CN221407550U - Battery cell, battery and electricity utilization device - Google Patents

Abstract

The application discloses a battery monomer, a battery and an electricity utilization device, wherein the battery monomer comprises: a housing having a first face; the pressure release piece comprises a pressure release part and a connecting part, the pressure release part and the first surface are positioned on the same side of the shell and are arranged at intervals, the connecting part is an annular part surrounding the circumferential edge of the pressure release part, and the connecting part is connected with the pressure release part and the shell; an electrode assembly disposed within the case; the end cover assembly covers the opening of the shell. According to the application, the pressure relief part and the first surface of the shell are not on the same plane, and when the electrode assembly deforms to extrude the shell, the tearing force formed when the tearing force passes through the connecting part and reaches the pressure relief part can be dispersed, so that the stress of the pressure relief part can be reduced, the influence of the deformation of the electrode assembly on the pressure relief part is reduced, the cracking probability of the pressure relief part under the non-design condition is further reduced, and the service performance, the service life and the reliability of the battery cell can be improved.

Description

Battery cell, battery and electricity utilization device

Technical Field

The application relates to the technical field of batteries, in particular to a battery monomer, a battery and an electric device.

Background

In recent years, new energy automobiles have been developed dramatically, and in the field of electric automobiles, a power battery plays an important role as a power source of the electric automobile. The battery is composed of a box body and a plurality of battery monomers accommodated in the box body. The battery is used as a core part of the new energy automobile, and has high requirements on safety and service life. However, a large amount of gas or heat can be generated in the battery cell during the continuous charge and discharge use process, so that the service performance, service life and reliability of the battery cell are seriously affected.

Disclosure of utility model

The embodiment of the application provides a battery monomer, a battery and an electricity utilization device, which can effectively improve the service performance, service life and reliability of the battery monomer.

In a first aspect, an embodiment of the present application provides a battery cell, including: a housing having a first face; the pressure release piece comprises a pressure release part and a connecting part, the pressure release part and the first surface are positioned on the same side of the shell and are arranged at intervals, the connecting part is an annular part surrounding the circumferential edge of the pressure release part, and the connecting part is connected with the pressure release part and the shell; an electrode assembly disposed within the case; the end cover assembly covers the opening of the shell.

In the above technical scheme, set to including pressure release portion and connecting portion through adopting the pressure release piece, pressure release portion is spaced apart with the first face of casing to and the structural design of pressure release portion and casing is connected to connecting portion, make pressure release portion and the first face of casing not on the coplanar, can be dispersed when electrode assembly takes place deformation and the tear force that forms when extrusion casing reachs pressure release portion through connecting portion, thereby can reduce pressure release portion atress, reduce electrode assembly deformation to pressure release portion's influence, and then reduce the probability that pressure release piece takes place the fracture under non-design condition, can improve battery cell's performance, life and reliability.

In some embodiments of the present application, the housing has a second face, the second face is disposed opposite to the first face and is located on the same wall as the first face, a distance between the second face and the first face is L1, the pressure relief portion has a third face facing the first face, and a distance between the third face and the first face is L2, wherein a ratio of L2 to L1 is 0.5 to 3.

In the technical scheme, the ratio of the distance between the third face and the first face of the pressure relief part to the distance between the second face and the first face of the shell is set in the range of 0.5-3, so that on one hand, the tearing force on the first face can be transmitted to the pressure relief part through the connecting part to have a better weakening effect, the pressure relief part is not easy to crack under the non-design condition, on the other hand, the volume of the pressure relief part is more suitable, too much space is not occupied, and the volume of the battery cell is reduced.

In some embodiments of the application, the first face is located on the outside of the housing and the second face is located on the inside of the housing.

In the above technical scheme, on the one hand, because the first face and the decompression position are located the same side of casing, consequently decompression portion and connecting portion are located the outside of casing equally, and decompression portion and connecting portion can not occupy the casing inner space, and the electrode assembly of bigger volume can fully be placed to the casing inner space, is favorable to improving battery cell's energy density. On the other hand, because pressure release portion and connecting portion are located the outside of casing, also conveniently assemble pressure release portion and connecting portion, can reduce the assembly degree of difficulty, be favorable to the maintenance or the change of pressure release portion and connecting portion.

