Battery and electric device

Abstract

The utility model provides a battery and a power utilization device. The battery comprises a box body and a bottom protection plate, and the bottom protection plate is connected with the box body. Wherein the bottom protection plate is of a multi-layer structure, and a buffer cavity is formed between the bottom protection plate and the box body and / or between every two adjacent layers of the bottom protection plate. According to the technical scheme provided by the invention, the reliability of the battery can be effectively improved.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] In the development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently. Utility Model Content

[0004] 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.

[0005] In a first aspect, the present application provides a battery, the battery comprising a box body and a bottom guard plate. The bottom guard plate is connected to the box body. 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.

[0006] 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.

[0007] 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.

[0008] In the above scheme, 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, so that the bottom guard plate has high reliability, thereby improving the reliability of the battery.

[0009] According to some embodiments of the present application, at least one of the following conditions is met:

[0010] The buffer cavity is formed between the first protective layer and the box body;

[0011] The buffer cavity is formed between the first protection layer and the metal layer;

[0012] The buffer cavity is formed between the metal layer and the second protection layer.

[0013] In the above scheme, a variety of buffer cavity arrangement positions are provided, which can provide a variety of options for battery manufacturing and adapt to different impact situations. For example, by arranging the buffer cavity between the first protective layer and the box body, the second protective layer, the metal layer and the first protective layer can absorb the impact first, and then use the buffer cavity to collapse and deform to absorb energy, so that when encountering a smaller impact, the risk of the entire bottom guard plate being scrapped due to the buffer cavity being broken or broken can be reduced. For example, by arranging the buffer cavity between the metal layer and the second protective layer, the impact can be absorbed at a relatively outer position of the battery, which can effectively reduce the impact on the internal structure of the box body.

[0014] According to some embodiments of the present application, the first protective layer includes a first body and a first flange portion, the first flange portion is disposed around the first body, and the first flange portion is 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 a buffer cavity is formed between the first body and the box body.

[0015] In the above solution, the first protective layer has a simple structure and can be effectively connected to the box body through the first flange portion. By arranging at least a portion of the first body to protrude toward the side away from the box body, a recessed area can be formed on the side facing the box body, thereby forming a buffer cavity between the box body and the first protective layer to alleviate the impact on the bottom of the battery, so that the battery has higher reliability.

[0016] 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 a portion 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.

[0017] In the above solution, the outer contour of the metal layer can match the outer contour of the first protective layer, and the metal layer includes a second flange portion corresponding to the first flange portion, and a second body corresponding to the first body. The metal layer can be closely attached to the first protective layer, so that the bottom guard plate structure is stable and the space utilization rate is high, thereby making the space utilization rate of the battery high, which is conducive to improving the volume energy density of the battery.

[0018] 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.

[0019] In the above scheme, the outer contour of the metal layer can be matched with the outer contour of the first protective layer and the metal layer. By providing a third body that is bonded to the second body and a third flange portion that is bonded to the second flange portion, on the one hand, the bottom guard plate structure can be made stable and the space utilization rate is high, thereby making the space utilization rate of the battery high, which is beneficial to the improvement of the battery volume energy density; 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.

[0020] 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.

[0021] In the above solution, by providing the first through hole and the first protection part, on the one hand, the first protection part can be connected to the first protection layer and the second protection layer through the first through hole, and on the other hand, the first protection part can cover the hole wall of the first through hole, thereby reducing the risk of corrosion of the metal layer, thereby 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, thereby realizing the assembly of the bottom guard plate and the box body.

[0022] According to some embodiments of the present application, the first through hole extends to the outer circumferential surface of the second flange portion.

[0023] 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 hot pressing bonding can be improved, and the hot pressing bonding 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.

[0024] According to some embodiments of the present application, the bottom guard plate also 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.

[0025] 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 to improve 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.

[0026] 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.

[0027] 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 causing the structural strength of the bottom guard plate to be lower. 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, the anti-corrosion effect of the metal layer and the structural strength of the bottom guard plate can be taken into account.

[0028] 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.

[0029] In the above solution, by arranging the first protective layer, the second protective layer, the first protective part and the second protective part 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.

[0030] 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 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 also includes a first connector, the bottom guard plate is connected to the box body through the first connector and through the third flange portion, and at least a portion of the third body protrudes from the first connector in a direction away from the box body.

