Laminated cell and battery

Abstract

The utility model relates to the technical field of batteries, in particular to a laminated battery cell and a battery, the laminated battery cell comprises a laminated pole group, a positive tab assembly and a negative tab assembly, the positive tab assembly and the negative tab assembly are respectively connected with the laminated pole group, and both the positive tab assembly and the negative tab assembly are arranged at the end part of the laminated pole group in a first direction; each of the positive tab assembly and the negative tab assembly is of an integrally connected multi-layer solid structure, each layer of the multi-layer solid structure is stacked along a first direction, and the size of the multi-layer solid structure in the first direction is 0.8-2.5 mm. According to the laminated battery cell and the battery provided by the invention, the situation that the tabs occupy too much battery cell space is avoided, the space utilization rate of the battery cell is improved, the connection strength and stability of the tabs are improved, and the probability that the tabs are extremely prone to local tearing, damage, breakage and the like under the extreme conditions of vibration, collision and the like of the battery is effectively reduced; the stability and the service life of the battery cell are improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a laminated battery cell and a battery. Background Art

[0002] At present, the tabs of the electrode group of the battery cell need to extend a long distance from the electrode group, and the electrical connection between the laminated electrode group and the electrical connection structure of the connecting plate, pole column, etc. is realized by bending the tabs. However, the current tabs are relatively long relative to the laminated electrode group, and need to be bent repeatedly (for example, Chinese patent documents CN219717199U, CN111029490A, CN220753689U, etc.). On the one hand, in the structure where the electrode group is connected to the outside through the tabs, the bending of the tabs needs to occupy a large battery cell space; on the other hand, the bending structure of the long tabs is relatively thin and has poor stability. In extreme cases such as vibration and collision, the tabs are very likely to be partially torn, damaged or even broken, which in turn causes short circuits and short circuits in the battery cell. Utility Model Content

[0003] The purpose of the present application is to provide a laminated battery cell and a battery, so as to solve the technical problems existing in the prior art to a certain extent that the bending of the pole ear requires a large battery cell space and the bending structure of the long pole ear is relatively thin and has poor stability. Under extreme conditions such as vibration and collision of the battery, the pole ear is very likely to be partially torn, damaged or even broken, which may lead to short circuit and other phenomena in the battery cell.

[0004] According to a first aspect of the present application, a laminated battery cell is provided, comprising a laminated electrode group, a positive electrode ear assembly and a negative electrode ear assembly, wherein the positive electrode ear assembly and the negative electrode ear assembly are respectively connected to the laminated electrode group, and the positive electrode ear assembly and the negative electrode ear assembly are both arranged at the ends of the laminated electrode group in a first direction, and the positive electrode ear assembly and the negative electrode ear assembly are both multi-layer solid structures connected as one, and each layer of the multi-layer solid structure is stacked along the first direction, and the size of the multi-layer solid structure in the first direction is 0.8 mm to 2.5 mm.

[0005] Preferably, the laminated electrode group comprises positive electrode sheets and negative electrode sheets, and the positive electrode sheets and the negative electrode sheets are alternately stacked along a second direction, and the second direction is perpendicular to the first direction.

[0006] Preferably, the end of the positive electrode sheet in the first direction is provided with a positive electrode ear portion, and the positive electrode ears of the positive electrode sheets included in the laminated electrode group are stacked to form the positive electrode ear assembly;

[0007] The end of the negative electrode sheet in the first direction is provided with a negative electrode ear portion, and the negative electrode ears of the negative electrode sheets included in the laminated electrode group are stacked to form the negative electrode ear assembly.

[0008] Preferably, the positive electrode tab assembly and the negative electrode tab assembly are both arranged at the same end of the laminated electrode group in the first direction;

[0009] The positive electrode tab assembly and the negative electrode tab assembly are spaced apart along a third direction, and the third direction is perpendicular to a plane defined by the first direction and the second direction.