In some embodiments of the application, the shell wall on which the second face and the first face are located is a flat wall, the first face is an outer wall surface of the flat wall, and the second face is an inner wall surface of the flat wall.

In the technical scheme, the shell wall where the second surface and the first surface are located is a flat plate-shaped wall part with equal thickness everywhere, and the shell wall where the second surface and the first surface are located has simpler structure in the mode, so that the manufacturing process of the shell can be simplified, and the manufacturing cost is reduced.

In some embodiments of the present application, the shell wall on which the first surface is located is a setting wall, the setting wall has a retaining portion located in an annular area surrounded by the connecting portion, and the retaining portion is provided with a pressure release hole.

In the above technical scheme, the first surface is arranged on the setting wall and is provided with the reserved part positioned in the annular area surrounded by the connecting part, and the reserved part can improve the structural strength of the setting wall, so that the deformation caused by the extrusion of the setting wall due to the deformation of the electrode assembly is reduced, the tearing force applied to the pressure release part is reduced, and the influence of the setting wall on the pressure release part is reduced.

In some embodiments of the present application, the pressure relief holes are one or more, the sum of the hole areas of the one or more pressure relief holes is S1, the pressure relief portion has a third surface facing the first surface, and the area of the third surface is S2, where the ratio of S1 to S2 is 0.2 to 0.5.

In the above technical scheme, the sum of the hole areas of the one or more pressure relief holes is S1, the area of the third surface of the pressure relief part facing the first surface is S2, and the ratio of the two areas is set in the range of 0.2-0.5, so that the hole areas of the pressure relief holes are suitable, the exhaust can be smooth, the reserved area of the reserved part is suitable, and the effect of reinforcing the structural strength of the set wall is good.

In some embodiments of the present application, when the pressure relief holes are multiple, the pressure relief holes are at least one row, and the pressure relief holes are at least two. In the technical scheme, the number of the pressure relief holes is increased to increase the exhaust path, so that exhaust is carried out from a plurality of positions, and the exhaust smoothness is improved.

In some embodiments of the application, the shape of the pressure relief vent includes circular and rectangular. In this scheme, the shape of pressure release hole can be circular, and convenient processing is more pleasing to the eye, and the shape of pressure release hole also can be the rectangle, and also convenient processing.

In some embodiments of the application, the pressure relief portion is a sheet member. In the technical scheme, the pressure relief part is a sheet-shaped part, so that the pressure relief part has relatively high structural strength, and is beneficial to reducing the cracking probability under the non-design condition.

In some embodiments of the application, the pressure relief piece further includes a protective cover having an opening, the protective cover being disposed on the first face, the connection portion and the pressure relief portion being located within the protective cover.

In the technical scheme, the protective cover can isolate the connecting part and the pressure relief part from the external environment, so that the damage probability of the connecting part and the pressure relief part caused by other factors such as components in the external environment is reduced, the cracking probability of the pressure relief part under the non-design condition is reduced, and the safety of the pressure relief part is improved.

In a second aspect, an embodiment of the present application further provides a battery, including the above battery cell.

In the technical scheme, the battery monomer can reduce the influence of the deformation of the internal electrode assembly on the pressure relief part, reduce the probability of cracking of the pressure relief part under the non-design condition, and be favorable for improving the service performance, service life and reliability of the battery.

In a third aspect, an embodiment of the present application further provides an electrical apparatus, including the above battery cell or the battery.

In the technical scheme, the battery cell or the battery can reduce the influence of the deformation of the internal electrode assembly on the pressure relief part, reduce the probability of cracking of the pressure relief part under the non-design condition, and be favorable for improving the service performance, service life and reliability of the battery.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

Fig. 2 is an exploded view of a battery according to some embodiments of the present application;

fig. 3 is a schematic diagram illustrating a structure of a battery cell according to some embodiments of the present application;

FIG. 4 is a partial schematic view of a battery cell according to some embodiments of the present application;

FIG. 5 is a schematic view of FIG. 4 taken along line A-A;

Fig. 6 is a schematic structural diagram of a battery cell according to some embodiments of the present application.

Icon: 1000. a vehicle; 100. a battery; 10. a case; 11. a first tank body; 12. a second tank body; 20. a battery cell; 21. a housing; 211. a first face; 212. an opening; 213. a second face; 214. setting a wall; 215. a retaining portion; 216. a pressure relief hole; 22. a pressure release member; 221. a pressure relief portion; 2211. a third face; 222. a connection part; 223. a protective cover; 223a, openings; 23. an electrode assembly; 24. an end cap assembly; 200. a controller; 300. a motor.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

The term "plurality" as used herein refers to two or more (including two).

