Battery pack and electric device

Abstract

The embodiment of the application is applied to the field of batteries, and specifically provides a battery pack and a power consumption device. The battery pack comprises a battery group, a battery support and a blocking plate. The battery group comprises at least one battery monomer, and the bottom surface of the battery monomer is provided with an explosion-proof valve. The battery support is arranged below the battery group, and the battery support is provided with a through hole corresponding to the position of the explosion-proof valve of the battery monomer. The blocking plate is arranged below the battery support, and a containing cavity is formed between the through hole of the battery support and the blocking plate. A buffer layer is arranged in the containing cavity. The projection of the explosion-proof valve in the height direction of the battery monomer is located in the projection of the buffer layer in the height direction of the battery monomer. The thickness of the buffer layer is A mm, the distance between two adjacent explosion-proof valves is E mm, and A×E satisfies 8≤A×E≤30. The battery pack can buffer high-temperature and high-pressure fluid by using the buffer layer, and prevent the spread of thermal runaway of adjacent battery monomers.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a battery pack and an electrical device. Background Technology

[0002] During battery operation, factors such as overcharging, external short circuits, or high-temperature environments can induce thermal runaway. During thermal runaway, violent exothermic chemical reactions occur inside the battery, generating large amounts of high-temperature, high-pressure fluids. The accumulation of these gases within the sealed casing can lead to casing rupture and explosion, posing a safety risk.

[0003] To mitigate such risks, batteries are typically equipped with explosion-proof valves. When the internal pressure exceeds the preset opening threshold of the explosion-proof valve, it ruptures, creating a pressure relief channel to release the high-pressure gas into the external environment. Some battery systems place the explosion-proof valve at the bottom of the casing. This is to deflect the ejection direction away from the main electrical component area, preventing the high-temperature, high-speed gas from directly impacting electrical connections or insulation structures. This reduces the risk of short circuits or insulation degradation caused by the ejection, achieves spatial isolation between the heat source and electrical areas, and improves system safety.

[0004] However, in some current battery pack designs, if a single cell experiences thermal runaway and triggers the opening of the explosion-proof valve, the ejected high-temperature, high-pressure fluid will spread along the mounting gap between the battery and the base plate. If this ejected fluid reaches the explosion-proof valve area of ​​an adjacent battery, it may cause a chain reaction of explosion-proof valve ruptures through heat conduction or pressure impact, leading to a chain reaction of thermal runaway and posing a serious threat to the overall safety of the battery system. Utility Model Content

[0005] In view of this, the present application aims to provide a battery pack and electrical equipment to solve the technical problem that the high-temperature and high-pressure fluid ejected from the explosion-proof valve of a certain battery cell in the existing battery pack may cause a chain reaction of explosion-proof valve rupture, thereby leading to thermal runaway and posing a serious threat to the overall safety of the battery system.

[0006] The first aspect of this application provides a battery pack, including a battery pack, a battery bracket, and a baffle plate; The battery pack includes at least one battery cell, and an explosion-proof valve is provided on the bottom surface of the battery cell. The battery bracket is located below the battery pack, and the battery bracket has a through-hole corresponding to the position of the explosion-proof valve of the individual battery cell. The baffle plate is disposed below the battery bracket and forms a receiving cavity with the through opening of the battery bracket, and a buffer layer is disposed inside the receiving cavity; Furthermore, the projection of the explosion-proof valve along the height direction of the battery cell is located within the projection of the buffer layer along the height direction of the battery cell; The thickness of the buffer layer is A mm, the distance between two adjacent explosion-proof valves is E mm, and A×E satisfies 8≤A×E≤30.

[0007] In the battery pack of this application embodiment, a buffer layer can be used to buffer the high-temperature and high-pressure fluid. The flow velocity and temperature of the fluid ejected from the explosion-proof valve after breaking through the baffle plate will be reduced. At the same time, since a buffer layer is provided on the baffle plate, the buffer layer at the corresponding position of the adjacent battery cell after the valve can increase the obstruction and buffering of airflow, enhance the impact resistance of the baffle plate, and effectively prevent abnormal valve opening of adjacent battery cells, which could lead to secondary thermal runaway. Furthermore, when the product A×E of the thickness A mm of the buffer layer and the distance E mm between two adjacent explosion-proof valves satisfies 8 ≤ A×E ≤ 30, the buffering effect of the buffer layer can be effectively guaranteed, and the space utilization of the battery pack can be improved, thereby increasing the energy density of the battery pack. Attached Figure Description

[0008] It should be understood that the following figures only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0009] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0010] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0011] Figure 1 This is a perspective view of the battery pack according to an embodiment of this application.

[0012] Figure 2 This is a partial bottom view of the battery pack according to an embodiment of this application.

[0013] Figure 3 This is a cross-sectional schematic diagram of the battery pack according to an embodiment of this application.

[0014] Figure 4 This is a partial cross-sectional schematic diagram of the battery pack according to an embodiment of this application.

[0015] Figure 5 This is another perspective view of the battery pack according to an embodiment of this application.

[0016] Figure 6 This is a partial perspective view of the battery pack according to an embodiment of this application.

[0017] Figure 7 This is a partial bottom view of the battery pack according to an embodiment of this application.

[0018] Attached image labels: 10. Battery pack; 1. Battery cell; 11. Housing; 12. Explosion-proof valve; 2. Battery bracket; 21. Through opening; 22. Support; 23. Receiving groove; 24. Channel; 3. Baffle plate; 4. Receiving cavity; 41. Opening; 5. Buffer layer; 6. Base plate; 61. Exhaust port; 7. Bottom guard plate; 71. Exhaust space; 72. Main exhaust port.

