Battery cell, battery and electric equipment

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell, a battery and electric equipment, the battery cell comprises a first pole piece group, a second pole piece group, a diaphragm group and a first bus piece; the first pole piece group comprises a plurality of first pole pieces, and each first pole piece comprises a first current collector and a first tab; the second pole piece group comprises a plurality of second pole pieces, the plurality of first pole pieces and the plurality of second pole pieces are alternately stacked, and each second pole piece comprises a second current collector; the diaphragm group comprises a plurality of diaphragms; the first tabs of the two adjacent first pole pieces are partially overlapped; the first bus piece is welded with all the first tabs in the first pole piece group; according to the battery cell provided by the invention, the two adjacent first tabs are partially overlapped, so that the first bus piece and all the first tabs in the first pole piece group can be welded through welding equipment after the pole pieces of the battery cell are stacked, the welding process is simple, and the production cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] In order to improve the energy density and safety of batteries, a composite current collector composed of a polymer film and a metal coating has gradually attracted attention. The polymer film is used in the middle of the composite current collector, and the insulating layer formed by the polymer film makes the metal coatings on both sides unable to conduct, so that the traditional welding method is no longer applicable, that is, directly welding the tabs of the multi-layer composite current collector cannot be successfully welded. However, in order to overcome the high resistance of the composite current collector, the battery adopts a multi-tab or gasket process, the welding process is complicated, and the production cost is high. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. It aims to provide a battery cell, a battery having the battery cell, and an electrical device having the battery. The welding process of the battery cell is simple and the production cost is low.

[0004] In order to achieve the above-mentioned purpose, in the first aspect, the present invention provides a battery cell, the battery cell has a first direction, a second direction and a third direction intersecting each other, the battery cell comprises a first pole piece group, a second pole piece group, a diaphragm group and a first current collector; the first pole piece group comprises a plurality of first pole pieces, the first pole piece comprises a first current collector and a first pole ear, the first pole ear is integrally formed at one end of the first current collector in the second direction; the second pole piece group comprises a plurality of second pole pieces, a plurality of the first pole pieces and a plurality of the second pole pieces are alternately stacked along the first direction, the second pole piece comprises a second current collector; the diaphragm group comprises a plurality of diaphragms, and the diaphragms are provided between adjacent first current collectors and second current collectors along the first direction; in the first pole piece group, along the first direction, the first pole ears of two adjacent first pole pieces partially overlap; the first current collector is located on one side of the first pole piece group in the first direction, and the first current collector is welded to all the first pole ears in the first pole piece group.

[0005] Two opposite surfaces of the first electrode tab in the first direction are respectively a first surface and a second surface.

[0006] For ease of understanding, among two adjacent first pole lugs, the two first pole lugs are respectively named as a first first pole lug and a second first pole lug.

[0007] In some embodiments, along the third direction, the size of the first busbar is a, and the total size of all first pole tabs in the first pole piece group is b, satisfying: a>b.

[0008] In some embodiments, the battery cell further includes a second bus bar, the second bus bar is located on a side of the first pole piece group facing away from the first bus bar in the first direction, and the second bus bar is welded to all the first pole tabs in the first pole piece group.

[0009] In some embodiments, the second pole piece further includes a second pole ear, and the second pole ear is integrally formed at an end of the second current collector away from the first pole ear in the second direction.

[0010] In some embodiments, the second pole piece further includes a second pole ear, and the second pole ear is integrally formed at one end of the second current collector in the third direction.

[0011] In some embodiments, the battery cell also includes a third bus; along the first direction, in the second pole piece group, the second pole tabs of two adjacent second pole pieces partially overlap; the third bus is located on one side of the second pole piece group in the first direction, and the third bus is welded to all the second pole tabs in the second pole piece group.

[0012] In some embodiments, along the third direction, the size of the third busbar is c, and the total size of all second pole tabs in the second pole piece group is d, satisfying: c>d.

[0013] In some embodiments, the battery cell further includes a fourth bus bar, the fourth bus bar is located on a side of the second pole piece group away from the third bus bar in the first direction, and the fourth bus bar is welded to all the second pole tabs in the second pole piece group.

[0014] In a second aspect, the present invention further provides a battery, comprising a battery cell according to any one of the above items.

[0015] In a third aspect, the present invention further provides an electrical device, wherein the electrical device comprises a battery according to any one of the above items.

