Battery cell, battery, and electrical device

Abstract

A battery cell (20), a battery (100), and an electrical device, relating to the field of batteries. The battery cell (20) comprises a casing (21), an electrode assembly (22), a current collecting member (23), and a pressure relief component (24); the casing (21) comprises an accommodating cavity, the electrode assembly (22) is located in the accommodating cavity, the electrode assembly (22) comprises a main body portion (221) and a tab (222) protruding from the main body portion (221), and the main body portion (221) has a central hole (2211) extending in the height direction of the battery cell (20) and running through the electrode assembly (22); the current collecting member (23) is located in the accommodating cavity and is electrically connected to the tab (222); the pressure relief component (24) is connected to the casing (21), and the side of the pressure relief component (24) facing the electrode assembly (22) is in fluid communication with the central hole (2211); the current collecting member (23) comprises at least one fluid channel (2313), and the fluid channel (2313) is configured to make a gap between the electrode assembly (22) and the casing (21) be in fluid communication with the central hole (2211). By providing the fluid channel (2313) in the current collecting member (23), a guiding effect can be provided for gas flow inside the battery cell (20), thereby facilitating guiding gas to the position of the pressure relief component (24) and achieving smooth gas venting.

Description

Battery cells, batteries and electrical devices

[0001] Cross-references

[0002] This application refers to Chinese Patent Application No. 202420559496.5, filed on March 21, 2024, entitled “Battery Cell, Battery and Electrical Device,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

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

[0005] During the charge and discharge process of a battery cell, the electrode assembly generates gas. This gas accumulates inside the battery cell, gradually increasing the pressure inside the cell and affecting the battery's safety. Therefore, it is necessary to vent the gas from a designated location when the pressure inside the battery cell reaches a certain level. However, the compact internal structure of the battery cell can hinder gas flow to a certain extent, resulting in poor or undirected exhaust.

[0006] Summary of the Invention

[0007] The present application aims to solve at least one of the technical problems existing in the background art. To this end, one object of the present application is to provide a battery cell, a battery and an electrical device to improve the problem of poor exhaust of the battery cell.

[0008] An embodiment of the first aspect of the present application provides a battery cell, comprising a shell, an electrode assembly, a current collecting component and a pressure relief component; the shell comprises a accommodating cavity, the electrode assembly is located in the accommodating cavity, the electrode assembly comprises a main body and a tab protruding from the main body, the main body has a central hole extending along the height direction of the battery cell and passing through the electrode assembly; the current collecting component is located in the accommodating cavity and is electrically connected to the tab; the pressure relief component is connected to the shell, and the side of the pressure relief component facing the electrode assembly is fluidically connected to the central hole; wherein the current collecting component comprises at least one fluid channel, and the fluid channel is constructed to fluidically connect the gap between the electrode assembly and the shell and the central hole.

[0009] In the technical solution of the embodiment of the present application, by providing a fluid channel in the current collecting component that connects the gap between the electrode assembly and the shell and the center hole, a guide can be provided for the gas flow inside the battery cell, thereby facilitating the gas to be directed to the location of the pressure relief component and achieving smooth exhaust.

[0010] In some embodiments, the current collecting member includes a first portion disposed opposite the central hole. A concave cavity is formed in the first portion of the current collecting member on a first surface facing the electrode assembly. The fluid channel is in fluid communication with the central hole via the concave cavity. The concave cavity allows for greater gas storage and simplifies the fluid connection between the fluid channel and the central hole, forming a more reliable gas-guiding channel.

[0011] In some embodiments, a first protrusion is formed on a first portion of a second surface of the current collecting member facing away from the electrode assembly, and the first protrusion is located on the back side of the cavity. Providing the first protrusion on the back side of the cavity can increase the thickness of the cavity, thereby enhancing the structural strength of the first portion of the current collecting member and improving the deformation resistance of the current collecting member.

[0012] In some embodiments, the first portion is provided with a through hole extending through the flow collecting member, and the orthographic projection of the central hole on the flow collecting member at least partially overlaps with the through hole. This facilitates the discharge of airflow within the central hole, preventing airflow from accumulating there, while also reducing kinetic energy loss, resulting in smoother exhaust and improved exhaust efficiency.

[0013] In some embodiments, the current collecting member further includes a second portion located on the periphery of the first portion and connected to the first portion. The first surface is provided with a groove in the second portion serving as a fluid passage. One end of the groove communicates with the concave cavity, and the other end communicates with the gap between the electrode assembly and the housing. This helps reduce the volume of the battery cell occupied by the current collecting member, thereby helping to increase the energy density of the battery cell.

[0014] In some embodiments, at least one second protrusion is formed on the first portion of the second surface of the current collecting member, which faces away from the electrode assembly. The second protrusion is located behind the groove and corresponds to the groove in a one-to-one manner. By providing the second protrusion on the back of the groove, a raised reinforcement rib is formed where the fluid channel is located, thereby enhancing the deformation resistance of the current collecting member and improving the quality of the battery cell.

