Cylindrical battery cell, battery, and electric device

Abstract

A cylindrical battery cell (20), a battery (100), and an electrical device are disclosed. The cylindrical battery cell (20) includes: an electrode assembly (21) having a wound structure, the electrode assembly (21) including a first tab (212a); a housing (22) having an internally defined receiving space for accommodating the electrode assembly (21); and a current collector (23) including a first connecting portion (231) and a second connecting portion (232) connected together, the second connecting portion (232) being connected to the outer edge of the first connecting portion (231) and protruding in a direction away from the electrode assembly (21), the first connecting portion (231) being electrically connected to the first tab (212a), and the second connecting portion (232) being directly connected to the housing (22), the first connecting portion (231) having at least one first notch (231a) recessed from its outer edge toward the center, the first notch (231a) being used to connect the spaces on both sides of the first connecting portion (231) along its thickness direction. By providing a first notch (231a) on the current collector (23), the exhaust efficiency of the cylindrical battery cell (20) can be improved.

Description

Cylindrical battery cells, batteries and electrical devices

[0001] Cross-referencing

[0002] This disclosure incorporates, in its entirety, Chinese Patent Application No. 202421616683.9, filed on July 9, 2024, entitled “Cylindrical Battery Cell, Battery and Electrical Device”, which is incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a cylindrical battery cell, a battery, and an electrical device. Background Technology

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0005] During the charging and discharging process, the electrode components release a large amount of gas over a short period. If this gas cannot be quickly expelled from the battery cells, it may lead to combustion, explosion, or other problems. Therefore, improving the venting efficiency of battery cells has become an urgent problem to be solved.

[0006] Summary of the Invention

[0007] This application aims to at least solve one of the technical problems existing in the background art. Therefore, one object of this application is to provide a cylindrical battery cell, a battery, and an electrical device to improve the exhaust efficiency of the cylindrical battery cell.

[0008] An embodiment of the first aspect of this application provides a cylindrical battery cell, comprising: an electrode assembly having a wound structure, the electrode assembly including a first tab; a housing having an internally defined receiving space for accommodating the electrode assembly; and a current collector including a first connecting portion and a second connecting portion connected to each other, the second connecting portion being connected to the outer edge of the first connecting portion and protruding in a direction away from the electrode assembly, the first connecting portion being electrically connected to the first tab, the second connecting portion being directly connected to the housing, the first connecting portion having at least one first notch recessed from its outer edge toward the center, the first notch being used to connect the spaces on both sides of the first connecting portion along its thickness direction.

[0009] In the technical solution of this application embodiment, the first notch of the first connecting part is located on the outer side of the first connecting part near the shell, and the first notch connects the space on both sides of the first connecting part along its thickness direction, so that the first notch can connect the space between the electrode assembly and the side wall of the shell. In this way, the gas generated on the outside of the electrode assembly can be directly discharged through the first notch, reducing the exhaust distance of the gas generated on the outside of the electrode assembly and improving the exhaust efficiency. Furthermore, the second connecting part is connected to the outer edge of the first connecting part and protrudes in a direction away from the electrode assembly, which can offset the weld between the current collector and the shell from the first notch, improving the reliability of the current collector's flow and exhaust.

[0010] In some embodiments, the cylindrical battery cell further includes: an end cap located on the side of the current collector away from the electrode assembly and connected to the housing to close the opening of the receiving space; the end cap is provided with a pressure relief component, which is spaced apart from the first connecting portion and configured to break open when the internal pressure of the cylindrical battery cell reaches a preset threshold. The spaced arrangement of the end cap and the first connecting portion allows them to form a space with a certain height, providing sufficient exhaust channels for the discharged gas, further improving the exhaust efficiency of the cylindrical battery cell, while reducing the risk of the current collector deforming and touching the pressure relief component, thus improving the reliability of the pressure relief component.

[0011] In some embodiments, there are multiple second connecting portions, which are arranged at intervals along the outer periphery of the first connecting portion, with a second notch formed between adjacent second connecting portions. The second notch can provide a certain deformation capability for the second connecting portion, allowing the second connecting portion to fit tightly against the inner wall of the housing, thereby enhancing the reliability of the connection between the second connecting portion and the housing.

[0012] In some embodiments, the first notch and the second notch are interconnected. The second notch exposes the inner wall of the housing, and the first notch is connected to the second notch, allowing the first notch to directly communicate with the inner wall of the housing. This creates a larger space between the first notch and the inner wall of the housing, providing a larger exhaust channel for gas discharge and further improving the exhaust efficiency of the cylindrical battery cell.

[0013] In some embodiments, the number of first notches and second notches is multiple and equal, with each of the multiple first notches corresponding to a single multiple second notch. This improves the fit between the second connecting portion and the inner wall of the housing while simultaneously increasing the size of the venting channel formed at the first notch, which is beneficial for improving the stability of the cylindrical battery cell and thus enhancing the overall performance of the cylindrical battery cell.

[0014] In some embodiments, the housing includes a sidewall, and on a projection plane perpendicular to the winding axis of the electrode assembly, the orthographic projection of the gap between the electrode assembly and the inner wall surface of the sidewall at least partially coincides with the orthographic projection of the first notch. That is, the gap between the electrode assembly and the inner wall surface of the housing sidewall is directly opposite the first notch, allowing gas generated on the outside of the electrode assembly to be directly discharged through the first notch, further reducing the exhaust distance of the gas generated on the outside of the electrode assembly and further improving exhaust efficiency.

[0015] In some embodiments, the electrode assembly further includes a main body, a first tab located at the end of the main body along the winding axis of the electrode assembly, and a first connecting portion having a maximum diameter less than or equal to the inner diameter of the housing, but greater than the diameter of the main body. Thus, while enabling a second connecting portion on the outer periphery of the first connecting portion to be located within the housing and directly connected to the inner wall surface of the housing sidewall, the orthographic projection of the main body onto the first connecting portion is located within the first connecting portion. This allows the first notch of the first connecting portion to align with the gap between the main body and the inner wall surface of the housing sidewall, enabling gas generated on the outside of the electrode assembly to be directly discharged through the first notch.

[0016] In some embodiments, the first connecting portion further includes a through hole, which is disposed opposite to and communicates with the central hole of the electrode assembly. Thus, gas discharged from the electrode assembly into the central hole can be discharged through the through hole, reducing gas accumulation in the central hole and improving exhaust efficiency.

[0017] In some embodiments, the first connecting portion further includes a plurality of perforated grooves arranged circumferentially along the through hole, any one of which extends in a direction away from the through hole. The perforated grooves can also form an exhaust channel for gas inside the cylindrical battery cell, and the perforated grooves can reduce the structural strength of the current collector, so that when a large amount of gas is generated inside the electrode assembly and the pressure becomes too high, the current collector can rupture, thereby increasing the exhaust channel and further improving the exhaust efficiency of the cylindrical battery cell.

