CN217788606U

CN217788606U - Battery monomer, battery and consumer

Info

Publication number: CN217788606U
Application number: CN202221560484.1U
Authority: CN
Inventors: 金海族; 谷慧; 姜玲燕; 刘超
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-06-21
Filing date: 2022-06-21
Publication date: 2022-11-11
Anticipated expiration: 2032-06-21

Abstract

The embodiment of the application provides a single battery, a battery and electric equipment, and belongs to the technical field of batteries. The battery cell comprises an electrode assembly and a shell. The case accommodates the electrode assembly, and has a wall portion disposed opposite to the electrode assembly in a thickness direction of the wall portion. The wall portion is convexly provided with a first reinforcing portion, the first reinforcing portion extends along the circumferential direction of the wall portion, the wall portion comprises a first area located on the outer circumferential side of the first reinforcing portion, and the first area is formed with a weak portion, and the weak portion is configured to be cracked when the battery cell discharges pressure. The first reinforcing portion reinforces the wall portion, enhancing the strength of the weak portion. Because the weak part is formed in the first area positioned on the outer peripheral side of the first reinforcing part, when the wall part is subjected to external force and the part positioned on the inner peripheral side of the first reinforcing part is deformed, the first reinforcing part can reduce the influence of the external force on the weak part, reduce the deformation of the weak part, ensure the normal initiation pressure of the battery cell and prolong the service life of the battery cell.

Description

Battery monomer, battery and consumer

Technical Field

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

Background

At present, with the development of new energy technology, batteries are more and more widely applied, for example, to mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, and the like.

The battery cell serves as an energy storage element, and generally, an electrode assembly and an electrolyte chemically react with each other to output electric energy. In battery technology, not only the safety of the battery cell but also the service life of the battery cell need to be considered. Therefore, how to increase the service life of the battery cell is an urgent problem to be solved in the battery technology.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a single battery, a battery and electric equipment, which can effectively prolong the service life of the single battery.

In a first aspect, an embodiment of the present application provides a battery cell, including an electrode assembly and a case; a case accommodating the electrode assembly, the case having a wall portion disposed opposite the electrode assembly in a thickness direction of the wall portion; the wall portion is convexly provided with a first reinforcing portion, the first reinforcing portion extends along the circumferential direction of the wall portion, the wall portion comprises a first area located on the outer circumferential side of the first reinforcing portion, the first area is provided with a weak portion, and the weak portion is configured to be cracked when the battery cell releases pressure.

Among the above-mentioned technical scheme, the protruding first rib that is equipped with of wall portion, first rib plays the reinforcing action to wall portion, has strengthened weak portion intensity. Because the weak part is formed in the first area located on the outer periphery side of the first reinforcing part, when the wall part is subjected to external force and the part located on the inner periphery side of the first reinforcing part is deformed, the first reinforcing part can reduce the influence of the external force on the weak part, reduce the deformation of the weak part, ensure the normal detonation pressure of the battery cell and prolong the service life of the battery cell.

In some embodiments, the wall portion further includes a second region located on an inner peripheral side of the first reinforcement portion, the second region being provided with the pour hole. The liquid injection hole is formed in the second area of the wall portion, and electrolyte is conveniently injected into the battery cell. When pouring into electrolyte through annotating the liquid hole to battery monomer inside, the second region receives the extrusion force that priming device applyed to be out of shape to battery monomer's inside easily, and first rib can reduce the regional deformation of second and to the influence of weak part to reduce the deformation of weak part, reduce and lead to weak part to warp through annotating the in-process of liquid hole to battery monomer inside pouring into electrolyte, and cause the weak part just cracked risk in not reaching detonating pressure.

In some embodiments, the pour hole is disposed coaxially with the first reinforcement. Thus, when the electrolyte is injected into the battery cell through the injection hole, the first reinforcing portion is uniformly stressed, and the deformation of the weak portion can be further reduced.

In some embodiments, the first reinforcing portion is provided protruding from a side of the wall portion facing the electrode assembly in a thickness direction of the wall portion. Therefore, the first reinforcing part faces the interior of the battery cell, the first reinforcing part is reduced to occupy excessive external space, and the size of the battery cell is reduced.

In some embodiments, the first reinforcement portion abuts against the electrode assembly in a thickness direction of the wall portion. When the wall portion receives an external force and the portion located on the inner circumferential side of the first reinforcing portion deforms towards the interior of the battery cell, the first reinforcing portion abuts against the electrode assembly, the electrode assembly limits the first reinforcing portion, and the risk of deformation of the weak portion is reduced.

In some embodiments, a first concave portion is provided at a position corresponding to the first reinforcing portion on a side of the wall portion facing away from the electrode assembly in a thickness direction of the wall portion. The first reinforcing part has good buffering capacity due to the arrangement of the first concave part, and plays a good role in buffering when the wall part is deformed at the inner peripheral side of the first reinforcing part due to external force, so that the external force is prevented from being transmitted to the weak part, and the deformation of the weak part is further reduced.

In some embodiments, the first reinforcement portion has a width a in the radial direction of the wall portion ₁ The first reinforcing part has an inner diameter r ₁ The radius of the wall portion is R, satisfying: a is more than or equal to 0.05 ₁ the/R is less than or equal to 0.8; and/or, r is more than or equal to 0.05 ₁ /R≤0.8。

In some embodiments, the first region is embossed with a second reinforcement portion extending in a circumferential direction of the wall portion; the first region includes a first connection portion connecting the first reinforcement portion and the second reinforcement portion, the first connection portion being located on an outer peripheral side of the first reinforcement portion, the second reinforcement portion being located on an outer peripheral side of the first connection portion; wherein the weak portion is formed at the first connection portion. The weak portion is formed at a first connection portion connected between the first reinforcing portion and the second reinforcing portion, and the second reinforcing portion may also reinforce the strength of the weak portion.

In some embodiments, the second reinforcing part is convexly disposed on a side of the first region facing the electrode assembly, and the second reinforcing part has a first surface facing the electrode assembly along a thickness direction of the wall portion, and the first surface abuts against the electrode assembly to electrically connect the wall portion and the electrode assembly. The first surface is abutted against the electrode assembly, so that on one hand, the wall part is electrically connected with the electrode assembly, and the electric energy of the battery cell is output through the wall part; on the other hand, the second reinforcement part supports the electrode assembly, improving the stability of the electrode assembly inside the case.

In some embodiments, the first reinforcement does not extend beyond the first surface in a direction along the wall portion toward the electrode assembly. In this way, it is ensured that the first surface can effectively abut against the electrode assembly.

In some embodiments, the first reinforcement part has a second surface facing the electrode assembly in a thickness direction of the wall part, the second surface being flush with the first surface. The second surface and the first surface can abut against the electrode assembly, on one hand, the flow area is increased, on the other hand, the first reinforcing portion abuts against the electrode assembly, and the influence of force on the weak portion by the portion, located on the inner circumferential side of the first reinforcing portion, of the wall portion is reduced.

In some embodiments, the wall portion has a third surface facing away from the electrode assembly and farthest from the first surface in a thickness direction of the wall portion, and the first connection portion is located between the first surface and the third surface in the thickness direction of the wall portion. Make first connecting portion between first surface and third surface in the thickness direction of wall portion like this for external force is hardly directly used to first connecting portion, thereby effectively reduces the influence of external force to weak part in battery monomer production process and use.

In some embodiments, the first region further comprises an edge portion connected to the second reinforcement portion and located at an outer peripheral side of the second reinforcement portion; the surface of the edge portion facing away from the electrode assembly in the thickness direction of the wall portion is a third surface. The edge portion protects the first connecting portion, so that external force is hardly directly applied to the first connecting portion.

In some embodiments, the distance between the third surface and the first surface in the thickness direction of the wall portion is H, and the height of the first reinforcement portion protruding out of the wall portion is H ₁ The height of the protruding wall portion of the second reinforcing portion is h ₂ Satisfies the following conditions: h is not less than 0.1 ₁ H is less than or equal to 0.9; and/or 0.1-h ₂ /H≤0.9。

In some embodiments, a second concave portion is provided at a position corresponding to the second reinforcing portion on a side of the first region facing away from the electrode assembly in a thickness direction of the wall portion. The second concave part enables the second reinforcing part to have good buffering capacity, and when the area of the wall part on the outer periphery side of the second reinforcing part is subjected to external force, the second reinforcing part plays a good buffering role, prevents the external force from being transmitted to the weak part, and further reduces deformation of the weak part.