[0031] 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.

[0032] According to some embodiments of the present application, the density of the first protective layer is lower than the density of the metal layer; and / or the density of the second protective layer is lower than the density of the metal layer.

[0033] 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 causing the bottom guard plate to be 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.

[0034] 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.

[0035] 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 still another 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.

[0036] According to some embodiments of the present application, the bottom guard plate further includes a foam material layer, and the foam material layer is disposed on a side of the second protective layer facing away from the metal layer.

[0037] In the above scheme, by arranging a foam material layer on the outer side of the bottom guard plate, on the one hand, the foam material has a buffering 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 a vehicle, it can improve the NVH performance (Noise, Vibration, Harshness) of the vehicle and improve the driving experience of the vehicle.

[0038] In a second aspect, the present application provides an electrical device, comprising a battery provided in any one of the first aspects, wherein the battery is used to provide electrical energy.

[0039] The above description is only an overview of the technical solution of the embodiment 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

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a schematic diagram of the structure of a vehicle in some embodiments of the present application;

[0042] Figure 2 A three-dimensional exploded view of a battery in some embodiments of the present application;

[0043] Figure 3 A three-dimensional diagram of the partial structure of the bottom guard plate and the box body in some embodiments of the present application;

[0044] Figure 4 This is a schematic diagram of the structure of the partial structure of the bottom guard plate and the box body in some embodiments of the present application;

[0045] Figure 5 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;

[0046] Figure 6 for Figure 5 The enlarged view of point A in the middle;

[0047] Figure 7 It is a schematic diagram of the internal structure of the partial structure of the bottom guard plate in other embodiments of the present application;

[0048] Figure 8 It is an internal schematic diagram of a partial structure of a bottom guard plate in some other embodiments of the present application;

[0049] Fig. 9 This is a three-dimensional exploded view of the bottom guard plate in some embodiments of the present application;

[0050] Fig.10 for Fig. 9 The enlarged view of point B in the middle;

[0051] Fig.11 It is a partial schematic diagram of the internal structure of the bottom guard plate in some embodiments of the present application;

[0052] Fig.12 It is a three-dimensional exploded view of the bottom guard plate in some other embodiments of the present application;

[0053] Fig.13 for Fig.12 Enlarged view of point C in the middle;

[0054] Fig.14 This is a schematic diagram of the structure of the bottom guard plate in other embodiments of the present application.

[0055] Icon: 100-battery; 10-casing; 11-lower casing; 12-upper casing; 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

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0058] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0059] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0060] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0061] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0062] The term "plurality" used in the present application refers to two or more (including two).

[0063] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0064] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0065] For electric vehicles, battery technology is an important factor related to its development. In the development of battery technology, how to improve the reliability of batteries is a technical problem that needs to be solved urgently.

[0066] The batteries of electric vehicles are generally arranged under the chassis of the vehicle, and the batteries are exposed to a large area under the vehicle. When the vehicle presses on stones, bricks and other materials on the road during driving, these materials will splash or hit the bottom of the battery; when the vehicle goes uphill, the bottom of the battery is also easy to scrape the ground; or when passing by speed bumps or hitting curbs, it is also easy to cause damage to the bottom of the battery. 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 function 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 protect the battery cells in the box. In order 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 to form a bottom guard plate.

[0067] However, the current bottom guard plate is in the shape of a flat plate, which has low impact resistance and cannot provide effective protection for the battery cells in the box, thus affecting the reliability of the battery.

[0068] In view of this, in order 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 box, some embodiments of the present application provide a battery, the battery includes a box and a bottom guard plate. The bottom guard plate is connected to the box. The bottom guard plate is a multi-layer structure, and a buffer cavity is formed between the bottom guard plate and the box and / or between two adjacent layers of the bottom guard plate.

[0069] 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.

[0070] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0071] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a new energy vehicle, which may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0072] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0073] Figure 1 This is a schematic diagram of the structure of a vehicle in some embodiments of the present application.

[0074] A controller 200, a motor 300 and a battery 100 may be disposed inside the vehicle 1000, and the controller 200 is used to control the battery 100 to power the motor 300. For example, the battery 100 may be disposed 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 be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1000. In another embodiment of the present application, the battery 100 may not only be used as an operating power source for the vehicle 1000, but may also be used 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.

