Laminated battery cell

Abstract

The utility model discloses a laminated battery cell, which is any one of a plurality of battery cells formed by cutting a composite battery cell group along a preset position, the composite battery cell group comprises a first pole piece group, a second pole piece group and a first diaphragm, and the first pole piece group comprises a plurality of cathode units; the second pole piece group comprises a plurality of positive pole units, negative pole pieces are arranged on the outermost sides of the negative pole units, and positive pole pieces are arranged on the outermost sides of the positive pole units; the first diaphragm comprises a plurality of main body parts and bending parts which are alternately and continuously arranged, the first pole piece groups and the second pole piece groups are alternately arranged along the thickness direction of the first pole piece groups, the adjacent first pole piece groups and second pole piece groups are separated by the main body parts, the negative pole units in the first pole piece groups are arranged at intervals, and the negative pole units and the positive pole units are oppositely arranged; the preset positions refer to the positions between the adjacent negative electrode units in the length direction of the main body part. The battery cell production device achieves the technical effects of improving the battery cell production efficiency and being high in alignment degree.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a stacked battery cell. Background Art

[0002] The stacked battery cell of a lithium battery is prepared by a Z-type folding process. The Z-type folding process is to alternately place positive electrode sheets and negative electrode sheets on a separator that makes a Z-type swing. The number of times the separator is folded is relatively large, the processing procedures are numerous, and the efficiency is low. Utility Model Content

[0003] An embodiment of this application provides a stacked battery cell, which is obtained by cutting a composite battery cell group along a preset position. In the composite battery cell group, a first separator is folded to form a plurality of main body parts and bending parts. Adjacent first electrode sheet groups and second electrode sheet groups are separated by the main body parts. The first electrode sheet group has a plurality of positive electrode units, and the second electrode sheet group has a plurality of negative electrode units. Both the positive electrode unit and the negative electrode unit have a multi-layer structure, achieving the technical effects of fewer folding times of the first separator, fewer processing procedures, and high processing efficiency.

[0004] An embodiment of this application provides a stacked battery cell, which is any one of a plurality of stacked battery cells cut from a composite battery cell group along a preset position. Among them, the composite battery cell group includes:

[0005] A plurality of first electrode sheet groups, each of the first electrode sheet groups includes a plurality of negative electrode units arranged in sequence;

[0006] A plurality of second electrode sheet groups, each of the second electrode sheet groups includes a plurality of positive electrode units arranged in sequence. The number of the negative electrode units is the same as that of the positive electrode units; and both the negative electrode unit and the positive electrode unit include a negative electrode sheet and a positive electrode sheet. Along the thickness direction of the negative electrode sheet, the negative electrode sheet and the positive electrode sheet are alternately arranged. A negative electrode tab is provided on the negative electrode sheet, and a positive electrode tab is provided on the positive electrode sheet. The outermost sides of the negative electrode units are all negative electrode sheets, and the outermost sides of the positive electrode units are all positive electrode sheets;

[0007] A first separator, including a plurality of alternately and continuously arranged main body parts and bending parts. Along the thickness direction of the first electrode sheet group, the first electrode sheet group and the second electrode sheet group are alternately arranged. Adjacent first electrode sheet groups and second electrode sheet groups are separated by the main body parts. Along the length direction of the main body part, the plurality of negative electrode units of the first electrode sheet group are arranged at intervals in sequence. The negative electrode unit is arranged opposite to the positive electrode unit. At least part of the negative electrode tab and the positive electrode tab extends out of the outside of the first separator;

[0008] The preset position refers to the position between adjacent negative electrode units along the length direction of the main body part.

[0009] Optionally, the negative electrode sheet and the positive electrode sheet are separated by a second separator, and any adjacent second separators in the first electrode group and / or the second electrode group are connected to each other.

[0010] Optionally, the negative electrode sheet and the positive electrode sheet are separated by a second separator, and any two adjacent second separators in the first electrode group and / or the second electrode group are arranged at intervals.

[0011] Optionally, the distance between any two adjacent second separators in the first electrode group and / or the second electrode group is the same.

[0012] Optionally, along the thickness direction of the second separator, the projections of the negative electrode sheet and the positive electrode sheet on the second separator fall within the second separator;

[0013] and / or, along the thickness direction of the second separator, the projection of the positive electrode sheet on the negative electrode sheet completely falls within the continuous planar region enclosed by the outer contour of the negative electrode sheet.

[0014] Optionally, along the thickness direction, the negative electrode unit includes two negative electrode sheets;

[0015] and / or, the positive electrode unit includes two positive electrode sheets.

[0016] Optionally, the negative electrode sheet and the positive electrode sheet in the negative electrode unit are respectively thermally compounded and connected to the second separator;

[0017] and / or, the negative electrode sheet and the positive electrode sheet in the positive electrode unit are respectively thermally compounded and connected to the second separator.

[0018] Optionally, the distance between adjacent negative electrode units in the composite battery cell group is d1, where 3 mm ≤ d1 ≤ 5 mm;

[0019] and / or, the distance between adjacent positive electrode units in the composite battery cell group is d2, where 3 mm ≤ d2 ≤ 5 mm.

[0020] Optionally, the distance d1 between adjacent negative electrode units in the composite battery cell group is the same as the distance d2 between adjacent positive electrode units.

[0021] Optionally, the bending portion is provided with an incompletely cut structure, and the first separator is folded at the incompletely cut structure.

[0022] Optionally, the outermost negative electrode sheet in the composite battery cell group is a single-sided electrode sheet, and other negative electrode sheets are double-sided electrode sheets.

[0023] Optionally, the negative electrode sheet includes a negative electrode current collector and a negative electrode active layer. The thickness of the negative electrode current collector is D1, and the thickness of the negative electrode active layer is D2, where 4 μm ≤ D1 ≤ 6 μm, and / or 50 μm ≤ D2 ≤ 200 μm.

[0024] Optionally, the composite battery cell group includes M first electrode sheet groups and N second electrode sheet groups, where M and N are positive integers, and M - N = 1.

