Battery cell assembly, single battery, battery pack and electric equipment

Abstract

The utility model relates to the technical field of batteries, and provides a battery cell assembly, a single battery, a battery pack and electric equipment. The battery cell assembly comprises: a battery cell unit, wherein the battery cell unit comprises a plurality of battery cells stacked along a first direction; the battery cell comprises a battery cell main body, and a positive tab and a negative tab led out from the same side; in a plane perpendicular to the first direction, the orthographic projections of the positive and negative tabs in the same battery cell are not overlapped; orthographic projections of positive tabs belonging to different battery cells in the battery cell unit are not overlapped, and orthographic projections of negative tabs are not overlapped; the battery cell assembly comprises a first Tab piece and a second Tab piece, and the first Tab piece is arranged on one side of the positive tabs in the first direction and is connected with the positive tabs in the battery cell unit to form a positive tab part; and the second Tab sheet is arranged on one side of the negative tabs and is connected with the plurality of negative tabs in the battery cell unit to form a negative tab part. According to the battery cell assembly, the connection effect of the tabs in the battery cell and the connecting sheets can be improved, so that the service life of welding equipment is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery core assembly, a single battery, a battery pack and electrical equipment. Background Art

[0002] At present, the power soft-pack lithium battery mainly uses ultrasonic metal welding to connect the battery cell tabs with the tabs. For special-purpose batteries, such as high-power discharge batteries, in order to improve battery performance, it is necessary to reduce the surface density and increase the number of pole pieces; for high-capacity batteries, when the battery height or width is limited, it is necessary to increase the battery thickness, that is, the number of pole pieces.

[0003] When the number of positive or negative electrode sheets in the battery is ≥60, the ultrasonic metal welding process will become difficult to control, and the tension or adhesion rate between the battery cell tab and the tab sheet will easily fail to meet the standard. A higher power is required to meet the welding strength requirements, but welding with too high a power will easily crack the tab. This will seriously affect the performance and life of the lithium battery, and even cause safety hazards. At the same time, a large number of welding layers will significantly shorten the service life of the welding equipment. Utility Model Content

[0004] The utility model provides a battery core assembly, a single battery, a battery pack and electrical equipment. The battery core assembly can improve the connection effect between a pole ear in the battery core and a Tab sheet, and can extend the service life of welding equipment.

[0005] In order to achieve the above object, the utility model provides the following technical solutions:

[0006] According to a first aspect of the utility model, there is provided a battery core assembly, comprising:

[0007] A battery cell unit, wherein the battery cell unit comprises at least two battery cells, and at least two of the battery cells are stacked along a first direction, wherein the first direction is parallel to the thickness direction of the battery cell; the battery cell comprises a battery cell body and a positive electrode ear and a negative electrode ear extending from the same side of the battery cell body, wherein the negative electrode ear forms a second direction from the extension direction of the battery cell body, and the second direction is perpendicular to the first direction; in a plane perpendicular to the first direction, the orthographic projection of the positive electrode ear in the same battery cell does not overlap with the orthographic projection of the negative electrode ear; and in a plane perpendicular to the first direction, the orthographic projections of the positive electrode ears belonging to different battery cells in the battery cell unit do not overlap, and the orthographic projections of the negative electrode ears belonging to different battery cells in the battery cell unit do not overlap;

[0008] The battery cell assembly also includes a first Tab sheet and a second Tab sheet. Along the first direction, the first Tab sheet is placed on one side of the positive electrode ear, and the first Tab sheet connects multiple positive electrode ears in the battery cell unit to form a positive electrode ear portion; along the first direction, the second Tab sheet is placed on one side of the negative electrode ear, and the second Tab sheet connects multiple negative electrode ears in the battery cell unit to form a negative electrode ear portion.

[0009] According to a second aspect of the present invention, a single cell is provided, comprising a cell assembly as provided by any technical solution in the first aspect above.

[0010] According to a third aspect of the present invention, a battery pack is provided, comprising a single battery provided by any technical solution in the second aspect.

[0011] According to a fourth aspect of the utility model, there is provided an electrical device, comprising a battery pack as provided by any technical solution in the third aspect above.

[0012] It should be noted that in the battery cell assembly provided by the present application, the number of battery cells in the battery cell unit is at least two, replacing the original single thick battery cell solution. Multiple battery cells in the battery cell unit can be connected in parallel through the first Tab sheet and the second Tab sheet, which is convenient for the connection operation of multi-layer tab high-rate stacked battery cells. It is worth noting that when the first Tab sheet and the second Tab sheet are used for staggered parallel connection, the first Tab sheet is connected to the positive pole ear of each battery cell respectively, and the positive pole ears of multiple battery cells have no overlapping relationship, which can reduce the connection difficulty of the first Tab sheet and the positive pole ear, and improve the connection effect of the first Tab sheet and the positive pole ear; similarly, the second Tab sheet is connected to the negative pole ear of each battery cell respectively, and the negative pole ears of multiple battery cells have no overlapping relationship, which can reduce the connection difficulty of the second Tab sheet and the negative pole ear, and improve the connection effect of the second Tab sheet and the negative pole ear.

[0013] At the same time, in the battery cell assembly provided by the present application, multiple battery cells cooperate to achieve the effect of the original single thick battery cell. Under the premise of unchanged flow area, the number of internal pole pieces of the positive ear connected to the first Tab sheet and the number of internal pole pieces of the negative ear connected to the second Tab sheet can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment. Accordingly, the structural setting in the present application can reduce the requirements for the connection equipment through staggered parallel welding under the premise of ensuring the flow area, so as to extend the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to better understand the present disclosure, reference may be made to the embodiments shown in the following drawings. The components in the drawings are not necessarily to scale, and related elements may be omitted in order to emphasize and clearly illustrate the technical features of the present disclosure. In addition, related elements or components may have different arrangements as known in the art. In addition, in the drawings, the same reference numerals represent the same or similar components in each drawing. Among them:

[0015] Figure 1 A schematic diagram of the three-dimensional structure of a battery cell assembly provided in an embodiment of the present application;

[0016] Figure 2 for Figure 1 A schematic diagram of the structure of a battery cell;

[0017] Figure 3 for Figure 2 A schematic diagram of the structure of the battery cell at another angle;

[0018] Figure 4 for Figure 2 Schematic diagram of the structure of the battery cell at another angle;

[0019] Figure 5 for Figure 2 The structural diagram of the positive electrode sheet in the battery cell;

[0020] Figure 6 for Figure 2 The structural diagram of the negative electrode sheet in the battery cell;

[0021] Figure 7 for Figure 1 A schematic diagram of the structure of another battery cell;

