Bottom plate, battery pack and electric device

Abstract

The utility model provides a bottom plate, a battery pack and an electric device, the bottom plate is used for being connected with an upper box body of the battery pack, and the bottom plate comprises a first composite material layer, a second composite material layer and a metal layer located between the first composite material layer and the second composite material layer; at the edge of the bottom plate, the first composite material layer comprises a first extension part exceeding the metal layer, and the second composite material layer comprises a second extension part exceeding the metal layer; and a third composite material is arranged between the first extension part and the second extension part. The first composite material layer and the second composite material layer both exceed the metal layer, that is, the metal layer is only located in the middle area of the bottom plate, so that the battery monomers can be protected, the weight of the battery pack is reduced, and the energy density of the battery pack is improved. By arranging the third composite material, the thickness vacancy caused by the small metal layer at the edge of the bottom plate can be filled, so that the overall thickness of the bottom plate is more balanced, and meanwhile, the metal layer can be prevented from being corroded due to direct contact with the outside.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and specifically provides a base plate, a battery pack and an electrical device. Background Art

[0002] Due to their environmental advantages, new energy sources are rapidly developing across various industries, particularly in power-consuming devices such as electric vehicles. The battery system is a key component of electric vehicles, and the power battery pack (hereafter referred to as the battery pack) is a core component. Technological developments in power battery packs are significantly impacting the growth of the electric vehicle industry.

[0003] Energy density is one of the most important performance characteristics of a power battery pack. A high energy density battery pack can provide longer driving time. Low energy density can cause range anxiety, a significant concern for consumers and can seriously impact their acceptance of electric vehicles, especially pure electric vehicles. Therefore, increasing the energy density of power battery packs is a pressing technical challenge. Utility Model Content

[0004] In order to improve the energy density of the battery pack, the utility model provides a base plate for connecting to the upper box body of the battery pack, the base plate includes a first composite material layer, a second composite material layer and a metal layer located between the first composite material layer and the second composite material layer; at the edge of the base plate, the first composite material layer includes a first extension portion extending beyond the metal layer, and the second composite material layer includes a second extension portion extending beyond the metal layer; a third composite material is arranged between the first extension portion and the second extension portion.

[0005] Arranging the first and second composite material layers beyond the metal layer, meaning the metal layer is located only in the middle of the base plate, protects the battery cells within the battery pack. This also reduces the weight of the battery pack and increases its energy density compared to a scenario where the metal layer and the first and second composite material layers are the same size. Providing a third composite material between the first and second extensions fills the gap in thickness at the base plate's edge caused by the smaller metal layer, resulting in a more balanced overall base plate thickness. This also prevents the metal layer from being corroded by direct contact with the outside world.

[0006] In an optional technical solution of this embodiment, the third composite material is bonded to the first composite material layer and the second composite material layer, thereby preventing the third composite material from abnormally falling out of the base plate and making the overall structure of the base plate more stable.

[0007] In an optional technical solution of this embodiment, the distance L1 between the third composite material and the end of the metal layer satisfies: L1≤50mm. Setting L1 within the above numerical range can ensure the overall stability of the bottom plate and avoid large depressions.

[0008] In an optional technical solution of this embodiment, the distance L2 from the end of the metal layer to the end of the first extension satisfies the following condition: 40 mm ≤ L2 ≤ 120 mm. Setting L2 within this numerical range ensures that the metal layer is sufficiently large to provide good protection for the battery cells within the battery pack and reduce the risk of thermal runaway, while also preventing the metal layer from being too large and ensuring a high energy density and safety of the battery pack.

[0009] In the optional technical solution of this embodiment, the material of the above-mentioned first composite material layer includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber, the material of the above-mentioned second composite material layer includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber, and the material of the above-mentioned metal layer includes at least one of steel or aluminum.

[0010] In an optional technical solution of this embodiment, the metal layer is integrally formed or includes multiple metal plates.

[0011] In an optional technical solution of this embodiment, the bottom plate includes a first region and a second region. The first region surrounds the second region, the first region being used to connect to the upper case, and the second region being used to support the components within the battery pack. The second region is provided with a first protrusion extending along a first direction. The first protrusion extending along the first direction is provided in the second region of the bottom plate. The three-layer structure of the first composite material layer, the metal layer, and the second composite material layer together forms the first protrusion. Compared to a bottom plate with a flat second region, the bottom plate of the present invention has increased rigidity and stronger resistance to deformation, thereby better protecting the battery cells within the case and further improving the safety of the battery pack.

[0012] In an optional technical solution of this embodiment, along the second direction, the depth H1 of the first protrusion satisfies: 1 mm ≤ H1 ≤ 15 mm.

[0013] In an optional technical solution of this embodiment, a second protrusion extending along a third direction is further provided on the second area.

