Current collecting piece, end cover assembly and battery monomer

Abstract

The utility model provides a current collector, an end cover assembly and a battery monomer, and relates to the technical field of batteries. The current collector is applied to a battery monomer, and comprises a first connecting part and a second connecting part; the first connecting part is configured to be connected with a tab of a battery monomer; one end of the second connecting part is connected with the first connecting part, and the other end of the second connecting part penetrates through the cover plate of the battery monomer, extends out of the accommodating cavity of the battery monomer, and is connected with the electrode terminal of the battery monomer. One end of the current collecting piece penetrates through the cover plate of the battery single body and then is connected with the electrode terminal of the battery single body, so that the welding part of the current collecting piece and the electrode terminal is positioned outside the battery single body, and metal chips generated at the joint between the current collecting piece and the electrode terminal due to welding can be prevented from falling into the battery single body; furthermore, the amount of metal chips falling into the battery monomers during the welding of the current collecting pieces can be reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a current collector, an end cover assembly, and a battery cell. Background Art

[0002] In related technologies, a battery cell consists of a housing, an electrode assembly and current collector disposed within the housing, a cover plate that closes the housing opening to define a chamber, and electrode terminals that penetrate the cover plate. The ends of the current collector are welded to the ends of the electrode terminals within the housing and to the electrode assembly, respectively. The welding of the current collector to the corresponding components can easily generate metal shavings. These shavings can fall into the housing and easily cause short circuits within the battery cell. Utility Model Content

[0003] The embodiments of the present application provide a current collecting member, an end cover assembly, and a battery cell, which can reduce the amount of metal chips generated during welding of the current collecting member that fall into the housing.

[0004] In the first aspect, an embodiment of the present application provides a current collecting part, which is applied to a battery cell, and the current collecting part includes a first connecting part and a second connecting part; the first connecting part is configured to be connected to the tab of the battery cell; one end of the second connecting part is connected to the first connecting part, and the other end is configured to pass through the cover plate of the battery cell and extend to the outside of the accommodating cavity of the battery cell, and is configured to be connected to the electrode terminal of the battery cell.

[0005] In one embodiment, the current collecting part includes two first connecting parts and two second connecting parts, the two first connecting parts are respectively connected to the two second connecting parts, along the first direction, the two first connecting parts are arranged opposite to each other, the two second connecting parts are arranged opposite to each other, and the two first connecting parts are located between the two second connecting parts, and the first direction is perpendicular to the direction in which the second connecting parts pass through the cover plate of the battery cell.

[0006] In one embodiment, the second connecting portion includes an extension portion and a bending portion, one end of the extension portion is connected to the first connecting portion, and the other end is configured to pass through the cover plate of the battery cell and extend to the outside of the accommodating cavity and be connected to the bending portion, and the bending portion is configured to be in surface contact with the electrode terminal of the battery cell.

[0007] In one embodiment, the bent portions of the two second connecting portions are bent away from each other.

[0008] In one embodiment, the current collecting member further includes a bridging portion, and two ends of the bridging portion are respectively connected to ends of the two second connecting portions away from the first connecting portion.

[0009] In one embodiment, the second connection portion has a welding area configured to be welded to the electrode terminal of the battery cell, and a relief hole is provided at a portion of the bridge portion opposite to the welding area.

[0010] In one embodiment, the two first connecting portions are spaced apart from each other, and / or the two second connecting portions are located between the electrode terminals of the battery cells and the first connecting portions and are in contact with each other.

[0011] In one embodiment, the battery cell is a cylindrical battery cell, the first connecting portion is a flat plate structure, and the contour line of the projection of the first connecting portion in the plane parallel to the first connecting portion includes an arc segment and a straight line segment, the two ends of the arc segment are respectively connected to the two ends of the straight line segment, and the arc segment is configured to be coaxial with the battery cell.

[0012] In one embodiment, the central angle of the arc segment is α, which satisfies: 170°≤α<180°.

[0013] In one embodiment, along the second direction, at the connection between the first connection portion and the second connection portion, the first connection portion has a width dimension w1, and the second connection portion has a width dimension w2, satisfying: w2<w1, and 5mm≤w2≤20mm.

[0014] In one embodiment, the second connection portion is located between the first connection portion and the electrode terminal of the battery cell and is a plate-shaped structure, and the plate-shaped structure is arranged parallel to the axis of the battery cell.

[0015] In the second aspect, an embodiment of the present application provides an end cap assembly, which includes a sealing ring, a cover plate, an electrode terminal, an upper plastic part, a lower plastic part and the aforementioned current collecting part; the cover plate is provided with a first through hole; the electrode terminal is provided on one side of the cover plate; the upper plastic part is located between the cover plate and the electrode terminal, and the two sides of the upper plastic part are respectively connected to the cover plate and the electrode terminal; the lower plastic part is connected to the other side of the cover plate; the first connecting part is located on the side of the lower plastic part away from the cover plate, and the end of the second connecting part away from the first connecting part passes through the first through hole and is connected to the electrode terminal; wherein the sealing ring seals the mating part between the first through hole and the second connecting part.

