A bottom plate, a battery, a battery pack and an electric device

Abstract

The present application provides a bottom support plate, a battery, a battery pack and an electrical device, relating to the technical field of batteries. The bottom support plate includes a support plate body, and connection holes are provided on the support plate body. The connection holes are used to communicate with explosion-proof valves. Among them, the high-temperature aperture change rate of the connection holes is A, and the high-temperature thickness change rate of the support plate body is B, and 0 < A×B ≤ 0.002. Thus, while ensuring the exhaust effect of the connection holes, the strength of the support plate body at high temperatures is ensured, preventing the support plate body from deforming and blocking the explosion-proof valves, and ensuring the pressure relief effect of the explosion-proof valves.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a base plate, a battery, a battery pack, and an electrical device. Background Technology

[0002] The battery casing typically contains a battery cell and a base plate. The base plate is located between the battery cell and the casing to support the battery cell. In some batteries, the explosion-proof valve is located opposite the casing and the base plate. In this case, the base plate needs to be able to allow gas to pass through in the event of thermal runaway of the battery, so that the gas can smoothly enter the explosion-proof valve.

[0003] The common practice is to set holes corresponding to the explosion-proof valve on the base plate. However, in actual applications, the base plate is usually made of plastic. When the battery thermally runs away, the base plate is prone to deformation, blocking the explosion-proof valve and making it difficult for the explosion-proof valve to effectively relieve pressure. Utility Model Content

[0004] This application provides a base plate, a battery, a battery pack, and an electrical device to solve the problem that existing base plates are prone to deformation during battery thermal runaway, blocking the explosion-proof valve and making it difficult for the explosion-proof valve to effectively relieve pressure.

[0005] In a first aspect, this application provides a base plate for placement inside a battery casing, wherein an explosion-proof valve is provided on the casing, and the base plate includes a base plate body, wherein a connection hole is provided on the base plate body for communicating with the explosion-proof valve;

[0006] Wherein, the high-temperature aperture change rate of the connecting hole is A, and the high-temperature thickness change rate of the tray body is B, 0 <A×B≤0.002;

[0007] The high-temperature aperture change rate is the ratio of the absolute value of the difference between the radial dimension of the connecting hole and the initial radial dimension of the connecting hole (120) after the pallet body is left to stand at 200℃-500℃ for 20-40 minutes to the initial radial dimension of the connecting hole; the high-temperature thickness change rate is the ratio of the absolute value of the difference between the thickness of the pallet body and the initial thickness of the pallet body after the pallet body is left to stand at 200℃-500℃ for 20-40 minutes to the initial thickness of the pallet body.

[0008] In some possible implementations, the tray body is made of polypropylene, phenolic plastic, polyphenylene sulfide, liquid crystal polymer plastic or polyetheretherketone.

[0009] In some possible implementations, the thickness of the pallet body is 0.1mm-5mm.

[0010] In some possible implementations, the energy storage modulus of the pallet body is 100MPa-30000MPa.

[0011] In some possible embodiments, a plurality of the connection holes are provided on the pallet body, and the connection holes extend from the first surface of the pallet body to the second surface of the pallet body. On the first surface, the total area of the plurality of connection holes accounts for 10%-90% of the total area of the first surface.

[0012] In some possible embodiments, the pallet body is provided with a support portion for supporting the battery cell in the housing.

[0013] In some possible embodiments, the distance between one end of the support portion away from the pallet body and the pallet body is 0.1 mm - 1 mm.

[0014] In a second aspect, the present application provides a battery, including a housing, a battery cell, an explosion-proof valve, and the bottom pallet according to any one of the first aspect. The battery cell and the bottom pallet are located in the housing, the explosion-proof valve is provided at the bottom of the housing, and the bottom pallet is located between the battery cell and the explosion-proof valve.

[0015] In some possible embodiments, the area of the explosion-proof valve is 100 mm 2 -1500 mm 2 .

