Battery cell, battery, and electric device

Abstract

The present application relates to a battery cell, a battery, and an electric device. The battery cell comprises a casing, a cell core, a current collecting disc, and a cover plate. During assembly of the cover plate, the cover plate covers an opening of the casing, and a protruding portion of the cover plate extends into the casing from the opening. The side surface of the protruding portion abuts against positioning portions of a flange, so that the cover plate can be positioned in the radial direction. Since a welding region of the flange is located between every two adjacent positioning portions, a weld mark generated by welding the flange and the inner wall of the casing is also located between the two positioning portions. Moreover, since in the radial direction of the current collecting disc, the height of each weld mark is not higher than the height of each positioning portion, the weld mark can be prevented from abutting against the protruding portion under the support of the positioning portion, or the weld mark is just in contact with the protruding portion without affecting the abutting between the positioning portion and the protruding portion. Therefore, even if uneven weld marks are formed, the radial positioning accuracy of the cover plate is not affected, thereby improving the assembly accuracy of the battery cell.

Description

Battery cells, batteries and electrical devices

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202422563304.0, filed on October 23, 2024, entitled "Battery Cell, Battery and Electrical Device"; Chinese Patent Application No. 202422562861.0, filed on October 23, 2024, entitled "Battery Cell, Battery and Electrical Device"; and Chinese Patent Application No. 202422623171.1, filed on October 29, 2024, entitled "A Battery Cell, Battery and Electrical Device", the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] During battery cell assembly, a current collector is typically used to connect the casing and the cell, thus treating the casing as an electrode. A battery cell includes an electrode assembly and a current collector. When the current collector is pressed down and squeezed against the electrode assembly, the electrode assembly is easily damaged, affecting battery safety. Simultaneously, to ensure a larger current flow area and better heat dissipation, the current collector needs to be flanged to increase its contact area with the inner wall of the casing. However, on the one hand, the flanged current collector may interfere with the bottom cover, preventing proper positioning and affecting assembly accuracy. On the other hand, the flanged current collector can create uneven weld marks during welding, which may interfere with the cover plate, resulting in poor cover plate positioning accuracy and consequently affecting the overall assembly accuracy of the battery cell.

[0005] Application content

[0006] Therefore, it is necessary to provide a battery cell, battery, and power device that can improve assembly accuracy in response to the above problems.

[0007] According to a first aspect of this application, a battery cell is provided, the battery cell comprising: a housing; an electrode assembly housed within the housing, the electrode assembly having an axial end face disposed along its axial direction, the axial end face including a tab region and an outer edge region, the outer edge region being disposed around the tab region circumferentially around the electrode assembly; and a current collector housed within the housing and disposed on one side of the electrode assembly along the axial direction, the current collector facing the axial end face, the current collector including a body, an edge portion and a flange, the edge portion being disposed around the body circumferentially around the current collector, the flange extending relative to the edge portion in a direction away from the electrode assembly and electrically connected to the housing; wherein, the body has a welding portion, the welding portion having a welding surface, the welding surface being in contact with the tab region, the edge portion and the flange together covering the outer edge region on the axial end face along the axial direction of the electrode assembly, and the edge portion and the flange being spaced apart from the outer edge region.

[0008] In some embodiments, the edge portion includes a first segment and a second segment, the first segment being connected to the main body and the second segment being connected between the first segment and the folded edge; at least the distance between the second segment and the outer edge region gradually decreases radially outward from the collector plate.

[0009] In some implementations, the cross-section of the second segment is arc-shaped.

[0010] In some implementations, the distance between the folded edge and the connection point of the second segment and the outer edge area is L2, where 0.02mm≤L2≤0.1mm.

[0011] In some embodiments, the main body also includes multiple reinforcing parts, and the welding part includes a central welding part and multiple outer welding parts. The outer welding parts and reinforcing parts are alternately arranged outside the central welding part along the circumference of the collector plate, and both the outer welding parts and the reinforcing parts are connected to the edge part. The surface of the reinforcing part facing the electrode assembly is recessed relative to the welding surface in the direction away from the electrode assembly and is spaced apart from the tab area. The surface of the reinforcing part facing away from the electrode assembly protrudes from the portion of the welding part that has a welding surface and is parallel to the axial end face.

[0012] In some implementations, the distance between the edge portion and the outer edge region gradually increases radially outward from the collector plate.

[0013] In some embodiments, the main body also includes multiple reinforcing portions, and the welding portion includes a central welding portion and multiple outer welding portions. The outer welding portions and reinforcing portions are alternately arranged outside the central welding portion along the circumference of the collector plate, and both the outer welding portions and the reinforcing portions are connected to the edge portion. The surface of the reinforcing portion facing the electrode assembly is recessed relative to the welding surface in the direction away from the electrode assembly and is spaced apart from the electrode tab region. The surface of the reinforcing portion away from the electrode assembly protrudes from the portion of the welding portion having a welding surface and parallel to the axial end face, and the edge portion protrudes from the surface of the reinforcing portion away from the electrode assembly.

[0014] In some implementations, the width of the outer edge region is L4, where 2mm ≤ L4 ≤ 3mm.

[0015] Compared with the prior art, this application has the following beneficial effects:

[0016] The aforementioned battery cells, batteries, and power devices all have their edges and folds projected onto the axial end face along the axis of the electrode assembly, collectively covering the outer edge region. Furthermore, the edges and folds are spaced apart from the outer edge region. Therefore, when the current collector is pressed down, the edges and folds will not contact the outer edge, and consequently, the current collector will not contact the outer edge region. This reduces the risk of damage to the outer edge region caused by the current collector's pressure, thereby reducing the risk of damage to the electrode assembly and improving battery safety.

[0017] According to a second aspect of this application, a battery cell is provided, including a housing, a battery cell, a current collector, and a cover plate; the housing has an opening at at least one end, and the battery cell is housed within the housing; the current collector includes a disk body and a flange extending along the periphery of the disk body, the current collector is housed within the housing, and the flange is welded to the inner wall of the housing; the cover plate includes a protrusion that extends into the housing through the opening and abuts against the inner wall of the housing, and the flange provides clearance for the protrusion.

[0018] In some embodiments, the flange is inclined outward relative to the disc body, and the collector disc is interference-fitted with the housing so that the flange elastically abuts against the inner wall of the housing.

[0019] In some embodiments, the flange has multiple notches spaced apart along the extension direction of the flange.

[0020] In some embodiments, the outer diameter of the protrusion decreases along the axial direction of the housing from the opening toward the interior of the housing.

[0021] In some embodiments, the outer diameter of the protrusion remains consistent along the axial direction of the housing from the opening towards the interior of the housing.

[0022] In some embodiments, the cover plate is partially recessed inward to form a circular groove on the side of the cover plate facing away from the battery cell, and a protrusion is formed on the side of the cover plate facing the battery cell.

