A battery pack

Abstract

The application discloses a battery pack, which comprises a plurality of battery modules, a frame and a bottom guard plate of a box body form a containing space, a heat exchange plate is arranged at the bottom of the battery module, the heat exchange plate comprises a rigid member and a flexible member which are arranged in a stack, a flow channel is formed between the rigid member and the flexible member, and the battery module is cooled by passing a heat exchange medium into the flow channel; a plurality of weight-reducing portions are formed in the rigid member, the orthographic projection of the weight-reducing portions on the bottom guard plate avoids the orthographic projection of the flow channel on the bottom guard plate, the projection area of all the weight-reducing portions on the bottom guard plate is A1 mm 2 , the projection area of the flow channel on the bottom guard plate is A2 mm 2 , and 0.3≤A1 / A2≤0.7, so that, by setting 0.3≤A1 / A2≤0.7, the heat exchange plate is lightened while ensuring that the flow channel has sufficient occupation area on the heat exchange plate to cool the battery module, and the weight of the heat exchange plate and the heat dissipation area of the heat exchange plate are considered.

Description

Technical Field

[0001] This application relates to the field of battery pack technology, and more specifically, to a battery pack. Background Technology

[0002] In the prior art, heat exchange plates are usually used to dissipate heat from the battery modules inside the battery pack. Currently, with the increasing demand for lightweight battery packs, weight reduction parts are set on the heat exchange plates to reduce weight. However, how to balance the weight of the heat exchange plate with its heat dissipation area is a problem that urgently needs to be solved by those skilled in the art.

[0003] In summary, how to balance the weight of the heat exchange plate with its heat dissipation area is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a battery pack that balances the weight of the heat exchange plate with the heat dissipation area of ​​the heat exchange plate.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A battery pack includes a plurality of battery modules. The battery pack comprises: a housing including a frame and a bottom protective plate; a heat exchange plate disposed at the bottom of the battery modules, the heat exchange plate including a rigid member and a flexible member stacked together, with a flow channel for the flow of a heat exchange medium formed between the rigid member and the flexible member; the rigid member being located on the side of the heat exchange plate closer to the battery modules; and a plurality of weight-reducing portions provided on the rigid member, the orthographic projection of the weight-reducing portions on the bottom protective plate avoiding the orthographic projection of the flow channel on the bottom protective plate, the total projected area of ​​all the weight-reducing portions on the bottom protective plate being A1 mm. 2 The projected area of ​​the flow channel on the bottom protective plate is A2 mm. 2 Where 0.3≤A1 / A2≤0.7.

[0007] The battery pack provided in this application includes several battery modules. The frame and bottom cover of the housing form a housing space. A heat exchange plate is provided at the bottom of the battery modules. The heat exchange plate includes rigid and flexible components stacked together, and a flow channel for introducing a heat exchange medium is formed between the rigid and flexible components to cool the battery modules by introducing the heat exchange medium into the flow channel. The rigid component is located on the side of the heat exchange plate closer to the battery module. Several weight-reducing parts are provided on the rigid component. The orthographic projection of the weight-reducing parts on the bottom cover avoids the orthographic projection of the flow channel on the bottom cover. The projected area of ​​all weight-reducing parts on the bottom cover is A1 mm. 2 The projected area of ​​the flow channel on the bottom liner is A2 mm. 20.3≤A1 / A2≤0.7. By setting 0.3≤A1 / A2≤0.7, the heat exchange plate can be reduced in weight while ensuring that the flow channel has sufficient area on the heat exchange plate to dissipate heat from the battery module, thus balancing the weight of the heat exchange plate with the heat dissipation area of ​​the heat exchange plate. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the battery pack structure provided in an embodiment of this application;

[0010] Figure 2 This is a schematic diagram of the disassembled structure of the battery pack provided in an embodiment of this application;

[0011] Figure 3 This is a schematic diagram of the structure of a heat exchange plate provided in an embodiment of this application;

[0012] Figure 4 This is a schematic diagram of another heat exchange plate provided in an embodiment of this application;

[0013] Figure 5 This is a schematic diagram showing the relationship between the weight reduction section and the flow channel in the heat exchange plate provided in an embodiment of this application.

[0014] Explanation of reference numerals in the attached figures:

[0015] 100-Battery Module;

[0016] 200 - Box body, 210 - Frame, 220 - Bottom guard plate;

[0017] 300-Heat exchange plate, 310-Rigid component, 311-Weight reduction section, 320-Flexible component, 330-Flow channel. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise.