[0025] The stacked battery cell provided by the embodiment of the present application is any one of multiple battery cells obtained by cutting a composite battery cell group along a preset position. The composite battery cell group includes a first electrode sheet group, a second electrode sheet group, and a first separator. The first electrode sheet group includes multiple negative electrode units, and the second electrode sheet group includes multiple positive electrode units. Both the negative electrode unit and the positive electrode unit include a negative electrode sheet and a positive electrode sheet. The outermost sides of the negative electrode units are all negative electrode sheets, and the outermost sides of the first electrode sheet group composed of negative electrode units are also all negative electrode sheets. The outermost sides of the positive electrode units are all positive electrode sheets, and the outermost sides of the second electrode sheet group composed of positive electrode units are also all positive electrode sheets. The first separator is folded to form multiple continuous and alternating main body parts and bending parts. The first electrode sheet group and the second electrode sheet group are arranged alternately, and adjacent first electrode sheet groups and second electrode sheet groups are separated by the main body parts. The preset position is the position between adjacent negative electrode units. By cutting the composite battery cell group along the area between the negative electrode units, multiple battery cells are prepared. The number of folds of the first separator is small, which is beneficial to the alignment of the stacked battery cells, and multiple battery cells can be prepared simultaneously. The alignment degree of the stacked battery cells on the cutting side is high, achieving the technical effects of improving the production efficiency and alignment degree of the battery cells. Description of the Drawings

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

[0027] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings. Among them, the same reference numerals in the following description represent the same parts.

[0028] Figure 1 It is a cross-sectional schematic diagram of the first form of the composite battery cell group provided by the embodiment of the present application.

[0029] Figure 2 It is a cross-sectional schematic diagram of the second form of the composite battery cell group provided by the embodiment of the present application.

[0030] Figure 3 It is a cross-sectional schematic diagram of one form of the first electrode sheet group provided by the embodiment of the present application.

[0031] Figure 4 Schematic cross-sectional view of a form of the second electrode assembly provided in this embodiment.

[0032] Figure 5 Schematic cross-sectional view of a form of the negative electrode unit provided in an embodiment of the present application.

[0033] Figure 6 Schematic cross-sectional view of a form of the positive electrode unit provided in an embodiment of the present application.

[0034] Figure 7 Schematic cross-sectional view of a stacked battery cell prepared by the method for preparing a stacked battery cell provided in this embodiment.

[0035] Figure 8 Top view schematic diagram of the composite battery cell group provided in an embodiment of the present application.

[0036] Figure 9 Partial schematic diagram of the bent portion of the first separator provided in an embodiment of the present application.

[0037] Figure 10 Schematic cross-sectional view of a stacked battery cell of the first structure provided in an embodiment of the present application.

[0038] Figure 11 Schematic cross-sectional view of a stacked battery cell of the second structure provided in an embodiment of the present application.

[0039] Figure 12 Schematic cross-sectional view of a stacked battery cell of the third structure provided in an embodiment of the present application. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0041] Refer to Figure 1 and Figure 2 , an embodiment of the present application provides a stacked battery cell 50. The stacked battery cell 50 is any one of a plurality of stacked battery cells 50 cut from a composite battery cell group 30 along a preset position 40. Among them, the composite battery cell group 30 includes a first electrode assembly 10, a second electrode assembly 20, and a first separator 300. The stacked battery cell can be used as an energy storage unit of a battery. The battery can convert the energy stored in the battery cell into current and supply it to an electronic device for use.

[0042] In some embodiments, refer toFigure 1 and Figure 2 As shown in Figure 2 , the composite battery cell group 30 includes a plurality of first electrode sheet groups 10, a plurality of second electrode sheet groups 20, and a first separator 300. Each first electrode sheet group 10 includes a plurality of negative electrode units 100 arranged at intervals in sequence. The negative electrode unit 100 includes a negative electrode sheet 110 and a positive electrode sheet 130. Along the thickness direction of the negative electrode sheet 110, the negative electrode sheet 110 and the positive electrode sheet 130 are arranged alternately. The outermost sides of the negative electrode units 100 are all negative electrode sheets 110, that is, the polarity of the outermost electrode sheet part of the negative electrode unit 100 is negative. Each second electrode sheet group 20 includes a plurality of positive electrode units 200 arranged at intervals in sequence. The positive electrode unit 200 includes a negative electrode sheet 110 and a positive electrode sheet 130. Along the thickness direction of the negative electrode sheet 110, the negative electrode sheet 110 and the positive electrode sheet 130 are arranged alternately. The outermost sides of the positive electrode units 200 are all positive electrode sheets 130, that is, the polarity of the outermost electrode sheet part of the positive electrode unit 200 is positive. The first separator 300 is a continuous strip-shaped film material, and the first separator 300 is folded in a Z shape to form a plurality of alternately and continuously arranged main body parts 310 and bending parts 320. Along the thickness direction of the first electrode sheet group 10, the first electrode sheet group 10 and the second electrode sheet group 20 are arranged alternately, and the adjacent first electrode sheet group 10 and second electrode sheet group 20 are separated by the main body part 310. The number of negative electrode units 100 in each first electrode sheet group 10 is the same as the number of positive electrode units 200 in each second electrode sheet group 20. Along the length direction Y of the main body part 310, the plurality of negative electrode units 100 in the first electrode sheet group 10 located on one side of the main body part 310 are arranged at intervals in sequence, and the plurality of positive electrode units 200 in the second electrode sheet group 20 located on the other side of the main body part 310 are arranged at intervals in sequence. Along the thickness direction X of the main body part 310, the negative electrode unit 100 and the positive electrode unit 200 at the same position are arranged in alignment.

[0043] See Figure 8 , a negative electrode tab 140 is provided on the negative electrode sheet 110, a positive electrode tab 150 is provided on the positive electrode sheet 210, and at least a part of the negative electrode tab 140 and the positive electrode tab 150 extends out of the outer side of the first separator 300.

[0044] See Figure 1 and Figure 2 As shown in Figure 2 , the preset position 40 refers to the position between adjacent negative electrode units 100 along the length direction Y of the main body part 310.