[0023] In some embodiments, the cover plate is partially recessed inward to form a circumferentially extending annular groove on the side of the cover plate opposite to the battery cell, and a protrusion is formed on the side of the cover plate facing the battery cell.

[0024] In some embodiments, the cover plate also includes a retaining portion extending circumferentially along the protrusion, the retaining portion overlapping the end face of the opening to position the cover plate axially along the housing.

[0025] In some embodiments, the outer diameter of the abutment is less than or equal to the outer diameter of the housing and greater than the inner diameter of the opening.

[0026] In some embodiments, the disk body is recessed on the side facing the battery cell to form a receiving cavity, and an upwardly convex structure is formed on the side of the disk body facing away from the battery cell, with the battery cell portion located inside the receiving cavity.

[0027] In some embodiments, the upper convex structure abuts against the protrusion along the axial direction of the housing.

[0028] In some implementations, a gap is formed between the cover plate and the disc body.

[0029] In some embodiments, a flexible support is also included, which fills the gap.

[0030] In some embodiments, the total height of the manifold and cover plate in the axial direction of the housing is greater than or equal to 1.5 mm and less than or equal to 5 mm.

[0031] In some embodiments, the edge of the protrusion facing the inner wall of the housing forms a first chamfer, and the edge of the flange facing away from the inner wall of the housing forms a second chamfer, with the first chamfer and the second chamfer overlapping in the radial projection of the housing.

[0032] Compared with the prior art, this application has the following beneficial effects:

[0033] In the aforementioned battery cell, during cover assembly, the cover is placed over the opening of the housing. The protruding part of the cover extends into the housing through the opening and abuts against the inner wall of the housing, thereby radially positioning the cover. The supporting part of the cover abuts against the end face of the opening, thereby axially positioning the cover. Furthermore, because the flange provides clearance for the protruding part and does not extend between the side wall of the protruding part and the inner wall of the housing, the flange does not interfere with the cover. Therefore, the positioning accuracy of the cover is high, thereby improving the assembly accuracy of the aforementioned battery cell.

[0034] According to a third aspect of this application, a battery cell is provided, including a housing, a cell, a current collector, and a cover plate. The housing has an opening at at least one end. The current collector includes a disk body and a flange extending along the periphery of the disk body. The flange has a plurality of spaced positioning portions and a welding area located between two adjacent positioning portions in the circumferential direction. The inner wall of the flange protrudes to form the positioning portions. The welding area is welded to the inner wall of the housing to form a weld mark, and the height of the weld mark in the radial direction of the current collector is not higher than the height of the positioning portions. The cover plate includes a protrusion protruding in the direction of the current collector. The protrusion extends into the housing through the opening and abuts against the positioning portions to position the cover plate radially along the housing.

[0035] In some embodiments, the flange is partially recessed inward, the outer wall of the flange is correspondingly formed with a recess, and a positioning part is formed on the inner wall of the flange at a position corresponding to the recess.

[0036] In some implementations, the wall thickness of the positioning part is less than the wall thickness of the welding area.

[0037] In some embodiments, the wall thickness of the area where the positioning part is located is greater than the wall thickness of the area where the welding area is located, and the outer wall of the flange has a smoothly transitioning curved surface.

[0038] In some embodiments, multiple positioning parts are equally spaced along the circumference of the flange, and a solder mark is formed between each pair of adjacent positioning parts.

[0039] In some embodiments, the width of the positioning part in the circumferential direction of the flange is smaller than the width of the welding area in the circumferential direction of the flange.

[0040] In some embodiments, the width of the positioning part in the circumferential direction of the flange is greater than or equal to 10 mm.

[0041] In some embodiments, the height of the positioning part in the radial direction of the collector plate is greater than or equal to 0.3 mm and less than or equal to 2 mm.

[0042] In some embodiments, the flange is inclined outward relative to the disc body, and the collector disc is interference-fitted with the housing, with the flange elastically abutting against the inner wall of the housing.

[0043] In some embodiments, the cover plate also includes a retaining portion extending circumferentially along the protrusion, the retaining portion overlapping the end face of the opening to position the cover plate axially along the housing.

[0044] In some embodiments, the outer diameter of the abutment is less than or equal to the outer diameter of the housing and greater than the inner diameter of the opening.

[0045] In some embodiments, the cover plate is partially recessed inward, with a circular groove formed on the side of the cover plate facing away from the battery cell, and a protrusion formed on the side of the cover plate facing the battery cell.

[0046] In some embodiments, the cover plate is partially recessed inward, with a corresponding annular groove extending circumferentially formed on the side of the cover plate facing away from the battery cell, and a corresponding protrusion formed on the side of the cover plate facing the battery cell.

[0047] In some embodiments, the disk body is recessed on the side facing the battery cell to form a receiving cavity, and a protruding structure is formed on the side of the disk body facing away from the battery cell, with the battery cell portion located inside the receiving cavity.

[0048] In some embodiments, the protrusion abuts against the protrusion along the axial direction of the housing.

[0049] Compared with the prior art, this application has the following beneficial effects:

[0050] In the aforementioned battery cell, during cover assembly, the cover is placed over the opening of the housing, with the protruding portion of the cover extending into the housing through the opening. The side of the protruding portion abuts against the positioning portion of the flange, thus achieving radial positioning of the cover. Since the welding area of ​​the flange is located between two adjacent positioning portions, the weld marks resulting from the welding of the flange to the inner wall of the housing are also located between the two positioning portions. Furthermore, since the height of the weld marks in the radial direction of the current collector is no higher than the height of the positioning portions, the support of the positioning portions prevents the weld marks from contacting the protruding portion, or ensures that they just make contact without affecting the contact between the positioning portions and the protruding portion. Therefore, even if the weld marks are uneven, they will not affect the radial positioning accuracy of the cover, thereby improving the assembly accuracy of the aforementioned battery cell.

[0051] According to a fourth aspect of this application, a battery is provided, comprising the aforementioned battery cell.

