Battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery pack, the battery pack comprises a battery box, a battery cell assembly and an expansion beam, the battery cell assembly is arranged in the battery box, the expansion beam is fixed in the battery box, the expansion beam comprises a first side wall and a second side wall which are oppositely arranged, the first side wall is bonded with the battery cell assembly, and the second side wall is bonded with the battery cell assembly. And the connection reliability of the expansion beam and the battery cell assembly is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery pack. Background Art

[0002] In the related art, an expansion beam is usually provided in the battery box, and the two ends of the expansion beam are respectively welded to the two inner walls of the battery box, and the side walls of the expansion beam abut against the ends of the battery cell assembly. When the battery cell assembly expands during charging and discharging, the expansion beam applies a force to the battery cell assembly in the opposite direction of the expansion, so that the battery cell assembly is in a clamped state, while also preventing the battery box from deforming.

[0003] The expansion beam and the battery cell assembly are connected only by extrusion force and friction force, which makes the reliability of the connection between the two poor. When the battery pack collides or vibrates, the connection between the expansion beam and the battery cell assembly is prone to failure, and the expansion beam cannot apply the above-mentioned force to the battery cell assembly.

[0004] Therefore, it is urgent to propose a battery pack to solve the above technical problems. Utility Model Content

[0005] The utility model aims to provide a battery pack, which can improve the reliability of the connection between the expansion beam and the battery core assembly.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] Battery pack, including:

[0008] Battery box;

[0009] A battery cell assembly, wherein the battery cell assembly is arranged in the battery box;

[0010] An expansion beam is fixed in the battery box. The expansion beam comprises a first side wall and a second side wall which are arranged opposite to each other. The first side wall is bonded to the battery core assembly.

[0011] Optionally, the second side wall is arranged to be inclined, and an angle between the second side wall and a bottom surface of the expansion beam is smaller than an angle between the second side wall and a top surface of the expansion beam.

[0012] Optionally, the included angle between the second side wall and the bottom surface of the expansion beam is 80°-85°.

[0013] Optionally, the first side wall has a groove with an opening toward the battery core assembly, and the groove is used to fill with glue.

[0014] Optionally, a glue injection port is provided on the groove wall of the groove, and the glue can be injected into the groove through the glue injection port.

[0015] Optionally, the battery pack further includes a connecting bar and a connecting wire, and the connecting bar and / or the connecting wire are fixed on the second side wall, or the connecting bar and / or the connecting wire are fixed on the surface of the expansion beam.

[0016] Optionally, the battery pack further includes a fixing member, a mounting hole is provided on the top surface of the second side wall or the expansion beam, the fixing member is fixed in the mounting hole, and the connecting row and / or connecting wire are arranged on the fixing member.

[0017] Optionally, the battery pack further includes a BMS and a mounting structure, and the BMS is mounted on the second side wall or the top surface of the expansion beam through the mounting structure.

[0018] Optionally, the mounting structure includes a first mounting member and a second mounting member, the first mounting member is arranged on the BMS, the second mounting member is arranged on the second side wall or the top surface of the expansion beam, and the first mounting member is detachably connected to the second mounting member.

[0019] Optionally, the mounting structure further includes a first protrusion and a second protrusion, the first protrusion is protruded from the outer wall of the BMS, the first mounting member is arranged on the first protrusion, the second protrusion is arranged on the second side wall or the top of the expansion beam, and the second mounting member is arranged on the second protrusion.

[0020] Optionally, a first socket is provided on the first protrusion, the first mounting member is a bolt, and the first mounting member is passed through the first socket, a second socket is provided on the second protrusion, the second mounting member is inserted into the second socket, and the second mounting member is a rivet nut that cooperates with the bolt thread.

[0021] Optionally, a weight reduction cavity is provided between the first side wall and the second side wall.

[0022] Optionally, the expansion beam further includes at least one reinforcing rib, which is disposed in the weight-reducing cavity, and two ends of the reinforcing rib are respectively fixedly connected to the first side wall and the second side wall.

