Battery pack

Abstract

The utility model belongs to the technical field of battery packs, and discloses a battery pack. The battery pack comprises at least two batteries and a bottom plate, wherein the bottom plate can support the batteries. The bottom plate comprises a first area and a second area, the first area is at least partially overlapped with the battery, and the bottom plate comprises a first insulating layer, a second insulating layer and a third insulating layer positioned between the first insulating layer and the second insulating layer in the first area along the thickness direction of the bottom plate; the second area is at least partially not overlapped with the battery, and the bottom plate comprises a first insulating layer and a second insulating layer in the second area along the thickness direction of the bottom plate. According to the battery pack provided by the utility model, the insulation requirements of different positions on the bottom plate can be met regionally, so that a high-voltage circuit is protected, the electric shock risk of passengers and pedestrians is reduced, and the weight of the bottom plate is greatly reduced.

Description

Battery pack Technical Field

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

[0002] The battery pack includes an upper casing and a base plate, which can be fixedly connected and define an installation space. The battery cells, busbars and other structures can be fixedly installed in the installation space.

[0003] The insulation performance of the base plate is crucial. When an electrical connection is formed between the high-voltage circuits (cells, busbars) inside the battery pack and the base plate, two problems arise: first, it can easily lead to short circuits within the high-voltage circuits, resulting in thermal runaway and potential fire hazards; second, the base plate is in direct contact with the vehicle body or external environment, allowing high-voltage current to be conducted through the base plate to the vehicle body, potentially posing a contact risk to occupants and pedestrians. However, enhancing insulation performance often leads to a more complex base plate structure and increased weight, which is detrimental to the lightweight design of the battery pack.

[0004] Therefore, there is an urgent need for a battery pack to solve the aforementioned technical problems. Summary of the Invention

[0005] One objective of this invention is to provide a battery pack that offers both good insulation performance and low weight.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Battery pack, including:

[0008] At least two batteries;

[0009] A base plate supports at least two of the batteries; the base plate includes a first region and a second region, wherein:

[0010] The first region at least partially overlaps with the orthographic projection of the battery on the base plate. Within the first region, along the thickness direction of the base plate, the base plate includes a first insulating layer and a second insulating layer, and a third insulating layer located between the first insulating layer and the second insulating layer. The second region at least partially does not overlap with the orthographic projection of the battery on the base plate. Within the second region, along the thickness direction of the base plate, the base plate includes the first insulating layer and the second insulating layer.

[0011] The beneficial effects of the battery pack of this utility model are: the battery pack can meet the insulation requirements of different positions on the base plate in different areas, which not only protects the high voltage circuit, but also reduces the risk of electric shock to passengers and pedestrians, and greatly reduces the weight of the base plate and the battery pack. Attached Figure Description

[0012] Figure 1 is a top view of a base plate provided by this utility model;

[0013] Figure 2 is a cross-sectional view along the AA direction in Figure 1;

[0014] Figure 3 is a magnified view of part C in Figure 2;

[0015] Figure 4 is a top view of another type of base plate provided by this utility model;

[0016] Figure 5 is a cross-sectional view along the BB direction in Figure 1;

[0017] Figure 6 is a magnified view of part D in Figure 5;

[0018] Figure 7 is a perspective view of the base plate provided by this utility model;

[0019] Figure 8 is a schematic diagram of the installation of the bottom plate in this utility model.

[0020] In the picture:

[0021] 1. Base plate; 101. First area; 102. Second area; 11. First insulation layer; 12. Second insulation layer; 13. Third insulation layer; 14. Metal layer; 15. Groove; 16. Countersunk hole; 17. Mounting hole;

[0022] 2. Upper shell. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0024] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," "fixed," and "abutting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0027] The battery pack provided by this utility model is described below with reference to Figures 1 to 8.

[0028] As shown in Figure 1, this utility model provides a battery pack, which includes a battery and a base plate 1. Along a direction parallel to the base plate 1, i.e., perpendicular to the thickness direction of the base plate 1, the base plate 1 includes a first region 101 and a second region 102. The first region 101 is generally rectangular and accommodates the battery. The circumference of the first region 101 is set as the second region 102, as shown in Figures 2 and 3. In Figure 3, the portion to the left of the dashed line is the second region 102, and the portion to the right is the first region 101. The base plate 1 has a multi-layer structure, and the first region 101 and the second region 102 have different numbers of layers. Along the thickness direction of the base plate 1, the first region 101 has a first insulating layer 11 and a second insulating layer 12, and a third insulating layer 13 disposed between the first insulating layer 11 and the second insulating layer 12. Compared to the first region 101, the second region 102 does not have a third insulating layer 13, i.e., no third insulating layer 13 is disposed between the first insulating layer 11 and the second insulating layer 12.