[0075] According to some embodiments of the present application, a battery 100 is provided. Figure 2-Figure 6 , Figure 2 This is a three-dimensional exploded view of a battery 100 in some embodiments of the present application. Figure 3 This is a three-dimensional diagram of the partial structure of the bottom guard plate 30 and the box body 10 in some embodiments of the present application. Figure 4 Schematic diagram of the structure of the bottom guard plate 30 and the local structure of the box body 10 in some embodiments of the present application. Figure 5Schematic diagram of the internal structure of the bottom guard plate 30 and the partial structure of the box body 10 in some embodiments of the present application. Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0076] The battery 100 includes a box body 10 and a bottom guard plate 30. The bottom guard plate 30 is connected to the box body 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 box body 10 and / or between two adjacent layers of the bottom guard plate 30.

[0077] In some embodiments, the box 10 can provide a chamber for the battery cell 20, or the box 10 and the bottom guard plate 30 can jointly provide a chamber for the battery cell 20. The box 10 can adopt a variety of structures. Figure 2 In some embodiments, the box 10 may include a lower box 11 and an upper box 12, the lower box 11 and the upper box 12 cover each other, and the lower box 11 and the upper box 12 jointly define a chamber for accommodating the battery cell 20. The lower box 11 may be a hollow structure with one end open, and the upper box 12 may be a plate-like structure, and the upper box 12 covers the open side of the lower box 11, so that the lower box 11 and the upper box 12 jointly define a chamber; the lower box 11 and the upper box 12 may also be hollow structures with one side open, and the open side of the lower box 11 covers the open side of the upper box 12. Of course, the box 10 formed by the lower box 11 and the upper box 12 may be in various shapes, such as a cylinder, a cuboid, etc. In some embodiments, the connection relationship 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 may be disposed at the bottom of the lower box body 11 , and the connection relationship between the bottom guard plate 30 and the lower box body 11 includes but is not limited to riveting, welding, screw connection or other connection methods.

[0078] In some embodiments, the box body 10 may include an upper box body 12 and a lower box body 11, the bottom of the lower box body 11 is hollowed out, and the bottom guard plate 30 is disposed at the bottom of the lower box body 11, so that the bottom guard plate 30, the lower box body 11 and the upper box body 12 together define a chamber for accommodating the battery cell 20. For example, see Figure 3 The lower box body 11 of the box body 10 includes a plurality of side walls, which are connected end to end in sequence to form a frame, in which a plurality of cross beams are arranged. The bottom guard plate 30 is arranged at the bottom of the lower box body 11 and is connected to the plurality of side walls and the plurality of cross beams through a first connecting member 50.

[0079] 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 (such as a bolt), or each battery cell 20 may be fixed to the housing 10 by bonding. The electrode lead-out portions of the plurality of battery cells 20 may be connected by a current collecting member.

[0080] “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-metal 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-metal 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 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.

[0081] The "buffer cavity 40" can be understood as a space that allows the bottom guard plate 30 to deform when impacted. For example, when the bottom of the battery 100 is impacted, the impact causes the bottom guard plate 30 to deform. Because the buffer is provided, the deformed part may not contact other structures 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 a groove or depression on the surface of the structural layer.

[0082] “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 a variety of positions, and one possible solution is that the buffer cavity 40 is arranged between the bottom guard plate 30 and the box body 10, for example, see Figure 6 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, which 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.

[0083] 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 body 10 can be reduced, so that the battery 100 has higher reliability.

[0084] 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 which are stacked together. The first protective layer 31 is arranged on a side of the metal layer 32 close to the box body 10, and the second protective layer 33 is arranged on a side of the metal layer 32 away from the box body 10.

