Battery pack and manufacturing method thereof, and vehicle

Abstract

The present invention provides a battery pack and a manufacturing method thereof, and a vehicle. The battery pack includes a tray, a frame, a support structure, and a battery cell. The frame encloses an installation space that matches the shape of the tray, so that the frame is fixed to the periphery of the tray so that the frame abuts against the outer surface of the side wall of the tray, the bottom surface of the support structure is fixed to the upper surface of the bottom wall of the tray, and the outer periphery of the support structure is fixed to the inner surface of the side wall of the tray, so that the loading space of the tray is divided into a plurality of positioning cavities for placing the battery cells. The battery pack provided by the present invention has good strength and rigidity, and can well meet the requirements of lightweight, reduce energy consumption, and improve safety.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle batteries, and in particular to a battery pack, a method for manufacturing a battery pack, and a vehicle having a battery pack. Background Art

[0002] The power battery box is the carrier of the power battery of new energy vehicles. It consists of an upper cover and a lower shell. It is mainly used to protect the lithium battery from damage when it is hit or squeezed by the outside world. As the carrier of the battery module, the battery box plays a key role in the safe operation and protection of the battery module.

[0003] There are currently two main types of battery packs in the market: aluminum alloy and steel. Aluminum alloy benefits from its excellent processability, corrosion resistance and recyclability, making the application of aluminum alloy materials in power battery box products the current mainstream. Three different types of aluminum materials, aluminum plates, extruded aluminum and cast aluminum, have been used in batches in different projects. However, with the decline in new energy subsidies and the complete withdrawal policy by the end of 2022, the high cost of aluminum alloy raw materials has become a huge disadvantage. In addition, the preparation of aluminum alloy materials is not conducive to the needs of energy conservation and environmental protection. After collision and extrusion, the properties of aluminum alloy materials themselves make it face greater problems in dealing with combustion-hindering working conditions. Although ordinary steel shells have high strength and can well protect the safety of power batteries, their own weight is large, resulting in a large curb weight of the entire vehicle, which affects the battery life and energy consumption of electric vehicles. Summary of the invention

[0004] In view of the above, the present invention provides a battery pack, a method for manufacturing a battery pack, and a vehicle having a battery pack, which have good strength and rigidity, and can well meet the requirements of lightweighting, reduce energy consumption, and improve safety.

[0005] The technical solution of the present invention:

[0006] The present invention provides a battery pack, including a tray, a frame, a support structure and a battery cell. The frame encloses an installation space that is compatible with the shape of the tray, so that the frame is fixed to the periphery of the tray so that the frame abuts against the outer surface of the side wall of the tray, the bottom surface of the support structure is fixed to the upper surface of the bottom wall of the tray, and the outer periphery of the support structure is fixed to the inner surface of the side wall of the tray, so that the loading space of the tray is divided into multiple positioning cavities for placing battery cells.

[0007] Furthermore, the pallet includes side walls, a bottom wall and a flange outer edge. The bottom side of the side wall is enclosed around the bottom wall to form a loading space for the pallet. The flange outer edge is enclosed around the top side of the side wall. The side wall, bottom wall and flange outer edge are made of steel plates by hot forming and stamping.

[0008] Furthermore, a triangular surface is formed at the junction between the side wall corner and the bottom wall.

[0009] Further, when the side wall draft angle β is 8°, the triangular surface draft angle γ ranges from 35° to 40°; when the side wall draft angle β is 12°, the triangular surface draft angle γ ranges from 30° to 40°.

[0010] Furthermore, the frame includes a first welding wall, an inner supporting wall, a lower outer wall, a lower supporting wall, an inner wall, an upper supporting wall, an upper outer wall and a second welding wall which are connected in sequence in a "sun" shaped cross-section structure. The first welding wall is welded and fixed to the inner surface of the inner wall, and the second welding wall is welded to the inner supporting wall, so that the lower outer wall and the upper outer wall together form the outer wall of the frame, and the inner supporting wall is supported between the outer wall and the inner wall of the frame.

