CN115832547B

CN115832547B - End cover, end cover assembly, welding method, battery cell, battery and power utilization device

Info

Publication number: CN115832547B
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: 2023-12-15
Anticipated expiration: 2042-07-19
Also published as: CN115832547A

Abstract

The invention relates to an end cover, an end cover assembly, a welding method, a battery monomer, a battery and an electric device. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and then welding the exhaust port on the exhaust runner. 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing is effectively avoided, and the sealing performance is improved.

Description

End cover, end cover assembly, welding method, battery cell, battery and power utilization 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 battery cell, a battery and an electric device.

Background

In the battery manufacturing process, after the battery is filled with liquid, sealing components such as sealing nails and the like are needed to seal the liquid filling holes on the end covers. In the sealing operation, the sealing member and the pouring hole are welded together by welding. However, the defects are limited by the structural design of the end cover, so that welding explosion point defects are easily formed at the welding closure, and the sealing performance of the battery is seriously affected.

Disclosure of Invention

Based on the above, it is necessary to provide an end cover, an end cover assembly, a welding method, a battery cell, a battery and an electric device, which can effectively avoid the explosion point defect of the liquid injection hole during welding and sealing and improve the sealing performance.

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 exhaust runner is arranged on the plate main body, at least part of the projection of the exhaust runner along the thickness direction of the plate main body is located outside the projection of the liquid injection hole along the thickness direction of the plate main body, the exhaust runner extends to the side wall of the liquid injection hole so that the exhaust runner is communicated with the liquid injection hole, an exhaust port used for being communicated with the outside is formed on the first surface of the plate main body, and the first surface is a surface of the plate main body far away from the inside of the battery monomer.

According to the end cover, the exhaust runner communicated with the liquid injection hole is arranged outside the liquid injection hole, so that the plate main body is provided with the space area far away from the liquid injection hole, steam generated in the welding process of the liquid injection hole can flow into the exhaust runner, liquid splashing into the exhaust runner in the liquid injection operation can be avoided, and the liquid pollution degree in the exhaust runner is reduced. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and then welding the exhaust port on the exhaust runner. 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing is effectively avoided, and the sealing performance is improved.

In some embodiments, the vent extends along a predetermined trajectory onto the edge of the pour hole on the first surface of the plate body. Therefore, the exhaust port extends to the edge of the liquid injection hole along the preset track, so that the exhaust port is also directly communicated with the liquid injection hole, the post welding operation is convenient, and the assembly efficiency of the end cover assembly is improved.

In some embodiments, the preset trajectory is a straight trajectory. The preset track is designed into a linear track, so that the opening operation of the exhaust port is simplified; and the welding operation of the exhaust port is convenient, and the welding sealing efficiency is improved.

In some embodiments, the vent includes a tip distal from the rim of the pour spout, and a first side and a second side connecting the tip and the rim of the pour spout, the first side and the second side having a space therebetween. By the design, a space is reserved between the first side edge and the second side edge, and the welding mode of the exhaust port can be direct welding or indirect welding, so that 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 spacing between the first side edge and the second side edge is denoted as W, the spacing W satisfying: and the distance W is less 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 predetermined trajectory is denoted as L, where 2 mm.ltoreq.L.ltoreq.15 mm. Therefore, the length L of the exhaust runner is reasonably controlled, the reduction of the steam quantity during welding closure can be ensured, the generation of welding explosion point defects is avoided, and the structural stability of the end cover can be ensured.

In some embodiments, the spacing between the first side edge and the second side edge is denoted as W, the spacing W satisfying: w is more than or equal to 0.5mm and less than or equal to 2mm. The size of the interval W is reasonably controlled, on the premise of realizing effective direct welding, the influence of too small interval on smooth exhaust is avoided, the stability of the formed welding seam structure is ensured, the occurrence of explosion point defects is avoided, and the sealing performance of the battery is improved.

In some embodiments, the length of the exhaust runner along the predetermined trajectory is denoted as L, where 1 mm.ltoreq.L.ltoreq.5 mm. The length L of the exhaust runner is reasonably controlled, so that the reduction of steam quantity during welding closing can be ensured, 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 vent flow channel includes a bottom wall opposite the vent port in a thickness direction of the plate body, the bottom wall configured to direct liquid into the liquid injection hole. So, design the diapire for guiding liquid to get into annotate the liquid hole, restriction liquid remains, is favorable to reducing the steam that produces in the welding of gas vent department, further avoids producing defects such as exploding the point in welding closure department, promotes welding quality.

In some embodiments, the bottom wall is disposed obliquely to the first surface, and an end of the bottom wall distant from the liquid injection hole is closer to the first surface in the thickness direction of the plate body. Therefore, the bottom wall is obliquely arranged, so that liquid on the bottom wall falls into the liquid injection hole, liquid is not remained, steam is reduced or not generated during welding, the defects of explosion points and the like at the welding closing position are effectively avoided, and the welding quality is improved.

In some embodiments, the angle between the bottom wall and the thickness direction of the plate body is denoted as θ, where 110+.θ+.170 °. So, the inclination of rational control diapire for in the liquid on the diapire smoothly drops the notes liquid hole, can not remain liquid on the assurance diapire, with the welding quality that improves gas vent department.

In some embodiments, the inner wall of the exhaust runner further comprises two side walls arranged on the bottom wall at intervals, and each side wall is in arc transition connection with the inner wall of the liquid injection hole. Therefore, the side wall is in arc transitional connection with the inner wall of the liquid injection hole, 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 is improved.

In some embodiments, the liquid injection hole includes a first liquid injection section and a second liquid injection section that are communicated in a thickness direction of the plate body, the second liquid injection section is further away from the exhaust port relative to the first liquid injection section, and the exhaust runner extends to a side wall of the first liquid injection section so that the exhaust runner is communicated with the first liquid injection section. By the design, the liquid injection hole is divided into an upper section and a lower section, and double-section sealing can be performed during later-stage welding sealing, so that the sealing performance on the end cover assembly is better.

