CN115832547A

CN115832547A - End cover, end cover assembly, welding method, battery monomer, battery and electric device

Info

Publication number: CN115832547A
Application number: CN202210845330.5A
Authority: CN
Inventors: 潘峰
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-07-19
Filing date: 2022-07-19
Publication date: 2023-03-21
Anticipated expiration: 2042-07-19
Also published as: CN115832547B

Abstract

The invention relates to an end cover, an end cover assembly, a welding method, a battery monomer, a battery and an electric device, wherein an exhaust runner communicated with a liquid injection hole is arranged outside the liquid injection hole, so that a space area far away from the liquid injection hole is formed in a plate main body, and therefore steam generated in the welding process of the liquid injection hole can flow into the exhaust runner, liquid splashing to the exhaust runner in the liquid injection operation can be avoided, and the degree of liquid pollution in the exhaust runner is reduced. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and welding the exhaust port on the exhaust flow passage. After the operation, the steam welded at the liquid filling hole can be discharged through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

Description

End cover, end cover assembly, welding method, battery monomer, battery and electric device

Technical Field

The application relates to the technical field of batteries, in particular to an end cover, an end cover assembly, a welding method, a single battery, a battery and an electric device.

Background

In the manufacturing process of the battery, after the battery is filled with liquid, a sealing component such as a sealing nail and the like is adopted to seal the liquid filling hole on the end cover. In the sealing operation, the sealing member and the pour hole are generally welded together by welding. However, the end cap is limited by structural design defects, and welding explosion point defects are easily formed at welding closure positions, so that the sealing performance of the battery is seriously influenced.

Disclosure of Invention

Therefore, the end cover assembly, the welding method, the single battery, the battery and the electric device are needed to be provided, the defect of explosion points of the liquid injection hole during welding and sealing is effectively avoided, and the sealing performance is improved.

In a first aspect, the present application provides an end cap for a battery cell, comprising: the plate main body is provided with a liquid injection hole in a penetrating manner along the thickness direction of the plate main body; the plate main body is provided with an exhaust flow channel, the projection of the exhaust flow channel along the thickness direction of the plate main body is at least partially positioned outside the projection of the liquid injection hole along the thickness direction of the plate main body, the exhaust flow channel extends to the side wall of the liquid injection hole, so that the exhaust flow channel is communicated with the liquid injection hole, an exhaust port used for being communicated with the outside is formed in the first surface of the plate main body of the exhaust flow channel, and the first surface is a surface of the plate main body far away from the inside of the battery cell.

The exhaust runner is arranged outside the liquid injection hole and communicated with the end cover, so that a space area far away from the liquid injection hole is formed in the plate main body, steam generated in the welding process of the liquid injection hole can flow into the exhaust runner, liquid splashing to the exhaust runner in the liquid injection operation can be avoided, and the degree of liquid pollution in the exhaust runner is reduced. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and welding the exhaust port on the exhaust flow passage. After the operation, the steam welded at the liquid filling hole can be discharged through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

In some embodiments, the gas exhaust port extends on the first surface of the plate body to an edge of the liquid injection hole along a predetermined trajectory. So, on extending to the edge of annotating the liquid hole with the gas vent along predetermineeing the orbit, make it also keep directly communicating with each other with annotating the liquid hole, the later stage welding operation of being convenient for like this is favorable to improving the assembly efficiency of end cover subassembly.

In some embodiments, the predetermined trajectory is a straight trajectory. The preset track is designed into a straight track, which is beneficial to simplifying the opening operation of the exhaust port; but also the welding operation of the exhaust port is convenient, and the welding sealing efficiency is improved.

In some embodiments, the vent includes an end distal from the pour hole edge, and first and second sides connecting the end and the pour hole edge, the first and second sides being spaced apart from each other. Due to the design, the distance is reserved between the first side edge and the second side edge, the welding mode of the exhaust port can be direct welding or indirect welding, the assembly of different end cover assemblies is convenient to adapt, and the welding mode of the exhaust port is more flexible.

In some embodiments, the distance between the first side edge and the second side edge is denoted as W, and the distance W satisfies: w is more than or equal to 2mm and less than or equal to 8mm, so that the size of the distance W is reasonably controlled, the welding workload is reduced and the welding efficiency is improved on the premise of realizing effective indirect welding.

In some embodiments, the length of the exhaust runner along the preset track is recorded as L, wherein L is more than or equal to 2mm and less than or equal to 15mm. So, reasonable control exhaust runner length L can guarantee the reduction of steam volume when the welding is closed, avoids the production of welding fried point defect, can guarantee the stable in structure of end cover again.

In some embodiments, the distance between the first side edge and the second side edge is denoted as W, and the distance W satisfies: w is more than or equal to 0.5mm and less than or equal to 2mm. The size of control interval W rationally like this, under the prerequisite of realizing effectual direct welding, avoid the interval undersize and influence the exhaust smooth and easy, guarantee the welding seam stable in structure who forms, avoid exploding the appearance of some defect, promote the sealing performance of battery.

In some embodiments, the length of the exhaust runner along the preset track is recorded as L, wherein L is more than or equal to 1mm and less than or equal to 5mm. The length L of the exhaust flow channel is reasonably controlled, the reduction of steam quantity during welding closure can be guaranteed, the generation of welding explosion point defects is avoided, the welding workload can be reduced, and the welding efficiency is improved.

In some embodiments, the inner wall of the exhaust gas flow passage includes a bottom wall opposite to the exhaust port in a thickness direction of the plate main body, the bottom wall being configured to guide the liquid into the liquid injection hole. So, annotate the liquid hole for the guide liquid entering with the diapire design, restriction liquid remains, is favorable to reducing produced steam in the welding of gas vent department, further avoids producing defects such as fried point in the closed department of welding, promotes welding quality.

In some embodiments, the bottom wall is disposed obliquely with respect to the first surface, and an end of the bottom wall remote from the pour hole is closer to the first surface in the thickness direction of the plate main body. From this, set up the diapire slope for liquid drops to annotating the liquid hole on the diapire, makes it not remain liquid, reduces or can not produce steam like this when the welding, effectively avoids producing defects such as fried point in welding closure department, promotes welding quality.

In some embodiments, the bottom wall is at an angle θ relative to the thickness of the plate body, wherein θ is 110 ≦ 170. So, the inclination of reasonable control diapire for liquid on the diapire smoothly drops to annotating the liquid hole in, can not remain liquid on the assurance diapire, with the welding quality who improves gas vent department.

In some embodiments, the inner wall of the exhaust channel further comprises two side walls spaced apart from the bottom wall, and each side wall is in arc transition connection with the inner wall of the liquid injection hole. So, with the inner wall circular arc transitional coupling of lateral wall and notes liquid hole, reduce the internal stress of connecting between the two and concentrate, promote end cover overall structure's stability.

In some embodiments, the liquid injection hole includes a first liquid injection section and a second liquid injection section that are communicated with each other in a thickness direction of the plate main body, the second liquid injection section is farther from the gas discharge port with respect to the first liquid injection section, and the gas discharge flow passage extends to a side wall of the first liquid injection section so that the gas discharge flow passage is communicated with the first liquid injection section. By the design, the liquid injection hole is divided into the upper section and the lower section, and double-section sealing can be performed during later welding sealing, so that the end cover assembly has better sealing performance.

