CN221226383U - Battery monomer, battery and electric equipment - Google Patents

Abstract

The application discloses a battery monomer, a battery and electric equipment. The battery cell includes shell, electrode assembly and end cover, the shell has first tip and the second tip relative with first tip, first tip is formed with the opening, the shell includes interior wall surface and outer wall surface, the outer wall surface is equipped with weak structure, weak structure is close to the opening more for the second tip, the shell includes first wall and the second wall of being connected with first wall, the area of first wall is greater than the area of second wall, the outer wall surface of first wall is formed with weak structure, electrode assembly sets up in the shell, end cover and shell sealing connection and closed opening. So, electrode assembly can constantly expand and shrink, and weak structure can be when electrode assembly expands the preferential deformation, reduces the degree of deformation that electrode assembly inflation produced shell and end cover junction, reduces the fracture risk of shell and end cover junction, improves the life of shell to improve battery monomer's stability.

Description

Battery monomer, battery and electric equipment

Technical Field

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

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry. In this case, the electric vehicle is an important component for sustainable development of the automobile industry due to the advantage of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor for development.

In the process of charging and discharging the battery monomer, the electrode assembly of the battery monomer can be continuously expanded and contracted, and the joint of the outer shell of the battery monomer and the end cover is easy to crack after long-time use, so that the stability of the battery monomer is reduced.

Disclosure of utility model

In view of the above problems, the present application provides a battery cell, a battery and electric equipment, which can improve the stability of the battery cell and reduce the influence on the insulation performance of the battery cell.

The battery cell comprises a shell, an electrode assembly and an end cover, wherein the shell is provided with a first end part and a second end part opposite to the first end part, an opening is formed in the first end part, the shell comprises an inner wall surface and an outer wall surface, the outer wall surface is provided with a weak structure, the weak structure is closer to the opening relative to the second end part, the shell comprises a first wall and a second wall connected with the first wall, the area of the first wall is larger than that of the second wall, the weak structure is formed in the outer wall surface of the first wall, the electrode assembly is arranged in the shell, and the end cover is connected with the shell in a sealing mode and seals the opening.

In the battery cell of the embodiment of the application, the electrode assembly can be continuously expanded and contracted in the charge and discharge process, the weak structure can be preferentially deformed when the electrode assembly is expanded, the deformation degree of the expansion of the electrode assembly on the joint of the shell and the end cover is reduced, the cracking risk of the joint of the shell and the end cover is reduced, the service life of the shell is prolonged, and the stability of the battery cell is improved. In addition, because the area of first wall is greater than the area of second wall, the first wall warp more easily under electrode assembly's effect, consequently, through set up weak structure at the outer wall surface of first wall, the deformation that the shell produced can be absorbed better to weak structure, reduces electrode assembly inflation and to the deformation that first wall and end cover junction produced, reduces the fracture risk of the junction of first wall and end cover to improve the life of shell.

In some embodiments, the outer wall surface of the second wall is formed with a weakened structure.

So, through set up weak structure at the outer wall surface of second wall, the impact when the outer wall surface that the second wall received the electrode assembly inflation can be preferentially absorbed to weak structure, reduces the deformation that electrode assembly inflation produced second wall and end cover junction, reduces the fracture risk of second wall and end cover junction to improve the life of shell.

In some embodiments, the weakening structure has a groove formed in an outer wall surface of the housing, the groove in the outer wall surface of the first wall interconnecting the groove in the outer wall surface of the second wall.

So, the recess can attenuate the thickness of shell to form weak structure more easily, be located the recess interconnect of the outer wall face of first wall and be located the outer wall face of second wall, make weak structure in the same position department deformation uniformity of shell better, be favorable to improving weak structure and absorb the ability that the shell received the impact.

In some embodiments, the housing includes a first portion and a second portion connected to the first portion, the first portion formed with a first end, the second portion formed with a second end distal from the first portion, a ratio of a height of the first portion to a height of the second portion in a direction of the first end toward the second end being greater than or equal to 3: the weakening structure is located on the second portion.