[0016] In a third aspect, the present application provides a battery pack, including the battery according to any one of the second aspect.

[0017] In a fourth aspect, the present application provides an electrical device, including the battery according to any one of the second aspect or the battery pack according to the third aspect.

[0018] In the bottom pallet, battery, battery pack, and electrical device provided by the present application, the bottom pallet is provided with a pallet body, and connection holes communicating with the explosion-proof valve are provided on the pallet body. The high-temperature aperture change rate of the connection holes is A, and the high-temperature thickness change rate of the pallet body is B. When the battery is out of control thermally, the temperature rises, which will cause the size of the connection holes to become larger and the thickness of the pallet body to become smaller. The larger A is, the greater the change in the size of the connection holes; the larger B is, the poorer the support strength of the pallet body. If the support strength of the pallet body is too small, it may cause the battery cell to move downward and block the explosion-proof valve. If 0 < A×B ≤ 0.002, the area of the connection holes after high-temperature deformation can be made appropriate, while ensuring the exhaust effect, the strength of the pallet body will not be too low, and the deformation of the pallet body can be avoided, so as to prevent the explosion-proof valve from being blocked, effectively ensuring the pressure relief effect of the explosion-proof valve and improving the safety of battery use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0020] Figure 1 This is a schematic diagram of the structure of the base plate provided in the embodiments of this application;

[0021] Figure 2 A schematic diagram of the battery structure provided in the embodiments of this application. Figure 1 ;

[0022] Figure 3 A schematic diagram of the battery structure provided in the embodiments of this application. Figure 2 ;

[0023] Figure 4 Partial cross-sectional view of the battery provided in the embodiments of this application Figure 1 ;

[0024] Figure 5 Partial cross-sectional view of the battery provided in the embodiments of this application Figure 2 ;

[0025] Figure 6 for Figure 5 Enlarged schematic diagram of the structure within the dashed box.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100-Base plate;

[0028] 110-pallet body;

[0029] 120 - Connection hole;

[0030] 200-Explosion-proof valve;

[0031] 300 - Housing;

[0032] 400-cell;

[0033] 500-Pole Column.

[0034] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0035] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0036] As described in the background art, the bottom plate is usually made of plastic. When the battery is in thermal runaway, the internal temperature will rise significantly. In this case, the bottom plate is prone to deformation, blocking the explosion-proof valve by the battery cell.

[0037] Specifically, when the battery is in thermal runaway, the internal temperature rises rapidly, and a large amount of gas will be generated by the chemical reaction inside the battery cell, causing the battery cell to expand. At this time, the battery cell may move towards the bottom plate, exerting pressure on the bottom plate. At the same time, the high temperature may cause the bottom plate to deform, and the deformation of the bottom plate will cause the battery cell to move further downward, resulting in the battery cell or the bottom plate possibly directly blocking the explosion-proof valve. Once the battery cell or the bottom plate blocks the explosion-proof valve, causing the explosion-proof valve to fail to open normally, the pressure inside the battery will not be effectively released, which will greatly increase the risk of battery explosion or other dangerous situations, reducing the safety of battery use.

[0038] To avoid the above problems, the bottom plate is provided with a plate body, and a connection hole communicating with the explosion-proof valve is provided on the plate body. The high-temperature aperture change rate of the connection hole is A, and the high-temperature thickness change rate of the plate body is B. When the battery is in thermal runaway, as the temperature rises, the size of the connection hole will increase, and the thickness of the plate body will decrease. The larger A is, the greater the change in the size of the connection hole; the larger B is, the poorer the support strength of the plate body. If the support strength of the plate body is too small, it may cause the battery cell to move downward and block the explosion-proof valve. If 0 < A × B ≤ 0.002, the area of the connection hole after high-temperature deformation can be made appropriate, while ensuring the exhaust effect, the strength of the plate body will not be too low, and excessive deformation of the plate body can be avoided, thereby preventing the explosion-proof valve from being blocked and effectively ensuring the pressure relief effect of the explosion-proof valve, improving the safety of battery use.