[0023] Beneficial effects:

[0024] The battery pack provided by the utility model comprises an expansion beam comprising a first side wall and a second side wall arranged opposite to each other, wherein the first side wall is bonded to the battery cell assembly. When the battery pack collides or vibrates, the probability of failure of the connection between the expansion beam and the battery cell assembly is low, thereby greatly improving the reliability of the connection between the expansion beam and the battery cell assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic cross-sectional structure diagram of an expansion beam and a battery core assembly provided by an embodiment of the utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the expansion beam provided by the embodiment of the utility model Figure 1 ;

[0027] Figure 3 It is a structural schematic diagram of an expansion beam, a battery cell assembly and a BMS provided by an embodiment of the utility model;

[0028] Figure 4 This is a schematic diagram of the structure of the expansion beam provided by the embodiment of the utility model Figure 2 .

[0029] In the figure:

[0030] 100, battery cell assembly; 200, expansion beam; 210, first side wall; 211, groove; 212, glue injection port; 220, second side wall; 221, mounting hole; 230, weight reduction cavity; 240, reinforcing rib; 300, adhesive; 400, BMS; 510, first protrusion; 511, first socket; 520, second mounting piece; 530, second protrusion; 531, second socket. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0033] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] This embodiment provides a battery pack that can improve the reliability of the connection between the expansion beam and the battery cell assembly.

[0036] Specifically, Figures 1 to 3 As shown, the battery pack includes a battery box (not shown in the figure), a battery cell assembly 100 and an expansion beam 200, wherein the battery cell assembly 100 is arranged in the battery box, the two ends of the expansion beam 200 are respectively fixedly connected to the two inner side walls of the battery box, and / or the bottom of the expansion beam 200 is fixedly connected to the inner bottom wall of the battery box, and the expansion beam 200 includes a first side wall 210 and a second side wall 220 arranged opposite to each other, and the first side wall 210 is bonded to the battery cell assembly 100.

[0037] Based on the above design, the first side wall 210 of the expansion beam 200 is bonded to the battery cell assembly 100. When the battery pack collides or vibrates, the probability of failure of the connection between the expansion beam 200 and the battery cell assembly 100 is low, which greatly improves the reliability of the connection between the expansion beam 200 and the battery cell assembly 100.

[0038] It should be noted that the battery cell assembly 100 can be sandwiched between the expansion beam 200 and the inner wall of the battery box, or can be sandwiched between two expansion beams 200, depending on the actual application situation.

[0039] Existing expansion beams are roughly divided into two structures: an expansion beam with a rectangular longitudinal section and an expansion beam with an L-shaped longitudinal section. When the expansion beam with a rectangular longitudinal section applies a force opposite to the expansion direction to the battery cell assembly, concentrated stress will be generated at the welds at both ends of the expansion beam, which may cause weld cracking in severe cases. Therefore, the thickness of this expansion beam is generally thicker to improve its anti-expansion ability; the expansion beam with an L-shaped longitudinal section has a horizontal section that can support the vertical section, so this expansion beam has better anti-expansion ability, but this expansion beam needs to occupy a larger space in the battery box, which is not conducive to improving the energy density of the battery pack.

[0040] To solve the above technical problems, Figures 1 to 3As shown, the second side wall 220 is inclined, and the angle between the second side wall 220 and the bottom surface of the expansion beam 200 is smaller than the angle between the second side wall 220 and the top surface of the expansion beam 200, that is, the second side wall 220 is inclined toward the battery cell assembly 100. When the battery cell assembly 100 expands, the second side wall 220 can support the expansion beam 200, thereby improving the anti-expansion ability of the expansion beam 200. In addition, this structural arrangement will not take up too much space in the battery box, which is beneficial to improving the energy density of the battery pack.

[0041] Preferably, the angle between the second side wall 220 and the bottom surface of the expansion beam 200 is 80°-85°. For example, the angle can be 80°, 83° or 85°, among which 85° is preferred, which can make the expansion beam 200 have better anti-expansion ability without occupying too much internal space of the battery box.