[0016] In one embodiment, a connecting cavity is provided inside the electrode terminal, a second through hole is provided on the side of the electrode terminal facing the cover plate, the second through hole is connected to the connecting cavity, and an end of the second connecting part away from the first connecting part also passes through the second through hole and is connected to the cavity wall of the connecting cavity.

[0017] In one embodiment, the electrode terminal includes a terminal pressing block and a sealing plate. One side of the terminal pressing block is connected to the upper plastic part and is provided with a second through hole, and the other side is provided with a matching groove. The sealing plate closes the opening of the matching groove to define a connecting cavity.

[0018] In one embodiment, the notch of the mating groove is provided with a first step, which extends in a ring shape around the circumference of the notch of the mating groove. One side of the sealing plate overlaps the first step, and the other side is coplanar with the side of the terminal pressing block facing away from the cover plate.

[0019] In one embodiment, the electrode terminal is configured to be electrically connected to the tab of the battery cell through the current collector, the material of the terminal pressing block is consistent with the material of the tab connected thereto, and the sealing plate is made of aluminum.

[0020] In one embodiment, a connection groove is provided on a side of the electrode terminal close to the cover plate, and a connection block is provided on a side of the upper plastic part facing the electrode terminal. The connection block cooperates with the connection groove and is connected to the inner wall of the connection groove.

[0021] In one embodiment, the upper plastic part is provided with a third through hole, one end of the second connecting portion passes through the first through hole and the third through hole and is connected to the electrode terminal, and the sealing ring also seals the mating portion between the third through hole and the second connecting portion.

[0022] In one embodiment, the surface area of ​​the electrode terminal facing away from the end cap is 50 mm 2 ~300mm 2 .

[0023] In a third aspect, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly, a first pole ear and the aforementioned end cover assembly; the electrode assembly is arranged in the shell, and one end of the first pole ear is connected to the electrode assembly; the cover plate is covered with the shell, and the first pole ear is connected to the first connecting portion.

[0024] Beneficial effects of the embodiments of the present application:

[0025] In an embodiment of the present application, by passing one end of the current collector through the cover plate of the battery cell and then connecting it to the electrode terminal of the battery cell, the welding portion between the current collector and the electrode terminal can be located outside the battery cell, thereby preventing metal chips generated by welding at the connection between the current collector and the electrode terminal from falling into the interior of the battery cell, and further reducing the amount of metal chips falling into the interior of the battery cell when the current collector is welded. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 is a schematic structural diagram of a current collecting member provided in an embodiment of the present application;

[0028] Figure 2 This is a structural diagram of another current collecting component provided in an embodiment of the present application;

[0029] Figure 31 is a schematic structural diagram of another current collecting member provided in an embodiment of the present application;

[0030] Figure 4 yes Figure 2 A side view of the current collecting member is shown;

[0031] Figure 5 yes Figure 3 A side view of the current collecting member is shown;

[0032] Figure 6 is a projection schematic diagram of the first connecting portion provided in an embodiment of the present application;

[0033] Figure 7 is a side view of a connection between a first connection portion and a second connection portion provided in an embodiment of the present application;

[0034] Figure 8 is a top view of an end cap assembly provided in an embodiment of the present application;

[0035] Figure 9 It is along Figure 8 Cross-sectional view of AA;

[0036] Figure 10 It's another Figure 8 Cross-sectional view of AA;

[0037] Figure 11 yes Figure 9 Enlarged view of point B in the middle;

[0038] Figure 12 yes Figure 10 Enlarged view of point C in the middle;

[0039] Figure 13 is an exploded view of an electrode terminal provided in an embodiment of the present application;

[0040] Figure 14 1 is a schematic structural diagram of a terminal pressing block provided in an embodiment of the present application;

[0041] Figure 15 Schematic diagram of the structure of the upper plastic part provided in an embodiment of the present application;

[0042] Figure 16 is a schematic structural diagram of a battery cell provided in an embodiment of the present application;

[0043] Figure 17 This is a structural diagram of another battery cell provided in an embodiment of the present application.

[0044] Description of reference numerals:

[0045] 001-current collecting parts;

[0046] 011-first connecting portion; 111-arc segment; 112-straight segment; 012-second connecting portion; 121-extension portion; 122-bend portion;

[0047] 013-bridge portion; 131-avoidance hole;

[0048] 002-end cover assembly;

[0049] 021-sealing ring;

[0050] 022-cover plate; 221-first through hole;

[0051] 023 - electrode terminal; 231 - connecting cavity; 232 - second through hole; 233 - terminal pressing block; 2331 - matching groove; 2332 - first step; 234 - sealing plate; 235 - connecting groove;

[0052] 024-upper plastic part; 241-connecting block; 242-third through hole;

[0053] 025-lower plastic part;

[0054] 003-battery monomer;

[0055] 031-shell; 032-electrode assembly; 033-first electrode tab. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0057] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application. In the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0058] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0059] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0060] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0061] See also Figure 1 , Figure 1 : This is a schematic diagram of the structure of the current collector 001 provided in an embodiment of the present application. The embodiment of the present application provides a current collector 001, which is applied to a battery cell. The current collector 001 includes a first connecting portion 011 and a second connecting portion 012. The first connecting portion 011 is configured to connect to the tab of the battery cell. One end of the second connecting portion 012 is connected to the first connecting portion 011, and the other end is configured to extend through the cover of the battery cell to the outside of the battery cell's accommodating cavity and is configured to connect to the electrode terminal of the battery cell.