[0018] In some embodiments, at least one of the plurality of perforated slots communicates with a through hole. This allows gas discharged through the through hole to be guided to the perforated slot for discharge, providing guidance for the gas inside the cylindrical battery cell and reducing gas accumulation at the central hole. Furthermore, the perforated slots extend away from the through hole and communicate with it, making the first connecting portion more prone to rupture when the pressure inside the cylindrical battery cell becomes excessive, thus providing a certain degree of pressure relief and reducing the risk of the cylindrical battery cell exploding, thereby improving the safety of the cylindrical battery cell.

[0019] In some embodiments, the plurality of perforated slots include at least one first perforated slot and at least one second perforated slot. The first perforated slot communicates with a through hole, and the second perforated slot is spaced apart from the through hole. The first perforated slot and the second perforated slot are alternately spaced along the circumference of the first connecting portion. This can balance the exhaust channel area and structural strength on the current collecting component, thereby ensuring the stability of the cylindrical battery cell to a certain extent.

[0020] In some embodiments, the perforated groove and the first notch are alternately spaced along the circumference of the first connection portion. This maintains a certain distance between the perforated groove and the first notch, giving the first connection portion a certain strength, so that under normal internal pressure of the cylindrical battery cell, the current collector can form a stable electrical connection with the electrode assembly and the casing.

[0021] In some embodiments, the first connecting portion further includes at least one positioning hole, which extends through the first connecting portion along its thickness direction and is spaced apart from the through hole. By providing the positioning hole, the position of the current collector component docking with the electrode assembly and the housing can be quickly located during the installation of the current collector component into the housing, which is beneficial to improving the manufacturing efficiency of cylindrical battery cells and increasing production capacity.

[0022] In some embodiments, the housing includes a sidewall, the inner wall surface of which is parallel to the winding axis of the electrode assembly, and the second connecting portion is welded to the inner wall surface of the sidewall. This improves the connection strength between the second connecting portion and the sidewall, and also creates a certain venting space on the side of the first connecting portion near the second connecting portion, further improving the venting efficiency of the cylindrical battery cell.

[0023] In some embodiments, the cylindrical battery cell further includes: electrode terminals, which are insulated from and connected to the housing; wherein the electrode assembly includes a second electrode with a polarity different from that of the first electrode, and the second electrode is electrically connected to the electrode terminals. The electrodes with different polarities can effectively maintain a stable circuit state between the positive and negative electrodes of the cylindrical battery cell, enabling the cylindrical battery cell to operate normally.

[0024] An embodiment of the second aspect of this application provides a battery comprising the cylindrical battery cell described in the above embodiments.

[0025] An embodiment of the third aspect of this application provides an electrical device that includes the battery described in the above embodiments.

[0026] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0027] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0028] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0029] Figure 2 is an exploded structural diagram of a battery according to some embodiments of this application;

[0030] Figure 3 is a three-dimensional structural diagram of a cylindrical battery cell according to some embodiments of this application;

[0031] Figure 4 is a top view of the cylindrical battery cell according to some embodiments of this application;

[0032] Figure 5 is a schematic diagram of the cross-sectional structure along the AA direction in Figure 4;

[0033] Figure 6 is an enlarged structural diagram of the area within the dashed box in Figure 5;

[0034] Figure 7 is an exploded structural diagram of a cylindrical battery cell according to some embodiments of this application;

[0035] Figure 8 is a top view of the current collection component according to some embodiments of this application;

[0036] Figure 9 is a side view of the current collection component according to some embodiments of this application;

[0037] Figure 10 is a three-dimensional structural schematic diagram of the current collection component according to some other embodiments of this application;

[0038] Figure 11 is a top view of the current collection component according to some other embodiments of this application;

[0039] Figure 12 is a side view of the current collection component according to some other embodiments of this application;

[0040] Figure 13 is an exploded structural diagram of a cylindrical battery cell according to some other embodiments of this application.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1000 vehicles;

[0043] First hollowed-out groove 2341, second hollowed-out groove 2342;

[0044] Battery 100;

[0045] Controller 200, main body 211, electrode tab 212, first electrode tab 212a, second electrode tab 212b, center hole 213, electrode terminal 214, current collector 215, first connecting part 231, first notch 231a, second connecting part 232, second notch 232a, through hole 233, hollow groove 234, positioning hole 235, aluminum nail 261, glue nail 262;

[0046] Motor 300;

[0047] Box 10, Part 11, Part 2 12;

[0048] Cylindrical battery cell 20, electrode assembly 21, housing 22, current collector 23, pressure relief component 24, end cap 25, cover plate 26;

[0049] First angle R1, second angle R2. Detailed Implementation

[0050] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0051] Unless otherwise defined, 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0052] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0055] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0056] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0057] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0058] Under extreme conditions, cylindrical battery cells may experience thermal runaway, which can lead to the rapid decomposition of the electrolyte and other battery materials, generating a large amount of gas inside the casing. If the gas cannot be released in time, it can cause excessive pressure inside the cylindrical battery cell, resulting in a dangerous situation.

[0059] Gas can be generated at different points within the electrode assembly. In related technologies, to better expel the gas generated by the electrode assembly, the assembly has a central hole, through which all the gas generated by the assembly gathers and is then discharged. However, for gas generated on the outside of the electrode assembly, the distance to the central hole is greater, resulting in a longer gas flow path and consequently, the gas generated on the outside of the electrode assembly cannot be discharged in a timely manner.

[0060] Furthermore, due to the compact internal structure of the cylindrical battery cell casing, the gas flow path is easily blocked. For example, the cylindrical battery cell casing contains current collectors, and the current collectors themselves, as well as the weld marks formed by their welding to the tabs and electrode terminals, can obstruct the flow of gas, causing most of the gas to be confined in the gap between the casing and the electrode assembly, making it difficult for it to escape.

[0061] Based on the above considerations, a cylindrical single-cell unit is designed, including a shell, an electrode assembly located within the shell, and a current collector. The current collector includes a first connecting portion electrically connected to a first tab of the electrode assembly and a second connecting portion electrically connected to the shell. The first connecting portion has at least one first notch recessed from its outer edge towards the center. That is, the first notch is located on the outer side of the first connecting portion near the shell, and the first notch connects the spaces on both sides of the first connecting portion along the thickness direction, allowing the first notch to connect the space between the electrode assembly and the sidewall of the shell. In this way, gas generated on the outside of the electrode assembly can be directly discharged through the first notch, reducing the exhaust distance of the gas generated on the outside of the electrode assembly and improving exhaust efficiency. Furthermore, the second connecting portion is connected to the outer edge of the first connecting portion and protrudes away from the electrode assembly, which can offset the solder joint between the current collector and the shell from the first notch, improving the reliability of current flow and exhaust of the current collector.

