Battery pack and electric device

Abstract

The application relates to a battery pack (100) and a power utilization device, comprising a box (10) and a battery monomer (20), the box (10) is enclosed to form a containing cavity (s), the box (10) comprises a bottom cover (12) located at the bottom of the box (10) and used for defining the containing cavity (s), and the battery monomer (20) is contained in the containing cavity, wherein the bottom cover (12s) has a characteristic surface (d) facing the containing cavity (s), and the characteristic surface (d) is configured as a plane.

Description

Technical Field

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

[0002] With the increasing maturity of new energy technologies, 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] The driving range of battery packs has always been a focus of attention in the field of new energy vehicles. Currently, the driving range of battery packs is generally not high, and improving the driving range of battery packs is an urgent problem to be solved. Summary of the Invention

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

[0005] In a first aspect, this application provides a battery pack, including a housing and battery cells. The housing is enclosed to form a receiving cavity. The housing includes a bottom cover located at its bottom and used to define the receiving cavity. The battery cells are received within the receiving cavity. The bottom cover has a feature surface facing the receiving cavity, and the feature surface is configured as a plane.

[0006] In the scheme of this application, when the feature surface is planar, the feature surface can maintain a relatively equal distance (this distance can be zero) from each battery cell housed in the housing cavity. When the distance between the feature surface and the battery cell is relatively equal, the housing cavity can accommodate more battery cells, that is, the space utilization rate of the housing cavity is higher, the battery pack can have a higher energy density, and the battery pack has a longer range.

[0007] In some embodiments, the area S1 of the orthographic projection of the feature surface and the area S2 of the orthographic projection of the bottom cover satisfy: S1 / S2≥0.2. In this case, the battery pack has high energy density and good range.

[0008] In some embodiments, the orthographic projection of the feature surface in the vertical direction is rectangular. In this case, more battery cells can be arranged within the housing cavity, increasing the energy density of the battery pack.

[0009] In some embodiments, the bottom cover has a cover portion and a mounting portion, the mounting portion surrounding and connecting to the edge of the cover portion, the cover portion defining the receiving cavity, and the mounting portion being mounted on the portion of the housing excluding the bottom cover. The cover portion is configured to form the feature surface on its inner surface facing the receiving cavity. In this case, the bottom cover defines the receiving cavity via the cover portion and is connected to the main body via the mounting portion, resulting in a clear structure and convenient installation.

[0010] In some embodiments, the outer surface of the cover, which faces away from the receiving cavity, is parallel to the feature surface. In this case, the planar outer surface of the cover can significantly reduce the wind resistance generated by the battery pack, which helps to reduce vehicle drag, reduce vehicle energy consumption, and improve the battery pack's range.

[0011] In some embodiments, the cover portion protrudes from the mounting portion in a direction away from the receiving 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 reinforcing structure for the bottom cover, improving the bending resistance of the bottom cover.

[0012] In some embodiments, the thickness of the cover portion and the mounting portion are equal. In this case, the structure of the bottom cover is simpler and the processing is more convenient.

[0013] In some embodiments, the bottom cover and the battery cells are spaced apart. In this case, it can prevent external forces acting on the bottom cover from being transmitted to the battery cells and damaging them. 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 and other objects on the ground can easily fly to the bottom of the battery pack and hit the bottom cover during vehicle operation. In this case, the buffer space can interrupt the transmission of external forces to the battery cells and prevent them from being affected.

[0014] In some embodiments, the housing further includes a support member located on its top, which defines a receiving cavity, and the battery cells are suspended from the support member. In this case, the battery cells are suspended below the support member, and the bottom cover is located at the bottom of the housing. When performing internal maintenance on the battery pack, the battery cells can be exposed by removing the bottom cover without removing the support member. Simultaneously, when maintaining the battery pack, the battery cells can be installed and removed from below onto the support member, especially when the support member is at least part of the vehicle chassis and bears stress; in this case, the battery cells can be installed and removed only from below the support member without removing the support member itself, facilitating battery pack maintenance. Furthermore, the battery cells suspended on the support member strengthen the support member, thereby increasing the rigidity of the top of the battery pack.

[0015] In some embodiments, the outer surface of the battery cell facing the carrier is the first outer surface. The battery cell includes electrode terminals, which are arranged on the outer surface of the battery cell other than the first outer surface. In this case, with the electrode terminals located on the outer surface of the battery cell other than the first outer surface, various components connecting the electrode terminals (such as sampling harnesses, high-voltage harnesses, protective structures, 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, making the arrangement of each component more convenient. Furthermore, by connecting the battery cell to the carrier through the first outer surface without electrode terminals, the battery cell and the carrier can be fitted together, saving space between the battery cell and the carrier and improving the space utilization rate of the battery pack.

[0016] In some embodiments, the battery cell has a second outer surface disposed opposite to the first outer surface, and electrode terminals are arranged on the second outer surface. In this case, a buffer space exists between the second outer surface and the bottom cover, and the portion of the electrode terminals extending beyond the battery cell is located within this buffer space. Thus, wiring harnesses and connecting pieces connected to the electrode terminals can be arranged within the buffer space. Simultaneously, the buffer space can also prevent external forces striking the bottom cover from damaging the battery cell. Therefore, the buffer space not only interrupts the influence of external forces but also allows for the arrangement of wiring harnesses, etc., achieving two benefits at once.

[0017] In some embodiments, the battery cells are bonded to the carrier. This not only facilitates the connection between the battery cells and the carrier but also simplifies the structure of the battery pack.

[0018] In some embodiments, the main body includes a frame and a carrier. The frame encloses a cavity that extends through both ends in the vertical direction. The bottom cover and the carrier respectively cover the opposite ends of the cavity in the vertical direction. The bottom cover, frame, and carrier together enclose a receiving cavity. In this case, the receiving cavity of the battery pack can be formed by using the frame as a base and connecting the carrier and the bottom cover to the vertical ends of the frame, resulting in a relatively simple box structure.

[0019] In some embodiments, the carrier component is fixedly connected to the frame or integrally formed. When the carrier component and the frame are integrally formed, and the main body is integrally formed, the main body only needs to be connected to the bottom cover to achieve the assembly of the box, making the assembly of the box convenient. When the carrier component is fixedly connected to the frame, the forming process of the carrier component and the frame is relatively simple, which can reduce the manufacturing cost of the box.

[0020] Secondly, this application also provides an electrical device, including the aforementioned battery pack, which is used to provide electrical energy to the electrical device.

[0021] In some embodiments, the electrical device includes a vehicle, and the battery pack is disposed at the bottom of the vehicle body. In this case, placing the battery pack at the bottom of the vehicle body does not occupy interior space, which helps to reduce the vehicle's size and weight.

[0022] In some embodiments, the main body includes a carrier located at the top of the housing, the carrier defining a receiving cavity, and the battery pack being mounted to the vehicle body via the carrier. When individual battery cells are mounted on the carrier, the structure formed by the battery cells and the carrier is connected to the vehicle body, which can improve the top strength of the battery pack, thereby improving the installation strength of the battery pack.

[0023] In some embodiments, the carrier is configured to form at least a portion of the vehicle chassis. In this case, the space occupied by the gap between the conventional chassis and the battery pack can be allocated within 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 vehicle's range.

[0024] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0027] Figure 2 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0028] Figure 3 This is a schematic diagram of the structure of a battery pack provided in some embodiments of this application;

[0029] Figure 4 for Figure 3 The diagram shown is an exploded view of the battery pack.

[0030] Figure 5 This is a schematic diagram of the structure of the bottom cover provided in some embodiments of this application;

[0031] Figure 6 for Figure 5 Top view of the bottom cover;

[0032] Figure 7 for Figure 5 The front view of the bottom cover is shown;

[0033] Figure 8 This is a schematic diagram of the structure of the bottom cover provided in some other embodiments of this application;

[0034] Figure 9 for Figure 4 A cross-sectional view of the battery pack shown;

[0035] Figure 10 for Figure 6 The diagram shows the orthographic projection of the bottom cover in the vertical direction;

[0036] Figure 11 This is a schematic diagram of the external shape of a single battery cell in some embodiments of this application;

[0037] Figure 12 for Figure 11 The front view of the battery cell shown;

[0038] Figure 13 This is a schematic diagram of the structure of the carrier in some embodiments of this application;

[0039] Figure 14 This is a schematic diagram of the structure of the carrier in some other embodiments of this application;

[0040] Figure 15 for Figure 14 The above is a vertical orthographic projection of the support component.

[0041] Figure 16 for Figure 4 The front view of the battery pack shown;

[0042] Figure 17 This is a schematic diagram illustrating the application of a battery pack to a vehicle body in some embodiments of this application;

[0043] Figure 18 for Figure 17 The first decomposition state diagram of the structure shown;

[0044] Figure 19 for Figure 17 The second decomposition state diagram of the structure shown;

[0045] Figure 20 This is a schematic diagram illustrating the installation relationship between the battery pack and the vehicle body in some embodiments of this application.

