Current collecting piece, end cover assembly and battery monomer

Abstract

The invention 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 the related art, a battery cell includes a shell, an electrode assembly and a current collector disposed in the shell, a cover plate that closes the shell opening to define a receiving cavity, and an electrode terminal that penetrates the cover plate. The two ends of the current collector are respectively welded to the ends of the electrode terminal located in the shell and the electrode assembly. When the current collector is welded to the corresponding parts, metal chips are easily generated. The metal chips fall into the shell, which may cause a short circuit in the battery cell. Summary of the invention

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

[0004] In the first aspect, an embodiment of the present application provides a current collector, which is applied to a battery cell, and the current collector includes a first connecting portion and a second connecting portion; the first connecting portion is configured to be connected to a pole ear of the battery cell; one end of the second connecting portion is connected to the first connecting portion, and the other end is configured to pass through a cover plate of the battery cell and extend to the outside of a receiving cavity of the battery cell, and is configured to be connected to an 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 penetrate 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 connection portions are arranged at intervals, and / or the two second connection portions are located between the electrode terminals of the battery cells and the first connection 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 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.

[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 configured to be 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, and the sealing plate closes the opening of the matching groove to define a connecting cavity.

[0018] In one embodiment, 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 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 one side of the electrode terminal close to the cover plate, and a connection block is provided on one 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 matching 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, thereby 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 drawings required for use in the description of the embodiments will be briefly introduced below. 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 is a structural schematic diagram of another current collecting member provided in an embodiment of the present application;

[0029] Figure 3is a structural schematic 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 collector is shown;

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

[0032] Figure 6 is a projection schematic diagram of a 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] Fig. 9 is along Figure 8 Sectional view of AA in the middle;

[0036] Fig.10 It's another Figure 8 Sectional view of AA in the middle;

[0037] Fig.11 yes Fig. 9 The enlarged view of point B in the middle;

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

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

[0040] Fig.14 is a schematic diagram of the structure of a terminal pressing block provided in an embodiment of the present application;

[0041] Fig.15 is a schematic structural diagram of an upper plastic part provided in an embodiment of the present application;

[0042] Fig.16 is a schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0043] Fig.17 It is a schematic 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-bending portion;

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

[0048] 002-end cover assembly;

[0049] 021-seal 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 ear. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work 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 used to limit the present application. In the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0058] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0059] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0060] To facilitate understanding of the scheme 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 : 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 connection portion 011 and a second connection portion 012. The first connection portion 011 is configured to be connected to the pole ear of the battery cell. One end of the second connection portion 012 is connected to the first connection portion 011, and the other end is configured to extend to the outside of the accommodating cavity of the battery cell after passing through the cover plate of the battery cell, and is configured to be connected 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, 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] In addition, the shape of the first connection portion 011 can be adaptively adjusted according to the shape of the welding surface formed by the stacked and bent tabs of the battery cell. For example, when the battery cell is a square battery cell, the welding surface formed by the stacked and bent tabs is rectangular, and correspondingly, the first connection portion 011 is rectangular.

[0064] In this embodiment, by passing one end of the current collector 001 through the cover plate of the battery cell and connecting it to the electrode terminal of the battery cell, the welding part of the current collector 001 and the electrode terminal can be located outside the battery cell, thereby preventing the metal chips generated by welding at the connection between the current collector 001 and the electrode terminal from falling into the battery cell, thereby reducing the amount of metal chips falling into the battery cell when the current collector 001 is welded. In this way, the reliability of the battery cell can be improved, and the probability of short circuit caused by welding metal chips inside the battery cell can be effectively reduced.

[0065] Furthermore, by passing one end of the current collector 001 through the cover plate of the battery cell and connecting it to the electrode terminal of the battery cell, a larger operating space can be provided when welding the current collector 001 and the electrode terminal. This can not only improve the ease of connection between the current collector 001 and the electrode terminal, but also improve the reliability of welding.