[0042] Alternatively, if Figures 1 to 3 As shown, the first side wall 210 is provided with a groove 211 opening toward the battery cell assembly 100, and the groove 211 is filled with adhesive 300. The first side wall 210 is bonded to the battery cell assembly 100 by the adhesive 300 to reduce the total width of the expansion beam 200 and the battery cell assembly 100 after bonding, thereby achieving the effect of saving the internal space of the battery box.

[0043] Alternatively, if Figures 1 to 3 As shown, the number of grooves 211 is multiple, for example, the grooves 211 can be two, four, six, seven, etc., and the multiple grooves 211 are arranged at intervals along the extension direction of the expansion beam 200, and each groove 211 is filled with adhesive 300 to increase the number of bonding points between the first side wall 210 and the battery cell assembly 100, and improve the reliability of bonding between the expansion beam 200 and the battery cell assembly 100. In addition, when an expansion beam 200 is bonded to two or more battery cell assemblies 100, the multiple grooves 211 can correspond to different battery cell assemblies 100 respectively. In this embodiment, six grooves 211 are provided, and one expansion beam 200 is bonded to two battery cell assemblies 100, and each battery cell assembly 100 corresponds to three grooves 211, that is, each battery cell assembly 100 has three bonding points bonded to the first side wall 210, which not only improves the reliability of bonding between each battery cell assembly 100 and the expansion beam 200, but also can make full use of the internal space of the battery box, which has the effect of further improving the energy density of the battery pack. Of course, in other embodiments, one expansion beam 200 may be bonded to three or even more battery cell assemblies 100 , and the number of grooves 211 corresponding to different battery cell assemblies 100 may be the same or different, depending on the specific application.

[0044] Alternatively, if Figures 1 to 3As shown, a glue injection port 212 is provided on the side wall of the groove 211, and the glue 300 can be injected into the groove 211 through the glue injection port 212. Further, the glue injection port 212 can be located on the top surface of the expansion beam 200, or on the side of the first side wall 210. In this embodiment, the glue injection port 212 is located on the top surface of the expansion beam 200, which further facilitates glue injection.

[0045] It can be understood that, in the present embodiment, each groove 211 is provided with a glue injection port 212. In other implementation schemes, some of the grooves 211 may be provided with a glue injection port 212, while the remaining grooves 211 may not have a glue injection port 212; or some of the grooves 211 may have a glue injection port 212, and all the grooves 211 may be interconnected or not interconnected; or all the grooves 211 may not have a glue injection port 212, all depending on actual assembly requirements.

[0046] Alternatively, if Figures 1 to 3 As shown, a weight reduction cavity 230 is provided between the first side wall 210 and the second side wall 220 to reduce the weight of the expansion beam 200, thereby reducing the weight of the battery pack and improving the energy density of the battery pack.

[0047] Furthermore, if Figures 1 to 3 As shown, the expansion beam 200 further includes at least one reinforcing rib 240, which is disposed in the weight-reducing cavity 230, and the two ends of the reinforcing rib 240 are respectively fixedly connected to the first side wall 210 and the second side wall 220, and this structural arrangement can further improve the anti-expansion capability of the expansion beam 200 without occupying additional space in the battery box. In this embodiment, three reinforcing ribs 240 are disposed in the weight-reducing cavity 230, and in other embodiments, one, two, five or even more reinforcing ribs 240 may be disposed, depending on the height size of the expansion beam 200.

[0048] Optionally, the battery pack also includes a connecting bar, a detection element (such as a temperature sensor or a voltage sensor, etc.), a connecting wire and a battery management system (BMS), wherein the connecting bar is an element with a conductive function such as a copper bar, and the multiple battery cells in the battery cell assembly 100 are electrically connected through the connecting bar. The detection element is arranged on the connecting bar or on the battery cell to detect the real-time status of the battery cell such as the temperature or voltage. The connecting wire is respectively connected to the detection element and the BMS400 to transmit the data signal detected by the detection element to the BMS400, so as to realize real-time monitoring of the battery module.