[0020] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0021] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0022] The terms "parallel" and "perpendicular" used in this application refer to "basically parallel" and "basically perpendicular" in practical operation. "Basically parallel" can be understood as parallelism with a certain degree of error, and similarly, "basically perpendicular" can be understood as perpendicularity with a certain degree of error.

[0023] like Figures 1-5As shown in the embodiment of this application, the battery pack includes a plurality of battery modules 100. The battery pack includes: a housing 200, which includes a frame 210 and a bottom protective plate 220, the frame 210 and the bottom protective plate 220 forming an accommodating space; and a heat exchange plate 300, which is disposed at the bottom of the battery modules 100. The heat exchange plate 300 includes rigid members 310 and flexible members 320 stacked together, and a flow channel 330 for the flow of heat exchange medium is formed between the rigid members 310 and the flexible members 320. The battery module 100 is cooled by introducing a heat exchange medium into the flow channel 330, and the rigid member 310 is located on the side of the heat exchange plate 300 close to the battery module 100. The rigid member 310 is provided with several weight-reducing parts 311, the orthogonal projection of the weight-reducing parts 311 on the bottom protective plate 220 avoiding the orthogonal projection of the flow channel 330 on the bottom protective plate, so that the weight-reducing parts 311 are evenly distributed on the rigid member 310, and the projected area of ​​all weight-reducing parts 311 on the bottom protective plate 220 is A1 mm. 2 The projected area of ​​the flow channel 330 on the bottom guard plate 220 is A2mm². 2 Wherein, 30%≤A1 / A2≤70% (i.e. 0.3≤A1 / A2≤0.7), by setting 30%≤A1 / A2≤70%, the heat exchange plate 300 is made lighter while ensuring that the flow channel 330 has sufficient area on the heat exchange plate 300 to dissipate heat from the battery module 100, thus balancing the weight of the heat exchange plate 300 and the heat dissipation area of ​​the heat exchange plate 300.

[0024] For example, A1 / A2 can be any one of the following values ​​or any value between two of them: 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%.

[0025] It should be noted that the battery module 100 is fixedly connected to the rigid member 310 on the side away from the flexible member 320 by adhesive bonding, so as to provide support for the battery module 100 through the rigid member 310 and improve the heat dissipation and cooling effect of the battery module 100. The bottom guard plate 220 is located at the bottom of the heat exchange plate 300 to protect the heat exchange plate 300.

[0026] It should be noted that the battery pack includes a battery pack composed of multiple battery modules connected in series and / or in parallel, a battery management system (BMS), a thermal management system, an electrical connection system (high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective components. All of these components are placed inside the enclosure and sealed with a cover plate to form a complete functional unit that can directly output electrical energy.

[0027] A battery pack, as a type of rechargeable battery, is the power source for new energy vehicles. It generally includes battery modules, BMS control modules, and a housing that contains the battery modules and BMS control modules.

[0028] The battery pack includes a housing and multiple battery modules housed within the housing. The housing is divided into upper and lower parts, which are sealed together.

[0029] The battery pack includes at least two battery modules, a BMS control assembly, a housing, and an isolation plate. The battery modules and the isolation plate are both located in the housing. The isolation plate is located on the side of the battery cell away from the bottom wall of the housing, separating the battery cell from other devices located above the battery module, thus serving an isolation function.

[0030] It should be noted that the battery module 100 is a battery pack formed by connecting multiple battery cells with similar capacity and internal resistance in series or in parallel.

[0031] It should be noted that the enclosure 200 refers to a closed or semi-closed structure made of materials such as metal and plastic. It is the physical carrier of the battery pack, and its design and manufacturing must meet the safety, reliability and functionality requirements of the battery pack in different usage scenarios.

[0032] The enclosure 200 provides installation space for battery packs, BMS, cooling system, electrical connection components, etc., and fixes these components in the enclosure through reasonable structural design to ensure that they maintain a relatively stable position during battery pack operation, and avoid damage to components or loosening of connections due to vibration, impact or other factors.

[0033] The housing 200 includes a lower housing, including a bottom protective plate 220 and a side plate connected to and surrounding the bottom protective plate 220; and an upper housing, connected to the side plate, having a cover plate opposite to the bottom protective plate 220. The upper housing and the lower housing together enclose a receiving chamber.

