A battery pack

Abstract

This utility model discloses a battery pack, including a housing. The housing includes a frame and a base plate connected together. Multiple cylindrical batteries and structural beams are arranged on the base plate. The cylindrical batteries are arranged along the extension direction of the structural beams. Explosion-proof valves on the cylindrical batteries are positioned close to the structural beams, with the distance between the explosion-proof valves and their projection onto the structural beams being 9-19 mm. This battery pack not only ensures battery safety in the event of thermal runaway but also improves the space utilization of the housing's storage compartment.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] Cylindrical lithium-ion batteries (referred to as cylindrical batteries) have advantages such as high single-cell energy density, high consistency, and high production efficiency, and are widely used in new energy passenger vehicles, electric two-wheelers, power tools and other fields.

[0003] To release excess gas and prevent battery explosion in the event of thermal runaway, an explosion-proof valve is installed at the bottom of the cylindrical battery. To minimize the increase in the height of the battery pack, the cylindrical batteries within the pack can be arranged horizontally. When multiple cylindrical batteries are arranged horizontally, it is necessary to consider not only the overall space utilization of the battery pack but also the safety of the battery pack under thermal runaway conditions. Utility Model Content

[0004] In view of this, the present invention provides a battery pack that not only ensures the safety of the battery in the event of thermal runaway, but also improves the space utilization of the housing cavity.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A battery pack includes a housing, the housing including a frame and a base plate connected together, the base plate having a plurality of cylindrical batteries and a structural beam, the plurality of cylindrical batteries being arranged along the extension direction of the structural beam, and an explosion-proof valve on each cylindrical battery being disposed close to the structural beam, the explosion-proof valve being 9-19 mm away from its orthogonal projection on the structural beam.

[0007] As can be seen from the above technical solution, the battery pack provided by this utility model ensures the distance between the explosion-proof valve and the structural beam by limiting the distance D between the explosion-proof valve and its orthogonal projection on the structural beam. This prevents the explosion-proof valve of the cylindrical battery from being too close to the structural beam, allowing the gas discharged from the explosion-proof valve to quickly diffuse and escape during thermal runaway of the cylindrical battery, without affecting the gas diffusion inside the battery. Setting the distance between the explosion-proof valve and its orthogonal projection on the structural beam within a set range not only ensures the rapid diffusion of gas inside the battery during thermal runaway, guaranteeing the battery's safety, but also improves the space utilization of the enclosure. If the distance D between the explosion-proof valve and its orthogonal projection on the structural beam is too large, although it will not affect the discharge of gas inside the battery during thermal runaway, it will reduce the utilization of the enclosure and result in a less compact structure. If the distance D between the explosion-proof valve and its orthogonal projection on the structural beam is too small, it will affect the smooth discharge of gas inside the battery during thermal runaway. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 A schematic diagram of the battery pack housing from one angle, provided in an embodiment of this utility model;

[0010] Figure 2 This is a structural schematic diagram of the battery pack housing from another angle, provided in an embodiment of the present invention.

[0011] Figure 3 Provided for an embodiment of this utility model Figure 2 A schematic diagram of the cross-sectional structure at position AA in the middle;

[0012] Figure 4 This is a schematic diagram of the connection structure between the structural beam and the partition beam provided in an embodiment of the present invention;

[0013] Figure 5 for Figure 4 A structural diagram of a beam at one angle is provided in the embodiment;

[0014] Figure 6 for Figure 4 The embodiment provides a structural diagram of the beam from another angle;

[0015] Figure 7 for Figure 6 A cross-sectional view of the BB position;

[0016] Figure 8 This is a structural schematic diagram of a structural beam at one angle, provided in another embodiment of the present invention;

[0017] Figure 9 for Figure 8 The embodiment provides a structural diagram of the beam from another angle;

[0018] Figure 10 for Figure 9 A cross-sectional view of the CC position in one embodiment;

[0019] Figure 11 for Figure 9 A cross-sectional view of the CC position in another embodiment;

[0020] Figure 12 This is a cross-sectional structural diagram of the structural beam provided in the third embodiment of the present utility model;

[0021] Figure 13 This is a cross-sectional structural diagram of the structural beam provided in the fourth embodiment of this utility model.