In some embodiments, the second reinforcement part is welded to the electrode assembly to electrically connect the wall part with the electrode assembly; or, the battery cell further comprises a current collecting member arranged between the wall part and the electrode assembly along the thickness direction of the wall part, the current collecting member is connected to the electrode assembly, and the second reinforcing part is welded to the current collecting member so as to realize the electrical connection between the wall part and the electrode assembly. Whether the second reinforcing portion is welded to the electrode assembly or the second reinforcing portion is welded to the current collecting member, the stability of the electrical connection of the wall portion and the electrode assembly may be improved.

In some embodiments, the second reinforcement portion has a width a in a radial direction of the wall portion ₂ The radius of the wall part is R, and the distance from the outer edge of the second reinforcing part to the outer edge of the wall part is L ₁ The distance between the first reinforcing part and the second reinforcing part is L ₂ Satisfies the following conditions: a is more than or equal to 0.05 ₂ the/R is less than or equal to 0.8; and/or, L is more than or equal to 0.02 ₁ R is less than or equal to 0.8; and/or, L is not less than 0.05 ₂ /R≤0.8。

In some embodiments, the first connecting portion partially protrudes in the thickness direction of the wall portion to form a third reinforcing portion, the third reinforcing portion extends in the circumferential direction of the wall portion, and the weak portion is formed at the third reinforcing portion. The third reinforcing portion can enhance the strength of the first connecting portion and further reduce the influence of the wall portion deformed by a force on the weak portion.

In some embodiments, the third reinforcement portion has a width a in the radial direction of the wall portion ₃ The radius of the wall portion is R, satisfying: a is more than or equal to 0.05 ₃ /R≤0.8。

In some embodiments, the first region is provided with a score, and the first region forms a frangible portion where the score is provided. The first area is correspondingly formed with the weak part in a nicking mode, so that the thickness of the weak part is thinner than that of other areas, the weak part is easier to break, and the forming mode of the weak part is simple.

In some embodiments, the score is disposed about the first reinforcement; the nicks are non-closed structures with distances between the head end and the tail end; or the nicks are of closed structures connected end to end. Like this, when battery monomer pressure release, the region that the wall part was injectd at the nick can be opened for battery monomer has great pressure release area, has improved pressure release efficiency.

In some embodiments, the housing comprises a shell and an end cap; one end of the shell is provided with an opening, and the shell is provided with a bottom wall opposite to the opening; the end cover is connected with the shell and closes the opening; wherein one of the bottom wall and the end cap is a wall portion. The bottom wall of the shell can be used as a wall part, so that the bottom wall of the shell has pressure relief capacity; it is also possible that the end cap of the housing acts as a wall, so that the end cap has a pressure relief capability.

In some embodiments, the battery cell further includes an electrode terminal disposed at an end of the case opposite to the wall portion in a thickness direction of the wall portion, the electrode terminal being electrically connected to the electrode assembly. The electric energy of the battery cell can be conveniently output through the electrode terminal.

In some embodiments, the electrode terminal has a first outer surface facing away from the electrode assembly in a thickness direction of the wall portion, the electrode terminal is provided with a groove recessed from the first outer surface in a direction close to the electrode assembly, the electrode terminal forms a second connection portion where the groove is provided, and the second connection portion is connected to the electrode assembly. The arrangement of the groove on the electrode terminal reduces the weight of the electrode terminal and reduces the production cost. In addition, after the electrode terminal is provided with the groove, the second connecting part of the electrode terminal is thinner, so that the external welding of the electrode terminal can be realized, and the stability of the electrical connection between the electrode terminal and the electrode assembly is improved.

In some embodiments, the battery cell further includes a sealing member connected to the electrode terminal and sealing the groove; in the thickness direction of the wall portion, the sealing member has a second outer surface facing away from the electrode assembly, the second outer surface being flush with the first outer surface. The second surface of shutoff piece and the first surface of electrode terminals can form level and smooth interface jointly, is favorable to realizing with other part welding, realizes overflowing by a large scale.

In a second aspect, an embodiment of the present application provides a battery, which includes a case and a battery cell provided in any one of the embodiments of the first aspect, where the battery cell is accommodated in the case.

In a third aspect, an embodiment of the present application further provides an electric device, including the battery provided in any one of the embodiments of the second aspect.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

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

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

fig. 3 is an exploded view of a battery cell provided in some embodiments of the present application;

fig. 4 is a cross-sectional view of the battery cell shown in fig. 3;

fig. 5 is a partially enlarged view of the battery cell shown in fig. 4;

FIG. 6 is a schematic view of the wall portion of FIG. 5;

FIG. 7 is a schematic illustration of a wall portion according to further embodiments of the present application;

FIG. 8 is a top view of the wall shown in FIG. 6;

fig. 9 is a cross-sectional view of a battery cell provided in accordance with other embodiments of the present application;

fig. 10 is a partially enlarged view of the battery cell shown in fig. 9 at a.

Icon: 1-a housing; 11-a housing; 111-a bottom wall; 12-an end cap; 13-a wall portion; 131-a first reinforcement; 1311-a second surface; 132-a first region; 1321-a weakened portion; 1322-a first connection; 1323-edge portion; 1324-a third surface; 1325-a third reinforcement; 1326-third recess; 1327-scoring; 133-a second region; 1331-liquid injection hole; 134-a first recess; 135-a second reinforcement; 1351-a first surface; 136-a second recess; 2-an electrode assembly; 21-a tab; 21 a-positive tab; 21 b-negative tab; 3-an electrode terminal; 31-a first outer surface; 32-grooves; 321-a first groove; 322-a second slot; 33-a second connecting portion; 34-a first inner surface; 4-a current collecting member; 5-plugging piece; 51-a second outer surface; 10-a battery cell; 20-a box body; 201-a first portion; 202-a second portion; 100-a battery; 200-a controller; 300-a motor; 1000-a vehicle; z-thickness direction.

Detailed Description

In order to make the objects, 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 with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

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

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the 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 the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "attached" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.

The term "and/or" in this application is only one kind of association relationship describing the association object, and means that there may be three kinds of relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this application generally indicates that the former and latter related objects are in an "or" relationship.

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only illustrative and should not constitute any limitation to the present application.

The appearances of "a plurality" in this application are intended to mean more than two (including two).

In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the cylindrical battery monomer, the square battery monomer and the soft package battery monomer are also not limited in the embodiment of the application.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.

The battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive plate, a negative plate and an isolating membrane. The battery cell mainly depends on metal ions moving between the positive plate and the negative plate to work. The positive plate comprises a positive current collector and a positive active substance layer, the positive active substance layer is coated on the surface of the positive current collector, the positive current collector which is not coated with the positive active substance layer protrudes out of the positive current collector which is coated with the positive active substance layer, and the positive current collector which is not coated with the positive active substance layer is used as a positive tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative pole mass flow body and negative pole active substance layer, and the surface of negative pole mass flow body is scribbled to the negative pole active substance layer, and the negative pole mass flow body protrusion in the negative pole mass flow body of having scribbled the negative pole active substance layer of not scribbling the negative pole active substance layer, and the negative pole mass flow body of not scribbling the negative pole active substance layer is as negative pole ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, a plurality of positive electrode tabs are stacked, and a plurality of negative electrode tabs are stacked. The material of the isolation film may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The development of battery technology requires consideration of various design factors, such as energy density, cycle life, discharge capacity, charge/discharge rate, and other performance parameters, as well as battery safety.

In the single battery, in order to improve the safety of the single battery, a pressure relief mechanism can be arranged in the single battery, and when the pressure inside the single battery reaches the detonation pressure, the pressure inside the single battery is relieved through the pressure relief mechanism.

In order to reduce the manufacturing cost of the pressure relief mechanism, a weak part can be formed on the wall part of the shell, so that the pressure relief mechanism is formed, and when the pressure in the battery monomer reaches the detonation pressure, the weak part is cracked, so that the purpose of pressure relief is achieved.

The inventors have noted that, in the case of a battery cell in which the pressure relief mechanism is formed by the weak portion of the wall portion, it is easy for the weak portion to abnormally rupture without reaching the detonation pressure inside the battery cell, so that the service life of the battery cell is reduced.

