Battery cell, battery apparatus and electrical device

Abstract

A battery cell, a battery apparatus and an electrical device. The battery cell comprises: a casing provided with an accommodating space, the casing comprising a first wall part, and the first wall part being provided with a pressure relief mechanism; an electrode assembly provided in the accommodating space; and a bottom support plate provided in the accommodating space, arranged between the first wall part and the electrode assembly in a third direction, and used for supporting the electrode assembly. The bottom support plate comprises a plate body and a first support part. The plate body has a first region and second region arranged in a second direction, the orthographic projection of the pressure relief mechanism on the plate body in the third direction being located in the first region. At least one first support part is provided on the side of the second region facing the first wall part, the size of the first support part in the first direction being less than L1, so that a gap is formed between the plate body and the first wall part. The gap connects a space located on the side of the plate body facing away from the pressure relief mechanism to the pressure relief mechanism.

Description

Battery cell, battery device and electric equipment

[0001] The present application claims priority to the Chinese patent application No. 202411388127.5, filed on September 30, 2024, and entitled "Battery cell, battery device and electric equipment", which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery cell, a battery device and an electric equipment. BACKGROUND

[0003] With the development of battery technology, battery devices are applied to more and more fields, and gradually replace traditional petrochemical energy in the field of automobile power and the like. In order to effectively release the pressure inside the shell of the battery cell, a pressure relief mechanism is arranged on the shell of the battery cell.

[0004] In the related art, the electrode assembly is supported on the pressure relief mechanism, and the distance between the pressure relief mechanism and the electrode assembly is extremely small, so that the high-pressure gas inside the shell is not easy to reach the pressure relief mechanism. When the battery cell occurs thermal runaway, it is easy to cause fire, explosion and other risks due to the blocking of the pressure relief mechanism by the bottom plate, thereby reducing the reliability of the battery cell. SUMMARY

[0005] In view of the above problems, the present application provides a battery cell, a battery device and an electric equipment to reduce or eliminate the risk of fire, explosion and the like caused by thermal runaway of the battery cell, thereby improving the reliability of the battery cell.

[0006] In a first aspect, the application provides a battery cell, comprising: a shell formed with an accommodation space, the shell comprising a first wall portion provided with a pressure relief mechanism, a dimension of the pressure relief mechanism along a first direction being L1 and a dimension of the pressure relief mechanism along a second direction perpendicular to the first direction being L2, wherein L1>L2; an electrode assembly arranged in the accommodation space; and a bottom support plate arranged in the accommodation space and between the first wall portion and the electrode assembly along a third direction perpendicular to the first direction and the second direction, for supporting the electrode assembly, wherein the bottom support plate comprises a plate body and a first support portion, the plate body has a first region and a second region arranged along the second direction, a normal projection of the pressure relief mechanism on the plate body along the third direction is located in the first region, at least one first support portion is arranged on a side of the second region of the plate body facing the first wall portion, a side of the first support portion away from the plate body abuts against the first wall portion, and a dimension of the first support portion along the first direction is less than L1, so as to form a gap between the second region of the plate body and the first wall portion, and the gap is in communication with a space on a side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. By arranging the bottom support plate between the first wall portion where the pressure relief mechanism is located and the electrode assembly, and arranging the normal projection of the pressure relief mechanism on the plate body along the third direction in the first region of the plate body, the first region and the second region of the plate body are arranged along the second direction, and at least one first support portion is arranged on the side of the second region of the plate body facing the first wall portion, and the dimension of the first support portion along the first direction is less than the dimension L1 of the pressure relief mechanism along the first direction, so as to form a gap between the second region of the plate body and the first wall portion, and the gap is in communication with the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. On the one hand, since the dimension L1 of the pressure relief mechanism along the first direction is greater than the dimension L2 of the pressure relief mechanism along the second direction, arranging at least one first support portion on the second region of the plate body can improve the support stability of the bottom support plate and reduce or eliminate the risk of the region of the bottom support plate corresponding to the pressure relief mechanism sagging or collapsing towards the pressure relief mechanism, thereby reducing the possibility of the bottom support plate blocking the pressure relief mechanism, reducing or eliminating the risk of fire or explosion caused by the bottom support plate blocking the pressure relief mechanism when the battery cell is in thermal runaway, and improving the reliability of the battery cell. On the other hand, since the second region of the plate body and the pressure relief mechanism are arranged along the second direction, the speed of high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism flowing to the pressure relief mechanism can be improved, so that the pressure inside the accommodation space can be quickly released, thereby maintaining the balance of the gas pressure inside and outside the battery cell, reducing or eliminating the risk of fire or explosion caused by the battery cell in thermal runaway, and further improving the reliability of the battery cell.

[0007] In some embodiments, the second region is provided with a plurality of first support portions towards the side of the first wall portion, and the plurality of first support portions are spaced apart along the first direction. By spacing apart the plurality of first support portions along the first direction, a plurality of gaps are formed between the plate body and the first wall portion, which are spaced apart along the first direction. This not only further improves the discharge efficiency and stability of the high-pressure gas on the side of the plate body away from the pressure relief mechanism, so that the pressure relief mechanism can continuously and efficiently relieve pressure, thereby improving the pressure relief efficiency, but also reduces the discharge noise of the high-pressure gas, thereby improving the user experience.

[0008] In some embodiments, the sum of the dimensions of the plurality of first support portions along the first direction is L3, and the dimension of the first support portion along the third direction is h, wherein 0.21≤h×(L1-L3) / L1≤1.11. By making the product of the ratio between the difference between the dimension L1 of the pressure relief mechanism along the first direction and the sum L3 of the dimensions of the plurality of first support portions along the first direction X-X and the dimension L1 of the pressure relief mechanism along the first direction and the dimension h of the first support portion along the third direction satisfy 0.21≤h×(L1-L3) / L1≤1.11, the sum of the flow areas of the gaps in the first direction and the third direction is large, so that the high-pressure gas generated when the battery cell is in thermal runaway can more smoothly reach the pressure relief mechanism, and the pressure relief rate of the pressure relief mechanism can be much greater than the pressure rise rate inside the second accommodating cavity, thereby reducing the risk of fire, explosion, and the like of the battery cell.

[0009] In some embodiments, the plate body has two second regions, which are respectively located on opposite sides of the first region along the second direction, and the first support portion is arranged towards the side of each of the two second regions away from the first wall portion. By distributing the two second regions on opposite sides of the first region along the second direction and arranging the first support portion towards the side of each of the two second regions away from the first wall portion, on the one hand, the support force can be uniformly distributed on the bottom support plate, thereby reducing or eliminating the risk of the bottom support plate shaking, tilting, and sagging or collapsing towards the pressure relief mechanism, so that the bottom support plate can stably support the electrode assembly, thereby reducing the risk of displacement or damage of the battery cell, and further improving the reliability of the battery device; on the other hand, a plurality of gaps are formed on opposite sides of the first region along the second direction, which communicate the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism, thereby increasing the exhaust path and exhaust area inside the battery cell, making the exhaust more smooth, and being conducive to improving the exhaust efficiency.

[0010] In some embodiments, the first support portion comprises a composite layer protruding from a side of the plate body facing the first wall portion. The composite layer has better high-temperature resistance, so that the first support portion will not be damaged by the heat flowing through when the battery cell is in thermal runaway, and the risk of the bottom plate shaking, tilting, or sagging or collapsing towards the pressure relief mechanism due to the damage of the first support portion by heat can be reduced or eliminated, so that the high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism can be normally discharged to the pressure relief mechanism, thereby inhibiting the chain reaction caused by the thermal runaway of the battery cell, so that the bottom plate can provide sufficient safety protection when the battery cell is in thermal runaway.

