Battery pack and power device

Abstract

The present application relates to a battery pack (100) and an electrical device, comprising a box (10) and a battery cell (20); the box (10) comprises a main body (11) and a bottom cover (12) detachably connected to the bottom of the main body (11); the main body (11) and the bottom cover (12) together enclose a receiving cavity (s) for receiving the battery cell (20).

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery packs and electrical devices. Background Art

[0002] As new energy technologies become more mature, new energy vehicles are gradually entering the public eye. The core technology of new energy vehicles lies in the battery pack, and the safety and stability of the battery pack directly determine the performance of the entire vehicle.

[0003] A battery pack generally includes a case and battery cells installed in the case. When components in the battery pack are damaged or fail (such as thermal failure of the battery cells), the components in the battery pack need to be maintained or replaced. Therefore, it is necessary to provide a battery pack that is easy to maintain. Summary of the invention

[0004] In view of this, the present application provides a battery pack and an electrical device.

[0005] In a first aspect, the present application provides a battery pack including a box body and a battery cell. The box body includes a main body and a bottom cover detachably connected to the bottom of the main body. The main body and the bottom cover together enclose a receiving cavity for receiving the battery cell.

[0006] In the technical solution of the present application, the main body can be directly installed on the mounting body, and the bottom cover and the main body together form a accommodating cavity. When the components in the accommodating cavity (such as a battery cell) need to be replaced or maintained, the components in the battery pack can be exposed and maintained or replaced by simply removing the bottom cover. There is no need to remove the entire battery pack from the mounting body, which greatly improves the convenience of maintenance of the battery pack.

[0007] In some embodiments, the bottom cover is detachably connected to the main body via a fastener. In this case, the bottom cover is detachably connected to the main body via a fastener, which is not only convenient for disassembly and assembly, but also simple in structure and economical.

[0008] In some embodiments, the bottom cover has a cover portion and a mounting portion, the mounting portion is enclosed and connected to the edge of the cover portion, the cover portion is used to define the accommodating cavity, and the mounting portion is detachably connected to the main body. In this case, the bottom cover defines the accommodating cavity via the cover portion, and is connected to the main body via the mounting portion, the structure is clear, and installation is convenient.

[0009] In some embodiments, the cover portion is protruded relative to the mounting portion in a direction away from the accommodating cavity. In this case, the cover portion protrudes relative to the mounting portion, and the cover portion of the bottom cover can serve as a reinforcement structure of the bottom cover to improve the bending resistance of the bottom cover.

[0010] In some embodiments, the minimum thickness h of the bottom cover satisfies: 0.2 mm < h < 20 mm. It has been proven that when the minimum thickness h of the bottom cover satisfies 0.2 mm < h < 20 mm, the weight of the battery pack can be effectively reduced, and the strength structure is reasonable.

[0011] In some embodiments, the weight m of the battery cell and the minimum thickness h of the bottom cover satisfy: 0.03 mm / Kg≤h / m≤100 mm / Kg. In this case, the battery pack not only has good structural strength, but also has high energy density and is not prone to fire and explosion.

[0012] In some embodiments, the battery cell is spaced apart from the bottom cover. In this case, it is possible to prevent the external force acting on the bottom cover from being transmitted to the battery cell and damaging the battery cell. In particular, when the battery pack is installed at the bottom of the vehicle and the bottom cover is at the lowest point of the battery pack, stones on the ground are likely to fly to the bottom of the battery pack and hit the bottom cover during the vehicle's driving. In this case, the buffer space can interrupt the external force from being transmitted to the battery cell and causing damage to the battery cell.

[0013] In some embodiments, the main body includes a carrier located at the top of the box body, the carrier is used to define the accommodating cavity, and the battery cell is suspended from the carrier. In this case, the battery cell is suspended below the carrier, and the bottom cover is located at the bottom of the box body. When repairing the interior of the battery pack, the battery cell can be exposed by removing the bottom cover without removing the carrier; at the same time, when repairing the battery pack, the battery cell can be disassembled and assembled on the carrier from the bottom, especially when the carrier is subjected to force as at least a part of the vehicle chassis, it is only necessary to disassemble and assemble the battery cell from the bottom of the carrier without removing the carrier, so as to facilitate the repair of the battery pack. Moreover, the battery cell suspended on the carrier can strengthen the strength of the carrier, thereby improving the rigidity of the top of the battery pack.

[0014] In some embodiments, the outer surface of the battery cell facing the carrier is the first outer surface, and the battery cell includes an electrode terminal, which is arranged on the outer surface of the battery cell other than the first outer surface. In this case, the electrode terminal is located on the outer surface of the battery cell other than the first outer surface, and various components connected to each electrode terminal (such as sampling harness, high-voltage harness, protective structure, etc.) can be arranged through the space between the battery cell and the bottom cover and / or the space between the battery cell and the inner side of the main body, which is more convenient for the arrangement of various components. Moreover, in this case, by connecting the first outer surface without the electrode terminal to the carrier, the battery cell and the carrier can be fitted, which can save the space between the battery cell and the carrier and improve the space utilization of the battery pack.

[0015] In some embodiments, the battery cell has a second outer surface disposed opposite to the first outer surface, and the electrode terminal is arranged on the second outer surface. In this case, there is a buffer space between the second outer surface and the bottom cover, and the portion of the electrode terminal extending outside the battery cell is located in the buffer space, so that the wiring harness and the connecting piece connected to the electrode terminal can be arranged in the buffer space. At the same time, the buffer space can also block the external force hitting the bottom cover from acting on the battery cell and damaging the battery cell. Therefore, the buffer space can not only interrupt the influence of external force, but also arrange the wiring harness, etc., killing two birds with one stone.

[0016] In some embodiments, the battery cell is bonded to the carrier, which not only facilitates the connection between the battery cell and the carrier, but also simplifies the structure of the battery pack.

[0017] In some embodiments, the main body includes a carrier and a frame, the frame encloses a cavity that is set through at both ends in the vertical direction, the bottom cover and the carrier are respectively covered at the opposite ends of the cavity in the vertical direction, and the bottom cover, the frame and the carrier together enclose a receiving cavity. In this case, the battery pack receiving cavity can be formed by taking the frame as the basis and connecting the carrier and the bottom cover to the two ends of the frame in the vertical direction, and the box structure is relatively simple.

[0018] In some embodiments, the carrier is fixedly connected to the frame or integrally formed. When the carrier is integrally formed with the frame and the main body is integrally formed, the main body only needs to be connected to the bottom cover to realize the assembly of the box, and the box is easy to assemble. When the carrier is fixedly connected to the frame, the molding process of the carrier and the frame is relatively easy, which can reduce the process cost of the box.

[0019] In a second aspect, the present application also provides an electrical device, comprising the above-mentioned battery pack, and the battery pack is used to provide electrical energy to the electrical device.

[0020] In some embodiments, the electric device includes a vehicle, and the battery pack is disposed at the bottom of the vehicle body. In this case, the battery pack is disposed at the bottom of the vehicle body, which does not occupy the space inside the vehicle body, and helps to reduce the volume and weight of the vehicle body.

[0021] In some embodiments, the main body includes a carrier located at the top of the box body, the carrier is used to define the accommodating cavity, and the battery pack is installed on the vehicle body via the carrier. When the battery cell is arranged on the carrier, the structure formed by the battery cell and the carrier is connected to the vehicle body, which can improve the top strength of the battery pack and further improve the installation strength of the battery pack.

[0022] In some embodiments, the carrier is configured to form at least a portion of the chassis of the vehicle body. In this case, the space occupied by the gap between the conventional chassis and the battery pack can be divided into the battery pack to increase the space of the battery pack, which helps to increase the energy of the battery pack and thus improve the endurance of the vehicle.

[0023] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0025] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0026] Figure 2 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0027] Figure 3 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application;

[0028] Figure 4 for Figure 3 An exploded view of the battery pack shown;

[0029] Figure 5 This is a schematic diagram of the structure of the bottom cover provided in some embodiments of the present application;

[0030] Figure 6 for Figure 5 a top view of the bottom cover;

[0031] Figure 7 for Figure 5 A front view of the bottom cover shown;

[0032] Figure 8 A schematic diagram of the structure of a bottom cover provided in some other embodiments of the present application;

[0033] Fig. 9 for Figure 4 A cross-sectional view of the battery pack shown;

[0034] Fig.10 for Figure 6 The bottom cover is shown in a vertical projection diagram;

[0035] Fig.11 A schematic diagram of the appearance of a battery cell in some embodiments of the present application;

[0036] Fig.12 for Fig.11 A front view of a battery cell is shown;

[0037] Fig.13 It is a schematic diagram of the structure of the carrier in some embodiments of the present application;

[0038] Fig.14 It is a schematic diagram of the structure of the bearing member in some other embodiments of the present application;

[0039] Fig.15 for Fig.14 The vertical projection of the bearing member shown;

[0040] Fig.16 for Figure 4 A front view of the battery pack shown;

[0041] Fig.17 This is a schematic diagram of a battery pack applied to a vehicle body in some embodiments of the present application;

[0042] Fig.18 for Fig.17 a diagram of a first exploded state of the structure shown;

[0043] Fig.19 for Fig.17 a second exploded state diagram of the structure shown;

[0044] Fig. 20 Schematic diagram of the installation relationship between the battery pack and the vehicle body in some embodiments of the present application.

[0045] 1000, vehicle; 100, battery pack; 200, vehicle body; 10, box; 11, main body; 11a, load-bearing member; 11a1, load-bearing part; 11a2, connecting part; 11b, frame; 12, bottom cover; 12a, cover; 12b, mounting part; 12c, fixing hole; 13, fastener; s, accommodating cavity; q, cavity; f, load-bearing surface; f1, first load-bearing edge; f2, second load-bearing edge; f3, third load-bearing edge; f4, fourth load-bearing edge; d, characteristic surface; d1, first characteristic edge; d2, second characteristic edge; d3, third characteristic edge; d4, fourth characteristic edge; 20, battery cell; 21, end cap; 21a, electrode terminal; 22, shell; 23, electrode assembly; m1, first outer surface; m2, second outer surface; m3, third outer surface. DETAILED DESCRIPTION

[0046] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0048] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0049] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0051] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0052] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0053] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0054] At present, judging from the development of the market situation, the application of battery packs is becoming more and more extensive. Battery packs are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of battery packs, the market demand is also constantly expanding.

[0055] The inventors have noticed that when a battery pack is used in an electrical device such as a vehicle, the entire battery pack needs to be removed from the mounting body (a structure in the electrical device for mounting the battery pack), and then the box body needs to be disassembled before the components inside the box body (such as battery cells) can be replaced and maintained, which is very inconvenient.