[0015] In some embodiments, there are multiple fluid channels, which are spaced apart along the circumference of the flow collecting member. This can increase the exhaust volume and improve the exhaust efficiency, and make the exhaust more uniform.

[0016] In some embodiments, the second portion includes a plurality of tab connection portions spaced circumferentially and electrically connected to the tabs, with the fluid passage located between two adjacent tab connection portions. Placing the fluid passage between two adjacent tab connection portions allows the fixed connection between the tab connection portions to maintain the shape and flow of the fluid passage, thereby achieving reliable gas communication and improving exhaust flow.

[0017] In some embodiments, the fluid channel includes a first end in fluid communication with the central hole and a second end in fluid communication with the gap between the electrode assembly and the housing. The cross-sectional area of ​​the fluid channel gradually decreases from the first end to the second end. This can accelerate the flow rate and create a pressure drop as the air flows from the gap between the electrode assembly and the housing toward the center of the current collecting member, thereby achieving better convergence and guidance, and smoother exhaust.

[0018] In some embodiments, the housing includes a housing body and an end cap, the housing body defining a receiving cavity and an opening at one end of the receiving cavity; the end cap is connected to the housing body to cover the opening; and the pressure relief component is located on the end cap, with an orthographic projection of the center hole on the end cap at least partially overlapping the pressure relief component. Positioning the pressure relief component on the end cap opposite the center hole facilitates directional valve opening and improves the reliability of valve opening by the pressure relief component.

[0019] In some embodiments, the tabs include a first tab and a second tab of different polarity, respectively located at opposite ends of the main body along the extension direction of the central hole. The current collecting member is either a first current collecting member electrically connected to the first tab or a second current collecting member electrically connected to the second tab. Positioning the tabs of different polarity and the corresponding current collecting members at opposite ends of the electrode assembly facilitates connection during assembly and facilitates the introduction of gas into the central hole, improving gas discharge efficiency.

[0020] An embodiment of the second aspect of the present application provides a battery, which includes the battery cell in the above embodiment.

[0021] An embodiment of the third aspect of the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the drawings without paying creative work.

[0024] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0025] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0026] FIG3 is a schematic structural diagram of a battery cell according to some embodiments of the present application;

[0027] FIG4 is a cross-sectional view taken along the AA direction in FIG3 ;

[0028] FIG5 is a schematic structural diagram of a current collecting component in some embodiments of the present application;

[0029] FIG6 is a cross-sectional view taken along the BB direction in FIG5;

[0030] FIG7 is a cross-sectional view taken along the CC direction in FIG5 ;

[0031] FIG8 is a side view along the D direction in FIG5;

[0032] FIG9 is a top view of a current collecting component according to some embodiments of the present application;

[0033] FIG10 is a schematic structural diagram of current collecting components according to other embodiments of the present application.

[0034] Explanation of the accompanying drawings: Vehicle 1000; Battery 100, Controller 200, Motor 300; Housing 10, First Part 11, Second Part 12; Battery Cell 20, Shell 21, Shell Body 211, End Cap 212, Electrode Assembly 22, Main Body 221, Center Hole 2211, Tab 222, First Tab 2221, Second Tab 2222, Current Collecting Member 23, First Current Collecting Member 231, Second Current Collecting Member 232, First Surface 231A, Second Surface 231B, First Part 2311, Second Part 2312, Fluid Channel 2313, Concave Cavity 2311A, First Protrusion 2311B, Groove 2312A, Second Protrusion 2312B, Through-hole 2314, Tab Connecting Portion 2315, Pressure Relief Component 24, Electrode Terminal 25. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0038] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0040] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0041] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0042] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0043] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0044] The electrode assembly of a battery cell generates gas during the charge and discharge process. To prevent excessive gas from causing excessive pressure inside the battery cell and potentially causing accidents, a pressure relief component can be installed on the battery cell so that the gas inside the battery cell can be discharged from the location of the pressure relief component when the pressure reaches a certain level. However, due to the compact internal structure of the battery cell shell, the path for gas flow is easily blocked. For example, in a cylindrical battery cell, both ends of the electrode assembly are fixedly connected to a disc-shaped current collecting member. The current collecting member itself and the weld marks formed by welding it to the tabs and electrode terminals will block the flow direction of the gas, so that most of the gas is confined to the gap between the shell and the electrode assembly, making it difficult for the gas to reach the location of the pressure relief component, resulting in poor exhaust or undirected exhaust.

[0045] In order to alleviate the problem of poor exhaust, a fluid channel can be designed to provide a path for the gas flow within the battery cell, so that the gas generated by the electrode assembly can flow smoothly to the location of the pressure relief component, and when the pressure reaches a certain level, the pressure relief component will rupture and be discharged from the interior of the battery cell.