[0062] The cylindrical battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using cylindrical battery cells and batteries as disclosed in this application. This is beneficial for improving the exhaust efficiency of the cylindrical battery cells and enhancing battery reliability.

[0063] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0065] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is installed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0066] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Please refer to Figure 2, which is an exploded structural diagram of a battery provided in some embodiments of this application. The battery 100 includes a housing 10 and cylindrical battery cells 20, with the cylindrical battery cells 20 housed within the housing 10. The housing 10 provides a accommodating space for the cylindrical battery cells 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a accommodating space for the cylindrical battery cells 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the accommodating space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the box 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0068] In battery 100, there can be multiple cylindrical battery cells 20. These multiple cylindrical battery cells 20 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple cylindrical battery cells 20 are connected in both series and parallel. Multiple cylindrical battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple cylindrical battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple cylindrical battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, battery 100 may also include a busbar component for realizing the electrical connection between multiple cylindrical battery cells 20.

[0069] Cylindrical battery cell 20 refers to the smallest unit that makes up a battery. Each cylindrical battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. Cylindrical battery cell 20 can be cylindrical, flat, cuboid, or other shapes. Unless otherwise specified, the embodiments of this application use a cylindrical battery cell as an example for illustration.

[0070] Referring to Figures 3 to 9, Figure 3 is a three-dimensional structural schematic diagram of a cylindrical battery cell according to some embodiments of the present application; Figure 4 is a top view structural schematic diagram of a cylindrical battery cell according to some embodiments of the present application; Figure 5 is a cross-sectional structural schematic diagram along the AA direction in Figure 4; Figure 6 is an enlarged structural schematic diagram of the area within the dashed box in Figure 5; Figure 7 is an exploded structural schematic diagram of a cylindrical battery cell according to some embodiments of the present application; Figure 8 is a top view structural schematic diagram of a current collector according to some embodiments of the present application; and Figure 9 is a side view structural schematic diagram of a current collector according to some embodiments of the present application.

[0071] This application provides a cylindrical battery cell, including: an electrode assembly 21, which is a wound structure, the electrode assembly 21 including a first tab 212a; a housing 22, which internally defines a receiving space for accommodating the electrode assembly 21; and a current collector 23, including a first connecting portion 231 and a second connecting portion 232 connected together, the second connecting portion 232 being connected to the outer edge of the first connecting portion 231 and protruding in a direction away from the electrode assembly 21, the first connecting portion 231 being electrically connected to the first tab 212a, the second connecting portion 232 being directly connected to the housing 22, the first connecting portion 231 having at least one first notch 231a recessed from its outer edge toward the center, the first notch 231a being used to connect the spaces on both sides of the first connecting portion 231 along its thickness direction.

[0072] The housing 22 is a component used to form the internal environment of the cylindrical battery cell 20, wherein the formed internal environment can accommodate the electrode assembly 21, electrolyte, and other components. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Exemplarily, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 21. The housing 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0073] Electrode assembly 21 is the component in the cylindrical battery cell 20 where the electrochemical reaction occurs. The housing 22 may contain one or more electrode assemblies 21. Electrode assembly 21 is mainly formed by winding and placing positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body 211 of the electrode assembly 21, while the portions of the positive and negative electrode plates without active material each constitute tabs 212. Tabs 212 may include a first tab 212a and a second tab 212b of different polarities, wherein the first tab 212a and the second tab 212b may be located together in a section of the main body 211 or respectively at both ends of the main body 211. The first tab 212a may be located on one of the positive or negative electrode plates, and the second tab 212b may be located on the other of the positive or negative electrode plates. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tab 212 connects to the electrode terminals to form a current loop.

[0074] The current collector 23 is electrically connected to the first tab 212a for outputting or inputting electrical energy from the cylindrical battery cell 20. The current collector 23 may be made of a conductive material, such as copper or a copper alloy.

[0075] The first connecting part 231 of the current collector 23 can be electrically connected to the first electrode 212a by welding, such as laser welding, ultrasonic welding or friction welding.

[0076] There is a gap between the electrode assembly 21 and the inner wall of the housing 22. The first notch 231a can connect the space between the electrode assembly 21 and the inner wall of the housing 22 and the space of the first connecting part 231 away from the electrode assembly 21.

[0077] In some embodiments, the orthographic projection of the gap between the electrode assembly 21 and the sidewall of the housing 22 onto the current collector 23 coincides with at least a portion of the first notch 231a. In other words, the entire first notch 231a communicates with the gap between the electrode assembly 21 and the inner wall of the housing 22, or a portion of the first notch 231a communicates with the gap between the electrode assembly 21 and the inner wall of the housing 22, while the remaining portion is covered by the electrode assembly 21.

[0078] In some embodiments, the number of first notches 231a may be only one. In other embodiments, the number of first notches 231a may also be multiple, for example, two, three, four or more.

[0079] In some embodiments, when there are multiple first notches 231a, the multiple first notches 231a can be evenly spaced along the circumference of the first connecting portion 231.

[0080] Referring to Figure 8, the angle between the lines connecting the two sides of the first notch 231a to the center of the first connecting part 231 is the first angle R1, and the first angle R1 corresponding to the multiple first notches 231a is equal.

[0081] In other embodiments, when there are multiple first notches 231a, the multiple first notches 231a may also be arranged at uneven intervals along the circumference of the first connecting portion 231. For example, the first angles R1 corresponding to the multiple first notches 231a may all be unequal, or only some of the first notches 231a may correspond to the same first angle R1.

[0082] In some embodiments, the first angle R1 can be 10 degrees (°) to 60 degrees.

[0083] In some embodiments, the shape of the first notch 231a may include, but is not limited to, regular or irregular shapes such as triangles, U-shapes, rectangles, semicircles, or polygons.

[0084] In some embodiments, the second connecting portion 232 may be perpendicular to the first connecting portion 231, so that the second connecting portion 232 fits more tightly against the inner wall of the housing 22.

[0085] In some embodiments, the height of the second connecting portion 232 can be from 1 mm to 3 mm, for example, it can be 1 mm, 2 mm, 2.5 mm or 3 mm. Within the above range, on the one hand, the second connecting portion 232 can form a large space with the first connecting portion 231, providing a large exhaust channel for the gas generated inside the cylindrical battery cell, and the area of ​​the second connecting portion 232 itself is large enough to form a large contact area with the housing 22, thereby forming a relatively stable electrical connection with the housing 22. On the other hand, the size of the second connecting portion 232 itself is not too large, so as not to occupy too much space inside the housing 22, keeping the structure of the cylindrical battery cell compact.

