Battery cell, battery, and electric device

Abstract

The embodiment of the application provides a battery monomer, a battery and an electric equipment, and belongs to the technical field of batteries. The battery monomer comprises a shell, an electrode assembly, an end cover and a current collecting member. The shell has an opening. The electrode assembly is accommodated in the shell. The end cover is connected to the shell and closes the opening. The current collecting member is located in the shell, the current collecting member is arranged on a side of the electrode assembly facing the end cover, and the current collecting member is connected to the end cover and the electrode assembly. The end cover comprises a connecting portion connected to the current collecting member, along the thickness direction of the end cover, a surface of the current collecting member facing the end cover is provided with an accommodation groove, and the connecting portion is at least partially accommodated in the accommodation groove. The accommodation groove can provide a relief space for the connecting portion, thereby reducing the extrusion force of the connecting portion on the current collecting member after the end cover is connected to the shell, reducing the deformation amount of the current collecting member, reducing the risk that the deformation amount of the current collecting member is too large due to the extrusion force of the connecting portion, causing the connection failure of the current collecting member and the electrode assembly, and improving the stability of the electrical connection between the end cover and the electrode assembly.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, and an electrical device. Background Technology

[0002] With the development of new energy technologies, batteries are being used more and more widely, such as in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] As energy storage elements, battery cells typically output electrical energy through a chemical reaction between electrode assemblies and electrolyte. Within a battery cell, the end cap and electrode assemblies are electrically connected via current collectors. To ensure the normal operation of the battery cell, the stability of this electrical connection between the end cap and electrode assemblies must be guaranteed. Therefore, improving the stability of this electrical connection is a pressing issue in battery technology. Summary of the Invention

[0004] This application provides a battery cell, a battery, and an electrical device that can effectively improve the stability of the electrical connection between the end cap and the electrode assembly.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a housing, an electrode assembly, an end cap, and a current collector; the housing has an opening; the electrode assembly is housed within the housing; the end cap is connected to the housing and closes the opening; the current collector is located within the housing, and is disposed on the side of the electrode assembly facing the end cap, the current collector connecting the end cap and the electrode assembly; wherein, the end cap includes a connecting portion connected to the current collector, and along the thickness direction of the end cap, the surface of the current collector facing the end cap is provided with a receiving groove, the connecting portion being at least partially housed within the receiving groove.

[0006] In the above technical solution, the connection part connecting the end cap and the current collector is at least partially accommodated in the receiving groove. The receiving groove can provide clearance space for the connection part. The end cap can form a stress buffer zone at the location where the receiving groove is set, thereby reducing the squeezing force of the connection part on the current collector after the end cap is connected to the housing, reducing the deformation of the current collector, reducing the risk of excessive deformation of the current collector due to the squeezing force of the connection part, causing the connection between the current collector and the electrode assembly to fail, and improving the stability of the electrical connection between the end cap and the electrode assembly.

[0007] In some embodiments, the receiving groove is a closed groove that extends circumferentially along the flow collecting member and is connected end to end. This type of receiving groove has better adaptability to the connecting part, and the connecting part can be accommodated in the receiving groove regardless of its circumferential position on the end cap, reducing the difficulty of installing the end cap.

[0008] In some embodiments, the receiving groove is an annular groove. An annular receiving groove has a simple structure and is easy to form.

[0009] In some embodiments, the receiving groove has a first groove bottom surface and a first groove side surface, the first groove side surface being connected to the first groove bottom surface; along the thickness direction, the first groove bottom surface faces the connecting portion; along a first direction, the first groove side surface is located inside the connecting portion, the first direction being perpendicular to the thickness direction; wherein, the angle between the first groove side surface and the first groove bottom surface is θ1, satisfying: 90°<θ1<180°. The first groove side surface located inside the connecting portion is set at an obtuse angle to the first groove bottom surface, and the first groove side surface is in an inclined state. The first groove side surface plays a guiding role for the connecting portion, making it easier for the connecting portion to enter the receiving groove and improving the installation efficiency of the end cap.

[0010] In some embodiments, the receiving groove further includes a second groove side surface, which is connected to the bottom surface of the first groove. Along a first direction, the first groove side surface is located outside the connecting portion. The angle between the second groove side surface and the bottom surface of the first groove is θ2, satisfying: 90° < θ2 < 180°. The second groove side surface, located outside the connecting portion, is set at an obtuse angle to the bottom surface of the first groove. The second groove side surface is in an inclined state and guides the connecting portion, making it easier for the connecting portion to enter the receiving groove and improving the installation efficiency of the end cap.

[0011] In some embodiments, along the first direction, both the first groove side surface and the second groove side surface are spaced apart from the connecting portion. This gap between the first groove side surface and the second groove side surface is greater than the width of the portion of the connecting portion located within the receiving groove. This makes it easier for the connecting portion to enter the receiving groove, and reduces the risk of the connecting portion exerting pressure on the first and second groove side surfaces, thereby increasing the deformation of the current collecting member.

[0012] In some embodiments, the receiving groove has a first groove bottom surface and a second groove side surface, the second groove side surface being connected to the first groove bottom surface; along the thickness direction, the first groove bottom surface faces the connecting portion; along a first direction, the second groove side surface is located outside the connecting portion, the first direction being perpendicular to the thickness direction; wherein, the angle between the second groove side surface and the first groove bottom surface is θ2, satisfying: 90°<θ2<180°. The second groove side surface located outside the connecting portion is set at an obtuse angle to the first groove bottom surface, the second groove side surface is in an inclined state, and the second groove side surface plays a guiding role for the connecting portion, making it easier for the connecting portion to enter the receiving groove.

[0013] In some embodiments, the receiving groove includes a first groove side and a second groove side, which are located on opposite sides of the connecting portion along a first direction, perpendicular to the thickness direction. The distance between the first groove side and the second groove side in the first direction gradually decreases along the depth direction of the receiving groove. Thus, the width of the receiving groove gradually narrows from its opening position along the depth direction, making it easier for the connecting portion to enter the receiving groove.