[0056] In order to improve the maintenance convenience of the battery pack, the applicant has discovered that the part of the box that is not directly connected to the mounting body can be made detachable. When the battery cells in the battery pack need to be maintained or replaced, it is only necessary to detach the structure in the box that is not directly connected to the mounting body to expose the components in the battery pack. The components in the battery pack can be maintained and replaced without removing the entire battery pack.

[0057] Based on the above considerations, in order to improve the maintenance convenience of the battery pack, the inventor has designed a battery pack after in-depth research. The battery pack includes a box body and a battery cell. The box body includes a main body and a bottom cover detachably connected to the bottom of the main body. The main body and the bottom cover together form a receiving cavity for receiving the battery cell. In this case, the main body can be directly installed on the mounting body, and the bottom cover and the main body together form a receiving cavity. When the components in the receiving cavity (such as the battery cell) need to be replaced or maintained, the components in the battery pack can be exposed and maintained or replaced by removing the bottom cover. There is no need to remove the entire battery pack from the mounting body, which greatly improves the maintenance convenience of the battery pack.

[0058] The battery pack disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships or aircraft. The battery pack disclosed in the present application can be used to form a power supply system of the electrical device. The mounting body involved in the present application is a structure for mounting a battery pack in an electrical device.

[0059] The embodiment of the present application provides an electric device using a battery pack as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0060] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0061] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery pack 100 is provided inside the vehicle 1000, and the battery pack 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery pack 100 may be used to power the vehicle 1000, for example, the battery pack 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller and a motor, and the controller is used to control the battery pack 100 to power the motor, for example, for starting, navigating and driving the vehicle 1000.

[0062] In some embodiments of the present application, the battery pack 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0063] Please refer to Figure 2 , Figure 2 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit constituting the battery pack 100. Figure 2 As shown, the battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23 and other functional components.

[0064] The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and safety can also be improved. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminal 21a can be used to electrically connect to the electrode assembly 23 for outputting or inputting electrical energy of the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection portion 11a2 in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, or the like.

[0065] The shell 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 22 and the end cap 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 21 at the opening. Without limitation, the end cap 21 and the shell 22 can also be integrated. Specifically, the end cap 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cap 21 covers the shell 22. The shell 22 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0066] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be included in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body 11 of the electrode assembly 23, and the parts of the positive and negative electrode sheets without active materials each constitute. The positive electrode tab and the negative electrode tab may be located together at one end of the main body 11 or respectively at both ends of the main body 11. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals 21a to form a current loop.

[0067] Figure 3 A schematic diagram of the structure of a battery pack 100 provided in some embodiments of the present application, Figure 4 for Figure 3 The structure of the battery pack 100 is shown in FIG. Figure 3 and Figure 4 The embodiment of the present application provides a battery pack 100, including a battery cell 20 and a box body 10, wherein the box body 10 is formed with a receiving cavity s, and the battery cell 20 is received in the receiving cavity s.

[0068] In the battery pack 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. Multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery pack 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery pack 100 may also include other structures. For example, the battery pack 100 may also include a confluence component for realizing electrical connection between multiple battery cells 20. Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0069] The box body 10 can be in various shapes, such as a cylinder, a cuboid, etc., and the specific structure of the box body 10 can adopt various structural modes.

[0070] In some embodiments, please refer to Figure 3 and Figure 4 The box body 10 includes a main body 11 and a bottom cover 12 disposed at the bottom of the main body 11 . The bottom cover 12 and the main body 11 together enclose a receiving cavity s for receiving the battery cell 20 .

[0071] The main body 11 can be an integrally formed structure or can be formed by assembling a plurality of parts. The main body 11 can be a hollow shell 22 structure, which defines a first space, the bottom of the first space is open, and the bottom cover 12 covers the opening of the first space. The bottom cover 12 can be a hollow structure with one side open, and can have a second space. The second space of the bottom cover 12 and the first space of the main body 11 form a storage chamber s as a whole. The bottom cover 12 itself may not have a space to form a storage chamber s. When the bottom cover 12 is set at the opening of the first space of the main body 11, the bottom cover 12 seals the first space of the main body 11 and the two enclose to form a storage chamber s equivalent to the first space. At this time, the bottom cover 12 can be a flat plate structure. Of course, the storage chamber s of the box body 10 can also be formed by part of the first space of the main body 11. At this time, the bottom cover 12 can cover the opening of the first space and be recessed into the first space and occupy part of the first space. The first space removes the part of the space occupied by the bottom cover 12 to form the storage chamber s of the box body 10.

[0072] Understandably, the bottom cover 12 is located at the bottom of the box 10 and is used to define the accommodating cavity s together with the main body 11. Specifically, the bottom cover 12 can be, but is not limited to, a plate-like structure, a block-like structure, etc., and can be a flat plate, a curved plate, etc., without specific limitation.

[0073] When the battery cell 20 is located in the accommodation cavity s, the battery cell 20 may be disposed on the bottom cover 12 and / or the body 11 .

[0074] When the main body 11 is formed by assembling a plurality of parts, the battery cell 20 can be arranged on one of the parts or on all the parts. In one embodiment, the main body 11 may include a top cover (not shown), a panel (not shown) and a support plate (not shown), the panel encloses a third space with openings at both ends in the vertical direction, the top cover and the bottom cover 12 are respectively sealed and covered at both ends of the third space in the vertical direction, the top cover, the panel and the bottom cover 12 are enclosed together to form a receiving cavity s, the support plate is located in the third space, and the battery cell 20 is supported on the support plate. In other embodiments, the main body 11 may include the carrier 11a and the frame 11b described below, which will be described in detail below.

[0075] The bottom cover 12 and the main body 11 can be fixed by welding, hot-melt connection, bonding, fastening connection, snap connection and the like. The fastening connection refers to the connection achieved by the fastener 13, and the fastener 13 includes components such as bolts, latches, rivets, pins, screws, etc. The snap connection refers to the fixation achieved by the snap-fit ​​structure, for example, the bottom cover 12 has a hook, and the main body 11 has a bayonet, and the bottom cover 12 and the main body 11 can be snap-fitted and fixed when the hook is snapped into the bayonet. Of course, the connection method between the bottom cover 12 and the main body 11 is not limited to this, and will not be exhaustively listed in this application.

[0076] In some embodiments, the bottom cover 12 is sealed and connected to the main body 11 and together form a closed accommodating cavity s.

[0077] There are many ways to seal the bottom cover 12 and the main body 11, which can be but are not limited to: a seal is set between the bottom cover 12 and the main body 11, and the bottom cover 12 and the main body 11 are sealed by the seal; the bottom cover 12 and the main body 11 are sealed by a sealant; the bottom cover 12 and the main body 11 are plugged into each other and sealed by a blocking structure formed by the plug-in surface.

[0078] At this time, the box body 10 of the battery pack 100 forms a sealed accommodating cavity s through its own bottom cover 12 and its own main body 11. There is no need to set up other additional sealing structures in the box body 10, which can simplify the structure of the battery pack 100, reduce the cost of the battery pack 100, and ensure the safety and service life of the battery pack 100.

[0079] In the description of the present application, the bottom cover 12 of the battery pack 100 is located at the bottom of the main body 11. Figure 3 and Figure 4 The bottom cover 12 is located at the bottom of the main body 11 in the upper and lower positions. In actual use, Figure 3 and Figure 4 The upper and lower directions shown may be, but are not limited to, the vertical direction, depending on the actual installation of the battery pack 100. It should be noted that in the following description of the present application, the positional relationship, size, etc. of each structure of the battery pack 100 are described with reference to the vertical direction, which is not a limitation on the use of the battery pack 100, but is only for a clearer explanation and description of the solution.

[0080] In some embodiments, the bottom cover 12 is sealed to the main body 11 via a seal.

[0081] The seal refers to a component that can prevent fluid or solid particles from leaking from adjacent joint surfaces, and can prevent external impurities such as dust and moisture from invading the battery pack 100. The seal seals the main body 11 and the bottom cover 12, which means that the seal is connected between the two opposite surfaces of the main body 11 and the bottom cover 12, and has a circular contact interface with the two surfaces, which can prevent external moisture from entering the battery pack 100 through the contact section between the seal and the two surfaces, thereby achieving a sealing effect.

[0082] The sealing member may be a sealing ring or a sealing pad. Specifically, the sealing member may be made of materials such as rubber or silicone. Specifically, the sealing member may be an O-shaped sealing member, a square sealing member, a special-shaped sealing member, etc. The specific shape of the sealing member may be adapted to the shapes of the two opposite surfaces of the bottom cover 12 and the main body 11. For example, when the two opposite surfaces of the bottom cover 12 and the main body 11 are annular surfaces, the sealing member may be an O-shaped sealing member.

[0083] At this time, the bottom cover 12 is sealed and connected to the main body 11 through the sealing member, so the sealing is reliable and the cost is low.

[0084] It should be noted that after the bottom cover 12 is sealed with the main body 11 by the seal, it can also be fixedly connected with the main body 11 by other means. Other means include but are not limited to snap-on, plug-in, threaded connection, riveting, welding, bonding, etc. It is understandable that when the bottom cover 12 is sealed with the main body 11 by the sealant, according to the adhesion of the sealant, when the adhesion of the sealant is good enough to meet the requirements (that is, the bottom cover 12 and the main body 11 are fixed and not separated), other means may not be used to fix the two.

[0085] In some embodiments, the bottom cover 12 is detachably connected to the bottom of the main body 11 .

[0086] The detachable connection between the bottom cover 12 and the main body 11 means that when the bottom cover 12 is connected to the main body 11, the bottom cover 12 has a first state relative to the main body 11 in which it is completely connected to the main body 11 and forms a accommodating cavity s, and has a second state in which it is incompletely connected to or separated from the main body 11 and can expose the battery cell 20. The bottom cover 12 can be switched from the first state to the second state and from the second state to the first state under external force operation, without damaging any parts in the process.

[0087] When the bottom cover 12 is in a second state relative to the main body 11 in which it is not completely connected to the main body 11 and the accommodating cavity s is open, the installation method of the bottom cover 12 and the main body 11 can be: the bottom cover 12 and the main body 11 are rotatably connected and can be fixedly connected via the fastener 13 or a snap-fit ​​method. When the bottom cover 12 is rotated relative to the main body 11 to close the accommodating cavity s, the bottom cover 12 and the main body 11 can be fixedly connected to the main body 11 via the fastener 13 or a snap-fit ​​method, and the battery cell 20 is accommodated in the accommodating cavity s and cannot be seen. At this time, the bottom cover 12 is in the first state. When the fastener 13 is removed or the snap-fit ​​connection is released, the bottom cover 12 can be rotated relative to the main body 11 to open the accommodating cavity s and expose the battery cell 20. At this time, the bottom cover 12 is in the second state. Among them, the rotatable connection between the bottom cover 12 and the main body 11 can be, but is not limited to, the bottom cover 12 and the main body 11 are rotatably connected via a rotating shaft.