[0022] in:

[0023] 1. Box body,

[0024] 101. Base plate; 102. Box frame;

[0025] 2. Structural beams

[0026] 201. Groove structure; 2011. First groove; 2012. Second groove; 202. Through cavity.

[0027] 3. Cylindrical battery,

[0028] 4. Dividing beam,

[0029] 5. Explosion-proof valve. Detailed Implementation

[0030] This utility model discloses a battery pack that not only ensures the safety of the battery in the event of thermal runaway, but also improves the space utilization of the housing cavity.

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] See Figures 1 to 13 The battery pack of this utility model includes a housing 1, which includes a frame 102 and a base plate 101 connected together. The frame 102 surrounds the base plate 101 to form a placement cavity. Multiple cylindrical batteries 3 and structural beams 2 are disposed on the base plate 101, and the cylindrical batteries 3 and structural beams 2 are disposed within the placement cavity. The cylindrical batteries 3 are placed horizontally on the base plate 101, that is, the axes of the cylindrical batteries 3 are parallel to the base plate 101. The multiple cylindrical batteries 3 are arranged along the extension direction of the structural beams 2 to form a battery pack, such as... Figure 1 and Figure 2 As shown. In order to prevent the high-temperature gas emitted by the explosion-proof valve 5 on the cylindrical battery 3 from affecting other cylindrical batteries 3 in the event of thermal runaway, the explosion-proof valve 5 on the cylindrical battery is set close to the structural beam 2, and the distance D between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2 is 9-19mm.

[0033] The cylindrical battery 3 can be arranged in one layer or multiple layers. For example... Figure 1The diagram shows a structural schematic of a single layer of cylindrical batteries 3. The height of the structural beam 2 is not less than the height of the highest point of the explosion-proof valve 5 of the top cylindrical battery 3, so as to block flames or high-temperature airflows in the event of battery thermal runaway. Preferably, the height of the structural beam 2 is higher than the total height of the cylindrical batteries 3 after their arrangement.

[0034] This utility model's battery pack, by limiting the distance D between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2 to 9-19mm, ensures a safe distance between the explosion-proof valve 5 and the structural beam 2. This prevents the explosion-proof valve 5 of the cylindrical battery 3 from being too close to the structural beam 2, allowing the gas discharged from the explosion-proof valve 5 to quickly diffuse and escape during thermal runaway of the cylindrical battery 3, without affecting the gas diffusion inside the battery. Setting the distance D between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2 within the above range not only ensures the rapid diffusion of gas inside the battery during thermal runaway, guaranteeing battery safety, but also improves the space utilization of the housing 1's placement cavity. If the distance D between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2 is too large, although it will not affect the discharge of gas inside the battery during thermal runaway, it will reduce the utilization of the housing 1's placement cavity, resulting in a less compact structure. If the distance D between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2 is too small, it will affect the smooth discharge of gas inside the battery during thermal runaway.

[0035] Among them, structural beam 2 can be a hollow beam with a through cavity 202. The hollow beam design of structural beam 2 results in lighter weight and higher strength, which helps reduce the weight of the battery pack. The hollow beam can withstand greater loads while reducing its own weight. To reduce the space occupied by the hollow beam structure of structural beam 2 in the placement cavity of the housing 1, a groove structure 201 is provided at the position of structural beam 2 corresponding to the explosion-proof valve 5. The size of the groove structure 201 is not smaller than the size of the explosion-proof valve 5. By providing the groove structure 201 on the surface of structural beam 2 corresponding to the explosion-proof valve 5, even if the cylindrical battery 3 is close to the surface of structural beam 2, the interval distance requirement for the venting of the explosion-proof valve 5 can still be met. Figure 3 As shown, this facilitates the rapid diffusion of gas at the location of the explosion-proof valve 5. It is understandable that when the surface of the structural beam 2 has a groove structure 201, the orthogonal projection of the explosion-proof valve 5 onto the structural beam 2 is located at the bottom of the groove structure 201. To facilitate the diffusion of gas injected into the groove structure 201, a distance is set between the explosion-proof valve 5 and the surface of the structural beam 2 to avoid affecting gas outflow. By setting the groove structure 201 on the hollow beam 2, it ensures that the gas generated during battery thermal runaway has a longer diffusion channel, allowing the gas to diffuse fully. It also compensates for the larger space occupied by the hollow beam compared to a solid plate beam, allowing the explosion-proof valve 5 to be positioned at a smaller distance from the surface of the hollow beam 2 to meet the requirement of a longer gas diffusion distance.