[0034] The battery pack housing 200 is generally composed of an upper housing and a lower housing. The lower housing generally has four side panels and a bottom protective plate 220. The four side panels and the bottom protective plate 220 can be integrally formed or separately fixedly connected.

[0035] The housing 200 may include a bottom cover 220 and a cover plate, the bottom cover 220 and the cover plate covering each other, the bottom cover 220 and the cover plate together defining a receiving space for accommodating the battery module 100.

[0036] The enclosure 200 can be cast from materials such as steel plate and aluminum alloy, or lightweight materials such as glass fiber reinforced composite materials and carbon fiber reinforced composite materials.

[0037] The shape of the box 200 can be a cylinder, cuboid, cube, etc.

[0038] It should be noted that the frame 210 is the frame structure of the battery pack housing 200, which serves to support, protect and connect the components.

[0039] Frame 210 can be formed by splicing together multiple beams.

[0040] The frame 210 includes four sub-frames that are joined together to form an enclosed space. The enclosed space is closed by the top cover and the bottom plate to form a receiving cavity.

[0041] The frame 210 can be made of various materials, such as aluminum alloy, copper alloy, steel, plastic, etc.

[0042] The frame 210 can be rectangular, circular, polygonal, etc., and there are no specific limitations.

[0043] The interior of frame 210 can be a solid structure or contain a cavity.

[0044] It should be noted that the heat exchange plate 300 is used to dissipate heat from the battery module 100 in order to regulate the temperature of the battery module 100.

[0045] The heat exchange plate 300 can be configured as a liquid cooling plate or a phase change cooling plate and is thermally connected to the battery.

[0046] The heat exchange plate 300 can contain refrigerant, which cools the battery module 100 through phase change. The refrigerant can be gas, solid, or liquid. Liquid refrigerant can also contain liquids with high specific heat capacity, such as water, as coolant to achieve liquid cooling of the battery module 100.

[0047] The heat exchange plate 300 is located at the bottom of the housing 200, connecting to the bottom of the side wall to form a sealed housing structure. The air-cooling plate can be fixed to the side wall of the housing using nuts or other methods. In order to form an airflow cavity inside the housing, the bottom plate is placed inside the barrel-shaped structure. Since the bottom of the battery is flat, the bottom plate also needs to be set parallel to the air-cooling plate, with a gap between the air-cooling plate and the bottom plate, so that the bottom plate, side wall, and air-cooling plate together form an airflow cavity.

[0048] The heat exchange plate 300 has a flow channel 330. Specifically, the shape of the flow channel 330 can be various, such as "U", "return" or "S" type. Optionally, the heat exchange plate 300 also includes a liquid inlet and a liquid outlet, both of which are connected to the collector for the inlet and outlet of the heat exchange medium.

[0049] The heat exchange plate 300 can be made of a material with a certain degree of hardness and strength (such as stainless steel). This makes the heat exchange plate 300 less prone to deformation when the battery cell is subjected to pressure or impact, allowing the battery cell to have higher structural strength and improved safety performance. The liquid cooling plate can be made of various materials, including but not limited to: copper, iron, aluminum, stainless steel, and aluminum alloys.

[0050] The heat exchange plate 300 can also be made of nylon, plastic, etc.

[0051] It should be noted that the rigidity in rigid component 310 refers to the material properties of the structure. This type of property can be due to the large mass of the material, or it can be due to at least one of the following properties: thickness, stiffness, strength, elastic modulus, elongation at break, etc. As an example, the material of rigid component 310 can be selected from conventional metal plates such as aluminum plates or steel plates, or materials with composite materials, etc., and its rigidity can be controlled by the thickness, width, length, and type of material of rigid component 310. In this embodiment of the present disclosure, by setting the heat exchange plate 300 to include rigid component 310, it can support the flexible component 320, which is beneficial to improving the overall structural strength and stability of heat exchange plate 300.

[0052] It should be noted that the flexibility in the flexible component 320 refers to the material properties of the structure. This type of property can be due to the material's light weight, or it can be due to at least one of the material's properties such as thickness, stiffness, strength, elastic modulus, and elongation at break. As an example, the material of the flexible component 320 can be selected as a material that is lighter than conventional aluminum plates, steel plates, etc., and its flexibility can be controlled by the thickness, width, length, and type of material of the flexible component 320. In this embodiment, by setting the heat exchange plate 3000 to include the flexible component 320, it is beneficial to reduce the weight of the heat exchange plate 300.

