Battery pack and vehicle

Abstract

According to the battery pack and the vehicle provided by the invention, the situation that a side beam of the battery pack turns over and topples over to extrude a battery cell when a side column of the vehicle is collided can be improved, so that the safety of the battery pack is improved. The battery pack comprises a battery box body and a plurality of battery cells located in the battery box body, a longitudinal beam extending in the longitudinal direction is arranged in the battery box body, and the longitudinal beam is provided with a beam body connecting structure used for being connected with a vehicle body; the battery pack further comprises a buffer part, the longitudinal beam is provided with two side parts distributed in the transverse direction, and the transverse direction is perpendicular to the longitudinal direction; a gap is formed between the side part of the longitudinal beam and the battery cell, the buffer pieces are located in the gap, and the buffer pieces are distributed on the two sides of the beam body connecting structure in the transverse direction.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a battery pack and a vehicle. Background Technology

[0002] Please refer to Figure 7 and Figure 8 , Figure 7 This is a structural schematic diagram of the location of the longitudinal beam inside a battery pack. Figure 8 for Figure 7 A schematic diagram of the structure when the central longitudinal beam tilts over.

[0003] The battery pack has a longitudinal beam 02 inside the battery box, with battery cells 01 on both sides of the longitudinal beam 02. The longitudinal beam 02 is equipped with a connecting component 03 that connects to the vehicle body, and there is a gap d between the longitudinal beam 02 and the battery cells 01 on both sides.

[0004] To improve driving safety, passenger vehicles must undergo side pole impact testing during development. For example, one test involves impacting a rigid pillar with a diameter of 254mm at a 75° angle at a speed of 32 km / h. During the impact, the vehicle's side panels, sill beams, and seat crossbeams directly bear the impact and crumple zone, absorbing energy and reducing intrusion and damage to the passenger compartment. At this time, due to the inertia of the battery pack, the longitudinal beam 02 of the battery pack will overturn and tip over, causing the longitudinal beam 02 to compress and intrude into the upper part of the battery cell 01. Figure 8 As shown, it can be seen that in the event of a collision, the overturning and tipping of the battery pack based on the longitudinal beam 02 may cause the battery cell 01 to have its own casing cracked, which will endanger the safety of the battery, the vehicle and the people. Utility Model Content

[0005] The purpose of this application is to provide a battery pack and a vehicle that can improve the safety of the battery pack by reducing the pressure on the battery cells caused by the side beams of the battery pack flipping and tilting during a side pillar collision.

[0006] The battery pack provided in this application includes a battery housing and a plurality of battery cells located inside the battery housing. The battery housing has a longitudinal beam extending in a longitudinal direction, and the longitudinal beam has a beam connection structure for connecting with the vehicle body.

[0007] The battery pack also includes a buffer, the longitudinal beam has two sides distributed in a transverse direction, the transverse direction being perpendicular to the longitudinal direction; there is a gap between the side of the longitudinal beam and the battery cell, the buffer is located in the gap, and the buffer is distributed on both sides of the beam connection structure in the transverse direction.

[0008] Optionally, the width of the buffer is greater than the width of the beam connection structure, and both the width of the buffer and the width of the beam connection structure are dimensions along the longitudinal direction.

[0009] Optionally, the battery cell has a thickness T-cell, the thickness of which is the dimension along the longitudinal direction, and the buffer has a width w, satisfying: 1.5T-cell≤w≤3T-cell.

[0010] Optionally, the top of the buffer and the top of the battery cell have a height difference h1, and the height of the welding heat-affected zone on the top of the battery cell is h2, satisfying: h1≥h2.

[0011] Optionally, the buffer has a height H-glue, and the battery cell has a height H-cell, with the height direction perpendicular to the longitudinal and transverse directions, satisfying: H-cell·50%≤H-glue≤H-cell-h2.

[0012] Optionally, the side surface of the buffer member facing the battery cell has an area S, satisfying: 2000mm²≤S≤20000mm².