[0011] Furthermore, the support structure includes a cross beam and a longitudinal beam, the bottom surfaces of the cross beam and the longitudinal beam are welded to the upper surface of the bottom wall, and the two ends of the cross beam and the longitudinal beam are welded to the inner surface of the side wall.

[0012] Furthermore, it also includes a liquid cooling plate. The liquid cooling plate is pressed from a steel plate to form a container structure with a cooling groove. The cooling groove extends in a zigzag manner and covers the entire liquid cooling plate. Both ends of the cooling groove penetrate the edge of the liquid cooling plate to form a liquid inlet hole and a liquid outlet hole, respectively. The liquid cooling plate is seal-welded to the lower surface of the bottom wall of the tray. The bottom wall is formed with convex ribs corresponding to the cooling grooves. The convex ribs protrude downward into the cooling grooves. The convex ribs cooperate with the cooling grooves to form channels for the circulation of coolant.

[0013] Furthermore, it also includes a bottom reinforcement member, both ends of which are fixed to the frame to support the liquid cooling plate and the tray.

[0014] The present invention also provides a method for manufacturing a battery pack, comprising the following steps:

[0015] First, the thermoformed tray obtained by stamping according to the process parameters is connected to the liquid cooling plate by a roll welding process, and the tray is welded to the frame;

[0016] The supporting structure is then welded into the tray;

[0017] Then, the bottom reinforcement member and the bottom shield are fixed to the frame, and the bottom reinforcement member and the bottom shield are welded together;

[0018] Place the heating film in the tray or stick the heating film on the bottom of the battery cell, and then place the battery cells into the positioning cavity one by one;

[0019] Use bolts to fix the top cover to the frame and support structure to complete the overall assembly of the battery pack.

[0020] The present invention also provides a vehicle, comprising the above-mentioned battery pack.

[0021] Beneficial effects of the present invention:

[0022] The battery pack provided by the present invention improves the strength and rigidity of the battery pack by setting a frame on the outer periphery of the tray to abut against the outer surface of the tray side wall, and setting a support structure inside the tray to abut against the inner surface of the tray side wall and the upper surface of the tray. The tray side wall is clamped by the frame and the support structure, and cooperates with the bottom wall of the tray under the support of the support structure, so as to meet the lightweight requirements, reduce energy consumption, and improve safety. The loading space of the tray is divided into multiple positioning cavities for placing the battery cells through the support structure, which can effectively protect the battery cells, meet the different requirements of various extrusion, collision and bottom intrusion working conditions, and further improve the safety and reliability of the battery pack.

[0023] The battery pack manufacturing method has reasonable assembly steps and is easy to operate, which is beneficial to improving the production efficiency and product quality of the battery pack.

[0024] The preferred embodiments of the present invention and their beneficial effects will be further described in detail in conjunction with specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but should not constitute a limitation of the present invention.

[0026] Figure 1 A partial assembly diagram of the battery pack of the present invention;

[0027] Figure 2 A partial exploded view of the battery pack of the present invention;

[0028] Figure 3 It is a three-dimensional diagram of an existing rounded square tray;

[0029] Figure 4 for Figure 3 Partial cross-section along line AA;

[0030] Figure 5 A three-dimensional diagram of a triangular square tray of the present invention;

[0031] Figure 6 for Figure 5 The local section along line BB;

[0032] Figure 7 is a cross-sectional view of the frame of the battery pack of the present invention;

[0033] Figure 8 This is an overall assembly diagram of the battery pack of the present invention;

[0034] Fig. 9 It is an overall exploded view of the battery pack of the present invention;

[0035] Fig.10 is a cross-sectional view of a battery pack of the present invention;

[0036] Fig.11 for Fig.10 A partial enlarged view of .