[0045] In the embodiment of the present application, the first electrode sheet group 10 includes a plurality of negative electrode units 100, the second electrode sheet group 20 includes a plurality of positive electrode units 200. After assembling the first electrode sheet group 10, the second electrode sheet group 20, and the first separator 300 into the composite battery cell group 30, the composite battery cell group 30 is cut to prepare a plurality of stacked battery cells 50. The number of times of folding the first separator 300 and the number of times of stacking the electrode sheets are reduced, thereby reducing the processing procedures and improving the processing efficiency of the stacked battery cells 50.

[0046] Exemplarily, referring to Figure 1 、 Figure 2 、 Figure 10 、 Figure 11 and Figure 12 When i negative electrode units 100 are provided in the first electrode sheet group 10 and i positive electrode units 200 are provided in the second electrode sheet group 20, where i is a positive integer and i≥2, the composite battery cell group 30 is cut along a preset position 40 to obtain i battery cells. The i battery cells include the following several structures:

[0047] The first structure is: Referring to Figure 10 , along the thickness direction X of the battery cell, from bottom to top, the negative electrode units 100 and the positive electrode units 200 are alternately arranged. The adjacent negative electrode unit 100 and positive electrode unit 200 are separated by a cut part of the main body 310. A cut part of the main body 310 is also provided on the side of the outermost negative electrode unit 100 facing away from the positive electrode unit 200. One end of the negative electrode unit 100 is provided with a bent part 320.

[0048] The second structure is: Referring to Figure 11 , along the thickness direction X of the battery cell, from bottom to top, the negative electrode units 100 and the positive electrode units 200 are alternately arranged. The adjacent negative electrode unit 100 and positive electrode unit 200 are separated by a cut part of the main body 310. A cut part of the main body 310 is also provided on the side of the outermost negative electrode unit 100 facing away from the positive electrode unit 200.

[0049] The third structure is: Referring to Figure 12 , along the thickness direction X of the battery cell, from bottom to top, the negative electrode units 100 and the positive electrode units 200 are alternately arranged. The adjacent negative electrode unit 100 and positive electrode unit 200 are separated by a cut part of the main body 310. A cut part of the main body 310 is also provided on the side of the outermost negative electrode unit 100 facing away from the positive electrode unit 200. One end of the positive electrode unit 200 is provided with a bent part 320.

[0050] It can be understood that in this embodiment, the layered structures of the negative electrode unit 100 and the positive electrode unit 200 in the first electrode sheet group 10 are few, and the alignment degree of each electrode sheet and the second separator 120 is controllable. The alignment degree of the composite battery cell group 30 stacked by the first electrode sheet group 10 and the second electrode sheet group 20 is good. When assembling the first electrode sheet group 10, the second electrode sheet group 20 and the first separator 300, the number of folding times of the first separator 300 is reduced, and the processing flow is reduced. Along the thickness direction of the composite battery cell group 30, a plurality of negative electrode units 100 or a plurality of positive electrode units 200 are arranged in each layer. The composite battery cell group 30 is cut along the positions between adjacent negative electrode units 100 to prepare a plurality of battery cells, which further improves the processing efficiency and the alignment degree of the cutting side. The technical effects of reducing the battery cell processing procedures, improving the battery cell production efficiency and the battery cell alignment degree are achieved.

[0051] In some embodiments, referring to Figure 1 and Figure 2 , the length dimensions, width dimensions, and thickness dimensions of all the negative electrode sheets 110 in the composite battery cell group 30 are the same, and the length dimensions, width dimensions, and thickness dimensions of all the positive electrode sheets 130 are the same.

[0052] In the embodiments of the present application, the dimensions of all the negative electrode sheets 110 in the composite battery cell group 30 are the same, and the dimensions of all the positive electrode sheets 130 are the same. Along the thickness direction of the composite battery cell group 30, the sides of the stacked negative electrode sheets 110 are located at the same position. When the composite battery cell group 30 is cut along any position between adjacent negative electrode sheets 110, the cutting position maintains a safe distance from the negative electrode sheets 110 in each layer, avoiding the situation of cutting the electrode sheets and facilitating the cutting operation.

[0053] In some embodiments, referring to Figure 1 and Figure 2 , the composite battery cell group 30 includes M first electrode sheet groups 10, N second electrode sheet groups 20, and a first separator 300, where M and N are positive integers, and M - N = 1.

[0054] In the embodiments of the present application, the number of the first electrode sheet groups 10 is one more than the number of the second electrode sheet groups 20, ensuring that the outermost sides of the stacked battery cells 50 are all negative electrode sheets 110, so that there are negative electrode sheets 110 on both sides of each positive electrode sheet 130. It is ensured that the lithium ions coming out from both sides of the positive electrode sheet 130 are received by the negative electrode sheets 110, avoiding the situation of lithium deposition.

[0055] In some embodiments, referring to 1 and Figure 2 , the negative electrode sheet 110 and the positive electrode sheet 130 are separated by a second separator 120.

[0056] In an embodiment of the present application, the negative electrode sheet 110 and the positive electrode sheet 130 are separated by the second separator 120 to prevent the negative electrode sheet 110 and the positive electrode sheet 130 from coming into direct contact, thereby ensuring the electrical safety of the stacked battery cell 50.

[0057] In some embodiments, referring to Figure 1 and Figure 3 , any adjacent second separators 120 in the first electrode sheet group 10 are connected to each other. That is, in the first electrode sheet group 10, the second separator 120 is a continuous separator.

[0058] In some embodiments, referring to Figure 1 and Figure 4 , the second separator 120 in the second electrode sheet group 20 is a film material with a continuous structure. It can be understood that the second separators 120 of any two adjacent positive electrode units 200 are connected to each other.

[0059] In an embodiment of the present application, the second separator 120 being a film material with a continuous structure means that in a first electrode sheet group 10 or a second electrode sheet group 20, the second separator 120 on one side of a plurality of negative electrode sheets 110 is an integral body. The length of the second separator 120 is designed according to the number and size of the negative electrode sheets 110 to be installed on its side, ensuring that the projections of the plurality of negative electrode sheets 110 on one side within the plane where the second separator 120 is located completely fall within the second separator 120, preventing the negative electrode sheets 110 and the positive electrode sheets 130 on both sides of the second separator 120 from coming into direct contact, and improving electrical safety.