[0086] In the above technical solution, the first notch 231a of the first connecting portion 231 is located on the outer side of the first connecting portion 231 near the housing 22, and the first notch 231a connects the spaces on both sides of the first connecting portion 231 along its thickness direction, so that the first notch 231a can connect the space between the electrode assembly 21 and the housing 22. In this way, the gas generated on the outside of the electrode assembly 21 can be directly discharged through the first notch 231a, reducing the exhaust distance of the gas generated on the outside of the electrode assembly 21 and improving the exhaust efficiency. Furthermore, the second connecting portion 232 extends along the outer edge of the first connecting portion 231 and protrudes in a direction away from the electrode assembly 21, which can offset the solder mark between the current collector and the housing 22 from the first notch 231a, improving the reliability of the current collector's flow and exhaust.

[0087] Referring to Figures 5 to 7, in some embodiments, the cylindrical battery cell further includes an end cap located on the side of the current collector away from the electrode assembly and connected to the housing to close the opening of the receiving space; the end cap is provided with a pressure relief component, which is spaced apart from the first connection portion, and the pressure relief component is configured to break open when the internal pressure of the cylindrical battery cell reaches a preset threshold.

[0088] End cap 25 refers to a component that closes onto the opening of housing 22 to isolate the internal environment of cylindrical battery cell 20 from the external environment. The end cap may be located on the side of current collector 23 away from electrode assembly 21. Unrestricted, the shape of end cap 25 may be adapted to the shape of housing 22 to fit the housing 22. Housing 22 and end cap 25 may be separate components, with an opening provided on housing 22, and the end cap 25 closing the opening to form the internal environment of cylindrical battery cell 20. Unrestricted, end cap 25 and housing 22 may also be integrated. For example, end cap 25 and housing 22 may form a common connection surface before other components are inserted into the housing, and end cap 25 closes housing 22 only when the interior of housing 22 needs to be encapsulated.

[0089] The end cap 25 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0090] Referring to Figure 7, the pressure relief component 24 is located on the side of the current collector 23 away from the electrode assembly 21. The pressure relief component 24 is configured to break open when the internal pressure of the cylindrical battery cell reaches a certain threshold, allowing the gas inside the cylindrical battery cell to be released, thereby reducing the internal gas pressure.

[0091] The pressure relief component 24 can be located in a weak structure on the end cap 25. When the internal pressure of the cylindrical battery cell 20 increases to a certain level, the weak part of the structure will be destroyed first, allowing gas to be released and pressure relieved. In some embodiments, the pressure relief component 24 can be a weak part of the structure formed by one or more grooves provided at a designated position on the housing 22.

[0092] The end cap 25 and the first connecting part 231 are spaced apart so that they form a space with a certain height, providing sufficient exhaust channels for the discharged gas, further improving the exhaust efficiency of the cylindrical battery cell, while reducing the risk of the current collector 23 touching the pressure relief component 24 when it deforms, and improving the reliability of the pressure relief component 24.

[0093] Referring to Figures 10 to 13, Figure 10 is a three-dimensional structural schematic diagram of a current collector component according to some embodiments of the present application; Figure 11 is a top view structural schematic diagram of a current collector component according to some embodiments of the present application; Figure 12 is a side view structural schematic diagram of a current collector component according to some embodiments of the present application; and Figure 13 is an exploded structural schematic diagram of a cylindrical battery cell according to some embodiments of the present application.

[0094] According to some embodiments of this application, there are multiple second connecting portions 232, and the multiple second connecting portions 232 are arranged at intervals along the outer periphery of the first connecting portion 231, with a second notch 232a formed between adjacent second connecting portions 232.

[0095] The second notch 232a provides a certain degree of deformation capability for the second connecting part 232. When the second connecting part 232 extends into the inner wall of the housing 22, the second connecting part 232 can deform to adapt to the size of the housing 22, so that the second connecting part 232 can fit tightly with the inner wall of the housing 22, thereby improving the electrical connection performance between the second connecting part 232 and the inner wall of the housing 22.

[0096] In some embodiments, the number of second notches 232a may be only one. In other embodiments, the number of second notches 232a may be multiple, for example, two, three, four or more.

[0097] In some embodiments, when there are multiple second notches 232a, the multiple second notches 232a can be evenly spaced around the outer edge of the first connecting portion 231. Wherein, the angle between the lines connecting the two sides of the second notch 232a to the center of the first connecting portion 231 is the second angle R2, and the second angle R2 corresponding to the multiple second notches 232a is equal.

[0098] In other embodiments, when there are multiple second notches 232a, the multiple second notches 232a may also be arranged unevenly around the outer edge of the first connecting portion 231. For example, the second angles R2 corresponding to the multiple second notches 232a may all be unequal, or only some of the second notches 232a may correspond to the same second angle R2.

[0099] In some embodiments, the shape of the second notch 232a may include, but is not limited to, regular or irregular shapes such as triangles, U-shapes, rectangles, semicircles, or polygons.

[0100] It is understood that in other embodiments, the second connecting portion 232 may also extend along the outer edge of the first connecting portion 231 to form a ring.

[0101] In the above technical solution, the second notch 232a can provide a certain deformation capability for the second connecting part 232, so that the second connecting part 232 can fit tightly with the inner wall of the housing 22, thereby enhancing the reliability of the connection between the second connecting part 232 and the housing 22.

[0102] According to some embodiments of this application, the first notch 231a and the second notch 232a are interconnected.

[0103] The second connecting portion 232 is electrically connected to the inner wall of the housing 22. A second notch 232a is formed in the second connecting portion 232, allowing the inner wall of the housing 22 to be exposed. The first notch 231a communicates with the second notch 232a, allowing the first notch 231a to directly communicate with the inner wall of the housing 22. In other words, there is no second connecting portion 232 between the first notch 231a and the housing 22, which increases the gap between the first notch 231a and the housing 22.

[0104] The first gap 231a and the second gap 232a can be interconnected in such a way that the orthographic projection of the second gap 232a on the first connecting part 231 is located in the plane where the first gap 231a is located; or, the orthographic projection of the second gap 232a on the first connecting part 231 partially coincides with the plane where the first gap 231a is located.

[0105] In the above technical solution, a large space is formed between the first notch 231a and the inner wall of the casing 22, which can provide a larger exhaust channel for the gas to be discharged, and further improve the exhaust efficiency of the cylindrical battery cell.

[0106] It is understood that in some other embodiments, the first notch 231a and the second notch 232a may not be interconnected.

[0107] According to some embodiments of this application, the number of first notches 231a and second notches 232a is multiple and equal, and the multiple first notches 231a are configured in a one-to-one correspondence with the multiple second notches 232a.

[0108] A one-to-one correspondence means that the first gap 231a and the corresponding second gap 232a are connected. The definition of the connection between the first gap 231a and the second gap 232a can be found in the above description. For example, the number of both the first gap 231a and the second gap 232a can be four.

[0109] It is understood that in some other embodiments, the number of first gaps 231a may be greater than the number of second gaps 232a, and each second gap 232a corresponds to a different first gap 231a and is connected to the corresponding first gap 231a.