[0011] In some embodiments, the side of the plate body close to the electrode assembly abuts against the electrode assembly. By abutting the side of the plate body close to the electrode assembly against the electrode assembly, the plate body can be stably supported on the plate body, so that the electrode assembly will not displace or deform during use of the battery device, and thus the plate body can support and protect the electrode assembly; and the high-pressure gas and heat in the battery cell can quickly flow through the gap between the second region of the plate body and the first wall portion to the pressure relief mechanism, reducing or avoiding the gas and heat remaining between the electrode assembly and the plate body.

[0012] In some embodiments, the distance between the first support portion and the pressure relief mechanism in the second direction is d, where d≥2mm. By making the distance d between the first support portion and the pressure relief mechanism in the second direction greater than or equal to 2mm, on the one hand, the risk of the first support portion blocking the pressure relief mechanism can be reduced, so that the high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism can smoothly reach the pressure relief mechanism; on the other hand, since the pressure near the pressure relief mechanism is relatively large and the temperature is also relatively high, by separating the first support portion from the pressure relief mechanism by a certain distance, the risk of the gas pressure and heat damaging the first support portion can be reduced, thereby reducing the risk of the bottom plate blocking the pressure relief mechanism due to shaking, tilting, or sagging or collapsing towards the pressure relief mechanism.

[0013] In some embodiments, the first region is provided with a first through hole; and / or the region of the second region where the first support portion is not provided is provided with a second through hole. By providing the first through hole on the first region of the plate body and / or the second through hole on the second region of the plate body, the first through hole and the second through hole both communicate the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism, so that when the battery cell is in thermal runaway, the high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism will not accumulate on the side of the bottom plate away from the first wall portion, and can play a role in alleviating the intensification of thermal runaway.

[0014] In some embodiments, the plate body further comprises a third region and a fourth region, the third region and the fourth region are respectively located on opposite sides of the first region along the first direction; a second support portion is arranged on a side of the third region facing the first wall portion and / or a side of the fourth region facing the first wall portion, the second support portion is arranged spaced apart from the first support portion, and a side of the second support portion facing away from the plate body abuts against the first wall portion. By arranging the second support portion on the side of the third region and / or the fourth region facing the first wall portion, and the side of the second support portion facing away from the plate body abutting against the first wall portion, the support capacity and protection effect of the electrode assembly by the support plate can be improved, and the risk of the electrode assembly shaking or displacing can be reduced.

[0015] In some embodiments, the shell further comprises a second wall portion and a third wall portion arranged opposite in the second direction, and the first wall portion is connected between the second wall portion and the third wall portion; in the third region, a first channel is formed between the second support portion and the second wall portion and / or between the second support portion and the third wall portion, and the first channel communicates a space on a side of the plate body facing away from the pressure relief mechanism and the pressure relief mechanism; in the fourth region, a second channel is formed between the second support portion and the second wall portion and / or between the second support portion and the third wall portion, and the second channel communicates the space on the side of the plate body facing away from the pressure relief mechanism and the pressure relief mechanism. By arranging the first channel and the second channel to increase the exhaust path and the exhaust area inside the battery monomer, the high-pressure gas in the space on the side of the plate body facing away from the pressure relief mechanism can flow to the pressure relief mechanism through the first channel and the second channel in addition to flowing to the pressure relief mechanism through the gap between the second region of the plate body and the first wall portion, which can further improve the release rate of the pressure inside the containing space, further reduce the probability of causing fire, explosion, etc. when the battery monomer is in thermal runaway, and further improve the reliability of the battery monomer, so that the reliability of the battery device is further improved.

[0016] In some embodiments, the second support portion comprises a first sub-support portion and a second sub-support portion arranged spaced apart along the second direction, and a third channel is formed between the first sub-support portion and the second sub-support portion, and the third channel communicates the space on the side of the plate body facing away from the pressure relief mechanism and the pressure relief mechanism. By forming the third channel between the first sub-support portion and the second sub-support portion, the exhaust path and the exhaust area inside the battery monomer are further increased, so that the exhaust amount can be more effectively increased when the battery monomer is in thermal runaway, and the accumulation of pressure inside the containing space is further reduced, thereby further reducing the impact of thermal runaway on the battery monomer.

[0017] In some embodiments, the third region and / or the fourth region where the second support portion is not arranged is provided with a third through hole. By arranging the third through hole in the third region and / or the fourth region where the second support portion is not arranged, the third through hole communicates the space on the side of the plate body away from the pressure relief mechanism with the pressure relief mechanism, so that when the battery cell is in thermal runaway, the high-pressure gas in the space on the side of the plate body away from the pressure relief mechanism can flow to the pressure relief mechanism through the third through hole, further reducing the air pressure on the side of the bottom support plate away from the first wall portion, and further relieving the thermal runaway.

[0018] In some embodiments, the area S1 of the pressure relief mechanism in the preset plane and the area S2 of the first wall portion in the preset plane satisfy: S1 / S2≥0.5; and the preset plane is parallel to the first direction and the second direction. By making the area S1 of the pressure relief mechanism in the preset plane and the area S2 of the first wall portion in the preset plane satisfy: S1 / S2≥0.5, the area of the pressure relief mechanism is larger, which can more effectively release the pressure and heat inside the containing space, thereby reducing the air pressure and temperature inside the containing space, reducing the risk of fire, explosion, etc. of the electrode assembly, and further improving the reliability of the battery device.

[0019] In a second aspect, the present application provides a battery device, which comprises a box body and the battery cell in any of the above embodiments, and the battery cell is arranged in the box body.

[0020] In a third aspect, the present application provides a power consumption device, which comprises the above battery device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments and are not to be considered as restrictive of the application. Moreover, in the drawings, like reference numerals refer to similar components throughout the several views. In the drawings:

[0022] FIG. 1 is a structural schematic diagram of an embodiment of a power consumption device provided by the present application;

[0023] FIG. 2 is an exploded structural schematic diagram of an embodiment of a battery device provided by the present application;

[0024] FIG. 3 is a structural schematic diagram of an embodiment of a battery cell provided by the present application after the structure of a part is exploded;

[0025] FIG. 4 is a structural schematic diagram of a first embodiment of a bottom support plate of a battery device provided by the present application;

[0026] FIG. 5 is a structural schematic diagram of a second embodiment of a bottom support plate of a battery device provided by the present application;

[0027] Fig. 6 is a structural schematic diagram of a third embodiment of a bottom support plate of a battery device provided by the present application;

[0028] Fig. 7 is a structural schematic diagram of a fourth embodiment of a bottom support plate of a battery device provided by the present application;

[0029] Fig. 8 is a structural schematic diagram of a fifth embodiment of a bottom support plate of a battery device provided by the present application.

[0030] The reference signs in the detailed description of the embodiments are as follows: vehicle 1000a, battery cell 20, housing 21, accommodation space 21a, first wall portion 211, second wall portion 212, third wall portion 213, opening portion 2111, pressure relief mechanism 22, bottom support plate 24, plate body 241, first region 2411, second region 2412, third region 2413, fourth region 2414, first support portion 242, composite layer 2421, second support portion 243, first sub-support portion 2431, second sub-support portion 2432, gap 242a, first gap 242a1, second gap 242a2, first through hole 2411a, second through hole 2412a, third through hole 2413a, first channel 244, second channel 245, third channel 246, protective film 25, explosion-proof valve 30, thermal insulation pad 40, busbar member 50, protective member 60, battery device 100a, controller 200a, motor 300a, box 10, first portion 11, second portion 12. DETAILED DESCRIPTION

[0031] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0033] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0035] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0037] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate heat medium; it can be the communication inside two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] With the development of battery technology, battery devices are applied to more and more fields, and gradually replace traditional petrochemical energy in the field of automobile power and the like. In order to effectively release the pressure inside the shell of the battery monomer, a pressure relief mechanism is arranged on the shell of the battery monomer. The pressure relief mechanism can quickly respond and release the high-pressure gas inside the shell when the battery monomer is in thermal runaway, so as to reduce the pressure inside the shell, thereby reducing the accumulation of heat and gas pressure inside the shell. If the electrode assembly is directly supported on the pressure relief mechanism, the distance between the pressure relief mechanism and the electrode assembly will be extremely small, and the high-pressure gas inside the shell will not be easily discharged through the pressure relief mechanism.