[0060] The second separator 120 is a film material with a continuous structure, and the first electrode sheet group 10 or the second electrode sheet group 20 is an integral structure. During the folding process of the first separator 300, the first electrode sheet group 10 or the second electrode sheet group 20 is integrally attached to one side surface of the main body portion 310. There is no need to cut the first electrode sheet group 10 or the second electrode sheet group 20, reducing the process flow, improving the processing efficiency, and reducing the processing cost.

[0061] In some embodiments, referring to Figure 1 , the first electrode sheet group 10 and the second electrode sheet group 20 have the same length dimension, and the first electrode sheet group 10 and the second electrode sheet group 20 have the same width dimension. That is, the second separator 120 in the first electrode sheet group 10 has the same size as the second separator 120 in the second electrode sheet group 20, the negative electrode sheets 110 in the first electrode sheet group 10 have the same size as the negative electrode sheets 110 in the second electrode sheet group 20, and the positive electrode sheets 130 in the first electrode sheet group 10 have the same size as the positive electrode sheets 130 in the second electrode sheet group 20. Herein, the dimension includes the length dimension and the width dimension.

[0062] In the embodiments of the present application, the first electrode assembly 10 and the second electrode assembly 20 are designed to have the same size. In the composite battery cell assembly 30, the sides of all the second separators 120 are aligned, the sides of all the negative electrodes 110 are aligned, and the sides of all the positive electrodes 130 are aligned. This is beneficial for cutting the composite battery cell assembly 30, and the alignment degree of the stacked battery cells 50 prepared by cutting the composite battery cell assembly 30 is high.

[0063] In some embodiments, referring to Figure 1 、 Figure 3 and Figure 4 , along the length direction Y of the second separator 120, the negative electrodes 110 located on the same side of the second separator 120 are arranged at intervals in sequence, the positive electrodes 130 located on the same side of the second separator 120 are arranged at intervals in sequence, and along the thickness direction of the second separator 120, the projection of the positive electrode 130 on the negative electrode 110 completely falls within the continuous planar area surrounded by the outer contour of the negative electrode 110.

[0064] Exemplarily, referring to Figure 1 、 Figure 3 and Figure 4 , the distance between any two adjacent negative electrodes 110 among the negative electrodes 110 located on the same side of the second separator 120 is the same, and the distance between any two adjacent positive electrodes 130 among the positive electrodes 130 located on the same side of the second separator 120 is the same. The composite battery cell assembly 30 is cut along the area between adjacent negative electrodes 110, such as cutting the composite battery cell assembly 30 along the central area between adjacent negative electrodes 110, so that the sizes of the stacked battery cells 50 formed after cutting are the same.

[0065] In the embodiments of the present application, the negative electrodes 110 on one side of the second separator 120 are arranged at intervals, the positive electrodes 130 on the other side of the second separator 120 are arranged at intervals, and the positive electrodes 130 and the negative electrodes 110 are arranged in a corresponding manner, which is beneficial for aligning the positive electrodes 130 and the negative electrodes 110 and facilitating the stacking and processing of the positive electrodes 130, the negative electrodes 110 and the second separator 120.

[0066] In some embodiments, referring to Figure 2 shown, the second separators 120 between any two adjacent negative electrode units 100 in the first electrode assembly 10 are arranged at intervals; and / or, the second separators 120 between any two adjacent positive electrode units 200 in the second electrode assembly 20 are arranged at intervals.

[0067] In the embodiments of the present application, along the length direction Y of the second separator 120, adjacent second separators 120 have no connection relationship, or the sides of adjacent second separators 120 are in contact. Each negative electrode unit 100 in the first electrode assembly 10 is an independent structure. Each positive electrode unit 200 in the second electrode assembly 20 is an independent structure. This is convenient for transferring the negative electrode units 100 and the positive electrode units 200 to the first separator 300, which is beneficial for the processing of the stacked battery cells 50.

[0068] Exemplarily, the size of the second separator 120 is related to the size of a single negative electrode sheet 110. The length dimension of the second separator 120 is set to be greater than the length dimension of the negative electrode sheet 110, and the width dimension of the second separator 120 is greater than the width dimension of the negative electrode sheet 110.

[0069] In the embodiments of the present application, the size of the second separator 120 is designed to be greater than the size of the negative electrode sheet 110, reducing the probability of short - circuit caused by direct contact between the negative electrode sheet 110 and the positive electrode sheet 130, and improving the electrical safety of the stacked battery cell 50.

[0070] In some embodiments, referring to Figure 2 、 Figure 5 and Figure 6 , along the thickness direction X of the second separator 120, the projections of the negative electrode sheet 110 and the positive electrode sheet 130 on the second separator 120 completely fall within the second separator 120, and the negative electrode sheet 110 and the positive electrode sheet 130 are alternately arranged.

[0071] In the embodiments of the present application, when the second separator 120, the negative electrode sheet 110, and the positive electrode sheet 130 are in a one - to - one correspondence structure, correspondingly, multiple negative electrode units 100 in the first electrode group 10 are sequentially arranged at intervals along the length direction of the first separator 300, and multiple positive electrode units 200 in the second electrode group 20 are sequentially arranged at intervals along the length direction of the first separator 300. The number of negative electrode sheets 110 and positive electrode sheets 130 in each negative electrode unit 100 and positive electrode unit 200 is small, and the alignment degree during the stacking process is controllable, and the alignment degree of each negative electrode unit 100 and positive electrode unit 200 is high. Along the thickness direction X of the second separator 120, multiple negative electrode units 100 and multiple positive electrode units 200 are alternately arranged to form the stacked battery cell 50. The required number of negative electrode units 100 and positive electrode units 200 is small, which is beneficial to the alignment of the negative electrode units 100 and positive electrode units 200, thereby ensuring the alignment degree of the stacked battery cell 50.

[0072] In some embodiments, referring to Figure 5 , along the thickness direction X of the negative electrode unit 100, the negative electrode unit 100 is sequentially stacked by a negative electrode sheet 110, a second separator 120, a positive electrode sheet 130, a second separator 120, and a negative electrode sheet 110.