In some embodiments, the cross-sectional area of the second liquid injection section in a direction perpendicular to the thickness direction of the plate body is smaller than the cross-sectional area of the first liquid injection section in a direction perpendicular to the thickness direction of the plate body. Therefore, the liquid injection hole is designed into a hole structure with two sections of different cross-sectional areas, so that the liquid injection hole is designed as a counter bore, and the liquid injection operation is convenient.

In a second aspect, the present application provides an end cap assembly comprising: an end cap as claimed in any one of the preceding claims; the first sealing piece seals one end of the liquid injection hole, keeps communication between the exhaust runner and the liquid injection hole, and the exhaust port is in a closed state.

The end cover assembly adopts the end cover, and the liquid injection hole can be welded preferentially in the welding process; and then welding the exhaust port on the exhaust runner. 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing is effectively avoided, and the sealing performance is improved.

In some embodiments, the first seal includes a first member that seals one end of the pour hole and a second member coupled to the first member that seals the vent. Thus, the first seal is designed in two parts: the first part and the second part enable the sealing of the exhaust port to be achieved when the liquid injection hole is sealed, and the assembly efficiency of the end cover assembly is improved.

In some embodiments, the end cap assembly further comprises a second seal member that seals the other end of the pour spout. Therefore, the second sealing piece is arranged at the other end of the liquid injection hole and forms double-layer sealing with the first sealing piece, so that the sealing performance of the end cover assembly is greatly improved.

In some embodiments, there is a gap between the first seal and the pour hole in a direction perpendicular to the thickness direction of the plate body. Therefore, a gap is arranged between the first sealing piece and the liquid injection hole, so that communication between the exhaust runner and the liquid injection hole is ensured, and steam generated in the welding process can be always discharged from the exhaust runner.

In a third aspect, the present application provides a method of welding an end cap assembly for preparing an end cap assembly of any one of the above, comprising the steps of: placing at least a portion of the first seal in the pour hole and forming a first gap between the first seal and a sidewall of the pour hole; and welding the side walls of the first sealing piece and the liquid injection hole, and welding the airtight exhaust port, wherein the final welding end point is positioned on the exhaust port.

The welding method of the end cover assembly can ensure that steam welded at the liquid injection hole is 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing is effectively avoided, and the sealing performance is improved.

In some embodiments, the step of welding the first seal to the sidewall of the pour hole and welding the closed vent includes: the first part and the second part of the first sealing piece are respectively covered in the liquid injection hole and the air outlet, a first gap is formed between the first part and the side wall of the liquid injection hole, a second gap and a third gap are respectively formed between the second part and the two side walls of the air outlet, and the second gap and the third gap are communicated with the first gap; taking any part of the second gap or the third gap as an initial welding position, and welding along the edge of the first sealing piece; the weld is stopped at the start weld location.

Therefore, the 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, so that steam generated during welding closing is weaker or does not exist, a welding line in a melting shape is not broken upwards, the explosion point defect of a 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 to the sidewall of the pour hole and welding the closed vent includes: a fourth gap is formed between the first side edge and the second side edge of the control exhaust port, and one end of the fourth gap is communicated with the first gap; taking any part of the first gap as an initial welding position, and welding the first gap to the initial welding position along the edge of the first sealing piece; and continuing to weld from the communication part of the fourth gap and the first gap to the tail end of the fourth gap far away from the liquid injection hole.

Therefore, the fourth gap is preferably completed, the final welding end point can be effectively controlled on the fourth gap, so that steam generated during welding closing is weaker or does not exist, a welding line in a melting shape cannot be broken upwards, the defect of explosion points of a liquid injection hole during welding sealing is effectively avoided, and sealing performance is improved.

In a fourth aspect, the present application provides a battery cell comprising: a housing having an opening at an end; an electrode assembly accommodated in the case; an end cap assembly as claimed in any preceding claim, wherein the end cap assembly is provided to cover the opening.

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

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

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 present application;

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

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

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

FIG. 5 is a second schematic structural view of an end cap according to some embodiments of the present application;

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

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

FIG. 8 is a cross-sectional view of the end cap of FIG. 7 taken along the direction A-A;

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

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

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 of FIG. 9;

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

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

FIG. 15 is a schematic view of a welded structure of an end cap assembly according to some embodiments of the present application;

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

Fig. 17 is a schematic diagram 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 case; 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 liquid injection section; 122. a second liquid injection section; 123. an end face; 13. an exhaust runner; 131. a bottom wall; 132. a sidewall; 14. an exhaust port; 141. a first side; 142. a second side; 143. a terminal end; 20. a first seal; 21. a first component; 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; 40. a housing; 41. an opening; 50. an electrode assembly; 60. an adapter; x, a preset track.

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.

The inventors have noted that in battery injection, electrolyte more or less remains in the injection hole. When the liquid injection holes are welded, the high temperature generated by the welding can evaporate the residual electrolyte to form electrolyte steam. As welding continues, the generated steam escapes from the unwelded area; when the final welding stage is performed, namely the final welding closing operation, the generated steam cannot escape, and the welding seam in a molten state can be broken upwards, so that a welding explosion point defect is formed in the welding seal.

Based on this, in order to solve the problem that the explosion point defect is easily formed in the welding seal of the liquid injection hole, the present inventors have made intensive studies and devised an end cap in which an exhaust flow passage is provided outside the liquid injection hole, the exhaust flow passage communicates with the liquid injection hole, and at least a part of the exhaust flow passage forms an exhaust port for communicating with the outside on the surface of the plate main body.