[0046] Based on this, an embodiment of the present application provides a battery cell, comprising a housing, an electrode assembly, a current collecting member, and a pressure relief member. The housing includes a housing cavity, the electrode assembly is located within the housing cavity, the electrode assembly includes a main body and a tab protruding from the main body, the main body having a central hole extending along the height direction of the battery cell and penetrating the electrode assembly. The current collecting member is located within the housing cavity and electrically connected to the tab. The pressure relief member is connected to the housing, and the side of the pressure relief member facing the electrode assembly is in fluid communication with the central hole. The current collecting member includes at least one fluid channel, which is configured to fluidically connect the gap between the electrode assembly and the housing with the central hole. By providing a fluid channel in the current collecting member that connects the gap between the electrode assembly and the housing with the central hole, a guiding effect can be provided for gas flow within the battery cell, thereby facilitating the gas flow to the location of the pressure relief member, thereby achieving smooth exhaust.

[0047] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to alleviate poor exhaust flow in the battery cells and improve battery reliability.

[0048] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0049] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0050] Please refer to Figure 1, which is a schematic diagram of the structure of the vehicle provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an 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 power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0051] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0052] Please refer to Figure 2, which is a schematic diagram of the exploded structure of a battery provided in some embodiments of the present application. Battery 100 includes a housing 10 and battery cells 20, with battery cells 20 housed within housing 10. Housing 10 is used to provide storage space for battery cells 20 and can have various structures. In some embodiments, housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for battery cells 20. Second portion 12 can be a hollow structure with one end open. First portion 11 can be a plate-like structure, with first portion 11 overlapping the open side of second portion 12, so that the first and second portions 11 and 12 together define a storage space. Alternatively, first portion 11 and second portion 12 can each be a hollow structure with one end open, with the open side of first portion 11 overlapping the open side of second portion 12. Of course, housing 10 formed by first portion 11 and second portion 12 can have various shapes, such as a cylinder or a rectangular parallelepiped.

[0053] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0054] A battery cell 20 is the smallest unit that makes up a battery. Each 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 thereto. A battery cell 20 can be cylindrical, flat, rectangular, or in other shapes. Unless otherwise specified, the embodiments of this application use cylindrical battery cells as an example.

[0055] Please refer to Figures 3 to 5. Figure 3 is a structural schematic diagram of a battery cell provided in some embodiments of the present application. Figure 4 is a cross-sectional view along the AA direction in Figure 3. Figure 5 is a structural schematic diagram of a current collecting component provided in some embodiments of the present application.

[0056] An embodiment of the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22, a current collecting component 23 and a pressure relief component 24; the shell 21 includes a accommodating cavity, the electrode assembly 22 is located in the accommodating cavity, the electrode assembly 22 includes a main body 221 and a pole ear 222 protruding from the main body 221, the main body 221 has a central hole 2211 extending along the height direction of the battery cell 20 and passing through the electrode assembly 22; the current collecting component 23 is located in the accommodating cavity and is electrically connected to the pole ear 222; the pressure relief component 24 is connected to the shell 21, and the side of the pressure relief component 24 facing the electrode assembly 22 is fluidically connected to the central hole 2211; wherein, the current collecting component 23 includes at least one fluid channel 2313, and the fluid channel 2313 is constructed to fluidically connect the gap between the electrode assembly 22 and the shell 21 and the central hole 2211.

[0057] The housing 21 is a component used to form the internal environment of the battery cell 20, wherein this internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 21 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylinder, a hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined by the specific shape and size of the electrode assembly 22. The housing 21 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0058] The electrode assembly 22 is the component within the battery cell 20 where the electrochemical reaction occurs. The housing 21 may contain one or more electrode assemblies 22. The electrode assembly 22 is primarily formed by winding or stacking positive and negative electrode sheets, typically with a separator between the two sheets. The portions of the positive and negative sheets containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive and negative sheets without active material each constitute a tab 222. The tabs 222 protrude from the main body 221 to facilitate connection with the current collecting member 23. Tabs of different polarity can be located together at one end of the main body 221 or separately at opposite ends. During the battery's charge and discharge processes, the positive and negative active materials react with the electrolyte, and the tabs 222 connect to the electrode terminals 25 to form a current circuit. The center of the electrode assembly 22 has a central hole 2211 formed by the wound electrode sheets. This hole 2211 extends along the height of the battery cell 20 and penetrates the electrode assembly 22. The center hole 2211 may be a cylindrical through hole, and the central axis of the center hole 2211 may be coaxial with the central axis of the housing 21. It is understood that to facilitate the insertion of the electrode assembly 22 into the housing and to accommodate the electrolyte, the inner diameter of the housing 21 is larger than the outer diameter of the electrode assembly 22, which results in a certain gap between the electrode assembly 22 and the housing 21.