The inventor further researches and discovers that the wall part is easy to deform under external force during the normal use of the battery unit, so that the weak part is deformed, the strength of the weak part is reduced, and the weak part is abnormally cracked. For example, the wall portion is forced by another member outside the battery cell, causing the central region of the wall portion to deform toward the inside of the battery cell, resulting in a decrease in the strength of the weak portion. For another example, the pressure inside the battery cell increases with an increase in temperature, and the wall portion receives the force of the gas inside the battery cell, causing the central region of the wall portion to deform toward the outside of the battery cell, resulting in a decrease in the strength of the weak portion. Ultimately affecting the service life of the cells.

In view of this, the embodiment of the present application provides a battery cell, in which a first reinforcing portion is provided in a protruding manner on a wall portion of a housing, the first reinforcing portion extending in a circumferential direction of the wall portion, so that the wall portion forms a first region on an outer circumferential side of the first reinforcing portion, and a weak portion is formed in the first region.

In such a battery cell, the wall portion is provided with the first reinforcing portion in a protruding manner, and the first reinforcing portion reinforces the wall portion, thereby enhancing the strength of the weak portion. Because the weak part is formed in the first area positioned on the outer peripheral side of the first reinforcing part, when the wall part is subjected to external force and the part positioned on the inner peripheral side of the first reinforcing part is deformed, the first reinforcing part can reduce the influence of the external force on the weak part, reduce the deformation of the weak part, ensure the normal initiation pressure of the battery cell and prolong the service life of the battery cell.

The technical scheme described in the embodiment of the application is suitable for the battery and the electric equipment using the battery.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above-mentioned electric devices.

For convenience of explanation, the following embodiments will be described by taking an electric device as an example of a vehicle.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000.

The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

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

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a battery cell 10 and a case 20, and the battery cell 10 is accommodated in the case 20.

The case 20 is a component for accommodating the battery cell 10, the case 20 provides an accommodating space for the battery cell 10, and the case 20 may have various structures. In some embodiments, the case 20 may include a first portion 201 and a second portion 202, and the first portion 201 and the second portion 202 are covered with each other to define a receiving space for receiving the battery cell 10. The first portion 201 and the second portion 202 may be in various shapes, such as a rectangular parallelepiped, a cylinder, and the like. The first portion 201 may be a hollow structure with one side open, the second portion 202 may also be a hollow structure with one side open, and the open side of the second portion 202 is closed to the open side of the first portion 201, so as to form the box body 20 with a receiving space. The first portion 201 may have a hollow structure with one side open, the second portion 202 may have a plate-like structure, and the second portion 202 may cover the open side of the first portion 201 to form the case 20 having the receiving space. The first portion 201 and the second portion 202 may be sealed by a sealing element, which may be a sealing ring, a sealant, or the like.

In the battery 100, one or more battery cells 10 may be provided. If there are a plurality of battery cells 10, the plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel, where the series-parallel refers to that the plurality of battery cells 10 are connected in series or in parallel. A plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form a whole, and may be accommodated in the case 20. Or all the single batteries 10 can be directly connected in series or in parallel or in series-parallel, and the whole formed by all the single batteries 10 is accommodated in the box 20.

In some embodiments, the battery 100 may further include a bus member, and the plurality of battery cells 10 may be electrically connected to each other through the bus member, so as to connect the plurality of battery cells 10 in series or in parallel or in series-parallel. The bus member may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, or the like.

Referring to fig. 3 and 4, fig. 3 is an exploded view of a battery cell 10 according to some embodiments of the present disclosure, and fig. 4 is a cross-sectional view of the battery cell 10 shown in fig. 3. The battery cell 10 may include a case 1 and an electrode assembly 2.

The case 1 is a member for accommodating the electrode assembly 2. The housing 1 may be in various shapes, such as a cylinder, a rectangular parallelepiped, etc. The housing 1 may include a case 11 and an end cap 12.

The housing 11 may be a hollow structure having one end formed to be open. The material of the housing 11 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

The end cap 12 is a member that closes the opening of the case 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 defines a sealed space for accommodating the electrode assembly 2, the electrolyte, and other components together with the case 11. The end cap 12 may be connected to the housing 11 by welding or crimping to close the opening of the housing 11. The shape of the end cap 12 may be adapted to the shape of the housing 1, for example, the housing 11 is a rectangular parallelepiped structure, the end cap 12 is a rectangular plate structure adapted to the housing 1, and for example, the housing 11 is a cylinder, and the end cap 12 is a circular plate structure adapted to the housing 11. The end cap 12 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.

The electrode assembly 2 is a component in the battery cell 10 where electrochemical reactions occur. The electrode assembly 2 may include a positive electrode tab, a negative electrode tab, and a separator. The electrode assembly 2 may have a winding type structure formed by winding a positive electrode sheet, a separator, and a negative electrode sheet, or a lamination type structure formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet. The electrode assembly 2 has tabs 21, and the tabs 21 are divided into positive tabs 21a and negative tabs 21b, and the positive tabs 21a may be portions of the positive electrode sheets to which the positive electrode active material layer is not applied, and the negative tabs 21b may be portions of the negative electrode sheets to which the negative electrode active material layer is not applied.

The battery cell 10 may further include an electrode terminal 3, and the electrode terminal 3 is used to electrically connect with a tab 21 of the electrode assembly 2 to output electric power of the battery cell 10. The electrode terminal 3 may be provided on the end cap 12 or may be provided on the case 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, the electrode terminal 3 and the tab 21 are directly welded. The electrode terminal 3 and the tab 21 may be indirectly connected, for example, the electrode terminal 3 and the tab 21 are indirectly connected through the current collecting member 4. The current collecting member 4 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like.

As shown in fig. 3 and 4, taking the example in which the electrode terminal 3 is provided at one end of the case 1 opposite to the end cap 12, the positive electrode tab 21a is electrically connected to the electrode terminal 3 via one current collecting member 4, and the negative electrode tab 21b is electrically connected to the case 11 via the other current collecting member 4.

Referring to fig. 5, fig. 5 is a partially enlarged view of the battery cell 10 shown in fig. 4. The embodiment of the application provides a battery cell 10, which comprises a shell 1 and an electrode assembly 2. The case 1 accommodates the electrode assembly 2, and the case 1 has a wall portion 13, the wall portion 13 being disposed opposite to the electrode assembly 2 in a thickness direction Z of the wall portion 13. The wall 13 is provided with a first reinforcing portion 131 in a protruding manner, the first reinforcing portion 131 extends along the circumferential direction of the wall 13, the wall 13 includes a first region 132 located on the outer circumferential side of the first reinforcing portion 131, the first region 132 is formed with a weak portion 1321, and the weak portion 1321 is configured to be ruptured when the battery cell 10 releases pressure.

The wall portion 13 may be the end cap 12 of the housing 1, or may be a wall provided opposite the end cap 12 of the case 11. The wall portion 13 may be circular or rectangular. If the housing 1 is cylindrical, the wall 13 is circular; if the housing 1 is a rectangular parallelepiped, the wall portion 13 is rectangular. Taking the case 1 as a cylinder as an example, the axial direction of the case 1 is the thickness direction Z of the wall portion 13.

The wall portion 13 may serve as an electric power output part of the battery cell 10, and the wall portion 13 is electrically connected to the electrode assembly 2 to output electric power of the battery cell 10. Illustratively, in fig. 4 and 5, the wall 13 is an end cap 12, and the end cap 12 is electrically connected to a tab 21 of the electrode assembly 2 via the current collecting member 4.

The wall portion 13 is provided with a first reinforcing portion 131 in a protruding manner, that is, the first reinforcing portion 131 is provided on the wall portion 13 and protrudes from the wall portion 13. Along the thickness direction Z of the wall portion 13, the first reinforcing portion 131 may be protruded at a side of the wall portion 13 facing the electrode assembly 2, such that the first reinforcing portion 131 faces the inside of the battery cell 10, and the first reinforcing portion 131 may also be protruded at a side of the wall portion 13 facing away from the electrode assembly 2, such that the first reinforcing portion 131 faces the outside of the battery cell 10.

The first reinforcement portion 131 may be an annular structure, such as a circular ring, a square ring, or the like. Taking the wall portion 13 as a circular shape as an example, the first reinforcing portion 131 may form a circular ring structure extending along the circumferential direction of the wall portion 13.