In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application. The battery cells are generally classified into three types according to the packaging method: the cylindrical battery cell, the square battery cell and the soft package battery cell are not limited in this embodiment.

Reference to a battery in accordance with an embodiment of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module, a battery pack, or the like. The battery generally includes a case for housing one or more battery cells or a plurality of battery modules. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell includes a case, an electrode assembly, and an electrolyte, and the case is used to accommodate the electrode assembly and the electrolyte. The electrode assembly comprises a positive electrode plate, a negative electrode plate and a separation film. The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the high current is passed without fusing, the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together.

The material of the separator may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may be a wound structure or a lamination structure, and embodiments of the present application are not limited thereto.

In recent years, new energy automobiles have been developed dramatically, and in the field of electric automobiles, a power battery plays an important role as a power source of the electric automobile. The battery is composed of a box body and a plurality of battery monomers accommodated in the box body. The battery is used as a core part of a new energy automobile, and has high requirements on safety and cycle service life.

In a general battery cell, in order to prevent a thermal runaway accident, unbalance of internal and external pressures of the battery cell is avoided, and meanwhile, a large amount of toxic gas is instantaneously generated when the battery cell is on fire, so that a pressure release piece is required to be arranged on the battery cell to timely and directionally release the gas in the shell, and the pressure release piece is arranged on the shell of the battery cell in the related art. However, in normal use of the battery cell, the negative electrode material (for example, graphite) in the electrode assembly expands greatly, so that the thickness of the electrode assembly increases, the large surface walls on both sides of the casing are pressed outwards, and simultaneously tearing force along the plane direction can be applied to the pressure release member by the large surface walls, so that the pressure release member cracks under non-design conditions, and the service performance, service life and reliability of the battery cell are poor.

Based on the above consideration, in order to solve the problem that the service performance, service life and reliability of the battery are seriously affected by cracking of the pressure release member under non-design conditions due to the extrusion of the larger surface wall of the case due to the volume expansion of the negative electrode material in the battery unit. The inventor designs a battery cell comprising a housing, a pressure relief piece, an electrode assembly and an end cap assembly, the housing having a first face; the pressure relief piece comprises a pressure relief part and a connecting part, the pressure relief part and the first surface are positioned on the same side of the shell and are arranged at intervals, the connecting part is an annular part surrounding the circumferential edge of the pressure relief part, and the connecting part is connected with the pressure relief part and the shell; the electrode assembly is arranged in the shell; the end cover assembly covers the opening of the shell.

In the battery monomer of this kind of structure, through setting up the pressure release piece to including pressure release portion and connecting portion, pressure release portion and the first face of casing are spaced apart, and connecting portion then connect pressure release portion and casing, adopt this kind of structure can make pressure release portion and the casing that is used for discharging gas stagger and arrange, both are not in the coplanar, pressure release portion is equivalent to the setting of protrusion casing, when electrode assembly's negative pole material takes place to expand and when the great two big face walls of extrusion casing, the tearing force that is transmitted by first face can act on connecting portion earlier, and be eliminated partly by connecting portion, then can act on pressure release portion, and because the effort that pressure release portion received and the tearing effort on the first face are not in the coplanar, consequently, can effectively reduce electrode assembly deformation to pressure release portion's influence, thereby make the probability of weak part fracture in the pressure release portion reduce, and then can promote battery's performance, service life and reliability.

The battery disclosed by the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but is not limited to the electric devices. The power supply system with the battery thermal management system, the battery and the like which form the power utilization device can be used, so that the application range of the battery thermal management system is favorably improved, and the assembly difficulty of the battery thermal management system is reduced.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft and the like. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of description, the following embodiment will take an electric device according to an embodiment of the present application as an example of the vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a case 10 and a plurality of battery cells 20, and the battery cells 20 are accommodated in the case 10. The case 10 is used to provide an assembly space for the battery cells 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first case body 11 and a second case body 12, the first case body 11 and the second case body 12 being covered with each other, the first case body 11 and the second case body 12 together defining an assembly space for accommodating the battery cell 20. The second box body 12 may have a hollow structure with one end opened, the first box body 11 may have a plate-shaped structure, and the first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 define an assembly space together; the first tank body 11 and the second tank body 12 may each have a hollow structure with one side opened, and the open side of the first tank body 11 may be closed to the open side of the second tank body 12. Of course, the case 10 formed by the first case body 11 and the second case body 12 may be various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the plurality of battery cells 20 may be connected in series or parallel or a series-parallel connection, wherein a series-parallel connection refers to that the plurality of battery cells 20 are connected in series or parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting a plurality of battery cells 20 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for making electrical connection between the plurality of battery cells 20.

