WO2023240746A1 - Shell, battery cell, battery, and electric device - Google Patents

Abstract

The present application relates to the technical field of batteries, and provides a shell, a battery cell, a battery, and an electric device. The shell is used for accommodating an electrode assembly, and the shell comprises: an end cover and a housing. The end cover is provided with a pressure relief portion, and a pressure relief groove is formed on the pressure relief portion; a disassembling groove is formed in the housing; a ratio of the depth of the disassembling groove to the thickness of the housing is L1, a ratio of the depth of the pressure relief groove to the thickness of the pressure relief portion is L2, and L1<L2. Because the disassembling groove is provided, when external force is provided, the housing can be separated at the disassembling groove, and disassembling is more convenient; moreover, a groove depth proportion of the disassembling groove is smaller than a groove depth proportion of the pressure relief groove of the pressure relief portion, when the pressure or temperature inside the shell reaches a threshold value, the shell cracks along the pressure relief groove, pressure relief is achieved, and normal use of the battery cell can not be affected by the disassembling groove.

Description

Housing, battery cells, batteries and electrical equipment

Cross-references to related applications

This application requires priority for the application documents with the filing date of June 14, 2022, the application number 202221473696.6, and the names of casings, battery cells, batteries and electrical equipment.

Technical field

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

Background technique

Lithium-ion batteries are widely used because of their excellent electrochemical properties. Especially in recent years, with the development of the new energy vehicle industry, more and more lithium-ion batteries are widely used in electric vehicles. However, the service life of lithium-ion batteries is generally 5 to 8 years. As the service life of lithium-ion batteries ends, the issue of recycling them becomes particularly important.

Utility model content

This application provides a casing, a battery cell, a battery and electrical equipment, which can make battery recycling more convenient.

In a first aspect, embodiments of the present application provide a housing for accommodating an electrode assembly. The housing includes: an end cover and a housing; a pressure relief portion is provided on the end cover, and a pressure relief groove is provided on the pressure relief portion; and the housing A disassembly groove is provided on the top; the ratio of the depth of the disassembly groove to the thickness of the shell is L1, and the ratio of the depth of the pressure relief groove to the thickness of the pressure relief part is L2, L1<L2.

In the above technical solution, due to the setting of the disassembly groove, when external force is provided, the shell can be separated at the disassembly groove, making disassembly more convenient and making battery recycling more convenient; at the same time, the depth ratio of the disassembly groove The groove depth ratio of the pressure relief groove is smaller than the pressure relief part. When the pressure or temperature inside the casing reaches the threshold, the casing will crack along the pressure relief groove to achieve pressure relief, so that the disassembly groove will not affect the normal operation of the battery cells. use.

In some embodiments, the end cap cover is installed at the opening of the casing and welded to the edge of the opening of the casing, and the minimum distance D1 between the disassembly groove and the end cap is >0.3 cm. The welding of the end cover and the shell will produce a welding heat effect. In this application, the minimum distance D1 between the disassembly tank and the end cover is >0.3cm, so that the area where the disassembly tank is set can avoid the area of the welding heat effect, thereby improving the overall strength of the shell. higher.

In some embodiments, the housing includes a peripheral wall, and the disassembly groove includes a first annular groove, and the first annular groove is circumferentially disposed on the peripheral wall. An external force can be applied along the first annular groove to cause the housing to split along the first annular groove, thereby separating the housing into two parts so that the electrode assembly inside the housing can be taken out to recycle the battery.

In some embodiments, the angle between the surface where the first annular groove is located and the surface where the opening of the peripheral wall is located is less than 5°. The surface where the first annular groove is located is basically parallel to the surface where the opening of the peripheral wall is located. The annular groove can be formed for disassembly and at the same time, the length of the annular groove can be shortened, thereby ensuring the strength of the shell to a certain extent.

In some embodiments, the disassembly groove further includes a second annular groove, the second annular groove is circumferentially disposed on the peripheral wall, and the first annular groove intersects with the second annular groove. When disassembling the shell, you can first apply external force to the intersection of the first annular groove and the second annular groove, and use this as a starting point for disassembly, which is more labor-saving; at the same time, when you continue to apply external force for disassembly, you can Apply external force to the area between the two annular grooves to make disassembly more convenient and avoid scratching your hands, making disassembly more convenient.

In some embodiments, the end cap is further provided with a positive electrode terminal and a negative electrode terminal, and the distance between the intersection point of the first annular groove and the second annular groove and the positive electrode terminal is smaller than the distance between the intersection point and the negative electrode terminal. When external force is applied for disassembly, the intersection point cracks, which may cause the shell at the edge of the intersection point to move inward and may come into contact with the tab; setting the intersection point close to the positive electrode side can avoid the case from contacting the negative electrode. contact, thereby improving the safety performance of the battery during disassembly.

In some embodiments, the disassembly groove further includes a second annular groove, the second annular groove is circumferentially disposed on the peripheral wall, and the second annular groove is located on a side of the first annular groove away from the end cap. When disassembling the shell, external force is directly applied to the area between the two annular grooves to make the disassembly more convenient and avoid scratching the hands, making the disassembly more convenient.

In some embodiments, the angle between the surface where the second annular groove is located and the surface where the opening of the peripheral wall is located is less than 5°. The surface where the second annular groove is located is basically parallel to the surface where the opening of the peripheral wall is located. The annular groove can be formed for disassembly and at the same time, the length of the annular groove can be shortened, thereby ensuring the strength of the shell to a certain extent.

In some embodiments, the disassembly groove further includes an auxiliary groove, the auxiliary groove is provided on the peripheral wall, and the two ends of the auxiliary groove are respectively connected to the first annular groove and the second annular groove. When disassembling the shell, you can first apply external force to the intersection of the first annular groove, the second annular groove and the auxiliary groove, and use this as a starting point for disassembly, which is more labor-saving; at the same time, when continuing to apply external force for disassembly, External force can be applied along the area between the two annular grooves to make disassembly more convenient and avoid scratching the hands, making disassembly more convenient.

In some embodiments, the connection between the auxiliary groove and the first annular groove is a first connection point, the connection between the auxiliary groove and the second annular groove is a second connection point, and the connection between the first connection point and the second connection point is The distance is the minimum distance between the first annular groove and the second annular groove. The length of the auxiliary groove is relatively short, which not only facilitates disassembly, but also ensures the strength of the shell to a certain extent.