[0014] In some embodiments, the current collector includes a first connection region and a second connection region; the first connection region is connected to the connecting portion, and the location where the receiving groove is provided on the current collector forms the first connection region; the second connection region is connected to the electrode assembly; wherein the projections of the first connection region and the second connection region on a plane perpendicular to the thickness direction do not overlap. This structure allows the first connection region and the second connection region to be staggered, so that the first connection region and the second connection region do not affect each other, and the connection between the first connection region and the connecting portion does not affect the connection between the second connection region and the electrode assembly, thereby improving the stability of the connection between the current collector and the electrode assembly.

[0015] In some embodiments, the first connection region is arranged around the outside of the second connection region. This structure allows the first connection region to have a larger size, thereby increasing the flow area between the current collector and the end cap.

[0016] In some embodiments, the thickness of the second connection region is L, and the depth of the receiving groove is H, satisfying: 0.15 ≤ H / L < 1. The ratio of the depth of the receiving groove to the thickness of the second connection region is set within a reasonable range so that the depth of the receiving groove is not too small, in order to accommodate more of the connection part and reduce the deformation of the current collecting member.

[0017] In some embodiments, the receiving groove has a first groove bottom surface, and the connecting portion abuts against the first groove bottom surface along the thickness direction. This structure increases the contact area between the connecting portion and the flow collecting member, thereby increasing the flow area between the flow collecting member and the end cap.

[0018] In some embodiments, the current collector is welded to the connecting part. The current collector and the connecting part are firmly connected, achieving stable current flow between the current collector and the connecting part.

[0019] In some embodiments, the connecting portion is a closed structure that extends circumferentially along the end cap and is connected end to end. This structure, on the one hand, ensures that the compressive force of the connecting portion is uniform around the flow collector, effectively reducing the deformation of the flow collector; on the other hand, it increases the flow area between the flow collector and the end cap.

[0020] In some embodiments, the end cap further includes a body portion and a recess. The body portion is connected to the housing and has opposing inner and outer surfaces along the thickness direction. The inner surface faces the current collecting member, and the connecting portion protrudes from the inner surface. The recess is disposed at a position corresponding to the connecting portion of the body portion, and the recess is recessed from the outer surface towards the current collecting member. The recess reduces the thickness of the end cap at the connecting portion position, making it easier to connect the connecting portion to the current collecting member and enhancing the stability of the connection after the connecting portion and the current collecting member are connected.

[0021] In some embodiments, the body includes a pressure relief portion, and a connecting portion surrounds the pressure relief portion. The pressure relief portion is provided with a groove. This structure enables the end cap to have a pressure relief function. The location where the groove is provided in the pressure relief portion forms a weak area, so that it can crack when the pressure or temperature inside the battery cell reaches a threshold, thereby releasing the pressure inside the battery cell.

[0022] In some embodiments, the pressure relief portion partially protrudes towards the current collector to form a boss, and a groove is formed on the side of the pressure relief portion away from the current collector, corresponding to the boss; a scoring groove is provided on the surface of the boss facing the current collector; and / or, the groove has a second groove bottom surface, and a scoring groove is provided on the second groove bottom surface. This structure makes the area of ​​the end cover with the scoring groove recessed into the battery cell as a whole. When the end cover is subjected to an impact force from outside the battery cell, the impact force is less likely to directly act on the area of ​​the end cover with the groove, thereby protecting the area of ​​the end cover with the scoring groove and reducing the risk of the end cover being damaged and cracked due to impact.

[0023] In some embodiments, the boss and the current collector are spaced apart along the thickness direction. This gap prevents the current collector from affecting the pressure relief of the end cap, ensuring that the end cap can properly relieve pressure when the internal pressure or temperature of the battery cell reaches a threshold.

[0024] Secondly, embodiments of this application provide a battery, including a housing and a battery cell provided in any of the embodiments of the first aspect above, wherein the battery cell is housed within the housing.

[0025] Thirdly, embodiments of this application provide an electrical device including the battery provided in any of the embodiments of the second aspect described above. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0028] Figure 2 Exploded views of batteries provided for some embodiments of this application;

[0029] Figure 3 Cross-sectional views of a battery cell provided in some embodiments of this application;

[0030] Figure 4 for Figure 3 A partial view of the battery cell shown;

[0031] Figure 5 for Figure 4 The diagram shows the structure of the current collection component;

[0032] Figure 6 for Figure 5 A cross-sectional view of the flow collector shown;

[0033] Figure 7 for Figure 4 A magnified view of part A of the shown battery cell;

[0034] Figure 8 Schematic diagrams of the current collection components provided in other embodiments of this application;

[0035] Figure 9 for Figure 4 The diagram shows the connection between the end cap and the flow collector.

[0036] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Housing shell; 22-Electrode assembly; 221-Taper; 23-End cap; 231-Connector; 232-Body body; 2321-Inner surface; 2322-Outer surface; 2323-Pressure relief part; 2324-Groove; 2325-Boss; 2326-Groove; 2326a-Bottom surface of the second groove; 233-Recess; 24-Current collector; 241-Receiving groove; 2411-Bottom surface of the first groove; 2412-Side surface of the first groove; 2413-Side surface of the second groove; 242-First surface; 243-Second surface; 244-First connection area; 245-Second connection area; 246-Center hole; 25-Electrode terminal; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle; Z-Thickness direction; X-First direction. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0039] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0041] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0042] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0043] In this application, "multiple" means two or more (including two).

[0044] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these. Battery cells are generally divided into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these.

[0045] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0046] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The uncoated positive current collector protrudes from the coated positive current collector and serves as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The uncoated negative current collector protrudes from the coated negative current collector and serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. To ensure that a large current can pass through without melting, multiple positive tabs and multiple negative tabs are stacked together. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0047] In a single battery cell, the electrode assembly and the end cap are electrically connected via a current collector, allowing the battery cell's electrical energy to be output through the end cap or the casing connected to the end cap. The current collector is connected to the electrode assembly, and the connecting portion of the end cap is connected to the current collector.

