CN219419348U - a battery pack - Google Patents

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pack. The battery pack includes: a box body and a cell module. The box body includes a bottom plate, a cover plate, and a frame connected between the bottom plate and the cover plate. The bottom plate includes an upper layer plate and a lower layer plate arranged in parallel at intervals. A reinforcing rib is arranged between the upper layer plate and the lower layer plate. By setting the bottom plate as a double-layer board structure including an upper board and a lower board arranged in parallel at intervals, and connecting the two boards through reinforcing ribs, the strength of the bottom board is strengthened. The bottom board supports the battery module. The bottom board of the double-layer board structure has functions such as energy absorption and buffering during force transmission, and the upper board and the lower board are connected by oblique ribs, which further strengthens the stability of the structure. .

Description

a battery pack

technical field

The utility model relates to the technical field of batteries, in particular to a battery pack.

Background technique

With the vigorous development of new energy vehicles, the safety of electric vehicles has received more and more attention. During the driving process of electric vehicles, various complex working conditions will be encountered. As the power source of electric vehicles, the battery pack has a major impact on the safety of the whole vehicle. Therefore, in order to improve the ability of electric vehicles to cope with various working conditions, it is necessary to improve the safety performance of the battery pack.

At present, spontaneous combustion of battery packs due to impact, especially bottom impact, accounts for a certain proportion of electric vehicle safety accidents. The bottom surface of the battery pack not only bears the gravitational effect of the cell module, but also directly bears external impacts. Therefore, the bottom surface of the battery pack in the prior art is usually easily damaged by impacts, and the impact resistance of the bottom is weak, which is not conducive to the safety of the battery pack.

Utility model content

Therefore, the technical problem to be solved by the utility model is to overcome the defect of weak impact resistance of the bottom surface of the battery pack in the prior art, so as to provide a battery pack capable of improving the impact resistance of the bottom.

In order to solve the above problems, the utility model provides a battery pack, comprising: a box body, including a bottom plate, a cover plate and a frame connected between the bottom plate and the cover plate, the bottom plate includes an upper plate and a lower plate arranged in parallel at intervals, a reinforcing rib is arranged between the upper plate and the lower plate, and the reinforcing rib is arranged obliquely between the upper plate and the lower plate; the cell module is installed in the box.

Optionally, the value range of the angle a between the stiffener and the lower plate is 25°-65°.

Optionally, the thickness b of the bottom plate ranges from 1/10 to 1/4 of the height of the box.

Optionally, the thickness c of the ribs ranges from 1/5 to 1/2 of the thickness b of the bottom plate; and/or, the distance d between two adjacent ribs is 6 to 9 times the thickness b of the bottom plate.

Optionally, a cooling structure is provided between the upper plate and the lower plate to reduce the temperature of the battery module; and/or, an elastic material is filled between the upper plate and the lower plate to buffer the bottom plate.

Optionally, the bottom plate is one or a combination of aluminum plates, steel plates, and plastic plates.

Optionally, an exhaust channel is provided on the bottom plate, and the exhaust channel runs through the upper layer and the lower layer, so as to discharge the high-temperature smoke in the box when the battery module thermal runaway occurs.

Optionally, the width e of the exhaust channel is 1.2-1.5 times the size of the explosion-proof valve on the battery module; and/or, the length f of the exhaust channel is 1.1-1.3 times the length of the battery module.

Optionally, the battery pack further includes: a first adhesive disposed between the bottom plate and the cell module to bond the bottom plate and the cell module; a second adhesive disposed between the cover plate and the cell module to bond the cover plate and the cell module.

Optionally, the cover plate is a liquid cooling plate to cool down the battery module.

The utility model has the following advantages:

1. By setting the bottom plate as a double-layer board structure including an upper board and a lower board arranged in parallel at intervals, and connecting the two boards through reinforcing ribs, the strength of the bottom board is strengthened, and the bottom board supports the battery module. The bottom board of the double-layer board structure has functions such as energy absorption and buffering during force transmission, and the upper board and the lower board are connected by oblique ribs, which further strengthens the stability of the structure. Comprehensive protection.

