Battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery pack which comprises a frame, a supporting longitudinal beam, a middle longitudinal beam and a battery cell group, a pressure relief channel is arranged in the frame, and a first anti-explosion valve hole is formed in the periphery of the frame. The supporting longitudinal beam divides the cavity into two chambers; the middle longitudinal beams are arranged on the two sides of the supporting longitudinal beam respectively, each chamber is divided into a plurality of mounting cavities by the middle longitudinal beams, exhaust channels communicated with the pressure relief channels are formed in the middle longitudinal beams, and a plurality of air inlets are formed in at least one side of each middle longitudinal beam; the battery cell group is arranged in the mounting cavity, the battery cell group comprises a plurality of single batteries which are sequentially stacked, second anti-explosion valve holes are formed in the side surfaces, opposite to the middle longitudinal beam, of the single batteries, and the second anti-explosion valve holes are opposite to and communicated with the air inlet holes; the width a of the middle longitudinal beam is smaller than that of the supporting longitudinal beam, and a is smaller than or equal to 30 mm; according to the battery pack, the safety performance, the energy density and the structural strength can be effectively considered.

Description

Technical Field

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

[0002] In recent years, with the rapid development of new energy vehicles, the battery pack, as a key technology for the development of new energy vehicles, has become a research and development hotspot.

[0003] The battery pack usually needs to integrate multiple groups of battery cell groups. When designing the battery pack, it is necessary to comprehensively consider safety performance, energy density, and structural strength. However, in the prior art, it is difficult to take into account these three performance indicators at the same time. Utility Model Content

[0004] The purpose of this application is to provide a battery pack that can effectively take into account safety performance, energy density, and structural strength.

[0005] The purpose of this application is achieved through the following technical solutions:

[0006] A battery pack, comprising:

[0007] A frame enclosing a chamber with openings at both ends. A pressure relief channel is provided inside the frame, and a first explosion-proof valve hole communicating with the pressure relief channel is provided on the outer periphery of the frame;

[0008] Support longitudinal beams, the two ends of which are respectively connected to two opposite inner walls of the frame, and divide the chamber into two compartments;

[0009] At least two middle longitudinal beams are respectively arranged on both sides of the support longitudinal beam. The middle longitudinal beams are arranged in parallel with the support longitudinal beam and are respectively connected to two opposite inner walls of the frame at both ends. The middle longitudinal beams divide each compartment into at least two installation cavities. An exhaust channel is provided inside the middle longitudinal beams, and the exhaust channel communicates with the pressure relief channel. At least one side of the two side walls for defining the installation cavity on the middle longitudinal beam is provided with a plurality of air inlet holes;

[0010] Multiple groups of battery cell groups are respectively arranged in each installation cavity. Each battery cell group includes a plurality of battery monomers stacked in sequence along the extension direction of the support longitudinal beam. A second explosion-proof valve hole is provided on the outer surface of the battery monomer. The number of the air inlet holes is the same as the number of the second explosion-proof valve holes, and the plurality of second explosion-proof valve holes are opposite to and communicate with the plurality of air inlet holes one by one;

[0011] Wherein, the width of the middle longitudinal beam is a, and the width of the support longitudinal beam is b, satisfying the relational expression: b > a, a ≤ 30 mm.

[0012] In some embodiments of this application, b ≤ 70 mm.

[0013] In some embodiments of the present application, the exhaust passage passes through two end surfaces of the middle longitudinal beam, and an air vent connected to the pressure relief passage is opened on the inner wall of the frame, and the air vent is connected to the end of the middle longitudinal beam.

[0014] In some embodiments of the present application, in any of the compartments, at least one of the middle longitudinal beams is a double-channel middle longitudinal beam, both sides of the double-channel middle longitudinal beam are provided with air inlet holes, and a partition is provided inside the double-channel middle longitudinal beam, the partition divides the exhaust channel into two exhaust cavities respectively connected to the air inlet holes on both sides, and each of the exhaust cavities is respectively connected to the pressure relief channel.

[0015] In some embodiments of the present application, when observed along the cross section of the middle longitudinal beam, a first deformation cavity is provided on the outer periphery of the exhaust passage.

[0016] In some embodiments of the present application, the frame includes: two side cross beams spaced apart and arranged in parallel and two side longitudinal beams spaced apart and arranged in parallel, the two side cross beams are connected end to end in sequence with the two side longitudinal beams, and the side longitudinal beams are arranged in parallel with the supporting longitudinal beams;

[0017] Both ends of the supporting longitudinal beam and both ends of the middle longitudinal beam are respectively connected to the inner wall of one of the side cross beams, at least one of the side cross beams is a pressure relief beam, the pressure relief channel is opened on the pressure relief beam, and the first explosion-proof valve hole is opened on the side of the pressure relief beam away from the chamber.