[0048] To reduce the movement of the electrode assembly within the housing, a compressive force can be applied to the current collector through the connection of the end cap. After the end cap is connected to the housing, the electrode assembly and the current collector will be confined within the housing. The inventors noted that for battery cells with this structure, electrical connection failure between the end cap and the electrode assembly is prone to occur.

[0049] The inventors discovered that during the assembly of a battery cell, after the end cap is connected to the casing, the connection part of the end cap will exert a large compressive force on the current collector, causing the current collector to deform significantly. This leads to the failure of the connection between the current collector and the electrode assembly, resulting in the failure of the electrical connection between the end cap and the electrode assembly, and thus poor stability of the electrical connection between the end cap and the electrode assembly.

[0050] In view of this, this application provides a battery cell by providing a receiving groove on the surface of the current collector facing the end cap to accommodate at least a portion of the connection portion of the end cap. The receiving groove can provide clearance space for the connection portion, and the end cap can form a stress buffer zone at the location where the receiving groove is provided, thereby reducing the squeezing force of the connection portion on the current collector after the end cap is connected to the housing, reducing the deformation of the current collector, reducing the risk of excessive deformation of the current collector due to the squeezing force of the connection portion, causing the connection between the current collector and the electrode assembly to fail, and improving the stability of the electrical connection between the end cap and the electrode assembly.

[0051] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0052] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0053] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0054] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 may 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.

[0055] 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, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0056] 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.

[0057] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery 100 provided for some embodiments of this application. The battery 100 includes a housing 10 and battery cells 20, the housing 10 being used to house the battery cells 20.

[0058] The housing 10 is a component that houses the battery cell 20, providing a space for the battery cell 20. The housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, which overlap each other to define a space for accommodating the battery cell 20. The first part 11 and the second part 12 can have various shapes, such as a cuboid or a cylinder. The first part 11 can be a hollow structure open on one side, and the second part 12 can also be a hollow structure open on one side, with the open side of the second part 12 overlapping the open side of the first part 11, thus forming a housing 10 with a accommodating space. Alternatively, the first part 11 can be a hollow structure open on one side, and the second part 12 can be a plate-like structure, with the second part 12 overlapping the open side of the first part 11, thus forming a housing 10 with a accommodating space. The first part 11 and the second part 12 can be sealed using a sealing element, such as a sealing ring or sealant.

[0059] In battery 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0060] In some embodiments, the battery 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other, enabling series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0061] Please refer to Figure 3 , Figure 3 This is a cross-sectional view of a battery cell 20 provided in some embodiments of this application. The battery cell 20 includes a housing 21, an electrode assembly 22, an end cap 23, and a current collector 24.

[0062] The housing 21 is a component used to house the electrode assembly 22. The housing 21 can be a hollow structure with an opening at one end, or it can be a hollow structure with openings at both opposite ends. The housing 21 can be in various shapes, such as a cylinder or a cuboid. The housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0063] Electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction occurs. Electrode assembly 22 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 22 can be a wound structure formed by winding the positive electrode, separator, and negative electrode, or a stacked structure formed by arranging the positive electrode, separator, and negative electrode in layers. Electrode assembly 22 has tabs 221, which are divided into positive tabs and negative tabs. The positive tab can be the part of the positive electrode that is not coated with a positive active material layer, and the negative tab can be the part of the negative electrode that is not coated with a negative active material layer.

[0064] End cap 23 is a component that closes the opening of housing 21 to isolate the internal environment of battery cell 20 from the external environment. End cap 23 and housing 21 together define a sealed space for accommodating electrode assembly 22, electrolyte, and other components. The shape of end cap 23 can be adapted to the shape of housing 21; for example, if housing 21 is a cuboid structure, end cap 23 can be a rectangular structure adapted to housing 21; or, if housing 21 is a cylindrical structure, end cap 23 can be a circular structure adapted to housing 21. End cap 23 can also be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. End cap 23 and housing 21 can be connected together by welding.

[0065] In the battery cell 20, there can be one or two end caps 23. If the housing 21 is a hollow structure with an opening at one end, then one end cap 23 can be provided. If the housing 21 is a hollow structure with openings at both ends, then two end caps 23 can be provided, with the two end caps 23 respectively closing the two openings of the housing 21.

[0066] The current collector 24 is a component that enables electrical connection between two parts. For example, the current collector 24 enables electrical connection between the electrode assembly 22 and the end cap 23. The tabs 221 (positive or negative tabs) of the electrode assembly 22 and the end cap 23 are both connected to the current collector 24 to enable electrical connection between the end cap 23 and the electrode assembly 22.

[0067] In some embodiments, such as Figure 3 As shown, electrode terminals 25 can also be provided in the battery cell 20. The housing 21 is a hollow structure with an opening at one end. The end cap 23 is connected to the housing 21 and closes the opening of the housing 21. The electrode terminal 25 can be provided at the end of the housing 21 opposite to the end cap 23. The electrode terminal 25 is electrically connected to one tab 221 of the electrode assembly 22. The end cap 23 is electrically connected to the other tab 221 of the electrode assembly 22 through the current collector 24.

[0068] For example, electrode terminal 25 is riveted to the end of housing 21 opposite to end cap 23. The tab 221 that is electrically connected to electrode terminal 25 of electrode assembly 22 is the positive tab, and the tab 221 that is electrically connected to end cap 23 of electrode assembly 22 is the negative tab.