[0037] Explanation of the accompanying drawings: tray 1, frame 2, supporting structure 3, side wall 11, bottom wall 12, positioning cavity 10, flange outer edge 13, triangular surface 14, side wall draft angle α, side wall draft angle β, triangular surface draft angle γ, first welding wall 21, inner supporting wall 22, lower outer wall 23, lower supporting wall 24, inner wall 25, upper supporting wall 26, upper outer wall 27, second welding wall 28, groove 29, lifting ear 20, cross beam 31, longitudinal beam 32, liquid cooling plate 4, cooling groove 41, liquid inlet hole 42, liquid outlet hole 43, convex rib 15, bottom reinforcement 5, bottom shield 6, top cover 7. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0039] See also Figure 1 and Figure 2 The present invention provides a battery pack, including a tray 1, a frame 2, a support structure 3 and a battery cell. The frame 2 encloses an installation space that matches the shape of the tray 1, so that the frame 2 is fixed to the periphery of the tray 1, so that the frame 2 abuts against the outer surface of the side wall 11 of the tray 1. The bottom surface of the support structure 3 is fixed to the upper surface of the bottom wall 12 of the tray 1, and the outer periphery of the support structure 3 is fixed to the inner surface of the side wall 11 of the tray 1, so as to divide the loading space of the tray 1 into a plurality of positioning cavities 10 for placing the battery cells.

[0040] The battery pack provided by the present invention has a frame 2 disposed on the outer periphery of the tray 1 to abut against the outer surface of the side wall of the tray 1, and a support structure 3 disposed inside the tray 1 to abut against the inner surface of the side wall of the tray 1 and the upper surface of the tray 1. The side wall of the tray 1 is clamped by the frame 2 and the support structure 3, and the bottom wall 12 of the tray 1 is supported by the support structure 3, thereby improving the strength and rigidity of the battery pack, meeting the lightweight requirements, reducing energy consumption, and improving safety. The loading space of the tray 1 is divided into a plurality of positioning cavities 10 for placing the battery cells by the support structure 3, which can effectively protect the battery cells, meet the different requirements of various extrusion, collision and bottom intrusion working conditions, and further improve the safety and reliability of the battery pack.

[0041] In this embodiment, the pallet 1 includes a side wall 11, a bottom wall 12 and a flange outer edge 13. The bottom side of the side wall 11 is surrounded by the periphery of the bottom wall 12 to form a loading space for the pallet 1. The flange outer edge 13 is surrounded by the periphery of the top side of the side wall 11. The side wall 11, the bottom wall 12 and the flange outer edge 13 are made of steel plates by hot forming and stamping. Optionally, the flange outer edge 13 fixes the pallet 1 to the frame 2 by bolts, but is not limited to this. The flange outer edge 13 can also fix the pallet 1 to the frame 2 by riveting or welding.

[0042] Since the tray 1 is made of steel plates by hot stamping, it is inevitable to consider the forming properties of the material during the stamping process. In order to facilitate the placement of more battery cells and improve the energy density of the battery system, the larger the effective volume of the tray 1, the better. At the same time, the tray 1 should have good forming properties. The tray 1 was analyzed using forming analysis software, and it was found that the junction between the corner of the side wall 11 and the bottom wall 12 is most likely to crack and wrinkle during forming. In order to ensure that the material thinning rate at each position of the junction between the corner of the side wall 11 and the bottom wall 12 can meet the design requirements during material forming without sacrificing the effective volume of the tray 1, the present invention proposes for the first time to design a triangular surface 14 at the junction between the corner of the side wall 11 and the bottom wall 12, and analyzes a reasonable range. Please refer to Figures 3 to 6 The battery pack tray of the present invention is hexagonal in shape. The hexagonal tray and the square tray with triangular surface design have the same technical effect. For the convenience of comparative analysis, the square tray is taken as an example for explanation, as follows:

[0043] In this embodiment, the basic parameters of the square tray are as follows:

[0044] Pallet depth mm Flange outer edge size mm*mm Material thickness(mm) R1(mm) R2(mm) 120 1210*1746 1.0 20 15