[0110] In some other embodiments, the number of first gaps 231a may be less than the number of second gaps 232a, and each first gap 231a corresponds to a different second gap 232a and is connected to the corresponding second gap 232a.

[0111] In the above technical solution, multiple first notches 231a and multiple second notches 232a are arranged in a one-to-one correspondence. On the one hand, each first notch 231a can form a large exhaust channel. On the other hand, the number of second notches 232a is not too many compared to the number of first notches 231a, so that the second connecting part 232 has sufficient size to form an electrical connection with the shell 22, which is beneficial to improving the stability of the cylindrical battery cell and thus improving the overall performance of the cylindrical battery cell.

[0112] According to some embodiments of this application, the housing 22 includes a sidewall, and on a projection plane perpendicular to the winding axis of the electrode assembly 21, the orthographic projection of the gap between the electrode assembly 21 and the inner wall surface of the sidewall at least partially coincides with the orthographic projection of the first notch 231a.

[0113] The sidewalls of the housing form a receiving space for accommodating the electrode assembly. A gap exists between the electrode assembly 21 and the inner wall surface of the sidewall, through which gas generated outside the electrode assembly 21 is discharged. The orthographic projection of the gap between the electrode assembly 21 and the inner wall surface of the sidewall at least partially coincides with the orthographic projection of the first notch 231a. That is, along the winding axis of the electrode assembly 21, the gap between the electrode assembly 21 and the inner surface of the sidewall is at least partially opposite to the first notch 231a.

[0114] In the above technical solution, the gap between the inner wall surface of the electrode assembly 21 and the side wall of the housing 22 is at least partially aligned with the first notch 231a, and the gas generated on the outside of the electrode assembly 21 can be directly discharged through the first notch 231a, further reducing the exhaust distance of the gas generated on the outside of the electrode assembly 21 and further improving the exhaust efficiency.

[0115] According to some embodiments of this application, the electrode assembly 21 further includes a main body 211, a first tab 212a located at the end of the main body 211 along the winding axis of the electrode assembly 21, and the maximum diameter of the first connecting portion 231 is less than or equal to the inner diameter of the housing 22 and greater than the diameter of the main body.

[0116] The maximum diameter of the first connecting portion 231 referred to here is the diameter of the portion of the first connecting portion 231 without the first notch 231a.

[0117] The maximum diameter of the first connecting part 231 is less than or equal to the inner diameter of the housing 22, that is, the first connecting part 231 can be located inside the housing 22. In this way, the second connecting part 232 connected to the edge of the first connecting part 231 can also be located inside the housing 22, so that the second connecting part 232 can be directly connected to the inner wall surface of the side wall of the housing 22.

[0118] It is understandable that when the maximum diameter of the first connecting portion 231 is smaller than the inner diameter of the housing 22, the included angle between the first connecting portion 231 and the second connecting portion 232 can be 90° or greater than 90°. When the included angle between the first connecting portion 231 and the second connecting portion 232 is 90°, the second connecting portion 232 can be completely fitted to the inner wall surface of the side wall of the housing. When the included angle between the first connecting portion 231 and the second connecting portion 232 is greater than 90°, the end of the second connecting portion 232 away from the first connecting portion 231 is connected to the inner wall surface of the side wall of the housing 22.

[0119] The maximum diameter of the first connecting portion 231 is greater than the diameter of the main body portion. That is, the orthographic projection of the main body portion on the first connecting portion 231 is located inside the first connecting portion 231, thereby enabling the first notch 231a of the first connecting portion 231 to be aligned with the gap between the main body portion and the inner wall surface of the side wall of the housing 22.

[0120] In the above technical solution, while enabling the second connecting part 232 on the outer periphery of the first connecting part 231 to be located inside the housing 22 and directly connected to the inner wall surface of the side wall of the housing 22, the gas generated on the outside of the electrode assembly 21 can be directly discharged through the first notch 231a.

[0121] Referring to Figures 5 and 8 to 12, according to some embodiments of this application, the first connecting portion 231 further includes a through hole 233, which is disposed opposite to and communicates with the center hole 213 of the electrode assembly 21.

[0122] The central hole 213 can be formed by winding the electrode sheet of the electrode assembly 21. The central hole 213 extends along the height direction of the cylindrical battery cell and penetrates the electrode assembly 21. The central hole 213 can be a cylindrical through hole 233, and the central axis of the central hole 213 can be coaxial with the central axis of the housing 22. Gas generated by the electrode assembly 21 can be discharged through the central hole 213.

[0123] The through hole 233 is positioned opposite to the center hole 213 of the electrode assembly 21, meaning that the orthographic projection of the center hole 213 on the first connecting portion 231 at least partially overlaps with the through hole 233.

[0124] The through hole 233 can be any shape, such as a rhombus or a circle.

[0125] In some embodiments, the number of through holes 233 may be one. In other embodiments, the number of through holes 233 may be multiple, and each through hole 233 is connected to the central hole 213.

[0126] In some embodiments, the through hole 233 may be located in the central region of the first connector, and the center line of the through hole 233 may coincide with the center line of the central hole 213.

[0127] In the above technical solution, the gas discharged from the electrode assembly 21 to the central hole 213 can be discharged through the through hole 233, reducing the accumulation of airflow in the central hole 213 and improving the exhaust efficiency.

[0128] Referring to Figures 8 to 12, according to some embodiments of this application, the first connecting portion 231 further includes a plurality of hollow grooves 234 arranged circumferentially along the through hole 233, any one of the plurality of hollow grooves 234 extending in a direction away from the through hole 233.

[0129] In some embodiments, a plurality of hollow grooves 234 can be evenly spaced along the circumference of the through hole 233, so that the plurality of hollow grooves 234 can evenly correspond to each part of the electrode assembly 21, and can provide an exhaust channel for the gas generated at each part of the electrode assembly 21.

[0130] In other embodiments, the plurality of hollow slots 234 may also be arranged at uneven intervals along the circumference of the through hole 233.

[0131] The perforated groove 234 extends in a long strip shape away from the through hole 233, giving the perforated groove 234 a larger area, which increases the amount of gas discharged from the perforated groove 234. Furthermore, the long strip design increases the speed at which gas is discharged from the perforated groove 234.

[0132] The number of perforated grooves 234 can be two, three, four, or more. For example, the number of perforated grooves 234 can be four. Within this range, on the one hand, a larger exhaust channel can be provided for the gas. On the other hand, the number of perforated grooves 234 in the first connecting part 231 is not too large, the area of ​​the non-perforated area in the first connecting part 231 is not too small, the strength of the first connecting part 231 itself is maintained at a high level, and a larger welding space can be provided for welding the first connecting part 231 and the first electrode tab 212a.