[0010] Preferably, the positive electrode ear portion comprises a first connecting end and a first free end opposite to each other, the positive electrode ear portion is connected to the positive electrode sheet via the first connecting end, and relative to the first free end, a first fold line extending along a third direction is provided on a side of the positive electrode ear portion close to the first connecting end, and the positive electrode ear portion forms a bending angle at the first fold line, so that a portion of the positive electrode ear portion located between the first fold line and the first free end is perpendicular to the first direction;

[0011] The negative electrode ear portion includes a second connecting end and a second free end opposite to each other, the negative electrode ear portion is connected to the negative electrode sheet via the second connecting end, and relative to the second free end, a second fold line extending along the third direction is provided on a side of the negative electrode ear portion close to the second connecting end, and the negative electrode ear portion forms a bending angle at the second fold line so that a portion of the negative electrode ear portion located between the second fold line and the second free end is perpendicular to the first direction, and the third direction is perpendicular to a plane defined by the first direction and the second direction.

[0012] Preferably, the distance between the first connecting end and the first free end is 0.8 mm to 4 mm;

[0013] The distance between the second connecting end and the second free end is 0.8 mm to 4 mm.

[0014] Preferably, the positive electrode ear portion includes a plurality of first cutting lines, and when the positive electrode ear portion is not bent along the first folding line, the first cutting lines extend from the first free end along the first direction to the first connecting end, and the plurality of first cutting lines are arranged at equal intervals along a third direction to divide the positive electrode ear portion into a plurality of first connecting fingers, and the third direction is perpendicular to a plane defined by the first direction and the second direction;

[0015] The negative electrode ear portion includes a plurality of second cutting lines. When the negative electrode ear portion is not bent along the second fold line, the second cutting lines extend from the second free end along the first direction to the second connecting end. The plurality of second cutting lines are arranged at equal intervals along the third direction to divide the negative electrode ear portion into a plurality of second connecting fingers.

[0016] Preferably, the dimensions of the first connecting finger and the second connecting finger in the third direction are both 0.2 mm to 1 mm.

[0017] Preferably, the laminated electrode group further includes a diaphragm, and the adjacent positive electrode sheets and the negative electrode sheets are separated by the diaphragm;

[0018] And / or, the dimension of the laminated pole group in the second direction is 15 mm to 30 mm.

[0019] According to the second aspect of the present application, a battery is provided, comprising the laminated battery cell described in any of the above technical solutions, and thus having all the beneficial technical effects of the laminated battery cell, which will not be described in detail herein.

[0020] Compared with the prior art, the beneficial effects of this application are:

[0021] The laminated battery cell provided in the present application, by arranging the positive electrode ear assembly and the negative electrode ear assembly into a multi-layer solid structure in which each layer is stacked along a first direction, and controlling the size of the multi-layer solid structure in the first direction to be within the range of 0.8mm to 2.5mm, on the one hand, effectively controls the size of the ear (i.e., the positive electrode ear assembly and the negative electrode ear assembly) extending relative to the laminated electrode group, thereby avoiding the ear from occupying too much battery cell space and improving the space utilization of the battery cell; on the other hand, designing the ear into a multi-layer solid structure can effectively increase the connection strength and stability of the ear, effectively reducing the probability of local tearing, damage, breakage, etc. of the ear in extreme conditions such as vibration and collision of the battery, thereby improving the stability and service life of the battery cell.

[0022] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of the isometric structure of a laminated battery cell provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the front view structure of the positive electrode sheet provided in an embodiment of the present application in an unbent state;

[0026] Figure 3This is a schematic diagram of the front view structure of the negative electrode sheet provided in an embodiment of the present application in an unbent state.

[0027] Reference numerals:

[0028] 1-laminated electrode group; 11-positive electrode sheet; 12-negative electrode sheet; 2-positive electrode ear assembly; 20-positive electrode ear; 201-first connecting end; 202-first free end; 21-first connecting finger; 22-first cutting line; 23-first fold line; 3-negative electrode ear assembly; 30-negative electrode ear; 301-second connecting end; 302-second free end; 31-second connecting finger; 32-second cutting line; 33-second fold line.

[0029] F1-first direction; F2-second direction; F3-third direction. DETAILED DESCRIPTION

[0030] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0031] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed, but merely represents the selected embodiments of the present application.

[0032] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0033] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] Refer to the following Figures 1 to 3 The laminated battery cell and the battery according to some embodiments of the present application are described.