[0039] It should be noted that the batteries to which the bottom plate can be applied include but are not limited to lithium-ion batteries, sodium-ion batteries, nickel-metal hydride batteries, and lead-acid batteries.

[0040] The technical solution of the present application and how the technical solution of the present application solves the above technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0041] An embodiment of the present application provides a bottom plate 100, which is applied to a battery. Please refer to Figure 1 、 Figure 2 、 Figure 3 As shown, an explosion-proof valve 200 is provided on the housing 300 of the battery, a battery cell 400 is provided inside the housing 300, and the bottom plate 100 is also provided inside the housing 300, and the bottom plate 100 is located between the battery cell 400 and the explosion-proof valve 200.

[0042] Cell 400 is the core component of the battery, responsible for storing and releasing electrical energy. The base plate 100 is located below cell 400, providing structural support and protection. The explosion-proof valve 200 automatically opens to release pressure when the internal pressure of the battery becomes too high, such as when the internal pressure reaches a specific pressure threshold, preventing the battery from exploding. The explosion-proof valve 200 can be of a common design.

[0043] For example, the explosion-proof valve 200 is a diaphragm type explosion-proof valve 200, which is composed of a thin film or diaphragm. When the internal pressure of the battery rises to a certain level, the diaphragm will be stretched or torn, thereby releasing the pressure and preventing the battery from exploding.

[0044] For example, the explosion-proof valve 200 is a rupture disc type explosion-proof valve 200, which consists of a metal or plastic rupture disc and is installed at a weak point in the housing 300. When the pressure inside the battery reaches the design limit of the rupture disc, the rupture disc will rupture and release the pressure.

[0045] It should be noted that the above is only an example. In actual application, an explosion-proof valve 200 with a suitable structure can be selected according to the battery conditions.

[0046] During installation, the battery cell 400 can be placed on the base plate 100. The base plate 100 maintains a certain gap between the battery cell 400 and the explosion-proof valve 200 to ensure that even if the battery cell 400 expands, it will not directly block the explosion-proof valve 200.

[0047] To ensure the explosion-proof valve 200 can release pressure smoothly, please refer to [link / reference needed]. Figure 1 , Figure 4 , Figure 5 and Figure 6 As shown, the base plate 100 includes a plate body 110, and a connection hole 120 is provided on the plate body 110. The connection hole 120 is used to communicate with the explosion-proof valve 200. When the pressure inside the battery is too high, the pressure can be released through the connection hole 120 and the explosion-proof valve 200.

[0048] It should be noted that the connection hole 120 can be of any shape, such as a round hole, a square hole, an oval hole, or other common shapes, as long as it can connect to the explosion-proof valve 200.

[0049] Among them, the high-temperature aperture change rate of the connecting hole 120 is A, and the high-temperature thickness change rate of the support plate body 110 is B, where 0 < A×B ≤ 0.002. The larger the high-temperature aperture change rate A of the connecting hole 120, the poorer the support strength of the support plate body 110. At this time, it is required that the high-temperature thickness change rate B of the support plate body 110 is smaller. The relationship between A and B can be effectively limited by the value range of A×B, so as to ensure the exhaust effect while ensuring the strength of the support plate body 110 at high temperature, and avoid the deformation of the support plate body 110 from blocking the explosion-proof valve 200 to ensure the pressure relief effect of the explosion-proof valve 200.

[0050] It should be noted that the high-temperature change rate usually refers to the rate of change of the physical or chemical properties of a material under high-temperature conditions. Here, the high-temperature aperture change rate refers to the aperture of the connecting hole 120, that is, the change in the radial dimension, and the high-temperature thickness change rate refers to the change in the thickness of the support plate body 110.