[0073] In the embodiments of the present application, the negative electrode unit 100 has a five - layer structure and belongs to the smallest unit negative electrode unit 100. Since the number of layers of the negative electrode unit 100 is small, it is convenient for processing, and the alignment degree of the negative electrode sheet 110, the second separator 120, and the positive electrode sheet 130 is controllable. Using the negative electrode unit 100 with this structure to process the stacked battery cell 50 can not only reduce the processing procedures, but also ensure the alignment degree of the stacked battery cell 50. According to needs, the negative electrode unit 100 can be used to stack stacked battery cells 50 of different specifications, and has good versatility.

[0074] In some embodiments, referring to Figure 6 , along the thickness direction X of the positive electrode unit 200, the positive electrode unit 200 is sequentially stacked by a positive electrode sheet 130, a second separator 120, a negative electrode sheet 110, a second separator 120, and a positive electrode sheet 130.

[0075] In the embodiments of the present application, the positive electrode unit 200 has a five-layer structure and belongs to the positive electrode unit 200 of the smallest unit. Since the number of layers of the positive electrode unit 200 is small, it is convenient for processing, and the alignment of the negative electrode sheet 110, the second separator 120, and the positive electrode sheet 130 is controllable. The laminated battery cell 50 processed by using the positive electrode unit 200 with this structure can not only reduce the processing procedures, but also ensure the alignment of the laminated battery cell 50. According to needs, the positive electrode unit 200 can be used to stack laminated battery cells 50 of different specifications, and has good versatility.

[0076] Exemplarily, referring to Figure 5 and Figure 6 , the second separator 120, the negative electrode sheet 110, and the positive electrode sheet 130 correspond one by one. The length dimension of the second separator 120 is greater than the length dimension of the negative electrode sheet 110, the length dimension of the negative electrode sheet 110 is greater than the length dimension of the positive electrode sheet 130, and the width dimension of the second separator 120 is greater than the width dimension of the negative electrode sheet 110, and the width dimension of the negative electrode sheet 110 is greater than the width dimension of the positive electrode sheet 130. The negative electrode sheet 110 and the positive electrode sheet 130 are separated by the second separator 120, and the outermost layers of the negative electrode unit 100 are all negative electrode sheets 110, and the outermost sides of the positive electrode unit 200 are all positive electrode sheets 130.

[0077] In the embodiments of the present application, the size of the second separator 120 is set to be greater than the sizes of the negative electrode sheet 110 and the positive electrode sheet 130, so that the negative electrode sheet 110 and the positive electrode sheet 130 are completely separated by the second separator 120 passed through, thereby reducing the probability of short circuit caused by the direct contact between the negative electrode sheet 110 and the positive electrode sheet 130, and ensuring the electrical safety of each negative electrode unit 100 or positive electrode unit 200. The size of the negative electrode sheet 110 is set to be greater than the size of the positive electrode sheet 130, so that the lithium ions embedded from the positive electrode sheet 130 can all enter the corresponding negative electrode sheet 110, preventing lithium deposition on the surface of the negative electrode sheet 110, and reducing the occurrence of the situation where the second separator 120 and the first separator 300 are pierced by lithium deposition, thereby improving the reliability of the laminated battery cell 50.

[0078] In other embodiments, the negative electrode unit 100 and the positive electrode unit 200 may also adopt a structure with more than five layers, as long as it can be realized that the outermost layer of the negative electrode unit 100 is a negative electrode sheet 110 and the outermost side of the positive electrode unit 200 is a positive electrode sheet 130.

[0079] In other embodiments, in the negative electrode unit 100 or the positive electrode unit 200, along the thickness direction of the negative electrode sheet 110, any two second separators 120 are connected, and the second separator 120 is folded in a Z shape to form continuous horizontal and vertical portions, and the adjacent negative electrode sheets 110 and positive electrode sheets 130 are separated by the horizontal portion. The second separator 120 may be a single-layer separator or a double-layer separator, and no specific limitation is made in this embodiment.

[0080] In the embodiments of the present application, the second separator 120 in each negative electrode unit 100 or each positive electrode unit 200 is a continuous separator, and the negative electrode unit 100 or the positive electrode unit 200 can be processed by a folding process, and the processing process is simple.

[0081] In some embodiments, the negative electrode sheet 110 and the positive electrode sheet 130 in the negative electrode unit 100 are respectively thermally compounded and connected to the second separator 120; and / or, the negative electrode sheet 110 and the positive electrode sheet 130 in the positive electrode unit 200 are respectively thermally compounded and connected to the second separator 120.

[0082] Wherein, the thermal compound connection between the negative electrode sheet 110 and the positive electrode sheet 130 and the second separator 120 means that the negative electrode sheet 110 and the positive electrode sheet 130 are fixed on the surface of the second separator 120 through a thermal compound process. Exemplarily, the thermal compound process is as follows: the positive electrode material roll, the negative electrode material roll, and the separator are fed simultaneously. Before entering the heating device, the positive electrode sheet and the negative electrode sheet are cut into single electrode sheets of the required size by a cutter. The combination of the positive electrode sheet, the negative electrode sheet, and the separator enters the heating system under the action of a roller. The separator is a coated separator and has adhesiveness after being heated. The positive electrode sheet and the negative electrode sheet after baking are thermally compounded with the separator, and then are roll-pressed and cut to form the negative electrode unit 100 or the positive electrode unit 200.

[0083] In some embodiments, referring to Figure 3 , the distance between adjacent negative electrode units 100 is d1, where 3 mm ≤ d1 ≤ 5 mm. In this embodiment, the distance between the negative electrode units 100 refers to the gap between adjacent negative electrode sheets 110 in the same layer of adjacent negative electrode units 100. The value of d1 can be 3 mm, 3.3 mm, 3.7 mm, 3.9 mm, 4 mm, 4.6 mm, 5 mm or other unlisted values.

[0084] In some embodiments, referring to Figure 4 , the distance between adjacent positive electrode units 200 is d2, where 3 mm ≤ d2 ≤ 5 mm. In this embodiment, the distance between the positive electrode units 200 refers to the gap between adjacent negative electrode sheets 110 in the same layer of adjacent positive electrode units 200. The value of d2 can be 3 mm, 3.3 mm, 3.7 mm, 3.9 mm, 4 mm, 4.6 mm, 5 mm or other unlisted values.