[0018] In some embodiments of the present application, the pressure relief channel runs through both end surfaces of the pressure relief beam, and the two side longitudinal beams respectively block the two end surfaces of the pressure relief channel.

[0019] In some embodiments of the present application, when observed along the cross section of the pressure relief beam, a second deformation cavity is provided on the outer periphery of the pressure relief channel.

[0020] In some embodiments of the present application, an electrode assembly is provided on the outer surface of the battery cell, and the electrode assembly and the second explosion-proof valve hole are respectively provided on different sides of the battery cell.

[0021] In some embodiments of the present application, the battery pack further includes:

[0022] A bottom plate, disposed at one end of the frame and covering an opening at one end of the chamber; and

[0023] The upper cover is arranged at the other end of the frame and covers the other end opening of the chamber.

[0024] For the battery pack of the present application, a support longitudinal beam and a middle longitudinal beam are arranged in the chamber. There are interconnected flow channels between the middle longitudinal beam and the frame. The outer periphery of the frame is provided with a first explosion-proof valve hole, and an air inlet hole is opened on the side surface of the middle longitudinal beam. The second explosion-proof valve hole on the battery cell is correspondingly communicated with the air inlet hole. Based on this, when heat is concentrated in the battery cell, the heat in each battery cell can be ejected from the outer periphery of the battery pack after passing through the middle longitudinal beam and the frame, effectively avoiding thermal runaway caused by heat concentration, and the ejection direction avoids the cockpit, further improving the safety performance. In the present application, the support longitudinal beam provides the support force, and the middle longitudinal beam provides the exhaust channel. Based on this, the width dimensions of the support longitudinal beam and the middle longitudinal beam are optimized. The width of the middle longitudinal beam is not greater than 30 mm, and the width of the support longitudinal beam is greater than that of the middle longitudinal beam. There is no need to set an intermediate cross beam. While ensuring the structural strength, the space occupied by the support structure can be reduced, more battery cells can be integrated in the battery pack, and the energy density can be improved. Description of the Drawings

[0025] The following further describes the present application in detail with reference to the drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are only drawn for the purpose of explaining the preferred embodiments and should not be used as a limitation to the scope of the present application. In addition, unless otherwise specified, the drawings are only intended to conceptually represent the composition or structure of the described object and may include exaggerated displays, and the drawings are not necessarily drawn to scale.

[0026] Figure 1 is an exploded schematic view of a battery pack according to some embodiments of the present application;

[0027] Figure 2 is a structural schematic view of the middle longitudinal beam of a battery pack according to some embodiments of the present application;

[0028] Figure 3 is a structural schematic view of the pressure relief beam of a battery pack according to some embodiments of the present application;

[0029] Figure 4 is a structural schematic view of the battery cell group of a battery pack according to some embodiments of the present application.

[0030] In the figure:

[0031] 1. Frame; 11. Chamber; 111. Compartment; 1111. Installation cavity; 12. Pressure relief channel; 13. First explosion-proof valve hole; 14. Ventilation hole; 15. Side cross beam; 16. Side longitudinal beam; 17. Pressure relief beam; 171. Second deformation cavity;

[0032] 2. Support longitudinal beam;

[0033] 3. Middle longitudinal beam; 31. Exhaust channel; 32. Air inlet hole; 33. Double-channel middle longitudinal beam; 331. Partition; 34. First deformation cavity;

[0034] 4. Battery cell group; 41. Battery cell; 411. Second explosion-proof valve hole; 412. Electrode assembly;

[0035] 5. Bottom plate;

[0036] 6. Upper cover. Detailed implementation manners

[0037] The preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are only descriptive and exemplary, and should not be construed as limiting the protection scope of the present application.

[0038] In the description of the present application, it should also be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected, or indirectly connected through an intermediate medium.

[0039] It should be noted that the term "including" does not exclude other elements or steps, and "one" or "a" does not exclude a plurality.

[0040] In addition, it should also be pointed out that for any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the drawings, combinations can still be continued between these technical features (or their equivalents) to obtain other embodiments of the present application not directly mentioned herein.

[0041] It should also be understood that the terms "first", "second", etc. are used herein to describe various information, but this information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0042] It should be noted that in different drawings, the same reference numerals represent the same or substantially the same components.