[0039] In the related art, a bottom support plate is supported between the pressure relief mechanism and the electrode assembly to increase the distance between the pressure relief mechanism and the electrode assembly, so as to facilitate the high-pressure gas inside the shell to reach the pressure relief mechanism and be discharged through the pressure relief mechanism. However, the support portion of the existing bottom support plate is arranged outside both ends of the bottom support plate along the length direction of the pressure relief mechanism. When the length of the pressure relief mechanism is relatively long, the region corresponding to the bottom support plate and the pressure relief mechanism is prone to sag or collapse towards the pressure relief mechanism, and there is a risk of blocking the pressure relief mechanism. When the battery monomer occurs thermal runaway, the bottom support plate is prone to block the pressure relief mechanism, which may cause fire, explosion and other risks, thereby reducing the reliability of the battery device.

[0040] Based on the above considerations, the present application provides a battery monomer, a battery device and an electric equipment. The battery monomer comprises a shell, an electrode assembly and a bottom support plate. The shell forms an accommodation space. The shell comprises a first wall portion, and the first wall portion is provided with a pressure relief mechanism. The size of the pressure relief mechanism along a first direction is defined as L1, and the size of the pressure relief mechanism along a second direction perpendicular to the first direction is defined as L2, wherein L1>L2. The electrode assembly is arranged in the accommodation space. The bottom support plate is arranged in the accommodation space and is arranged between the first wall portion and the electrode assembly along a third direction to support the electrode assembly. The third direction is perpendicular to the first direction and the second direction. The bottom support plate comprises a plate body and a first support portion. The plate body has a first region and a second region arranged along the second direction. The orthographic projection of the pressure relief mechanism on the plate body along the third direction is located in the first region. At least one first support portion is arranged on the side of the second region of the plate body facing the first wall portion. The side of the first support portion away from the plate body abuts against the first wall portion. The size of the first support portion along the first direction is smaller than L1, so as to form a gap between the second region of the plate body and the first wall portion. The gap is connected with the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. The side of the first support portion away from the plate body abuts against the first wall portion.

[0041] By setting the bottom supporting plate between the first wall part where the pressure relief mechanism is located and the electrode assembly, and the orthographic projection of the pressure relief mechanism on the plate body in the third direction is located in the first region of the plate body, the first region and the second region of the plate body are arranged in the second direction, at least one first supporting part is arranged on the side of the second region of the plate body facing the first wall part, and the size of the first supporting part in the first direction is smaller than the size L1 of the pressure relief mechanism in the first direction, so as to form a gap between the second region of the plate body and the first wall part, and the gap is communicated with the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism. On the one hand, since the size L1 of the pressure relief mechanism in the first direction is larger than the size L2 of the pressure relief mechanism in the second direction, at least one first supporting part is arranged in the second region of the plate body, which can improve the supporting stability of the bottom supporting plate, reduce or eliminate the risk of the corresponding area of the bottom supporting plate sagging or collapsing towards the pressure relief mechanism, thereby reducing the possibility of the bottom supporting plate blocking the pressure relief mechanism, reducing or eliminating the risk of fire, explosion and the like caused by the bottom supporting plate blocking the pressure relief mechanism when the battery monomer is in thermal runaway, and improving the reliability of the battery monomer. On the other hand, since the second region of the plate body and the pressure relief mechanism are arranged in the second direction, the rate of high-pressure gas flowing from the space on the side of the plate body away from the pressure relief mechanism to the pressure relief mechanism can be improved, so that the pressure inside the accommodation space can be quickly released, thereby maintaining the balance of the gas pressure inside and outside the battery monomer, reducing or eliminating the risk of fire, explosion and the like caused by the battery monomer in thermal runaway, and further improving the reliability of the battery monomer.

[0042] The battery monomer, the battery device and the electric equipment disclosed by the embodiments of the present application can be used in electric equipment using the battery device as a power supply or various energy storage systems using the battery device as an energy storage element. The electric equipment can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft and the like. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric automobile toys, electric ship toys and electric aircraft toys and the like, and the spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft and the like.

[0043] The following embodiments are described by taking a vehicle 1000a as an example for convenience of description.

[0044] Referring to FIG. 1, the vehicle 1000a can be a pure electric vehicle, a hybrid vehicle, or a range extended vehicle, etc. The vehicle 1000a is internally provided with a battery device 100a, which can be arranged at the bottom of the vehicle 1000a. The battery device 100a can be used for power supply of the vehicle 1000a, for example, the battery device 100a can be used as an operating power source of the vehicle 1000a. The vehicle 1000a can further include a controller 200a and a motor 300a, the controller 200a is used to control the battery device 100a to supply power to the motor 300a, for example, for the power demand of starting, navigation and driving of the vehicle 1000a.

[0045] In some embodiments of the present application, the battery device 100a can not only be used as an operating power source of the vehicle 1000a, but also be used as a driving power source of the vehicle 1000a, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000a.

[0046] In some embodiments, the battery device 100a can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0047] Referring to FIG. 2, the battery device 100a mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells 20 connected in series, in parallel or in a mixed manner through a busbar component 50. Two adjacent busbar components 50 are provided with a protection component 60. The protection component 60 can be an insulating member, which can reduce or eliminate the risk of short circuit caused by direct contact between the two adjacent busbar components 50, and can improve the reliability of the battery device 100a.

[0048] In some embodiments, a heat insulation pad 40 is arranged between two adjacent battery cells 20. The heat insulation pad 40 can not only reduce or eliminate the heat transfer between the two adjacent battery cells 20, reduce the risk of affecting other battery cells 20 due to the temperature of one battery cell 20 being too high, but also can fix the battery cells 20, so that the battery cells 20 do not swing during use, and reduce or eliminate the risk of interference between the two adjacent battery cells 20.

[0049] In the embodiments of the present application, the battery cell 20 can be a secondary battery, which refers to a battery cell 20 that can be activated by charging after discharging.

[0050] The battery cell 20 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc., which is not limited in the embodiments of the present application.

[0051] In some embodiments, the battery device 100a comprises a box 10 and battery cells 20 arranged in the box 10.

[0052] In some embodiments, the box 10 can be a part of the chassis structure of the vehicle 1000a. For example, the box 10 can be at least a part of the chassis of the vehicle 1000a, or the box 10 can be at least a part of the cross beam and the longitudinal beam of the vehicle 1000a.

[0053] Please continue to refer to FIG. 2, the box 10 can have various structures. In some embodiments, the box 10 can comprise a first part 11 and a second part 12, the first part 11 and the second part 12 are overlapped with each other, and the first part 11 and the second part 12 together define a receiving cavity 10a for accommodating the battery cells 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate structure, which is overlapped with the open end of the second part 12 to define the receiving cavity 10a together with the second part 12. Alternatively, the first part 11 and the second part 12 can both be hollow structures with one side open, and the open end of the first part 11 is overlapped with the open end of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0054] In some embodiments, the first part 11 is provided with an explosion-proof valve 30, which can be automatically opened when the pressure in the receiving cavity 10a exceeds a safe range, so as to release the high-pressure gas in the receiving cavity 10a, thereby reducing or eliminating the risk of fire or explosion due to excessive internal pressure in the receiving cavity 10a.

