WO2023240553A1

WO2023240553A1 - Battery cell, battery and electric device

Info

Publication number: WO2023240553A1
Application number: PCT/CN2022/099230
Authority: WO
Inventors: 林蹬华; 陈龙; 陈新祥; 郑于炼; 王鹏; 金海族
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-06-16
Filing date: 2022-06-16
Publication date: 2023-12-21
Also published as: CN117941165A

Abstract

The present application provides a battery cell, a battery and an electric device and relates to the field of batteries. The battery cell comprises an electrode assembly, a casing, a pressure relief mechanism and an insulating member. The casing is used for accommodating the electrode assembly. The casing is provided with a wall portion which is arranged opposite to the electrode assembly in a first direction. The pressure relief mechanism is arranged on the wall portion. In the first direction, the insulating member is at least partially located between the electrode assembly and the wall portion. An avoidance portion is provided at the position on the insulating member corresponding to the pressure relief mechanism, the avoidance portion being used for avoiding the pressure relief mechanism. The insulating member of the battery cell not only can insulate the electrode assembly from the casing, but also is provided with the avoidance portion capable of avoiding the pressure relief mechanism at the position corresponding to the pressure relief mechanism. Thus, even in a vibration working condition or pressed by the electrode assembly, the insulating member will not interact with the pressure relief mechanism or have an effect on the normal operation of the pressure relief mechanism, allowing the pressure relief mechanism to be normally activated when the internal pressure of the battery cell reaches initiation pressure and thus ensuring the normal operation of the battery cell.

Description

Battery cells, batteries and electrical equipment

Technical field

The present application relates to the field of batteries, specifically, to a battery cell, a battery and electrical equipment.

Background technique

Batteries are widely used in the field of new energy, such as electric vehicles and new energy vehicles. New energy vehicles and electric vehicles have become a new development trend in the automobile industry. The battery cell is provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure of the battery cell reaches the detonation pressure. However, the pressure relief mechanism often cannot be opened normally, resulting in the failure to achieve the normal pressure relief function.

Contents of the invention

The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, which aims to improve the problem in the related art that the pressure relief mechanism often cannot be opened normally, resulting in the inability to realize the normal pressure relief function.

In a first aspect, embodiments of the present application provide a battery cell. The battery cell includes an electrode assembly, a casing, a pressure relief mechanism and an insulator. The casing is used to accommodate the electrode assembly. The casing The body has a wall portion opposite to the electrode assembly along a first direction, and the pressure relief mechanism is disposed on the wall portion; along the first direction, the insulating member is at least partially located between the electrode assembly and the electrode assembly. between the wall parts; wherein, an escape portion is provided at a position corresponding to the insulating member and the pressure relief mechanism, and the escape portion is used to avoid the pressure relief mechanism.

In the above technical solution, the insulating member of the battery cell can not only insulate and isolate the electrode assembly and the casing, but also has an escape portion that can avoid the pressure relief mechanism at a position corresponding to the pressure relief mechanism, so that even if the insulating member vibrates Working conditions or being squeezed by the electrode assembly will not block or exert greater pressure on the pressure relief mechanism, and will not affect the normal operation of the pressure relief mechanism, causing the pressure relief mechanism to reach the detonation pressure when the internal pressure of the battery cell reaches the detonation pressure. It can be opened normally and will not be opened in advance or delayed, thus ensuring the normal operation of the battery cells.

As an optional technical solution of the embodiment of the present application, along the first direction, the projection of the outline of the escape portion on the wall portion is arranged around the pressure relief mechanism.

In the above technical solution, the outline of the escape portion defines an escape space, and the projection of the outline of the escape portion on the wall is arranged around the pressure relief mechanism, that is, the pressure relief mechanism falls within the escape space, so that the escape portion has a strong influence on the pressure relief mechanism. Better avoidance effect.

As an optional technical solution of the embodiment of the present application, along the first direction, the insulating member has a first surface facing the wall portion, and the avoidance portion is along the edge away from the first surface and away from the wall portion. The wall is recessed in the direction of the groove.

In the above technical solution, the avoidance part is a groove opened on the insulating member. The internal space of the groove can avoid the pressure relief mechanism, so that the insulating member will not interact with the pressure relief mechanism under vibration conditions or when being squeezed by the electrode assembly. Mechanical contact will not affect the normal operation of the pressure relief mechanism, allowing the pressure relief mechanism to open normally and achieve normal pressure relief functions. In addition, since the escape portion does not penetrate the insulating member, the insulating member can still insulate the isolation electrode assembly and the wall without providing other insulating components.

As an optional technical solution of the embodiment of the present application, along the first direction, the insulating member has a first surface and a second surface arranged oppositely, and the avoidance portion is formed through the first surface and the second surface. Through-holes on the second surface.

In the above technical solution, the escape portion is a through hole penetrating the first surface and the second surface of the insulating member oppositely arranged in the first direction. The escape part is set as a through hole to ensure that sufficient escape space is formed to avoid the pressure relief mechanism. Since the avoidance part is a through hole, it may affect the insulation performance of the insulating part. Therefore, an additional insulating part may be provided to isolate the electrode assembly and the wall part. The solution in which the escape part is a through hole can be applied to situations where the thickness of the part of the insulating member located between the electrode assembly and the wall is thin, so as to achieve a better avoidance effect.

As an optional technical solution in the embodiment of the present application, along the length direction of the escape part, the size of the escape part is a ₁ , and the size of the pressure relief mechanism is a ₂ , satisfying: 0.1≤a ₂ / a ₁ ≤1.

In the above technical solution, along the length direction of the escape part, the size of the pressure relief mechanism is 0.1 to 1 times the size of the escape part. In this way, while ensuring a good avoidance effect, the insulation effect of the insulating part will not be greatly affected. In addition, when the insulating member supports the electrode assembly, the supporting effect of the insulating member will not be greatly affected. If a ₂ /a ₁ is less than 0.1, the size of the relief part will be too large along the length direction of the relief part, which may easily lead to a significant weakening of the insulation effect of the insulating member. When the insulating member supports the electrode assembly, the supporting effect is greatly deteriorated. And if a ₂ /a ₁ is greater than 1, then along the length direction of the escape part, the size of the escape part is smaller than the size of the pressure relief mechanism, which may make it impossible for the escape part to completely avoid the pressure relief mechanism.