[0046] 1000, Vehicle; 100, Battery Pack; 200, Vehicle Body; 10, Housing; 11, Main Body; 11a, Support Component; 11a1, Supporting Part; 11a2, Connecting Part; 11b, Frame; 12, Bottom Cover; 12a, Cover Part; 12b, Mounting Part; 12c, Fixing Hole; 13, Fastener; s, Receiving Cavity; q, Cavity; f, Supporting Surface; f1, First Supporting Edge; f2, Second Supporting Edge; f3, Third Supporting Edge; f4, Fourth Supporting Edge; d, Feature Surface; d1, First Featureing Edge; d2, Second Featureing Edge; d3, Third Featureing Edge; d4, Fourth Featureing Edge; 20, Battery Cell; 21, End Cap; 21a, Electrode Terminal; 22, Housing; 23, Electrode Assembly; m1, First Outer Surface; m2, Second Outer Surface; m3, Third Outer Surface. Detailed Implementation

[0047] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0049] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0050] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0051] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0053] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0054] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0055] Currently, judging from market trends, battery packs are being used more and more widely. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As the application areas of battery packs continue to expand, the market demand is also constantly increasing.

[0056] The inventors have noticed that the bottom cover of existing battery pack housings is usually designed to protrude outwards. The purpose of this design is to prevent the external force that hits the bottom cover from being transmitted to the individual battery cells through the bottom cover. As a result, the space occupied by the protruding bottom cover reduces the space utilization of the battery pack, which in turn reduces the energy density of the battery pack and is not conducive to improving the battery pack's range.

[0057] To improve the battery pack's range, the applicant discovered that the bottom cover could be designed as a flat plate to reduce its footprint on the housing and maximize the space available for installing individual battery cells, thereby increasing the battery pack's energy density and range.

[0058] Based on the above considerations, and to improve the safety and lifespan of the battery pack, the inventors, after in-depth research, designed a battery pack comprising a housing and individual battery cells. The housing encloses a cavity, and includes a bottom cover at its bottom that defines the cavity. The battery cells are housed within the cavity. The bottom cover has a planar feature surface facing the cavity. When the feature surface is planar, it can maintain a relatively even distance (this distance can be zero) from each battery cell housed within the cavity. When the distance between the feature surface and the battery cells is relatively even, the cavity can accommodate more battery cells, resulting in higher space utilization, higher energy density, and longer battery life.

[0059] The battery packs disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using the battery packs disclosed in this application. The mounting structure involved in this application is a structure used to mount the battery pack in an electrical device.

[0060] This application provides an electrical device that uses a battery pack as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0061] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0062] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery pack 100 is disposed inside the vehicle 1000, and the battery pack 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery pack 100 can be used to power the vehicle 1000; for example, the battery pack 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller and a motor. The controller is used to control the battery pack 100 to supply power to the motor, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0063] In some embodiments of this application, the battery pack 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0064] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery cell 20 refers to the smallest unit that makes up the battery pack 100. For example... Figure 2 As shown, the battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0065] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved safety. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection portion 11a2 within the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating element may be made of plastic, rubber, etc.

[0066] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0067] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 11 of the electrode assembly 23, while the portions without active material are formed separately. The positive and negative electrode tabs may be located together at one end of the main body 11 or at opposite ends of the main body 11. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 21a to form a current loop.

[0068] Figure 3 This is a schematic diagram of the structure of the battery pack 100 provided in some embodiments of this application. Figure 4 for Figure 3 The diagram shows an exploded view of the battery pack 100. For some embodiments of this application, please refer to... Figure 3 and Figure 4 This application provides a battery pack 100, including a battery cell 20 and a housing 10. The housing 10 has a receiving cavity s, in which the battery cell 20 is received.

[0069] In the battery pack 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel connections. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery pack 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. The battery pack 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20. Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0070] The box 10 can be in various shapes, such as a cylinder or a cuboid, and the specific structure of the box 10 can adopt various structural methods.

[0071] In some embodiments, please continue to refer to Figure 3 and Figure 4 The housing 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 cavity s for accommodating the battery cell 20.

[0072] The main body 11 can be a one-piece structure or assembled from multiple parts. The main body 11 can be a hollow shell structure 22, defining a first space with an open bottom. A bottom cover 12 closes to the open portion of the first space. The bottom cover 12 can be a hollow structure with an opening on one side, and can possess a second space. The second space of the bottom cover 12 and the first space of the main body 11 together form a receiving cavity s. Alternatively, the bottom cover 12 may not possess a space forming the receiving cavity s. When the bottom cover 12 is placed over the open portion 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 together form a receiving cavity s equivalent to the first space. In this case, the bottom cover 12 can be a flat structure. Of course, the receiving cavity s of the box 10 can also be formed from a portion of the first space of the main body 11. In this case, the bottom cover 12 closes to the open portion of the first space and recesses into the first space, occupying a portion of the first space. The first space, excluding the portion occupied by the bottom cover 12, forms the receiving cavity s of the box 10.

[0073] Understandably, at this time, the bottom cover 12 is located at the bottom of the housing 10 and is used together with the main body 11 to define the receiving cavity s. Specifically, the bottom cover 12 may be, but is not limited to, a plate-like structure, a block-like structure, etc., and may be flat, curved, etc., without specific limitations.

[0074] When the battery cell 20 is located in the receiving cavity s, the battery cell 20 can be disposed on the bottom cover 12 and / or the main body 11.

[0075] When the main body 11 is assembled from multiple components, the battery cell 20 can be disposed on one of the components or on all the components. In one embodiment, the main body 11 may include a top cover (not shown), a surrounding plate (not shown), and a support plate (not shown). The surrounding plate encloses a third space with openings at both ends in the vertical direction. The top cover and bottom cover 12 respectively seal and cover the vertical ends of the third space. The top cover, surrounding plate, and bottom cover 12 together enclose a receiving cavity s. The support plate is located within the third space, and the battery cell 20 is supported on the support plate. In other embodiments, the main body 11 may include a carrier 11a and a frame 11b described below, as detailed below.

[0076] The bottom cover 12 and the main body 11 can be fixed together by welding, hot-melt connection, bonding, fastening, snap-fitting, etc. Fastening refers to the connection using fasteners 13, which include bolts, pins, rivets, dowels, screws, etc. Snap-fitting refers to fixing through a snap-fit ​​structure; for example, the bottom cover 12 has a hook, and the main body 11 has a latch. When the hook engages with the latch, the bottom cover 12 and the main body 11 are locked together. Of course, the connection methods between the bottom cover 12 and the main body 11 are not limited to these, and are not exhaustively described in this application.

[0077] In some embodiments, the bottom cover 12 is sealed to the body 11 and together form a closed receiving cavity s.

[0078] There are several ways to seal the bottom cover 12 and the main body 11, including but not limited to: setting a sealing element between the bottom cover 12 and the main body 11, and sealing the bottom cover 12 and the main body 11 through the sealing element; sealing the bottom cover 12 and the main body 11 through sealant; or sealing the bottom cover 12 and the main body 11 by interlocking with each other through a barrier structure formed by the interlocking surfaces.

[0079] At this time, the battery pack 100's housing 10 forms a sealed receiving cavity s by its own bottom cover 12 and its own body 11. There is no need to set other sealing structures inside the housing 10, which simplifies the structure of the battery pack 100, reduces the cost of the battery pack 100, and ensures the safety and service life of the battery pack 100.

[0080] In the description of this application, the bottom cover 12 of the battery pack 100 is located at the bottom of the main body 11, that is... Figure 3 and Figure 4 The bottom cover 12, located at the bottom of the main body 11, is positioned at the top and bottom. In actual use, Figure 3 and Figure 4 The vertical orientation shown may be, but is not limited to, vertical, depending on the actual installation of the battery pack 100. It should be noted that in the following description of this application, the positional relationships and dimensions of the various structures of the battery pack 100 are described with reference to the vertical direction. This is not a limitation on the usage of the battery pack 100, but only to more clearly illustrate and explain the solution.

[0081] In some embodiments, the bottom cover 12 is sealed to the body 11 via a seal.

[0082] A seal is a component that prevents fluid or solid particles from leaking between adjacent mating surfaces, preventing external impurities such as dust and moisture from entering the battery pack 100. The seal connects the main body 11 and the bottom cover 12 by connecting the seal between the two opposing surfaces of the main body 11 and the bottom cover 12, and has a ring-shaped contact interface with these two surfaces. This prevents external moisture from entering the battery pack 100 through the contact surface between the seal and the two surfaces, thus achieving a sealing effect.

[0083] The sealing element can be a sealing ring or a sealing gasket. Specifically, the sealing element can be made of materials such as rubber or silicone. Specifically, the sealing element can be an O-ring, a square seal, or a non-circular seal. The specific shape of the sealing element can be adapted to the shape of the two opposing surfaces of the bottom cover 12 and the main body 11. For example, when the two opposing surfaces of the bottom cover 12 and the main body 11 are annular surfaces, the sealing element can be an O-ring.

[0084] At this time, the bottom cover 12 is sealed to the main body 11 through a sealing element, which is reliable and low cost.

