Battery and electric device

Abstract

A battery and an electric device. The battery comprises a case and a bottom protective plate, wherein the bottom protective plate is connected to the case, the bottom protective plate is of a multi-layer structure, and a buffer cavity is formed between the bottom protective plate and the case and / or between two adjacent layers of the bottom protective plate. The battery structure can effectively improve the reliability of the battery.

Description

Batteries and electrical devices CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese patent application No. 202420427897.5, filed on March 5, 2024, entitled “Battery and Electrical Device,” and the entire contents of the above application are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery and an electrical device. Background Art

[0003] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0004] In the development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The present application provides a battery and an electrical device. The technical solution provided in the present application can effectively improve the reliability of the battery.

[0006] In a first aspect, the present application provides a battery comprising a housing and a bottom guard plate. The bottom guard plate is connected to the housing. The bottom guard plate has a multi-layer structure, and a buffer cavity is formed between the bottom guard plate and the housing and / or between two adjacent layers of the bottom guard plate.

[0007] In the above solution, by providing a buffer cavity, the impact on the bottom of the battery can be effectively alleviated, the risk of damage to the battery cells in the box is reduced, and the battery has higher reliability.

[0008] According to some embodiments of the present application, the bottom guard plate includes a first protective layer, a metal layer, and a second protective layer that are stacked together. The first protective layer is arranged on a side of the metal layer close to the box body, and the second protective layer is arranged on a side of the metal layer away from the box body.

[0009] In the above solution, the metal layer has high strength and can provide effective protection for the battery cells in the box. By arranging the metal layer between the first protective layer and the second protective layer, the risk of the metal layer being exposed to the outside and corroded can be effectively reduced, thereby making the bottom guard plate have higher reliability, thereby improving the reliability of the battery.

[0010] According to some embodiments of the present application, at least one of the following conditions is met:

[0011] The buffer cavity is formed between the first protective layer and the box body;

[0012] A buffer cavity is formed between the first protective layer and the metal layer;

[0013] The buffer cavity is formed between the metal layer and the second protection layer.

[0014] The above solution provides a variety of buffer cavity placement locations, which can provide multiple options for battery manufacturing and adapt to different impact situations. For example, by arranging the buffer cavity between the first protective layer and the casing, the second protective layer, the metal layer, and the first protective layer can first absorb the impact, and then the buffer cavity can be used to collapse and deform to absorb energy. This can reduce the risk of the entire bottom guard plate being scrapped due to the buffer cavity being broken or damaged in the event of a minor impact. For example, by arranging the buffer cavity between the metal layer and the second protective layer, impact absorption can be achieved at a position relatively outside the battery, which can effectively reduce the impact of the impact on the internal structure of the casing.

[0015] According to some embodiments of the present application, the first protective layer includes a first body and a first flange portion, wherein the first flange portion is disposed around the first body and connected to the housing. At least a portion of the first body protrudes from the first flange portion in a direction away from the housing, and a buffer cavity is formed between the first body and the housing.

[0016] In the above solution, the first protective layer has a simple structure and can be effectively connected to the housing via the first flange. By configuring at least a portion of the first body to protrude toward the side facing away from the housing, a recessed area is formed on the side facing the housing, thereby forming a buffer cavity between the housing and the first protective layer. This cushions impacts on the bottom of the battery, thereby enhancing battery reliability.

[0017] According to some embodiments of the present application, the metal layer includes a second body and a second flange portion, the second flange portion is surrounded by the second body, at least part of the second body protrudes from the second flange portion in a direction away from the box body, the second body is fitted with the first body, and the second flange portion is fitted with the first flange portion.

[0018] In the above solution, the outer contour of the metal layer can match the outer contour of the first protective layer. The metal layer includes a second flange portion corresponding to the first flange portion, and a second body portion corresponding to the first body portion. This allows the metal layer and the first protective layer to fit tightly together, resulting in a stable bottom guard plate structure and high space utilization. This, in turn, increases battery space utilization, thereby facilitating increased battery volumetric energy density.

[0019] According to some embodiments of the present application, the second protective layer includes a third body and a third flange portion, the third flange portion is surrounded by the third body, at least a portion of the third body protrudes from the third flange portion in a direction away from the box body, the second body is clamped between the first body and the third body, and the second flange portion is clamped between the first flange portion and the third flange portion.

[0020] In the above scheme, the outer contour of the metal layer can fit with the outer contour of the first protective layer and the metal layer. By providing a third body that fits with the second body and a third flange portion that fits with the second flange portion, on the one hand, the bottom guard plate structure can be made stable and the space utilization rate can be high, thereby making the space utilization rate of the battery high, which is conducive to improving the volume energy density of the battery; on the other hand, the metal layer can be stably located between the first protective layer and the second protective layer, thereby reducing the risk of corrosion of the metal layer and improving the reliability of the battery.

[0021] According to some embodiments of the present application, the second flange portion is provided with a first through hole, the bottom guard plate also includes a first protective portion, the first protective portion is arranged in the first through hole and connects the first protective layer and the second protective layer, and the bottom guard plate is provided with a second through hole that penetrates the first protective layer, the first protective portion and the second protective layer.

[0022] In the above solution, by providing the first through-hole and the first protective portion, on the one hand, the first protective portion can connect the first protective layer and the second protective layer through the first through-hole, and on the other hand, the first protective portion can cover the hole wall of the first through-hole, thereby reducing the risk of corrosion of the metal layer and thus improving the reliability of the battery. At the same time, by providing the second through-hole, the connecting member can pass through the second through-hole to assemble the bottom guard plate to the bottom of the box body, thus completing the assembly of the bottom guard plate and the box body.

[0023] According to some embodiments of the present application, the first through hole extends to the outer circumferential surface of the second flange portion.

[0024] In the above scheme, the first protective layer and the second protective layer can be combined into one by hot pressing. To this end, by extending the outer peripheral surface of the second flange portion of the first through hole extension device, the efficiency of the hot pressing combination can be improved, and the hot pressing combination area of ​​the first protective layer and the second protective layer can be increased, thereby improving the connection stability of the first protective layer and the second protective layer.

[0025] According to some embodiments of the present application, the bottom guard plate further includes a second protective portion, which wraps around the outer circumference of the second flange portion, and the second protective portion connects the first protective layer and the second protective layer.

[0026] In the above scheme, by setting the second protective part, on the one hand, the first protective layer and the second protective layer can be connected to each other, thereby improving the structural stability of the bottom guard plate; on the other hand, the second protective part can cover the outer peripheral surface of the metal layer to reduce the risk of the metal layer being exposed and corroded.

[0027] According to some embodiments of the present application, along a direction perpendicular to the outer peripheral surface of the metal layer, the thickness of the second protection portion is greater than or equal to 1 mm and less than or equal to 20 mm.

