Laminated cell and battery

Abstract

The laminated battery cell comprises M first battery cell units, N second battery cell units and continuous diaphragms, each of the first battery cell units and the second battery cell units comprises a negative plate, a diaphragm and a positive plate, the negative plates and the positive plates are alternately arranged in the thickness direction, and the negative plates and the positive plates are separated by the diaphragms, the outermost side of each first battery cell unit is a negative plate, the outermost side of each second battery cell unit is a positive plate, M and N are positive integers, and M-N is equal to 1; the continuous diaphragm comprises a plurality of main body parts and bending parts which are alternately and continuously arranged, the first battery cell units and the second battery cell units are alternately arranged along the thickness direction, and the adjacent first battery cell units and second battery cell units are separated by the main body parts. According to the invention, the problems of low processing efficiency and poor alignment degree of the existing laminated battery cell are solved, and the laminated battery cell has the advantages of high processing efficiency and good alignment degree.

Description

Technical Field

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

[0002] The stacked cells of lithium batteries are prepared using a Z-type stacking process. The Z-type folding process is to alternately place the positive and negative electrode sheets on a diaphragm that swings in a Z shape. The diaphragm is folded many times in a row, and the processing steps are many, the efficiency is low, and the alignment of the negative and positive electrode sheets is poor. Utility Model Content

[0003] The embodiments of the present application provide a laminated battery cell and a battery to solve the problems of low processing efficiency and poor alignment of existing laminated battery cells.

[0004] In a first aspect, an embodiment of the present application provides a laminated battery cell, comprising:

[0005] M first battery cell units;

[0006] N second battery cell units, the first battery cell unit and the second battery cell unit both include a negative electrode sheet, a separator and a positive electrode sheet, the negative electrode sheets and the positive electrode sheets are alternately arranged in the thickness direction, and the negative electrode sheets and the positive electrode sheets are separated by the separator, the outermost sides of the first battery cell units are the negative electrode sheets, and the outermost sides of the second battery cell units are the positive electrode sheets, wherein M and N are both positive integers, and MN=1;

[0007] The continuous separator comprises a plurality of main bodies and bending parts which are arranged alternately and continuously. The first battery cell units and the second battery cell units are arranged alternately along the thickness direction. Adjacent first battery cell units and second battery cell units are separated by the main bodies.

[0008] Optionally, the negative electrode sheet is a single-body structure electrode sheet or a continuous structure electrode sheet.

[0009] Optionally, the diaphragm is a membrane material with a monomer structure or a membrane material with a continuous structure.

[0010] Optionally, the first battery cell unit is formed by stacking the negative electrode sheet, the separator, the positive electrode sheet, the separator and the negative electrode sheet in a monomer structure in sequence;

[0011] And / or, the second battery cell unit is formed by stacking the positive electrode sheet, the separator, the negative electrode sheet, the separator and the positive electrode sheet in a single structure in sequence.

[0012] Optionally, the first battery cell unit is formed by stacking a negative electrode sheet with a continuous structure, a separator with a continuous structure, and a positive electrode sheet with a single structure, wherein the negative electrode sheet is adhered to one side of the separator, the negative electrode sheet and the separator are bent, and the positive electrode sheet is located in the space where the separator is bent and is adhered to the separator on both sides.

[0013] Optionally, the first battery cell unit is formed by stacking a negative electrode sheet with a continuous structure, two separators with a continuous structure and a plurality of positive electrode sheets with a single structure, wherein the length of one separator is smaller than the length of the other separator, and the negative electrode sheet is compounded between the two separators. The composite structure formed by the negative electrode sheet and the separator is folded in a Z shape to form a plurality of first horizontal portions and first connecting portions which are alternately and continuously arranged. The outermost sides of the negative electrode sheets on the first horizontal portions on both sides are exposed, and along the thickness direction of the positive electrode sheets, the first horizontal portions and the positive electrode sheets are alternately arranged.

[0014] Optionally, the second battery cell unit is formed by stacking a negative electrode sheet with a single-body structure, a separator with a continuous structure, and two positive electrode sheets with a single-body structure, wherein the separator is bent to form a separating portion, the negative electrode sheet is located between the two positive electrode sheets, and the negative electrode sheet and the positive electrode sheet are separated by the separating portion.

[0015] Optionally, the second battery cell unit is formed by stacking the negative electrode sheet with a continuous structure, two continuous structure membranes and a plurality of single structure positive electrode sheets, wherein the negative electrode sheet is compounded between the two membranes, and the composite structure formed by the negative electrode sheet and the membrane is folded in a Z shape to form a plurality of alternating and continuously arranged second horizontal portions and second connecting portions, and along the thickness direction of the positive electrode sheet, the positive electrode sheet and the second horizontal portions are alternately arranged.