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 into the exhaust runner in the liquid injection operation can be avoided, and the liquid pollution degree in the exhaust runner is reduced. Therefore, in the welding process, the liquid injection hole can be welded preferentially; and then welding the exhaust port on the exhaust runner. 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing 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 into the exhaust runner in the liquid injection operation can be avoided, and the liquid pollution degree in the exhaust runner is reduced.

In the welding process, the liquid injection hole can be welded preferentially; and then welding the exhaust port on the exhaust runner. 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 runner is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the defect of explosion points of the liquid injection hole in welding sealing is effectively avoided, and the sealing performance is improved.

The battery cell disclosed by the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but is not limited to the electric devices. A power supply system having the battery cell, the battery, and the like disclosed in the present application constituting the power utilization device 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 car, 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 will take an electric device according to an embodiment of the present application as an example of a vehicle.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 10000 according to some embodiments of the present application. The vehicle 10000 can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle. The battery 1000 is provided inside the vehicle 10000, 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 be used as an operation power source of the vehicle 10000. The vehicle 10000 can also include a controller 2000 and a motor 3000, the controller 2000 being configured to control the battery 1000 to power the motor 3000, for example, for operating power requirements during starting, navigation and driving of the vehicle 10000.

In some embodiments of the application, battery 1000 may not only serve as an operating power source for vehicle 10000, but also as a driving power source for vehicle 10000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 10000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 1000 according to some embodiments of the present application. The battery 1000 includes a case 200 and a battery cell 100, and the battery cell 100 is accommodated in the case 200. The case 200 is used to provide an accommodating 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 being overlapped with each other, the first portion 210 and the second portion 220 together defining an accommodating space for accommodating the battery cell 100. The second portion 220 may be a hollow structure with one end of the exhaust port 14, the first portion 210 may be a plate-shaped structure, and the first portion 210 covers the exhaust port 14 side of the second portion 220, so that the first portion 210 and the second portion 220 together define an accommodating space; the first portion 210 and the second portion 220 may also be hollow structures with one side of the exhaust port 14, and the exhaust port 14 side of the first portion 210 is closed to 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 be of various shapes, such as a cylinder, a rectangular parallelepiped, etc.

In the battery 1000, 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 200; of course, the battery 1000 may be a form of a plurality of battery cells 100 connected in series or parallel or series-parallel to form a battery 1000 module, and a plurality of battery 1000 modules connected in series or parallel or series-parallel to form a whole and accommodated in the case 200. The battery 1000 may further include other structures, for example, the battery 1000 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, fig. 3 is an exploded view of a battery cell 100 according to some embodiments of the application. The battery cell 100 refers to the smallest unit constituting the battery 1000. As shown in fig. 3, the battery cell 100 includes the end cap 10, the case 40, the electrode assembly 50, and other functional components.

The end cap 10 refers to a member that is covered at the exhaust port 14 of the case 40 to isolate 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 cover 10 may be made of a material having a certain hardness and strength (such as an aluminum alloy), so that the end cover 10 is not easy to deform when being extruded and collided, so that the battery cell 100 can have a higher structural strength, and the safety performance can be improved. The cap 10 may be provided with functional parts such as electrode terminals and the like. The electrode terminals may be used to be electrically connected with the electrode assembly 50 for outputting or inputting electric power of the battery cell 100. In some embodiments, the end cap 10 may also be provided with a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold. The material of the end cap 10 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiment of the present application. In some embodiments, insulation may also be provided on the inside of the end cap 10, which may be used to isolate electrical connection components within the housing 40 from the end cap 10 to reduce the risk of short circuits. By way of example, the insulation 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 case 40 and the end cap 10 may be separate components, and the exhaust port 14 may be provided on the case 40, so that the internal environment of the battery cell 100 is formed by covering the exhaust port 14 with the end cap 10 at the exhaust port 14. It is also possible to integrate the end cap 10 and the housing 40, but specifically, the end cap 10 and the housing 40 may form a common connection surface before other components are put into the housing, and when the interior of the housing 40 needs to be sealed, the end cap 10 is then covered with 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., which is not particularly limited in the embodiment of the present application.

The electrode assembly 50 is a component in which electrochemical reactions occur in the battery cell 100. 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 provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode sheets having active material constitute the main body portion of the electrode assembly 50, and the portions of the positive and negative electrode sheets having no active material constitute the tabs, respectively. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or located at two ends of the main body portion respectively. During charge and discharge of the battery 1000, the positive and negative electrode active materials react with the electrolyte, and the tab is connected to the electrode terminal to form a current loop.

Referring to fig. 4, an end cap 10 for a battery cell is provided according to some embodiments of the present application. The end cap 10 includes a plate body 11. The plate body 11 is provided with a liquid injection hole 12 penetrating in its thickness direction. Wherein, the plate main body 11 is further provided with an exhaust runner 13, and the projection of the exhaust runner 13 along the thickness direction of the plate main body 11 is at least partially located outside the projection of the liquid injection hole 12 along the thickness direction of the plate main 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 fact that the projection of the exhaust runner 13 along the thickness direction of the plate main body 11 is at least partially located outside the projection of the liquid injection hole 12 along the thickness direction of the plate main body 11 means that the exhaust runner 13 cannot be completely inside the liquid injection hole 12, so that electrolyte is prevented from splashing into the exhaust runner 13 in the liquid injection process, and the liquid pollution degree in the exhaust runner 13 is reduced.

The distribution of the exhaust runners 13 outside the injection holes 12 can be varied, such as: the exhaust runner 13 extends outward in the radial direction of the liquid injection hole 12; or the extending direction of the exhaust flow path 13 does not pass through the center of the liquid injection hole 12, e.g., the exhaust flow path 13 extends along the length or width direction of the plate body 11, etc. Meanwhile, the number of the exhaust runners 13 may be one or a plurality. When the exhaust runners 13 are plural, the plural exhaust runners 13 may be arranged in various ways, such as: the plurality of exhaust runners 13 are arranged at intervals around the circumference of the liquid injection hole 12, and the like.