So, the weak structure is located the second portion for the weak structure is farther from the end cover, and then can make the deformation of shell when electrode assembly inflation concentrate on the second portion, reduces the influence that causes the first portion, reduces the risk of the junction fracture of the shell of first portion and end cover, thereby improves the life of shell.

In some embodiments, the weakened structure has a groove formed in the outer wall surface, and the ratio of the thickness of the second portion at the groove to the maximum thickness of the second portion is greater than or equal to 0.4.

Thus, the weak structure is easy to deform and absorb the impact received by the shell, and the strength is proper and the shell is not easy to break.

In some embodiments, the weakening structure has a groove formed in the outer wall surface.

In this way, the groove can reduce the thickness of the housing, thereby making it easier to form a weak structure.

In some embodiments, the height of the groove along the direction from the first end to the second end is h,0.2 mm.ltoreq.h.ltoreq.7 mm.

So, when the height of recess along first tip to second tip direction is above-mentioned within range, can be convenient for the formation of recess to form weak structure more easily, reduce the manufacturing degree of difficulty of shell, simultaneously, be favorable to improving weak structure and absorb the ability that the shell received the impact.

In some embodiments, 0.5 mm.ltoreq.h.ltoreq.4 mm.

So, when the height of recess along first tip to second tip direction is above-mentioned within range, can be convenient for the formation of recess to form weak structure more easily, reduce the manufacturing degree of difficulty of shell, simultaneously, be favorable to improving weak structure and absorb the ability that the shell received the impact.

In certain embodiments, the groove is spaced from the opening by a distance H, t-0.5 mm.ltoreq.H.ltoreq.8t, where t is the thickness of the end cap in mm.

Thus, when the distance between the groove and the opening is in the range, the deformation of the shell when the electrode assembly expands can be concentrated in the weak structure, the influence on the opening area is reduced, the risk of cracking at the joint of the shell and the end cover is reduced, and the service life of the shell is prolonged.

In certain embodiments, t.ltoreq.H.ltoreq.5 t.

Thus, when the distance between the groove and the opening is in the range, the deformation of the shell when the electrode assembly expands can be concentrated in the weak structure, the influence on the opening area is reduced, the risk of cracking at the joint of the shell and the end cover is reduced, and the service life of the shell is prolonged.

In some embodiments, the bottom surface of the groove forms an obtuse angle with the side surface of the groove.

Therefore, the angle formed by the bottom surface of the groove and the side surface of the groove is an obtuse angle, so that the groove can be conveniently formed, the manufacturing difficulty of the shell is reduced, and the processing precision of the shell and the service life of the grinding tool are improved.

In some embodiments, the bottom surface of the groove forms an angle with the side surface of the groove of 95 ° to 175 °.

Therefore, when the angle formed by the bottom surface of the groove and the side surface of the groove is in the range, the groove can be conveniently formed, the manufacturing difficulty of the shell is reduced, and the processing precision of the shell and the service life of the grinding tool are improved.

In some embodiments, the bottom surface of the groove forms an angle with the side surface of the groove of 110 ° to 160 °.

Therefore, when the angle formed by the bottom surface of the groove and the side surface of the groove is in the range, the groove can be conveniently formed, the manufacturing difficulty of the shell is reduced, and the processing precision of the shell and the service life of the grinding tool are improved.

The battery of the embodiment of the application comprises a battery cell.

The electric equipment provided by the embodiment of the application comprises a battery cell or a battery, wherein the battery cell or the battery is used for providing electric energy for the electric equipment.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

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

fig. 2 is a schematic view of a battery according to some embodiments of the present application;

Fig. 3 is a schematic structural view of a battery cell according to some embodiments of the present application;

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

fig. 5 is a front view of a battery cell according to some embodiments of the present application;

FIG. 6 is a top view of a battery cell according to some embodiments of the application;

Fig. 7 is a left side view of a battery cell according to some embodiments of the application;

FIG. 8 is a cross-sectional view taken along line A-A of FIG. 5;

FIG. 9 is an enlarged schematic view of section I of FIG. 8;

Fig. 10 is an enlarged schematic view of section ii of fig. 8.