[0036] In one specific embodiment, the groove structure 201 includes a plurality of first grooves 2011, as shown in the figure. Figures 4 to 7 Each cylindrical battery 3 has an explosion-proof valve 5 corresponding to a first groove 2011, the size of which is not smaller than the size of the explosion-proof valve 5. Since multiple cylindrical batteries 3 are arranged along the length of the structural beam 2, multiple first grooves 2011 are also arranged along the length of the structural beam 2. When multiple layers of cylindrical batteries 3 are arranged, multiple rows of first grooves 2011 are also arranged accordingly.

[0037] Specifically, the first groove 2011 is a circular groove, such as... Figure 5 As shown, the groove diameter of the first groove 2011 is larger than the diameter of the explosion-proof valve 5.

[0038] To further improve gas diffusion capability, a weak area is provided on the bottom plate of the first groove 2011. The thickness of the weak area is thinner than other parts of the first groove 2011, so that the high-pressure gas ejected from the explosion-proof valve 5 can open the weak area. Some gas is discharged through the cavity 202, and some gas flows along the groove wall of the first groove 2011 into the placement cavity of the housing 1 and then is discharged through the exhaust port of the housing. To facilitate gas discharge through the cavity 202, the battery pack also includes a partition beam 4. Each end of the structural beam 2 is connected to a partition beam 4. An exhaust channel is provided in the partition beam 4. The cavity 202 of the structural beam 2 is connected to the exhaust channel in the partition beam 4. The exhaust channel is connected to the exhaust port on the housing frame 102, thereby facilitating the diffusion and discharge of gas in the cavity 202. The weak area can be a serrated strip or a thin sheet sealing the through hole of the bottom plate of the first groove 2011. No limitation is made here.

[0039] When a weak area is provided on the bottom plate of the first groove 2011, the gas inside the battery can diffuse through the weak area during the thermal runaway state of the battery. In this case, the distance D between the bottom surface of the first groove 2011 and the explosion-proof valve 5 is 13-19mm. The gas generated during the thermal runaway of the battery has a longer diffusion channel, and the gas can diffuse out fully without causing gas blockage.

[0040] In another specific embodiment, the groove structure 201 includes a second groove 2012, such as Figures 8 to 10As shown, the second groove 2012 extends along the length direction of the structural beam 2, that is, the second groove 2012 is a long strip groove. The length of the second groove 2012 is not less than the arrangement length of the plurality of cylindrical batteries 3, so that the explosion-proof valves 5 of each cylindrical battery 3 in the same layer can correspond to the second groove 2012. The height of the second groove 2012 is not less than the dimension of the explosion-proof valve 5 along the height direction of the second groove 2012, so that the gas ejected from the battery explosion-proof valve 5 can flow along the second groove 2012 and diffuse as soon as possible. Among them, the height direction of the second groove 2012 is the direction perpendicular to the bottom plate 101. It can be understood that one second groove 2012 is correspondingly arranged for each layer of cylindrical batteries 3. There are as many second grooves 2012 correspondingly arranged on the structural beam 2 as there are layers of cylindrical batteries 3, so as to facilitate the diffusion of gas when the batteries in different layers are thermally out of control. The distance D between the groove bottom surface of the second groove 2012 and the explosion-proof valve 5 is 13 - 19 mm. When the battery is thermally out of control, the generated gas has a longer diffusion channel, and the gas can diffuse out sufficiently without causing gas blockage.

[0041] To improve the smoothness of the gas flowing out of the second groove 2012, the groove side wall of the second groove 2012 is set as an inclined surface, as Figure 11 shown, the inclined surface is a surface that slopes outward from the bottom to the top of the second groove 2012.

[0042] Among them, the cross-section of the structural beam 2 is a square shape or a C-shaped. As Figure 5 and Figure 8 shown, the cross-section of the structural beam 2 is a square shape. As Figure 12 shown, the cross-section of the structural beam 2 is a C-shaped.

[0043] In other embodiments, the structural beam 2 can also be a solid plate beam, as Figure 13 shown. The distance D between the surface of the structural beam 2 and the explosion-proof valve 5 is 9 - 13 mm, as Figure 13 shown.