[0052] According to a fifth aspect of this application, an electrical device is also provided, comprising the aforementioned battery cell or the aforementioned battery. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0055] Figure 2 is a cross-sectional view of the battery cell shown in Figure 1;

[0056] Figure 3 is an enlarged schematic diagram of a portion A in the battery cell shown in Figure 2 in one embodiment of this application;

[0057] Figure 4 is a schematic diagram of the current collector in the battery cell shown in Figure 1 in one embodiment of this application;

[0058] Figure 5 is an enlarged schematic diagram of part B in the collector plate shown in Figure 4;

[0059] Figure 6 is a schematic diagram of the cover plate in the battery cell shown in Figure 1;

[0060] Figure 7 is an enlarged schematic diagram of a portion A in the battery cell shown in Figure 2 in another embodiment of this application;

[0061] Figure 8 is a schematic diagram of the structure of the cover plate in the battery cell shown in Figure 1 in another embodiment of this application;

[0062] Figure 9 is an enlarged schematic diagram of a portion A in the battery cell shown in Figure 2 in another embodiment of this application;

[0063] Figure 10 is an enlarged schematic diagram of a portion A in the battery cell shown in Figure 2 in another embodiment of this application;

[0064] Figure 11 is a schematic diagram of the current collector in the battery cell shown in Figure 1 in another embodiment of this application;

[0065] Figure 12 is a schematic diagram of the current collector in the battery cell shown in Figure 1 in another embodiment of this application;

[0066] Figure 13 is a schematic diagram of the structure of a single battery cell in another embodiment of this application;

[0067] Figure 14 is a top view of the battery cell in the battery cell shown in Figure 13;

[0068] Figure 15 is a schematic diagram of the structure of the battery cell shown in Figure 13 after the cover is removed;

[0069] Figure 16 is a top view of the battery cell shown in Figure 15;

[0070] Figure 17 is a cross-sectional view of the battery cell shown in Figure 16 along the CC direction;

[0071] Figure 18 is an enlarged schematic diagram of a local structure D in the battery cell shown in Figure 17;

[0072] Figure 19 is a schematic diagram of the structure of partial structure D in the battery cell shown in Figure 18 after the shell is removed;

[0073] Figure 20 is a schematic diagram of the current collector in the battery cell shown in Figure 15;

[0074] Figure 21 is a cross-sectional view of the manifold shown in Figure 20 along the EE direction;

[0075] Figure 22 is an enlarged schematic diagram of a local structure G in the collector plate shown in Figure 21;

[0076] Figure 23 is a cross-sectional view of the collector plate shown in Figure 20 along the FF direction;

[0077] Figure 24 is an enlarged schematic diagram of a local structure H in the collector plate shown in Figure 23;

[0078] Figure 25 is a schematic diagram of the structure of a single battery cell in another embodiment of this application;

[0079] Figure 26 is a schematic diagram of the structure of the battery cell shown in Figure 25 after the cover is removed;

[0080] Figure 27 is a top view of the battery cell shown in Figure 26;

[0081] Figure 28 is a cross-sectional view of the battery cell shown in Figure 27 along direction II;

[0082] Figure 29 is an enlarged schematic diagram of a local structure J in the battery cell shown in Figure 28;

[0083] Figure 30 is a schematic diagram of the current collector in the battery cell shown in Figure 26;

[0084] Figure 31 is a cross-sectional view of the collector plate shown in Figure 30 along the KK direction;

[0085] Figure 32 is an enlarged schematic diagram of a local structure L in the collector plate shown in Figure 31;

[0086] Figure 33 is a cross-sectional view of the collector plate shown in Figure 30 along the MM direction;

[0087] Figure 34 is an enlarged schematic diagram of a local structure N in the collector plate shown in Figure 33.

[0088] The above figures include the following reference numerals:

[0089] 100. Battery cell; 101. Gap; 110. Casing; 120. Cell; 121. Axial end face; 1211. Tab area; 1212. Outer edge area; 1213. Inner edge area; 1214. Center hole; 130. Current collector; 131. Disk body; 1311. Welded part; 1311a. Center welded part; 1311b. Outer welded part; 1311c. Welded surface; 1312. Reinforcing part; 1 313. Receiving cavity; 1314. Protruding structure; 132. Flanged edge; 1321. Positioning part; 1322. Weld mark; 1323. Recessed part; 1324. Second chamfer; 1325. Notch; 133. Edge part; 1331a. First section; 1331b. Second section; 140. Cover plate; 141. Protrusion; 1411. First chamfer; 142. Supporting part; 143. Circular groove; 144. Annular groove. Detailed Implementation

[0090] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0091] In the description of this application, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0094] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0095] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0096] Please refer to Figure 1. This application provides a battery cell 100. Furthermore, this application also provides a battery and an electrical device.

[0097] The aforementioned electrical device includes the aforementioned battery or the aforementioned battery cell 100, and is capable of being powered by the aforementioned battery or the aforementioned battery cell 100. The aforementioned electrical device may be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, energy storage device, amusement equipment, elevator, and lifting equipment, etc. Spacecraft may 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, or 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.; energy storage devices may be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment may be a carousel, a drop tower, etc. It should be understood that the technical solutions described in the embodiments of this application are not limited to the aforementioned electrical devices.

[0098] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended vehicles, etc. For new energy vehicles, the aforementioned battery can serve as a driving power source, thereby replacing fossil fuels to provide propulsion. This application does not impose any special restrictions on the aforementioned electrical devices.

[0099] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells 100. The multiple battery cells 100 can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system to form a battery pack. The battery management system controls and monitors the operating status of each battery cell 100. Alternatively, the multiple battery cells 100 can first be connected in series and / or parallel, and then connected with a module management system to form a battery module. These battery modules can then be electrically connected in series, parallel, or a combination of series and parallel connections, and together with the battery management system, form a battery pack.

[0100] In this battery pack or module, multiple battery cells 100 can be mounted on supporting structures such as housings, frames, or brackets. The individual battery cells 100 and the battery management system can be electrically connected via busbars. Each battery cell 100 can be a lithium-ion, sodium-ion, or magnesium-ion battery, and its external outline can be cylindrical. Specifically, in this embodiment, the battery cell 100 is a cylindrical lithium-ion battery.

[0101] Please refer to Figures 2 and 3 together. In one embodiment of this application, the battery cell 100 includes a housing 110, a cell 120, a current collector 130, and a cover plate 140.

[0102] The housing 110 can be formed from materials such as aluminum or stainless steel, and has an internal space to accommodate the battery cell 120, electrolyte, and other components. Furthermore, the housing 110 has an opening at at least one end, through which the battery cell 120 can be inserted. Specifically, the housing 110 is cylindrical, and the battery cell 120, matching the internal space of the housing 110, is generally also cylindrical.

[0103] The current collector 130 is disposed inside the housing 110 and is used to connect the battery cell 120 and the inner wall of the housing 110, thereby making the housing 110 an electrode of the battery cell 100, such as the negative electrode. Specifically, the current collector 130 can be pre-welded to the tab of the battery cell 120 and inserted into the housing 110 together with the battery cell 120 through the opening, and then welded to the inner wall of the housing 110. The cover plate 140 is welded to the housing 110 and covers the opening of the housing 110, thereby sealing the opening of the housing 110 to form a relatively sealed environment inside the housing 110.

