Battery packs and electrical devices

Abstract

The present application relates to a battery pack (100) and an electric device, wherein the battery pack (100) comprises a battery cell (20) and a case (10). The case (10) comprises a main body (11) and a lower cover (12) installed on the lower part of the main body (11), wherein the lower cover (12) and the main body (11) are sealedly connected and together form a sealed receiving cavity (s), and the battery cell (20) is located within the receiving cavity (s).

Description

Technology Field

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

[0002] As new energy technologies mature day by day, new energy vehicles have gradually come into the public eye. The key core technology of new energy vehicles lies in the battery pack, and the safety and stability of the battery pack are direct determinants of the finished vehicle's performance.

[0003] A battery pack generally includes a case and battery cells installed inside the case; if external water vapor enters the case, it corrodes the battery cells and other components within the case, seriously affecting the safety and lifespan of the battery pack. means of solving the problem

[0004] In light of this, the present application provides a battery pack and an electric device aimed at improving the safety and service life of the battery pack.

[0005] In a first aspect, the present application provides a battery pack comprising a battery cell and a case, wherein the case comprises a main body and a lower cover installed on the lower part of the main body, wherein the lower cover and the main body are sealedly connected and together form a sealed receiving cavity, and the battery cell is located within the receiving cavity.

[0006] In the solution of the present application, the case of the battery pack can form a sealed receiving cavity surrounded by its own lower cover and its own body without the need to install additional sealing structures within the case, thereby simplifying the structure of the battery pack, reducing the cost of the battery pack, and ensuring the safety and service life of the battery pack.

[0007] In some embodiments, the lower cover is sealedly connected to the main body through a sealing member. In this case, since the lower cover implements a sealed connection with the main body through the sealing member, the seal is secure and the cost is relatively low.

[0008] In some embodiments, the minimum thickness (h) of the bottom cover satisfies 0.2 mm < h < 20 mm. When the minimum thickness (h) of the bottom cover satisfies 0.2 mm < h < 20 mm, the weight of the battery pack can be effectively reduced and the structural strength is proven to be reasonable.

[0009] In some embodiments, the weight (m) of the battery cell and the minimum thickness (h) of the bottom cover satisfy 0.03 mm / kg ≤ h / m ≤ 100 mm / kg. At this time, the battery pack not only has relatively good structural strength but also relatively high energy density, and ignition and explosion do not occur easily.

[0010] In some embodiments, the lower cover has a cover portion and a mounting portion, the mounting portion is connected by surrounding the edge of the cover portion, the cover portion is used to define a receiving cavity, and the mounting portion is sealedly connected to the main body. In this case, the lower cover defines the receiving cavity through the cover portion and implements a connection with the main body through the mounting portion, so the structure is clear and mounting is convenient.

[0011] In some embodiments, the cover portion is installed to protrude in a direction facing away from the receiving cavity relative to the mounting portion. In this case, the cover portion protrudes relative to the mounting portion, and the cover portion of the lower cover acts as a reinforcing structure for the lower cover, thereby improving the flexibility of the lower cover.

[0012] In some embodiments, the lower cover and the battery cell are installed with a gap between them. In this case, external forces acting on the lower cover can be avoided from being transmitted to the battery cell and damaging the battery cell. In particular, when the battery pack is mounted on the underside of a vehicle and the lower cover is at the lowest point of the battery pack, stones or other debris from the ground may fly into the bottom of the battery pack and impact the lower cover while the vehicle is in motion. In this case, the buffer space can prevent external forces affecting the battery cell from being transmitted to the battery cell.

[0013] In some embodiments, the main body includes a support member located on the upper part of the case, the support member is used to define a receiving cavity, and a battery cell is suspended from the support member. At this time, since the battery cell is suspended below the support member and the lower cover is located on the lower part of the case, the battery cell can be exposed by removing only the lower cover without the need to remove the support member when performing maintenance on the interior of the battery pack; at the same time, when maintaining the battery pack, the battery cell can be removed and assembled from below the support member, and particularly when the support member is subjected to force as at least part of the vehicle chassis, the battery cell can be removed and assembled from below the support member without the need to remove the support member, thus making the implementation of battery pack maintenance convenient. In addition, the battery cell suspended from the support member can reinforce the strength of the support member and further improve the rigidity of the upper part of the battery pack.

[0014] In some embodiments, the outer surface facing the support member of the battery cell is a first outer surface, and the battery cell includes electrode terminals, and the electrode terminals are disposed on an outer surface of the battery cell other than the first outer surface. At this time, since the electrode terminals are located on an outer surface of the battery cell other than the first outer surface, each component connecting each electrode terminal (e.g., sampling harness, high voltage harness, protective structure, etc.) can be disposed through the space between the battery cell and the lower cover and / or the space between the battery cell and the inner surface of the main body, making the placement of each component more convenient. Furthermore, since the connection between the battery cell and the support member can be achieved through the connection of the first outer surface where the electrode terminals are not installed and the support member, the space between the battery cell and the support member can be saved, and the space utilization rate of the battery pack can be improved.

[0015] In some embodiments, the battery cell has a second outer surface installed facing away from the first outer surface, and the electrode terminal is disposed on the second outer surface. At this time, there is a buffer space between the second outer surface and the lower cover, and the portion of the electrode terminal protruding outside the battery cell is located within this buffer space, so that the harness and connecting member connected to the electrode terminal can be disposed within the buffer space. At the same time, the buffer space can also prevent the impact of external forces applied to the lower cover from acting on the battery cell and damaging the battery cell. Therefore, the buffer space is a win-win situation as it can not only block the influence of external forces but also allow for the placement of the harness and the like.

[0016] In some embodiments, the battery cell and the support member are bonded. In this case, the connection between the battery cell and the support member is not only convenient but also the structure of the battery pack can be simplified.

[0017] In some embodiments, the main body includes a frame and a support member, and a cavity is formed by being enclosed by the frame and having both ends in the vertical direction installed through it. A lower cover and a support member are respectively covered at both ends facing each other in the vertical direction of the cavity, and the lower cover, frame, and support member are together enclosed to form a receiving cavity. At this time, since a battery pack receiving cavity can be formed by connecting the support member and the lower cover to both ends in the vertical direction of the frame based on the frame, the case structure is relatively simple.

[0018] In some embodiments, the support member and the frame are fixedly connected or integrally molded. If the support member and the frame are integrally molded, the main body is integrally molded, and since the assembly of the case can be achieved solely by connecting the main body and the lower cover, case assembly is convenient. If the support member and the frame are fixedly connected, the molding process of the support member and the frame is relatively easy, which can reduce the manufacturing cost of the case.

[0019] In a second aspect, the present application further provides an electric device comprising the battery pack, wherein the battery pack is used to supply electrical energy to the electric device.

[0020] In some embodiments, the electrical device includes a vehicle, and the battery pack is installed in the lower part of the vehicle body. In this case, installing the battery pack in the lower part of the vehicle body does not occupy space inside the vehicle body, which helps to reduce the volume and weight of the vehicle body.

[0021] In some embodiments, the main body includes a support member located on the upper part of the case, the support member is used to define a receiving cavity, and the battery pack is mounted to the vehicle body through the support member. When the battery cell is installed on the support member, the structure formed by the battery cell and the support member is connected to the vehicle body, which can improve the upper strength of the battery pack and further improve the mounting strength of the battery pack.

[0022] In some embodiments, the support member is configured to form at least a portion of the vehicle body chassis. In this case, the space occupied by the gap between the traditional chassis and the battery pack can be incorporated into the battery pack to increase the space of the battery pack, thereby helping to improve the energy of the battery pack and further improve the vehicle's cruising capability.

[0023] Details of one or more embodiments of the present application are set forth in the drawings and description below. Other features, purposes, and advantages of the present application will become more apparent from the specification, drawings, and claims. Brief explanation of the drawing

[0024] Those skilled in the art will gain a clearer understanding of the various other advantages and benefits from the detailed description of the preferred embodiments described below. The drawings are intended to illustrate preferred embodiments and should not be construed as a limitation to this application. Additionally, the same symbols are used in all drawings to denote the same parts. The drawings are introduced as follows. FIG. 1 is a configuration diagram of a vehicle according to some embodiments of the present application. FIG. 2 is a diagram showing the configuration of a battery cell according to some embodiments of the present application. FIG. 3 is a configuration diagram of a battery pack according to some embodiments of the present application. Figure 4 is an exploded view of the battery pack shown in Figure 3. FIG. 5 is a diagram showing the configuration of a lower cover according to some embodiments of the present application. Figure 6 is an aerial view of the lower cover shown in Figure 5. Fig. 7 is a front view of the lower cover shown in Fig. 5. FIG. 8 is a diagram showing the configuration of a lower cover according to another embodiment of the present application. Figure 9 is a cross-sectional view of the battery pack shown in Figure 4. FIG. 10 is an orthographic projection in the vertical direction of the lower cover shown in FIG. 6. FIG. 11 is an external view of a battery cell according to some embodiments of the present application. Fig. 12 is a front view of the battery cell shown in Fig. 11. FIG. 13 is a diagram showing the configuration of a support member according to some embodiments of the present application. FIG. 14 is a diagram showing the configuration of a support member according to another embodiment of the present application. FIG. 15 is an orthographic projection in the vertical direction of the support member shown in FIG. 14. Fig. 16 is a front view of the battery pack shown in Fig. 4. FIG. 17 is a figure showing a battery pack according to some embodiment of the present application applied to a vehicle body. FIG. 18 is a first exploded state diagram of the structure shown in FIG. 17. FIG. 19 is a second exploded state diagram of the structure shown in FIG. 17. FIG. 20 is a diagram showing the mounting relationship between a battery pack and a vehicle body according to some embodiments of the present application. Specific details for implementing the invention

[0025] The following describes embodiments of the technical solution of the present application in detail in conjunction with the drawings. The following embodiments are used only as examples to clearly explain the technical solution of the present application and are not intended to limit the scope of protection of the present application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art of this application. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application. In the specification, claims, and description of the drawings, the terms 'comprising' and 'having' and any variations thereof are intended for non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first," "second," etc., are used to distinguish different objects and should not be understood as indicating or implying relative importance, or implicitly pointing to the quantity, specific order, or master-slave relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means one or more unless otherwise clearly and specifically limited.

[0028] The term "Examples" as used herein means that specific features, structures, or characteristics described in connection with an Example may be included in at least one Example of this Application. As this word appears in various places in the specification, it does not necessarily refer to the same Example, nor does it refer to independent or alternative Examples that are mutually exclusive from another Example. It should be understood by those skilled in the art, both explicitly and implicitly, that the Examples described herein may be combined with other Examples.

[0029] In the description of the embodiments of the present application, the term 'and / or' indicates that there may be three relationships when describing the association of associated objects. For example, A and / or B may represent the case where A exists alone, the case where A and B exist simultaneously, or the case where B exists alone. Additionally, the symbol ' / ' here signifies that the preceding and succeeding associated objects have an 'or' relationship.

[0030] In the description of the embodiments of the present application, the term 'multiple' means two or more (including two), likewise 'multiple groups' means two or more groups (including two groups), and 'multiple sheets' indicates two or more sheets (including two sheets).

[0031] In the description of the embodiments of the present application, orientations or positional relationships indicated by technical terms such as 'center', 'vertical', 'horizontal', 'length', 'width', 'thickness', 'top', 'bottom', 'front', 'back', 'left', 'right', 'vertical', 'horizontal', 'top', 'bottom', 'inside', 'outside', 'clockwise', 'counterclockwise', 'axial', 'radial', 'circumferential', etc. are based on the orientations or positional relationships depicted in the drawings. This does not indicate or imply that the indicated device or part must have a specific orientation or be configured and operated according to a specific orientation, but is merely intended to aid in and simplify the description of the embodiments of the present application and should not be understood as a limitation on the embodiments of the present application.