[0085] It should be noted that after the bottom cover 12 is sealed to the main body 11 by the sealing element, it can also be fixedly connected to the main body 11 by other means. Other means include, but are not limited to, snap-fit, plug-in, threaded connection, riveting, welding, and bonding. Understandably, when the bottom cover 12 is sealed to the main body 11 by sealant, depending on the adhesive properties of the sealant, if the adhesive performance of the sealant meets the requirements (i.e., the bottom cover 12 and the main body 11 are fixed and do not separate), it is not necessary to use other means to fix the two together.

[0086] In some embodiments, the bottom cover 12 is detachably attached to the bottom of the body 11.

[0087] 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 in which it is fully connected to the main body 11 and forms a receiving cavity s, and a second state in which it is not fully 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.

[0088] When the bottom cover 12 is in a second state relative to the main body 11, where it is not fully connected to the main body 11 and the receiving 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 fastener 13 or a snap-fit ​​method. When the bottom cover 12 rotates relative to the main body 11 to close the receiving cavity s, the bottom cover 12 and the main body 11 can be fixedly connected via fastener 13 or a snap-fit ​​method, and the battery cell 20 is accommodated in the receiving cavity s and is not visible. 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 rotate relative to the main body 11 to open the receiving cavity s and expose the position of the battery cell 20. At this time, the bottom cover 12 is in the second state. The rotatable connection between the bottom cover 12 and the main body 11 can be, but is not limited to, a rotatable connection between the bottom cover 12 and the main body 11 via a pivot.

[0089] When the bottom cover 12 is in a second state relative to the main body 11, separating from the main body 11 and opening the receiving cavity s, the bottom cover 12 and the main body 11 can be installed in a way that the bottom cover 12 and the main body 11 are fixedly connected only by fasteners 13 or by a snap-fit ​​mechanism. When the fasteners 13 are installed on the bottom cover 12 and the main body 11, or when the snap-fit ​​structure of the bottom cover 12 and the main body 11 is engaged, the bottom cover 12 and the main body 11 are completely fixed and together form the receiving cavity s, in which case the battery cell 20 is contained within the receiving cavity s and is not visible. At this time, the bottom cover 12 is in the first state. When the fasteners 13 are 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.

[0090] When the bottom cover 12 is in the first state, it forms a receiving cavity s with the main body 11, which can protect the battery cell 20. When the bottom cover 12 is in the second state, the battery pack 100 is exposed, which makes it convenient for relevant personnel to maintain or replace the battery cell 20.

[0091] In some embodiments, please refer to Figure 4 The bottom cover 12 and the main body 11 are detachably connected via fasteners 13.

[0092] Fastener 13 refers to a component that can fasten two or more parts (or components) together into a whole, and may include, but is not limited to: screws, bolts, rivets, pins, pins, welding studs, etc.

[0093] At this point, the bottom cover 12 and the main body 11 are detachably connected by fasteners 13, which is not only convenient for disassembly and assembly, but also simple in structure and economical.

[0094] Figure 5 This is a schematic diagram of the structure of the bottom cover 12 provided in some embodiments of this application. Figure 6 for Figure 5 Top view of the bottom cover 12, Figure 7 for Figure 5 The front view of the bottom cover 12 shown. Figure 8 This is a schematic diagram of the structure of the bottom cover 12 provided in some other embodiments of this application.

[0095] In some embodiments, the minimum thickness h of the bottom cover 12 satisfies: 0.2mm < h < 20mm.

[0096] The thickness of the bottom cover 12 refers to the distance between the two vertical surfaces of the bottom cover 12 in a vertical cross-section. The minimum thickness h of the bottom cover 12 is the shortest distance between the two vertical surfaces of the bottom cover 12. When the thickness of the bottom cover 12 is uniform throughout, the bottom cover 12 can be flat (e.g., Figure 8As shown, the minimum thickness of the bottom cover 12 is the same thickness at all points on the bottom cover 12. When the thickness of the bottom cover 12 is not uniform, the minimum thickness of the bottom cover 12 is the thickness at the thinnest point of the bottom cover 12.

[0097] Specifically, the minimum thickness h of the bottom cover 12 can be selected from 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.

[0098] At this point, it has been proven that when the minimum thickness h of the bottom cover 12 satisfies 0.2mm < h < 20mm, the weight of the battery pack 100 can be effectively reduced, and the strength structure is reasonable.

[0099] 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 vertical surfaces of the structure in a cross-section. The term "thickness" will not be explained in detail in the following description; please refer to the description here. Of course, it is understood that the vertical direction is only for the convenience of illustrating the solution of this application and is not a limitation on the usage of the battery pack 100.

[0100] In some embodiments, the weight m of the battery cell 20 and the minimum wall thickness h of the bottom cover 12 satisfy the following condition: 0.03 mm / Kg ≤ h / m ≤ 100 mm / Kg.

[0101] The weight m of a single battery cell 20 refers to the weight m of a single battery cell 20. When the battery pack 100 includes multiple battery cells 20, the weight of a single battery cell 20 is the weight of each individual battery cell 20.

[0102] 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, or 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.

[0103] Table 1. Impact of the ratio of minimum wall thickness h of bottom cover 12 to weight m of individual battery cell 20 on the safety performance of battery pack 100

[0104]

[0105] Table 1 shows the test results of the influence of the ratio of the minimum wall thickness h of several bottom covers 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 GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". Table 1 shows that when h / m equals 0.02 mm / kg, the battery pack 100 is prone to fire and explosion, mainly because the structural strength of the battery pack 100 cannot meet the requirements. When h / m is greater than 0.02 mm / kg, the structural strength of the bottom cover 12 is better, and the battery pack 100 is less likely to fire or explode. However, an excessively large h / m can lead to wasted space and low energy density; therefore, h / m should ideally not exceed 100 mm / kg.

[0106] At this point, it has been proven 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 high energy density and is not easy to catch fire or explode.

[0107] In some embodiments, please refer to Figures 5 to 7 The bottom cover 12 has a cover portion 12a and a mounting portion 12b. The mounting portion 12b surrounds and is connected to the edge of the cover portion 12a. The cover portion 12a is used to define the receiving cavity s. The mounting portion 12b is connected to the main body 11.

[0108] The cover portion 12a defines the receiving cavity s; that is, the cover portion 12a and the main body 11 together enclose and form the receiving cavity s. The mounting portion 12b is connected to the main body 11 and does not participate in defining the receiving cavity s. The cover portion 12a can be a plate-shaped or block-shaped component, or a flat or curved plate-shaped component; its specific form is not limited. Figure 6 It can be seen that the mounting part 12b surrounding the edge of the cover part 12a means that the mounting part 12b is continuously arranged along the edge of the cover part 12a in a closed-end structure. Understandably, in its vertical projection, the mounting part 12b has a certain width, thus providing an appropriate contact area with the main body 11. This not only facilitates the positioning and installation of the mounting part 12b with the main body 11, but also facilitates the installation of sealing elements and helps improve the sealing performance between the mounting part 12b and the main body 11.

[0109] The cover 12a and the mounting part 12b can be integrally molded. When the bottom cover 12 is made of metal (such as aluminum, iron, stainless steel, etc.), the cover 12a and the mounting part 12b can be integrally molded 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 part 12b can be integrally molded by injection molding. The cover 12a and the mounting part 12b can also be molded separately and then connected together. When the cover 12a and the mounting part 12b are made of metal, they can be welded or bonded together. When the cover 12a and the mounting part 12b are made of plastic, they can be bonded together. Of course, the cover 12a and the mounting part 12b can also be fixedly connected together by snap-fit, riveting, or other methods.

[0110] The cover portion 12a and the mounting portion 12b can be located in the same plane. Specifically, optionally, the two surfaces of the cover portion 12a and the mounting portion 12b facing the body 11 are in the same plane, and / or the two surfaces of the cover portion 12a and the mounting portion 12b facing away from the body 11 are in the same plane. When the two surfaces of the cover portion 12a and the mounting portion 12b facing the body 11 and the two surfaces facing away from the body 11 are both in the same plane, the cover portion 12a and the mounting portion 12b can form a flat bottom cover 12 (e.g., ...). Figure 8 (As shown).

[0111] The cover portion 12a and the mounting portion 12b may not be located in the same plane. Specifically, the cover portion 12a may be recessed towards the main body 11 relative to the mounting portion 12b, or the cover portion 12a may protrude away from the main body 11 relative to the mounting portion 12b; the specific design is not limited. The thickness of the cover portion 12a and the mounting portion 12b may be equal or unequal; the specific design is not limited.

[0112] At this time, the bottom cover 12 defines the receiving cavity s via the cover portion 12a and is connected to the main body 11 via the mounting portion 12b, with a clear structure and convenient installation.

[0113] Understandably, 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 using a sealing element, a sealing connection using sealant, etc., and will not be exhaustive. The sealing element can be any of the sealing elements mentioned above, and the arrangement of the sealing element can be referred to the above description, the difference being that the sealing element is arranged between the mounting portion 12b and the main body 11. When the mounting portion 12b and the main body 11 are sealed to each other using sealant, the sealant can be applied to all surfaces of the mounting portion 12b that come into contact with the main body 11.