[0016] Compared with the prior art, the battery cell according to the embodiment of the present invention has the following beneficial effects:

[0017] (1) By partially overlapping the first pole ears of two adjacent first pole sheets in the first direction, the first surface of the second first pole ear facing the first first pole ear can have a first overlapping area and a first non-overlapping area relative to the first first pole ear in the two adjacent first pole ears; at the same time, since the first pole ears of the two adjacent first pole sheets partially overlap in the first direction, the positions of the first pole ears of the two adjacent first pole sheets are different, so that the multiple first pole sheets in the first pole sheet group can be stacked according to the positions of the first pole ears, so that the first non-overlapping areas of the multiple first pole ears are staggered in the third direction. The first busbars are arranged neatly, and then the first non-overlapping area of ​​the first plurality of neatly arranged first pole ears can be welded to enable the first busbars to be welded to all the first pole ears in the first pole sheet group to achieve mutual conduction among the plurality of first pole sheets in the first pole sheet group; that is, after the pole sheets arranged in the battery cell are stacked, the first busbars can be welded to all the first pole ears in the first pole sheet group by welding equipment to achieve mutual conduction among all the first pole sheets in the first pole sheet group without adding additional metal gaskets or external pole ears between each layer of the first pole sheets, the welding process is simple, and the production cost is low.

[0018] (2) By partially overlapping the first pole ears of two adjacent first pole sheets in the first direction and welding the first surfaces of all the first pole ears in the first pole sheet group to the first bus bar, the areas of two adjacent first pole ears in the first pole sheet group can be equal or unequal, so that the welding area between the first bus bar and any first pole ear can be increased by making the first non-overlapping area of ​​the second first pole ear have a larger area among the two adjacent first pole ears, so that the contact between the first pole ear and the first bus bar is closer, which helps to improve the connection stability between the first bus bar and the first pole ears and improve the welding effect.

[0019] (3) Since the first pole ears of two adjacent first pole sheets partially overlap in the first direction, when all the first pole ears in the first pole sheet group are welded together through the first bus bar, the overlapping areas of the two adjacent first pole ears can contact each other; that is, the multiple first pole ears in the first pole sheet group can be connected by welding through the first bus bar, and can also be contacted and connected by mutual contact of the overlapping areas, and the effect of connecting and conducting between the multiple first pole ears in the first pole sheet group is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of a battery cell provided in Embodiment 1 of the present invention;

[0021] Figure 2 is a comparison diagram of all first pole ears in the first busbar and the first pole piece provided in the first embodiment of the present invention;

[0022] Figure 3 is a bottom view of a battery cell provided in Embodiment 1 of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of a battery cell provided by Embodiment 1 of the present invention when no busbar is welded;

[0024] Figure 5 is a cross-sectional view of a battery cell provided by the first embodiment of the present invention when no busbar is welded;

[0025] Figure 6 is a top view of a first pole piece provided in the first embodiment of the present invention;

[0026] Figure 7 is a top view of the second first pole piece provided in the first embodiment of the present invention;

[0027] Figure 8 is a schematic structural diagram of two first pole pieces stacked together according to the first embodiment of the present invention;

[0028] Fig. 9 is a schematic structural diagram of two second pole pieces provided in the first embodiment of the present invention when they are stacked;

[0029] Fig.10 This is a first structural schematic diagram of a battery cell provided by Embodiment 2 of the present invention when no busbar is welded thereto;

[0030] Fig.11 This is a second structural schematic diagram of a battery cell provided in the second embodiment of the present invention when no bus bar is welded.

[0031] In the figure, 100, first pole piece group; 100A, first first pole piece group; 100B, second first pole piece group; 200, second pole piece group; 200A, first second pole piece group; 200B, second second pole piece group; 300, diaphragm group;

[0032] 1. first pole piece; 11. first current collector; 12. first pole ear; 12A. first first pole ear; 12B. second first pole ear; 121. first surface; 122. second surface; 1211. first overlapping region; 1212. first non-overlapping region; 1221. second overlapping region; 1222. second non-overlapping region;

[0033] 2. second pole piece; 21. second current collector; 22. second pole ear; 22A. first second pole ear; 22B. second second pole ear; 221. third surface; 222. fourth surface; 2211. third overlapping region; 2212. third non-overlapping region; 2221. fourth overlapping region; 2222. fourth non-overlapping region;

[0034] 3. Diaphragm;

[0035] 4. First busbar; 41. First weld mark;

[0036] 5. second busbar; 51. second weld mark;

[0037] 6. The third busbar; 61. The third weld mark;

[0038] 7. Fourth busbar; 71. Fourth weld mark;

[0039] Z, first direction; X, second direction; Y, third direction. DETAILED DESCRIPTION

[0040] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0046] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0047] Embodiment 1

[0048] like Figure 1-Figure 9 As shown, a battery cell provided in the first embodiment of the present invention has a first direction Z, a second direction X and a third direction Y intersecting each other, and the battery cell includes a first pole piece group 100, a second pole piece group 200, a diaphragm group 300 and a first busbar 4.