In some embodiments, the auxiliary groove is a line segment groove, and the angle between the extending direction of the line segment groove and the surface where the opening of the peripheral wall is located is 85° to 90°. The extension direction of the auxiliary groove is basically perpendicular to the surface where the opening of the peripheral wall is located. The auxiliary groove can be formed for disassembly and at the same time, the length of the auxiliary groove can be shortened, thereby ensuring the strength of the shell to a certain extent.

In some embodiments, the end cap is further provided with a positive electrode terminal and a negative electrode terminal, and the distance between the auxiliary groove and the positive electrode terminal is smaller than the distance between the auxiliary groove and the negative electrode terminal. When external force is applied for disassembly, the auxiliary groove cracks, which may cause the shell on the edge of the auxiliary groove to move inward, which may come into contact with the pole tab; setting the auxiliary groove close to the positive electrode side can avoid the case The body is in contact with the negative electrode, thereby improving the safety performance of the battery during disassembly.

In some embodiments, the peripheral wall is square, and includes two relatively large surfaces with larger areas and two opposite side surfaces with smaller areas, and the auxiliary grooves are provided on the large surfaces. The setting of the auxiliary groove is more convenient, and at the same time, it is also more convenient when applying external force to the edge of the auxiliary groove and the position between the two annular grooves.

In some embodiments, the minimum distance between the first annular groove and the second annular groove is not less than 1.5 cm. It can facilitate the application of external force. For example, when pressing the position between the first annular groove and the second annular groove with your hand, your hand will not be scratched.

In some embodiments, the housing further includes a bottom wall. The bottom wall is located at one end of the peripheral wall and is integrally formed with the peripheral wall. The peripheral wall forms an opening at an end opposite to the bottom wall. The strength of the shell can be made higher.

In some embodiments, the disassembly grooves are disassembly scores. It is more convenient to set up the disassembly notch, and the width of the notch is smaller, which has less impact on the strength and appearance of the casing.

In some embodiments, the disassembly groove is recessed from the outside inward. It is convenient to observe the position of the disassembly groove, so that when the shell needs to be disassembled, it is easy to find the position of the disassembly groove and disassemble it.

In a second aspect, embodiments of the present application provide a battery cell, including: a casing and an electrode assembly as provided in the first aspect; the electrode assembly is placed in the casing, and the end cap is installed at the opening of the casing.

In the above technical solution, the disassembly of the casing can be facilitated, so that the electrode assembly can be disassembled from the casing, thereby facilitating the recycling of the battery.

In some embodiments, the minimum distance between the disassembly groove and the main body of the electrode assembly is greater than 0. If external force is applied to disassemble the housing at the disassembly groove, part of the housing may move toward the interior of the housing. Limiting the position of the disassembly groove within the above range can prevent the part moving toward the interior of the housing from puncturing the electrode. The main body of the assembly to facilitate recycling of the electrode assembly.

In a third aspect, embodiments of the present application provide a battery, including a battery cell and a box as provided in the second aspect; the box is used to accommodate the battery cell.

In a fourth aspect, embodiments of the present application provide an electrical device, including the battery provided in the third aspect, and the battery is used to provide electric energy.

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 a schematic diagram of the exploded structure of a battery cell provided by some embodiments of the present application;

Figure 4 is a schematic exploded view of the end cap assembly provided by some embodiments of the present application;

Figure 5 is a schematic structural diagram of a housing provided by some embodiments of the present application;

Figure 6 is a cross-sectional view along the A-A direction in Figure 5;

Figure 7 is an enlarged view of B in Figure 6;

Figure 8 is a first schematic diagram of a housing provided by some embodiments of the present application;

Figure 9 is a second schematic diagram of a housing provided by some embodiments of the present application;

Figure 10 is a third schematic diagram of a housing provided by some embodiments of the present application;

Figure 11 is a fourth schematic diagram of a housing provided by some embodiments of the present application;

Figure 12 is a fifth schematic diagram of a housing provided by some embodiments of the present application;

Figure 13 is a sixth schematic diagram of a housing provided by some embodiments of the present application;

Figure 14 is a seventh schematic diagram of a housing provided by some embodiments of the present application.

Icon: 1000-vehicle; 100-battery; 200-controller; 300-motor; 10-box; 20-battery cell; 11-first part; 12-second part; 21-casing; 22-electrode assembly; 23-end cover assembly; 212-casing; 231-end cover; 232-pressure relief part; 233-insulator; 221-main part; 222-positive pole tab; 223-negative pole tab; 234-positive electrode terminal; 235-negative electrode terminal; 2321-pressure relief groove; 2121-disassembly groove; 2122-peripheral wall; 2123-bottom wall; 2121a-first annular groove; 2121b-second annular groove; 2121c-intersection; 2121d-auxiliary groove; 2121e-first connection point; 2121f-second connection point.

Detailed ways

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

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to this application; the terms used herein are for the purpose of describing specific embodiments only and are not intended to be used in Limitation of this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the description of the embodiments of this application, "plurality" means two or more, unless otherwise explicitly and specifically limited.

Reference herein to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The 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. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of this application, the term "and/or" is only an association relationship describing associated objects, indicating that there can be three relationships, such as A and/or B, which can mean: A exists alone, and A exists simultaneously and B, there are three cases of B alone. In addition, the character "/" in this article generally indicates that the related objects are an "or" relationship.

In the description of the embodiments of this application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to It is more than two pieces (including two pieces).

In the description of the embodiments of this application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right" and "vertical" The orientation or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the embodiments of the present application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the implementation of the present application. Example limitations.

In the description of the embodiments of this application, unless otherwise clearly stated and limited, technical terms such as "installation", "connection", "connection" and "fixing" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. It can be disassembled and connected, or integrated; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

At present, judging from the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. . As the application fields of power batteries continue to expand, their market demand is also constantly expanding. Therefore, the recycling of power batteries is also particularly important.

The core unit of the power battery is the battery cell. The battery cell includes an electrode assembly, electrolyte and casing. The casing includes an end cover and a casing. The positive tab of the electrode assembly is fixedly connected to the positive electrode terminal on the end cover. The negative electrode tab is fixedly connected to the negative electrode terminal on the end cover, then the electrode assembly is placed in the housing, the end cover is installed at the opening of the housing, and the end cover is fixedly connected to the housing, and then the electrolyte is injected into the housing Inside.