The first region 132 is a portion of the wall 13 located on the outer peripheral side of the first reinforcing portion 131. The outer peripheral side of the first reinforcing portion 131 is the outer side of the first reinforcing portion 131 in the thickness direction Z perpendicular to the wall portion 13, taking the wall portion 13 as a circular shape as an example, the outer peripheral side of the first reinforcing portion 131 is the outer side of the first reinforcing portion 131 in the radial direction of the wall portion 13, and the first region 132 is an annular portion of the wall portion 13 surrounding the outer side of the first reinforcing portion 131.

The weak portion 1321 is a portion where the wall portion 13 is weaker, and the weak portion 1321 is more easily broken in the wall portion 13 than in other regions. When the pressure inside the battery cell 10 reaches the initiation pressure and needs to be relieved, the weak portion 1321 can be ruptured, so that the exhaust inside the battery cell 10 can be discharged, and the purpose of relieving the pressure inside the battery cell 10 is achieved.

In the embodiment of the present application, the wall portion 13 is provided with the first reinforcing portion 131 in a protruding manner, and the first reinforcing portion 131 reinforces the wall portion 13, so that the strength of the weak portion 1321 is enhanced. Since the weak portion 1321 is formed in the first region 132 on the outer peripheral side of the first reinforcing portion 131, when the wall portion 13 receives an external force to deform the portion on the inner peripheral side of the first reinforcing portion 131, the first reinforcing portion 131 can reduce the influence of the external force on the weak portion 1321, reduce the deformation of the weak portion 1321, ensure the normal detonation pressure of the battery cell 10, and improve the service life of the battery cell 10.

In some embodiments, with continued reference to fig. 5, the wall 13 further includes a second region 133 located on the inner peripheral side of the first reinforcing portion 131, and the second region 133 is provided with a liquid injection hole 1331. The liquid injection hole 1331 is provided in the second region 133 of the wall portion 13 to facilitate injection of the electrolyte into the battery cell 10.

The second region 133 is a portion of the wall portion 13 located on the inner peripheral side of the first reinforcing portion 131. The first reinforcing portion 131 partitions the wall portion 13 into two regions, one region being a first region 132 located on the outer peripheral side of the first reinforcing portion 131, the other region being a second region 133 located on the inner peripheral side of the first reinforcing portion 131, the second region 133 being a central region of the wall portion 13. The inner peripheral side of the first reinforcing portion 131 is the inner side of the first reinforcing portion 131 in the thickness direction Z perpendicular to the wall portion 13, and taking the wall portion 13 as a circular shape as an example, the inner peripheral side of the first reinforcing portion 131 is the inner side of the first reinforcing portion 131 in the radial direction of the wall portion 13, and the second region 133 is a portion of the wall portion 13 located inside the first reinforcing portion 131.

The liquid inlet 1331 is a passage provided in the second region 133 for allowing the electrolytic solution to enter the battery cell 10. The liquid inlet 1331 may be provided at the center of the second region 133, or may be offset from the center of the second region 133. After the electrolyte is injected into the battery cell 10 through the injection hole 1331, the injection hole 1331 may be closed by a sealing pin.

When the electrolyte is injected into the battery cell 10 through the injection hole 1331, the second region 133 is easily deformed toward the inside of the battery cell 10 by the pressing force applied by the injection device (e.g., an injection needle), and the first reinforcing part 131 can reduce the influence of the deformation of the second region 133 on the weak part 1321, thereby reducing the deformation of the weak part 1321, and reducing the risk that the weak part 1321 is deformed in the process of injecting the electrolyte into the battery cell 10 through the injection hole 1331, and the weak part 1321 is cracked without reaching the initiation pressure.

In some embodiments, the injection hole 1331 is provided coaxially with the first reinforcement 131.

It is understood that the liquid injection hole 1331 is provided at the center of the second region 133. The liquid injection hole 1331 is provided such that the second region 133 has an annular structure surrounding the inside of the first reinforcement 131.

Taking the case where the liquid inlet 1331 is a circular hole and the first reinforcing portion 131 is circular, the center line of the liquid inlet 1331 coincides with the central axis of the first reinforcing portion 131. The diameter of the liquid injection hole 1331 may be 0.05-10 mm.

In the present embodiment, the liquid injection hole 1331 is provided coaxially with the first reinforcing portion 131, and when the electrolyte is injected into the battery cell 10 through the liquid injection hole 1331, the second region 133 is deformed into the battery cell 10 by a force, and the first reinforcing portion 131 is uniformly stressed, so that the risk of deformation of the weak portion 1321 due to a local excessive stress on the first reinforcing portion 131 is reduced, and the deformation of the weak portion 1321 can be further reduced.

In some embodiments, with reference to fig. 5, the first reinforcing portion 131 is protruded from a side of the wall portion 13 facing the electrode assembly 2 along the thickness direction Z of the wall portion 13. Thus, the first reinforcing part 131 faces the inside of the battery cell 10, and the first reinforcing part 131 occupies an excessive external space, reducing the volume of the battery cell 10.

In some embodiments, with reference to fig. 5, the first reinforcing portion 131 abuts against the electrode assembly 2 along the thickness direction Z of the wall portion 13.

The first reinforcing part 131 may directly abut against the electrode assembly 2, for example, the first reinforcing part 131 directly abuts against the tab 21 of the electrode assembly 2; the first reinforcing part 131 may also indirectly abut against the electrode assembly 2, for example, as shown in fig. 5, the first reinforcing part 131 indirectly abuts against the tab 21 of the electrode assembly 2 through the current collecting member 4.

When the wall portion 13 receives an external force and the portion located on the inner circumferential side of the first reinforcing portion 131 is deformed toward the inside of the battery cell 10, the first reinforcing portion 131 abuts against the electrode assembly 2, so that the electrode assembly 2 restricts the first reinforcing portion 131, and the risk of deformation of the weak portion 1321 is reduced.

In some embodiments, with reference to fig. 5, along the thickness direction Z of the wall portion 13, a first concave portion 134 is disposed at a position corresponding to the first reinforcing portion 131 on a side of the wall portion 13 facing away from the electrode assembly 2.

The shape of the first concave portion 134 is the same as the shape of the first reinforcing portion 131, and for example, if the first reinforcing portion 131 is circular, the first concave portion 134 is also circular. The first recess 134 may be stamped and formed. After the first concave portion 134 is press-formed, the first reinforcing portion 131 may be formed on the side of the wall portion 13 facing the electrode assembly 2.

In the present embodiment, the first concave portion 134 is provided to provide the first reinforcing portion 131 with a good buffering capacity, and when the wall portion 13 receives an external force to deform the portion located on the inner peripheral side of the first reinforcing portion 131, the first reinforcing portion 131 plays a good buffering role to prevent the external force from being transmitted to the weak portion 1321, and further reduce the deformation of the weak portion 1321.

In some embodiments, please refer to fig. 6, fig. 6 is a schematic structural diagram of the wall 13 shown in fig. 5. The first reinforcing portion 131 has a width a in the radial direction of the wall portion 13 ₁ The first reinforcing part 131 has an inner diameter r ₁ The radius of the wall portion 13 is R, satisfying: a is more than or equal to 0.05 ₁ R is less than or equal to 0.8; and/or r is not less than 0.05 ₁ /R≤0.8。

In the present embodiment, the wall portion 13 is circular, and the first reinforcing portion 131 is circular. Half of the difference between the outer diameter and the inner diameter of the first reinforcing part 131 is the width of the first reinforcing part 131 in the radial direction of the wall part 13.

a ₁ the/R may be any value between 0.05 and 0.8, such as 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. r is ₁ The value of/R may be any value between 0.05 and 0.8, for example, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

In some embodiments, with continued reference to fig. 5 and 6, the first region 132 is provided with a second reinforced portion 135, and the second reinforced portion 135 extends along the circumferential direction of the wall 13. The first region 132 includes a first connection portion 1322, the first connection portion 1322 connects the first reinforcement portion 131 and the second reinforcement portion 135, the first connection portion 1322 is located on an outer circumferential side of the first reinforcement portion 131, and the second reinforcement portion 135 is located on an outer circumferential side of the first connection portion 1322. The weak portion 1321 is formed at the first connection portion 1322.