[0104] Please refer to Figures 4, 5, and 11 together. The current collector 130 includes a body 131 and a flange 132, which extends along the periphery of the body 131. The body 131 and the flange 132 are usually integrally formed. The flange 132 is bent relative to the body 131 and protrudes axially relative to the surface of the body 131. The body 131 is generally coaxially arranged with the housing 110 and welded to the tabs of the cell 120, while the flange 132 is attached to and welded to the inner wall of the housing 110.

[0105] Specifically, in this embodiment, the flange 132 is inclined outward relative to the disk body 131, and the collector disk 130 is interference-fitted with the housing 110 so that the flange 132 elastically abuts against the inner wall of the housing 110. Thus, during the process of the collector disk 130 being installed into the housing 110, the inner wall of the housing 110 will force the flange 132 to undergo elastic deformation, thereby generating an elastic force acting on the inner wall of the housing 110. Under the action of this elastic force, the flange 132 can fit tightly against the inner wall of the housing 110, thereby ensuring that the relative position between the flange 132 and the inner wall of the housing 110 remains stable.

[0106] Furthermore, the flange 132 has a plurality of spaced-apart positioning portions 1321 and a welding area located between two adjacent positioning portions 1321 along the circumferential direction. The positioning portions 1321 are formed by protrusions on the inner wall of the flange 132, and the welding area is welded to the inner wall of the housing 110 to form a weld mark 1322. Moreover, the height of the weld mark 1322 in the radial direction of the manifold 130 is not higher than the height of the positioning portions 1321.

[0107] The weld marks 1322 between the flange 132 and the inner wall of the housing 110 are discontinuous rather than continuous, with multiple discontinuous weld marks 1322 separated by positioning portions 1321. Furthermore, since the height of the weld marks 1322 is no higher than the height of the positioning portions 1321, the weld marks 1322 can only be flush with the positioning portions 1321, or the weld marks 1322 are confined between the two positioning portions 1321 and do not extend beyond the outer edge of the positioning portions 1321. In one embodiment, the height of the weld marks 1322 is lower than the height of the positioning portions 1321, thus the weld marks 1322 are confined between the two positioning portions 1321 and do not extend beyond the outer edge of the positioning portions 1321.

[0108] Understandably, in the radial direction of the manifold 130, the height of the positioning part 1321 refers to the protrusion height of the positioning part 1321 relative to the inner wall of the flange 132, and the height of the solder mark 1322 can be understood as the thickness of the solder mark 1322.

[0109] Specifically, in this embodiment, the height of the positioning part 1321 in the radial direction of the collector plate 130 is greater than or equal to 0.3 mm and less than or equal to 2 mm. Specifically, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm...1.8 mm, 1.9 mm, 2.0 mm. This is because the height of the weld mark 1322 formed by laser welding is generally less than 0.3 mm. Therefore, setting the height of the positioning part 1321 in the radial direction of the collector plate 130 to be greater than or equal to 0.3 mm ensures that the height of the weld mark 1322 is lower than the height of the positioning part 1321. However, if the height of the positioning part 1321 is greater than 2 mm, the size of the flange 132 will be increased, resulting in greater processing difficulty.

[0110] Specifically, in this embodiment, the width of the positioning part 1321 in the circumferential direction of the flange 132 is smaller than the width of the welding area in the circumferential direction of the flange 132. That is, the welding area accounts for a larger proportion of the flange 132 compared to the positioning part 1321, thus increasing the area of ​​the welding area. This ensures that the formed weld mark 1322 has a larger size, thereby guaranteeing the flow area between the collector plate 130 and the housing 110 and avoiding the flow capacity between the collector plate 130 and the housing 110 being affected by the discontinuous structure of the formed weld mark 1322.

[0111] Furthermore, in this embodiment, the flange 132 is partially recessed inward to form a recessed portion 1323 on the outer wall of the flange 132, and a positioning portion 1321 is formed on the inner wall of the flange 132 at a position corresponding to the recessed portion 1323.

[0112] As can be understood, the inner wall of the flange 132 refers to the flange 132 being away from the surface of the housing 110 in the radial direction of the collecting plate 130; the outer wall of the flange 132 refers to the flange 132 being towards the surface of the housing 110 in the radial direction of the collecting plate 130; and "inward" refers to the direction from the outer wall of the flange 132 to the inner wall of the flange 132.

[0113] Specifically, the recess 1323 and the positioning portion 1321 can be simultaneously formed on the flange 132 by stamping. This eliminates the need for additional material during the forming of the positioning portion 1321, thus helping to reduce the weight of the manifold 130 and simplify manufacturing. Furthermore, a gap is formed between the area of ​​the outer wall of the flange 132 corresponding to the recess 1323 and the inner wall of the housing 110. This gap allows for the release of welding stress, preventing stress concentration during welding of the flange 132 and avoiding problems such as deformation or cracking at the weld.

[0114] Furthermore, since the stamping process compresses the material in the stamped area, resulting in a reduction in the thickness of that area, the wall thickness of the positioning part 1321 is generally less than that of the welding area. Specifically, during the stamping process, the material in the stamped area flows to the unstamped area, thus relatively reducing the thickness of the positioning part 1321 and correspondingly increasing the thickness of the welding area. This relatively increased thickness of the welding area helps ensure the weld penetration depth, thereby further guaranteeing the weld quality.

[0115] Of course, the positioning portion 1321 can also be formed on the flange 132 by locally thickening it. For example, in another embodiment, the wall thickness of the area where the positioning portion 1321 is located is greater than the wall thickness of the area where the welding area is located, and the outer wall of the flange 132 has a smoothly transitioned curved surface.

[0116] At this point, there is no need to stamp the flange 132, so the outer wall of the flange 132, i.e. the side facing the inner wall of the housing 110, is a smoothly transitioned curved surface. In this way, when the flange 132 fits against the inner wall of the housing 110, it will not be easy for gaps to be generated between them, thereby increasing the contact area between the collector plate 130 and the inner wall of the housing 110 and improving assembly stability.

[0117] The positioning part 1321 can abut against the cover plate 140, thereby positioning the cover plate 140 radially along the housing 110. More specifically, in this embodiment, the width of the positioning part 1321 in the circumferential direction of the flange 132 is greater than or equal to 10 mm. If the width of the positioning part 1321 is less than 10 mm, the contact area between the positioning part 1321 and the protrusion 141 of the cover plate 140 will be too small during subsequent positioning, thus affecting the radial positioning effect of the cover plate 140.

[0118] Please refer to Figures 3, 6 to 7, and 9 to 10. The cover plate 140 includes a protrusion 141 that protrudes toward the collector plate 130. The protrusion 141 extends into the housing 110 through the opening and abuts against the positioning part 1321 to position the cover plate 140 radially along the housing 110.