When the battery cells need to be recycled, the shell of the battery cells is usually disassembled first, and then the electrode assembly is taken out to recycle the battery cells. When disassembling the casing, you need to use tools such as knives and pliers to form an opening in the casing and separate the casing into two parts so that the end cap and the electrode assembly fixedly connected to the end cap can be taken out together and the electrode assembly can be inspected. Recycle. However, when using tools such as knives and pliers to open the housing, it is usually time-consuming and labor-intensive, and disassembly is troublesome.

In view of this, embodiments of the present application provide a casing, which includes an end cover and a casing; the end cover is provided with a pressure relief portion, and the pressure relief portion is provided with a pressure relief groove; the casing is provided with a disassembly groove; disassembly The ratio of the depth of the groove to the thickness of the housing is L1, and the ratio of the depth of the pressure relief groove to the thickness of the pressure relief part is L2, L1<L2.

In such a battery cell, due to the setting of the disassembly groove, when external force is provided, the shell can be separated at the disassembly groove, making disassembly more convenient and making battery recycling more convenient; at the same time, the disassembly groove The groove depth ratio is smaller than that of the pressure relief groove of the pressure relief part. When the pressure or temperature inside the casing reaches the threshold, the casing will crack along the pressure relief groove to achieve pressure relief, so that the disassembly groove will not affect the battery cells. normal use of the body.

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. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.; spacecraft include aircraft, rockets, space shuttles, spaceships, etc.; electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more. The embodiments of this application impose no special restrictions on the above electrical equipment.

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

Figure 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. Please refer to Figure 1 . The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. Cars 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 .

FIG. 2 is an exploded view of the battery 100 provided by some embodiments of the present application. Please refer to FIG. 2 . The battery 100 includes a box 10 and a battery cell 20 . The battery cell 20 is accommodated in the box 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 100 modules are connected in series, parallel, or mixed to form a module form. Multiple battery 100 modules are then 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 100 or a primary battery 100; it may also be a lithium-sulfur battery 100, a sodium-ion battery 100 or a magnesium-ion battery 100, 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.

FIG. 3 is an exploded structural diagram of a battery cell 20 provided by some embodiments of the present application. Please refer to FIG. 3 . The battery cell 20 refers to the smallest unit that constitutes the battery 100 . As shown in FIG. 3 , the battery cell 20 includes a housing 21 , an electrode assembly 22 and other functional components; the housing 21 includes an end cap assembly 23 and a housing 212 .

FIG. 4 is a schematic exploded view of the end cap assembly 23 provided in some embodiments of the present application. Please refer to FIG. 4 . The end cover assembly 23 includes an end cover 231. The end cover 231 refers to a component that covers the opening of the housing 212 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 231 may be adapted to the shape of the housing 212 to fit the housing 212 . Optionally, the end cap 231 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 231 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.

Please continue to refer to FIGS. 3 and 4 . The end cover 231 may also be provided with a pressure relief portion 232 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The end cap 231 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. In some embodiments, an insulating member 233 may be provided inside the end cover 231 , and the insulating member 233 may be used to isolate the electrical connection components in the housing 212 from the end cover 231 to reduce the risk of short circuit. For example, the insulating member 233 may be plastic, rubber, or the like.

The housing 212 is a component used to cooperate with the end cover 231 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 22 , electrolyte, and other components. The housing 212 and the end cover 231 may be independent components, and an opening may be provided on the housing 212. The end cover 231 covers the opening at the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 231 and the shell 212 can also be integrated. Specifically, the end cap 231 and the shell 212 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 212 When the end cap 231 is closed, the housing 212 is closed. The housing 212 may be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 212 can be determined according to the specific shape and size of the electrode assembly 22 . The housing 212 may be made of a variety of 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 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained within housing 212 . The electrode assembly 22 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and is usually provided with a separator between the positive electrode sheet and the negative electrode sheet. The material of the separator film may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene). Ethylene) etc.

Please continue to refer to Figure 3. 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 coated positive electrode active material layer. The positive electrode current collector with the material layer and the positive electrode current collector without the positive electrode active material layer is used as the positive electrode tab 222 . 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 without the negative electrode active material layer is used as the negative electrode tab 223 . 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 a large current can pass through without melting, the number of positive electrode tabs 222 is multiple and stacked together, and the number of negative electrode tabs 223 is multiple and stacked together.

Please continue to refer to FIG. 3 . The positive electrode tab 222 and the negative electrode tab 223 can be located together at one end of the main body 221 of the electrode assembly 22 or respectively located at both ends of the main body 221 . Functional components such as a positive electrode terminal 234 and a negative electrode terminal 235 may be provided on the end cap 231 . The positive electrode terminal 234 can be electrically connected to the positive tab 222 of the electrode assembly 22 , and the negative electrode terminal 235 can be electrically connected to the negative tab 223 of the electrode assembly 22 for outputting or inputting electric energy of the battery cell 20 . 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.

Figure 5 is a schematic structural diagram of the housing 21 provided in some embodiments of the present application; Figure 6 is a cross-sectional view along the A-A direction in Figure 5; Figure 7 is an enlarged view of B in Figure 6. Referring to Figures 3 to 7, the end cover 231 is provided with a pressure relief portion 232, and the pressure relief portion 232 is provided with a pressure relief groove 2321; the housing 212 is provided with a disassembly groove 2121; the depth of the disassembly groove 2121 is the same as the depth of the disassembly groove 2121. The ratio of the thickness of the body 212 is L1, and the ratio of the depth of the pressure relief groove 2321 to the thickness of the pressure relief portion 232 is L2, L1<L2.

The pressure relief portion 232 on the end cover 231 refers to a metal film (for example, a film of copper, iron, aluminum, stainless steel, aluminum alloy, etc.) on the end cover 231. The metal film is provided with a pressure relief groove 2321. The pressure relief groove 2321 does not penetrate both surfaces of the metal film, so that the metal film can be an integral film layer. That is to say, when the internal pressure of the battery cell 20 is normal pressure, there will be no air leakage at the metal film, but it is relatively Compared with other positions of the metal film, the connection strength of the metal film at the pressure relief groove 2321 is lower. When the pressure or temperature inside the battery cell 20 reaches a threshold value, the pressure relief groove 2321 on the pressure relief portion 232 cracks, thus Can relieve internal pressure.