[0059] The current collecting members 23 are components that electrically connect the tabs 222 and the electrode terminals 25. They include a first current collecting member 231 and a second current collecting member 232, each connected to a tab of different polarity. The first and second current collecting members 231 and 232 can be positioned according to the location of the corresponding tabs, for example, at either end of the main body 221. The current collecting members 23 can be made of a conductive material, such as copper or a copper alloy. The current collecting members 23 can be electrically connected to the tabs 222 or the electrode terminals 25 using welding methods, such as laser welding, ultrasonic welding, or friction welding. The current collecting component 23 includes a first surface 231A facing the electrode assembly 22 and a second surface 231B facing away from the electrode assembly 22. The fluid channel 2313 can be set on the first surface 231A or the second surface 231B. The two ends of the fluid channel 2313 are respectively connected to the center hole 2211 and the gap between the electrode assembly 22 and the shell 21, so that the gas generated by the electrode assembly 22 can flow from the gap between the electrode assembly 22 and the shell 21 to the center hole 2211, and flow to the position of the pressure relief component 24 through the center hole 2211.

[0060] The pressure relief component 24 is configured to rupture when the internal pressure of the battery cell 20 reaches a certain threshold, allowing the gas inside the battery cell 20 to escape, thereby reducing the internal air pressure. The pressure relief component 24 can be a separate component connected to the housing 21, or it can be integrally formed on the housing 21. For example, a structurally weakened portion can be formed on the housing 21 to serve as the pressure relief component 24. When the internal pressure of the battery cell 20 increases to a certain level, the structurally weakened portion will be the first to rupture, allowing the gas to escape and relieve the pressure. In some embodiments, the pressure relief component 24 can be a structurally weakened portion formed by one or more notched grooves provided at designated locations on the housing 21.

[0061] By providing a fluid channel 2313 in the current collecting component 23 that connects the gap between the electrode assembly 22 and the shell 21 and the center hole 2211, guidance can be provided for the gas flow inside the battery cell 20, thereby facilitating guiding the gas to the position where the pressure relief component 24 is located, thereby achieving pressure relief at the designated position and smooth exhaust.

[0062] Please refer to Figures 5 to 8. Figure 5 is a structural schematic diagram of the current collecting component of some embodiments of the present application; Figure 6 is a cross-sectional view along the BB direction in Figure 5; Figure 7 is a cross-sectional view along the CC direction in Figure 5; and Figure 8 is a side view along the D direction in Figure 5.

[0063] According to some embodiments of the present application, the current collecting member 23 includes a first portion 2311 arranged opposite to the central hole 2211, and a first surface 231A of the current collecting member 23 facing the electrode assembly 22 is formed with a cavity 2311A in the first portion 2311; the fluid channel 2313 is fluidically connected to the central hole 2211 through the cavity 2311A.

[0064] As shown in Figures 5 and 6, the current collecting member 23 can be either a first current collecting member 231 or a second current collecting member 232. The first portion 2311 can be located in the center of the current collecting member 23 and opposite the center hole 2211. The first surface 231A is recessed inward from the first portion 2311 to form a cavity 2311A. The cross-sectional shape of the cavity 2311A can be any shape, such as a circle, a polygon, or other irregular shape. The fluid channel 2313 can be directly connected to the cavity 2311A, thereby achieving fluid communication with the center hole 2211. The fluid channel 2313 can be connected to the sidewall of the cavity 2311A or to the top of the cavity 2311A. In some embodiments, the second surface 231B can be a flat surface. This allows the overall thickness of the current collecting member 23 to be reduced, even though the thickness of the current collecting member 23 is relatively thin at the location of the cavity 2311A, thereby increasing the energy density of the battery cell 20.

[0065] By providing the cavity 2311A, a gas accommodating space can be formed between the electrode assembly 22 and the current collecting member 23, which is convenient for storing more gas. At the same time, it can also simplify the fluid connection between the fluid channel 2313 and the central hole 2211, forming a more reliable gas guiding channel.

[0066] According to some embodiments of the present application, as shown in FIG. 6 , a first protrusion 2311B is formed on a first portion 2311 of a second surface 231B of the current collecting member 23 facing away from the electrode assembly 22 . The first protrusion 2311B is located on the back side of the cavity 2311A.

[0067] The first protrusion 2311B and the concave cavity 2311A are respectively located on two surfaces of the same part of the current collecting member 23 and can be formed by one-step processing. For example, the first protrusion 2311B and the concave cavity 2311A can be obtained by stamping the first portion 2311 in the central area of ​​the flat current collecting member 23 .

[0068] The current collecting member 23 may be a first current collecting member 231, and a second surface 231B of the first current collecting member 231 may be electrically connected to the electrode terminal 25. In some embodiments, the electrode terminal 25 may be welded to the upwardly protruding first protrusion 2311B of the current collecting member 23, so that the welding position of the electrode terminal 25 can be staggered with the welding position of the tab 222, thereby preventing mutual influence between the two.