[0119] Specifically, a cover plate 140 with protrusions 141 can be formed by stamping a sheet material. By stamping, a structure with opposing concave and convex sections is obtained on both sides of the cover plate 140, increasing its structural strength. Furthermore, the protrusions, serving as protrusions 141, do not require additional material, reducing the weight of the cover plate 140 and saving costs. In one embodiment, referring to Figures 3 and 6, the cover plate 140 is partially recessed inward to form a circular groove 143 on the side of the cover plate 140 facing away from the battery cell 120, and a protrusion 141 is formed on the side of the cover plate 140 facing the battery cell 120. That is, the recessed area on the side of the cover plate 140 facing away from the battery cell 120 is larger, resulting in a columnar protrusion 141.

[0120] In another embodiment, referring to Figures 7 and 8, the cover plate 140 is partially recessed inward to form an annular groove 144 extending circumferentially on the side of the cover plate 140 opposite to the battery cell 120, and a protrusion 141 is formed on the side of the cover plate 140 facing the battery cell 120. That is, the recessed area of ​​the cover plate 140 on the side opposite to the battery cell 120 is annular, and the resulting protrusion 141 is cylindrical.

[0121] Since the height of the weld mark 1322 on the radial side of the collector plate 130 is no higher than the height of the positioning part 1321, the weld mark 1322 can avoid contact with the protrusion 141 when it abuts against the positioning part 1321. Alternatively, the weld mark 1322 can just contact the protrusion 141, but will not interfere with the contact between the positioning part 1321 and the protrusion 141. It can be seen that the radial positioning of the cover plate 140 is achieved by the cooperation between the side of the protrusion 141 and the positioning part 1321 of the flange 132, and does not depend on the collector plate 130. Therefore, even if the weld mark 1322 is uneven, it will not affect the radial positioning accuracy of the cover plate 140.

[0122] Furthermore, in this embodiment, multiple positioning portions 1321 are evenly spaced along the circumference of the flange 132, and a solder mark 1322 is formed between every two adjacent positioning portions 1321. Therefore, when the positioning portions 1321 cooperate with the protrusion 141 for positioning, the multiple positioning portions 1321 apply force to the protrusion 141, making the force on the protrusion 141 more balanced and the positioning effect better. Moreover, the solder mark 1322 is also distributed at intervals along the circumference of the flange 132, which helps to improve the reliability of the welding between the collector plate 130 and the housing 110.

[0123] Please refer to Figure 3 again. Since the flange 132 extends between the protrusion 141 and the inner wall of the housing 110, the cover plate 140 and the current collector 130 can share part of the space in the axial direction of the housing 110, thereby improving the space utilization rate inside the housing 110 and helping to improve the energy density of the battery cell 100.

[0124] Obviously, considering the need to save internal space of the housing 110, the cover plate 140 can also contact the disc 131, as long as the disc 131 does not interfere with the fit between the protrusion 141 and the inner wall of the housing 110.

[0125] Furthermore, in this embodiment, as shown in FIG9, the disk 131 is recessed on the side facing the cell 120 to form a receiving cavity 1313, and a protruding structure 1314 is formed on the side of the disk 131 facing away from the cell 120, with the cell 120 partially located within the receiving cavity 1313. It can be seen that the cell 120 and the current collector 130 can also share a portion of the space in the axial direction of the housing 110, thereby improving the space utilization rate inside the housing 110 and helping to further improve the energy density of the battery cell 100.

[0126] Furthermore, the protruding structure 1314 protrudes towards the cover plate 140 and can abut against the protrusion 141 along the axial direction of the housing 110. Therefore, the cooperation between the protruding structure 1314 and the protrusion 141 can also increase the stability of the overall structure along the axial direction of the battery cell 100, thereby preventing shaking inside the battery cell 100.

[0127] Please refer again to Figures 3, 6 to 7, and 9 to 10. In this embodiment, the cover plate 140 further includes a supporting portion 142 extending circumferentially along the protrusion 141. The supporting portion 142 overlaps with the end face of the opening of the housing 110 to position the cover plate 140 along the axial direction of the housing 110.

[0128] When assembling the cover plate 140, the protrusion 141 is first inserted into the opening of the housing 110 until the supporting part 142 abuts against the end face of the opening of the housing 110, thus achieving radial and axial positioning of the cover plate 140. It can be seen that the protrusion 141 does not need to abut against the collector plate 130 to axially position the cover plate 140, thereby avoiding the cover plate 140 applying axial pressure to the collector plate 130 and preventing the flange 132 from detaching from the inner wall of the housing 110 due to axial pressure. Moreover, since the axial positioning of the cover plate 140 does not depend on the collector plate 130, the accuracy of axial positioning is also high.

[0129] On the other hand, since the supporting part 142 overlaps with the end face of the opening of the housing 110, it can also provide a better welding position. Specifically, laser caulking welding can be used to weld the joint between the housing 110 and the cover plate 140 along the side, thereby avoiding the welding laser from welding through the cover plate 140 in the axial direction and damaging the components such as the battery cell 120 inside the housing 110.

[0130] Furthermore, in this embodiment, the outer diameter of the supporting portion 142 is less than or equal to the outer diameter of the housing 110 and greater than the inner diameter of the opening.

[0131] When the supporting portion 142 overlaps the end face of the opening of the housing 110, in the radial direction, the outer edge of the supporting portion 142 is located between the outer wall and the inner wall of the housing 110, or the outer edge of the supporting portion 142 is flush with the outer wall of the housing 110. When the outer edge of the supporting portion 142 is located between the outer wall and the inner wall of the housing 110, a step can be formed between the outer edge of the supporting portion 142 and the end face of the opening of the housing 110. When the cover plate 140 is welded to the housing 110, a molten pool weld mark will be formed on this step, and the laser weld mark between the housing 110 and the cover plate 140 will be contained within the step, preventing the laser weld mark from protruding from the outer wall of the housing 110 to ensure the flatness of the overall appearance of the battery cell 100. When the outer edge of the supporting portion 142 is flush with the outer wall of the housing 110, the height difference at the joint will be eliminated, thus helping to improve the welding effect.

[0132] When assembling the cover plate 140, the battery cell 100 is placed over the opening of the housing 110, and the protrusion 141 of the cover plate 140 extends into the housing 110 through the opening. The side of the protrusion 141 abuts against the positioning portion 1321 of the flange 132, thereby positioning the cover plate 140 radially. Since the welding area of ​​the flange 132 is located between two adjacent positioning portions 1321, the weld mark 1322 produced by welding the flange 132 to the inner wall of the housing 110 is also located between the two positioning portions 1321. Moreover, since the height of the weld mark 1322 in the radial direction of the collector 130 is not higher than the height of the positioning portion 1321, the support of the positioning portion 1321 prevents the weld mark 1322 from contacting the protrusion 141, or just makes contact but does not affect the contact between the positioning portion 1321 and the protrusion 141. Therefore, even if the solder mark 1322 is uneven, it will not affect the radial positioning accuracy of the cover plate 140, thereby improving the assembly accuracy of the battery cell 100.