[0022] Figure 8 for Figure 7 A schematic diagram of the structure of the battery cell at another angle;

[0023] Fig. 9 for Figure 7 Schematic diagram of the structure of the battery cell at another angle;

[0024] Fig.10 for Figure 7 The structural diagram of the positive electrode sheet in the battery cell;

[0025] Fig.11 for Figure 7 The structural diagram of the negative electrode sheet in the battery cell;

[0026] Fig.12 for Figure 1 A schematic plan view of the cell assembly;

[0027] Fig.13 for Figure 1A schematic diagram of the battery cell assembly at another angle;

[0028] Fig.14 for Figure 1 A schematic diagram of the China battery cell assembly at another angle;

[0029] Fig.15 A schematic diagram of a process for preparing a battery cell assembly according to an embodiment of the present application;

[0030] Figures 16 to 21 A schematic diagram of the structure of a preparation method for a battery cell assembly provided in an embodiment of the present application during the preparation process;

[0031] Fig. 22 for Fig.19 A magnified schematic diagram of the structure. DETAILED DESCRIPTION

[0032] The following will be combined with the accompanying drawings in the exemplary embodiments of the present disclosure to clearly and completely describe the technical solutions in the exemplary embodiments of the present disclosure. The exemplary embodiments described herein are only for illustrative purposes and are not intended to limit the scope of protection of the present disclosure. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present disclosure.

[0033] In the description of the present disclosure, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; the term "and / or" includes any and all combinations of one or more associated listed items. In particular, reference to "the / the" object or "an" object is also intended to indicate one of a possible plurality of such objects.

[0034] Unless otherwise specified or explained, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0035] Further, in the description of the present disclosure, it should be understood that the directional words such as "upper", "lower", "inner", "outer" and the like described in the exemplary embodiments of the present disclosure are described at the angles shown in the accompanying drawings and should not be understood as limitations on the exemplary embodiments of the present disclosure. It should also be understood that, in the context, when it is mentioned that an element or feature is connected to another element (one or more) "upper", "lower", or "inner", "outer", it can not only be directly connected to the other (one or more) elements "upper", "lower", "inner", "outer", but also can be indirectly connected to the other (one or more) elements "upper", "lower", "inner", "outer" through an intermediate element.

[0036] In a first aspect, the present application provides a battery cell assembly. Figures 1 to 14 The structure shown in the figure, the battery cell assembly includes: a battery cell unit 10, the battery cell unit 10 includes at least two battery cells, and at least two battery cells are stacked along a first direction, and the first direction is parallel to the thickness direction of the battery cell. Figure 1 As shown, the battery cell unit 10 includes two battery cells, namely, the battery cell 100 and the battery cell 200, which are stacked along a first direction. It should be understood that there are many possible numbers of battery cells, such as three, four or five, which will not be described in detail.

[0037] like Figure 1 As shown, taking a battery cell 100 as an example, the battery cell 100 includes a battery cell body 110 and a positive electrode ear 120 and a negative electrode ear 130 led out from the same side of the battery cell body, and the negative electrode ear 130 is led out from the battery cell body 110 to form a second direction, and the second direction is perpendicular to the first direction. In a plane perpendicular to the first direction, the orthographic projection of the positive electrode ear 120 and the orthographic projection of the negative electrode ear 130 in the same battery cell do not overlap.

[0038] like Figure 1 As shown, taking the battery cell 100 and the battery cell 200 as examples, the positive electrode tab 120 and the negative electrode tab 130 in the battery cell 100, and the positive electrode tab 220 and the negative electrode tab 230 in the battery cell 200 have no overlap in their orthographic projections in a plane perpendicular to the first direction. That is, in a plane perpendicular to the first direction, the orthographic projections of the positive electrode tabs belonging to different battery cells in the battery cell unit 10 have no overlap, and the orthographic projections of the negative electrode tabs belonging to different battery cells in the battery cell unit 10 have no overlap.

[0039] Please continue to refer to Figure 1In the structure shown, the battery cell assembly also includes a first Tab sheet 20 and a second Tab sheet 30. Along the first direction, the first Tab sheet 20 is placed on the side of the positive ear, and the first Tab sheet 20 connects multiple positive ears in the battery cell unit 10 to form a positive ear portion; along the first direction, the second Tab sheet 30 is placed on the side of the negative ear, and the second Tab sheet 30 connects multiple negative ears in the battery cell unit 10 to form a negative ear portion. It should be understood that the first Tab sheet 20 and the second Tab sheet 30 are collectively referred to as Tab sheets, which are suitable for soft packs. After being packaged with aluminum-plastic film, the Tab sheet can be extended to the outside of the battery as a current collector. In other words, the Tab sheet plays the role of gathering the current on the ear and conducting it to the outside of the battery. The Tab sheet is usually connected to the positive ear or the negative ear by welding, and then packaged with the aluminum-plastic film by hot melting.

[0040] It is understandable that if Figure 1 As shown, the positive ear 120 and the positive ear 220 constituting the positive ear are staggeredly connected by the first Tab sheet 20, and the negative ear 130 and the negative ear 230 constituting the negative ear are staggeredly connected by the second Tab sheet 30. Exemplarily, taking the position of the positive ear as an example, in the battery cell assembly provided in the embodiment of the present application, along the first direction, the first Tab sheet 20 is affixed to one side of the positive ear 120, and at the same time, the first Tab sheet 20 is affixed to one side of the positive ear 220. At this time, the first Tab sheet 20 is connected to the positive ear 120 and the positive ear 220 through the affixed portion. It is worth noting that this connection method can ensure the flow area, as well as ensure the firmness of the connection, which can improve the service life of the battery cell assembly.

[0041] It should be noted that in the battery cell assembly provided in the embodiment of the present application, the number of battery cells in the battery cell unit 10 is at least two, replacing the original single thick battery cell solution. The multiple battery cells in the battery cell unit 10 can be connected in parallel through the first Tab sheet 20 and the second Tab sheet 30, which is convenient for the connection operation of the multi-layer tab high-rate stacked battery cells. It is worth noting that when the first Tab sheet 20 and the second Tab sheet 30 are used for staggered parallel connection, the first Tab sheet 20 is connected to the positive pole ear of each battery cell respectively, and the positive pole ears of multiple batteries are not overlapped, which can reduce the connection difficulty of the first Tab sheet 20 and the positive pole ear, and improve the connection effect of the first Tab sheet 20 and the positive pole ear; similarly, the second Tab sheet 30 is connected to the negative pole ear of each battery cell respectively, and the negative pole ears of multiple batteries are not overlapped, which can reduce the connection difficulty of the second Tab sheet 30 and the negative pole ear, and improve the connection effect of the second Tab sheet 30 and the negative pole ear.