[0045] Table 1 above shows the basic parameters of the pallet model established by the simulation analysis of the present invention. In order to more intuitively compare the advantages and disadvantages of the two pallet solutions, it is necessary to design their key parameters and conduct corresponding analysis, as follows:

[0046] Table 2 below is a simulation analysis of existing rounded corner design solutions:

[0047] Serial number Side wall draft angle α° Side wall angle radius mm Effective area m^2 Maximum thinning rate % 1 8 300 1.300 14.2 2 12 225 1.399 14.7 3 8 150 1.511 25.3 4 8 200 1.439 19.6

[0048] Table 3 below is a simulation analysis of the triangular surface design scheme of the present invention:

[0049]

[0050]

[0051] From the comparative analysis results of Table 2 and Table 3, we can see that:

[0052] Using the rounded corner design, when the side wall draft angle α is 8° and the side wall angle radius is ≤200mm, the maximum thinning rate is greater than the threshold of 15%. Therefore, although the effective area is increased, the forming performance cannot be met; when the side wall draft angle α is 12°, the side wall angle radius is 225mm, the effective area does not increase significantly, but the thinning rate is close to the critical value of 15%.

[0053] For the triangular surface design of the present invention, when the side wall draft angle β is 8° and the triangular surface draft angle γ is 35°, the maximum thinning rate is 14.1%, which meets the design requirements, and the effective area is significantly increased compared with the rounded corner design; however, when the triangular surface draft angle γ≤30°, the effective area does not increase significantly, and the maximum thinning rate exceeds the critical value of 15%, which poses a risk of molding cracking.

[0054] In addition, when the side wall draft angle β is 12° and the triangular surface draft angle γ ≥ 30°, the maximum thinning rate is less than the critical value of 15%, which meets the design requirements, and the effective area is also significantly increased compared with the rounded corner design scheme; however, when the triangular surface draft angle γ ≤ 25°, the effective area does not increase significantly, and the maximum thinning rate exceeds the critical value of 15%, which poses a risk of molding cracking.

[0055] Therefore, when the triangular surface design scheme is defined, when the side wall draft angle β is 8°, the triangular surface draft angle γ ranges from 35° to 40°; when the side wall draft angle β is 12°, the triangular surface draft angle γ ranges from 30° to 40°.

[0056] Definition of effective area: horizontal area at the bottom of the tray, the area enclosed by the midpoints of the arc of the tray's rounded corner area or the midpoints of the edges of the triangular faces, that is, the area of ​​the dotted rectangle in the figure is the effective area. Since the outer edge dimensions of the designed tray 1 are the same, the depth of the tray 1 is also the same, but the effective areas of the bottom of the tray 1 corresponding to different design schemes are different, resulting in certain differences in effective volume.

[0057] The raw material used for the steel battery pack designed by the present invention is a hot-formed steel matrix, and the matrix composition (mass percentage wt%) is C: 0.1-0.5; Si: 0.1-0.5; Mn: 0.5-2.0; P≤0.01; S≤0.01; micro-alloying elements are added as Ti, Nb, V, Ni, Mo and other alloying elements or any combination thereof, and Ti+Nb+V+Ni+Mo≤1, and the rest are Fe and unavoidable impurities.

[0058] The thickness of the steel plate used to press the tray 1 ranges from 0.5 to 1.5 mm, and the surface state of the steel is Al-Si coating, because the Al-Si coating has a significantly better effect of resisting the corrosion of the coolant than other coated products or uncoated products.

[0059] The tray preparation process is: blanking → heating → transfer → stamping → pressure holding quenching → laser cutting → finished tray.

[0060] The hot forming heating process is to heat at 870 - 950 °C for a holding time of 2 - 10 min. After heating, the sheet is transferred to the press die, followed by stamping and closing the die, and maintaining pressure in the die for a certain period of time. The pressure holding time is 5 - 20 s. The formed part is transferred to a laser cutting machine for laser trimming. For the tray after hot forming, its mechanical properties are: Rp0.2 ≥ 950 MPa; Rm ≥ 1350 MPa; A80 ≥ 5%.