[0036] See also Figures 1 to 3 As shown, an embodiment of the first aspect of the present application provides a laminated battery cell, which includes a laminated electrode group 1, a positive electrode ear assembly 2 and a negative electrode ear assembly 3, the positive electrode ear assembly 2 and the negative electrode ear assembly 3 are respectively connected to the laminated electrode group 1, the positive electrode ear assembly 2 and the negative electrode ear assembly 3 are both arranged at the end of the laminated electrode group 1 in the first direction F1, the positive electrode ear assembly 2 and the negative electrode ear assembly 3 are both connected as a whole multi-layer solid structure, each layer of the multi-layer solid structure is stacked along the first direction F1, and the size of the multi-layer solid structure in the first direction F1 is 0.8mm~2.5mm.

[0037] According to the laminated battery cell provided by the above technical features, by arranging the positive electrode ear assembly 2 and the negative electrode ear assembly 3 into a multi-layer solid structure in which each layer is stacked along the first direction F1, and controlling the size of the multi-layer solid structure in the first direction F1 to be within the range of 0.8mm to 2.5mm, on the one hand, the extension size of the ear (i.e., the positive electrode ear assembly 2 and the negative electrode ear assembly) relative to the laminated electrode group 1 is effectively controlled, thereby avoiding the ear from occupying too much battery cell space and improving the space utilization rate of the battery cell; on the other hand, designing the ear into a multi-layer solid structure can effectively increase the connection strength and stability of the ear, effectively reducing the probability of local tearing, damage, breakage, etc. of the ear in extreme conditions such as vibration and collision of the battery, thereby improving the stability and service life of the battery cell.

[0038] Preferably, the above-mentioned laminated electrode group 1 may include a positive electrode sheet 11 and a negative electrode sheet 12, and the positive electrode sheet 11 and the negative electrode sheet 12 are alternately stacked along the second direction F2 to form the above-mentioned laminated electrode group 1. It should be noted that the stacking method of the laminated electrode group 1 is the existing technology in the field and will not be repeated here.

[0039] like Figures 1 to 3As shown, F1 shown in the figure may be an example of the first direction F1, and F2 shown in the figure may be an example of the second direction F2, wherein the second direction F2 may be perpendicular to the first direction F1. For ease of description, a direction perpendicular to a plane determined by both the first direction F1 and the second direction F2 is defined as a third direction F3. F3 shown in the figure may be an example of the third direction F3.

[0040] Preferably, although not shown in the figures, the laminated electrode group 1 may further include a separator, and adjacent positive electrode sheets 11 and negative electrode sheets 12 are separated by the separator.

[0041] Preferably, the size of the laminated electrode group 1 in the second direction F2 may be 15 mm to 30 mm to adapt to the size of the battery cell.

[0042] Preferably, if Figure 2 As shown, a positive electrode ear portion 20 is provided at the end of the positive electrode sheet 11 in the first direction F1 , and the positive electrode ear portions 20 of the positive electrode sheets 11 included in the laminated electrode group 1 are stacked to form the above-mentioned positive electrode ear assembly 2 .

[0043] It should be noted that the multiple layers in the multi-layer solid structure formed by the positive electrode ear assembly 2 can be understood as a multi-layer structure formed by overlapping the positive electrode ear parts 20 .

[0044] Preferably, if Figure 2 As shown, the positive electrode ear 20 may include a first connection end 201 and a first free end 202 opposite to each other. The positive electrode ear 20 is connected to the positive electrode sheet 11 via the first connection end 201. Relative to the first free end 202, a first fold line 23 extending along a third direction F3 is provided on one side of the positive electrode ear 20 close to the first connection end 201. The positive electrode ear 20 forms a bending angle at the first fold line 23, so that a portion of the positive electrode ear 20 located between the first fold line 23 and the first free end 202 is perpendicular to the first direction F1, as shown in FIG. Therefore, the positive ear assembly 2 can be fitted with the end face of the laminated electrode group 1 in the first direction F1. On the one hand, the contact area between the positive ear assembly 2 and the laminated electrode group 1 is effectively improved, and the connection strength between the positive ear assembly 2 and the laminated electrode group 1 and the stability of the setting of the positive ear assembly 2 are further improved; on the other hand, the bent positive ear portion 20 forms an end face perpendicular to the first direction F1 at the upper end of the positive ear assembly 2, which makes it easier to connect the positive ear assembly 2 with other positive electrode connection structures of the battery cell (for example, positive connecting pieces, positive pole columns, etc.).