In some embodiments, a cross-sectional area of the second injection section in a direction perpendicular to the thickness direction of the plate body is smaller than a cross-sectional area of the first injection section in a direction perpendicular to the thickness direction of the plate body. So, will annotate the liquid hole design and become the different pore structure of two sections cross-sectional area for annotate the liquid hole and be the counter bore design, conveniently annotate the liquid operation.

In a second aspect, the present application provides an end cap assembly comprising: an end cap as in any of the above; and the first sealing element seals one end of the liquid injection hole, keeps the communication between the exhaust flow passage and the liquid injection hole, and closes the exhaust port.

The end cover assembly adopts the end cover, and the liquid injection hole can be welded preferentially in the welding process; and welding the exhaust port on the exhaust flow passage. After the operation, the steam welded at the liquid filling hole can be discharged through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

In some embodiments, the first sealing member includes a first member that seals one end of the pour hole and a second member that is connected to the first member and that seals the vent. As such, the first seal is designed in two parts: the first component and the second component can realize the sealing of the exhaust port while sealing the liquid injection hole, and are favorable for improving the assembly efficiency of the end cover assembly.

In some embodiments, the end cap assembly further includes a second sealing member that seals the other end of the pour hole. So, set up the second sealing member at the other end of annotating the liquid hole, constitute double-deck sealed with first sealing member, greatly promote end cover assembly's sealing performance.

In some embodiments, there is a gap between the first seal member and the pour hole in a direction perpendicular to the thickness direction of the plate main body. So, set up the clearance between first sealing member and notes liquid hole, guarantee the exhaust runner and annotate the intercommunication between the liquid hole for steam that welding process produced can be followed all the time and discharged in the exhaust runner.

In a third aspect, the present application provides an end cap assembly welding method for preparing an end cap assembly of any one of the above, comprising the steps of: placing at least part of the first sealing element in the liquid injection hole, and enabling a first gap to be formed between the first sealing element and the side wall of the liquid injection hole; and welding the first sealing element and the side wall of the liquid injection hole, and welding the sealed exhaust port, wherein the final welding end point is positioned on the exhaust port.

The end cover assembly welding method can ensure that steam welded at the liquid injection hole is exhausted through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

In some embodiments, the step of welding the first seal member to the sidewall of the pour spout and the step of welding the vent port closed includes: the first component and the second component of the first sealing element are respectively arranged in the liquid injection hole and the exhaust hole in a covering manner, a first gap is formed between the first component and the side wall of the liquid injection hole, a second gap and a third gap are respectively formed between the second component and the two side walls of the exhaust hole, and the second gap and the third gap are both communicated with the first gap; taking any position on the second gap or the third gap as an initial welding position, and welding along the edge of the first sealing element; welding is stopped at the initial weld site.

Therefore, welding is started from any position of the second gap or the third gap, the final welding end point can be effectively controlled on the second gap or the third gap, steam generated during welding closing is weak or does not exist, a molten welding seam cannot be broken upwards, the defect of an explosive point of the liquid injection hole during welding sealing is effectively avoided, and the sealing performance is improved.

In some embodiments, the step of welding the first seal member to the sidewall of the pour spout and the step of welding the vent port closed includes: a fourth gap is formed between the first side edge and the second side edge of the control exhaust port, wherein one end of the fourth gap is communicated with the first gap; taking any position on the first gap as an initial welding position, and welding the position to the initial welding position along the edge of the first sealing element; and continuing to weld the fourth gap to the tail end of the fourth gap far away from the liquid injection hole from the communication part of the fourth gap and the first gap.

Therefore, the fourth gap is preferentially completed, the final welding end point can be effectively controlled on the fourth gap, steam generated during welding closing is weak or does not exist, the molten welding seam cannot be broken upwards, the defect that the explosion point occurs when the liquid injection hole is sealed in welding is effectively avoided, and the sealing performance is improved.

In a fourth aspect, the present application provides a battery cell comprising: a housing having an opening at an end thereof; an electrode assembly housed in the case; an end cap assembly as in any one of the above, the end cap assembly covering the opening.

In a fifth aspect, the present application provides a battery including the above battery cell.

In a sixth aspect, the present application provides an electric device comprising the above battery for providing electric energy.

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

Various additional 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. Moreover, like reference numerals are used to refer to like elements throughout. In the drawings:

FIG. 1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

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

fig. 3 is an exploded view of a battery cell according to some embodiments of the present disclosure;

FIG. 4 is a first schematic structural view of an end cap according to some embodiments of the present disclosure;

FIG. 5 is a second structural schematic view of an end cap provided in accordance with some embodiments of the present application;

FIG. 6 is an enlarged view of the structure at circle B in FIG. 5;

FIG. 7 is another perspective view of the end cap construction provided in FIG. 4;

FIG. 8 isbase:Sub>A cross-sectional view of the end cap of FIG. 7 taken along line A-A;

fig. 9 is a schematic view of a portion of a battery cell according to some embodiments of the present disclosure;

fig. 10 is a schematic diagram of a portion of a battery cell according to some embodiments of the present disclosure;

FIG. 11 is a schematic view of the first seal of FIG. 9;

FIG. 12 is a cross-sectional view of the end cap assembly construction of FIG. 9;

FIG. 13 is a first flowchart of a method of welding an end cap assembly according to some embodiments of the present disclosure;

FIG. 14 is a flow chart of a second method of welding an end cap assembly according to some embodiments of the present application;

FIG. 15 is a first schematic view of a welding configuration of an end cap assembly according to some embodiments of the present disclosure;

FIG. 16 is a third flowchart of a welding method for an end cap assembly according to some embodiments of the present application;

fig. 17 is a second schematic view of a welding structure of an end cap assembly according to some embodiments of the present application.

10000. A vehicle; 1000. a battery; 2000. a controller; 3000. a motor; 100. a battery cell; 200. a box body; 210. a first portion; 220. a second portion; 10. an end cap; 11. a plate main body; 111. a first surface; 12. a liquid injection hole; 121. a first injection section; 122. a second injection section; 123. an end face; 13. an exhaust flow passage; 131. a bottom wall; 132. a side wall; 14. an exhaust port; 141. a first side edge; 142. a second side edge; 143. a terminal end; 20. a first seal member; 21. a first member; 22. a second component; 23. a first gap; 24. a second gap; 25. starting a welding position; 26. a third gap; 27. a fourth gap; 30. a second seal member; 40. a housing; 41. an opening; 50. an electrode assembly; 60. an adapter; x, a preset track.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

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 "including" and "having," and any variations thereof in the description and claims of this application and the description of the figures above, are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or to implicitly indicate the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. 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. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, 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 "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

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

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the directions or positional relationships indicated in the drawings, and are only for convenience of description of the embodiments of the present application and for simplicity of description, but do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used in a broad sense, and for example, may be fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

At present, the application of the power battery is more and more extensive 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 and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The applicant has noted that during battery filling, a greater or lesser amount of electrolyte remains in the filling hole. When the liquid injection hole is welded, the residual electrolyte is evaporated at high temperature generated by welding to form electrolyte steam. As welding continues, the steam generated escapes from the unwelded area; when the welding ending stage is carried out, namely the final welding closing operation, the generated steam cannot escape and can upwards break through a welding seam in a molten state, so that the defect of a welding explosion point is formed in the welding seal.