[0042] At the same time, in the battery cell assembly provided in the embodiment of the present application, multiple battery cells are combined to achieve the effect of the original single thick battery cell. Under the premise that the current flow area remains unchanged, the number of pole pieces inside the positive ear connected to the first Tab sheet 20 and the number of pole pieces inside the negative ear connected to the second Tab sheet 30 can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment.

[0043] It should be understood that n is related to the number of battery cells in the battery cell unit 10 . When the battery cell unit 10 includes two battery cells, n is equal to 2; when the battery cell unit includes three battery cells, n is equal to 3.

[0044] Accordingly, the structural arrangement in the embodiment of the present application can reduce the requirements for the connection equipment through staggered parallel welding while ensuring the flow area, thereby extending the service life of the equipment.

[0045] For example, it can reduce the loss of ultrasonic welding machine, triple group and base life, and is also beneficial to subsequent process operations such as primary packaging and packing. It should be understood that the triple group refers to: the ultrasonic welding machine triple group includes three parts: transducer, amplitude modulation rod and welding head.

[0046] It is worth noting that the battery cell assembly provided in the embodiment of the present application can be widely used in the manufacture of special battery cells with high power or high capacity requirements and a large number of pole pieces, so as to effectively reduce the number of pole pieces welded by a single ultrasonic welding, reduce the welding difficulty and the risk of cold welding and over-welding.

[0047] In one embodiment, along the first direction, the first Tab sheet 20 is placed on the same side of the plurality of positive tabs in the battery cell unit 10. For example, Figure 1 As shown, the first Tab sheet 20 is located on the same side of the positive electrode tab 120 and the positive electrode tab 220 to reduce the connection difficulty and improve the preparation efficiency.

[0048] Of course, when the second Tab sheet 30 and the negative electrode ear are connected, the same setting can also be performed, that is, along the first direction, the second Tab sheet 30 is placed on the same side of the multiple negative electrode ears in the battery cell unit 10, so as to reduce the connection difficulty and improve the preparation efficiency. Figure 1 As shown, the second Tab 30 is located on the same side of the negative electrode tab 130 and the negative electrode tab 230 .

[0049] It is worth noting that, in the above solution, the position designs of the first Tab sheet 20 and the second Tab sheet 30 can be selected at the same time, or only one of them can be selected.

[0050] In a specific embodiment, please continue to refer to Figure 1The structure shown, when simultaneously arranged: along the first direction, the first Tab sheet 20 is placed on the same side of multiple positive tabs; along the first direction, the second Tab sheet 30 is placed on the same side of multiple negative tabs, the first Tab sheet 20 and the second Tab sheet 30 are located on the same side of the battery cell unit 10.

[0051] It should be noted that the scheme setting in this specific embodiment can further reduce the connection difficulty and effectively improve the connection efficiency.

[0052] Taking the first Tab sheet 20, the positive electrode tab 120 and the positive electrode tab 220 as an example, the first Tab sheet 20 can be placed on the carrier; then the positive electrode tab 120 and the positive electrode tab 220 are placed on the surface; after the placement is completed, the connection operation is performed. Of course, the first Tab sheet 20 can also be placed on the surface of the positive electrode tab 120 and the positive electrode tab 220, and the details are not repeated here.

[0053] In one embodiment, the positive electrode ear is ultrasonically welded to the first Tab sheet 20; the negative electrode ear is ultrasonically welded to the second Tab sheet 30. It can be understood that the positive electrode ear and the negative electrode ear prepared by the ultrasonic welding structure are more solid, which can improve the stability and service life of the battery cell assembly. At the same time, the ultrasonic welding method is easier to operate and can reduce the difficulty and cost of preparation.

[0054] Of course, it is also possible to only ultrasonically weld the positive electrode tab and the first Tab sheet 20 , or only ultrasonically weld the negative electrode tab and the second Tab sheet 30 , which will not be described in detail.

[0055] It is worth noting that the material and cross-sectional area of ​​the Tab sheet directly affect the flow capacity, and the thickness of the Tab sheet affects the difficulty of ultrasonic welding, one-time packaging, packing and other processes. In one embodiment, the first Tab sheet 20 is an aluminum sheet; the first Tab sheet 20 has a first packaging area and a first welding area, and a portion of the surface of the first Tab sheet 20 located in the first packaging area is provided with an adhesive layer; the second Tab sheet 30 is a copper-nickel plated sheet; the second Tab sheet 30 has a second packaging area and a second welding area, and a portion of the surface of the second Tab sheet 30 located in the second packaging area is provided with an adhesive layer. Exemplarily, the above-mentioned adhesive layer can be a pole ear glue. The adhesive layer is used to bond with the aluminum-plastic film after hot melting to reduce the difficulty of packaging.

[0056] In one embodiment, please continue to refer to Figure 1 In the structure shown, the battery cell unit 10 is divided into a first part and a second part by a dividing plane (shown by a dotted line), and the dividing plane is parallel to the plane formed by the first direction and the second direction. The positive electrode ears in the battery cell unit 10 are all located in the first part, and the negative electrode ears in the battery cell unit 10 are all located in the second part. For example, Figure 1As shown, when the battery cell only includes the battery cell 100 and the battery cell 200, the positive electrode tab 120 of the battery cell 100 and the positive electrode tab 220 of the battery cell 200 are both located in the first part, and the negative electrode tab 130 of the battery cell 100 and the negative electrode tab 230 of the battery cell 200 are both located in the second part.

[0057] It should be noted that the embodiment of the present application divides the tabs of different polarities into zones, and after the first Tab sheet 20 and the second Tab sheet 30 are connected, the risk of short circuit in the battery cell assembly can be reduced.

[0058] In one embodiment, Fig.12 As shown, along the third direction perpendicular to the first direction and the second direction, among adjacent positive ears located in the first part and belonging to different battery cells, one positive ear and another positive ear have a gap W1 at their edges facing each other. Exemplarily, the positive ear 120 and the positive ear 220 have a gap W1, and the range of W1 is 1 mm to 2 mm.

[0059] It should be noted that the size of the interval W1 between adjacent positive tabs affects the misalignment state between the positive tabs. If W1 is too small, there will be a risk of overlapping adjacent positive tabs and increasing the number of welding layers, which will further affect the connection state between the positive tabs and the first Tab sheet 20.

[0060] Similarly, if Fig.12 As shown, it can be set according to needs: along the third direction perpendicular to the first direction and the second direction, in adjacent negative electrode ears located in the second part and belonging to different battery cells, one negative electrode ear and another negative electrode ear have a gap W2 at the edges facing each other. Exemplarily, the negative electrode ear 130 and the negative electrode ear 230 have a gap W2, and the range of W2 is 1mm to 2mm.