[0029] Specifically, in this embodiment, both the first insulating layer 11 and the second insulating layer 12 are fiber-reinforced plastic structural components, such as glass fiber structural components, manufactured using a prepreg molding process. These fiber-reinforced plastic structural components have high strength and can be installed at the bottom of the battery pack to support or protect the batteries (which can be either cells or battery modules) within the pack. Simultaneously, the fiber-reinforced material has a low density, which helps reduce the overall weight of the battery pack, achieving a lightweight improvement effect.

[0030] The third insulating layer 13 is preferably made of mica sheet or a sheet doped with mica powder, which can provide excellent heat insulation and insulation performance. The first insulating layer 11 and the second insulating layer 12 are circumferentially fixedly connected, thereby fixing the third insulating layer 13 between the first insulating layer 11 and the second insulating layer 12. For example, two fiber-reinforced plastic sheets are joined together at their outer peripheral edges by hot pressing, where one fiber-reinforced plastic sheet is defined as the first insulating layer 11 and the other fiber-reinforced plastic sheet is defined as the second insulating layer 12. Before hot pressing, the mica sheet is placed between the two fiber-reinforced plastic sheets, such that along the thickness direction of the mica sheet, one side of the mica sheet is limited by the first insulating layer 11 and the other side is limited by the second insulating layer 12, and along a direction parallel to the mica sheet, the mica sheet is limited by the joint of the two fiber-reinforced plastic sheets, thereby fixing the mica sheet between the two fiber-reinforced plastic sheets.

[0031] It should be noted that since the batteries in the battery pack do not contact the entire area of ​​the base plate 1, only a portion of the base plate 1 has a high insulation requirement. Therefore, in this invention, the area with a high insulation requirement is defined as the first region 101, which at least partially overlaps with the orthographic projection of the battery on the base plate 1; the area with a low insulation requirement is defined as the second region 102, which at least partially does not overlap with the orthographic projection of the battery on the base plate 1. In the second region 102, the third insulating layer 13 can be omitted, thereby further reducing the weight of the entire base plate 1. Furthermore, in the second region 102, the connection strength between the first insulating layer 11 and the second insulating layer 12 can be further strengthened by hot-pressing two fiber-reinforced plastics together.

[0032] The base plate 1 provided in this utility model can meet the insulation requirements of different locations on the base plate 1 in sections, which not only protects the high-voltage circuit, but also reduces the risk of electric shock to occupants and pedestrians, and greatly reduces the weight of the base plate 1. Furthermore, when the third insulation layer 13 includes heat insulation material, the base plate 1 can also achieve better heat insulation, insulation and protection effects by only implementing the base plate 1 installation steps, which can meet the requirements of heat insulation, impact resistance and high structural strength, thus combining the functions of mica plate and base plate 1 in the prior art, and simplifying the battery pack assembly process and reducing the production cost of the battery pack.

[0033] Of course, in some embodiments, the first insulating layer 11 and the second insulating layer 12 can be directly connected by adhesive bonding, and the third insulating layer 13 can be fixed between the first insulating layer 11 and the second insulating layer 12 by adhesive bonding. Alternatively, a fiber-reinforced plastic board doped with mica powder can be used as the third insulating layer 13 and hot-pressed together with the other two fiber-reinforced plastic boards. Therefore, the connection method between the first insulating layer 11 and the second insulating layer 12 is not specifically limited in this utility model.

[0034] Optionally, the bond strength between the first insulating layer 11 and the second insulating layer 12 is k1, and the bond strength between the first insulating layer 11 and the third insulating layer 13 is k2, where k1 is greater than k2. That is, the first insulating layer 11 and the second insulating layer 12 have high cohesion at the joint, high tensile strength, and high shear strength, thus providing a better restraining effect on the third insulating layer 13. Specifically, the bond strength can be obtained by measuring the average peel strength. For example, in this embodiment, k1 is not less than 20 (N·mm) / mm and not greater than 120 (N·mm) / mm, such as peel strengths of 20 (N·mm) / mm, 40 (N·mm) / mm, 60 (N·mm) / mm, 80 (N·mm) / mm, 10 (N·mm) / mm, 120 (N·mm) / mm, etc., which ensures a strong connection between the first insulating layer 11 and the second insulating layer 12 without excessively high process costs. Similarly, in this embodiment, k2 is not less than 150 (N·mm) / mm and not greater than 350 (N·mm) / mm, such as peel strengths of 150 (N·mm) / mm, 200 (N·mm) / mm, 250 (N·mm) / mm, 300 (N·mm) / mm, 350 (N·mm) / mm, etc., which can ensure the strong connection between the first insulating layer 11 and the third insulating layer 13 without causing excessive process costs.