[0069] Please refer to Figure 4 , Figure 4 for Figure 3A partial view of the battery cell 20 shown. This application embodiment provides a battery cell 20, which includes a housing 21, an electrode assembly 22, an end cap 23, and a current collector 24. The housing 21 has an opening. The electrode assembly 22 is housed within the housing 21. The end cap 23 is connected to the housing 21 and closes the opening. The current collector 24 is located within the housing 21 and is disposed on the side of the electrode assembly 22 facing the end cap 23, connecting the end cap 23 and the electrode assembly 22. The end cap 23 includes a connecting portion 231 connected to the current collector 24. Along the thickness direction Z of the end cap 23, the surface of the current collector 24 facing the end cap 23 has a receiving groove 241, and the connecting portion 231 is at least partially housed within the receiving groove 241.

[0070] The current collector 24 is a component that enables the electrical connection between the end cap 23 and the electrode assembly 22. The current collector 24 can be of various shapes, such as circular or rectangular. The shape of the current collector 24 can be adapted to the shape of the housing 21. For example, if the housing 21 is cylindrical, the current collector 24 can be circular; the current collector 24 can also be called a current collector plate. The current collector 24 is connected to both the electrode assembly 22 and the end cap 23. The current collector 24 is connected to the tab 221 of the electrode assembly 22, and the current collector 24 is connected to the connecting portion 231 of the end cap 23. The connection between the current collector 24 and the tab 221 of the electrode assembly 22 can be such that they are only in contact and not fixed, for example, the current collector 24 and the tab 221 of the electrode assembly 22 abut against each other; or the connection can be such that they are fixed to each other, for example, the current collector 24 and the tab 221 of the electrode assembly 22 are welded together. The connection between the connecting part 231 and the current collector 24 can be such that they are only in contact and not fixed, for example, the connecting part 231 and the current collector 24 abut against each other; or the connection between the connecting part 231 and the current collector 24 can be such that they are fixed to each other, for example, the connecting part 231 and the current collector 24 are welded together. It should be noted that the tab 221 in the electrode assembly 22 that is connected to the current collector 24 can be a positive tab or a negative tab.

[0071] The connecting part 231 is the part that connects the end cover 23 to the current collector 24. The connecting part 231 may be a protrusion of the end cover 23 that protrudes towards the inside of the battery cell 20. The protrusion contacts the end cover 23 to realize the flow between the end cover 23 and the current collector 24.

[0072] The receiving groove 241 forms a recessed space to accommodate the connecting portion 231. The receiving groove 241 can accommodate the entire connecting portion 231 or only a part of it. The receiving groove 241 is disposed on the surface of the current collecting member 24 facing the end cover 23. The surface of the current collecting member 24 facing the end cover 23 is the first surface 242, and the surface of the current collecting member 24 away from the end cover 23 is the second surface 243. The second surface 243 abuts against the tab 221 of the electrode assembly 22. The receiving groove 241 may penetrate the outer peripheral surface of the current collecting member 24 or may not penetrate it. The shape of the receiving groove 241 can be the same as the shape of the connecting portion 231. For example, both the receiving groove 241 and the connecting portion 231 can be annular structures. Alternatively, the shape of the receiving groove 241 can be different from the shape of the connecting portion 231. For example, the receiving groove 241 can be annular, and the connecting portion 231 can be semi-annular.

[0073] In this embodiment, the connecting portion 231 connecting the end cap 23 and the current collector 24 is at least partially accommodated in the receiving groove 241. The receiving groove 241 can provide clearance space for the connecting portion 231. The end cap 23 can form a stress buffer zone at the location where the receiving groove 241 is provided, thereby reducing the squeezing force of the connecting portion 231 on the current collector 24 after the end cap 23 is connected to the housing 21, reducing the deformation of the current collector 24, reducing the risk of excessive deformation of the current collector 24 due to the squeezing force of the connecting portion 231, causing the connection between the current collector 24 and the electrode assembly 22 to fail, and improving the stability of the electrical connection between the end cap 23 and the electrode assembly 22.

[0074] In some embodiments, please continue to refer to Figure 4 The receiving trough 241 is a closed trough that extends circumferentially along the collecting member 24 and is connected end to end.

[0075] The receiving groove 241 extends along a closed trajectory that connects end to end to form a closed groove. The closed trajectory can be rectangular or circular. If the closed trajectory is circular, the receiving groove 241 is annular, and the recessed space formed by the receiving groove 241 is an annular space. The closed trajectory can be adapted to the shape of the flow collecting member 24. For example, if the flow collecting member 24 is rectangular, the closed trajectory is a rectangle concentric with the flow collecting member 24; or if the flow collecting member 24 is circular, the closed trajectory is circular with the flow collecting member 24.

[0076] In this embodiment, the receiving groove 241 is a closed groove that extends circumferentially along the flow collecting member 24 and is connected end to end. The receiving groove 241 has better adaptability to the connecting part 231. The connecting part 231 can be accommodated in the receiving groove 241 in different positions in the circumferential direction of the end cover 23, reducing the installation difficulty of the end cover 23.

[0077] In some embodiments, please refer to Figure 5 , Figure 5 for Figure 4 The schematic diagram of the flow collection component 24 shown shows that the receiving groove 241 is an annular groove.

[0078] For example, the flow collecting member 24 is circular, and the receiving groove 241 is concentrically arranged with the flow collecting member 24.

[0079] exist Figure 5 In this embodiment, the receiving groove 241 does not penetrate the outer peripheral surface of the collecting member 24, and the receiving groove 241 has an outer side and an inner side. In other embodiments, the receiving groove 241 may also penetrate the outer peripheral surface of the collecting member 24, in which case the receiving groove 241 only has an inner side but not an outer side.

[0080] In this embodiment, the annular receiving groove 241 has a simple structure and is easy to form.

[0081] In some embodiments, please refer to Figure 6 , Figure 6 for Figure 5 The cross-sectional view of the flow collector 24 shown shows that the receiving groove 241 has a first groove bottom surface 2411 and a first groove side surface 2412, with the first groove side surface 2412 connected to the first groove bottom surface 2411. Along the thickness direction Z of the end cap 23, the first groove bottom surface 2411 faces the connecting portion 231 (…). Figure 6 (Not shown). Along the first direction X, the first groove side surface 2412 is located inside the connecting portion 231, and the first direction X is perpendicular to the thickness direction Z of the end cap 23. The angle between the first groove side surface 2412 and the first groove bottom surface 2411 is θ1, satisfying: 90° < θ1 < 180°. Understandably, the first groove side surface 2412 and the first groove bottom surface 2411 are set at an obtuse angle.