Reference numerals illustrate: 100. a battery cell; 10. a housing; 11. a first end; 111. an opening; 12. a second end; 13. an inner wall surface; 14. an outer wall surface; 141. a weak structure; 142. a groove; 143. a bottom surface; 144. a side surface; 15. a first wall; 16. a second wall; 17. a first portion; 18. a second portion; 20. an end cap; 200. a battery; 210. a case; 300. a controller; 400. a motor; 1000. a vehicle.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the 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 herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

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

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

Currently, the application of power batteries is more widespread from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles, and the like, and a plurality of fields such as military equipment, aerospace, and the like. With the continuous expansion of the application field of the power battery, the market demand of the power battery is also continuously expanding.

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

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

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

The battery cell further includes a case that protects the electrode assembly from the outside to prevent foreign substances from affecting the charge or discharge of the electrode assembly, and an end cap. The end cap and the case together define a receiving space for receiving the electrode assembly, the electrolyte, and other components.

In the prior art, in the process of charging and discharging the battery monomer, the electrode assembly of the battery monomer can be continuously expanded and contracted, and the joint of the outer shell of the battery monomer and the end cover is easy to crack after long-time use, so that the service life of the outer shell is reduced, and the stability of the battery monomer is reduced.

In order to improve stability of a battery monomer, the application provides a shell, which is used for the battery monomer, wherein a weak structure is arranged on the outer wall surface of the shell, and deformation generated when an electrode assembly expands is concentrated at the weak structure, so that the deformation generated at the joint of the shell and an end cover is reduced, the risk of cracking at the joint of the shell and the end cover is reduced, the service life of the shell is prolonged, and the stability of the battery monomer is improved.

The battery monomer disclosed by the embodiment of the application can be used in electric equipment such as vehicles, ships or aircrafts, but is not limited to the electric equipment. The power supply system with the electric equipment can be composed of the battery monomer, the battery and the like.

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

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

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 200 is provided in the interior of the vehicle 1000, and the battery 200 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 200 may be used for power supply of the vehicle 1000, for example, the battery 200 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 300 and a motor 400, the controller 300 being configured to control the battery 200 to power the motor 400, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the application, battery 200 may be used not only as an operating power source for vehicle 1000, but also as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

In some embodiments, battery 200 may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

Referring to fig. 2, fig. 2 is an exploded view of a battery 200 according to some embodiments of the application. The battery 200 includes a case 210 and a battery cell 100, and the battery cell 100 is accommodated in the case 210. The case 210 is used to provide an accommodating space for the battery cell 100, and the case 210 may have various structures.

In the battery 200, the number of the battery cells 100 may be plural, and the plural battery cells 100 may be connected in series, parallel, or series-parallel, where series-parallel refers to both of the plural battery cells 100 being connected in series and parallel. The plurality of battery cells 100 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 100 is accommodated in the box 210; of course, the battery 200 may also be a battery module formed by connecting a plurality of battery cells 100 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 210. The battery 200 may further include other structures, for example, the battery 200 may further include a bus bar member for making electrical connection between the plurality of battery cells 100.

Wherein each battery cell 100 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 100 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Referring to fig. 3-5, fig. 3 is a schematic diagram illustrating a structure of a battery cell 100 according to some embodiments of the present application; fig. 4 is an exploded view of a battery cell 100 according to some embodiments of the present application; fig. 5 is a front view of a battery cell 100 according to some embodiments of the present application. The battery cell 100 of the embodiment of the present application includes a case 10, an electrode assembly, and an end cap 20, the case 10 having a first end 11 and a second end 12 opposite to the first end 11, the first end 11 being formed with an opening 111, the case 10 including an inner wall surface 13 and an outer wall surface 14, the outer wall surface 14 being provided with a weak structure 141, the weak structure 141 being closer to the opening 111 than the second end 12, the electrode assembly being disposed in the case 10, the end cap 20 being hermetically connected to the case 10 and closing the opening 111.