[0066] Furthermore, 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, there is no need to configure space inside the battery cell for arranging and installing the pole. In this way, not only can more space be configured inside the battery cell for arranging the electrode assembly under the same volume, but also the energy density of the battery cell can be improved; in addition, the pole is omitted, and the part of the current collector 001 passing through the cover of the battery cell is used as the pole, which simplifies the manufacturing steps and improves the manufacturing efficiency.

[0067] In addition, by passing one end of the current collector 001 through the cover plate 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 pole ear and the part where the current collector 001 is connected to the pole column can be increased, thereby reducing the mutual influence between these two parts and the corresponding components during welding, thereby improving the reliability of the connection between the current collector 001 and other components.

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

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

[0070] A first connection part 011 and a second connection part 012 connected thereto form a current collector, and another first connection part 011 and another second connection part 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 two current collecting components may be connected, or the second connecting portions 012 of two current collecting components may be connected, to form the current collecting component 001 .

[0072] In this embodiment, the above arrangement can not only increase the connection area between the current collector 001 and the tab, but also increase 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] Furthermore, compared with the method of extending from the edge of the portion connected to the pole 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 collector 001 is connected to the electrode terminal is located in the middle of the portion where the current collector 001 is connected to the pole tab, so that the first connection portion 011 collects current in the middle and then transfers 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 can be understood that if the two current collector 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 collector components to insulate and isolate the two current collector 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 plate of the battery cell and then extend to the outside of the accommodating cavity and connect to the bend portion 122. The bend portion 122 is configured to be in surface contact with the electrode terminal of the battery cell.

[0076] It can be understood that the portion where the bent portion 122 is in 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 contact surface area 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. In this way, compared with bending the bent portions 122 of the two second connection portions 012 in the same direction, the two second connection portions 012 can be prevented from overlapping, thereby reducing the welding thickness of the bent portions 122, and further facilitating the penetration welding and fixing of the bent portions 122, so as to improve the connection reliability between the bent portions 122 and the electrode terminal.

[0079] See also Figure 3 , Figure 3 001 is a schematic diagram of the structure of another current collecting member 001 provided in 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 one end 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 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 bridging 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 bridging portion 013 is provided with an avoidance hole 131 at a position 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 to 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 member 001 is shown, Figure 5 yes Figure 3 The side view of the current collector 001 is shown. In one embodiment, the two first connection parts 011 are arranged at intervals, and / or the two second connection parts 012 are located between the electrode terminals of the battery cell and the first connection parts 011 and are attached to 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 parts 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 parts 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 collector 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 1 is a 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, the first connection portion 011 is a flat plate structure, and the contour line of the projection of the first connection portion 011 in the plane parallel to 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, and the arc segment 111 is configured to be coaxially arranged with the battery cell.

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

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

[0092] In addition, if one end of the battery cell is used only as an output of an electrode, only one current collector can be configured at one end of the battery cell, and the first connection portion 011 of the current collector is a superior arc plate structure. Specifically, in the orthographic projection in the plane parallel to the first connection portion 011, the contour line of the projection of the first connection portion 011 includes an arc segment 111 and a straight line segment 112, and 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 be specifically 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 pole ear, and on the other hand, the two first connection portions 011 can be arranged at intervals to form a gap for electrolyte flow, thereby improving the wetting efficiency of the battery cell.

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

[0097] It will be appreciated 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 limitation, on the one hand, the current carrying capacity of the connection between the first connection part 011 and the second connection part 012 can be guaranteed to meet the current carrying 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 also Figure 1 In one embodiment, the second connection portion 012 is located between the first connection portion 011 and the electrode terminal of the battery cell and is a plate-like structure, and the plate-like structure is configured to be parallel to the axis of the battery cell.

[0100] In this embodiment, through the above arrangement, after the first connection portion 011 collects the current, the current can be directly transferred 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, through the above-mentioned angle, the bending angle of the current collecting member 001 can also be reduced, thereby improving the stress state of the current collecting member 001 and enhancing its reliability.