In order to solve the problems that the weld seal of the liquid injection hole is easy to cause the formation of the explosive spot defect, the applicant of the present invention has conducted extensive studies and has devised an end cap in which an exhaust flow passage is provided outside the liquid injection hole, the exhaust flow passage is communicated with the liquid injection hole, and at least a part of the exhaust flow passage is formed on the surface of the plate main body with an exhaust port for communication with the outside.

The exhaust runner communicated with the liquid injection hole is arranged outside the liquid injection hole, so that a space area far away from the liquid injection hole is formed in the plate main body, steam generated in the welding process of the liquid injection hole can flow into the exhaust runner, liquid splashing to the exhaust runner in the liquid injection operation can be avoided, and the degree of liquid pollution in the exhaust runner is reduced. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and welding the exhaust port on the exhaust flow passage. After the operation, the steam welded at the liquid injection hole can be discharged through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

The exhaust runner communicated with the liquid injection hole is arranged outside the liquid injection hole, so that a space area far away from the liquid injection hole is formed in the plate main body, steam generated in the welding process of the liquid injection hole can flow into the exhaust runner, liquid splashing to the exhaust runner in the liquid injection operation can be avoided, and the degree of liquid pollution in the exhaust runner is reduced.

In the welding process, the liquid injection hole can be welded preferentially; and welding the exhaust port on the exhaust flow passage. After the operation, the steam welded at the liquid injection hole can be discharged through the exhaust runner and the exhaust port; meanwhile, when the final welding closing operation is carried out, because the pollution of liquid in the exhaust flow passage is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole is welded and sealed is effectively avoided, and the sealing performance is improved.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. A power supply system including the electric device composed of the battery cell, the battery, and the like disclosed in the present application may be used.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments are described by taking an electric device as an example of a vehicle according to an embodiment of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 10000 according to some embodiments of the present disclosure. The vehicle 10000 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range-extended automobile and the like. The inside of the vehicle 10000 is provided with a battery 1000, and the battery 1000 may be provided at the bottom or the head or the tail of the vehicle 10000. The battery 1000 may be used for power supply of the vehicle 10000, for example, the battery 1000 may serve as an operation power source of the vehicle 10000. The vehicle 10000 can further include a controller 2000 and a motor 3000, wherein the controller 2000 is used for controlling the battery 1000 to supply power to the motor 3000, for example, for starting, navigation and operation power demand of the vehicle 10000.

In some embodiments of the present application, the battery 1000 may be used as an operating power source of the vehicle 10000, and may also be used as a driving power source of the vehicle 10000 to provide driving power for the vehicle 10000 instead of or partially instead of fuel or natural gas.

Referring to fig. 2, fig. 2 is an exploded view of a battery 1000 according to some embodiments of the present disclosure. The battery 1000 includes a case 200 and the battery cell 100, and the battery cell 100 is accommodated in the case 200. The case 200 is used to provide a receiving space for the battery cell 100, and the case 200 may have various structures. In some embodiments, the case 200 may include a first portion 210 and a second portion 220, the first portion 210 and the second portion 220 cover each other, and the first portion 210 and the second portion 220 together define a receiving space for receiving the battery cell 100. The second part 220 may be a hollow structure with an air outlet 14 at one end, the first part 210 may be a plate-shaped structure, and the first part 210 covers the air outlet 14 side of the second part 220, so that the first part 210 and the second part 220 jointly define a containing space; the first portion 210 and the second portion 220 may be hollow structures each having one side exhaust port 14, and the exhaust port 14 side of the first portion 210 may be covered on the exhaust port 14 side of the second portion 220. Of course, the case 200 formed by the first and

second portions

210 and 220 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 1000, the number of the battery cells 100 may be multiple, and the multiple battery cells 100 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 100. The plurality of battery monomers 100 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery monomers 100 is accommodated in the box body 200; of course, the battery 1000 may also be formed by connecting a plurality of battery cells 100 in series, in parallel, or in series-parallel to form a battery 1000 module, and then connecting a plurality of battery 1000 modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 200. The battery 1000 may further include other structures, for example, the battery 1000 may further include a bus member for achieving electrical connection between the plurality of battery cells 100.

Wherein, each battery cell 100 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 100 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 100 according to some embodiments of the present disclosure. The battery cell 100 refers to the smallest unit constituting the battery 1000. Referring to fig. 3, the battery cell 100 includes an end cap 10, a case 40, an electrode assembly 50, and other functional components.

The end cap 10 refers to a member that covers the exhaust port 14 of the case 40 to insulate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cap 10 may be adapted to the shape of the housing 40 to fit the housing 40. Alternatively, the end cap 10 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 10 is not easily deformed when being extruded and collided, and thus the battery cell 100 may have a higher structural strength and safety performance may be improved. The end cap 10 may be provided with functional parts such as electrode terminals. The electrode terminals may be used to electrically connect with the electrode assembly 50 for outputting or inputting electric energy of the battery cell 100. In some embodiments, the end cap 10 may further include a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold value. The material of the end cap 10 may also be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention. In some embodiments, insulation may also be provided on the inside of the end cap 10, which may be used to isolate the electrical connections within the housing 40 from the end cap 10 to reduce the risk of shorting. Illustratively, the insulator may be plastic, rubber, or the like.

The case 40 is an assembly for mating with the end cap 10 to form an internal environment of the battery cell 100, wherein the formed internal environment may be used to house the electrode assembly 50, electrolyte, and other components. The housing 40 and the end cap 10 may be separate components, and the vent 14 may be disposed on the housing 40, and the end cap 10 covers the vent 14 at the vent 14 to form the internal environment of the battery cell 100. Without limitation, the end cap 10 and the housing 40 may be integrated, and specifically, the end cap 10 and the housing 40 may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 40, the end cap 10 covers the housing 40. The housing 40 may be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 40 may be determined according to the specific shape and size of the electrode assembly 50. The material of the housing 40 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present invention is not limited thereto.

The electrode assembly 50 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 50 may be contained within the housing 40. The electrode assembly 50 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally disposed between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode sheets having the active material constitute the body portion of the electrode assembly 50, and the portions of the positive and negative electrode sheets having no active material each constitute a tab. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charge and discharge of the battery 1000, the positive and negative active materials react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.

Referring to fig. 4, according to some embodiments of the present application, an end cap 10 for a battery cell is provided. The end cap 10 includes a plate body 11. The plate body 11 has a liquid injection hole 12 formed therethrough in the thickness direction thereof. Wherein, the plate body 11 is also provided with an exhaust flow passage 13, and the projection of the exhaust flow passage 13 along the thickness direction of the plate body 11 is at least partially positioned outside the projection of the liquid injection hole 12 along the thickness direction of the plate body 11. The exhaust flow path 13 extends to the side wall of the liquid injection hole 12 so that the exhaust flow path 13 communicates with the liquid injection hole 12, and the exhaust flow path 13 is formed with an exhaust port 14 for communicating with the outside on the first surface 111 of the plate main body 11. The first surface 111 is a surface of the plate body 11 away from the inside of the battery cell.

The projection of the exhaust flow channel 13 along the thickness direction of the plate main body 11 is at least partially positioned outside the projection of the liquid injection hole 12 along the thickness direction of the plate main body 11, which means that the exhaust flow channel 13 is not completely positioned inside the liquid injection hole 12, thus avoiding the electrolyte from splashing into the exhaust flow channel 13 in the liquid injection process and reducing the liquid pollution degree in the exhaust flow channel 13.