[0088] When the bottom cover 12 is in the second state relative to the main body 11, which is separated from the main body 11 and makes the accommodation cavity s open, the installation method of the bottom cover 12 and the main body 11 can be: the bottom cover 12 and the main body 11 are fixedly connected only by the fastener 13 or the snap-fit ​​method. When the fastener 13 is installed on the bottom cover 12 and the main body 11 or the snap-fit ​​structure of the bottom cover 12 and the main body 11 is snap-fitted, the bottom cover 12 and the main body 11 are completely fixed and form the accommodation cavity s together, and the battery cell 20 is accommodated in the accommodation cavity s and cannot be seen. At this time, the bottom cover 12 is in the first state. When the fastener 13 is removed or all snap-fit ​​connections are released, the bottom cover 12 can be separated from the main body 11, thereby exposing the battery cell 20. At this time, the bottom cover 12 is in the second state.

[0089] When the bottom cover 12 is in the first state, it forms a receiving cavity s with the main body 11 to protect the battery cell 20. When the bottom cover 12 is in the second state, the battery pack 100 is exposed, so that it is convenient for relevant personnel to maintain or replace the battery cell 20.

[0090] In some embodiments, please refer to Figure 4 The bottom cover 12 is detachably connected to the main body 11 via a fastener 13 .

[0091] The fastener 13 refers to a component that can fasten two or more parts (or components) into a whole, and can be, but is not limited to: a screw, a bolt, a rivet, a latch, a pin, a welding nail, etc.

[0092] At this time, the bottom cover 12 and the main body 11 are detachably connected via the fasteners 13, which is not only convenient for disassembly and assembly, but also simple in structure and economical.

[0093] Figure 5 This is a schematic diagram of the structure of the bottom cover 12 provided in some embodiments of the present application. Figure 6 for Figure 5 The top view of the bottom cover 12, Figure 7 for Figure 5 A front view of the bottom cover 12 is shown. Figure 8 It is a schematic structural diagram of the bottom cover 12 provided in some other embodiments of the present application.

[0094] In some embodiments, the minimum thickness h of the bottom cover 12 satisfies: 0.2 mm<h<20 mm.

[0095] The thickness of the bottom cover 12 refers to the distance between the two side surfaces of the bottom cover 12 in the vertical direction on the vertical cross section. The minimum thickness h of the bottom cover 12 is the shortest distance between the two side surfaces of the bottom cover 12 in the vertical direction. When the thickness of the bottom cover 12 is uniform everywhere, the bottom cover 12 can be in the shape of a flat plate (such as Figure 8As shown in FIG. 1 , the minimum thickness of the bottom cover 12 is the equal thickness of each part of the bottom cover 12. When the thickness of the bottom cover 12 is uneven, the minimum thickness of the bottom cover 12 is the thickness of the thinnest part of the bottom cover 12.

[0096] Specifically, the minimum thickness h of the bottom cover 12 can be selected as 0.3mm, 0.5mm, 0.8mm, 1mm, 1.5mm, 1.8mm, 2mm, 2.5mm, 2.8mm, 3mm, 3.5mm, 3.8mm, 4mm, 4.5mm, 4.7mm, 5mm, 5.5mm, 5.8mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, etc. Preferably, 0.5mm≤h≤3mm.

[0097] At this time, it has been proved that when the minimum thickness h of the bottom cover 12 satisfies 0.2 mm<h<20 mm, the weight of the battery pack 100 can be effectively reduced, and the strength structure is reasonable.

[0098] It should be noted that in the description of this application, with the vertical direction as a reference, the "thickness" of a structure refers to the distance between the two side surfaces of the structure in the vertical direction on the cross section in the vertical direction. In the following description, "thickness" is not explained too much, and the description here can be referred to. Of course, it is understandable that the vertical direction is only for the purpose of more conveniently explaining the solution of this application, and is not a limitation on the use of the battery pack 100.

[0099] In some embodiments, the weight m of the battery cell 20 and the minimum wall thickness h of the bottom cover 12 satisfy: 0.03 mm / Kg≤h / m≤100 mm / Kg.

[0100] The weight m of the battery cell 20 refers to the weight m of a single battery cell 20 . When the battery pack 100 includes a plurality of battery cells 20 , the weight m of the battery cell 20 refers to the weight of each battery cell 20 .

[0101] Specifically, the ratio of the minimum wall thickness h of the bottom cover 12 to the weight m of the battery cell 20 can be selected as 0.04mm / Kg, 0.05mm / Kg, 0.1mm / Kg, 0.4mm / Kg, 0.8mm / Kg, 1mm / Kg, 1.5mm / Kg, 2mm / Kg, 2.5mm / Kg, 3mm / Kg, 3.5mm / Kg, 4mm / Kg, 5mm / Kg, 6mm / Kg, 8mm / Kg, 10mm / Kg, 12mm / Kg. g, 13mm / Kg, 15mm / Kg, 16mm / Kg, 18mm / Kg, 20mm / Kg, 30mm / Kg, 35mm / Kg, 40mm / Kg, 45mm / Kg, 50mm / Kg, 55 / Kg, 60mm / Kg, 65mm / Kg, 68mm / Kg, 70mm / Kg, 75mm / Kg, 80mm / Kg, 85mm / Kg, 90mm / Kg, 95mm / Kg, 98mm / Kg.

[0102] Table 1 Effect of the ratio of the minimum wall thickness h of the bottom cover 12 to the weight m of the battery cell 20 on the safety performance of the battery pack 100

[0103]

[0104] Table 1 shows the test results of the influence of the ratio of the minimum wall thickness h of the bottom cover 12 and the weight m of the battery cell 20 on the safety performance of the battery pack 100 when tested according to the standard of GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". It can be seen from Table 1 that when h / m is equal to 0.02mm / Kg, the battery pack 100 is prone to fire and explosion. The reason is that the structural strength of the battery pack 100 cannot meet the requirements. When h / M is greater than 0.02mm / Kg, the structural strength of the bottom cover 12 is better, and the battery pack 100 is not easy to catch fire and explode, but h / m is too large and it is easy to cause space waste and low energy density, so h / m is preferably not more than 100mm / Kg.

[0105] At this time, it has been proved that when the minimum thickness h of the bottom cover 12 and the weight m of the battery cell 20 satisfy 0.03mm / Kg≤h / m≤100mm / Kg, the battery pack 100 not only has good structural strength, but also has a high energy density and is not prone to fire and explosion.

[0106] In some embodiments, please refer to Figures 5 to 7 The bottom cover 12 has a cover portion 12 a and a mounting portion 12 b . The mounting portion 12 b is connected to the edge of the cover portion 12 a . The cover portion 12 a is used to define the accommodating cavity s. The mounting portion 12 b is connected to the main body 11 .

[0107] The cover 12a is used to define the accommodating cavity s, which means that the cover 12a and the main body 11 together enclose the accommodating cavity s, and the mounting portion 12b is connected to the main body 11 and does not participate in the definition of the accommodating cavity s. The cover 12a can be a plate-shaped or block-shaped component, a flat plate-shaped component, or a curved plate-shaped component, which is not specifically limited. Figure 6 It can be seen that the mounting portion 12b is enclosed at the edge of the cover portion 12a, which means that the mounting portion 12b is continuously arranged along the edge of the cover portion 12a to form a closed connection from end to end. Understandably, in the vertical projection, the mounting portion 12b has a certain width, so that there is an appropriate contact area between the main body 11, which not only facilitates the positioning and installation between the mounting portion 12b and the main body 11, but also facilitates the setting of the sealing member, and also helps to improve the sealing performance between the mounting portion 12b and the main body 11.

[0108] The cover 12a and the mounting portion 12b can be integrally formed. When the bottom cover 12 is made of metal (such as aluminum, iron, stainless steel, etc.), the cover 12a and the mounting portion 12b can be integrally formed by die casting, forging, hot pressing, cold pressing, etc. When the bottom cover 12 is made of plastic (such as PP, PE, ABS, etc.), the cover 12a and the mounting portion 12b can be integrally formed by injection molding. The cover 12a and the mounting portion 12b can also be connected together after being formed separately. When the cover 12a and the mounting portion 12b are made of metal, the cover 12a and the mounting portion 12b can be welded and bonded together. When the cover 12a and the mounting portion 12b are made of plastic, the cover 12a and the mounting portion 12b can be bonded together. Of course, the cover 12a and the mounting portion 12b can also be fixedly connected together by other methods such as clamping and riveting.

[0109] The cover 12a and the mounting portion 12b may be located in the same plane. Specifically, the two surfaces of the cover 12a and the mounting portion 12b facing the main body 11 are located in the same plane, and / or the two surfaces of the cover 12a and the mounting portion 12b facing away from the main body 11 are located in the same plane. When the two surfaces of the cover 12a and the mounting portion 12b facing the main body 11 and the two surfaces facing away from the main body 11 are located in the same plane, the cover 12a and the mounting portion 12b may form a flat bottom cover 12 (such as Figure 8 shown).

[0110] The cover 12a and the mounting portion 12b may not be located in the same plane. Specifically, the cover 12a is recessed relative to the mounting portion 12b toward the main body 11, or the cover 12a is convex relative to the mounting portion 12b away from the main body 11, which is not specifically limited. The thickness of the cover 12a and the mounting portion 12b may be equal or different, which is not specifically limited.

[0111] At this time, the bottom cover 12 defines the accommodating cavity s via the cover portion 12a, and is connected to the main body 11 via the mounting portion 12b, so the structure is clear and the installation is convenient.

[0112] It is understandable that when the bottom cover 12 is sealed to the main body 11, the bottom cover 12 is sealed to the main body 11 via the mounting portion 12b, that is, the mounting portion 12b is sealed to the main body 11. The sealing connection between the mounting portion 12b and the main body 11 can be a sealing connection, a sealing connection with a sealant, etc., and the specific examples are not exhaustive. The sealing member can be the sealing member mentioned in the above description, and the setting method of the sealing member can refer to the above record, except that the sealing member is set between the mounting portion 12b and the main body 11. When the mounting portion 12b and the main body 11 are sealed with a sealant, the sealant can be applied to all surfaces of the mounting portion 12b in contact with the main body 11.