[0102] See also Figure 8 , Fig. 9 and Fig.10 , Figure 8 is a top view of the end cap assembly provided in an embodiment of the present application, Fig. 9 is along Figure 8 The cross-sectional view of AA in the figure, Fig.10 It's another Figure 8 AA cross-sectional view. 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 collector 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. Both sides of the upper plastic part 024 are connected to the cover plate 022 and the electrode terminal 023, respectively. 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 member 001 is Figure 2 When the structure shown is Figure 8 The cross-sectional view of AA is Fig. 9 The structure shown; the current collecting member 001 is Figure 3 When the structure shown is Figure 8 The cross-sectional view of AA is Fig.10 The structure shown.

[0104] Specifically, the upper plastic part 024 can be bonded or connected to the electrode terminal 023 and the cover plate 022 by adhesive bonding or injection molding; the lower plastic part 025 can be bonded or connected to the cover plate 022 by adhesive bonding or injection molding.

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

[0106] In this embodiment, by using the aforementioned current collector 001, one end of the current collector 001 is connected to the electrode terminal 023 of the battery cell after passing through the cover plate 022 of the battery cell, so that the welding part of the current collector 001 and the electrode terminal 023 is located outside the battery cell, thereby preventing the metal chips generated by welding at the connection between the current collector 001 and the electrode terminal 023 from falling into the battery cell, thereby reducing the amount of metal chips falling into the battery cell when the current collector 001 is welded. In this way, the reliability of the battery cell can be improved, and the probability of short circuit caused by welding metal chips inside the battery cell can be effectively reduced.

[0107] See also Fig.11 or Fig.12 , Fig.11 yes Fig. 9 The enlarged view of point B in the middle. Fig.12 yes Fig.10 In one embodiment, a connection cavity 231 is provided inside 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 is connected to the connection cavity 231. The end of the second connection portion 012 away from the first connection portion 011 also passes through the second through hole 232 and is connected to the cavity wall of the connection cavity 231.

[0108] In this embodiment, through the above-mentioned arrangement, on the one hand, the end of the current collector 001 can be protected to avoid damage due to impact; on the other hand, the area of ​​the connection portion between the current collector 001 and the electrode terminal 023 can be increased, thereby improving the reliability of the connection between the current collector 001 and the electrode terminal 023.

[0109] See also Fig.13 , Fig.13 2 is an exploded view of the electrode terminal 023 provided in an embodiment of the present application. In one embodiment, the electrode terminal 023 includes a terminal pressing block 233 and a sealing plate 234. One side of the terminal pressing block 233 is connected to the upper plastic part 024 and is provided with a second through hole 232. The other side is provided with a matching groove 2331. The sealing plate 234 closes the opening of the matching groove 2331 to define a connecting cavity 231.

[0110] In this embodiment, the above arrangement can improve the operability of connecting the second connecting portion 012 with the cavity wall of the connecting cavity 231 , thereby improving the reliability of connecting the second connecting portion 012 with 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 pressing 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 consistent with the material of the tab connected thereto. The sealing plate 234 is made of aluminum.

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

[0115] In this embodiment, through the above arrangement, the materials of the current collector 001 and the terminal pressing block 233 can be 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 Fig.14 and Fig.15 , Fig.14 is a schematic diagram of the structure of the terminal pressing block 233 provided in an embodiment of the present application, Fig.15 024 is a schematic diagram of the structure of the upper plastic part 024 provided in an embodiment of the present application. In one embodiment, a connection groove 235 is provided on a side of the electrode terminal 023 close to the cover plate 022. A connection block 241 is provided on a side of the upper plastic part 024 facing the electrode terminal 023. The connection block 241 cooperates with the connection groove 235 and is connected 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 Fig.11 and Fig.12In one embodiment, the upper plastic part 024 is provided with a third through hole 242. One end of the second connection part 012 passes through the first through hole 221 and the third through hole 242 and is connected to the electrode terminal 023. The sealing ring 021 also seals the matching part between the third through hole 242 and the second connection part 012. In this way, the sealing performance of the part where the current collector 001 protrudes from the inside of the battery cell can be further improved, thereby improving the reliability of the battery cell.