[0019] X - First direction, Y - Second direction, Z - Height direction. Detailed Implementation

[0020] Numerous specific details are set forth below to provide an understanding of the structure, function, and use of the embodiments described and illustrated in the specification and figures. It is to be understood that the embodiments described and illustrated herein are non-limiting examples, and thus it will be appreciated that the particular structural and functional details disclosed herein are representative and exemplary. Variations and changes may be made to these embodiments without departing from the scope of the claims.

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] This application provides a battery pack for supplying power to external devices, which in turn can charge the battery pack. Figures 1 to 7As shown, the battery pack of this application embodiment includes at least a battery pack 10, a battery support 2, and a baffle plate 3. The battery pack 10 includes multiple battery cells 1 arranged in a row. Specifically, multiple battery cells 1 with similar capacity and internal resistance can be connected in series or parallel to form the battery pack 10. Each battery cell 1 can store chemical energy and controllably convert it into electrical energy. In a recyclable battery, after discharge, the active materials can be activated by charging for continued use. It is understood that each battery cell 1 includes at least a housing 11 and a cover plate fixedly connected to each other, as well as a battery cell and an electrolyte. The housing 11 and the cover plate together house the battery cell and the electrolyte. The cover plate may be provided with at least one positive electrode post and at least one negative electrode post for electrical connection to the outside. The battery cell includes one or more electrode assemblies, which are formed by stacking or winding positive electrode plates, negative electrode plates, and a separator. The separator is located between adjacent positive and negative electrode plates to insulate them. At least one end of the electrode assembly has a tab, which is electrically connected to the electrode post. It is understood that the battery cell 1 in the embodiments of this application can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, ternary high-nickel battery, etc., and no limitation is made here.

[0023] Specifically, a battery pack may also include a battery management system (BMS), a thermal management system, an electrical connection system (which may include high-voltage / low-voltage connectors, wiring harnesses, etc.), structural components (casing, brackets, etc.), and protective parts, as well as a housing, forming a complete functional unit that directly outputs electrical energy. As a rechargeable energy storage device, the battery pack can serve as a power source for electrical equipment such as new energy vehicles.

[0024] like Figure 2 and Figure 3 As shown, since an explosion-proof valve 12 is provided on the bottom surface of the battery cell 1, that is, the explosion-proof valve 12 is located at the bottom end of the battery cell 1 in the height direction; when the internal pressure of the battery cell 1 reaches the pressure relief strength of the explosion-proof valve 12, the explosion-proof valve 12 connects with the outside and releases pressure in time; the ejected material and other fluids from the explosion-proof valve 12 are discharged downwards to avoid direct contact with the electrical components above the battery cell 1, so as to achieve thermal and electrical separation and improve the overall safety of the battery pack.

[0025] An explosion-proof valve 12 is a component or part that can be actuated to release internal pressure or temperature when the internal pressure or temperature of a single battery cell 1 reaches a predetermined threshold. During battery use, the explosion-proof valve 12 is mainly used to allow gas to escape from the battery and reduce internal pressure in the event of thermal runaway or other situations, preventing excessive pressure buildup that could cause deformation or explosion. The material of the explosion-proof valve 12 is not limited, including but not limited to aluminum, steel, and alloys. The shape of the explosion-proof valve 12 is not limited, such as square, oblong, elliptical, racetrack-shaped, etc. The type of explosion-proof valve 12 is not limited, such as a notched explosion-proof valve 12, which can be formed by stamping or laser etching.

[0026] like Figure 3 and Figure 4 As shown, the battery bracket 2 is located below the battery pack 10, and the baffle plate 3 is located below the battery bracket 2. The battery bracket 2 is used to support each battery cell 1 of the battery pack 10, and the baffle plate 3 is used to insulate the bottom surface of the battery bracket 2 and the bottom surface of the battery cell 1 from other structures, and also has a certain structural protection function and heat insulation and flame retardant function.

[0027] like Figure 3 and Figure 4 As shown, the battery bracket 2 is provided with a through-hole 21 corresponding to the position of the explosion-proof valve 12. The baffle plate 3 and the through-hole 21 of the battery bracket 2 form a receiving cavity 4. A buffer layer 5 is provided in the receiving cavity 4. Furthermore, the projection of the explosion-proof valve 12 along the height direction of the battery cell 1 is located within the projection of the buffer layer 5 along the height direction of the battery cell 1.

[0028] Thus, during the operation of the battery pack in this embodiment, when the internal pressure of the battery cell 1 reaches the pressure relief strength of the explosion-proof valve 12, the explosion-proof valve 12 ruptures and ejects high-temperature, high-pressure fluid downwards. This fluid first sprays onto the buffer layer 5, then breaks through the buffer layer 5, and finally sprays onto the baffle plate 3, breaking through the baffle plate 3 before being discharged below the battery bracket 2. Simultaneously, because the baffle plate 3 is equipped with the buffer layer 5, after the valve is ejected, the buffer layer 5 at the corresponding position of the adjacent battery cell 1 can increase the obstruction and buffering of airflow, enhancing the impact resistance of the baffle plate 3 and effectively preventing abnormal valve opening by adjacent battery cells 1, thus avoiding secondary thermal runaway.

[0029] Among them, such as Figure 2 and Figure 4As shown, the thickness of the buffer layer 5 is A mm, and the distance between two adjacent explosion-proof valves 12 is E mm, where A × E satisfies 8 ≤ A × E ≤ 30. It can be understood that the distance E mm between two adjacent explosion-proof valves 12 is the shortest distance between the outer contours of the two explosion-proof valves 12. Specifically, the value of A × E can be selected from specific values ​​such as 8, 9, 11, 14, 18, 22, 25, 27, 29, 30, etc., and is not limited here.