[0051] Specifically, the high-temperature aperture change rate A of the connecting hole 120 and the high-temperature thickness change rate B of the support plate body 110 can be measured in the following way:

[0052] According to the usage scenario, determine the aperture of the connecting hole 120 to be tested and the thickness of the support plate body 110, and then prepare multiple support plate bodies 110 with the same size using the same material, and set connecting holes 120 with the same size at the same position of each support plate body 110;

[0053] Place multiple support plate bodies 110 under the same test conditions, and the test conditions include: the same high temperature, such as 200°C - 500°C, the same pressure applied to the support plate body 110 (the pressure can be adjusted according to the actual situation, usually greater than or equal to 0 kg), and the same placement time, such as 20 min - 40 min;

[0054] Finally, test the aperture of the connecting hole 120 and the thickness of the support plate body 110, and compare them with the initial aperture and the thickness of the support plate body 110 to obtain the absolute value of the difference between the finally tested aperture and the initial aperture, and the absolute value of the difference between the finally tested thickness and the initial thickness. The ratio of the absolute value of the difference between the finally tested thickness and the initial thickness to the initial thickness is the high-temperature deformation rate B1 of the corresponding support plate body 110, and the ratio of the absolute value of the difference between the finally tested aperture and the initial aperture to the initial aperture is the high-temperature deformation rate A1 of the corresponding connecting hole 120;

[0055] Average all B1 values to obtain the high-temperature thickness change rate B of the support plate body 110, and average all A1 values to obtain the high-temperature aperture change rate A of the connecting hole 120.

[0056] To improve the measurement accuracy, the number of pallet bodies 110 for each experiment can be appropriately increased, such as 4, 5 or more.

[0057] Exemplarily, assume that the current battery requires a pallet body 110 with a thickness of 0.3 - 3 mm, and a round hole with a diameter of 4 mm is provided on the pallet body 110 as the connection hole 120. Then, at this time, the high-temperature aperture change rate A of the connection hole 120 and the high-temperature thickness change rate B of the pallet body 110 can be obtained in the following manner:

[0058] Prepare 4 rectangular sheets with an area of 10 mm × 10 mm as the pallet bodies 110 to be tested. The thickness of the pallet body 110 is one value within the range of 0.3 - 3 mm. Of course, the thicknesses of the 4 pallet bodies 110 to be tested are the same;

[0059] Open a round hole with a diameter of 4 mm at the center of each pallet body 110 to be tested;

[0060] Arrange the 4 pallet bodies 110 to be tested into a 100 mm × 100 mm square according to the outer edge contour, with a regular shape and tight fitting, so as to facilitate applying pressure to the pallet bodies 110 to be tested later;

[0061] Use a cuboid with a projection size of 100 mm × 100 mm and a weight of 3.5 kg - 35 kg (the weight can be adjusted according to the pressure that the pallet body 110 needs to bear during application) to press on the 4 pallet bodies 110 to be tested;

[0062] Place the 4 pallet bodies 110 pressed by the cuboid in a high temperature of 300 °C (the temperature can be adjusted according to the thermal runaway temperature of the battery using the pallet body 110) for 30 min (the time can be adjusted according to the actual situation);

[0063] Take out the 4 pallet bodies 110 to be tested, measure the aperture of the connection hole 120 and the thickness of the pallet body 110, and then calculate the high-temperature aperture change rate A of the connection hole 120 and the high-temperature thickness change rate B of the pallet body 110.

[0064] Under this condition, the high-temperature aperture change rate A is usually 0.1% - 2%, and the high-temperature thickness change rate B is 0.1% - 10%. Then, limit the connection hole 120 and the pallet body 110 according to 0 < A × B ≤ 0.002 to ensure the pressure relief effect.

[0065] It can be understood that at different temperatures, different pressures and different standing times, the measured values of A and B are different, as long as 0 < A × B ≤ 0.002 is ensured.