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

[0120] In one embodiment, the surface area of ​​the electrode terminal 023 facing away from the end cap is 50 mm2 to 300 mm2.

[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 definition, 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 Fig.16 or Fig.17 , Fig.16 is a schematic diagram of the structure of a battery cell 003 provided in an embodiment of the present application, Fig.17003 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. The battery cell 003 includes a shell 031, an electrode assembly 032, a first pole ear 033 and the aforementioned end cap assembly 002. The electrode assembly 032 is disposed in the shell 031. One end of the first pole ear 033 is connected to the electrode assembly 032. The cover plate 022 covers the shell 031. The first pole ear 033 is connected to the first connecting portion 011.

[0124] in, Fig.16 The current collector 001 in Figure 2 The current collecting piece 001 shown; Fig.17 The current collector 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 may be a positive electrode tab or a negative electrode tab.

[0127] The battery cell 003 may include one of the aforementioned end cap assemblies 002, or may include two of the aforementioned end cap assemblies 002. When the battery cell 003 includes one of the aforementioned end cap assemblies 002, the pole ear of any polarity is connected to the current collector 001. When the battery cell 003 includes two of the aforementioned end cap assemblies 002, the positive pole ear and the negative pole ear are connected to the current collectors 001 of the two end cap assemblies 002, respectively.

[0128] In this embodiment, by using the aforementioned end cap assembly 002, one end of the current collector 001 is connected to the electrode terminal 023 of the battery cell 003 after passing through the cover plate 022 of the battery cell 003, so that the welding position of the current collector 001 and the electrode terminal 023 is located outside the battery cell 003, thereby preventing the metal chips generated by welding at the connection between the current collector 001 and the electrode terminal 023 from falling into the battery cell 003, thereby reducing the amount of metal chips falling into the battery cell 003 when the current collector 001 is welded. In this way, the reliability of the battery cell 003 can be improved, and the probability of short circuit caused by welding metal chips inside the battery cell 003 can be effectively reduced.

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

[0130] The first connection part 011 of the current collector 001 is welded to the pole ear, 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. Then the sealing plate is 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 pole ear after assembly, thereby increasing the operating space for welding the current collector 001 to the pole ear, and further improving the ease of welding between the current collector 001 and the pole ear.

[0131] The embodiments of the present application are introduced in detail above. Specific examples are used in this article 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 technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method 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 comprises: A first connection portion, configured to be connected to a tab of the battery cell; The second connection part has one end connected to the first connection part, and the other end is configured to pass through the cover plate of the battery cell and then 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 penetrate 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 extending portion and a bending portion, one end of the extending 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, and two ends of the bridging portion are respectively connected to ends of two second connecting portions away from the first connecting portions.

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 connection parts are arranged at intervals, and / or the two second connection parts are located between the electrode terminals of the battery cells and the first connection parts 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 center angle of the arc segment is α, which satisfies: 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 is a plate-shaped structure, and the plate-shaped structure is configured to be parallel to the axis of the battery cell.

12. An end cap assembly, characterized in that: include: Sealing ring; A cover plate, provided with a first through hole; The electrode terminal is arranged on one side of the cover plate; An upper plastic part, located between the cover plate and the electrode terminal, and two sides of the upper plastic part are respectively connected to the cover plate and the electrode terminal; A lower plastic part connected to the other side of the cover plate; 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 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, characterized in that: 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.

14. The end cap assembly according to claim 13, characterized in that: 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, characterized in that: 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 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 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.

17. The end cap assembly according to any one of claims 13 to 16, characterized in that: A connection groove is arranged on one side of the electrode terminal close to the cover plate, and a connection block is arranged on one 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.

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 part 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 part between the third through hole and the second connecting part.

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 is disposed in the housing; A first electrode tab, one end of which is connected to the electrode assembly; And, in the end cover assembly as described in any one of claims 12-19, the cover plate is covered with the shell, and the first pole ear is connected to the first connecting portion.

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