[0133] In existing battery cells, the flange of the current collector may interfere with the cover plate, causing the bottom cover to be unable to be positioned smoothly, thus affecting the assembly accuracy.

[0134] Furthermore, in another embodiment of this application, the battery cell 100 also has the housing 110, cell 120, current collector 130 and cover plate 140 with the above-described structure. The difference is that a part of the structure of the current collector 130 and the radial positioning method of the cover plate 140 are different from those in the above embodiment.

[0135] Specifically, the protrusion 141 extends into the housing 110 through the opening and abuts against the inner wall of the housing 110 to position the cover plate 140 radially along the housing 110.

[0136] Furthermore, the flange 132 provides clearance from the protrusion 141. That is, when the protrusion 141 abuts against the inner wall of the housing 110 to achieve radial positioning of the cover plate 140, the flange 132 does not extend between the side wall of the protrusion 141 and the inner wall of the housing 110, and therefore is not abutted by the protrusion 141. It is evident that the radial positioning of the cover plate 140 is achieved by the side of the protrusion 141 engaging with the inner wall of the housing 110, and is not related to the manifold 130. Therefore, even if welding causes unevenness on the surface of the flange 132, it will not affect the radial positioning accuracy of the cover plate 140.

[0137] Furthermore, in another embodiment of this application, as shown in FIG12, a plurality of notches 1325 are provided on the flange 132 at intervals along the extending direction of the flange 132. The notches 1325 on the flange 132 can be used to release welding stress, thereby avoiding stress concentration during welding of the flange 132, which could cause deformation, cracking, or other problems at the weld. It is understood that the aforementioned extending direction of the flange 132 refers to the circumferential extending direction of the flange 132.

[0138] In another embodiment of this application, the outer diameter of the protrusion 141 remains consistent along the axial direction of the housing 110 from the opening towards the interior of the housing 110. That is, the protrusion 141 is generally cylindrical, and its side surface is generally parallel to the inner wall of the housing 110. Therefore, when the side surface of the protrusion 141 abuts against the inner wall of the housing 110, the contact area between the two can be increased, thereby ensuring a better radial positioning effect.

[0139] In some other embodiments, the outer diameter of the protrusion 141 decreases along the axial direction of the housing 110 from the opening towards the interior of the housing 110. That is, the protrusion 141 has a structure that is thicker at the top and thinner at the bottom, and its side is inclined relative to the inner wall of the housing 110. In this way, the protrusion 141 can play a guiding role during insertion into the housing 110, and the side of the protrusion 141 can gradually press against the inner wall of the housing 110.

[0140] Please refer to Figure 10 again. In this embodiment, the protrusion 141 forms a first chamfer 1411 on the edge facing the inner wall of the housing 110, and the flange 132 forms a second chamfer 1324 on the edge facing away from the inner wall of the housing 110. The first chamfer 1411 and the second chamfer 1324 overlap in the radial projection of the housing 110.

[0141] Specifically, the first chamfer 1411 and the second chamfer 1324 can be rounded or straight chamfers. The arrangement of the first chamfer 1411 and the second chamfer 1324 can ensure that the edge of the flange 132 does not rub against the edge of the protrusion 141. Moreover, while ensuring that the flange 132 does not interfere with the protrusion 141, the current collector 130 and the cover plate 140 can be as close as possible, thereby saving axial space inside the housing 110 and helping to improve the energy density of the battery cell 100.

[0142] To further improve the energy density of the battery cell 100, specifically in this embodiment, the total height of the current collector 130 and the cover plate 140 in the axial direction of the housing 110 is greater than or equal to 1.5 mm and less than or equal to 5 mm. Specifically, this height can be 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm... 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm. In this way, the current collector 130 and the cover plate 140 occupy less space within the housing 110, effectively avoiding wasted space along the axial direction inside the housing 110, thereby reserving more space for the arrangement of the power cell 120 and improving the energy density. Specifically, the height of the cover plate 140 is generally between 0.5mm and 2mm, specifically, it can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm...1.7mm, 1.8mm, 1.9mm, 2.0mm; while the height of the manifold 130 is generally between 0.6mm and 2mm, specifically, the height of the manifold 130 is 0.6mm, 0.7mm, 0.8mm...1.8mm, 1.9mm, 2.0mm.

[0143] Furthermore, in this embodiment, a gap 101 is formed between the cover plate 140 and the disk body 131. This gap 101 can provide buffer space for the cell 120 to expand along the height direction, that is, the axial expansion of the battery cell 100, thereby preventing the cell 120 from expanding and breaking through the cover plate 140.

[0144] Furthermore, in this embodiment, the battery cell 100 also includes a flexible support member that fills the gap 101. Specifically, the flexible support member can be formed using flexible materials such as foam or silicone, providing flexible support for the battery cell 120 and playing a certain axial limiting role. Moreover, the flexible support member can also absorb vibration impact under vibration conditions, which helps to improve the reliability of the battery cell 100.

[0145] When assembling the cover plate 140, the battery cell 100 is placed over the opening of the housing 110. The protrusion 141 of the cover plate 140 extends into the housing 110 through the opening and abuts against the inner wall of the housing 110, thereby radially positioning the cover plate 140. Furthermore, since the flange 132 provides clearance for the protrusion 141 and does not extend between the side wall of the protrusion 141 and the inner wall of the housing 110, the flange 132 does not interfere with the cover plate 140. Therefore, the positioning accuracy of the cover plate 140 is high, thereby improving the assembly accuracy of the battery cell 100.

[0146] In the battery cell manufacturing process, when welding the tabs and current collectors of the cell, it is necessary to first use a tool to press down the current collector so that the current collector can fit tightly with the tabs, and then weld the tabs and current collectors to ensure welding quality and improve the battery's current carrying capacity.

[0147] However, when the current collector presses down and squeezes the cell, it can easily damage the cell, affecting battery safety. Careful research revealed that the main reason for this damage is that the cell has a wound structure. In the radial direction of the cell, from the inside out, the outer edge region, closer to the axial end face of the cell, experiences the greatest radial pressure and force. When the current collector presses down and contacts the axial end face of the cell, the outer edge region is also squeezed by the current collector. Under the combined effect of the large radial force and the squeezing action of the current collector, the outer edge region is easily damaged, leading to cell damage and compromising battery safety.