The battery 100 includes a plurality of rows of battery cells 20, the plurality of rows of battery cells 20 may be arranged along a length direction of the case 10, each row of battery cells 20 may include a plurality of battery cells 20, and the plurality of battery cells 20 of each row may be arranged along a width direction of the case 10; or a plurality of rows of the battery cells 20 may be arranged in the width direction of the case 10, each row of the battery cells 20 may include a plurality of the battery cells 20, and the plurality of the battery cells 20 of each row may be arranged in the length direction of the case 10.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc. The battery cell 20 may be cylindrical in shape, for example.

According to some embodiments of the present application, referring to fig. 3, an embodiment of the present application provides a battery cell 20, comprising: a housing 21, a pressure relief member 22, an electrode assembly 23, and an end cap assembly 24. The housing 21 has a first face 211. The pressure relief piece 22 includes a pressure relief portion 221 and a connection portion 222, the pressure relief portion 221 and the first surface 211 are located on the same side of the housing 21 and are disposed at a distance, the connection portion 222 is an annular member surrounding a circumferential edge of the pressure relief portion 221, and the connection portion 222 is connected to the pressure relief portion 221 and the housing 21. The electrode assembly 23 is provided in the case 21. The end cap assembly 24 covers the opening 212 in the housing 21.

The housing 21 and the end cap assembly 24 together form the enclosure previously described, the housing 21 having an opening 212, the end cap assembly 24 being adapted to close the opening 212. The cap assembly 24 may include an end cap provided on the opening 212 and electrode terminals provided on the end cap and electrically connected to the electrode assembly 23.

The end cap assembly 24 and the opening 212 may be provided on either end of the housing 21 and on a different wall than the pressure relief member 22, and the end cap assembly 24 and the opening 212 may be disposed opposite or adjacent the pressure relief member 22.

Referring to fig. 3 and 4, for example, when the end cap assembly 24 and the opening 212 are disposed opposite to the pressure relief member 22, the end cap assembly 24 and the pressure relief member 22 may be located at both ends of the housing 21 in a first direction X, which may refer to a length direction of the housing 21, at both ends of the housing in a second direction Y, which may refer to a width direction of the housing 21, or at both ends of the housing 21 in a third direction Z, which may refer to a height direction of the housing 21.

The electrode assembly 23 may be constructed as described above, including a positive electrode tab, a negative electrode tab, and a separator, and correspondingly, the electrode terminals may include a positive electrode terminal electrically connected to the positive electrode tab and a negative electrode terminal electrically connected to the negative electrode tab, specifically, the positive electrode terminal may refer to a positive electrode post, and the negative electrode terminal may refer to a negative electrode post.

The pressure release member 22 is configured to be ruptured when the design condition is reached to release the gas in the housing 21. "design condition" may mean that the pressure in the housing 21 reaches a set value. The pressure relief portion 221 plays a role of cracking and pressure relief, for example, the pressure relief portion 221 may be a thin sheet with a weak design such as a score, or may be a thin film. The connecting portion 222 plays a role of connecting the pressure relief portion 221 and the housing 21, and is used for fixing the pressure relief portion 221 on the housing 21, and the connecting portion 222 is an annular component, so that the pressure relief portion 221, the connecting portion 222 and the housing 21 form a closed space, and gas in the housing 21 cannot leak from the pressure relief piece 22 in a normal state.