[0061] It is worth noting that when arranging the battery cell assembly provided in the embodiment of the present application, it is also possible to set only the interval between adjacent positive electrode ears to W1, or only the interval between adjacent negative electrode ears to W2, which will not be described in detail.

[0062] In one embodiment, along the third direction, the positive electrode tabs in the battery cell unit 10 have the same width, illustratively, the positive electrode tab 120 has the same width as the positive electrode tab 220 ; and / or, along the third direction, the negative electrode tabs in the battery cell unit 10 have the same width, illustratively, the negative electrode tab 130 has the same width as the negative electrode tab 230 .

[0063] It should be noted that this structural arrangement can reduce the difficulty of preparation and improve the preparation efficiency. Moreover, when the widths of the positive and / or negative tabs in the third direction are the same, it is convenient to connect with the Tab sheet.

[0064] In one embodiment, the length of the first Tab sheet 20 in the third direction is P1, the sum of the lengths of the positive ears in the battery cell unit in the third direction is M1, and the sum of the gaps between the positive ears belonging to different battery cells is A1, then M1+A1-P1≥2mm should be satisfied; and / or, the length of the second Tab sheet 30 in the third direction is P2, the sum of the lengths of the positive ears in the battery cell unit 10 in the third direction is M1, and the sum of the gaps between the negative ears belonging to different battery cells is A1, then M2+A2-P2≥2mm should be satisfied.

[0065] Exemplarily, when the battery cell unit 10 includes only two battery cells, battery cell 100 and battery cell 200, the total width of the Tab sheet is less than or equal to the sum of the widths of the tabs + the total width of the gaps. It is understandable that, taking the first Tab sheet 20 as an example, if the first Tab sheet 20 is larger, it will occupy a larger space and affect the overall size of the battery cell assembly; if the first Tab sheet 20 is smaller, it will affect the connection area between the first Tab sheet 20 and each positive tab in the battery cell unit 10, reduce the flow area between the two, and affect the connection stability between the two.

[0066] It should be noted that when specifically setting the length of the first Tab piece 20 and the second Tab piece 30 in the third direction, it is preferred to perform the above-mentioned setting to ensure the connection effect between the first Tab piece 20 and each positive electrode ear in the battery cell unit 10, and to ensure the connection effect between the second Tab piece 30 and each negative electrode ear in the battery cell unit 10.

[0067] Of course, in specific settings, it is also possible to set only the first Tab sheet 20 and each positive electrode lug in the battery cell unit 10 to have the above relationship, or to set only the second Tab sheet 30 and each negative electrode lug in the battery cell unit 10 to have the above relationship, and the details will not be repeated.

[0068] For example, when the battery cell unit includes only two battery cells, battery cell 100 and battery cell 200, taking the first Tab sheet 20 as an example, the width of the first Tab sheet 20 in the third direction can be set to be slightly less than twice the width of a single positive tab in the third direction. The reason is that the tab is usually not completely fixed to the Tab sheet in the width direction, and only needs to meet the welding stamp size requirements and the flow area.

[0069] In one embodiment, the thickness of the first Tab sheet 20 in the first direction is D1, the flow area of ​​the first Tab sheet 20 is D1 multiplied by P1, and the range of D1 is 0.2 mm to 1 mm; the thickness of the second Tab sheet 30 in the first direction is D2, the flow area of ​​the second Tab sheet 30 is D2 multiplied by P2, and the range of D2 is 0.2 mm to 1 mm. Of course, the above settings can also be performed only on the first Tab sheet 20 or the second Tab sheet 30, and the specific details are not repeated.

[0070] It is worth noting that the thickness D1 of the first Tab sheet 20 does not include the glue layer, and similarly, the thickness D2 of the second Tab sheet 30 does not include the glue layer.

[0071] The flow area of ​​the Tab sheet is related to the length of the Tab sheet in the third direction and the thickness of the Tab sheet in the first direction. It is understandable that, since the length of the first Tab sheet 20 and the second Tab sheet 30 in the embodiment of the present application is increased compared to the length of the Tab sheet used in a single thick battery cell, the thickness of the first Tab sheet 20 and the second Tab sheet 30 can be reduced under the premise of meeting the flow area requirements.

[0072] For example, the length of the Tab sheet is adjusted from 30mm and thickness of 0.3mm to 60mm and thickness of 0.2mm, which reduces the difficulty of sealing the top of the aluminum-plastic film. It is understandable that the thicker the Tab sheet, the larger the distance between the upper and lower layers of the Tab sheet, and the more difficult it is to seal near the Tab sheet.

[0073] In addition, it is worth noting that the cross-sectional area of ​​the Tab sheet in the above dimensions is 9mm 2 Increased to 12mm 2 , enhancing the discharge overcurrent capability.

[0074] In one embodiment, Figure 1 As shown, the partition surface coincides with the central axis of the battery cell unit 10 in the third direction. This arrangement can reduce the risk of short circuit and is convenient for optimizing the appearance of the battery cell assembly.

[0075] In one embodiment, it is worth noting that the battery cell unit 10 includes the battery cell 100 and the battery cell 200 as an example. Figure 1 refer to Figures 2 to 14 Along the third direction, the positive electrode ear 120 and the negative electrode ear 130 of the battery cell 100 are arranged opposite to each other, and the positive electrode ear 220 and the negative electrode ear 230 of the battery cell 200 are located between the positive electrode ear 120 and the negative electrode ear 130 of the battery cell 100 .

[0076] like Figure 3 As shown, along the third direction, the distance between the center of the positive electrode ear 120 and the center of the negative electrode ear 130 in the battery cell 100 is L1; Figure 7 As shown, along the third direction, the distance between the center of the positive electrode tab 220 and the center of the negative electrode tab 230 in the battery cell 200 is L2, and the size of L2 is different from that of L1, that is, the battery cell 100 and the battery cell 200 are staggered.

[0077] It should be understood that L1 and L2 can be understood as the center distance of the battery cell, which means the distance from the center of the positive ear to the center of the negative ear. The center distance of the battery cell is only applicable to the battery cell with the positive ear and the negative ear on the same side and symmetrical in center. It is worth noting that the center distance of the battery cell directly affects the design of the ultrasonic welding positioning tooling, the top sealing tooling and the pack mold. It is usually abbreviated as X1-X2, where X1 represents the center distance of the pole ear (or the center distance of the battery cell), and X2 represents the width of the pole ear / Tab sheet (i.e. the dimension in the third direction).