[0014] In an optional technical solution of this embodiment, the first composite material layer is located on the inner side of the bottom plate, and the second composite material layer is located on the outer side of the bottom plate. The thickness of the first composite material layer is less than that of the second composite material layer. The first composite material layer located on the inner side serves as an insulator, and the second composite material layer located on the outer side serves as an impact protector and external corrosion resistance. While the total thickness of the bottom plate remains unchanged, reducing the thickness of the first composite material layer located on the inner side and increasing the thickness of the second composite material layer located on the outer side can enhance the impact resistance and corrosion resistance of the outer side, thereby better protecting the battery cells in the box and improving the safety of the battery pack.

[0015] The utility model also provides a battery pack, which includes a box body and a battery cell arranged in the box body, and the box body includes an upper box body and the above-mentioned bottom plate.

[0016] The utility model also provides an electrical device, comprising the above-mentioned battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a battery pack 100;

[0018] Figure 2 is a schematic diagram of an embodiment of a base plate 400;

[0019] Figure 3 and Figure 4 are cross-sectional views of two embodiments of the base plate 400;

[0020] Figure 5-7 Schematic diagrams of three embodiments of the base plate 400;

[0021] Figure 8 for Figure 7 a cross-sectional view of the base plate 400;

[0022] Reference numerals

[0023] Battery pack 100;

[0024] Battery cell 200;

[0025] Upper box 300;

[0026] Base plate 400;

[0027] A first composite material layer 410 , a second composite material layer 420 , a metal layer 430 , a third composite material 440 , and a spacing region 450 ;

[0028] First area 460, second area 470;

[0029] a first protrusion 471;

[0030] through hole 431;

[0031] a first extension portion 411; DETAILED DESCRIPTION

[0032] The following describes optional embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "distance", "width", "thickness", "up", "down", "left", "right", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0034] In the description of this utility model, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. In the description of this utility model, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0035] Furthermore, it should be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0036] like Figure 1 As shown, the battery pack 100 includes a box body and a plurality of battery cells 200 disposed therein. The box body includes an upper box body 300 and a bottom plate 400 connected to the upper box body 300. The bottom plate 400 mainly supports the battery cells 200 and other components in the box body.

[0037] In order to improve the safety of the battery pack 100, as Figure 2-8As shown, the present application provides a base plate 400, which includes a first composite material layer 410, a second composite material layer 420, and a metal layer 430 located between the first composite material layer 410 and the second composite material layer 420. At the edge of the base plate 400, the first composite material layer 410 includes a first extension portion 411 extending beyond the metal layer 430, and the second composite material layer 420 includes a second extension portion 421 extending beyond the metal layer 430; a third composite material 440 is provided between the first extension portion 411 and the second extension portion 421. By arranging that both the first composite material layer 410 and the second composite material layer 420 extend beyond the metal layer 430, that is, the metal layer 430 is only located in the middle area of ​​the base plate 400, the battery cells 200 in the battery pack 100 can be protected. At the same time, compared with the case where the metal layer and the first / second composite material layers are the same size, the weight of the battery pack is reduced and the energy density of the battery pack is improved. The third composite material 440 is provided between the first extension portion 411 and the second extension portion 421 to fill the thickness gap at the edge of the bottom plate 400 caused by the small size of the metal layer 430, so that the overall thickness of the bottom plate 400 is more balanced, and at the same time, the metal layer 430 is prevented from being directly exposed to the outside world and corroded.

[0038] In an optional embodiment of the present invention, the battery pack 100 further includes a thermal management component, which includes components such as a cold plate (not shown) and a water pipe. The cold plate is used to perform heat exchange with the battery cell 200, thereby performing thermal management on the battery cell 200 and preventing the battery cell 200 from being overcooled or overheated. Specifically, a channel may be provided in the cold plate, and the channel is used to inject a cooling medium. Specifically, the cold plate may be provided at the bottom of a plurality of battery cells 200, and the plurality of battery cells 200 are bonded to the cold plate by thermally conductive adhesive. A buffer (not shown) may be provided between the cold plate and the bottom plate 400. When the battery pack 100 is impacted, the buffer may absorb the impact force to prevent the battery cell 200 and the cold plate from being damaged. Alternatively, the cold plate may also be provided between two adjacent battery cells 200, and the battery cell 200 is bonded to the cold plate by thermally conductive adhesive.