The first surface 211 may be an outer surface of the case 21 or an inner surface of the case 21. The pressure relief part 221 is spaced from the first surface 211, that is, the pressure relief part 221 and the first surface 211 are not on the same plane, the shell wall where the pressure relief part 221 and the first surface 211 are located is staggered, and when the first surface 211 refers to the outer side surface of the shell 21, the pressure relief part 221 can be located at the outer side of the shell 21; when the first surface 211 refers to an inner side surface of the case 21, the pressure relief portion 221 may be an inner side of the case 21. In this scheme, when the battery unit 20 is in normal use, the cathode material of the electrode assembly 23 expands in a larger volume, the electrode assembly 23 presses two walls of the casing 21, so that opposite tearing forces are formed on the first surface 211, and because the pressure release portion 221 and the first surface 211 are not on the same plane, the tearing forces on the first surface 211 are firstly transferred to the connecting portion 222, and because the first surface 211 and the pressure release portion 221 are located at two ends of the connecting portion 222, an included angle exists between the tearing forces and the pressure release portion 221 when being transferred along the connecting portion 222, the tearing forces are dispersed in the process of transferring the tearing forces to the pressure release portion 221 along the connecting portion 222, namely, the tearing forces are transferred to the pressure release portion 221 after a part of the tearing forces is eliminated, so that the stress of the pressure release portion 221 is reduced, the probability of cracking of the pressure release portion 221 under non-design conditions can be reduced, and the reliability of the pressure release piece 22 is improved.

In the above technical solution, by adopting the pressure relief part 22 to include the pressure relief part 221 and the connecting part 222, the pressure relief part 221 is spaced apart from the first surface 211 of the case 21, and the connecting part 222 is connected with the pressure relief part 221 and the structural design of the case 21, so that the pressure relief part 221 and the first surface 211 of the case 21 are not on the same plane, when the electrode assembly 23 deforms and presses the case 21, the tearing force formed when reaching the pressure relief part 221 through the connecting part 222 can be dispersed, thereby reducing the stress of the pressure relief part 221, reducing the influence of the deformation of the electrode assembly 23 on the pressure relief part 221, further reducing the probability of cracking of the pressure relief part 22 under the non-design condition, and improving the service performance, service life and reliability of the battery cell 20.

In some embodiments of the present application, as shown in fig. 3, 4 and 5, the housing 21 has a second surface 213, the second surface 213 is disposed opposite to the first surface 211 and is located on the same wall as the first surface 211, a distance between the second surface 213 and the first surface 211 is L1, the pressure relief portion 221 has a third surface 2211 facing the first surface 211, and a distance between the third surface 2211 and the first surface 211 is L2, wherein a ratio of L2 to L1 is 0.5 to 3.

The first surface 211 and the second surface 213 are opposite surfaces of the same wall on the housing 21, the first surface 211 may be a surface located outside the housing 21, the second surface 213 may be a surface located inside the housing 21, or the first surface 211 may be a surface located inside the housing 21, the second surface 213 may be a surface located outside the housing 21, or the first surface 211 and the second surface 213 may be partial wall surfaces on the wall, or the entire wall surface on the wall. Where "the distance L1 between the second surface 213 and the first surface 211" may refer to the wall thickness of the shell wall in the area where the second surface 213 and the first surface 211 are located.

The third surface 2211 may be a surface of the pressure relief portion 221 facing the first surface 211 and disposed opposite to each other. The "distance L2 between the third surface 2211 and the first surface 211" may refer to a distance between the third surface 2211 and the first surface 211.

It will be appreciated that the ratio of L2 to L1 cannot be smaller nor larger. If the ratio of L2 to L1 is smaller than 0.5, the distance between the pressure relief portion 221 and the first surface 211 is smaller, and the tearing force on the first surface 211 is less dispersed when passing through the connecting portion 222, so that the effect of weakening the stress of the pressure relief portion 221 is reduced; if the ratio of L2 to L1 is greater than 3, the distance between the pressure release portion 221 and the first surface 211 is relatively large, that is, the height of the pressure release member 22 protruding from the first surface 211 is relatively large, that is, the volume of the pressure release member 22 is relatively large, so that in the battery 100, the space occupied by the pressure release member 22 when the battery cell 20 is in the case 10 is relatively large, which is not beneficial to improving the energy density of the battery 100.

Alternatively, the ratio of L2 to L1 may be any one of 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, and of course, the ratio of L1 to L2 may be other values in the range of 0.5 to 3.0, which will not be described herein.