[0035] Referring again to Figures 1 and 3, preferably, the area of ​​the first region 101 is S1, the area of ​​the second region 102 is S2, and 0.6 ≤ S1 / S2 ≤ 18, for example, ratios of 0.6, 0.8, 1, 2, 4, 8, 10, etc. When S1 / S2 is less than 0.6, for example, 0.2, the proportion of the third insulating layer 13 to the total area of ​​the base plate 1 will be too small, resulting in poor overall insulation performance of the base plate 1, which is not conducive to setting more batteries in the battery pack. When S1 / S2 is greater than 18, for example, 20, the base plate 1 has a larger area of ​​the third insulating layer 13, which can improve the insulation performance and structural strength of the base plate 1. However, due to insufficient adhesion between the multilayer materials, the limiting ability of the third insulating layer 13 is poor, and the phenomenon of sliding and displacement of the third insulating layer 13 is prone to occur, resulting in a decrease in the overall structural strength of the base plate 1 and the insulation and heat insulation effect of the first region 101.

[0036] Furthermore, the area S1 of the first region 101 satisfies 0.6m 2 ≤S1≤4m 2 For example, 0.8m 2 1m 2 1.2m 2 1.6m 2 2m 2 2.6m 2 3m 2 The areas are equal. Furthermore, the area S2 of the second region 102 satisfies 0.2m². 2 ≤S2≤1.5m 2 For example, 0.3m 2 0.5m 2 0.7m 2 1m 2 1.3m 2 Equal area. When S1 is less than 0.6m 2 At times, for example, 0.4m 2 When S1 is greater than 4m, the area of ​​the third insulating layer 13 overlapping with the battery will be smaller, resulting in poor insulation performance; 2 For example, 6m 2 When S2 is less than 0.2m, it will result in poor adhesion between the first insulating layer 11 and the second insulating layer 12. 2 At times, for example, 0.1m 2 When S2 is greater than 1.5m, it results in a smaller direct bonding area between the first insulating layer 11 and the second insulating layer 12, leading to poorer adhesion between them. 2 For example, 2m 2 When this happens, it can lead to poor insulation performance.

[0037] It should be noted that the aforementioned first region 101 (or second region 102) can be either a continuous region or multiple regions spaced apart. As shown in Figure 1, in one embodiment, the first region 101 is a continuous region, while the second region 102 includes multiple independent regions. In this case, the area S2 of the second region 102 refers to the sum of the areas of the multiple independent regions. As shown in Figure 4, in another embodiment, the first region 101 includes multiple independent regions, while the second region 102 is a continuous region. In this case, the area S1 of the first region 101 refers to the sum of the areas of the multiple independent regions.

[0038] Referring again to Figure 3, in this embodiment, the thickness d1 of the first insulating layer 11 satisfies 0.2mm ≤ d1 ≤ 1.5mm, for example, 0.3mm, 0.4mm, 0.6mm, 0.8mm, 1mm, etc. Furthermore, the thickness d2 of the second insulating layer 12 satisfies 0.3mm ≤ d2 ≤ 3mm, for example, 0.3mm, 0.6mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, etc. Simultaneously, the thickness d3 of the third insulating layer 13 satisfies 0.1mm ≤ d3 ≤ 1.5mm, for example, 0.2mm, 0.6mm, 0.8mm, 1mm, 1.5mm, etc. This arrangement allows for a smaller overall thickness of the base plate 1, reducing the requirements for installation dimensions, while also ensuring that the insulation performance and structural strength of the base plate 1 meet the usage requirements. Preferably, the thickness d2 of the second insulating layer 12 is greater than the thickness d1 of the first insulating layer 11, and the second insulating layer 12 is positioned further away from the battery than the first insulating layer 11, so that the third insulating layer 13 and the battery can be better protected when facing an impact from the bottom of the battery pack.