[0114] Understandably, 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 part 12b, that is, the mounting part 12b is detachably connected to the main body 11. The method of detachable connection between the mounting part 12b and the main body 11 can refer to the detachable method of the bottom cover 12 and the main body 11 described above. It is only necessary to set the part of the bottom cover 12 that is detachably connected to the main body 11 as the mounting part 12b. Therefore, the detachable connection method of the mounting part 12b and the main body 11 will not be described in detail here.

[0115] In some embodiments, the mounting part 12b is detachably connected to the body 11.

[0116] Specifically, the bottom cover 12 also includes a fixing hole 12c provided on the mounting portion 12b. The fastener 13 passes through the fixing hole 12c on the mounting portion 12b and is then fastened to the main body 11. The fixing hole 12c is a through hole that penetrates 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 threaded through hole (such as when the fastener 13 is a screw), or a through hole of other types (such as a hexagonal hole, a square hole, an oblong hole, etc.). The specific form of the fixing hole 12c depends on the specific form and setting method of the fastener 13, and will not be elaborated here.

[0117] In some embodiments, the cover portion 12a and the mounting portion 12b have the same thickness.

[0118] When the cover portion 12a and the mounting portion 12b are integrally formed, they can be integrally formed in the manner described above, such as die casting, cold pressing, hot pressing, injection molding, etc., which will not be elaborated here. Since the cover portion 12a and the mounting portion 12b have the same thickness, they can be quickly processed from the same metal plate by stamping, cutting, etc.

[0119] At this time, the thickness of the cover 12a and the mounting part 12b are equal, and the stress is equal at all points during molding, which can improve the molding rate of the one-piece molding. It can also be quickly processed by simple methods such as plate cutting. The structure of the bottom cover 12 is simpler and the processing is more convenient.

[0120] In some embodiments, please refer to Figure 7 The cover portion 12a protrudes from the mounting portion 12b in a direction away from the receiving cavity s.

[0121] As can be seen from the above, the cover 12a defines the receiving cavity s, and the cover 12a protruding away from the receiving cavity s means that the cover 12a protrudes away from the main body 11. That is to say, the cover 12a and the mounting part 12b are staggered in the vertical direction, and the cover 12a is located at the lowest point of the bottom cover 12.

[0122] When the cover portion 12a protrudes away from the receiving cavity s relative to the mounting portion 12b, a certain amount of redundant space can be formed between the cover portion 12a and the mounting portion 12b. This redundant space can increase the distance between the cover portion 12a and the battery cell 20. When an external force is applied to the cover portion 12a, the redundant space can reduce the external force, thereby reducing or avoiding the external force acting on the battery cell 20 and causing 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 and other objects on the ground are easily thrown to the bottom of the battery pack 100, i.e., the bottom cover 12, and impact it 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 reinforcing structure for the bottom cover 12, improving the bending resistance of the bottom cover 12.

[0123] Understandably, in the embodiments of this application, the bottom cover 12 is located at the bottom of the housing 10 and is used to define the receiving cavity s.

[0124] Figure 9 for Figure 4 A cross-sectional view of the battery pack 100 is shown. In some embodiments, please refer to... Figure 9 The bottom cover 12 and the battery cell 20 are spaced apart.

[0125] The spacing between the bottom cover 12 and the battery cell 20 refers to the vertical distance r maintained between them. This spacing r creates a buffer space between the bottom cover 12 and the battery cell 20, preventing external forces acting on the bottom cover 12 from being transmitted to the battery cell 20 and damaging it. This is especially important when the battery pack 100 is installed at the bottom of the vehicle 1000 and the bottom cover 12 is at its lowest point. During vehicle operation, stones or other debris on the ground can easily fly to the bottom of the battery pack 100 and strike the bottom cover 12. In this case, the buffer space can interrupt the transmission of external forces to the battery cell 20, preventing any impact on the battery cell 20.

[0126] The bottom cover 12 and the battery cell 20 can be spaced apart by the redundant space formed between the protruding cover portion 12a and the mounting portion 12b in the above embodiment, or by maintaining a set distance between the end of the battery cell 20 located inside the main body 11 and facing the bottom cover 12 and the end of the main body 11 facing the bottom cover 12. That is, the battery cell 20 is only located within a portion of the receiving cavity s defined by the main body 11, and not within the receiving 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.

[0127] Understandably, when the battery pack 100 includes multiple battery cells 20, all battery cells 20 are spaced apart from the bottom cover 12. Furthermore, to ensure uniformity in the size of the battery cells 20, the spacing between each battery cell 20 and the bottom cover 12 is equal.

[0128] In some embodiments, please refer to Figure 5 and Figure 6 The bottom cover 12 has a feature surface d facing the receiving cavity s, and the feature surface d is constructed as a plane.

[0129] The fact that feature surface d faces the receiving cavity s indicates that feature surface d is the inner surface of the bottom cover 12 that defines the receiving cavity s. Feature surface d is constructed as a plane meaning that, in the arrangement direction of the main body 11 and the bottom cover 12, feature surface d is a plane perpendicular to that direction. In practice, when the main body 11 and the bottom cover 12 are arranged vertically, the feature 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 horizontally, the feature surface d of the bottom cover 12 is a plane parallel to the vertical plane.

[0130] When the feature surface d is a plane, the feature surface d can maintain a relatively equal distance (this distance can be zero) from each battery cell 20 housed in the housing cavity s. When the distance between the feature surface d and the battery cell 20 is relatively equal, the housing cavity s can accommodate more battery cells 20, that is, the space utilization rate of the housing cavity s is higher, the battery pack 100 can have a higher energy density, and the battery pack 100 has a longer range.

[0131] Understandably, when the bottom cover 12 has the aforementioned cover portion 12a and the aforementioned mounting portion 12b, the feature surface d can be formed by the inner surface of the cover portion 12a facing the receiving cavity s. Further understandably, when the bottom cover 12 is spaced apart from the battery cell 20, the feature surface d is spaced apart from the battery cell 20.

[0132] In some embodiments, the outer surface of the cover portion 12a, which is away from the receiving cavity s, is parallel to the feature surface d.

[0133] The outer surface of the cover 12a, facing away from the receiving cavity s, is arranged vertically opposite to the feature surface d. The outer surface of the cover 12a is for contact with the atmospheric environment and to withstand external impacts. When the outer surface of the cover 12a is a plane flush with the feature surface d, especially when the bottom cover 12 and the main body 11 are arranged vertically at the bottom of the vehicle 1000 and the bottom cover 12 is located at the lowest point of the battery pack 100, the flat outer surface of the cover 12a can greatly reduce the wind resistance generated by the battery pack 100, which helps to reduce the driving resistance of the vehicle 1000, reduce the driving energy consumption of the vehicle 1000, and improve the driving range of the battery pack 100.

[0134] Figure 10 for Figure 6 The diagram shows a vertical orthographic projection of the bottom cover 12. S1 represents the projected area of ​​feature surface d, and S2 represents the projected area of ​​the bottom cover 12.

[0135] In some embodiments, in the vertical direction, the area S1 of the orthographic projection of the feature 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.

[0136] exist Figure 10 In the illustrated embodiment, in the vertical orthographic projection, the feature surface d is formed by connecting the first feature edge d1, the second feature edge d2, the third feature edge d3, and the fourth feature edge d4 end to end. The area S1 of the orthographic projection of the feature surface d is the area defined by the first feature edge d1, the second feature edge d2, the third feature edge d3, and the fourth feature edge d4. The area S2 of the orthographic projection of the bottom cover 12 is the area defined by the edge of the bottom cover 12.

[0137] Specifically, the ratio of the area S1 of the orthographic projection of the feature surface d to the area S2 of the orthographic projection of the bottom cover 12 can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0138] Table 2 shows the impact of the ratio of area S1 to area S2 on the 100km driving range of the battery pack.

[0139]

[0140] Table 2 shows the impact of the ratio of the area S1 of the orthographic projection of several characteristic surfaces d to the area S2 of the orthographic projection of the bottom cover 12 on the driving 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 driving range of the battery pack 100 is poor. This is because when the characteristic surface d is small, the space utilization rate of the cavity s is low, the number of battery cells 20 housed in the battery pack 100 is small, and the energy density of the battery pack 100 is relatively low, resulting in a short driving range and poor test results. When the ratio of S1 / S2 reaches 0.2 or above (especially when S1 / S2 reaches 0.5 or above), the driving range of the battery pack 100 is better as the ratio increases. This is because the larger the characteristic surface d, the higher the space utilization rate of the cavity s, and the higher the energy density of the battery pack 100. Therefore, the driving range of the battery pack 100 increases, and the test results improve.

[0141] Since feature surface d is planar, the larger the area occupied by feature surface d in the bottom cover 12, the smaller the area of ​​the inner surface of the bottom cover 12 that is concave or convex relative to feature surface d. A concave inner surface relative to feature surface d will cause some space in the receiving cavity s to be irregular, making it impossible to install the battery cell 20, resulting in low space utilization of the receiving cavity s. Similarly, a portion of the space in the receiving cavity s formed by the convex inner surface relative to feature surface d will also be irregular and unable to accommodate the battery cell 20, resulting in low space utilization of the receiving cavity s. When the space utilization of the receiving 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 occupied by feature surface d in the bottom cover 12, the greater the space utilization of the battery pack 100, the higher the energy density of the battery pack 100, and the better the driving range of the battery pack 100.