[0053] The flexible component 320 is configured as a flexible structure. The flexible component 320 has certain expandable or contractible characteristics. It can also be understood that the flexible component 320 can be an elastically deformable structure. The flexible component 320 has the ability to deform and recover its deformation, so that the heat exchange plate 300 can be formed into a contour structure. The heat exchange plate 300 can better adapt to the external contour shape of the battery module 100 or other components, thereby improving the fit between the heat exchange plate 300 and the housing 200 and / or the battery module 100, thereby increasing the effective heat exchange area between the heat exchange plate 300 and the housing 200 and / or the battery module 100, and thus improving the heat exchange efficiency.

[0054] In this application, the projected area A1 mm of all weight-reducing parts 311 on the bottom guard plate 220 2 Meets the requirement of 300,000 mm. 2 ≤A1mm 2 ≤1200000mm 2 This ensures that the rigid component 310 can still maintain sufficient rigidity after the weight reduction section 311 is opened, while also enabling the rigid component 310 to achieve a certain degree of weight reduction, thereby making the battery pack lighter.

[0055] For example, A1 mm 2 The point value can be any one of the following: 300,000 mm², 400,000 mm², 500,000 mm², 600,000 mm², 700,000 mm², 800,000 mm², 900,000 mm², 1,000,000 mm², 1,100,000 mm², or 1,200,000 mm², or any value between two of them.

[0056] In this application, the projected area A2 mm of the flow channel 330 on the bottom guard plate 220 2 Meets the requirement of 600,000 mm. 2 ≤A2mm 2 ≤2420000mm 2 This ensures that the flow channel 330 has sufficient area to ensure heat dissipation, while also providing space for the weight reduction section 311 to be opened on the rigid member 310, so as to achieve weight reduction of the heat exchange plate 300.

[0057] For example, A2mm 2It can be a point value of any one of 600,000 mm², 700,000 mm², 800,000 mm², 900,000 mm², 1,000,000 mm², 1,100,000 mm², 1,200,000 mm², 1,300,000 mm², 1,400,000 mm², 1,500,000 mm², 1,600,000 mm², 1,700,000 mm², 1,800,000 mm², 1,900,000 mm², 2,000,000 mm², 2,100,000 mm², 2,200,000 mm², 2,300,000 mm², 2,400,000 mm², or 2,420,000 mm², or a point value between any two of them.

[0058] In this application, the area of ​​a single weight-reducing part 311 ranges from 1000 mm. 2 -10000mm 2 The size and area of ​​a single weight-reducing part 311 can be adjusted by the area and direction of the flow channel 330 so that the weight-reducing part 311 is evenly distributed on the rigid member 310.

[0059] For example, the area of ​​a single weight-reducing part 311 can be any one of the following values: 1000 mm², 2000 mm², 3000 mm², 4000 mm², 5000 mm², 6000 mm², 7000 mm², 8000 mm², 9000 mm², 10000 mm², or any value between two of them.

[0060] like Figures 3-5 As shown, in the first and second directions, the weight-reducing parts 311 are distributed sequentially at intervals, so that the weight-reducing parts 311 form an array distribution on the rigid member 310, thereby improving the uniformity of the distribution of the weight-reducing parts 311 on the rigid member 310.

[0061] It should be noted that both the first direction and the second direction are along the horizontal plane, and the first direction, the second direction, and the thickness direction of the bottom guard plate 220 are perpendicular to each other.

[0062] like Figure 5 As shown, in the first direction, the distance between the weight-reducing part 311 and the flow channel 330 is L1mm, 3mm≤L1mm≤10mm, in order to reduce the impact of the weight-reducing part 311 on the sealing performance of the formed flow channel 330, so as to ensure the stable flow of coolant, while improving the weight-reducing effect of the weight-reducing part 311 on the rigid member 310, so as to achieve both weight reduction of the heat exchange plate 300 and heat dissipation effect of the heat exchange plate 300.

[0063] For example, L1mm can be any one of the following point values: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, or any combination thereof.

[0064] like Figure 5 As shown, in the second direction, the distance between adjacent weight-reducing parts 311 is L2mm, 10mm≤L2mm≤50mm, so that there is an appropriate distance between adjacent weight-reducing parts 311 to ensure the overall strength of the rigid member 310, while improving the weight-reducing effect of the weight-reducing parts 311 on the rigid member 310, so as to achieve a balance between the strength of the rigid member 310 and the heat dissipation effect of the heat exchange plate 300.