[0013] Optionally, the buffer is a potting compound layer, and the battery pack includes adhesive strips, which are distributed at least on both sides of the buffer along the longitudinal direction.

[0014] Optionally, the adhesive strip includes lateral adhesive strip segments located on both sides of the buffer along the longitudinal direction and a bottom adhesive strip segment located at the bottom of the buffer.

[0015] Optionally, the adhesive strip has a thickness t, and the gap between the side of the longitudinal beam and the battery cell has a width d. The thickness of the adhesive strip and the width of the gap are both dimensions along the transverse direction, satisfying: d≤t≤3d.

[0016] Optionally, the buffer may be made of polyurethane, epoxy, acrylic or silicone.

[0017] This application also provides a vehicle including any of the battery packs described above.

[0018] In this application, a buffer is installed between the longitudinal beams and the battery cells of the battery pack, and the buffer is located on both sides of the beam connection structure. With this configuration, when the vehicle is involved in a side pole collision, the longitudinal beams of the battery pack deform due to inertia. The deformation of the longitudinal beams is mainly concentrated in the beam connection structure. The longitudinal beam portion corresponding to this location has the most obvious tendency to squeeze and intrude into the battery cells on one side. However, due to the presence of the buffer on either side of the beam connection structure, regardless of which side the collision occurs from, the load of the longitudinal beam deformation can be distributed to the side of the battery cell on the corresponding side, thereby reducing the local stress on the battery cell.

[0019] The vehicle provided in the application includes the battery pack described in any of the above-mentioned items, and therefore has the same technical effect as the battery pack described above. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the battery pack structure in one embodiment of this application;

[0021] Figure 2 for Figure 1 A structural schematic diagram showing the location of the longitudinal beams inside the battery pack.

[0022] Figure 3 for Figure 2 The main view;

[0023] Figure 4 for Figure 1 A schematic diagram showing the positional distribution of the buffer components and battery cells from a lateral perspective.

[0024] Figure 5 for Figure 2 A schematic diagram of the structure where the buffer component is located on one side of the battery cell;

[0025] Figure 6 for Figure 5 The main view, showing only the adhesive strip;

[0026] Figure 7 This is a structural schematic diagram of the location of the longitudinal beam inside a battery pack.

[0027] Figure 8 for Figure 7 A schematic diagram of the structure when the central longitudinal beam tilts over.

[0028] The annotations in the attached figures are explained as follows:

[0029] 100-battery pack;

[0030] 11-Battery cell;

[0031] 12-Longitudinal beam; 121-Beam connection structure;

[0032] 13-Connecting components;

[0033] 14-Buffer component; 141-Buffer element; 142-Adhesive strip; 1421-First lateral adhesive strip segment; 1422-Bottom adhesive strip segment; 1423-Second lateral adhesive strip segment;

[0034] 15-Battery housing;

[0035] 01-Battery cell; 02-Longitudinal beam; 03-Connecting component. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Please refer to Figure 1 and Figure 3 , Figure 1 This is a schematic diagram of the structure of the battery pack 100 in one embodiment of this application; Figure 2 for Figure 1 Structural diagram of the position of longitudinal beam 12 inside the middle battery pack 100; Figure 3 for Figure 2 The main view.

[0038] The battery pack 100 in this embodiment includes a battery housing 15. Figure 1 To illustrate the internal structure of the battery pack 100, the top of the battery housing 15 is not shown. The battery pack 100 also includes battery modules located within the battery housing 15. Each battery module includes multiple battery cells 11, which can be arranged in rows, with multiple rows of cells 11 arranged side-by-side within the battery housing 15. The battery housing 15 has longitudinal beams 12 extending longitudinally along the battery pack 100. Both ends of the longitudinal beams 12 are connected to the battery housing 15. The longitudinal direction of the battery pack 100 is typically the same as the longitudinal direction of the vehicle; however, the longitudinal direction of the battery pack 100 and the longitudinal direction of the vehicle can differ.