[0049] The first pole piece group 100 includes a plurality of first pole pieces 1, wherein the first pole piece 1 includes a first current collector 11 and a first pole ear 12, and the first pole ear 12 is integrally formed at one end of the first current collector 11 in the second direction X; the second pole piece group 200 includes a plurality of second pole pieces 2, wherein the plurality of first pole pieces 1 and the plurality of second pole pieces 2 are alternately stacked along the first direction Z, and the second pole piece 2 includes a second current collector 21; the diaphragm group 300 includes a plurality of diaphragms 3, and diaphragms 3 are provided between adjacent first current collectors 11 and second current collectors 21 along the first direction Z; in the first pole piece group 100, along the first direction Z, the first pole ears 12 of two adjacent first pole pieces 1 partially overlap; the first bus 4 is located on one side of the first pole piece group 100 in the first direction Z, and the first bus 4 is welded to all the first pole ears 12 in the first pole piece group 100.

[0050] The first electrode tab 12 has a first surface 121 and a second surface 122 opposite to each other in the first direction Z.

[0051] For ease of understanding, among two adjacent first electrode tabs 12 , the two first electrode tabs 12 are respectively named as a first first electrode tab 12A and a second first electrode tab 12B.

[0052] Based on this technical solution, by making the first pole ears 12 of two adjacent first pole sheets 1 partially overlap in the first direction Z, it can be made that in the two adjacent first pole ears 12, the first surface 121 of the second first pole ear 12B facing the first first pole ear 12A has a first overlapping area 1211 and a first non-overlapping area 1212 relative to the first first pole ear 12A; at the same time, because the first pole ears 12 of the two adjacent first pole sheets 1 partially overlap in the first direction Z, the positions of the first pole ears 12 of the two adjacent first pole sheets 1 are different, so that the multiple first pole sheets 1 in the first pole sheet group 100 can be stacked according to the positions of the first pole ears 12, so that the first non-overlapping areas 1212 of the multiple first pole ears 12 12 are neatly arranged in a staggered manner in the third direction Y, and then the first bus 4 can be welded to the first non-overlapping area 1212 of the plurality of neatly arranged first pole ears 12, so that the first bus 4 can be welded to all the first pole ears 12 in the first pole sheet group 100, so as to realize the mutual conduction of the plurality of first pole sheets 1 in the first pole sheet group 100; that is, after the stacking of the pole sheets arranged in the battery cell as described above is completed in the present application, the first bus 4 can be welded to all the first pole ears 12 in the first pole sheet group 100 by welding equipment, so as to realize the interconnection and conductivity of all the first pole sheets 1 in the first pole sheet group 100, without adding additional metal gaskets or external pole ears between each layer of the first pole sheets 1, the welding process is simple, and the production cost is low.

[0053] By partially overlapping the first pole ears 12 of two adjacent first pole sheets 1 in the first direction Z and welding the first surfaces 121 of all the first pole ears 12 in the first pole sheet group 100 to the first bus 4, the areas of two adjacent first pole ears 12 in the first pole sheet group 100 can be equal or unequal, so that the welding area between the first bus 4 and any first pole ear 12 can be increased by making the first non-overlapping region 1212 of the second first pole ear 12B have a larger area among the two adjacent first pole ears 12, so that the contact between the first pole ear 12 and the first bus 4 is closer, which helps to improve the connection stability between the first bus 4 and the first pole ears 12 and improve the welding effect.

[0054] Since the first pole ears 12 of two adjacent first pole sheets 1 partially overlap in the first direction Z, when all the first pole ears 12 in the first pole sheet group 100 are welded together through the first bus 4, the overlapping areas of the two adjacent first pole ears 12 can contact each other; that is, the multiple first pole ears 12 in the first pole sheet group 100 can be welded and connected through the first bus 4, and can also be contacted and connected through the mutual contact of the overlapping areas, and the effect of the connection and conductivity between the multiple first pole ears 12 in the first pole sheet group 100 is better.