[0049] Furthermore, the connecting bars and / or connecting wires are fixed on the second side wall 220, eliminating the need to provide a bracket for fixing the connecting bars and / or connecting wires in the battery box, thereby achieving the effect of reducing weight and cost.

[0050] Furthermore, if Figures 1 to 4 As shown, the second side wall 220 is provided with a mounting hole 221. When fixing the connecting row on the second side wall 220, a fixing member such as a pin or a bolt can be passed through the connecting row, and the fixing member can be fixed in the mounting hole 221. When fixing the connecting wire on the second side wall 220, a fixing member such as a pin or a bolt can be fixed in the mounting hole 221, and the connecting wire can be fixed to the fixing member by winding or bonding. Of course, if the height space of the battery box is sufficient, the mounting hole 221 can also be opened on the top surface of the expansion beam 200, that is, the connecting row and / or the connecting wire are fixed to the top surface of the expansion beam 200 by fixing members, depending on the internal space conditions of the battery box.

[0051] Optionally, the battery pack further includes a mounting structure, and the BMS400 is mounted on the second side wall 220 through the mounting structure, eliminating the need to set a bracket for fixing the BMS400 in the battery box, so that the integrity of the battery box is better. In addition, the BMS400, the connecting row and the connecting wire in this embodiment are all mounted on the expansion beam 200, which can not only improve the assembly efficiency of the battery pack, but also improve the assembly accuracy between the BMS400 and the connecting wire and between the connecting row and the connecting wire. Of course, if the height space of the battery box is sufficient, the BMS400 can also be installed on the top surface of the expansion beam 200 through the mounting structure. In this embodiment, setting the BMS400 on the second side wall 220 can avoid the problem of mutual interference between the BMS400 and the battery cell assembly 100 during installation.

[0052] Furthermore, if Figures 1 to 4 As shown, the mounting structure includes a first mounting member (not shown in the figure) and a second mounting member 520, the first mounting member is arranged on the BMS400, and the second mounting member 520 is arranged on the second side wall 220, and the first mounting member and the second mounting member 520 are detachably connected to install the BMS400 on the expansion beam 200.

[0053] Alternatively, if Figures 1 to 4 As shown, the mounting structure further includes a first protrusion 510 and a second protrusion 530. The first protrusion 510 is protruded from the outer wall of the BMS 400, the first mounting member is arranged on the first protrusion 510, the second protrusion 530 is protruded from the second side wall 220, and the second mounting member 520 is arranged on the second protrusion 530 to facilitate the arrangement of the first mounting member and the second mounting member 520.

[0054] Furthermore, if Figures 1 to 4As shown, the first protrusion 510 is provided with a first socket 511, the first mounting member is a bolt inserted into the first socket 511, the second protrusion 530 is provided with a second socket 531, the second mounting member 520 is inserted into the second socket 531, and the second mounting member 520 is a rivet nut matched with the bolt thread. When assembling the BMS400 and the expansion beam 200, the bolt can be screwed into the rivet nut.

[0055] In one embodiment, the second mounting member 520 is a slot provided on the second protruding portion 530, and the first mounting member is an insert block provided on the first protruding portion 510, and the insert block is detachably inserted into the slot. Of course, in other embodiments, the first mounting member and the second mounting member 520 may also be other detachably connected structures, which are not listed here one by one.

[0056] Alternatively, if Figures 1 to 4 As shown, a mounting structure is provided on both sides of the BMS400 to improve the reliability of the connection between the BMS400 and the expansion beam 200. Of course, two or more mounting structures can be provided on both sides of the BMS400, and the number of mounting structures can be determined according to the size of the BMS400; or, one or more mounting structures can be provided on both sides of the upper and lower sides of the BMS400, depending on the internal space distribution of the battery box.