[0030] When the product of the thickness A mm of the buffer layer 5 and the distance E mm between two adjacent explosion-proof valves 12, A×E, is greater than 30, it is not conducive to the opening of the valve of the battery cell 1, which affects the space utilization rate of the battery pack in this embodiment and thus affects the energy density of the battery pack in this embodiment. When the product of the thickness A mm of the buffer layer 5 and the distance E mm between two adjacent explosion-proof valves 12, A×E, is less than 8, the buffering effect of the buffer layer 5 is easily affected, and the influence between each battery cell 1 is also relatively large, which can easily lead to abnormal opening of the valve of adjacent battery cells 1, resulting in the chain ejection of explosion-proof valves.

[0031] Therefore, in the battery pack of this application embodiment, the buffer layer 5 can be used to buffer the high-temperature and high-pressure fluid. The flow rate and temperature of the fluid ejected from the explosion-proof valve 12 after breaking through the baffle plate 3 will be reduced, thereby preventing the high-temperature and high-pressure fluid from flowing under other battery cells 1 and causing the explosion-proof valves 12 of other battery cells 1 to be ejected in a chain reaction, preventing the spread of thermal runaway, and effectively improving the working safety of the battery pack. Furthermore, when the product A×E of the thickness A mm of the buffer layer 5 and the distance E mm between two adjacent explosion-proof valves 12 satisfies 8≤A×E≤30, the buffering effect of the buffer layer 5 can be effectively guaranteed, and the space utilization of the battery pack can be improved, thereby increasing the energy density of the battery pack.

[0032] like Figure 3 As shown, in one embodiment of this application, the battery pack further includes a base plate 6 and a bottom protective plate 7. The base plate 6 is disposed below the baffle plate 3, and the base plate 6 has an exhaust port 61 corresponding to the through opening 21. The base plate 6 and the bottom protective plate 7 form an exhaust space 71. Therefore, after the high-temperature and high-pressure fluid ejected downward from the explosion-proof valve 12 breaks through the buffer layer 5 and the baffle plate 3, it can be discharged from the exhaust port 61 on the base plate 6 into the exhaust space 71 formed between the base plate 6 and the bottom protective plate 7.

[0033] Furthermore, such as Figure 5As shown, in one embodiment of this application, a main vent 72 is provided on the bottom surface of the bottom cover plate 7, and the main vent 72 is connected to the exhaust space 71. Therefore, after the high-temperature and high-pressure fluid ejected downward from the explosion-proof valve 12 breaks through the buffer layer 5 and the baffle plate 3, it can be discharged from the exhaust port 61 on the bottom plate 6 into the exhaust space 71 formed between the bottom plate 6 and the bottom cover plate 7, and then discharged from the main vent 72 on the bottom surface of the bottom cover plate 7 to the outside of the battery pack of this embodiment.

[0034] It is understood that in the battery pack of the present application embodiment, the base plate 6 can be part of the housing, and the housing can also include a frame fixed to the outer periphery of the base plate 6. The base plate 6 and the frame form a receiving cavity, which is used to accommodate various structures required for the battery pack.

[0035] Specifically, the aforementioned enclosure can be a closed or semi-closed structure made of materials such as metal or plastic, serving as the physical carrier of the battery pack 10. The enclosure provides installation space for the battery pack 10, BMS, cooling system, electrical connection components, etc., and through a reasonable structural design, fixes these components within the enclosure, ensuring they maintain a relatively stable position during battery pack operation and preventing damage or loosening of connections due to vibration, impact, or other factors. The frame and base plate 6 can be integrally formed or manufactured separately and then fixedly connected. Specifically, the frame and base plate 6 are fixedly connected by welding, riveting, screwing, or other methods. In the case of a cubic enclosure, the lower enclosure frame generally has four side plates surrounding the perimeter of the base plate 6. In other embodiments, the enclosure shape can also be cylindrical or other shapes. The frame mainly serves a supporting, protective, and connecting function. The frame can be formed by splicing multiple beams together. The frame can be rectangular, circular, polygonal, etc., without limitation. The frame can be made of various materials, such as aluminum alloy, copper alloy, steel, plastic, etc. The beams of the frame can be solid or contain cavities. The base plate 6 is the main load-bearing component of the battery pack, used to support and fix the battery pack 10, battery management system, cooling system, and other components inside the battery pack. The base plate 6 is located at the bottom of the frame and can be fixed to the bottom of the frame by welding, riveting, screwing, etc. The size of the base plate 6 is determined by the number of battery cells contained in the battery pack and the size of the battery cells. The frame can be cast from materials such as steel and aluminum alloy, or processed from lightweight materials such as glass fiber reinforced composite materials and carbon fiber reinforced composite materials.

[0036] like Figure 6As shown, in one embodiment of this application, the battery holder 2 is provided with a receiving groove 23 that matches the battery cell 1. By providing the receiving groove 23 on the battery holder 2 that matches the battery cell 1, the receiving groove 23 can be used to limit the position of the battery cell 1, preventing the battery cell 1 from shifting relative to the battery holder 2, and ensuring that the battery cell 1 is fixed in the corresponding position. Figure 6 As shown, the through-hole 21 is opened on the bottom surface of the receiving tank 23 so that the high-temperature and high-pressure fluid ejected from the explosion-proof valve 12 can break through the buffer layer 5 baffle plate 3 and be discharged from the through-hole 21 on the bottom surface of the receiving tank 23 to below the battery bracket 2. Furthermore, as... Figure 6 As shown, the edge of the receiving groove 23 is provided with a support part 22. The receiving groove 23 can use the support part 22 to support the battery cell 1, thereby ensuring that the battery cell 1 will not directly transfer all its weight to the lower baffle plate 3.

[0037] Specifically, in one embodiment of this application, the buffer layer 5 is a structural adhesive layer. It is understood that when the buffer layer 5 is a structural adhesive layer, a potting process can be used to inject the structural adhesive into the accommodating cavity 4 to form the aforementioned buffer layer 5, effectively reducing the difficulty of forming the buffer layer 5.