[0085] When cutting the composite battery cell group 30, cut along the area between adjacent negative electrode sheets 110, such as cutting at a position of 1 / 2d1 between adjacent negative electrode units 100. While meeting the cutting requirements, the cutting position is appropriate, reducing the probability of scratching or cutting the negative electrode sheet 110 due to the cutting position being too close to one side of the negative electrode sheet 110. This ensures cutting safety and at the same time can avoid the situation of wasting the materials of the second separator 120 and the first separator 300 and increasing the production cost due to too large a reserved distance of the negative electrode sheet 110.

[0086] In some embodiments, referring to Figure 3 and Figure 4 , the distance d1 between adjacent negative electrode units 100 is the same as the distance d2 between adjacent positive electrode units 200.

[0087] In the embodiments of the present application, the distance d1 between adjacent negative electrode units 100 is set to be the same as the distance d2 between adjacent positive electrode units 200, so that in each layer of the composite battery cell group 30, the distances between adjacent negative electrode sheets 110 are the same, and the distances between adjacent positive electrode sheets 130 are the same. Along the thickness direction of the negative electrode sheet 110, the projections of all the negative electrode sheets 110 at the same laminated battery cell 50 position overlap. When cutting from top to bottom along the thickness direction of the composite battery cell group 30, no electrode sheet will be cut, facilitating the cutting operation.

[0088] In some embodiments, referring to Figure 9 , the bending portion 320 is provided with an incompletely cut structure 330, and the first separator 300 is folded at the incompletely cut structure 330. By providing the incompletely cut structure 330 on the first separator 300, the first separator 300 is folded along the incompletely cut structure 330, and the folding position is fixed, improving the alignment degree of the first electrode group 10 and the second electrode group 20 during the folding process. Reducing the situation of lithium deposition and piercing the first separator 300 due to the misalignment of the first electrode group 10 or the second electrode group 20, and improving the electrical performance such as the cycle life, fast charging capacity and safety of the laminated battery cell 50.

[0089] In some embodiments, referring to Figure 9, the incompletely cut structure 330 includes a plurality of through holes 331 penetrating the first diaphragm 300, and the plurality of through holes 331 are arranged at intervals along the width direction Z of the first diaphragm 300. Alternatively, the plurality of through holes 331 are arranged in an array, and are arranged in multiple columns of through holes 331 along the length direction Y of the first diaphragm 300. Each column of through holes 331 can be arranged along the width direction Z of the first diaphragm 300. Exemplarily, the arrangement directions of the multiple columns of through holes 331 can be parallel to each other. In some other embodiments, there may be at least an included angle between the arrangement direction of one column of through holes 331 and the arrangement direction of other columns of through holes 331. Exemplarily, the included angle can be less than or equal to 10°, for example, 1°, 2°, 5°, etc. In some other embodiments, the included angle can also be greater than 10°, and the embodiments of the present application do not limit this. Exemplarily, the plurality of through holes 331 in one of any two columns of through holes 331 can be arranged in one-to-one correspondence with the plurality of through holes 331 in the other column. In some other embodiments, there may be at least an interlaced arrangement of the plurality of through holes 331 in one column and the plurality of through holes 331 in other columns. If the projections of two through holes 331 in the length direction Y of the first diaphragm 300 do not overlap, it can be considered that the two through holes 331 are interlaced. For example: the plurality of through holes 331 in one of each adjacent two columns of through holes 331 can be interlaced with the plurality of through holes 331 in the other column. In some other embodiments, the incompletely cut structure 330 may also include a plurality of spaced-apart slits. The slits can be obtained by cutting the first diaphragm 300 with a tool or the like. In addition, the incompletely cut structure 330 can also be a reticular structure.

[0090] In the embodiments of the present application, by forming the incompletely cut structure 330 by arranging a plurality of through holes 331 in the first diaphragm 300, part of the material on the first diaphragm 300 is cut off, and along the width direction Z of the first diaphragm 300, the first diaphragm 300 is not completely cut off, so that the first diaphragm 300 around the through holes 331 is weak. When folding, the first diaphragm 300 will fold along the position of the through holes 331, realizing precise position folding, which is beneficial to the alignment of the stacked battery cells 50.

[0091] In some embodiments, referring to Figure 9 , the intervals between any two adjacent through holes 331 are the same. Wherein, the interval between adjacent through holes 331 refers to the distance between one side of a through hole 331 and one side of an adjacent through hole 331 along the width direction Z of the first diaphragm 300.

[0092] In the embodiments of the present application, the same interval between adjacent through holes 331 is beneficial to processing the through holes 331 on the first diaphragm 300, making the strength of the first diaphragm 300 on the straight line where the plurality of through holes 331 are located the same, and avoiding the situation of being pulled and broken during the folding process due to relatively weak local strength.

[0093] In some embodiments, referring toFigure 9 Along the width direction of the first diaphragm 300, the interval between adjacent through holes 331 is S1, where 5 mm ≤ S1 ≤ 20 mm. Here, the value of S1 can be 5.0 mm, 5.2 mm, 5.7 mm, 7.8 mm, 9.0 mm, 10.5 mm, 11.5 mm, 12.3 mm, 13.9 mm, 14.0 mm, 15.7 mm, 16.1 mm, 17.4 mm, 18.0 mm, 19.6 mm, 20.0 mm or other unlisted values.

[0094] In the embodiments of the present application, setting the interval S1 between the through holes 331 to be greater than or equal to 5 mm can avoid the situation that the structural strength of the first diaphragm 300 is affected due to the too small distance between the through holes 331 and the excessive number of through holes 331; setting the interval S1 between the through holes 331 to be less than or equal to 20 mm can avoid the situation that the through holes 331 cannot play a role in positioning folding during the folding process due to the too large distance between the through holes 331 and the small number of through holes 331. The interval design between the through holes 331 is reasonable, ensuring the folding quality.