2. By setting a cooling structure in the gap between the upper plate and the lower plate, the bottom plate can cool down the battery module, prevent the battery from being damaged due to excessive temperature, ensure the safety of the battery module, and make reasonable use of the space between the upper plate and the lower plate. The bottom plate also has cooling and supporting functions, reducing the height of the entire device, thereby reducing the volume of the battery pack and saving installation space.

3. The upper layer and the lower layer are filled with elastic material. The elastic material can absorb the external force when the bottom plate is impacted by the outside, play the role of shock absorption and buffering, reduce the rigid damage of the bottom plate, and thus protect the battery module.

4. By setting the exhaust channel on the bottom plate, it is especially suitable for the case where the explosion-proof valve of the battery module is facing downward. Preferably, the exhaust channel and the explosion-proof valve are set correspondingly, that is, the position corresponding to the explosion-proof valve on the bottom plate is designed as a hollow structure to form a pressure relief channel. Then when the battery module thermal runaway occurs, the high-temperature smoke from the explosion-proof valve can be directly discharged from the battery pack through the exhaust channel, reducing the stay and transmission of high-temperature smoke in the battery pack, improving and improving the thermal runaway exhaust performance, thereby reducing further damage to the battery module. .

Description of drawings

In order to more clearly illustrate the specific implementation of the utility model or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific implementation or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are some implementations of the utility model. For those of ordinary skill in the art, other accompanying drawings can also be obtained according to these drawings without paying creative work.

Fig. 1 shows the exploded schematic diagram of the battery pack of the utility model embodiment;

Fig. 2 shows the structural representation of the bottom plate of the utility model embodiment;

Fig. 3 shows a partially enlarged schematic view of the A-A section in Fig. 2;

Fig. 4 shows a partial schematic diagram of a top view of the bottom plate of Fig. 2;

Figure 5 shows a partial schematic view of the battery pack model;

Fig. 6 shows the simulation results of the deformation of the battery pack model using the bottom plate before being hit by a bottom ball;

Fig. 7 shows the simulation results of the deformation of the battery pack model using the base plate of the embodiment of the present invention after being hit by a bottom ball;

Figure 8 shows a schematic diagram of the box strain results of the battery pack before improvement;

Fig. 9 shows a schematic diagram of the case strain results of the battery pack according to the embodiment of the present invention;

Fig. 10 shows the stress curve of the case of the battery pack before improvement;

Fig. 11 shows the force curve of the case of the battery pack according to the embodiment of the present invention.

Explanation of reference signs:

10. Box body; 11. Bottom plate; 111. Upper layer plate; 112. Lower layer plate; 113. Reinforcing rib; 114. Exhaust channel; 12. Cover plate; 13. Frame; 20. Cell module; 31. First adhesive; 32. Second adhesive.

Detailed ways

The technical solutions of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the utility model, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and so on is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present utility model. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" 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 intermediary, or it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

As shown in FIGS. 1 to 4 , the battery pack of this embodiment includes: a box body 10 and a cell module 20. The box body 10 includes a bottom plate 11, a cover plate 12, and a frame 13 connected between the bottom plate 11 and the cover plate 12. The bottom plate 11 includes an upper layer plate 111 and a lower layer plate 112 arranged in parallel at intervals. A reinforcing rib 113 is arranged between the upper layer plate 111 and the lower layer plate 112. 2 are arranged obliquely; the cell module 20 is installed in the box body 10 .

Applying the battery pack of this embodiment, by setting the bottom plate 11 as a double-layer plate structure including an upper layer plate 111 and a lower layer plate 112 arranged at intervals and in parallel, and connecting the two layers of plates through reinforcing ribs 113, the strength of the bottom plate 11 is strengthened, and the bottom plate 11 supports the cell module 20. In order to ensure the stability of the structure, the bottom plate 11 can provide high-intensity deformation and force sharing when subjected to external impact force, thereby providing comprehensive protection for the battery module 20 .

It should be noted that the upper plate 111 of the bottom plate 11 is a layer facing the inside of the box body 10, and the lower layer plate 112 is a layer of plates facing the outside of the box body 10; the cell module 20 includes several cells arranged in sequence, the cell module 20 is installed in the box body 10, and the bottom plate 11 plays a supporting role for the cell module 20. The columns face the cells on both sides, and the bottom plate 11 of this embodiment also has a protective effect on the bottom of the cells, wherein, “down” refers to the “down” indicated by the arrow in FIG. 1 .