In the above technical solution, the ratio of the distance between the third surface 2211 of the pressure relief portion 221 and the first surface 211 to the distance between the second surface 213 of the housing 21 and the first surface 211 is set within the range of 0.5-3, so that on one hand, the tearing force on the first surface 211 can be transmitted to the pressure relief portion 221 through the connection portion 222 to have a better weakening effect, so that the pressure relief portion 221 is not easy to crack under non-design conditions, on the other hand, the volume of the pressure relief member 22 is more suitable, and too much space is not occupied, thereby being beneficial to reducing the volume of the battery cell 20.

In some embodiments of the present application, as shown in fig. 5 and 6, the first face 211 is located on the outside of the housing 21 and the second face 213 is located on the inside of the housing 21.

In the above technical solution, on the one hand, since the first surface 211 and the pressure relief portion 221 are located on the same side of the housing 21, the pressure relief portion 221 and the connection portion 222 are also located on the outer side of the housing 21, the pressure relief portion 221 and the connection portion 222 do not occupy the space inside the housing 21, and the electrode assembly 23 with a larger volume can be placed in the space inside the housing 21, which is beneficial to improving the energy density of the battery cell 20. On the other hand, since the pressure release portion 221 and the connecting portion 222 are located outside the housing 21, the pressure release portion 221 and the connecting portion 222 are also convenient to assemble, so that the assembling difficulty can be reduced, and the maintenance or replacement of the pressure release portion 221 and the connecting portion 222 is facilitated.

In some embodiments of the present application, as shown in fig. 3, 5 and 6, the shell wall where the second face 213 and the first face 211 are located is a flat wall, the first face 211 is an outer wall surface of the flat wall, and the second face 213 is an inner wall surface of the flat wall.

In the above technical solution, the shell wall where the second surface 213 and the first surface 211 are located is a flat plate-shaped wall portion with equal thickness everywhere, and in this way, the structure of the shell wall where the second surface 213 and the first surface 211 are located is relatively simple, so that the manufacturing process of the shell 21 can be simplified, and the manufacturing cost can be reduced.

In some embodiments of the present application, the wall of the shell where the second face 213 and the first face 211 are located is a set wall 214, the set wall 214 having a target portion with a wall thickness greater than the wall thickness of the rest of the set wall 214, the second face 213 and the first face 211 being disposed on the target portion.

That is, the second face 213 and the first face 211 are located on the portion of the set wall 214 having the larger wall thickness, and when the case 21 is expanded and pressed by the electrode assembly 23, the tearing force of the set wall 214 is transmitted from the portion having the smaller wall thickness to the target portion having the larger wall thickness, and at this time, since the deformation of the target portion is smaller due to the larger wall thickness, the tearing force transmitted to the first face 211 is also relatively reduced, and the possibility of cracking of the pressure relief portion 221 under the non-design condition can be further reduced.

In some embodiments of the present application, the wall on which the second face 213 and the first face 211 are located may be any wall of the housing 21. Referring to fig. 3 and 4, that is, the case wall of the case 21 may include a large wall and a small wall, the large wall being located at both sides of the first direction X, the small wall being located at both sides of the second direction Y, and the second surface 213 and the first surface 211 may be inner and outer walls of the large wall or inner and outer walls of the small wall.

In some embodiments of the present application, as shown in fig. 3 to 6, the shell wall where the first surface 211 is located is a setting wall 214, where the setting wall 214 has a retaining portion 215 located in an annular region surrounded by the connecting portion 222, and the retaining portion 215 is provided with a pressure release hole 216.

The retaining portion 215 may refer to a portion of the wall of the housing 21 extending into the annular region enclosed by the connecting portion 222.

The pressure release hole 216 is used to make the side of the pressure release portion 221 close to the housing 21 communicate with the inner space of the housing 21.

Compared with the prior art that a larger pressure relief hole is formed in the casing, the areas of the pressure relief hole and the pressure relief piece are approximately equal, in the application, the casing wall in the annular area surrounded by the connecting portion 222 is not cut off, but is selected to be reserved, and the reserved part of the casing wall is the reserved portion 215.

In the above-mentioned technical solution, the setting wall 214 where the first surface 211 is located is provided with the retaining portion 215 located in the annular region surrounded by the connecting portion 222, and the retaining portion 215 can improve the structural strength of the setting wall 214, so as to reduce the deformation amount caused by the deformation of the electrode assembly 23 and the extrusion of the setting wall 214, thereby reducing the tearing force applied to the pressure release portion 221 and reducing the influence of the setting wall 214 on the pressure release portion 221.