Specifically, the case 10 has a hollow structure, and an accommodating chamber for accommodating the electrode assembly and the electrolyte is formed therein. The housing 10 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the case 10 may be determined according to the specific shape of the electrode assembly. For example, if the electrode assembly has a cylindrical structure, the cylindrical housing 10 may be selected, and the shape of the opening 111 may be circular; if the electrode assembly has a rectangular parallelepiped structure, the rectangular parallelepiped case 10 may be selected, and the shape of the opening 111 may be square. The material of the housing 10 may be various, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc.

The first end 11 may be located at the top of the case 10, the second end 12 may be located at the bottom of the case 10, and the electrode assembly may be introduced into the inside of the case 10 through the opening 111 of the first end 11.

The inner wall surface 13 may be a surface of the housing 10 in contact with the internal environment, and the outer wall surface 14 may be a surface of the housing 10 in contact with the external environment. The outer wall surface 14 is provided with a weak structure 141, and the weak structure 141 serves to withstand deformation of the case 10 when the electrode assembly is expanded at the junction of the case and the cap 20. The weakening structure 141 may be formed by thinning the material, such as scoring, grooving, etc. the outer wall surface 14. On the outer wall surface 14, the thickness of the peripheral region of the weakening structure 141 is greater than the thickness at the weakening structure 141.

The electrode assembly is a core component for realizing the charge and discharge functions of the battery cell 100, and comprises a positive electrode plate, a negative electrode plate and a separator, wherein the positive electrode plate and the negative electrode plate are opposite in polarity, and the separator is used for insulating and isolating the positive electrode plate and the negative electrode plate. The electrode assembly operates primarily by means of metal ions moving between the positive and negative electrode sheets.

The end cap 20 is a member sealing the opening 111 of the case 10 to isolate the inner environment of the battery cell 100 from the outer environment, and the end cap 20 and the case 10 together define a receiving space for receiving the electrode assembly, electrolyte, and other components. The shape of the end cover 20 may be adapted to the shape of the housing 10, for example, the housing 10 is a cuboid structure, the end cover 20 is a rectangular plate structure adapted to the housing 10, for example, the housing 10 is a cylindrical structure, and the end cover 20 is a circular plate structure adapted to the housing 10. The material of the end cap 20 may be various, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc., and the material of the end cap 20 and the casing 10 may be the same or different. The number of the end caps 20 may be one, and the end caps 20 and the housing 10 may be connected by welding.

In the battery cell 100 according to the embodiment of the application, the electrode assembly is continuously expanded and contracted in the charge and discharge process, the weak structure 141 can be preferentially deformed when the electrode assembly is expanded, the degree of deformation of the connection part of the casing 10 and the end cover 20 caused by the expansion of the electrode assembly is reduced, the cracking risk of the connection part of the casing 10 and the end cover 20 is reduced, and the service life of the casing 10 is prolonged, so that the stability of the battery cell 100 is improved.

Referring to fig. 4, 6 and 7, fig. 6 is a top view of a battery cell 100 according to some embodiments of the application; fig. 7 is a left side view of a battery cell 100 according to some embodiments of the application. In some embodiments, the housing 10 includes a first wall 15 and a second wall 16 connected to the first wall 15, the first wall 15 having an area greater than an area of the second wall 16, the outer wall 14 of the first wall 15 being formed with a weakened structure 141.

Specifically, the first wall 15 and the second wall 16 may be side walls of the housing 10, and when the housing 10 is of a rectangular parallelepiped structure, the first wall 15 may be disposed perpendicular to the second wall 16, and the first wall 15 and the second wall 16 may be perpendicular to the second end 12. The first wall 15 and the second wall 16 may be rectangular plate-like structures, the number of the first wall 15 and the second wall 16 may be two, the two first walls 15 are disposed opposite to each other, and the two second walls 16 are disposed opposite to each other. When the lengths of the first wall 15 and the second wall 16 are identical, the width of the first wall 15 may be greater than the width of the second wall 16.