[0065] For example, L2mm can be any one of the following values ​​or a value between any two: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm.

[0066] like Figure 5 As shown, the distance between the weight-reducing part 311 and the side wall of the rigid member 310 is L3mm, 10mm≤L3mm≤50mm. By setting an appropriate distance between the weight-reducing part 311 and the side wall of the rigid member 310, the forming process of the weight-reducing part 311 on the rigid member 310 is facilitated, while ensuring the weight-reducing effect of the weight-reducing part 311 on the rigid member 310.

[0067] For example, L3mm can be any one of the following values ​​or a value between any two: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm.

[0068] like Figure 5As shown, in both the first and second directions, there are some flow channels 330 located between adjacent weight-reducing parts 311 so that the weight-reducing parts 311 are evenly distributed. In practice, the weight-reducing parts 311 can be adjusted according to the actual shape and direction of the flow channels 330 so that the weight-reducing parts 311 can adapt to different flow channels 330.

[0069] In some embodiments, such as Figure 4 As shown, the weight reduction part 311 is a through hole that penetrates the rigid member 310, and the projection of the through hole on the bottom cover plate 220 does not coincide with the projection of the flow channel 330 on the bottom cover plate 220, so as to ensure the sealing of the flow channel 330. By setting it as a through hole, the weight of the rigid member 310 is further reduced, so as to further improve the lightweight of the battery pack.

[0070] In some other embodiments, such as Figure 3 As shown, the weight reduction part 311 is a recessed groove on the rigid member 310, and a thinning area is formed on the rigid member 310 corresponding to the groove. The thickness of the thinning area is less than the thickness of the non-thinning area on the rigid member 310, so as to reduce the weight of the rigid member 310. At the same time, since the groove is not through, the influence on the flow channel 330 is reduced, and the distribution of the groove is increased to improve the uniformity of the weight reduction part 311 distribution.

[0071] When the weight reduction section 311 is a sink, the thickness of the rigid member 310 is D1mm, the thickness of the thinning area is D2mm, and the range of (D1-D2)mm is satisfied: 0.3mm≤(D1-D2)mm≤2mm, so as to achieve weight reduction of the rigid member 310, while ensuring that the rigid member 310 has sufficient strength.

[0072] For example, (D1-D2) mm can be any one of the following values: 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, or any value between two of them.

[0073] In this application, the thickness D1mm of the rigid member 310 satisfies: 0.8mm≤D1mm≤3mm. For example, D1mm can be any one of the following values ​​or any value between two of them: 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, and 3.0mm.

[0074] In this application, the thickness D2mm of the thinning region satisfies: 0.5mm≤D1mm≤1mm. For example, D1mm can be any one of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm or any value between two of them.

[0075] In this application, the weight reduction part 311 can be of various shapes such as round hole, square hole, racetrack-shaped hole, etc. In actual practice, it can be selected according to the shape of the flow channel 330. This application embodiment does not limit this, so as to improve the applicability of the rigid part 310.

[0076] like Figure 5 As shown, the flow channel 330 includes a straight segment extending along a first direction or a second direction, and a bent segment connecting two straight segments. The distance between adjacent straight segments is L4mm, and 15mm≤L4mm≤50mm, so that the flow channel 330 is evenly distributed to ensure the heat dissipation and cooling effect of the battery module 100. At the same time, there is a certain interval between adjacent flow channels 330 to provide space for the weight reduction part 311, so as to achieve weight reduction of the rigid part 310.

[0077] For example, L4mm can be any one of the following values ​​or a value between any two: 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm.

[0078] like Figure 5 As shown, the distance between the flow channel 330 and the side wall of the rigid component 310 is L5mm, 15mm≤L5mm≤50mm, so that the distribution of the flow channel 330 can meet the cooling effect of the battery module 100, and at the same time, there is a certain gap between the flow channel 330 and the side wall of the rigid component 310 to facilitate the forming of the flow channel 330.

[0079] For example, L5mm can be any one of the following values ​​or a value between any two: 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm.

[0080] In some embodiments, the width of the straight section of the flow channel 330 is equal to the width of the bent section, so as to facilitate the forming of the flow channel 330.