[0133] In some embodiments, when there are four slots 234, the four slots 234 can form a cross-shaped structure. That is, two slots 234 arranged opposite to each other extend in opposite directions. In this way, while maintaining the high strength of the first connecting part 231 and providing a large welding space for welding the first electrode tab 212a, the slots 234 can provide a uniform exhaust channel for the gas generated at various points of the electrode assembly 21.

[0134] In the above technical solution, the hollow groove 234 can also form an exhaust channel for the gas inside the cylindrical battery cell, and the hollow groove 234 can reduce the structural strength of the current collector 23, so that when a large amount of gas is generated inside the electrode assembly 21 and the pressure is too high, the current collector 23 can rupture, thereby increasing the exhaust channel.

[0135] According to some embodiments of this application, at least one of the plurality of hollowed-out grooves 234 is in communication with the through hole 233.

[0136] Among the multiple hollow slots 234, only one hollow slot 234 may be connected to one through hole 233, or more than one number of hollow slots 234 may be connected to through holes 233.

[0137] The connection between the perforated groove 234 and the through hole 233 allows for partial contact between the outer peripheries of the perforated groove 234 and the through hole 233. Because the perforated groove 234 and the through hole 233 are connected, a larger exhaust channel is provided for the gas, increasing the gas exhaust volume. Consequently, when the pressure inside the cylindrical battery cell reaches a certain threshold, the connected perforated groove 234 and through hole 233 are more prone to rupture, which helps accelerate the exhaust of gas from inside the cylindrical battery cell.

[0138] In some embodiments, if more than one number of slots 234 are connected to through holes 233, then at least two slots 234 connected to the through holes 233 are located on opposite sides of the through holes 233 and extend in a direction away from each other. That is, two opposite slots 234 are connected through the through holes 233 and are located on the same straight line, thus forming a longer strip shape, which can further increase the gas discharge speed at that location.

[0139] In the above technical solution, at least one of the multiple hollow grooves 234 is connected to the through hole 233. On the one hand, this allows the gas discharged through the through hole 233 to be guided to the hollow groove 234 for discharge, providing guidance for the gas inside the cylindrical battery cell and reducing the accumulation of airflow at the central hole 213. On the other hand, it makes the first connecting part 231 more prone to rupture when the pressure inside the cylindrical battery cell is too high, further reducing the risk of the cylindrical battery cell explosion and improving the safety of the cylindrical battery cell.

[0140] According to some embodiments of this application, the plurality of hollow slots 234 include at least one first hollow slot 2341 and at least one second hollow slot 2342. The first hollow slot 2341 communicates with the through hole 233, and the second hollow slot 2342 is spaced apart from the through hole 233. The first hollow slot 2341 and the second hollow slot 2342 are alternately spaced along the circumference of the first connecting portion 231.

[0141] The number of first hollow slots 2341 can be one or more. The number of second hollow slots 2342 can also be one or more. The number of first hollow slots 2341 can be equal to or different from the number of second hollow slots 2342.

[0142] In some embodiments, there are multiple first hollow slots 2341. Among the multiple first hollow slots 2341, at least two first hollow slots 2341 are located on opposite sides of the through hole 233, and the two first hollow slots 2341 extend in opposite directions.

[0143] In some embodiments, there are multiple second hollow slots 2342. Among the multiple second hollow slots 2342, at least two second hollow slots 2342 are located on opposite sides of the through hole 233, and the two second hollow slots 2342 extend in opposite directions.

[0144] For example, there can be two first hollow slots 2341 and two second hollow slots 2342. The two first hollow slots 2341 are located on opposite sides of the through hole 233 and extend in a direction away from each other. The two second hollow slots 2342 are located on opposite sides of the through hole 233 and extend in a direction away from each other. In one example, the two first hollow slots 2341 and the two second hollow slots 2342 can form a cross-shaped structure. That is, the line connecting the centers of the two first hollow slots 2341 can be perpendicular to the line connecting the centers of the two second hollow slots 2342. In this way, when the gas pressure inside the cylindrical battery cell reaches a certain threshold, the two connected first hollow slots 2341 are more likely to break, providing a better pressure relief channel inside the cylindrical battery cell. The two unconnected second hollow slots 2342 are less likely to break, so that the first connecting part 231 also has a certain structural strength, so that a stable electrical connection is formed between the first connecting part 231 and the first tab 212a.

[0145] The above technical solution can take into account both the exhaust channel area and structural strength on the current collector 23, thus ensuring the stability of the cylindrical battery cell to a certain extent.

[0146] According to some embodiments of this application, the hollowed-out groove 234 and the first notch 231a are alternately spaced along the circumference of the first connecting portion 231.

[0147] In other words, the first notch 231a can be directly aligned with the area between two adjacent perforated slots 234. This makes the shortest distance between the first notch 231a and the perforated slot 234 larger, which can, to some extent, avoid the problem that the area between the first notch 231a and the perforated slot 234 is prone to cracking due to the distance between them being too small.

[0148] It is understandable that the alternating arrangement of the hollowed-out groove 234 and the first notch 231a referred to here does not only include the case where one hollowed-out groove 234 and one first notch 231a are alternately arranged, that is, the hollowed-out groove 234 and the first notch 231a may not be in a one-to-one correspondence.

[0149] In some embodiments, the number of cutouts 234 can be greater than the number of first gaps 231a. In this case, a cutout 234 can be spaced between two adjacent first gaps 231a, and multiple cutouts 234 can be spaced between two adjacent first gaps 231a in other parts; or, multiple cutouts 234 can be spaced between each pair of adjacent first gaps 231a.

[0150] In some other embodiments, the number of cutouts 234 may be less than the number of first gaps 231a. In this case, a first gap 231a may be spaced between two adjacent cutouts 234, and multiple first gaps 231a may be spaced between two adjacent cutouts 234 in other parts; or, multiple first gaps 231a may be spaced between every two adjacent cutouts 234.

[0151] In some other embodiments, the number of hollowed-out grooves 234 is the same as the number of first notches 231a, so the hollowed-out grooves 234 and the first notches 231a can be alternately arranged.

[0152] In the above technical solution, a certain distance can be maintained between the hollow groove 234 and the first notch 231a, so that the first connecting part 231 has a certain strength. Under normal pressure inside the cylindrical battery cell, the current collector 23 can form a stable electrical connection with the electrode assembly 21 and the housing 22.

[0153] Referring again to Figures 8 to 12, according to some embodiments of this application, the first connecting portion 231 further includes at least one positioning hole 235, which extends through the first connecting portion 231 along the thickness direction and is spaced apart from the through hole 233.

[0154] When the second connecting part 232 is welded to the inner wall of the housing 22, a welding device can be used to weld the second connecting part 232 and the housing 22. When the current collecting member 23 is located inside the housing 22 and the second connecting part 232 is in contact with the inner wall of the housing 22, the welding device welds the outer periphery of the second connecting part 232 and the contact position of the inner wall of the housing 22.