The weakened structure 141 may be formed by removing a portion of the material from the outer wall surface 14 of the first wall 15 in the direction of the inner wall surface 13 of the first wall 15, for example, by scoring, grooving, or the like, from the outer wall surface 14 of the first wall 15. On the outer wall surface 14 of the first wall 15, the thickness of the peripheral region of the weakening structure 141 is greater than the thickness at the weakening structure 141.

Thus, since the area of the first wall 15 is larger than that of the second wall 16, the first wall 15 is easier to deform under the action of the electrode assembly, and therefore, the weak structure 141 can better absorb the deformation generated by the casing 10 by arranging the weak structure 141 on the outer wall surface 14 of the first wall 15, so that the deformation of the joint of the first wall 15 and the end cover 20 caused by the expansion of the electrode assembly is reduced, the cracking risk of the joint of the first wall 15 and the end cover 20 is reduced, and the service life of the casing 10 is prolonged.

Referring to fig. 4 and 7, in some embodiments, the outer wall surface 14 of the second wall 16 is formed with a weakened structure 141.

Specifically, the weakened structure 141 may be formed by removing a part of the material from the outer wall surface 14 of the second wall 16 toward the inner wall surface 13 of the second wall 16, for example, by scoring, grooving, or the like from the outer wall surface 14 of the second wall 16. On the outer wall surface 14 of the second wall 16, the thickness of the peripheral region of the weakening structure 141 is greater than the thickness at the weakening structure 141.

In this way, by providing the weak structure 141 on the outer wall surface 14 of the second wall 16, the weak structure 141 can preferentially absorb the impact of the expansion of the electrode assembly on the outer wall surface 14 of the second wall 16, reduce the deformation of the expansion of the electrode assembly on the joint between the second wall 16 and the end cover 20, and reduce the risk of cracking at the joint between the second wall 16 and the end cover 20, thereby improving the service life of the casing 10.

Referring to fig. 8-10, fig. 8 is a cross-sectional view along A-A of fig. 5; FIG. 9 is an enlarged schematic view of section I of FIG. 8; fig. 10 is an enlarged schematic view of section ii of fig. 8. In some embodiments, the weakening structure 141 has a groove 142 formed in the outer wall surface 14 of the housing 10, the groove 142 in the outer wall surface 14 of the first wall 15 interconnecting the groove 142 in the outer wall surface 14 of the second wall 16.

Specifically, the groove 142 may be formed by removing a portion of the material from the outer wall surface 14, and the cross-sectional shape of the groove 142 may be arc-shaped, square, trapezoid, or the like. The groove 142 may extend from the outer wall surface 14 toward the inner wall surface 13 in the thickness direction of the case 10, the groove 142 may be disposed circumferentially along the outer wall surface 14 of the case 10, and the groove 142 may be disposed such that the thickness of the region of the case 10 where the weak structure 141 is disposed is reduced.

In this way, the thickness of the casing 10 can be reduced by the groove 142, so that the weak structure 141 is easier to form, the groove 142 located on the outer wall surface 14 of the first wall 15 and the groove 142 located on the outer wall surface 14 of the second wall 16 are connected with each other, so that the weak structure 141 has better deformation consistency at the same position of the casing 10, and the weak structure 141 is beneficial to improving the capability of absorbing the impact of the casing 10.

Referring to fig. 4, in some embodiments, the housing 10 includes a first portion 17 and a second portion 18 connected to the first portion 17, the first portion 17 is formed with a first end 11, an end of the second portion 18 remote from the first portion 17 is formed with a second end 12, and a ratio of a height of the first portion 17 to a height of the second portion 18 along the first end 11 toward the second end 12 is greater than or equal to 3:7, the weakening structure 141 is located on the second portion 18.

