes, the plurality of frames are distributed along the circumferential direction of the first side wall, and the plurality of frames are enclosed to form a space for absorbing the expansion of the battery monomers; the plurality of frames are all attached to the first side wall, one side, close to the first side wall, of at least part of the frames is provided with an extending part, and in the third direction, the projection of the extending part and the projection of the thinned area on the plane perpendicular to the third direction are at least partially overlapped. In the embodiment of the invention, the extension part can apply a certain force to the thinned area, so that the distance between the pole pieces in the thinned area is reduced, the propagation distance of lithium ions is shortened, and the cycle life of the battery monomer is prolonged.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a battery module and a battery pack. Background Art

[0002] With the development of technology, battery modules are gradually evolving towards advanced technologies with high energy density, high safety, and fast chargeability. As the charging speed increases, the battery cells in the battery module are prone to defects such as uneven swelling and large lithium-ion transfer distances, which can easily lead to a sharp reduction in the service life of the battery cells.

[0003] In the prior art, a loop frame is usually connected to both sides of the battery cell to provide a certain buffer space for the swelling of the battery cell. However, during the cyclic swelling of the battery cell, the problem of gradually increasing the gap between the electrodes in the thinning area at the top of the battery cell easily occurs, resulting in a reduction in the cycle life of the battery cell. Summary of the Utility Model

[0004] This application aims to provide a battery module and a battery pack to solve the problem of the relatively low cycle life of the single battery cells in the existing battery modules.

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

[0006] This application discloses a battery module, which includes a frame body and battery cells. The battery cells include a housing and a core accommodated in the housing. The housing has a first side wall. The core includes a body area and a thinning area connected to the body area. The frame body includes: a plurality of side frames, which are circumferentially distributed along the first side wall, and the plurality of side frames enclose a space for absorbing the swelling of the battery cells;

[0007] All of the plurality of side frames are in contact with the first side wall, and at least a part of the side frames are provided with extension parts on the side close to the first side wall. Along a third direction, at least a part of the projection of the extension part and the thinning area on a plane perpendicular to the third direction overlaps.

[0008] Optionally, the part of the thinning area connected to the body area is a part of the circumferential edge. Along the direction from the center to the edge of the battery cell, the thickness of the thinning area decreases, and along the direction from the center to the edge of the frame body, the thickness of the side frame provided with the extension part increases.

[0009] Optionally, the frame body is a rectangular frame body. The side frames include a first side frame and a second side frame spaced apart along a first direction, and a third side frame and a fourth side frame spaced apart along a second direction. The second direction intersects the first direction. The extension part is provided on at least one of the first side frame and the second side frame.

[0010] Optionally, an adhesive layer is further provided on a side of the frame adjacent to the battery cell, and the adhesive layer is adhered to the first side wall and the frame.

[0011] Optionally, a recessed portion is provided on a side of the frame adjacent to the battery cell, and the adhesive layer is embedded in the recessed portion.

[0012] Optionally, a side wall of the frame that abuts against the battery cell is a first side surface, and the first side surface is an inclined surface that is inclined with respect to a plane where the frame is located.

[0013] Optionally, an included angle between the first side surface and the plane where the frame is located is a°, and a ≤ 7.

[0014] Optionally, a distance between an outer periphery of the frame and a side edge of the battery cell is D3 mm, satisfying: 1.5 ≤ D3 ≤ 2.5;

[0015] A distance between an inner periphery of the frame and a side edge of the battery cell is D4 mm, satisfying: 6 ≤ D4 ≤ 8.

[0016] Optionally, the plurality of frames are connected end to end along a circumferential direction of the first side wall.