[0028] In the above scheme, the thickness of the second protective part is set to be greater than or equal to 1 mm along the direction perpendicular to the outer peripheral surface of the metal layer, which can effectively make the second protective part cover the outer peripheral surface of the metal layer to reduce the risk of the metal layer being exposed and corroded; the thickness of the second protective part is set to be less than or equal to 20 mm, which can reduce the risk of the second protective part occupying too much space, resulting in a smaller space occupied by the metal layer, and thus resulting in lower structural strength of the bottom guard plate. To this end, by setting the thickness of the second protective part to be greater than or equal to 1 mm and less than or equal to 20 mm along the direction perpendicular to the outer peripheral surface of the metal layer, it is possible to take into account both the anti-corrosion effect of the metal layer and the structural strength of the bottom guard plate.

[0029] According to some embodiments of the present application, the first protective layer, the second protective layer, the first protective portion, and the second protective portion are integrally formed.

[0030] In the above solution, by arranging the first protective layer, the second protective layer, the first protective portion and the second protective portion to be integrally formed, the connection stability of the first protective layer and the second protective layer and the manufacturing efficiency of the bottom guard plate can be improved.

[0031] According to some embodiments of the present application, the second protective layer includes a third body and a third flange portion, the third flange portion being disposed around the third body, and at least a portion of the third body protruding from the third flange portion in a direction away from the battery case. The battery further includes a first connector, through which the bottom guard plate is connected to the battery case through the third flange portion, and at least a portion of the third body protruding from the first connector in a direction away from the battery case.

[0032] In the above scheme, by setting at least a portion of the third body to protrude from the third flange portion in a direction away from the box body, the space occupied by the first connecting member in the direction away from the box body can be reasonably utilized, thereby increasing the volume of the buffer cavity or the overall thickness of the bottom guard plate as much as possible, thereby improving the impact resistance of the bottom guard plate, and thus making the battery have higher reliability.

[0033] According to some embodiments of the present application, the density of the first protective layer is less than the density of the metal layer; and / or the density of the second protective layer is less than the density of the metal layer.

[0034] In the above scheme, by setting the density of the first protective layer and / or the second protective layer to be smaller, the risk of the bottom guard plate becoming heavier due to the anti-corrosion effect of the first protective layer and the second protective layer on the metal layer can be reduced, thereby reducing the impact of the bottom guard plate on the weight energy density of the battery.

[0035] According to some embodiments of the present application, the first protective layer is a fiber-reinforced non-metallic material layer; and / or the second protective layer is a fiber-reinforced non-metallic material layer.

[0036] In the above scheme, by limiting the first protective layer and / or the second protective layer to a fiber-reinforced non-metallic material layer, on the one hand, the influence of the battery weight energy density can be reduced; on the other hand, the impact energy resistance of the bottom guard plate can be effectively improved, so that the battery has higher reliability; on the other hand, the metal layer can be effectively coated to reduce the risk of the metal layer being exposed to the outside and corroded, so that the battery has higher reliability.

[0037] According to some embodiments of the present application, the bottom guard plate further includes a foam material layer, and the foam material layer is arranged on a side of the second protective layer facing away from the metal layer.

[0038] In the above solution, by arranging a foam material layer on the outer side of the bottom guard plate, on the one hand, the foam material has a cushioning effect, thereby improving the impact resistance of the bottom guard plate; on the other hand, the foam material has an absorption effect, that is, when the battery is applied to the vehicle, it can improve the NVH performance (Noise, Vibration, Harshness) of the vehicle and improve the driving experience of the vehicle.

[0039] In a second aspect, the present application provides an electrical device, comprising a battery provided in any one of the first aspects, the battery being used to provide electrical energy.

[0040] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0042] FIG1 is a schematic structural diagram of a vehicle in some embodiments of the present application;

[0043] FIG2 is an exploded perspective view of a battery in some embodiments of the present application;

[0044] FIG3 is a perspective view of a partial structure of a bottom guard plate and a box body in some embodiments of the present application;

[0045] FIG4 is a schematic structural diagram of a partial structure of a bottom guard plate and a box body in some embodiments of the present application;

[0046] FIG5 is a schematic diagram of the internal structure of the bottom guard plate and the partial structure of the box body in some embodiments of the present application;

[0047] Figure 6 is an enlarged view of point A in Figure 5;

[0048] FIG7 is a schematic diagram of the internal structure of a partial bottom guard plate in other embodiments of the present application;

[0049] FIG8 is a schematic diagram of the internal structure of a partial bottom guard plate in some other embodiments of the present application;

[0050] FIG9 is an exploded perspective view of a bottom guard plate in some embodiments of the present application;

[0051] Figure 10 is an enlarged view of point B in Figure 9;

[0052] FIG11 is a partial schematic diagram of the internal structure of the bottom guard plate in some embodiments of the present application;

[0053] FIG12 is an exploded perspective view of a bottom guard plate in some other embodiments of the present application;

[0054] FIG13 is an enlarged view of point C in FIG12;

[0055] FIG14 is a schematic structural diagram of the bottom guard plate in other embodiments of the present application.

[0056] Icon: 100-battery; 10-box; 11-lower box; 12-upper box; 20-battery cell; 30-bottom guard plate; 31-first protective layer; 310-first body; 311-first flange; 32-metal layer; 320-second body; 321-second flange; 3210-first through hole; 33-second protective layer; 330-third body; 331-third flange; 34-first protective part; 340-second through hole; 35-second protective part; 40-buffer chamber; 50-first connecting piece; 60-foaming material layer; 1000-vehicle; 200-controller; 300-motor. DETAILED DESCRIPTION

[0057] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0058] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0059] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0061] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0062] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0063] The term "plurality" used in this application refers to two or more (including two).

[0064] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, and the embodiments of this application are not limited thereto. Battery cells may be cylindrical, flat, rectangular, or in other shapes, and the embodiments of this application are not limited thereto.

[0065] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. A battery generally includes a housing that encloses one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0066] Battery technology is a crucial factor in the development of electric vehicles. Improving battery reliability is a pressing technical issue that needs to be addressed.

[0067] The batteries of electric vehicles are generally placed under the chassis of the vehicle, with a large area of ​​the batteries exposed under the vehicle. When the vehicle runs over materials such as stones or bricks on the road, these materials will splash or hit the bottom of the battery; when the vehicle is driving uphill, the bottom of the battery is also likely to scrape against the ground; or when passing over speed bumps or hitting curbs, the bottom of the battery is also easily damaged. In addition, the bottom of the battery is exposed to the outside for a long time and will be damaged by highly corrosive environments such as acids and alkalis. These damages may affect the normal use of the battery pack and even cause safety accidents such as thermal runaway or fire and explosion. For this reason, a bottom guard plate is often provided at the bottom of the box to protect the bottom of the battery and the battery cells inside the box. To take into account both corrosion resistance and impact resistance, the current bottom guard plate is often a multi-layer structure, such as a glass fiber layer, a metal layer, and a glass fiber layer stacked together to form a bottom guard plate.