In this embodiment, the angle a between the reinforcing rib 113 and the lower plate 112 ranges from 25° to 65°. Wherein, the angle a is the acute angle formed between the rib 113 and the lower plate 112, and its size is also equal to the angle of the acute angle formed between the rib 113 and the upper plate 111. When the angle a is between 25° and 65°, the bottom plate 11 formed by the upper plate 111, the lower plate 112 and the rib 113 has higher strength and cushioning performance.

In this embodiment, the thickness b of the bottom plate 11 ranges from 1/10 to 1/4 of the height of the box body 10 . Wherein, the height of the box body 10 refers to the dimension along the “height direction” indicated by the arrow in FIG. 1 after the box body 10 is assembled; the thickness b of the bottom plate 11 refers to the dimension of the bottom plate 11 along the “height direction” shown in FIG. Arrangement of internal battery cell modules 20 and other components.

In this embodiment, the thickness c of the reinforcing rib 113 ranges from 1/5 to 1/2 of the thickness b of the bottom plate 11. The reinforcing rib 113 has a certain thickness, which can better play a role of connection and support, and when the thickness of the reinforcing rib 113 is within this range, it can not only meet the strength required for the support, but also avoid excessive mass of the bottom plate 11 due to excessive thickness, so that the weight of the bottom plate 11 can be relatively reduced, that is, the weight of the entire battery pack can be reduced, which is conducive to improving the energy density of the battery pack.

In this embodiment, the distance d between two adjacent reinforcing ribs 113 is 6 to 9 times the thickness b of the bottom plate 11, so that the distribution density of the reinforcing ribs 113 can not only satisfy the supporting function of the reinforcing ribs 113, but also can relatively reduce the mass of the bottom plate 11, and realize the lightweight of the battery pack.

In this embodiment, a cooling structure is provided between the upper plate 111 and the lower plate 112 to reduce the temperature of the battery module 20 . By arranging a cooling structure in the gap between the upper plate 111 and the lower plate 112, the base plate 11 can cool down the cell module 20, prevent the cell from being damaged due to excessive temperature, ensure the safety of the cell module 20, and make reasonable use of the space between the upper plate 111 and the lower plate 112. The base plate 11 also has cooling and supporting functions, reducing the height of the entire device, thereby reducing the volume of the battery pack and saving installation space. Specifically, the cooling structure may be a pipeline with liquid, which takes away the heat of the battery module 20 through heat exchange; the cooling structure may also be a filling material with heat absorption performance filled between the upper plate 111 and the lower plate 112, and realizes the cooling effect by absorbing the heat of the battery module 20.

In this embodiment, an elastic material is filled between the upper plate 111 and the lower plate 112 to buffer the bottom plate 11 . The elastic material can absorb the external force when the bottom plate 11 is impacted by the outside, play the role of shock absorption and buffering, reduce the rigidity damage of the bottom plate 11 , and thus protect the battery module 20 .

Wherein, only one of the cooling structure and the elastic material may be provided between the upper plate 111 and the lower plate 112, or both the cooling structure and the elastic material may be provided at the same time, which may be selected according to actual needs. Of course, it is also possible to fill the gap between the upper plate 111 and the lower plate 112 with a multi-phase medium or a solid-liquid medium that has both heat absorption function and elastic properties, and at the same time realize cooling of the cell module 20 and buffering of external impact. It should be noted that when setting the cooling joint and/or elastic material, it is necessary to avoid the exhaust passage 114 to ensure the smooth flow of the exhaust passage 114 .

In this embodiment, the bottom plate 11 is one of aluminum plate, steel plate and plastic plate, and may also be a combination of multiple types of the above plates. Both aluminum and steel have high strength, and plastic has light weight and corrosion resistance, etc., which can be selected according to the actual environment and needs.