In addition, the exhaust flow passage 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 portion of the exhaust flow path 13 (e.g., one end of the exhaust flow path 13, etc.) passes out of the first surface 111 of the plate body 11, forming an exhaust port 14 that is spaced from the liquid injection hole 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 is not limited to, circular, oval, triangular, quadrilateral, etc. design.

The exhaust runner 13 is communicated with the liquid injection hole 12, namely, a communication port is arranged on the inner wall of the liquid injection hole 12, and the exhaust runner 13 is communicated with the liquid injection hole 12 through the communication port. Wherein, the intercommunication mouth is when the design, need pay attention to can not be sheltered from or cut off in the end cover subassembly assembly process, say: the position of the communication port on the inner wall of the liquid injection hole 12 can be moved downwards; alternatively, a sealing member, such as first seal member 20, on the end cap assembly may be correspondingly apertured so that the aperture corresponds to the communication port; alternatively, when the sealing member is sealed in the pouring orifice 12, a certain gap is provided between the circumferential direction of the sealing member and the pouring orifice 12, so that the circulation of the steam between the pouring orifice 12 and the exhaust flow passage 13 is ensured.

In the welding process, the liquid injection hole 12 can be welded preferentially; and then the exhaust port 14 on the exhaust runner 13 is welded. After the operation, the steam welded at the liquid injection hole 12 can 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 runner 13 is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the explosion point defect of the liquid injection hole 12 in the welding sealing process is effectively avoided, and the sealing performance is improved.

Optionally, referring to fig. 4, according to some embodiments of the present application, the vent 14 extends along a predetermined trajectory X onto the edge of the pouring orifice 12 on the first surface 111 of the plate body 11.

The extension of the vent 14 to the edge of the fill port 12 is understood to be: the air outlet 14 extends on the surface of the plate body 11 and extends to communicate with the liquid injection hole 12. Thus, when the liquid injection hole 12 is sealed, the upper sealing part can be covered on the air exhaust port 14 at the same time, so that the simultaneous sealing effect is realized, and the sealing efficiency is convenient to improve.

The predetermined trajectory X may be a straight trajectory or a curved trajectory, and it is only necessary to ensure that one end of the air outlet 14 extends 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 may be of various designs, such as: the width of the exhaust port 14 is designed to be too large, so that the exhaust port 14 can be covered by a sealing component, and the sealing component and the exhaust port 14 can be welded during welding; 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 apparatus, or the like.

The exhaust port 14 extends to the edge of the liquid injection hole 12 along the preset track X, so that the exhaust port is directly communicated with the liquid injection hole 12, the later welding operation is facilitated, and the assembly efficiency of the end cover assembly is improved.

According to some embodiments of the present application, referring to fig. 4, optionally, the preset track X is a straight track.

The straight track means that the exhaust port 14 extends linearly on the first surface 111 and has a certain direction as a whole. The extending direction of the straight track may or may not pass through the center of the liquid injection hole 12.

The preset track is designed into a linear track, which is not only beneficial to simplifying the opening operation of the exhaust port 14; and the welding operation of the exhaust port 14 is facilitated, and the welding sealing efficiency is improved.

Optionally, referring to fig. 4 and 5, the vent 14 includes a distal end 143 remote from the edge of the pouring orifice 12, and a first side 141 and a second side 142 connecting the distal end 143 and the edge of the pouring orifice 12. The first side 141 and the second side 142 have a space therebetween.

The first side 141 and the second side 142 may be welded together directly or indirectly. When a sufficient space is provided between the first side 141 and the second side 142, an intermediate structure may be provided between the first side 141 and the second side 142, and welding may be performed between the first side 141 and the intermediate structure, and between the second side 142 and the intermediate structure, so that the first side 141 and the second side 142 are connected through the intermediate structure, i.e. the first side 141 and the second side 142 are indirectly welded together; when the distance between the first side 141 and the second side 142 is narrower, the welding operation can be directly performed on the first side 141 and the second side 142 by the welding device, so that the first side 141 and the second side 142 are directly connected together.

The end 143 refers to an intersection point formed by gradually approaching the end of the first side 141 and the end of the second side 142, and is not the side of the vent 14 farthest from the injection hole 12. Of course, the portions of the first side 141 and the second side 142 near the end 143 may be spliced to form a linear short side, etc.

The space between the first side 141 and the second side 142 can realize direct welding or indirect welding of the welding mode of the exhaust port 14, so that the assembly of different end cover components is convenient to adapt, and the welding mode of the exhaust port 14 is more flexible.

Optionally, referring to fig. 4, the distance between the first side 141 and the second side 142 is denoted as W, where the distance W satisfies: 2 mm.ltoreq.W.ltoreq.8 mm to allow the first side 141 and the second side 142 to be indirectly welded together.

The spacing W is controlled to be 2-8 mm, so that the situation that the first side edge 141 and the second side edge 142 cannot be welded separately due to the fact that the spacing W is too small is avoided; when the pitch is too large, the number of welding positions to be performed on the exhaust port 14 increases, which increases the workload and also causes leakage from the welding positions, thereby deteriorating the sealing performance of the battery 1000.

The spacing W satisfies: any value of 2 mm.ltoreq.W.ltoreq.8mm, such as: the spacing W is preferably, but not limited to, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, etc.

The size of the interval W is reasonably controlled, and on the premise of realizing effective indirect welding, the welding workload is reduced, 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 preset trajectory X is denoted by L, where 2 mm.ltoreq.L.ltoreq.15 mm.