The second reinforcing portion 135 is disposed in the first region 132 and protrudes from the first region 132. Along the thickness direction Z of the wall portion 13, the second reinforcing portion 135 may be protruded at a side of the first region 132 facing the electrode assembly 2 such that the second reinforcing portion 135 faces the inside of the battery cell 10, and the second reinforcing portion 135 may also be protruded at a side of the wall portion 13 facing away from the electrode assembly 2 such that the second reinforcing portion 135 faces the outside of the battery cell 10.

The second reinforcing portion 135 surrounds the outer side of the first reinforcing portion 131, the second reinforcing portion 135 may be a ring structure, such as a circular ring, a square ring, etc., and the second reinforcing portion 135 is disposed coaxially with the first reinforcing portion 131. Illustratively, as shown in fig. 5 and 6, the wall portion 13 has a circular shape, and the second reinforcing portion 135 and the first reinforcing portion 131 each have a circular ring shape. The second reinforcement portion 135 is disposed coaxially with the first reinforcement portion 131.

The first connection portion 1322 is a portion where the first region 132 is connected to the first reinforcement portion 131 and the second reinforcement portion 135 in the thickness direction Z perpendicular to the wall portion 13. The first connection portion 1322 is connected to the second region 133 by the first reinforcement portion 131. Taking the first reinforcement part 131 and the second reinforcement part 135 as an example, the first connection part 1322 is an annular structure connected between the first reinforcement part 131 and the second reinforcement part 135.

Illustratively, as shown in fig. 5 and 6, the first connecting portion 1322 and the second region 133 are both flat plate structures, and the first connecting portion 1322 is substantially flush with the second region 133 along the thickness direction Z of the wall portion 13.

In the present embodiment, the weak portion 1321 is formed at the first connection portion 1322 connected between the first reinforcing portion 131 and the second reinforcing portion 135, and the second reinforcing portion 135 may also reinforce the strength of the weak portion 1321.

In some embodiments, with continued reference to fig. 5 and fig. 6, the second reinforced portion 135 is convexly disposed on a side of the first region 132 facing the electrode assembly 2, and along the thickness direction Z of the wall portion 13, the second reinforced portion 135 has a first surface 1351 facing the electrode assembly 2, and the first surface 1351 abuts against the electrode assembly 2 to electrically connect the wall portion 13 and the electrode assembly 2.

The first surface 1351 is an end surface of the second reinforcing portion 135 facing the electrode assembly 2 in the thickness direction Z of the wall portion 13. The first surface 1351 may abut directly against the electrode assembly 2, for example, the first surface 1351 abuts directly against the tab 21 of the electrode assembly 2 to electrically connect the wall portion 13 with the electrode assembly 2; the first surface 1351 may also indirectly abut against the electrode assembly 2, for example, as shown in fig. 5, the first surface 1351 directly abuts against the current collecting member 4, and the current collecting member 4 directly abuts against the tab 21 of the electrode assembly 2, so as to electrically connect the wall 13 and the electrode assembly 2.

The first surface 1351 of the second reinforcement portion 135 abuts against the electrode assembly 2, on the one hand, achieving electrical connection of the wall portion 13 with the electrode assembly 2 so as to output electrical energy of the battery cell 10 through the wall portion 13; on the other hand, the second reinforcement part 135 supports the electrode assembly 2, improving the stability of the electrode assembly 2 inside the case 1.

In some embodiments, with continued reference to fig. 5 and 6, the first reinforcement portion 131 does not extend beyond the first surface 1351 in a direction along the wall portion 13 toward the electrode assembly 2.

The direction in which the wall portion 13 is directed toward the electrode assembly 2 is the direction in which the wall portion 13 faces the electrode assembly 2 in the thickness direction Z.

In the present embodiment, the first reinforcement part 131 does not protrude beyond the first surface 1351, ensuring that the first surface 1351 can effectively abut against the electrode assembly 2.

In some embodiments, the first reinforcement part 131 has a second surface 1311 facing the electrode assembly 2 along the thickness direction Z of the wall part 13, and the second surface 1311 is flush with the first surface 1351.

The second surface 1311 is an end surface of the first reinforcing portion 131 facing the electrode assembly 2 in the thickness direction Z of the wall portion 13. Second surface 1311 is flush with first surface 1351 such that second surface 1311 and first surface 1351 lie in the same plane, and both second surface 1311 and first surface 1351 can abut electrode assembly 2. On the one hand, the flow area is increased, and taking the case that the second surface 1311 and the first surface 1351 are directly abutted to the current collecting member 4, the current collecting member 4 is directly abutted to the tab 21 of the electrode assembly 2, and the second surface 1311 and the first surface 1351 are in contact with the current collecting member 4, so that the flow area between the current collecting member 4 and the wall portion 13 is increased. On the other hand, the first reinforcing portion 131 abuts on the electrode assembly 2, and the influence of the force on the weak portion 1321 by the portion of the wall portion 13 on the inner circumferential side of the first reinforcing portion 131 can be reduced.

In other embodiments, along the thickness direction Z of the wall portion 13, the second surface 1311 may be farther from the electrode assembly 2 than the first surface 1351.

In some embodiments, with continued reference to fig. 5 and 6, the wall portion 13 has a third surface 1324 facing away from the electrode assembly 2 and furthest from the first surface 1351 along the thickness direction Z of the wall portion 13, and the first connection 1322 is located between the first surface 1351 and the third surface 1324 along the thickness direction Z of the wall portion 13.

The third surface 1324 may be formed on the first region 132 and also on the second region 133.

In the present embodiment, the first connection part 1322 is interposed between the first surface 1351 and the third surface 1324 in the thickness direction Z of the wall part 13, so that an external force is hardly directly applied to the first connection part 1322, thereby effectively reducing the influence of the external force on the weak part 1321 during the production process and the use process of the battery cell 10. For example, when the housing 1 is placed on an object, the third surface 1324 of the wall portion 13 contacts with the object, and the first connecting portion 1322 is in a suspended state and does not directly contact with the object to be stressed, so as to protect the weak portion 1321.

In some embodiments, with continued reference to fig. 5 and 6, the first region 132 further includes an edge portion 1323, the edge portion 1323 is connected to the second reinforcing portion 135 and is located on an outer peripheral side of the second reinforcing portion 135, and a surface of the edge portion 1323 facing away from the electrode assembly 2 along the thickness direction Z of the wall portion 13 is a third surface 1324.

The edge portion 1323 may be a circular ring structure disposed around the second reinforcement portion 135, and the outer diameter of the edge portion 1323 is the diameter of the wall portion 13. Taking the wall 13 as the end cap 12 of the housing 1 as an example, the rim 1323 may be connected to the shell 11 of the housing 1, for example, by welding, so that the end cap 12 closes the opening of the shell 11.

The edge portion 1323 protects the first connection portion 1322, when the housing 1 is placed on an object, the edge portion 1323 contacts with the object, the first connection portion 1322 is in a suspended state, and does not directly contact with the object to bear force, so that external force is difficult to directly act on the first connection portion 1322.

In some embodiments, with continued reference to fig. 6, the distance between the third surface 1324 and the first surface 1351 along the thickness direction Z of the wall 13 is H, and the height H of the first reinforcement portion 131 protruding the wall 13 is ₁ The height of the second reinforcing portion 135 from the projecting wall portion 13 is h ₂ Satisfies the following conditions: h is not less than 0.1 ₁ H is less than or equal to 0.9; and/or 0.1-h ₂ /H≤0.9。

h ₁ The value of/H can be any value between 0.1 and 0.9, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9.h is ₂ The value of/H may be any value between 0.1 and 0.9, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9.

h ₁ And h ₂ May or may not be equal. In embodiments where first surface 1351 is flush with second surface 1311, h ₁ ＝h ₂ 。

In some embodiments, with continued reference to fig. 5 and 6, along the thickness direction Z of the wall portion 13, a second concave portion 136 is disposed at a position corresponding to the second reinforcing portion 135 on a side of the first region 132 facing away from the electrode assembly 2.

The shape of the second recess 136 is the same as the shape of the second reinforcing portion 135, and for example, if the second reinforcing portion 135 is circular, the second recess 136 is also circular. The second recess 136 may be stamped and formed. After the second concave portion 136 is press-formed, a second reinforcement portion 135 may be correspondingly formed at a side of the first region 132 facing the electrode assembly 2.