[0081] In some other embodiments, the width of the straight segment of the flow channel 330 is not equal to the width of the bent segment, and the difference between the width of the straight segment and the width of the bent segment is in the range of 1mm-5mm. For example, the difference can be any one of 1mm, 2mm, 3mm, 4mm, 5mm or any value between the two, so that the flow channel 330 has a variety of shapes, so that the flow channel 330 can adapt to different battery modules 100 and improve the uniformity of heat dissipation of the battery module 100.

[0082] In this application, the width of the cross-section of the flow channel 330 ranges from 7mm to 25mm. For example, the width can be any one of 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, and 25mm, or any value between two of them, so that the flow channel 330 can ensure the smooth flow of coolant and ensure the heat dissipation and cooling effect on the battery module 100.

[0083] In this application, a groove is provided on the flexible member 320, and the rigid member 310 and the flexible member 320 are hot-pressed together to form a flow channel 330. A hot-pressed area is formed on the rigid member 310, and the projected area of ​​the hot-pressed area on the bottom protective plate 220 is A3 mm. 2 The projected area of ​​rigid member 310 on bottom guard plate 220 is A4 mm. 2 Furthermore, the range of A3 / A4 satisfies: 40%≤A3 / A4≤70% (i.e., 0.4≤A3 / A4≤0.7). Since the hot-pressing area needs to ensure the sealing of the flow channel 330, the weight-reducing part 311 is not set in the hot-pressing area. In this way, by limiting 40%≤A3 / A4≤70%, the area of ​​the flow channel 330 and the area occupied by the weight-reducing part 311 can be taken into account, while ensuring the stable operation of the heat exchange plate 300 as a whole.

[0084] For example, A3 / A4 can be any one of the following values ​​or any combination of two values: 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%.

[0085] In this application, the projected area A3 mm of the hot-pressed region on the bottom protective plate 220 is... 2 Meets the following requirements: 900,000 mm 2 ≤A3mm 2 ≤2100000mm 2 For example, A3 mm 2 It can be a point value from any one of 900,000 mm², 1,000,000 mm², 1,100,000 mm², 1,200,000 mm², 1,300,000 mm², 1,400,000 mm², 1,500,000 mm², 1,600,000 mm², 1,700,000 mm², 1,800,000 mm², 1,900,000 mm², 2,000,000 mm², or 2,100,000 mm², or a point value between any two of them.

[0086] In this application, the projected area A4 mm of the rigid member 310 on the bottom guard plate 220 2 Meets the requirement of: 1,500,000 mm 2 ≤A4mm 2 ≤3000000mm 2 For example, A4mm 2 It can be a point value from any one of the following: 1500000mm², 1600000mm², 1700000mm², 1800000mm², 1900000mm², 2000000mm², 2100000mm², 2200000mm², 2300000mm², 2400000mm², 2500000mm², 2600000mm², 2700000mm², 2800000mm², 2900000mm², 3000000mm², or a point value between any two.

[0087] In this application, since the rigid member 310 is located on the side of the heat exchange plate 300 close to the battery module 100, the thermal conductivity of the rigid member 310 is greater than that of the flexible member 320, so as to improve the heat exchange efficiency between the rigid member 310 and the battery module 100, thereby improving the cooling effect on the battery module 100.

[0088] In this application, the thermal conductivity of the rigid component 310 is 20 W / (m·K) - 200 W / (m·K) to ensure that the rigid component 310 can meet the thermal conductivity requirements.

[0089] For example, the thermal conductivity of rigid component 310 can be any one of the following values ​​or any value between two of them: 20 W / (m·K), 30 W / (m·K), 40 W / (m·K), 50 W / (m·K), 60 W / (m·K), 70 W / (m·K), 80 W / (m·K), 90 W / (m·K), 100 W / (m·K), 110 W / (m·K), 120 W / (m·K), 130 W / (m·K), 140 W / (m·K), 150 W / (m·K), 160 W / (m·K), 170 W / (m·K), 180 W / (m·K), 190 W / (m·K), and 200 W / (m·K).

[0090] In this application, the rigid component 310 can be either an aluminum plate or a steel plate to ensure that the rigid component 310 has sufficient strength and thermal conductivity. The choice can be made according to the actual situation, and this application embodiment does not limit this.

[0091] In this application, the flexible component 320 has a three-layer structure, including a flexible non-metallic layer and a metal layer, and the flexible non-metallic layer, the metal layer, and the flexible non-metallic layer are stacked in sequence, and the flexible non-metallic layer and the metal layer are bonded and fixed together by thermally conductive adhesive to ensure the overall strength of the flexible component 320.