[0017] In an embodiment of the present application, the battery module may include a frame body and a battery cell. The battery cell may include a housing and an electrode core accommodated in the housing. The housing has a first side wall. A thinning area is provided on the electrode core close to the first side wall. The frame body may include a plurality of frames. The plurality of frames are distributed along a circumferential direction of the first side wall. The plurality of frames enclose a space for absorbing expansion of the battery cell; the plurality of frames abut against the first side wall, and at least part of the frames are provided with extension portions. Along a third direction, at least part of a projection of the extension portion and the thinning area on a plane perpendicular to the third direction overlaps. The third direction may specifically be a thickness direction of the battery module. During the expansion of the battery cell, due to at least partial overlap of the extension portion and the thinning area on a plane perpendicular to the third direction, the extension portion can apply a force to the thinning area to a certain extent, reduce a distance between electrode sheets in the thinning area, shorten a propagation distance of lithium ions, and improve a cycle life of the battery cell.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0020] Figure 1 is a schematic structural view of a simple battery module according to an embodiment of the present application;

[0021] Figure 2 is Figure 1 a schematic exploded view of the battery module described above;

[0022] Figure 3 is a schematic structural view of a housing according to an embodiment of the present application;

[0023] Figure 4 is Figure 3 a schematic cross-sectional view of the housing A - A shown above;

[0024] Figure 5 is Figure 3 a schematic cross-sectional view of the frame in the housing B - B shown above;

[0025] Figure 6 is a schematic structural view of a battery module according to an embodiment of the present application;

[0026] Figure 7 is a schematic view of the cooperation structure of the electrode core and the frame according to an embodiment of the present application.

[0027] Reference numerals: 10 - housing, 100 - frame, 1011 - extension portion, 102 - first frame, 103 - second frame, 104 - third frame, 105 - fourth frame, 106 - adhesive layer, 107 - recessed portion, 108 - first side, 109 - second side, 20 - battery cell, 201 - thinned area, 202 - first side wall, 203 - housing, 204 - electrode core, X - first direction, Y - second direction, Z - third direction. Detailed implementation manners

[0028] Hereinafter, embodiments of the present invention will be described in detail. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0029] The terms "first" and "second" in the description and claims of this application may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0030] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0031] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] Referring to Figure 1 , a schematic structural diagram of a simple battery module according to an embodiment of this application is shown. Referring to Figure 2 , it shows Figure 1 The exploded structural diagram of the battery module, where Figure 2 The curved arrow in Figure 6 is a schematic diagram of the assembly direction. Referring to Figure 6As shown in the figure, the battery module may specifically include a housing 10 and battery cells 20. The battery cell 20 may include a housing 203 and an electrode core 204 accommodated in the housing 203. The housing 203 has a first side wall 202. The electrode core 204 includes a body region and a thinned region 201 connected to the body region. The housing 10 may include: a plurality of side frames 100, which are distributed along the circumference of the first side wall 202, and the plurality of side frames 100 enclose a space for absorbing the expansion of the battery cell 20; the plurality of side frames 100 are attached to the first side wall 202, and at least part of the side frames 100 are provided with extension portions 1011 on one side close to the first side wall 202. Along the third direction Z, at least part of the projection of the extension portion 1011 and the thinned region 201 on a plane perpendicular to the third direction Z overlaps.

[0033] In the embodiment of the present application, the third direction Z may specifically be the thickness direction of the battery module. During the expansion of the battery cell 20, since at least part of the extension portion 1011 and the thinned region 201 overlap on a plane perpendicular to the third direction Z, the extension portion 1011 can apply a resisting force to the thinned region 201 to a certain extent, reduce the distance between the electrode sheets in the thinned region 201, shorten the propagation distance of lithium ions, and improve the cycle life of the battery cell 20.

[0034] In a specific application, the extension portion 1011 may be provided on the side frame 100 corresponding to the thinned region 201, and the extension portion 1011 may extend toward the thinned region 201 so that at least part of the projection of the extension portion 1011 and the thinned region 201 on a plane perpendicular to the third direction Z overlaps. In this way, during the expansion of the battery cell 20, since the extension portion 1011 extends toward the thinned region 201, the extension portion 1011 can squeeze the first side wall 202 of the housing 203 toward the thinned region 201, reduce the distance between the electrode sheets in the thinned region 201, shorten the propagation distance of lithium ions, and improve the cycle life of the battery cell 20.

