Battery pack

Abstract

This invention discloses a battery pack. [Solution] The battery pack includes a case, a cell pack, and a reinforcing plate. The reinforcing plate includes a foamed rubber layer and a glass cloth layer, with the foamed rubber layer enclosing the glass cloth layer. The cell pack is located inside the case, with one reinforcing plate provided on each side wall in the longitudinal direction of the cell pack, and the foamed rubber layer is provided in close contact with the side wall of the cell pack. Based on the lever principle, the longitudinal direction of the cell pack is the weakest point in terms of bending strength and shear resistance. By attaching reinforcing plates to both sides in the longitudinal direction of the cell pack, the bending strength and shear resistance performance of the battery pack can be improved.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with the application number 202422271455.9, which was filed with the Chinese Patent Office on September 14, 2024, and the entire content of the above application is incorporated herein by reference. The present invention relates to the field of battery technology, and particularly to battery packs.

Background Art

[0002] With the rapid development of the electric vehicle market, the requirements for the energy density, safety, and reliability of batteries are increasing. Currently, as a central component of the battery pack of an electric vehicle, a battery pack is usually a combination of multiple cells connected in series or parallel. However, such a multiple-cell structure increases the energy density but also brings many deficiencies.

Summary of the Invention

Problems to be Solved by the Invention

[0003] First, by combining multiple cells, the integrity of the cell pack becomes weak. Since there are gaps and connectors between cells, these gaps and connectors are likely to be areas where stress concentrates when the battery pack is subjected to external impacts or vibrations, and the battery pack may be deformed or broken. Therefore, if the strength of the battery pack is low, the safety risk of the battery pack increases.

[0004] Second, in the case of a battery pack for a new energy vehicle or other applications that require a high battery capacity, the overall volume of the battery pack increases due to the stacking and arrangement of multiple cells. According to the lever principle, the bending resistance and shear resistance of the entire battery pack are significantly reduced. Especially when used in new energy vehicles, it is often involved in downhill slopes or other pitching roads, and the battery pack receives various complex forces from the road surface. If the bending resistance and shear resistance of the battery pack are insufficient, deformation and damage are likely to occur, which may also lead to serious consequences such as battery short circuits, fires, and explosions.

[0005] Finally, while the insulation of cells within a battery pack is generally achieved through a potting process, forming an insulating structure where the potting layer surrounds the cells, the potting layer only enhances the insulation performance of the cells and does not increase the rigidity of the battery pack, thus the battery pack still poses safety concerns. [Means for solving the problem]

[0006] The present invention provides a battery pack comprising a case, a cell pack, and a reinforcing plate, wherein the cell pack is disposed inside the case, and the reinforcing plate is provided on each of the longitudinal side walls of the cell pack and includes a glass cloth layer and a foamed rubber layer enclosing the glass cloth layer, wherein the foamed rubber layer is provided in close contact with the side wall of the cell pack. (Effects of the invention)

[0007] The beneficial effects of the battery pack provided by this invention are as follows: By adopting the above design, based on the principle of leverage, the longitudinal direction of the cell pack becomes the weakest point in terms of bending strength and shear resistance. By attaching reinforcing plates to both sides of the longitudinal direction of the cell pack, the bending strength and shear resistance performance of the battery pack can be improved according to the purpose. Furthermore, since the reinforcing plates are composed of a foamed rubber layer and a glass cloth layer, the rigidity of the battery pack is increased, while the self-weight and volume values ​​of both are reduced, so the self-weight of the battery pack is not significantly increased, and the space inside the case is not taken up unnecessarily, thus ensuring high-density energy storage inside the battery pack. In addition, both the foamed rubber layer and the glass cloth layer are good insulating materials, further improving the safety of the battery pack.