The second recess 136 provides the second reinforcing portion 135 with a good cushioning ability, and when the region of the wall portion 13 located on the outer peripheral side of the second reinforcing portion 135 receives an external force, the second reinforcing portion 135 performs a good cushioning function, and prevents the external force from being transmitted to the weak portion 1321, thereby further reducing the deformation of the weak portion 1321. For example, taking the wall portion 13 as the end cap 12 of the housing 1 as an example, when the wall portion 13 is assembled with the housing 11, the edge portion 1323 of the wall portion 13 receives a force applied by the housing 11, and in this process, the buffer action of the second reinforcing portion 135 reduces the deformation of the weak portion 1321.

In some embodiments, the second reinforcement portion 135 is welded to the electrode assembly 2 to electrically connect the wall portion 13 with the electrode assembly 2.

Specifically, the first surface 1351 of the second reinforcing part 135 directly abuts against the tab 21 of the electrode assembly 2, and the second reinforcing part 135 is welded to the tab 21 of the electrode assembly 2.

In the present embodiment, welding the second reinforcement portion 135 to the electrode assembly 2 can effectively improve the stability of the electrical connection between the wall portion 13 and the electrode assembly 2.

In the embodiment in which the first region 132 is provided with the second recess 136, the second recess 136 may be regarded as a welding groove, and the provision of the second recess 136 may reduce the thickness of the second reinforcement portion 135, which may enhance the firmness of welding the second reinforcement portion 135 to the tab 21.

In the embodiment in which the injection hole 1331 is provided in the second region 133, since the injection hole 1331 is provided in the second region 133 and the second protruding portion is provided in the first region 132, the injection hole 1331 is located at a relatively long distance from the second protruding portion, and therefore, after the electrolyte is injected into the battery cell 10 through the injection hole 1331, the electrolyte remaining in the vicinity of the injection hole 1331 is less likely to flow into the second recessed portion 136, and the weld strength between the second reinforcement portion 135 and the tab 21 is less likely to be impaired. In the embodiment in which the wall portion 13 is provided with the first recessed portions 134, the first recessed portions 134 can block the flow of the electrolyte into the second recessed groove 32, and the risk that the electrolyte remaining in the vicinity of the injection hole 1331 flows into the second recessed portions 136 and affects the weld strength between the second reinforcing portion 135 and the tab 21 is further reduced.

In other embodiments, with reference to fig. 5, the battery cell 10 further includes a current collecting member 4, the current collecting member 4 is disposed between the wall portion 13 and the electrode assembly 2 along the thickness direction Z of the wall portion 13, the current collecting member 4 is connected to the electrode assembly 2, and the second reinforcing portion 135 is welded to the current collecting member 4 to electrically connect the wall portion 13 and the electrode assembly 2.

The shape of the current collecting member 4 may be the same as the shape of the wall portion 13, for example, the wall portion 13 and the current collecting member 4 are both circular.

Specifically, the current collecting member 4 is disposed between the tab 21 and the wall portion 13 of the electrode assembly 2, and the current collecting member 4 is connected to the tab 21. Illustratively, the current collecting member 4 is welded to the tab 21.

In the present embodiment, the second reinforcing portion 135 is welded to the current collecting member 4, improving the stability of the electrical connection of the wall portion 13 and the electrode assembly 2.

In the embodiment in which the first region 132 is provided with the second recess 136, the provision of the second recess 136 can reduce the thickness of the second reinforcing portion 135, enabling to enhance the robustness of the welding of the second reinforcing portion 135 with the current collecting member 4.

In the embodiment in which the liquid injection hole 1331 is provided in the second region 133, since the liquid injection hole 1331 is provided in the second region 133 and the second protruding portion is provided in the first region 132, the liquid injection hole 1331 is spaced apart from the second protruding portion, and therefore, after the electrolyte is injected into the battery cell 10 through the liquid injection hole 1331, the electrolyte remaining in the vicinity of the liquid injection hole 1331 is less likely to flow into the second recessed portion 136, and the weld strength between the second reinforcing portion 135 and the current collecting member 4 is less likely to be impaired. In the embodiment in which the wall portion 13 is provided with the first recessed portion 134, the first recessed portion 134 can block the flow of the electrolyte into the second concave groove 32, and the risk that the electrolyte remaining in the vicinity of the liquid injection hole 1331 flows into the second recessed portion 136 and affects the weld strength between the second reinforcing portion 135 and the current collecting member 4 is further reduced.

In some embodiments, the second reinforcement portion 135 has a width a along the radial direction of the wall portion 13 ₂ The radius of the wall portion 13 is R, and the distance from the outer edge of the second reinforcement portion 135 to the outer edge of the wall portion 13 is L ₁ The first reinforcement portion 131 and the second reinforcement portion 135 are spaced apart from each other by a distance L ₂ And satisfies the following conditions: a is more than or equal to 0.05 ₂ R is less than or equal to 0.8; and/or, L is more than or equal to 0.02 ₁ the/R is less than or equal to 0.8; and/or, L is more than or equal to 0.05 ₂ /R≤0.8。

In the present embodiment, the wall portion 13 is circular, and the second reinforcing portion 135 is circular. Half of the difference between the outer diameter and the inner diameter of the second reinforcing portion 135 is the width of the second reinforcing portion 135 in the radial direction of the wall portion 13. The distance between the outer edge of the first reinforcement part 131 and the inner edge of the second reinforcement part 135 is the distance between the first reinforcement part 131 and the second reinforcement part 135. In embodiments where the first region 132 includes a rim portion 1323, the outer edge of the rim portion 1323 is the outer edge of the wall portion 13.

a ₂ The value of/R may be any value between 0.05 and 0.8, such as 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. L is ₁ the/R may be any value between 0.02 and 0.8, such as 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. L is ₂ the/R may be any value between 0.05 and 0.8, such as 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

In some embodiments, referring to fig. 7, fig. 7 is a schematic structural diagram of a wall portion 13 according to other embodiments of the present disclosure, in a thickness direction Z of the wall portion 13, a first connecting portion 1322 partially protrudes to form a third reinforcing portion 1325, the third reinforcing portion 1325 extends along a circumferential direction of the wall portion 13, and a weak portion 1321 is formed in the third reinforcing portion 1325.

The third reinforcement portion 1325 may have an annular structure, such as a circular ring, a square ring, etc., and the third reinforcement portion 1325 may have an annular structure extending along the circumferential direction of the wall portion 13, for example, when the wall portion 13 is circular. The third reinforcement portion 1325 may be disposed coaxially with the first reinforcement portion 131. One or more third reinforcing portions 1325 may be formed at the first connecting portion 1322.

The first connection portion 1322 is formed with a third recess 1326 at a position corresponding to the third reinforcement portion 1325, and the shape of the third recess 1326 is the same as the shape of the third reinforcement portion 1325. The third recess 1326 may be press-formed. After the second concave portion 136 is press-formed on one side of the first connection portion 1322 along the thickness direction Z of the wall portion 13, a third reinforcement portion 1325 may be correspondingly formed on the other side of the first connection portion 1322.

The first reinforcement portion 131, the second reinforcement portion 135, and the third reinforcement portion 1325 may be located on the same side of the wall portion 13 or may be located on different sides in the thickness direction Z of the wall portion 13. Illustratively, in fig. 7, the first reinforcement portion 131, the second reinforcement portion 135, and the third reinforcement portion 1325 are located on the same side of the wall portion 13, and all face the electrode assembly 2 (not shown in fig. 7).

In the embodiment in which the first connection portion 1322 is located between the first surface 1351 and the third surface 1324 in the thickness direction Z of the wall portion 13, since the third reinforcement portion 1325 is a part of the first connection portion 1322, the third reinforcement portion 1325 is also located between the first surface 1351 and the third surface 1324 in the thickness direction Z of the wall portion 13.

In this embodiment, the third reinforcement portion 1325 can reinforce the strength of the first connection portion 1322 and further reduce the influence of the force deformation of the wall portion 13 on the weak portion 1321.

In other embodiments, the weak portion 1321 may be formed at other regions of the first connection portion 1322 than the third reinforcing portion 1325.