[0045] Preferably, if Figure 2As shown, the distance between the first connecting end 201 and the first free end 202 can be 0.8 mm to 4 mm. In other words, when the positive electrode sheet 11 is in a bent state, the length of the positive electrode ear 20 in the first direction F1 (i.e. Figure 2 The S1 value shown can be 0.8 mm to 4 mm, so that the positive electrode ear 20 is bent at the end surface of the laminated electrode group 1 in the first direction F1.

[0046] Correspondingly, if Figure 3 As shown, a negative electrode ear portion 30 is provided at the end of the negative electrode sheet 12 in the first direction F1 , and the negative electrode ears 30 of the negative electrode sheets 12 included in the laminated electrode group 1 are stacked to form the negative electrode ear assembly 3 .

[0047] It should be noted that the multiple layers in the multi-layer solid structure formed by the above-mentioned negative electrode ear assembly 3 can be understood as a multi-layer structure formed by overlapping arrangement of the negative electrode ear parts 30 .

[0048] Similarly, if Figure 3 As shown, the negative electrode ear 30 may include a second connection end 301 and a second free end 302 opposite to each other. The negative electrode ear 30 is connected to the negative electrode sheet 12 via the second connection end 301. Relative to the second free end 302, a second fold line 33 extending along a third direction F3 is provided on one side of the negative electrode ear 30 close to the second connection end 301. The negative electrode ear 30 forms a bending angle at the second fold line 33 so that the portion of the negative electrode ear 30 located between the second fold line 33 and the second free end 302 is perpendicular to the first direction F1. The beneficial effects of this structure are similar to those of the above-mentioned positive electrode ear assembly 2 and are not repeated here.

[0049] Correspondingly, if Figure 3 As shown, the distance between the second connecting end 301 and the second free end 302 can be 0.8 mm to 4 mm. In other words, when the negative electrode sheet 12 is in an unbent state, the length of the negative electrode ear 30 in the first direction F1 (i.e. Figure 3 The S2 value shown can be 0.8 mm to 4 mm, so that the negative electrode ear 30 is bent at the end surface of the laminated electrode group 1 in the first direction F1.

[0050] Preferably, each layer of the positive electrode ear portion 20 in the positive electrode ear assembly 2 can be flattened layer by layer through a flattening process, so that the positive electrode ear assembly 2 forms the multi-layer solid structure. Correspondingly, each layer of the negative electrode ear portion 30 in the negative electrode ear assembly 3 can also be flattened layer by layer through a flattening process, so that the negative electrode ear assembly 3 forms the multi-layer solid structure.

[0051] However, it is not limited thereto, as long as each layer of the positive ear portion 20 in the positive ear assembly 2 (or each layer of the negative ear portion 30 in the negative ear assembly 3) can form a solid structure, the above-mentioned positive ear assembly 2 (or negative ear assembly 3) can also be made by other molding processes, such as a rolling process, a rolling process, etc.

[0052] It should be noted that the above-mentioned “the size of the multi-layer solid structure in the first direction F1 is 0.8 mm to 2.5 mm” can be understood as the size of the multi-layer solid structure in the first direction F1 formed by the above-mentioned positive electrode ear 20 (or negative electrode ear 30) after the bending and flattening process (i.e. Figure 1 The l value shown) is 0.8mm to 2.5mm.

[0053] Alternatively, if Figure 1 As shown, the positive ear portions 20 stacked along the second direction F2 are separated by the midline of the laminated electrode group 1 in the second direction F2, and the positive ear portions 20 located behind the midline are bent forward, and the positive ear portions 20 located in front of the midline are bent backward. In the bending and flattening process of the positive ear assembly 2, the positive ear portions 20 on both sides of the midline are bent and flattened alternately in sequence from the midline to the edge, so as to form a multi-layer solid structure of the positive ear assembly 2.

[0054] Similarly, the bent and flattened structure of the multi-layer solid structure of the negative electrode tab assembly 3 is similar to that of the positive electrode tab assembly 2 and will not be described in detail.