[0008] In addition to the beneficial effects mentioned above, using a reinforcing plate made by combining a foamed rubber layer and a glass cloth layer offers greater convenience. Since battery packs undergo a potting process on the cell pack during manufacturing, the glass cloth layer can be pre-positioned in the corresponding location before injecting the foamed rubber. A portion of the foamed rubber solidifies on the surface of the glass cloth layer, forming the foamed rubber layer. This reduces the processing steps in the manufacturing process, so adding a reinforcing plate to the battery pack does not affect the time required for normal battery pack processing. Furthermore, the glass cloth layer inherently has burrs due to its material properties, which can break through air bubbles in the foamed rubber, increasing the density of the foamed rubber. The foamed rubber layer tends to have adhesive properties, further increasing the strength and hardness of the reinforcing plate. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of the three-dimensional structure of the present invention. [Figure 2] Figure 2 is a schematic diagram of the exploded structure of the present invention. [Figure 3] Figure 3 is an enlarged view of section A in Figure 2. [Figure 4] Figure 4 is a schematic diagram illustrating the separation of the cell, reinforcing plate, and liquid cooling plate according to the present invention. [Figure 5] Figure 5 is a schematic diagram of the three-dimensional structure of a part of the cell pack, reinforcing plate, and liquid cooling plate of the present invention. [Figure 6] Figure 6 is a schematic top view of a portion of the cell pack, reinforcing plate, and liquid cooling plate structure of the present invention. [Modes for carrying out the invention]

[0010] Referring to Figures 1 and 2, the present invention discloses a battery pack comprising a case 1, a cell pack 2, and a reinforcing plate 3, wherein the reinforcing plate 3 includes a foamed rubber layer and a glass cloth layer, the foamed rubber layer enclosing the glass cloth layer, the cell pack 2 being provided inside the case 1, one reinforcing plate 3 provided on each side wall in the longitudinal direction of the cell pack 2, and the foamed rubber layer being provided in close contact with the side wall of the cell pack 2.

[0011] Specifically, the battery pack consists of a case 1, a cell pack 2, and a reinforcing plate 3. The cell pack 2 is provided inside the case 1, and the reinforcing plate 3 is configured to enclose a glass cloth layer within a foamed rubber layer. The foamed rubber layer is made of foamed rubber, and the glass cloth layer is made of glass cloth. One reinforcing plate 3 is provided on each side wall in the longitudinal direction of the cell pack 2, and the reinforcing plates 3 are provided in close contact with the side walls of the cell pack 2. Since the side walls of the cell pack 2 are where the most stress is concentrated, the reinforcing plates 3 are provided in close contact with the side walls of the cell pack 2, that is, the foamed rubber layer is provided in close contact with the side walls of the cell pack 2, thereby improving the strength of the side walls in the longitudinal direction of the battery pack. These side walls may be the upper and bottom side walls of the cell pack 2, or they may be the side walls corresponding to the cylindrical surfaces of the cells 21 in the longitudinal direction of the cell pack 2. In other words, if the proper installation of a relief valve in cell 21 of cell pack 2 does not affect the outcome, the reinforcing plate 3 may be provided on the upper and bottom walls of cell pack 2, or on the left and right side walls corresponding to the longitudinal direction of cell pack 2. Furthermore, the shape of the reinforcing plate 3 can be provided according to the shape of the side walls of cell pack 2, that is, the foamed rubber layer and the glass cloth layer can be provided according to the shape of the side walls of cell pack 2.

[0012] The specific processing process for the reinforcing plate 3 involves pre-spraying foamed rubber onto the outside of the glass cloth layer to create the reinforcing plate 3. Alternatively, the glass cloth layer can be placed inside the case 1 on the side wall of the cell pack 2, and during the potting process on the cell pack 2, a portion of the foamed rubber can solidify on the surface of the glass cloth layer to form a foamed rubber layer. This reduces the number of steps in the manufacturing process, and adding the reinforcing plate 3 to the battery pack does not affect the time required for the normal battery pack processing. Furthermore, because the glass cloth layer itself has burrs, it can break through the air bubbles in the foamed rubber, increasing the density of the foamed rubber, causing the foamed rubber layer to actually have adhesive properties, and further increasing the strength and hardness of the reinforcing plate 3.