[0035] In a specific application, the plurality of side frames 100 are connected end to end along the circumference of the first side wall 202 to connect the plurality of side frames 100 into a whole and improve the structural stability of the housing 10.

[0036] Exemplarily, the side frames 100 may be connected by connection methods such as welding and clamping, or the plurality of side frames 100 may also be an integrally formed structure. The embodiment of the present application does not limit the connection method between the side frames 100.

[0037] In the embodiment of the present application, the thinned area 201 is connected to a partial circumferential edge of the body area. Along the direction from the center to the edge of the battery cell 20, the thickness of the thinned area 201 decreases. Along the direction from the center to the edge of the frame 10, the thickness of the frame 100 provided with the extension portion 1011 increases, so that the shape of the extension portion 1011 on the frame 100 can be adapted to the shape of the thinned area 201, and the gap width between the extension portion 1011 and the thinned area 201 is reduced as much as possible, the propagation distance of lithium ions is shortened, and the cycle life of the battery cell 20 is improved.

[0038] Referring to Figure 3 , a schematic structural diagram of a frame according to an embodiment of the present application is shown. As Figure 3 shown, the frame 10 is a rectangular frame. The frame 100 includes a first frame 102 and a second frame 103 spaced apart along a first direction X, and a third frame 104 and a fourth frame 105 spaced apart along a second direction Y. The second direction Y intersects the first direction X. The extension portion 1011 is provided on at least one of the first frame 102 and the second frame 103, so that the extension portion 1011 and the thinned area 201 overlap at least partially in a plane perpendicular to the second direction Y.

[0039] In a specific application, the first direction X may be the up-down direction of the battery module, and the second direction Y may be the left-right direction of the battery module. That is, the first frame 102 and the second frame 103 may be spaced apart along the up-down direction, and the third frame 104 and the fourth frame 105 may be spaced apart along the left-right direction. The thinned area 201 may be close to or disposed at the top of the battery cell 20. Correspondingly, the extension portion 1011 may be correspondingly provided on the first frame 102 and / or the second frame 103 corresponding to the thinned area 201.

[0040] In a specific application, when the thinned area 201 is only close to the top of the battery cell 20, the extension portion 1011 may be provided only on the first frame 102; when the thinned area 201 is only close to the bottom of the battery cell 20, the extension portion 1011 may be provided only on the second frame 103; when the thinned area 201 is close to the top and the bottom of the battery cell 20 respectively, the extension portion 1011 may be provided on both the first frame 102 and the second frame 103 at the same time. The embodiment of the present application does not make a specific limitation on the setting position of the extension portion 1011.

[0041] In practical applications, the first direction X and the second direction Y may be perpendicular, or the included angle between the first direction X and the second direction Y may also be an acute angle or an obtuse angle. The embodiment of the present application does not make a specific limitation on this.

[0042] As Figure 3As shown, an adhesive layer 106 is further provided on the side of the frame 100 adjacent to the battery cell 20. The adhesive layer 106 is adhered to the first side wall 202 and the frame 100. In practical applications, the adhesive layer 106 can be used to adhere to the battery cell 20 to connect the frame 10 to the battery cell 20, thereby improving the connection reliability between the frame 10 and the battery cell 20.

[0043] Exemplarily, the material of the adhesive layer 106 can include but is not limited to back glue, tape, glue, or solid glue, etc. The embodiments of the present application do not specifically limit the material of the adhesive layer 106.

[0044] It should be noted that Figure 4 only the case where the adhesive layer 106 is provided on the third frame 104 and the fourth frame 105 is shown. In practical applications, those skilled in the art can also set the adhesive layer 106 on the first frame 102 and / or the second frame 103 according to actual needs. The embodiments of the present application do not specifically limit the position of the adhesive layer 106.

[0045] Referring to Figure 4 shows Figure 3 the schematic cross-sectional structure diagram of the frame A-A section shown in Figure 4 As shown, a recess 107 is provided on the side of the frame 100 adjacent to the battery cell 20, and the adhesive layer 106 is embedded in the recess 107 to improve the connection reliability of the adhesive layer 106 on the frame 100.