[0061] At the junction between the corner of the side wall 11 and the bottom wall 12 of the tray 1 of the present invention, a triangular surface 14 is formed. When the draft angle β of the side wall is 8°, the draft angle γ of the triangular surface ranges from ≥ 35°; when the draft angle β of the side wall is 12°, the draft angle γ of the triangular surface ranges from ≥ 30°. In this way, the technical possibility of using a hot - formed steel tray is realized, and the contradictory relationship between the forming performance and the effective volume of the traditional steel tray is solved. Using the tray solution of the present invention not only ensures that the steel tray has a high effective volume, but also ensures good forming performance during the stamping process. Compared with traditional aluminum alloy or mild steel materials, using hot - formed steel materials, the strength of the tray is greatly improved, thereby enhancing the ability of the tray to resist the intrusion of foreign objects at the bottom and improving the safety and reliability of the battery pack.

[0062] Please refer to Figure 7 , in this embodiment, the frame 2 is formed by rolling a steel plate. The frame 2 includes a first welding wall 21, an inner support wall 22, a lower outer wall 23, a lower support wall 24, an inner wall 25, an upper support wall 26, an upper outer wall 27, and a second welding wall 28 that are sequentially connected in a "day" - shaped cross - section structure. The first welding wall 21 is welded and fixed to the inner surface of the inner wall 25, and the second welding wall 28 is welded to the inner support wall 22, so that the lower outer wall 23 and the upper outer wall 27 together form the outer wall of the frame 2, and the inner support wall 22 is supported between the outer wall of the frame 2 and the inner wall 25. Optionally, grooves 29 are formed on both the lower outer wall 23 and the upper outer wall 27 to further improve the structural strength and rigidity of the frame 2. The side wall 11 of the tray 1 abuts against the inner wall 25, and the flange outer edge 13 of the tray 1 is fixed to the upper support wall 26. After analysis and verification, the frame 2 with a "day" - shaped cross - section structure can meet strict extrusion and collision conditions. Under the condition of ensuring production efficiency, it has low requirements for the rolling die, and has good strength and rigidity, which can well protect the inside of the battery pack and further improve the safety and reliability of the battery pack. As Figure 1 shown, in order to facilitate assembly, a plurality of lifting lugs 20 are fixed on the outer wall of the frame 2.

[0063] Please refer to Figure 1 and Figure 2In this embodiment, the support structure 3 includes a crossbeam 31 and a longitudinal beam 32. The bottom surfaces of the crossbeam 31 and the longitudinal beam 32 are welded to the upper surface of the bottom wall 12 of the pallet 1. Both ends of the crossbeam 31 and the longitudinal beam 32 are welded to the inner surface of the side wall 11 of the pallet 1. The longitudinal beam 32 is arranged perpendicular to the crossbeam 31 to divide the loading space of the pallet 1 into a plurality of positioning cavities 10 for placing the power supply cores. It can be understood that the support structure 3 is not limited to the above-mentioned structural form. For example, the support structure 3 can also be arranged with only the crossbeam 31 or only the longitudinal beam 32. Optionally, the crossbeam 31 and the longitudinal beam 32 can be pressed into a "J"-shaped cross-sectional structure using steel plates.