The distribution of the exhaust flow path 13 outside the liquid injection hole 12 may be various, for example: the exhaust flow passage 13 extends outward in the radial direction of the liquid injection hole 12; alternatively, the extending direction of the exhaust flow path 13 does not pass through the center of the liquid inlet 12, and the exhaust flow path 13 extends along the length or width direction of the plate body 11. Meanwhile, the number of the exhaust runners 13 may be one or more. When there are a plurality of exhaust runners 13, the arrangement of the plurality of exhaust runners 13 may be various, for example: the plurality of exhaust flow passages 13 are arranged at intervals around the circumferential direction of the liquid injection hole 12, and the like.

The exhaust flow path 13 may be provided on the first surface 111 of the plate body 11 or may be provided inside the plate body 11. When the exhaust flow path 13 is provided inside the plate body 11, at least a part of the exhaust flow path 13 (e.g., an end of the exhaust flow path 13) passes through the first surface 111 of the plate body 11 to form an exhaust port 14 spaced apart from the liquid inlet 12.

The shape of the exhaust port 14 on the surface of the plate body 11 has various designs, such as: the exhaust port 14 may be of, but not limited to, circular, oval, triangular, quadrilateral, etc. design.

The exhaust flow path 13 is communicated with the liquid inlet 12, that is, a communication opening is provided on the inner wall of the liquid inlet 12, and the exhaust flow path 13 is communicated with the liquid inlet 12 through the communication opening. Wherein, the intercommunication mouth need be noticed not sheltered from or cut off at end cover subassembly assembling process when the design, for example: the position of the communication port on the inner wall of the liquid injection hole 12 can be moved downwards; alternatively, a sealing member on the endcap assembly, such as the first seal 20, is correspondingly apertured such that the aperture corresponds with the communication port; alternatively, when the sealing member is sealed in the liquid inlet 12, a certain gap is provided between the sealing member and the liquid inlet 12 in the circumferential direction so as to ensure the flow of the steam between the liquid inlet 12 and the exhaust gas flow path 13.

In the welding process, the liquid injection hole 12 can be welded preferentially; the exhaust port 14 on the exhaust flow path 13 is welded. After the operation, the steam welded at the liquid injection hole 12 can be ensured to be discharged through the exhaust runner 13 and the exhaust port 14; meanwhile, when the final welding closing operation is carried out, because the pollution of the liquid in the exhaust flow passage 13 is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole 12 is welded and sealed is effectively avoided, and the sealing performance is improved.

According to some embodiments of the present application, optionally, referring to fig. 4, the gas outlet 14 extends on the first surface 111 of the plate body 11 to the edge of the liquid injection hole 12 along a preset trajectory X.

The extension of the vent 14 onto the edge of the pour hole 12 should be understood as: the exhaust port 14 extends on the surface of the plate body 11 and extends to communicate with the pour hole 12. Thus, when the liquid filling hole 12 is sealed, the upper sealing member can simultaneously cover the exhaust port 14, so as to realize the simultaneous sealing effect and improve the sealing efficiency.

The preset track X can be a straight track or a curved track, and only one end of the exhaust port 14 is required to be ensured to extend to the edge of the liquid injection hole 12.

The width of the exhaust port 14 along the direction intersecting (e.g., perpendicular to) the predetermined trajectory X can be designed in various ways, such as: the width of the exhaust port 14 is designed to be too large, so that the sealing component can be covered in the exhaust port 14, and thus, when welding is carried out, the sealing component and the exhaust port 14 can be welded; alternatively, the width of the exhaust port 14 is designed to be too small so that both side edges of the exhaust port 14 can be directly welded together by a welding device, or the like.

The exhaust port 14 is extended to the edge of the liquid injection hole 12 along the preset track X, so that the exhaust port and the liquid injection hole 12 are also kept in direct communication, thereby facilitating the later welding operation and being beneficial to improving the assembly efficiency of the end cover assembly.

According to some embodiments of the present application, optionally, referring to fig. 4, the predetermined trajectory X is a straight-line trajectory.

The straight line locus means that the exhaust port 14 extends linearly on the first surface 111, and is oriented as a whole. The extending direction of the straight track may or may not pass through the center of the liquid inlet 12.

The preset track is designed to be a straight track, which is beneficial to simplifying the opening operation of the exhaust port 14; but also facilitates the welding operation of the exhaust port 14 and improves the welding sealing efficiency.

According to some embodiments of the present application, referring to FIGS. 4 and 5, the vent 14 includes an end 143 away from the edge of the pour hole 12, and a first side 141 and a second side 142 connecting the end 143 and the edge of the pour hole 12. The first side 141 and the second side 142 are spaced apart from each other.

The first side 141 and the second side 142 may be welded directly or indirectly. When there is a sufficient distance between the first side 141 and the second side 142, an intermediate structure may be disposed between the first side 141 and the second side 142, and the first side 141 and the intermediate structure, and the second side 142 and the intermediate structure may be welded during welding, so that the first side 141 and the second side 142 are connected by the intermediate structure, which is to say, the first side 141 and the second side 142 are welded together indirectly; when the distance between the first side 141 and the second side 142 is narrow, the welding device can directly perform welding operation on the first side 141 and the second side 142 to directly connect the first side 141 and the second side 142, which is to directly weld the first side 141 and the second side 142 together.

The end 143 is a point where the end of the first side 141 and the end of the second side 142 gradually approach each other, and is not the side of the vent 14 farthest from the pour hole 12. Of course, the portions of the first side edge 141 and the second side edge 142 near the end 143 may be spliced into a linear short edge, etc.

Set up the interval between first side 141 and second side 142, can realize that the welding mode of gas vent 14 can be direct welding or indirect welding, be convenient for like this adapt to the assembly of different end cover subassemblies for the welding mode of gas vent 14 department is more nimble.

According to some embodiments of the present application, optionally, referring to fig. 4, a distance between the first side 141 and the second side 142 is denoted as W, and the distance W satisfies: w is more than or equal to 2mm and less than or equal to 8mm, so that the first side edge 141 and the second side edge 142 can be indirectly welded together.

The distance W is controlled to be 2 mm-8 mm, so that the situation that the first side edge 141 and the second side edge 142 cannot be separated for welding due to the fact that the distance W is too small is avoided; on the other hand, if the distance is too large, the number of welding positions required for the exhaust port 14 increases, which not only increases the amount of work, but also makes it easy for leakage from the welding positions to occur, which in turn reduces the sealing performance of the battery 1000.

The distance W satisfies: 2mm ≦ W ≦ 8mm, such as: the spacing W may be, but is not limited to, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, etc.

The size of the distance W is reasonably controlled, the welding workload is reduced on the premise of realizing effective indirect welding, and the welding efficiency is improved.

According to some embodiments of the present application, optionally, referring to fig. 4, the length of the exhaust runner 13 along the predetermined track X is denoted as L, where L is greater than or equal to 2mm and less than or equal to 15mm.

The longer the length L of the exhaust duct 13 along the predetermined trajectory X, the further away the end of the exhaust duct 13 from the pour hole 12 and the lower the degree of contamination of the interior thereof by the electrolyte, so that the less steam is generated during the welding closing operation, or even near zero. However, the exhaust flow path 13 is designed to be excessively long, the structural strength of the end cap 10 is weakened, and the electrode assembly 50 is easily expanded to cause structural deformation, thereby deteriorating stability. Meanwhile, the exhaust flow passage 13 is too long, and more welding seals are needed, so that the risk of leakage is increased invisibly.