[0046] In practical applications, a recess 107 can be first provided on the battery cell 20 on one side of the battery cell 20, and then the adhesive layer 106 is embedded in the recess 107 to improve the connection reliability of the adhesive layer 106 on the frame 100. Specifically, in order to improve the connection reliability of the adhesive layer 106 in the recess 107, the shape of the recess 107 can be adapted to the shape of the adhesive layer 106.

[0047] Referring to Figure 5 shows Figure 3 the schematic cross-sectional structure diagram of the frame of the frame shown in Figure 5 As shown, the side wall of the frame 100 abuting against the battery cell 20 is the first side surface 108, and the first side surface 108 is an inclined surface. The part of the inclined surface extending towards the battery cell 20 is the extension part 1011.

[0048] In specific applications, by setting the first side surface 108 as an inclined surface, not only can the processing of the first side surface 108 be facilitated, but also the shape of the first side surface 108 can be adapted to the shape of the thinning area 201, further reducing the distance between the electrodes in the thinning area 201, shortening the propagation distance of lithium ions, and improving the cycle life of the battery cell 20.

[0049] In some alternative embodiments of the present application, the angle between the first side surface 108 and the plane where the frame 100 is located is a°, and a ≤ 7, so as to facilitate the adaptation of the inclination of the first side surface 108 and the inclination of the thinning area 201, and further reduce the distance between the electrodes in the thinning area 201. Moreover, it is also convenient for the processing of the first side surface 108.

[0050] In practical applications, a° can be adapted according to the inclination of the thinning area 201 to further reduce the distance between the electrodes in the thinning area 201. For example, when the inclination of the thinning area 201 is 3 degrees, a° can be set to 3 degrees accordingly; when the inclination of the thinning area 201 is 6 degrees, a° can also be set to 6 degrees accordingly. The embodiments of the present application do not make specific limitations on a°.

[0051] As Figure 5 shown, the frame 100 may further include a second side surface 109 disposed opposite to the first side surface 108. The first side surface 108 may be in contact with the battery cell 20, and the second side surface 109 may or may not be in contact with the battery cell 20. As Figure 5 shown, when the second side surface 109 does not need to be in contact with the battery cell 20, the second side surface 109 may be set as a plane.

[0052] In a specific application, the battery cells 20 and the frame 10 in the battery module may be alternately arranged, and it is only necessary to ensure that the frame 10 is connected to both sides of the battery cell 20. Therefore, the frame 10 may be disposed between two battery cells 20, or may only need to be connected to one battery cell 20. In practical applications, when the frame 10 is connected between two battery cells 20, both the first side surface 108 and the second side surface 109 may be inclined surfaces; when the frame 10 only needs to be connected to one battery cell 20, the first side surface 108 may be set as an inclined surface, and the second side surface 109 may be set as a plane.

[0053] In some alternative embodiments of the present application, the distance between the outer periphery of the frame 100 and the side of the battery cell 20 is D3 mm, satisfying 1.5 ≤ D3 ≤ 2.5. This can avoid the chamfer of the side of the battery cell 20 at the outer periphery of the frame 100, improving the connection reliability between the frame 100 and the battery cell 20. At the same time, it can also make the frame 100 as close as possible to the side of the battery cell 20, which is beneficial to the position correspondence between the extension part 1011 on the frame 100 and the thinning area 201 on the battery cell 20.

[0054] For example, the distance D3 between the outer periphery of the frame 100 and the side of the battery cell 20 can be any one or any value between any two of 1.5 mm, 1.8 mm, 2.2 mm, 2.7 mm, and 3 mm. The value of D3 in the embodiments of the present application is not specifically limited.

[0055] Optionally, the distance between the inner periphery of the frame 100 and the side of the battery cell 20 is D4 mm, satisfying: 6 ≤ D4 ≤ 8, so that the width of the frame 100 is more reasonable. In this way, not only can the frame 100 fully support the battery cell 20 and provide sufficient expansion space for the battery cell 20, but also the overall weight of the frame 10 can be controlled, which is beneficial to the overall weight reduction design of the battery module.