[0064] See also Figure 8 and Fig.11 In this embodiment, the battery pack of the present invention further includes a liquid cooling plate 4. The liquid cooling plate 4 is pressed from a steel plate into a container structure having a cooling groove 41. The cooling groove 41 extends in a zigzag manner and covers the entire liquid cooling plate 4. Both ends of the cooling groove 41 penetrate the edge of the liquid cooling plate 4 to form a liquid inlet 42 and a liquid outlet 43, respectively. The liquid cooling plate 4 is sealed and welded to the lower surface of the bottom wall 12 of the tray 1. The bottom wall 12 is formed with convex ribs 15 corresponding to the cooling grooves 41. The convex ribs 15 protrude downward into the cooling grooves 41. The convex ribs 15 cooperate with the cooling grooves 41 to form a channel for the circulation of the coolant. The coolant enters the cooling groove 41 through the liquid inlet 42 to cool the tray 1 and the battery cell, and then flows out from the liquid outlet 43. The bottom wall 12 of the tray 1 is provided with convex ribs 15 corresponding to the cooling grooves 41. In this way, the flatness, structural strength and rigidity of the inner side of the bottom wall 12 of the tray are improved, thereby improving the safety and reliability of the battery pack. The structure of using the rib 15 and the cooling groove 41 to cooperate to form a channel for the circulation of the coolant can increase the heat dissipation area while ensuring the flow rate of the coolant, improve the heat dissipation efficiency of the battery pack, and is convenient to achieve using existing roller welding.

[0065] In this embodiment, the battery pack of the present invention further includes a bottom reinforcement member 5, both ends of which are fixed to the bottom surface of the frame 2 to support the liquid cooling plate 4 and the tray 1. This can further improve the bonding strength and rigidity of the frame 2 and the tray 1.

[0066] In this embodiment, the battery pack of the present invention further includes a bottom shield 6, the periphery of which is fixed to the bottom surface of the frame 2, and the bottom shield 6 is welded to the bottom reinforcement 5. The bottom shield 6 can protect the liquid cooling plate 4 and the tray 1, enhance the tray's ability to resist the intrusion of foreign objects at the bottom, and improve the safety and reliability of the battery pack.

[0067] In this embodiment, the battery pack of the present invention further includes a top cover 7 , the periphery of the top cover 7 is fixed to the frame 2 by bolts, and the top cover 7 and the support structure 3 are fixed by bolts to fix the battery cell in the positioning cavity 10 .

[0068] The tray 1, frame 2, support structure 3, liquid cooling plate 4, bottom reinforcement 5, bottom shield 6 and top cover 7 of the battery pack of the present invention can all be formed by pressing and welding steel plates to form a battery pack with a full steel structure.

[0069] The present invention also provides a method for manufacturing a battery pack as follows:

[0070] First, the thermoformed tray 1 obtained by stamping according to the process parameters is connected to the liquid cooling plate 4 by a roll welding process, and the tray 1 is welded to the frame 2;

[0071] Then, the support structure 3 is welded inside the tray 1;

[0072] Then, the bottom reinforcement member 5 and the bottom shield 6 are fixed to the frame 2, and the bottom reinforcement member 5 and the bottom shield 6 are welded together;

[0073] Place a heating film in the tray 1 or stick the heating film on the bottom surface of the battery cell, and then place the battery cells one by one into the positioning cavity 10;

[0074] The top cover 7 is fixed to the frame 2 and the support structure 3 by bolts to complete the overall assembly of the battery pack.

[0075] The battery pack manufacturing method has reasonable assembly steps and is easy to operate, which is beneficial to improving the production efficiency and product quality of the battery pack.

[0076] The present invention also provides a vehicle using the above battery pack, which includes an electric vehicle, a hybrid vehicle, etc.

[0077] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention 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 understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying importance; the words "bottom surface" and "top surface", "inside" and "outside" refer to the geometric direction toward or away from a specific component, respectively.

[0078] In the description of the present invention, it should be noted that, unless otherwise clearly 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 it can be an indirect connection through an intermediate medium, or it can be a connection between the inside of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: It includes a tray (1), a frame (2), a support structure (3) and battery cells. The frame (2) encloses an installation space adapted to the outer shape of the tray (1) to fix the frame (2) around the tray (1), such that the frame (2) abuts against the outer surface of the side wall (11) of the tray (1). The bottom surface of the support structure (3) is fixed to the upper surface of the bottom wall (12) of the tray (1), and the outer periphery of the support structure (3) is fixed to the inner surface of the side wall (11) of the tray (1) to divide the loading space of the tray (1) into multiple positioning cavities (10) for placing the battery cells. A triangular surface (14) is formed at the intersection between the corner of the side wall (11) and the bottom wall (12). When the draft angle (β) of the side wall is 8°, the draft angle (γ) of the triangular surface ranges from 35° to 40°; when the draft angle (β) of the side wall is 12°, the draft angle (γ) of the triangular surface ranges from 30° to 40°.