[0016] Optionally, the negative electrode sheet includes a negative electrode current collector and a negative electrode active layer, and the negative electrode active layer covers two side surfaces of the negative electrode current collector.

[0017] Optionally, the outermost negative electrode sheets in the first battery cell units on both sides are attached to the main body.

[0018] Optionally, the outermost negative electrode sheets in the first battery cell units on both sides include a negative electrode current collector and a negative electrode active layer, and the negative electrode active layer is provided on a side of the negative electrode current collector close to the main body.

[0019] Optionally, all of the first battery core units and all of the second battery core units form a stacking structure, and after the continuous separator is folded in a Z-shape, the remaining continuous separator wraps around the stacking structure for at least one circle.

[0020] Optionally, the projection of the positive electrode sheet within the plane where the negative electrode sheet is located completely falls within the negative electrode sheet.

[0021] Optionally, a distance between an outer contour of a projection of the positive electrode sheet within the plane where the negative electrode sheet is located and a side edge corresponding to the negative electrode sheet is D1, wherein 0.5 mm ≤ D1 ≤ 3.5 mm.

[0022] Optionally, the projection of the negative electrode sheet within the plane where the diaphragm is located completely falls into the diaphragm.

[0023] Optionally, a distance between an outer contour of a projection of the negative electrode sheet within the plane where the diaphragm is located and a side edge corresponding to the diaphragm is D2, wherein 1 mm ≤ D2 ≤ 4 mm.

[0024] In a second aspect, an embodiment of the present application further provides a battery, comprising: a laminated battery cell as described in any one of the above.

[0025] The laminated battery cell and battery provided in the embodiments of the present application include a first battery cell unit, a second battery cell unit and a continuous separator, the first battery cell unit and the second battery cell unit both include a negative electrode sheet, a positive electrode sheet and a separator, the negative electrode sheets and the positive electrode sheets in the first battery cell unit and the second battery cell unit are alternately arranged in the thickness direction, and the negative electrode sheets and the positive electrode sheets are separated by the separator, the outermost electrode sheets of the first battery cell unit are all negative electrode sheets, the outermost electrode sheets of the second battery cell unit are all positive electrode sheets, the first battery cell unit and the second battery cell unit are alternately arranged in the thickness direction, the continuous separator is folded in a Z shape to form a main body and a bending portion, and adjacent The main body is connected by a bending portion, and the adjacent first battery cell units and second battery cell units are separated by the main body. The first battery cell unit and the second battery cell unit are both multi-layer electrode sheets. The alignment of the negative electrode sheets and the positive electrode sheets in the first battery cell unit and the second battery cell unit is controllable. The alignment of the first battery cell unit and the second battery cell unit is high. The alignment of the stacked battery cell formed by assembling the first battery cell unit and the second battery cell unit through a continuous diaphragm is high. The continuous diaphragm is folded less times, which reduces the processing steps, overcomes the problems of low processing efficiency and poor alignment of existing stacked battery cells, and has the advantages of high processing efficiency and good alignment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

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

[0028] Figure 1 A cross-sectional schematic diagram of a first form of a laminated battery cell provided in an embodiment of the present application.

[0029] Figure 2 A cross-sectional schematic diagram of a second form of a laminated battery cell provided in an embodiment of the present application.

[0030] Figure 3 A cross-sectional schematic diagram of form one of the first battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0031] Figure 4 A cross-sectional schematic diagram of form II of the first battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0032] Figure 5 A schematic cross-sectional view of form three of the first battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0033] Figure 6 A schematic cross-sectional view of form four of the first battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0034] Figure 7 A cross-sectional schematic diagram of form one of the second battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0035] Figure 8 A cross-sectional schematic diagram of form 2 of the second battery cell unit of the laminated battery cell provided in an embodiment of the present application.

[0036] Fig. 9 A schematic cross-sectional view of a third embodiment of the second cell unit of the laminated cell provided in the embodiment of the present application

[0037] Fig.10 A cross-sectional schematic diagram of a third form of a laminated battery cell provided in an embodiment of the present application.

[0038] Fig.11 A cross-sectional schematic diagram of the fourth form of the laminated battery cell provided in an embodiment of the present application.