[0039] In an optional embodiment of the present invention, as Figure 2 As shown, metal layer 430 is provided with through-holes 431, and first composite material layer 410 and second composite material layer 420 are bonded together at the locations of through-holes 431. The provision of through-holes 431 in metal layer 430 can increase the bonding area between first composite material layer 410 and second composite material layer 420, thereby improving the stability of the three-layer structure of base plate 400. Specifically, first composite material layer 410 and second composite material layer 420 can be bonded together at through-holes 431 using an adhesive, hot-melt bonding, or by providing an adhesive in the materials of first composite material layer 410 and second composite material layer 420 to impart self-adhesiveness, thereby bonding them together at through-holes 431. Figure 4Only two through holes 431 are provided for exemplary purposes. The number, size and shape of the through holes 431 can be adjusted according to actual needs, and the present invention does not impose any restrictions thereon.

[0040] In an optional embodiment of the present invention, the third composite material 440 is bonded to the first composite material layer 410 and the second composite material layer 420. This prevents the third composite material 440 from being accidentally released from the base plate 400, thereby further stabilizing the overall structure of the base plate 400. The third composite material 440 can be bonded to the first composite material layer 410 and the second composite material layer 420 using an adhesive, hot melt bonding, or by adding an adhesive to the first composite material layer 410, the second composite material layer 420, and the third composite material to make them self-adhesive, thereby bonding them to each other.

[0041] In an optional embodiment of the present invention, as Figure 3 and Figure 4 As shown, the distance L1 between the third composite material 440 and the end of the metal layer 430 satisfies: L1≤50mm. Setting L1 within the above numerical range can ensure the overall stability of the bottom plate 400 and avoid large depressions. Figure 3 The figure shows that the distance L1 between the metal layer 430 and the third composite material 440 is zero. The third composite material 440 fills the gap at the end of the metal layer 430, making the overall thickness of the bottom plate 400 more balanced and the structure more stable. Optionally, the third composite material 440 can be bonded to the metal layer 430. Figure 4 FIG. 4 shows a case where the distance L1 between the end of the third composite material 440 and the metal layer 430 is greater than zero, that is, a spacing region 450 is provided between the metal layer 430 and the third composite material 440. Figure 3 and Figure 4 As shown, the position of the edge of the metal layer 430 is not limited and can be adjusted according to actual needs.

[0042] In an optional embodiment of the present invention, the distance L2 from the end of the metal layer 430 to the end of the first extension 411 satisfies the following: 40 mm ≤ L2 ≤ 120 mm. Setting L2 within this numerical range ensures that the metal layer 430 is sufficiently large to provide good protection for the battery cells 200 within the battery pack 100, reducing the risk of thermal runaway. It also prevents the metal layer 430 from being too large, while also ensuring a high energy density and safety for the battery pack 100.

[0043] In an optional embodiment of the present invention, the material of the first composite material layer 410 includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber, the material of the second composite material layer 420 includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber, and the material of the metal layer 430 includes at least one of steel or aluminum. The metal layer 430 can be integrally formed or can include multiple metal plates. The first composite material layer 410 and the second composite material layer 420 can be reinforced thermoplastic composite materials with a base material such as polypropylene, nylon, nylon 66, etc. mixed with at least one of the above-mentioned continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber. Of course, the first composite material layer 410 and the second composite material layer 420 can also be reinforced thermosetting composite materials with a base material such as epoxy resin, polyurethane, etc. mixed with at least one of the above-mentioned continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber.

[0044] In an optional embodiment of the present invention, as Figure 5 As shown, the bottom plate 400 includes a first region 460 and a second region. The first region 460 surrounds the second region. The first region 460 is used to connect to the upper case 300, while the second region is used to support the components within the battery pack 100. A first protrusion 470 extending along the first direction (parallel to the Y axis) is provided on the second region. Specifically, the first protrusion 470 is formed by punching a portion of the second region of the bottom plate in the second direction (parallel to the Z axis). The first protrusion 470 extending along the first direction is provided in the second region of the bottom plate 400. The three-layer structure of the first composite material layer 410, the metal layer 430, and the second composite material layer 420 together form the first protrusion 470. Compared to bottom plates with a flat second region, the bottom plate of the present invention has increased rigidity and stronger resistance to deformation, thereby better protecting the battery cells 200 within the case and further enhancing the safety of the battery pack 100. In this embodiment, the first protrusion 470 extends along the first direction to the first region 460, but the first protrusion can also be provided only in the second region. Along the second direction, the depth H1 of the first protrusion satisfies: 1 mm ≤ H1 ≤ 15 mm. Specifically, H1 can be 1 mm, 2 mm, 3 mm, 5 mm, 10 mm, or 15 mm.

[0045] In an optional embodiment of the present invention, as Figure 6As shown, the second region is also provided with a second protrusion 480 extending along a third direction (parallel to the X-axis). In this embodiment, the base plate 400 is provided with a plurality of first protrusions 470 and a plurality of second protrusions 480. The plurality of first protrusions 470 and a plurality of second protrusions 480 are interwoven into a grid pattern, which can function similarly to the crossbeams and longitudinal beams in a traditional battery pack, further increasing the rigidity of the base plate and its ability to resist deformation. It is understood that along the second direction, the first protrusions 470 and the second protrusions 480 can be arranged in either direction of the Z-axis.