[0069] Providing the first protrusion 2311B on the back side of the cavity 2311A can increase the thickness of the cavity 2311A, thereby enhancing the structural strength of the first portion 2311 of the current collecting member 23 and improving the deformation resistance of the current collecting member, while also facilitating the connection between the current collecting member 23 and the electrode terminal 25.

[0070] According to some embodiments of the present application, as shown in FIG. 4 and FIG. 5 , the first portion 2311 is provided with a through hole 2314 penetrating the current collecting member 23 , and the orthographic projection of the central hole 2211 on the current collecting member 23 at least partially overlaps with the through hole 2314 .

[0071] Through hole 2314 can be any shape, such as a circle. There can be one or more through holes 2314. In some embodiments, through hole 2314 is located in the center of flow collecting member 23, and the centerline of through hole 2314 can coincide with the centerline of center hole 2211. This allows gas collected in fluid channel 2313 to flow through through hole 2314 to the location of pressure relief component 24 on housing 21.

[0072] The through hole 2314 that at least partially overlaps the center hole 2211 is provided to facilitate the discharge of the airflow in the center hole 2211 and flow it to the location of the pressure relief component 24 to prevent the airflow from accumulating in the center hole 2211. In addition, it can also reduce the kinetic energy loss of the airflow, making the exhaust smoother and improving the exhaust efficiency.

[0073] According to some embodiments of the present application, as shown in Figures 5 and 7, the current collecting member 23 also includes a second part 2312 located at the periphery of the first part 2311 and connected to the first part 2311, and the first surface 231A is provided with a groove 2312A serving as a fluid channel 2313 in the second part 2312, one end of the groove 2312A is connected to the concave cavity 2311A, and the other end is connected to the gap between the electrode assembly 22 and the shell 21.

[0074] The groove 2312A is a groove-like structure formed by the depression of the first surface 231A. The groove 2312A can extend in the radial direction of the current collecting member 23. The groove 2312A can be a straight line or a curve, such as an arc or a wavy line. One end of the groove 2312A is connected to the cavity 2311A, and the other end is connected to the gap between the electrode assembly 22 and the shell 21. In this way, the gas accumulated in the gap between the electrode assembly 22 and the shell 21 can flow to the cavity 2311A through the groove 2312A, and then flow to the center hole 2211 through the cavity 2311A, and then flow from the center hole 2211 to the location of the pressure relief component 24.

[0075] The groove 2312A can form the fluid channel 2313 without increasing the thickness of the current collecting member 23 , which helps reduce the volume of the battery cell occupied by the current collecting member 23 , thereby helping to improve the energy density of the battery cell.

[0076] According to some embodiments of the present application, as shown in Figures 5, 7 and 8, the second surface 231B of the current collecting member 23 facing away from the electrode assembly 22 is formed with at least one second protrusion 2312B in the second portion 2312, and the second protrusion 2312B is located on the back side of the groove 2312A and is arranged one-to-one with the groove 2312A.

[0077] The second protrusion 2312B and the groove 2312A are located on two surfaces at the same position on the current collecting member 23. The number of second protrusions 2312B can be one or more, and can specifically be the same as the number of grooves 2312A. In some embodiments, the second protrusion 2312B and the groove 2312A can be formed by stamping the disc-shaped current collecting member 23. In other embodiments, the height of the second protrusion 2312B can be the same as that of the first protrusion 2311B, thereby improving the utilization of the internal space of the battery cell.

[0078] By providing the second protrusion 2312B on the back side of the groove 2312A, a protruding reinforcement rib can be formed where the fluid channel 2313 is located, thereby enhancing the deformation resistance of the current collecting member 23 and improving the quality of the battery cell.

[0079] According to some embodiments of the present application, as shown in FIG. 5 , there are multiple fluid channels 2313 , and the multiple fluid channels 2313 are arranged at intervals along the circumference of the flow collecting component 23 .

[0080] The plurality of fluid channels 2313 may be evenly spaced around the circumference of the concave cavity 2311A. The plurality of fluid channels 2313 may have the same or different structures. In some embodiments, the fluid channels 2313 may be disposed on the second portion 2312 of the current collecting member 23 or on the sidewalls of the concave cavity 2311A formed in the first portion 2311 of the current collecting member 23.

[0081] Providing multiple fluid channels 2313 spaced apart along the circumference can guide the airflow in the gaps at different circumferential positions within the battery cell 20. This can increase the exhaust volume and improve the exhaust efficiency on the one hand, and make the exhaust more uniform on the other.

[0082] Please refer to FIG. 9 , which is a top view of the current collecting component in some embodiments of the present application.