[0062] The first connection part 011 and the second connection part 012 can be welded, riveted, or integrally formed. Specifically, when integrally formed, a metal plate can be punched to form the first connection part 011 and the second connection part 012 connected as one body, and then the second connection part 012 can be bent relative to the first connection part 011 to form Figure 1 The structure shown.

[0063] Furthermore, the shape of the first connecting portion 011 can be adaptively adjusted based on the shape of the weld surface formed by the stacked and bent tabs of the battery cell. For example, if the battery cell is a prismatic battery cell, the weld surface formed by the stacked and bent tabs is rectangular, and accordingly, the first connecting portion 011 is rectangular.

[0064] In this embodiment, by passing one end of the current collector 001 through the battery cell cover and connecting it to the battery cell electrode terminal, the welding area between the current collector 001 and the electrode terminal can be located outside the battery cell. This prevents metal shavings generated by welding between the current collector 001 and the electrode terminal from falling into the battery cell, thereby reducing the amount of metal shavings that fall into the battery cell during welding of the current collector 001. This improves the reliability of the battery cell and effectively reduces the probability of short circuits caused by metal shavings in the battery cell.

[0065] Furthermore, by passing one end of the current collector 001 through the battery cell cover plate and connecting it to the battery cell electrode terminal, more space is available for welding the current collector 001 to the electrode terminal. This not only improves the ease of connection between the current collector 001 and the electrode terminal, but also enhances welding reliability.

[0066] Furthermore, by passing one end of the current collector 001 through the battery cell cover and connecting it to the battery cell's electrode terminal, there's no need for a terminal post inside the battery cell. This not only allows for more space inside the battery cell for the electrode assembly within the same volume, thereby increasing the battery cell's energy density, but also eliminates the need for a terminal post, allowing the portion of the current collector 001 protruding from the battery cell cover to serve as the terminal post, simplifying manufacturing steps and improving efficiency.

[0067] In addition, by passing one end of the current collector 001 through the cover of the battery cell and connecting it to the electrode terminal of the battery cell, the distance between the part where the current collector 001 is connected to the tab and the part where the current collector 001 is connected to the pole can be increased, thereby reducing the mutual influence between these two parts when welding with the corresponding components, and further improving the reliability of the connection between the current collector 001 and other components.

[0068] Moreover, by directly connecting the current collector 001 to the electrode terminal, the pole is omitted, which can effectively reduce the resistance and improve the current carrying capacity.

[0069] See also Figure 2 , Figure 2 This is a schematic structural diagram of another current collector 001 provided in an embodiment of the present application. In one embodiment, current collector 001 includes two first connecting portions 011 and two second connecting portions 012. The two first connecting portions 011 are respectively connected to the two second connecting portions 012. Along a first direction, the two first connecting portions 011 are arranged opposite each other, and the two second connecting portions 012 are arranged opposite each other. The two first connecting portions 011 are located between the two second connecting portions 012. The first direction is perpendicular to the direction in which the second connecting portions 012 penetrate the cover plate of the battery cell.

[0070] A first connection portion 011 and a second connection portion 012 connected thereto form a current collector, and another first connection portion 011 and another second connection portion 012 connected thereto form another current collector. Optionally, along the axial direction of the battery cell, the two current collectors are symmetrical to each other.

[0071] During implementation, two current collecting components may be manufactured separately and then assembled into the current collecting component 001 ; or the first connecting portions 011 of the two current collecting components may be connected, or the second connecting portions 012 of the two current collecting components may be connected to form the current collecting component 001 .

[0072] In this embodiment, the above arrangement not only increases the connection area between the current collector 001 and the tab, but also increases the flow area between the tab and the electrode terminal, thereby improving the flow capacity of the current collector 001 and further improving the flow capacity of the battery cell.

[0073] Moreover, compared with the method of extending from the edge of the portion connected to the tab and bending to connect to the electrode terminal, the present embodiment arranges the two first connection portions 011 between the two second connection portions 012, so that the portion where the current collecting piece 001 is connected to the electrode terminal is located in the middle of the portion where the current collecting piece 001 is connected to the tab, so that the first connection portion 011 collects current in the middle and then transmits it to the electrode terminal through the second connection portion 012, thereby shortening the current collection path and improving the current collection efficiency.