[0085] In some embodiments, the bottom guard plate 30 may be a three-layer structure, which includes a first protective layer 31, a metal layer 32, and a second protective layer 33. The material of the metal layer 32 includes, but is not limited to, steel, aluminum, aluminum alloy, and the like. In some embodiments, the metal layer 32 may be a metal material having good rigidity and ductility. The first protective layer 31 and the second protective layer 33 may be made of non-metallic materials, and the first protective layer 31 and the second protective layer 33 may have a certain structural strength, which may effectively prevent damage such as the impact of gravel at the bottom, and may reduce the risk of the internal metal layer 32 being corroded by the external environment. Exemplarily, the first protective layer 31 and the second protective layer 33 may be composite material layers, for example, the manufacturing material of the first protective layer 31 and the second protective layer 33 includes a fiber-reinforced non-metallic material, and the matrix resin of the first protective layer 31 and the second protective layer 33 may be a thermoplastic resin such as PP (polypropylene) and PA (polyamide), or may be a thermosetting resin such as epoxy or polyurethane; the fiber may be glass fiber, carbon fiber, or basalt fiber, etc.

[0086] 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 size of the metal layer 32 is smaller than the size of 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.

[0087] The first protective layer 31 is the structural layer closest to the box body 10 among the three-layer structure of the bottom guard plate 30, and the second protective layer 33 is the structural layer farthest from the box body 10 among the three-layer structure of the bottom guard plate 30. In some embodiments, the relationship between the bottom guard plate 30 and the box body 10 includes that the first protective layer 31 is bonded, clamped or riveted to the box body 10, or the connecting member passes through the second protective layer 33, the metal layer 32 and the first protective layer 31 to connect with the box body 10, or the connecting member passes through the second protective layer 33 and the first protective layer 31 to connect with the box body 10.

[0088] In the above scheme, 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, so that the bottom guard plate 30 has higher reliability, thereby improving the reliability of the battery 100.

[0089] According to some embodiments of this application, see Figure 6-Figure 8 , Figure 7 Schematic diagram of the internal structure of the bottom guard plate 30 in some other embodiments of the present application. Figure 8It is a schematic internal diagram of the local structure of the bottom guard plate 30 in some other embodiments of the present application.

[0090] At least one of the following conditions must be met:

[0091] The buffer cavity 40 is formed between the first protective layer 31 and the box body 10;

[0092] The buffer cavity 40 is formed between the first protection layer 31 and the metal layer 32;

[0093] The buffer cavity 40 is formed between the metal layer 32 and the second protection layer 33 .

[0094] In some embodiments, see Figure 6 "The buffer cavity 40 is formed between the first protective layer 31 and the box body 10" can be understood as providing a groove or a pit at one or more positions on the surface of the first protective layer 31 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 box body 10. Exemplarily, three spaced pits can be provided on the surface of the first protective layer 31 away from the metal layer 32. When the bottom guard plate 30 is impacted and deformed, the three pits can accommodate the deformed parts of the bottom guard plate 30 to reduce the impact of the deformed parts on the battery cell 20. Exemplarily, the first protective layer 31 can form a pit on the surface 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.

[0095] In other embodiments, see Figure 7 "The 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, and the gap can form at least part of the buffer cavity 40 to accommodate the part of the bottom guard plate 30 that is deformed by impact, so as to reduce the impact of the deformed part on the battery cell 20. Exemplarily, the formation of at least part of the buffer cavity 40 may include but is not limited to providing a groove or a pit on the surface of the first protective layer 31 facing the metal layer 32, and providing a groove or a pit on the surface of the metal layer 32 facing the first protective layer 31.

[0096] In some other embodiments, see Figure 8 "The 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, and the gap can form at least part of the buffer cavity 40 to accommodate the part of the bottom guard plate 30 that is deformed by impact, so as to reduce the impact of the deformed part on the battery cell 20. Exemplarily, the formation of at least part of the buffer cavity 40 may include but is not limited to providing a groove or a pit on the surface of the second protective layer 33 facing the metal layer 32, and providing a groove or a pit on the surface of the metal layer 32 facing the second protective layer 33.

[0097] In some embodiments, a groove or pit may be formed on the surface of the first protective layer 31 that is away from the metal layer 32. At the same time, a gap may be formed between the first protective layer 31 and the metal layer 32. At the same time, a gap may 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 portion is located between the metal layer 32 and the second protective layer 33.

[0098] In the above scheme, a variety of buffer chamber 40 arrangements are provided, which can provide a variety of options for the manufacture of the battery 100 and adapt to different impact situations. For example, by arranging the buffer chamber 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 absorb the impact first, and then use the buffer chamber 40 to collapse and deform to absorb energy, so that when encountering a smaller impact, the risk of the entire bottom guard plate 30 being scrapped due to the buffer chamber 40 being broken or broken can be reduced. For example, by arranging the buffer chamber 40 between the metal layer 32 and the second protective layer 33, the impact can be absorbed at a relatively outer position of the battery 100, which can effectively reduce the impact on the internal structure of the box body 10.