[0044] In this embodiment, the explosion-proof valve 5 is arranged at the bottom end of the cylindrical battery 3. Since both the explosion-proof valve 5 and the structural beam 2 are made of metal, in order to insulate the explosion-proof valve 5 and the structural beam 2, an insulating structure is arranged between the explosion-proof valve 5 and the structural beam 2.

[0045] In one embodiment, the insulating structure is an insulating coating. The insulating coating can be applied to the surface of the explosion-proof valve 5, or to the surface of the structural beam 2, or to both the explosion-proof valve 5 and the structural beam 2. In another embodiment, the insulating structure is an insulating diaphragm, which is attached to the surface of the explosion-proof valve 5, or to the surface of the structural beam 2, or to both the explosion-proof valve 5 and the structural beam 2. In the event of battery thermal runaway, the insulating diaphragm on the explosion-proof valve 5 can be ruptured to allow gas to escape. The insulating diaphragm is a plastic diaphragm.

[0046] The battery pack of this utility model ensures the distance between the explosion-proof valve 5 and the structural beam 2 by limiting the distance between the explosion-proof valve 5 and its orthogonal projection on the structural beam 2. This allows the gas discharged from the explosion-proof valve 5 to be quickly discharged and diffused when the cylindrical battery 3 experiences thermal runaway, without the gas diffusion being affected by the explosion-proof valve 5 being too close to the structural beam 2.

[0047] In the description of this solution, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this solution, "multiple" means two or more, unless otherwise explicitly specified.

[0048] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0049] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery pack, comprising a housing, the housing including a frame and a base plate connected together, the base plate being provided with a plurality of cylindrical batteries and structural beams, characterized in that, Multiple cylindrical batteries are arranged along the extension direction of the structural beam. The explosion-proof valves on the cylindrical batteries are located close to the structural beam, and the distance between the explosion-proof valves and their orthogonal projection on the structural beam is 9-19 mm.

2. The battery pack according to claim 1, characterized in that, The structural beam is a hollow beam with a through cavity, and a groove structure is provided at the position of the structural beam corresponding to the explosion-proof valve. The size of the groove structure is not smaller than the size of the explosion-proof valve.

3. The battery pack according to claim 2, characterized in that, The groove structure includes a plurality of first grooves, and each of the cylindrical batteries has an explosion-proof valve corresponding to a first groove, wherein the size of the first groove is not smaller than the size of the explosion-proof valve; Multiple first grooves are arranged along the length of the structural beam.

4. The battery pack according to claim 3, characterized in that, It also includes a partition beam, with both ends of the structural beam connected to the partition beam. An exhaust channel is provided inside the partition beam. A weak area is provided on the bottom plate of the first groove. The cavity of the structural beam is connected to the exhaust channel, and the exhaust channel is connected to the exhaust port on the box frame.

5. The battery pack according to claim 2, characterized in that, The distance between the bottom surface of the groove structure and the explosion-proof valve is 13-19mm.

6. The battery pack according to claim 2, characterized in that, The groove structure includes a second groove, which extends along the length of the structural beam. The length of the second groove is not less than the arrangement length of the cylindrical battery, and the height of the second groove is not less than the dimension of the explosion-proof valve along the height direction of the second groove.

7. The battery pack according to claim 6, characterized in that, Each layer of the cylindrical battery is provided with a corresponding second groove.

8. The battery pack according to claim 6, characterized in that, The sidewall of the second groove is set as an inclined surface, which is a surface that is inclined outward from the bottom to the top of the second groove.

9. The battery pack according to claim 2, characterized in that, The cross-section of the structural beam is either square or U-shaped.

10. The battery pack according to claim 1, characterized in that, The structural beam is a solid plate beam, and the distance between the surface of the structural beam and the explosion-proof valve is 9-13mm.

11. The battery pack according to claim 1, characterized in that, The explosion-proof valve is located at the bottom of the cylindrical battery, and an insulating structure is provided between the explosion-proof valve and the structural beam.

12. The battery pack according to claim 11, characterized in that, The insulating structure is an insulating coating, which is applied to the surface of at least one of the explosion-proof valve or the structural beam.

13. The battery pack according to claim 11, characterized in that, The insulating structure is an insulating diaphragm, which is attached to at least one of the surfaces of the explosion-proof valve or the structural beam.

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