[0038] like Figure 4 As shown, in one embodiment of this application, the thickness of the buffer layer 5 is A mm, where A mm satisfies 0.5 mm ≤ A mm ≤ 1.5 mm. When the thickness A mm of the buffer layer 5 is less than 0.5 mm, the buffering effect of the buffer layer 5 is poor. After the fluid ejected from the explosion-proof valve 12 breaks through the buffer layer 5 and the baffle plate 3, the flow rate and temperature are still high, and there is still a possibility of triggering a chain reaction of explosion-proof valves 12 of other battery cells 1. When the thickness A mm of the buffer layer 5 is greater than 1.5 mm, the buffering effect of the buffer layer 5 is too strong, and it cannot be guaranteed that the fluid ejected from the explosion-proof valve 12 can break through the buffer layer 5 and the baffle plate 3, which can easily cause poor pressure relief and lead to problems such as continuous heating of battery cells 1. Therefore, when the thickness A mm of the buffer layer 5 satisfies 0.5 mm ≤ A mm ≤ 1.5 mm, the buffering effect of the buffer layer 5 is relatively moderate. This ensures that the fluid ejected from the explosion-proof valve 12, after breaking through the buffer layer 5 and the baffle plate 3 and flowing under other battery cells 1, will not trigger a chain reaction of explosion-proof valves 12 in other battery cells 1, nor will it cause poor pressure relief, ensuring smooth pressure relief for the battery cells 1. Furthermore, under normal operating conditions of the battery pack, the buffer layer 5 provides good heat preservation, which is beneficial for improving the battery performance of the battery cells 1 in low-temperature environments. In specific embodiments, the thickness A mm of the buffer layer 5 can be selected from specific values ​​such as 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.25 mm, 1.3 mm, 1.4 mm, and 1.5 mm, and is not limited here.

[0039] like Figure 4 As shown, in one embodiment of this application, the distance between two adjacent explosion-proof valves 12 is E mm, where E mm satisfies 16 mm ≤ E mm ≤ 20 mm. When the distance E mm between two adjacent explosion-proof valves 12 is less than 16 mm, the influence between each battery cell 1 is significant, easily leading to a chain reaction of explosion-proof valves 12 being ejected. When the distance E mm between two adjacent explosion-proof valves 12 is greater than 20 mm, it affects the space utilization rate of the battery pack in this embodiment, thereby affecting the energy density of the battery pack in this embodiment.

[0040] Therefore, when the distance E mm between two adjacent explosion-proof valves 12 satisfies 16 mm ≤ E mm ≤ 20 mm, the mutual influence between individual battery cells 1 can be effectively reduced, the situation of chain ejection of explosion-proof valves 12 can be avoided, and the space utilization rate of the battery pack can be improved, thereby increasing the energy density of the battery pack.

[0041] In a specific embodiment, the distance E mm between two adjacent explosion-proof valves 12 can be selected from specific values ​​such as 16 mm, 16.3 mm, 16.7 mm, 17.1 mm, 17.5 mm, 17.9 mm, 18.4 mm, 18.8 mm, 19.2 mm, and 20 mm, and is not limited here. Figure 7 As shown, in one embodiment of this application, the projected area of ​​the explosion-proof valve 12 along the height direction of the battery cell 1 is s mm. 2 The projected area of ​​the buffer layer 5 along the height direction of the battery cell 1 is t mm. 2 The ratio s / t satisfies 0.5 ≤ s / t ≤ 0.95. The projected area s mm of the explosion-proof valve 12 along the height direction of the battery cell 1. 2 The projected area of ​​the buffer layer 5 along the height direction of the battery cell 1 is t mm. 2 The s / t condition is 0.5 ≤ s / t ≤ 0.95.

[0042] Along the height direction of battery cell 1, the projected area s mm of the explosion-proof valve 12 of battery cell 1 is... 2 The projected area t mm of the buffer layer 5 2 When the ratio s / t is less than 0.5, the fluid ejected from the explosion-proof valve 12 cannot be guaranteed to be completely ejected onto the buffer layer 5. Some fluid may directly eject onto the baffle plate 3, causing a localized breach in the baffle plate 3. Most of the fluid will then flow downwards through this breach, rendering the buffer layer 5 ineffective. Furthermore, the projected area s mm of the explosion-proof valve 12 in the battery cell 1... 2 The projected area t mm of the buffer layer 5 2When the ratio s / t is greater than 0.95, the required area of ​​the buffer layer 5 is too large, requiring a lot of arrangement space. In addition, the required area of ​​the corresponding through-hole 21 is also relatively large. If the area of ​​the through-hole 21 is too large, it will easily affect the structural strength of the battery bracket 2.

[0043] Therefore, along the height direction of the battery cell 1, the projected area s mm of the explosion-proof valve 12 of the battery cell 1 is... 2 The projected area t mm of the buffer layer 5 2 When the ratio s / t satisfies 0.5≤s / t≤0.95, it can be ensured that all the fluid sprayed from the explosion-proof valve 12 is sprayed onto the buffer layer 5, so as to ensure that the buffer layer 5 can effectively exert its buffering effect. It can also effectively reduce the arrangement space of the buffer layer 5 and the corresponding through-hole 21, thereby improving the structural strength of the battery bracket 2 and ensuring that the battery bracket 2 can stably support the battery cell 1. In a specific embodiment, the projected area s mm of the explosion-proof valve 12 of the battery cell 1 is... 2 The projected area t mm of the buffer layer 5 2 The ratio s / t can be selected from specific values ​​such as 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, and 0.95, and there are no restrictions here.

[0044] Furthermore, such as Figure 7 As shown, in one embodiment of this application, the projected area s mm of the explosion-proof valve 12 along the height direction of the battery cell 1 is... 2 Meets 600 mm 2 ≤s mm 2 ≤1100 mm 2 .