[0082] In an embodiment where the collecting member 24 is circular, the first direction X is the radial direction of the collecting member 24. In an embodiment where the collecting member 24 is rectangular, the first direction X can be either the length direction or the width direction of the collecting member 24. The first groove side surface 2412 is located inside the connecting portion 231 in the first direction X, and the first groove side surface 2412 is the inner side surface of the receiving groove 241.

[0083] The bottom surface 2411 of the first groove is the surface of the receiving groove 241 at its deepest position in the depth direction, and the bottom surface 2411 of the first groove can be perpendicular to the thickness direction Z of the end cap 23. The side surface 2412 of the first groove can be an inclined plane or a conical surface. Understandably, in an embodiment where the receiving groove 241 is an annular groove, the side surface 2412 of the first groove is a conical surface.

[0084] In this embodiment, the first groove side surface 2412 located inside the connecting part 231 is set at an obtuse angle to the first groove bottom surface 2411. The first groove side surface 2412 is in an inclined state. The first groove side surface 2412 plays a guiding role for the connecting part 231, making it easier for the connecting part 231 to enter the receiving groove 241.

[0085] In some embodiments, please continue to refer to Figure 6 The receiving groove 241 also includes a second groove side surface 2413, which is connected to the bottom surface 2411 of the first groove. Along the first direction X, the first groove side surface 2412 is located outside the connecting portion 231. The angle between the second groove side surface 2413 and the bottom surface 2411 of the first groove is θ2, satisfying: 90° < θ2 < 180°. In other words, the second groove side surface 2413 and the bottom surface 2411 of the first groove are set at an obtuse angle.

[0086] The second groove side surface 2413 is located outside the connecting portion 231 in the first direction X, and the second groove side surface 2413 is the outer side surface of the receiving groove 241. The second groove side surface 2413 can be an inclined plane or a conical surface. Understandably, in the embodiment where the receiving groove 241 is an annular groove, the second groove side surface 2413 is a conical surface, and the space between the second groove side surface 2413 and the first groove side surface 2412 is the recessed space of the receiving groove 241.

[0087] In this embodiment, the second groove side surface 2413 located outside the connecting part 231 is set at an obtuse angle to the bottom surface 2411 of the first groove. The second groove side surface 2413 is in an inclined state and guides the connecting part 231, making it easier for the connecting part 231 to enter the receiving groove 241.

[0088] In some embodiments, please refer to Figure 7 for Figure 4 The image shows a partial enlarged view of point A on the battery cell 20. Along the first direction X, both the first groove side surface 2412 and the second groove side surface 2413 are spaced apart from the connecting portion 231.

[0089] Understandably, the connecting portion 231 does not contact either the first groove side surface 2412 or the second groove side surface 2413. The connecting portion 231 abuts against the bottom surface 2411 of the first groove of the receiving groove 241 to achieve electrical connection between the connecting portion 231 and the current collecting member 24.

[0090] Taking the example that both the receiving groove 241 and the connecting part 231 are annular structures, the first direction X is the radial direction of the flow collecting member 24. Along the first direction X, the first groove side 2412 of the receiving groove 241 is separated from the inner side of the connecting part 231, and the second groove side 2413 of the receiving groove 241 is separated from the outer side of the connecting part 231.

[0091] In this embodiment, the first groove side surface 2412 and the second groove side surface 2413 are both spaced apart from the connecting portion 231 in the first direction X, such that the gap between the first groove side surface 2412 and the second groove side surface 2413 is greater than the width of the portion of the connecting portion 231 located in the receiving groove 241. On the one hand, this makes it easier for the connecting portion 231 to enter the receiving groove 241. On the other hand, it reduces the risk of the connecting portion 231 exerting a squeezing force on the first groove side surface 2412 and the second groove side surface 2413, thereby increasing the deformation of the current collecting member 24.

[0092] In other embodiments, the inner and outer sides of the connecting portion 231 may also abut against the first groove side 2412 and the second groove side 2413 of the receiving groove 241, respectively, and the connecting portion 231 is supported by the inclined first groove side 2412 and the second groove side 2413, so that the connecting portion 231 and the first groove bottom surface 2411 of the receiving groove 241 are separated.

[0093] In some embodiments, please refer to Figure 8 , Figure 8 This is a structural schematic diagram of the current collection member 24 provided in other embodiments of this application. The receiving groove 241 has a first groove bottom surface 2411 and a second groove side surface 2413, and the second groove side surface 2413 is connected to the first groove bottom surface 2411. Along the thickness direction Z of the end cap 23, the first groove bottom surface 2411 faces the connecting portion 231 ( Figure 8 (Not shown). Along the first direction X, the second groove side surface 2413 is located outside the connecting portion 231, and the first direction X is perpendicular to the thickness direction Z of the end cap 23. The angle between the second groove side surface 2413 and the first groove bottom surface 2411 is θ2, satisfying: 90° < θ2 < 180°. Understandably, the second groove side surface 2413 and the first groove bottom surface 2411 are set at an obtuse angle.

[0094] The bottom surface 2411 of the first groove is the surface of the receiving groove 241 at its deepest point in the depth direction, and the bottom surface 2411 of the first groove can be perpendicular to the thickness direction Z of the end cap 23. The side surface 2413 of the second groove is the outer side surface of the receiving groove 241. The side surface 2413 of the second groove can be an inclined plane or a conical surface.

[0095] For example, such as Figure 8 As shown, the receiving groove 241 is circular, and the side surface 2413 of the second groove is a conical surface. The space defined by the side surface 2413 of the second groove is the recessed space of the receiving groove 241.