[0032] In the description of the embodiments of this application, technical terms such as 'mounting,' 'connecting to one another,' 'connection,' and 'fixing' should be understood in a broad sense unless otherwise clearly defined and limited. For example, a connection may be fixed, a detachable connection, or an integral type. Additionally, a connection may be mechanical or electrical. Furthermore, a connection may be direct or indirect through an intermediate medium, or it may be communication within two parts or an interaction relationship between two parts. A person skilled in the art can understand the specific meaning of the above terms in the embodiments of this application depending on the specific circumstances.

[0033] Currently, given the development of the market landscape, the applications of battery packs are becoming increasingly widespread. Battery packs are applied not only to energy storage power systems such as hydroelectric, thermal, wind, and solar power plants, but also to electric transportation vehicles like electric bicycles, motorcycles, and cars, as well as various fields including military equipment and aerospace. As the application areas of battery packs continue to expand, the market demand is also constantly increasing.

[0034] The inventors noted that when external water vapor enters the case, it corrodes the battery cells and other components inside the case, thereby degrading the safety and service life of the battery pack. In related technologies, a sealing structure (e.g., a sealing plate) is additionally installed inside the case to improve the sealability of the battery pack; however, the additional sealing structure increases the structural complexity of the battery pack and is relatively expensive.

[0035] The applicant discovered through research that designing the case itself as a sealed structure can reduce the complexity of the battery pack structure and the cost of the battery pack in order to improve the safety and service life of the battery pack.

[0036] Based on the above considerations, in order to solve the issues of safety and service life of the battery pack, the inventors have designed a battery pack after extensive research. This battery pack comprises a case and a battery cell. The case includes a main body and a lower cover installed on the lower part of the main body. The lower cover and the main body are sealedly connected to form a sealed receiving cavity. In this case, the airtightness of the battery pack is ensured through the sealing properties of the case itself, eliminating the need for other sealing structures. Consequently, the battery pack structure is simpler, and at the same time, the safety and service life of the battery pack are guaranteed.

[0037] The battery pack according to the embodiments of the present application may be used in electrical devices such as vehicles, ships, or aircraft, but is not limited thereto. The power system of the electrical device may be configured using the battery pack according to the present application. The mounting device mentioned in the present application is a structure used to mount the battery pack within the electrical device.

[0038] The embodiments of the present application provide an electric device that uses a battery pack as a power source. The electric device may be, but is not limited to, a mobile phone, tablet PC, laptop, electric toy, power tool, battery car, electric vehicle, ship, space equipment, etc. Here, electric toys may include stationary or mobile electric toys such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and space equipment may include airplanes, rockets, space shuttles, spaceships, etc.

[0039] For convenience of explanation, in the following examples, a vehicle (1000) is used as an example to explain an electrical device according to one embodiment of the present application.

[0040] Referring to FIG. 1, FIG. 1 is a configuration diagram of a vehicle (1000) according to some embodiment of the present application. The vehicle (1000) may be an internal combustion engine vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery pack (100) is installed inside the vehicle (1000), and the battery pack (100) may be installed in the lower part, the head part, or the rear part of the vehicle (1000). The battery pack (100) may be used to supply power to the vehicle (1000). For example, the battery pack (100) may be used as an operating power source for the vehicle (1000). The vehicle (1000) may also include a controller and a motor, and the controller is used to control the battery pack (100) to supply power to the motor, for example, to meet the operating power demands during starting, navigation, and driving of the vehicle (1000).

[0041] In some embodiments of the present application, the battery pack (100) may not only be used as an operating power source for the vehicle (1000), but may also provide driving power to the vehicle (1000) by completely or partially replacing fuel or natural gas as a driving power source for the vehicle (1000).

[0042] Referring to FIG. 2, FIG. 2 is a configuration diagram of a vehicle (1000) according to some embodiment of the present application. A battery cell (20) refers to the smallest unit constituting a battery pack (100). As shown in FIG. 2, the battery cell (20) includes an end cover (21), a housing (22), an electrode assembly (23), and other functional parts.

[0043] The end cover (21) refers to a member that covers an opening of the housing (22) to block the internal environment of the battery cell (20) from the external environment. Non-limitingly, the shape of the end cover (21) may correspond to the shape of the housing (22) for coupling with the housing (22). Optionally, the end cover (21) may be made of a material having a certain hardness and strength (e.g., aluminum alloy) so that the end cover (21) does not easily deform when pressed or struck. As a result, the battery cell (20) may have higher structural strength and safety may be improved. Functional components such as electrode terminals (21a) may be installed on the end cover (21). The electrode terminals (21a) may be electrically connected to an electrode assembly (23) to output or input electrical energy of the battery cell (20). In some embodiments, the end cover (21) may be equipped with a pressure relief mechanism used to release internal pressure when the internal pressure or temperature of the battery cell (20) reaches a critical value. The material of the end cover (21) may vary, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and is not specifically limited thereto in the embodiments of the present application. In some embodiments, an insulating member may be provided on the inner side of the end cover (21), and the insulating member may be used to isolate the end cover (21) from the electrical connection member within the housing (22) to reduce the risk of a short circuit. For example, the insulating member may be plastic, rubber, etc.

[0044] The housing (22) is an assembly that is combined with the end cover (21) to form an internal environment of the battery cell (20), wherein the formed internal environment can be used to accommodate the electrode assembly (23), electrolyte, and other components. The housing (22) and the end cover (21) may be independent components, and an opening may be installed in the housing (22), and the end cover (21) forms the internal environment of the battery cell (20) by covering the opening at the opening point. Non-limitingly, the end cover (21) and the housing (22) may be integrated. Specifically, the end cover (21) and the housing (22) may first form a common connection surface before other components enter the housing, and the end cover (21) covers the housing (22) when the interior of the housing (22) needs to be sealed. The housing (22) may have various shapes and various dimensions, such as a rectangular prism, a cylindrical prism, a hexagonal prism, etc. Specifically, the shape of the housing (22) may be determined according to the specific shape and dimensional size of the electrode assembly (23). The material of the housing (22) may vary, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and is not specifically limited thereto in the embodiments of the present application.

[0045] The electrode assembly (23) is a component that causes an electrochemical reaction in the battery cell (20). The housing (22) may contain one or more electrode assemblies (23). The electrode assembly (23) is formed mainly by winding or laminating a positive plate and a negative plate, and a separator is generally installed between the positive plate and the negative plate. The portions of the positive plate and the negative plate that have active material constitute the main body of the electrode assembly (23), and the portions of the positive plate and the negative plate that do not have active material each constitute a positive tab and a negative tab, respectively. The positive tab and the negative tab may be located together at one end of the main body or at each end of the main body. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs connect to the electrode terminals (21a) to form a current circuit.

[0046] FIG. 3 is a configuration diagram of a battery pack (100) according to some embodiment of the present application, and FIG. 4 is an exploded view of the battery pack (100) shown in FIG. 3. According to some embodiment of the present application, with reference to FIG. 3 and FIG. 4, the present application embodiment provides a battery pack (100) comprising a battery cell (20) and a case (10), wherein a receiving cavity (s) is formed in the case (10), and the battery cell (20) is received within the receiving cavity (s).

[0047] In the battery pack (100), there may be multiple battery cells (20), and the multiple battery cells (20) may be connected in series, in parallel, or in a mixed manner. A mixed connection means that the multiple battery cells (20) are connected in series and in parallel. The multiple battery cells (20) may be directly connected in series, in parallel, or in a mixed manner, and the entire structure composed of the multiple battery cells (20) may be housed within the case (10). Of course, the battery pack (100) may be in the form of a battery module in which the multiple battery cells (20) are first connected in series, in parallel, or in a mixed manner, and the multiple battery modules may again be connected in series, in parallel, or in a mixed manner to form a single whole that is housed within the case (10). The battery pack (100) may include other structures. For example, the battery pack (100) may further include a busbar for implementing electrical connections between the multiple battery cells (20). Here, each battery cell (20) may be a secondary battery or a primary battery; It may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell (20) may be a cylinder, a flat body, a rectangular prism, or other shape.

[0048] The case (10) can have various shapes such as a cylinder, a rectangular prism, etc., and the specific structure of the case (10) can adopt various configuration methods.

[0049] In some embodiments, continuing with reference to FIGS. 3 and FIGS. 4, the case (10) includes a main body (11) and a lower cover (12) installed on the lower part of the main body (11), and the lower cover (12) and the main body (11) are together enclosed to form a receiving cavity(s) for accommodating a battery cell (20).

[0050] The main body (11) may be formed as a single-piece molded structure or by assembling multiple parts. The main body (11) may be a hollow housing (22) structure that defines a first space itself, the first space having an open bottom, and a lower cover (12) covers the open point of the first space. The lower cover (12) may be a hollow structure with one side open and may have a second space itself, and the second space of the lower cover (12) is integrated with the first space of the main body (11) to form a receiving cavity (s). The lower cover (12) itself may not have a space to form a receiving cavity (s), and when the lower cover (12) covers the open point of the first space of the main body (11), the lower cover (12) seals the first space of the main body (11), and the two surround to form a receiving cavity (s) equivalent to the first space, and at this time, the lower cover (12) may be a flat plate structure. Of course, the receiving cavity(s) of the case (10) may be formed as a part of the first space of the main body (11), and the lower cover (12) may cover the open point of the first space and be sunken toward the first space to occupy a part of the first space, and the receiving cavity(s) of the case (10) is formed by subtracting the part of the space occupied by the lower cover (12) from the first space.

[0051] At this time, it can be understood that the lower cover (12) is located at the bottom of the case (10) and is used to define the receiving cavity(s) together with the main body (11). Specifically, the lower cover (12) may be a plate-shaped structure, a block-shaped structure, etc., but is not limited thereto, and may be a flat plate shape, a curved plate shape, etc., but is not limited thereto.

[0052] When the battery cell (20) is located in the receiving cavity(s), the battery cell (20) can be installed in the lower cover (12) and / or the main body (11).

[0053] When the main body (11) is formed by the assembly of a plurality of parts, the battery cell (20) may be installed in one of the parts or in all of the parts. In one embodiment, the main body (11) may include an upper cover (not shown), a perimeter plate (not shown), and a support plate (not shown), the perimeter plate may surround to form a third space with both ends in the vertical direction open, the upper cover and the lower cover (12) each cover and seal both ends in the vertical direction of the third space, the upper cover, the perimeter plate, and the lower cover (12) together surround to form 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 support member (11a) and a frame (11b) described below, and specifically described as follows.

[0054] The fixation between the lower cover (12) and the main body (11) can be achieved through methods such as welding, heat fusion connection, bonding, fastening connection, and snap-fit ​​connection. Here, fastening connection refers to a connection through fasteners (13), and fasteners (13) include components such as bolts, cotters, rivets, pins, and screws. Here, snap-fit ​​connection refers to achieving fixation through a snap-fit ​​coupling structure; for example, the lower cover (12) has a hook and the main body (11) has an insertion groove, and snap-fit ​​coupling fixation between the lower cover (12) and the main body (11) can be achieved when the hook is snap-fit ​​coupled within the insertion groove. Of course, the method of connecting the lower cover (12) and the main body (11) is not limited to this, and is not listed individually in this application.

[0055] In some embodiments, the lower cover (12) and the main body (11) are sealedly connected and together form a sealed receiving cavity(s).

[0056] The sealing connection method between the lower cover (12) and the main body (11) is varied and includes, but is not limited to, a method in which a sealing member is installed between the lower cover (12) and the main body (11) and the lower cover (12) and the main body (11) are sealedly connected through the sealing member; a method in which the lower cover (12) and the main body (11) are sealedly connected through a sealant; and a method in which the lower cover (12) and the main body (11) are inserted and connected to each other and are sealedly connected through a stop structure composed of an insertion connection surface.