[0039] In the figure:

[0040] 100, first battery cell; 110, negative electrode sheet; 111, negative electrode current collector; 112, negative electrode active layer; 120, separator; 121, separator; 122, first horizontal portion; 123, first connecting portion; 124, second horizontal portion; 125, second connecting portion; 130, positive electrode sheet;

[0041] 200. a second battery cell unit;

[0042] 300, continuous diaphragm; 310, main body; 320, bending portion. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0044] The embodiments of the present application provide a laminated battery core to solve the problems of low processing efficiency and poor alignment of existing laminated battery cores.

[0045] See also Figure 1 and Figure 2 As shown, Figure 1 A cross-sectional schematic diagram of a first form of a laminated battery cell provided in an embodiment of the present application, Figure 2 A cross-sectional schematic diagram of a second form of a laminated battery cell provided in an embodiment of the present application. A laminated battery cell includes a first battery cell unit 100 , a second battery cell unit 200 and a continuous separator 300 .

[0046] In this embodiment, see Figure 1 and Figure 2 As shown, M first battery cell units 100 are provided, and the first battery cell units 100 include negative electrode sheets 110, separators 120 and positive electrode sheets 130. The negative electrode sheets 110 and the positive electrode sheets 130 are alternately arranged, and the negative electrode sheets 110 and the positive electrode sheets 130 are separated by the separators 120. The outermost sides of the first battery cell units 100 are all negative electrode sheets 110.

[0047] In this embodiment, see Figure 1 and Figure 2 As shown, N second battery cell units 200 are provided, and the second battery cell units 200 include a negative electrode sheet 110 , a separator 120 and a positive electrode sheet 130 . The negative electrode sheet 110 and the positive electrode sheet 130 are separated by the separator 120 , and the outermost sides of the second battery cell units 200 are all positive electrode sheets 130 .

[0048] In this embodiment, see Figure 1 and Figure 2As shown, the continuous diaphragm 300 is folded in a Z shape to form a main body 310 and a bending portion 320, and adjacent main bodies 310 are connected by the bending portions 320. The first battery cell units 100 and the second battery cell units 200 are alternately arranged along the thickness direction, M and N are both positive integers, MN=1, and the number of first battery cell units 100 is one more than the number of second battery cell units 200. From bottom to top, they are the first battery cell unit 100, the second battery cell unit 200, and the first battery cell unit 100, and so on to the last first battery cell unit 100. Adjacent first battery cell units 100 and second battery cell units 200 are separated by the main body 310.

[0049] It can be understood that in this embodiment, the first battery cell unit 100 and the second battery cell unit 200 are both layered structures of multiple pole pieces. Compared with the single negative pole piece and the positive pole piece assembled into the laminated battery cell, the number of times the continuous separator 300 is folded is reduced, and the processing efficiency of the laminated battery cell is improved. The number of layers of the first battery cell unit 100 and the second battery cell unit 200 is limited, which is conducive to controlling the alignment of the pole pieces in the first battery cell unit 100 and the second battery cell unit 200. When the alignment of the first battery cell unit 100 and the second battery cell unit 200 is good, the alignment of the laminated battery cell prepared by combining the first battery cell unit 100 and the second battery cell unit 200 is also good, ensuring the alignment of the laminated battery cell.

[0050] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the negative electrode sheet 110 is a single-body structure electrode sheet or a continuous structure electrode sheet.

[0051] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the diaphragm 120 is a membrane material with a single structure or a membrane material with a continuous structure.

[0052] The first battery cell unit 100 includes the following four forms:

[0053] Form 1: See Figure 3 As shown, when the negative electrode sheet 110 of the first battery cell unit 100 is a single-structure electrode sheet, the diaphragm 120 of the first battery cell unit 100 is a continuous structure film material, the diaphragm 120 is folded in a Z shape, and the diaphragm 120 forms an isolation portion 121. The negative electrode sheet 110 and the positive electrode sheet 130 are respectively attached to the two sides of the isolation portion 121. The negative electrode sheet 110 and the positive electrode sheet 130 can be connected to the diaphragm 120 by thermal recombination, and the outermost side of the first battery cell unit 100 is the negative electrode sheet 110.

[0054] Form 2: See Figure 4 As shown, when the negative electrode sheet 110 of the first battery cell unit 100 is a single-structure electrode sheet, the diaphragm 120 of the first battery cell unit 100 is also a single-structure membrane material, and the size of the diaphragm 120 is larger than the size of the negative electrode sheet 110, and the negative electrode sheet 110 and the positive electrode sheet 130 are respectively attached to the two sides of the diaphragm 120, and the outermost side of the first battery cell unit 100 is the negative electrode sheet 110.