[0068] However, the current bottom guard plate is flat and has low impact resistance, which cannot provide effective protection for the battery cells in the box, affecting the reliability of the battery.

[0069] In view of this, to improve the problem that the current multi-layer bottom guard plate has low impact resistance and cannot effectively protect the battery cells in the casing, some embodiments of the present application provide a battery comprising a casing and a bottom guard plate. The bottom guard plate is connected to the casing. The bottom guard plate has a multi-layer structure, and a buffer cavity is formed between the bottom guard plate and the casing and / or between two adjacent layers of the bottom guard plate.

[0070] In the above solution, by providing a buffer cavity, the impact on the bottom of the battery can be effectively alleviated, the risk of damage to the battery cells in the box is reduced, and the battery has higher reliability.

[0071] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0072] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include new energy vehicles, which may include pure electric vehicles, hybrid electric vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0073] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0074] FIG1 is a schematic structural diagram of a vehicle in some embodiments of the present application.

[0075] A controller 200, a motor 300, and a battery 100 may be provided inside the vehicle 1000. The controller 200 is used to control the battery 100 to power the motor 300. For example, the battery 100 may be provided at the bottom, front, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000 and for the circuit system of the vehicle 1000, for example, for the starting, navigation, and operating power requirements of the vehicle 1000. In another embodiment of the present application, the battery 100 may serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0076] According to some embodiments of the present application, a battery 100 is provided, please refer to Figures 2 to 6. Figure 2 is a three-dimensional exploded view of the battery 100 in some embodiments of the present application, Figure 3 is a three-dimensional view of the local structure of the bottom guard plate 30 and the box body 10 in some embodiments of the present application, Figure 4 is a structural schematic diagram of the local structure of the bottom guard plate 30 and the box body 10 in some embodiments of the present application, Figure 5 is a schematic diagram of the internal structure of the local structure of the bottom guard plate 30 and the box body 10 in some embodiments of the present application, and Figure 6 is an enlarged view of point A in Figure 5.

[0077] The battery 100 includes a housing 10 and a bottom guard plate 30. The bottom guard plate 30 is connected to the housing 10. The bottom guard plate 30 is a multi-layer structure, and a buffer cavity 40 is formed between the bottom guard plate 30 and the housing 10 and / or between two adjacent layers of the bottom guard plate 30.

[0078] In some embodiments, the housing 10 can provide a chamber for the battery cells 20, or the housing 10 and the bottom guard plate 30 can jointly provide a chamber for the battery cells 20. The housing 10 can have various structures. As shown in Figure 2, in some embodiments, the housing 10 can include a lower housing 11 and an upper housing 12. The lower housing 11 and the upper housing 12 cover each other, and the lower housing 11 and the upper housing 12 together define a chamber for accommodating the battery cells 20. The lower housing 11 can be a hollow structure with one end open, and the upper housing 12 can be a plate-like structure. The upper housing 12 covers the open side of the lower housing 11, so that the lower housing 11 and the upper housing 12 jointly define a chamber. The lower housing 11 and the upper housing 12 can also be hollow structures with one end open, with the open side of the lower housing 11 covering the open side of the upper housing 12. Of course, the housing 10 formed by the lower housing 11 and the upper housing 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc. In some embodiments, the connection between the upper box 12 and the lower box 11 includes, but is not limited to, riveting, welding, screw connection, or other connection methods. The bottom guard plate 30 can be disposed at the bottom of the lower box 11. The connection between the bottom guard plate 30 and the lower box 11 includes, but is not limited to, riveting, welding, screw connection, or other connection methods.

[0079] In some embodiments, the housing 10 may include an upper housing 12 and a lower housing 11, wherein the bottom of the lower housing 11 is hollowed out. A bottom guard plate 30 is disposed at the bottom of the lower housing 11, such that the bottom guard plate 30, the lower housing 11, and the upper housing 12 collectively define a chamber for accommodating the battery cells 20. For example, referring to FIG3 , the lower housing 11 of the housing 10 includes multiple side walls, which are connected end to end to form a frame, within which multiple cross beams are disposed. The bottom guard plate 30 is disposed at the bottom of the lower housing 11 and is connected to the multiple side walls and the multiple cross beams via a first connector 50.

[0080] In the battery 100, there may be one or more battery cells 20, and each battery cell 20 may be fixed to the housing 10 by a connector (e.g., bolts), or each battery cell 20 may be fixed to the housing 10 by bonding. The electrode lead portions of the multiple battery cells 20 may be connected by a current collecting member.

[0081] "The bottom guard plate 30 is a multi-layer structure" can be understood as that the bottom guard plate 30 includes multiple structural layers, and the multiple structural layers are stacked on each other. For example, the bottom guard plate 30 includes at least two structural layers, and the at least two-layer structure can include a metal layer 32, a non-metallic layer 32 and / or other structural layers. The side of the metal layer 32 facing away from the box body 10 is stacked with a non-metallic layer 32 and / or other structural layers. For another example, the bottom guard plate 30 includes a three-layer structure, and the three-layer structure includes a first protective layer 31, a metal layer 32 and a second protective layer 33. The metal layer 32 is sandwiched between the first protective layer 31 and the second protective layer 33. The first protective layer 31 is connected to the box body 10. The first protective layer 31 and the second protective layer 33 can be used to isolate the metal layer 32 from the outside world to reduce the risk of corrosion of the metal layer 32. For another example, the bottom guard plate 30 can also be formed by stacking multiple metal structural layers.

[0082] The "buffer cavity 40" can be understood as a space that allows the bottom guard plate 30 to deform during an impact. For example, when the bottom of the battery 100 is impacted, the impact causes the bottom guard plate 30 to deform. However, due to the presence of a buffer, the deformed portion is prevented from contacting other components of the battery 100. In some embodiments, the buffer cavity 40 can be formed by increasing the distance between two structural layers or by providing grooves or depressions in the surface of a structural layer.

[0083] “A buffer cavity 40 is formed between the bottom guard plate 30 and the box body 10 and / or between two adjacent layers of the bottom guard plate 30” can be understood as that the buffer cavity 40 can be located in various positions, and one possible solution is that the buffer cavity 40 is provided between the bottom guard plate 30 and the box body 10. For example, referring to FIG6 , the surface of the bottom guard plate 30 facing the box body 10 is recessed toward the outside of the box body 10, and a buffer cavity 40 is formed between the recessed portion and the connection surface between the box body 10 and the bottom guard plate 30. Another possible solution is that the buffer cavity 40 is formed inside the bottom guard plate 30. For example, the bottom guard plate 30 includes a three-layer structure, and the three-layer structure includes a first protective layer 31, a metal layer 32, and a second protective layer 33. The buffer cavity 40 is formed between the first protective layer 31 and the metal layer 32 or between the metal layer 32 and the second protective layer 33.