[0155] The welding apparatus includes a welding head for applying welding energy to the second connecting portion 232 and the inner wall of the housing 22. The welding head needs to be aligned with the connection between the outer periphery of the second connecting portion 232 and the inner wall of the housing 22 for welding. In other words, when welding the second connecting portion 232 and the housing 22, the welding head needs to be aligned with the outer periphery of the second connecting portion 232.

[0156] The welding device may have a reference part corresponding to the positioning hole 235. When the welding device welds the current collecting member 23, the welding head of the welding device can be aligned with the outer periphery of the second connecting part 232 simply by aligning the positioning hole 235 with the reference part of the welding device, thereby enabling the welding position of the second connecting part 232 and the inner wall of the housing 22 to be quickly positioned.

[0157] In some embodiments, the alignment of the positioning hole 235 with the reference portion can be such that the positioning hole 235 is directly opposite the reference portion but does not contact it. In other embodiments, the alignment of the positioning hole 235 with the reference portion can also be such that the positioning hole 235 is fixed to the reference portion.

[0158] In some embodiments, the number of positioning holes 235 may be one. In other embodiments, the number of positioning holes 235 may be multiple, such as two, three or more.

[0159] In some embodiments, the positioning hole 235 may communicate with the hollowed-out groove 234, for example, it may communicate with the end of the second hollowed-out groove 2342 away from the through hole 233.

[0160] In other embodiments, the positioning hole 235 may not be connected to the hollowed-out groove 234.

[0161] In the above technical solution, by setting the positioning hole 235, the position of the current collector 23 docking with the electrode assembly 21 and the housing 22 can be quickly positioned during the process of installing the current collector 23 into the housing 22, which is conducive to improving the preparation efficiency of cylindrical battery cells and increasing production capacity.

[0162] According to some embodiments of this application, the housing 22 includes a sidewall, the inner wall surface of which is parallel to the winding axis of the electrode assembly 21, and the second connecting portion 232 is welded to the inner wall surface of the sidewall.

[0163] The second connecting part 232 can be connected to the inner wall surface of the side wall by means including but not limited to laser welding, ultrasonic welding or friction welding.

[0164] For example, the second connection part 232 and the inner wall surface of the side wall can be welded by any method such as internal welding or external welding to adapt to different welding needs and help ensure welding quality.

[0165] Internal welding refers to the laser being emitted from inside the housing 22 outwards, penetrating the second connecting portion 232 along a direction intersecting the winding axis of the electrode assembly 21, and forming a fusion portion between it and the sidewall. For example, the laser can be emitted in a direction perpendicular to the winding axis of the electrode assembly 21 to the second connecting portion 232. After penetrating the second connecting portion 232, the laser is then projected onto the housing 22, causing the second connecting portion 232 to be welded to the housing 22 to form a fusion portion. When using internal welding, the laser emission direction is towards the outside of the housing 22, which can avoid the laser hitting the electrode assembly during welding and causing electrode damage, thus improving the safety of the welding operation.

[0166] External welding refers to the laser beam entering the housing 22 from the outside and penetrating the second connection portion 232 along a direction intersecting the winding axis of the electrode assembly 21, forming a fusion portion between the laser and the sidewall. Using external welding allows for ample space for the laser to be positioned outside the battery, which improves the precision of laser welding and thus enhances welding quality.

[0167] The first connecting part 231 and the second connecting part 232 are not coplanar, so that the welded part formed by welding the second connecting part 232 and the inner wall surface of the side wall, as well as the connection position of the first connecting part 231 and the first electrode 212a, are located in different orientations, so as to avoid mutual interference during welding.

[0168] The above technical solution can improve the connection strength between the second connecting part and the side wall, and can form a certain exhaust space on the side of the first connecting part near the second connecting part, thereby further improving the exhaust efficiency of the cylindrical battery cell.

[0169] Referring to Figure 5, according to some embodiments of this application, the cylindrical battery cell further includes: an electrode terminal 214, which is insulated from the housing 22; wherein, the electrode assembly 21 includes a second electrode 212b with a polarity different from that of the first electrode 212a, and the second electrode 212b is electrically connected to the electrode terminal 214.

[0170] The first electrode tab 212a can be a positive electrode tab, and the second electrode tab 212b can be a negative electrode tab. Alternatively, the first electrode tab 212a can be a negative electrode tab, and the second electrode tab 212b can be a positive electrode tab.

[0171] The insulated connection between electrode terminal 214 and housing 22 means that electrode terminal 214 can be fixed to housing 22, but insulation is formed between them to reduce the risk of short circuit. In some embodiments, an insulating member may be provided on the inner side of housing 22 to isolate electrode terminal 214 and housing 22. Exemplarily, the insulating member may be plastic, rubber, etc.

[0172] Referring to Figures 5, 7 and 13, in some embodiments, the cylindrical battery cell further includes a current collector 215 located at the end of the housing 22 away from the current collector member 23.

[0173] The current collector 215 can be electrically connected to the second electrode tab 212b and is insulated from the housing 22, reducing the risk of short circuit. The current collector 215 can be electrically connected to the second electrode tab 212b by welding, such as laser welding, ultrasonic welding, or friction welding. The second electrode tab 212b can be electrically connected to the electrode terminal 214 through the current collector 215.

[0174] In some embodiments, the cylindrical battery cell may further include a cover plate 26 located on the side of the current collector 215 away from the electrode assembly 21, and covering the opening of the housing 22 away from the current collector 23. In some embodiments, the cover plate 26 may have an injection port for injecting electrolyte, such as battery electrolyte, into the cylindrical battery cell. The cover plate 26 may also have aluminum nails 261 and adhesive nails 262 for sealing the injection port, the adhesive nails 262 being sleeved on the outside of the aluminum nails 261 and connected and fixed integrally with the aluminum nails 261.

[0175] In the above technical solution, the tabs of different polarities can effectively maintain a stable circuit state between the positive and negative electrodes of the cylindrical battery cell, enabling the cylindrical battery cell to work normally.

[0176] This application provides a battery comprising the cylindrical battery cell described in the above embodiments.

[0177] The structure of the battery and cylindrical battery cell can be found in the descriptions in the above embodiments.

[0178] In the above technical solution, the reliability of the battery is improved because the exhaust efficiency of the cylindrical battery cell is increased.

[0179] This application provides an electrical device that includes the battery described in the above embodiments.

[0180] The battery is used to provide electrical power to the electrical device. A description of the electrical device can be found in the relevant descriptions in the above embodiments.