[0083] According to some embodiments of the present application, the second portion 2312 includes a plurality of tab connecting portions 2315 that are circumferentially spaced apart and electrically connected to the tabs 222 , respectively. The fluid channel 2313 is located between two adjacent tab connecting portions 2315 .

[0084] The tab connection portion 2315 is used to connect to the tab 222. The specific connection method can be laser welding or ultrasonic welding, so that the tab 222 and the tab connection portion 2315 of the current collecting member 23 are melted and connected together. The size and shape of the multiple tab connection portions 2315 can be the same or different. In some embodiments, the tab connection portions 2315 and the fluid channels 2313 are arranged in a sequentially spaced manner along the circumference.

[0085] The fluid channel 2313 is arranged between two adjacent tab connecting portions 2315 , and the shape and fluidity of the fluid channel 2313 can be maintained by the fixed connection between the tab connecting portion 2315 and the tab 222 , thereby achieving reliable gas communication and improving the smoothness of exhaust.

[0086] Please refer to FIG. 10 , which is a schematic structural diagram of current collecting components in other embodiments of the present application.

[0087] According to some embodiments of the present application, the fluid channel 2313 includes a first end connected to the fluid of the center hole 2211, and a second end connected to the gap between the electrode assembly 22 and the shell 21, and the cross-sectional area of ​​the fluid channel 2313 gradually decreases from the first end to the second end.

[0088] In some embodiments, the current collecting member 23 is disc-shaped, and the fluid channel 2313 extends from the concave cavity 2311A in the central region of the current collecting member 23 to the edge of the current collecting member 23, respectively connecting the central hole 2211 and the gap between the electrode assembly 22 and the housing 21. The first end of the fluid channel 2313 is the end closest to the central hole 2211 and can be directly connected to the concave cavity 2311A. The second end is the end away from the central hole 2211 and located at the edge of the current collecting member 23. The cross-section of the fluid channel 2313 can be polygonal or semicircular. In some embodiments, the cross-section of the fluid channel 2313 is rectangular, and the width of the rectangle gradually increases from the first end to the second end.

[0089] The change in the cross-sectional area of ​​the fluid channel 2313 can accelerate the flow rate and form a pressure drop when the airflow flows from the gap between the electrode assembly 22 and the shell 21 to the center of the collecting component 23, thereby playing a better converging and guiding role and making the exhaust smoother.

[0090] According to some embodiments of the present application, as shown in Figure 4, the shell 21 includes a shell body 211 and an end cover 212, the shell body 211 defines an accommodating cavity and an opening located at one end of the accommodating cavity; the end cover 212 is connected to the shell body 211 to cover the opening; and wherein, the pressure relief component 24 is located on the end cover 212, and the positive projection of the center hole 2211 on the end cover 212 at least partially overlaps with the pressure relief component 24.

[0091] The housing body 211 and the end cap 212 can be separate components. An opening can be provided in the housing body 211, and the end cap 212 can be placed over the opening to create an internal environment for the battery cell 20. Alternatively, the end cap 212 and the housing body 211 can be integrated. Specifically, the end cap 212 and the housing body 211 can form a common connection surface before other components are inserted into the housing. When the interior of the housing body 211 needs to be encapsulated, the end cap 212 can be placed over the housing body 211.

[0092] The housing body 211 may include a bottom wall and side walls connected to each other. The bottom wall is provided with a through hole 2314 to allow the electrode terminal 25 to pass through and be electrically connected to the electrode assembly 23 .

[0093] The end cap 212 is a component that covers the opening of the housing body 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 212 can be adapted to the shape of the housing body 211 to fit the housing body 211. In some embodiments, the end cap 212 can be made of a material with a certain degree of hardness and strength (such as an aluminum alloy). This prevents the end cap 212 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. Functional components such as electrode terminals 25 can be provided on the end cap 212. The electrode terminals 25 can be used to electrically connect to the electrode assembly 22 to transfer electrical energy to or from the battery cell 20. The end cap 212 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating member can be provided on the inside of the end cap 212 to isolate the electrical connection components within the housing body 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating member may be made of plastic, rubber, or the like.

[0094] The end cover 212 may also be provided with a pressure relief component 24 for releasing the internal pressure when the internal pressure of the battery cell 20 reaches a threshold value. The pressure relief component 24 may be an independent component or a partial weak area on the end cover 212, which ruptures to release the internal pressure when the internal pressure of the battery cell reaches a threshold value.

[0095] In some embodiments, the pressure relief component 24 can be located in the central area of ​​the end cap 212 and disposed directly opposite the central hole 2211 of the electrode assembly 22. It is understood that when a current collecting member 23 is further disposed between the electrode assembly 22 and the end cap 212, the central hole 2211 of the electrode assembly 22 and the through-hole 2314 on the current collecting member 23 at least partially overlap, and their projections on the end cap 212 along the extension direction of the central hole 2211 at least partially overlap with the location of the pressure relief component 24. In this way, the gas introduced into the central hole 2211 can flow directly to the location of the pressure relief component 24, and when the pressure reaches a threshold, it can directly break through the pressure relief component 24 and be discharged from the battery cell 20.