[0039] The top of the longitudinal beam 12 is provided with a connecting component 13 for connecting with the vehicle body. The connecting component 13 is, for example, a fastening bolt that can be threaded onto the vehicle body. Of course, the connecting component 13 can also be other connecting structures, as long as it can fix the battery pack 100 to the vehicle body. Figure 1 The schematic battery box 15 is provided with one longitudinal beam 12. It can be seen that two or more longitudinal beams 12 can also be provided. Each longitudinal beam 12 can be provided with one connecting component 13, or more connecting components 13 can be provided distributed longitudinally along the longitudinal direction of the longitudinal beam 12 to ensure connection reliability.

[0040] The longitudinal beam 12 divides the inner cavity of the battery box 15. The longitudinal beam 12 has two sides distributed laterally, which is perpendicular to the longitudinal direction. Both the lateral and longitudinal directions are perpendicular to the height direction of the battery pack 100. The two sides of the longitudinal beam 12 correspond to the end faces of a row of battery cells 11. The battery cells 11 are generally as follows: Figure 1 The diagram shows a cuboid configuration, with the side surface of the battery cell 11 having the largest area being the large face. Each row of battery cells 11 is arranged with their large faces facing each other, and the ends of the battery cells 11 are the smaller side faces. Of course, the battery cells 11 can also be arranged in other ways. Regardless of the arrangement, both sides of the longitudinal beam 12 will be opposite to several battery cells 12. There is a gap between the longitudinal beam 12 and the end faces of the battery cells 11 to form an assembly gap, allowing the battery cells 11 to be smoothly installed. The width of the gap, d, is, for example, about 4 mm.

[0041] It is worth noting that a buffer 141 is provided between the battery cell 11 and the longitudinal beam 12 in this embodiment. That is, a buffer 141 is provided in the gap mentioned above. In this embodiment, the buffer 141 is a potting compound layer. Specifically, the structure of the longitudinal beam 12 used to connect with the vehicle body is defined as the beam connection structure 121. In this embodiment, the beam connection structure 121 is connected to the connecting component 13 to indirectly connect with the vehicle body. It can be seen that the beam connection structure 121 and the connecting component 13 can also be an integral structure. For example... Figure 2 As shown, the connecting component 13 is a fastening bolt, with a portion of the threaded section of the fastening bolt located on the longitudinal beam 12. A through hole is provided at the top of the longitudinal beam 12, through which the fastening bolt passes to connect with the longitudinal beam 12. Therefore, the beam connection structure 121 includes this through hole. It can be seen that the connection method between the connecting component 13 and the longitudinal beam 12 is not limited to this. For example, it can be welded to the top of the longitudinal beam 12. In this case, the beam connection structure 121 includes the portion of the longitudinal beam 12 used for welding the connecting component 13. The structural form of the beam connection structure 121 is not specifically limited. The beam connection structure 121 is the portion of the longitudinal beam 12 used to establish a connection with the connecting component 13 and to transmit force.

[0042] The beam connection structure 121 has buffers 141 distributed on both sides in the transverse direction. That is, the buffers 141 on both sides of the beam connection structure 121 are distributed in the transverse direction. Therefore, the projection of the beam connection structure 121 along the height direction of the battery pack 100 is located between the two buffers 141.

[0043] With this configuration, when the vehicle experiences a side pole collision, the connection between the battery pack 100 and the vehicle body is the beam connection structure 121. Due to inertia, the longitudinal beam 12 of the battery pack 100 deforms, and the deformation of the longitudinal beam 12 is mainly concentrated in the beam connection structure 121. The longitudinal beam 12 at this location tends to squeeze and intrude into the battery cell 11 on one side. However, based on the presence of the buffer 141 on either side of the beam connection structure 121, regardless of which side the collision occurs from, the load of the longitudinal beam 12 deformation can be distributed to the side of the battery cell 11 on the corresponding side, thereby reducing the local stress on the battery cell 11, reducing the local deformation and intrusion of the battery cell 11, protecting the structural safety of the battery cell 11 itself, and thus improving the safety of the battery pack 100.