The longer the length L of the exhaust runner 13 along the preset trajectory X, the further the end of the exhaust runner 13 is away from the liquid injection hole 12, the lower the degree of contamination of the inside thereof with the electrolyte, so that the less, or even almost zero, vapor is generated during the welding closing operation. However, the exhaust flow channel 13 is too long in design, the structural strength of the end cap 10 becomes weak, and the structural deformation is easily generated by the expansion of the electrode assembly 50, thereby degrading the stability. At the same time, too long an exhaust runner 13 requires more welded seals, which also increases the risk of leakage in an invisible manner.

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

The length L of the exhaust runner 13 is reasonably controlled, so that the reduction of steam quantity during welding closing can be ensured, the generation of welding explosion point defects can be avoided, and the structural stability of the end cover 10 can be ensured.

Optionally, referring to fig. 6, the distance between the first side 141 and the second side 142 is denoted as W, where the distance W satisfies: w.ltoreq.0.5 mm.ltoreq.2 mm to allow the first side 141 and the second side 142 to be welded directly together.

The spacing W is controlled to be 0.5-2 mm, so that the phenomenon that the air displacement at the air outlet 14 is too low and the steam generated in the welding process cannot be effectively discharged due to the too small spacing W is avoided; however, the spacing W is too large, so that the first side 141 and the second side 142 cannot be directly welded, for example: when the distance W is larger than the width of the welding end of the welding apparatus, the welding end cannot be simultaneously applied to the first side 141 and the second side 142, and thus, a direct welding operation or the like cannot be achieved.

The spacing W satisfies: any value of W.ltoreq.2 mm is 0.5mm or less, such as: the spacing W is preferably, but not limited to, 0.5mm, 1mm, 1.5mm, 2mm, etc.

The size of the interval W is reasonably controlled, on the premise of realizing effective direct welding, the influence of the too small interval on the smooth exhaust is avoided, the stability of the formed welding seam structure is ensured, the occurrence of explosion point defects is avoided, and the sealing performance of the battery 1000 is improved.

Optionally, referring to FIG. 6, the length of the exhaust runner 13 along the predetermined trajectory X is denoted by L, where 1 mm.ltoreq.L.ltoreq.5 mm.

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

In addition, since the exhaust port 14 on the exhaust runner 13 is directly welded, the width of the exhaust port 14 is relatively narrow compared with the width of the exhaust port 14 indirectly welded, and the possibility of liquid contamination in the exhaust runner 13 is relatively low, the length of the exhaust runner 13 can be relatively short in design, i.e., the length of the exhaust runner 13 in direct welding can be lower than that of the exhaust runner 13 in indirect welding.

The length L is designed as follows: any value of 1 mm.ltoreq.L.ltoreq.5 mm, such as: the length L is preferably, but not limited to, 1mm, 2mm, 3mm, 4mm, 5mm, etc.

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

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

The bottom wall 131 guides the liquid into the liquid injection hole 12, so as to limit the liquid residue, and the implementation manner can be as follows: the bottom wall 131 is obliquely arranged, and the liquid on the bottom wall 131 flows back into the liquid injection hole 12 by utilizing the gradient; alternatively, the bottom wall 131 may be formed to be arched, and the splashed liquid may be caused to flow toward the pouring hole 12 by the arched arc.

The bottom wall 131 is designed to guide liquid into the liquid injection hole 12, limit liquid residue, facilitate reducing steam generated in welding at the air exhaust port 14, further avoid the defects of explosion point and the like at the welding closing position, and improve welding quality.

Optionally, referring to fig. 8, the bottom wall 131 is disposed obliquely with respect to the first surface 111 according to some embodiments of the present application. In the thickness direction of the plate body 11, an end of the bottom wall 131 away from the pouring orifice 12 is closer to the first surface 111.

The end that diapire 131 is close to annotating liquid hole 12 is less than the other end for diapire 131 wholly is towards annotating liquid hole 12 direction slope setting, can guarantee like this that liquid on diapire 131 drops into annotating liquid hole 12 along diapire 131, can not remain electrolyte after annotating liquid completion.

The bottom wall 131 is obliquely arranged, so that liquid on the bottom wall 131 falls to the liquid injection hole 12, liquid is not remained, steam is reduced or not generated during welding, the defects of explosion points and the like at the welding closing position are effectively avoided, and the welding quality is improved.

Alternatively, referring to FIG. 8, the angle between the bottom wall 131 and the thickness direction of the plate body 11 is denoted as θ, where 110 θ+.ltoreq.170 °.

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

The angle θ between the bottom wall 131 and the thickness direction of the plate main 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 the like.

The inclination of the bottom wall 131 is reasonably controlled, so that liquid on the bottom wall 131 smoothly falls into the liquid injection hole 12, and the bottom wall 131 is ensured not to remain liquid, so that the welding quality of the exhaust port 14 is improved.

Optionally, referring to fig. 4, according to some embodiments of the present application, the inner wall of the exhaust runner 13 further includes two side walls 132 spaced apart from the bottom wall 131. Each side wall 132 is connected with the inner wall of the liquid injection hole 12 in a circular arc transition manner.

The circular arc transition connection between the side wall 132 and the inner wall of the liquid injection hole 12 means: the side wall 132 and the inner wall of the pouring orifice 12 have a circular arc wall therebetween, so that the connection of the two is smoothly transited, which is advantageous in eliminating the internal stress between the side wall 132 and the inner wall of the pouring orifice 12.

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 the connection between the side wall 132 and the inner wall is reduced, and the stability of the whole structure of the end cover 10 is improved.

Optionally, referring to fig. 8, the liquid injection hole 12 includes a first liquid injection section 121 and a second liquid injection section 122 that are communicated with each other along a thickness direction of the plate body 11 according to some embodiments of the present application. The second priming section 122 is further from the exhaust port 14 than the first priming section 121. The exhaust runner 13 extends to a side wall of the first liquid injection section 121 so that the exhaust runner 13 communicates with the first liquid injection section 121.