[0055] It should be noted that the partial overlap of the first pole ears 12 of the two adjacent first pole pieces 1 along the first direction Z means that, along the first direction Z, in the two adjacent pole ears, the orthographic projection of a part of the first pole ear on the preset plane perpendicular to the first direction Z overlaps with the orthographic projection of a part of the second pole ear on the preset plane perpendicular to the first direction Z, and the orthographic projection of another part of the first pole ear on the preset plane perpendicular to the first direction Z does not overlap with the orthographic projection of another part of the second pole ear on the preset plane perpendicular to the first direction Z; of course, the "overlap" of the two mentioned below refers to the overlap of the orthographic projections of the two on the preset plane. In addition, the "non-overlap" of the two mentioned below refers to the non-overlap of the orthographic projections of the two on the preset plane.

[0056] In this embodiment, the first direction Z is the thickness direction of the battery cell, and the preset plane is the top view plane of the battery cell.

[0057] It should be noted that the first overlapping area 1211 and the first non-overlapping area 1212 of the first surface 121 of the first pole lug 12 mean that along the first direction Z, if there is another first pole lug 12 in the direction in which the first surface 121 of the first pole lug 12 faces, then the overlapping area of ​​the first surface 121 of the first pole lug 12 and the other first pole lug 12 is the first overlapping area 1211, and the non-overlapping area of ​​the first surface 121 of the first pole lug 12 and the other first pole lug 12 is the first non-overlapping area 1212; if there is no other first pole lug 12 in the direction in which the first surface 121 of the first pole lug 12 faces, then the first surface 121 of the first pole lug 12 is the first non-overlapping area 1212.

[0058] In this embodiment, the first surface 121 is the upper surface of the first pole ear 12, and the second surface 122 is the lower surface of the first pole ear 12; therefore, the upper surface of the first pole ear 12 located in the uppermost layer in the first pole piece group 100 has a first non-overlapping area 1212 but does not have a first non-overlapping area 1212, and all the first pole ears 12 in the first pole piece group 100 except the first pole ear 12 located in the uppermost layer have both a first overlapping area 1211 and a first non-overlapping area 1212.

[0059] In some other embodiments, the first surface 121 may be the lower surface of the first electrode tab 12 , and the second surface 122 may be the upper surface of the first electrode tab 12 .

[0060] In this embodiment, the first pole piece 1 is a negative pole piece, and the second pole piece 2 is a positive pole piece.

[0061] In some other embodiments, the first pole piece 1 may be a positive pole piece, and the second pole piece 2 may be a negative pole piece.

[0062] In this embodiment, the first current collector 11 is a negative electrode composite current collector, and the second current collector 21 is a positive electrode composite current collector.

[0063] In this embodiment, the battery cell includes a first electrode plate group 100 and a second electrode plate group 200 .

[0064] In this embodiment, a first pole piece group 100 includes six first pole pieces 1 , and a second pole piece group 200 includes six second pole pieces 2 .

[0065] In other embodiments, the number of first pole pieces 1 in each first pole piece group 100 may also be flexibly increased or decreased, which will not be described in detail herein.

[0066] In other embodiments, the number of the second pole pieces 2 in each second pole piece group 200 may also be flexibly increased or decreased, which will not be described in detail herein.

[0067] See also Figure 1 A first welding mark 41 is formed in the area where the first current collector 4 is welded to the first surface 121 .

[0068] See also Figure 2 Along the third direction Y, the size of the first busbar 4 is a, and the total size of all first pole tabs 12 in the first pole piece group 100 is b, which satisfies: a>b. This facilitates welding the first busbar 4 to all first pole tabs 12 in the first pole piece group 100.

[0069] See also Figure 1-Figure 2 The battery cell provided in the first embodiment of the present invention further includes a second busbar 5, which is located on a side of the first pole piece group 100 away from the first busbar 4 in the first direction Z, and is welded to all the first pole tabs 12 in the first pole piece group 100. By respectively arranging the first busbar 4 and the second busbar 5 on both sides of the first pole piece group 100 and respectively welding the first surface 121 and the second surface 122 of the first pole tab 12, double-sided welding conduction of all the first pole tabs 12 in the first pole piece group 100 can be achieved, and the conduction effect is better.