[0084] In the above solution, by providing the buffer cavity 40 , the impact on the bottom of the battery 100 can be effectively alleviated, and the risk of damage to the battery cells 20 in the box 10 is reduced, so that the battery 100 has higher reliability.

[0085] According to some embodiments of the present application, the bottom guard plate 30 includes a first protective layer 31, a metal layer 32, and a second protective layer 33 that are stacked together. The first protective layer 31 is arranged on the side of the metal layer 32 close to the box body 10, and the second protective layer 33 is arranged on the side of the metal layer 32 away from the box body 10.

[0086] In some embodiments, the bottom guard plate 30 may have a three-layer structure, comprising a first protective layer 31, a metal layer 32, and a second protective layer 33. The metal layer 32 may be made of, but not limited to, steel, aluminum, or aluminum alloys. In some embodiments, the metal layer 32 may be a metal material with both good rigidity and ductility. The first and second protective layers 31, 33 may be made of non-metallic materials. These materials may provide a certain degree of structural strength, effectively preventing damage from impacts such as rock fragments on the bottom and reducing the risk of corrosion of the metal layer 32 from the external environment. For example, the first and second protective layers 31, 33 may be composite materials. For example, the first and second protective layers 31, 33 may be made of a fiber-reinforced non-metallic material. The matrix resin of the first and second protective layers 31, 33 may be a thermoplastic resin such as PP (polypropylene) or PA (polyamide), or a thermosetting resin such as epoxy or polyurethane. The fibers may be glass fiber, carbon fiber, or basalt fiber.

[0087] In some embodiments, the sizes of the first protective layer 31, the metal layer 32, and the second protective layer 33 may be the same or different. For example, the metal layer 32 is smaller than the first protective layer 31 and the second protective layer 33, and the metal layer 32 is sandwiched between the first protective layer 31 and the second protective layer 33, that is, the outer edge of the metal layer 32 can be isolated from the outside world.

[0088] The first protective layer 31 is the structural layer closest to the housing 10 among the three layers of the bottom guard plate 30, and the second protective layer 33 is the structural layer farthest from the housing 10 among the three layers of the bottom guard plate 30. In some embodiments, the relationship between the bottom guard plate 30 and the housing 10 includes the first protective layer 31 being bonded, clamped, or riveted to the housing 10, or a connecting member passing through the second protective layer 33, the metal layer 32, and the first protective layer 31 to connect to the housing 10, or a connecting member passing through the second protective layer 33 and the first protective layer 31 to connect to the housing 10.

[0089] In the above solution, the metal layer 32 has high strength and can provide effective protection for the battery cells 20 in the box body 10. By arranging the metal layer 32 between the first protective layer 31 and the second protective layer 33, the risk of the metal layer 32 being exposed to the outside and corroded can be effectively reduced, thereby making the bottom guard plate 30 have higher reliability, thereby improving the reliability of the battery 100.

[0090] According to some embodiments of the present application, please refer to Figures 6 to 8. Figure 7 is an internal schematic diagram of the local structure of the bottom guard plate 30 in other embodiments of the present application, and Figure 8 is an internal schematic diagram of the local structure of the bottom guard plate 30 in other embodiments of the present application.

[0091] At least one of the following conditions must be met:

[0092] The buffer cavity 40 is formed between the first protective layer 31 and the box body 10;

[0093] The buffer cavity 40 is formed between the first protection layer 31 and the metal layer 32;

[0094] The buffer cavity 40 is formed between the metal layer 32 and the second protection layer 33 .

[0095] In some embodiments, referring to FIG6 , “a buffer cavity 40 is formed between the first protective layer 31 and the housing 10 ” can be understood as providing grooves or pits at one or more locations on the surface of the first protective layer 31 facing away from the metal layer 32 so as to form at least part of the buffer cavity 40 between the first protective layer 31 and the housing 10. Exemplarily, three spaced pits can be provided on the surface of the first protective layer 31 facing away from the metal layer 32. When the bottom guard plate 30 is impacted and deformed, the three pits can accommodate the deformed portions of the bottom guard plate 30 to reduce the impact of the deformed portions on the battery cells 20. Exemplarily, the first protective layer 31 can form pits on the surface facing away from the metal layer 32 by stamping, and a protrusion can be formed on the surface facing the metal layer 32 at a position corresponding to the pit.

[0096] In other embodiments, referring to FIG. 7 , "a buffer cavity 40 is formed between the first protective layer 31 and the metal layer 32" can be understood as a gap between the first protective layer 31 and the metal layer 32, which can form at least a portion of the buffer cavity 40 to accommodate the deformed portion of the bottom guard plate 30 caused by impact, thereby reducing the impact of the deformed portion on the battery cell 20. Exemplarily, the formation of at least a portion of the buffer cavity 40 can include, but is not limited to, providing a groove or pit on the surface of the first protective layer 31 facing the metal layer 32, and providing a groove or pit on the surface of the metal layer 32 facing the first protective layer 31.

[0097] In some other embodiments, referring to FIG8 , "a buffer cavity 40 is formed between the metal layer 32 and the second protective layer 33" can be understood as a gap between the metal layer 32 and the second protective layer 33. This gap can form at least a portion of the buffer cavity 40 to accommodate the deformed portion of the bottom guard plate 30 due to impact, thereby reducing the impact of the deformed portion on the battery cell 20. Exemplarily, the formation of at least a portion of the buffer cavity 40 can include, but is not limited to, providing a groove or pit on the surface of the second protective layer 33 facing the metal layer 32, and providing a groove or pit on the surface of the metal layer 32 facing the second protective layer 33.

[0098] In some embodiments, grooves or pits can be formed on the surface of the first protective layer 31 away from the metal layer 32. At the same time, a gap can be formed between the first protective layer 31 and the metal layer 32. At the same time, a gap can be formed between the metal layer 32 and the second protective layer 33, so that the buffer cavity 40 is partially located between the first protective layer 31 and the box body 10, partially located between the first protective layer 31 and the metal layer 32, and the remaining part is located between the metal layer 32 and the second protective layer 33.

[0099] The above solution provides a variety of buffer cavity 40 placement locations, which can provide multiple options for the manufacture of the battery 100 and adapt to different impact situations. For example, by arranging the buffer cavity 40 between the first protective layer 31 and the box body 10, the second protective layer 33, the metal layer 32, and the first protective layer 31 can first absorb the impact, and then the buffer cavity 40 can be used to collapse and deform to absorb energy. Therefore, when encountering a smaller impact, the risk of the entire bottom guard plate 30 being scrapped due to the buffer cavity 40 being broken or damaged can be reduced. For example, by arranging the buffer cavity 40 between the metal layer 32 and the second protective layer 33, the impact can be absorbed at a position relatively outside the battery 100, which can effectively reduce the impact of the impact on the internal structure of the box body 10.