[0045] The projected area s mm of the explosion-proof valve 12 in battery cell 1 2 Less than 600 mm 2 In cases where the area of ​​the explosion-proof valve 12 is too small, it is easy for the explosion-proof valve 12 to fail to rupture even after the internal pressure of the battery cell 1 reaches the set pressure. This can lead to excessively high internal temperature and pressure in the battery cell 1, causing the battery cell 1 to catch fire or explode. Consequently, this can result in dangerous situations such as thermal runaway of the entire battery pack, affecting the safety performance of the battery pack in this embodiment. The projected area s mm of the explosion-proof valve 12 in the battery cell 1... 2 Greater than 1100 mm 2In some cases, if the area of ​​the explosion-proof valve 12 is too large, it may weaken the structural strength of the explosion-proof valve 12, resulting in a decrease in the critical pressure opening pressure of the explosion-proof valve 12. This may cause the explosion-proof valve 12 to rupture prematurely before the pressure inside the battery cell 1 reaches the set pressure. It may also affect the sealing reliability of the explosion-proof valve 12 and increase the possibility of high-temperature and high-pressure fluid flowing to the area below the explosion-proof valve 12, causing the explosion-proof valve 12 to be ejected in a chain reaction.

[0046] Therefore, in the projected area s mm of the explosion-proof valve 12 2 Meets 600 mm 2 ≤s mm 2 ≤1100 mm 2 Under these conditions, it can ensure that the battery cell 1 will rupture normally after the internal pressure reaches the preset pressure, thereby allowing the battery cell 1 to release pressure normally. This also effectively improves the sealing reliability of the explosion-proof valve 12 and minimizes the possibility of high-temperature, high-pressure fluid flowing to the area below the explosion-proof valve 12 and causing a chain reaction of ejection from the valve, thus improving the operational safety of the battery pack in this embodiment. In a specific embodiment, the projected area of ​​the explosion-proof valve 12 is s mm. 2 Specific values ​​such as 600mm², 650mm², 700mm², 750mm², 800mm², 850mm², 900mm², 950mm², 1000mm², and 1100mm² can be selected, and there are no restrictions here.

[0047] Furthermore, such as Figure 7 As shown, in one embodiment of this application, the explosion-proof valve 12 has a circular outer contour projected along the height direction of the battery cell 1, and the diameter of the explosion-proof valve 12 is D(1) mm, where D(1) mm satisfies 28 mm ≤ D(1) mm ≤ 36 mm.

[0048] When the diameter D(1)mm of the explosion-proof valve 12 with a circular outer contour is less than 28 mm, the area of ​​the explosion-proof valve 12 is too small, which may cause the explosion-proof valve 12 to fail to rupture even after the internal pressure of the battery cell 1 reaches the set pressure. This may result in excessively high internal temperature and pressure of the battery cell 1, leading to fire and explosion of the battery cell 1, which may cause the battery pack to experience thermal runaway and other dangerous situations, affecting the safety performance of the battery pack in this embodiment. When the diameter D(1)mm of the explosion-proof valve 12 with a circular outer contour is greater than 36 mm, the area of ​​the explosion-proof valve 12 is too large, which may weaken the structural strength of the explosion-proof valve 12, reduce the critical pressure opening pressure of the explosion-proof valve 12, and cause the explosion-proof valve 12 to rupture prematurely before the internal pressure of the battery cell 1 reaches the set pressure. This may also affect the sealing reliability of the explosion-proof valve 12 and increase the possibility of high-temperature and high-pressure fluid flowing to the area below the explosion-proof valve 12, causing the explosion-proof valve 12 to be ejected in a chain reaction.

[0049] Therefore, when the diameter D(1) mm of the explosion-proof valve 12 with a circular outer contour satisfies 28 mm ≤ D(1) mm ≤ 36 mm, it can ensure normal rupture after the internal pressure of the battery cell 1 reaches the preset pressure, thereby allowing the battery cell 1 to release pressure normally. This also effectively improves the sealing reliability of the explosion-proof valve 12 and minimizes the possibility of high-temperature and high-pressure fluid flowing to the area below the explosion-proof valve 12 and causing a chain reaction of the explosion-proof valve 12, thus improving the working safety of the battery pack in this embodiment. In specific embodiments, the diameter D(1) mm of the explosion-proof valve 12 can be selected from specific values ​​such as 28 mm, 28.5 mm, 29 mm, 30 mm, 31.5 mm, 32 mm, 33.5 mm, 34 mm, 35 mm, and 36 mm, and is not limited here.

[0050] Similarly, such as Figure 7 As shown, in one embodiment of this application, the projected area t mm of the buffer layer 5 along the height direction of the battery cell 1 is... 2 Meets 700 mm 2 ≤t mm 2 ≤1300mm 2 The projected area t mm of buffer layer 5 2 Less than 700mm 2 In some cases, the fluid ejected from the explosion-proof valve 12 cannot be guaranteed to be completely ejected onto the buffer layer 5. Some fluid may directly eject onto the baffle plate 3, causing a localized breach in the baffle plate 3. Most of the fluid will then flow downwards through this breach, rendering the buffer layer 5 ineffective. Furthermore, in the projected area t mm of the buffer layer 5… 2 Greater than 1300mm 2 In this case, the required area of ​​the buffer layer 5 is too large, requiring a lot of layout space. In addition, the required area of ​​the corresponding through-hole 21 is also relatively large. If the area of ​​the through-hole 21 is too large, it will easily affect the structural strength of the battery bracket 2.