[0142] In some embodiments, please refer to Figure 10 In the vertical direction, the orthographic projection of the feature surface d is a rectangle.

[0143] like Figure 10As shown, the rectangular feature surface d is the region enclosed by the first feature side d1, the second feature side d2, the third feature side d3, and the fourth feature side d4. In the battery pack 100, most of the multiple battery cells 20 are assembled to form a rectangular structure. Constructing the feature surface d to be rectangular can adapt to the overall structure formed by the battery cells 20 within the battery pack 100, which helps to arrange more battery cells 20 within the receiving cavity s and improve the energy density of the battery pack 100.

[0144] Of course, in other embodiments, the orthographic projection of the feature surface d in the vertical direction can also be other shapes, such as circles, polygons, ellipses and other irregular shapes.

[0145] In the embodiments of this application, the main body 11 includes a carrier 11a.

[0146] The support member 11a can be a component in the main body 11 used to define the receiving cavity s (e.g., the support member 11a is the top cover or frame mentioned above), or it can be a component that is not used to define the receiving cavity s but is located within the receiving cavity s (e.g., the support member 11a is the support plate mentioned above), and there is no specific limitation. When the support member 11a is used to define the receiving cavity s, the support member 11a can be a component in the main body 11 that is directly connected to the bottom cover 12 (such as the frame mentioned above), or it can be a component that is not connected to the bottom cover 12 (such as the top cover mentioned above).

[0147] In some embodiments, the battery cell 20 is disposed on the surface of the carrier 11a.

[0148] At this point, the support component 11a is a part capable of supporting the weight of the battery cell 20. It can be a support plate, support rod, support block, support piece, support frame, support rope, etc., and the specific type is not limited. Specifically, the battery cell 20 can be supported on the support component 11a, and in this case, the battery cell 20 can be positioned above the support component 11a. Alternatively, the battery cell 20 can be hung on the support component 11a, and in this case, the battery cell 20 can be hung on the wall surface of the support component 11a that is parallel to the direction of gravity of the battery cell 20.

[0149] The battery cell 20 can be positioned above the support member 11a (e.g., when the support member 11a serves as a support plate located within the receiving cavity s), the battery cell 20 can be positioned below the support member 11a (e.g., when the support member 11a serves as a top cover for defining the receiving cavity s), or the battery cell 20 can be positioned to the side of the support member 11a (e.g., when the support member 11a serves as a frame for defining the receiving cavity s).

[0150] In some embodiments, the battery cell 20 is bonded to the carrier 11a.

[0151] Specifically, the battery cell 20 and the carrier 11a can be bonded together using adhesives such as epoxy resin or acrylic resin, without limitation. This bonding between the battery cell 20 and the carrier 11a not only facilitates connection but also simplifies the structure of the battery pack 100.

[0152] In some embodiments, the battery cell 20 is disposed on the surface of the support member 11a, and the minimum thickness H of the support member 11a and the weight M of the battery pack 100 satisfy: 0.0002mm / kg<H / M≤0.2mm / kg.

[0153] The thickness of the support member 11a refers to the distance between one side surface of the support member 11a used to mount the battery cell 20 and its opposite side surface. When the battery cell 20 is mounted on the vertical surface of the support member 11a, the minimum thickness H of the support member 11a refers to the point where the distance between the two vertical surfaces of the support member 11a is minimum. When the battery cell 20 is mounted on the horizontal surface of the support member 11a, the thickness of the support member 11a refers to the point where the distance between the two horizontal surfaces of the support member 11a is minimum.

[0154] The weight of the battery pack 100 includes the entire weight of the main body 11, the bottom cover 12, the battery cells 20, and other components (such as wiring harnesses, thermal management systems, power management systems, etc.).

[0155] Specifically, the ratio between the minimum thickness H of the carrier 11a and the weight M of the battery pack 100 can be designed as follows: 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, and 0.02mm / kg.

[0156] Table 3. Impact of the ratio of minimum thickness H of load-bearing component 11a to weight M of battery pack 100 on the safety performance of battery pack 100.

[0157]

[0158]

[0159] Table 3 shows the impact of the ratio of the minimum thickness H of the load-bearing component 11a to the weight M of the battery pack 100 on the safety performance of several groups of load-bearing components 11a tested according to GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". Table 3 shows that when the H / M ratio does not exceed 0.0002 mm / kg, the battery pack 100 will catch fire and explode, because the structural strength of the battery pack 100 does not meet the requirements. When the H / M ratio exceeds 0.0002 mm / kg, the battery pack 100 will not catch fire or explode. However, when H / M is too large (e.g., exceeding 0.1), due to the small weight of the battery pack 100 and the large thickness of the load-bearing plate, the proportion of battery cells 20 per unit volume in the battery pack 100 is low, resulting in low space utilization, low energy density, and high operating costs. Furthermore, if 0.0005mm / Kg≤H / M≤0.1mm / Kg, 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 range and will not cause safety accidents such as fire or explosion.

[0160] In some embodiments, the minimum thickness H of the support member 11a satisfies: 0.2mm < H < 20mm.

[0161] Specifically, the minimum thickness H of the support member 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, or 19mm. Further, 0.5mm ≤ H ≤ 10mm. At this thickness, the support member 11a has good structural strength, the battery pack 100 has good overall strength, and the battery pack 100 is less prone to fire and explosion. Simultaneously, the support member 11a occupies a small volume in the battery pack 100, resulting in high space utilization and high energy density.

[0162] In some embodiments, please refer to Figure 3 and Figure 4 The battery cell 20 is suspended from the support member 11a.

[0163] The battery cell 20 being suspended from the support member 11a means that the battery cell 20 is positioned vertically below the support member 11a, and the weight of the battery cell 20 is borne by the support member 11a. The battery cell 20 can be suspended from the support member 11a in the following ways: the battery cell 20 is directly adhered to the lower surface of the support member 11a; the battery cell 20 is connected to the support member 11a via fasteners 13 and is positioned below the support member 11a; or the battery cell 20 is hung on the support member 11a via hooks or the like and is positioned below the support member 11a.

[0164] At this time, the battery cell 20 is suspended below the support member 11a, and the bottom cover 12 is located at the bottom of the housing 10. When repairing the inside of the battery pack 100, the battery cell 20 can be exposed by removing the bottom cover 12 without removing the support member 11a, making 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 removed and installed on the support member 11a from below. In particular, when the support member 11a is at least part of the chassis of the vehicle 1000 and bears the load, the battery cell 20 only needs to be removed and installed from below the support member 11a without removing the support member 11a, which facilitates the maintenance of the battery pack 100.

[0165] Figure 11 This is a schematic diagram of the external shape of a battery cell 20 in some embodiments of this application. Figure 12 for Figure 11 The front view of the battery cell 20 shown.

[0166] In some embodiments, please refer to Figure 4 and Figure 11 The outer surface of the battery cell 20 facing the support member 11a is the first outer surface m1. The battery cell 20 includes an electrode terminal 21a, which is arranged on the outer surface of the battery cell 20 other than the first outer surface m1.

[0167] As described above, electrode terminal 21a is used for electrical connection with electrode assembly 23 inside battery cell 20 to output or input electrical energy to battery cell 20. Electrode terminal 21a extends at least partially outside battery cell 20 for external electrical connection. Series and parallel connections between battery cells 20 are achieved through series and parallel connections between their respective electrode terminals 21a. Electrode terminal 21a is conductive to enable electrical transmission and can be aluminum electrode, copper electrode, etc.

[0168] Electrode terminals 21a are arranged on the outer surface of the battery cell 20, excluding the first outer surface m1. The first outer surface m1 faces the support member 11a and is typically a smooth surface without any protruding or recessed structures such as electrode terminals 21a or liquid injection holes. When the battery cell 20 is suspended from the support member 11a, the first outer surface m1 is the upward-facing outer surface of the battery cell 20. In one specific embodiment, the battery cell 20 includes the housing 22 and end cap 21 mentioned above. The housing 22 and end cap 21 form the internal environment of the battery cell 20 that accommodates the electrode assembly 23. The end cap 21 is located at one end of the housing 22, and the electrode terminals 21a are arranged on the end cap 21. In this case, any outer surface of the housing 22 can serve as the first outer surface m1 of the battery cell 20.

[0169] Electrode terminal 21a includes a positive terminal and a negative terminal. The positive terminal is used for electrical connection with the positive electrode plate in the electrode assembly 23, and the negative terminal is used for electrical connection with the negative electrode plate in the electrode assembly 23. It should be noted that the positive and negative terminals can be arranged on the same outer surface of the battery cell 20 (e.g., a square battery cell 20), or they can be arranged on two different outer surfaces of the battery cell 20 (e.g., a cylindrical battery cell 20). When the positive and negative terminals 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 these two outer surfaces.