The second liquid injection section 122 is away from the exhaust port 14 with respect to the first liquid injection section 121, that is, the second liquid injection section 122 is located below the first liquid injection section 121 in the thickness direction of the plate body 11; of course, it is also understood that: when the end cap assembly is placed over the housing 40, the second priming segment 122 is positioned closer to the housing 40 than the first priming segment 121.

The cross-sectional area of the second priming section 122 may or may not be consistent with the cross-sectional area of the first priming section 121. Such as: the cross-sectional area of the second priming section 122 is smaller than the cross-sectional area of the first priming section 121. For convenience of description, taking the circular structure as an example of the injection hole 12, the diameter of the second injection section 122 is smaller than that of the first injection section 121, and an end face 123 is provided between the second injection section 122 and the first injection section 121. In some embodiments, the angle α between the bottom wall 131 of the exhaust runner 13 and the end face 123 is 100+.alpha.ltoreq.160 °. At the same time, one end of the bottom wall 131 is higher or flush with the end face 123, so that liquid on the end face 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 in the later welding sealing process, so that the sealing performance on the end cover assembly is better.

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 main 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 main body 11 according to some embodiments of the present application.

The difference between the cross-sectional area of the second filling section 122 and the cross-sectional area of the first filling section 121 may be based on the physical dimensions 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 the liquid injection operation is convenient.

Referring to fig. 9 and 10, an end cap assembly is provided according to some embodiments of the present application. 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 liquid injection hole 12 and maintains communication between the exhaust runner 13 and the liquid injection hole 12. The exhaust port 14 is in a closed state.

The first sealing member 20 is a member capable of sealing one end of the pouring spout 12, and the connection between the first sealing member and the pouring spout 12 may be a welding type. The shape of the first seal 20 may be dependent on the shape of the pour spout 12, such as: round, oval, square, etc. Meanwhile, the structure of the first sealing member 20 may be variously selected, such as stainless steel nails, aluminum nails, etc.

The first seal 20, when sealed at one end of the liquid injection hole 12, cannot affect the communication relationship between the exhaust flow channel 13 and the liquid injection hole 12 because the vapor generated in the liquid injection hole 12 needs to be discharged to the exhaust port 14 through the exhaust flow channel 13 at the time of welding sealing. The first sealing member 20 does not affect the communication between the exhaust runner 13 and the liquid injection hole 12, and the implementation manner may be: the first sealing member 20 does not seal a port of the exhaust flow channel 13 when sealing on the liquid injection hole 12; alternatively, the first seal member 20 is provided with a corresponding hole so that the hole corresponds to one port of the exhaust flow path 13; alternatively, when the first seal 20 is sealed in the injection hole 12, a certain gap is provided between the circumferential direction of the first seal 20 and the injection hole 12, so as to ensure that steam flows between the injection hole 12 and the exhaust runner 13.

The exhaust port 14 is closed after the end cap assembly is formed, i.e., when the end cap assembly is applied to the battery cell 100 as a finished product, the exhaust port 14 is closed to prevent the electrolyte in the battery cell 100 from leaking out of the exhaust port 14. There are various ways of closing the exhaust port 14, for example: directly welding and sealing the exhaust port 14 by using welding equipment; alternatively, the intermediate structure is welded in the exhaust port 14 using a welding apparatus 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; and then the exhaust port 14 on the exhaust runner 13 is welded. After the operation, the steam welded at the liquid injection hole 12 can 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 runner 13 is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the explosion point defect of the liquid injection hole 12 in the welding sealing process is effectively avoided, and the sealing performance is improved.

In accordance with some embodiments of the present application, referring to fig. 11 and 12, optionally, the first sealing member 20 includes a first component 21 and a second component 22 disposed on the first component 21. The first member 21 seals one end of the pouring orifice 12, and the second member 22 seals the gas outlet 14.

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

The first seal 20 is designed in two parts: the first component 21 and the second component 22 can seal the liquid injection hole 12 and realize the sealing of the air outlet 14, thereby being beneficial to improving the assembly efficiency of the end cover assembly.

Optionally, referring to fig. 9 and 10, the end cap assembly further includes a second seal 30, according to some embodiments of the present application. The second seal 30 seals the other end of the pour spout 12.

The second sealing member 30 is a member capable of sealing one end of the pouring spout 12, and the connection between the second sealing member and the pouring spout 12 may be a welding type. The shape of the second seal 30 may be dependent on the shape of the fill port 12, such as: round, oval, square, etc. At the same time, there are various options for the construction of the second seal member 30, such as a rubber spike, which is inserted into one end of the pouring spout 12 at the time of sealing.

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

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

When the first sealing member 20 is placed in the liquid injection hole 12, a certain gap is formed between the periphery of the first sealing member 20 and the side wall of the liquid injection hole 12, so that the communication between the exhaust runner 13 and the liquid injection hole 12 is not affected when the first sealing member 20 is placed in the liquid injection hole 12.

A gap is provided between the first sealing member 20 and the liquid injection hole 12 to ensure communication between the exhaust runner 13 and the liquid injection hole 12, so that steam generated in the welding process can be always discharged from the exhaust runner 13.

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

s100, placing at least part of the first sealing element 20 in the liquid injection hole 12, and forming a first gap 23 between the first sealing element 20 and the side wall of the liquid injection hole 12;

and S200, welding the side walls of the first sealing piece 20 and the liquid injection hole 12, and welding the sealed exhaust port 14, wherein the final welding terminal point is positioned on the exhaust port 14.

The first gap 23 refers to a space defined as the first gap 23 between the periphery of the first seal 20 and the periphery of the pouring orifice 12 when the first seal 20 is placed over the pouring orifice 12.

In step S200, the final welding end point may be understood as the ending operation in the welding process on the end cover assembly, which is the last step of welding on the end cover assembly, and after this operation, the welding operation on the end cover assembly may be finished.