[0044] As mentioned earlier, the buffer 141 is mainly installed on both sides of the beam connection structure 121 to address the impact of deformation on the battery cell 11 caused by the vehicle body collision transmitted to the longitudinal beam 12. Obviously, the area of ​​the side surface of the buffer 141 facing the battery cell 11 or the longitudinal beam 12 should not be too small to ensure the dispersion of the load generated by the deformation of the longitudinal beam 12. The larger the area of ​​the battery cell 11 covered by the buffer 141, the wider the load distribution of the longitudinal beam 12, which is more conducive to reducing the local stress on the battery cell 11. However, considering cost factors and the weakening effect of load dispersion at locations too far from the beam connection structure 121, the area of ​​the buffer 141 should not be too large. In this embodiment, the area of ​​the side surface of the buffer 141 facing the battery cell 11 or the longitudinal beam 12 is defined as S. The recommended value is 2000mm²≤S≤20000mm². Within this area range, the amount of intrusion into the battery cell 11 when the longitudinal beam 12 deforms can be reduced to below the required value, for example, below 4mm.

[0045] Please continue to refer to this. Figure 4 , Figure 4 for Figure 1 A schematic diagram showing the positional distribution of the buffer 141 and the battery cell 11 from a lateral perspective.

[0046] In this embodiment, the top of the buffer 141 and the top of the battery cell 11 have a height difference h1, with the top of the buffer 141 being lower than the top of the battery cell 11. The battery cell 11 has a housing, which includes a main housing with an upper opening and a top cover for sealing the opening. An electrical connector 111 is also provided on the top cover. The top cover constitutes the top of the battery cell 11 and needs to be welded to the main housing of the battery cell 11. The area around the weld between the top cover and the main housing is a relatively weak area in the structural strength of the battery cell 11. The stress on the welding position around the top should be minimized. According to the actual situation, the welding heat-affected zone around the top of the battery cell 11 can be defined. That is, for the housing of the battery cell 11, the part located within a predetermined distance radiating outward from the top welding position belongs to the welding heat-affected zone. The predetermined distance, for the end face of the battery cell 11, is represented by height. That is, the portion of the end face of the battery cell 11 at a predetermined distance from the top in the height direction belongs to the weld heat-affected zone. This predetermined distance can be defined as h2, and the height of the weld heat-affected zone of the battery cell 11 is h2. In this embodiment, the height h2 is, for example, 7 mm. Therefore, when designing the buffer 141, h1 ≥ h2 can be satisfied, meaning the buffer 141 can avoid the weld heat-affected zone, thereby reducing or preventing the transfer of the load from the deformation of the longitudinal beam 12 to the weld heat-affected zone of the battery cell 11.

[0047] like Figure 4As shown, the buffer 141 is defined with a height H-glue. As mentioned earlier, the distance between the top of the buffer 141 and the top of the battery cell 11 is the height h1. The height of the battery cell 11 is defined as H-cell, which satisfies: H-glue ≤ H-cell - h2. However, it is obvious that the height H-glue of the buffer 141 should not be too small, so as to distribute the load in the height direction. In this embodiment, H-glue is also limited to ≥ H-cell·50%, that is, the height can not be less than half the height of the battery cell 11 to avoid concentrated load distribution. It can be seen that the height H-glue of the buffer 141 can satisfy: H-cell·50% ≤ H-glue ≤ H-cell - h2.