The length L is designed as: any value from 2mm to 15mm, such as: the length L may be, but is not limited to, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm, 12mm, 14mm, 15mm, etc.

The length L of the exhaust flow passage 13 is reasonably controlled, so that the reduction of the steam amount during welding closure can be ensured, the generation of welding explosion point defects is avoided, and the stable structure of the end cover 10 can be ensured.

According to some embodiments of the present application, optionally, referring to fig. 6, a distance between the first side 141 and the second side 142 is denoted as W, and the distance W satisfies: w is more than or equal to 0.5mm and less than or equal to 2mm, so that the first side edge 141 and the second side edge 142 can be directly welded together.

The distance W is controlled to be 0.5 mm-2 mm, so that the phenomenon that the exhaust volume at the exhaust port 14 is too low due to too small distance W, and steam generated in the welding process cannot be effectively discharged is avoided; the distance W is too large, so that the first side 141 and the second side 142 cannot be welded directly, for example: when the distance W is larger than the width of the welding end of the welding apparatus, the welding end cannot simultaneously act on the first side 141 and the second side 142, direct welding work cannot be performed, and the like.

The distance W satisfies: any value of 0.5mm ≦ W ≦ 2mm, such as: the spacing W may be, but is not limited to, 0.5mm, 1mm, 1.5mm, 2mm, etc.

The size of reasonable control interval W is under the prerequisite of realizing effectual direct welding, and it is smooth and easy to avoid the interval undersize and influence the exhaust, guarantees formed welding seam stable in structure, avoids exploding the appearance of some defects, promotes battery 1000's sealing performance.

According to some embodiments of the present application, optionally, referring to fig. 6, the length of the exhaust runner 13 along the predetermined track X is denoted as L, where L is greater than or equal to 1mm and less than or equal to 5mm.

When the exhaust port 14 is in the direct welding mode, the longer the length L of the exhaust flow channel 13 along the preset track X is, the farther the end of the exhaust flow channel 13 is away from the liquid injection hole 12, and the lower the degree of contamination of the inside by the electrolyte, so that the less steam is generated during the welding closing operation, and the steam is even near zero. However, the exhaust flow channel 13 is too long, which increases the welding workload and reduces the welding efficiency.

In addition, since the exhaust port 14 on the exhaust flow path 13 is directly welded, the width of the exhaust port 14 is narrower than that of the indirectly welded exhaust port 14, and the possibility of liquid contamination in the exhaust flow path 13 is relatively low, the length of the exhaust flow path 13 can be relatively short in design, that is, the length of the exhaust flow path 13 during direct welding can be shorter than that of the exhaust flow path 13 during indirect welding.

The length L is designed as: 1mm L5 mm, such as: the length L may be, but is not limited to, 1mm, 2mm, 3mm, 4mm, 5mm, etc.

The length L of the exhaust flow channel 13 is reasonably controlled, so that the reduction of steam amount during welding closure can be ensured, the generation of welding explosion point defects is avoided, the welding workload can be reduced, and the welding efficiency is improved.

According to some embodiments of the present application, optionally, referring to fig. 7 and 8, the inner wall of the exhaust flow passage 13 includes a bottom wall 131 opposite to the exhaust port 14 in the thickness direction of the plate main body 11, the bottom wall 131 being configured to guide the liquid into the liquid injection hole 12.

The bottom wall 131 guides the liquid into the liquid injection hole 12, and can limit the liquid residue, and the implementation manner can be as follows: the bottom wall 131 is arranged obliquely, and the liquid on the bottom wall 131 flows back to the liquid injection hole 12 by using the gradient; alternatively, the bottom wall 131 is set so as to be raised, and the splashed liquid is poured into the pouring hole 12 by the raised curvature.

The bottom wall 131 is designed to guide liquid to enter the liquid injection hole 12, so that liquid residue is limited, steam generated in welding at the exhaust port 14 is reduced, the defects of explosion points and the like at the welding closed position are further avoided, and the welding quality is improved.

According to some embodiments of the present application, optionally, referring to fig. 8, the bottom wall 131 is disposed obliquely to the first surface 111. In the thickness direction of the plate main body 11, the end of the bottom wall 131 remote from the pour hole 12 is closer to the first surface 111.

The end of the bottom wall 131 close to the injection hole 12 is lower than the other end, so that the bottom wall 131 is inclined towards the injection hole 12, thereby ensuring that the liquid on the bottom wall 131 falls into the injection hole 12 along the bottom wall 131, and no electrolyte is left after the injection is completed.

With diapire 131 slope setting for liquid drops to annotating liquid hole 12 on the diapire 131, makes it not remain liquid, reduces like this when the welding or can not produce steam, effectively avoids producing defects such as fried point in the closed department of welding, promotes welding quality.

According to some embodiments of the present application, optionally, referring to FIG. 8, the included angle between the bottom wall 131 and the thickness direction of the plate body 11 is denoted as θ, wherein 110 ≦ θ ≦ 170.

The included angle between the bottom wall 131 and the thickness direction of the plate body 11 is 110 ° ≦ θ ≦ 170 °, and of course, the inclined angle of the bottom wall 131 may also be characterized by referring to the end face 123 of the liquid injection hole 12, such as: the included angle between the bottom wall 131 and the end face 123 of the liquid injection hole 12 is alpha which is more than or equal to 100 degrees and less than or equal to 160 degrees.

The included angle θ between the bottom wall 131 and the thickness direction of the plate body 11 may be any value between 110 ° and 170 °, for example: the included angle θ may be, but is not limited to, 110 °, 120 °, 130 °, 140 °, 150 °, 160 °, 170 °, and so forth.

The inclination angle of the bottom wall 131 is reasonably controlled, so that the liquid on the bottom wall 131 smoothly drops into the liquid injection hole 12, and the bottom wall 131 is ensured not to have residual liquid, thereby improving the welding quality at the exhaust port 14.

According to some embodiments of the present application, optionally, referring to fig. 4, the inner wall of the exhaust channel 13 further includes two sidewalls 132 spaced apart from each other on the bottom wall 131. Each side wall 132 is in transition connection with the inner wall arc of the pour hole 12.

The arc transition connection between the side wall 132 and the inner wall of the liquid injection hole 12 is as follows: a section of arc wall is arranged between the side wall 132 and the inner wall of the liquid filling hole 12, so that the connection between the side wall 132 and the inner wall of the liquid filling hole 12 is smoothly transited, and the internal stress between the side wall 132 and the inner wall of the liquid filling hole 12 is favorably eliminated.

The side wall 132 is in arc transition connection with the inner wall of the liquid injection hole 12, so that the internal stress concentration of connection between the side wall and the inner wall is reduced, and the stability of the whole structure of the end cover 10 is improved.

According to some embodiments of the present application, optionally, referring to fig. 8, the liquid injection hole 12 includes a first liquid injection section 121 and a second liquid injection section 122 communicating with each other in the thickness direction of the plate main body 11. The second injection section 122 is further from the exhaust port 14 relative to the first injection section 121. The exhaust flow channel 13 extends to the side wall of the first injection section 121, so that the exhaust flow channel 13 is communicated with the first injection section 121.

The second injection section 122 is far away from the exhaust port 14 relative to the first injection section 121, that is, the second injection section 122 is located below the first injection section 121 in the thickness direction of the plate body 11; it is of course also understood that: the second injection section 122 is disposed closer to the housing 40 than the first injection section 121 when the end cap assembly is capped on the housing 40.