[0096] In this embodiment, the second groove side surface 2413 located outside the connecting part 231 is set at an obtuse angle to the bottom surface 2411 of the first groove. The second groove side surface 2413 is in an inclined state and guides the connecting part 231, making it easier for the connecting part 231 to enter the receiving groove 241.

[0097] In some embodiments, please continue to refer to Figure 6 and Figure 7 The receiving groove 241 includes a first groove side surface 2412 and a second groove side surface 2413. Along the first direction X, the first groove side surface 2412 and the second groove side surface 2413 are respectively located on both sides of the connecting portion 231. The first direction X is perpendicular to the thickness direction Z of the end cap 23. The distance between the first groove side surface 2412 and the second groove side surface 2413 in the first direction X gradually decreases along the depth direction of the receiving groove 241.

[0098] Along the thickness direction Z of the end cap 23, the current collecting member 24 has a first surface 242 and a second surface 243 facing each other. The first surface 242 faces the end cap 23, and the second surface 243 faces away from the end cap 23. The receiving groove 241 is recessed from the first surface 242 toward the direction close to the second surface 243. The receiving groove 241 forms an opening on the first surface 242. The direction from the first surface 242 to the second surface 243 is the depth direction of the receiving groove 241.

[0099] In an embodiment where the receiving groove 241 has an annular structure, the distance between the first groove side surface 2412 and the second groove side surface 2413 in the first direction X is the difference in their radii. Of course, the distance between the first groove side surface 2412 and the second groove side surface 2413 in the first direction X can be made to gradually decrease along the depth direction of the receiving groove 241 in various ways. For example, both the first groove side surface 2412 and the second groove side surface 2413 can be set at an obtuse angle to the bottom surface 2411 of the first groove. Alternatively, one of the first groove side surface 2412 and the second groove side surface 2413 can be set at an obtuse angle to the bottom surface 2411 of the first groove, while the other can be set at a right angle to the bottom surface 2411 of the first groove.

[0100] In this embodiment, the width of the receiving groove 241 gradually narrows from its opening position along the depth direction, making it easier for the connecting part 231 to enter the receiving groove 241.

[0101] In some embodiments, please continue to refer to Figure 6 and Figure 7The current collecting member 24 includes a first connecting region 244 and a second connecting region 245. The first connecting region 244 is connected to the connecting portion 231, and the first connecting region 244 is formed at the location where the receiving groove 241 is provided on the current collecting member 24. The second connecting region 245 is connected to the electrode assembly 22. The projections of the first connecting region 244 and the second connecting region 245 onto a plane perpendicular to the thickness direction Z of the end cap 23 do not overlap.

[0102] The first connection area 244 is the part where the current collecting member 24 connects to the connecting part 231. After the current collecting member 24 is provided with the receiving groove 241, the remaining part of the current collecting member 24 corresponding to the position of the receiving groove 241 is the first connection area 244. In other words, in the thickness direction Z of the end cap 23, the part of the current collecting member 24 located between the bottom surface 2411 and the second surface 243 of the receiving groove 241 is the first connection area 244. Taking the welding of the first connection area 244 and the connecting part 231 as an example, the weld mark formed by welding the first connection area 244 and the connecting part 231 is located in the first connection area 244.

[0103] The second connection area 245 is the part where the current collector 24 connects to the electrode assembly 22. Taking the welding of the second connection area 245 to the tab 221 of the electrode assembly 22 as an example, the weld mark formed by welding the second connection area 245 to the tab 221 is located in the second connection area 245. It is understood that the projections of the weld mark formed by welding the first connection area 244 to the connection part 231 and the weld mark formed by welding the second connection area 245 to the tab 221 on the plane perpendicular to the thickness direction Z of the end cap 23 do not overlap.

[0104] In this embodiment, the first connection area 244 and the second connection area 245 are staggered, and the first connection area 244 and the second connection area 245 do not affect each other. The connection between the first connection area 244 and the connection part 231 does not affect the connection between the second connection area 245 and the electrode assembly 22, thereby improving the stability of the connection between the current collector 24 and the electrode assembly 22. For example, after the second connection area 245 is welded to the tab 221 of the electrode assembly 22, and the connection part 231 and the first connection area 244 are welded, the staggered arrangement of the first connection area 244 and the second connection area 245 can avoid secondary welding of the second connection area 245, reducing the impact on the connection strength between the second connection area 245 and the tab 221 of the electrode assembly 22.

[0105] In some embodiments, please continue to refer to Figure 6 and Figure 7 The first connecting area 244 is arranged around the outside of the second connecting area 245.

[0106] In this embodiment, the first connecting area 244 is an annular structure, and the corresponding receiving groove 241 is also an annular structure. The portion of the flow collecting member 24 located inside the first connecting area 244 is the second connecting area 245.

[0107] In this embodiment, the first connection area 244 is arranged around the outside of the second connection area 245, so that the first connection area 244 has a larger size, which can increase the flow area between the current collecting member 24 and the end cap 23.

[0108] It should be noted that in other embodiments, the second connection area 245 may be arranged around the outside of the first connection area 244.

[0109] In some embodiments, please continue to refer to Figure 6 The thickness of the second connecting area 245 is L, and the depth of the receiving groove 241 is H, satisfying: 0.15≤H / L<1.

[0110] The thickness of the second connecting area 245 is the same as the thickness of the current collecting member 24. Figure 6 In the middle, the thickness of the second connecting area 245 is the distance between the first surface 242 and the second surface 243 in the thickness direction Z of the end cap 23, and the depth of the receiving groove 241 is the distance between the first surface 242 and the bottom surface 2411 of the first groove in the thickness direction Z of the end cap 23.

[0111] For example, 0.1mm ≤ H ≤ 1mm.

[0112] In this embodiment, the ratio of the depth of the receiving groove 241 to the thickness of the second connecting area 245 is set within a reasonable range so that the depth of the receiving groove 241 is not too small, so as to accommodate more of the connecting part 231 and reduce the deformation of the current collecting member 24.