[0039] Preferably, as shown in Figures 5 and 6, in some embodiments, the base plate 1 further includes a metal layer 14, which is disposed between the first insulating layer 11 and the second insulating layer 12. This metal layer 14 can further improve the structural strength of the base plate 1, enhance its support capacity for the internal structure of the battery pack, and improve its protective capacity for the internal structure of the battery pack, such as meeting the 300J ball impact resistance test requirement. The metal layer 14 can be made of metal plates such as steel plates or aluminum plates. Specifically, when manufacturing the base plate 1, the steel plate and the third insulating layer 13 can be placed between two fiber-reinforced plastic plates, and then the two fiber-reinforced plastic plates can be pressed together by hot pressing, which can limit and fix the steel plate and the third insulating layer 13, thereby forming the aforementioned base plate 1. Optionally, in some embodiments, an adhesive layer can also be provided between the fiber-reinforced plastic plates, the third insulating layer 13, and the steel plate, which can not only prevent misalignment of the plates during hot pressing, but also further improve the structural strength of the base plate 1 after molding.

[0040] Preferably, as shown in FIG6, the metal layer 14 is disposed between the third insulating layer 13 and the second insulating layer 12. Specifically, when assembling the base plate 1 into the battery pack, by selecting the installation direction of the base plate 1, it is ensured that the metal layer 14 is on the side of the third insulating layer 13 away from the battery. In this way, the metal layer 14 can not only provide a certain impact protection effect for the battery, but also provide impact protection effect for the third insulating layer 13, thereby ensuring the integrity of the third insulating layer 13 and ensuring the insulation performance of the base plate 1.

[0041] Furthermore, in this embodiment, the thickness d3 of the third insulating layer 13 satisfies 0.1mm ≤ d3 ≤ 1.5mm. Since a metal layer 14 is provided, a thinner third insulating layer 13 can be appropriately selected to meet the overall structural strength and insulation requirements of the base plate 1. For example, the thickness d3 can be set to 0.2mm, 0.3mm, etc. When the metal layer 14 is not provided, the thickness d3 of the third insulating layer 13 can be set according to a larger value among the aforementioned 0.1mm ≤ d3 ≤ 1.5mm, for example, 0.8mm, 1mm, 1.2mm, 1.5mm, etc.

[0042] It should be noted that in any of the above embodiments, when the third insulating layer 13 is made of a heat-insulating material or a composite material incorporating heat-insulating materials through doping, coating, or other methods, changes in its thickness will also lead to changes in its heat insulation performance. For example, when the thickness of the third insulating layer 13 increases, its structural strength, insulation performance, and heat insulation performance will all increase. Similarly, the first insulating layer 11 and the second insulating layer 12 can also be made of different materials with heat insulation performance, corrosion resistance, etc., as required, and this utility model does not make specific limitations in this regard.

[0043] Optionally, the base plate 1 is further provided with reinforcing ribs to further balance the structural strength and overall weight of the base plate 1. Exemplarily, in some embodiments, the base plate 1 has elongated or circular protrusions along its thickness direction, thus forming reinforcing ribs. In other embodiments, reinforcing ribs can also be provided in fiber-reinforced material or steel plate, thereby forming reinforcing ribs only in one or more layered structures within the base plate 1. The location of the reinforcing ribs is not specifically limited in this invention, as long as the base plate 1 achieves high structural strength with a relatively small overall weight.

[0044] As shown in Figure 6, the base plate 1 has a groove 15, which is recessed towards the side facing the second insulating layer 12. Specifically, the groove 15 is at least located in the first insulating layer 11, thereby ensuring a buffer space is formed between the battery and the base plate 1. This allows the base plate 1 to be cushioned and protected by deformation when impacted. Preferably, the depth of the groove 15 is not less than 1 mm and not more than 5 mm, for example, thicknesses of 1 mm, 1.3 mm, 1.8 mm, 2 mm, 3 mm, 4 mm, and 5 mm. When the depth of the groove 15 is less than 1 mm, the base plate will deform and come into contact with the battery even with a slight impact, resulting in weak cushioning protection. When the depth of the groove 15 is greater than 5 mm, it leads to a large waste of space within the battery pack, reducing space utilization.

[0045] As shown in Figure 7, the groove 15 has a mounting hole 17 at its opening, which can be connected to other parts of the battery pack via a threaded connector, so that the end face of the groove can abut against other parts of the battery pack structure.