[0148] Please refer to Figures 13 to 24. To alleviate the above-mentioned problems, this application also provides a battery cell 100. The battery cell 100 includes a casing, a cell 120, and a current collector 130, both of which are housed within the casing. The cell 120 has an axial end face 121 disposed along its axial direction. The axial end face 121 includes a tab region 1211 and an outer edge region 1212. The outer edge region 1212 is disposed circumferentially around the tab region 1211 of the cell 120. A current collector 130 is arranged along the axial direction of the battery cell 120 on one side of the battery cell 120, and the current collector 130 is positioned facing the axial end face 121. The current collector 130 includes a disk body 131, an edge portion 133, and a flange 132. The edge portion 133 is arranged around the disk body 131 in the circumferential direction of the current collector 130. The flange 132 extends relative to the edge portion 133 in a direction away from the battery cell 120 and is electrically connected to the outer casing. The disk body 131 has a welding portion 1311, and the welding portion 1311 has a welding surface 1311c. The welding surface 1311c is in contact with the tab region 1211. The orthogonal projections of the edge portion 133 and the flange 132 along the axial direction of the battery cell 120 onto the axial end face 121 together cover the outer edge region 1212, and the edge portion 133 and the flange 132 are spaced apart from the outer edge region 1212.

[0149] As an example, the outer casing is cylindrical and includes a housing 110 and a cover plate 140. The housing 110 can be a structure with one end open and one end closed, or with both ends open. The cover plate 140 is disposed at the opening of the housing 110 and seals with the housing 110 to define the internal environment of the battery cell 100. When the battery cell 120 and the current collector 130 are disposed inside the housing, the housing can isolate the battery cell 120 and the current collector 130 from the external environment to reduce the impact of the external environment on the battery cell 120 and the current collector 130.

[0150] The battery cell 120 is the main component for charging and discharging the battery cell 100, and it has a wound structure. The axial end face 121 of the battery cell 120 also includes an inner edge region 1213, which surrounds and forms a central hole 1214 for electrolyte penetration. A tab region 1211 is circumferentially disposed around the inner edge region 1213, and an outer edge region 1212 is circumferentially disposed around the tab region 1211. The width of the outer edge region 1212 is L4, where 2mm ≤ L4 ≤ 3mm (as shown in Figure 14). Specifically, L4 is 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, or 3mm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The width of the outer edge region 1212 is the radial diameter of the outer edge region 1212 within the battery cell 120. The tab region 1211 of the axial end face 121 refers to the area covered by the flattened tab in the cell 120, while the inner edge region 1213 and outer edge region 1212 of the axial end face 121 are the areas outside the flattened tab. Flattening is understood to be a tab shaping method, whereby the tab is bent and fitted to the axial end face 121 of the cell 120 using specific tools or equipment.

[0151] The disk body 131 of the current collector 130 is the portion of the current collector 130 that is welded to the tab region 1211 of the axial end face 121. The disk body 131 has a welding portion 1311, which has a welding surface 1311c. The welding surface 1311c faces the battery cell 120 and is in contact with the tab region 1211 of the axial end face 121 of the battery cell 120. After contact, the welding portion 1311 is welded to the tab region 1211, thereby realizing the connection between the current collector 130 and the battery cell 120. The area of ​​the welding surface 1311c can be smaller than the area of ​​the tab region 1211, and the welding surface 1311c is partially attached to the tab region 1211. Alternatively, the area of ​​the welding surface 1311c can be equal to the area of ​​the tab region 1211, and the welding surface 1311c overlaps and is attached to the tab region 1211. The specific dimensions can be set as needed, as long as the orthographic projection of the welding surface 1311c on the axial end face 121 completely falls within the tab region 1211. The orthographic projection of the edge portion 133 on the axial end face 121 completely falls within the outer edge region 1212, while the orthographic projection of the flange 132 on the axial end face 121 at most partially falls within the outer edge region 1212. The flange 132 extends relative to the edge portion 133 in a direction away from the battery cell 120 and is electrically connected to the housing to achieve the connection between the current collector 130 and the housing. As an example, the flange 132 is perpendicular to the axial end face 121.

[0152] The orthographic projections of the edge portion 133 and the flange 132 along the axial direction of the cell 120 onto the axial end face 121 together cover the outer edge region 1212, and the edge portion 133 and the flange 132 are spaced apart from the outer edge region 1212. Therefore, when the current collector 130 is pressed down, the edge portion 133 and the flange 132 will not contact the outer edge, and consequently the current collector 130 will not contact the outer edge region 1212, thereby reducing the risk of the outer edge region 1212 being damaged by the current collector 130 (resulting in electrode material loss, short circuits, etc.), which in turn reduces the risk of damage to the cell 120 and improves the safety of the battery.

[0153] Furthermore, according to the formula P (pressure) = F (force) / S (area of ​​contact), to achieve the same pressure, since the contact area between the current collector 130 and the axial end face 121 of the cell 120 is only the area of ​​the welding surface 1311c, the contact area is reduced. Therefore, less pressure is required. In other words, under the design of this application, less pressure is needed to ensure that the welding part 1311 of the current collector 130 can be pressed down and that the welding surface 1311c fits tightly with the tab region 1211.

[0154] Referring to Figures 25 to 34, in some embodiments, the distance between the edge portion 133 and the outer edge region 1212 (specifically shown as L3 in Figure 29) gradually increases radially outward from the collector plate 130. This increases the distance between the edge portion 133 and the outer edge region 1212, thereby ensuring that the edge portion 133 does not contact the outer edge region 1212 when the collector plate 130 is pressed down, further reducing the risk of damage to the cell 120.

[0155] Referring to Figures 17 to 19, in some embodiments, the edge portion 133 includes a first segment 1331a and a second segment 1331b. The first segment 1331a is connected to the disk body 131, and the second segment 1331b is connected between the first segment 1331a and the flange 132. At least the distance between the second segment 1331b and the outer edge region 1212 (specifically shown as L1 in Figure 19) gradually decreases radially outward from the collector disk 130, and the distance at the connection point between the second segment 1331b and the flange 132 reaches its minimum. It can be understood that the connection point between the second segment 1331b and the flange 132 can also be considered as the lowest point of the flange 132. At this time, the lowest point of the flange 132 is closer to the axial end face 121. With the distance between the end face of the flange 132 away from the cell 120 and the axial end face 121 of the cell 120 remaining constant, the closer the lowest point of the flange 132 is to the axial end face 121, the larger the width of the flange 132 in the axial direction of the cell 120. This allows for maximizing the weldable area between the flange 132 and the housing 110 while ensuring that the outer edge region 1212 of the cell 120 is not compressed, thereby improving the welding reliability and connection stability of the flange 132 and the housing 110.

[0156] As shown in Figure 18, in some embodiments, the cross-section of the second segment 1331b is arc-shaped. In this way, the second segment 1331b can extend towards the cell 120 in a more rounded shape, making the stress distribution of the second segment 1331b more balanced, reducing the risk of damage to the second segment 1331b under stress, and helping to extend the service life of the current collector 130.