[0051] Therefore, the projected area t mm of the buffer layer 5 2 Meets 700 mm 2 ≤t mm 2 ≤1300mm 2 In this case, it can be ensured that all the fluid sprayed from the explosion-proof valve 12 is sprayed onto the buffer layer 5, so as to ensure that the buffer layer 5 can effectively exert its buffering effect. It can also effectively reduce the arrangement space of the buffer layer 5 and the corresponding through-hole 21, thereby improving the structural strength of the battery bracket 2 and ensuring that the battery bracket 2 can stably support the battery cell 1. In a specific embodiment, the projected area t mm of the buffer layer 5 is... 2Specific values ​​such as 700mm², 770mm², 850mm², 920mm², 1000mm², 1080mm², 1150mm², 1220mm², 1270mm², and 1300mm² can be selected, and there are no restrictions here.

[0052] Furthermore, such as Figure 7 As shown, in one embodiment of this application, the projection of the buffer layer 5 along the height direction of the battery cell 1 is circular, and the diameter of the buffer layer 5 is D(2) mm, where D(2) mm satisfies 30 mm ≤ D(2) mm ≤ 40 mm.

[0053] When the diameter D(2)mm of the circular buffer layer 5 is less than 30 mm, the fluid sprayed from the explosion-proof valve 12 cannot be guaranteed to be sprayed onto the buffer layer 5. Some fluid may be sprayed directly onto the baffle plate 3, causing a local break in the baffle plate 3. Most of the fluid flows down from the break, and the buffer layer 5 cannot play its buffering role. When the diameter D(2)mm of the circular buffer layer 5 is greater than 40 mm, the required arrangement area of ​​the buffer layer 5 is too large, requiring more arrangement space. In addition, the required area of ​​the corresponding through-hole 21 is also relatively large. The excessively large area of ​​the through-hole 21 may affect the structural strength of the battery bracket 2.

[0054] Therefore, when the diameter D(2) mm of the buffer layer 5 satisfies 30 mm ≤ D(2) mm ≤ 40 mm, it can be ensured that all the fluid sprayed from the explosion-proof valve 12 is sprayed onto the buffer layer 5, so as to ensure that the buffer layer 5 can effectively play its buffering role. It can also effectively reduce the arrangement space of the buffer layer 5 and the corresponding through-hole 21, so as to improve the structural strength of the battery bracket 2 and ensure that the battery bracket 2 can stably support the battery cell 1. In a specific embodiment, the diameter D(2) mm of the buffer layer 5 can be selected from specific values ​​such as 30 mm, 31.5 mm, 33 mm, 34.5 mm, 36 mm, 37.5 mm, 38 mm, 39 mm, 39.5 mm, 40 mm, etc., and is not limited here.

[0055] like Figure 6 and Figure 7 As shown, in one embodiment of this application, a channel 24 is provided on the bottom surface of the battery holder 2, and the channel 24 connects the accommodating cavity 4 and the opening 41 provided on the side wall of the battery holder 2. Since the channel 24 is provided on the bottom surface of the battery holder 2, and the channel 24 connects the accommodating cavity 4 and the opening 41 provided on the side wall of the battery holder 2, the material required for the buffer layer 5 can be injected into the accommodating cavity 4 from the opening 41 provided on the side wall of the battery holder 2 using the channel 24, thereby forming the buffer layer 5 in the accommodating cavity 4, effectively reducing the difficulty of forming the buffer layer 5 and improving the formation efficiency of the buffer layer 5.

[0056] Furthermore, such as Figure 6 and Figure 7 As shown, in one embodiment of this application, multiple channels 24 are provided, each channel 24 extending in at least two different directions. Because multiple channels 24 are provided, each extending in at least two different directions, during the processing of the buffer layer 5, the material of the buffer layer 5 can be simultaneously injected into each receiving cavity 4 using multiple channels 24 extending in at least two different directions. This ensures that the material of the buffer layer 5 can be effectively injected into each receiving cavity 4, thereby forming the buffer layer 5 in each receiving cavity 4 and avoiding the situation where some receiving cavities 4 do not form the buffer layer 5, effectively improving the processing yield of the buffer layer 5.

[0057] like Figure 6 and Figure 7 As shown, in one embodiment of this application, for the receiving cavity 4, the channel 24 forms at least two openings 41 on the inner wall of the receiving cavity 4, and the openings 41 communicate with the receiving cavity 4. That is, each receiving cavity 4 has at least two openings 41 on its side wall. Figure 7 The battery holder 2 shown in the figure has four openings 41 on the side wall of each accommodating cavity 4. This ensures that the material of the buffer layer 5 can enter the accommodating cavity 4 through at least two openings 41 on the side wall, thereby forming a buffer layer 5 in each accommodating cavity 4. This avoids the situation where some accommodating cavities 4 do not form a buffer layer 5, and further improves the processing yield of the buffer layer 5.

[0058] Furthermore, such as Figure 7 As shown, in one embodiment of this application, multiple channels 24 extend along a first direction and a second direction, respectively, and the first direction and the second direction are perpendicular to each other. That is, as... Figure 7 As shown, multiple channels 24 are distributed in a square grid pattern, which can effectively reduce the processing difficulty of the channels 24 and facilitate the connection between the channels 24 and the accommodating cavity 4. It can be understood that the first direction and the second direction are two mutually perpendicular directions on the bottom surface of the battery holder 2. In one embodiment of this application, the first direction and the second direction can be the extension directions of the long side and the short side of the bottom surface of the battery holder 2, respectively; while in another embodiment of this application, the first direction and the second direction may not be the extension directions of the long side and the short side of the bottom surface of the battery holder 2, but may form an angle with the long side and the short side of the bottom surface of the battery holder 2, respectively. The specific angle is not limited here.