[0046] Optionally, the thickness d4 of the metal layer 14 satisfies 0.2mm ≤ d4 ≤ 1.5mm, for example, 0.3mm, 0.4mm, 0.6mm, 1mm, 1.2mm, etc. When d4 is less than 0.2mm, for example, 0.1mm, it will result in poor structural strength and protection; when d4 is greater than 1.5mm, for example, 2mm, it will result in the overall weight of the base plate 1. Furthermore, when the aforementioned groove 15 is provided, since the groove 15 enhances the protective performance of the base plate 1, the thickness d4 of the metal layer 14 can be adaptively reduced, for example, set to no more than 1mm, thereby further achieving the effect of weight reduction.

[0047] As shown in Figures 6 and 7, in this embodiment, the base plate 1 is also provided with a countersunk hole 16. The countersunk hole 16 can be used to install threaded connectors, thereby fixing the middle part of the base plate 1 and the structural beam inside the battery pack, improving the structural strength of the entire battery pack. It is worth noting that since the area near the countersunk hole 16 is used to install threaded connectors, a third insulating layer 13 is not provided. Therefore, the third insulating layer 13 can be omitted within the preset circumferential range of the countersunk hole 16, that is, the preset circumferential range of the countersunk hole 16 is the second region 102.

[0048] As shown in Figure 8, the battery pack also includes an upper housing 2. The upper housing 2 and the base plate 1 are fixedly connected and define an installation space, in which the battery is fixedly installed. This battery pack can meet the insulation requirements of different locations on the base plate 1 in different areas, which not only protects the high-voltage circuit, but also reduces the risk of electric shock to occupants and pedestrians, and greatly reduces the weight of the base plate 1 and the battery pack.

[0049] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery pack, characterized in that, include: At least two batteries; The base plate supports at least two of the batteries. The base plate (1) includes a first region (101) and a second region (102), wherein: the first region (101) at least partially overlaps with the orthographic projection of the battery on the base plate (1), and within the first region (101), along the thickness direction of the base plate (1), the base plate (1) includes a first insulating layer (11) and a second insulating layer (12), and a third insulating layer (13) located between the first insulating layer (11) and the second insulating layer (12); the second region (102) at least partially does not overlap with the orthographic projection of the battery on the base plate (1), and within the second region (102), along the thickness direction of the base plate (1), the base plate (1) includes the first insulating layer (11) and the second insulating layer (12).

2. The battery pack according to claim 1, characterized in that, The bonding strength between the first insulating layer (11) and the second insulating layer (12) is k1, and the bonding strength between the first insulating layer (11) and the third insulating layer (13) is k2, and k1 is greater than k2.

3. The battery pack according to claim 2, characterized in that, The area of ​​the first region (101) is S1, the area of ​​the second region (102) is S2, and S1 and S2 satisfy: 0.6≤S1 / S2≤18.

4. The battery pack according to claim 3, characterized in that, The area S1 of the first region (101) satisfies: 0.6m 2 ≤S1≤4m 2 And the area S2 of the second region (102) satisfies: 0.2m 2 ≤S2≤1.5m 2 .

5. The battery pack according to claim 1, characterized in that, The thickness d1 of the first insulating layer (11) satisfies: 0.2mm≤d1≤1.5mm, the thickness d2 of the second insulating layer (12) satisfies: 0.3mm≤d2≤3mm, and the thickness d3 of the third insulating layer (13) satisfies: 0.1mm≤d3≤1.5mm.

6. The battery pack according to claim 1, characterized in that, The base plate (1) further includes a metal layer (14) disposed between the first insulating layer (11) and the second insulating layer (12).

7. The battery pack according to claim 6, characterized in that, The metal layer (14) is disposed between the third insulating layer (13) and the second insulating layer (12), and the metal layer (14) is located on the side of the third insulating layer (13) away from the battery.

8. The battery pack according to claim 7, characterized in that, The thickness d3 of the third insulating layer (13) satisfies: 0.1mm≤d3≤1.5mm.

9. The battery pack according to claim 1, characterized in that, The base plate (1) is provided with reinforcing ribs.

10. The battery pack according to claim 1, characterized in that, The base plate (1) is provided with a groove (15), which is recessed on the side facing the second insulating layer (12).

11. The battery pack according to claim 6, characterized in that, The thickness d4 of the metal layer (14) satisfies: 0.2mm≤d4≤1.5mm.

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