[0055] Preferably, if Figure 1 As shown, the positive ear assembly 2 and the negative ear assembly 3 can be arranged at the same end of the laminated electrode group 1 in the first direction F1. In this way, the positive ear assembly 2 and the negative ear assembly 3 both occupy the space on the same side of the laminated electrode group 1, which is not only convenient for connecting the battery cells and wiring, but also can further save the space occupied by the ear.

[0056] However, it is not limited thereto, and as not shown in the figure, the positive electrode tab assembly 2 and the negative electrode tab assembly 3 may also be respectively disposed at two ends of the laminated electrode group 1 in the first direction F1.

[0057] Preferably, if Figures 1 to 3 As shown, the positive electrode ear assembly 2 and the negative electrode ear assembly 3 are arranged at intervals along the third direction F3. In other words, the two opposite ends of the laminated electrode group 1 in the third direction F3 are defined as the first end and the second end, the positive electrode ear 20 can be arranged close to the first end of the positive electrode sheet 11, and the negative electrode ear 30 can be arranged close to the second end of the negative electrode sheet 12, and when the positive electrode sheet 11 and the negative electrode sheet 12 are stacked on each other, the positive electrode ear 20 and the negative electrode ear 30 are staggered with each other, so as to avoid interference between the positive electrode ear 20 and the negative electrode ear 30 during the stacking of the laminated battery cell.

[0058] In an embodiment, preferably, Figure 2 As shown, the positive ear 20 may include a plurality of first cutting lines 22. When the positive ear 20 is in a state where it is not bent along the first fold line 23 (i.e., in an unfolded state), the first cutting line 22 extends from the first free end 202 along the first direction F1 to the first connecting end 201. The plurality of first cutting lines 22 are arranged at equal intervals along the third direction F3 to divide the positive ear 20 into a plurality of first connecting fingers 21. In this way, dividing the positive ear 20 into a plurality of first connecting fingers 21 through the first cutting lines 22 can make the positive ear 20 more conducive to deformation. Furthermore, under the action of the flattening process, the multi-layer positive ear 20 can be more tightly connected, thereby improving the compactness of the multi-layer solid structure and further improving the setting stability of the positive ear assembly 2.

[0059] It should be noted that Figure 2 Taking the orientation shown as an example, the first cutting line 22 can be understood as the part of the positive electrode ear 20 located on the left side and the part on the right side of the first cutting line 22 are not connected in the area where the first cutting line 22 is located. In other words, the positive electrode ear 20 can be cut along the first cutting line to form the plurality of first connecting fingers 21.

[0060] Preferably, the size of the first connecting finger 21 in the third direction F3 may be 0.2 mm to 1 mm, so as to facilitate the bending and flattening of the first connecting finger 21 .

[0061] Preferably, the size of the first connecting finger 21 in the third direction F3 may be 0.45 mm to 0.55 mm, so as to further facilitate the bending and flattening of the first connecting finger 21 .

[0062] Similarly, if Figure 3 As shown, the negative electrode ear 30 may include a plurality of second cutting lines 32. When the negative electrode ear 30 is not bent along the second fold line 33, the second cutting line 32 extends from the second free end 302 along the first direction F1 to the second connection end 301. The plurality of second cutting lines 32 are arranged at equal intervals along the third direction F3 to divide the negative electrode ear 30 into a plurality of second connection fingers 31. The beneficial effect of the second connection finger 31 is similar to that of the first connection finger 21, and the structure of the second cutting line 32 is similar to that of the first cutting line 22, which will not be repeated here.

[0063] Preferably, the size of the second connecting finger 31 in the third direction F3 may also be 0.2 mm to 1 mm, so as to facilitate the bending and flattening of the second connecting finger 31 .

[0064] Preferably, the size of the second connecting finger 31 in the third direction F3 may also be 0.45 mm to 0.55 mm, so as to further facilitate the bending and flattening of the second connecting finger 31 .

[0065] The embodiment of the second aspect of the present application further provides a battery, comprising the laminated battery cell described in any of the above embodiments, and thus having all the beneficial technical effects of the laminated battery cell, which will not be elaborated here.