[0055] Form 3: See Figure 5 As shown, the negative electrode sheet 110 of the first battery cell unit 100 is a continuous structure electrode sheet, and when a positive electrode sheet 130 is provided, the diaphragm 120 of the first battery cell unit 100 is a continuous structure film material, the negative electrode sheet 110 is bonded to one side of the diaphragm 120, the negative electrode sheet 110 and the diaphragm 120 are bent in a U shape, and the positive electrode sheet 130 is located in the bent space of the diaphragm 120 and is bonded to the diaphragm 120 on both sides.

[0056] Form 4: See Figure 6 As shown, the first battery cell unit 100 is formed by stacking a negative electrode sheet 110 with a continuous structure, two separators 120 with a continuous structure, and a plurality of positive electrode sheets 130 with a single structure, wherein the length of one separator 120 is smaller than the length of the other separator 120, the negative electrode sheet 110 is compounded between the two separators 120, and the compound structure formed by the negative electrode sheet 110 and the separator 120 is folded in a Z shape to form a plurality of first horizontal portions 122 and first connecting portions 123 that are alternately and continuously arranged, the outermost sides of the negative electrode sheets 110 on the first horizontal portions 122 on both sides are exposed, and the size of the exposed portion is larger than that of the positive electrode sheet 130, along the thickness direction of the positive electrode sheet 130, the first horizontal portions 122 and the positive electrode sheets 130 are alternately arranged, the positive electrode sheets 130 and the horizontally arranged negative electrode sheets 110 are separated by the separator 120, and the outermost sides of the first battery cell unit 100 are all negative electrode sheets 110.

[0057] The second battery cell unit 200 includes the following three forms:

[0058] Form 1: See Figure 7 As shown, the second battery cell unit 200 is formed by stacking a negative electrode sheet 110 with a single structure, a separator 120 with a continuous structure, and two positive electrode sheets 130 with a single structure, wherein the separator 120 is bent to form a separation portion 121, the negative electrode sheet 110 is located between the two positive electrode sheets 130, and the negative electrode sheet 110 and the positive electrode sheet 130 are separated by the separation portion 121, the negative electrode sheet 110 and the positive electrode sheet 130 can be connected to the separator 120 by thermal recombination, and the outermost side of the second battery cell unit 200 is the positive electrode sheet 130.

[0059] Form 2: See Figure 8As shown, when the negative electrode sheet 110 of the second battery cell unit 200 is a single-structure electrode sheet, the diaphragm 120 of the second battery cell unit 200 is a single-structure membrane material, and the size of the diaphragm 120 is larger than the size of the negative electrode sheet 110, and the negative electrode sheet 110 and the positive electrode sheet 130 are respectively adhered to both sides of the diaphragm 120, and the outermost side of the second battery cell unit 200 is the positive electrode sheet 130.

[0060] Form 3: See Fig. 9 As shown, the second battery cell unit 200 is formed by stacking a negative electrode sheet 110 with a continuous structure, two separators 120 with a continuous structure and a plurality of positive electrode sheets 130 with a single structure, wherein the negative electrode sheet 110 is compounded between the two separators 120, and the composite structure formed by the negative electrode sheet 110 and the separator 120 is folded in a Z shape to form a plurality of alternating and continuously arranged second horizontal portions 124 and second connecting portions 125, and along the thickness direction of the positive electrode sheet 130, the positive electrode sheet 130 and the second horizontal portion 124 are alternately arranged, and the outermost side of the second battery cell unit 200 is the positive electrode sheet 130.

[0061] It can be understood that the four forms of the first battery cell units 100 can be arbitrarily combined with the three forms of the second battery cell units 200 to form a laminated battery cell.

[0062] In some embodiments, see Figure 1 and Figure 2 As shown, the first battery cell unit 100 is formed by stacking a single-structure negative electrode sheet 110, a separator 120, a positive electrode sheet 130, a separator 120 and a negative electrode sheet 110 in sequence.

[0063] It can be understood that in this embodiment, the first battery cell unit 100 adopts a five-layer structure, with the first battery cell unit 100 as the smallest unit, which is suitable for assembly of laminated batteries of various thicknesses, and the number of layers of the first battery cell unit 100 is reasonably designed to ensure the alignment of the first battery cell unit 100.

[0064] In some embodiments, see Figure 1 and Figure 2 As shown, the second battery cell unit 200 is formed by stacking a single-structure positive electrode sheet 130, a separator 120, a negative electrode sheet 110, a separator 120 and a positive electrode sheet 130 in sequence.