[0092] In some embodiments, the metal layer may be one or more of aluminum foil, copper foil, and steel foil to improve the structural strength of the flexible component 320; the non-metallic layer may be one or more of polypropylene, polyphenylene sulfide, polyphthalamide, and polyethylene to improve the waterproof and corrosion-resistant properties of the flexible component 320.

[0093] In this application, the elastic modulus of the bottom guard plate 220 is greater than that of the flexible member 320, so that the rigidity and hardness of the bottom guard plate 220 are greater than those of the flexible member 320, thereby improving the bottom guard plate 220's ability to resist impact and ensuring the normal operation of the heat exchange plate 300.

[0094] It should be noted that, here, the elastic modulus of a portion of the bottom guard plate 220 may be greater than that of the flexible component 320, or the elastic modulus of the entire bottom guard plate 220 may be greater than that of the flexible component 320.

[0095] It should be noted that the elastic modulus describes the magnitude of unit strain caused by unit stress when a solid is subjected to force within a certain range, and it is one of the fundamental physical quantities of materials. The larger the elastic modulus, the greater the stiffness of the material and the stronger its compressive strength. The elastic modulus is a physical quantity that describes the elasticity of a material.

[0096] Methods for measuring the modulus of elasticity may include at least one of the following: static tensile testing, dynamic testing, sound velocity method, nanoindentation method, and bending method. Measuring instruments may include a nanoindenter and a universal testing machine.

[0097] For example, the elastic modulus of the flexible part 320 or the bottom cover plate 220 can be measured by nanoindentation under normal temperature and pressure. Nanoindentation uses a tiny indenter to indent the surface of the flexible part 320 or the bottom cover plate 220, and calculates the elastic modulus by analyzing the relationship between the indentation depth and the load.

[0098] The battery pack provided in this embodiment uses a heat exchange plate 300 to cool the battery module 100 inside the battery pack. The heat exchange plate 300 includes a rigid member 310 and a flexible member 320 stacked together. A flow channel 330 for the flow of coolant is formed between the rigid member 310 and the flexible member 320. The rigid member 310 is provided with a plurality of weight-reducing parts 311. The projected area of ​​all weight-reducing parts 311 on the bottom protective plate 220 is A1 mm. 2 The projected area of ​​the flow channel 330 on the bottom guard plate 220 is A2 mm. 2 Wherein, 30%≤A1 / A2≤70%, by setting 30%≤A1 / A2≤70%, the heat exchange plate 300 is reduced in weight while ensuring that the flow channel 330 has sufficient area on the heat exchange plate 300 to dissipate heat from the battery module 100, thus balancing the weight of the heat exchange plate 300 and the heat dissipation area of ​​the heat exchange plate 300.

[0099] The above description of the embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery pack, characterized in that, The battery pack includes several battery modules, and the battery pack includes: The enclosure includes a frame and a bottom panel; A heat exchange plate is disposed at the bottom of the battery module. The heat exchange plate includes rigid and flexible components stacked together. A flow channel for the flow of heat exchange medium is formed between the rigid and flexible components. The rigid component is located on the side of the heat exchange plate closer to the battery module. The rigid component is provided with a plurality of weight-reducing parts, the orthographic projection of the weight-reducing parts on the bottom protective plate avoiding the orthographic projection of the flow channel on the bottom protective plate, and the total projected area of ​​all the weight-reducing parts on the bottom protective plate is A1mm. 2 The projected area of ​​the flow channel on the bottom protective plate is A2mm. 2 Where 0.3≤A1 / A2≤0.

7.

2. The battery pack according to claim 1, characterized in that, The projected area A1mm of all the weight-reducing components on the bottom guard plate 2 Meets the requirement of 300,000 mm. 2 ≤A1mm 2 ≤1200000mm 2 .

3. The battery pack according to claim 1, characterized in that, The projected area of ​​the flow channel on the bottom protective plate is A2mm. 2 Meets the requirement of 600,000 mm. 2 ≤A2mm 2 ≤2420000mm 2 .

4. The battery pack according to claim 2, characterized in that, The area of ​​a single weight-reducing part ranges from 1000 mm². 2 -10000mm 2 .