[0099] In the above scheme, a variety of buffer chamber 40 arrangements are provided, which can provide a variety of options for the manufacture of the battery 100 and adapt to different impact situations. For example, by arranging the buffer chamber 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 absorb the impact first, and then use the buffer chamber 40 to collapse and deform to absorb energy, so that when encountering a smaller impact, the risk of the entire bottom guard plate 30 being scrapped due to the buffer chamber 40 being broken or broken can be reduced. For example, by arranging the buffer chamber 40 between the metal layer 32 and the second protective layer 33, the impact can be absorbed at a relatively outer position of the battery 100, which can effectively reduce the impact on the internal structure of the box body 10.

[0100] According to some embodiments of this application, see Figure 6 , Fig. 9 and Fig.10 , Fig. 9 This is a three-dimensional exploded view of the bottom guard plate 30 in some embodiments of the present application. Fig.10 for Fig. 9 Enlarged view of point B in the middle.

[0101] 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 box body 10. At least a portion of the first body 310 protrudes from the first flange 311 in a direction away from the box body 10, and the buffer cavity 40 is formed between the first body 310 and the box body 10.

[0102] 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 the first flange 311 is connected to the box 10. Exemplarily, the first flange 311 is connected to the box 10 by bolts.

[0103] “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 that is 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 positions corresponding to the surface of the first body 310 that is away from the box body 10.

[0104] In the above solution, the first protective layer 31 has a simple structure and can be effectively connected to the box body 10 through the first flange portion 311. By setting at least a portion of the first body 310 to protrude toward the side away from the box body 10, a recessed area can be formed on the side facing the box body 10, thereby forming a buffer cavity 40 between the box body 10 and the first protective layer 31 to alleviate the impact on the bottom of the battery 100, so that the battery 100 has higher reliability.

[0105] According to some embodiments of this application, see Figure 6 , Fig. 9 and Fig.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.

[0106] 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 .

[0107] “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 sunken compared to the plane where the second flange portion 321 is located, so as to accommodate the protrusion of the first body 310.

[0108] “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 .

[0109] In some embodiments, the metal layer 32 and the first protective layer 31 may be connected as a whole by bonding, clamping, etc. In some embodiments, the metal layer 32 may be sandwiched between the first protective layer 31 and the second protective layer 33, and 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.

[0110] In the above solution, the outer contour of the metal layer 32 can match the outer contour of the first protective layer 31, and 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. The metal layer 32 can be closely attached to the first protective layer 31, so that the bottom guard plate 30 has a stable structure and high space utilization, thereby making the space utilization of the battery 100 high, which is conducive to improving the volume energy density of the battery 100.

[0111] 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 .

[0112] According to some embodiments of this application, see Figure 6 , Fig. 9 and Fig.10The 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.

[0113] In some embodiments, the outer contour of the second protective layer 33 can be set to 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 is set to correspond to the second body 320 of the metal layer 32, so that the second body 320 can be sandwiched between the third body 330 and the first body 310. The third flange portion 331 of the second protective layer 33 is set to correspond to the second flange portion 321 of the metal layer 32, so that the second flange portion 321 can be sandwiched between the third flange portion 331 and the first flange portion 311.

[0114] “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 sunken compared to the plane where the third flange portion 331 is located, so as to accommodate the protrusion of the second body 320.

[0115] For example, see Fig. 9 The number of protrusions on the surface of the third body 330 facing away from the metal layer 32 is three, and the corresponding pits of 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.

[0116] 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 .

[0117] In the above scheme, the outer contour of the metal layer 32 can be matched with the outer contour of the first protective layer 31 and the metal layer 32. By providing a third body 330 that is in contact with the second body 320 and a third flange portion 331 that is in contact 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.

[0118] In some other embodiments, the third protective layer may be in the shape of a 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 may accommodate the first body 310 and the second body 320 .

[0119] According to some embodiments of this application, see Fig.10 and Fig.11 , Fig.11 This is a partial schematic diagram of the internal structure of the bottom guard plate 30 in some embodiments of the present application.