Specifically, the first portion 17 may be a portion where the housing 10 is connected to the end cover 20, the thickness of the first portion 17 along the direction from the first end 11 to the second end 12 is gradually reduced, the second portion 18 may be an equal thickness structure, and the first portion 17 and the second portion 18 may be integrally formed. The ratio of the height of the first portion 17 to the height of the second portion 18 in the direction of the first end 11 towards the second end 12 may be 3:7, may be 2:3 or 1:1, etc., for example, when the height of the housing 10 in the direction of the first end 11 toward the second end 12 is 100mm, the height of the first portion 17 may be 30mm, the height of the second portion 18 may be 70mm, the height of the first portion 17 may be 40mm, the height of the second portion 18 may be 60mm, the height of the first portion 17 may be 50mm, and the height of the second portion 18 may be 50mm.

In this way, the weak structure 141 is located on the second portion 18, so that the weak structure 141 is far away from the end cover 20, and further the deformation of the casing 10 when the electrode assembly expands can be concentrated on the second portion 18, so that the influence on the first portion 17 is reduced, the risk of cracking at the joint of the casing 10 and the end cover 20 of the first portion 17 is reduced, and the service life of the casing 10 is prolonged.

Referring to fig. 9 and 10, in some embodiments, the weak structure 141 has a groove 142 formed on the outer wall 14, and a ratio of a thickness of the second portion 18 at the groove 142 to a maximum thickness of the second portion 18 is greater than or equal to 0.4.

Specifically, the thickness of the second portion 18 at the groove 142 may be a distance between the bottom surface 143 of the groove 142 and the inner wall surface 13, the maximum thickness of the second portion 18 may be a distance between the outer wall surface 14 and the inner wall surface 13, and a ratio of the thickness of the second portion 18 at the groove 142 to the maximum thickness of the second portion 18 may be a point value of any one of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or a range value between any two. When the ratio of the thickness of the second portion 18 at the groove 142 to the maximum thickness of the second portion 18 is less than 0.4, the strength of the weak structure 141 is low and the weak structure 141 is easily broken.

In this way, the weak structure 141 is easily deformed to absorb the impact applied to the case 10, and has appropriate strength, and is not easily broken.

Referring to fig. 9 and 10, in some embodiments, the weakening structure 141 has a groove 142 formed in the outer wall surface 14.

Specifically, the groove 142 may be formed by removing a portion of the material from the outer wall surface 14, and the cross-sectional shape of the groove 142 may be arc-shaped, square, trapezoid, or the like. The groove 142 may extend from the outer wall surface 14 toward the inner wall surface 13 in the thickness direction of the case 10, and the groove 142 may be provided on the outer wall surface 14 of the first wall 15, may be provided on the outer wall surface 14 of the second wall 16, may be provided along the outer wall surface 14 of the case 10 in the circumferential direction, and the groove 142 may be provided so that the thickness of the region of the case 10 where the weak structure 141 is provided is reduced.

In this manner, the groove 142 may reduce the thickness of the housing 10, thereby more easily forming the weak structure 141.

Referring to FIGS. 4, 9 and 10, in some embodiments, the height of the groove 142 along the direction from the first end 11 to the second end 12 is h, and h is 0.2 mm.ltoreq.h.ltoreq.7 mm.

Specifically, the height of the groove 142 along the direction from the first end 11 to the second end 12 may be a distance between two connection points of the groove 142 and the outer wall surface 14, and h may be a point value of any one of 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, or a range value between any two of them.

When the height of the groove 142 along the direction from the first end 11 to the second end 12 is less than 0.2mm, the processing difficulty of the groove 142 is high, thereby improving the manufacturing difficulty of the housing 10; when the height of the groove 142 in the direction from the first end 11 to the second end 12 is greater than 7mm, the effect of the weak structure 141 undergoing deformation is not significantly improved.

In this way, when the height of the groove 142 along the direction from the first end 11 to the second end 12 is within the above range, the formation of the groove 142 is facilitated, so that the weak structure 141 is easier to form, the manufacturing difficulty of the housing 10 is reduced, and at the same time, the capability of the weak structure 141 for absorbing the impact of the housing 10 is improved.

Referring to FIG. 9, in some embodiments, 0.5 mm.ltoreq.h.ltoreq.4 mm.