[0113] In some embodiments, please refer to Figure 7 Along the thickness direction Z of the end cap 23, the connecting part 231 abuts against the bottom surface 2411 of the first groove of the receiving groove 241.

[0114] It should be noted that when the connecting part 231 abuts against the bottom surface 2411 of the first groove of the receiving groove 241, both the first side surface 2412 and the second side surface 2413 of the receiving groove 241 can contact the connecting part 231, or they can be spaced apart. For example, in... Figure 7 In the middle, the first groove side 2412 and the second groove side 2413 of the receiving groove 241 are both connected by a gap 231.

[0115] In this embodiment, the connecting part 231 abuts against the bottom surface 2411 of the first groove of the receiving groove 241 along the thickness direction Z of the end cover 23, which increases the contact area between the connecting part 231 and the current collecting member 24, thereby increasing the flow area between the current collecting member 24 and the end cover 23.

[0116] In some embodiments, the current collector 24 is welded to the connecting portion 231. The current collector 24 and the connecting portion 231 are firmly connected, achieving stable current flow between the current collector 24 and the connecting portion 231.

[0117] In the embodiment where the flow collecting member 24 abuts against the bottom surface 2411 of the first groove of the receiving groove 241, the connecting part 231 can be welded and fixed to the first connecting area 244 of the flow collecting member 24 by through welding.

[0118] In some embodiments, the connecting portion 231 is a closed structure that extends circumferentially along the end cap 23 and is connected end to end.

[0119] For example, the connecting part 231 is an annular structure, and the receiving groove 241 is also an annular structure.

[0120] In this embodiment, the connecting part 231 is a closed structure with the ends connected. This structure ensures that the pressure from the connecting part 231 is uniform around the flow collecting member 24, which can effectively reduce the deformation of the flow collecting member 24. On the other hand, it increases the flow area between the flow collecting member 24 and the end cap 23.

[0121] In some embodiments, please refer to Figure 9 , Figure 9 for Figure 4 The diagram shows the connection between the end cap 23 and the current collecting member 24. The end cap 23 also includes a body portion 232 and a recess 233. The body portion 232 is connected to the housing 21. Along the thickness direction Z of the end cap 23, the body portion 232 has an inner surface 2321 and an outer surface 2322. The inner surface 2321 faces the current collecting member 24, and the connecting portion 231 protrudes from the inner surface 2321. The recess 233 is provided at a position corresponding to the connecting portion 231 on the body portion 232, and the recess 233 is recessed from the outer surface 2322 toward the current collecting member 24.

[0122] The main body 232 and the housing 21 can be connected and fixed by welding. The main body 232 can be circular, rectangular, etc. Taking a circular main body 232 as an example, along the radial direction of the main body 232, the portion of the main body 232 that extends beyond the outer side of the connecting portion 231 can be welded to the housing 21.

[0123] The shape of the recess 233 is the same as the shape of the connecting portion 231. For example, both the recess 233 and the connecting portion 231 are annular structures, and both the recess 233 and the connecting portion 231 are coaxially arranged with the body portion 232.

[0124] In this embodiment, the recess 233 reduces the thickness of the end cap 23 at the connection portion 231, making it easier to connect the connection portion 231 to the current collector 24 and enhancing the stability of the connection between the connection portion 231 and the current collector 24. For example, when welding the connection portion 231 to the current collector 24, reducing the thickness of the end cap 23 at the connection portion 231 makes the welding of the connection portion 231 to the current collector 24 more robust.

[0125] In some embodiments, please continue to refer to Figure 9 The main body 232 includes a pressure relief part 2323, and a connecting part 231 is disposed around the pressure relief part 2323. The pressure relief part 2323 is provided with a groove 2324.

[0126] The portion of the main body 232 located within the inner side of the connecting portion 231 is the pressure relief portion 2323. Taking the connecting portion 231 as an annular structure as an example, the pressure relief portion 2323 is a circular structure located within the inner side of the connecting portion 231. The groove 2324 on the pressure relief portion 2323 can be of various shapes, such as circular, U-shaped, or straight.

[0127] The pressure relief section 2323 has a groove 2324 at a location that forms a weak area, so that it can crack when the pressure or temperature inside the battery cell 20 reaches a threshold, thereby releasing the pressure inside the battery cell 20. This structure of the end cap 23 has a pressure relief function, improving the safety of the battery cell 20.

[0128] In some embodiments, please continue to refer to Figure 9 The pressure relief portion 2323 partially protrudes towards the collector member 24 to form a boss 2325, and a groove 2326 is formed on the side of the pressure relief portion 2323 facing away from the collector member 24, corresponding to the boss 2325. The surface of the boss 2325 facing the collector member 24 is provided with a scoring groove 2324; and / or, the groove 2326 has a second groove bottom surface 2326a, and the second groove bottom surface 2326a is provided with a scoring groove 2324.

[0129] The boss 2325 on the pressure relief part 2323 can be formed by stamping. After stamping the side of the pressure relief part 2323 away from the current collecting member 24, a groove 2326 will be formed on the side of the pressure relief part 2323 away from the current collecting member 24, and a boss 2325 will be formed on the side of the pressure relief part 2323 facing the current collecting member 24.

[0130] For example, both the boss 2325 and the groove 2326 are circular, the boss 2325 and the groove 2326 are coaxially arranged, and the diameter of the boss 2325 is larger than the diameter of the groove 2326.

[0131] The bottom surface 2326a of the second groove is the surface at the deepest point of the groove 2326 in the depth direction, and the direction from the outer surface 2322 of the body portion 232 to the inner surface 2321 is the depth direction of the groove 2326. For example, along the thickness direction Z of the end cap 23, the bottom surface 2326a of the second groove is located between the outer surface 2322 and the inner surface 2321 of the body portion 232.

[0132] For example, in Figure 9 In the middle, the groove 2324 is provided on the surface of the boss 2325 facing the flow collector 24, that is, the groove 2324 is recessed from the surface of the boss 2325 facing the flow collector 24 toward the bottom surface 2326a of the second groove.