As an optional technical solution in the embodiment of the present application, along the width direction of the escape part, the size of the escape part is b ₁ , and the size of the pressure relief mechanism is b ₂ , satisfying: 0.05≤b ₂ / b ₁ .

In the above technical solution, along the width direction of the escape part, the size of the pressure relief mechanism is greater than 0.05 times the size of the escape part. In this way, while ensuring a good avoidance effect, the insulation effect of the insulating part will not be greatly affected. In addition, when the insulating member supports the electrode assembly, the supporting effect of the insulating member will not be greatly affected. If b ₂ /b ₁ is less than 0.05, the size of the relief part will be too large along the width direction of the relief part, which may easily lead to a significant weakening of the insulation effect of the insulating member. When the insulating member supports the electrode assembly, the supporting effect is greatly deteriorated.

As an optional technical solution in the embodiment of the present application, along the width direction of the escape part, the size b ₁ of the escape part and the size b ₂ of the pressure relief mechanism also satisfy: b ₂ /b ₁ ≤5 .

In the above technical solution, since the insulating member may have a gap in the width direction of the escape portion, along the first direction, the outline of the escape portion can be arranged to semi-surround the pressure relief mechanism in the projection of the wall to achieve a better escape effect. For example, if one side of the insulating member is higher than the other side along the width direction of the escape portion, then the escape portion only needs to be arranged on the higher side to achieve the effect of avoiding the pressure relief mechanism. At this time, along the width direction of the relief part, the size of the pressure relief mechanism may be larger than the size of the relief part. In order to satisfy the relationship of projection and semi-surrounding, b ₂ /b ₁ ≤5 is made to achieve better avoidance effect.

As an optional technical solution in the embodiment of the present application, along the first direction, the depth of the avoidance portion is h, satisfying 0.05mm≤h≤1mm.

In the above technical solution, by making the depth of the escape part greater than 0.05 mm and less than 1 mm, it is possible to ensure a better escape effect while allowing the insulating member to retain a better insulation effect and support effect. If the depth of the avoidance portion along the first direction is less than 0.05, the avoidance effect will be poor. If the depth of the avoidance part is greater than 1mm, the insulation effect of the insulating part will be weakened.

As an optional technical solution in the embodiment of the present application, along the first direction, the projected area of the electrode assembly on the wall is S ₁ , and the area enclosed by the outline of the escape portion is S ₂ , Satisfy: 0.002＜S ₂ /S ₁ <0.8.

In the above technical solution, the area enclosed by the outline of the escape portion is 0.002 to 0.8 times the projected area of the electrode assembly on the wall along the first direction. In this way, the size of the avoidance part is more appropriate and can achieve a better avoidance effect. At the same time, it will not have a great impact on the insulation effect and support effect of the insulating member. If S ₂ /S ₁ ≤ 0.002, the avoidance part is small and cannot provide an avoidance effect for the pressure relief mechanism. If S ₂ /S ₁ ≥0.8, the avoidance part will be larger, causing the insulation member to lose its insulation effect and support effect.

As an optional technical solution of the embodiment of the present application, the insulating member includes an insulating plate, the insulating plate is disposed between the electrode assembly and the wall along the first direction, and the insulating plate is disposed There is said avoidance section.

In the above technical solution, the insulating plate can be used as a support member to support the electrode assembly and stabilize the electrode assembly in the housing. Under vibration conditions or when being squeezed by the electrode assembly, the insulating plate is not easily deformed and has good insulation and support effects. Set an avoidance part on the insulating plate to prevent the insulating plate from blocking the pressure relief mechanism and ensure the pressure relief capability of the pressure relief mechanism.

As an optional technical solution of the embodiment of the present application, the insulating member includes a covering body, the covering body covers the electrode assembly along the circumferential direction of the electrode assembly, and the covering body is provided with The avoidance part.

In the above technical solution, the coating body can cover the circumferential direction of the electrode assembly, which can better separate the electrode assembly and the casing, and achieve a better insulation effect. An avoidance part is provided on the covering body to prevent the covering body from contacting the pressure relief mechanism and blocking the pressure relief mechanism under vibration conditions or when being squeezed by the electrode assembly, thereby affecting the normal operation of the pressure relief mechanism.

As an optional technical solution of the embodiment of the present application, the coating body has a first coating part and a second coating part located between the electrode assembly and the wall part, along the first direction , the first coating part and the second coating part are stacked, and the first coating part is closer to the wall than the second coating part; wherein, the first coating part The avoidance part is provided in the whole part.

In the above technical solution, the first coating part and the second coating part are stacked, and the first coating part is a coating part located in the outer layer. The first covering part is easy to contact with the pressure relief mechanism and block the pressure relief mechanism. Therefore, the escape part is provided on the first covering part to achieve a better avoidance effect. At the same time, the second covering part can still play a good insulation role.

As an optional technical solution in the embodiment of the present application, the escape part is a notch opened in the first covering part.

In the above technical solution, the first coating part and the second coating part are stacked, the first coating part blocks a part of the second coating part, and the other part of the second coating part is exposed. In this way, the position of the first cladding part is higher than the exposed part of the second cladding part. The exposed part of the second covering part is not easily in contact with the pressure relief mechanism and affects the normal operation of the pressure relief mechanism. The escape part is set as a notch opened in the first covering part, and the notch faces the exposed part of the second covering part. The projection of the contour of the notch on the wall semi-surrounds the pressure relief mechanism to achieve a better avoidance effect, so that the pressure relief mechanism will not come into contact with the covering body and affect the normal operation of the pressure relief mechanism.