[0070] A second weld mark 51 is formed in the area where the second bus bar 5 is welded to the second surface 122 .

[0071] Specifically, since the first pole ears 12 of two adjacent first pole sheets 1 partially overlap in the first direction Z, among the two adjacent first pole ears 12, the second surface 122 of the first first pole ear 12A facing the second first pole ear 12B has a second overlapping area 1221 and a second non-overlapping area 1222 relative to the second pole ear, and the second bus 5 and the second non-overlapping area 1222 of the second surface 122 of the first pole ear 12 are welded.

[0072] See also Figure 1-Figure 5 The second pole piece 2 further includes a second pole ear 22, which is integrally formed at one end of the second current collector away from the first pole ear 12 in the second direction X. In this way, the first pole ear 12 and the second pole ear 22 can be placed on different sides, which facilitates welding of the first bus 4 with the plurality of first pole ears 12 in the first pole piece group 100. It also facilitates welding of the third bus 6 with the plurality of second pole ears 22 in the second pole piece group 200.

[0073] In some other embodiments, the second pole tab 22 may also be integrally formed at one end of the second current collector in the third direction Y. In this way, the first pole tab 12 and the second pole tab 22 may be on different sides.

[0074] Two opposite surfaces of the second electrode tab 22 in the first direction Z are a third surface 221 and a fourth surface 222 .

[0075] See also Figure 1-Figure 3 , Figure 8 and Fig. 9 , the electrical property provided by the first embodiment of the present invention also includes a third busbar 6; along the first direction Z, in the second pole piece group 200, the second pole tabs 22 of two adjacent second pole pieces 2 partially overlap; the third busbar 6 is located on one side of the second pole piece group 200 in the first direction Z, and the third busbar 6 is welded to all the second pole tabs 22 in the second pole piece group 200. By welding the third busbar 6 and the multiple second pole tabs 22 of the second pole piece group 200 with welding equipment, the connection and conduction of all the second pole pieces 2 in the second pole piece group 200 can be achieved, without adding additional metal gaskets or external pole tabs between each layer of the second pole piece 2, the welding process is simple, and the production cost is low.

[0076] By using the first bus 4 and the first surface 121 of the multiple first pole tabs 12 in the first pole piece group 100 for welding, and using the third bus 6 and the third surface 221 of the multiple second pole tabs 22 in the second pole piece group 200 for welding, the processes of bending the pole tabs and pre-welding the pole tabs of the composite current collector can be omitted, which helps to simplify the production process of the battery cell and reduce the production cost of the battery cell.

[0077] For ease of understanding, among two adjacent second electrode tabs 22 , the two second electrode tabs 22 are respectively named as a first second electrode tab 22A and a second second electrode tab 22B.

[0078] A third welding mark 61 is formed in the area where the third bus bar 6 is welded to the third surface 221 .

[0079] Specifically, since the second pole ears 22 of two adjacent second pole pieces 2 partially overlap in the first direction Z, among the two adjacent second pole ears 22, the third surface 221 of the first second pole ear 22A facing the second second pole ear 22B has a third overlapping area 2211 and a third non-overlapping area 2212 relative to the second pole ear, and the second bus 5 and the third non-overlapping area 2212 of the second surface 122 of the first pole ear 12 are welded.

[0080] Along the third direction Y, the size of the third busbar 6 is c, and the total size of all second pole tabs 22 in the second pole piece group 200 is d, which satisfies: c>d. This facilitates welding the second busbar 5 to all second pole tabs 22 in the second pole piece group 200.

[0081] The battery cell further includes a fourth busbar 7, which is located on a side of the second pole piece group 200 away from the third busbar 6 in the first direction Z, and is welded to all the second pole tabs 22 in the second pole piece group 200. By respectively arranging the third busbar 6 and the fourth busbar 7 on both sides of the first pole piece group 100 and respectively welding the third surface 221 and the fourth surface 222 of the second pole tab 22, double-sided welding conduction of all the second pole tabs 22 in the second pole piece group 200 can be achieved, and the conduction effect is better.

[0082] A fourth weld mark 71 is formed in the area where the fourth bus bar 7 is welded to the fourth surface 222 .

[0083] Specifically, since the second pole ears 22 of two adjacent second pole pieces 2 partially overlap in the first direction Z, among the two adjacent second pole ears 22, the second surface 122 of the first first pole ear 12A facing the second first pole ear 12B has a fourth overlapping area 2221 and a fourth non-overlapping area 2222 relative to the second pole ear, and the second bus 5 and the fourth non-overlapping area 2222 of the second surface 122 of the first pole ear 12 are welded.