In some embodiments, with continued reference to fig. 7, the third reinforcement 1325 has a width a along the radial direction of the wall 13 ₃ The radius of the wall portion 13 is R, satisfying: a is more than or equal to 0.05 ₃ /R≤0.8。

In the present embodiment, the wall portion 13 is circular, and the third reinforcing portion 1325 is annular. Half of the difference between the outer diameter and the inner diameter of the third reinforcing portion 1325 is the width of the third reinforcing portion 1325 in the radial direction of the wall portion 13.

a ₃ The value of/R may be any value between 0.05 and 0.8, such as 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc.

In some embodiments, referring to fig. 6 and 7, the first region 132 is provided with a score 1327, and the first region 132 forms a weak portion 1321 at the position where the score 1327 is provided.

After the score 1327 is formed in the first region 132, the remaining portion of the first region 132 at the score 1327 is the weakened portion 1321. The shape of the weak portion 1321 is the same as the shape of the score 1327. Score 1327 can be a variety of shapes, such as, for example, rectangular, circular, oval, annular, U-shaped, C-shaped, H-shaped, and the like. The score 1327 can be formed in a variety of ways, such as, for example, punch forming, milling, etc.

The weakened portion 1321 is formed by providing the score 1327 in the first region 132, so that the thickness of the weakened portion 1321 is thinner and easier to break than the thickness of other regions, and the weakened portion 1321 is formed in a simple manner.

In some embodiments, please refer to fig. 8, fig. 8 is a top view of the wall 13 shown in fig. 6. Score 1327 is disposed around first reinforcement 131, score 1327 being a non-closed structure spaced end-to-end.

Illustratively, score 1327 is C-shaped.

When the single battery 10 is decompressed, the wall part 13 can be opened in an outward turnover manner in the area defined by the notch 1327, so that the single battery 10 has a large decompression area, and the decompression efficiency is improved.

In other embodiments, score 1327 is disposed around first reinforcement 131, and score 1327 is a closed structure connected end-to-end.

Illustratively, score 1327 is circular.

When the single battery 10 is decompressed, the wall part 13 can be opened in an outward separation mode in the area defined by the notch 1327, so that the single battery 10 has a large decompression area, and the decompression efficiency is improved.

In some embodiments, referring to fig. 9, fig. 9 is a cross-sectional view of a battery cell 10 according to other embodiments of the present disclosure. The housing 1 includes a case 11 and an end cap 12, wherein an opening is formed at one end of the case 11, the case 11 has a bottom wall 111 opposite to the opening, and the end cap 12 is connected to the case 11 and closes the opening. One of the bottom wall 111 and the end cap 12 is a wall portion 13. If the bottom wall 111 of the housing 11 is used as the wall 13, the bottom wall 111 of the housing 11 has a pressure relief capability; if the end cap 12 of the housing 1 is the wall portion 13, the end cap 12 has a pressure relief capability.

Illustratively, in fig. 9, the end cap 12 serves as the wall portion 13.

In some embodiments, with continued reference to fig. 9, the battery cell 10 further includes an electrode terminal 3, the electrode terminal 3 is disposed at an end of the case 1 opposite to the wall portion 13 along the thickness direction Z of the wall portion 13, and the electrode terminal 3 is electrically connected to the electrode assembly 2.

The electrode terminals 3 and the electrode assembly 2 may be directly connected, for example, the electrode terminals 3 are welded to the tabs 21 of the electrode assembly 2. As shown in fig. 9, the electrode terminal 3 and the electrode assembly 2 may also be indirectly connected through the current collecting member 4.

In the embodiment in which the bottom wall 111 of the case 11 serves as the wall portion 13, the electrode terminal 3 is provided to the end cap 12, and the electrode terminal 3 is caulked to the end cap 12 while being insulated from the end cap 12. As shown in fig. 9, in the embodiment in which the end cap 12 is the wall portion 13, the electrode terminal 3 is provided on the bottom wall 111 of the case 11, and the electrode terminal 3 is caulked to the bottom wall 111 of the case 11 and is insulated from the bottom wall 111.

In the present embodiment, the electric power of the battery cell 10 can be conveniently output through the electrode terminal 3.

In some embodiments, referring to fig. 10, fig. 10 is a partially enlarged view of a portion a of the battery cell 10 shown in fig. 9. The electrode terminal 3 has a first outer surface 31 facing away from the electrode assembly 2 in the thickness direction Z of the wall portion 13, the electrode terminal 3 is provided with a groove 32 recessed from the first outer surface 31 in a direction close to the electrode assembly 2, the electrode terminal 3 forms a second connection portion 33 at a position where the groove 32 is provided, and the second connection portion 33 is connected to the electrode assembly 2.

The first outer surface 31 is an end surface of the electrode terminal 3 facing away from one end of the electrode assembly 2 in the thickness direction Z of the wall portion 13. The electrode terminal 3 further includes a first inner surface 34 opposite to the first outer surface 31 in the thickness direction Z of the wall portion 13, and a portion of the electrode terminal 3 between the groove bottom surface of the groove 32 and the first inner surface 34 is a second connecting portion 33.

Illustratively, the second connection portion 33 is indirectly connected to the tab 21 of the electrode assembly 2 through the current collecting member 4, the second connection portion 33 is welded to the current collecting member 4, and the current collecting member 4 is welded to the tab 21 of the electrode assembly 2. In the embodiment in which the liquid injection hole 1331 is provided in the second region 133 of the wall portion 13, the liquid injection hole 1331 is provided in the electrode terminal 3, so that the electrode terminal 3 is prevented from being cold-soldered due to the residual electrolyte in the vicinity of the liquid injection hole 1331 when the liquid injection hole 1331 is provided in the electrode terminal 3.

In the present embodiment, the provision of the groove 32 on the electrode terminal 3 reduces the weight of the electrode terminal 3 and the production cost. In addition, when the electrode terminal 3 is provided with the groove 32, the second connection part 33 of the electrode terminal 3 is thin, so that external welding to the electrode terminal 3 can be achieved, and the stability of electrical connection between the electrode terminal 3 and the electrode assembly 2 can be improved.

In some embodiments, with continued reference to fig. 10, the battery cell 10 further includes a sealing member 5, wherein the sealing member 5 is connected to the electrode terminal 3 and seals the groove 32. Along the thickness direction Z of the wall portion 13, the blocking piece 5 has a second outer surface 51 facing away from the electrode assembly 2, the second outer surface 51 being flush with the first outer surface 31.

The blocking member 5 may be made of a metal material, such as copper, iron, aluminum, stainless steel, aluminum alloy, or the like. The blocking piece 5 and the electrode terminal 3 may be welded and fixed.

Illustratively, the groove 32 includes a first groove 321 and a second groove 322, the first groove 321 and the second groove 322 are arranged along a depth direction of the groove 32, the first groove 321 is recessed from the first outer surface 31 along the depth direction of the groove 32, the second groove 322 is recessed from a groove bottom surface of the first groove 321 along the depth direction of the groove 32, a groove bottom surface of the second groove 322 is a groove bottom surface of the groove 32, and the blocking member 5 abuts against the groove bottom surface of the first groove 321 to block the groove 32.

The second outer surface 51 of the blocking piece 5 and the first outer surface 31 of the electrode terminal 3 can jointly form a flat interface, which is beneficial to realizing welding with other components (such as a confluence component) and realizing large-area overflowing. Further, the second outer surface 51 is flush with the first outer surface 31, facilitating butt welding of the block piece 5 with the electrode terminal 3.

The embodiment of the present application provides a battery 100, including a box 20 and the single battery 10 provided in any one of the above embodiments, where the single battery 10 is accommodated in the box 20.

The embodiment of the present application further provides an electric device, including any one of the above embodiments, which provides the battery 100.

In addition, as shown in fig. 4 to 6, the present embodiment also provides a cylindrical battery 100 including a case 1, an electrode assembly 2, an electrode terminal 3, and a current collecting member 4, wherein the electrode assembly 2 is accommodated in the case 1. The housing 1 includes a case 11 and an end cap 12, the case 11 having an opening, the end cap 12 closing the opening of the case 11. The end cap 12 is provided with a first reinforcing portion 131 in a protruding manner, and the end cap 12 includes a first region 132 located on the outer peripheral side of the first reinforcing portion 131 and a second region 133 located on the inner peripheral side of the first reinforcing portion 131. The first region 132 is provided with a second reinforcement portion 135 in a protruding manner, and the first reinforcement portion 131 and the second reinforcement portion 135 each extend in the circumferential direction of the end cap 12. The second region 133 includes a first connection portion 1322 connecting the first reinforcing portion 131 and the second reinforcing portion 135, the first connection portion 1322 being located on an outer circumferential side of the first reinforcing portion 131, and the second reinforcing portion 135 being located on an outer circumferential side of the first connection portion 1322. The first connection part 1322 is formed with a weak part 1321, and the weak part 1321 is configured to be ruptured when the battery cell 10 releases pressure. The second region 133 is provided with a liquid injection hole 1331. The electrode terminal 3 is disposed at one end of the case 1 opposite to the end cap 12, the positive electrode tab 21a of the electrode assembly 2 is electrically connected to the electrode terminal 3 through one current collecting member 4, and the negative electrode tab 21b of the electrode assembly 2 is electrically connected to the second reinforcing portion 135 through the other current collecting member 4.