As an optional technical solution in the embodiment of the present application, the second covering part is provided with the avoidance part.

In the above technical solution, the escape parts are provided on both the first covering part and the second covering part, and the avoidance effect is better.

In a second aspect, embodiments of the present application further provide a battery. The battery includes a box and the above-mentioned battery cell, and the battery cell is accommodated in the box.

In a third aspect, embodiments of the present application further provide an electrical device, where the electrical device includes the above-mentioned battery.

Description of the drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

Figure 2 is an exploded view of a battery provided by some embodiments of the present application;

Figure 3 is an exploded view of a battery cell provided by some embodiments of the present application;

Figure 4 is a schematic front view of a battery cell provided by some embodiments of the present application;

Figure 5 is a cross-sectional view at position A-A in Figure 4;

Figure 6 is an enlarged view of position B in Figure 5;

Figure 7 is a schematic structural diagram of an insulator provided by some embodiments of the present application;

Figure 8 is a schematic front view of an insulator provided by some embodiments of the present application;

Figure 9 is a schematic front view of a housing provided by some embodiments of the present application;

Figure 10 is a schematic front view of a housing provided by other embodiments of the present application;

Figure 11 is a schematic structural diagram of an insulating member provided by other embodiments of the present application;

Figure 12 is a schematic front view of an insulator provided by other embodiments of the present application;

Figure 13 is a schematic structural diagram of an insulating member provided by some embodiments of the present application.

Icon: 10-box; 11-first part; 12-second part; 20-battery cell; 21-electrode assembly; 22-casing; 221-end cover; 222-shell main body; 2221-wall; 2222 -Pressure relief mechanism; 23-insulation part; 231-avoidance part; 232-insulation plate; 233-covering body; 2331-first covering part; 2332-second covering part; 100-battery; 200-controller ;300-motor;1000-vehicle.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are Apply for some of the embodiments, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the technical field of this application; the terms used in the specification of this application are only for describing specific implementations. The purpose of the examples is not intended to limit the application; the terms "including" and "having" and any variations thereof in the description and claims of the application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or priority relationship.

Reference in this application 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 this phrase 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 this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense. For example, it can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

The term "and/or" in this application is just an association relationship describing related objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, alone There are three situations B. In addition, the character "/" in this application generally indicates that the related objects are an "or" relationship.

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

"Plural" appearing in this application means two or more (including two).

In this application, battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells or magnesium ion battery cells, etc., The embodiments of the present application are not limited to this. The battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this. Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this.

The battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

The battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode current collector that is coated with the positive electrode active material layer. , the cathode current collector without coating the cathode active material layer serves as the cathode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode current collector that is coated with the negative electrode active material layer. , the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that large currents can pass through without melting, 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 isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.

The development of battery technology must consider multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety also needs to be considered.

For battery cells, in order to ensure the safety of the battery cells, a pressure relief mechanism can be installed on the battery cells. When the internal pressure of the battery cell reaches the detonation pressure, the pressure relief mechanism opens to release the pressure inside the battery cell to reduce the risk of battery cell explosion and fire.

The inventor noticed that the pressure relief mechanism often cannot be opened normally, resulting in the inability to realize the normal pressure relief function.

The inventor further studied and found that under vibration conditions, the electrode assembly squeezes the insulating part, making it easy for the insulating part to come into contact with the pressure relief mechanism, causing blockage or damage to the pressure relief mechanism, causing the pressure relief mechanism to be unable to open normally to relieve pressure, and even The pressure relief mechanism completely loses its function. In addition, after a battery cell is used for a period of time, the electrode assembly will expand and squeeze the insulating parts, making it easy for the insulating parts to come into contact with the pressure relief mechanism, causing blockage or damage to the pressure relief mechanism, which will also affect the normal function of the pressure relief mechanism. Work.

In view of this, embodiments of the present application provide a battery cell that avoids the pressure relief mechanism by arranging an escape portion on the insulating member at a position corresponding to the pressure relief mechanism, so that the insulating member can be used even under vibration conditions. conditions or being squeezed by the electrode assembly, it will not block or exert greater pressure on the pressure relief mechanism, and will not affect the normal operation of the pressure relief mechanism, so that when the pressure inside the battery cell reaches the detonation pressure, the pressure relief mechanism can It opens normally and will not open in advance or delay, thus ensuring the normal operation of the battery cells.

The technical solutions described in the embodiments of this application are applicable to batteries and electrical equipment using batteries.

Power-consuming devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc. Spacecraft include airplanes, rockets, space shuttles, spaceships, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.; electric tools include metal Cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and planers, etc. The embodiments of this application impose no special restrictions on the above electrical equipment.

In the following embodiments, for convenience of explanation, the electric equipment is the vehicle 1000 as an example.

Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 . The battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 . The vehicle 1000 may also include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .

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

Please refer to FIG. 2 , which is an exploded view of the battery 100 provided by some embodiments of the present application. The battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 . Among them, the box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12 , the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a space for accommodating the battery cells 20 of accommodation space. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define a receiving space. ; The first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 is covered with the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.

In the battery 100, there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 . The battery 100 may also include other structures. For example, the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .

Each battery cell 20 may be a secondary battery cell or a primary battery cell; it may also be a lithium-sulfur battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.

Please refer to FIG. 3 , which is an exploded view of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery 100 . As shown in FIG. 3 , the battery cell 20 includes an electrode assembly 21 , a case 22 and other functional components. The casing 22 includes an end cover 221 and a casing main body 222. The end cover 221 is connected to the casing main body 222.

The end cap 221 refers to a component that covers the opening of the case body 222 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 221 may be adapted to the shape of the shell body 222 to fit the shell body 222 . Optionally, the end cap 221 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 221 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher durability. Structural strength and safety performance can also be improved. The end cap 221 may be provided with functional components such as electrode terminals. The electrode terminals may be used to electrically connect with the electrode assembly 21 for outputting or inputting electrical energy of the battery cell 20 . The end cap 221 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.