[0120] The second flange portion 321 is provided with a first through hole 3210, and the bottom guard plate 30 also includes a first protection portion 34, which is arranged in the first through hole 3210 and connects the first protection layer 31 and the second protection layer 33, and the bottom guard plate 30 is provided with a second through hole 340 that penetrates the first protection layer 31, the first protection portion 34 and the second protection layer 33.

[0121] In some embodiments, along the stacking direction of the first protective layer 31, the metal layer 32 and the second protective layer 33, the second flange portion 321 is provided with a through first through hole 3210, and the first protective portion 34 is provided in the first through hole 3210 to connect 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, and the first protective layer 31 and the second protective layer 33 are blended into one at the position corresponding to the first through hole 3210 by hot pressing, and the blended position can be the first protective portion 34. In some other embodiments, the first protective portion 34 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 as one, and at the position corresponding to the first through hole 3210, the first protective portion 34 is formed by bonding or welding to connect the first protective layer 31 and the second protective layer 33.

[0122] 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 passing bolts through the second through hole 340.

[0123] 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.

[0124] In some embodiments, the aperture of the second through hole 340 may be smaller than the aperture 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 .

[0125] In the above solution, by providing the first through hole 3210 and the first protection part 34, on the one hand, the first protection part 34 can be connected to the first protection layer 31 and the second protection layer 33 through the first through hole 3210, and on the other hand, the first protection part 34 can cover the hole wall of the first through hole 3210, thereby reducing the risk of corrosion of the metal layer 32, thereby improving the reliability of the battery 100. At the same time, by providing the second through hole 340, the connecting member (such as a bolt, a screw, etc.) can pass through the second through hole 340 to assemble the bottom guard plate 30 at the bottom of the box body 10, thereby realizing the assembly of the bottom guard plate 30 and the box body 10.

[0126] 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.

[0127] According to other embodiments of the present application, see Fig.12 and Fig.13 , Fig.12 This is a three-dimensional exploded view of the bottom guard plate 30 in some other embodiments of the present application. Fig.13 for Fig.12 Enlarged view of point C in the middle.

[0128] The first through hole 3210 extends to the outer circumferential surface of the second flange portion 321 .

[0129] 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 .

[0130] 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.

[0131] 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.

[0132] According to some embodiments of this application, see Fig.11 The bottom guard plate 30 also includes a second protection portion 35 , which wraps the outer circumference of the second flange portion 321 , and the second protection portion 35 connects the first protection layer 31 and the second protection layer 33 .

[0133] In some embodiments, the size of the metal layer 32 may be smaller than the size of the first protective member and the second protective member. For example, there is a gap 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. The second protective member may be provided at this gap. 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 compounding process, the sizes of the first protective layer 31 and the second protective layer 33 are relatively large. 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 part may 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 to connect the first protective layer 31 and the second protective layer 33.

[0134] According to some embodiments of the present application, along a direction perpendicular to the outer peripheral surface 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.

[0135] See also Fig.11 , along a direction perpendicular to the outer peripheral surface of the metal layer 32 , the thickness of the second protection portion 35 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.

[0136] 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.

[0137] 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 causing the bottom guard plate 30 to have a lower structural strength. 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.

[0138] 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.

[0139] 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.

[0140] In the above scheme, 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.

[0141] According to some embodiments of this application, please combine Figure 4 and Figure 6 The second protective layer 33 includes a third body 330 and a third flange 331. The third flange 331 is disposed around the third body 330. At least a portion of the third body 330 protrudes from the third flange 331 in a direction away from the box body 10. The battery 100 further includes a first connector 50. The bottom guard plate 30 is connected to the box body 10 through the first connector 50 and the third flange 331. At least a portion of the third body 330 protrudes from the first connector 50 in a direction away from the box body 10.

[0142] 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.

[0143] The third body 330 is part of the third protective layer. The third flange 331 is disposed around the third body 330 . The first connector 50 passes through the third flange 331 , that is, part of the first connector can protrude from the third flange 331 away from the surface of the box 10 .

[0144] 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 .

[0145] In the above scheme, by setting at least a portion of the third main 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 further making the battery 100 have higher reliability.

[0146] According to some embodiments of the present application, the density of the first protective layer 31 is lower than the density of the metal layer 32 ; and / or the density of the second protective layer 33 is lower than the density of the metal layer 32 .