[0096] Placing the pressure relief component 24 on the end cover 212 and facing the center hole 2211 facilitates directional valve opening and improves the reliability of the pressure relief component 24 in opening the valve.

[0097] According to some embodiments of the present application, the electrode tab 222 includes a first electrode tab 2221 and a second electrode tab 2222 with different polarities, and the first electrode tab 2221 and the second electrode tab 2222 are respectively located at the two ends of the main body 221 along the extension direction of the center hole 2211; the current collecting component 23 can be a first current collecting component 231 electrically connected to the first electrode tab 2221, or a second current collecting component 232 electrically connected to the second electrode tab 2222.

[0098] The first electrode tab 2221 can be a positive electrode tab, and the second electrode tab 2222 can be a negative electrode tab. The first electrode tab 2221 and the second electrode tab 2222 respectively protrude from both ends of the main body 221. The first surface 231A of the first current collecting member 231 is electrically connected to the first electrode tab 2221, and the second surface 231B is electrically connected to the electrode terminal 25, which passes through the housing body 211 and is insulated from the housing body 211. The second current collecting member 232 is located between the second electrode tab 2222 and the end cap 212, and electrically connects the second electrode tab 222 and the end cap 212, respectively, so that the housing 21 serves as another electrode terminal 25 of the battery cell 20.

[0099] In some embodiments, the current collecting member 23 can be either a first current collecting member 231 or a second current collecting member 232, so that gas in the gap between the electrode assembly 22 and the housing 21 can enter the central hole 2211 through the fluid channel 2313 and ultimately reach the location of the pressure relief component 24. In other embodiments, the structures of the first current collecting member 231 and the second current collecting member 232 are the same as those of the current collecting member 23, that is, both are provided with at least one fluid channel 2313.

[0100] The pole ears 222 and the current collecting member 23 of different polarities are respectively located at both ends of the electrode assembly 22, which is beneficial for connecting the two during assembly and also beneficial for introducing gas into the central hole 2211 to improve the efficiency of gas discharge.

[0101] An embodiment of the present application provides a battery 100 , which includes the battery cell 20 in the above embodiment.

[0102] An embodiment of the present application provides an electrical device, which includes the battery 100 in the above embodiment, and the battery 100 is used to provide electrical energy.

[0103] The battery cell 20 of the present application is further described in detail below with reference to a specific embodiment.

[0104] As shown in FIG3 to FIG10 , the battery cell 20 is a cylindrical battery. The battery cell 20 includes a housing 21 , an electrode assembly 22 , a current collecting member 23 , a pressure relief component 24 and an electrode terminal 25 .

[0105] The housing 21 includes a housing body 211 and an end cap 212. The housing body 211 includes a bottom wall and side walls connected to each other, the bottom wall and the side walls forming a receiving cavity and an opening at one end of the receiving cavity away from the bottom wall. The end cap 212 is connected to the side wall to cover the opening.

[0106] The electrode assembly 22 is located in the accommodating cavity. The electrode assembly 22 includes a main body 221 and a pole ear 222. The pole ear 222 includes a first pole ear 2221 and a second pole ear 2222 respectively located at both ends of the main body 221 and protruding from the main body 221. The main body 221 has a central hole 2211 extending along the height direction of the battery cell 20 and passing through the electrode assembly 22.

[0107] The battery cell 20 includes a first current collecting member 231 and a second current collecting member 232 located at both ends of the main body 221 in the accommodating cavity. The first current collecting member 231 is electrically connected to the first electrode tab 2221, and the second current collecting member 232 is electrically connected to the second electrode tab 2222. The current collecting member 23 can be the first current collecting member 231 or the second current collecting member 232.

[0108] The structures of the first current collecting member 231 and the second current collecting member 232 can be the same, both of which include a first part 2311 located in the center and a second part 2312 connected to the first part 2311 and circumferentially surrounding the first part 2311, as well as a first surface 231A facing the electrode assembly 22 and a second surface 231B facing away from the electrode assembly 22, the first surface 231A is recessed in the first part 2311 to form a cavity 2311A, the first surface 231A is recessed in the second part 2312 to form at least one groove 2312A serving as a fluid channel 2313, one end of the groove 2312A is connected to the cavity 2311A, and the other end is connected to the gap between the electrode assembly 22 and the shell 21.

[0109] The second surface 231B has a first protrusion 2311B formed on the first portion 2311, and the first protrusion 2311B is located on the back of the cavity 2311A. The second surface 231B has at least one second protrusion 2312B formed on the second portion 2312, and the second protrusion 2312B is located on the back of the groove 2312A and is arranged one-to-one with the groove 2312A.