The case body 222 is a component used to cooperate with the end cover 221 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 21 , electrolyte, and other components. The case main body 222 and the end cover 221 may be independent components, and an opening may be provided on the case main body 222. The end cover 221 covers the opening at the opening to form the internal environment of the battery cell 20. Without limitation, the end cover 221 and the shell main body 222 can also be integrated. Specifically, the end cover 221 and the shell main body 222 can form a common connection surface before other components are put into the shell. When it is necessary to encapsulate the inside of the shell main body 222 At this time, the end cover 221 covers the main body 222 of the shell. The shell body 222 may be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the shell body 222 can be determined according to the specific shape and size of the electrode assembly 21 . The shell body 222 may be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.

The electrode assembly 21 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 21 may be contained within the housing 22 . The electrode assembly 21 is mainly formed by winding or stacking positive electrode sheets and negative electrode sheets, and an isolation film is usually provided between the positive electrode sheets and the negative electrode sheets. The portions of the positive electrode sheet and the negative electrode sheet that contain active material constitute the main body of the electrode assembly 21 , and the portions of the positive electrode sheet and the negative electrode sheet that do not contain active material each constitute tabs. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively located at both ends of the main body. During the charging and discharging process of the battery 100, the positive active material and the negative active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.

Please refer to Figures 3, 4, 5 and 6. Figure 4 is a schematic front view of a battery cell 20 provided in some embodiments of the present application. Figure 5 is a cross-sectional view at position A-A in Figure 4 . Figure 6 is an enlarged view of position B in Figure 5. The embodiment of the present application provides a battery cell 20 . The battery cell 20 includes an electrode assembly 21 , a case 22 , a pressure relief mechanism 2222 and an insulator 23 . The housing 22 is used to accommodate the electrode assembly 21 . The housing 22 has a wall portion 2221 opposite to the electrode assembly 21 along the first direction, and the pressure relief mechanism 2222 is provided on the wall portion 2221. Along the first direction, the insulating member 23 is at least partially located between the electrode assembly 21 and the wall portion 2221 . Wherein, the insulating member 23 is provided with an escape portion 231 at a position corresponding to the pressure relief mechanism 2222, and the escape portion 231 is used to avoid the pressure relief mechanism 2222.

The first direction is the direction in which the wall portion 2221 provided with the pressure relief mechanism 2222 on the housing 22 points toward the electrode assembly 21 along an axis perpendicular to itself.

The housing 22 has multiple walls, such as bottom walls, side walls, top walls, etc. The wall portion 2221 refers to the wall on which the pressure relief mechanism 2222 is provided. For example, if the pressure relief mechanism 2222 is disposed on the bottom wall, the wall portion 2221 refers to the bottom wall of the housing 22 . For another example, if the pressure relief mechanism 2222 is disposed on the top wall, the wall portion 2221 refers to the top wall of the housing 22 . For another example, if the pressure relief mechanism 2222 is disposed on the side wall, the wall portion 2221 refers to the side wall of the housing 22 . For another example, the pressure relief mechanism 2222 is provided on the end cover 221 , and the wall portion 2221 may also refer to the end cover 221 .

In this embodiment, the first direction is the C direction as shown in FIG. 3 .

The insulating member 23 is a component made of insulating material and has insulating properties. Insulating materials include but are not limited to plastic or rubber. The insulator 23 is used to insulate the electrode assembly 21 and the wall portion 2221 from each other to prevent the electrode assembly 21 from being electrically connected to the wall portion 2221 and causing a short circuit in the battery cell 20 . The insulating member 23 may be entirely located between the electrode assembly 21 and the wall portion 2221 , or may be partially located between the electrode assembly 21 and the wall portion 2221 .

The escape portion 231 is a portion of the insulating member 23 that has an escape function. The escape portion 231 can enclose an escape space, so that the pressure relief mechanism 2222 is accommodated in the escape space to avoid the insulating member 23 . The shape of the escape portion 231 is not limited. For example, the escape portion 231 may be rectangular, elliptical, circular, triangular, hexagonal, etc.

The insulating member 23 of the battery cell 20 can not only insulate and isolate the electrode assembly 21 and the case 22 , but also has an escape portion 231 at a position corresponding to the pressure relief mechanism 2222 to avoid the pressure relief mechanism 2222 , so that even if the insulating member 23 Under vibration conditions or being squeezed by the electrode assembly 21, the pressure relief mechanism 2222 will not be blocked or exert greater pressure, nor will it affect the normal operation of the pressure relief mechanism 2222, causing the internal pressure of the battery cell 20 to reach When the detonation pressure reaches the detonation pressure, the pressure relief mechanism 2222 can be opened normally and will not be opened in advance or delayed, thereby ensuring the normal operation of the battery cell 20 .

In some embodiments, along the first direction, the projection of the outline of the escape portion 231 on the wall portion 2221 is disposed around the pressure relief mechanism 2222 .

The "outline of the escape part 231" refers to the structure composed of the walls of the escape part 231 that surround the escape space. Taking the escape part 231 as a hole as an example, the outline of the escape part 231 is the side wall of the hole.

"The projection of the outline of the escape part 231 on the wall part 2221 is arranged around the pressure relief mechanism 2222" includes not only the projection of the outline of the escape part 231 on the wall part 2221 semi-surrounding the pressure relief mechanism 2222, but also includes the outline of the escape part 231 on the wall part 2221 The projection completely surrounds the pressure relief mechanism 2222. In addition, the fact that the projection of the outline of the escape part 231 on the wall part 2221 coincides with the outer circumference of the pressure relief mechanism 2222 should also be understood to mean that the projection of the outline of the escape part 231 on the wall part 2221 is arranged around the pressure relief mechanism 2222.

The outline of the escape portion 231 defines an escape space, and the projection of the outline of the escape portion 231 on the wall portion 2221 is arranged around the pressure relief mechanism 2222, that is, the pressure relief mechanism 2222 falls within the escape space, so that the escape portion 231 is opposite to the pressure relief mechanism 2222. Has better avoidance effect.