[0170] In addition to the individual battery cells 20, the battery pack 100 typically includes components such as sampling harnesses for electrically connecting each battery cell 20, high-voltage wiring harnesses, and protective structures for protecting the battery cells 20. In this case, the electrode terminals 21a are arranged on surfaces of the battery cells 20 other than the first outer surface m1. When the sampling harnesses, high-voltage wiring harnesses, and protective structures are placed on the electrode terminals 21a, they are not restricted by the support member 11a and can be arranged through the space between the battery cells 20 and other structures of the main body 11 other than the support member 11a (such as the space between the battery cells and the bottom cover and / or the space between the battery cells and the inner side of the main body), making the arrangement of each component more convenient. Simultaneously, since the first outer surface m1 is a smooth surface, it can be fitted to the support member 11a, thus achieving a close fit between the battery cells 20 and the support member 11a without needing to reserve space between them, which helps improve the space utilization of the battery pack 100.

[0171] In some embodiments, please refer to Figure 11 and Figure 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.

[0172] The second outer surface m2 is the outer surface of the battery cell 20 that is positioned opposite to the first outer surface m1. When the battery cell 20 is suspended from the support member 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 beyond the battery cell 20 is located within this buffer space. Thus, the wiring harness and connecting piece connected to the electrode terminal 21a can be arranged within the buffer space. At the same time, the buffer space also has the ability, as mentioned above, to prevent external forces striking the bottom cover 12 from affecting the battery cell 20 and damaging it. Therefore, the buffer space not only interrupts the influence of external forces but also allows for the arrangement of wiring harnesses, etc., achieving two benefits at once. In addition, the space utilization of the buffer space and the battery pack 100 is also improved.

[0173] Of course, in other embodiments, refer to Figure 11 and Figure 12 The electrode terminal 21a can also be arranged on the third outer surface of the battery cell 20 that intersects with the first outer surface m1.

[0174] In some embodiments of this application, please refer to Figure 4 , Figure 5 and Figure 9 The support member 11a is located at the top of the housing 10 and defines the receiving cavity s. Since the bottom cover 12 is located at the bottom of the housing 10, the support member 11a is arranged opposite to the bottom cover 12. As the structure at the top of the housing 10, the housing 10 can be mounted on the mounting body via the support member 11a. At this time, the battery cells 20 provided on the support member 11a can strengthen the strength of the support member 11a, thereby improving the rigidity of the top of the battery pack 100. This allows the application scenarios of the battery pack 100 to be extended to scenarios where the top is subjected to stress, such as its use as part of the chassis of a vehicle 1000.

[0175] Figure 13 This is a schematic diagram of the structure of the carrier 11a in some embodiments of this application. Figure 14 This is a schematic diagram of the structure of the carrier 11a in some other embodiments of this application. Figure 15 for Figure 14 The above is a vertical orthographic projection of the support member 11a.

[0176] In some embodiments, the carrier 11a has a carrier surface f facing the receiving cavity s, and the carrier surface f is configured as a plane.

[0177] The bearing surface f is the inner surface of the bearing member 11a facing the receiving cavity s, and it defines the receiving cavity s. The bearing surface f is constructed as a plane because, 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 practice, when the main body 11 and the bottom cover 12 are arranged vertically, the bearing member 11a and the bottom cover 12 are arranged opposite each other vertically, 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 horizontally, the bearing member 11a and the bottom cover 12 are arranged opposite each other horizontally, and the bearing surface f of the bearing member 11a is a plane parallel to the vertical plane.

[0178] like Figure 13 As shown, the support member 11a can be the entire inner surface of the support member 11a facing the receiving cavity s, in which case the support member 11a can be flat. For example... Figure 14 and Figure 15 As shown, the carrier 11a can also be a part of the inner surface of the carrier 11a facing the receiving cavity s. In this case, the carrier surface f is only the part of the inner surface of the carrier 11a used to define the receiving cavity s.

[0179] When the bearing surface f is a plane, the bearing surface f can maintain a relatively equal distance (this distance can be zero) from each battery cell 20 housed in the housing cavity s. When the distance between the bearing surface f and the battery cell 20 is relatively equal, the housing cavity s can accommodate more battery cells 20, which means that the space utilization of the housing cavity s is higher, the battery pack 100 can have a higher energy density, and the battery pack 100 has a longer range.

[0180] 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 fasteners 13, etc., or welded or snapped to the bearing surface f, and the specific method is not limited.

[0181] Because the bearing surface f is planar, it has a larger contact area with the battery cells 20 mounted on it, resulting in more stable installation of the battery cells 20. Furthermore, compared to curved or uneven surfaces, the planar bearing surface f can connect with a greater number of battery cells 20, increasing the number of battery cells 20 installed within the battery pack 100, thereby improving the space utilization and energy density of the battery pack 100.

[0182] Understandably, when the battery cell 20 is suspended from the support member 11a, the battery cell 20 is suspended from the support surface f.

[0183] 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.

[0184] exist Figure 15 In the illustrated embodiment, 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. The area N1 of the orthographic projection 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 area N2 of the orthographic projection of the bearing member 11a is the area defined by the edge of the bearing member 11a.

[0185] 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 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0186] Table 4 shows the impact of the ratio of area N1 to area N2 on the 100km driving range of the battery pack.

[0187]

[0188] Table 4 shows the impact of the ratio of the area N1 of the orthographic projection of several bearing surfaces f to the area N2 of the orthographic projection of the bearing component 11a on the driving range of the battery pack 100 when tested according to the NEDC (New European Driving Cycle) standard. When N1 / N2 is less than 0.2, the driving range of the battery pack 100 is poor. This is because when the bearing surface f is small, the number of battery cells 20 supported on the bearing component 11a is small, the space utilization of the cavity s is low, and the energy density of the battery pack 100 is relatively low, resulting in a short driving range and poor test results. When the ratio of N1 / N2 reaches 0.2 or above (especially when N1 / N2 reaches 0.5 or above), the driving range of the battery pack 100 is better as the ratio increases. This is because the larger the bearing surface f, the more battery cells 20 are supported on the bearing component 11a, the higher the space utilization of the cavity s, and the higher the energy density of the battery pack 100. Therefore, the driving range of the battery pack 100 is increasingly higher, and the test structure is increasingly better. When the bearing 11a is Figure 13 When the flat plate structure is shown, the projected area N1 of the bearing surface f is equal to the projected area N2 of the bearing member 11a, and the battery pack 100 has the best battery life.

[0189] In some embodiments, the orthographic projection of the bearing surface f in the vertical direction is rectangular.

[0190] like Figure 15 As shown, the rectangular 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. In the battery pack 100, most of the multiple battery cells 20 are assembled to form a rectangular structure. Constructing the bearing surface f to be rectangular can adapt to the overall structure formed by the battery, which helps to arrange more battery cells 20 in the housing cavity s and improve the energy density of the battery pack 100.

[0191] Of course, in other embodiments, the orthographic projection of the bearing surface f in the vertical direction can also be other shapes, such as circles, polygons, ellipses and other irregular shapes.

[0192] In some embodiments, please refer to Figure 14 The support member 11a has a support portion 11a1 and a connecting portion 11a2. The connecting portion 11a2 surrounds and connects to the edge of the support portion 11a1. The support portion 11a1 is used to define the receiving cavity s. The connecting portion 11a2 is connected to the part of the housing 10 other than the support member 11a.

[0193] The supporting part 11a1 defines the receiving cavity s, and the connecting part 11a2 connects to the part of the housing 10 other than the supporting member 11a, and does not participate in defining the receiving cavity s. The supporting part 11a1 can be a plate-shaped or block-shaped component, or a flat plate-shaped or curved plate-shaped component; its specific form is not limited. Figure 14 As can be seen, the connection portion 11a2 enclosing the edge of the support portion 11a1 means that the connection portion 11a2 is a structure that is continuously connected end-to-end along the edge of the support portion 11a1. Understandably, in the vertical projection, the connection portion 11a2 has a certain width, thus allowing for an appropriate contact area with other structures of the housing 10 besides the support member 11a, and more easily facilitating the installation connection between the connection portion 11a2 and other structures of the housing 10 besides the support member 11a.

[0194] The supporting part 11a1 and the connecting part 11a2 can be integrally molded. When the supporting part 11a is made of metal (such as aluminum, iron, stainless steel, etc.), the supporting part 11a1 and the connecting part 11a2 can be integrally molded by die casting, forging, hot pressing, cold pressing, etc. When the supporting part 11a is made of plastic (such as PP, PE, ABS, etc.), the supporting part 11a1 and the connecting part 11a2 can be integrally molded by injection molding. The supporting part 11a1 and the connecting part 11a2 can also be molded separately and then connected together. When the supporting part 11a1 and the connecting part 11a2 are made of metal, they can be welded or bonded together. When the supporting 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 supporting part 11a1 and the connecting part 11a2 can also be fixedly connected together by snap-fitting, riveting, or other methods.

[0195] Specifically, the connecting part 11a2 is connected to the part of the main body 11 other than the bearing member 11a. The connection method can be either integral molding or fixed connection. When the connecting part 11a2 is integrally molded with the part of the main body 11 other than the bearing member 11a, that is, the main body 11 is an integrally molded part, it can be integrally molded by die casting, forging, hot pressing, cold pressing, injection molding, etc. When the connecting part 11a2 is fixedly connected to the part of the main body 11 other than the bearing member 11a, it can be fixedly connected by fastener 13, snap-fit ​​structure, etc., and the specific method is not limited.