[0078] In one embodiment, please combine Figure 1 refer to Figures 2 to 14 The battery cell body includes a diaphragm and positive and negative electrode sheets arranged alternately in a first direction, and the diaphragm separates the positive electrode sheet from the negative electrode sheet; wherein:

[0079] The positive electrode sheet includes a first foil and a first coating layer, wherein the first coating layer is located on at least one side of the first foil in a thickness direction; the first coating layer covers a portion of the first foil, and the first foil not covered by the first coating layer forms a positive electrode ear;

[0080] The negative electrode sheet includes a second foil and a second coating layer, wherein the second coating layer is located on at least one side of the second foil in the thickness direction and covers a portion of the second foil, and the second foil not covered by the second coating layer forms a negative electrode ear.

[0081] It can be understood that the tab refers to the portion of the foil material outside the coating layer, which is used for welding. Exemplarily, the first foil material of the positive tab of the lithium battery is aluminum foil, and the second foil material of the negative tab is copper foil.

[0082] It is worth noting that when the foil is formed into the tab, it may be cut to form the tab shape that meets the requirements. The tab size and position are determined by the pole die cutter. The width of the tab and the thickness of the foil used directly affect the current capacity and resistance of the battery cell.

[0083] It is worth noting that the electrode sheets in each battery cell will be stacked or wound during the process of forming the battery cell body. After this process, the foil material of the electrode sheets not covered by the coating layer forms the electrode ears.

[0084] For example, Figure 2 The battery body 110 of the battery cell 100 shown in FIG. 1 includes a positive electrode sheet 111, a negative electrode sheet 112 and a separator 113, wherein the positive electrode sheet 111 is as shown in FIG. Figure 5 As shown, the negative electrode sheet 112 is as Figure 6 It is worth noting that Figure 5 The dotted lines in the figure separate the areas of the first foil material covered by the first coating layer and the areas not covered by the first coating layer. Figure 6 The dotted lines in FIG. 1 and FIG. 2 separate the areas of the second foil material covered by the second coating layer and the areas not covered by the second coating layer. It should be understood that Figure 5The area of ​​the first foil material not covered by the first coating area is used to form the positive electrode ear 120, Figure 6 The area of ​​the second foil not covered by the second coating area is used to form the negative electrode ear 130 .

[0085] Similarly, if Figure 7 The battery body 210 of the battery cell 200 shown in FIG. 1 includes a positive electrode sheet 211, a negative electrode sheet 212 and a separator 213, wherein the positive electrode sheet 211 is as shown in FIG. Fig.10 As shown, the negative electrode sheet 212 is as shown in Fig.11 It is worth noting that Fig.10 The dotted lines in the figure separate the areas of the first foil material covered by the first coating layer and the areas not covered by the first coating layer. Fig.11 The dotted lines in FIG. 1 and FIG. 2 separate the areas of the second foil material covered by the second coating layer and the areas not covered by the second coating layer. It should be understood that Fig.10 The area of ​​the first foil material not covered by the first coating area is used to form the positive electrode ear 220, Fig.11 The area of ​​the second foil not covered by the second coating area is used to form the negative electrode ear 230 .

[0086] In one embodiment, the battery cell is a wound battery cell or a laminated battery cell.

[0087] It should be noted that the stacking method has a high degree of alignment after the foils are overlapped, which can improve the product yield of the battery cell assembly provided in the embodiment of the present application. The winding method has a simple preparation method and can improve the preparation efficiency.

[0088] like Figure 2 As shown, taking the battery cell 100 as an example, after the positive electrode sheet 111, the negative electrode sheet 112 and the separator 113 are wound or folded, they need to be aligned and fixed with tape 140. It is worth noting that in the process of winding or stacking to form the battery cell body 110, the electrode sheets follow the arrangement principle of negative, positive, negative, positive, negative. In other words, along the first direction, the outermost electrode sheets in the battery cell body 110 are all negative electrode sheets 112.

[0089] like Figure 7 As shown, taking the battery cell 200 as an example, after the positive electrode sheet 211 , the negative electrode sheet 212 and the separator 213 are wound or folded, they need to be aligned and fixed using a tape 240 .

[0090] In a second aspect, the present application provides a method for preparing a battery cell assembly. Figures 1 to 14 For reference Fig.15 , the preparation method provided in the embodiment of the present application comprises:

[0091] Step S1502: stacking at least two battery cells along a first direction to form a battery cell unit 10, wherein the first direction is parallel to the thickness direction of the battery cell; in a plane perpendicular to the first direction, the orthographic projection of the positive electrode ear in the same battery cell does not overlap with the orthographic projection of the negative electrode ear; and in a plane perpendicular to the first direction, the orthographic projections of the positive electrode ears belonging to different battery cells in the battery cell unit 10 do not overlap, and the orthographic projections of the negative electrode ears belonging to different battery cells in the battery cell unit 10 do not overlap;

[0092] Step S1504: Use the first Tab sheet 20 to connect multiple positive ears in the battery cell unit 10 to form a positive ear portion, and use the second Tab sheet 30 to connect multiple positive ears in the battery cell unit 10 to form a negative ear portion; wherein the first Tab sheet 20 is placed on one side of the positive ear along the first direction; and the second Tab sheet 30 is placed on one side of the negative ear along the first direction.

[0093] It should be noted that in the battery cell assembly prepared by the present preparation method, the number of battery cells in the battery cell unit 10 is at least two, replacing the original single thick battery cell solution. The multiple battery cells in the battery cell unit 10 can be connected in parallel by the first Tab sheet 20 and the second Tab sheet 30, which is convenient for the connection operation of the multi-layer tab high-rate stacked battery cells. It is worth noting that when the first Tab sheet 20 and the second Tab sheet 30 are used for staggered parallel connection, the first Tab sheet 20 is connected to the positive pole ear of each battery cell respectively, and the positive pole ears of the multiple battery cells are not overlapped, which can reduce the connection difficulty of the first Tab sheet 20 and the positive pole ear, and improve the connection effect of the first Tab sheet 20 and the positive pole ear; similarly, the second Tab sheet 30 is connected to the negative pole ear of each battery cell respectively, and the negative pole ears of the multiple battery cells are not overlapped, which can reduce the connection difficulty of the second Tab sheet 30 and the negative pole ear, and improve the connection effect of the second Tab sheet 30 and the negative pole ear.

[0094] At the same time, in the battery cell assembly, multiple battery cells cooperate to achieve the effect of the original single thick battery cell. Under the premise of unchanged flow area, the number of positive pole pieces connected to the first Tab sheet 20 and the number of negative pole pieces connected to the second Tab sheet 30 can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment. Accordingly, the structural setting in the present application can reduce the requirements for the connection equipment through staggered parallel welding under the premise of ensuring the flow area, so as to extend the service life of the equipment.