[0100] The above solution provides a variety of buffer cavity 40 placement locations, which can provide multiple options for the manufacture of the battery 100 and adapt to different impact situations. For example, by arranging the buffer cavity 40 between the first protective layer 31 and the box body 10, the second protective layer 33, the metal layer 32, and the first protective layer 31 can first absorb the impact, and then the buffer cavity 40 can be used to collapse and deform to absorb energy. Therefore, when encountering a smaller impact, the risk of the entire bottom guard plate 30 being scrapped due to the buffer cavity 40 being broken or damaged can be reduced. For example, by arranging the buffer cavity 40 between the metal layer 32 and the second protective layer 33, the impact can be absorbed at a position relatively outside the battery 100, which can effectively reduce the impact of the impact on the internal structure of the box body 10.

[0101] According to some embodiments of the present application, please refer to Figures 6, 9 and 10. Figure 9 is a three-dimensional exploded view of the bottom guard plate 30 in some embodiments of the present application, and Figure 10 is an enlarged view of point B in Figure 9.

[0102] The first protective layer 31 includes a first body 310 and a first flange 311. The first flange 311 is disposed around the first body 310 and is connected to the housing 10. At least a portion of the first body 310 protrudes from the first flange 311 in a direction away from the housing 10. The buffer chamber 40 is formed between the first body 310 and the housing 10.

[0103] In some embodiments, the first protective layer 31 includes a first body 310 and a first flange 311. The first flange 311 is arranged around the outer edge of the first body 310 and connected to the box body 10. For example, the first flange 311 is connected to the box body 10 by bolts.

[0104] “At least part of the first body 310 protrudes from the first flange portion 311 in a direction away from the box body 10” can be understood as that part or all of the first body 310 protrudes from the first flange portion 311 in a direction away from the box body 10, so as to form a groove or pit that is recessed compared to the plane where the first flange portion 311 is located on the surface of the first body 310 facing the box body 10, so as to form a buffer cavity 40 between the first protective layer 31 and the box body 10. At the same time, a convex portion is formed at a position corresponding to the surface of the first body 310 facing away from the box body 10. Exemplarily, there may be three parts of the first body 310 that protrude from the first flange portion 311 in a direction away from the box body 10, that is, three grooves or pits are formed on the surface of the first body 310 facing the box body 10, and three convex portions are formed at a position corresponding to the surface of the first body 310 facing away from the box body 10.

[0105] In the above solution, the first protective layer 31 has a simple structure and can be effectively connected to the housing 10 via the first flange portion 311. By configuring at least a portion of the first body 310 to protrude toward the side facing away from the housing 10, a recessed area is formed on the side facing the housing 10, thereby forming a buffer cavity 40 between the housing 10 and the first protective layer 31. This cushions the impact on the bottom of the battery 100, thereby ensuring higher reliability of the battery 100.

[0106] According to some embodiments of the present application, referring to Figures 6, 9 and 10, the metal layer 32 includes a second body 320 and a second flange portion 321, the second flange portion 321 is surrounded by the second body 320, at least a portion of the second body 320 protrudes from the second flange portion 321 in a direction away from the box body 10, the second body 320 is in contact with the first body 310, and the second flange portion 321 is in contact with the first flange portion 311.

[0107] In some embodiments, the outer contour of the metal layer 32 may correspond to the outer contour of the first protective layer 31 . The second body 320 of the metal layer 32 corresponds to the first body 310 of the first protective layer 31 , and the second flange 321 of the metal layer 32 corresponds to the first flange 311 of the first protective layer 31 .

[0108] “At least a portion of the second body 320 protrudes from the second flange portion 321 in a direction away from the box body 10” can be understood as that a portion or all of the second body 320 protrudes from the second flange portion 321 in a direction away from the box body 10, so as to form a groove or pit on the surface of the second body 320 facing the box body 10 that is concave than the plane where the second flange portion 321 is located, so as to accommodate the protrusion of the first body 310.

[0109] “The second body 320 is bonded to the first body 310 , and the second flange 321 is bonded to the first flange 311 ” can be understood as that the surface of the metal layer 32 facing the first protective layer 31 is bonded to the surface of the first protective layer 31 facing the metal layer 32 .

[0110] In some embodiments, the metal layer 32 and the first protective layer 31 can be connected as a whole by bonding, clamping, etc. In some embodiments, the metal layer 32 can be sandwiched between the first protective layer 31 and the second protective layer 33. The first protective layer 31 and the second protective layer 33 are connected to each other so that the metal layer 32 is stably located between the first protective layer 31 and the second protective layer 33.

[0111] In the above solution, the outer contour of the metal layer 32 can match the outer contour of the first protective layer 31. The metal layer 32 includes a second flange portion 321 corresponding to the first flange portion 311, and a second body 320 corresponding to the first body 310. This allows the metal layer 32 to fit tightly with the first protective layer 31, resulting in a stable structure and high space utilization for the bottom guard plate 30. This, in turn, improves the space utilization of the battery 100, thereby increasing the volumetric energy density of the battery 100.

[0112] In some other embodiments, the metal layer 32 may not have the second flange portion 321 . For example, the metal layer 32 is only a flat plate structure, and the metal layer 32 is sandwiched between the first protective layer 31 and the second protective layer 33 .

[0113] According to some embodiments of the present application, referring to Figures 6, 9 and 10, the second protective layer 33 includes a third body 330 and a third flange portion 331, the third flange portion 331 is surrounded by the third body 330, and at least a portion of the third body 330 protrudes from the third flange portion 331 in a direction away from the box body 10, the second body 320 is clamped between the first body 310 and the third body 330, and the second flange portion 321 is clamped between the first flange portion 311 and the third flange portion 331.

[0114] In some embodiments, the outer contour of the second protective layer 33 can correspond to the outer contours of the first protective layer 31 and the metal layer 32. The third body 330 of the second protective layer 33 corresponds to the second body 320 of the metal layer 32, allowing the second body 320 to be sandwiched between the third body 330 and the first body 310. The third flange 331 of the second protective layer 33 corresponds to the second flange 321 of the metal layer 32, allowing the second flange 321 to be sandwiched between the third flange 331 and the first flange 311.

[0115] “At least a portion of the third body 330 protrudes from the third flange portion 331 in a direction away from the box body 10” can be understood as that a portion or all of the third body 330 protrudes from the third flange portion 331 in a direction away from the box body 10, so as to form a groove or pit on the surface of the third body 330 facing the box body 10 that is concave than the plane where the third flange portion 331 is located, so as to accommodate the protrusion of the second body 320.