[0113] It is understandable that when the bottom cover 12 is detachably connected to the main body 11, the bottom cover 12 is detachably connected to the main body 11 via the mounting portion 12b, that is, the mounting portion 12b is detachably connected to the main body 11. The manner in which the mounting portion 12b is detachably connected to the main body 11 can refer to the detachable manner of the bottom cover 12 and the main body 11 described above, and it is only necessary to set the portion of the bottom cover 12 that is detachably connected to the main body 11 as the mounting portion 12b. Therefore, the detachable manner in which the mounting portion 12b is detachably connected to the main body 11 is not described in detail here.

[0114] In some embodiments, the mounting portion 12 b is detachably connected to the main body 11 .

[0115] Specifically, the bottom cover 12 also includes a fixing hole 12c provided on the mounting portion 12b, and the fastener 13 is fastened to the main body 11 after passing through the fixing hole 12c on the mounting portion 12b. The fixing hole 12c is a through hole that passes through the mounting portion 12b in the vertical direction. Specifically, the fixing hole 12c can be a smooth through hole (such as when the fastener 13 is a rivet), a through hole with a thread (such as when the fastener 13 is a screw), or a through hole in other forms (such as a hexagonal hole, a square hole, a waist-shaped hole, etc.). The specific form of the fixing hole 12c depends on the specific form and specific setting method of the fastener 13, which will not be repeated here.

[0116] In some embodiments, the cover portion 12a and the mounting portion 12b have the same thickness.

[0117] When the cover 12a and the mounting portion 12b are integrally formed, the two can be integrally formed in the manner described above, such as die-casting integrally formed, cold-pressing integrally formed, hot-pressing integrally formed, injection molding integrally formed, etc., which will not be described in detail here. Since the cover 12a and the mounting portion 12b have the same thickness, they can be quickly processed out by stamping, cutting, etc. based on the same metal plate during molding.

[0118] At this time, the thickness of the cover portion 12a and the mounting portion 12b are equal, and the stress is even at all locations during molding, which can improve the molding rate of one-piece molding. It can also be quickly processed by simple methods such as plate cutting, and the structure of the bottom cover 12 is simpler and the processing is more convenient.

[0119] In some embodiments, please refer to Figure 7 The cover portion 12a is protruded in a direction away from the accommodating cavity s compared to the mounting portion 12b.

[0120] As can be seen from the above, the cover 12a defines the accommodating cavity s, and the cover 12a protruding away from the accommodating cavity s means that the cover 12a protrudes away from the main body 11. That is, the cover 12a and the mounting portion 12b are staggered in the vertical direction, and the cover 12a is at the lowest point of the bottom cover 12.

[0121] When the cover portion 12a protrudes away from the accommodating cavity s compared to the mounting portion 12b, a certain redundant space can be formed between the cover portion 12a and the mounting portion 12b, and the redundant space can increase the distance between the cover portion 12a and the battery cell 20. When external force acts on the cover portion 12a, the redundant space can reduce the external force, reduce or avoid the external force acting on the battery cell 20, and cause damage to the battery cell 20. In particular, when the battery pack 100 is installed at the bottom of the vehicle 1000 and the bottom cover 12 is at the lowest point of the battery pack 100, stones on the ground are easy to fly to the bottom of the battery pack 100, that is, the bottom cover 12, and hit the bottom cover 12 during the driving of the vehicle 1000. At this time, the redundant space can reduce the impact of external force on the battery cell 20. At the same time, the cover portion 12a protrudes relative to the mounting portion 12b, and the cover portion 12a of the bottom cover 12 can serve as a reinforcement structure of the bottom cover 12 to improve the bending resistance of the bottom cover 12.

[0122] It can be understood that in the embodiment of the present application, the bottom cover 12 is located at the bottom of the box body 10 and is used to define the accommodating cavity s.

[0123] Fig. 9 for Figure 4 A cross-sectional view of the battery pack 100 is shown. In some embodiments, please refer to Fig. 9 The bottom cover 12 is spaced apart from the battery cell 20 .

[0124] The spacing between the bottom cover 12 and the battery cell 20 means that a set spacing r is maintained between the bottom cover 12 and the battery cell 20 in the vertical direction. Under the effect of the set spacing r, a buffer space is formed between the bottom cover 12 and the battery cell 20, which can prevent the external force acting on the bottom cover 12 from being transmitted to the battery cell 20 and damaging the battery cell 20. In particular, when the battery pack 100 is installed at the bottom of the vehicle 1000 and the bottom cover 12 is at the lowest point of the battery pack 100, stones on the ground are easy to fly to the bottom of the battery pack 100 and hit the bottom cover 12 during the driving of the vehicle 1000. At this time, the buffer space can interrupt the transmission of external force to the battery cell 20 and affect the battery cell 20.

[0125] The bottom cover 12 and the battery cell 20 may be spaced apart in such a manner that they are formed by the redundant space between the protruding cover portion 12a and the mounting portion 12b in the above-mentioned embodiment, or a set distance is maintained between one end of the battery cell 20 located in the main body 11 and facing the bottom cover 12 and one end of the main body 11 facing the bottom cover 12, that is, the battery cell 20 is only located within a partial range of the accommodating cavity s defined by the main body 11, and not within the range of the accommodating cavity s defined by the bottom cover 12, thereby ensuring that a set distance r is maintained between the battery cell 20 and the bottom cover 12 to form a buffer space.

[0126] It is understandable that when the battery pack 100 includes a plurality of battery cells 20, all of the battery cells 20 are spaced apart from the bottom cover 12. Further, in order to unify the size of the battery cells 20, the spacing distance between each battery cell 20 and the bottom cover 12 is equal.

[0127] In some embodiments, please refer to Figure 5 and Figure 6 The bottom cover 12 has a characteristic surface d facing the accommodating cavity s, and the characteristic surface d is configured as a plane.

[0128] The characteristic surface d faces the accommodating cavity s, indicating that the characteristic surface d is an inner surface of the bottom cover 12 that can define the accommodating cavity s. The characteristic surface d is configured as a plane, which means that in the arrangement direction of the main body 11 and the bottom cover 12, the characteristic surface d is a plane perpendicular to the arrangement direction. In actual conditions, when the main body 11 and the bottom cover 12 are arranged in the vertical direction, the characteristic surface d of the bottom cover 12 is a plane parallel to the horizontal plane. When the main body 11 and the bottom cover 12 are arranged in the horizontal direction, the characteristic surface d of the bottom cover 12 is a plane parallel to the vertical plane.

[0129] When the characteristic surface d is a plane, the characteristic surface d can maintain a relatively equal distance from each battery cell 20 contained in the accommodating cavity s (this distance can be zero). When the distance between the characteristic surface d and the battery cell 20 is relatively equal, the accommodating cavity s can accommodate more battery cells 20, that is, the space utilization rate of the accommodating cavity s is higher, the battery pack 100 can have a higher energy density, and the battery pack 100 has a higher endurance.

[0130] Understandably, when the bottom cover 12 has the cover portion 12a and the mounting portion 12b, the characteristic surface d can be formed by the inner surface of the cover portion 12a facing the accommodating cavity s. Further understandably, when the bottom cover 12 is spaced apart from the battery cell 20, the characteristic surface d is spaced apart from the battery cell 20.

[0131] In some embodiments, the outer surface of the cover portion 12a facing away from the accommodating cavity s is parallel to the characteristic surface d.

[0132] The outer surface of the cover 12a facing away from the accommodating cavity s is arranged opposite to the characteristic surface d in the vertical direction. The outer surface of the cover 12a is used to contact the atmospheric environment and withstand external force. When the outer surface of the cover 12a is a plane flush with the characteristic surface d, especially when the bottom cover 12 and the main body 11 are arranged at the bottom of the vehicle 1000 in the vertical direction and the bottom cover 12 is located at the lowest point of the battery pack 100, the outer surface of the cover 12a is flat, which can greatly reduce the wind resistance generated by the battery pack 100, help reduce the driving resistance of the vehicle 1000, reduce the driving energy consumption of the vehicle 1000, and improve the endurance of the battery pack 100.

[0133] Fig.10 for Figure 6 The schematic diagram of the vertical projection of the bottom cover 12 is shown, wherein S1 represents the projection area of ​​the characteristic surface d, and S2 represents the projection area of ​​the bottom cover 12.

[0134] In some embodiments, in the vertical direction, the area S1 of the orthographic projection of the characteristic surface d and the area S2 of the orthographic projection of the bottom cover 12 satisfy: S1 / S2≥0.2. Further, S1 / S2≥0.5.

[0135] exist Fig.10 In the embodiment shown, in the vertical orthographic projection, the characteristic surface d is formed by the first characteristic edge d1, the second characteristic edge d2, the third characteristic edge d3, and the fourth characteristic edge d4 connected end to end, and the orthographic projection area S1 of the characteristic surface d is the area defined by the first characteristic edge d1, the second characteristic edge d2, the third characteristic edge d3, and the fourth characteristic edge d4. The orthographic projection area S2 of the bottom cover 12 is the area defined by the edge of the bottom cover 12.

[0136] Specifically, the ratio of the area S1 of the orthographic projection of the characteristic surface d to the area S2 of the orthographic projection of the bottom cover 12 may be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0137] Table 2 Effect of the ratio of area S1 to area S2 on the range of battery pack 100

[0138]

[0139] Table 2 shows the influence of the ratio of the area S1 of the orthographic projection of several sets of characteristic surfaces d to the area S2 of the orthographic projection of the bottom cover 12 on the cruising range of the battery pack 100 tested according to the NEDC (New European Driving Cycle) standard. When S1 / S2 is less than 0.2, the cruising range of the battery pack 100 is poor. The reason is that when the characteristic surface d is small, the space utilization rate of the accommodating cavity s is low, the number of battery cells 20 accommodated in the battery pack 100 is small, and the energy density of the battery pack 100 is relatively low, resulting in a short cruising range of the battery pack 100 and poor test results. When the ratio of S1 / S2 reaches 0.2 or above (especially when S1 / S2 reaches 0.5 or above), as the ratio increases, the cruising range of the battery pack 100 is better. The reason is that the larger the characteristic surface d, the higher the space utilization rate of the accommodating cavity s, and the higher the energy density of the battery pack 100. Therefore, the cruising range of the battery pack 100 is getting higher and higher, and the test results are getting better and better.