[0066] Optionally, the battery may include one or more of the battery cells.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laminated battery cell, characterized in that: It includes a laminated electrode group, a positive electrode ear assembly and a negative electrode ear assembly, wherein the positive electrode ear assembly and the negative electrode ear assembly are respectively connected to the laminated electrode group, and the positive electrode ear assembly and the negative electrode ear assembly are both arranged at the end of the laminated electrode group in the first direction, and the positive electrode ear assembly and the negative electrode ear assembly are both connected as a whole multi-layer solid structure, and each layer of the multi-layer solid structure is stacked along the first direction, and the size of the multi-layer solid structure in the first direction is 0.8mm~2.5mm.

2. The laminated battery cell according to claim 1, characterized in that: The laminated electrode group includes a positive electrode sheet and a negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are alternately stacked along a second direction, and the second direction is perpendicular to the first direction.

3. The laminated battery cell according to claim 2, characterized in that: The end of the positive electrode sheet in the first direction is provided with a positive electrode ear portion, and the positive electrode ears of the positive electrode sheets included in the laminated electrode group are stacked to form the positive electrode ear assembly; The end of the negative electrode sheet in the first direction is provided with a negative electrode ear portion, and the negative electrode ears of the negative electrode sheets included in the laminated electrode group are stacked to form the negative electrode ear assembly.

4. The laminated battery cell according to claim 2, characterized in that: The positive electrode tab assembly and the negative electrode tab assembly are both arranged at the same end of the laminated electrode group in the first direction; The positive electrode tab assembly and the negative electrode tab assembly are spaced apart along a third direction, and the third direction is perpendicular to a plane defined by the first direction and the second direction.

5. The laminated battery cell according to claim 3, characterized in that: The positive electrode ear portion comprises a first connecting end and a first free end opposite to each other, the positive electrode ear portion is connected to the positive electrode sheet via the first connecting end, and relative to the first free end, a first fold line extending along a third direction is provided on a side of the positive electrode ear portion close to the first connecting end, and the positive electrode ear portion forms a bending angle at the first fold line, so that a portion of the positive electrode ear portion located between the first fold line and the first free end is perpendicular to the first direction; The negative electrode ear portion includes a second connecting end and a second free end opposite to each other, the negative electrode ear portion is connected to the negative electrode sheet via the second connecting end, and relative to the second free end, a second fold line extending along the third direction is provided on a side of the negative electrode ear portion close to the second connecting end, and the negative electrode ear portion forms a bending angle at the second fold line so that a portion of the negative electrode ear portion located between the second fold line and the second free end is perpendicular to the first direction, and the third direction is perpendicular to a plane defined by the first direction and the second direction.

6. The laminated battery cell according to claim 5, characterized in that: The distance between the first connecting end and the first free end is 0.8 mm to 4 mm; The distance between the second connecting end and the second free end is 0.8 mm to 4 mm.

7. The laminated battery cell according to claim 5, characterized in that: The positive electrode ear portion includes a plurality of first cutting lines, and when the positive electrode ear portion is not bent along the first folding line, the first cutting lines extend from the first free end along the first direction to the first connecting end, and the plurality of first cutting lines are arranged at equal intervals along a third direction to divide the positive electrode ear portion into a plurality of first connecting fingers, and the third direction is perpendicular to a plane defined by the first direction and the second direction; The negative electrode ear portion includes a plurality of second cutting lines. When the negative electrode ear portion is not bent along the second fold line, the second cutting lines extend from the second free end along the first direction to the second connecting end. The plurality of second cutting lines are arranged at equal intervals along the third direction to divide the negative electrode ear portion into a plurality of second connecting fingers.

8. The laminated battery cell according to claim 7, characterized in that: The sizes of the first connecting finger and the second connecting finger in the third direction are both 0.2 mm to 1 mm.

9. The laminated battery core according to any one of claims 2 to 8, characterized in that: The laminated electrode group further includes a diaphragm, and the adjacent positive electrode sheets and the negative electrode sheets are separated by the diaphragm; And / or, the dimension of the laminated pole group in the second direction is 15 mm to 30 mm.

10. A battery, characterized in that: A laminated battery core comprising any one of claims 1 to 9.

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