Specifically, h may be a point value of any one of 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm or a range value therebetween.

In this way, when the height of the groove 142 along the direction from the first end 11 to the second end 12 is within the above range, the formation of the groove 142 is facilitated, so that the weak structure 141 is easier to form, the manufacturing difficulty of the housing 10 is reduced, and at the same time, the capability of the weak structure 141 for absorbing the impact of the housing 10 is improved.

Referring to FIGS. 4, 9 and 10, in some embodiments, the distance between the recess 142 and the opening 111 is H, t-0.5 mm.ltoreq.H.ltoreq.8t, where t is the thickness of the end cap 20 in mm.

Specifically, the distance between the groove 142 and the opening 111 may be the distance between the connection point between the groove 142 and the outer wall 14 near the first end 11 and the opening 111, and when the thickness of the end cover 20 is 1.5mm, the distance H between the groove 142 and the opening 111 is 1 mm-12 mm, that is, the distance H between the groove 142 and the opening 111 may be any one of 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm or any range between the two.

When the distance H between the groove 142 and the opening 111 is less than t-0.5mm, the groove 142 is closer to the opening 111, so that deformation of the case 10 when the electrode assembly expands affects the area of the opening 111, thereby increasing the risk of cracking at the junction of the case 10 and the end cap 20; when the distance H of the groove 142 from the opening 111 is greater than 8t, the groove 142 is farther from the opening 111, reducing the concentration of deformation of the housing 10 at the weakened structure 141, thereby increasing the risk of cracking at the connection of the housing 10 to the end cap 20.

In this way, when the distance between the groove 142 and the opening 111 is within the above range, the deformation of the case 10 when the electrode assembly expands can be concentrated on the weak structure 141, the influence on the area of the opening 111 is reduced, and the risk of cracking at the connection between the case 10 and the end cap 20 is reduced, thereby improving the service life of the case 10.

Referring to FIG. 9, in some embodiments, t.ltoreq.H.ltoreq.5t.

Specifically, when the thickness of the end cap 20 is 1.5mm, the distance H between the groove 142 and the opening 111 is 1.5mm to 7.5mm, i.e. the distance H between the groove 142 and the opening 111 may be any one of 1.5mm, 2.5mm, 3.5mm, 4.5mm, 5.5mm, 6.5mm, 7.5mm, or a range between any two.

In this way, when the distance between the groove 142 and the opening 111 is within the above range, the deformation of the case 10 when the electrode assembly expands can be concentrated on the weak structure 141, the influence on the area of the opening 111 is reduced, and the risk of cracking at the connection between the case 10 and the end cap 20 is reduced, thereby improving the service life of the case 10.

Referring to fig. 10, in some embodiments, the bottom 143 of the groove 142 and the side 144 of the groove 142 form an obtuse angle θ.

Specifically, the groove 142 may be formed of one bottom surface 143 and two side surfaces 144, the bottom surface 143 of the groove 142 may be parallel to the outer wall surface 14, and the side surfaces 144 of the groove 142 may connect the bottom surface 143 of the groove 142 and the outer wall surface 14 of the housing 10. When the cross-sectional shape of the groove 142 is square, the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 may be 90 °; when the cross-sectional shape of the groove 142 is trapezoidal, the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 may form an angle θ greater than 90 °.

In this way, the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 is an obtuse angle, which can facilitate the formation of the groove 142 and reduce the manufacturing difficulty of the housing 10, thereby improving the processing precision of the housing 10 and the service life of the grinding tool.

Referring to fig. 10, in some embodiments, the bottom 143 of the groove 142 and the side 144 of the groove 142 form an angle θ of 95 ° to 175 °.

Specifically, the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 may be any one of a point value of 95 °, 105 °, 115 °, 125 °, 135 °, 145 °, 155 °, 165 °, 175 °, or a range value between any two.

In this way, when the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 is in the above range, the groove 142 can be conveniently formed, and the manufacturing difficulty of the housing 10 is reduced, so that the processing precision of the housing 10 and the service life of the grinding tool are improved.