[0074] In addition, it is understandable that if two current collecting components are respectively connected to the positive and negative tabs of the battery cell, an insulating component needs to be provided between the two current collecting components to insulate and isolate the two current collecting components.

[0075] See also Figure 2 In one embodiment, the second connection portion 012 includes an extension portion 121 and a bend portion 122. One end of the extension portion 121 is connected to the first connection portion 011, and the other end is configured to pass through the cover of the battery cell and extend outside the accommodating cavity to connect to the bend portion 122. The bend portion 122 is configured to make surface-to-surface contact with the electrode terminals of the battery cell.

[0076] It can be understood that the portion where the bent portion 122 is in surface-to-surface contact with the electrode terminal of the battery cell is the portion where the bent portion 122 is welded to the electrode terminal of the battery cell.

[0077] In this embodiment, by providing the bending portion 122, the area of ​​the contact surface between the current collector 001 and the electrode terminal can be increased, thereby increasing the area of ​​the welding portion between the bending portion 122 and the electrode terminal of the battery cell, and further improving the reliability of the connection between the bending portion 122 and the electrode terminal of the battery cell.

[0078] See also Figure 2In one embodiment, the bent portions 122 of the two second connection portions 012 are bent in opposite directions. This prevents the two second connection portions 012 from overlapping, compared to bending the bent portions 122 in the same direction. This reduces the weld thickness of the bent portions 122, facilitates penetrating welding of the bent portions 122, and improves the connection reliability between the bent portions 122 and the electrode terminal.

[0079] See also Figure 3 , Figure 3 001 according to an embodiment of the present application. In one embodiment, the current collecting member 001 further includes a bridging portion 013. Both ends of the bridging portion 013 are respectively connected to ends of the two second connecting portions 012 away from the first connecting portion 011.

[0080] In this embodiment, by providing a bridge portion 013 to connect the two second connection portions 012 , the current collecting member 001 can be formed as an integrally formed member, thereby improving the structural reliability and molding efficiency of the current collecting member 001 .

[0081] Specifically, a metal sheet is punched out to form a first connecting portion 011, a second connecting portion 012, a bridge portion 013, another second connecting portion 012, and another first connecting portion. Then, it is bent to obtain Figure 3 The current collecting piece 001 of the structure shown.

[0082] See also Figure 3 In one embodiment, the second connection portion 012 has a welding area configured to be welded to the electrode terminal of the battery cell. A relief hole 131 is provided at a portion of the bridge portion 013 opposite to the welding area.

[0083] It can be understood that the portion of the bridge portion 013 opposite to the welding area will affect the welding between the welding area and the electrode terminal.

[0084] Based on this, in this embodiment, by setting the avoidance hole 131, the welding head of the welding equipment can directly pass through the avoidance hole 131 and contact the welding area to weld the welding area to the electrode terminal, thereby facilitating the penetration welding and fixing of the welding area, thereby improving the reliability of the connection between the welding area and the electrode terminal.

[0085] See also Figure 4 and Figure 5 , Figure 4 yes Figure 2 The side view of the current collecting piece 001 is shown. Figure 5 yes Figure 3 The side view of the current collecting member 001 is shown. In one embodiment, the two first connecting portions 011 are spaced apart, and / or the two second connecting portions 012 are located between the electrode terminals of the battery cell and the first connecting portions 011 and are in contact with each other.

[0086] Specifically, the two first connection parts 011 are arranged at intervals, or the two second connection parts 012 are located between the electrode terminal of the battery cell and the first connection part 011 and are fitted together, or the two first connection parts 011 are arranged at intervals, and the two second connection parts 012 are located between the electrode terminal of the battery cell and the first connection part 011 and are fitted together.

[0087] In this embodiment, the first connecting parts 011 are arranged at intervals so that when the battery cell is injected, the electrolyte flows into the top of the current collecting member 001 from the injection hole on the cover plate, and then flows into the electrode assembly from at least the interval between the two first connecting parts 011, thereby improving the battery cell infiltration efficiency.

[0088] In addition, by fitting the two second connection parts 012 between the electrode terminal of the battery cell and the first connection part 011, the size of the current collector 001 at this part can be reduced, thereby reducing the hole diameter of the part on the cover plate penetrated by it, and further improving the strength of the cover plate.

[0089] See also Figure 6 , Figure 6 Schematic diagram of the projection of the first connection portion 011 provided in an embodiment of the present application. In one embodiment, the battery cell is a cylindrical battery cell, and the first connection portion 011 is a flat plate. When projected orthographically onto a plane parallel to the first connection portion 011, the contour of the projection of the first connection portion 011 includes an arc segment 111 and a straight line segment 112. The two ends of the arc segment 111 are respectively connected to the two ends of the straight line segment 112. The arc segment 111 is configured to be coaxial with the battery cell.

[0090] Specifically, the second connection portion 012 may be connected to the edge of the first connection portion 011 where the straight line segment 112 is located.