[0116] For example, referring to Figure 9, the number of protrusions on the surface of the third body 330 facing away from the metal layer 32 is three, and the pits corresponding to the three protrusions can accommodate the three protrusions of the second body 320. Similarly, the three pits formed on the surface of the second body 320 facing the first body 310 can accommodate the three protrusions of the first body 310, and three pits are formed on the surface of the first body 310 facing the box body 10.

[0117] In some embodiments, the bottom guard plate 30 may be connected to the box body 10 by bolts, and the bolts may pass through the third flange portion 331 , the second flange portion 321 , and the first flange portion 311 to be connected to the box body 10 .

[0118] In the above scheme, the outer contour of the metal layer 32 can fit the outer contour of the first protective layer 31 and the metal layer 32. By providing a third body 330 that fits with the second body 320 and a third flange portion 331 that fits with the second flange portion 321, on the one hand, the structure of the bottom guard plate 30 can be made stable and the space utilization rate is high, thereby making the space utilization rate of the battery 100 high, which is beneficial to the improvement of the volume energy density of the battery 100; on the other hand, the metal layer 32 can be stably located between the first protective layer 31 and the second protective layer 33, thereby reducing the risk of corrosion of the metal layer 32 and improving the reliability of the battery 100.

[0119] In some other embodiments, the third protective layer may be in the shape of a flat plate as a whole, and a groove may be formed on the surface of the third protective layer facing the metal layer 32 , and the groove can accommodate the first body 310 and the second body 320 .

[0120] According to some embodiments of the present application, please refer to Figures 10 and 11. Figure 11 is a partial schematic diagram of the internal structure of the bottom guard plate 30 in some embodiments of the present application.

[0121] The second flange portion 321 is provided with a first through hole 3210, and the bottom guard plate 30 also includes a first protective portion 34, which is arranged in the first through hole 3210 and connects the first protective layer 31 and the second protective layer 33. The bottom guard plate 30 is provided with a second through hole 340 that passes through the first protective layer 31, the first protective portion 34 and the second protective layer 33.

[0122] In some embodiments, the second flange portion 321 is provided with a first through-hole 3210 extending therethrough along the stacking direction of the first protective layer 31, the metal layer 32, and the second protective layer 33. The first protective portion 34 is disposed within the first through-hole 3210 to connect the first protective layer 31 and the second protective layer 33. For example, during the manufacture of the bottom guard plate 30, the first protective layer 31, the metal layer 32, and the second protective layer 33 are stacked together and then thermally pressed together to fuse the first protective layer 31 and the second protective layer 33 together at a location corresponding to the first through-hole 3210. This fused location may constitute the first protective portion 34. In other embodiments, the first protective portion 34 may be a bonded or welded structure. During the manufacture of the bottom guard plate 30, the first protective layer 31, the metal layer 32, and the second protective layer 33 are stacked together and bonded or welded together at a location corresponding to the first through-hole 3210 to form the first protective portion 34 and connect the first protective layer 31 and the second protective layer 33.

[0123] The second through hole 340 is a hole-shaped structure that penetrates the first protective layer 31, the first protective portion 34, and the second protective layer 33. In some embodiments, the bottom guard plate 30 is connected to the box body 10 by bolts passing through the second through hole 340.

[0124] In some embodiments, the second through hole 340 may be circular, square, or other shapes. The first through hole 3210 may be circular, square, or other shapes.

[0125] In some embodiments, the diameter of the second through hole 340 may be smaller than that of the first through hole 3210 , so that the hole wall of the first through hole 3210 can be effectively covered by the first protection portion 34 .

[0126] In the above solution, by providing the first through hole 3210 and the first protective portion 34, on the one hand, the first protective portion 34 can connect the first protective layer 31 and the second protective layer 33 through the first through hole 3210, and on the other hand, the first protective portion 34 can cover the hole wall of the first through hole 3210, thereby reducing the risk of corrosion of the metal layer 32 and improving the reliability of the battery 100. At the same time, by providing the second through hole 340, connecting members (such as bolts, screws, etc.) can be passed through the second through hole 340 to assemble the bottom guard plate 30 to the bottom of the box body 10, thereby achieving assembly of the bottom guard plate 30 with the box body 10.

[0127] In some other embodiments, the second body 320 may form a through hole, and the first body 310 and the third body 330 may be connected to each other through the through hole.

[0128] According to other embodiments of the present application, please refer to Figures 12 and 13. Figure 12 is a three-dimensional exploded view of the bottom guard plate 30 in other embodiments of the present application, and Figure 13 is an enlarged view of point C in Figure 12.

[0129] The first through hole 3210 extends to the outer circumference of the second flange portion 321 .

[0130] In some embodiments, the first through hole 3210 may be a U-shaped hole, that is, the first through hole 3210 has an opening. In other words, the outer edge of the second flange portion 321 is recessed inward to form the first through hole 3210 .

[0131] In some embodiments, the bottom guard plate 30 can be connected to the box body 10 by bolts passing through the second through hole 340. Since the first through hole 3210 extends to the outer peripheral surface of the second flange portion 321, the bolts can compress the first protective layer 31 and the second protective layer 33 at the opening of the first through hole 3210 when locking, so that the first protective layer 31 and the second protective layer 33 are deformed, thereby improving the sealing of the locking.

[0132] In the above scheme, the first protective layer 31 and the second protective layer 33 can be combined into one by hot pressing. To this end, by extending the first through hole 3210 to the outer peripheral surface of the second flange portion 321 of the device, the efficiency of the hot pressing combination can be improved, and the hot pressing combination area of ​​the first protective layer 31 and the second protective layer 33 can be increased, thereby improving the connection stability of the first protective layer 31 and the second protective layer 33.

[0133] According to some embodiments of the present application, referring to FIG. 11 , the bottom guard plate 30 further includes a second protective portion 35 , which wraps around the outer circumference of the second flange portion 321 , and the second protective portion 35 connects the first protective layer 31 and the second protective layer 33 .

[0134] In some embodiments, the size of the metal layer 32 can be smaller than the size of the first protective member and the second protective member. For example, there is a distance between the outer circumference of the second flange portion 321 of the metal layer 32 and the outer circumference of the first flange portion 311 and the outer circumference of the third flange portion 331. This distance allows the second protective member to be provided. The second protective member is provided along the outer circumference of the second flange portion 321 and connects the first protective layer 31 and the second protective layer 33. For example, when manufacturing the bottom guard plate 30, the first protective layer 31, the metal layer 32, and the second protective layer 33 are stacked as one. During the hot pressing and laminating process, the sizes of the first protective layer 31 and the second protective layer 33 are larger. There is an area on the outside of the metal layer 32 that does not support the first protective layer 31 and the second protective layer 33. The first protective layer 31 and the second protective layer 33 are integrated into one in this area. The integrated portion can form the second protective portion 35. In some other embodiments, the second protective portion 35 can be a bonding structure or a welding structure. When manufacturing the bottom guard plate 30, the first protective layer 31, the metal layer 32 and the second protective layer 33 are stacked together, and the second protective portion 35 is formed on the periphery of the metal layer 32 by bonding or welding, and the first protective layer 31 and the second protective layer 33 are connected.