[0057] In this embodiment, the expansion beam 200 is an aluminum extruded profile. The aluminum extrusion molding process is a relatively conventional production process in the art, which is conducive to reducing production costs.

[0058] It should be noted that the battery pack provided in this embodiment is suitable for the traditional battery pack structure (that is, the battery cell assembly 100 is sandwiched between two end plates to form a battery module, and the battery module is installed in a battery box), and is also suitable for an integrated battery structure (CTP structure) in which the battery cell assembly 100 is directly arranged in the battery box.

[0059] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A battery pack, characterized in that: include: Battery box; A battery cell assembly (100), wherein the battery cell assembly (100) is arranged in the battery box; An expansion beam (200) is fixed in the battery box, the expansion beam (200) comprises a first side wall (210) and a second side wall (220) which are arranged opposite to each other, and the first side wall (210) is bonded to the battery cell assembly (100).

2. The battery pack according to claim 1, characterized in that: The second side wall (220) is arranged at an angle, and the angle between the second side wall (220) and the bottom surface of the expansion beam (200) is smaller than the angle between the second side wall (220) and the top surface of the expansion beam (200).

3. The battery pack according to claim 2, characterized in that: The included angle between the second side wall (220) and the bottom surface of the expansion beam (200) is 80°-85°.

4. The battery pack according to any one of claims 1 to 3, characterized in that: The first side wall (210) has a groove (211) opening toward the battery cell assembly (100), and the groove (211) is used to be filled with adhesive (300).

5. The battery pack according to claim 4, characterized in that: A glue injection port (212) is provided on the groove wall of the groove (211), and the adhesive (300) can be injected into the groove (211) through the glue injection port (212).

6. The battery pack according to any one of claims 1 to 3, characterized in that: The battery pack further comprises a connection row and a connection line, wherein the connection row and / or the connection line are fixed on the second side wall (220), or the connection row and / or the connection line are fixed on the top surface of the expansion beam (200).

7. The battery pack according to claim 6, characterized in that: The battery pack also includes a fixing member, the second side wall (220) or the top surface of the expansion beam (200) is provided with a mounting hole (221), the fixing member is fixed in the mounting hole (221), and the connecting row and / or the connecting line are arranged on the fixing member.

8. The battery pack according to any one of claims 1 to 3, characterized in that: The battery pack further includes a BMS (400) and a mounting structure, and the BMS (400) is mounted on the second side wall (220) or the top surface of the expansion beam (200) through the mounting structure.

9. The battery pack according to claim 8, characterized in that: The mounting structure comprises a first mounting member and a second mounting member (520), wherein the first mounting member is arranged on the BMS (400), and the second mounting member (520) is arranged on the second side wall (220) or the top surface of the expansion beam (200), and the first mounting member and the second mounting member (520) are detachably connected.

10. The battery pack according to claim 9, characterized in that: The mounting structure further comprises a first protrusion (510) and a second protrusion (530), wherein the first protrusion (510) is protruded from the outer wall of the BMS (400), and the first mounting member is arranged on the first protrusion (510), and the second protrusion (530) is protruded from the second side wall (220) or the top of the expansion beam (200), and the second mounting member (520) is arranged on the second protrusion (530).

11. The battery pack according to claim 10, characterized in that: The first protruding portion (510) is provided with a first insertion hole (511), the first mounting member is a bolt, and the first mounting member is inserted into the first insertion hole (511), the second protruding portion (530) is provided with a second insertion hole (531), the second mounting member (520) is inserted into the second insertion hole (531), and the second mounting member (520) is a rivet nut that matches the thread of the bolt.

12. The battery pack according to any one of claims 1 to 3, characterized in that: A weight reduction cavity (230) is provided between the first side wall (210) and the second side wall (220).

13. The battery pack according to claim 12, characterized in that: The expansion beam (200) further comprises at least one reinforcing rib (240), wherein the reinforcing rib (240) is disposed in the weight reduction cavity (230), and two ends of the reinforcing rib (240) are respectively fixedly connected to the first side wall (210) and the second side wall (220).

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