[0066] It should be noted that the above example is only an illustration of the measurement method of the high-temperature aperture change rate A of the connecting hole 120 and the high-temperature thickness change rate B of the tray body 110. Other feasible methods can also be used for measurement, as long as the consistency and stability of the test are guaranteed.

[0067] During use, the battery cell 400 is placed on the tray body 110. The tray body 110 needs to withstand a certain amount of pressure. If the battery thermally runs away and the internal temperature rises to a high range, it will cause the tray body 110 to deform, its thickness to change, and the connection hole 120 to also deform, and its area to increase. If the tray body 110 deforms too much, it will become very thin. After the battery cell 400 expands at high temperature, it will easily block the explosion-proof valve 200, preventing the explosion-proof valve 200 from releasing pressure normally.

[0068] By adjusting the high-temperature aperture change rate A of the connection hole 120 and the high-temperature thickness change rate B of the tray body 110, it is possible to ensure that the size expansion of the connection hole 120 is appropriate, so that gas can pass through effectively. At the same time, it is possible to ensure that the thickness change of the tray body 110 is appropriate, so that the explosion-proof valve 200 will not be blocked by the tray body 110 and the battery cell 400 due to severe deformation of the tray body 110. This can effectively ensure the pressure relief effect of the explosion-proof valve 200 and improve the safety of battery use.

[0069] It should be noted that the methods for adjusting the high-temperature aperture change rate A of the connecting hole 120 and the high-temperature thickness change rate B of the pallet body 110 are well known to those skilled in the art. For example, the shape of the pallet body 110 can be changed, reinforcing ribs can be added, the thickness can be adjusted, or the aperture of the connecting hole 120 can be changed or a reinforcing structure can be added around the connecting hole 120, or the type of existing material used to make the pallet body 110 can be changed. These methods will not be elaborated here.

[0070] In some embodiments of this application, the thickness of the tray body 110 is 0.1mm-5mm.

[0071] This thickness is suitable for the use requirements of most common batteries, while also ensuring that the tray body 110 maintains appropriate strength and avoids excessive thickness change rate of the tray body 110 at high temperatures.

[0072] Furthermore, the pallet body 110 can be made of polypropylene, phenolic plastic, polyphenylene sulfide, liquid crystal polymer plastic or polyetheretherketone.

[0073] These materials can generally maintain their original shape well below 200℃ without deformation. Furthermore, by adjusting the ratio of each material, their heat distortion temperature can be increased. Thus, by selecting different materials to prepare the pallet body 110, the high-temperature thickness change rate B of the pallet body 110 can be changed to a certain extent.

[0074] Furthermore, the energy storage modulus of the pallet body 110 is 100MPa-30000MPa.

[0075] Storage modulus is a measure of a material’s ability to resist deformation. The higher the value of storage modulus, the more rigid the material is and the less likely it is to deform. The storage modulus is used to limit the material used in the pallet body 110 and ensure the strength of the pallet body 110.

[0076] The energy storage modulus can be obtained through DMA (Dynamic Mechanical Analysis) testing. For example, during the test, a small oscillating stress with an oscillation frequency of 1Hz is applied to the pallet body 110 at a normal temperature environment, such as 21℃-25℃, and the strain response of the pallet body 110 is measured to obtain the value of the energy storage modulus.

[0077] For example, the energy storage modulus of the pallet body 110 can be adjusted by selecting different materials to make the pallet body 110. The pallet body 110 can provide good support and protection for the battery cell 400 in the range of 100MPa-30000MPa.

[0078] In some embodiments of this application, a plurality of connection holes 120 are provided on the tray body. The connection holes 120 extend from the first surface of the tray body 110 to the second surface of the tray body 110. On the first surface, the total area of ​​the plurality of connection holes 120 accounts for 10%-90% of the total area of ​​the first surface.