The cross-sectional area of the second injection section 122 may or may not be uniform with the cross-sectional area of the first injection section 121. Such as: the cross-sectional area of the second injection section 122 is smaller than the cross-sectional area of the first injection section 121. For convenience of illustration, taking the injection hole 12 as a circular structure as an example, the diameter of the second injection segment 122 is smaller than that of the first injection segment 121, and an end face 123 is formed between the second injection segment 122 and the first injection segment 121. In some embodiments, the angle α between the bottom wall 131 of the exhaust channel 13 and the end face 123 is 100 ° α or more and 160 ° or less. Meanwhile, the end of the bottom wall 131 is higher or flush with the end surface 123, so that the liquid on the end surface 123 does not overflow onto the bottom wall 131.

The liquid injection hole 12 is divided into an upper section and a lower section, and double-section sealing can be performed during later welding and sealing, so that the sealing performance on the end cover assembly is better.

According to some embodiments of the present application, optionally, referring to fig. 8, a cross-sectional area of the second liquid injection section 122 in a direction perpendicular to the thickness direction of the plate body 11 is smaller than a cross-sectional area of the first liquid injection section 121 in a direction perpendicular to the thickness direction of the plate body 11.

The difference between the cross-sectional area of the second injection section 122 and the cross-sectional area of the first injection section 121 may be determined by the actual size of the end cap 10.

The liquid injection hole 12 is designed into a hole structure with two sections of different cross-sectional areas, so that the liquid injection hole 12 is designed as a counter bore, and liquid injection operation is facilitated.

Referring to fig. 9 and 10, according to some embodiments of the present application, an end cap assembly is provided. The end cap assembly includes: a first seal 20 and an end cap 10 as in any of the above aspects. The first seal 20 seals one end of the pour hole 12, and maintains communication between the exhaust flow passage 13 and the pour hole 12. The exhaust port 14 is in a closed state.

The first seal 20 is a member that can cover one end of the pour hole 12, and the connection method with the pour hole 12 may be a welding method. The shape of the first sealing member 20 may be determined according to the shape of the pour hole 12, such as: circular, oval, square, etc. Meanwhile, there are various options for the structure of the first sealing member 20, such as stainless steel nails, aluminum nails, etc.

When the first sealing member 20 is sealed at one end of the pour hole 12, the communication between the exhaust gas flow passage 13 and the pour hole 12 cannot be affected because the steam generated in the pour hole 12 needs to be exhausted to the exhaust port 14 through the exhaust gas flow passage 13 during the welding sealing. The first seal member 20 does not affect the communication between the exhaust gas flow passage 13 and the liquid injection hole 12, and may be implemented by: the first sealing element 20 does not block one port of the exhaust flow passage 13 when being sealed on the liquid injection hole 12; alternatively, the first sealing member 20 is correspondingly perforated so that the hole corresponds to one port of the exhaust flow passage 13; alternatively, when the first seal 20 is sealed in the pour hole 12, a certain gap is provided between the pour hole 12 and the circumferential direction of the first seal 20 to ensure the flow of steam between the pour hole 12 and the exhaust gas flow path 13.

The vent 14 is in a closed state after the end cap assembly is formed, that is, when the end cap assembly is applied to the battery cell 100 as a finished product, the vent 14 is in a closed state, so as to prevent the electrolyte in the battery cell 100 from leaking from the vent 14. The exhaust port 14 may be closed in various ways, for example: directly welding and sealing the exhaust port 14 by using welding equipment; alternatively, an intermediate structure is welded in the exhaust port 14 by a welding device to achieve closure of the exhaust port 14, or the like.

The end cover assembly adopts the end cover 10, and the liquid injection hole 12 can be welded preferentially in the welding process; the exhaust port 14 on the exhaust flow path 13 is welded. After the operation, the steam welded at the liquid injection hole 12 can be ensured to be discharged through the exhaust runner 13 and the exhaust port 14; meanwhile, when the final welding closing operation is carried out, because the pollution of the liquid in the exhaust flow passage 13 is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole 12 is welded and sealed is effectively avoided, and the sealing performance is improved.

According to some embodiments of the present application, optionally, referring to fig. 11 and 12, the first sealing member 20 includes a first member 21 and a second member 22 disposed on the first member 21. The first member 21 seals one end of the pour hole 12, and the second member 22 seals the exhaust port 14.

The connection between the first member 21 and the second member 22 can be, but is not limited to, welding, bonding, screwing, integral molding, etc. Wherein the integral molding is injection molding, die casting, extrusion and the like.

The first seal 20 is designed in two parts: the first member 21 and the second member 22 make it possible to seal the pour hole 12 and also to seal the vent hole 14, which is advantageous for improving the assembling efficiency of the head cover assembly.

According to some embodiments of the present application, optionally, referring to fig. 9 and 10, the end cap assembly further includes a second seal 30. The second sealing member 30 seals the other end of the pour hole 12.

The second sealing member 30 is a member capable of covering one end of the pour hole 12, and the connection with the pour hole 12 may be by welding. The shape of the second seal 30 may depend on the shape of the pour hole 12, such as: circular, oval, square, etc. Meanwhile, there are various options for the structure of the second sealing member 30, such as a rubber nail, which is inserted into one end of the liquid injection hole 12 during sealing.

The second sealing element 30 is arranged at the other end of the liquid injection hole 12 and forms double-layer sealing with the first sealing element 20, and the sealing performance of the end cover assembly is greatly improved.

According to some embodiments of the present application, optionally, referring to fig. 9 and 10, a gap is provided between the first seal member 20 and the pour hole 12 in a direction perpendicular to the thickness direction of the plate main body 11.

When the first sealing member 20 is placed in the pour hole 12, there is a certain clearance between the periphery of the first sealing member 20 and the side wall of the pour hole 12, which ensures that the placement of the first sealing member 20 in the pour hole 12 does not interfere with the communication between the exhaust gas flow passage 13 and the pour hole 12.

A gap is arranged between the first sealing element 20 and the liquid injection hole 12, so that the communication between the exhaust flow passage 13 and the liquid injection hole 12 is ensured, and steam generated in the welding process can be exhausted from the exhaust flow passage 13 all the time.

Referring to fig. 13, according to some embodiments of the present application, there is provided an end cap assembly welding method for preparing an end cap assembly of any one of the above, comprising the steps of:

s100, placing at least part of the first sealing member 20 in the liquid injection hole 12, and enabling a first gap 23 to be formed between the first sealing member 20 and the side wall of the liquid injection hole 12;

and S200, welding the first sealing element 20 and the side wall of the liquid injection hole 12, and welding and sealing the exhaust port 14, wherein the final welding end point is positioned on the exhaust port 14.

The first gap 23 is defined as a gap between the periphery of the first seal 20 and the periphery of the pour hole 12 when the first seal 20 is placed on the pour hole 12, and this gap is defined as the first gap 23.

In step S200, the final welding end point may be understood as a final step in the welding process of the end cap assembly, and the welding operation of the end cap assembly may be finished after the final step of the welding process of the end cap assembly.

Controlling the final welding end point on the vent 14 means that the final ending operation in the welding process is placed on the welding of the vent 14, so that a large amount of steam is not generated to break through the welding seam in a molten state when the welding is closed, thereby avoiding the formation of explosion points or pinhole-shaped explosion point defects.