In this embodiment, the bottom plate 11 is provided with an exhaust channel 114, and the exhaust channel 114 runs through the upper plate 111 and the lower plate 112 of the bottom plate 11, so as to discharge the high-temperature smoke in the box 10 when the battery module 20 has thermal runaway. By setting the exhaust channel 114 on the bottom plate 11, it is especially suitable for the case where the explosion-proof valve of the cell module 20 faces downward. Preferably, the exhaust channel 114 is arranged corresponding to the explosion-proof valve, that is, the position corresponding to the explosion-proof valve on the bottom plate 11 is designed as a hollow structure to form a pressure relief channel. When the thermal runaway of the cell module 20 occurs, the high-temperature smoke ejected from the explosion-proof valve can be directly discharged from the battery pack through the exhaust channel 114, reducing the stay and transmission of high-temperature smoke in the battery pack, improving and Improve thermal runaway exhaust performance, thereby reducing further damage to the battery module 20 . Further, the number of exhaust passages can be set according to the arrangement of the battery cells of the battery module 20. Preferably, the battery module 20 includes two rows of batteries, and the number of exhaust passages 114 is two. The two exhaust passages 114 are arranged at intervals along the width direction of the bottom plate 11, and each exhaust passage 114 corresponds to an explosion-proof valve on a row of batteries, which increases the exhaust area and improves the exhaust effect.

In this embodiment, the width e of the exhaust passage 114 is 1.2 to 1.5 times the size of the explosion-proof valve on the cell module 20 , so as to ensure that the gas ejected from the explosion-proof valve can be discharged through the exhaust passage 114 smoothly. Wherein, the width refers to the dimension along the "width direction" indicated by the arrow in FIG. 4; the explosion-proof valve refers to the explosion-proof valve on the battery cells in the cell module 20, and the cell module 20 includes several cell cells, and each cell cell is provided with an explosion-proof valve.

In this embodiment, the length f of the exhaust channel 114 is 1.1-1.3 times the length of the cell module 20 . Wherein, the length refers to the dimension along the “length direction” indicated by the arrows in FIG. 1 and FIG. 4. By setting the length of the exhaust channel 114 to be greater than the length of the battery module 20, it can be ensured that the gas ejected from the battery cells at any position on the battery module 20 can be smoothly discharged through the exhaust channel 114, further improving the safety of the battery pack.

In this embodiment, the battery pack further includes: a first adhesive 31 and a second adhesive 32, the first adhesive 31 is disposed between the bottom plate 11 and the cell module 20 to bond the bottom plate 11 and the cell module 20; the second adhesive 32 is disposed between the cover plate 12 and the cell module 20 to bond the cover plate 12 and the cell module 20. By providing the first adhesive 31 between the bottom plate 11 and the cell module 20 and the second adhesive 32 between the cover plate 12 and the cell module 20, the adhesion between the bottom plate 11 and the cell module 20, the cover plate 12 and the cell module 20 is improved, the cell module 20 is prevented from shaking, and the stability of the structure is improved.

In this embodiment, the cover plate 12 is a liquid-cooled plate to cool down the battery module 20. The cover plate 12 can cool down the battery module 20 at the same time as the bottom plate 11 to increase the cooling effect and protect the battery under high-power fast charging conditions.

The performance of the battery pack of this embodiment is compared with the performance of the battery pack before improvement as follows:

As shown in Figure 5, the battery pack is modeled using structural simulation software. The original height of the battery pack is 130.020mm, and by applying a ball hit to the bottom of the battery pack, the working condition of the battery pack being impacted by the outside world is simulated. Specifically, an external force of the same magnitude is applied to the battery pack before improvement and the battery pack of this embodiment in the form of a ball hit. The comparison of the simulation results of the battery pack on the bottom plate 11 of the example is analyzed in detail as follows:

Figure 6 and Figure 7 show the comparison of the deformation of the battery pack before improvement and the battery pack of this embodiment when the force on the bottom plate reaches 25KN. It can be seen that the height of the battery pack before improvement becomes 126.914mm, and the height of the battery pack of this embodiment becomes 129.040mm. Compared with the deformation of the battery pack before improvement which is 3.11mm, the deformation of the battery pack of this embodiment drops to 0.98mm, which is less than the reference requirement of 2.0mm, and the simulation The results show that the shell of the battery cell, that is, the explosion-proof valve, is not broken, indicating that the battery pack of this embodiment meets the safety performance requirements and the deformation after being subjected to external impact force is greatly reduced, and the performance of the battery pack is improved;

Figure 8 and Figure 9 show the comparison of the strain on the box 10 of the battery pack before improvement and the battery pack of this embodiment when the force on the bottom plate reaches 25KN. It can be seen that the maximum strain on the battery pack before improvement is 3.077mm, and the maximum strain on the battery pack of this embodiment is 1.019mm.