[0135] According to some embodiments of the present application, along a direction perpendicular to the outer circumference of the metal layer 32 , the thickness of the second protection portion 35 is greater than or equal to 1 mm and less than or equal to 20 mm.

[0136] Referring to FIG. 11 , the thickness of the second protection portion 35 along a direction perpendicular to the outer peripheral surface of the metal layer 32 is marked as T, and the value of T is greater than or equal to 1 mm and less than or equal to 20 mm.

[0137] In some embodiments, the value of T can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm...18 mm, 19 mm, 20 mm or any value between two adjacent values.

[0138] In the above scheme, the thickness of the second protective portion 35 is set to be greater than or equal to 1 mm along the direction perpendicular to the outer peripheral surface of the metal layer 32, which can effectively make the second protective portion 35 cover the outer peripheral surface of the metal layer 32 to reduce the risk of the metal layer 32 being exposed and corroded; the thickness of the second protective portion 35 is set to be less than or equal to 20 mm, which can reduce the risk of the second protective portion 35 occupying too much space, resulting in a smaller space occupied by the metal layer 32, and thus resulting in a lower structural strength of the bottom guard plate 30. To this end, by setting the thickness of the second protective portion 35 to be greater than or equal to 1 mm and less than or equal to 20 mm along the direction perpendicular to the outer peripheral surface of the metal layer 32, both the anti-corrosion effect of the metal layer 32 and the structural strength of the bottom guard plate 30 can be taken into account.

[0139] According to some embodiments of the present application, the first protective layer 31 , the second protective layer 33 , the first protective portion 34 and the second protective portion 35 are integrally formed.

[0140] In some embodiments, the first protective layer 31 and the second protective layer 33 can be combined into one by hot pressing. For example, when manufacturing the bottom guard plate 30, the first protective layer 31, the metal layer 32 and the second protective layer 33 are stacked together, and a high temperature environment and a certain pressure are provided to the first protective layer 31, the metal layer 32 and the second protective layer 33 so that a first protective portion 34 and a second protective portion 35 are formed between the first protective layer 31 and the second protective layer 33.

[0141] In the above solution, by arranging the first protective layer 31, the second protective layer 33, the first protective portion 34 and the second protective portion 35 to be integrally formed, the connection stability of the first protective layer 31 and the second protective layer 33 and the manufacturing efficiency of the bottom guard plate 30 can be improved.

[0142] According to some embodiments of the present application, referring to Figures 4 and 6 , the second protective layer 33 includes a third body 330 and a third flange portion 331. The third flange portion 331 is disposed around the third body 330, and at least a portion of the third body 330 protrudes from the third flange portion 331 in a direction away from the housing 10. The battery 100 also includes a first connector 50. The bottom guard plate 30 is connected to the housing 10 through the third flange portion 331 via the first connector 50. At least a portion of the third body 330 protrudes from the first connector 50 in a direction away from the housing 10.

[0143] In some embodiments, the bottom guard plate 30 is connected to the box body 10 through a first connecting member 50 that passes through the bottom guard plate 30. For example, the first connecting member 50 can be a bolt, part of which can be located inside the bottom guard plate 30 and the box body 10, and the other part of the bolt is located on the side of the bottom guard plate 30 that is away from the box body 10.

[0144] The third body 330 is part of the third protective layer. The third flange portion 331 is arranged around the third body 330. The third flange portion 331 allows the first connecting member 50 to pass through. That is, part of the first connecting portion can protrude from the third flange portion 331 away from the surface of the box body 10.

[0145] All or part of the third body 330 can protrude from the third flange portion 331 , and the size of the portion protruding from the third flange portion 331 can be greater than or equal to the size of the first connection portion protruding from the third flange portion 331 .

[0146] In the above scheme, by setting at least a portion of the third body 330 to protrude from the third flange portion 331 in a direction away from the box body 10, the space occupied by the first connecting member 50 in a direction away from the box body 10 can be reasonably utilized, thereby increasing the volume of the buffer cavity 40 or the overall thickness of the bottom guard plate 30 as much as possible, thereby improving the impact resistance of the bottom guard plate 30, and thus making the battery 100 have higher reliability.

[0147] According to some embodiments of the present application, the density of the first protective layer 31 is less than the density of the metal layer 32 ; and / or the density of the second protective layer 33 is less than the density of the metal layer 32 .

[0148] In some embodiments, the sealing density of the first protective layer 31 and / or the second protective layer 33 may be lower than that of the metal layer 32 . For example, the first protective layer 31 and / or the second protective layer 33 may be made of ceramic, carbon fiber or other materials with lower density.

[0149] In the above scheme, by setting the density of the first protective layer 31 and / or the second protective layer 33 to be smaller, the risk of the bottom guard plate 30 becoming heavier due to the anti-corrosion effect of the first protective layer 31 and the second protective layer 33 on the metal layer 32 can be reduced, thereby reducing the impact of the bottom guard plate 30 on the weight energy density of the battery 100.

[0150] According to some embodiments of the present application, the first protective layer 31 is a fiber-reinforced non-metallic material layer; and / or the second protective layer 33 is a fiber-reinforced non-metallic material layer.

[0151] In some embodiments, the first protective layer 31 and / or the second protective layer 33 are fiber-reinforced non-metallic materials, the matrix resin of which can be thermoplastic resins such as PP, PA, or thermosetting resins such as epoxy or polyurethane; the fibers can be glass fibers, carbon fibers, or basalt fibers, etc.

[0152] In the above scheme, by limiting the first protective layer 31 and / or the second protective layer 33 to a fiber-reinforced non-metallic material layer, on the one hand, the influence of the weight energy density of the battery 100 can be reduced; on the other hand, the impact energy resistance of the bottom guard plate 30 can be effectively improved, so that the battery 100 has higher reliability; on the other hand, the metal layer 32 can be effectively coated to reduce the risk of the metal layer 32 being exposed to the outside and corroded, so that the battery 100 has higher reliability.

[0153] According to other embodiments of the present application, please refer to Figure 14, which is a schematic structural diagram of the bottom guard plate 30 in other embodiments of the present application.

[0154] The bottom guard plate 30 further includes a foam material layer 60 , which is disposed on a side of the second protective layer 33 facing away from the metal layer 32 .

[0155] In some embodiments, the foam material layer 60 may include PVC (polyvinyl chloride) foam or polyurethane foam.

[0156] The foam material layer 60 can be disposed on the side of the second protective layer 33 away from the metal layer 32 by bonding or hot pressing.