[0055] In some embodiments, referring to FIGS. 2-5, the battery cell 20 includes a housing 21, an electrode assembly, and a bottom support plate 24. The housing 21 forms an accommodation space 21a, and includes a first wall portion 211 provided with a pressure relief mechanism 22. The pressure relief mechanism 22 has a dimension L1 along a first direction X-X and a dimension L2 along a second direction Y-Y perpendicular to the first direction X-X, where L1>L2. The electrode assembly is disposed in the accommodation space 21a. The bottom support plate 24 is disposed in the accommodation space 21a and between the first wall portion 211 and the electrode assembly along a third direction Z-Z perpendicular to the first direction X-X and the second direction Y-Y, and is configured to support the electrode assembly. The bottom support plate 24 includes a plate body 241 and a first support portion 242. The plate body 241 has a first region 2411 and a second region 2412 arranged along the second direction Y-Y. A normal projection of the pressure relief mechanism 22 on the plate body 241 along the third direction Z-Z is located in the first region 2411. The second region 2412 is provided with at least one first support portion 242 on a side facing the first wall portion 211. The first support portion 242 is in abutment with the first wall portion 211 on a side facing away from the plate body 241. The first support portion 242 has a dimension along the first direction X-X smaller than L1, so as to form a gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211. The gap 242a is in communication with a space 21a on a side of the plate body 241 facing away from the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0056] The housing 21 is a component for accommodating the electrode assembly. The housing 21 can be a hollow structure having an opening at one end. The opening is located on a different side from the first wall portion 211. The battery cell 20 further includes an end cover assembly covering the opening and connected with the housing 21, so as to form the accommodation space 21a for accommodating the electrode assembly. The accommodation space 21a is filled with an electrolyte, such as an electrolyte solution. The housing 21 can have various shapes, such as a square, a cuboid, a cylinder, a prism, etc. The embodiments of the present application take the cuboid as an example for illustration.

[0057] The electrode assembly is a component in which electrochemical reactions occur in the battery cell 20. The battery cell 20 includes one or more electrode assemblies. The electrode assembly has a positive electrode tab, a negative electrode tab, and a separator, which are wound or stacked to form the electrode assembly, with the separator being located between the positive electrode tab and the negative electrode tab. The positive electrode tab and the negative electrode tab have portions of active material that constitute a main body of the electrode assembly, and portions of the positive electrode tab and the negative electrode tab that do not have active material constitute positive and negative electrode tabs, respectively. The positive and negative electrode tabs can be located together at one end of the main body or at opposite ends of the main body. During charging and discharging of the battery, the positive and negative active materials react with the electrolyte, and the positive and negative electrode tabs are connected to electrode terminals to form a current loop.

[0058] In some embodiments, the housing 21 is provided with a pressure relief mechanism 22. The pressure relief mechanism 22 is used to release the internal pressure of the battery cell 20.

[0059] As an example, the pressure relief mechanism 22 is actuated to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 20 reaches the predetermined threshold, the pressure relief mechanism 22 performs an action or a weak structure provided in the pressure relief mechanism 22 is broken, thereby forming an opening or passage for the internal pressure or temperature to be released. The threshold value is designed differently according to design requirements. The threshold value can depend on the material of one or more of the positive electrode tab, the negative electrode tab, the electrolyte, and the separator in the battery cell 20.

[0060] As an example, the pressure relief mechanism 22 can be integrally formed with the housing 21, for example, a notch is made on the housing 21 to form a weak structure, which serves as the pressure relief mechanism 22.

[0061] The pressure relief mechanism 22 can also be provided separately from the housing 21 and connected thereto, for example, the pressure relief mechanism 22 is connected to the housing 21 by welding or other components. As an example, a notch is provided on the pressure relief mechanism 22 to form a weak structure.

[0062] As an example, the pressure relief mechanism 22 can take the form of a rupture disc, a balance valve, a gas valve, a pressure relief valve, or a safety valve, etc.

[0063] In some embodiments, the pressure relief mechanism 22 is provided on a first wall portion 211 of the housing, which can be a bottom wall or a side wall of the housing 21. The bottom support plate 24 can be provided between the bottom wall of the housing 21 and the electrode assembly, or between the side wall of the housing 21 and the electrode assembly. The present application takes the first wall portion 211 as the bottom wall of the housing 21, and the bottom support plate 24 is provided between the bottom wall of the housing 21 and the electrode assembly as an example for illustration.

[0064] In some embodiments, as shown in FIG. 3, the first wall portion 211 has an opening portion 2111. The opening portion 2111 communicates the accommodating cavity 10a and the accommodation space 21a. The pressure relief mechanism 22 is arranged at the opening portion 2111 of the first wall portion 211. The pressure relief mechanism 22 can quickly respond when the battery cell 20 occurs thermal runaway and release the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 to the accommodating cavity 10a, thereby reducing the pressure in the accommodation space 21a and reducing the accumulation of heat and gas pressure.

[0065] The plane in which the first wall portion 211 is located is parallel to the first direction X-X and the second direction Y-Y. The pressure relief mechanism 22 extends along the first direction X-X, the size of the pressure relief mechanism 22 along the first direction X-X is L1, the size of the pressure relief mechanism 22 along the second direction Y-Y is L2, and the first size L1 of the pressure relief mechanism 22 is greater than the second size L2.

[0066] The electrode assembly, the bottom support plate 24, and the first wall portion 211 are arranged in the third direction Z-Z. The bottom support plate 24 not only can support the electrode assembly, but also can increase the distance between the electrode assembly and the first wall portion 211, so that the electrode assembly does not block the pressure relief mechanism 22.

[0067] The pressure relief mechanism 22 corresponds to the first region 2411 of the plate body 241, the second region 2412 of the plate body 241 corresponds to the region where the pressure relief mechanism 22 is not arranged on at least one side of the first wall portion 211 along the second direction Y-Y, and the first support portion 242 arranged on the side of the second region 2412 towards the first wall portion 211 is arranged spaced apart from the pressure relief mechanism 22, so that the first support portion 242 does not damage the pressure relief mechanism 22 or affect the normal pressure relief of the pressure relief mechanism 22.

[0068] In some embodiments, as shown in FIG. 3, the battery device 100a further comprises a protective film 25. The protective film 25 is arranged on the side of the pressure relief mechanism 22 away from the bottom support plate 24. The protective film 25 is used to protect the pressure relief mechanism and can reduce the influence of dust and other impurities on the pressure relief mechanism 22.

[0069] In some embodiments, the first support portion 242 is integrally formed on the side of the plate body 241 towards the first wall portion 211; or the first support portion 242 is fixedly connected to the side of the plate body 241 towards the first wall portion 211. The way in which the first support portion 242 is fixedly connected to the plate body 241 includes but is not limited to gluing or welding.

[0070] In some embodiments, the bottom support plate 24 can be selected from a metal material or a non-metal material. When the bottom support plate 24 is selected from a metal material, the material of the bottom support plate 24 can be aluminum, copper, aluminum alloy, aluminum-manganese alloy, or stainless steel, but is not limited thereto. When the bottom support plate 24 is selected from a non-metal material, the material of the bottom support plate 24 can be polyethylene, polypropylene, polyimide, polytetrafluoroethylene, polyfluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, or propylene-tetrafluoroethylene copolymer, but is not limited thereto.

[0071] In some embodiments, the bottom support plate 24 can be selected from a metal material or a non-metal material. When the bottom support plate 24 is selected from a metal material, the material of the bottom support plate 24 can be aluminum, copper, aluminum alloy, aluminum-manganese alloy, or stainless steel, but is not limited thereto. When the bottom support plate 24 is selected from a non-metal material, the material of the bottom support plate 24 can be polyethylene, polypropylene, polyimide, polytetrafluoroethylene, polyfluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, or propylene-tetrafluoroethylene copolymer, but is not limited thereto. When the bottom support plate 24 is selected from a metal material, the material of the bottom support plate 24 can be aluminum, copper, aluminum alloy, aluminum-manganese alloy, or stainless steel, but is not limited thereto. When the bottom support plate 24 is selected from a non-metal material, the material of the bottom support plate 24 can be polyethylene, polypropylene, polyimide, polytetrafluoroethylene, polyfluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, or propylene-tetrafluoroethylene copolymer, but is not limited thereto.