[0157] Please refer to Figures 18 and 19. In some embodiments, the distance between the connection point of the flange 132 and the second segment 1331b and the outer edge region 1212 is L2 (as shown in Figure 19), where 0.02mm ≤ L2 ≤ 0.1mm. Specifically, L2 is 0.02mm, 0.04mm, 0.05mm, 0.06mm, 0.08mm, or 0.1mm, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. Under this design, while ensuring that the outer edge region 1212 of the cell 120 is not compressed, the weldable area of ​​the flange 132 and the housing 110 can be increased as much as possible, improving the welding reliability and connection stability of the flange 132 and the housing 110.

[0158] In some embodiments, the disk body 131 further includes a plurality of reinforcing portions 1312, and the welding portion 1311 includes a central welding portion 1311a and a plurality of outer welding portions 1311b. The outer welding portions 1311b and the reinforcing portions 1312 are alternately arranged outside the central welding portion 1311a along the circumference of the collector disk 130, and both the outer welding portions 1311b and the reinforcing portions 1312 are connected to the edge portion 133. The surface of the reinforcing portion 1312 facing the cell 120 is recessed relative to the welding surface 1311c in the direction away from the cell 120, and is spaced apart from the tab region 1211. The surface of the reinforcing portion 1312 facing away from the cell 120 protrudes from the portion of the welding portion 1311 having the welding surface 1311c and parallel to the axial end face 121. The edge portion 133 protrudes from the surface of the reinforcing portion 1312 facing away from the cell 120 (as shown by R in FIG. 18, and the R portion and the T portion constitute the welding portion). The design of the reinforcing part 1312 results in a concave-convex structural change between the reinforcing part 1312 and the welding part 1311. This form helps to improve the mechanical strength of the collector plate 130, thereby reducing the risk of deformation of the collector plate 130 and extending the service life of the collector plate 130.

[0159] As shown in Figures 29 to 34, it is worth mentioning that in the embodiment where the distance between the edge portion 133 and the outer edge region 1212 gradually increases radially outward from the current collector 130, the edge portion 133 also protrudes from the reinforcing portion 1312 and faces away from the surface of the cell 120.

[0160] Please refer to Figures 13 to 24. The aforementioned battery cell 100, battery, and power device all have their edge portions 133 and flanges 132 projected onto the axial end face 121 along the axial direction of the cell 120, collectively covering the outer edge region 1212. Furthermore, both edge portions 133 and flanges 132 are spaced apart from the outer edge region 1212. Therefore, when the current collector 130 is pressed down, neither edge portions 133 nor flanges 132 will contact the outer edge, and consequently, the current collector 130 will not contact the outer edge region 1212. This reduces the risk of damage to the outer edge region 1212 due to pressure from the current collector 130, thereby reducing the risk of damage to the cell 120 and improving battery safety.

[0161] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, comprising a casing (110), a battery cell (120), a current collector (130), and a cover plate (140), wherein the casing (110) has an opening at at least one end, characterized in that, The collector plate (130) includes a plate body (131) and a flange (132) extending along the periphery of the plate body (131). The flange (132) has a plurality of spaced positioning portions (1321) and a welding area located between two adjacent positioning portions (1321) in the circumferential direction. The inner wall of the flange (132) protrudes to form the positioning portions (1321). The welding area is welded to the inner wall of the housing (110) to form a weld mark (13). 22), and the height of the solder mark (1322) in the radial direction of the collector plate (130) is not higher than the height of the positioning part (1321); the cover plate (140) includes a protrusion (141) protruding in the direction of the collector plate (130), the protrusion (141) extending into the housing (110) through the opening and abutting against the positioning part (1321) to position the cover plate (140) radially along the housing (110).

2. The battery cell according to claim 1, characterized in that, The flange (132) is partially recessed inward, and a recessed portion (1323) is formed on the outer wall of the flange (132). The positioning portion (1321) is formed on the inner wall of the flange (132) at a position corresponding to the recessed portion (1323).

3. The battery cell according to claim 2, characterized in that, The wall thickness of the positioning part (1321) is less than the wall thickness of the welding area.

4. The battery cell according to claim 1, characterized in that, The wall thickness of the area where the positioning part (1321) is located is greater than the wall thickness of the area where the welding area is located, and the outer wall of the flange (132) has a smooth transition curved surface.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The plurality of positioning portions (1321) are equally spaced along the circumference of the flange (132), and the solder mark (1322) is formed between each two adjacent positioning portions (1321).

6. The battery cell according to claim 1, characterized in that, The width of the positioning part (1321) in the circumferential direction of the flange (132) is smaller than the width of the welding area in the circumferential direction of the flange (132).

7. The battery cell according to claim 1, characterized in that, The width of the positioning part (1321) in the circumferential direction of the flange (132) is greater than or equal to 10 mm.

8. The battery cell according to claim 1, characterized in that, The height of the positioning part (1321) in the radial direction of the collector plate (130) is greater than or equal to 0.3 mm and less than or equal to 2 mm.

9. The battery cell according to claim 1, characterized in that, The flange (132) is inclined outward relative to the disk body (131), and the collector disk (130) is interference-fitted with the housing (110), and the flange (132) elastically abuts against the inner wall of the housing (110).

10. The battery cell according to claim 1, characterized in that, The cover plate (140) further includes a retaining portion (142) extending circumferentially along the protrusion (141), the retaining portion (142) overlapping the end face of the opening to position the cover plate (140) axially along the housing (110).

11. The battery cell according to claim 10, characterized in that, The outer diameter of the abutment (142) is less than or equal to the outer diameter of the housing (110) and greater than the inner diameter of the opening.

12. The battery cell according to claim 1, characterized in that, The cover plate (140) is partially recessed inward, and a circular groove (143) is formed on the side of the cover plate (140) facing away from the battery cell (120), and a protrusion (141) is formed on the side of the cover plate (140) facing the battery cell (120).

13. The battery cell according to claim 1, characterized in that, The cover plate (140) is partially recessed inward, and an annular groove (144) extending circumferentially is formed on the side of the cover plate (140) facing away from the battery cell (120), and the protrusion (141) is formed on the side of the cover plate (140) facing the battery cell (120).

14. The battery cell according to claim 1, characterized in that, The disc body (131) is recessed on the side facing the battery cell (120) to form a receiving cavity (1313), and a protruding structure (1314) is formed on the side of the disc body (131) facing away from the battery cell (120), with part of the battery cell (120) located in the receiving cavity (1313).

15. The battery cell according to claim 14, characterized in that, The protruding structure (1314) abuts against the protrusion (141) along the axial direction of the housing (110).

16. A battery, characterized in that, Includes the battery cell as described in any one of claims 1 to 15 above.

17. An electrical appliance, characterized in that, Includes the battery cell described in any one of claims 1 to 15 or the battery described in claim 16.

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