The fact that at least part of the first sealing element 20 is placed in the pouring opening 12 is to be understood as: the first sealing piece 20 is only used for covering the liquid injection hole 12; alternatively, a part of the first seal 20 may cover the pour hole 12 and the other part may cover the vent hole 14. When the first sealing member 20 covers the pouring hole 12 and the exhaust port 14, the welding operation for the exhaust port 14 is to weld the gap between the first sealing member 20 and the exhaust port 14.

In the end cover assembly welding method, at least part of the first sealing piece 20 is placed in the liquid injection hole 12 in the welding process to form a first gap 23 to be welded; then, the first gap 23 and the exhaust port 14 are welded, respectively, and the final closing operation is controlled to be performed on the exhaust port 14. After the operation, the steam welded at the liquid injection hole 12 can be ensured to be discharged through the exhaust runner 13 and the exhaust port 14; meanwhile, when the final welding closing operation is carried out, because the pollution of the liquid in the exhaust flow passage 13 is small, the generated steam is weak or does not exist, and the molten welding line cannot be broken upwards, so that the defect of point explosion when the liquid injection hole 12 is welded and sealed is effectively avoided, and the sealing performance is improved.

According to some embodiments of the present application, optionally, referring to fig. 14 and 15, S200, the step of welding the first sealing member 20 and the sidewall of the pour hole 12, and welding the hermetic seal of the vent 14 includes:

s210, covering the first member 21 and the second member 22 of the first sealing member 20 in the liquid injection hole 12 and the exhaust port 14 respectively, and enabling a first gap 23 to be formed between the first member 21 and the side wall of the liquid injection hole 12, and a second gap 24 and a third gap 26 to be formed between the second member 22 and the two side walls of the exhaust port 14 respectively, wherein the two opposite ends of the second gap 24 are communicated with the first gap 23 at intervals;

s220, taking any position on the second gap 24 or the third gap 26 as an initial welding position 25, and welding along the edge of the first sealing element 20;

and S230, stopping welding at the initial welding position 25.

The second gap 24 and the third gap 26 are defined as a gap between the periphery of the second member 22 and the periphery of the vent 14 when the second member 22 covers the vent 14, and the gap is defined as the second gap 24 and the third gap 26. Meanwhile, the second gap 24 and the third gap 26 are both communicated with the first gap 23, and at the moment, after the welding head moves from one end of the second gap 24 to the first gap 23 in the welding process, the welding head can move from the other end of the second gap 24 to the third gap 26 on the first gap 23. In addition, the point at which the end of the first gap 23 remote from the pour hole 12 intersects the end of the second gap 24 remote from the pour hole 12 can be understood to be the distal end 143 of the vent 14.

Either the second gap 24 or the third gap 26 serves as an initial weld site 25, such that when the horn moves to weld along the second gap 24 or the third gap 26 and the first gap 23 in sequence, the horn eventually moves back onto the second gap 24 or the third gap 26 and a weld closure is performed at the initial weld site 25. In particular, in some embodiments, the start weld site 25 is located at an end of the second gap 24 that is distal from the first gap 23, such that the last weld closure point is further from the pour hole 12, and less or no steam is generated, resulting in better weld quality.

The specific welding process is as follows: starting welding from the initial welding position 25 on the second gap 24, and moving the welding head to the first gap 23 along the second gap 24 to complete welding of the second gap 24, which can be referred to in fig. 15 (a); next, moving the welding head along the circumferential direction of the first gap 23 to complete all welding on the first gap 23, which can be referred to in fig. 15 (b); then, welding is started from the end of the connection between the first gap 23 and the third gap 26, and the welding head is moved to the initial welding position 25 along the unwelded portion of the third gap 26, so as to complete all welding operations between the first sealing member 20 and the pour hole 12, as shown in fig. 15 (c).

The welding is started from any position of the second gap 24 or the third gap 26, so that the final welding closing operation can be effectively controlled on the second gap 24 or the third gap 26, the steam generated during the welding closing is weak or does not exist, the molten welding seam cannot be broken upwards, the explosive point defect of the liquid injection hole 12 during the welding sealing is effectively avoided, and the sealing performance is improved.

According to some embodiments of the present application, optionally, referring to fig. 16 and 17, S200, the step of welding the first sealing member 20 and the sidewall of the pour hole 12, and welding the hermetic outlet 14 includes:

s240, controlling a fourth gap 27 formed between the first side 141 and the second side 142 of the exhaust port 14, wherein one end of the fourth gap 27 is communicated with the first gap 23;

s250, taking any position on the first gap 23 as an initial welding position 25, and welding the position to the initial welding position 25 along the edge of the first sealing element 20;

s260, continuing to weld to the end 143 of the fourth gap 27 away from the pour hole 12 from the place where the fourth gap 27 communicates with the first gap 23.

The fourth gap 27 refers to a gap directly formed between the first side 141 and the second side 142. Meanwhile, one end of the fourth gap 27 is communicated with the first gap 23, that is, the fourth gap 27 is substantially in a strip structure, and at this time, in the welding process, after the welding head moves from one end of the first gap 23 to the fourth gap 27, the welding of the fourth gap 27 can be completed only by continuing to move.

Any position on the first gap 23 is used as an initial welding position 25, so that when the welding head moves to the initial welding position 25 again along the circumferential direction of the first gap 23 in sequence, all welding on the first gap 23 is completed; then, starting from the connection end between the first gap 23 and the fourth gap 27, it is possible to move along the fourth gap 27 and to complete all the welding on the fourth gap 27. It should be noted that when the first gap 23 is welded, it is ensured that the exhaust gas flow passage 13 is communicated with the pour hole 12. In particular, in some embodiments, the initial welding position 25 is disposed at the connecting end between the first gap 23 and the fourth gap 27, so that when the welding of the first gap 23 is completed, the welding head can be directly transferred to the fourth gap 27 without lifting the welding head to reposition the end of the fourth gap 27, thereby facilitating the welding operation.

The specific welding process is as follows: starting welding from the initial welding position 25 on the first gap 23, and moving the welding head to the initial welding position 25 again along the first gap 23 to complete all welding of the first gap 23, which can be referred to in fig. 17 (a); next, all welds in the fourth gap 27 are completed by moving the welding head from the connection end between the first gap 23 and the fourth gap 27 and along the fourth gap 27, as can be seen in fig. 17 (b).

The first gap 23 is preferably completed, so that the final welding closing operation can be effectively controlled on the fourth gap 27, steam generated during welding closing is weak or does not exist, a molten welding seam cannot be broken upwards, the defect of explosive points during welding sealing of the liquid injection hole 12 is effectively avoided, and the sealing performance is improved.

According to some embodiments of the present application, a battery cell 100 is provided. The battery cell 100 includes: a case 40, an electrode assembly 50, and an end cap assembly. The housing 40 has an opening 41 at an end thereof. The electrode assembly 50 is housed in the case 40. The end cap assembly covers the opening 41.

According to some embodiments of the present application, a battery 1000 is provided that includes the above battery cell 100.

According to some embodiments of the present application, there is provided an electric device including the battery of the above aspect, wherein the battery is used for providing electric energy.