[0046] In an optional embodiment of the present invention, as Figure 7 As shown, the first composite material layer 410 is located on the inner side of the bottom plate 400, and the second composite material layer 420 is located on the outer side of the bottom plate 400. The thickness of the first composite material layer 410 is less than that of the second composite material layer 420. The first composite material layer 410 located on the inner side serves as an insulator, while the second composite material layer 420 located on the outer side serves as an impact and corrosion resistant layer. While the total thickness of the bottom plate 400 remains unchanged, reducing the thickness of the first composite material layer 410 located on the inner side and increasing the thickness of the second composite material layer 420 located on the outer side can enhance the impact resistance and corrosion resistance of the outer side, thereby better protecting the battery cells 200 in the box and improving the safety of the battery pack 100.

[0047] In an optional embodiment of the present invention, as Figure 8 As shown, the thickness H2 of the first composite material layer 410 and the thickness H3 of the second composite material layer 420 satisfy the following conditions: 0.2mm≤H2≤0.8mm, 0.8mm≤H3≤1.2mm. Setting H2 within the above numerical range ensures that the first composite material layer 410, located on the inside, has good insulation properties while preventing excessive thickness of the first composite material layer 410 from reducing the energy density of the battery pack 100. Setting H3 within the above numerical range ensures that the second composite material layer 420, located on the outside, has good resistance to external corrosion and impact while preventing excessive thickness of the second composite material layer 420 from reducing the energy density of the battery pack 100. Specifically, H2 can be 0.2mm, 0.3mm, 0.5mm, 0.6mm, or 0.8mm, and H3 can be 0.8mm, 0.9mm, 1mm, 1.1mm, or 1.2mm. In an optional embodiment of the present invention, the thickness H4 of the metal layer 430 satisfies the following conditions: 0.6mm≤H4≤1.2mm. Specifically, H3 can be 0.6mm, 0.7mm, 0.8mm, 1mm, or 1.2mm.

[0048] The present invention also provides an electrical device including a battery pack according to an optional embodiment. The electrical device may include, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. The spacecraft may include airplanes, rockets, space shuttles, and spacecraft.

[0049] Thus far, the technical solutions of the present invention have been described in conjunction with the optional embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A bottom plate for connecting to the upper box of a battery pack, characterized in that: The bottom plate includes a first composite material layer, a second composite material layer, and a metal layer located between the first composite material layer and the second composite material layer; At an edge of the bottom plate, the first composite material layer includes a first extension beyond the metal layer, and the second composite material layer includes a second extension beyond the metal layer; A third composite material is disposed between the first extension portion and the second extension portion.

2. The base plate according to claim 1, wherein: The third composite material is bonded to the first composite material layer and the second composite material layer.

3. The base plate according to claim 1, wherein: A distance L1 between the third composite material and an end portion of the metal layer satisfies: L1≤50 mm.

4. The base plate according to claim 1, wherein: A distance L2 from an end portion of the metal layer to an end portion of the first extending portion satisfies the following: 40 mm ≤ L2 ≤ 120 mm.

5. The base plate according to claim 1, wherein: The material of the first composite material layer includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber; the material of the second composite material layer includes at least one of continuous or discontinuous glass fiber, aramid fiber, basalt fiber and carbon fiber; the material of the metal layer includes at least one of steel or aluminum.

6. The base plate according to claim 1, wherein The metal layer is integrally formed or includes a plurality of metal plates.

7. The base plate according to claim 1, wherein: The bottom plate includes a first area and a second area, the first area surrounds the second area, the first area is used to connect with the upper box, and the second area is used to support the components in the battery pack; A first protrusion extending along a first direction is provided on the second area.

8. The base plate according to claim 7, wherein: Along the second direction, the depth H1 of the first protrusion satisfies: 1 mm ≤ H1 ≤ 15 mm.

9. The base plate according to claim 7, wherein: The second area is further provided with a second protrusion extending along the third direction.

10. The base plate according to claim 1, wherein The first composite material layer is located on the inner side of the bottom plate, the second composite material layer is located on the outer side of the bottom plate, and the thickness of the first composite material layer is smaller than that of the second composite material layer.

11. A battery pack, characterized in that: The invention comprises a box body and a battery cell arranged in the box body, wherein the box body comprises an upper box body and a bottom plate, and the bottom plate is the bottom plate according to any one of claims 1 to 10.

12. An electrical device, characterized in that: Including the battery pack according to claim 11.

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