Figures 10 and 11 show the curves of force changes on the bottom plate of the battery pack before the improvement and the battery pack of this embodiment after the ball is hit on the bottom plate of the battery pack. It can be seen that the slope of the force curve on the bottom plate of the battery pack before the improvement basically shows a gradual increase trend, while the slope of the force curve on the bottom plate of the battery pack of this embodiment remains unchanged. Performance is better.

To sum up, compared with the battery pack before the improvement, the battery pack of this embodiment has smaller deformation, smaller strain on the box body and more uniform force on the bottom plate when the bottom plate is impacted by the same external force. Therefore, the battery pack of this embodiment has better impact resistance performance and better safety performance of the battery pack.

From the above description, it can be seen that the above-mentioned embodiments of the present invention have achieved the following technical effects:

1. The bottom plate 11 adopts the structural form of double-layer plates, and oblique ribs are connected between the upper plate 111 and the lower plate 112, so that the overall structure is compact, the rigidity is high, and the weight is relatively light.

2. By setting the exhaust channel 114 on the bottom plate 11, a multi-functional protective plate that combines the bottom protection and exhaust functions of the bottom plate 11 can be realized. At the same time, the cooling structure and/or elastic material can be set in the middle gap layer of the bottom plate 11 to realize the cooling and/or buffering effect of the bottom plate 11. The structure design is ingenious, and the materials and structures are matched and synthesized.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the scope of protection of the utility model.

Claims (10)

1. A battery pack, characterized in that, comprising: The box body includes a bottom plate, a cover plate, and a frame connected between the bottom plate and the cover plate, the bottom plate includes an upper plate and a lower plate arranged in parallel at intervals, a reinforcing rib is arranged between the upper plate and the lower plate, and the reinforcing rib is arranged obliquely between the upper plate and the lower plate; The battery module is installed in the box. 2 . The battery pack according to claim 1 , wherein the angle a between the reinforcing rib and the lower plate ranges from 25° to 65°. 3 . The battery pack according to claim 1 , wherein the thickness b of the bottom plate ranges from 1/10 to 1/4 of the height of the box. 4 . 4. The battery pack according to claim 3, wherein the value range of the thickness c of the reinforcing rib is 1/5 to 1/2 of the thickness b of the bottom plate; And/or, the distance d between two adjacent reinforcing ribs is 6-9 times the thickness b of the bottom plate. 5. The battery pack according to claim 1, wherein a cooling structure is provided between the upper plate and the lower plate to reduce the temperature of the battery module; And/or, an elastic material is filled between the upper layer board and the lower layer board to buffer the bottom board. 6. The battery pack according to claim 1, wherein the bottom plate is one or a combination of aluminum plates, steel plates, and plastic plates. 7 . The battery pack according to claim 1 , wherein an exhaust channel is provided on the bottom plate, and the exhaust channel runs through the upper layer plate and the lower layer plate to discharge high-temperature flue gas in the box when thermal runaway occurs in the cell module. 8. The battery pack according to claim 7, wherein the width e of the exhaust channel is 1.2 to 1.5 times the size of the explosion-proof valve on the cell module; And/or, the length f of the exhaust channel is 1.1-1.3 times the length of the battery module. 9. The battery pack according to any one of claims 1 to 8, wherein the battery pack further comprises: a first adhesive, the first adhesive is disposed between the base plate and the cell module to bond the base plate and the cell module; A second adhesive, the second adhesive is disposed between the cover plate and the cell module to bond the cover plate and the cell module. 10. The battery pack according to any one of claims 1 to 8, wherein the cover plate is a liquid cooling plate to cool down the battery module.