[0059] like Figure 7As shown, in one embodiment of this application, the width of channel 24 is B mm, where B mm satisfies 2 mm ≤ B mm ≤ 4 mm. When the width B of channel 24 is less than 2 mm, the cross-sectional area of ​​channel 24 is relatively small, which can easily affect the flow efficiency of the material of buffer layer 5 along channel 24, and thus affect the processing efficiency of buffer layer 5. When the width B of channel 24 is greater than 2 mm, the area occupied by channel 24 on the bottom surface of battery bracket 2 is large, and the area of ​​battery bracket 2 without channel 24 is small, thereby affecting the contact area between battery bracket 2 and base plate 6, resulting in excessive pressure on local areas of base plate 6, which can easily cause local collapse and deformation of base plate 6.

[0060] Therefore, when the width B mm of channel 24 satisfies 2 mm ≤ B mm ≤ 4 mm, it ensures that the material flow efficiency of the buffer layer 5 along channel 24 meets the requirements, effectively improving the processing efficiency of the buffer layer 5. Simultaneously, it ensures the contact area between the battery bracket 2 and the base plate 6, preventing excessive pressure on local areas of the base plate 6 and thus preventing local collapse and deformation. In specific embodiments, the width B mm of channel 24 can be selected from specific values ​​such as 2 mm, 2.3 mm, 2.6 mm, 2.9 mm, 3.2 mm, 3.5 mm, 3.7 mm, 3.8 mm, 3.9 mm, and 4 mm, and is not limited here.

[0061] like Figure 7 As shown, in one embodiment of this application, the height of channel 24 is C mm, where C mm satisfies 3 mm ≤ C mm ≤ 5 mm. When the width C of channel 24 is less than 3 mm, the cross-sectional area of ​​channel 24 is relatively small, which can easily affect the flow efficiency of the material of buffer layer 5 along channel 24, and thus affect the processing efficiency of buffer layer 5. When the width C of channel 24 is greater than 3 mm, the width of the portion between the top surface of battery bracket 2 and channel 24 is small, which can affect the support strength of the area on battery bracket 2 where channel 24 is provided for battery pack 10, and can easily cause the area on battery bracket 2 where channel 24 is provided to collapse and deform.

[0062] Therefore, when the width C mm of channel 24 satisfies 3 mm ≤ C mm ≤ 5 mm, it ensures that the material flow efficiency of the buffer layer 5 along channel 24 meets the requirements, effectively improving the processing efficiency of the buffer layer 5. Simultaneously, it ensures the support strength of the area on the battery bracket 2 with channel 24 for the battery pack 10, preventing localized collapse and deformation of the battery bracket 2. In specific embodiments, the width C mm of channel 24 can be selected from specific values ​​such as 3 mm, 3.3 mm, 3.6 mm, 3.9 mm, 4.2 mm, 4.5 mm, 4.7 mm, 4.8 mm, 4.9 mm, and 5 mm, and is not limited here.

[0063] like Figure 4 As shown, in one embodiment of this application, the thickness of the baffle plate 3 is D mm, where D mm satisfies 0.3 mm ≤ D mm ≤ 0.8 mm. When the thickness D mm of the baffle plate 3 is less than 0.3 mm, the blocking effect of the baffle plate 3 is poor. After the fluid ejected from the explosion-proof valve 12 breaks through the baffle plate 3, the flow rate and temperature are still high, and there is still a possibility of triggering a chain reaction of explosion-proof valves 12 of other battery cells 1. When the thickness D mm of the baffle plate 3 is greater than 0.8 mm, the blocking effect of the baffle plate 3 is too strong, and it cannot be guaranteed that all the fluid ejected from the explosion-proof valve 12 can break through the baffle plate 3, which can easily cause poor pressure relief and lead to problems such as continuous heating of battery cells 1. Therefore, when the thickness D mm of the baffle plate 3 satisfies 0.3 mm ≤ D mm ≤ 0.8 mm, the blocking effect of the baffle plate 3 is relatively moderate. It can ensure that the fluid ejected from the explosion-proof valve 12 will not trigger a chain reaction of explosion-proof valves 12 of other battery cells 1 after passing under the baffle plate 3, and will not cause poor pressure relief, thus ensuring smooth pressure relief of battery cells 1. In specific embodiments, the thickness D mm of the baffle plate 3 can be selected from specific values ​​such as 0.3 mm, 0.35 mm, 0.42 mm, 0.48 mm, 0.53 mm, 0.58 mm, 0.64 mm, 0.69 mm, 0.75 mm, and 0.8 mm, and is not limited here.

[0064] In one embodiment of this application, the baffle plate 3 is a mica plate. When the baffle plate 3 is a mica plate, it can ensure that the baffle plate 3 can achieve the insulation performance between the bottom surface of the battery bracket 2, the bottom surface of the battery cell 1 and the base plate 6, and also ensure that the baffle plate 3 has structural protection and good heat insulation and flame retardant effect.

[0065] like Figure 2 As shown, in one embodiment of this application, the bottom surface of the battery cell 1 is circular, and the explosion-proof valve 12 is disposed at the bottom of the battery cell 1, and the explosion-proof valve 12 has an annular structure. That is, the battery cell 1 in this embodiment can be a cylindrical battery with an annular explosion-proof valve 12 at the bottom. The single battery cell 1 has high mechanical strength, a short heat dissipation path, and good working stability. In another embodiment of this application, the battery cell 1 can be a prismatic battery, a blade battery, or other battery shapes, which are not limited here.

[0066] like Figure 2As shown, in one embodiment of this application, the battery cells 1 in the battery pack 10 are arranged in an equilateral triangular array or a square array. Since the battery cells 1 in the battery pack 10 are arranged in an equilateral triangular array or a square array, the installation density of the battery cells 1 can be effectively increased, and it is also convenient to open the above-mentioned through-hole 21 at the corresponding position of the battery bracket 2, and reduce the impact on the structural strength of the battery bracket 2.

[0067] This application also provides an electrical device that includes at least one of the aforementioned battery packs. It is understood that this electrical device can be any type of electrical device, such as an electric vehicle, an appliance with a battery pack, or an energy storage device, and is not limited thereto.