In some embodiments, along the first direction, the insulating member 23 has a first surface facing the wall portion 2221. The relief portion 231 is a groove recessed from the first surface in a direction away from the wall portion 2221 .

The first surface is a surface of the insulating member 23 opposite to the wall portion 2221 . “The escape part 231 is a groove recessed from the first surface in a direction away from the wall part 2221” can be understood to mean that the escape part 231 is a groove opened on the first surface. The groove here can also be understood as a blind hole.

The avoidance part 231 is a groove opened on the insulator 23. The internal space of the groove can avoid the pressure relief mechanism 2222, so that the insulator 23 will not interact with the pressure relief mechanism under vibration conditions or when being squeezed by the electrode assembly 21. 2222 contact, it will not affect the normal operation of the pressure relief mechanism 2222, so that the pressure relief mechanism 2222 can be opened normally to achieve the normal pressure relief function. In addition, since the escape portion 231 does not penetrate the insulating member 23, the insulating member 23 can still insulate the isolation electrode assembly 21 and the wall portion 2221 without providing other insulating components.

In some embodiments, along the first direction, the insulating member 23 has a first surface and a second surface arranged oppositely, and the avoidance portion 231 is a through hole penetrating the first surface and the second surface.

The first surface and the second surface are two opposite surfaces on the insulating member 23 . The first surface may be a surface opposite to the wall part 2221, and the second surface may be a surface opposite to the wall part 2221.

"The escape part 231 is a through hole penetrating the first surface and the second surface" can also be understood to mean along the first direction. The escape portion 231 is a through hole that is recessed from the first surface in a direction away from the wall portion 2221 and extends to the second surface. hole.

The escape portion 231 is a through hole penetrating the first surface and the second surface of the insulating member 23 that are oppositely arranged in the first direction. The escape portion 231 is provided as a through hole to ensure that sufficient escape space is formed to avoid the pressure relief mechanism 2222. Since the escape portion 231 is a through hole, it may affect the insulation performance of the insulating member 23 . Therefore, an additional insulating member may be provided to isolate the electrode assembly 21 and the wall portion 2221 . Optionally, the solution that the avoidance part 231 is a through hole can be applied to the case where the thickness of the part of the insulating member 23 between the electrode assembly 21 and the wall part 2221 is thin, so as to achieve a better avoidance effect.

Please refer to Figures 7, 8, 9 and 10. Figure 7 is a schematic structural diagram of the insulating member 23 provided in some embodiments of the present application. Figure 8 is a schematic front view of the insulating member 23 provided by some embodiments of the present application. Figure 9 is a schematic front view of the housing 22 provided by some embodiments of the present application. Figure 10 is a schematic front view of the housing 22 provided in other embodiments of the present application. In some embodiments, along the length direction of the relief portion 231, the size of the relief portion 231 is a ₁ , and the size of the pressure relief mechanism 2222 is a ₂ , which satisfies: 0.1≤a ₂ /a ₁ ≤1.

Taking the escape part 231 as a rectangular shape as an example, the length direction of the escape part 231 is parallel to or coincides with the long side of the rectangle. Taking the relief part 231 as an ellipse as an example, the length direction of the relief part 231 coincides with the major axis of the ellipse.

In the embodiment of the present application, the shape of the pressure relief mechanism 2222 is not limited. The pressure relief mechanism 2222 may be in the shape of a "king" or a racetrack shape. Along the length direction of the relief part 231 , the size of the pressure relief mechanism 2222 refers to the distance from one end to the other end of the pressure relief mechanism 2222 in the length direction of the relief part 231 .

Along the length direction of the escape part 231, the ratio of the size of the pressure relief mechanism 2222 to the size of the escape part 231 may be: a ₂ /a ₁ =0.1, 0.3, 0.5, 0.7, 0.9, etc.

Along the length direction of the relief portion 231 , the size of the pressure relief mechanism 2222 is 0.1 to 1 times the size of the relief portion 231 . In this way, while ensuring a better avoidance effect, the insulation effect of the insulating member 23 will not be greatly affected. In addition, when the insulating member 23 supports the electrode assembly 21 and the wall portion 2221, it will not greatly affect the supporting effect of the insulating member 23 and the avoiding effect of the escape portion 231. That is to say, when it is subjected to external impact, vibration, or internal or external extrusion , the part of the insulating member 23 located between the electrode assembly 21 and the wall 2221, except for the avoidance part 231, first contacts the wall part 2221, thereby preventing the avoidance part 231 from contacting the pressure relief mechanism 2222, so that the avoidance part 231 can achieve avoidance. . Once the avoidance part 231 occupies too large an area on the insulating member between the electrode assembly 21 and the wall part 2221, the insulating part 23 cannot have enough area to support the electrode assembly 21 or the wall part 2221, and the avoidance part 231 cannot function well. There is a certain gap between the ground and the pressure relief mechanism 2222, which serves as an avoidance function. If a ₂ /a ₁ <0.1, the size of the relief portion 231 along the length direction of the relief portion 231 is too large, which may easily cause the insulation effect of the insulating member 23 to be greatly weakened. When the insulating member 23 supports the electrode assembly 21, the supporting effect is greatly deteriorated. If a ₂ /a ₁ >1, along the length direction of the escape part 231 , the size of the escape part 231 is smaller than the size of the pressure relief mechanism 2222 , which may prevent the escape part 231 from completely avoiding the pressure relief mechanism 2222 .

In some embodiments, along the width direction of the relief portion 231, the size of the relief portion 231 is b1, and the size of the pressure relief mechanism 2222 is _b2 , which satisfies: _0.05≤b2 / _b1 .

Taking the relief part 231 as a rectangular shape as an example, the width direction of the relief part 231 is parallel to or coincident with the short side of the rectangle. Taking the relief part 231 as an ellipse as an example, the width direction of the relief part 231 coincides with the minor axis of the ellipse.