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

At least a portion of the first seal 20 disposed in the pour spout 12 is understood to be: the first seal 20 is used only to cover the pouring orifice 12; alternatively, the first seal 20 may cover the pour spout 12 in part and the vent 14 in part. When the first sealing member 20 covers both the pouring orifice 12 and the vent 14, the welding operation to the vent 14 is to weld the gap between the first sealing member 20 and the vent 14.

In the above-mentioned end cap assembly welding method, at least part of the first sealing member 20 is placed in the liquid injection hole 12 during the welding process, so as 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 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 runner 13 is small, the generated steam is weak or does not exist, and the welding seam in a molten state cannot be broken upwards, so that the explosion point defect of the liquid injection hole 12 in the welding sealing process is effectively avoided, and the sealing performance is improved.

Optionally, referring to fig. 14 and 15, S200, the step of welding the first sealing member 20 to the sidewall of the injection hole 12 and welding the airtight vent 14 includes:

s210, covering the first part 21 and the second part 22 of the first sealing element 20 in the liquid injection hole 12 and the air outlet 14 respectively, and enabling a first gap 23 to be formed between the first part 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 part 22 and the two side walls of the air outlet 14 respectively, wherein 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 piece 20;

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

The second gap 24 and the third gap 26 refer to a space defined by the second gap 24 and the third gap 26 between the periphery of the second member 22 and the periphery of the exhaust port 14 when the second member 22 is covered on the exhaust port 14. Meanwhile, the second gap 24 and the third gap 26 are both communicated with the first gap 23, and in this case, 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 in the first gap 23. In addition, a point at which an end of the first gap 23 remote from the pouring orifice 12 intersects an end of the second gap 24 remote from the pouring orifice 12 may be understood as a tip 143 of the gas outlet 14.

Either the second gap 24 or the third gap 26 serves as an initial weld location 25 such that as the weld head moves sequentially along the second gap 24 or the third gap 26 and the first gap 23 for welding, the weld head eventually moves back over the second gap 24 or the third gap 26 and a weld closure occurs at the initial weld location 25. In particular, in some embodiments, the initial weld 25 is disposed on the end of the second gap 24 remote from the first gap 23 such that the final weld closing point is further away from the pour hole 12, and the generated vapor is weaker or no vapor, resulting in better weld quality.

The specific welding process is as follows: starting welding from an initial welding position 25 on the second gap 24, and moving the welding head onto the first gap 23 along the second gap 24 to finish welding of the second gap 24, referring to fig. 15 (a); next, moving the welding head along the circumferential direction of the first gap 23 to complete all the welding on the first gap 23, referring specifically to fig. 15 (b); then, the 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 non-welded portion of the third gap 26, so as to complete all the welding operations between the first seal member 20 and the liquid injection hole 12, referring specifically to 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, and steam generated during welding closing is weaker or does not exist, and a welding seam in a melting shape is not broken upwards, so that the explosion point defect of the liquid injection hole 12 during welding sealing is effectively avoided, and the sealing performance is improved.

Optionally, referring to fig. 16 and 17, S200, the step of welding the first sealing member 20 to the sidewall of the injection hole 12 and welding the airtight vent 14 includes:

S240, forming a fourth gap 27 between the first side 141 and the second side 142 of the control exhaust port 14, wherein one end of the fourth gap 27 is communicated with the first gap 23;

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

and S260, continuing welding from the communication position of the fourth gap 27 and the first gap 23 to the end 143, far away from the liquid injection hole 12, of the fourth gap 27.

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

Any part of the first gap 23 serves as an initial welding position 25, so that when the welding heads sequentially move to the initial welding position 25 along the circumferential direction of the first gap 23, all welding on the first gap 23 is completed; then, starting from the connecting end between the first gap 23 and the fourth gap 27, all the welds on the fourth gap 27 can be moved along the fourth gap 27 and completed. It should be noted that, when the first gap 23 is welded, communication between the exhaust runner 13 and the liquid injection hole 12 should be ensured. In particular, in some embodiments, the initiation weld 25 is disposed on the connection end between the first gap 23 and the fourth gap 27 such that when the welding of the first gap 23 is completed, the weld head can be transferred directly to the fourth gap 27 without lifting the weld 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 a starting welding position 25 on the first gap 23, and moving the welding head to the starting welding position 25 again along the first gap 23 to finish all welding of the first gap 23, and referring to fig. 17 (a); next, all the welds on the fourth gap 27 are completed by moving the welding head from the connecting end between the first gap 23 and the fourth gap 27 and along the fourth gap 27, referring specifically to 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, so that steam generated during welding closing is weaker or does not exist, and a welding line in a molten state cannot be broken upwards, thereby effectively avoiding the explosion point defect of the liquid injection hole 12 during welding sealing and improving the sealing performance.

According to some embodiments of the present application, the present application provides a battery cell 100. 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 the end. The electrode assembly 50 is accommodated in the case 40. The end cap assembly covers the opening 41.

According to some embodiments of the present application, the present application provides a battery 1000 including the above battery cell 100.

According to some embodiments of the application, the application provides an electric device, including the battery in the above scheme, wherein the battery is used for providing electric energy.

Referring to fig. 4 to 17, a novel liquid injection hole 12 and aluminum nail structure are provided according to some embodiments of the present application. The liquid injection hole 12 adopts a slope step and an arc step design. And the sealing is realized by adopting a glue nail sealing mode and an aluminum nail laser welding mode, and the sealing is realized by the two modes. The first layer is sealed by a glue nail and mainly plays a role in preventing electrolyte from overflowing from the battery cell and solid particles from falling in when the laser cleans the liquid injection hole 12; the second layer adopts an aluminum nail welding sealing structure, the aluminum nail is of a 'table tennis racket' structure matched with the slope step and the arc step of the liquid injection hole 12, and the arc starting and receiving closure of laser welding is positioned at the 'racket handle', so that the defect of arc starting and receiving connection explosion points can be effectively avoided.