[0068] It should be noted that the elements described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0069] It should be understood that multiple components and / or parts can be provided by a single integrated component or part. Alternatively, a single integrated component or part can be divided into multiple separate components and / or parts. The use of the public designation "a" or "an" to describe a component or part does not imply the exclusion of other components or parts.

[0070] It should be understood that while terms such as "first" or "second" may be used in this application to describe various elements, these elements are not limited by these terms; these terms are merely used to distinguish one element from another. The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms "a," "the," and "the" as used in one or more embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0071] In this document, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, and not to define the absolute position of these related parts. Terms such as "equal" and "same" are not strict mathematical and / or geometric limitations, and also include errors that are understandable to those skilled in the art and permissible in manufacturing or use. Unless otherwise stated, numerical ranges in this document include not only the entire range within its two endpoints, but also several subranges contained therein.

[0072] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0073] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery pack, characterized in that, Includes battery pack (10), battery bracket (2) and baffle plate (3); The battery pack (10) includes at least one battery cell (1), and an explosion-proof valve (12) is provided on the bottom surface of the battery cell (1). The battery bracket (2) is located below the battery pack (10), and the battery bracket (2) is provided with a through-hole (21) corresponding to the position of the explosion-proof valve (12) of the battery cell (1). The baffle plate (3) is located below the battery bracket (2) and forms a receiving cavity (4) with the through opening (21) of the battery bracket (2). A buffer layer (5) is provided in the receiving cavity (4). Furthermore, the projection of the explosion-proof valve (12) along the height direction of the battery cell (1) is located within the projection of the buffer layer (5) along the height direction of the battery cell (1); The thickness of the buffer layer (5) is A mm, the distance between two adjacent explosion-proof valves (12) is E mm, and A×E satisfies 8≤A×E≤30.

2. The battery pack according to claim 1, characterized in that, The thickness of the buffer layer (5) is A mm, where A mm satisfies 0.5 mm ≤ A mm ≤ 1.5 mm; and / or the distance between two adjacent explosion-proof valves (12) is E mm, where E mm satisfies 16 mm ≤ E mm ≤ 20 mm.

3. The battery pack according to claim 1, characterized in that, The projected area of ​​the explosion-proof valve (12) along the height direction of the battery cell (1) is s mm. 2 The projected area of ​​the buffer layer (5) along the height direction of the battery cell (1) is t mm. 2 The s / t condition is 0.5 ≤ s / t ≤ 0.

95.

4. The battery pack according to claim 3, characterized in that, The projected area s mm of the explosion-proof valve (12) along the height direction of the battery cell (1) 2 Meets 600 mm 2 ≤s mm 2 ≤1100 mm 2 ; And / or, the projected area t mm of the buffer layer (5) along the height direction of the battery cell (1) 2 Meets 700 mm 2 ≤t mm 2 ≤1300mm 2 .

5. The battery pack according to claim 4, characterized in that, The outer contour of the explosion-proof valve (12) along the height direction of the battery cell (1) is circular, and the diameter of the explosion-proof valve (12) is D(1) mm, where D(1) mm satisfies 28 mm ≤ D(1) mm ≤ 36 mm.

6. The battery pack according to claim 4, characterized in that, The projection of the buffer layer (5) along the height direction of the battery cell (1) is circular, and the diameter of the buffer layer (5) is D(2) mm, where D(2) mm satisfies 30 mm ≤ D(2) mm ≤ 40 mm.

7. The battery pack according to any one of claims 1 to 6, characterized in that, The bottom surface of the battery holder (2) is provided with multiple channels (24), which connect the accommodating cavity (4) and the opening (41) provided on the side wall of the battery holder (2); each of the channels (24) extends in at least two different directions.

8. The battery pack according to claim 7, characterized in that, The plurality of channels (24) extend along a first direction and a second direction, respectively, the first direction and the second direction being perpendicular to each other.

9. The battery pack according to claim 7, characterized in that, For the accommodating cavity (4), the channel (24) forms at least two openings (41) on the inner wall of the accommodating cavity (4), and the openings (41) are in communication with the accommodating cavity (4).

10. The battery pack according to claim 7, characterized in that, The width of the channel (24) is B mm, where B mm satisfies 2 mm ≤ B mm ≤ 4 mm; and / or the height of the channel (24) is C mm, where C mm satisfies 3 mm ≤ C mm ≤ 5 mm.

11. The battery pack according to any one of claims 1 to 6, characterized in that, The baffle plate (3) is a mica plate, and the thickness of the baffle plate (3) is D mm, where D mm satisfies 0.3 mm ≤ D mm ≤ 0.8 mm.

12. The battery pack according to any one of claims 1 to 6, characterized in that, The buffer layer (5) is a structural adhesive layer.

13. The battery pack according to any one of claims 1 to 6, characterized in that, The battery holder (2) is provided with a receiving groove (23) that matches the battery cell (1), and the through opening (21) is opened on the bottom surface of the receiving groove (23).

14. The battery pack according to claim 13, characterized in that, The bottom surface of the battery cell (1) is circular, and the explosion-proof valve (12) is located at the bottom of the battery cell (1), and the explosion-proof valve (12) has an annular structure.

15. The battery pack according to any one of claims 1 to 6, characterized in that, The battery pack also includes a base plate (6) and a bottom guard plate (7). The base plate (6) is located below the baffle plate (3), and the base plate (6) is provided with an exhaust port (61) corresponding to the through opening (21). The base plate (6) and the bottom guard plate (7) form an exhaust space (71).

16. The battery pack according to claim 15, characterized in that, The bottom surface of the bottom guard plate (7) is provided with a main air outlet (72), which is connected to the exhaust space (71).

17. An electrical appliance, characterized in that, Includes the battery pack according to any one of claims 1 to 16.

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