[0095] In one embodiment, in step S1504, before using the first Tab sheet 20 to connect multiple positive electrode ears in the battery cell unit 10 to form a positive electrode ear portion, and using the second Tab sheet 30 to connect multiple positive electrode ears in the battery cell unit 10 to form a negative electrode ear portion, the preparation method further includes:

[0096] like Figures 16 to 18 As shown, the positive electrode ears belonging to the same battery cell are pre-welded, and the negative electrode ears belonging to the same battery cell are pre-welded. Fig.16 as well as Fig. 22 Welding S is shown schematically in FIG.

[0097] It should be noted that pre-welding is to initially combine the loose battery cell tabs after lamination to facilitate positioning and cutting. Cutting is to ensure that the top of the battery cell tab is neat and the tab length is appropriate, so that the top of the tab does not exceed the tab glue / top seal glue on the Tab after the tab is welded to the Tab.

[0098] In one embodiment, when pre-welding the positive electrode ears belonging to the same battery cell, the pre-welding operation of the positive electrode ears belonging to different battery cells in the battery cell unit is performed simultaneously; and / or, when pre-welding the negative electrode ears belonging to the same battery cell, the pre-welding operation of the negative electrode ears belonging to different battery cells in the battery cell unit is performed simultaneously.

[0099] It should be noted that simultaneous welding can reduce the number of welding times as much as possible, avoid the interference of welding slag and welding vibration on other battery cell tabs, and improve the preparation efficiency.

[0100] In one embodiment, the total number of weld points of the positive tabs belonging to different battery cells after pre-welding is 2 to 4; and / or, the total number of weld points of the negative tabs belonging to different battery cells after pre-welding is 2 to 4. It should be understood that the number of weld points in the weld mark S affects the gathering effect of the multi-layer foil in the tab, and therefore, the number of weld points cannot be too small. At the same time, since the pre-welding points themselves will also affect the strength of the foil, it is not advisable to have too many weld points during pre-welding to avoid welding a large area of ​​foil twice.

[0101] In one embodiment, before pre-welding the positive electrode ears belonging to the same battery cell and pre-welding the negative electrode ears belonging to the same battery cell, the preparation method further includes: cutting the foil material forming the positive electrode ears and cutting the foil material forming the negative electrode ears. This structural setting enables the size of the electrode ears to meet the requirements.

[0102] Please combine Figures 16 to 18 refer to Figures 19 to 22 In the structure shown, taking the battery cells 100 and 200 as examples, the pre-welded and cut positive tabs 120 and the positive tabs 220 are ultrasonically welded on the first Tab sheet 20 at the same time; after welding, the interval between the positive tabs 120 and the positive tabs 220 on the first Tab sheet 20 is 1 mm to 2 mm, so as to ensure that there is no overlapping area when the positive tabs 120 and the positive tabs 220 are welded on the first Tab sheet 20, thereby avoiding an increase in the number of welding layers.

[0103] In one embodiment, the method for preparing the battery cell assembly provided in the embodiment of the present application further includes: placing the battery cell unit 10 after welding the first Tab sheet 20 and the second Tab sheet 30 into an aluminum-plastic film, and sealing the aluminum-plastic film by hot melting.

[0104] It is worth noting that in order to more clearly understand the battery cell assembly and the preparation method thereof in the embodiments of the present application, taking the battery cell assembly including two battery cells, battery cell 100 and battery cell 200, as an example, the battery cell assembly is applied in a specific single cell battery for explanation.

[0105] Taking the soft-pack 16186220 battery as an example, 16 means the maximum thickness of the finished battery cell is 16mm, 186 means the maximum width of the finished battery cell is 186mm, and 220 means the maximum height of the finished battery cell is 220mm. It is required to support 180A continuous discharge and 360A pulse discharge.

[0106] According to the conventional design of soft-pack batteries, the number of ultrasonically welded electrode layers is 72 for positive electrodes and 73 for negative electrodes. The width of the positive and negative electrodes in the battery cell is 30 mm. The size of the first Tab sheet is 0.4 mm*30 mm, and the size of the second Tab sheet is 0.3 mm*30 mm, as shown in Table 1.

[0107] Table 1 Related parameters of existing soft pack batteries

[0108] Components data Positive electrode layer number 72 pieces Negative electrode layer number 73 pieces Positive / negative ear width 30mm Cell center distance (90-30)mm First Tab 20 0.4mm*30mm Second Tab 30 0.3mm*30mm

[0109] It is understandable that the number of pole pieces is large, and ultrasonic welding is difficult, which affects production. The difficulties of the existing solution are: 1. After evaluation, the ultrasonic welding machine manufacturer believes that the existing welding machine and the existing welding head and base are difficult to achieve welding of more than 65 layers of pole pieces; 2. Even if the welding machine and the welding head base are replaced to achieve welding, welding under high power conditions will cause a significant reduction in the service life of the welding machine, triple group, and base.

[0110] In the embodiment of the present application, the battery is designed to have two cells, cell 100 and cell 200. The number of ultrasonically welded electrode layers is 36 positive electrode sheets and 37 negative electrode sheets. The center distance between the cells is (122-30) mm, the center distance between the cells is (58-30) mm, the width of the positive / negative ear is 30 mm, the size of the first Tab sheet 20 is 0.2 mm*60 mm, and the size of the second Tab sheet 30 is 0.2 mm*60 mm, as shown in Table 2.

[0111] Table 2 Related parameters of the soft pack battery in the present embodiment

[0112] Components data Number of positive electrode sheets in cell 100 / cell 200 36 pieces / 36 pieces Number of negative electrode layers in cell 100 / cell 200 37 pieces / 37 pieces Center distance of battery cell 100 (122-30)mm Battery cell 200 center distance (58-30)mm Width of positive / negative tabs 30mm First Tab 20 0.2mm*60mm Second Tab 30 0.2mm*60mm

[0113] It should be noted that, as can be seen from Table 2, the technical solution in the embodiment of the present application is relative to the technical solution in the prior art. The width of the positive / negative tab remains unchanged at 30mm, the width of the first Tab sheet 20 and the second Tab sheet 30 increases from 30mm to 60mm, and the thickness of the first Tab sheet 20 and the second Tab sheet 30 decreases, which reduces the difficulty of top sealing. Compared with the structure in Table 1, the cross-sectional area of ​​the first Tab sheet 20 in the technical solution in the embodiment of the present application remains unchanged, and the cross-sectional area of ​​the second Tab sheet 30 increases from 9mm to 60mm. 2 Increased to 12mm 2 , enhancing the discharge overcurrent capability.