[0196] The supporting portion 11a1 and the connecting portion 11a2 can be located in the same plane. Specifically, optionally, the two surfaces of the supporting portion 11a1 and the connecting portion 11a2 facing the bottom cover 12 are in the same plane, and / or the two surfaces of the supporting portion 11a1 and the connecting portion 11a2 facing away from the bottom cover 12 are in the same plane. When the two surfaces of the supporting portion 11a1 and the connecting portion 11a2 facing the bottom cover 12 and the two surfaces facing away from the bottom cover 12 are both in the same plane, the supporting portion 11a1 and the connecting portion 11a2 can form a flat supporting member 11a (e.g., ...). Figure 13 (As shown).

[0197] The supporting portion 11a1 and the connecting portion 11a2 may not be located in the same plane. Specifically, the supporting portion 11a1 may protrude away from the receiving cavity s relative to the connecting portion 11a2, or the supporting portion 11a1 may be recessed towards the receiving cavity s relative to the connecting portion 11a2; the specific details are not limited. The thicknesses of the supporting portion 11a1 and the connecting portion 11a2 may be equal or unequal; the specific details are not limited.

[0198] At this time, the carrier 11a defines the receiving cavity s via the carrier portion 11a1 and is connected to the main body 11 by the connecting portion 11a2, except for the carrier 11a, and the structure is clearly defined.

[0199] Understandably, when the support member 11a includes the aforementioned support portion 11a1 and the aforementioned connecting portion 11a2, the battery cell 20 is disposed on the support portion 11a1.

[0200] Understandably, when the carrier 11a includes the aforementioned carrier portion 11a1 and the aforementioned connecting portion 11a2, the inner surface of the carrier portion 11a1 facing the receiving cavity s is configured to form a carrier surface f.

[0201] In some embodiments, the support portion 11a1 protrudes from the connecting portion 11a2 in a direction away from the receiving cavity s.

[0202] As described above, the supporting portion 11a1 defines the receiving cavity s, and the fact that the supporting portion 11a1 protrudes away from the receiving cavity s means that the supporting portion 11a1 and the connecting portion 11a2 are arranged offset in the vertical direction. The supporting portion 11a1 is located at the highest point of the supporting member 11a. At this time, a certain space can be formed between the supporting portion 11a1 and the connecting portion 11a2, which is part of the receiving cavity s and can accommodate the battery cell 20.

[0203] When the bearing portion 11a1 protrudes away from the receiving cavity s relative to the connecting portion 11a2, the bearing portion 11a1 can serve as a reinforcing structure for the bearing member 11a, thereby improving the bending resistance of the bearing member 11a.

[0204] In some embodiments, the thickness of the supporting portion 11a1 and the connecting portion 11a2 is equal.

[0205] When the thickness of the supporting part 11a1 and the connecting part 11a2 are equal, the supporting part 11a1 and the connecting part 11a2 can be integrally formed from the same sheet metal through die casting, cold pressing, and hot pressing, making the forming of the supporting part 11a more convenient. At the same time, the equal thickness of the supporting part 11a1 and the connecting part 11a2 ensures uniform stress throughout the forming process, which can improve the forming rate of the supporting part 11a.

[0206] In some embodiments, the outer surface of the support portion 11a1 facing away from the receiving cavity s is parallel to the support surface f.

[0207] The outer surface of the support portion 11a1, which is opposite to the outer surface of the receiving cavity s, is vertically opposed to the support surface f. The outer surface of the support portion 11a1 can be in contact with the atmospheric environment. When the battery pack 100 is installed in the vehicle 1000, the planar outer surface of the support portion 11a1 can reduce the driving resistance of the vehicle 1000, reduce the driving energy consumption of the vehicle 1000, and improve the driving range of the battery pack 100.

[0208] In some embodiments, please refer to Figure 3 , Figure 4 and Figure 9 The main body 11 includes a frame 11b and a support member 11a. The frame 11b encloses and forms a cavity q that is through at both ends in the vertical direction. The bottom cover 12 and the support member 11a respectively cover the opposite ends of the cavity q in the vertical direction. The bottom cover 12, the frame 11b and the support member 11a together enclose and form a receiving cavity s.

[0209] The frame 11b itself encloses a cavity q that extends vertically through both ends. The support member 11a covers the top of the cavity q, and the bottom cover 12 covers the bottom of the cavity q. That is, the support member 11a is located at the top of the housing 10 and defines the receiving cavity s, while the bottom cover 12 is located at the bottom of the housing 10 and defines the receiving cavity s. The frame 11b, support member 11a, and bottom cover 12 together form the receiving cavity s. The frame 11b, support member 11a, and bottom cover 12 can be made of the same material, such as aluminum alloy, copper alloy, steel, or plastic. Of course, the frame 11b, support member 11a, and bottom cover 12 can also be made of different materials; there is no specific limitation. In its vertical orthographic projection, the frame 11b can be rectangular, circular, polygonal, etc., without specific limitation.

[0210] When the support member 11a includes the support portion 11a1 and the connecting portion 11a2, the support member 11a is connected to the frame 11b via the connecting 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.

[0211] At this point, based on the frame 11b, the battery pack 100 can be formed by connecting the carrier 11a and the bottom cover 12 to the two ends of the frame 11b in the vertical direction. The structure of the box 10 is relatively simple.

[0212] 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 fasteners 13, snap-fit ​​structures, welding, bonding, hot-melt connection, etc.

[0213] When the support component 11a and the frame 11b are integrally formed, and the main body 11 is integrally formed, the main body 11 only needs to be connected to the bottom cover 12 to realize the assembly of the box 10, making the assembly of the box 10 convenient. When the support component 11a and the frame 11b are fixedly connected, the forming process of the support component 11a and the frame 11b is relatively easy, which can reduce the process cost of the box 10.

[0214] Understandably, when the support member 11a has a support portion 11a1 and a connecting portion 11a2, it is connected to the frame 11b by the connecting portion 11a2. When the bottom cover 12 has a cover portion 12a and a mounting portion 12b, it is connected to the frame 11b by the mounting portion 12b.

[0215] Figure 16 for Figure 4 The front view of the battery pack 100 is shown. Please refer to... Figure 16 and Figure 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.

[0216] 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 vertically. Figure 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 to it.

[0217] The height Hp of the battery pack 100 refers to the maximum length of the battery pack 100 in the vertical direction when the main body 11 and the bottom cover 12 are arranged in a vertical direction.

[0218] Specifically, the ratio of the height Hc of the battery cell 20 to the height Hp of the battery pack 100 can 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.

[0219] Table 5. Impact of the ratio of cell height Hc (20) to battery pack height Hp (100) on the safety of battery pack 100.

[0220]

[0221] Table 5 shows the impact of the ratio of the height Hc of several battery cells 20 to the height Hp of the battery pack 100 on the safety of the battery pack 100, tested according to GB 38031-2020 "Safety Requirements for Power Batteries for Electric Vehicles". As can be seen from Table 5, when Hc / Hp exceeds 0.98, the structure of the housing 10 occupies a very small portion of the battery pack 100's height, and the strength of the housing 10 cannot meet the requirements, potentially leading to fire and explosion accidents. When 0.02 ≤ Hc / Hp, the structural strength of the housing 10 meets the requirements, and fire and explosion will not occur. When Hc / Hp is less than 0.2, although the structural strength of the housing 10 meets the requirements, the space utilization rate of the battery pack 100 is low, and the energy density is too low.

[0222] Furthermore, with 0.5 ≤ Hc / Hp < 0.94, not only does the strength of the battery pack 100 meet the requirements and prevent fire and explosion accidents, but the battery pack 100 also has a high space utilization rate and a high energy density.

[0223] According to some embodiments of this application, the battery pack 100 includes a housing 10 and battery cells 20. The housing 10 encloses a receiving cavity s, and the housing 10 includes a bottom cover 12 located at its bottom and used to define the receiving cavity s. The battery cells 20 are received within the receiving cavity s. The bottom cover 12 has a feature surface d facing the receiving cavity s, and the feature surface d is constructed as a plane. When the feature surface d is a plane, the feature surface d can maintain a relatively equal distance (this distance can be zero) from each battery cell 20 received within the receiving cavity s. When the distance between the feature surface d and the battery cell 20 is relatively equal, the receiving cavity s can accommodate more battery cells 20, that is, the space utilization rate of the receiving cavity s is higher, the battery pack 100 can have a higher energy density, and the battery pack 100 has a longer driving range.

[0224] On the other hand, this application also provides an electrical device. This electrical device includes the battery pack 100 provided in any of the above embodiments, the battery pack 100 being used to provide electrical energy to the electrical device. The description of the electrical device is as described above and will not be repeated here.

[0225] Since the power device includes the battery pack 100 described above, it possesses all the beneficial effects described in the above embodiments, which will not be elaborated here.

[0226] Figure 17 This is a schematic diagram of the battery pack 100 applied to the vehicle body 200 in some embodiments of this application. Figure 18 for Figure 17 The first decomposition state diagram of the structure shown. Figure 19 for Figure 17 The second decomposition state diagram of the structure shown.