[0057] At this time, the case (10) of the battery pack (100) can form a sealed receiving cavity(s) by surrounding its own lower cover (12) and its own main body (11) without the need to install additional sealing structures within the case (10), thereby simplifying the structure of the battery pack (100), reducing the cost of the battery pack (100), and ensuring the safety and service life of the battery pack (100).

[0058] In the description of the present application, the lower cover (12) of the battery pack (100) is located at the bottom of the main body (11). That is, in the vertical orientation shown in FIGS. 3 and 4, the lower cover (12) is located at the bottom of the main body (11). In actual use, the vertical orientation shown in FIGS. 3 and 4 may be vertical, but is not limited thereto, and may be determined according to the actual mounting situation of the battery pack (100). In the description below of the present application, the positional relationship, dimensions, etc. of each structure of the battery pack (100) are described based on the vertical direction, and it is necessary to point out that this is not a limitation on the method of use of the battery pack (100), but is intended to interpret and explain the solution more clearly.

[0059] In some embodiments, the lower cover (12) is sealedly connected to the main body (11) through a sealing member.

[0060] A sealing member refers to a component capable of preventing fluid or solid particles from leaking from adjacent bonding surfaces, which can prevent external impurities such as dust and moisture from entering the battery pack (100). The sealing member is connected to the main body (11) and the lower cover (12) in a sealed manner, so that the sealing member is connected between the two opposing surfaces of the main body (11) and the lower cover (12) and forms a ring-shaped contact interface with these two surfaces, thereby preventing external moisture from entering the battery pack (100) through the contact surface between the main body and the two surfaces, and furthermore, creates a sealing effect.

[0061] The sealing member is optionally a sealing ring or a gasket. Specifically, the sealing member is optionally manufactured from materials such as rubber or silica gel. Specifically, the sealing member is optionally an O-shaped sealing member, a rectangular sealing member, a different-shaped sealing member, etc. The specific shape of the sealing member may match the shape of the two opposing surfaces of the lower cover (12) and the main body (11). For example, if the two opposing surfaces of the lower cover (12) and the main body (11) are ring-shaped surfaces, the sealing member may be an O-shaped sealing member.

[0062] At this time, the lower cover (12) implements a sealed connection with the main body (11) through a sealing member, so the seal is secure and the cost is relatively low.

[0063] It should be noted that the lower cover (12) can be fixedly connected to the main body (11) through other methods after sealing with the main body (11) through a sealing member. Other methods include, but are not limited to, snap-fit ​​connection, insertion connection, screw connection, rivet connection, welding, and bonding. It can be understood that when the lower cover (12) is sealed with the main body (11) through a sealant, if the adhesive performance of the sealant can satisfy the requirements (i.e., the lower cover (12) and the main body (11) are fixed and not separated) according to the adhesiveness of the sealant, it is not necessary to adopt other methods for the fixed connection between the two.

[0064] In some embodiments, the lower cover (12) is detachably connected to the lower part of the main body (11).

[0065] The fact that the lower cover (12) is detachably connected to the main body (11) means that when the lower cover (12) is connected to the main body (11), it has a first state in which the lower cover (12) is completely connected to the main body (11) to form a receiving cavity(s), and a second open state in which it is incompletely connected to or separated from the main body (11) to expose the battery cell (20), and the lower cover (12) can be switched from the first state to the second state and from the second state to the first state under the action of an external force, and that no parts are damaged in this process.

[0066] When the lower cover (12) has a second state in which it is incompletely connected to the main body (11) to open the receiving cavity (s), the mounting method of the lower cover (12) and the main body (11) may be such that the lower cover (12) and the main body (11) are rotatably connected and a fixed connection is implemented through a fastener (13) or a snap-fit ​​coupling method. When the lower cover (12) rotates relative to the main body (11) until the receiving cavity (s) is closed, the lower cover (12) and the main body (11) are fixedly connected to the main body through a fastener (13) or a snap-fit ​​coupling method, and the battery cell (20) is received within the receiving cavity (s) and is not visible, at which time the lower cover (12) is in the first state. When removing the fastener (13) or releasing the snap-fit ​​connection, the lower cover (12) can rotate relative to the main body (11) until the receiving cavity(s) is opened to expose the location of the battery cell (20), at which time the lower cover (12) is in a second state. Here, the lower cover (12) and the main body (11) being rotatably connected includes, but is not limited to, the lower cover (12) and the main body (11) being rotatably connected through a rotation axis.

[0067] When the lower cover (12) has a second state in which it is separated from the main body (11) and opens the receiving cavity (s), the mounting method of the lower cover (12) and the main body (11) may be such that the lower cover (12) and the main body (11) are fixedly connected only through a fastener (13) or a snap-fit ​​coupling method. When the fastener (13) is mounted on the lower cover (12) and the main body (11), or when the lower cover (12) is snap-fit ​​coupled with the snap-fit ​​coupling structure of the main body (11), the lower cover (12) and the main body (11) achieve complete fixation and together form the receiving cavity (s), and the battery cell (20) is received within the receiving cavity (s) and is not visible, at which time the lower cover (12) is in the first state. When removing the fastener (13) or releasing all snap-fit ​​connections, the lower cover (12) can be separated from the main body (11) and further expose the battery cell (20), at which time the lower cover (12) is in a second state.

[0068] When the lower cover (12) is in the first state, it forms a receiving cavity(s) with the main body (11) to protect the battery cell (20). When the lower cover (12) is in the second state, the battery cell (20) is exposed, thereby making it convenient for a worker to perform maintenance or replacement of the battery cell (20).

[0069] In some embodiments, referring to FIG. 4, the lower cover (12) and the main body (11) are detachably connected through a fastener (13).

[0070] A fastener (13) means a member capable of fastening two or more parts (or members) into one whole, and may be a screw, bolt, rivet, cotter, pin shaft, welded stud, etc., but is not limited thereto.

[0071] At this time, the lower cover (12) and the main body (11) are detachably connected through a fastener (13), making removal and assembly convenient, as well as having a simple, economical, and practical structure.

[0072] FIG. 5 is a configuration diagram of a lower cover (12) according to some embodiment of the present application, FIG. 6 is an aerial view of the lower cover (12) shown in FIG. 5, and FIG. 7 is a front view of the lower cover (12) shown in FIG. 5. FIG. 8 is a configuration diagram of a lower cover (12) according to another embodiment of the present application.

[0073] In some embodiments, the minimum thickness (h) of the lower cover (12) satisfies 0.2 mm < h < 20 mm.

[0074] The thickness of the lower cover (12) refers to the distance between the two vertical surfaces of the lower cover (12) in a vertical cross-section. The minimum thickness (h) of the lower cover (12) is the shortest distance between the two vertical sides of the lower cover (12). When the thickness at each point of the lower cover (12) is uniform, the lower cover (12) is flat (as shown in FIG. 8), and the minimum thickness of the lower cover (12) is the same thickness at each point of the lower cover (12). When the thickness of the lower cover (12) is non-uniform, the minimum thickness of the lower cover (12) is the thickness at the thinnest point of the lower cover (12).

[0075] Specifically, the minimum thickness (h) of the lower cover (12) is optionally 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, These are 18mm, 18.5mm, 19mm, 19.5mm, etc. Preferably, 0.5mm≤h≤3mm.

[0076] At this time, when the minimum thickness (h) of the lower cover (12) satisfies 0.2 mm < h < 20 mm, the weight of the battery pack (100) can be effectively reduced and the structural strength is proven to be reasonable.

[0077] In the description of the present application, with respect to the vertical direction, the 'thickness' of any structure refers to the distance between the two surfaces in the vertical direction of the structure in the vertical cross-section, and it should be noted that the description provided here may be referenced as no further interpretation of 'thickness' is provided in the description below. Of course, it should be understood that the vertical direction is merely for the convenience of describing the solution of the present application and is not a limitation on the method of use of the battery pack (100).

[0078] In some embodiments, the weight (m) of the battery cell (20) and the minimum thickness (h) of the lower cover (12) satisfy 0.03 mm / kg ≤ h / m ≤ 100 mm / kg.

[0079] The weight (m) of the battery cell (20) refers to the weight (m) of a single battery cell (20). When a battery pack (100) contains multiple battery cells (20), the weight of the battery cell (20) is the weight of each battery cell (20).

[0080] Specifically, the ratio of the minimum thickness (h) of the lower cover (12) to the weight (m) of the battery cell (20) is optionally 0.04mm / kg, 0.05mm / kg, 0.1mm / kg, 0.4mm / kg, 0.8mm / kg, 1mm / kg, 1.5mm / kg, 2mm / kg, 2.5mm / kg, 3mm / kg, 3.5mm / kg, 4mm / kg, 5mm / kg, 6mm / kg, 8mm / kg, 10mm / kg, 12mm / kg, 13mm / kg, 15mm / kg, 16mm / kg, 18mm / kg, 20mm / kg, 30mm / kg, 35mm / kg, 40mm / kg, 45mm / kg, 50mm / Kg, 55mm / Kg, 60mm / Kg, 65mm / Kg, 68mm / Kg, 70mm / Kg, 75mm / Kg, 80mm / Kg, 85mm / Kg, 90mm / Kg, 95mm / Kg, 98mm / Kg.

[0081] Table 1 Influence of the ratio of the minimum thickness (h) of the lower cover (12) and the weight (m) of the battery cell (20) on the safety performance of the battery pack (100)

[0082] No. h(mm) m(Kg) h / m(mm / Kg) Measurement results 1 0.2 10 0.02 ignition, explosion 2 0.5 10 0.05 Unexploded, fire explosion 3 1.2 3 0.4 Unexploded, fire explosion 4 3 1 3 Unexploded, fire explosion 5 5 1.5 3.33 Unexploded, fire explosion 6 8 1.8 4.45 Unexploded, fire explosion 7 10 2 5 Unexploded, fire explosion 8 12 1.6 7.5 Unexploded, fire explosion 9 15 1.7 8.82 Unexploded, fire explosion 10 20 2 10 Unexploded, fire explosion 11 20 1 20 Unexploded, fire explosion 12 20 0.5 40 Unexploded, fire explosion 13 20 0.32 62.5 Unexploded, fire explosion 14 20 0.25 80 Unexploded, fire explosion 15 20 0.2 100 Unexploded, fire explosion

[0083] Table 1 shows the results of measuring the effect of the ratio of the minimum thickness (h) of the lower cover (12) and the weight (m) of the battery cell (20) on the safety performance of the battery pack (100) according to the standard of GB 38031-2020 "Safety requirements for power batteries for electric vehicles." As can be seen from Table 1, when h / m is 0.02 mm / Kg, ignition and explosion easily occur in the battery pack (100), and the reason is that 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 lower cover (12) is relatively good, so ignition and explosion do not easily occur in the battery pack (100), but if h / m is too large, space is wasted and energy density is lowered, so it is desirable that h / m not exceed 100 mm / Kg.

[0084] At this time, it was proven that if the minimum thickness (h) of the lower cover (12) and the weight (m) of the battery cell (20) satisfy 0.03 mm / kg ≤ h / m ≤ 100 mm / kg, the battery pack (100) not only has relatively good structural strength but also relatively high energy density and does not easily ignite or explode.

[0085] In some embodiments, referring together to FIGS. 5 to 7, the lower cover (12) has a cover portion (12a) and a mounting portion (12b), the mounting portion (12b) is connected to the edge of the cover portion (12a), the cover portion (12a) is used to define a receiving cavity(s), and the mounting portion (12b) is connected to the main body (11).

[0086] The fact that the cover portion (12a) is used to define the receiving cavity(s) means that the cover portion (12a) and the main body (11) surround each other to form the receiving cavity(s), and 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) may be a plate-shaped or block-shaped member, or a flat plate-shaped or curved plate-shaped member, and is not specifically limited thereto. As can be seen in FIG. 6, the fact that the mounting portion (12b) surrounds the edge of the cover portion (12a) means that the mounting portion (12b) is installed continuously along the edge of the cover portion (12a) and connected so that the ends are sealed. In the vertical projection, the mounting portion (12b) has a constant width, so it has a suitable contact area with the main body (11), making it convenient to position and mount between the mounting portion (12b) and the main body (11), as well as convenient to install the sealing member, which helps to improve the sealing performance between the mounting portion (12b) and the main body (11).