[0013] In some embodiments, to increase the bonding strength between the glass cloth layer and the foamed rubber layer, the glass cloth layer has voids and burrs, the burrs penetrate into the foamed rubber layer, and the foamed rubber layer penetrates into the voids.

[0014] Specifically, due to the material properties of the glass cloth constituting the glass cloth layer, which include voids and burrs, the burrs penetrate into the foamed rubber layer, and the foamed rubber layer penetrates into the voids. By combining this with an installation method that allows the burrs to penetrate into the foamed rubber layer and the foamed rubber layer to penetrate into the voids, the contact area between the glass cloth layer and the foamed rubber layer is significantly increased, effectively enhancing the bonding strength between the glass cloth layer and the foamed rubber layer. Selectively, due to the structural characteristics of the glass cloth, when processing the reinforcing plate 3, the glass cloth constituting the glass cloth layer can be fixed into the mold for processing the reinforcing plate 3, and then the foamed rubber constituting the foamed rubber layer can be injected into the mold. Because the glass cloth layer has voids and burrs, the foamed rubber flows into the gaps in the glass cloth layer, and accordingly, the burrs of the foamed rubber also break through the air bubbles in the foamed rubber, promoting an increase in the density of the foamed rubber constituting the foamed rubber layer. This causes the foamed rubber layer to actually have adhesive properties, significantly improving the strength and hardness of the foamed rubber layer.

[0015] In some embodiments, the number of cells 21 is increased to increase the charge storage capacity of the battery pack, and the cell pack 2 includes multiple cells 21, which are arranged in N columns, with (N-1) gaps between the N columns of cells 21, and a reinforcing plate 3 is provided in at least one gap, with the foamed rubber layer of the reinforcing plate 3 in close contact with the adjacent cells 21.

[0016] Specifically, the cell pack 2 consists of multiple cells 21, which are arranged in N rows, forming (N-1) gaps between the N rows of cells 21, and depending on the actual requirements for strength and insulation, it is possible to choose to install reinforcing plates 3 in one or more of these gaps, thereby allowing the foamed rubber layer of the reinforcing plate 3 to adhere closely to the side walls of adjacent cells 21.

[0017] In some embodiments, in order to prevent the overheating of the battery pack from affecting the use of the battery pack, the battery pack further includes a liquid cooling plate 4, and the liquid cooling plate 4 is provided in at least one row of gaps. The arrangement of the liquid cooling plate 4 and the reinforcing plate 3 is to selectively arrange the liquid cooling plate 4 or the reinforcing plate 3 in the gap. When the requirement for heat dissipation is high, a plurality of liquid cooling plates 4 can be arranged. When the requirement for heat dissipation is met, the reinforcing plate 3 can be selectively arranged in other gaps. In this way, the battery pack can simultaneously meet the requirements for heat dissipation, strength, and insulation.

[0018] Referring to FIG. 4, in some embodiments, when the cell 21 employs a cylindrical cell, both the foamed rubber layer of the reinforcing plate 3 and the liquid cooling plate 4 are provided with a convex structure 31 facing the cell 21. The convex structure 31 extends between two adjacent cylindrical cells in the same row, and the convex structure 31 is in close contact with the cylindrical surface of the cylindrical cell.

[0019] Specifically, the convex structure 31 is provided corresponding to the side wall of the cylindrical cell, thereby improving the contact area between the liquid cooling plate 4 and the cell 21, further improving the heat dissipation performance, and improving the contact area between the reinforcing plate 3 and the cell 21, thereby improving the strength and insulation performance of the battery pack.

[0020] It should be noted that in FIG. 4, in order to show the relationship between the shape of the convex structure 31 and the cylindrical cell, the gap between the reinforcing plate 3, the liquid cooling plate 4 and the cylindrical cell is increased, and in actuality, they are provided in a close contact state.