[0079] Specifically, the pallet body 110 can have multiple connection holes 120 evenly distributed across its entire surface, rather than just the corresponding positions of the explosion-proof valve 200. This saves costs and also allows for adjustments to the strength of the pallet body 110. Furthermore, having multiple connection holes 120 ensures that even if the pallet body 110 deforms due to high temperatures and the connection holes 120 corresponding to the explosion-proof valve 200 shift, there will still be connection holes 120 available to connect to the explosion-proof valve 200, further guaranteeing the pressure relief effect.

[0080] The connecting hole 120 extends along the thickness direction of the tray body 110. The connecting hole 120 has common structures such as round hole and square hole. The size and shape of the connecting hole 120 are consistent along the thickness direction of the tray body 110. The first surface and the second surface are the two large surfaces at both ends of the thickness direction of the tray body 110. The ratio of the total area of ​​all the ports of the connecting holes 120 at one end of the first surface to the total area of ​​the first surface is 10%-90%. Of course, the surface areas of the first surface and the second surface are usually the same. Therefore, the ratio of the total area of ​​all the ports of the connecting holes 120 at one end of the second surface to the total area of ​​the second surface is also 10%-90%. As long as the total area of ​​the connecting holes 120 is controlled within this range, the strength of the tray body 110 can be guaranteed, and the support and protection effect of the tray body 110 on the battery cell 400 can be avoided. At this time, the number and position of the connecting holes 120 can be adjusted arbitrarily.

[0081] For some embodiments of this application, please refer to Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the tray body 110 is also provided with a support part for supporting the battery cell 400.

[0082] The support part contacts the bottom of the battery cell 400 and can be used to fix and support the battery cell 400, prevent the battery cell 400 from being displaced or damaged due to vibration or impact, and ensure the stability and safety of the battery cell 400 within the housing 300.

[0083] For example, the support portion can be a protruding columnar, rib-shaped or other geometrically shaped component of the tray body 110 facing the battery cell 400, and the specific shape of the support portion can be adjusted according to the shape and size of the battery cell 400.

[0084] The support and the battery cell 400 can be fixed together using adhesives or other common methods such as mechanical fixing. When using adhesives, the adhesive can be applied to the surfaces of the support and the battery cell 400 in contact to increase friction and improve the fixing effect. When using mechanical fixing, screws or clips can be used to fix the battery cell 400 to the support, improving stability.

[0085] In addition, cushioning materials, such as rubber pads, can be added to the surface of the support to better absorb vibration and impact and protect the battery cell 400.

[0086] In some embodiments of this application, the distance between the end of the support portion away from the tray body 110 and the tray body 110 is 0.1mm-1mm.

[0087] That is, the distance between the bottom of the battery cell 400 and the surface of the tray body 110 facing the battery cell 400 is 0.1mm-1mm. This provides sufficient distance between the battery cell 400 and the tray body 110. Even if the tray body 110 deforms due to high temperature, this distance can provide sufficient space for the battery cell 400 to move, further reducing the probability of the battery cell 400 blocking the explosion-proof valve 200 and ensuring the pressure relief effect of the explosion-proof valve 200.

[0088] High-temperature pore size change rate A High-temperature pore size change rate A High-temperature thickness change rate B This application embodiment also provides a battery, including a casing 300, a cell 400, an explosion-proof valve 200 and the bottom support plate 100 in the above embodiment.

[0089] The explosion-proof valve 200 is located at the bottom of the housing 300, the battery cell 400 and the base plate 100 are located inside the housing 300, the battery cell 400 is placed on the base plate 100 and is supported and protected by the base plate 100, and at the same time, the connection hole 120 on the base plate 100 is at least partially connected to the explosion-proof valve 200 for pressure relief.

[0090] The top or side of the housing 300 may also be provided with a pole post 500, which is connected to the tab of the battery cell 400.