5. The battery pack according to claim 1, characterized in that, The weight-reducing parts are distributed sequentially at intervals along the first and second directions, so that the weight-reducing parts are arranged in an array on the rigid member.

6. The battery pack according to claim 5, characterized in that, In the first direction, the distance between the weight reduction part and the flow channel is L1mm, where 3mm≤L1mm≤10mm.

7. The battery pack according to claim 5, characterized in that, In the second direction, the distance between adjacent weight-reducing parts is L2mm, where 10mm≤L2mm≤50mm.

8. The battery pack according to claim 5, characterized in that, The distance between the weight-reducing part and the side wall of the rigid member is L3mm, where 10mm≤L3mm≤50mm.

9. The battery pack according to claim 5, characterized in that, In the first direction and the second direction, a portion of the flow channel is located between adjacent weight-reducing portions.

10. The battery pack according to claim 1, characterized in that, The weight-reducing part is a through hole penetrating the rigid member, and the projection of the through hole on the bottom protective plate does not coincide with the projection of the flow channel on the bottom protective plate.

11. The battery pack according to claim 1, characterized in that, The weight-reducing part is an inwardly recessed groove on the rigid member, and a thinning area is formed on the rigid member corresponding to the groove. The thickness of the thinning area is less than the thickness of the non-thinning area on the rigid member.

12. The battery pack according to claim 11, characterized in that, The thickness of the rigid component is D1mm, and the thickness of the thinning zone is D2mm, wherein the range of (D1-D2)mm satisfies: 0.3mm≤(D1-D2)mm≤2mm.

13. The battery pack according to claim 1, characterized in that, The weight-reducing part is one of the following: round hole, square hole, or racetrack-shaped hole.

14. The battery pack according to claim 1, characterized in that, The flow channel includes a straight segment extending along a first direction or a second direction, and a bent segment connecting the straight segment; The distance between adjacent straight segments is L4, where 15mm ≤ L4mm ≤ 50mm.

15. The battery pack according to claim 14, characterized in that, The distance between the flow channel and the sidewall of the rigid member is L5, where 15mm ≤ L5mm ≤ 50mm.

16. The battery pack according to claim 14, characterized in that, The width of the straight segment is equal to the width of the bent segment.

17. The battery pack according to claim 14, characterized in that, The width of the straight segment is not equal to the width of the bent segment, and the difference between the width of the straight segment and the width of the bent segment is in the range of 1mm-5mm.

18. The battery pack according to claim 14, characterized in that, The width of the cross-section of the flow channel ranges from 7mm to 25mm.

19. The battery pack according to claim 1, characterized in that, The flexible component has a groove, and the rigid component and the flexible component are hot-pressed together to form the flow channel; The flexible component has a hot-pressed area, and the projected area of ​​the hot-pressed area on the bottom protective plate is A3 mm. 2 The projected area of ​​the rigid member on the bottom protective plate is A4 mm. 2 The range of A3 / A4 satisfies: 0.4≤A3 / A4≤0.

7.

20. The battery pack according to claim 1, characterized in that, The thermal conductivity of the rigid component is greater than that of the flexible component.

21. The battery pack according to claim 20, characterized in that, The thermal conductivity of the rigid component ranges from 20 W / (m·K) to 200 W / (m·K).

22. The battery pack according to claim 1, characterized in that, The rigid component is either an aluminum plate or a steel plate.

23. The battery pack according to claim 1, characterized in that, The flexible component is either aluminum or aluminum-plastic film.

24. The battery pack according to claim 1, characterized in that, The flexible component has a three-layer structure, including a flexible non-metallic layer and a metal layer, and the flexible non-metallic layer, the metal layer, and the flexible non-metallic layer are stacked sequentially.

25. The battery pack according to claim 24, characterized in that, The flexible non-metallic layer is bonded and fixed to the metallic layer by thermally conductive adhesive.

26. The battery pack according to claim 24, characterized in that, The metal layer is one or more of aluminum foil, copper foil, and steel foil.

27. The battery pack according to claim 24, characterized in that, The flexible non-metallic layer is one or more of the following: a polypropylene material layer, a polyphenylene sulfide material layer, a polyphthalamide material layer, and a polyethylene material layer.

28. The battery pack according to claim 1, characterized in that, The elastic modulus of the bottom protective plate is greater than that of the flexible component.

29. The battery pack according to claim 1, characterized in that, The battery module is fixedly connected to the rigid component on the side opposite to the flexible component by adhesive bonding.

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