[0021] Referring to FIGS. 5 and 6, when adopting cylindrical cells for the cells 21, in order to increase the density of the cells 21 in the battery pack, two adjacent rows of cells 21 are arranged offset, and the gap has a serpentine shape along with the offset of the cells 21. Correspondingly, both the reinforcing plate 3 and the liquid cooling plate 4 are provided in a serpentine shape corresponding to the serpentine gap. That is, both the foamed rubber layer and the glass cloth layer of the reinforcing plate 3 are provided in a serpentine shape corresponding to the serpentine gap. Thereby, it becomes easy to arrange the foamed rubber layer, the glass cloth layer, and the liquid cooling plate 4 in the serpentine gap, minimizing the gap between the cells 21, ensuring the density of the cells 21 required for the battery pack, and also ensuring the contact area between the foamed rubber layer and the cells 21 and the contact area between the liquid cooling plate 4 and the cells 21, and ensuring the heat dissipation performance required for the installation of the liquid cooling plate 4 and the strength and insulation performance required for the installation of the reinforcing plate 3.

[0022] In some embodiments, in order to ensure uniform heat dissipation of the cell pack 2, among the N - 1 rows of gaps, in two adjacent rows of gaps, the liquid cooling plate 4 is mounted in one gap and the reinforcing plate 3 is mounted in the other gap, that is, the liquid cooling plate 4 and the reinforcing plate 3 are mounted in an installation relationship where they are arranged at intervals. In this way, while ensuring uniform heat dissipation of the cell pack 2, the reinforcing plate 3 is also evenly arranged, improving the rigidity and safety of the battery pack.

[0023] Also, some battery packs adopt the installation method of the single - side liquid cooling plate 4 when installing the liquid cooling plate 4. In the case of this installation method of the battery pack, the reinforcing plate 3 can be installed in the gap where the liquid cooling plate 4 is not installed. When it does not affect the installation method of the single - side liquid cooling plate 4, the reinforcing plate 3 can be installed at intervals to enhance the rigidity and safety of the battery pack.

[0024] In some embodiments, a relief valve is provided in the cell pack 2 to ensure the safety of the battery. When the cell pack 2 consists of multiple cells 21, the relief valves of each cell 21 are oriented in the same direction to facilitate the drainage of thermal runaway substances that may be generated from the multiple cells 21. The relief valve is oriented toward the bottom surface 12 of the case 1, that is, corresponding to the bottom side wall of the cell pack 2, the surface opposite the bottom surface 12 of the case 1 is the top surface 11, and a reinforcing plate 3 is provided on the side of the top surface 11 facing the cell pack 2, and / or on the side of the top surface 11 facing away from the cell pack 2. Accordingly, in order to facilitate the installation of relief valves for multiple cells 21 in the cell pack 2, the reinforcing plate 3 is not installed in the direction in which the relief valve is installed in the cell 21.

[0025] Specifically, the reinforcing plate 3 can be installed on the side of the top surface 11 of case 1 facing the cell pack 2, on the side of the top surface 11 of case 1 facing away from the cell pack 2, or in both of the above positions. This improves the strength of the top surface 11 of the cell pack 2, enhancing the safety of the battery pack during use, transportation, and stacked storage. In other words, the foamed rubber layer provides a high energy absorption effect during use, transportation, and stacked storage. Furthermore, the combination of the glass cloth layer and the foamed rubber layer provides a certain bending strength to the entire top surface of the battery pack, improving the safety of the battery pack.

[0026] Referring to Figure 3, based on the structure in which the reinforcing plate 3 is provided on the side of the top surface 11 of case 1 that is facing away from the cell pack 2, a mounting groove 111 is provided on the top surface 11 of case 1, and the reinforcing plate 3 is installed in the mounting groove 111 and is flush with the outer surface of the top surface 11 of case 1. This makes it easy to install the reinforcing plate 3 and makes the foamed rubber layer of the reinforcing plate 3 flush with the outer surface of the top surface 11 of case 1, so that the integrity of case 1 can be maintained even after the reinforcing plate 3 is installed in the mounting groove 111.