[0091] In this embodiment, the above arrangement allows the first connecting portion 011 to have a larger area for connection with the tab when applied to a cylindrical battery cell, thereby increasing the current collecting surface area of ​​the current collecting member 001 and further improving the current collecting capacity of the current collecting member 001 .

[0092] Furthermore, if one end of a battery cell serves only as an electrode output, only one current collector can be configured at that end, and the first connection portion 011 of the current collector has a superior arc-shaped plate structure. Specifically, when projected onto a plane parallel to the first connection portion 011, the contour of the projection of the first connection portion 011 includes an arc segment 111 and a straight segment 112. The arc segment 111 is configured to be coaxial with the battery cell, and the central angle corresponding to the arc segment 111 is not less than 180°, and can specifically be 260° to 350°.

[0093] See also Figure 6 In one embodiment, the central angle of the arc segment 111 is α, which satisfies: 170°≤α<180°.

[0094] It can be understood that the central angle α of the arc segment 111 includes but is not limited to 170°, 171°, 172°, 173°, 173.5°, 174°, 175°, 176°, 177.2°, 177.6°, 178°, 179°, 179.2°, and 179.6°.

[0095] In this embodiment, through the above arrangement, on the one hand, the first connection portion 011 can have a larger area for connection with the tab, and on the other hand, the two first connection portions 011 can be spaced apart to form a gap for electrolyte flow, thereby improving the wetting efficiency of the battery cell.

[0096] See also Figure 7 , Figure 7 This is a side view of the connection between the first connection portion 011 and the second connection portion 012 provided in an embodiment of the present application. In one embodiment, along the second direction, at the connection between the first connection portion 011 and the second connection portion 012, the first connection portion 011 has a width dimension w1, and the second connection portion 012 has a width dimension w2, satisfying the following conditions: w2 < w1, and 5 mm ≤ w2 ≤ 20 mm. The second direction is parallel to the first connection portion 011 and the second connection portion 012.

[0097] It will be understood that w2 includes but is not limited to 5mm, 6mm, 7mm, 8mm, 9mm, 10.1mm, 11mm, 12mm, 13mm, 14.5mm, 15mm, 16mm, 17mm, 18mm, 18.3mm, 19mm, and 20mm.

[0098] In this embodiment, through the above-mentioned limitations, on the one hand, the flow capacity of the connection between the first connection part 011 and the second connection part 012 can be guaranteed to meet the flow requirements of the battery cell; on the other hand, the material layer of the second connection part 012 can be controlled to avoid its excessive size resulting in a significant increase in material costs.

[0099] See Figure 1 In one embodiment, the second connection portion 012 located between the first connection portion 011 and the electrode terminal of the battery cell is a plate-shaped structure, and the plate-shaped structure is configured to be parallel to the axis of the battery cell.

[0100] In this embodiment, through the above arrangement, the first connection portion 011 can collect current and then directly transmit the current to the electrode terminal along the axis of the battery cell, thereby shortening the current collection path and improving the current collection efficiency.

[0101] Furthermore, the above-mentioned angle can also reduce the bending angle of the current collecting member 001, thereby improving the stress state of the current collecting member 001 and enhancing its reliability.

[0102] See also Figure 8 、 Figure 9 and Figure 10 , Figure 8 is a top view of the end cap assembly provided in an embodiment of the present application, Figure 9 It is along Figure 8 The cross-sectional view of AA in the figure, Figure 10 It's another Figure 8 Cross-sectional view of AA in the figure. Accordingly, an embodiment of the present application provides an end cap assembly 002, which includes a sealing ring 021, a cover plate 022, an electrode terminal 023, an upper plastic part 024, a lower plastic part 025 and the aforementioned current collecting part 001. The cover plate 022 is provided with a first through hole 221. The electrode terminal 023 is provided on one side of the cover plate 022. The upper plastic part 024 is located between the cover plate 022 and the electrode terminal 023. The two sides of the upper plastic part 024 are respectively connected to the cover plate 022 and the electrode terminal 023. The lower plastic part 025 is connected to the other side of the cover plate 022. The first connecting portion 011 is located on the side of the lower plastic part 025 away from the cover plate 022. The end of the second connecting portion 012 away from the first connecting portion 011 passes through the first through hole 221 and is connected to the electrode terminal 023. The sealing ring 021 seals the matching portion between the first through hole 221 and the second connecting portion 012 .

[0103] It can be understood that the current collecting part 001 is Figure 2 When the structure shown is Figure 8 The cross-sectional view of AA is Figure 9 The structure shown; the current collecting part 001 is Figure 3 When the structure shown is Figure 8 The cross-sectional view of AA is Figure 10 The structure shown.

[0104] Specifically, the upper plastic part 024 can be bonded or injection-molded to the electrode terminal 023 and the cover plate 022 ; the lower plastic part 025 can be bonded or injection-molded to the cover plate 022 .