[0133] In this embodiment, the area of ​​the end cap 23 with the groove 2324 is recessed into the battery cell 20. When the end cap 23 is subjected to an impact force from outside the battery cell 20, the impact force is less likely to directly act on the area of ​​the end cap 23 with the groove 2326, thereby protecting the area of ​​the end cap 23 with the groove 2324 and reducing the risk of the end cap 23 being damaged and cracked due to the impact force.

[0134] In some embodiments, please continue to refer to Figure 9 Along the thickness direction Z of the end cap 23, the boss 2325 is spaced apart from the current collecting member 24.

[0135] Understandably, a gap is formed between the surface of the boss 2325 facing the flow collector 24 and the first surface 242 of the flow collector 24.

[0136] For example, the flow collector 24 is provided with a central hole 246, and the gap between the boss 2325 and the flow collector 24 is connected to the central hole 246.

[0137] In this embodiment, there is a certain gap between the boss 2325 and the current collector 24, so that the current collector 24 is less likely to affect the pressure relief of the end cover 23, ensuring that the end cover 23 can relieve pressure normally when the internal pressure or temperature of the battery cell 20 reaches the threshold.

[0138] This application provides a battery 100, including a housing 10 and a battery cell 20 provided in any of the above embodiments, wherein the battery cell 20 is housed within the housing 10.

[0139] This application provides an electrical device, including the battery 100 provided in any of the above embodiments.

[0140] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0141] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The shell has an opening; An electrode assembly is housed within the housing. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The electrode assembly is a wound structure formed by winding the positive electrode, the separator, and the negative electrode. An end cap, connected to the housing, closes the opening; A current collector is located inside the housing and disposed on the side of the electrode assembly facing the end cap; the current collector connects the end cap and the electrode assembly. The end cap includes a connecting portion connected to the current collecting member. Along the thickness direction of the end cap, the surface of the current collecting member facing the end cap is provided with a receiving groove. The connecting portion is at least partially accommodated in the receiving groove. The receiving groove has a first groove bottom surface and a first groove side surface. The first groove side surface is connected to the first groove bottom surface. Along the thickness direction, the first groove bottom surface faces the connecting portion. Along a first direction, the first groove side surface is located inside the connecting portion. The first direction is perpendicular to the thickness direction. The receiving groove also includes a second groove side surface. The second groove side surface is connected to the first groove bottom surface. Along the first direction, the second groove side surface is located outside the connecting portion. Along the first direction, both the first groove side surface and the second groove side surface are spaced apart from the connecting portion.

2. The battery cell according to claim 1, characterized in that, The receiving groove is a closed groove that extends circumferentially along the flow collecting member and is connected end to end.

3. The battery cell according to claim 2, characterized in that, The receiving groove is an annular groove.

4. The battery cell according to claim 1, characterized in that, The angle between the side surface of the first groove and the bottom surface of the first groove is θ1, which satisfies: 90°<θ1<180°.

5. The battery cell according to claim 4, characterized in that, The angle between the side surface of the second groove and the bottom surface of the first groove is θ2, which satisfies: 90°<θ2<180°.

6. The battery cell according to claim 1, characterized in that, The angle between the side surface of the second groove and the bottom surface of the first groove is θ2, which satisfies: 90°<θ2<180°.

7. The battery cell according to claim 1, characterized in that, The receiving groove includes a first groove side and a second groove side. Along a first direction, the first groove side and the second groove side are respectively located on both sides of the connecting portion. The first direction is perpendicular to the thickness direction. The distance between the side surface of the first groove and the side surface of the second groove in the first direction gradually decreases along the depth direction of the receiving groove.

8. The battery cell according to any one of claims 1-7, characterized in that, The current collection component includes: A first connection area is connected to the connection part, and the first connection area is formed at the position where the receiving groove is located on the flow collecting member; The second connection area is connected to the electrode assembly; Wherein, the projections of the first connection area and the second connection area onto a plane perpendicular to the thickness direction do not overlap.

9. The battery cell according to claim 8, characterized in that, The first connection area is arranged around the outside of the second connection area.

10. The battery cell according to claim 8, characterized in that, The thickness of the second connection area is L, and the depth of the receiving groove is H, satisfying: 0.15≤H / L<1.

11. The battery cell according to any one of claims 1-7, characterized in that, The receiving groove has a first groove bottom surface, and the connecting portion abuts against the first groove bottom surface along the thickness direction.

12. The battery cell according to any one of claims 1-7, characterized in that, The current collection component is welded to the connecting part.

13. The battery cell according to any one of claims 1-7, characterized in that, The connecting part is a closed structure that extends circumferentially along the end cap and is connected end to end.

14. The battery cell according to any one of claims 1-7, characterized in that, The end cap also includes: The body portion is connected to the housing. Along the thickness direction, the body portion has opposing inner and outer surfaces. The inner surface faces the current collecting member, and the connecting portion protrudes from the inner surface. A recess is provided at a position corresponding to the connecting portion of the main body portion, and the recess is recessed from the outer surface towards the current collecting member.

15. The battery cell according to claim 14, characterized in that, The main body includes a pressure relief section, the connecting section surrounds the pressure relief section, and the pressure relief section is provided with a groove.

16. The battery cell according to claim 15, characterized in that, The pressure relief section protrudes locally toward the flow collecting member and forms a boss, and a groove is formed on the side of the pressure relief section away from the flow collecting member at a position corresponding to the boss; The boss has a groove on its surface facing the current collecting member; and / or, the groove has a second bottom surface, and the groove is provided on the second bottom surface.

17. The battery cell according to claim 16, characterized in that, Along the thickness direction, the boss is spaced apart from the current collecting member.

18. A battery, characterized in that, include: Box; The battery cell as described in any one of claims 1-17, wherein the battery cell is housed within the casing.

19. An electrical appliance, characterized in that, Includes the battery as described in claim 18.

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