[0043] For the sake of convenience of description, a coordinate system XYZ as Figure 1 shown is established; wherein, the X direction, the Y direction, and the Z direction are perpendicular to each other pairwise.

[0044] As Figures 1-4 shown, some embodiments of the present application provide a battery pack, which includes: a bottom plate 5, an upper cover 6, a frame 1, a support longitudinal beam 2, at least two middle longitudinal beams 3, and multiple groups of battery cell groups 4.

[0045] Among them, the frame 1 is in a grid shape. The frame 1 encloses to form a chamber 11. Both ends of the chamber 11 in the Z direction have openings respectively. A pressure relief channel 12 is arranged inside the frame 1, and a first explosion-proof valve hole 13 communicated with the pressure relief channel 12 is arranged on the outer peripheral wall of the frame 1.

[0046] The bottom plate 5 and the upper cover 6 are respectively arranged at both ends of the frame 1 in the Z direction, and respectively seal the bottom opening and the top opening of the chamber 11. Cooling structures such as cooling channels can be arranged on the bottom plate 5.

[0047] The support longitudinal beam 2 extends in the Y direction. The support longitudinal beam 2 is located inside the chamber 11. Both ends of the support longitudinal beam 2 are respectively connected to two opposite inner walls of the frame 1, and the chamber 11 is divided into two compartments 111; middle longitudinal beams 3 are respectively arranged on both sides of the support longitudinal beam 2. The middle longitudinal beams 3 are arranged at intervals and in parallel with the support longitudinal beam 2. Both ends of the middle longitudinal beams 3 are respectively connected to two opposite inner walls of the frame 1. The middle longitudinal beams 3 divide each compartment 111 into at least two installation cavities 1111. An exhaust channel 31 is arranged inside the middle longitudinal beams 3. The exhaust channel 31 is communicated with the pressure relief channel 12. At least one side of the two side surfaces of the middle longitudinal beams 3 in the X direction is provided with a plurality of air inlet holes 32.

[0048] A group of battery cell groups 4 are arranged in each installation cavity 1111. The battery cell group 4 includes a row of battery monomers 41 stacked in sequence in the Y direction. A second explosion-proof valve hole 411 is arranged on one side of the battery monomer 41 in the X direction. The number of the air inlet holes 32 is the same as the number of the second explosion-proof valve holes 411, and the plurality of second explosion-proof valve holes 411 and the plurality of air inlet holes 32 are arranged in one-to-one correspondence and communicated with each other.

[0049] Define the width of the middle longitudinal beam 3 in the X direction as a, and define the width of the support longitudinal beam 2 in the X direction as b. The following relational expression needs to be satisfied: b > a, a ≤ 30 mm.

[0050] Based on the above technical solution, the second explosion-proof valve hole 411 is arranged on the side surface of the battery monomer 41, avoiding the position of the upper cockpit, preventing hot air from spraying upwards, and thus effectively protecting the cockpit; on this basis, the exhaust channel 31 is arranged on the middle longitudinal beam 3, the pressure relief channel 12 is arranged inside the frame 1, and the first explosion-proof valve hole 13 is arranged on the outer peripheral wall of the frame 1. When heat accumulates in a battery monomer 41, the hot air flow sprays out from the first explosion-proof valve hole 13, and sequentially passes through the exhaust channel 31 and the pressure relief channel 12, and finally sprays out from the first explosion-proof valve hole 13, which can prevent thermal runaway caused by heat accumulation in the installation cavity 1111, and at the same time avoid other battery monomers 41 being implicated due to the thermal runaway of a single battery monomer 41, and avoid the spread of thermal runaway; thus, it can effectively improve the safety performance of the battery pack.

[0051] In addition, in the above embodiments, in addition to setting the outer peripheral frame 1, support longitudinal beams 2 and middle longitudinal beams 3 are also provided. The width of the support longitudinal beam 2 is wider than that of the middle longitudinal beam 3, which is mainly used to provide the overall support in the middle of the battery pack. The middle longitudinal beam 3 only needs to meet the requirement of being able to open the exhaust channel 31, and its width can be reduced to a maximum of no more than 30 mm. Thus, there is no need to set an intermediate cross beam in the chamber 11, and the overall structural strength can be ensured, and more battery cells 41 can be integrated in each chamber 11. At the same time, the narrow middle longitudinal beam 3 can further reduce the space occupation inside the chamber 11. Especially for a battery pack with a large number of battery cell groups 4, the energy density can be effectively improved.

[0052] It should be noted that the middle longitudinal beam 3 in the present application can also function as a heat insulation and insulation pad. The two battery cell groups 4 are separated by the middle longitudinal beam 3, and there is no need to separately set a heat insulation pad, which can reduce costs.