[0105] In addition, the contact portion of the two second connection portions 012 can be welded or glued together to improve the integrity of the contact portion and prevent the electrolyte from flowing from the contact portion to the outside of the battery cell.

[0106] In this embodiment, the aforementioned current collector 001 is used, with one end of the current collector 001 passing through the battery cell cover 022 and then connected to the battery cell electrode terminal 023. This ensures that the welded portion between the current collector 001 and the electrode terminal 023 is located outside the battery cell. This prevents metal shavings generated by welding between the current collector 001 and the electrode terminal 023 from falling into the battery cell, thereby reducing the amount of metal shavings that fall into the battery cell during welding. This improves the reliability of the battery cell and effectively reduces the probability of short circuits caused by metal shavings in the battery cell.

[0107] See also Figure 11 or Figure 12 , Figure 11 yes Figure 9 The enlarged view of point B in the middle. Figure 12 yes Figure 10 Enlarged view of point C in the middle; in one embodiment, a connection cavity 231 is provided within the electrode terminal 023. A second through-hole 232 is provided on the side of the electrode terminal 023 facing the cover plate 022. The second through-hole 232 communicates with the connection cavity 231. The end of the second connecting portion 012, distal from the first connecting portion 011, also passes through the second through-hole 232 and connects to the wall of the connection cavity 231.

[0108] In this embodiment, through the above-mentioned arrangement, on the one hand, the end of the current collecting member 001 can be protected to prevent it from being damaged by impact; on the other hand, the area of ​​the connection portion between the current collecting member 001 and the electrode terminal 023 can be increased, thereby improving the reliability of the connection between the current collecting member 001 and the electrode terminal 023.

[0109] See also Figure 13 , Figure 13 This is an exploded view of an electrode terminal 023 provided in an embodiment of the present application. In one embodiment, electrode terminal 023 includes a terminal pressing block 233 and a sealing plate 234. One side of terminal pressing block 233 is connected to upper plastic component 024 and is provided with a second through-hole 232. The other side is provided with a mating groove 2331. The sealing plate 234 seals the opening of mating groove 2331 to define a connection cavity 231.

[0110] In this embodiment, the above arrangement can improve the operability of connecting the second connecting portion 012 to the cavity wall of the connecting cavity 231 , thereby improving the reliability of the connection between the second connecting portion 012 and the cavity wall of the connecting cavity 231 .

[0111] In one embodiment, the notch of the mating groove 2331 is provided with a first step 2332, and the first step 2332 extends in a ring shape around the circumference of the notch of the mating groove 2331. One side of the sealing plate 234 overlaps the first step 2332, and the other side is coplanar with the side of the terminal block 233 facing away from the cover plate 022.

[0112] In this embodiment, by overlapping the sealing plate 234 with the first step 2332, on the one hand, the sealing plate 234 can be positioned by the first step 2332, thereby improving the ease of welding between the sealing plate 234 and the terminal block 233, thereby improving the welding efficiency; on the other hand, the first step 2332 can increase the mating surface between the sealing plate 234 and the terminal block 233, thereby improving the reliability of the connection between the sealing plate 234 and the terminal block 233.

[0113] In one embodiment, the electrode terminal 023 is configured to be electrically connected to the tab of the battery cell through the current collector 001, and the material of the terminal pressing block 233 is the same as the material of the tab to which it is connected. The sealing plate 234 is made of aluminum.

[0114] Specifically, when the negative electrode tab is made of copper, the negative electrode current collector 001 connected to the negative electrode tab is made of copper. Correspondingly, the negative electrode terminal pressing block 233 connected to the negative electrode current collector 001 is also made of copper.

[0115] In this embodiment, through the above arrangement, the materials of the current collecting member 001 and the terminal pressing block 233 can be made consistent, thereby improving the conductivity therebetween, and the sealing plate 234 is made of aluminum material, which can reduce the weight of the electrode terminal 023, thereby controlling the weight of the battery cell.

[0116] See also Figure 14 and Figure 15 , Figure 14 is a structural diagram of the terminal pressing block 233 provided in an embodiment of the present application, Figure 15 Figure 2 is a schematic diagram of the structure of the upper plastic member 024 provided in an embodiment of the present application. In one embodiment, a connection groove 235 is provided on the side of the electrode terminal 023 near the cover plate 022. A connection block 241 is provided on the side of the upper plastic member 024 facing the electrode terminal 023. The connection block 241 engages with the connection groove 235 and connects to the inner wall of the connection groove 235.

[0117] In this embodiment, by providing the connection block 241 and the connection groove 235 , the area of ​​the connection surface between the electrode terminal 023 and the upper plastic part 024 can be increased, thereby improving the reliability of the connection between the electrode terminal 023 and the upper plastic part 024 .

[0118] See also Figure 11 and Figure 12In one embodiment, the upper plastic component 024 is provided with a third through-hole 242. One end of the second connecting portion 012 passes through the first through-hole 221 and the third through-hole 242 to connect to the electrode terminal 023. The sealing ring 021 also seals the mating area between the third through-hole 242 and the second connecting portion 012. This further improves the sealing performance of the portion where the current collector 001 protrudes from the interior of the battery cell, thereby enhancing the reliability of the battery cell.