[0084] A method for preparing a battery cell according to any one of the above items comprises the following steps:

[0085] Active material coating: coating a first active material on a first preset area of ​​a first metal foil, the first preset area being used as a first foil material current collector area, leaving a first blank area on the first metal foil without coating the first active material, the first blank area being used as a first foil material tab area; coating a second active material on second preset areas on the front and back sides of the second metal foil, the second preset areas being used as a second foil material current collector area, leaving a second blank area on the second metal foil without coating the second active material, the second blank area being used as a first foil material tab area;

[0086] Preparation of pole pieces: cutting a first metal foil by a laser film-making device, cutting a first current collector 11 in a first foil current collector region of the first metal foil, cutting a first pole ear 12 connected to the first current collector 11 in a first foil pole ear region of the first metal foil, and preparing at least two or more first pole pieces 1 with different first pole ear 12 positions; cutting a second metal foil by a laser film-making device, cutting a second current collector 21 in a second foil current collector region of the second metal foil, cutting a second pole ear 22 connected to the first current collector 11 in a second foil pole ear region of the second metal foil, and preparing at least two or more second pole pieces 2 with different second pole ear 22 positions;

[0087] Prepare a bare battery cell, and laminate multiple first pole sheets 1, multiple diaphragms 3, and multiple second pole sheets 2 according to the position of the first pole ear 12 and the position of the second pole ear 22 to obtain a bare battery cell, wherein along the thickness direction of the bare battery cell, the first pole ears 12 of two adjacent first pole sheets 1 partially overlap, and the second pole ears 22 of two adjacent second pole sheets 2 partially overlap;

[0088] Welding busbars: welding the first busbar 4 to all first pole tabs 12 on the bare battery cell by welding equipment, and welding the third busbar 6 to all second pole tabs 22 on the bare battery cell by welding equipment.

[0089] The welding equipment may include but is not limited to ultrasonic welding equipment, laser welding equipment, etc.

[0090] In this embodiment, the first electrode sheet 1 is a negative electrode sheet, the first active material is a negative electrode active material, and the material of the first metal foil may include but is not limited to aluminum material, aluminum alloy material, etc.

[0091] The second electrode sheet 2 is a positive electrode sheet, the second active material is a positive active material, and the material of the second metal foil may include but is not limited to copper material, copper alloy material, etc.

[0092] Embodiment 2

[0093] See also Figure 10-11Embodiment 2 of the present invention further provides a battery cell. Different from the battery cell provided in Embodiment 1, the battery cell provided in Embodiment 2 includes two first electrode sheet groups 100 and two second electrode sheet groups 200. The two first electrode sheet groups 100 are respectively a first first electrode sheet group 100A and a second first electrode sheet group 100B, and the two second electrode sheet groups 200 are respectively a first second electrode sheet group 200A and a second second electrode sheet group 200B.

[0094] In other embodiments, the number of the first pole piece groups 100 may be flexibly increased or decreased, which will not be described in detail herein.

[0095] In other embodiments, the number of the second pole piece groups 200 may be flexibly increased or decreased, which will not be described in detail herein.

[0096] The arrangement of the multiple first pole pieces 1 of the first first pole piece group 100A in the third direction Y is different from the arrangement of the multiple first pole pieces 1 of the second first pole piece group 100B in the third direction Y, and a first pole ear 12 in the first first pole piece group 100A that is closest to the second first pole piece group 100B in the first direction Z partially overlaps with a first pole ear 12 in the second first pole piece group 100B that is closest to the first first pole piece group 100A in the first direction Z. A first busbar 4 can be welded to the first surface 121 of the multiple first pole pieces 12 of the first first pole piece group 100A to achieve connectivity and conductivity of the multiple first pole pieces 1 in the first first pole piece group 100A, another first busbar can be welded to the second surface 122 of the multiple first pole pieces 12 of the second first pole piece group 100B to achieve connectivity and conductivity of the multiple first pole pieces 1 in the second first pole piece group 100B, and another first busbar 4 can also be welded to the second surface 122 of a first pole piece 12 in the first first pole piece group 100A that is closest to the second first pole piece group 100B to achieve connectivity and conductivity of the first first pole piece group 100A and the second first pole piece group 100B.