[0114] It is worth noting that, from Table 2, it can be seen that in the battery cell assembly provided in the embodiment of the present application, the center distance L1 of the positive electrode sheet 111 and the negative electrode sheet 112 in the battery cell 100 is 122-30, and the center distance L2 of the positive electrode sheet 211 and the negative electrode sheet 212 in the battery cell 200 is 58-30. Accordingly, when preparing the battery cell assembly, two sets of A / B die cutters are respectively used for the positive and negative electrodes.

[0115] Afterwards, two stacking machines can be used to stack battery cells 100 and battery cells 200 respectively, and then battery cells 100 and battery cells 200 are combined. The 2mm reserved in the middle cutting die of the tabs of battery cells 100 and battery cells 200 is to prevent the tabs from overlapping and increasing the number of welding layers. Compared with the original single thick battery cell, the thickness of the combined battery cells 100 and battery cells 200 is increased by 1 layer of negative electrode sheet and 3 layers of separator, and the thickness space can still meet the design requirements. Afterwards, the tabs can be pre-welded, tab cut, and ultrasonically final welded for the combined battery cell unit 10.

[0116] It should be noted that the staggered parallel welding scheme for multiple battery cell tabs provided by the embodiment of the present disclosure can significantly reduce the difficulty of ultrasonic welding, reduce the life loss of the welding machine, the triple group, and the base; and increase the cross-sectional area of ​​the Tab sheet and enhance the discharge overcurrent capacity; at the same time, the thickness of the Tab sheet is thinned to reduce the difficulty of top sealing.

[0117] In a third aspect, an embodiment of the present application provides a single cell battery, comprising a cell assembly as provided by any technical solution in the first aspect above. The single cell battery is a soft pack battery.

[0118] It should be noted that in the single cell provided in the embodiment of the present application, the number of cells in the cell unit 10 of the cell assembly is at least two, replacing the original single thick cell solution. The multiple cells in the cell unit 10 can be connected in parallel through the first Tab sheet 20 and the second Tab sheet 30, which is convenient for the connection operation of the multi-layer tab high-rate stacked cells. It is worth noting that when the first Tab sheet 20 and the second Tab sheet 30 are used for staggered parallel connection, the first Tab sheet 20 is connected to the positive pole ear of each cell respectively, and the positive pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the first Tab sheet 20 and the positive pole ear, and improve the connection effect of the first Tab sheet 20 and the positive pole ear; similarly, the second Tab sheet 30 is connected to the negative pole ear of each cell respectively, and the negative pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the second Tab sheet 30 and the negative pole ear, and improve the connection effect of the second Tab sheet 30 and the negative pole ear.

[0119] At the same time, in the battery cell assembly, multiple battery cells cooperate to achieve the effect of the original single thick battery cell. Under the premise of unchanged flow area, the number of positive pole pieces connected to the first Tab sheet 20 and the number of negative pole pieces connected to the second Tab sheet 30 can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment. Accordingly, the structural setting in the present application can reduce the requirements for the connection equipment through staggered parallel welding under the premise of ensuring the flow area, so as to extend the service life of the equipment.

[0120] In a fourth aspect, an embodiment of the present application provides a battery pack, which includes a single battery provided by any technical solution in the third aspect.

[0121] It should be noted that in the battery pack provided in the embodiment of the present application, the number of cells in the cell unit 10 of the cell assembly is at least two, replacing the original single thick cell solution. The multiple cells in the cell unit 10 can be connected in parallel through the first Tab sheet 20 and the second Tab sheet 30, which is convenient for the connection operation of the multi-layer tab high-rate stacked cells. It is worth noting that when the first Tab sheet 20 and the second Tab sheet 30 are used for staggered parallel connection, the first Tab sheet 20 is connected to the positive pole ear of each cell respectively, and the positive pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the first Tab sheet 20 and the positive pole ear, and improve the connection effect of the first Tab sheet 20 and the positive pole ear; similarly, the second Tab sheet 30 is connected to the negative pole ear of each cell respectively, and the negative pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the second Tab sheet 30 and the negative pole ear, and improve the connection effect of the second Tab sheet 30 and the negative pole ear.

[0122] At the same time, in the battery cell assembly, multiple battery cells cooperate to achieve the effect of the original single thick battery cell. Under the premise of unchanged flow area, the number of positive pole pieces connected to the first Tab sheet 20 and the number of negative pole pieces connected to the second Tab sheet 30 can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment. Accordingly, the structural setting in the present application can reduce the requirements for the connection equipment through staggered parallel welding under the premise of ensuring the flow area, so as to extend the service life of the equipment.

[0123] In a fifth aspect, an embodiment of the present application provides an electric device, which includes a battery pack provided by any technical solution in the fourth aspect.

[0124] It should be noted that in the electrical equipment provided in the embodiment of the present application, the number of cells in the cell unit 10 of the cell assembly is at least two, replacing the original single thick cell solution. The multiple cells in the cell unit 10 can be connected in parallel through the first Tab sheet 20 and the second Tab sheet 30, which is convenient for the connection operation of the multi-layer tab high-rate stacked cells. It is worth noting that when the first Tab sheet 20 and the second Tab sheet 30 are used for staggered parallel connection, the first Tab sheet 20 is connected to the positive pole ear of each cell respectively, and the positive pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the first Tab sheet 20 and the positive pole ear, and improve the connection effect of the first Tab sheet 20 and the positive pole ear; similarly, the second Tab sheet 30 is connected to the negative pole ear of each cell respectively, and the negative pole ears of the multiple cells are not overlapped, which can reduce the connection difficulty of the second Tab sheet 30 and the negative pole ear, and improve the connection effect of the second Tab sheet 30 and the negative pole ear.

[0125] At the same time, in the battery cell assembly, multiple battery cells cooperate to achieve the effect of the original single thick battery cell. Under the premise of unchanged flow area, the number of positive pole pieces connected to the first Tab sheet 20 and the number of negative pole pieces connected to the second Tab sheet 30 can be reduced to one-n of the original number, thereby greatly reducing the connection difficulty and reducing the loss of welding equipment. Accordingly, the structural setting in the present application can reduce the requirements for the connection equipment through staggered parallel welding under the premise of ensuring the flow area, so as to extend the service life of the equipment.

[0126] Those skilled in the art will readily come up with other embodiments of the present disclosure after considering the specification and practicing the utility model disclosed herein. The present disclosure is intended to cover any variation, use or adaptation of the present utility model, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and example embodiments are to be regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0127] It should be understood that the present disclosure is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from its scope. The scope of protection of the present disclosure is limited only by the appended claims.