In such a battery cell 10, when the electrolyte is injected into the battery cell 10 through the injection hole 1331, the second region 133 is easily deformed toward the inside of the battery cell 10 by the pressing force applied by the injection device, and the first reinforcing portion 131 can reduce the influence of the deformation of the second region 133 on the weak portion 1321, thereby reducing the deformation of the weak portion 1321, reducing the risk that the weak portion 1321 is deformed in the process of injecting the electrolyte into the battery cell 10 through the injection hole 1331, and the weak portion 1321 is cracked without reaching the initiation pressure, and improving the service life of the battery cell 10.

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

The above embodiments are merely for illustrating the technical solutions of the present application and are not intended to limit the present application, and those skilled in the art can make various modifications and variations of the present application. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, comprising:

an electrode assembly;

a case that houses the electrode assembly, the case having a wall portion that is disposed opposite to the electrode assembly in a thickness direction of the wall portion;

wherein the wall portion is provided with a first reinforcing portion in a protruding manner, the first reinforcing portion extending in a circumferential direction of the wall portion, the wall portion including a first region located on an outer circumferential side of the first reinforcing portion, the first region being formed with a weak portion configured to be ruptured when the battery cell discharges pressure.

2. The battery cell according to claim 1, wherein the wall portion further includes a second region located on an inner peripheral side of the first reinforcing portion, the second region being provided with a liquid injection hole.

3. The battery cell according to claim 2, wherein the liquid injection hole is provided coaxially with the first reinforcement portion.

4. The battery cell according to claim 1, wherein the first reinforcing portion is provided protruding from the wall portion on a side of the wall portion facing the electrode assembly in a thickness direction of the wall portion.

5. The battery cell according to claim 4, wherein the first reinforcement portion abuts against the electrode assembly in a thickness direction of the wall portion.

6. The battery cell according to claim 4, wherein a first concave portion is provided at a position corresponding to the first reinforcing portion on a side of the wall portion facing away from the electrode assembly in a thickness direction of the wall portion.

7. The battery cell as recited in claim 1, wherein the first reinforcing portion has a width a in a radial direction of the wall portion ₁ The first reinforcing part has an inner diameter r ₁ The radius of the wall part is R, and the following conditions are satisfied: a is more than or equal to 0.05 ₁ the/R is less than or equal to 0.8; and/or, r is more than or equal to 0.05 ₁ /R≤0.8。

8. The battery cell according to any one of claims 1 to 7, wherein the first region is provided with a second reinforcing portion that extends in a circumferential direction of the wall portion;

the first region includes a first connecting portion that connects the first reinforcing portion and the second reinforcing portion, the first connecting portion being located on an outer peripheral side of the first reinforcing portion, the second reinforcing portion being located on an outer peripheral side of the first connecting portion;

wherein the weak portion is formed at the first connection portion.

9. The battery cell as recited in claim 8, wherein the second reinforcing portion is provided protruding from the first region on a side facing the electrode assembly, and the second reinforcing portion has a first surface facing the electrode assembly in a thickness direction of the wall portion, the first surface abutting against the electrode assembly to electrically connect the wall portion and the electrode assembly.

10. The battery cell as recited in claim 9, wherein the first reinforcement portion does not extend beyond the first surface in a direction in which the wall portion is directed toward the electrode assembly.

11. The battery cell according to claim 9, wherein the first reinforcement portion has a second surface facing the electrode assembly in a thickness direction of the wall portion, the second surface being flush with the first surface.

12. The battery cell according to claim 9, wherein the wall portion has a third surface facing away from the electrode assembly and farthest from the first surface in a thickness direction of the wall portion, and the first connection portion is located between the first surface and the third surface in the thickness direction of the wall portion.

13. The battery cell as recited in claim 12, wherein the first region further comprises an edge portion connected to the second reinforcing portion and located at an outer peripheral side of the second reinforcing portion;

the surface of the edge portion facing away from the electrode assembly in the thickness direction of the wall portion is the third surface.

14. The battery cell as recited in claim 12, wherein a distance H between the third surface and the first surface in a thickness direction of the wall portion, and a height H at which the first reinforcing portion protrudes from the wall portion ₁ The height of the second reinforcing part protruding out of the wall part is h ₂ And satisfies the following conditions: h is not less than 0.1 ₁ H is less than or equal to 0.9; and/or 0.1-h ₂ /H≤0.9。

15. The battery cell according to claim 9, wherein a second recess is provided at a position corresponding to the second reinforcement portion on a side of the first region facing away from the electrode assembly in a thickness direction of the wall portion.

16. The battery cell as recited in claim 9 wherein the second reinforcement portion is welded to the electrode assembly to electrically connect the wall portion with the electrode assembly; or

The battery cell further comprises a current collecting member, the current collecting member is arranged between the wall portion and the electrode assembly along the thickness direction of the wall portion, the current collecting member is connected to the electrode assembly, and the second reinforcing portion is welded to the current collecting member so as to achieve the electrical connection between the wall portion and the electrode assembly.

17. The battery cell as recited in claim 8, wherein the second reinforcing portion has a width a in a radial direction of the wall portion ₂ The radius of the wall portion is R, and the distance from the outer edge of the second reinforcing portion to the outer edge of the wall portion is L ₁ The distance between the first reinforcing part and the second reinforcing part is L ₂ And satisfies the following conditions: a is more than or equal to 0.05 ₂ the/R is less than or equal to 0.8; and/or, L is more than or equal to 0.02 ₁ the/R is less than or equal to 0.8; and/or, L is more than or equal to 0.05 ₂ /R≤0.8。

18. The battery cell as recited in claim 8, wherein the first connecting portion partially protrudes in a thickness direction of the wall portion to form a third reinforcing portion that extends in a circumferential direction of the wall portion, and the weak portion is formed at the third reinforcing portion.

19. The battery cell as recited in claim 18, wherein the third reinforcing portion has a width a in a radial direction of the wall portion ₃ The radius of the wall part is R, and the following conditions are satisfied: a is more than or equal to 0.05 ₃ /R≤0.8。

20. The battery cell according to any one of claims 1 to 7, wherein the first region is provided with a notch, and the first region forms the weak portion at a position where the notch is provided.

21. The battery cell of claim 20, wherein the score is disposed about the first reinforcement portion;

the nicks are non-closed structures with distances between the head end and the tail end; or

The nick is a closed structure with two ends connected end to end.

22. The battery cell of any of claims 1-7, wherein the housing comprises:

a housing having an opening formed at one end, the housing having a bottom wall opposite the opening;

an end cap connected to the housing and closing the opening;

wherein one of the bottom wall and the end cap is the wall portion.

23. The battery cell according to any one of claims 1 to 7, further comprising an electrode terminal provided at an end of the case opposite to the wall portion in a thickness direction of the wall portion, the electrode terminal being electrically connected to the electrode assembly.

24. The battery cell as recited in claim 23, wherein the electrode terminal has a first outer surface facing away from the electrode assembly in a thickness direction of the wall portion, the electrode terminal is provided with a groove recessed from the first outer surface in a direction approaching the electrode assembly, the electrode terminal forms a second connection portion where the groove is provided, and the second connection portion is connected to the electrode assembly.

25. The battery cell as recited in claim 24, further comprising a blocking member connected to the electrode terminal and blocking the groove; the sealant has a second outer surface facing away from the electrode assembly in a thickness direction of the wall portion, the second outer surface being flush with the first outer surface.

26. A battery, comprising:

a box body;

the battery cell of any of claims 1-25, the battery cell housed within the case.

27. An electrical device comprising the battery of claim 26.