[0140] Since the characteristic surface d is a plane, the larger the area of ​​the bottom cover 12 occupied by the characteristic surface d, the smaller the area of ​​the inner surface of the bottom cover 12 that is concave or convex relative to the characteristic surface d. The concave inner surface relative to the characteristic surface d will make part of the space in the accommodating cavity s irregular and unable to install the battery cell 20, resulting in low space utilization of the accommodating cavity s. Part of the space of the accommodating cavity s formed by the convex inner surface relative to the characteristic surface d is also irregular and unable to accommodate the battery cell 20, resulting in low space utilization of the accommodating cavity s. When the space utilization of the accommodating cavity s is low, the volume occupied by the battery cell 20 per unit space in the battery pack 100 is small, and the energy density of the battery pack 100 is low. Therefore, the larger the area of ​​the bottom cover 12 occupied by the characteristic surface d, the greater the space utilization of the battery pack 100, the higher the energy density of the battery pack 100, and the better the cruising range of the battery pack 100.

[0141] In some embodiments, please refer to Fig.10 , in the vertical direction, the orthographic projection of the characteristic surface d is rectangular.

[0142] like Fig.10As shown, the rectangular characteristic surface d is an area enclosed and defined by the first characteristic side d1, the second characteristic side d2, the third characteristic side d3 and the fourth characteristic side d4. In the battery pack 100, a plurality of battery cells 20 are mostly assembled to form a rectangular structure. The characteristic surface d is constructed in a rectangular shape, which can be adapted to the overall structure formed by the battery cells 20 in the battery pack 100, and is helpful to arrange more battery cells 20 in the accommodating cavity s, thereby improving the energy density of the battery pack 100.

[0143] Of course, in other embodiments, in the vertical direction, the orthographic projection of the characteristic surface d may also be in other shapes, such as a circle, a polygon, an ellipse, or other special shapes.

[0144] In the embodiment of the present application, the main body 11 includes a carrier 11 a .

[0145] The carrier 11a may be a component in the main body 11 used to define the accommodating cavity s (for example, the carrier 11a is the top cover or frame mentioned above), or a component not used to define the accommodating cavity s but located in the accommodating cavity s (for example, the carrier 11a is the support plate mentioned above), and the specific details are not limited. When the carrier 11a is used to define the accommodating cavity s, the carrier 11a may be a component in the main body 11 that is directly connected to the bottom cover 12 (such as the frame mentioned above), or a component that is not connected to the bottom cover 12 (such as the top cover mentioned above).

[0146] In some embodiments, the battery cells 20 are disposed on the surface of the carrier 11 a .

[0147] At this time, the carrier 11a is a component that can bear the weight of the battery cell 20, and can be a carrier plate, a carrier rod, a carrier block, a carrier sheet, a carrier frame, a carrier rope, etc., and is not specifically limited. Specifically, the battery cell 20 can be supported on the carrier 11a, and the battery cell 20 can be arranged above the carrier 11a. Specifically, the battery cell 20 can also be hung on the carrier 11a, and the battery cell 20 can be hung on the wall of the carrier 11a parallel to the gravity direction of the battery cell 20.

[0148] The battery cell 20 can be arranged above the carrier 11a (such as when the carrier 11a serves as a support plate located in the accommodating cavity s), the battery cell 20 can also be arranged below the carrier 11a (such as when the carrier 11a serves as a top cover for defining the accommodating cavity s), and the battery cell 20 can also be arranged on the side of the carrier 11a (such as when the carrier 11a serves as a frame for defining the accommodating cavity s).

[0149] In some embodiments, the battery cell 20 is bonded to the carrier 11 a .

[0150] Specifically, the battery cell 20 and the carrier 11a can be bonded with adhesives such as epoxy resin glue, acrylate glue, etc., which are not particularly limited. At this time, the battery cell 20 and the carrier 11a are bonded, which not only facilitates the connection, but also simplifies the structure of the battery pack 100.

[0151] In some embodiments, the battery cells 20 are disposed on the surface of the carrier 11 a , and the minimum thickness H of the carrier 11 a and the weight M of the battery pack 100 satisfy: 0.0002 mm / kg<H / M≤0.2 mm / kg.

[0152] The thickness of the carrier 11a refers to the distance between one side surface of the carrier 11a for arranging the battery cell 20 and the other side surface opposite to it. When the battery cell 20 is arranged on the vertical surface of the carrier 11a, the minimum thickness H of the carrier 11a refers to the minimum distance between the two side surfaces of the carrier 11a in the vertical direction. When the battery cell 20 is on the horizontal surface of the carrier 11a, the thickness of the carrier 11a refers to the minimum distance between the two side surfaces of the carrier 11a in the horizontal direction.

[0153] The weight of the battery pack 100 includes the total weight of the main body 11 , the bottom cover 12 , the battery cells 20 and other components (such as wiring harness, thermal management system, power management system, etc.).

[0154] Specifically, the ratio between the minimum thickness H of the carrier 11a and the weight M of the battery pack 100 can be designed to be: 0.0003mm / kg, 0.0005mm / kg, 0.0008mm / kg, 0.001mm / kg, 0.003mm / kg, 0.005mm / kg, 0.008mm / kg, 0.01mm / kg, 0.03mm / kg, 0.05mm / kg, 0.06mm / kg, 0.08mm / kg, 0.1mm / kg, 0.12mm / kg, 0.15mm / kg, 0.16mm / kg, 0.19mm / kg, 0.02mm / kg.

[0155] Table 3 Effect of the ratio of the minimum thickness H of the carrier 11a to the weight M of the battery pack 100 on the safety performance of the battery pack 100

[0156]

[0157]

[0158] Table 3 shows the effect of the ratio of the minimum thickness H of several groups of carriers 11a to the weight M of the battery pack 100 on the safety performance of the battery pack 100 tested according to the standard of GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". It can be seen from Table 3 that when the ratio of H / M does not exceed 0.0002mm / Kg, the battery pack 100 will catch fire and explode. The reason is that the structural strength of the battery pack 100 does not meet the requirements. When the ratio of H / M exceeds 0.0002mm / Kg, the battery pack 100 will not catch fire and explode. However, when H / M is too large (such as exceeding 0.1), due to the small weight of the battery pack 100 and the large thickness of the carrier plate, the battery pack 100 has a low proportion of battery cells 20 per unit volume, low space utilization, low energy density of the battery pack 100, and high cost of use of the battery pack 100. Furthermore, 0.0005mm / Kg≤H / M≤0.1mm / Kg. At this time, the structural strength of the battery pack 100 meets the requirements and the energy density of the battery pack 100 is relatively high. The battery pack 100 has a stronger endurance and will not cause safety accidents such as fire and explosion.

[0159] In some embodiments, the minimum thickness H of the carrier 11 a satisfies: 0.2 mm<H<20 mm.

[0160] Specifically, the minimum thickness H of the carrier 11a can be: 0.3mm, 0.5mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 9mm, 10mm, 12mm, 15mm, 16mm, 18mm, 19mm. Further, 0.5mm≤H≤10mm, at this time the carrier 11a has good structural strength, the overall strength of the battery pack 100 is good, and the battery pack 100 is not easy to catch fire and explode. At the same time, the carrier 11a occupies a small volume of the battery pack 100 as a whole, the space utilization rate of the battery pack 100 is high, and the energy density of the battery pack 100 is high.

[0161] In some embodiments, please refer to Figure 3 and Figure 4 , the battery cell 20 is suspended on the supporting member 11 a.

[0162] The battery cell 20 is suspended on the carrier 11a, which means that the battery cell 20 is arranged below the carrier 11a in the vertical direction, and the weight of the battery cell 20 is borne by the carrier 11a. The battery cell 20 is suspended on the carrier 11a in the following ways: the battery cell 20 is directly bonded to the lower surface of the carrier 11a, the battery cell 20 is connected to the carrier 11a through the fastener 13 and is located below the carrier 11a, the battery cell 20 is hung on the carrier 11a through a hook and is located below the carrier 11a, etc.

[0163] At this time, the battery cell 20 is suspended below the carrier 11a, and the bottom cover 12 is located at the bottom of the box 10. When the interior of the battery pack 100 is repaired, the battery cell 20 can be exposed by removing the bottom cover 12 without removing the carrier 11a, which makes the maintenance of the battery pack 100 more convenient. At the same time, when repairing the battery pack 100, the battery cell 20 can be disassembled and assembled on the carrier 11a from below. In particular, when the carrier 11a is subjected to force as at least a part of the chassis of the vehicle 1000, it is only necessary to disassemble and assemble the battery cell 20 from below the carrier 11a without removing the carrier 11a, which facilitates the maintenance of the battery pack 100.

[0164] Fig.11 Schematic diagram of the appearance of a battery cell 20 in some embodiments of the present application. Fig.12 for Fig.11 A front view of a battery cell 20 is shown.

[0165] In some embodiments, please refer to Figure 4 and Fig.11 The outer surface of the battery cell 20 facing the carrier 11 a is a first outer surface m1 . The battery cell 20 includes an electrode terminal 21 a . The electrode terminal 21 a is arranged on the outer surface of the battery cell 20 except the first outer surface m1 .

[0166] As described above, the electrode terminal 21a is used to electrically connect to the electrode assembly 23 inside the battery cell 20, so as to be used as a component for outputting or inputting the electrical energy of the battery cell 20. The electrode terminal 21a at least partially extends out of the battery cell 20 to be electrically connected to the outside. The series connection and parallel connection between the battery cells 20 are both realized through the series connection and parallel connection between their respective electrode terminals 21a. The electrode terminal 21a has conductivity to realize electrical transmission, and can be an aluminum electrode, a copper electrode, etc.

[0167] The electrode terminal 21a is arranged on the outer surface of the battery cell 20 except the first outer surface m1. The first outer surface m1 faces the carrier 11a, and is usually a smooth surface, on which there are no protruding or recessed structures such as the electrode terminal 21a and the injection hole. When the battery cell 20 is suspended on the carrier 11a, the first outer surface m1 is the outer surface of the battery cell 20 facing upward. Specifically in one embodiment, the battery cell 20 includes the shell 22 and the end cover 21 mentioned above, and the shell 22 and the end cover 21 form an internal environment for the battery cell 20 to accommodate the electrode assembly 23. The end cover 21 is located at one end of the shell 22, and the electrode terminal 21a is arranged on the end cover 21. At this time, any outer surface of the shell 22 can be used as the first outer surface m1 of the battery cell 20.

[0168] The electrode terminal 21a includes a positive terminal and a negative terminal, the positive terminal is used to be electrically connected to the positive electrode sheet in the electrode assembly 23, and the negative terminal is used to be electrically connected to the negative electrode sheet in the electrode assembly 23. It should be noted that the positive terminal and the negative terminal can be arranged on the same outer surface of the battery cell 20 (such as a square battery cell 20), or can be arranged on two different outer surfaces of the battery cell 20 (such as a cylindrical battery cell 20). When the positive terminal and the negative terminal are arranged on two different outer surfaces of the battery cell 20, the first outer surface m1 is a surface of the battery cell 20 that is different from the two outer surfaces.