[0087] The cover portion (12a) and the mounting portion (12b) can be integrally molded. If the lower cover (12) is made of a metal material (e.g., aluminum, iron, stainless steel, etc.), the cover portion (12a) and the mounting portion (12b) can be integrally molded by methods such as die casting, forging, hot compression, or cold compression. If the lower cover (12) is made of a plastic material (e.g., PP, PE, ABS, etc.), the cover portion (12a) and the mounting portion (12b) can be integrally molded through injection molding. The cover portion (12a) and the mounting portion (12b) may be molded individually and then connected as one. If the cover portion (12a) and the mounting portion (12b) are made of a metal material, the cover portion (12a) and the mounting portion (12b) can be welded or bonded together as one. If the cover portion (12a) and the mounting portion (12b) are made of a plastic material, the cover portion (12a) and the mounting portion (12b) can be bonded together as one. Of course, the cover part (12a) and the mounting part (12b) can be fixedly connected as one through other methods such as snap-fit ​​connection, rivet connection, etc.

[0088] The cover portion (12a) and the mounting portion (12b) may be located on the same plane. Specifically, the two surfaces of the cover portion (12a) and the mounting portion (12b) facing the main body (11) are on the same plane, and / or the two surfaces of the cover portion (12a) and the mounting portion (12b) facing away from the main body (11) are on the same plane. When the two surfaces of the cover portion (12a) and the mounting portion (12b) facing the main body (11) and the two surfaces facing away from the main body (11) are each on the same plane, the cover portion (12a) and the mounting portion (12b) may form a single flat-shaped lower cover (12) (e.g., as shown in FIG. 8).

[0089] The cover portion (12a) and the mounting portion (12b) may not be located on the same plane. Specifically, the cover portion (12a) may be recessed toward 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), but this is not specifically limited thereto. The thickness of the cover portion (12a) and the mounting portion (12b) may be the same or different, and this is not specifically limited thereto.

[0090] At this time, the lower cover (12) defines a receiving cavity(s) through the cover portion (12a) and implements a connection with the main body (11) through the mounting portion (12b), so that the structure is clear and mounting is convenient.

[0091] When the lower cover (12) and the main body (11) are sealedly connected, the lower cover (12) is sealedly connected to the main body (11) through the mounting portion (12b), that is, it can be understood that the mounting portion (12b) is sealedly connected to the main body (11). The method of sealing connection between the mounting portion (12b) and the main body (11) may be a sealing connection by a sealing member, a sealing connection by a sealant, etc., which are not listed here. The sealing member may be the sealing member mentioned in the above description, and the method of installing the sealing member may refer to the above description; the difference is that the sealing member is installed between the mounting portion (12b) and the main body (11). When the mounting portion (12b) and the main body (11) are sealedly connected by a sealant, the sealant may be coated on all surfaces of the mounting portion (12b) and the main body (11) that come into contact with each other.

[0092] When the lower cover (12) and the main body (11) are detachably connected, the lower cover (12) is detachably connected to the main body (11) through the mounting part (12b), that is, it can be understood that the mounting part (12b) is detachably connected to the main body (11). The detachable connection method between the mounting part (12b) and the main body (11) can be referenced from the detachable connection method between the lower cover (12) and the main body (11) described above. Since it is sufficient to install the part of the lower cover (12) that is detachably connected to the main body (11) as the mounting part (12b), a detailed description of the detachable connection method between the mounting part (12b) and the main body (11) is omitted here.

[0093] In some embodiments, the mounting part (12b) and the main body (11) are detachably connected.

[0094] Specifically, the lower cover (12) further includes a fixing hole (12c) installed in the mounting portion (12b), and the fastener (13) passes through the fixing hole (12c) in the mounting portion (12b) and is fastened to the main body (11). The fixing hole (12c) is a through hole that penetrates the mounting portion (12b) in a vertical direction. Specifically, the fixing hole (12c) may be a smooth through hole (e.g., the fastener (13) is a rivet), a through hole with threads (e.g., the fastener (13) is a screw), or a through hole of other types (e.g., a hexagonal hole, a square hole, a waist-shaped hole, etc.). The specific shape of the fixing hole (12c) may be determined according to the specific shape and specific setting method of the fastener (13), and a detailed description is omitted here.

[0095] In some embodiments, the thickness of the cover portion (12a) and the mounting portion (12b) is the same.

[0096] When the cover portion (12a) and the mounting portion (12b) are integrally molded, the two can adopt the method described above to implement integral molding such as die-casting integral molding, cold compression integral molding, hot compression integral molding, and injection molding integral molding, and a detailed description is omitted here. Since the thickness of the cover portion (12a) and the mounting portion (12b) is the same, they can be processed quickly through methods such as stamping and cutting based on the same metal plate during molding.

[0097] At this time, if the thickness of the cover part (12a) and the mounting part (12b) is the same, each point receives a uniform force during molding, thereby improving the molding rate of the integral molding, and since it can be processed quickly by adopting a simple method such as sheet metal cutting, the structure of the lower cover (12) is simpler and processing is more convenient.

[0098] In some embodiments, referring to FIG. 7, the cover portion (12a) is installed so as to protrude in a direction facing away from the receiving cavity(s) compared to the mounting portion (12b).

[0099] As can be seen from the above description, the cover portion (12a) defines the receiving cavity(s), and the fact that the cover portion (12a) protrudes with its back to the receiving cavity(s) means that the cover portion (12a) protrudes with its back to the main body (11). In other words, the cover portion (12a) and the mounting portion (12b) are arranged offset from each other in the vertical direction, and the cover portion (12a) is at the lowest point of the lower cover (12).

[0100] When the cover portion (12a) protrudes with its back to the receiving cavity (s) compared to the mounting portion (12b), a certain clearance space may be formed between the cover portion (12a) and the mounting portion (12b). This clearance space increases the distance between the cover portion (12a) and the battery cell (20). When an external force is applied to the cover portion (12a), the external force can be reduced through this clearance space, thereby reducing or avoiding the external force acting on the battery cell (20) and damaging the battery cell (20). In particular, when the battery pack (100) is mounted on the lower part of the vehicle (1000) and the lower cover (12) is at the lowest point of the battery pack (100), stones or other debris from the ground may fly into the lower part of the battery pack (100), i.e., the lower cover (12), and impact the lower cover (12) while the vehicle (1000) is driving. At this time, the clearance space can reduce the impact on the battery cell (20) caused by the impact of the external force. At the same time, the cover portion (12a) protrudes relative to the mounting portion (12b), and the cover portion (12a) of the lower cover (12) acts as a reinforcing structure of the lower cover (12) to improve the flexibility of the lower cover (12).

[0101] In the embodiment of the present application, it can be understood that the lower cover (12) is located at the bottom of the case (10) and is used to define the receiving cavity(s).

[0102] FIG. 9 is a cross-sectional view of the battery pack (100) illustrated in FIG. 4. In some embodiments, with reference to FIG. 9, the lower cover (12) and the battery cell (20) are installed spaced apart.

[0103] The fact that the lower cover (12) and the battery cell (20) are installed apart means that a set gap (r) is maintained between the lower cover (12) and the battery cell (20) in the vertical direction. Under the action of this set gap (r), a buffer space is formed between the lower cover (12) and the battery cell (20), so that external forces acting on the lower cover (12) are not transmitted to the battery cell (20) and damage the battery cell (20). In particular, when the battery pack (100) is mounted on the lower part of the vehicle (1000) and the lower cover (12) is at the lowest point of the battery pack (100), it is easy for stones or other debris from the ground to fly into the lower part of the battery pack (100) and impact the lower cover (12) while the vehicle (1000) is driving. At this time, the buffer space can stop the transmission of external forces affecting the battery cell (20) to the battery cell (20).

[0104] The method of installing the lower cover (12) and the battery cell (20) apart may be formed by the clearance space formed between the protruding cover portion (12a) and the mounting portion (12b) in the above embodiment, or it may be a method of maintaining a set distance between one end facing the lower cover (12) and the other end facing the lower cover (12) of the main body (11) of the battery cell (20). In other words, the battery cell (20) is located only within a partial range of the receiving cavity (s) defined by the main body (11) and is not located within the range of the receiving cavity (s) defined by the lower cover (12), thereby forming a buffer space by maintaining a set distance (r) between the battery cell (20) and the lower cover (12).

[0105] When a plurality of battery cells (20) are included in the battery pack (100), all battery cells (20) are installed spaced apart from the lower cover (12). Additionally, to standardize the dimensions of the battery cells (20), the spacing between each battery cell (20) and the lower cover (12) is the same.

[0106] In some embodiments, referring to FIGS. 5 and 6, the lower cover (12) has a feature surface (d) facing the receiving cavity(s), and the feature surface (d) is configured as a plane.

[0107] The fact that the feature surface (d) faces the receiving cavity (s) indicates that the feature surface (d) is an inner surface capable of defining the receiving cavity (s) in the lower cover (12). The fact that the feature surface (d) is composed of a plane means that, in the arrangement direction of the main body (11) and the lower cover (12), the feature surface (d) is a plane perpendicular to this arrangement direction. In actual situations, when the main body (11) and the lower cover (12) are arranged along the vertical direction, the feature surface (d) of the lower cover (12) is a plane parallel to the horizontal plane. When the main body (11) and the lower cover (12) are arranged along the horizontal direction, the feature surface (d) of the lower cover (12) is a plane parallel to the vertical plane.

[0108] If the feature surface (d) is flat, the feature surface (d) can maintain a relatively uniform distance (this distance may be 0) from each battery cell (20) accommodated within the receiving cavity (s). When the distance between the feature surface (d) and the battery cell (20) is maintained relatively uniformly, 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 driving capability of the battery pack (100) is higher.

[0109] It can be understood that when the lower cover (12) has the cover portion (12a) and the mounting portion (12b), the feature surface (d) may be formed by the inner surface facing the receiving cavity (s) of the cover portion (12a). Additionally, when the lower cover (12) and the battery cell (20) are installed spaced apart, the feature surface (d) and the battery cell (20) are spaced apart.

[0110] In some embodiments, the outer surface facing away from the receiving cavity(s) of the cover portion (12a) is parallel to the feature surface (d).

[0111] The outer surface and the feature surface (d) facing away from the receiving cavity (s) of the cover portion (12a) are arranged facing away from each other along the vertical direction. The outer surface of the cover portion (12a) is used to contact the atmospheric environment and withstand the impact of external forces. When the outer surface of the cover portion (12a) is a flat plane that coincides with the feature surface (d), in particular, when the lower cover (12) and the main body (11) are positioned at the bottom of the vehicle (1000) along the vertical direction and the lower cover (12) is located at the lowest point of the battery pack (100), and the outer surface of the cover portion (12a) is flat, it helps to significantly reduce wind resistance generated by the battery pack (100), thereby helping to lower the driving resistance of the vehicle (1000), reduce the driving energy consumption of the vehicle (1000), and improve the cruising capability of the battery pack (100).

[0112] FIG. 10 is an orthographic projection in the vertical direction of the lower cover (12) shown in FIG. 6. Here, S1 represents the projected area of ​​the feature surface (d), and S2 represents the projected area of ​​the lower cover (12).

[0113] In some embodiments, the area of ​​the orthographic projection (S1) of the feature surface (d) in the vertical direction and the area of ​​the orthographic projection (S2) of the lower cover (12) satisfy S1 / S2 ≥ 0.2. Additionally, S1 / S2 ≥ 0.5.