In some embodiments of the present application, the pressure relief holes 216 are one or more, the sum of the hole areas of the one or more pressure relief holes 216 is S1, the pressure relief portion 221 has a third surface 2211 facing the first surface 211, and the area of the third surface 2211 is S2, where the ratio of S1 to S2 is 0.2 to 0.5.

The number of the pressure release holes 216 may be one or plural (refer to fig. 4). When the pressure relief holes 216 are one, S1 refers to the aperture area of the pressure relief hole 216; when the pressure relief holes 216 are plural, S1 refers to the sum of the aperture areas of the plurality of pressure relief holes 216. It will be understood that if the ratio of S1 to S2 is smaller, the sum of the aperture areas of the pressure relief holes 216 is smaller, and the exhaust rate of the pressure relief holes 216 is smaller, which is not beneficial to the normal exhaust of the housing 21; if the ratio of S1 to S2 is relatively large, the sum of the aperture areas of the pressure release holes 216 is relatively large, and accordingly, the area of the retaining portion 215 is relatively small, so that the reinforcing effect by the retaining portion 215 is relatively weak, and the effect of reducing the deformation amount caused by pressing the setting wall 214 due to deformation of the electrode assembly 23 is relatively weak. That is, by setting the ratio of S1 and S2 within a reasonable range, both the exhaust smoothness of the pressure release hole 216 and the reinforcing effect of the retaining portion 215 on the setting wall 214 can be achieved.

For example, the ratio of S1 to S2 may be any of 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5. Of course, the ratio of S1 to S2 may take other values within the range of 0.2 to 0.5, and will not be described in detail herein.

In the above technical solution, the sum of the hole areas of the one or more pressure relief holes 216 is S1, the area of the third surface 2211 of the pressure relief portion 221 facing the first surface 211 is S2, and the ratio of the two areas is set in the range of 0.2-0.5, so that, on one hand, the hole area of the pressure relief hole 216 is relatively suitable, and the exhaust can be relatively smooth, and on the other hand, the reserved area of the retaining portion 215 is relatively suitable, and the effect of enhancing the structural strength of the setting wall 214 is relatively good.

In some embodiments of the present application, when the pressure relief holes 216 are multiple, the pressure relief holes 216 are at least one row, and the pressure relief holes 216 are at least two.

For example, the plurality of relief holes 216 may be in a row, and the number of relief holes 216 in each row may include, but is not limited to, two, three, etc. (referring to fig. 4). The plurality of relief holes 216 may also include, but are not limited to, two rows, three rows, etc., and the number of relief holes 216 in each row may include, but is not limited to, two, three, etc.

In the above technical solution, the number of the pressure relief holes 216 is increased to increase the exhaust path, so as to exhaust from multiple positions, which is beneficial to improving the smoothness of exhaust.

In some embodiments of the present application, the shape of the pressure relief vent 216 includes circular and rectangular. In this technical solution, the shape of the pressure relief hole 216 may be circular (see fig. 4), which is convenient for processing, and is more attractive, and the shape of the pressure relief hole 216 may also be rectangular, which is also convenient for processing.

In some embodiments of the present application, as shown in fig. 3, 5 and 6, the pressure relief portion 221 is a sheet-like member.

That is, the pressure release portion 221 is a pressure release sheet, and a notch may be provided on the pressure release sheet, and the notch may form a weak portion on the pressure release sheet, and when the air pressure in the housing 21 reaches a set value, the air may break through the area where the notch is located, so that the pressure release portion 221 may be used for exhausting air. In this technical solution, since the pressure relief portion 221 is a sheet-like member, it has relatively high structural strength, which is advantageous in reducing the probability of cracking under non-design conditions.

In some embodiments of the present application, as shown in fig. 6, the pressure relief member 22 further includes a protective cover 223, the protective cover 223 has an opening 223a, the protective cover 223 is disposed on the first surface 211, and the connection portion 222 and the pressure relief portion 221 are located in the protective cover 223.

The protective cover 223 may refer to a case-like member having a groove and an opening, and since the pressure relief portion 221 is located in the protective cover 223, the provision of the opening 223a is advantageous in that gas can be discharged from the interior of the protective cover 223 when the pressure relief portion 221 is ruptured.