[0181] This application provides a cylindrical battery cell. Referring to Figures 3 to 6 and Figures 10 to 13, the cylindrical battery cell includes: an electrode assembly 21, which is a wound structure, and the electrode assembly 21 includes a first tab 212a; a housing 22, which internally defines a receiving space for accommodating the electrode assembly 21; and a current collector 23, including a first connecting portion 231 and a second connecting portion 232 connected together. The second connecting portion 232 is connected to the outer edge of the first connecting portion 231 and protrudes in a direction away from the electrode assembly 21. The second connecting portion 232 is perpendicular to the first connecting portion 231. The first connecting portion 231 is electrically connected to the first tab 212a, and the second connecting portion 232 is directly connected to the housing 22. The first connecting portion 231 has a plurality of first notches 231a recessed from its outer edge toward the center, and the first notches 231a are used to connect the spaces on both sides of the first connecting portion 231 along its thickness direction. There are multiple second connecting parts 232, which are arranged at intervals along the outer periphery of the first connecting part 231. A second gap 232a is formed between adjacent second connecting parts 232, and the second gap 232a is connected to the first gap 231a.

[0182] The number of first gaps 231a and second gaps 232a is multiple and equal, with each of the multiple first gaps 231a corresponding to one of the multiple second gaps 232a.

[0183] The first connecting part 231 also includes a through hole 233, which is correspondingly provided and connected to the center hole 213 of the electrode assembly 21.

[0184] The first connecting part 231 further includes: a first hollow groove 2341 and a second hollow groove 2342 arranged circumferentially along the through hole 233, wherein either the first hollow groove 2341 or the second hollow groove 2342 extends in a direction away from the through hole 233.

[0185] The first perforated groove 2341 is connected to the through hole 233, and the second perforated groove 2342 is spaced apart from the through hole 233. There are two first perforated grooves 2341, and the two first perforated grooves 2341 extend in opposite directions. There are also two second perforated grooves 2342, and the two second perforated grooves 2342 extend in opposite directions.

[0186] The first hollowed-out groove 2341 and the second hollowed-out groove 2342 are spaced apart from the first notch 231a along the circumferential direction of the first connecting portion 231.

[0187] The first connecting part 231 also includes two positioning holes 235, which are respectively connected to the ends of the two second hollowed-out grooves 2342 that are away from the through holes 233.

[0188] The cylindrical battery cell also includes: electrode terminal 214, which is insulated from the housing 22. The electrode assembly 21 includes a second electrode 212b with a polarity different from that of the first electrode 212a, and the second electrode 212b is connected to the electrode terminal 214.

[0189] The cylindrical battery cell also includes a current collector 215, which is located at the end of the housing 22 away from the current collector 23.

[0190] The collector plate 215 is electrically connected to the second electrode tab 212b by welding and is insulated from the housing 22.

[0191] The cylindrical battery cell also includes a cover plate 26, which is located on the side of the current collector 215 away from the electrode assembly 21 and covers the opening of the housing 22 away from the current collector 23. The cover plate 26 has an injection port and aluminum nails 261 and rubber nails 262 for sealing the injection port. The rubber nails 262 are sleeved on the outside of the aluminum nails 261 and are connected and fixed to the aluminum nails 261 as a whole.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cylindrical battery cell, comprising: The electrode assembly has a wound structure and includes a first electrode tab. The housing defines an internal space for accommodating the electrode assembly; as well as The current collector includes a first connecting portion and a second connecting portion connected together. The second connecting portion is connected to the outer edge of the first connecting portion and protrudes in a direction away from the electrode assembly. The first connecting portion is electrically connected to the first electrode tab, and the second connecting portion is directly connected to the housing. The first connecting portion has at least one first notch recessed from its outer edge toward the center. The first notch is used to connect the spaces on both sides of the first connecting portion along its thickness direction.

2. The cylindrical battery cell according to claim 1, wherein, Also includes: An end cap is located on the side of the current collector away from the electrode assembly and is connected to the housing to close the opening of the receiving space; The end cap is provided with a pressure relief component, which is spaced apart from the first connecting part and is configured to break open when the internal pressure of the battery cell reaches a preset threshold.

3. The cylindrical battery cell according to claim 1 or 2, wherein, The number of second connecting parts is multiple, and the multiple second connecting parts are arranged at intervals along the outer periphery of the first connecting part, with a second gap formed between adjacent second connecting parts.

4. The cylindrical battery cell according to claim 3, wherein, The first gap and the second gap are interconnected.

5. The cylindrical battery cell according to claim 4, wherein, The number of the first gap and the number of the second gap are multiple and equal, and the multiple first gaps are set in a one-to-one correspondence with the multiple second gaps.

6. The cylindrical battery cell according to any one of claims 1-5, wherein, The housing includes a sidewall, and on a projection plane perpendicular to the winding axis of the electrode assembly, the orthographic projection of the gap between the electrode assembly and the inner wall surface of the sidewall at least partially coincides with the orthographic projection of the first notch.

7. The cylindrical battery cell according to any one of claims 1-6, wherein, The electrode assembly further includes a main body, the first tab is located at the end of the main body along the winding axis of the electrode assembly, and the maximum diameter of the first connecting portion is less than or equal to the inner diameter of the housing, and greater than the diameter of the main body.

8. The cylindrical battery cell according to any one of claims 1-7, wherein, The first connecting part further includes: A through hole, which is disposed opposite to and communicates with the center hole of the electrode assembly.

9. The cylindrical battery cell according to claim 8, wherein, The first connecting part further includes: Multiple hollow grooves are arranged at intervals along the circumference of the through hole, and any one of the multiple hollow grooves extends in a direction away from the through hole.

10. The cylindrical battery cell according to claim 9, wherein, At least one of the plurality of hollowed-out grooves is connected to the through hole.

11. The cylindrical battery cell according to claim 9 or 10, wherein, The plurality of hollowed-out grooves include at least one first hollowed-out groove and at least one second hollowed-out groove. The first hollowed-out groove communicates with the through hole, and the second hollowed-out groove is spaced apart from the through hole. The first hollowed-out groove and the second hollowed-out groove are alternately spaced along the circumference of the first connecting portion.

12. The cylindrical battery cell according to any one of claims 9-11, wherein, The hollowed-out groove and the first notch are alternately spaced along the circumference of the first connecting part.

13. The cylindrical battery cell according to any one of claims 9-12, wherein, The first connecting portion further includes at least one positioning hole, which extends through the first connecting portion along its thickness direction and is spaced apart from the through hole.

14. The cylindrical battery cell according to any one of claims 1-13, wherein, The housing includes a sidewall, the inner wall surface of which is parallel to the winding axis of the electrode assembly, and the second connecting portion is welded to the inner wall surface of the sidewall.

15. The cylindrical battery cell according to any one of claims 1-14, wherein, Also includes: The electrode terminals are insulated from the housing. The electrode assembly includes a second electrode with a polarity different from that of the first electrode, and the second electrode is connected to the first electrode. The electrode terminals are electrically connected.

16. A battery comprising a cylindrical battery cell as claimed in any one of claims 1-15.

17. An electrical device comprising the battery as claimed in claim 16.

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