[0114] In the embodiment illustrated in FIG. 10, in the vertical orthographic projection, the feature surface (d) is formed by being surrounded by the first feature side (d1), the second feature side (d2), the third feature side (d3), and the fourth feature side (d4) connected at the head and tail, and the orthographic projection area (S1) of the feature surface (d) is the area of ​​the region defined by the first feature side (d1), the second feature side (d2), the third feature side (d3), and the fourth feature side (d4). The orthographic projection area (S2) of the lower cover (12) is the area of ​​the region defined by the edge of the lower cover (12).

[0115] Specifically, the ratio of the orthographic projection area (S1) of the feature surface (d) to the orthographic projection area (S2) of the lower cover (12) can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0116] Table 2 Influence of the ratio of area (S1) and area (S2) on the driving range of the battery pack (100)

[0117] No. S1 / mm 2 S2 / mm 2 S1 / S2 Measurement results 1 0.3×10 6 2.6×10 6 0.115 Bad 2 0.52×10 6 2.6×10 6 0.2 Relatively good 3 0.94×10 6 2.6×10 6 0.362 Relatively good 4 1.3×10 6 2.6×10 6 0.5 well 5 1.5×10 6 2.6×10 6 0.577 well 6 1.8×10 6 2.6×10 6 0.692 well 7 2.2×10 6 2.6×10 6 0.846 Excellence 8 2.4×10 6 2.6×10 6 0.923 Excellence 9 2.6×10 6 2.6×10 6 1 Excellence

[0118] Table 2 shows the effect of the ratio of the orthographic projection area (S1) of several sets of feature surfaces (d) measured according to the NEDC (New European Driving Cycle) standard and the orthographic projection area (S2) of the lower cover (12) on the driving range of the battery pack (100). When S1 / S2 is less than 0.2, the driving range of the battery pack (100) is relatively poor, and the reason is that when the feature surfaces (d) are relatively small, the space utilization rate of the receiving cavity (s) is relatively low, and the number of battery cells (20) accommodated in the battery pack (100) is relatively small, so the energy density of the battery pack (100) is relatively low, and as a result, the driving range of the battery pack (100) is relatively short and the measurement result is relatively poor. When the ratio of S1 / S2 reaches 0.2 and above (especially when S1 / S2 reaches 0.5 and above), the greater the ratio, the better the range of the battery pack (100). This is because the larger the feature surface (d), the higher the space utilization rate of the receiving cavity (s) and the higher the energy density of the battery pack (100). As a result, the range of the battery pack (100) increases and the measurement results improve.

[0119] Since the feature surface (d) is flat, the more the feature surface (d) occupies the area of ​​the lower cover (12), the smaller the area of ​​the inner surface that is recessed or protruded from the feature surface (d) in the lower cover (12). Due to the inner surface recessed from the feature surface (d), the partial space within the receiving cavity (s) becomes irregular, making it impossible to mount the battery cell (20), and thus the space utilization rate of the receiving cavity (s) is lowered. The partial space of the receiving cavity (s) formed by the inner surface protruding from the feature surface (d) also becomes irregular, making it impossible to accommodate the battery cell (20), and thus the space utilization rate of the receiving cavity (s) is lowered. When the space utilization rate of the receiving cavity (s) is low, the volume occupied by the battery cell (20) per unit space within the battery pack (100) is small, and thus the energy density of the battery pack (100) is low. Therefore, the more the feature surface (d) occupies the area of ​​the lower cover (12), the greater the space utilization rate of the battery pack (100), the higher the energy density of the battery pack (100), and the better the range of the battery pack (100).

[0120] In some embodiments, referring to FIG. 10, the orthographic projection of the feature plane (d) in the vertical direction is a rectangle.

[0121] As illustrated in FIG. 10, the rectangular feature plane (d) is a region defined by being enclosed by the first feature plane (d1), the second feature plane (d2), the third feature plane (d3), and the fourth feature plane (d4). In the battery pack (100), a plurality of battery cells (20) are mostly assembled to form a rectangular structure, and if the feature plane (d) is configured as a rectangle, it can adapt to the overall structure formed by the battery cells (20) within the battery pack (100), thereby helping to improve the energy density of the battery pack (100) by placing more battery cells (20) within the receiving cavity(s).

[0122] Of course, in other embodiments, the orthographic projection of the feature plane (d) in the vertical direction may be a circular, polygonal, elliptical, and other irregular shape.

[0123] In an embodiment of the present application, the main body (11) includes a support member (11a).

[0124] The support member (11a) may be a part used to define the receiving cavity(s) in the main body (11) (e.g., the support member (11a) is the upper cover or frame mentioned above), or a part 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 is not specifically limited thereto. When the support member (11a) is used to define the receiving cavity(s), the support member (11a) may be a part directly connected to the lower cover (12) in the main body (11) (e.g., the frame mentioned above), or a part not connected to the lower cover (12) (e.g., the upper cover mentioned above).

[0125] In some embodiments, the battery cell (20) is installed on the surface of the support member (11a).

[0126] At this time, the support member (11a) is a component capable of supporting the weight of the battery cell (20) and may be a support plate, support member, support block, support piece, support frame, support string, etc., and is not specifically limited thereto. Specifically, the battery cell (20) may be supported on the support member (11a), and the battery cell (20) may be installed on the upper side of the support member (11a). Specifically, the battery cell (20) may be installed by being suspended from the support member (11a), and the battery cell (20) may be suspended from a wall surface of the support member (11a) that is parallel to the direction of gravity of the battery cell (20).

[0127] The battery cell (20) may be installed on the upper side of the support member (11a) (e.g., when the support member (11a) is used as a support plate located within the receiving cavity(s)), the battery cell (20) may be installed on the lower side of the support member (11a) (e.g., when the support member (11a) is used as an upper cover for defining the receiving cavity(s)), or the battery cell (20) may be installed on the side of the support member (11a) (e.g., when the support member (11a) is used as a frame for defining the receiving cavity(s).

[0128] In some embodiments, the battery cell (20) and the support member (11a) are bonded.

[0129] Specifically, the bonding between the battery cell (20) and the support member (11a) can be achieved using an adhesive such as epoxy bond, steel epoxy, etc., and is not specifically limited thereto. At this time, since the battery cell (20) and the support member (11a) are bonded, not only is the connection convenient, but the structure of the battery pack (100) can also be simplified.

[0130] In some embodiments, the battery cell (20) is installed 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 0.0002 mm / kg < H / M ≤ 0.2 mm / kg.

[0131] The thickness of the support member (11a) refers to the distance between one side surface of the support member (11a) used to install the battery cell (20) and the other side surface opposite to it. When the battery cell (20) is installed on the vertical surface of the support member (11a), the minimum thickness (H) of the support member (11a) refers to the smallest distance between the two vertical surfaces of the support member (11a), and when the battery cell (20) is installed on the horizontal surface of the support member (11a), the minimum thickness (h) of the support member (11a) refers to the smallest distance between the two horizontal surfaces of the support member (11a).

[0132] The weight of the battery pack (100) includes the total weight of the main body (11), the lower cover (12), the battery cell (20), and other components (e.g., harness, thermal management system, power management system, etc.).

[0133] Specifically, the ratio of the minimum thickness (H) of the support member (11a) to the weight (M) of the battery pack (100) can be designed to be 0.0003 mm / kg, 0.0005 mm / kg, 0.0008 mm / kg, 0.001 mm / kg, 0.003 mm / kg, 0.005 mm / kg, 0.008 mm / kg, 0.01 mm / kg, 0.03 mm / kg, 0.05 mm / kg, 0.06 mm / kg, 0.08 mm / kg, 0.1 mm / kg, 0.12 mm / kg, 0.15 mm / kg, 0.16 mm / kg, 0.19 mm / kg, 0.2 mm / kg.

[0134] Table 3 Influence of the ratio of the minimum thickness (H) of the support member (11a) and the weight (M) of the battery pack (100) on the safety performance of the battery pack (100)

[0135] No. H(mm) M(Kg) H / M(mm / Kg) Measurement results 1 0.1 1000 0.0001 ignition, explosion 2 0.2 1000 0.0002 ignition, explosion 3 0.6 600 0.001 Unexploded, fire explosion 4 1.5 500 0.003 Unexploded, fire explosion 5 2.5 500 0.005 Unexploded, fire explosion 6 4 500 0.008 Unexploded, fire explosion 7 3 300 0.01 Unexploded, fire explosion 8 9 300 0.03 Unexploded, fire explosion 9 10 200 0.05 Unexploded, fire explosion 10 12 200 0.06 Unexploded, fire explosion 11 16 200 0.08 Unexploded, fire explosion 12 20 200 0.1 Unexploded, fire explosion 13 30 200 0.15 Unexploded, fire explosion 14 40 200 0.2 Unexploded, fire explosion

[0136] Table 3 shows the results of measurements on the effect of the ratio of the minimum thickness (H) of several sets of support members (11a) and the weight (M) of the battery pack (100) on the safety performance of the battery pack (100) according to the standard of GB 38031-2020 "Safety requirements for power batteries for electric vehicles". As can be seen from Table 3, if the ratio of H / M does not exceed 0.0002 mm / Kg, ignition and explosion occur in the battery pack (100), and the cause is that the structural strength of the battery pack (100) does not meet the requirements. If the ratio of H / M exceeds 0.0002 mm / Kg, ignition and explosion do not occur in the battery pack (100). However, if H / M is too large (e.g., exceeding 0.1), the weight of the battery pack (100) is small and the thickness of the support plate is large, so the ratio of the battery cell (20) per unit volume of the battery pack (100) is relatively low and the space utilization rate is relatively low, so the energy density of the battery pack (100) is too low and the cost of using the battery pack (100) is relatively high. Additionally, when 0.0005 mm / Kg ≤ H / M ≤ 0.1 mm / Kg, the structural strength of the battery pack (100) meets the requirements, the energy density of the battery pack (100) is relatively high, the cruising capability of the battery pack (100) is stronger, and safety accidents such as ignition and explosion do not occur.

[0137] In some embodiments, the minimum thickness (H) of the support member (11a) satisfies 0.2mm < H < 20mm.

[0138] Specifically, the minimum thickness (H) of the support member (11a) may be 0.3mm, 0.5mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 9mm, 10mm, 12mm, 15mm, 16mm, 18mm, 19mm. Additionally, when 0.5mm ≤ H ≤ 10mm, the support member (11a) has relatively good structural strength, and since the overall strength of the battery pack (100) is relatively good, ignition and explosion do not easily occur in the battery pack (100). At the same time, the support member (11a) occupies a relatively small portion of the total volume of the battery pack (100), the space utilization rate of the battery pack (100) is relatively high, and the energy density of the battery pack (100) is relatively high.

[0139] In some embodiments, referring to FIGS. 3 and FIGS. 4, the battery cell (20) is suspended from a support member (11a).

[0140] The fact that the battery cell (20) is suspended from the support member (11a) means that the battery cell (20) is installed on the lower side in the vertical direction of the support member (11a), and the weight of the battery cell (20) is borne by the support member (11a). The method of suspending the battery cell (20) from the support member (11a) includes a method in which the battery cell (20) is directly attached to the lower surface of the support member (11a), a method in which the battery cell (20) is connected to the support member (11a) through a fastener (13) and is located on the lower side of the support member (11a), and a method in which the battery cell (20) is suspended and installed on the support member (11a) through a connector, etc. and is located on the lower side of the support member (11a).

[0141] At this time, the battery cell (20) is suspended below the support member (11a), and the lower cover (12) is located at the bottom of the case (10). When performing maintenance on the interior of the battery pack (100), the battery cell (20) can be exposed by removing the lower cover (12) without the need to remove the support member (11a), thus making maintenance of the battery pack (100) more convenient. At the same time, when maintaining the battery pack (100), the battery cell (20) can be removed and assembled from the support member (11a) from below. In particular, when the support member (11a) receives force as at least a part of the vehicle (1000) chassis, the battery cell (20) can be removed and assembled from the bottom of the support member (11a) without the need to remove the support member (11a), thus making maintenance of the battery pack (100) more convenient.