[0072] In some embodiments, the second region 2412 toward the first wall portion 211 is provided with a plurality of first support portions 242, and the plurality of first support portions 242 are arranged at intervals along the first direction X-X.

[0073] By arranging the plurality of first support portions 242 along the first direction X-X, a plurality of gaps 242a arranged along the first direction X-X are formed between the plate body 241 and the first wall portion 211, which not only further improves the discharge efficiency and stability of the high-pressure gas on the side of the plate body 241 away from the pressure relief mechanism 22, so that the pressure relief mechanism 22 can continuously and efficiently relieve pressure, which helps to improve the pressure relief efficiency, but also reduces the discharge noise of the high-pressure gas, improving the user experience.

[0074] In some embodiments, as shown in FIG. 1, the sum of the dimensions of the plurality of first support portions 242 along the first direction X-X is defined as L3, and the dimension of the first support portion 242 along the third direction Z-Z is h, where 0.21≤h×(L1-L3) / L1≤1.11.

[0075] Wherein the dimension of the first support portion 242 along the third direction Z-Z is the thickness of the first support portion 242.

[0076] Wherein 0.21≤h×(L1-L3) / L1≤1.11 represents that the product of the ratio between the difference between the size L1 of the pressure relief mechanism 22 along the first direction X-X and the sum L3 of the dimensions of the plurality of first support portions 242 arranged along the first direction X-X along the first direction X-X, and the size L1 of the pressure relief mechanism 22 along the first direction X-X, and the dimension h of the first support portion 242 along the third direction Z-Z is greater than or equal to 0.21 and less than or equal to 1.11.

[0077] The product of the ratio between the difference between the size L1 of the pressure relief mechanism 22 along the first direction X-X and the sum L3 of the dimensions of the plurality of first support portions 242 arranged along the first direction X-X along the first direction X-X, and the size L1 of the pressure relief mechanism 22 along the first direction X-X, and the dimension h of the first support portion 242 along the third direction Z-Z can be 0.21, 0.25, 0.28, 0.3, 0.322, 0.351, 0.388, 0.4, 0.42, 0.455, 0.467, 0.49, 0.5, 0.52, 0.545, 0.56, 0.58, 0.6, 0.615, 0.63, 0.65, 0.675, 0.691, 0.7, 0.735, 0.75, 0.77, 0.785, 0.8, 0.825, 0.85, 0.88, 0.9, 0.93, 0.95, 0.968, 0.98, 1, 1.11, etc. The specific product can be selected according to actual needs, as long as the above product is within the range of 0.21 to 1.11.

[0078] By making the ratio between the difference between the sum L3 of the sizes of the plurality of first support portions 242 along the first direction X-X and the size L1 of the pressure relief mechanism 22 along the first direction X-X and the size L1 of the pressure relief mechanism 22 along the first direction X-X satisfy 0.21≤h×(L1-L3) / L1≤1.11, the sum of the flow areas of the gaps 242a in the first direction X-X and the third direction Z-Z is large, so that the high-pressure gas generated when the battery monomer 20 is in thermal runaway can more smoothly reach the pressure relief mechanism 22, and the pressure relief rate of the pressure relief mechanism 22 can be much greater than the pressure rise rate inside the second containing cavity, thereby reducing the risk of fire, explosion, and the like of the battery monomer 20.

[0079] In some embodiments, please continue to refer to FIGS. 4-5, the plate body 241 has two second regions 2412, which are respectively located on opposite sides of the first region 2411 along the second direction Y-Y, and each of the two second regions 2412 is provided with a first support portion 242 on the side facing the first wall portion 211.

[0080] In some embodiments, the first support portions 242 on the two second regions 2412 are one-to-one corresponding.

[0081] In some embodiments, the first support portions 242 on the two second regions 2412 are staggered.

[0082] By distributing the two second regions 2412 on opposite sides of the first region 2411 along the second direction Y-Y, and arranging the first support portions 242 on the side of the two second regions 2412 facing the first wall portion 211, on the one hand, the support force can be uniformly distributed on the bottom support plate 24, reducing or eliminating the risk of the bottom support plate 24 shaking, tilting, and sagging or collapsing towards the pressure relief mechanism 22, so that the bottom support plate 24 can stably support the electrode assembly, thereby reducing the risk of displacement or damage of the battery monomer 20, and further improving the reliability of the battery device 100a; on the other hand, the opposite sides of the first region 2411 along the second direction Y-Y are both formed with spaces communicating with the side of the plate body 241 away from the pressure relief mechanism 22 and the plurality of gaps 242a of the pressure relief mechanism 22, which can increase the exhaust path and exhaust area inside the battery monomer 20, making the exhaust more smooth, and is beneficial to improving the exhaust efficiency.

[0083] In some embodiments, please continue to refer to FIG. 4, the first support portion 242 comprises a composite layer 2421 protruding from the side of the plate body 241 facing the first wall portion 211.

[0084] In some embodiments, the composite layer 2421 can be composed of two or more polymeric materials such as polyethylene, polypropylene, polyimide, polytetrafluoroethylene, etc., but the material of the composite layer 2421 is not limited to the above-mentioned polymeric materials.

[0085] In some embodiments, the composite layer 2421 can be composed of two or more metallic materials such as copper, aluminum, aluminum alloy, aluminum-manganese alloy, stainless steel, etc., but the material of the composite layer 2421 is not limited to the above-mentioned metallic materials.

[0086] The composite layer 2421 has better high-temperature resistance, so that the first support part 242 will not be damaged by the heat flowing through when the battery cell 20 is in thermal runaway, and the risk of the bottom support plate 24 being shaken, tilted, or sagging or collapsing towards the pressure relief mechanism 22 due to the damage of the first support part 242 by heat can be reduced or eliminated, so that the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can be normally discharged to the pressure relief mechanism 22, thereby inhibiting the chain reaction caused by the thermal runaway of the battery cell 20, so that the bottom support plate 24 can provide sufficient safety protection when the battery cell 20 is in thermal runaway.

[0087] In some embodiments, the side of the plate body 241 close to the electrode assembly abuts against the electrode assembly.

[0088] In some embodiments, the side of the plate body 241 close to the electrode assembly is a flat surface.

[0089] By abutting the side of the plate body 241 close to the electrode assembly against the electrode assembly, the plate body 241 can be stably supported on the plate body 241, so that the electrode assembly will not displace or deform during the use of the battery device 100a, and thus the plate body 241 can support and protect the electrode assembly; and the high-pressure gas and heat in the battery cell 20 can quickly flow through the gap 242a between the second region 2412 of the plate body 241 and the first wall part 211 to the pressure relief mechanism 22, reducing or avoiding the gas and heat remaining between the electrode assembly and the plate body 241.

[0090] In some embodiments, please continue to refer to FIG. 5, along the second direction Y-Y, the distance between the first support part 242 and the pressure relief mechanism 22 is d, and d≥2mm.

[0091] In the second direction Y-Y, the distance d between the first support portion 242 and the pressure relief mechanism 22 can be 2 mm, 2.15 mm, 2.35 mm, 2.5 mm, 2.75 mm, 2.9 mm, 3 mm, 3.15 mm, 3.33 mm, 3.5 mm, 3.65 mm, 3.88 mm, 4 mm, 4.33 mm, 4.5 mm, 4.85 mm, 5 mm, etc. The specific value of the distance can be selected according to actual needs, as long as the distance is greater than or equal to 2 mm.