[0027] In some embodiments, it is optimal to provide three layers of glass cloth within the reinforcing plate 3. The structure of these three layers of glass cloth forms a stronger "skeleton," increasing the mechanical strength and rigidity of the reinforcing plate 3. This reduces deformation of the battery pack when subjected to external shocks, vibrations, or pressure, enhances the overall structural stability of the battery pack, and reduces the risk of damage to the battery pack due to external forces.

[0028] In some embodiments, to enhance the safety of the battery pack, a group of relief through-holes 121 corresponding to the cell pack 2 is provided on the bottom surface 12 of the case 1. Specifically, the relief through-hole group 121 is provided in accordance with the relief valve of the cell pack 2, and any thermal runaway substances that may be generated in the cell pack 2 are discharged to the outside of the battery pack through the relief through-hole group 121, thereby improving the safety of the battery pack. [Explanation of Symbols]

[0029] 1 case 11 Top surface 111 Mounting groove 12. Base 121 Relief Through Hole Group 2 Cell Pack 21 cells 3. Reinforcement plate 31 Convex structure 4 Liquid cooling plate

Claims

1. It is a battery pack, Case (1) and, A cell pack (2) is placed inside the case (1), The cell pack (2) includes a reinforcing plate (3) provided on each of its longitudinal side walls, which comprises a glass cloth layer and a foamed rubber layer enclosing the glass cloth layer, The battery pack is characterized in that the foamed rubber layer is provided in close contact with the side wall of the cell pack (2).

2. The battery pack according to claim 1, characterized in that the glass cloth layer has voids and burrs, the burrs penetrate the foamed rubber layer, and the foamed rubber layer penetrates the voids.

3. The battery pack according to claim 1, wherein the cell pack (2) includes a plurality of cells (21), the plurality of cells (21) are arranged in N rows, there are (N-1) rows of gaps between the cells (21) in the N rows, and the reinforcing plate (3) is provided in at least one of the rows of gaps, and the foamed rubber layer of the reinforcing plate (3) is in close contact with the adjacent cells (21).

4. The battery pack according to claim 3, further comprising liquid cooling plates (4), wherein the liquid cooling plates (4) are provided in at least one row of gaps.

5. The battery pack according to claim 4, characterized in that the cell (21) is a cylindrical cell, and both the foamed rubber layer of the reinforcing plate (3) and the liquid cooling plate (4) are provided with a convex structure (31) toward the cell (21), the convex structure (31) extends between two adjacent cylindrical cells in the same row, and the convex structure (31) is in close contact with the cylindrical surface of the cylindrical cell.

6. The battery pack according to claim 4, characterized in that two adjacent rows of cells (21) are offset from each other, the gap is snake-shaped, and the foamed rubber layer, the glass cloth layer, and the liquid cooling plate (4) are all curved to conform to the shape of the snake-shaped gap.

7. The battery pack according to claim 4, characterized in that the liquid cooling plate (4) is installed in the gap of one of two adjacent rows of gaps, and the reinforcing plate (3) is installed in the gap of the other row.

8. The battery pack according to claim 1, wherein the cell pack (2) has a relief valve, the relief valve faces the bottom surface (12) of the case (1), the surface of the case (1) facing the bottom surface (12) is the top surface (11), the reinforcing plate (3) is provided on the side of the top surface (11) facing the cell pack (2), and / or the reinforcing plate (3) is provided on the side of the top surface (11) facing away from the cell pack (2).

9. The battery pack according to claim 8, characterized in that a mounting groove (111) is provided on the top surface (11) of the case (1), the reinforcing plate (3) is provided in the mounting groove (111), and when the reinforcing plate (3) is positioned on the side of the top surface (11) that is away from the cell pack (2), the foamed rubber layer of the reinforcing plate (3) is flush with the outer peripheral surface of the top surface (11) of the case (1).

10. The battery pack according to any one of claims 1 to 9, characterized in that three layers of glass cloth are provided.

11. The battery pack according to claim 1, characterized in that a group of relief through-holes (121) corresponding to the cell pack (2) is provided on the bottom surface (12) of the case (1).

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