[0142] FIG. 11 is an external view of a battery cell (20) according to some embodiment of the present application. FIG. 12 is a front view of the battery cell (20) shown in FIG. 11.

[0143] In some embodiments, with reference to FIG. 4 and FIG. 11, the outer surface facing the support member (11a) of the battery cell (20) is a first outer surface (m1), the battery cell (20) includes an electrode terminal (21a), and the electrode terminal (21a) is disposed on an outer surface other than the first outer surface (m1) of the battery cell (20).

[0144] As described above, the electrode terminal (21a) is a component that is electrically connected to the electrode assembly (23) inside the battery cell (20) to output or input electrical energy of the battery cell (20). At least a portion of the electrode terminal (21a) protrudes out of the battery cell (20) to be electrically connected to the outside. Series and parallel connections between the battery cells (20) are all implemented through series and parallel connections between their respective electrode terminals (21a). The electrode terminal (21a) may be an aluminum electrode, a copper electrode, etc., which is conductive for electrical transmission.

[0145] The electrode terminal (21a) is disposed on an outer surface other than the first outer surface (m1) of the battery cell (20). The first outer surface (m1) faces the support member (11a) and is generally a smooth surface, and no protruding or recessed structures, such as the electrode terminal (21a) or the injection port, are installed thereon. When the battery cell (20) is suspended from the support member (11a), the first outer surface (m1) is the outer surface facing the battery cell (20). Specifically, in one embodiment, the battery cell (20) includes the housing (22) and the end cover (21), and the housing (22) and the end cover (21) form an internal environment for accommodating the electrode assembly (23) of the battery cell (20). The end cover (21) is located at one end of the housing (22), and the electrode terminal (21a) is placed on the end cover (21), and any outer surface of the housing (22) may be the first outer surface (m1) of the battery cell (20).

[0146] The electrode terminal (21a) includes a positive terminal and a negative terminal, the positive terminal is electrically connected to the positive plate of the electrode assembly (23), and the negative terminal is electrically connected to the negative plate of the electrode assembly (23). It should be noted that the positive terminal and the negative terminal may be placed on the same outer surface of the battery cell (20) (e.g., rectangular battery cell (20)) or on two different outer surfaces of the battery cell (20) (e.g., cylindrical battery cell (20)). When the positive terminal and the negative terminal are placed 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.

[0147] In the battery pack (100), in addition to the battery cell (20), additional components such as a sampling harness for electrically connecting each battery cell (20), a high-voltage harness, and a protective structure for protecting the battery cell (20) are installed. At this time, the electrode terminal (21a) is placed on a surface other than the first outer surface (m1) of the battery cell (20), and when placing components such as the sampling harness, high-voltage harness, and protective structure on the electrode terminal (21a), the components can be placed through the space between the battery cell (20) and the structure other than the support member (11a) of the main body (11) (e.g., the space between the battery cell and the lower cover and / or the space between the battery cell and the inner surface of the main body) without being restricted by the support member (11a), so that the installation of each component is more convenient. At the same time, since the first outer surface (m1) is a smooth surface, the first outer surface (m1) can be bonded to the support member (11a), thereby enabling bonded mounting of the battery cell (20) and the support member (11a), and since there is no need to leave space between the battery cell (20) and the support member (11a), it helps to improve the space utilization rate of the battery pack (100).

[0148] In some embodiments, referring to FIG. 11 and FIG. 12 together, the battery cell (20) has a second outer surface (m2) installed opposite to the first outer surface (m1), and the electrode terminal (21a) is disposed on the second outer surface (m2).

[0149] The second outer surface (m2) is an outer surface installed facing away from the first outer surface (m1) of the battery cell (20), and when the battery cell (20) is suspended from the support member (11a), the second outer surface (m2) and the lower cover (12) face each other. As described above, the battery cell (20) and the lower cover (12) can be installed spaced apart. At this time, there is a buffer space between the second outer surface (m2) and the lower cover (12), and the part of the electrode terminal (21a) protruding outside the battery cell (20) is located within this buffer space, and thus the harness and connecting member connected to the electrode terminal (21a) can be placed within the buffer space. At the same time, the buffer space can also prevent the impact of the external force applied to the lower cover (12) mentioned above from acting on the battery cell (20) and damaging the battery cell (20). Therefore, the buffer space can not only block the influence of external forces but also allow for the placement of harnesses, etc., thus killing two birds with one stone. In addition, the space utilization rate of the buffer space and the battery pack (100) is also improved.

[0150] Of course, in other embodiments, with reference to FIGS. 11 and FIGS. 12, the electrode terminal (21a) may be disposed on a third outer surface that intersects the first outer surface (m1) in the battery cell (20).

[0151] In some embodiments of the present application, referring to FIGS. 4, 5 and 9, a support member (11a) is positioned on the upper part of the case (10) and is used to define a receiving cavity(s). Since the lower cover (12) is positioned on the lower part of the case (10), the support member (11a) is positioned opposite the lower cover (12). The support member (11a) is a structure on the upper part of the case (10), and the case (10) is mounted to a mounting body through the support member (11a). At this time, the battery cell (20) installed on the support member (11a) can reinforce the strength of the support member (11a) and further improve the rigidity of the upper part of the battery pack (100), thereby expanding the application scenario of the battery pack (100) to a scenario where the upper part receives force, for example, and is used as part of the chassis of a vehicle (1000).

[0152] FIG. 13 is a configuration diagram of a support member (11a) according to some embodiment of the present application. FIG. 14 is a configuration diagram of a support member (11a) according to another embodiment of the present application. FIG. 15 is an orthographic projection in the vertical direction of the support member (11a) shown in FIG. 14.

[0153] In some embodiments, the support member (11a) has a support surface (f) facing the receiving cavity(s), and the support surface (f) is formed as a flat plane.

[0154] The support surface (f) is an inner surface facing the receiving cavity (s) of the support member (11a) and is used to define the receiving cavity (s). The fact that the support surface (f) is composed of a plane means that, in the arrangement direction of the main body (11) and the lower cover (12), the support surface (f) is a plane perpendicular to the arrangement direction. In actual situations, when the main body (11) and the lower cover (12) are arranged along the vertical direction, the support member (11a) and the lower cover (12) are installed facing each other along the vertical direction, and the support surface (f) of the support member (11a) is a plane parallel to the horizontal plane. When the main body (11) and the lower cover (12) are arranged along the horizontal direction, the support member (11a) and the lower cover (12) are installed facing each other along the horizontal direction, and the support surface (f) of the support member (11a) is a plane parallel to the vertical plane.

[0155] As illustrated in FIG. 13, the support surface (f) may be the entire inner surface facing the receiving cavity (s) of the support member (11a), wherein the support member (11a) is in the shape of a flat plate. As illustrated in FIG. 14 and FIG. 15, the support surface (f) may be a part of the inner surface facing the receiving cavity (s) of the support member (11a), wherein the support surface (f) is only the part of the inner surface of the support member (11a) that defines the receiving cavity (s).

[0156] If the support surface (f) is flat, the support surface (f) can maintain a relatively uniform distance (this distance may be 0) from each battery cell (20) accommodated within the receiving cavity (s). When the distance between the support surface (f) and the battery cell (20) is maintained relatively uniformly, 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 driving capability of the battery pack (100) is higher.

[0157] In some embodiments, the battery cell (20) is installed on the support surface (f). The battery cell (20) is mounted to the support member (11a) through the support surface (f). The battery cell (20) may be bonded to the support surface (f), fixedly connected to the support surface (f) via fasteners (13), or welded and snap-fit ​​connected to the support surface (f), and is not specifically limited thereto.

[0158] Since the support surface (f) is flat, the support surface (f) has a relatively large contact area with the battery cell (20) installed on itself, making the mounting of the battery cell (20) more robust. At the same time, if the support surface (f) is flat, compared to an uneven surface such as a curved surface, the support surface (f) can enable connection with a larger number of battery cells (20), increase the number of battery cells (20) mounted in the battery pack (100), and further improve the space utilization rate and energy density of the battery pack (100).

[0159] It can be understood that when the battery cell (20) is suspended from the support member (11a), the battery cell (20) is suspended from the support surface (f).

[0160] In some embodiments, the area of ​​the orthographic projection (N1) of the support surface (f) in the vertical direction and the area of ​​the orthographic projection (N2) of the support member (11a) satisfy N1 / N2 ≥ 0.2. Additionally, N1 / N2 ≥ 0.5.

[0161] In the embodiment illustrated in FIG. 15, in the vertical orthographic projection, the support surface (f) is formed by being surrounded by the first support side (f1), the second support side (f2), the third support side (f3), and the fourth support side (f4) connected at the head and tail, and the orthographic projection area (N1) of the support surface (f) is the area of ​​the region defined by the first support side (f1), the second support side (f2), the third support side (f3), and the fourth support side (f4). The orthographic projection area (N2) of the support member (11a) is the area of ​​the region defined by the edge of the support member (11a).

[0162] Specifically, the ratio of the orthographic projection area (N1) of the support surface (f) to the orthographic projection area (N2) of the support member (11a) can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0163] Table 4 Influence of the ratio of area (N1) and area (N2) on the driving range of the battery pack (100)

[0164] No. N1(mm 2 ) N2(mm 2 ) N1 / N2 Measurement results 1 1.8×10 5 2.16×10 6 0.083 Bad 2 2.16×10 5 2.16×10 6 0.1 Bad 3 4.32×10 5 2.16×10 6 0.2 Relatively good 4 8×10 5 2.16×10 6 0.37 Relatively good 5 1.2×10 6 2.16×10 6 0.56 well 6 1.7×10 6 2.16×10 6 0.787 Excellence 7 2.16×10 6 2.16×10 6 1 Optimal

[0165] Table 4 shows the effect of the ratio of the orthographic area (N1) of a set of support surfaces (f) and the orthographic area (N2) of a support member (11a), measured according to the NEDC (New European Driving Cycle) standard, on the driving range of the battery pack (100). When N1 / N2 is less than 0.2, the driving range of the battery pack (100) is relatively poor. The reason for this is that when the support surface (f) is relatively small, the number of battery cells (20) supported by the support member (11a) is relatively small, so the space utilization rate of the receiving cavity (s) is relatively low, and the energy density of the battery pack (100) is relatively low. As a result, the driving range of the battery pack (100) is relatively short, and the measurement results are relatively poor. When the ratio of N1 / N2 reaches 0.2 or higher (especially when N1 / N2 reaches 0.5 or higher), the greater the ratio, the better the range of the battery pack (100). This is because the larger the support surface (f), the greater the number of battery cells (20) supported by the support member (11a), the higher the space utilization rate of the receiving cavity (s) and the higher the energy density of the battery pack (100). As a result, the range of the battery pack (100) increases and the measurement results improve. When the support member (11a) is a flat plate structure as shown in FIG. 13, the orthographic projected area (N1) of the support surface (f) and the orthographic projected area (N2) of the support member (11a) are the same, and the range effect of the battery pack (100) is the best.

[0166] In some embodiments, the orthographic projection of the support surface (f) in the vertical direction is a rectangle.

[0167] As illustrated in FIG. 15, the rectangular support surface (f) is an area defined by being surrounded by the first support side (f1), the second support side (f2), the third support side (f3), and the fourth support side (f4). In the battery pack (100), the majority of the battery cells (20) form a rectangular structure through assembly, and if the support surface (f) is configured as a rectangle, it can adapt to the overall structure formed by the majority of the battery cells (20), thereby helping to improve the energy density of the battery pack (100) by placing more battery cells (20) within the receiving cavity(s).

[0168] Of course, in other embodiments, the orthographic projection of the support surface (f) in the vertical direction may be a circular, polygonal, elliptical, and other irregular shape.