[0092] By making the distance d between the first support portion 242 and the pressure relief mechanism 22 in the second direction Y-Y greater than or equal to 2 mm, on the one hand, the risk of the first support portion 242 blocking the pressure relief mechanism 22 can be reduced, so that the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can smoothly reach the pressure relief mechanism 22. On the other hand, since the pressure near the pressure relief mechanism 22 is relatively high, and the temperature is also relatively high, by making the first support portion 242 a certain distance away from the pressure relief mechanism 22, the risk of the gas pressure and heat damaging the first support portion 242 can be reduced, thereby reducing the risk of the support plate 24 shaking, tilting, or sagging or collapsing toward the pressure relief mechanism 22 and blocking the pressure relief mechanism 22.

[0093] In some embodiments, referring to FIG. 6, the first region 2411 is provided with a first through hole 2411a; and / or the region of the second region 2412 where the first support portion 242 is not provided is provided with a second through hole 2412a.

[0094] The first through hole 2411a and the second through hole 2412a each penetrate the plate body 241 in the third direction Z-Z and communicate the accommodation space 21a and the pressure relief mechanism 22.

[0095] In some embodiments, the first region 2411 is provided with one first through hole 2411a, and the shape of the first through hole 2411a can be the same as that of the pressure relief mechanism 22, and the first through hole 2411a can correspond to the pressure relief mechanism 22.

[0096] In some embodiments, the first region 2411 is provided with a plurality of first through holes 2411a, and the plurality of first through holes 2411a are arranged at intervals in the first direction X-X. The shape of the first through hole 2411a can be circular, elliptical, square, or other shapes.

[0097] In some embodiments, a second through hole 2412a is arranged between two adjacent first support portions 242. The number of through holes between the two adjacent first support portions 242 can be one or more. The shape of the second through hole 2412a can be circular, elliptical, square, or other shapes.

[0098] By arranging the first through hole 2411a on the first region 2411 of the plate body 241 and / or the second through hole 2412a on the second region 2412 of the plate body 241, the first through hole 2411a and the second through hole 2412a both communicate the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22, so that when the battery monomer 20 occurs thermal runaway, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 will not be gathered on the side of the bottom support plate 24 away from the first wall part 211, which can play a role in relieving the aggravation of thermal runaway.

[0099] In some embodiments, referring to FIG. 7, the plate body 241 further includes a third region 2413 and a fourth region 2414, the third region 2413 and the fourth region 2414 are respectively located on the opposite sides of the first region 2411 along the first direction X-X; the side of the third region 2413 facing the first wall part 211 and / or the side of the fourth region 2414 facing the first wall part 211 is provided with a second support part 243, the second support part 243 is arranged in a spaced manner with the first support part 242, and the side of the second support part 243 away from the plate body 241 abuts against the first wall part 211.

[0100] The second support part 243 is integrally formed on the side of the third region 2413 and / or the fourth region 2414 facing the first wall part 211, or the second support part 243 is fixedly connected to the side of the third region 2413 and / or the fourth region 2414 facing the first wall part 211. The way of fixedly connecting the second support part 243 to the third region 2413 and / or the fourth region 2414 includes but is not limited to gluing or welding.

[0101] By arranging the second support part 243 on the side of the third region 2413 and / or the fourth region 2414 facing the first wall part 211, and the side of the second support part 243 away from the plate body 241 abutting against the first wall part 211, the support ability and protection effect of the bottom support plate 24 on the electrode assembly can be improved, and the risk of the electrode assembly shaking or displacing is reduced.

[0102] In some embodiments, please continue to refer to FIG. 3 and FIG. 7, the shell 21 further comprises a second wall portion 212 and a third wall portion 213 oppositely arranged in the second direction Y-Y, and the first wall portion 211 is connected between the second wall portion 212 and the third wall portion 213; in the third region 2413, a first channel 244 is formed between the second wall portion 212 and the second support portion 243 and / or between the third wall portion 213 and the second support portion 243, and the first channel 244 communicates the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22; in the fourth region 2414, a second channel 245 is formed between the second wall portion 212 and the second support portion 243 and / or between the third wall portion 213 and the second support portion 243, and the second channel 245 communicates the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0103] The first channel 244 corresponds to the second region 2412 in the first direction X-X. The second channel 245 corresponds to the second region 2412 in the first direction X-X.

[0104] In some embodiments, the first channel 244 and the second channel 245 directly communicate the pressure relief mechanism 22, or communicate the pressure relief mechanism 22 through the gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211.

[0105] By arranging the first channel 244 and the second channel 245 to increase the exhaust path and the exhaust area inside the battery monomer 20, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can flow to the pressure relief mechanism 22 through the first channel 244 and the second channel 245 in addition to flowing to the pressure relief mechanism 22 through the gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211, which can further improve the release rate of the pressure inside the containing space 21a, further reduce the probability of causing fire, explosion and other risks when the battery monomer 20 occurs thermal runaway, and further improve the reliability of the battery monomer 20, so that the reliability of the battery device 100a is further improved.

[0106] In some embodiments, please refer to FIG. 8, the second support portion 243 comprises a first sub-support portion 2431 and a second sub-support portion 2432 arranged at intervals in the second direction Y-Y, and a third channel 246 is formed between the first sub-support portion 2431 and the second sub-support portion 2432, and the third channel 246 communicates the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22.

[0107] The second support portion 243 located on the third region 2413 and the second support portion 243 located on the fourth region 2414 each include a first sub-support portion 2431 and a second sub-support portion 2432, and a third channel 246 is formed between the first sub-support portion 2431 and the second sub-support portion 2432 on each region, and the third channel 246 corresponds to the first region 2411.

[0108] In some embodiments, the third channel 246 communicates with the pressure relief mechanism 22 through the gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211; and / or the third channel 246 communicates with the pressure relief mechanism 22 through the space between the first support portion 242 and the second support portion 243.

[0109] By forming the third channel 246 between the first sub-support portion 2431 and the second sub-support portion 2432, the exhaust path and the exhaust area inside the battery monomer 20 are further increased, so that the exhaust amount can be more effectively increased when the battery monomer 20 occurs thermal runaway, and the accumulation of pressure inside the containing space 21a is further reduced, thereby further reducing the impact of thermal runaway on the battery monomer 20.

[0110] In some embodiments, please continue to refer to FIG. 7, the region of the third region 2413 and / or the fourth region 2414 where the second support portion 243 is not arranged is provided with a third through hole 2413a.

[0111] The third through hole 2413a penetrates the plate body 241 along the third direction Z-Z, and communicates the containing space 21a and the pressure relief mechanism 22. The shape of the third through hole 2413a can be circular, oval, square or other shapes.

[0112] In some embodiments, the region of the plate body 241 corresponding to the first channel 244 and / or the region of the plate body 241 corresponding to the second channel 245 is provided with a third through hole 2413a.

[0113] In some embodiments, the side of the second support portion 243 located on the third region 2413 facing the second region 2412 and / or the side of the second support portion 243 located on the fourth region 2414 facing the second region 2412 is provided with a third through hole 2413a, which can correspond to the second region 2412, of course, the third through hole 2413a can also correspond to the first region 2411.

[0114] The third through hole 2413a is arranged in the region where the second support part 243 is not arranged in the third region 2413 and / or the fourth region 2414, and the third through hole 2413a communicates the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22, so that when the battery monomer 20 occurs thermal runaway, the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 can flow to the pressure relief mechanism 22 through the third through hole 2413a, further reducing the air pressure on the side of the bottom plate 24 away from the first wall part 211, and further relieving the thermal runaway.

[0115] In some embodiments, the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall part 211 in the preset plane satisfy: S1 / S2≥0.5; and the preset plane is parallel to the first direction X-X and the second direction Y-Y.

[0116] S1 / S2≥0.5 represents that the ratio between the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall part 211 in the preset plane is greater than or equal to 0.5.