[0227] In some embodiments, please refer to Figures 17 to 19 The electrical device includes a vehicle 1000, and a battery pack 100 is located at the bottom of the vehicle body 200. For details regarding the vehicle 1000, please refer to the description above; further details will not be repeated here.

[0228] The vehicle body 200 of vehicle 1000 refers to the part of vehicle 1000 used for carrying passengers and cargo, including the driver's cab, passenger compartment, engine compartment, luggage compartment, etc. The vehicle body 200 typically includes a body shell 22 and doors, windows, trim pieces, seats, air conditioning devices, etc., located on the body shell 22. The body shell 22 typically refers to the structure composed of the main load-bearing components of vehicle 1000, such as longitudinal beams, cross beams, chassis, and pillars, as well as the sheet metal parts connected to them. In the embodiments of this application, the battery pack 100 being located at the bottom of the vehicle body 200 mainly refers to the battery pack 100 being located at the bottom of the body shell 22.

[0229] At this point, placing the battery pack 100 at the bottom of the vehicle body 200 will not occupy the internal space of the vehicle body 200, which helps to reduce the size and weight of the vehicle body 200.

[0230] Figure 20 This is a schematic diagram illustrating the installation relationship between the battery pack 100 and the vehicle body 200 in some embodiments of this application. In some embodiments, please refer to... Figure 20 The main body 11 includes a support member 11a located at the top of the box 10. The support member 11a is used to define the receiving cavity s. In the vertical direction, the distance L between the support member 11a and the vehicle body 200 satisfies: L≥0.

[0231] Since the battery pack 100 is located at the bottom of the vehicle body 200, and the support member 11a is located at the top of the housing 10, the support member 11a is closest to the vehicle body 200 within the battery pack 100. The distance L between the support member 11a and the vehicle body 200 refers to the distance in the vertical direction between the highest point of the support member 11a and the vehicle body 200 located above it. When the support member 11a includes the aforementioned support portion 11a1 and the aforementioned connecting portion 11a2, the distance L between the support member 11a and the vehicle body 200 is the distance between the outer surface of the support portion 11a1 facing away from the receiving cavity s and the vehicle body 200 located above it.

[0232] When the distance L between the support member 11a and the vehicle body 200 is 0, the support member 11a is in contact with the vehicle body 200. When the distance L between the support member 11a and the vehicle body 200 is greater than 0, the support member 11a is spaced apart from the vehicle body 200 and is not in contact. Understandably, at this time, the bottom cover 12 is located at the bottom of the support member 11a, and the distance g between the bottom cover 12 and the vehicle body 200 is greater than 0.

[0233] When the battery pack 100 is installed below the vehicle body 200, the area 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 support member 11a is spaced apart from the vehicle body 200, there will be some wasted space between the battery pack 100 and the vehicle body 200. If the support member 11a is attached to the vehicle body 200, the wasted space between the battery pack 100 and the vehicle body 200 can be incorporated into the space of the battery pack 100. Thus, with the same space occupied below the vehicle body 200, attaching the battery pack 100 to 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.

[0234] At this point, 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 range. 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.

[0235] In some embodiments, please refer to Figures 17 to 19 The main body 11 includes a support member 11a located on top of the housing 10. The support member 11a is used to define the receiving cavity s. The battery pack 100 is mounted to the vehicle body 200 via the support member 11a.

[0236] 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 housing 10, the carrier 11a is closest to the vehicle body 200 in the battery pack 100. 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 by means of fasteners 13 (such as screws, bolts, rivets, etc.), welding, etc.

[0237] When the battery cell 20 is mounted on the support member 11a, the structure formed by the battery cell 20 and the support member 11a is connected to the vehicle body 200, which can improve the top strength of the battery pack 100 and thus improve the installation strength of the battery pack 100.

[0238] In some embodiments, the carrier 11a is configured to form at least a portion of the chassis of the vehicle body 200.

[0239] The chassis, as part of the vehicle body 200, is a combination of four parts: the transmission system, the running system, the steering system, and the braking system. It is used to support and install the engine of the vehicle 1000 and its various components and assemblies, forming the overall shape of the vehicle 1000, bearing the engine power, and ensuring normal driving.

[0240] The chassis is located at the bottom of the vehicle body 200, and the carrier member 11a directly serves as at least a part of the chassis. That is, the carrier member 11a is used to form at least a part of the chassis of the vehicle body 200. In this way, by integrating the carrier member 11a with the chassis of the vehicle body 200, the space occupied by the gap between the conventional chassis and the battery pack 100 can be allocated within the battery pack 100 to increase the space of the battery pack 100. This helps to increase the energy of the battery pack 100, thereby increasing the driving range of the vehicle 1000.

[0241] According to some embodiments of this application, please refer to Figures 17 to 19 The electrical device includes a vehicle 1000, and a battery pack 100 is disposed at the bottom of the vehicle body 200. The battery pack 100 includes a housing 10 and battery cells 20. The housing 10 includes a support member 11a located on its top. The battery cells 20 are located inside the housing 10 and suspended on the support member 11a, and the electrode terminals 21a of the battery cells 20 are located on the outer surface of the battery cells 20 facing away from the support member 11a. The support member 11a forms at least a part of the chassis of the vehicle 1000.

[0242] At this time, the battery cell 20 is suspended on the support member 11a, which increases the strength of the support member 11a and thus the strength of the top of the battery cell 20, enabling the support member 11a to meet certain stress requirements when used as a chassis. Simultaneously, the electrode terminals 21a of the battery cell 20 are positioned away from the support member 11a, allowing the battery cell 20 to be directly mounted on the support member 11a. This eliminates the gap between the battery cell 20 and the support member 11a, and the saved gap is used to increase the installation space for the battery cell 20, thereby increasing the energy of the battery pack 100 and ultimately improving the driving range of the vehicle 1000.

[0243] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0244] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery pack, characterized in that, include: A box body, enclosing a receiving cavity, the box body including a bottom cover located at its bottom and used to define the receiving cavity; and A single battery cell is housed within the receiving cavity; The bottom cover has a feature surface facing the receiving cavity. The feature surface is constructed as a plane, and the larger the area of ​​the bottom cover occupied by the feature surface, the smaller the area of ​​the inner surface of the bottom cover that is concave or convex relative to the feature surface.

2. The battery pack according to claim 1, characterized in that, In the vertical direction, the area S1 of the orthographic projection of the feature surface and the area S2 of the orthographic projection of the bottom cover satisfy: S1 / S2≥0.

2.

3. The battery pack according to claim 1, characterized in that, In the vertical direction, the orthographic projection of the feature surface is rectangular.

4. The battery pack according to claim 1, characterized in that, The bottom cover has a cover portion and a mounting portion, the mounting portion is connected to the edge of the cover portion, the cover portion is used to define the receiving cavity, and the mounting portion is installed on the part of the box body other than the bottom cover; The feature surface is formed on the inner surface of the cover facing the receiving cavity.

5. The battery pack according to claim 4, characterized in that, The outer surface of the cover, which is opposite to the receiving cavity, is parallel to the feature surface.

6. The battery pack according to claim 4, characterized in that, The cover portion protrudes from the mounting portion in a direction away from the receiving cavity.

7. The battery pack according to claim 4, characterized in that, The thickness of the cover portion is equal to that of the mounting portion.

8. The battery pack according to any one of claims 1 to 7, characterized in that, The bottom cover is spaced apart from the battery cell.

9. The battery pack according to any one of claims 1 to 7, characterized in that, The housing also includes a support member located on its top, which defines the receiving cavity, and the battery cell is suspended from the support member.

10. The battery pack according to claim 9, characterized in that, The outer surface of the battery cell facing the carrier is the first outer surface. The battery cell includes electrode terminals, which are arranged on the outer surface of the battery cell other than the first outer surface.

11. The battery pack according to claim 10, characterized in that, The battery cell has a second outer surface opposite to the first outer surface, and the electrode terminals are arranged on the second outer surface.

12. The battery pack according to claim 9, characterized in that, The battery cell is bonded to the carrier.

13. The battery pack according to any one of claims 1 to 7, characterized in that, The housing also includes a support member and a frame. The frame encloses a cavity that extends through both ends in the vertical direction. The bottom cover and the support member respectively cover the opposite ends of the cavity in the vertical direction. The bottom cover, the frame, and the support member together enclose the receiving cavity.

14. The battery pack according to claim 13, characterized in that, The support component is fixedly connected to the frame or integrally formed.

15. An electrical appliance, characterized in that, The battery pack includes any one of claims 1 to 14, the battery pack being used to provide electrical power to the electrical device.

16. The electrical appliance according to claim 15, characterized in that, The electrical device includes a vehicle, and the battery pack is disposed at the bottom of the vehicle body.

17. The electrical appliance according to claim 16, characterized in that, The housing also includes a support member located on its top, which defines the receiving cavity; The battery pack is mounted to the vehicle body via the carrier.

18. The electrical appliance according to claim 17, characterized in that, The carrier is configured to form at least a portion of the vehicle chassis.

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