[0169] In some embodiments, referring to FIG. 14, the support member (11a) has a support portion (11a1) and a connecting portion (11a2), the connecting portion (11a2) is connected to the edge of the support portion (11a1), the support portion (11a1) is used to define a receiving cavity(s), and the connecting portion (11a2) is connected to a part of the case (10) other than the support member (11a).

[0170] The support member (11a1) is used to define the receiving cavity(s), and the connecting member (11a2) is used to connect to parts other than the support member (11a) of the case (10) and does not participate in defining the receiving cavity(s). The support member (11a1) may be a plate-shaped or block-shaped member, or a flat plate-shaped or curved plate-shaped member, and is not specifically limited thereto. As can be seen in FIG. 14, the fact that the connecting member (11a2) surrounds the edge of the support member (11a1) means a structure in which the connecting member (11a2) is continuously connected along the edge of the support member (11a1) so as to be closed at the end. In a vertical projection, the connecting part (11a2) has a constant width and can have a suitable contact area with other structures other than the supporting member (11a) of the case (10), so it can be understood that mounting connection between the connecting part (11a2) and other structures other than the supporting member (11a) of the case (10) can be implemented more conveniently.

[0171] The support member (11a1) and the connecting member (11a2) can be integrally molded. If the support member (11a) is made of a metal material (e.g., aluminum, iron, stainless steel, etc.), the support member (11a1) and the connecting member (11a2) can be integrally molded by methods such as die casting, forging, hot compression, or cold compression. If the support member (11a) is made of a plastic material (e.g., PP, PE, ABS, etc.), the support member (11a1) and the connecting member (11a2) can be integrally molded through injection molding. The support member (11a1) and the connecting member (11a2) may be molded individually and then connected as one. If the support member (11a1) and the connecting member (11a2) are made of a metal material, the support member (11a1) and the connecting member (11a2) can be welded or bonded as one. If the support member (11a1) and the connecting member (11a2) are made of plastic material, the support member (11a1) and the connecting member (11a2) can be bonded together as one. Of course, the support member (11a1) and the connecting member (11a2) can be fixedly connected as one through other methods such as snap-fit ​​connection, rivet connection, etc.

[0172] Specifically, the connecting part (11a2) is connected to a part of the main body (11) other than the supporting member (11a), and the connection method may be integral molding or fixed connection. When the connecting part (11a2) and the part of the main body (11) other than the supporting member (11a) are integrally molded, that is, when the main body (11) is an integrally molded product, it may be integrally molded through methods such as die casting, forging, hot compression, cold compression, injection molding, etc. When the connecting part (11a2) and the part of the main body (11) other than the supporting member (11a) are fixedly connected, they may be fixedly connected by methods such as fastening connection through a fastener (13) or snap-fit ​​connection through a snap-fit ​​coupling structure, and are not specifically limited thereto.

[0173] The support member (11a1) and the connecting member (11a2) may be located on the same plane. Specifically, optionally, the two surfaces of the support member (11a1) and the connecting member (11a2) facing the lower cover (12) are on the same plane, and / or the two surfaces of the support member (11a1) and the connecting member (11a2) facing away from the lower cover (12) are on the same plane. When the two surfaces of the support member (11a1) and the connecting member (11a2) facing the lower cover (12) and the two surfaces facing away from the lower cover (12) are all on the same plane, the support member (11a1) and the connecting member (11a2) may form a single flat support member (11a) (e.g., as shown in FIG. 13).

[0174] The support member (11a1) and the connecting member (11a2) may not be located on the same plane. Specifically, the support member (11a1) may protrude away from the receiving cavity(s) relative to the connecting member (11a2), or the support member (11a1) may be recessed toward the receiving cavity(s) relative to the connecting member (11a2), and this is not specifically limited thereto. The thickness of the support member (11a1) and the connecting member (11a2) may be the same or different, and this is not specifically limited thereto.

[0175] At this time, the support member (11a) defines the receiving cavity(s) through the support portion (11a1) and implements a connection with a structure other than the support member (11a) of the main body (11) through the connection portion (11a2), so the structure is clear.

[0176] It can be understood that when the support member (11a) includes the support portion (11a1) and the connection portion (11a2), the battery cell (20) is installed on the support portion (11a1).

[0177] It can be understood that when the support member (11a) includes the support portion (11a1) and the connection portion (11a2), the inner surface structure facing the receiving cavity(s) of the support portion (11a1) forms a support surface (f).

[0178] In some embodiments, the support member (11a1) is installed to protrude in a direction facing away from the receiving cavity(s) relative to the connection member (11a2).

[0179] As can be seen from the above description, the support member (11a1) defines the receiving cavity(s), and the fact that the support member (11a1) protrudes away from the receiving cavity(s) means that the support member (11a1) and the connecting member (11a2) are arranged offset from each other in the vertical direction. The support member (11a1) is located at the highest point of the support member (11a). At this time, a certain space can be formed between the support member (11a1) and the connecting member (11a2) to be used as part of the receiving cavity(s), and this space can accommodate a battery cell (20).

[0180] If the support member (11a1) protrudes with its back to the receiving cavity(s) compared to the connection member (11a2), the support member (11a1) can be used as a reinforcing structure of the support member (11a) to improve the flexibility of the support member (11a).

[0181] In some embodiments, the thickness of the support portion (11a1) and the connection portion (11a2) is the same.

[0182] If the thickness of the support member (11a1) and the connection member (11a2) is the same, the support member (11a1) and the connection member (11a2) can be integrally formed through die casting, cold compression, and hot compression on the same plate material, making the forming of the support member (11a) more convenient. At the same time, if the thickness of the support member (11a1) and the connection member (11a2) is the same, each point receives a uniform force during forming, thereby improving the forming rate of the support member (11a).

[0183] In some embodiments, the outer surface facing away from the receiving cavity(s) of the support member (11a1) is parallel to the support surface (f).

[0184] The outer surface and the support surface (f), which are facing away from the receiving cavity (s) of the support member (11a1), are installed facing away from each other along the vertical direction. The outer surface of the support member (11a1) can come into contact with the atmospheric environment. When the battery pack (100) is mounted on the vehicle (1000), the support member (11a1), which has a flat outer surface, can lower the driving resistance of the vehicle (1000) and reduce the driving energy consumption of the vehicle (1000), thereby improving the driving capability of the battery pack (100).

[0185] In some embodiments, referring to FIGS. 3, 4 and 9, the main body (11) includes a frame (11b) and a support member (11a), and a cavity (q) is formed by being surrounded by the frame (11b) and having both ends in the vertical direction installed through it, and a lower cover (12) and a support member (11a) are each covered at both ends facing each other in the vertical direction of the cavity (q), and the lower cover (12), the frame (11b), and the support member (11a) are together surrounded to form a receiving cavity (s).

[0186] A cavity (q) is formed by being surrounded by the frame (11b) itself, with both ends in the vertical direction penetrating it, and a support member (11a) covers the upper part of the cavity (q), and a lower cover (12) covers the lower part of the cavity (q). That is, the support member (11a) is positioned on the upper part of the case (10) and is used to define the receiving cavity (s), and the lower cover (12) is positioned on the lower part of the case (10) and is used to define the receiving cavity (s). The receiving cavity (s) is formed by being surrounded by the frame (11b), the support member (11a), and the lower cover (12). The frame (11b), the support member (11a), and the lower cover (12) may be manufactured from the same material, such as aluminum alloy, copper alloy, steel, plastic, etc. Of course, the frame (11b), the support member (11a), and the lower cover (12) may also be manufactured from different materials, and this is not specifically limited here. In the vertical orthographic projection, the frame (11b) may be rectangular, circular, polygonal, etc., and is not specifically limited thereto.

[0187] 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) through the connecting portion (11a2). When the lower cover (12) includes the cover portion (12a) and the mounting portion (12b), the lower cover (12) is connected to the frame (11b) through the mounting portion (12b).

[0188] At this time, by connecting the support member (11a) and the lower cover (12) to each of the vertical ends of the frame (11b) based on the frame (11b), a receiving cavity (s) of the battery pack (100) can be formed, so the structure of the case (10) is relatively simple.

[0189] In some embodiments, the support member (11a) and the frame (11b) are fixedly connected or integrally formed. The support member (11a) and the frame (11b) may be integrally formed by methods such as injection molding, die casting, forging, cold compression, or hot compression. The support member (11a) and the frame (11b) may be fixedly connected through fastening connections via fasteners (13), snap-fit ​​connections via snap-fit ​​joint structures, welding, bonding, or heat fusion connections.

[0190] When the support member (11a) and the frame (11b) are integrally molded, the main body (11) is integrally molded, and since the assembly of the case (10) can be achieved simply by connecting the main body (11) and the lower cover (12), the assembly of the case (10) is convenient. When the support member (11a) and the frame (11b) are fixedly connected, the molding process of the support member (11a) and the frame (11b) is relatively easy, so the process cost of the case (10) can be reduced.

[0191] It can be understood that if the support member (11a) has a support portion (11a1) and a connecting portion (11a2), it is connected to the frame (11b) through the connecting portion (11a2). If the lower cover (12) has a cover portion (12a) and a mounting portion (12b), it is connected to the frame (11b) through the mounting portion (12b).

[0192] FIG. 16 is a front view of the battery pack (100) illustrated in FIG. 4. Referring to FIG. 16 and FIG. 12, in some embodiments, the height (Hc) of the battery cell (20) and the height (Hp) of the battery pack (100) in the vertical direction satisfy 0.02 ≤ Hc / Hp ≤ 0.98.

[0193] The height (Hc) of the battery cell (20) refers to the maximum length in the vertical direction of the battery cell (20) when the main body (11) and the lower cover (12) are arranged along the vertical direction. For example, with the battery cell (20) shown in FIG. 12, when the first outer surface (m1) of the battery cell (20) is installed facing away from the outer surface having the electrode terminal (21a), 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 having the electrode terminal (21a), 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 installed facing away from it.

[0194] The height (Hp) of the battery pack (100) refers to the maximum vertical length of the battery pack (100) when the main body (11) and the lower cover (12) are arranged along the vertical direction.

[0195] Specifically, the ratio of the height (Hc) of the battery cell (20) to the height (Hp) of the battery pack (100) may be 0.02, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.98.

[0196] Table 5. Influence of the ratio of battery cell (20) height (Hc) and battery pack (100) height (Hp) on the safety of the battery pack (100)

[0197] No. Hc / mm Hp / mm Hc / Hp Measurement results 1 248 252 0.984 ignition, explosion 2 138 150 0.92 Unexploded, fire explosion 3 115 135 0.85 Unexploded, fire explosion 4 90 120 0.75 Unexploded, fire explosion 5 78 120 0.65 Unexploded, fire explosion 6 110 200 0.55 Unexploded, fire explosion 7 60 200 0.3 Unexploded, fire explosion 8 60 600 0.1 Unexploded, fire explosion 9 50 1000 0.05 Unexploded, fire explosion

[0198] Table 5 shows the effect on the safety of the battery pack (100) of the ratio of the height (Hc) of several sets of battery cells (20) and the height (Hp) of the battery pack (100), measured according to the standard of GB 38031-2020 "Safety requirements for power batteries for electric vehicles." As can be seen from Table 5, if Hc / Hp exceeds 0.98, the structure of the case (10) occupies very little of the height of the battery pack (100), so the strength of the case (10) cannot meet the requirements, and safety accidents such as ignition and explosion occur. If 0.02 ≤ Hc / Hp, the structural strength of the case (10) can meet the requirements, so situations of ignition and explosion do not occur. If Hc / Hp is less than 0.2, the structural strength of the case (10) can meet the requirements, but the space utilization rate of the battery pack (100) is low, so the energy density is too low.

[0199] Additionally, if 0.5≤Hc / Hp<0.94, the strength of the battery pack (100) meets the requirements, so not only is there no safety accident of ignition or explosion, but the space utilization rate of the battery pack (100) is relatively high, and the energy density of the battery pack (100) is relatively high.