[0110] A through hole 2314 is further defined at the center of the first portion 2311 , and a central axis of the through hole 2314 coincides with a central axis of the central hole 2211 .

[0111] The second part 2312 is also provided with a plurality of pole ear connecting parts 2315 connected to the pole ears, and the fluid channel 2313 is located between two adjacent pole ear connecting parts 2315, and the plurality of fluid channels 2313 are arranged at circumferential intervals around the first part 2311. The fluid channel 2313 includes a first end connected to the fluid of the center hole 2211, and a second end connected to the gap between the electrode assembly 22 and the shell 21. The cross-sectional area of ​​the fluid channel 2313 is a constant from the first end to the second end, or gradually decreases from the first end to the second end.

[0112] The pressure relief component 24 is located on the end cover 212 , and the orthographic projections of the central hole 2211 and the through hole 2314 on the end cover 212 are located within the range of the pressure relief component 24 .

[0113] The electrode terminal 25 is insulated and penetrates the bottom wall of the case body 211 and is welded to the second surface 231B of the first current collecting member 231 to achieve electrical connection. The second current collecting member 232 is welded to the end cap 212 to achieve electrical connection.

[0114] The gas generated by the electrode assembly 22 in the battery cell 20 of this embodiment can be collected and guided into the center hole 2211 through the fluid channel 2313, and flow along the center hole 2211 to the position of the pressure relief component 24. When the pressure reaches a certain threshold, the pressure relief component 24 ruptures, allowing the gas to be discharged smoothly from the interior of the battery cell 20, realizing directional valve opening and smooth exhaust.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, comprising: The housing includes a receiving cavity, an electrode assembly located in the accommodating cavity, the electrode assembly comprising a main body and a tab protruding from the main body, the main body having a central hole extending along a height direction of the battery cell and penetrating the electrode assembly; A current collecting component is located in the accommodating cavity and is electrically connected to the tab; and a pressure relief component connected to the housing, wherein a side of the pressure relief component facing the electrode assembly is in fluid communication with the central hole; The current collecting member includes at least one fluid channel, and the fluid channel is configured to fluidically connect the gap between the electrode assembly and the shell with the central hole.

2. The battery cell according to claim 1, wherein: The current collecting member includes a first portion disposed opposite to the central hole, wherein a first surface of the current collecting member facing the electrode assembly is formed with a concave cavity in the first portion; The fluid passage is in fluid communication with the central bore through the cavity.

3. The battery cell according to claim 2, wherein: A first protrusion is formed on the first portion of a second surface of the current collecting member facing away from the electrode assembly, and the first protrusion is located at the back side of the cavity.

4. The battery cell according to claim 2 or 3, wherein: The first portion is provided with a through hole penetrating the current collecting member, and the orthographic projection of the central hole on the current collecting member at least partially overlaps with the through hole.

5. The battery cell according to any one of claims 2 to 4, wherein: The current collecting component also includes The second part is located on the outer periphery of the first part and connected to the first part, and the first surface is provided with a groove serving as the fluid channel in the second part, one end of the groove is connected to the concave cavity, and the other end is connected to the gap between the electrode assembly and the shell. The battery cell according to claim 5 , wherein: At least one second protrusion is formed on the first portion of the second surface of the current collecting member facing away from the electrode assembly. The second protrusion is located on the back side of the groove and is arranged in a one-to-one correspondence with the groove.

7. The battery cell according to any one of claims 1 to 6, wherein: There are a plurality of fluid channels, which are arranged at intervals along the circumference of the flow collecting component.

8. The battery cell according to claim 7, wherein: The second portion includes a plurality of tab connecting portions that are circumferentially spaced apart and electrically connected to the tabs, respectively. The fluid channel is located between two adjacent tab connecting portions.

9. The battery cell according to any one of claims 1 to 8, wherein: The fluid channel includes a first end in fluid communication with the central hole, and a second end in fluid communication with the gap between the electrode assembly and the shell. The cross-sectional area of ​​the fluid channel gradually decreases from the first end to the second end.

10. The battery cell according to any one of claims 1 to 9, wherein: The housing comprises: a housing body, defining the accommodating cavity and an opening at one end of the accommodating cavity; and an end cover connected to the housing body to cover the opening; And wherein, the pressure relief component is located on the end cover, and the orthographic projection of the central hole on the end cover at least partially overlaps with the pressure relief component.

11. The battery cell according to any one of claims 1 to 10, wherein: The tabs include a first tab and a second tab with different polarities, wherein the first tab and the second tab are respectively located at two ends of the main body along the extension direction of the central hole; The current collecting member is a first current collecting member electrically connected to the first electrode tab, or the current collecting member is a second current collecting member electrically connected to the second electrode tab.

12. A battery comprising the battery cell according to any one of claims 1 to 11.

13. An electrical device comprising the battery according to claim 12, wherein the battery is used to provide electrical energy.

Images