[0048] This embodiment can also limit the width of the buffer 141 along the longitudinal direction. The width of the buffer 141 can be greater than the width of the beam connection structure 121, so as to fully distribute and transmit the deformation force of the longitudinal beam 12 transmitted by the beam connection structure 121. The width of the buffer 141 and the width of the beam connection structure 121 are both longitudinal dimensions. Of course, considering cost factors, the width of the buffer 141 in the longitudinal direction does not need to be too large. For example, the battery cell 11 can be defined to have a thickness T-cell, and the thickness of the battery cell 11 is its longitudinal dimension. If the buffer 141 is defined to have a width w, then the following condition can be met: 1.5T-cell≤w≤3T-cell. That is, the width of the buffer 141 can be 1.5 times to 3 times the thickness of the battery cell 11. In this way, the buffer 141 can transmit the deformation force of the longitudinal beam 12 to more than one battery cell 11 to achieve the purpose of uniform load distribution. However, similar to the analysis principle of the area of ​​the buffer 141 mentioned above, if the width of the buffer 141 is too large, the number of corresponding battery cells 11 will be too large. Some battery cells 11 that are far away from the beam connection structure 121 will contribute less to the load transfer distribution. Therefore, considering the design cost, it is sufficient to meet the buffering requirements and control the cost by having the buffer 141 correspond to 2 to 3 battery cells 11 in the lateral direction. Here, "corresponding" means that after the collision, the buffer 141 can contact 2 to 3 battery cells 11 to transfer the load.

[0049] The buffer 141 described above can be made of any of polyurethane, epoxy, acrylic, or silicone, and has good cushioning performance. If the viscosity of the potting compound is too low, it will cause leakage; if the viscosity is too high, the potting process will be difficult. In this embodiment, the viscosity of the potting compound at 25°C is 5000~100000 mPa·s. The potting compound can be cured at room temperature, and the bond strength after 24 hours of potting is ≥2 mPa.

[0050] Can continue to combine Figure 5 and Figure 6 understand, Figure 5 for Figure 2A schematic diagram of the structure of the buffer component 141 located on one side of the battery cell 11; Figure 6 for Figure 5 The front view shows only the adhesive strip 142.

[0051] As mentioned above, the buffer 141 in this embodiment is specifically a potting compound layer. In this case, the battery pack 100 in this embodiment may also include an adhesive strip 142, which is distributed at least on both sides of the buffer 141 along the longitudinal direction. Figure 6 The middle adhesive strip 142 includes a first lateral adhesive strip segment 1421 and a second lateral adhesive strip segment 1423 along both longitudinal sides, and a bottom adhesive strip segment 1422 located at the bottom of the buffer 141. Specifically, the adhesive strip 142 has a U-shaped structure. The adhesive strip 142 can be pre-positioned between the battery cell 11 and the longitudinal beam 12. Thus, the adhesive strip 142, battery cell 11, and longitudinal beam 12 define a cavity with an open top, allowing potting compound to be poured in from the top downwards. After curing, it forms the buffer 141. In other words, the adhesive strip 142 uses an elastomer as a framework to define the filling area of ​​the potting compound, thereby constraining the shape and area of ​​the buffer 141. This facilitates control over the size, shape, and position of the buffer 141. Specifically, the first lateral adhesive strip segment 1421 and the second lateral adhesive strip segment 1423 help control the width of the buffer 141 along its longitudinal direction, and the bottom adhesive strip segment 1422 helps control the height of the buffer 141, etc. Therefore, it is not necessary to provide the adhesive strip 142. The buffer 141 is not limited to a potting compound layer, but can also be an elastic pad or other structures.

[0052] In this embodiment, the adhesive strip 142 can be a separate structure or a one-piece structure. For example, the first lateral adhesive strip segment 1421, the second lateral adhesive strip segment 1423, and the bottom adhesive strip segment 1422 can be a one-piece structure or spliced ​​together, as long as the filling area of ​​the potting compound can be defined.

[0053] like Figure 4 As shown, the adhesive strip 142 can be defined to have a thickness t, which is the dimension extending laterally perpendicular to the longitudinal direction. There is a gap between the longitudinal beam 12 and the battery cell 11, and the width d of the gap is also a lateral dimension, satisfying d ≤ t ≤ 3d. That is, the thickness of the adhesive strip 142 must not be less than the width d of the gap to ensure that the adhesive strip 142 can seal the gap, so that a buffer 141 of the required size and shape can be formed after potting. Of course, the thickness of the adhesive strip 142 should not be too large to facilitate pressing it between the longitudinal beam 12 and the battery cell 11.