[0095] In some embodiments, referring to Figure 9 , the through hole 331 has a first dimension L1 and a second dimension W1. The first dimension is the distance between two parallel planes that virtually abut against the two side walls of the through hole 331, and the second dimension is the distance between two parallel planes that virtually abut against the two end walls of the through hole 331, where 1 mm ≤ L1 ≤ 20 mm, and / or, 1 mm ≤ W1 ≤ 2 mm. In this embodiment, the value of L1 can be 1.1 mm, 1.2 mm, 1.5 mm, 2.3 mm, 3.4 mm, 4.2 mm, 5.0 mm, 6.8 mm, 7.8 mm, 8.8 mm, 9.0 mm, 10.3 mm, 11.1 mm, 12.5 mm, 13.8 mm, 14.1 mm, 15.0 mm, 16.6 mm, 17.7 mm, 18.2 mm, 19.1 mm, 20.0 mm or other unlisted values. In this embodiment, the value of W1 can be 1.1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2.0 mm or other unlisted values.

[0096] The two parallel planes that virtually abut the through hole 331 are introduced only for the convenience of understanding the first dimension and the second dimension, and do not actually exist in the solution of the present application. Exemplarily, the through hole 331 has a rectangular outer contour. To determine the first dimension and the second dimension, it is assumed that there are two groups of planes, each group of planes includes two parallel planes that are spaced apart, and the two parallel planes in each group can virtually abut the two opposite hole walls of the through hole 331 together. It can be understood that there is a distance between the two parallel planes in each group, the first dimension is the distance between the two planes that abut the hole walls on both sides of the through hole 331, and the second dimension is the distance between the two planes that abut the hole walls at both ends of the through hole 331.

[0097] In the embodiment of the present application, the size of the through hole 331 is reasonably designed to avoid affecting the structural strength of the first diaphragm 300 due to the through hole 331 being too large, or the through hole 331 being too small to play a role in positioning and folding during the folding process.

[0098] In some embodiments, see Figure 9 The through hole 331 is in a regular shape such as a rectangle, a circle, an ellipse or a regular polygon. In addition to being in a regular shape, the through hole 331 can also be in an irregular shape.

[0099] In some embodiments, see Figure 7 The outermost negative electrode sheet 110 in the composite battery cell group 30 is a single-sided electrode sheet 113, and the other negative electrode sheets 110 are double-sided electrode sheets 114. The outermost negative electrode sheet 110 in the composite battery cell group 30 is set as a single-sided electrode sheet 113, and the outermost side of the single-sided electrode sheet 113 does not need to be provided with an active material layer, thereby reducing material input and reducing costs.

[0100] For example, see Figure 7 The single-sided electrode sheet 113 includes a negative electrode current collector 111 and a negative electrode active layer 112. The negative electrode active layer 112 is disposed on one side of the negative electrode current collector 111 close to the second separator 120. The negative electrode current collector 111 may be made of copper, and the negative electrode active layer 112 may be made of graphite.

[0101] In the embodiment of the present application, the outermost negative electrode sheet 110 in the composite battery cell group 30 is set as a single-sided electrode sheet 113, which reduces the use of negative electrode active materials and reduces processing costs. The outermost side of the single-sided electrode sheet 113 does not need to be coated with a diaphragm, which reduces the diaphragm material and further reduces processing costs. Compared with the related art, two layers of negative electrode active layers 112 and two layers of diaphragms are reduced, and the thickness of the laminated battery cell 50 is reduced.

[0102] For example, see Figure 7The double-sided pole piece 114 includes a negative electrode current collector 111 and a negative electrode active layer 112. The negative electrode active layer 112 is disposed on both sides of the negative electrode current collector 111. The negative electrode current collector 111 may be made of copper, and the negative electrode active layer 112 may be made of graphite. The double-sided pole piece 114 meets the electrical requirements of the laminated battery cell 50.

[0103] In some embodiments, see Figure 7 The negative electrode sheet 110 includes a negative electrode current collector 111 and a negative electrode active layer 112. The thickness of the negative electrode current collector 111 is D1, 4μm≤D1≤6μm; the value of D1 can be 4.0μm, 4.1μm, 4.7μm, 5.0μm, 5.4μm, 5.6μm, 6.0μm or other unspecified values. The thickness of the negative electrode current collector 111 is reasonably designed to meet the electrical requirements of the negative electrode sheet 110.

[0104] In some embodiments, see Figure 7 , the thickness of the negative electrode active layer 112 is D2, 50μm≤D2≤200μm. The value of D2 can be 50μm, 65μm, 72μm, 89μm, 95μm, 108μm, 117μm, 122μm, 136μm, 144μm, 159μm, 162μm, 175μm, 187μm, 198μm, 200μm or other unspecified values. The thickness of the negative electrode active layer 112 is reasonably designed to meet the electrical requirements of the negative electrode sheet 110.

[0105] In some embodiments, the positive electrode sheet 130 includes a positive electrode current collector and a positive electrode active layer, and the positive electrode active layer is disposed on both sides of the positive electrode current collector. Exemplarily, the material of the positive electrode current collector may be aluminum foil, and the material of the positive electrode active layer may be one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, and lithium iron phosphate.

[0106] In some embodiments, see Figure 1 , Figure 2 and Figure 8 A negative electrode tab 140 is disposed on the negative electrode sheet 110 , and a positive electrode tab 150 is disposed on the positive electrode sheet 130 . The negative electrode tab 140 and the positive electrode tab 150 at least partially extend out of the outside of the second diaphragm 120 .

[0107] Exemplarily, in the negative electrode unit 100 or the positive electrode unit 200, the negative electrode sheet 110 and the positive electrode sheet 130 are rectangular, a negative electrode tab 140 is provided on one side of the negative electrode sheet 110, and a positive electrode tab 150 is provided on one side of the positive electrode sheet 130, and both the negative electrode tab 140 and the positive electrode tab 150 are at least partially located on the outside of the second diaphragm 120.