Along the width direction of the relief portion 231 , the size of the pressure relief mechanism 2222 refers to the distance from one end to the other end of the pressure relief mechanism 2222 in the width direction of the relief portion 231 .

Along the width direction of the relief part 231, the ratio of the size of the pressure relief mechanism 2222 to the size of the relief part 231 may be: b ₂ /b ₁ =0.01, 0.1, 0.3, 0.5, 0.7, 0.9, etc.

Along the width direction of the relief portion 231 , the size of the pressure relief mechanism 2222 is greater than 0.05 times the size of the relief portion 231 . In this way, while ensuring a better avoidance effect, the insulation effect of the insulating member 23 will not be greatly affected. In addition, when the insulating member 23 supports the electrode assembly 21, the supporting effect of the insulating member 23 will not be greatly affected. If b ₂ /b ₁ <0.05, the size of the relief portion 231 along the width direction of the relief portion 231 is too large, which may easily cause the insulation effect of the insulating member 23 to be greatly weakened. When the insulating member 23 supports the electrode assembly 21, the supporting effect is greatly deteriorated.

In some embodiments, along the width direction of the relief portion 231, the size b ₁ of the relief portion 231 and the size b ₂ of the pressure relief mechanism 2222 also satisfy: b ₂ /b ₁ ≤5.

Along the width direction of the relief part 231, the ratio of the size of the pressure relief mechanism 2222 to the size of the relief part 231 may be: b ₂ /b ₁ =1, 2, 3, 4, 5, etc.

Since the insulating member 23 may have a gap in the width direction of the escape portion 231 , along the first direction, if the outline of the escape portion 231 is arranged to half surround the pressure relief mechanism 2222 in the projection of the wall portion 2221 , a better escape effect can be achieved. For example, along the width direction of the escape portion 231, one side of the insulating member 23 is higher than the other side, then the escape portion 231 only needs to be disposed on the higher side to achieve the effect of avoiding the pressure relief mechanism 2222. At this time, along the width direction of the relief part 231, the size of the pressure relief mechanism 2222 may be larger than the size of the relief part 231. In order to satisfy the relationship of projection and semi-surrounding, b ₂ /b ₁ ≤5 is made to achieve better avoidance effect.

In some embodiments, along the first direction, the depth of the relief portion 231 is h, satisfying 0.05mm≤h≤1mm.

The depth of the relief portion 231 refers to the distance along the first direction that the relief portion 231 is recessed from the first surface in a direction away from the wall portion 2221 .

The depth of the relief portion 231 may be: h=0.05mm, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 0.9mm, etc.

By making the depth of the escape portion 231 greater than 0.05 mm and less than 1 mm, the insulation member 23 can retain a better insulation effect and support effect while ensuring a better avoidance effect. If the depth of the relief portion 231 along the first direction is less than 0.05, the relief effect will be poor. If the depth of the relief portion 231 is greater than 1 mm, the insulation effect of the insulating member 23 will be weakened.

In some embodiments, along the first direction, the projected area of the electrode assembly 21 on the wall portion 2221 is S ₁ , and the area enclosed by the outline of the escape portion 231 is S ₂ , which satisfies: 0.002<S ₂ /S ₁ <0.8.

When the electrode assembly 21 is rolled or stacked in a rectangular parallelepiped shape, along the first direction, the projected area of the electrode assembly 21 on the wall portion 2221 may be equal to the area of the surface of the electrode assembly 21 facing the wall portion 2221 . When the electrode assembly 21 is rolled into a cylinder and the first direction coincides with the axis of the cylinder, the projected area of the electrode assembly 21 on the wall 2221 is equal to the area of the top or bottom surface of the electrode assembly 21 .

The area enclosed by the outline of the relief portion 231 represents the size of the relief portion 231 . The larger the area enclosed by the outline of the relief portion 231 is, the larger the relief portion 231 is. The smaller the area enclosed by the outline of the relief portion 231 is, the smaller the relief portion 231 is.

The ratio of the area enclosed by the outline of the escape portion 231 to the projected area of the electrode assembly 21 on the wall portion 2221 along the first direction can be: S ₂ /S ₁ =0.005, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.7 , 0.75, etc.

The area enclosed by the outline of the escape portion 231 is 0.002 to 0.8 times (exclusive of 0.002 and 0.8) of the projected area of the electrode assembly 21 on the wall portion 2221 along the first direction. In this way, the size of the escape portion 231 is more appropriate and can achieve a better escape effect. At the same time, it will not have a great impact on the insulation effect and supporting effect of the insulating member 23 . If S ₂ /S ₁ ≤ 0.002, the escape portion 231 is small and cannot provide the escape effect for the pressure relief mechanism 2222 . If S ₂ /S ₁ ≥ 0.8, the escape portion 231 is larger, causing the insulating member 23 to lose the insulation effect and the supporting effect. Once the escape portion 231 occupies too much area on the insulating member between the electrode assembly 21 and the wall 2221 If it is too large, the insulating member 23 cannot have enough area to support the electrode assembly 21 and the wall portion 2221 or ensure insulation, and the avoidance portion 231 cannot maintain a certain gap with the pressure relief mechanism 2222 to play an avoidance role.

In some embodiments, the insulating member 23 includes an insulating plate 232 disposed between the electrode assembly 21 and the wall portion 2221 along the first direction, and the insulating plate 232 is provided with an avoidance portion 231 .

The insulating plate 232 has a plate-like structure. The insulating plate 232 is disposed between the electrode assembly 21 and the wall portion 2221 to insulate them. For example, the insulating plate 232 can be an insulating bottom support plate, the wall portion 2221 is the bottom wall of the housing 22 , and the pressure relief mechanism 2222 is provided on the bottom wall of the housing 22 . In this way, the insulating plate 232 can support the electrode assembly 21 .

The insulating plate 232 can serve as a supporting member to support the electrode assembly 21 and stabilize the electrode assembly 21 in the housing 22 . Under vibration conditions or when being squeezed by the electrode assembly 21, the insulating plate 232 is not easily deformed and has better insulation and support effects. An escape portion 231 is provided on the insulating plate 232 to prevent the insulating plate 232 from blocking the pressure relief mechanism 2222 and ensure the pressure relief capability of the pressure relief mechanism 2222.