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

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

a plate main body (11) through which a liquid injection hole (12) is formed in the thickness direction of the plate main body; the plate main body (11) is further provided with an exhaust runner (13), the projection of the exhaust runner (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), so that the exhaust runner (13) is communicated with the liquid injection hole (12), an exhaust port (14) for communicating with the outside is formed on a first surface (111) of the plate main body (11), and the first surface (111) is a surface of the plate main body (11) far away from the inside of the battery cell;

the liquid injection hole (12) comprises a first liquid injection section (121) and a second liquid injection section (122) which are communicated in the thickness direction of the plate main body (11), the second liquid injection section (122) is far away from the exhaust port (14) relative to the first liquid injection section (121), and the exhaust runner (13) extends from part of the side wall of the first liquid injection section (121) towards the direction far away from the center of the liquid injection hole.

2. End cap (10) according to claim 1, wherein the vent (14) extends along a predetermined trajectory (X) onto the edge of the pouring orifice (12) on the first surface (111) of the plate body (11).

3. End cap (10) according to claim 2, wherein the predetermined trajectory (X) is a rectilinear trajectory.

4. The end cap (10) of claim 2, wherein the vent (14) includes a tip (143) distal from an edge of the pour spout (12), and a first side (141) and a second side (142) connecting the tip (143) and the edge of the pour spout (12), the first side (141) and the second side (142) having a spacing therebetween.

5. The end cap (10) of claim 4, wherein a spacing between the first side (141) and the second side (142) is denoted as W, the spacing W satisfying: w is more than or equal to 2mm and less than or equal to 8mm.

6. The end cap (10) of claim 4, wherein the length of the exhaust runner (13) along the predetermined trajectory (X) is denoted as L, wherein 2mm ∈l ∈15mm.

7. The end cap (10) of claim 4, wherein a spacing between the first side (141) and the second side (142) is denoted as W, the spacing W satisfying: w is more than or equal to 0.5mm and less than or equal to 2mm.

8. The end cap (10) of claim 7, wherein the length of the exhaust runner (13) along the predetermined trajectory (X) is denoted as L, wherein 1mm ∈l ∈5mm.

9. End cap (10) according to any of claims 1-8, wherein the inner wall of the vent flow channel (13) comprises a bottom wall (131) opposite the vent (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. End cap (10) according to claim 9, wherein the bottom wall (131) is arranged obliquely with respect to the first surface (111), and an end of the bottom wall (131) distant from the liquid injection hole (12) is closer to the first surface (111) in the thickness direction of the plate body (11).

11. The end cap (10) according to claim 10, wherein an angle between the bottom wall (131) and the thickness direction of the plate main body (11) is denoted as θ, wherein 110 ° Σ is equal to or less than 170 °.

12. The end cap (10) of claim 9, wherein the inner wall of the exhaust runner (13) further comprises two side walls (132) spaced apart from the bottom wall (131), each side wall (132) being in circular arc transition with the inner wall of the liquid injection hole (12).

13. The end cap (10) according to claim 1, wherein a cross-sectional area of the second liquid injection section (122) in a direction perpendicular to the thickness direction of the plate main 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 main body (11).

14. An end cap assembly, comprising:

the end cap (10) of any of claims 1-13;

a first sealing member (20) seals one end of the liquid injection hole (12) and maintains communication between the exhaust runner (13) and the liquid injection hole (12), and the exhaust port (14) is in a closed state.

15. The end cap assembly of claim 14, wherein the first seal member (20) comprises a first member (21) and a second member (22) coupled to the first member (21), the first member (21) sealing one end of the pour spout (12), the second member (22) sealing the vent (14).

16. The end cap assembly of claim 14, further comprising a second seal (30), the second seal (30) sealing the other end of the pour spout (12).

17. The end cap assembly according to claim 14, wherein a gap is provided between the first seal member (20) and the liquid injection hole (12) in a direction perpendicular to a thickness direction of the plate main body (11).

18. The end cap assembly of claim 14, wherein the first seal (20) seals the liquid injection hole (12) and the vent flow channel (13), and wherein a welding end point of the first seal (20) and the plate body (11) is located at the vent flow channel (13).

19. A method of welding an end cap assembly for use in preparing an end cap assembly according to any one of claims 14 to 18, comprising the steps of:

placing at least part of a first seal (20) in a pour hole (12) and forming a first gap (23) between the first seal (20) and a sidewall of the pour hole (12);

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

20. The end cap assembly welding method of claim 19, wherein the step of welding the side wall connecting the first seal member (20) and the liquid injection hole (12) and welding the sealing the exhaust port (14) includes:

covering a first part (21) and a second part (22) of the first sealing element (20) in the liquid injection hole (12) and the air outlet (14) respectively, and enabling a first gap (23) to be formed between the first part (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 part (22) and the two side walls of the air outlet (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 piece (20);

the welding is stopped at the start welding position (25).

21. The end cap assembly welding method of claim 19, wherein the step of welding the side wall connecting the first seal member (20) and the liquid injection hole (12) and welding the sealing the exhaust port (14) includes:

controlling a fourth gap (27) to be formed between a first side edge (141) and a 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 one of the first gaps (23) as an initial welding location (25), welding to the initial welding location (25) along an edge of the first seal (20);

continuing to weld from the fourth gap (27) to the end (143) of the fourth gap (27) remote from the pouring orifice (12) where it communicates with the first gap (23).

22. A battery cell, comprising:

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

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

end cap assembly according to any of claims 14-18, which end cap assembly covers the opening (41).

23. A battery comprising the cell of claim 22.

24. An electrical device comprising the battery of claim 23 for providing electrical energy.