As shown in Figure 7, the depth of the pressure relief groove 2321 is L21, and the depth of the pressure relief groove 2321 is the groove depth of the pressure relief groove 2321, that is, the depth of the depression at the pressure relief groove 2321; the thickness of the pressure relief portion 232 is L22, and the pressure relief groove 2321 has a thickness of L22. The thickness of the portion 232 is the sum of the depth L21 of the pressure relief groove 2321 and the remaining thickness L23 of the pressure relief portion 232 where the pressure relief groove 2321 is provided, L22=L21+L23. The ratio of the depth of the pressure relief groove 2321 to the thickness of the pressure relief portion 232 is L2, L2=L21/L22.

The disassembly groove 2121 does not penetrate the wall of the casing 212, which allows the casing 212 to be an integral layer structure. When no external force is applied, the battery cell 20 will not leak air at the casing 212. However, compared with In other positions of the housing 212, the connection strength of the housing 212 at the disassembly groove 2121 is lower. When the disassembly groove 2121, its surroundings or edges are subjected to external force, it is easy to separate from the disassembly groove 2121, so that it can be achieved Disassembly of the battery cell 20 .

As shown in Figure 7, the depth of the disassembly groove 2121 is L11, and the depth of the disassembly groove 2121 is the depth of the disassembly groove 2121, that is, the depth of the depression at the disassembly groove 2121; the thickness of the shell 212 is L12, and the thickness of the shell 212 is L12. The thickness of is the sum of the depth L11 of the disassembly groove 2121 and the remaining thickness L13 of the housing 212 where the disassembly groove 2121 is provided, L12=L11+L13. The ratio of the depth of the disassembly groove 2121 to the thickness of the housing 212 is L1, L1=L11/L12.

In the above technical solution, the housing 212 of the housing 21 is provided with a disassembly groove 2121. When external force is provided, the housing 212 can be separated at the disassembly groove 2121, making disassembly more convenient; at the same time, L1 < L2, when When the pressure or temperature inside the casing 21 reaches a threshold value, the pressure relief groove 2321 of the pressure relief part 232 is cracked to realize pressure relief, so that the disassembly groove 2121 does not affect the normal use of the battery cell 20 .

In some embodiments, Figure 8 is a first schematic diagram of the housing 21 provided by some embodiments of the present application, Figure 9 is a second schematic diagram of the housing 21 provided by some embodiments of the present application, and Figure 10 is a second schematic diagram of the housing 21 provided by some embodiments of the present application. The third schematic diagram of the housing 21. Figure 11 is the fourth schematic diagram of the housing 21 provided by some embodiments of the present application. Figure 12 is the fifth schematic diagram of the housing 21 provided by some embodiments of the present application. Figure 13 is provided by some embodiments of the present application. The sixth schematic diagram of the housing 21; Figure 14 is the seventh schematic diagram of the housing 21 provided by some embodiments of the present application. Please refer to Figures 2, 3 and 8 to 14. The end cap 231 is installed at the opening of the housing 212 and is welded to the edge of the opening of the housing 212. The minimum distance D1 between the disassembly groove 2121 and the end cap 231 is >0.3 cm.

Please continue to refer to Figure 3. The housing 212 includes a peripheral wall 2122 and a bottom wall 2123. The bottom wall 2123 is connected to one end of the peripheral wall 2122 and closes the opening at one end of the peripheral wall 2122. The other end of the peripheral wall 2122 (the end opposite to the bottom wall 2123) is The opening of the housing 212. Optionally, the bottom wall 2123 and the peripheral wall 2122 are integrally formed, which can make the housing 212 stronger. In other embodiments, the bottom wall 2123 and the peripheral wall 2122 can also be provided separately and then welded or bonded together.

Please continue to refer to Figures 8 to 14. The welding of the opening edge of the end cover 231 and the housing 212 may form a welding heat effect area in the welding area of the end cover 231 and the housing 212 and around the welding area. Generally, welding The width of the thermal effect area is less than 0.3cm.

The end cap 231 may have an approximately flat plate structure. The end cap 231 has a first surface close to the housing 212 and a second surface away from the housing 212. The disassembly groove 2121 may have one (as shown in Figure 8 to Figure 10) or two (Figure 11 and Figure 12), three (Figure 13 and Figure 14), etc., the minimum distance D1 between the disassembly groove 2121 and the end cover 231 refers to: the point closest to the opening of the housing 212 of the disassembly groove 2121 distance from the first surface of the end cap 231 .

In the above technical solution, the minimum distance D1 between the disassembly groove 2121 and the end cover 231 is >0.3 cm, so that the area where the disassembly groove 2121 is arranged avoids the area affected by welding heat, thereby making the overall strength of the housing 21 higher.

Referring to FIG. 3 and FIG. 8 to FIG. 14 , the minimum distance between the disassembly groove 2121 and the main body 221 of the electrode assembly 22 is greater than 0.

The main body part 221 of the electrode assembly 22 refers to the part of the electrode assembly 22 with the active material layer, such as the lower part of the electrode assembly 22 as shown in FIG. 3 (excluding the positive electrode tab 222 and the negative electrode tab extending outside the main body part 221 223), and the dotted box portion shown in Figures 8 to 14. The minimum distance D2 between the disassembly groove 2121 and the main body part 221 of the electrode assembly 22 refers to the distance between the farthest point of the disassembly groove 2121 from the opening of the housing 212 and the main body part 221 .

In the above technical solution, if external force is applied to disassemble the casing 212 at the disassembly groove 2121, part of the casing 212 may move toward the inside of the casing 212. The position of the disassembly groove 2121 is limited to the main body 221, so that The portion moving toward the inside of the housing 212 is prevented from puncturing the main body portion 221 of the electrode assembly 22 so that the electrode assembly 22 can be recovered. In some embodiments, please continue to refer to FIGS. 8 to 10 , the disassembly groove 2121 includes a first annular groove 2121 a , and the first annular groove 2121 a is circumferentially disposed on the peripheral wall 2122 . Among them, the first annular groove 2121a is arranged in a circle along the circumferential direction of the peripheral wall 2122, and the end and end of the first annular groove 2121a are connected to form an annular closed groove.

The first annular groove 2121a can extend along the One lap.