[0169] In addition to the battery cells 20, the battery pack 100 is usually provided with components such as sampling harnesses, high-voltage wires, and protective structures for protecting the battery cells 20 that electrically connect the battery cells 20. At this time, the electrode terminal 21a is arranged on the surface of the battery cell 20 other than the first outer surface m1. When the sampling harness, high-voltage harness, protective structure, and other components are placed on the electrode terminal 21a, they will not be restricted by the carrier 11a, but can be arranged through the space between the battery cell 20 and the structure of the main body 11 other than the carrier 11a (such as through the space between the battery cell and the bottom cover and / or the space between the battery cell and the inner side of the main body), which is more convenient for the arrangement of each component. At the same time, since the first outer surface m1 is a smooth surface, the first outer surface m1 can be fitted with the carrier 11a, so that the battery cell 20 and the carrier 11a can be fitted and installed, and there is no need to reserve space between the battery cell 20 and the carrier 11a, which helps to improve the space utilization of the battery pack 100.

[0170] In some embodiments, please refer to Fig.11 and Fig.12 The battery cell 20 has a second outer surface m2 disposed opposite to the first outer surface m1, and the electrode terminal 21a is arranged on the second outer surface m2.

[0171] The second outer surface m2 is the outer surface of the battery cell 20 that is arranged opposite to the first outer surface m1. When the battery cell 20 is suspended on the carrier 11a, the second outer surface m2 is opposite to the bottom cover 12. As mentioned above, the battery cell 20 and the bottom cover 12 can be spaced apart. At this time, there is a buffer space between the second outer surface m2 and the bottom cover 12, and the portion of the electrode terminal 21a extending outside the battery cell 20 is located in the buffer space, so that the wiring harness and connecting piece connected to the electrode terminal 21a can be arranged in the buffer space. At the same time, the buffer space also has the function mentioned above of blocking the external force hitting the bottom cover 12 from acting on the battery cell 20 and damaging the battery cell 20. Therefore, the buffer space can not only interrupt the influence of external force, but also layout the wiring harness, etc., killing two birds with one stone. In addition, the space utilization of the buffer space and the battery pack 100 is also improved.

[0172] Of course, in other embodiments, refer to Fig.11 and Fig.12 , the electrode terminal 21 a may also be arranged on a third outer surface of the battery cell 20 intersecting with the first outer surface m1 .

[0173] In some embodiments of this application, please refer to Figure 4 , Figure 5 and Fig. 9 , the carrier 11a is located at the top of the box body 10, and is used to define the accommodating cavity s. Since the bottom cover 12 is located at the bottom of the box body 10, the carrier 11a is arranged opposite to the bottom cover 12. The carrier 11a serves as the structure at the top of the box body 10, and the box body 10 can be installed on the mounting body via the carrier 11a. At this time, the battery cell 20 arranged on the carrier 11a can strengthen the strength of the carrier 11a, thereby improving the rigidity of the top of the battery pack 100, so that the application scenario of the battery pack 100 can be expanded to the scenario where the top is subjected to force, such as being used as part of the chassis of the vehicle 1000.

[0174] Fig.13 Schematic diagram of the structure of the carrier 11a in some embodiments of the present application. Fig.14 Schematic diagram of the structure of the carrier 11a in some other embodiments of the present application. Fig.15 for Fig.14 The supporting member 11a is shown as an orthographic projection in the vertical direction.

[0175] In some embodiments, the carrier 11 a has a carrier surface f facing the accommodating cavity s, and the carrier surface f is configured as a plane.

[0176] The bearing surface f is the inner surface of the bearing member 11a facing the accommodating cavity s, and is used to define the accommodating cavity s. The bearing surface f is constructed as a plane, which means that in the arrangement direction of the main body 11 and the bottom cover 12, the bearing surface f is a plane perpendicular to the arrangement direction. In actual conditions, when the main body 11 and the bottom cover 12 are arranged in the vertical direction, the bearing member 11a and the bottom cover 12 are arranged opposite to each other in the vertical direction, and the bearing surface f of the bearing member 11a is a plane parallel to the horizontal plane. When the main body 11 and the bottom cover 12 are arranged in the horizontal direction, the bearing member 11a and the bottom cover 12 are arranged opposite to each other in the horizontal direction, and the bearing surface f of the bearing member 11a is a plane parallel to the vertical plane.

[0177] like Fig.13 As shown in FIG. 1 , the carrier 11a may be the entire inner surface of the carrier 11a facing the accommodating cavity s, and in this case, the carrier 11a may be in the shape of a flat plate. Fig.14 and Fig.15 As shown, the carrier 11a may also be a portion of the inner surface of the carrier 11a facing the accommodating cavity s. In this case, the bearing surface f is only the portion of the inner surface of the carrier 11a used to define the accommodating cavity s.

[0178] When the bearing surface f is a plane, the bearing surface f can maintain a relatively equal distance from each battery cell 20 contained in the accommodating cavity s (this distance can be zero). When the distance between the bearing surface f and the battery cell 20 is relatively equal, the accommodating cavity s can accommodate more battery cells 20, that is, the space utilization rate of the accommodating cavity s is higher, the battery pack 100 can have a higher energy density, and the battery pack 100 has a higher endurance.

[0179] In some embodiments, the battery cell 20 is disposed on the bearing surface f. The battery cell 20 is mounted on the bearing member 11a via the bearing surface f. The battery cell 20 can be bonded to the bearing surface f, fixedly connected to the bearing surface f via a fastener 13, etc., or welded or clamped to the bearing surface f, without limitation.

[0180] Since the bearing surface f is a plane, the bearing surface f can have a larger contact area with the battery cells 20 arranged on it, and the installation of the battery cells 20 is more stable. At the same time, when the bearing surface f is a plane, compared with an uneven surface such as a curved surface, the bearing surface f can be connected to a larger number of battery cells 20, which can increase the number of battery cells 20 installed in the battery pack 100, thereby improving the space utilization and energy density of the battery pack 100.

[0181] It can be understood that when the battery cell 20 is suspended on the supporting member 11 a , at this time, the battery cell 20 is suspended on the supporting surface f.

[0182] In some embodiments, in the vertical direction, the area N1 of the orthographic projection of the bearing surface f and the area N2 of the orthographic projection of the bearing member 11a satisfy: N1 / N2≥0.2. Further, N1 / N2≥0.5.

[0183] exist Fig.15 In the embodiment shown, in the vertical orthographic projection, the bearing surface f is formed by the first bearing edge f1, the second bearing edge f2, the third bearing edge f3 and the fourth bearing edge f4 connected end to end, and the orthographic projection area N1 of the bearing surface f is the area defined by the first bearing edge f1, the second bearing edge f2, the third bearing edge f3 and the fourth bearing edge f4. The orthographic projection area N2 of the bearing member 11a is the area defined by the edge of the bearing member 11a.

[0184] Specifically, the ratio of the area N1 of the orthographic projection of the bearing surface f to the area N2 of the orthographic projection of the bearing member 11a may be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0185] Table 4 Effect of the ratio of area N1 to area N2 on the range of battery pack 100

[0186]

[0187] Table 4 shows the influence of the ratio of the area N1 of the orthographic projection of several groups of bearing surfaces f to the area N2 of the orthographic projection of the bearing member 11a on the cruising range of the battery pack 100 when the test is carried out according to the NEDC (New European Driving Cycle) standard. When N1 / N2 is less than 0.2, the cruising range of the battery pack 100 is poor. The reason is that when the bearing surface f is small, the number of battery cells 20 carried on the bearing member 11a is small, the space utilization rate of the receiving cavity s is low, and the energy density of the battery pack 100 is relatively low, resulting in a short cruising range of the battery pack 100 and poor test results. When the ratio of N1 / N2 reaches 0.2 or above (especially when N1 / N2 reaches 0.5 or above), as the ratio increases, the cruising range of the battery pack 100 is better. The reason is that the larger the bearing surface f, the more battery cells 20 carried on the bearing member 11a, the higher the space utilization rate of the receiving cavity s, and the higher the energy density of the battery pack 100. Therefore, the cruising range of the battery pack 100 is getting higher and higher, and the test structure is getting better and better. When the carrier 11a is Fig.13 In the case of the flat plate structure shown, the orthographic projection area N1 of the carrying surface f is equal to the orthographic projection area N2 of the carrying member 11 a , and the battery pack 100 has the best battery life.

[0188] In some embodiments, in the vertical direction, the orthographic projection of the bearing surface f is rectangular.

[0189] like Fig.15 As shown, the rectangular bearing surface f is an area enclosed and defined by the first bearing edge f1, the second bearing edge f2, the third bearing edge f3 and the fourth bearing edge f4. In the battery pack 100, a plurality of battery cells 20 are mostly assembled to form a rectangular structure. The bearing surface f is constructed in a rectangular shape, which can be adapted to the overall structure formed by the battery, and is helpful to arrange more battery cells 20 in the accommodating cavity s, thereby improving the energy density of the battery pack 100.

[0190] Of course, in other embodiments, in the vertical direction, the orthographic projection of the bearing surface f may also be in other shapes, such as a circle, a polygon, an ellipse, or other special shapes.

[0191] In some embodiments, please refer to Fig.14 The carrier 11a has a carrier portion 11a1 and a connecting portion 11a2. The connecting portion 11a2 is connected to the edge of the carrier portion 11a1. The carrier portion 11a1 is used to define the accommodating cavity s. The connecting portion 11a2 is connected to the portion of the box body 10 other than the carrier 11a.

[0192] The bearing part 11a1 is used to define the accommodating cavity s, and the connecting part 11a2 is used to connect with the part of the box body 10 other than the bearing part 11a, and does not participate in the definition of the accommodating cavity s. The bearing part 11a1 can be a plate-shaped or block-shaped component, a flat plate-shaped component, or a curved plate-shaped component, which is not specifically limited. Fig.14 It can be seen that the connection part 11a2 is enclosed at the edge of the bearing part 11a1, which means that the connection part 11a2 is continuously connected along the edge of the bearing part 11a1 in a closed manner. It can be understood that in the vertical projection, the connection part 11a2 has a certain width, so that it can have an appropriate contact area with other structures of the box body 10 except the bearing part 11a, and more square edges can be used to realize the installation connection between the connection part 11a2 and other structures of the box body 10 except the bearing part 11a.