[0053] Specifically, the width b of the support longitudinal beam 2 ≤ 70 mm, which can minimize the space occupation inside the chamber 11 on the premise of ensuring the overall structural strength.

[0054] For the convenience of manufacturing and to achieve lightweight, the middle longitudinal beam 3 is made of aluminum profiles, and an insulating layer is usually sprayed on the outer surface of the aluminum profiles. Based on this, the exhaust channel 31 runs through the two end faces of the middle longitudinal beam 3, and ventilation holes 14 are opened on the frame 1, and the ventilation holes 14 are in relative communication with the end faces of the middle longitudinal beam 3.

[0055] In some embodiments, as Figure 1 shown, a middle longitudinal beam 3 is respectively provided on both sides of the support longitudinal beam 2. In order to meet the need for air flow discharge, each middle longitudinal beam 3 is a double-channel middle longitudinal beam 33. For the specific structure, refer to the attached Figure 2 shown. A plurality of intake holes 32 are opened on both sides of the double-channel middle longitudinal beam 33 along the X direction. A partition 331 is provided inside the double-channel middle longitudinal beam 33. The partition 331 divides the exhaust channel 31 into two exhaust cavities respectively communicating with the intake holes 32 on both sides. Each exhaust cavity is respectively communicated with the pressure relief channel 12. Since the two exhaust cavities are respectively used to communicate with the battery cell groups 4 installed in the two installation chambers 1111, by setting the partition 331 to separate the two exhaust cavities, the hot air reflux can be effectively prevented.

[0056] As an alternative solution, in some embodiments, two or more middle longitudinal beams 3 can be provided in the compartment 111. At this time, it is not necessary to select all the middle longitudinal beams 3 as double-channel middle longitudinal beams 33, that is, some middle longitudinal beams 3 do not need to open intake holes 32 on both sides, but only need to open intake holes 32 on one side.

[0057] In order to improve the structural strength, in some embodiments, the middle longitudinal beam 3, when viewed along the cross section, is provided with one or more first deformation cavities 34 on the periphery of the exhaust passage 31, that is, the cross section of the middle longitudinal beam 3 can be in the shape of a “日” character, a “目” character, a “田” character, a “双目” character, etc.; Figure 2 FIG. 3 shows a form in which two first deformation chambers 34 are respectively arranged on the upper and lower sides of the exhaust channel 31 .

[0058] In some embodiments, the frame 1 includes: two side cross beams 15 and two side longitudinal beams 16 arranged at intervals; the two side cross beams 15 are connected to the two side longitudinal beams 16 end to end in sequence, and the side longitudinal beams 16 are arranged in parallel with the supporting longitudinal beams 2, and the whole is rectangular; both ends of the supporting longitudinal beam 2 and both ends of the middle longitudinal beam 3 are respectively connected to the inner wall of the side cross beam 15, and one side cross beam 15 or two side cross beams 15 are pressure relief beams 17, see the attached Figure 3 As shown, the pressure relief channel 12 is opened on the pressure relief beam 17, and the first explosion-proof valve hole 13 is opened on the side of the pressure relief beam 17 away from the chamber 11; based on this, the hot air flow passes through the middle longitudinal beam 3 and flows into the pressure relief beam 17, and is ejected outward from the pressure relief beam 17, which can shorten the flow path of the hot air flow and effectively reduce heat accumulation.

[0059] Similarly, for the convenience of processing, the pressure relief beam 17 is usually made of aluminum profiles. At this time, the pressure relief channel 12 runs through the two end surfaces of the pressure relief beam 17, and the two side longitudinal beams 16 respectively block the two end surfaces of the pressure relief channel 12.

[0060] like Figure 3 As shown, observing along the cross section of the pressure relief beam 17, two second deformation cavities 171 are respectively provided at the upper and lower ends of the pressure relief channel 12, which can ensure the structural strength; as an alternative, the cross-sectional shape of the pressure relief beam 17 can be set to other forms such as "日", "目", "田", "双目" and so on.

[0061] In some embodiments, such as Figure 4 As shown, the electrode assembly 412 on the battery cell 41 is arranged to face the end surface of the upper cover 6, that is, the second explosion-proof valve hole 411 is arranged on different sides of the battery cell 41, which can avoid thermal and electrical concentration and improve safety performance.

[0062] As an alternative, the electrode assembly 412 may also be disposed on other side surfaces of the battery cell 41 that are different from the second explosion-proof valve hole 411 .

[0063] In summary, the present application provides a battery pack that, by optimizing the structure, can take into account safety performance, structural strength and energy density, thereby effectively improving the overall performance.