In the above technical solution, external force can be applied along the first annular groove 2121a, which can be pressed by hand, or other tools can be assisted to apply external force, so that the housing 212 can be cracked along the first annular groove 2121a, so that the housing 212 can be split in the first annular groove 2121a. The first annular groove 2121a is separated into two parts so that the electrode assembly 22 inside the housing 21 can be taken out to recycle the battery 100 .

In some embodiments, the angle between the surface where the first annular groove 2121a is located and the surface where the opening of the peripheral wall 2122 is located is less than 5°.

Please continue to refer to FIG. 8 . The first annular groove 2121 a extends along the X direction. The surface where the first annular groove 2121 a is located is parallel to the surface where the opening of the peripheral wall 2122 is located, and the angle between the two is 0°.

Please continue to refer to FIG. 9 . The first annular groove 2121 a extends obliquely. The angle between the surface where the first annular groove 2121 a is located and the surface where the opening of the peripheral wall 2122 is located is α, and α is less than 5°.

Please continue to refer to Figure 10. The extension direction of the first annular groove 2121a is irregular, so the surface where the first annular groove 2121a is located is the point between the farthest point from the end cap 231 and the closest point from the end cap 231 in the first annular groove 2121a. The straight line is formed along the surface perpendicular to the paper surface, as shown in Figure 10. The angle between the surface where the first annular groove 2121a is located and the surface where the opening of the peripheral wall 2122 is located is α, and α is less than 5°.

As an example, the angle α between the surface where the first annular groove 2121a is located and the surface where the opening of the peripheral wall 2122 is located may be 0°, 1°, 2°, 3°, 4° or 5°, or it may be is any value in the above range.

In the above technical solution, the surface where the first annular groove 2121a is located is basically parallel to the surface where the opening of the peripheral wall 2122 is located. The annular groove can be formed for disassembly and at the same time, the length of the annular groove can be made shorter, so that the annular groove can be disassembled to a certain extent. The strength of the shell 21 is ensured.

In other embodiments, a non-closed groove can also be provided on the peripheral wall 2122, and a tool can be used to open the non-closed groove to dismantle the housing, which can also make the disassembly more convenient.

In some embodiments, please continue to refer to FIG. 11 , the disassembly groove 2121 further includes a second annular groove 2121b, the second annular groove 2121b is circumferentially disposed on the peripheral wall 2122, and the first annular groove 2121a intersects the second annular groove 2121b. Among them, the second annular groove 2121b is arranged in a circle along the circumferential direction of the peripheral wall 2122, and the end and end of the second annular groove 2121b are connected to form an annular closed groove.

As shown in Figure 11, both the first annular groove 2121a and the second annular groove 2121b extend obliquely, so that the first annular groove 2121a and the second annular groove 2121b intersect. In another embodiment, the first annular groove 2121a may extend along the X direction, and the second annular groove 2121b may extend obliquely, so that the first annular groove 2121a and the second annular groove 2121b intersect. In another embodiment, the first annular groove 2121a may extend along the X direction, and the second annular groove 2121b may extend in a curve, so that the first annular groove 2121a and the second annular groove 2121b intersect. In another embodiment, the first annular groove 2121a can also extend obliquely, and the second annular groove 2121b can extend in a curve, so that the first annular groove 2121a and the second annular groove 2121b intersect.

In the above technical solution, when disassembling the housing 21, you can first apply external force to the intersection 2121c of the first annular groove 2121a and the second annular groove 2121b, and use this as a starting point for disassembly, which is more labor-saving; at the same time, continue to apply When disassembling by external force, external force can be applied along the area between the two annular grooves to make disassembly more convenient and avoid scratching the hands, making disassembly more convenient.

In some embodiments, please continue to refer to FIG. 11 , the distance between the intersection point 2121c of the first annular groove 2121a and the second annular groove 2121b and the positive electrode terminal 234 is less than the distance between the intersection point 2121c and the negative electrode terminal 235. That is, the intersection point 2121 c is provided on the side of the case 212 close to the positive electrode terminal 234 .

In the above technical solution, when external force is applied for disassembly, the housing 212 cracks from the intersection point 2121c, which may cause the housing 212 at the edge of the intersection point 2121c to move inward and may come into contact with the tab; set the intersection point 2121c At a position close to the positive electrode side, the case 212 can be prevented from contacting the negative electrode, thereby improving the safety performance of the battery 100 during disassembly.

In some embodiments, please continue to refer to Figure 11. The housing 212 is a rectangular parallelepiped, and the peripheral wall 2122 of the housing 212 is also a rectangular parallelepiped structure. It is defined that among the peripheral walls 2122 of the housing 212, the two opposite faces with larger areas are larger. The two opposite faces with smaller areas are the sides. The intersection point 2121c of the first annular groove 2121a and the second annular groove 2121b is located on the large surface. When pressing the junction of the first annular groove 2121a and the second annular groove 2121b with your hand, the force-bearing area of the hand can be larger. Can avoid scratching hands.

In some embodiments, please continue to refer to Figure 12, the disassembly groove 2121 also includes a second annular groove 2121b, the second annular groove 2121b is circumferentially disposed on the peripheral wall 2122, and the second annular groove 2121b is located at the far end of the first annular groove 2121a. One side of cover 231. When disassembling the housing 21, external force is directly applied to the area between the two annular grooves to facilitate the disassembly and avoid scratching the hands, making the disassembly more convenient.

In some embodiments, the angle between the surface where the second annular groove 2121b is located and the surface where the opening of the peripheral wall 2122 is located is less than 5°.

Please continue to refer to Figure 12. The second annular groove 2121b extends along the X direction. The surface where the second annular groove 2121b is located is parallel to the surface where the opening of the peripheral wall 2122 is located, and the angle between the two is 0°.

In another embodiment, the second annular groove 2121b extends obliquely, and the angle between the surface where the second annular groove 2121b is located and the surface where the opening of the peripheral wall 2122 is located is less than 5°. In another embodiment, the extension direction of the second annular groove 2121b is irregular, and the surface where the second annular groove 2121b is located is the point farthest from the end cap 231 and the point closest to the end cap 231 in the second annular groove 2121b. The angle formed between the straight line formed along the surface perpendicular to the paper surface and the surface where the second annular groove 2121b is located and the surface where the opening of the peripheral wall 2122 is located is less than 5°.