[0200] According to some embodiments of the present application, a battery pack (100) comprises a battery cell (20) and a case (10). The case (10) comprises a main body (11) and a lower cover (12) installed on the lower part of the main body (11), wherein the lower cover (12) and the main body (11) are sealedly connected and together form a sealed receiving cavity (s), and the battery cell (20) is located within the receiving cavity (s). At this time, the case (10) of the battery pack (100) can form a sealed receiving cavity (s) by being surrounded by its own lower cover (12) and its own main body (11) without the need to install additional sealing structures within the case (10), thereby simplifying the structure of the battery pack (100), reducing the cost of the battery pack (100), and ensuring the safety and service life of the battery pack (100).

[0201] In another aspect, the present application further provides an electric device. The electric device comprises a battery pack (100) according to any of the above embodiments, and the battery pack (100) is used to supply electrical energy to the electric device. For an introduction to the electric device, refer to the description above, and a detailed description is omitted here.

[0202] Since this electric device includes the battery pack (100), it has all the beneficial effects of the above embodiment, and a detailed description is omitted here.

[0203] FIG. 17 is a diagram showing a battery pack (100) according to some embodiment of the present application applied to a vehicle body (200). FIG. 18 is a first exploded view of the structure shown in FIG. 17. FIG. 19 is a second exploded view of the structure shown in FIG. 17.

[0204] In some embodiments, referring to FIGS. 17 through 19, the electrical device includes a vehicle (1000), and the battery pack (100) is installed on the lower part of the vehicle body (200) of the vehicle (1000). For an introduction to the vehicle (1000), refer to the description above, and a detailed description is omitted here.

[0205] The vehicle body (200) of the vehicle (1000) refers to the part of the vehicle (1000) used to carry people and load goods, and includes a cockpit, passenger compartment, engine compartment, cargo compartment, etc. The vehicle body (200) generally includes a body shell and doors, windows, trim, seats, air conditioning units, etc. installed on the body shell. The body shell generally refers to a structure formed by major load-bearing elements such as longitudinal beams, transverse beams, chassis, and pillars of the vehicle (1000), and sheet metal members connected thereto. In the embodiment of the present application, the fact that the battery pack (100) is installed at the bottom of the vehicle body (200) means that the battery pack (100) is mainly installed at the bottom of the body shell.

[0206] At this time, if the battery pack (100) is installed at the bottom of the vehicle body (200), it does not occupy space inside the vehicle body (200), which helps to reduce the volume and weight of the vehicle body (200).

[0207] FIG. 20 is a diagram showing the mounting relationship between a battery pack (100) and a vehicle body (200) according to some embodiments of the present application. In some embodiments, referring to FIG. 20, the main body (11) includes a support member (11a) located on the upper part of the case (10), the support member (11a) is used to define a receiving cavity(s), and the distance (L) between the support member (11a) and the vehicle body (200) in the vertical direction satisfies L≥0.

[0208] 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 case (10), the distance between the support member (11a) and the vehicle body (200) from the battery pack (100) is the shortest. The distance (L) between the support member (11a) and the vehicle body (200) refers to the distance between the highest point of the support member (11a) in the vertical direction and the vehicle body (200) located above it. When the support member (11a) includes the support portion (11a1) and the connection portion (11a2), the distance (L) between the support member (11a) and the vehicle body (200) is the distance between the outer surface facing away from the receiving cavity (s) of the support portion (11a1) and the vehicle body (200) located above it.

[0209] If the distance (L) between the support member (11a) and the vehicle body (200) is 0, the support member (11a) and the vehicle body (200) are joined, and if the distance (L) between the support member (11a) and the vehicle body (200) is greater than 0, the support member (11a) and the vehicle body (200) are separated and not joined. At this time, it can be understood that the lower cover (12) is located at the bottom of the support member (11a), and the distance (g) between the lower cover (12) and the vehicle body (200) is greater than 0.

[0210] When the battery pack (100) is installed on the underside of the vehicle body (200), the range within the distance from the bottom of the battery pack (100) to the vehicle body (200) is the mounting space occupied by the battery pack (100). When the support member (11a) and the vehicle body (200) are separated, there is a certain waste space between the battery pack (100) and the vehicle body (200). When the support member (11a) is joined to the vehicle body (200), the waste space existing between the battery pack (100) and the vehicle body (200) can be included within the space range of the battery pack (100). Thus, when the battery pack (100) and the vehicle body (200) are joined while occupying the same space on the underside of the vehicle body (200), the volume of the battery pack (100) can be improved, and furthermore, the power capacity and energy density of the battery pack (100) can be improved.

[0211] At this time, if the distance (L) between the support member (11a) and the vehicle body (200) is 0, the battery pack (100) can have a relatively large amount of power and a relatively high energy density, so the cruising ability of the vehicle (1000) is strong. If the distance (L) between the support member (11a) and the vehicle body (200) is greater than 0, the mounting of the support member (11a) is relatively flexible.

[0212] In some embodiments, referring to FIGS. 17 through 19, the main body (11) includes a support member (11a) located on the upper part of the case (10), the support member (11a) is used to define a receiving cavity(s), and the battery pack (100) is mounted to the vehicle body (200) through the support member (11a).

[0213] 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 case (10), the distance between the battery pack (100), the support member (11a), and the vehicle body (200) is shortest, and the battery pack (100) is mounted to the vehicle body (200) through the support member (11a). Specifically, the support member (11a) can be fixed to the vehicle body (200) by means of fasteners (13) (e.g., screws, bolts, rivets, etc.) or welding.

[0214] When the battery cell (20) is installed 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) to improve the upper strength of the battery pack (100) and further improve the mounting strength of the battery pack (100).

[0215] In some embodiments, the support member (11a) is configured to form at least a portion of the chassis of the vehicle body (200).

[0216] The chassis is a combination of four parts consisting of a power transmission system, a driving system, a steering system, and a braking system as part of the vehicle body (200), and is used to support and mount the vehicle (1000) engine and each part and assembly, forms the overall shape of the vehicle (1000), and ensures normal driving by receiving engine power.

[0217] The chassis is located at the bottom of the vehicle body (200), and the support member (11a) can directly become at least a part of the chassis. That is, the support member (11a) is used to form at least a part of the chassis of the vehicle body (200). By integrating the support member (11a) integrally with the chassis of the vehicle body (200), the space occupied by the gap between the traditional chassis and the battery pack (100) can be incorporated into the battery pack (100), thereby increasing the space of the battery pack (100), which helps to improve the energy of the battery pack (100) and further improve the cruising capability of the vehicle (1000).

[0218] According to some embodiments of the present application, with reference to FIGS. 17 through 19, the electric device comprises a vehicle (1000), and a battery pack (100) is installed on the lower part of the vehicle body (200) of the vehicle (1000). The battery pack (100) comprises a case (10) and a battery cell (20), the case (10) comprises a support member (11a) located on the upper part thereof, the battery cell (20) is located within the case (10) and is suspended from the support member (11a), the electrode terminal (21a) of the battery cell (20) is located on the outer surface facing away from the support member (11a) of the battery cell (20), and the support member (11a) forms at least a part of the chassis of the vehicle (1000).

[0219] At this time, when the battery cell (20) is suspended from the support member (11a), the strength of the support member (11a) can be improved, and furthermore, the strength of the upper part of the battery cell (20) can be improved, so that a certain stress requirement can be reached when the support member (11a) is used as a chassis. At the same time, when the electrode terminal (21a) of the battery cell (20) is facing away from the support member (11a), the battery cell (20) can be directly mounted on the support member (11a) to save space between the battery cell (20) and the support member (11a), and the saved space can be used to increase the mounting space of the battery cell (20), thereby improving the energy density of the battery pack (100) and further improving the cruising capability of the vehicle (1000).

[0220] Each technical feature of the embodiments described above may be combined arbitrarily, and for the sake of brevity, not all possible combinations of each technical feature are described in the embodiments; however, as long as such combinations of technical features are not contradictory, they should all be considered to be within the scope described herein.

[0221] The embodiments described above represent only a few embodiments of the present application. Although the description is relatively specific and detailed, it should not be interpreted as limiting the scope of the patent of the present application. It should be noted that a person skilled in the art may make several modifications and improvements without departing from the concept of the present application, and that all such modifications fall within the scope of protection of the present application. Accordingly, the scope of protection of the patent of the present application should be based on the appended claims. Explanation of the symbols

[0222] 1000-Vehicle; 100-Battery Pack; 200-Chassis; 10-Case; 11-Main Body; 11a-Support Member; 11a1-Support Part; 11a2-Connecting Part; 11b-Frame; 12-Lower Cover; 12a-Cover Part; 12b-Mounting Part; 12c-Fixing Hole; 13-Fastener; s-Receiving Cavity; q-Cavity; f-Supporting Surface; f1-First Supporting Valve; f2-Second Supporting Valve; f3-Third Supporting Valve; f4-Fourth Supporting Valve; d-Featured Surface; d1-First Featured Valve; d2-Second Featured Valve; d3-Third Featured Valve; d4-Fourth Featured Valve; 20-Battery Cell; 21-End Cover; 21a-Electrode Terminal; 22-Housing; 23-electrode assembly; m1-first outer surface; m2-second outer surface; m3-third outer surface.

Claims

Claim 1 A battery pack comprising: a battery cell; and a case - the case includes a main body and a lower cover installed on the lower part of the main body; the lower cover and the main body are sealedly connected and together form a sealed receiving cavity, the battery cell is located within the receiving cavity, the main body includes a support member located on the upper part of the case, the support member is used to define the receiving cavity, the battery cell is suspended from the support member, the lower cover and the battery cell are spaced apart, the lower cover has a cover portion and a mounting portion, the mounting portion is connected to surround the edge of the cover portion, the cover portion is used to define the receiving cavity, the mounting portion is sealedly connected to the main body, the cover portion is installed to protrude along a direction facing away from the receiving cavity relative to the mounting portion, and a clearance space is formed between the cover portion and the mounting portion. Claim 2 A battery pack according to claim 1, wherein the lower cover is sealedly connected to the main body through a sealing member. Claim 3 A battery pack according to claim 1, wherein the minimum thickness (h) of the lower cover satisfies 0.2 mm < h < 20 mm. Claim 4 A battery pack according to paragraph 3, wherein the weight (m) of the battery cell and the minimum thickness (h) of the lower cover satisfy 0.03 mm / kg ≤ h / m ≤ 100 mm / kg. Claim 5 A battery pack according to claim 1, wherein the outer surface of the battery cell facing the support member is a first outer surface, the battery cell includes an electrode terminal, and the electrode terminal is disposed on an outer surface of the battery cell other than the first outer surface. Claim 6 A battery pack according to claim 5, wherein the battery cell has a second outer surface installed opposite to the first outer surface, and the electrode terminal is disposed on the second outer surface. Claim 7 A battery pack according to any one of claims 1 to 6, wherein the battery cell and the support member are bonded. Claim 8 A battery pack according to any one of claims 1 to 6, wherein the main body comprises a frame and a support member, a cavity is formed that is enclosed by the frame and has both ends in the vertical direction through which it is installed, the lower cover and the support member each cover the ends facing each other in the vertical direction of the cavity, and the lower cover, the frame and the support member surround together to form the receiving cavity. Claim 9 A battery pack according to claim 8, wherein the support member and the frame are fixedly connected or integrally molded. Claim 10 An electric device comprising a battery pack according to any one of claims 1 to 6, wherein the battery pack is used to supply electrical energy to the electric device. Claim 11 In paragraph 10, the electrical device comprises a vehicle, and the battery pack is installed in the lower part of the vehicle body. Claim 12 An electrical device according to claim 11, wherein the main body comprises a support member located on the upper part of the case, the support member is used to define the receiving cavity, and the battery pack is mounted to the vehicle body through the support member. Claim 13 In paragraph 12, the electrical device is configured such that the support member forms at least a part of the vehicle body chassis. Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete

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