[0117] In some embodiments, the pressure relief mechanism 22 and the first wall part 211 are located on the same plane, and the plane where the pressure relief mechanism 22 and the first wall part 211 are located is the preset plane.

[0118] In some embodiments, the pressure relief mechanism 22 and the first wall part 211 are not located on the same plane, and the plane where the pressure relief mechanism 22 is located and the plane where the first wall part 211 is located are parallel to the preset plane.

[0119] The ratio between the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall part 211 in the preset plane can be 0.5, 0.52, 0.535, 0.555, 0.58, 0.6, 0.615, 0.64, 0.66, 0.685, 0.7, 0.73, 0.75, 0.778, 0.79, 0.8, 0.825, 0.86, 0.88, 0.9, etc. The specific ratio can be selected according to actual needs, as long as the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall part 211 in the preset plane satisfy: S1 / S2≥0.5.

[0120] In some embodiments, referring to FIG. 3, the first wall part 211 has a third dimension L4 along the first direction X-X. When the first dimension L1 of the pressure relief mechanism 22 along the first direction X-X approaches the third dimension L4 of the first wall part 211 along the first direction X-X, the third region 2413 and the fourth region 2414 can be cancelled, and at this time the plate body 241 only has the first region 2411 and the second region 2412 arranged along the second direction Y-Y.

[0121] By making the area S1 of the pressure relief mechanism 22 in the preset plane and the area S2 of the first wall portion 211 in the preset plane satisfy S1 / S2≥0.5, the area of the pressure relief mechanism 22 is larger, which can more effectively release the pressure and heat inside the containing space 21a, thereby reducing the internal gas pressure and temperature of the containing space 21a, reducing the risk of fire, explosion, etc. of the electrode assembly, and further improving the reliability of the battery device 100a.

[0122] In some embodiments, as shown in FIGS. 3-5, the battery cell 20 includes a shell 21, an electrode assembly, and a bottom support plate 24, the shell 21 is formed with a containing space 21a, the shell 21 includes a first wall portion 211, the first wall portion 211 is provided with a pressure relief mechanism 22, the pressure relief mechanism 22 has a size L1 along a first direction X-X and a size L2 along a second direction Y-Y perpendicular to the first direction X-X, wherein L1>L2; the electrode assembly is arranged in the containing space 21a; the bottom support plate 24 is arranged in the containing space 21a and is arranged between the first wall portion 211 and the electrode assembly along a third direction Z-Z for supporting the electrode assembly, the third direction Z-Z is perpendicular to the first direction X-X and the second direction Y-Y, the bottom support plate 24 includes a plate body 241 and a first support portion 242, the plate body 241 has a first region 2411 and a second region 2412 arranged along the second direction Y-Y, a normal projection of the pressure relief mechanism 22 on the plate body 241 along the third direction Z-Z is located in the first region 2411, at least one first support portion 242 is arranged on the side of the second region 2412 facing the first wall portion 211, the side of the first support portion 242 away from the plate body 241 abuts against the first wall portion 211, the size of the first support portion 242 along the first direction X-X is less than L1 to form a gap 242a between the second region 2412 of the plate body 241 and the first wall portion 211, the gap 242a communicates the space 21a on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22; the sum of the sizes of the plurality of first support portions 242 along the first direction X-X is defined as L3, the size of the first support portion 242 along the third direction Z-Z is h, wherein 0.21≤h×(L1-L3) / L1≤1.11.

[0123] In some embodiments, the plate body 241 further includes a third region 2413 and a fourth region 2414, the third region 2413 and the fourth region 2414 are respectively located on opposite sides of the first region 2411 along the first direction X-X; the side of the third region 2413 facing the first wall portion 211 and / or the side of the fourth region 2414 facing the first wall portion 211 is provided with a second support portion 243, the second support portion 243 is arranged spaced apart from the first support portion 242, and the side of the second support portion 243 away from the plate body 241 abuts against the first wall portion 211.

[0124] In some embodiments, as shown in FIG. 6, the first region 2411 is provided with a first through hole 2411a; the region of the second region 2412 where the first support part 242 is not arranged is provided with a second through hole 2412a.

[0125] In some embodiments, as shown in FIG. 7, the first region 2411 is provided with a first through hole 2411a; the region of the second region 2412 where the first support part 242 is not arranged is provided with a second through hole 2412a; the region of the third region 2413 and the fourth region 2414 where the second support part 243 is not arranged is provided with a third through hole 2413a; in the third region 2413, a first channel 244 is formed between the second support part 243 and the second wall part 212 and / or between the second support part 243 and the third wall part 213, the first channel 244 communicating the accommodation space 21a and the pressure relief mechanism 22; in the fourth region 2414, a second channel 245 is formed between the second support part 243 and the second wall part 212 and / or between the second support part 243 and the third wall part 213, the second channel 245 communicating the accommodation space 21a and the pressure relief mechanism 22.

[0126] In some embodiments, as shown in FIG. 8, the second support part 243 comprises a first sub-support part 2431 and a second sub-support part 2432 arranged at intervals along the second direction Y-Y, a third channel 246 is formed between the first sub-support part 2431 and the second sub-support part 2432, the third channel 246 communicating the accommodation space 21a and the pressure relief mechanism 22.

[0127] The features and performances of the present application are further described in detail below in conjunction with embodiments.

[0128] In some embodiments, as shown in FIG. 3 to FIG. 5, the battery cell 20 comprises a shell 21, an electrode assembly and a bottom support plate 24, the shell 21 is formed with an accommodation space 21a, the electrode assembly is arranged in the accommodation space 21a, and an internal heating film is placed in the accommodation space 21a; the shell 21 comprises a first wall part 211, the first wall part 211 is provided with a pressure relief mechanism 22, and the bottom support plate 24 is arranged between the first wall part 211 and the electrode assembly. The bottom support plate 24 comprises a plate body 241 and a first support part 242, the plate body 241 has a first region 2411 and a second region 2412 arranged along a second direction Y-Y, and a normal projection of the pressure relief mechanism 22 on the plate body 241 along a third direction Z-Z is located in the first region 2411; the plate body 241 has two second regions 2412, the two second regions 2412 are respectively located on opposite sides of the first region 2411 along the second direction Y-Y, and the two second regions 2412 are each provided with the first support part 242 on a side facing the first wall part 211, and the first support parts 242 on the two second regions 2412 correspond one by one.

[0129] In order to study the influence of different values of h x (L1-L3) / L1 on the battery monomer 20, a plurality of comparative experiments are set to test and compare the related parameters of the battery monomer 20. In the comparative experiment, examples 1-20 are set, wherein a plurality of first support portions 242 are arranged at intervals along the first direction X-X, the size of each first support portion 242 along the first direction X-X is 15 mm, the size of the first support portion 242 along the second direction Y-Y is 3 mm, the first size of the pressure relief mechanism 22 along the first direction X-X is L1, L1 = 95 mm, the sum of the sizes of the plurality of first support portions 242 arranged at intervals along the first direction X-X along the first direction X-X is L3, the size of the first support portion 242 along the third direction Z-Z is h, the number, position and spacing of the first support portion 242 along the first direction X-X are adjusted to adjust the value of L1-L3, and then the value of h x (L1-L3) / L1 is adjusted, and the other structures and experimental conditions in the examples are the same. The same size (31 mm*238 mm*117 mm) and the same energy density (760 Wh / L) of the square shell battery monomer 20 are used for testing. Before testing, the battery monomer 20 is fully discharged, a 1.5 mm diameter hole is punched on the top cover of the battery monomer 20, one end of a gas pipe with a diameter matching the hole in the top cover is inserted into the hole, AB glue is applied between the inner wall of the hole and the outer wall of the gas pipe for sealing, and the other end of the gas pipe is connected to a gas pressure sensor to detect the gas pressure in the containing space 21a. During testing, the battery monomer 20 is fully charged, and then a 40V voltage and a 10A current power supply is connected to the built-in heating film to trigger the battery monomer 20 to cause thermal runaway of the battery monomer 20, and the state of the battery monomer 20 after failure and the gas pressure value in the containing space 21a are observed.