In this technical solution, the protection cover 223 can isolate the connection portion 222 and the pressure relief portion 221 from the external environment, reduce the probability of damage to the connection portion 222 and the pressure relief portion 221 caused by other factors such as components in the external environment, and reduce the probability of cracking of the pressure relief portion 221 under non-design conditions, thereby improving the safety of the pressure relief portion 221.

According to the embodiment of the application, the battery unit 20 comprises a shell 21 and a pressure relief piece 22, wherein the shell 21 is an aluminum shell, the pressure relief piece 22 is an explosion-proof valve, the explosion-proof valve comprises an explosion-proof sheet and a connecting portion 222, the connecting portion 222 is an annular component and is arranged around the circumferential edge of the explosion-proof sheet, the connecting portion 222 is connected with the explosion-proof sheet and the shell 21, the explosion-proof sheet is higher than the plane of the shell 21 where the connecting portion 222 is located by 1.5mm, a circular hollowed-out hole is formed in the part of the shell 21 located in the connecting portion 222, and the area of the circular hollowed-out hole occupies 0.2 of the area of the part of the shell 21 in the connecting portion 222.

In a second aspect, as shown in fig. 2, an embodiment of the present application further provides a battery 100, including the above-mentioned battery cell 20. In the above technical solution, the use of the battery cell 20 can reduce the influence of the deformation of the internal electrode assembly 23 on the pressure relief portion 221, reduce the probability of cracking of the pressure relief member 22 under non-design conditions, and is beneficial to improving the service performance, service life and reliability of the battery 100.

In a third aspect, an embodiment of the present application further provides an electrical device, including the above-mentioned battery cell 20 or the battery 100. For example, as shown in fig. 1, the electric device may be a vehicle 1000, and in the above technical solution, the use of the battery cell 20 or the battery 100 can reduce the influence of the deformation of the electrode assembly 23 in the battery cell on the pressure release portion 221, reduce the probability of cracking the pressure release member 22 under non-design conditions, and is beneficial to improving the service performance, service life and reliability of the battery 100.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

The above is only a preferred embodiment of the present application, and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (12)

1. A battery cell, comprising:

A housing having a first face;

The pressure release piece comprises a pressure release part and a connecting part, wherein the pressure release part and the first surface are positioned on the same side of the shell and are arranged at intervals, the connecting part is an annular part surrounding the circumferential edge of the pressure release part, and the connecting part is connected with the pressure release part and the shell;

An electrode assembly disposed within the case;

and the end cover assembly is covered on the opening of the shell.

2. The battery cell according to claim 1, wherein the case has a second face, the second face is disposed opposite to the first face and is located on the same case wall as the first face, a distance between the second face and the first face is L1, the pressure release portion has a third face facing the first face, and a distance between the third face and the first face is L2, wherein a ratio of L2 and L1 is 0.5 to 3.

3. The battery cell of claim 2, wherein the first face is located on an outside of the housing and the second face is located on an inside of the housing.

4. The battery cell of claim 3, wherein the housing wall on which the second face and the first face are located is a flat wall, the first face is an outer wall surface of the flat wall, and the second face is an inner wall surface of the flat wall.

5. The battery cell as recited in claim 1, wherein the first side is a set wall, the set wall has a retaining portion located in an annular area surrounded by the connecting portion, and the retaining portion is provided with a pressure release hole.

6. The battery cell of claim 5, wherein the pressure relief holes are one or more, the sum of the hole areas of the one or more pressure relief holes is S1, the pressure relief portion has a third face facing the first face, and the area of the third face is S2, wherein the ratio of S1 to S2 is 0.2 to 0.5.

7. The battery cell of claim 5 or 6, wherein when the pressure relief holes are a plurality of, the pressure relief holes are at least one row, and the pressure relief holes of at least one row are at least two.

8. The battery cell of any one of claims 5 to 7, wherein the shape of the pressure relief vent comprises a circle and a rectangle.

9. The battery cell according to any one of claims 1 to 8, wherein the pressure relief portion is a sheet-like member.

10. The battery cell of any one of claims 1 to 9, wherein the pressure relief member further comprises a protective cover having an opening, the protective cover being disposed on the first face, the connection portion and the pressure relief portion being located within the protective cover.

11. A battery comprising the battery cell of any one of claims 1 to 10.

12. An electrical device comprising a battery cell according to any one of claims 1 to 10, or a battery according to claim 11.