2. The battery pack according to claim 1, characterized in that: The tray (1) includes a side wall (11), a bottom wall (12) and a flange outer edge (13). The bottom side of the side wall (11) encloses the periphery of the bottom wall (12) to form the loading space of the tray (1), and the flange outer edge (13) encloses the outer periphery of the top side of the side wall (11). The side wall (11), the bottom wall (12) and the flange outer edge (13) are made by hot stamping of steel plates.

3. The battery pack according to claim 1, characterized in that: The frame (2) includes a first welding wall (21), an inner support wall (22), a lower outer wall (23), a lower support wall (24), an inner wall (25), an upper support wall (26), an upper outer wall (27) and a second welding wall (28) which are sequentially connected with a "day"-shaped cross-sectional structure. The first welding wall (21) is welded and fixed to the inner surface of the inner wall (25), and the second welding wall (28) is welded to the inner support wall (22), such that the lower outer wall (23) and the upper outer wall (27) together form the outer wall of the frame (2), and the inner support wall (22) is supported between the outer wall and the inner wall (25) of the frame (2).

4. The battery pack according to claim 1, characterized in that: The support structure (3) includes cross beams (31) and longitudinal beams (32). The bottom surfaces of the cross beams (31) and the longitudinal beams (32) are both welded to the upper surface of the bottom wall (12), and both ends of the cross beams (31) and the longitudinal beams (32) are welded to the inner surface of the side wall (11).

5. The battery pack according to claim 1, characterized in that: It further includes a liquid cooling plate (4). The liquid cooling plate (4) is pressed from a steel plate into a container structure with cooling grooves (41). The cooling grooves (41) extend in a zigzag manner and cover the liquid cooling plate (4). Both ends of the cooling grooves (41) penetrate the edge of the liquid cooling plate (4) to respectively form a liquid inlet hole (42) and a liquid outlet hole (43). The liquid cooling plate (4) is hermetically welded to the lower surface of the bottom wall (12) of the tray (1). The bottom wall (12) is formed with ribs (15) corresponding to the cooling grooves (41) one by one. The ribs (15) protrude downward into the cooling grooves (41), and the ribs (15) and the cooling grooves (41) cooperate to form a channel for the coolant to flow through.

6. The battery pack according to claim 5, characterized in that: It further includes a bottom reinforcement (5). Both ends of the bottom reinforcement (5) are fixed to the frame (2) to support the liquid cooling plate (4) and the tray (1).

7. A method for manufacturing a battery pack according to claim 6, wherein the battery pack further comprises a bottom shield (6) and a top cover (7), wherein the periphery of the bottom shield (6) is fixed to the bottom surface of the frame (2), and the top cover (7) is fixed to the frame (2) and the supporting structure (3), characterized in that: The manufacturing method of the battery pack includes the following steps: First, a thermoformed tray (1) punched according to process parameters is connected to a liquid cooling plate (4) by a roller welding process, and the tray (1) is welded to the frame (2); Then, the supporting structure (3) is welded inside the tray (1); Then, the bottom reinforcement member (5) and the bottom protection shield (6) are fixed to the frame (2), and the bottom reinforcement member (5) and the bottom protection shield (6) are welded together; A heating film is placed in the tray (1) or the heating film is attached to the bottom surface of the battery cell, and then the battery cells are placed one by one in the positioning cavity (10); The top cover (7) is fixed to the frame (2) and the supporting structure (3) by means of bolts, thereby completing the overall assembly of the battery pack.

8. A vehicle, characterized in that: Comprising a battery pack as described in any one of claims 1 to 6.

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