[0064] This specification discloses the present application with reference to the accompanying drawings, and also enables those skilled in the art to implement the present application, including manufacturing and using any device or system, adopting suitable materials, and using any combined methods. The scope of the present application is defined by the claimed technical solutions and includes other examples that occur to those skilled in the art. As long as such other examples include structural elements that are not different from the literal language of the claimed technical solutions, or such other examples contain equivalent structural elements that have no substantial difference from the literal language of the claimed technical solutions, then such other examples should be considered to be within the scope of protection determined by the claimed technical solutions of the present application.

Claims

1. A battery pack, characterized in that: include: A frame encloses a chamber with openings at both ends, a pressure relief channel is provided in the frame, and a first explosion-proof valve hole communicating with the pressure relief channel is provided on the periphery of the frame; A supporting longitudinal beam, wherein two ends of the supporting longitudinal beam are respectively connected to two opposite inner walls of the frame and separate the chamber into two compartments; At least two middle longitudinal beams are respectively arranged on both sides of the supporting longitudinal beam, the middle longitudinal beam is arranged in parallel with the supporting longitudinal beam, and both ends are respectively connected to two opposite inner walls of the frame, the middle longitudinal beam divides each of the compartments into at least two installation cavities, an exhaust channel is arranged in the middle longitudinal beam, the exhaust channel is connected to the pressure relief channel, and at least one side of the two side walls of the middle longitudinal beam used to define the installation cavity is provided with a plurality of air inlet holes; A plurality of battery cell groups are arranged in each of the installation cavities in a one-to-one correspondence, the battery cell groups include a plurality of battery cells stacked in sequence along the extension direction of the supporting longitudinal beam, a second explosion-proof valve hole is arranged on the outer surface of the battery cell, the number of the air inlet holes is consistent with the number of the second explosion-proof valve holes, and the plurality of the second explosion-proof valve holes are opposite to and connected to the plurality of the air inlet holes one by one; Among them, the width of the middle longitudinal beam is a, and the width of the supporting longitudinal beam is b, satisfying the relationship: b>a, a≤30㎜.

2. The battery pack according to claim 1, characterized in that: b≤70㎜。 3. The battery pack according to claim 1, characterized in that: The exhaust passage passes through two end surfaces of the middle longitudinal beam, and an air vent connected to the pressure relief passage is provided on the inner wall of the frame, and the air vent is connected to the end of the middle longitudinal beam.

4. The battery pack according to claim 1, characterized in that: In any of the compartments, at least one of the middle longitudinal beams is a double-channel middle longitudinal beam, both sides of the double-channel middle longitudinal beam are provided with the air inlet holes, a partition is provided inside the double-channel middle longitudinal beam, the partition divides the exhaust channel into two exhaust cavities respectively connected to the air inlet holes on both sides, and each of the exhaust cavities is respectively connected to the pressure relief channel.

5. The battery pack according to claim 1, characterized in that: Observing along the cross section of the middle longitudinal beam, a first deformation cavity is provided on the outer periphery of the exhaust passage.

6. The battery pack according to claim 1, characterized in that: The frame comprises: two side cross beams arranged in parallel and at intervals and two side longitudinal beams arranged in parallel and at intervals, the two side cross beams are connected to the two side longitudinal beams end to end in sequence, and the side longitudinal beams are arranged in parallel with the supporting longitudinal beams; Both ends of the supporting longitudinal beam and both ends of the middle longitudinal beam are respectively connected to the inner wall of one of the side cross beams, at least one of the side cross beams is a pressure relief beam, the pressure relief channel is opened on the pressure relief beam, and the first explosion-proof valve hole is opened on the side of the pressure relief beam away from the chamber.

7. The battery pack according to claim 6, characterized in that: The pressure relief channel runs through the two end surfaces of the pressure relief beam, and the two side longitudinal beams respectively block the two end surfaces of the pressure relief channel.

8. The battery pack according to claim 7, characterized in that: Observing along the cross section of the pressure relief beam, a second deformation cavity is provided on the outer periphery of the pressure relief channel.

9. The battery pack according to claim 1, characterized in that: An electrode assembly is disposed on the outer surface of the battery cell, and the electrode assembly and the second explosion-proof valve hole are respectively disposed on different sides of the battery cell.

10. The battery pack according to any one of claims 1 to 9, characterized in that: Also includes: A bottom plate, disposed at one end of the frame and covering an opening at one end of the chamber; as well as The upper cover is arranged at the other end of the frame and covers the other end opening of the chamber.

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