[0108] In some embodiments, see Figure 1 , Figure 2 and Figure 8, in the negative electrode unit 100 or the positive electrode unit 200, along the thickness direction of the negative electrode sheet 110, the projections of all the negative electrode tabs 140 overlap, and / or the projections of all the positive electrode tabs 150 overlap. The negative electrode tabs 140 are stacked along with the negative electrode sheet 110, and the positive electrode tabs 150 are stacked along with the positive electrode sheet 130. Along the thickness direction, there is a thickness of a second separator 120 between adjacent negative electrode tabs 140, and the projections of all the negative electrode tabs 140 are at the same position. There is a thickness of a second separator 120 between adjacent positive electrode tabs 150, and the projections of all the positive electrode tabs 150 are at the same position. This facilitates welding all the negative electrode tabs 140 together, welding all the positive electrode tabs 150 together, and the negative electrode tabs 140 and the positive electrode tabs 150 occupy a small space.

[0109] In some embodiments, referring to Figure 1 , Figure 2 and Figure 8 , the projections of the negative electrode tabs 140 and the positive electrode tabs 150 in the plane of the second separator 120 are arranged side by side. The negative electrode tabs 140 and the positive electrode tabs 150 are on the same side of the second separator 120, and the projections of the negative electrode tabs 140 and the positive electrode tabs 150 in the plane of the second separator 120 are spaced apart, preventing interference between the negative electrode tabs 140 and the positive electrode tabs 150 and ensuring electrical safety.

[0110] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0111] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0112] The above has introduced the stacked battery cell provided by the embodiments of the present application in detail. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A laminated battery cell (50), characterized in that: The laminated battery core (50) is any one of a plurality of laminated battery cores (50) cut from a composite battery core group (30) along a preset position (40), wherein the composite battery core group (30) comprises: A plurality of first pole piece groups (10), wherein the first pole piece groups (10) include a plurality of negative electrode units (100) arranged in sequence; A plurality of second electrode sheet groups (20), wherein the second electrode sheet groups (20) include a plurality of positive electrode units (200) arranged in sequence, and the number of the negative electrode units (100) and the number of the positive electrode units (200) are the same; and the negative electrode units (100) and the positive electrode units (200) both include negative electrode sheets (110) and positive electrode sheets (130), and along the thickness direction of the negative electrode sheets (110), the negative electrode sheets (110) and the positive electrode sheets (130) are alternately arranged, the negative electrode sheets (110) are provided with negative electrode tabs (140), and the positive electrode sheets (130) are provided with positive electrode tabs (150), and the outermost sides of the negative electrode units (100) are all the negative electrode sheets (110), and the outermost sides of the positive electrode units (200) are all the positive electrode sheets (130); A first diaphragm (300) comprising a plurality of main bodies (310) and bent parts (320) arranged alternately and continuously, wherein along the thickness direction of the first pole piece group (10), the first pole piece group (10) and the second pole piece group (20) are arranged alternately, and adjacent first pole piece groups (10) and second pole piece groups (20) are separated by the main body (310); along the length direction of the main body (310), the plurality of negative electrode units (100) of the first pole piece group (10) are arranged in sequence and spaced apart, the negative electrode units (100) and the positive electrode units (200) are arranged opposite to each other, and the negative electrode tabs (140) and the positive electrode tabs (150) at least partially extend out of the outside of the first diaphragm (300); The preset position (40) refers to a position between adjacent negative electrode units (100) along the length direction of the main body (310).

2. The laminated battery core (50) according to claim 1, characterized in that: The negative electrode sheet (110) and the positive electrode sheet (130) are separated by a second separator (120), and any adjacent second separators (120) in the first electrode sheet group (10) and / or the second electrode sheet group (20) are connected to each other.

3. The laminated battery core (50) according to claim 1, characterized in that: The negative electrode sheet (110) and the positive electrode sheet (130) are separated by a second separator (120), and any two adjacent second separators (120) in the first electrode sheet group (10) and / or the second electrode sheet group (20) are arranged in a spaced relationship.

4. The laminated battery core (50) according to claim 3, characterized in that: The distance between any two adjacent second diaphragms (120) in the first pole piece group (10) and / or the second pole piece group (20) is the same.

5. The laminated battery core (50) according to claim 2 or 3, characterized in that: Along the thickness direction of the second diaphragm (120), the projections of the negative electrode sheet (110) and the positive electrode sheet (130) on the second diaphragm (120) fall into the second diaphragm (120); And / or, along the thickness direction of the second diaphragm (120), the projection of the positive electrode sheet (130) on the negative electrode sheet (110) completely falls within the continuous planar region enclosed by the outer contour of the negative electrode sheet (110).

6. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: Along the thickness direction, the negative electrode unit (100) comprises two negative electrode sheets (110); And / or, the positive electrode unit (200) includes two positive electrode sheets (130).

7. The laminated battery core (50) according to any one of claims 2 to 4, characterized in that: The negative electrode sheet (110) and the positive electrode sheet (130) in the negative electrode unit (100) are respectively thermally composite-connected with the second separator (120); And / or, the negative electrode sheet (110) and the positive electrode sheet (130) in the positive electrode unit (200) are respectively thermally composite-connected to the second separator (120).

8. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The distance between adjacent negative electrode units (100) in the composite battery cell group (30) is d1, wherein 3 mm ≤ d1 ≤ 5 mm; And / or, the distance between adjacent positive electrode units (200) in the composite battery cell group (30) is d2, wherein 3 mm ≤ d2 ≤ 5 mm.

9. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The distance d1 between adjacent negative electrode units (100) and the distance d2 between adjacent positive electrode units (200) in the composite battery cell group (30) are the same.

10. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The bending portion (320) is provided with an incompletely cut structure (330), and the first diaphragm (300) is folded at the incompletely cut structure (330).

11. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The outermost negative electrode sheet (110) in the composite battery cell group (30) is a single-sided electrode sheet (113), and the other negative electrode sheets (110) are double-sided electrode sheets (114).

12. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The negative electrode sheet (110) comprises a negative electrode current collector (111) and a negative electrode active layer (112), the thickness of the negative electrode current collector (111) is D1, the thickness of the negative electrode active layer (112) is D2, 4 μm≤D1≤6 μm, and / or, 50 μm≤D2≤200 μm.

13. The laminated battery core (50) according to any one of claims 1 to 4, characterized in that: The composite battery cell group (30) comprises M first pole piece groups (10) and N second pole piece groups (20), where M and N are positive integers, and MN=1.

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