[0193] The bearing part 11a1 and the connecting part 11a2 can be integrally formed. When the bearing part 11a is made of metal (such as aluminum, iron, stainless steel, etc.), the bearing part 11a1 and the connecting part 11a2 can be integrally formed by die casting, forging, hot pressing, cold pressing, etc. When the bearing part 11a is made of plastic (such as PP, PE, ABS, etc.), the bearing part 11a1 and the connecting part 11a2 can be integrally formed by injection molding. The bearing part 11a1 and the connecting part 11a2 can also be connected together after being formed separately. When the bearing part 11a1 and the connecting part 11a2 are made of metal, the bearing part 11a1 and the connecting part 11a2 can be welded or bonded together. When the bearing part 11a1 and the connecting part 11a2 are made of plastic, the cover part 12a and the mounting part 12b can be bonded together. Of course, the bearing part 11a1 and the connecting part 11a2 can also be fixedly connected together by other methods such as clamping and riveting.

[0194] Specifically, the connection portion 11a2 is connected to the portion of the main body 11 other than the carrier 11a, and the connection method can be either integrally formed or fixedly connected. When the connection portion 11a2 is integrally formed with the portion of the main body 11 other than the carrier 11a, that is, the main body 11 is an integrally formed part, which can be integrally formed by die casting, forging, hot pressing, cold pressing, injection molding, etc. When the connection portion 11a2 is fixedly connected to the portion of the main body 11 other than the carrier 11a, it can be fixedly connected by fastening connection with a fastener 13, snap-fit ​​connection with a snap-fit ​​structure, etc., without specific limitation.

[0195] The bearing portion 11a1 and the connecting portion 11a2 may be located in the same plane. Specifically, the bearing portion 11a1 and the connecting portion 11a2 may have two surfaces facing the bottom cover 12 in the same plane, and / or the bearing portion 11a1 and the connecting portion 11a2 may have two surfaces facing away from the bottom cover 12 in the same plane. When the bearing portion 11a1 and the connecting portion 11a2 may have two surfaces facing the bottom cover 12 and two surfaces facing away from the bottom cover 12 in the same plane, the bearing portion 11a1 and the connecting portion 11a2 may form a flat bearing member 11a (such as Fig.13 shown).

[0196] The bearing portion 11a1 and the connecting portion 11a2 may not be located in the same plane. Specifically, the bearing portion 11a1 protrudes away from the accommodating cavity s relative to the connecting portion 11a2, or the bearing portion 11a1 is recessed relative to the connecting portion 11a2 toward the accommodating cavity s, which is not specifically limited. The thickness of the bearing portion 11a1 and the connecting portion 11a2 may be equal or different, which is not specifically limited.

[0197] At this time, the carrier 11a defines the accommodating cavity s via the carrier portion 11a1, and is connected to the structure of the main body 11 except the carrier 11a via the connecting portion 11a2, so the structure is clear.

[0198] It can be understood that when the carrier 11 a includes the carrier portion 11 a 1 and the connecting portion 11 a 2 , the battery cell 20 is disposed on the carrier portion 11 a 1 .

[0199] It can be understood that when the bearing member 11a includes the bearing portion 11a1 and the connecting portion 11a2, the inner surface of the bearing portion 11a1 facing the accommodating cavity s forms a bearing surface f.

[0200] In some embodiments, the carrying portion 11 a 1 is arranged to protrude in a direction away from the accommodating cavity s compared to the connecting portion 11 a 2 .

[0201] As can be seen from the above, the bearing portion 11a1 defines the accommodating cavity s, and the bearing portion 11a1 protrudes away from the accommodating cavity s, which means that the bearing portion 11a1 and the connecting portion 11a2 are staggered in the vertical direction. The bearing portion 11a1 is located at the highest point of the bearing member 11a. At this time, a certain space as a part of the accommodating cavity s can be formed between the bearing portion 11a1 and the connecting portion 11a2, and the space can accommodate the battery cell 20.

[0202] When the bearing portion 11a1 protrudes away from the accommodating cavity s compared to the connecting portion 11a2, the bearing portion 11a1 can serve as a reinforcement structure of the bearing component 11a to improve the bending resistance of the bearing component 11a.

[0203] In some embodiments, the thickness of the carrying portion 11 a 1 and the connecting portion 11 a 2 are equal.

[0204] When the bearing portion 11a1 and the connecting portion 11a2 have the same thickness, the bearing portion 11a1 and the connecting portion 11a2 can be integrally formed from the same plate material by die casting, cold pressing, or hot pressing, and the forming of the bearing member 11a is more convenient. At the same time, the bearing portion 11a1 and the connecting portion 11a2 have the same thickness, and the stress is equalized at all locations during forming, which can improve the forming rate of the bearing member 11a.

[0205] In some embodiments, an outer surface of the carrying portion 11 a 1 facing away from the accommodating cavity s is parallel to the carrying surface f.

[0206] The outer surface of the bearing portion 11a1 facing away from the accommodating cavity s is arranged opposite to the bearing surface f in the vertical direction. The outer surface of the bearing portion 11a1 can be in contact with the atmospheric environment. When the battery pack 100 is installed on the vehicle 1000, the bearing portion 11a1 with a flat outer surface can reduce the driving resistance of the vehicle 1000, reduce the driving energy consumption of the vehicle 1000, and improve the endurance of the battery pack 100.

[0207] In some embodiments, please refer to Figure 3 , Figure 4 and Fig. 9 The main body 11 includes a frame 11b and a carrier 11a. The frame 11b encloses a cavity q that is set through at both ends in the vertical direction. The bottom cover 12 and the carrier 11a are respectively covered at the opposite ends of the cavity q in the vertical direction. The bottom cover 12, the frame 11b and the carrier 11a together enclose a accommodating cavity s.

[0208] The frame 11b itself encloses a cavity q that passes through both ends in the vertical direction, the carrier 11a covers the top of the cavity q, and the bottom cover 12 covers the bottom of the cavity q, that is, the carrier 11a is located at the top of the box body 10 and is used to define the accommodating cavity s, and the bottom cover 12 is located at the bottom of the box body 10 and is used to define the accommodating cavity s. The frame 11b, the carrier 11a and the bottom cover 12 enclose the accommodating cavity s. The frame 11b, the carrier 11a and the bottom cover 12 can be made of the same material, such as aluminum alloy, copper alloy, steel, plastic, etc. Of course, the frame 11b, the carrier 11a and the bottom cover 12 can also be made of different materials, which is not specifically limited. In the vertical orthographic projection, the frame 11b can be rectangular, circular, polygonal, etc., which is not specifically limited.

[0209] When the carrier 11a includes the carrier portion 11a1 and the connection portion 11a2, the carrier 11a is connected to the frame 11b via the connection portion 11a2. When the bottom cover 12 includes the cover portion 12a and the mounting portion 12b, the bottom cover 12 is connected to the frame 11b via the mounting portion 12b.

[0210] At this time, based on the frame 11b, the carrier 11a and the bottom cover 12 are respectively connected to the two ends of the frame 11b in the vertical direction to form the accommodating cavity s of the battery pack 100, and the structure of the box body 10 is relatively simple.

[0211] In some embodiments, the carrier 11a and the frame 11b are fixedly connected or integrally formed. The carrier 11a and the frame 11b can be integrally formed by injection molding, die casting, forging, cold pressing, hot pressing, etc. The carrier 11a and the frame 11b can be fixedly connected by fastening members 13, snap-fitting structures, welding, bonding, hot-melt connection, etc.

[0212] When the carrier 11a and the frame 11b are integrally formed, the main body 11 is integrally formed, and the main body 11 only needs to be connected to the bottom cover 12 to realize the assembly of the box 10, which is convenient for assembling the box 10. When the carrier 11a and the frame 11b are fixedly connected, the molding process of the carrier 11a and the frame 11b is relatively easy, which can reduce the process cost of the box 10.

[0213] It can be understood that when the carrier 11a has a carrier portion 11a1 and a connecting portion 11a2, the connecting portion 11a2 is connected to the frame 11b. When the bottom cover 12 has a cover portion 12a and a mounting portion 12b, the mounting portion 12b is connected to the frame 11b.

[0214] Fig.16 for Figure 4 The front view of the battery pack 100 is shown. Fig.16 and Fig.12In some embodiments, in the vertical direction, the height Hc of the battery cell 20 and the height Hp of the battery pack 100 satisfy: 0.02≤Hc / Hp≤0.98.

[0215] The height Hc of the battery cell 20 refers to the maximum length of the battery cell 20 in the vertical direction when the main body 11 and the bottom cover 12 are arranged in the vertical direction. Fig.12 Taking the battery cell 20 as an example, when the first outer surface m1 of the battery cell 20 is disposed opposite to the outer surface where the electrode terminal 21a is located, the maximum length of the battery cell 20 refers to the distance between the electrode terminal 21a and the first outer surface m1. Of course, when the first outer surface m1 of the battery cell 20 is adjacent to the outer surface where the electrode terminal 21a is located, the height Hc of the battery cell 20 refers to the distance between the first outer surface m1 of the battery cell 20 and the outer surface disposed opposite thereto.

[0216] The height Hp of the battery pack 100 refers to the maximum length of the battery pack 100 in the vertical direction when the body 11 and the bottom cover 12 are arranged in the vertical direction.

[0217] Specifically, the ratio of the height Hc of the battery cell 20 to the height Hp of the battery pack 100 may be 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, or 0.98.

[0218] Table 5 Effect of the ratio of the height Hc of the battery cell 20 to the height Hp of the battery pack 100 on the safety of the battery pack 100

[0219]

[0220] Table 5 shows the influence of the ratio of the height Hc of several groups of battery cells 20 to the height Hp of the battery pack 100 on the safety of the battery pack 100, which were tested according to the standard of GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". It can be seen from Table 5 that when Hc / Hp exceeds 0.98, the height of the battery pack 100 occupied by the structure of the box 10 is very small, the strength of the box 10 cannot meet the requirements, and safety accidents such as fire and explosion will occur. When 0.02≤Hc / Hp, the structural strength of the box 10 can meet the requirements, and there will be no fire or explosion. When Hc / Hp is less than 0.2, although the structural strength of the box 10 can meet the requirements, the space utilization rate of the battery pack 100 is low and the energy density is too low.

[0221] Furthermore, 0.5≤Hc / Hp<0.94, not only the strength of the battery pack 100 meets the requirement and there will be no safety accidents such as fire and explosion, but also the space utilization rate of the battery pack 100 is high and the energy density of the battery pack 100 is high.