[0056] For example, the distance D4 between the inner periphery of the frame 100 and the side of the battery cell 20 can be any one or any value between any two of 6 mm, 6.8 mm, 7.2 mm, 7.7 mm, and 8 mm. The value of D4 in the embodiments of the present application is not specifically limited.

[0057] In summary, the battery module of the embodiments of the present application can at least include the following advantages:

[0058] In the embodiments of the present application, the battery module may include a frame and a battery cell. The battery cell may include a housing and a core accommodated in the housing. The housing has a first side wall. A thinning area is provided on the core near the first side wall. The frame may include a plurality of frames. The plurality of frames are distributed along the circumference of the first side wall. The plurality of frames enclose a space for absorbing the expansion of the battery cell; the plurality of frames are attached to the first side wall, and at least some of the frames are provided with extension parts. Along the third direction, at least part of the projection of the extension part and the thinning area on a plane perpendicular to the third direction overlaps. The third direction may specifically be the thickness direction of the battery module. During the expansion of the battery cell, due to at least partial overlap of the extension part and the thinning area on a plane perpendicular to the third direction, the extension part can abut against the thinning area to a certain extent, reduce the distance between the electrode sheets in the thinning area, shorten the propagation distance of lithium ions, and improve the cycle life of the battery cell.

[0059] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery module, characterized in that: The battery module comprises a frame (10) and a battery cell (20), the battery cell (20) comprising a shell (203) and a pole core (204) accommodated in the shell, the shell (203) having a first side wall (202), the pole core (204) comprising a body region and a thinned region (201) connected to the body region, the frame (10) comprising: a plurality of frames (100), the plurality of frames (100) being distributed along the circumference of the first side wall (202) and being located on a side of the first side wall (202) away from the pole core, the plurality of frames (100) enclosing to form a space for absorbing the expansion of the battery cell (20); The plurality of frames (100) are all in contact with the first side wall (202); at least some of the frames (100) are provided with an extension portion (1011) on a side close to the first side wall (202); along a third direction (Z), the extension portion (1011) and the thinned area (201) are at least partially overlapped in projection on a plane perpendicular to the third direction (Z).

2. The battery module according to claim 1, characterized in that: The thinned area (201) is connected to a portion of the circumferential edge of the main body area, and along the direction from the center to the edge of the battery cell (20), the thickness of the thinned area (201) decreases, and the thickness of the extension portion (1011) increases.

3. The battery module according to claim 1, characterized in that: The frame (100) comprises a first frame (102) and a second frame (103) spaced apart along a first direction, and a third frame (104) and a fourth frame (105) spaced apart along a second direction, wherein the second direction intersects with the first direction, and the extension portion (1011) is arranged on at least one of the first frame (102) and the second frame (103).

4. The battery module according to claim 1, characterized in that: An adhesive layer (106) is also provided on the side of the frame (100) adjacent to the battery cell (20), and the adhesive layer (106) is bonded to the first side wall (202) and the frame (100).

5. The battery module according to claim 4, characterized in that: A recessed portion (107) is provided on one side of the frame (100) adjacent to the battery cell (20), and the adhesive layer (106) is embedded in the recessed portion (107).

6. The battery module according to claim 1, characterized in that: The side wall of the battery cell to which the extension portion (1011) is attached is the first side surface (108), and the first side surface (108) is an inclined surface, which is arranged at an inclination relative to the plane where the frame (100) is located.

7. The battery module according to claim 6, characterized in that: The angle between the first side surface (108) and the plane in which the frame (100) is located is a°, and a≤7.

8. The battery module according to claim 1, characterized in that: The distance between the outer periphery of the frame (100) and the side of the battery cell (20) is D3 mm, satisfying: 1.5≤D3≤2.5; And / or, the distance between the inner periphery of the frame and the side of the battery cell is D4 mm, satisfying: 6≤D4≤8.

9. The battery module according to claim 1, characterized in that: The multiple frames (100) are connected end to end along the circumference of the first side wall (202).

10. A battery pack, characterized in that: A battery module comprising any one of claims 1 to 9.

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