[0147] In some embodiments, the sealing density of the first protective layer 31 and / or the second protective layer 33 may be lower than the density 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.

[0148] 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 increasing the weight of the bottom guard plate 30 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 influence of the bottom guard plate 30 on the weight energy density of the battery 100.

[0149] 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.

[0150] In some embodiments, the first protective layer 31 and / or the second protective layer 33 are fiber-reinforced non-metallic materials, whose matrix resin 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.

[0151] 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 still another 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.

[0152] According to other embodiments of the present application, see Fig.14 , Fig.14 This is a schematic diagram of the structure of the bottom guard plate 30 in other embodiments of the present application.

[0153] 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 .

[0154] In some embodiments, the foam material layer 60 may include PVC (polyvinyl chloride) foam or polyurethane foam.

[0155] 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.

[0156] In the above scheme, by arranging the foam material layer 60 on the outer side of the bottom guard plate 30, on the one hand, the foam material has a buffering effect, thereby improving the impact resistance of the bottom guard plate 30, and 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.

[0157] According to some embodiments of the present application, there is provided an electrical device, which includes the battery 100 provided above, and the battery 100 is used to provide electrical energy.

[0158] In some embodiments, the electric device may include a vehicle, and the battery 100 may be disposed under a chassis of the vehicle.

[0159] According to some embodiments of the present application, a battery 100 is provided. Figure 2-Figure 13 .

[0160] The battery 100 includes a box body 10 and a bottom guard plate 30, which is arranged at the bottom of the box body 10. The bottom guard plate 30 is a multi-layer structure, which includes a stacked 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.

[0161] 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 box body 10. At least a portion of the first body 310 protrudes from the first flange 311 in a direction away from the box body 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 box body 10. The second body 320 is attached to the first body 310, and the second flange 321 is attached 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.

[0162] A concave pit is formed on the surface of the first body 310 facing the box body 10, so that a buffer cavity 40 is formed between the bottom guard plate 30 and the box body 10. The buffer cavity 40 can alleviate the impact on the bottom guard plate 30, thereby reducing the impact on the structural parts (such as the battery cell 20) in the box body 10. The position of the concave pit corresponds to the position where the first body 310 protrudes from the first flange portion 311 in the direction away from the box body 10.

[0163] The second flange portion 321 of the metal layer 32 is provided with a first through hole 3210, and the first through hole 3210 extends to the outer peripheral surface of the second flange portion 321. The size of the metal layer 32 is smaller than the size of the first protective layer 31 and the second protective layer 33. The first protective layer 31 and the second protective layer 33 are combined into one by hot pressing, and the first protective portion 34 and the second protective portion 35 are formed at the position corresponding to the first through hole 3210 and at the position around the outer periphery of the metal layer 32. The first protective portion 34 is provided with a second through hole 340, and the bolt passes through the second through hole 340 to connect with the box body 10, so as to realize the connection between the bottom guard plate 30 and the box body 10.

[0164] 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 body 10 can be reduced, so that the battery 100 has higher reliability.

[0165] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery, characterized in that: 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, characterized in that The bottom guard plate includes a first protective layer, a metal layer, and a second protective layer which 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, characterized in that 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, characterized in that The first protective layer includes a first body and a first flange portion, the first flange portion is disposed around the first body, and the first flange portion is 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, characterized in that The metal layer includes a second body and a second flange portion, the second flange portion is surrounded by the second body, at least a portion 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, characterized in that 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.

7. The battery according to claim 6, characterized in that 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, 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.

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

9. The battery according to claim 7, characterized in that The bottom guard plate also includes a second protection portion, which wraps around the outer circumference of the second flange portion, and the second protection portion connects the first protection layer and the second protection layer.

10. The battery according to claim 9, characterized in that Along a direction perpendicular to the outer peripheral surface of the metal layer, a 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, characterized in that 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, characterized in that: 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 11, characterized in that: 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 11, characterized in that: 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 11, characterized in that: The bottom guard plate further comprises a foam material layer, and the foam material layer is arranged on a side of the second protective layer away from the metal layer.

16. An electrical device, characterized in that: The battery comprising any one of claims 1 to 15 is used for providing electrical energy.

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