[0222] According to some embodiments of this application, please refer to Figure 3 and Figure 4 The present application provides a bolted battery pack 100, including a box body 10 and a battery cell 20. The box body 10 includes a main body 11 and a bottom cover 12 detachably connected to the bottom of the main body 11. The main body 11 and the bottom cover 12 together enclose a receiving cavity s for receiving the battery cell 20. At this time, the main body 11 can be directly installed on the mounting body, and the bottom cover 12 and the main body 11 together form a receiving cavity s. When the components in the receiving cavity s (such as the battery cell 20) need to be replaced or maintained, the components in the battery pack 100 can be exposed and maintained or replaced by removing the bottom cover 12, without removing the entire battery pack 100 from the mounting body, which greatly improves the convenience of maintenance of the battery pack 100.

[0223] On the other hand, the present application also provides an electric device. The electric device includes a battery pack 100 provided in any of the above embodiments, and the battery pack 100 is used to provide electric energy for the electric device. The introduction of the electric device is referred to the records in the above description, and will not be repeated here.

[0224] Since the electrical device includes the battery pack 100, it has all the beneficial effects of the above embodiments, which will not be described in detail here.

[0225] Fig.17 This is a schematic diagram of a battery pack 100 applied to a vehicle body 200 in some embodiments of the present application. Fig.18 for Fig.17 Diagram of the first exploded state of the structure shown. Fig.19 for Fig.17 A second exploded state diagram of the structure shown.

[0226] In some embodiments, please refer to Figures 17 to 19 The electric device includes a vehicle 1000, and a battery pack 100 is disposed at the bottom of a vehicle body 200 of the vehicle 1000. The introduction of the vehicle 1000 is described in the above description, and will not be repeated here.

[0227] The body 200 of the vehicle 1000 refers to the part of the vehicle 1000 used to carry people and cargo, including the cockpit, passenger compartment, engine compartment, luggage compartment, etc. The body 200 generally includes a body 200 shell 22 and doors, windows, decorative parts, seats, air conditioning devices, etc. arranged on the body 200 shell 22. The body 200 shell 22 generally refers to a structure composed of the main load-bearing components such as the longitudinal beams, cross beams, chassis and pillars of the vehicle 1000 and the sheet metal parts connected to them. In the embodiment of the present application, the battery pack 100 is arranged at the bottom of the body 200 mainly refers to the battery pack 100 being arranged at the bottom of the body 200 shell 22.

[0228] At this time, the battery pack 100 is arranged at the bottom of the vehicle body 200 , which does not occupy the space inside the vehicle body 200 and helps to reduce the volume and weight of the vehicle body 200 .

[0229] Fig. 20 Schematic diagram of the installation relationship between the battery pack 100 and the vehicle body 200 in some embodiments of the present application. Fig. 20 The main body 11 includes a supporting member 11a located at the top of the box body 10, and the supporting member 11a is used to define the accommodating cavity s. In the vertical direction, the distance L between the supporting member 11a and the vehicle body 200 satisfies: L≥0.

[0230] Since the battery pack 100 is located at the bottom of the vehicle body 200 and the carrier 11a is located at the top of the box 10, the carrier 11a in the battery pack 100 is closest to the vehicle body 200. The distance L between the carrier 11a and the vehicle body 200 refers to the distance between the highest point of the carrier 11a and the vehicle body 200 located above it in the vertical direction. When the carrier 11a includes the above-mentioned carrier portion 11a1 and the above-mentioned connecting portion 11a2, the distance L between the carrier 11a and the vehicle body 200 is the distance between the outer surface of the carrier portion 11a1 facing away from the accommodating cavity s and the vehicle body 200 located above it.

[0231] When the distance L between the carrier 11a and the vehicle body 200 is equal to 0, the carrier 11a fits the vehicle body 200, and when the distance L between the carrier 11a and the vehicle body 200 is greater than 0, the carrier 11a is spaced apart from the vehicle body 200 and does not fit. Understandably, at this time, the bottom cover 12 is at the bottom of the carrier 11a, and the distance g between the bottom cover 12 and the vehicle body 200 is greater than 0.

[0232] When the battery pack 100 is disposed under the vehicle body 200, the range from the bottom of the battery pack 100 to the vehicle body 200 is the installation space occupied by the battery pack 100. When the carrier 11a is spaced from the vehicle body 200, there will be a certain amount of wasted space between the battery pack 100 and the vehicle body 200. If the carrier 11a is fitted with the vehicle body 200, the wasted space between the battery pack 100 and the vehicle body 200 can be included in the space range of the battery pack 100. In this way, when the battery pack 100 occupies the same space under the vehicle body 200, the fitting of the battery pack 100 with the vehicle body 200 can increase the volume of the battery pack 100, thereby increasing the power and energy density of the battery pack 100.

[0233] At this time, when the distance L between the carrier 11a and the vehicle body 200 is zero, the battery pack 100 can have a large amount of power and a high energy density, and the vehicle 1000 has a strong endurance. When the distance L between the carrier 11a and the vehicle body 200 is greater than zero, the installation of the carrier 11a is more flexible.

[0234] In some embodiments, please refer to Figures 17 to 19 The main body 11 includes a carrier 11 a located at the top of the box body 10 , and the carrier 11 a is used to define the accommodating cavity s. The battery pack 100 is installed on the vehicle body 200 via the carrier 11 a.

[0235] Since the battery pack 100 is located at the bottom of the vehicle body 200 and the carrier 11a is located at the top of the box 10, the carrier 11a in the battery pack 100 is closest to the vehicle body 200, and the battery pack 100 is installed on the vehicle body 200 via the carrier 11a. Specifically, the carrier 11a can be fixed to the vehicle body 200 via fasteners 13 (such as screws, bolts, rivets, etc.), welding, etc.

[0236] When the battery cell 20 is disposed on the carrier 11 a , the structure formed by the battery cell 20 and the carrier 11 a is connected to the vehicle body 200 , which can improve the top strength of the battery pack 100 and further improve the installation strength of the battery pack 100 .

[0237] In some embodiments, the carrier 11 a is configured to form at least a portion of a chassis of the vehicle body 200 .

[0238] As a part of the vehicle body 200, the chassis is composed of a transmission system, a running system, a steering system and a braking system. It is used to support and install the engine of the vehicle 1000 and its components and assemblies to form the overall shape of the vehicle 1000, bear the engine power and ensure normal driving.

[0239] The chassis is located at the bottom of the vehicle body 200, and the carrier 11a directly serves as at least a part of the chassis. That is, the carrier 11a is used to form at least a part of the chassis of the vehicle body 200. In this way, the carrier 11a is integrated with the chassis of the vehicle body 200, so that the space occupied by the gap between the traditional chassis and the battery pack 100 can be divided into the battery pack 100 to increase the space of the battery pack 100, which helps to increase the energy of the battery pack 100, and further improve the endurance of the vehicle 1000.

[0240] According to some embodiments of this application, please refer to Figures 17 to 19 The electric device includes a vehicle 1000, and a battery pack 100 is arranged at the bottom of a vehicle body 200 of the vehicle 1000. The battery pack 100 includes a box body 10 and a battery cell 20, the box body 10 includes a carrier 11a located at the top thereof, the battery cell 20 is located in the box body 10 and suspended on the carrier 11a, and the electrode terminal 21a of the battery cell 20 is located on the outer surface of the battery cell 20 away from the carrier 11a, and the carrier 11a forms at least a part of the chassis of the vehicle 1000.

[0241] At this time, the battery cell 20 is suspended on the carrier 11a, which can improve the strength of the carrier 11a and thus improve the strength of the top of the battery cell 20, so that the carrier 11a can meet certain force requirements when used as a chassis. At the same time, the electrode terminal 21a of the battery cell 20 is away from the carrier 11a, and the battery cell 20 can be directly installed on the carrier 11a, eliminating the gap between the battery cell 20 and the carrier 11a, and the saved gap is used to increase the installation space of the battery cell 20, which can improve the energy of the battery pack 100 and thus improve the endurance of the vehicle 1000.

[0242] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0243] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A battery pack, comprising: Battery cells; and A box body, comprising a main body and a bottom cover detachably connected to the bottom of the main body, wherein the main body and the bottom cover together enclose a receiving cavity for receiving the battery cell; The main body includes a bearing member located at the top of the box body, the bearing member is used to define the accommodating cavity, and the battery cell is suspended from the bearing member; The battery cell is bonded to the carrier; Wherein, the bottom cover is detachably connected to the main body via a fastener.

2. The battery pack according to claim 1, wherein: The bottom cover comprises a cover portion and a mounting portion, wherein the mounting portion is enclosed and connected to the edge of the cover portion, the cover portion is used to define the accommodating cavity, and the mounting portion is detachably connected to the main body.

3. The battery pack according to claim 2, wherein: The cover portion is protruded from the mounting portion in a direction away from the accommodating cavity.

4. The battery pack according to any one of claims 1 to 3, wherein: The minimum thickness h of the bottom cover satisfies: 0.2 mm<h<20 mm.

5. The battery pack according to any one of claims 1 to 3, wherein: The weight m of the battery cell and the minimum thickness h of the bottom cover satisfy: 0.03 mm / Kg≤h / m≤100 mm / Kg.

6. The battery pack according to any one of claims 1 to 3, wherein: The battery cell is spaced apart from the bottom cover.

7. The battery pack according to claim 1, wherein: An outer surface of the battery cell facing the carrier is a first outer surface. The battery cell includes an electrode terminal. The electrode terminal is arranged on an outer surface of the battery cell except the first outer surface.

8. The battery pack according to claim 7, wherein: The battery cell has a second outer surface disposed opposite to the first outer surface, and the electrode terminal is arranged on the second outer surface.

9. The battery pack according to any one of claims 1 to 3, wherein: The main body includes a supporting member and a frame, the frame encloses a cavity with two through-going ends in the vertical direction, the bottom cover and the supporting member respectively cover the opposite ends of the cavity in the vertical direction, and the bottom cover, the frame and the supporting member together enclose the accommodating cavity.

10. The battery pack according to claim 9, wherein: The carrier is fixedly connected to the frame or formed integrally with it.

11. An electrical device, comprising the battery pack according to any one of claims 1 to 10, wherein the battery pack is used to provide electrical energy for the electrical device.

12. The electrical device according to claim 11, wherein: The power-consuming device includes a vehicle, and the battery pack is arranged at the bottom of the vehicle body.

13. The electrical device according to claim 12, wherein: The main body includes a bearing member located at the top of the box body, and the bearing member is used to define the accommodating cavity; The battery pack is mounted on the vehicle body via the carrier.

14. The electrical device according to claim 13, wherein: The carrier is configured to form at least a portion of the vehicle body chassis.

Images