As an example, the angle between the surface where the second annular groove 2121b is located and the surface where the opening of the peripheral wall 2122 is located may be 0°, 1°, 2°, 3°, 4° or 5°, or it may be Any value within the above range.

In the above technical solution, the surface where the second annular groove 2121b is located is basically parallel to the surface where the opening of the peripheral wall 2122 is located. The annular groove can be formed for disassembly and at the same time, the length of the annular groove can be made shorter, so that the annular groove can be disassembled to a certain extent. The strength of the shell 21 is ensured.

In some embodiments, please continue to refer to Figures 13 and 14. The disassembly groove 2121 also includes an auxiliary groove 2121d. The auxiliary groove 2121d is provided on the peripheral wall 2122, and the two ends of the auxiliary groove 2121d are respectively connected to the first annular groove 2121a and the second annular groove 2121d. Annular groove 2121b.

As shown in Figures 13 and 14, the two ends of the auxiliary groove 2121d are connected to the first annular groove 2121a and the second annular groove 2121b respectively, so that the auxiliary groove 2121d, the first annular groove 2121a and the second annular groove 2121b jointly form the disassembly groove 2121, to disassemble the housing 212.

In another embodiment, the two ends of the auxiliary groove 2121d can also penetrate the first annular groove 2121a and the second annular groove 2121b, that is, the two ends of the auxiliary groove 2121d exceed the first annular groove 2121a and the second annular groove 2121b. The groove 2121d may also form a disassembly groove 2121 together with the first annular groove 2121a and the second annular groove 2121b to disassemble the housing 212.

In the above technical solution, when disassembling the casing 21, external force can be first applied to the intersection of the first annular groove 2121a, the second annular groove 2121b and the auxiliary groove 2121d, and use this as a starting point for disassembly, which is more labor-saving; at the same time, When continuing to apply external force for disassembly, you can apply external force along the area between the two annular grooves to make disassembly more convenient and avoid scratching your hands, making disassembly more convenient.

In some embodiments, the connection between the auxiliary groove 2121d and the first annular groove 2121a is a first connection point 2121e, the connection between the auxiliary groove 2121d and the second annular groove 2121b is a second connection point 2121f, and the first connection point 2121e and The distance between the second connection points 2121f is the minimum distance between the first annular groove 2121a and the second annular groove 2121b.

As shown in Figure 13 and Figure 14, the connection line between the first connection point 2121e and the second connection point 2121f extends along the Y direction, and the length of the auxiliary groove 2121d is relatively short, which can facilitate disassembly and can also be carried out in a certain manner. Ensure the strength of the shell 21 to a certain extent.

In some embodiments, the auxiliary groove 2121d is a line segment groove, and the angle between the extending direction of the line segment groove and the surface where the opening of the peripheral wall 2122 is located is 85° to 90°. As shown in Figure 13, the auxiliary groove 2121d extends along the Y direction, and the angle between the extending direction of the auxiliary groove 2121d and the surface where the opening of the peripheral wall 2122 is located is 90°. In other embodiments, the angle between the extension direction of the auxiliary groove 2121d and the surface of the opening of the peripheral wall 2122 can also be 85°, 86°, 87°, 88° or 89°, or it can also be in the above range. Any value.

The extension direction of the auxiliary groove 2121d is basically perpendicular to the surface where the opening of the peripheral wall 2122 is located. The auxiliary groove 2121d can be formed for disassembly and at the same time, the length of the auxiliary groove 2121d can be shortened, thereby ensuring the strength of the housing 21 to a certain extent. .

In some embodiments, please continue to refer to FIG. 13 , the distance between the auxiliary groove 2121 d and the positive electrode terminal 234 is smaller than the distance between the auxiliary groove 2121 d and the negative electrode terminal 235 . That is, the auxiliary groove 2121d is provided on the side of the case 212 close to the positive electrode terminal 234.

In the above technical solution, when external force is applied for disassembly, the housing 212 cracks from the auxiliary groove 2121d, which may cause the housing 212 at the edge of the auxiliary groove 2121d to move inward, and may come into contact with the tab; The groove 2121d is disposed close to the positive electrode side, which can prevent the case 212 from contacting the negative electrode, thereby improving the safety performance of the battery 100 during disassembly.

In some embodiments, please continue to refer to Figures 13 and 14. The housing 212 is square, and the peripheral wall 2122 of the housing 212 is also a square structure. It is defined that two relatively large areas of the peripheral walls 2122 of the housing 212 are arranged oppositely. The face is the large face, and the two opposite faces with smaller areas are the side faces. The auxiliary groove 2121d is provided on the large surface of the peripheral wall 2122, so that the first connection point 2121e where the auxiliary groove 2121d intersects the first annular groove 2121a and the second connection point 2121f where the auxiliary groove 2121d intersects the second annular groove 2121b are both located on the large surface. at.

In the above technical solution, the arrangement of the auxiliary groove 2121d can be made more convenient. At the same time, it is also more convenient when external force is applied to the edge of the auxiliary groove 2121d and the position between the two annular grooves.

In some embodiments, the minimum distance between the first annular groove 2121a and the second annular groove 2121b is not less than 1.5 cm.

Please continue to refer to Figures 13 and 14. The first annular groove 2121a and the second annular groove 2121b both extend along the X direction. The minimum distance between the first annular groove 2121a and the second annular groove 2121b is the first annular groove 2121a and The distance between the second annular grooves 2121b.

In another embodiment, if the first annular groove 2121a and the second annular groove 2121b are arranged obliquely, the minimum distance between the first annular groove 2121a and the second annular groove 2121b may be: several line segments along the Y direction, Both ends of the line segment are respectively located at the first annular groove 2121a and the second annular groove 2121b, and the length of the shortest line segment is the minimum distance between the first annular groove 2121a and the second annular groove 2121b.

In the above technical solution, the application of external force can be facilitated. For example, when pressing the position between the first annular groove 2121a and the second annular groove 2121b by hand, the hand will not be scratched.

In some embodiments, the disassembly groove 2121 is a disassembly score. Generally, the disassembly score can be formed by scratching using a sharp tool. The disassembly score is more convenient to set, and the width of the score is smaller, which has less impact on the strength and appearance of the housing 212. .