[0157] In the above solution, by arranging a foam material layer 60 on the outer side of the bottom guard plate 30, on the one hand, the foam material has a cushioning effect, thereby improving the impact resistance of the bottom guard plate 30; on the other hand, the foam material has an absorption effect, that is, when the battery 100 is applied to a vehicle, it can improve the NVH performance (Noise, Vibration, Harshness) of the vehicle and improve the driving experience of the vehicle.

[0158] According to some embodiments of the present application, an electrical device is provided, which includes the battery 100 provided above, and the battery 100 is used to provide electrical energy.

[0159] In some embodiments, the electric device may include a vehicle, and the battery 100 may be disposed under a chassis of the vehicle.

[0160] According to some embodiments of the present application, a battery 100 is provided, see Figures 2 to 13 .

[0161] The battery 100 includes a housing 10 and a bottom protective plate 30, which is disposed at the bottom of the housing 10. The bottom protective plate 30 is a multi-layer structure, comprising a first protective layer 31, a metal layer 32, and a second protective layer 33. The first protective layer 31 and the second protective layer 33 are fiber-reinforced non-metallic material layers.

[0162] The first protective layer 31 includes a first body 310 and a first flange 311. The first flange 311 is disposed around the first body 310 and connected to the housing 10. At least a portion of the first body 310 protrudes from the first flange 311 in a direction away from the housing 10. The metal layer 32 includes a second body 320 and a second flange 321. The second flange 321 is disposed around the second body 320. At least a portion of the second body 320 protrudes from the second flange 321 in a direction away from the housing 10. The second body 320 is bonded to the first body 310, and the second flange 321 is bonded to the first flange 311. The second protective layer 33 includes a third body 330 and a third flange portion 331. The third flange portion 331 is surrounded by the third body 330. At least a portion of the third body 330 protrudes from the third flange portion 331 in a direction away from the box body 10. The second body 320 is clamped between the first body 310 and the third body 330. The second flange portion 321 is clamped between the first flange portion 311 and the third flange portion 331.

[0163] A recess is formed on the surface of the first body 310 facing the housing 10, creating a buffer cavity 40 between the bottom guard plate 30 and the housing 10. The buffer cavity 40 can mitigate impacts on the bottom guard plate 30, thereby reducing the impact on structural components within the housing 10 (such as the battery cells 20). The recess is located at the position where the first body 310 protrudes from the first flange portion 311 in a direction away from the housing 10.

[0164] The second flange portion 321 of the metal layer 32 is provided with a first through-hole 3210, which extends to the outer periphery of the second flange portion 321. The metal layer 32 is smaller than the first and second protective layers 31, 33. The first and second protective layers 31, 33 are laminated together via hot pressing. A first protective portion 34 and a second protective portion 35 are formed at locations corresponding to the first through-hole 3210 and around the periphery of the metal layer 32. The first protective portion 34 is provided with a second through-hole 340, through which bolts pass to connect to the housing 10, thereby connecting the bottom guard plate 30 to the housing 10.

[0165] In the above solution, by providing the buffer cavity 40 , the impact on the bottom of the battery 100 can be effectively alleviated, and the risk of damage to the battery cells 20 in the box 10 is reduced, so that the battery 100 has higher reliability.

[0166] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery, wherein: include: Box; a bottom guard plate connected to the box body; Wherein, the bottom guard plate is a multi-layer structure, and a buffer cavity is formed between the bottom guard plate and the box body and / or between two adjacent layers of the bottom guard plate.

2. The battery according to claim 1, wherein The bottom guard plate includes a first protective layer, a metal layer, and a second protective layer that are stacked. The first protective layer is arranged on a side of the metal layer close to the box body, and the second protective layer is arranged on a side of the metal layer away from the box body.

3. The battery according to claim 2, wherein At least one of the following conditions must be met: The buffer cavity is formed between the first protective layer and the box body; The buffer cavity is formed between the first protective layer and the metal layer; The buffer cavity is formed between the metal layer and the second protection layer.

4. The battery according to claim 2 or 3, wherein The first protective layer includes a first body and a first flange portion, wherein the first flange portion is disposed around the first body and connected to the box body; At least a portion of the first body protrudes from the first flange portion in a direction away from the box body, and the buffer cavity is formed between the first body and the box body.

5. The battery according to claim 4, wherein The metal layer includes a second body and a second flange portion, the second flange portion is surrounded by the second body, at least part of the second body protrudes from the second flange portion in a direction away from the box body, the second body is in contact with the first body, and the second flange portion is in contact with the first flange portion.

6. The battery according to claim 5, wherein The second protective layer includes a third body and a third flange portion, the third flange portion is surrounded by the third body, at least part of the third body protrudes from the third flange portion in a direction away from the box body, the second body is clamped between the first body and the third body, and the second flange portion is clamped between the first flange portion and the third flange portion.

7. The battery according to claim 6, wherein The second flange portion is provided with a first through hole, and the bottom guard plate also includes a first protective portion, which is arranged in the first through hole and connects the first protective layer and the second protective layer. The bottom guard plate is provided with a second through hole that penetrates the first protective layer, the first protective portion and the second protective layer.

8. The battery according to claim 7, wherein The first through hole extends to the outer circumferential surface of the second flange portion.

9. The battery according to claim 7 or 8, wherein The bottom guard plate further includes a second protective portion, which wraps around the outer circumference of the second flange portion, and the second protective portion connects the first protective layer and the second protective layer.

10. The battery according to claim 9, wherein In a direction perpendicular to the outer peripheral surface of the metal layer, the thickness of the second protection portion is greater than or equal to 1 mm and less than or equal to 20 mm.

11. The battery according to claim 9 or 10, wherein The first protection layer, the second protection layer, the first protection portion, and the second protection portion are integrally formed.

12. The battery according to any one of claims 2 to 11, wherein: The second protective layer includes a third body and a third flange portion, wherein the third flange portion is disposed around the third body, and at least a portion of the third body protrudes from the third flange portion in a direction away from the box body; The battery further includes a first connector, through which the bottom guard plate is connected to the box body through the third flange portion, and in a direction away from the box body, at least a portion of the third body protrudes from the first connector.

13. The battery according to any one of claims 2 to 12, wherein: The density of the first protective layer is less than the density of the metal layer; and / or, The density of the second protection layer is lower than that of the metal layer.

14. The battery according to any one of claims 2 to 13, wherein: The first protective layer is a fiber-reinforced non-metallic material layer; and / or, The second protective layer is a fiber-reinforced non-metallic material layer.

15. The battery according to any one of claims 2 to 14, wherein: The bottom guard plate further includes a foam material layer, which is arranged on a side of the second protective layer facing away from the metal layer.

16. An electrical device, wherein: The battery according to any one of claims 1 to 15 is used to provide electrical energy.

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