Referring to fig. 4 to 17, according to some embodiments of the present application, a novel injection hole 12 and aluminum nail structure are provided. The liquid injection hole 12 is designed by adopting a slope step and an arc step. And the glue nail sealing and the aluminum nail laser welding sealing are respectively adopted, and the two sealing are realized. The first layer is sealed by a rubber nail and mainly plays a role in preventing electrolyte from emerging from the battery core and preventing solid particles from falling when the electrolyte injection hole 12 is cleaned by laser; the second layer adopts aluminium nail welding seal structure, and the aluminium nail is for cooperating annotating "table tennis bat" type structure of liquid hole 12 slope steps + circular arc step, and laser welding plays the closed department in "handle" of receipts arc, can effectively avoid playing the fried defect of receipts arc welding.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. An end cap (10) for a battery cell, comprising:

a plate main body (11) having a liquid injection hole (12) formed therethrough in the thickness direction thereof;

the battery cell structure is characterized in that an exhaust flow channel (13) is further arranged on the plate main body (11), the projection of the exhaust flow channel (13) in the thickness direction of the plate main body (11) is at least partially located outside the projection of the liquid injection hole (12) in the thickness direction of the plate main body (11), the exhaust flow channel (13) extends to the side wall of the liquid injection hole (12) so that the exhaust flow channel (13) is communicated with the liquid injection hole (12), an exhaust port (14) used for being communicated with the outside is formed in the first surface (111) of the plate main body (11) of the exhaust flow channel (13), and the first surface (111) is the surface of the plate main body (11) far away from the inside of the battery cell.

2. The end cap (10) according to claim 1, wherein the gas vent (14) extends on the first surface (111) of the plate body (11) along a predetermined trajectory (X) to the edge of the liquid injection hole (12).

3. An end cap (10) according to claim 2, wherein the predetermined trajectory (X) is a straight trajectory.

4. The tip cap (10) according to claim 2, wherein the vent (14) comprises an end (143) distal from the edge of the pour spout (12), and a first side (141) and a second side (142) connecting the end (143) and the edge of the pour spout (12), the first side (141) and the second side (142) being spaced apart from each other.

5. The end cap (10) of claim 4, wherein the first side edge (141) and the second side edge (142) are spaced apart by a distance W, the distance W satisfying: w is more than or equal to 2mm and less than or equal to 8mm.

6. The end cover (10) according to claim 4, wherein the length of the exhaust gas flow passage (13) along the preset trajectory (X) is marked L, wherein L is larger than or equal to 2mm and smaller than or equal to 15mm.

7. The end cap (10) of claim 4, wherein the first side edge (141) and the second side edge (142) are spaced apart by a distance W, the distance W satisfying: w is more than or equal to 0.5mm and less than or equal to 2mm.

8. The end cover (10) according to claim 7, wherein the length of the exhaust gas flow passage (13) along the preset trajectory (X) is marked L, wherein L is larger than or equal to 1mm and smaller than or equal to 5mm.

9. The end cap (10) according to any one of claims 1 to 8, wherein the inner wall of the exhaust gas flow passage (13) includes a bottom wall (131) opposite to the exhaust port (14) in the thickness direction of the plate body (11), the bottom wall (131) being configured to guide liquid into the liquid injection hole (12).

10. The end cap (10) according to claim 9, wherein the bottom wall (131) is disposed obliquely with respect to the first surface (111), and an end of the bottom wall (131) remote from the pour hole (12) is closer to the first surface (111) in a thickness direction of the plate main body (11).

11. The end cap (10) of claim 10, wherein the bottom wall (131) is angled from the thickness direction of the plate body (11) by an angle θ, wherein θ is 110 ° θ 170 °.

12. The end cap (10) according to claim 9, wherein the inner wall of the exhaust gas flow passage (13) further comprises two side walls (132) spaced apart from the bottom wall (131), and each side wall (132) is in arc transition connection with the inner wall of the liquid injection hole (12).

13. The end cap (10) according to any one of claims 1 to 8, wherein the liquid injection hole (12) includes a first liquid injection section (121) and a second liquid injection section (122) that communicate with each other in a thickness direction of the plate main body (11), the second liquid injection section (122) is further away from the gas discharge port (14) with respect to the first liquid injection section (121), and the gas discharge flow passage (13) extends to a side wall of the first liquid injection section (121) to communicate the gas discharge flow passage (13) with the first liquid injection section (121).

14. The end cap (10) of claim 13, wherein a cross-sectional area of the second liquid injection section (122) in a direction perpendicular to a thickness direction of the plate body (11) is smaller than a cross-sectional area of the first liquid injection section (121) in a direction perpendicular to the thickness direction of the plate body (11).

15. An end cap assembly, comprising:

the end cap (10) of any of claims 1-14;

and a first sealing member (20) that seals one end of the liquid inlet (12), maintains communication between the exhaust gas flow path (13) and the liquid inlet (12), and closes the exhaust port (14).

16. An end cap assembly according to claim 15, wherein the first sealing member (20) comprises a first member (21) and a second member (22) connected to the first member (21), the first member (21) sealing one end of the pour hole (12) and the second member (22) sealing the vent (14).

17. The tip cap assembly according to claim 15, further comprising a second sealing member (30), the second sealing member (30) sealing the other end of the pour hole (12).

18. The end cap assembly according to claim 15, characterized in that there is a gap between the first seal member (20) and the pour hole (12) in a direction perpendicular to the thickness direction of the plate main body (11).

19. A method of welding an end cap assembly to produce an end cap assembly according to any one of claims 15 to 18, comprising the steps of:

placing at least part of a first seal (20) in the pouring hole (12) such that a first gap (23) is formed between the first seal (20) and the side wall of the pouring hole (12);

and welding and connecting the first sealing piece (20) and the side wall of the liquid injection hole (12), and welding and sealing the exhaust port (14), wherein the final welding end point is positioned on the exhaust port (14).

20. The method of welding an end cap assembly according to claim 19, wherein the step of welding the first seal member (20) to the side wall of the pour spout (12) and welding the vent opening (14) closed comprises:

covering a first member (21) and a second member (22) of the first sealing member (20) in the liquid injection hole (12) and the gas exhaust hole (14) respectively, and enabling a first gap (23) to be formed between the first member (21) and the side wall of the liquid injection hole (12), and enabling a second gap (24) and a third gap (26) to be formed between the second member (22) and the two side walls of the gas exhaust hole (14) respectively, wherein the second gap (24) and the third gap (26) are communicated with the first gap (23);

taking any one of the second gap (24) or the third gap (26) as an initial welding position (25), and welding along the edge of the first sealing member (20);

stopping welding at the start welding location (25).

21. The method of welding an end cap assembly according to claim 19, wherein the step of welding the first seal member (20) to the side wall of the pour spout (12) and welding the vent opening (14) closed comprises:

controlling a fourth gap (27) to be formed between the first side edge (141) and the second side edge (142) of the exhaust port (14), wherein one end of the fourth gap (27) is communicated with the first gap (23);

taking any place on the first gap (23) as a starting welding position (25), and welding to the starting welding position (25) along the edge of the first sealing member (20);

and continuously welding the fourth gap (27) to the tail end (143) of the fourth gap (27) far away from the liquid injection hole (12) from the communication part of the fourth gap (27) and the first gap (23).

22. A battery cell, comprising:

a housing (40) having an opening (41) at an end thereof;

an electrode assembly (50) housed in the case (40);

the end cap assembly of any one of claims 15-18, said end cap assembly covering said opening (41).

23. A battery comprising the cell of claim 22.

24. An electrical device comprising the battery of claim 23, wherein the battery is configured to provide electrical energy.