Referring to fig. 10, in some embodiments, the bottom 143 of the groove 142 and the side 144 of the groove 142 form an angle θ of 110 ° to 160 °.

Specifically, the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 may be any one of a point value or a range value between any two of 110 °, 120 °, 130 °, 140 °, 150 °, and 160 °.

In this way, when the angle θ formed by the bottom surface 143 of the groove 142 and the side surface 144 of the groove 142 is in the above range, the groove 142 can be conveniently formed, and the manufacturing difficulty of the housing 10 is reduced, so that the processing precision of the housing 10 and the service life of the grinding tool are improved.

Referring to fig. 4, a battery cell 100 according to an embodiment of the present application includes a case 10 having a first end 11 and a second end 12 opposite to the first end 11, the first end 11 being formed with an opening 111, the case 10 being provided with a weak structure 141, the weak structure 141 being closer to the opening 111 than the second end 12, an electrode assembly disposed in the case 10, and an end cap 20 sealing-coupled with the case 10 and closing the opening 111.

Thus, in the charge and discharge process of the battery cell 100, the electrode assembly is continuously expanded and contracted, the weak structure 141 can be preferentially deformed when the electrode assembly is expanded, the deformation degree of the electrode assembly expansion on the joint of the casing 10 and the end cover 20 is reduced, the cracking risk of the joint of the casing 10 and the end cover 20 is reduced, the service life of the casing 10 is prolonged, and the stability of the battery cell 100 is improved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (15)

1.A battery cell, comprising:

A housing having a first end portion and a second end portion opposite the first end portion, the first end portion being formed with an opening, the housing including an inner wall surface and an outer wall surface, the outer wall surface being provided with a weak structure, the weak structure being closer to the opening than the second end portion, the housing including a first wall and a second wall connected to the first wall, the first wall having an area larger than an area of the second wall, the outer wall surface of the first wall being formed with the weak structure;

An electrode assembly disposed in the case; and, a step of, in the first embodiment,

And the end cover is in sealing connection with the shell and seals the opening.

2. The battery cell of claim 1, wherein the outer wall surface of the second wall is formed with the weak structure.

3. The battery cell of claim 2, wherein the weak structure has a groove formed in an outer wall surface of the housing, the groove in an outer wall surface of the first wall interconnecting the groove in an outer wall surface of the second wall.

4. The battery cell according to claim 1, wherein the housing includes a first portion and a second portion connected to the first portion, the first portion is formed with the first end, an end of the second portion remote from the first portion is formed with the second end, and a ratio of a height of the first portion to a height of the second portion in a direction from the first end to the second end is 3 or more: the weakening structure is located on the second portion.

5. The battery cell as recited in claim 4, wherein the weak structure has a groove formed in the outer wall surface, and a ratio of a thickness of the second portion at the groove to a maximum thickness of the second portion is greater than or equal to 0.4.

6. The battery cell of claim 1, wherein the weak structure has a groove formed in the outer wall surface.

7. The battery cell of claim 5, wherein the groove has a height h in the direction of the first end toward the second end of 0.2mm ∈h ∈7mm.

8. The battery cell of claim 7, wherein 0.5 mm.ltoreq.h.ltoreq.4 mm.

9. The battery cell of claim 3, wherein the recess is spaced from the opening by a distance H, t-0.5mm +.h +.8t, where t is the thickness of the end cap in mm.

10. The battery cell of claim 9, wherein t is less than or equal to H is less than or equal to 5t.

11. The battery cell of claim 3, wherein the bottom surface of the groove forms an obtuse angle with the side surface of the groove.

12. The battery cell of claim 11, wherein the bottom surface of the groove forms an angle with the side surface of the groove of 95 ° to 175 °.

13. The battery cell of claim 12, wherein the bottom surface of the groove forms an angle with the side surface of the groove of 110 ° to 160 °.

14. A battery comprising the battery cell of any one of claims 1-13.

15. A powered device comprising the battery cell of any one of claims 1-13 or the battery of claim 14.