[0054] In addition, the width b of the adhesive strip 142 should not be too small to ensure that it can reliably limit the potting space after being placed between the longitudinal beam 12 and the battery cell 11, and the width b should not be too large to ensure that the area is mainly determined by the buffer 141. In this embodiment, the width of the adhesive strip 142 can be selected as 5~10mm.

[0055] In this embodiment, the material of the adhesive strip 142 can be foam material, including but not limited to melamine foam, polyurethane foam, silicone foam, neoprene foam, etc. with a closed-cell rate of more than 50%.

[0056] This embodiment also provides a vehicle that includes the battery pack 100 described in any of the above embodiments, which has the same technical effects as the battery pack 100 in the above embodiments, and will not be described again.

[0057] The above are merely preferred embodiments of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A battery pack, characterized in that, Includes a battery housing (15) and a plurality of battery cells (11) located within the battery housing (15), the battery housing (15) having a longitudinal beam (12) extending longitudinally, the longitudinal beam (12) having a beam connection structure (121) for connection with the vehicle body. The battery pack (100) also includes a buffer (141), the longitudinal beam (12) has two sides distributed in a transverse direction, the transverse direction being perpendicular to the longitudinal direction; there is a gap between the side of the longitudinal beam (12) and the battery cell (11), the buffer (141) is located in the gap, and the buffer (141) is distributed on at least one side of the beam connection structure (121) in the transverse direction.

2. The battery pack according to claim 1, characterized in that, The width of the buffer (141) is greater than the width of the beam connection structure (121), and the width of the buffer (141) and the width of the beam connection structure (121) are both dimensions along the longitudinal direction.

3. The battery pack according to claim 2, characterized in that, The cell (11) has a thickness T-cell, the thickness of the cell (11) being the dimension along the longitudinal direction, and the buffer (141) has a width w, satisfying: 1.5T-cell≤w≤3T-cell.

4. The battery pack according to claim 1, characterized in that, The top of the buffer (141) and the top of the battery cell (11) have a height difference h1, and the height of the welding heat-affected zone on the top of the battery cell (11) is h2, satisfying: h1≥h2.

5. The battery pack according to claim 4, characterized in that, The buffer (141) has a height H-glue, and the cell (11) has a height H-cell, the height direction being perpendicular to the longitudinal direction and the transverse direction, satisfying: H-cell·50%≤H-glue≤H-cell-h2.

6. The battery pack according to any one of claims 1-5, characterized in that, The buffer (141) has an area S on the side of the side facing the battery cell (11) that satisfies: 2000mm²≤S≤20000mm².

7. The battery pack according to any one of claims 1-5, characterized in that, The buffer (141) is a potting compound layer, and the battery pack (100) includes adhesive strips (142), which are distributed at least on both sides of the buffer (141) along the longitudinal direction.

8. The battery pack according to claim 7, characterized in that, The adhesive strip (142) includes a first lateral adhesive strip segment (1421), a second lateral adhesive strip segment (1423) located on both sides of the buffer (141) along the longitudinal direction, and a bottom adhesive strip segment (1422) located at the bottom of the buffer (141).

9. The battery pack according to claim 7, characterized in that, The adhesive strip (142) has a thickness t, and the gap between the side of the longitudinal beam (12) and the battery cell (11) has a width d. The thickness of the adhesive strip (142) and the width of the gap are both dimensions along the transverse direction, satisfying: d≤t≤3d.

10. The battery pack according to any one of claims 1-5, characterized in that, The buffer (141) is made of any one of polyurethane, epoxy, acrylic or silicone.

11. A vehicle, characterized in that, Includes the battery pack (100) as described in any one of claims 1-10.

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