In some embodiments, disassembly groove 2121 is recessed from the outside inward. The housing 212 may be formed first, and then the disassembly groove 2121 is provided on the outer surface of the peripheral wall 2122 of the housing 212; or the disassembly groove 2121 may be provided first, and then the housing 212 is formed. The notch of the disassembly groove 2121 is located on the outer surface of the housing 212, and the position of the disassembly groove 2121 can be easily observed, so that when the housing 21 needs to be disassembled, the position of the disassembly groove 2121 can be easily found and disassembled.

In other embodiments, the disassembly groove 2121 may also be recessed from the inside to the outside. The disassembly groove 2121 can be provided first, and then the housing 212 can be formed, which will not affect the appearance of the housing 212.

Please continue to refer to Figures 3 and 13. The embodiment of the present application provides a square housing 21. The housing 21 includes an end cover 231 and a housing 212. The housing 212 includes a peripheral wall 2122 and a bottom wall 2123. The bottom wall 2123 is located at one end of the peripheral wall 2122. It is integrally formed with the peripheral wall 2122. The peripheral wall 2122 forms an opening at an end opposite to the bottom wall 2123. The end cap 231 and the peripheral wall 2122 are welded at the edge of the opening. The peripheral wall 2122 is provided with a first annular groove 2121a, a second annular groove 2121b and an auxiliary groove 2121d. The first annular groove 2121a and the second annular groove 2121b are both circumferentially provided on the peripheral wall 2122. The second annular groove 2121b is located in the first annular groove. On the side of 2121a away from the end cover 231, the two ends of the auxiliary groove 2121d are respectively connected to the first annular groove 2121a and the second annular groove 2121b. The auxiliary groove 2121d is located on the large surface of the peripheral wall 2122. The minimum distance D1 between the first annular groove 2121a and the end cover 231 is >0.3 cm.

In such a casing 21, when you need to disassemble the battery cell 20, you can directly press the edge of the auxiliary groove 2121d with your hands to break the casing 212 from the auxiliary groove 2121d, and then continue to press the first annular groove 2121a with your hands. and the second annular groove 2121b, thereby forming a break in the casing 212, so that the electrode assembly 22 in the battery cell 20 can be taken out. At the same time, the minimum distance D1 between the first annular groove 2121a and the end cover 231 is >0.3 cm, which can prevent the welding heat effect from affecting the strength of the housing 212.

Please continue to refer to Figures 3 and 13. The embodiment of the present application provides a square battery cell 20. The battery cell 20 includes a square casing 21 and an electrode assembly 22. The casing 21 includes an end cover 231 and a casing 212. The casing 212 includes Peripheral wall 2122 and bottom wall 2123. The bottom wall 2123 is located at one end of the circumferential wall 2122 and is integrally formed with the circumferential wall 2122. The circumferential wall 2122 forms an opening at the opposite end of the bottom wall 2123. The electrode assembly 22 is placed in the cavity formed by the circumferential wall 2122 and the bottom wall 2123. , the end cap 231 and the peripheral wall 2122 are welded at the edge of the opening. The peripheral wall 2122 is provided with a first annular groove 2121a, a second annular groove 2121b and an auxiliary groove 2121d. The first annular groove 2121a and the second annular groove 2121b are both circumferentially provided on the peripheral wall 2122. The second annular groove 2121b is located in the first annular groove. On the side of 2121a away from the end cover 231, the two ends of the auxiliary groove 2121d are connected to the first annular groove 2121a and the second annular groove 2121b respectively. The minimum distance D1 between the first annular groove 2121a and the end cap 231 is >0.3 cm, and the minimum distance between the second annular groove 2121b and the main body 221 of the electrode assembly 22 is greater than 0.

In such a battery cell 20, when you need to disassemble the battery cell 20, you can directly press the edge of the auxiliary groove 2121d with your hands to break the casing 212 from the auxiliary groove 2121d, and then continue to press the first ring shape with your hands. The area between the groove 2121a and the second annular groove 2121b forms a break in the casing 212 so that the electrode assembly 22 in the battery cell 20 can be taken out. At the same time, the minimum distance D1 between the first annular groove 2121a and the end cover 231 is >0.3cm, which can prevent the welding heat effect from affecting the strength of the housing 212; the minimum distance between the second annular groove 2121b and the main body 221 of the electrode assembly 22 is greater than 0, which can This prevents the part of the housing 212 that is pressed inward from piercing the main body 221, thereby improving the recovery effect of the electrode assembly 22.

Example 1

Please refer to Figures 3 and 13. The battery cell 20 includes an electrode assembly 22 and a casing 21. The casing 21 includes a casing 212 and an end cap 231. The electrode assembly 22 is disposed in the casing 212. The end cap 231 is welded to the casing 212. Opening edge. The peripheral wall 2122 of the housing 212 is provided with two parallel first annular notches and a second annular notch along the X direction; an auxiliary notch along the Y direction is also provided; the first annular notch and the end The distance between the cover 231 is 0.5cm, the distance between the first annular score and the second annular score is 1.5cm, the distance between the second annular score and the main body 221 of the electrode assembly 22 is 0.5cm, and the distance between the second annular score and the main body 221 of the electrode assembly 22 is 0.5cm. The ratio of the depth to the thickness of the housing 212 is 0.2, and the ratio of the depth of the pressure relief groove 2321 of the pressure relief portion 232 on the end cover 231 to the thickness of the pressure relief portion 232 is 0.3.

Example 2

Please refer to Figures 3 and 8. The battery cell 20 includes an electrode assembly 22 and a casing 21. The casing 21 includes a casing 212 and an end cap 231. The electrode assembly 22 is disposed in the casing 212, and the end cap 231 is welded to the casing 212. Opening edges. A parallel first annular notch along the X direction is provided on the peripheral wall 2122 of the housing 212; the distance between the first annular notch and the end cover 231 is 0.5cm, and the ratio of the depth of the notch to the thickness of the housing 212 is 0.2. The ratio of the depth of the pressure relief groove 2321 of the pressure relief portion 232 on the end cover 231 to the thickness of the pressure relief portion 232 is 0.3.

Example 3

The difference between Embodiment 3 and Embodiment 1 is that the end cap 231 is glued to the opening edge of the housing 212, and the distance between the first annular notch and the end cap 231 is 0.2 cm.

Comparative example 1

The battery cell includes an electrode assembly and a casing. The casing includes a casing and an end cover. The electrode assembly is arranged in the casing. The end cover is welded to the opening edge of the casing. There are no marks on the peripheral wall of the casing.