Please refer to Figures 11 and 12. Figure 11 is a schematic structural diagram of an insulating member 23 provided by other embodiments of the present application. Figure 12 is a schematic front view of the insulating member 23 provided in other embodiments of the present application. In other embodiments, the insulating member 23 includes a covering body 233 that covers the electrode assembly 21 along the circumferential direction of the electrode assembly 21 , and the covering body 233 is provided with an escape portion 231 .

The covering body 233 is an insulating portion covering the electrode assembly 21 . For example, the coating 233 may be a mylar film. An escape portion 231 is provided on the mylar membrane to avoid the pressure relief mechanism 2222.

The covering body 233 can cover the circumferential direction of the electrode assembly 21, and can better separate the electrode assembly 21 and the housing 22, thereby achieving a better insulation effect. An escape portion 231 is provided on the covering body 233 to prevent the covering body 233 from contacting the pressure relief mechanism 2222 and blocking the pressure relief mechanism 2222 under vibration conditions or when being squeezed by the electrode assembly 21 and affecting the pressure relief mechanism. 2222 works normally.

In some embodiments, the covering body 233 has a first covering portion 2331 and a second covering portion 2332 located between the electrode assembly 21 and the wall portion 2221 . Along the first direction, the first coating part 2331 and the second coating part 2332 are stacked, and the first coating part 2331 is closer to the wall part 2221 than the second coating part 2332. Among them, the first covering portion 2331 is provided with an escape portion 231 .

The second coating part 2332 is the part where the coating body 233 is rolled first when coating the electrode assembly 21 . The second coating part 2332 is close to the electrode assembly 21 . The first coating part 2331 is where the coating body 233 is wrapped. The first covering portion 2331 covers the portion (or the ending portion) of the electrode assembly 21 that is subsequently rolled, away from the electrode assembly 21 and close to the wall portion 2221 . After the coating is completed, the first coating part 2331 and the second coating part 2332 are stacked and arranged in the first direction.

The first coating part 2331 and the second coating part 2332 are both located between the electrode assembly 21 and the wall part 2221, and both have parts corresponding to the pressure relief mechanism 2222. Since the first covering part 2331 is closer to the pressure relief mechanism 2222, the escape part 231 is provided on the first covering part 2331 to avoid the pressure relief mechanism 2222.

The first coating part 2331 and the second coating part 2332 are stacked, and the first coating part 2331 is a coating part located in the outer layer. The first covering part 2331 is easily in contact with the pressure relief mechanism 2222 and blocks the pressure relief mechanism 2222. Therefore, the escape part 231 is provided in the first covering part 2331 to achieve a better avoidance effect. At the same time, the second covering part 2332 can still play a better insulating effect.

In some embodiments, the escape portion 231 is a gap opened in the first covering portion 2331 .

The first covering part 2331 may completely block the second covering part 2332, or may partially block the second covering part 2332, so that a part of the second covering part 2332 is exposed. In this way, a height difference is formed between the surface of the first coating part 2331 close to the wall part 2221 and the surface of the second coating part 2332 close to the wall part 2221. In this way, it is only necessary to open a gap in the first covering part 2331 to avoid the pressure relief mechanism 2222.

The first coating part 2331 and the second coating part 2332 are stacked. The first coating part 2331 blocks a part of the second coating part 2332, and the other part of the second coating part 2332 is exposed. In this way, the first covering portion 2331 is located higher than the exposed portion of the second covering portion 2332 . The exposed portion of the second covering portion 2332 is not easily in contact with the pressure relief mechanism 2222 and affects the normal operation of the pressure relief mechanism 2222. The escape portion 231 is configured as a notch opened in the first covering portion 2331 , and the notch faces the exposed portion of the second covering portion 2332 . The outline of the notch semi-encloses the pressure relief mechanism 2222 in the projection of the wall 2221 to achieve a better avoidance effect, so that the pressure relief mechanism 2222 will not contact the covering body 233 and affect the normal operation of the pressure relief mechanism 2222.

Please refer to FIG. 13 , which is a schematic structural diagram of the insulating member 23 provided in some embodiments of the present application. In some embodiments, the second covering portion 2332 is provided with an escape portion 231 . Avoidance parts 231 are provided on both the first covering part 2331 and the second covering part 2332, and the avoidance effect is better.

In some embodiments, the insulating member 23 includes an insulating plate 232 and a covering body 233 , wherein the covering body 233 covers the electrode assembly 21 , and the insulating plate 232 is located between the covering body 233 and the wall portion 2221 . The insulating plate 232 is provided with an escape portion 231 , and the covering body 233 may be provided with the escape portion 231 , or may not be provided with the escape portion 231 .

The embodiment of the present application also provides a battery 100. The battery 100 includes a box 10 and the above-mentioned battery cells 20. The battery cells 20 are accommodated in the box 10.

An embodiment of the present application also provides an electrical device. The electrical device includes the above-mentioned battery 100 .

According to some embodiments of the present application, please refer to Figures 3 to 12.

The embodiment of the present application provides a battery cell 20 . The battery cell 20 includes an electrode assembly 21 , a case 22 , a pressure relief mechanism 2222 and an insulator 23 . The housing 22 is used to accommodate the electrode assembly 21 . The housing 22 has a wall portion 2221 opposite to the electrode assembly 21 along the first direction, and the pressure relief mechanism 2222 is provided on the wall portion 2221.

Along the first direction, the insulating member 23 is at least partially located between the electrode assembly 21 and the wall portion 2221 . Wherein, the insulating member 23 is provided with an escape portion 231 at a position corresponding to the pressure relief mechanism 2222, and the escape portion 231 is used to avoid the pressure relief mechanism 2222. Along the first direction, the insulating member 23 has a first surface facing the wall portion 2221 , and the relief portion 231 is a groove recessed from the first surface in a direction away from the wall portion 2221 . Along the first direction, the insulating member 23 has a first surface and a second surface arranged oppositely, and the relief portion 231 is a through hole penetrating the first surface and the second surface.