[0119] Furthermore, the sealing ring 021 also extends to the second through hole 232 to seal the fitting portion between the second through hole 232 and the current collecting member 001 .

[0120] In one embodiment, the area of ​​the surface of the electrode terminal 023 facing away from the end cap is 50 mm 2 to 300 mm 2 .

[0121] It is understood that the surface area of ​​the electrode terminal 023 facing away from the end cap includes but is not limited to 50 mm 2 , 60mm 2 , 80mm 2 , 91mm 2 , 100mm 2 , 110mm 2 , 120mm 2 , 154mm 2 , 175mm 2 , 190mm 2 , 200mm 2 , 223mm 2 , 240mm 2 , 250mm 2 , 260mm 2 , 280mm 2 , 300mm 2 .

[0122] In this embodiment, through the above-mentioned limitation, the electrode terminal 023 can have a sufficient connection area with the connection bar, thereby improving the reliability of the connection between the electrode terminal 023 and the connection bar and ensuring the overcurrent capacity of the electrode terminal 023.

[0123] See also Figure 16 or Figure 17 , Figure 16 is a schematic structural diagram of a battery cell 003 provided in an embodiment of the present application, Figure 17This is a schematic diagram of the structure of another battery cell 003 provided in an embodiment of the present application. Accordingly, an embodiment of the present application also provides a battery cell 003. Battery cell 003 includes a housing 031, an electrode assembly 032, a first tab 033, and the aforementioned end cap assembly 002. Electrode assembly 032 is disposed within housing 031. One end of first tab 033 is connected to electrode assembly 032. Cover plate 022 covers housing 031. First tab 033 is connected to first connector 011.

[0124] in, Figure 16 The current collecting part 001 in Figure 2 The current collecting piece 001 shown; Figure 17 The current collecting parts in Figure 3 The current collector shown.

[0125] It can be understood that the electrode assembly 032 includes at least a positive electrode sheet, a separator, and a negative electrode sheet that are stacked.

[0126] In addition, the first electrode tab 033 can be a positive electrode tab or a negative electrode tab.

[0127] Battery cell 003 may include one or two end cap assemblies 002. When battery cell 003 includes one end cap assembly 002, the tabs of either polarity are connected to current collector 001. When battery cell 003 includes two end cap assemblies 002, the positive tab and negative tab are connected to the current collector 001 of each end cap assembly 002, respectively.

[0128] In this embodiment, by using the aforementioned end cap assembly 002, one end of the current collector 001 passes through the cover plate 022 of the battery cell 003 and connects to the electrode terminal 023 of the battery cell 003. This ensures that the welded portion between the current collector 001 and the electrode terminal 023 is located outside the battery cell 003. This prevents metal shavings generated by welding at the connection between the current collector 001 and the electrode terminal 023 from falling into the interior of the battery cell 003, thereby reducing the amount of metal shavings that fall into the interior of the battery cell 003 during welding of the current collector 001. This improves the reliability of the battery cell 003 and effectively reduces the probability of short circuits caused by welding metal shavings inside the battery cell 003.

[0129] The assembly steps of battery cell 003 are mainly as follows:

[0130] The first connecting portion 011 of the current collector 001 is welded to the tab, and then the lower plastic part 025, the cover plate 022, the sealing ring 021, the upper plastic part 024 and the terminal pressing block 233 are installed on the extension part 121 in sequence, and then the bending part 122 is bent, and the bending part 122 is welded to the terminal pressing block 233, specifically by laser penetration welding. The sealing plate is then welded and sealed on the terminal pressing block 233. Finally, the cover plate 022 is sealed and welded to the shell 031. In this way, it is no longer necessary to weld the end cover assembly 002 to the tab after assembly, thereby increasing the operating space for welding the current collector 001 to the tab, and thus improving the operability of welding between the current collector 001 and the tab.

[0131] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A current collecting member, characterized in that: Applied to a battery cell, the current collecting member includes: A first connecting portion is configured to be connected to a tab of the battery cell; The second connection portion has one end connected to the first connection portion and the other end is configured to pass through the cover plate of the battery cell and extend to the outside of the accommodating cavity of the battery cell and is configured to be connected to the electrode terminal of the battery cell.

2. The current collecting member according to claim 1, characterized in that: The current collecting part includes two first connecting parts and two second connecting parts, the two first connecting parts are respectively connected to the two second connecting parts, along the first direction, the two first connecting parts are arranged opposite to each other, the two second connecting parts are arranged opposite to each other, and the two first connecting parts are located between the two second connecting parts, and the first direction is perpendicular to the direction in which the second connecting parts pass through the cover plate of the battery cell.