Comparative example 2

The difference between Comparative Example 2 and Embodiment 1 is that the distance between the first annular score and the end cap 231 is 0.2 cm.

Comparative example 3

The difference between Comparative Example 3 and Embodiment 1 is that: the ratio of the depth of the score to the thickness of the housing 212 is 0.2, and the ratio of the depth of the pressure relief groove 2321 of the pressure relief part 232 on the end cover 231 to the thickness of the pressure relief part 232 is 0.1.

Experimental example 1

The battery cells provided in Examples 1 to 3 and Comparative Examples 1 to 3 were fully charged and disassembled, wherein the battery cells provided in Examples 1 to 3 and Comparative Examples 2 to 3 were The battery cells are disassembled by pressing by hand. The battery cells provided in Comparative Example 1 are disassembled with a knife. The time for dismantling the casing is recorded in Table 1.

Table 1 Disassembly time of the casing in the battery cell

serial number	Shell disassembly time
Example 1	0.25min
Example 2	0.25min
Example 3	0.25min
Comparative example 1	5min
Comparative example 2	0.25min
Comparative example 3	0.25min

As can be seen from Table 1, after the disassembly notches are set on the housing, the housing can be disassembled by pressing with hands, and the disassembly efficiency is also very high.

Experimental example 2

The battery cells provided in Examples 1 to 3 and Comparative Examples 1 to 3 were overcharged respectively, and the safety performance of the battery cells (national standard: GBT/31485) was recorded as shown in Table 2.

Table 2 Safety performance of battery cells

serial number	Overcharge test@60℃200A 4.7V
Example 1	The pressure relief groove of the pressure relief part of the end cover is disconnected, HL4
Example 2	The pressure relief groove of the pressure relief part of the end cover is disconnected, HL4
Example 3	The pressure relief groove of the pressure relief part of the end cover is disconnected, HL4
Comparative example 1	The pressure relief groove of the pressure relief part of the end cover is disconnected, HL4
Comparative example 2	The shell is broken at the notch and the shell flies out, HL6
Comparative example 3	The shell is broken at the notch and the shell flies out, HL6

Combining Table 1 and Table 2, it can be seen that the method provided by this application to set the disassembly notch can not only realize the rapid disassembly of the casing, but also ensure the safety performance of the battery cells.

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 (21)

1. A housing used to accommodate electrode components, characterized in that the housing includes:

   An end cover, the end cover is provided with a pressure relief part, and the pressure relief part is provided with a pressure relief groove;

   A shell, with a disassembly groove provided on the shell;

   The ratio of the depth of the disassembly groove to the thickness of the housing is L1, and the ratio of the depth of the pressure relief groove to the thickness of the pressure relief part is L2, L1<L2.
2. The casing according to claim 1, wherein the end cover is installed at the opening of the casing and welded to the opening edge of the casing, and the minimum distance between the disassembly groove and the end cover is Distance D1＞0.3cm.
3. The shell of claim 1, wherein the housing includes a peripheral wall, the disassembly groove includes a first annular groove, and the first annular groove is circumferentially disposed on the peripheral wall.
4. The shell according to claim 3, wherein the angle between the surface where the first annular groove is located and the surface where the opening of the peripheral wall is located is less than 5°.
5. The shell of claim 3, wherein the disassembly groove further includes a second annular groove, the second annular groove is circumferentially disposed on the peripheral wall, and the first annular groove is connected to the second annular groove. The annular grooves intersect.
6. The casing according to claim 5, wherein the end cap is further provided with a positive electrode terminal and a negative electrode terminal, and the intersection point of the first annular groove and the second annular groove and the positive electrode terminal The distance is smaller than the distance between the intersection point and the negative electrode terminal.
7. The shell of claim 3, wherein the disassembly groove further includes a second annular groove, the second annular groove is circumferentially disposed on the peripheral wall, and the second annular groove is located on the first The side of the annular groove away from the end cap.
8. The shell according to claim 7, wherein the angle between the surface where the second annular groove is located and the surface where the opening of the peripheral wall is located is less than 5°.
9. The shell according to claim 7, wherein the disassembly groove further includes an auxiliary groove, the auxiliary groove is provided on the peripheral wall, and two ends of the auxiliary groove are respectively connected to the first annular groove and the first annular groove. the second annular groove.
10. The shell according to claim 9, wherein the connection point between the auxiliary groove and the first annular groove is a first connection point, and the connection point between the auxiliary groove and the second annular groove is a second connection point. connection point, the distance between the first connection point and the second connection point is the minimum distance between the first annular groove and the second annular groove.
11. The shell according to claim 10, wherein the auxiliary groove is a line-segment groove, and the angle between the extension direction of the line-segment groove and the surface where the opening of the peripheral wall is located is 85° to 90°.
12. The casing of claim 9, wherein the end cap is further provided with a positive electrode terminal and a negative electrode terminal, and the distance between the auxiliary groove and the positive electrode terminal is smaller than the distance between the auxiliary groove and the negative electrode. Distance between electrode terminals.
13. The casing according to claim 9, wherein the peripheral wall is square, the peripheral wall includes two relatively large surfaces with a larger area and two opposite side surfaces with a smaller area, and the auxiliary groove Set on the large surface.
14. The shell according to any one of claims 7 to 13, characterized in that the minimum distance between the first annular groove and the second annular groove is not less than 1.5 cm.
15. The housing according to any one of claims 3 to 13, wherein the housing further includes a bottom wall;

    The bottom wall is located at one end of the peripheral wall and is integrally formed with the peripheral wall. The peripheral wall forms an opening at an end opposite to the bottom wall.
16. The shell according to any one of claims 1 to 13, characterized in that the disassembly groove is a disassembly score.
17. The housing according to any one of claims 1 to 13, wherein the disassembly groove is recessed from outside to inside.
18. A battery cell, characterized in that it includes:

    The casing according to any one of claims 1 to 17,

    An electrode assembly is placed in the housing, and the end cover is installed at the opening of the housing.
19. The battery cell according to claim 18, wherein the minimum distance between the disassembly groove and the main body of the electrode assembly is greater than 0.
20. A battery, characterized in that it includes:

    The battery cell according to claim 18 or 19;

    A box is used to accommodate the battery cells.
21. An electrical device, characterized by comprising the battery according to claim 20, said battery being used to provide electrical energy.

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