[0097] Similarly, two third busbars 6 can also be used to achieve interconnection and conductivity of multiple second pole pieces 2 in the first second pole piece group 200A, interconnection and conductivity of multiple second pole pieces 2 in the second second pole piece group 200B, and interconnection and conductivity of the first second pole piece group 200A and the second second pole piece group 200B.

[0098] In the second embodiment, each first pole piece group 100 includes three first pole pieces 1 , and each second pole piece group 200 includes three second pole pieces.

[0099] In other embodiments, the number of the first pole pieces 1 in any first pole piece group 100 may be flexibly increased or decreased, which will not be described in detail herein.

[0100] In other embodiments, the number of the second pole pieces 2 in any second pole piece group 200 may also be flexibly increased or decreased, which will not be described in detail herein.

[0101] Embodiment 3

[0102] Embodiment 3 of the present invention further provides a battery, wherein the battery cell comprises any of the battery cells described above.

[0103] Embodiment 4

[0104] Embodiment 4 of the present invention further provides an electrical device, the electrical device comprising any of the above batteries.

[0105] The power-consuming device may be a device that requires a battery, such as a vehicle, a mobile phone, a tablet computer, a notebook, a smart watch, a smart bracelet, etc. The embodiment of the present application does not impose any special restrictions on the specific form of the above-mentioned power-consuming device.

[0106] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A battery cell having a first direction (Z), a second direction (X) and a third direction (Y) intersecting each other, characterized in that: include: A first pole piece group (100), the first pole piece group (100) comprising a plurality of first pole pieces (1), the first pole piece (1) comprising a first current collector (11) and a first pole ear (12), the first pole ear (12) being integrally formed at one end of the first current collector (11) in the second direction (X); A second pole piece group (200), the second pole piece group (200) comprising a plurality of second pole pieces (2), a plurality of the first pole pieces (1) and a plurality of the second pole pieces (2) being alternately stacked along the first direction (Z), and the second pole pieces (2) comprising a second current collector (21); A diaphragm group (300), the diaphragm group (300) comprising a plurality of diaphragms (3), wherein the diaphragms (3) are arranged between adjacent first current collectors (11) and second current collectors (21) along the first direction (Z); In the first pole piece group (100), along the first direction (Z), the first pole ears (12) of two adjacent first pole pieces (1) partially overlap; A first busbar (4), the first busbar (4) being located on one side of the first pole piece group (100) in the first direction (Z), and the first busbar (4) being welded to all the first pole tabs (12) in the first pole piece group (100).

2. The battery cell according to claim 1, characterized in that: Along the third direction (Y), the size of the first busbar (4) is a, and the total size of all first pole tabs (12) in the first pole piece group (100) is b, satisfying: a>b.

3. The battery cell according to claim 1, characterized in that: It also includes a second busbar (5), which is located on a side of the first pole piece group (100) away from the first busbar (4) in the first direction (Z), and the second busbar (5) is welded to all the first pole tabs (12) in the first pole piece group (100).

4. The battery cell according to claim 1, characterized in that: The second pole piece (2) further comprises a second pole ear (22), wherein the second pole ear (22) is integrally formed at an end of the second current collector away from the first pole ear (12) in the second direction (X).

5. The battery cell according to claim 1, characterized in that: The second pole piece (2) further comprises a second pole ear (22), wherein the second pole ear (22) is integrally formed at one end of the second current collector in the third direction (Y).

6. The battery cell according to claim 4 or claim 5, characterized in that: Also includes a third busbar (6); Along the first direction (Z), in the second pole piece group (200), the second pole ears (22) of two adjacent second pole pieces (2) partially overlap; The third busbar (6) is located on one side of the second pole piece group (200) in the first direction (Z), and the third busbar (6) is welded to all second pole tabs (22) in the second pole piece group (200).

7. The battery cell according to claim 6, characterized in that: Along the third direction (Y), the size of the third busbar (6) is c, and the total size of all second pole tabs (22) in the second pole piece group (200) is d, satisfying: c>d.

8. The battery cell according to claim 6, characterized in that: It also includes a fourth busbar (7), which is located on a side of the second pole piece group (200) away from the third busbar (6) in the first direction (Z), and the fourth busbar (7) is welded to all the second pole tabs (22) in the second pole piece group (200).

9. A battery, characterized in that: Comprising the battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: Comprising a battery according to claim 9.

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