3. The current collecting member according to claim 2, characterized in that: The second connecting portion includes an extension portion and a bending portion, one end of the extension portion is connected to the first connecting portion, and the other end is configured to pass through the cover plate of the battery cell and extend to the outside of the accommodating cavity and be connected to the bending portion, and the bending portion is configured to be in surface contact with the electrode terminal of the battery cell.

4. The current collecting member according to claim 3, characterized in that: The bent portions of the two second connecting portions are bent away from each other.

5. The current collecting member according to any one of claims 2 to 4, characterized in that: The current collecting member further includes a bridging portion, wherein two ends of the bridging portion are respectively connected to ends of the two second connecting portions away from the first connecting portion.

6. The current collecting member according to claim 5, characterized in that: The second connection portion has a welding area configured to be welded to the electrode terminal of the battery cell, and a relief hole is provided at a portion of the bridge portion facing the welding area.

7. The current collecting member according to any one of claims 2 to 4, characterized in that: The two first connecting portions are spaced apart from each other, and / or the two second connecting portions are located between the electrode terminals of the battery cells and the first connecting portions and are in contact with each other.

8. The current collecting member according to any one of claims 2 to 4, characterized in that: The battery cell is a cylindrical battery cell, the first connecting portion is a flat plate structure, and in an orthographic projection in a plane parallel to the first connecting portion, the contour line of the projection of the first connecting portion includes an arc segment and a straight line segment, the two ends of the arc segment are respectively connected to the two ends of the straight line segment, and the arc segment is configured to be coaxially arranged with the battery cell.

9. The current collecting member according to claim 8, characterized in that: The central angle of the arc segment is α, which satisfies the following: 170°≤α<180°.

10. The current collecting member according to any one of claims 1 to 4, characterized in that: Along the second direction, at the connection between the first connection portion and the second connection portion, the first connection portion has a width dimension w1, and the second connection portion has a width dimension w2, satisfying: w2<w1, and 5mm≤w2≤20mm.

11. The current collecting member according to any one of claims 1 to 4, characterized in that: The second connection portion is located between the first connection portion and the electrode terminal of the battery cell and has a plate-shaped structure. The plate-shaped structure is arranged parallel to the axis of the battery cell.

12. An end cap assembly, characterized in that: include: sealing ring; The cover plate is provided with a first through hole; The electrode terminal is provided on one side of the cover plate; an upper plastic member located between the cover plate and the electrode terminal, wherein two sides of the upper plastic member are respectively connected to the cover plate and the electrode terminal; a lower plastic part connected to the other side of the cover; And, the current collecting member according to any one of claims 1 to 11, wherein the first connecting portion is located on a side of the lower plastic member facing away from the cover plate, and an end of the second connecting portion away from the first connecting portion passes through the first through hole and is connected to the electrode terminal; Wherein, the sealing ring seals the matching portion between the first through hole and the second connecting portion.

13. The end cap assembly according to claim 12, wherein: A connecting cavity is provided inside the electrode terminal, and a second through hole is provided on the side of the electrode terminal facing the cover plate. The second through hole is connected to the connecting cavity, and the end of the second connecting part away from the first connecting part also passes through the second through hole and is connected to the cavity wall of the connecting cavity.

14. The end cap assembly according to claim 13, wherein: The electrode terminal includes a terminal pressing block and a sealing plate. One side of the terminal pressing block is connected to the upper plastic part and is provided with the second through hole, and the other side is provided with a matching groove. The sealing plate closes the opening of the matching groove to define the connecting cavity.

15. The end cap assembly according to claim 14, wherein: The notch of the matching groove is provided with a first step, which extends in a ring shape around the circumference of the notch of the matching groove. One side of the sealing plate overlaps the first step, and the other side is coplanar with the side of the terminal pressing block facing away from the cover plate.

16. The end cap assembly according to claim 14, wherein: The electrode terminal is configured to be electrically connected to the tab of the battery cell through the current collecting member. The material of the terminal pressing block is consistent with the material of the tab connected thereto, and the sealing plate is made of aluminum.

17. The end cap assembly according to any one of claims 13 to 16, wherein: A connecting groove is provided on a side of the electrode terminal close to the cover plate, and a connecting block is provided on a side of the upper plastic part facing the electrode terminal. The connecting block cooperates with the connecting groove and is connected to the inner wall of the connecting groove.

18. The end cap assembly according to claim 12, wherein: The upper plastic part is provided with a third through hole, one end of the second connecting portion passes through the first through hole and the third through hole and is connected to the electrode terminal, and the sealing ring also seals the matching portion between the third through hole and the second connecting portion.

19. The end cap assembly according to claim 12, wherein: The surface area of ​​the electrode terminal facing away from the end cap is 50 mm 2 ~300mm 2 .

20. A battery cell, characterized in that: include: case; an electrode assembly, disposed in the housing; a first electrode tab, one end of which is connected to the electrode assembly; And, in the end cover assembly according to any one of claims 12 to 19, the cover plate covers the shell, and the first electrode tab is connected to the first connecting portion.

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