Claims

1. A battery cell assembly, characterized in that: include: A battery cell unit, wherein the battery cell unit comprises at least two battery cells, and at least two of the battery cells are stacked along a first direction, wherein the first direction is parallel to the thickness direction of the battery cell; the battery cell comprises a battery cell body and a positive electrode ear and a negative electrode ear extending from the same side of the battery cell body, wherein the negative electrode ear forms a second direction from the extension direction of the battery cell body, and the second direction is perpendicular to the first direction; in a plane perpendicular to the first direction, the orthographic projection of the positive electrode ear in the same battery cell does not overlap with the orthographic projection of the negative electrode ear; and in a plane perpendicular to the first direction, the orthographic projections of the positive electrode ears belonging to different battery cells in the battery cell unit do not overlap, and the orthographic projections of the negative electrode ears belonging to different battery cells in the battery cell unit do not overlap; The battery cell assembly also includes a first Tab sheet and a second Tab sheet. Along the first direction, the first Tab sheet is placed on one side of the positive electrode ear, and the first Tab sheet connects multiple positive electrode ears in the battery cell unit to form a positive electrode ear portion; along the first direction, the second Tab sheet is placed on one side of the negative electrode ear, and the second Tab sheet connects multiple negative electrode ears in the battery cell unit to form a negative electrode ear portion.

2. The battery cell assembly according to claim 1, characterized in that: Along the first direction, the first Tab sheet is placed on the same side of the plurality of positive tabs in the battery cell unit; Alternatively, along the first direction, the second Tab sheet is placed on the same side of the multiple negative electrode ears in the battery cell unit.

3. The battery core assembly according to claim 1, characterized in that: Along the first direction, the first Tab sheet is placed on the same side of the plurality of positive tabs; along the first direction, the second Tab sheet is placed on the same side of the plurality of negative tabs, and the second Tab sheet and the first Tab sheet are located on the same side of the battery cell unit.

4. The battery core assembly according to claim 1, characterized in that: Ultrasonic welding between the positive electrode tab and the first Tab sheet; And / or, the negative electrode tab is ultrasonically welded to the second Tab sheet.

5. The battery core assembly according to claim 1, characterized in that: The first Tab sheet is an aluminum sheet; the first Tab sheet has a first packaging area and a first welding area, and a portion of the surface of the first Tab sheet located in the first packaging area is provided with an adhesive layer; The second Tab sheet is a copper-nickel plate; the second Tab sheet has a second packaging area and a second welding area, and a portion of the surface of the second Tab sheet located in the second packaging area is provided with an adhesive layer.

6. The battery core assembly according to any one of claims 1 to 5, characterized in that: The battery cell unit is divided into a first part and a second part by a dividing surface, and the dividing surface is parallel to the first direction and the second direction to form a plane, the positive pole ears in the battery cell unit are all located in the first part, and the negative pole ears in the battery cell unit are all located in the second part.

7. The battery cell assembly according to claim 6, characterized in that: Along a third direction perpendicular to the first direction and the second direction, in the adjacent positive electrode ears located in the first part and belonging to different battery cells, a positive electrode ear and another positive electrode ear have a gap at their edges facing each other, and the range of the gap is 1 mm to 2 mm; And / or, along a third direction perpendicular to the first direction and the second direction, among the adjacent negative electrode ears located in the second part and belonging to different battery cells, one negative electrode ear and another negative electrode ear have a gap at their edges facing each other, and the gap ranges from 1 mm to 2 mm.

8. The battery cell assembly according to claim 7, characterized in that: Along the third direction, the widths of the positive electrode tabs in the battery cell units are the same; And / or, along the third direction, the negative electrode ears in the battery cell units have the same width.

9. The battery core assembly according to claim 8, characterized in that: The length of the first Tab sheet in the third direction is P1, the sum of the lengths of the positive tabs in the cell unit in the third direction is M1, and the sum of the gaps between the positive tabs belonging to different cells is A1, then M1+A1-P1≥2mm should be satisfied; And / or, the length of the second Tab sheet in the third direction is P2, the sum of the lengths of the positive pole ears in the battery cell unit in the third direction is M1, and the sum of the gaps between the negative pole ears belonging to different battery cells is A1, then M2+A2-P2≥2mm should be satisfied.

10. The battery core assembly according to claim 9, characterized in that: In a plane perpendicular to the first direction, the orthographic projection of the first Tab sheet covers the orthographic projections of all positive tabs in the battery cell unit in the third direction; And / or, in a plane perpendicular to the first direction, the orthographic projection of the second Tab sheet covers the orthographic projections of all negative electrode ears in the battery cell unit in the third direction.

11. The battery core assembly according to claim 9, characterized in that: The thickness of the first Tab sheet in the first direction is D1, the flow area of ​​the first Tab sheet is D1 multiplied by P1, and the range of D1 is 0.2 mm to 1 mm; And / or, the thickness of the second Tab sheet in the first direction is D2, the flow area of ​​the second Tab sheet is D2 multiplied by P2, and the range of D2 is 0.2 mm to 1 mm.

12. The battery core assembly according to claim 6, characterized in that: The partition surface coincides with a central axis of the battery cell unit in a third direction, and the third direction is perpendicular to the first direction and the second direction.

13. The battery core assembly according to claim 6, characterized in that: The number of the battery cells is two.

14. The battery core assembly according to claim 13, characterized in that: Along a third direction perpendicular to the first direction and the second direction, the positive electrode tab and the negative electrode tab of one of the battery cells are arranged opposite to each other, and the positive electrode tab and the negative electrode tab of another of the battery cells are located between the positive electrode tab and the negative electrode tab of one of the battery cells.

15. The battery core assembly according to any one of claims 1 to 5, characterized in that: The battery cell body comprises a diaphragm and positive and negative electrode sheets arranged alternately in the first direction, wherein the diaphragm separates the positive electrode sheet from the negative electrode sheet; wherein: The positive electrode sheet comprises a first foil and a first coating layer, wherein the first coating layer is located on at least one side of the first foil in the thickness direction, and the first coating layer covers a portion of the first foil in the second direction, and the first foil not covered by the first coating layer is cut to form the positive electrode ear; The negative electrode sheet includes a second foil and a second coating layer, wherein the second coating layer is located on at least one side of the second foil in a thickness direction, and the second coating layer covers a portion of the second foil in the second direction, and the second foil not covered by the second coating layer is cut to form the negative electrode ear.

16. The battery core assembly according to claim 15, characterized in that: The battery cell is a wound battery cell or a laminated battery cell.

17. A single cell battery, characterized in that: Comprising a battery core assembly as described in any one of claims 1-16.

18. A battery pack, characterized in that: Comprising the single cell as claimed in claim 17.

19. An electrical equipment, characterized in that: Comprising the battery pack as claimed in claim 18.

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