[0091] Furthermore, the area of ​​the explosion-proof valve 200 is 100 mm². 2 -1500mm 2 The area of ​​the explosion-proof valve 200 refers to the effective flow area of ​​the valve, which reflects the opening size of the explosion-proof valve 200 when depressurizing, as well as the fluid flow rate it can handle.

[0092] The area of ​​the explosion-proof valve 200 is 100mm². 2 -1500mm 2 At the same time, it can keep the rate at which the explosion-proof valve 200 releases gas within a suitable range, avoiding other safety problems caused by excessively rapid release, and also avoiding excessively slow release, which would prevent effective pressure relief.

[0093] This application also provides a battery pack, including the battery described in the above embodiments.

[0094] It should be noted that battery packs typically also include components such as a casing and a battery management system. The battery is located inside the casing, and the battery management system can monitor the battery status in real time to ensure that the battery operates within a safe operating range.

[0095] This application embodiment also provides an electrical device, including the battery or battery pack in the above embodiments, the battery or battery pack being used to power the electrical device, and the electrical device having the energy to operate.

[0096] It should be noted that electrical equipment includes, but is not limited to, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, drones, energy storage systems, medical equipment, power tools, robots, and aerospace equipment.

[0097] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0098] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A base plate (100) for placement within a battery casing (300), wherein an explosion-proof valve (200) is provided on the casing (300), characterized in that, The bottom support plate (100) includes a support plate body (110), and the support plate body (110) is provided with a connection hole (120), which is used to communicate with the explosion-proof valve (200); Wherein, the high-temperature aperture change rate of the connecting hole (120) is A, and the high-temperature thickness change rate of the tray body (110) is B, 0 <A×B≤0.002; The high-temperature aperture change rate is the ratio of the absolute value of the difference between the radial dimension of the connecting hole (120) and the initial radial dimension of the connecting hole (120) after the pallet body (110) has been placed at 200℃-500℃ for 20-40 minutes to the initial radial dimension of the connecting hole (120); the high-temperature thickness change rate is the ratio of the absolute value of the difference between the thickness of the pallet body (110) and the initial thickness of the pallet body (110) after the pallet body (110) has been placed at 200℃-500℃ for 20-40 minutes to the initial thickness of the pallet body (110).

2. The base plate (100) according to claim 1, characterized in that, The tray body (110) is made of polypropylene, phenolic plastic, polyphenylene sulfide, liquid crystal polymer plastic or polyether ether ketone.

3. The base plate (100) according to claim 1, characterized in that, The thickness of the pallet body (110) is 0.1mm-5mm.

4. The base plate (100) according to claim 1, characterized in that, The energy storage modulus of the pallet body (110) is 100MPa-30000MPa.

5. The base plate (100) according to claim 1, characterized in that, The pallet body (110) is provided with a plurality of connection holes (120), which extend from the first surface of the pallet body (110) to the second surface of the pallet body (110). On the first surface, the total area of ​​the plurality of connection holes (120) accounts for 10%-90% of the total area of ​​the first surface.

6. The base plate (100) according to claim 1, characterized in that, The tray body (110) is provided with a support portion for supporting the battery cell (400) inside the housing (300).

7. The base plate (100) according to claim 6, characterized in that, The distance between the end of the support part away from the tray body (110) and the tray body (110) is 0.1mm-1mm.

8. A battery, characterized in that, The device includes a housing (300), a battery cell (400), an explosion-proof valve (200), and a base plate (100) according to any one of claims 1-7. The battery cell (400) and the base plate (100) are located inside the housing (300), the explosion-proof valve (200) is located at the bottom of the housing (300), and the base plate (100) is located between the battery cell (400) and the explosion-proof valve (200).

9. The battery according to claim 8, characterized in that, The explosion-proof valve (200) has an area of ​​100 mm². 2 -1500mm 2 .

10. A battery pack, characterized in that, Includes the battery as described in claim 8 or 9.

11. An electrical appliance, characterized in that, Includes the battery as described in claim 8 or 9, or the battery pack as described in claim 10.

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