[0130] The specific data is as follows in Table 1:

[0131] Table 1

[0132] From Table 1 above, when 0.47≤h x (L1-L3) / L1≤0.79, the maximum gas pressure in the containing space 21a≤0.6 MPa, and the shell 21 is complete, indicating that when the value of h x (L1-L3) / L1 is in the range of 0.47 to 0.79, the pressure relief efficiency of the pressure relief mechanism 22 is the highest, and the shell 21 remains complete. By limiting the value of h x (L1-L3) / L1 within the optimal range, the exhaust path and exhaust area from the containing space 21a to the pressure relief mechanism 22 can be better improved, so that the pressure inside the containing space 21a can be quickly released.

[0133] The application further provides a battery device 100a, which comprises the box 10 and the battery cell 20 in any of the above embodiments.

[0134] In the technical scheme of the embodiments of the application, the specific structure of the battery cell 20 is referred to the above embodiments. Since the battery device 100a provided by the application adopts all the technical schemes of the battery cell 20 in all the above embodiments, it at least has all the beneficial effects brought by the technical schemes of the above embodiments, which will not be repeated here.

[0135] According to some embodiments of the application, the above battery device 100a can be used on an electrical equipment. In this way, by arranging the bottom supporting plate 24 between the first wall portion 211 where the pressure relief mechanism 22 is located and the electrode assembly, and arranging the bottom supporting plate 24 such that the orthogonal projection of the pressure relief mechanism 22 on the plate body 241 along the third direction Y-Y is located in the first area 2411 of the plate body 241, and the first area 2411 and the second area 2412 of the plate body 241 are arranged along the second direction Y-Y, and at least one first supporting portion 242 is arranged on the side of the second area 2412 of the plate body 241 facing the first wall portion 211, and the size of the first supporting portion 242 along the first direction X-X is smaller than the size L1 of the pressure relief mechanism 22 along the first direction X-X, so as to form a gap 242a between the second area 2412 of the plate body 241 and the first wall portion 211, and the gap 242a communicates the space on the side of the plate body 241 away from the pressure relief mechanism 22 and the pressure relief mechanism 22. On the one hand, since the size L1 of the pressure relief mechanism 22 along the first direction X-X is larger than the size L2 of the pressure relief mechanism 22 along the second direction Y-Y, and at least one first supporting portion 242 is arranged on the second area 2412 of the plate body 241, the supporting stability of the bottom supporting plate 24 can be improved, and the risk of the corresponding area of the bottom supporting plate 24 sagging or collapsing towards the pressure relief mechanism 22 can be reduced or eliminated, thereby reducing the possibility of the bottom supporting plate 24 blocking the pressure relief mechanism 22, and reducing or eliminating the risk of fire or explosion caused by the bottom supporting plate 24 blocking the pressure relief mechanism 22 when the battery cell 20 is in thermal runaway, and improving the reliability of the battery cell 20. On the other hand, since the second area 2412 of the plate body 241 and the pressure relief mechanism 22 are arranged along the second direction Y-Y, the speed of the high-pressure gas in the space on the side of the plate body 241 away from the pressure relief mechanism 22 flowing to the pressure relief mechanism 22 can be improved, so that the pressure inside the accommodation space 21a can be quickly released, thereby maintaining the balance of the air pressure inside and outside the battery cell 20, reducing or eliminating the risk of fire or explosion caused by the battery cell 20 in thermal runaway, and further improving the reliability of the battery cell 20.

[0136] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, wherein, The battery cell comprises: a housing formed with an accommodation space, the housing comprising a first wall portion provided with a pressure relief mechanism, a dimension of the pressure relief mechanism along a first direction being defined as L1 and a dimension of the pressure relief mechanism along a second direction perpendicular to the first direction being defined as L2, wherein L1>L2; an electrode assembly arranged in the accommodation space; a bottom support plate arranged in the accommodation space and arranged between the first wall portion and the electrode assembly along a third direction perpendicular to the first direction and the second direction, for supporting the electrode assembly; wherein the bottom support plate comprises a plate body and a first support portion, the plate body having a first region and a second region arranged along the second direction, a normal projection of the pressure relief mechanism on the plate body along the third direction being located in the first region, at least one first support portion being arranged on a side of the second region facing the first wall portion, a side of the first support portion facing away from the plate body being in abutment with the first wall portion, a dimension of the first support portion along the first direction being less than L1, so as to form a gap between the second region of the plate body and the first wall portion, the gap being in communication with a space on a side of the plate body facing away from the pressure relief mechanism and the pressure relief mechanism.

2. The battery cell of claim 1, wherein, A plurality of first support portions are arranged on a side of the second region facing the first wall portion, and the plurality of first support portions are arranged in intervals along the first direction.

3. The battery cell of claim 2, wherein, A sum of dimensions of the plurality of first support portions along the first direction is defined as L3, and a dimension of the first support portion along the third direction is defined as h, wherein 0.21≤h×(L1-L3) / L1≤1.

11.

4. The battery cell of any one of claims 1 to 3, wherein, The plate body has two second regions, and the two second regions are respectively located on opposite sides of the first region along the second direction, and a first support portion is arranged on a side of each of the two second regions facing the first wall portion.

5. The battery cell of any one of claims 1 to 4, wherein, The first support portion comprises a composite layer protruding from a side of the plate body facing the first wall portion.

6. The battery cell of any one of claims 1 to 5, wherein, A side of the plate body close to the electrode assembly is in abutment with the electrode assembly.

7. The battery cell of any one of claims 1 to 6, wherein, A distance between the first support portion and the pressure relief mechanism along the second direction is defined as d, wherein d≥2mm.

8. The battery cell of any one of claims 1 to 7, wherein, The first region is provided with a first through hole, and / or a region of the second region where the first support portion is not arranged is provided with a second through hole.

9. The battery cell of any one of claims 1 to 8, wherein, The plate body further comprises a third region and a fourth region, and the third region and the fourth region are respectively located on opposite sides of the first region along the first direction; A second support portion is arranged on a side of the third region facing the first wall portion and / or a side of the fourth region facing the first wall portion, the second support portion is arranged in intervals with the first support portion, and a side of the second support portion facing away from the plate body is in abutment with the first wall portion.

10. The battery cell of claim 9, wherein, The housing further comprises a second wall portion and a third wall portion arranged in opposition in the second direction, and the first wall portion is connected between the second wall portion and the third wall portion. In the third region, a first passage is formed between the second support portion and the second wall portion and / or between the second support portion and the third wall portion, the first passage communicating a space on a side of the plate body away from the pressure relief mechanism and the pressure relief mechanism; In the fourth region, a second passage is formed between the second support portion and the second wall portion and / or between the second support portion and the third wall portion, the second passage communicating the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism.

11. The battery cell of claim 9 or 10, wherein, The second support portion includes a first sub-support portion and a second sub-support portion arranged at intervals along the second direction, and a third passage is formed between the first sub-support portion and the second sub-support portion, the third passage communicating the space on the side of the plate body away from the pressure relief mechanism and the pressure relief mechanism.

12. The battery cell of claim 9 or 10, wherein, The third region and / or the fourth region in which the second support portion is not arranged is provided with a third through hole.

13. The battery cell of any one of claims 1 to 12, wherein, An area S1 of the pressure relief mechanism in a preset plane and an area S2 of the first wall portion in the preset plane satisfy S1 / S2≥0.5; The preset plane is parallel to the first direction and the second direction.

14. A battery device, wherein, The battery device includes a case and the battery cell according to any one of claims 1 to 13, the battery cell being arranged in the case.

15. An electrical device, comprising: The electric device includes: The battery device according to claim 14.

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