The insulating member 23 includes an insulating plate 232 disposed between the electrode assembly 21 and the wall portion 2221 along the first direction, and the insulating plate 232 is provided with an escape portion 231 .

The insulating member 23 includes a covering body 233 , which covers the electrode assembly 21 along the circumferential direction of the electrode assembly 21 . The covering body 233 is provided with an escape portion 231 . The coating body 233 has a first coating part 2331 and a second coating part 2332 located between the electrode assembly 21 and the wall part 2221. The first coating part 2331 and the second coating part 2332 are stacked along the first direction. , the first covering part 2331 is closer to the wall part 2221 than the second covering part 2332; wherein, the first covering part 2331 is provided with an escape part 231.

The avoidance part 231 is a groove opened on the insulator 23. The internal space of the groove can avoid the pressure relief mechanism 2222, so that the insulator 23 will not interact with the pressure relief mechanism under vibration conditions or when being squeezed by the electrode assembly 21. 2222 contact, it will not affect the normal operation of the pressure relief mechanism 2222, so that the pressure relief mechanism 2222 can be opened normally to achieve the normal pressure relief function. In addition, since the escape portion 231 does not penetrate the insulating member 23, the insulating member 23 can still insulate the isolation electrode assembly 21 and the wall portion 2221 without providing other insulating components. The escape portion 231 is a through hole penetrating the first surface and the second surface of the insulating member 23 that are oppositely arranged in the first direction. The escape part 231 is provided as a through hole to ensure that sufficient escape space is formed to avoid the pressure relief mechanism 2222. Since the escape portion 231 is a through hole, it may affect the insulation performance of the insulating member 23 . Therefore, an additional insulating member may be provided to isolate the electrode assembly 21 and the wall portion 2221 . The solution that the escape part 231 is a through hole can be applied to the situation where the thickness of the part of the insulating member 23 between the electrode assembly 21 and the wall part 2221 is thin, so as to achieve a better avoidance effect.

The covering body 233 can cover the circumferential direction of the electrode assembly 21, and can better separate the electrode assembly 21 and the housing 22, thereby achieving a better insulation effect. An escape portion 231 is provided on the covering body 233 to prevent the covering body 233 from contacting the pressure relief mechanism 2222 and blocking the pressure relief mechanism 2222 under vibration conditions or when being squeezed by the electrode assembly 21 and affecting the pressure relief mechanism. 2222 works normally. The first coating part 2331 and the second coating part 2332 are stacked, and the first coating part 2331 is a coating part located in the outer layer. The first covering part 2331 is easily in contact with the pressure relief mechanism 2222 and blocks the pressure relief mechanism 2222. Therefore, the escape part 231 is provided in the first covering part 2331 to achieve a better avoidance effect. At the same time, the second covering part 2332 can still play a better insulating effect.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims

A battery cell, including:

electrode assembly;

A housing for accommodating the electrode assembly, the housing having a wall portion opposite to the electrode assembly along a first direction;

A pressure relief mechanism is provided on the wall;

an insulating member at least partially located between the electrode assembly and the wall along the first direction;

The insulating member is provided with an escape portion at a position corresponding to the pressure relief mechanism, and the escape portion is used to avoid the pressure relief mechanism.
The battery cell according to claim 1, wherein a projection of the outline of the escape portion on the wall portion is arranged around the pressure relief mechanism along the first direction.
The battery cell according to claim 2, wherein along the first direction, the insulating member has a first surface facing the wall, and the escape portion is formed along a direction away from the wall from the first surface. The groove is concave in the direction of the bottom.
The battery cell according to claim 2, wherein the insulating member has a first surface and a second surface arranged oppositely along the first direction, and the avoidance portion is a penetrating part of the first surface and the second surface. Two surface through holes.
The battery cell according to any one of claims 2 to 4, wherein along the length direction of the escape part, the size of the escape part is a 1 , and the size of the pressure relief mechanism is a 2 , satisfying: 0.1 ≤a 2 /a 1 ≤1.
The battery cell according to any one of claims 2 to 4, wherein along the width direction of the escape part, the size of the escape part is b 1 , and the size of the pressure relief mechanism is b 2 , satisfying: 0.05 ≤b 2 /b 1 .
The battery cell according to claim 6, wherein along the width direction of the relief part, the size b 1 of the relief part and the size b 2 of the pressure relief mechanism further satisfy: b 2 /b 1 ≤5.
The battery cell according to any one of claims 2 to 4, wherein the depth of the relief portion along the first direction is h, satisfying 0.05mm≤h≤1mm.
The battery cell according to any one of claims 2 to 4, wherein along the first direction, the projected area of the electrode assembly on the wall portion is S 1 , and the area enclosed by the outline of the escape portion is S 2 , satisfying: 0.002＜S 2 /S 1 <0.8.
The battery cell according to any one of claims 1 to 9, wherein the insulating member includes an insulating plate disposed between the electrode assembly and the wall along the first direction, The insulation board is provided with the escape portion.
The battery cell according to any one of claims 1 to 10, wherein the insulating member includes a covering body covering the electrode assembly in a circumferential direction of the electrode assembly, and the covering body The covering body is provided with the escape portion.
The battery cell according to claim 11, wherein the cladding body has a first cladding portion and a second cladding portion located between the electrode assembly and the wall portion, along the first direction, The first coating part and the second coating part are stacked, and the first coating part is closer to the wall than the second coating part;

The first covering part is provided with the escape part.
The battery cell according to claim 12, wherein the escape part is a notch opened in the first covering part.
The battery cell according to claim 12, wherein the second covering part is provided with the escape part.
A battery, including:

box;

The battery cell according to any one of claims 1 to 14, which is contained in the box.
An electrical device, comprising the battery according to claim 15.