[0065] It can be understood that in this embodiment, the second battery cell unit 200 adopts a five-layer structure, with the second battery cell unit 200 as the smallest unit, which is suitable for the assembly of laminated batteries of various thicknesses, and the number of layers of the second battery cell unit 200 is reasonably designed to ensure the alignment of the second battery cell unit 200.

[0066] In some embodiments, see Figure 2As shown, the negative electrode sheet 110 includes a negative electrode current collector 111 and a negative electrode active layer 112 , and the negative electrode active layer 112 covers both sides of the negative electrode current collector 111 .

[0067] In some embodiments, the negative electrode current collector 111 may be made of copper, and the negative electrode active layer 112 may be made of graphite.

[0068] In some embodiments, see Figure 2 As shown, the outermost negative electrode sheets 110 in the first battery cell units 100 on both sides are attached to the main body 310 .

[0069] Understandably, see Figure 2 As shown, the M first battery cell units 100 are, from bottom to top, the 1st first battery cell unit 100 ... the Mth first battery cell unit 100, and the N second battery cell units 200 are, from bottom to top, the 1st second battery cell unit 200 ... the Nth second battery cell unit 200, wherein the ith second battery cell unit 200 is located above the ith first battery cell unit 100. In this embodiment, the outermost negative electrode sheet 110 in the 1st first battery cell unit 100 is covered by a continuous diaphragm 120, and the outermost negative electrode sheet 110 in the Mth first battery cell unit 100 is covered by a continuous diaphragm 120, so as to ensure the electrical performance of the laminated battery cell.

[0070] In some embodiments, see Figure 2 As shown, the outermost negative electrode sheet 110 in the first battery cell units 100 on both sides includes a negative electrode collector 111 and a negative electrode active layer 112 . The negative electrode active layer 112 is disposed on one side of the negative electrode collector 111 close to the main body 310 .

[0071] It can be understood that in the present embodiment, the outermost negative electrode sheet 110 in the first first battery cell unit 100 and the outermost negative electrode sheet 110 in the Mth first battery cell unit 100 only include a negative electrode collector 111 and a negative electrode active layer 112, and the negative electrode active layer 112 is arranged on one side of the negative electrode collector 111 close to the main body 310, and the negative electrode collector 111 on the other side serves as the outermost side of the stacked battery cell. The required length of the continuous diaphragm 300 is reduced, which can also meet the electrical performance of the stacked battery cell, and can reduce the material usage of the negative electrode active layer 112 and the continuous diaphragm 300, thereby reducing costs.

[0072] In some embodiments, see Fig.10 and Fig.11 As shown, all the first battery cell units 100 and all the second battery cell units 200 form a stacking structure, and after the continuous separator 300 is folded in a Z-shape, the remaining continuous separator 300 wraps around the stacking structure for at least one circle.

[0073] In this embodiment, see Fig.10As shown, the continuous diaphragm 300 starts to be attached from one end of the outermost negative electrode sheet 110 of the first first battery cell unit 100 to the other end, and is folded in a Z shape until one end of the outermost negative electrode sheet 110 of the Mth first battery cell unit 100 ends. The remaining continuous diaphragm 300 wraps around the laminated structure for at least one week, so that the laminated structure is wrapped by the continuous diaphragm on all sides, avoiding exposure of the ends of the negative electrode sheet 110 and the positive electrode sheet 130, avoiding powder loss of the negative electrode sheet 110 and the positive electrode sheet 130, and improving the reliability of the laminated battery cell.

[0074] As a variant, see Fig.11 As shown, the continuous diaphragm 300 starts to be bonded from one end between the first first battery cell unit 100 and the first second battery cell unit 200, and is folded in a Z shape until it ends at one end of the outermost negative electrode sheet 110 of the Mth first battery cell unit 100. The remaining continuous diaphragm 300 wraps around the laminated structure for at least one week, so that the laminated structure is wrapped by the continuous diaphragm on all sides, thereby preventing the ends of the negative electrode sheet 110 and the positive electrode sheet 130 from being exposed, and preventing the negative electrode sheet 110 and the positive electrode sheet 130 from falling off, thereby improving the reliability of the laminated battery cell.

[0075] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the projection of the positive electrode sheet 130 in the plane where the negative electrode sheet 110 is located completely falls into the negative electrode sheet 110 .

[0076] It can be understood that in this embodiment, the size of the negative electrode sheet 110 is larger than that of the positive electrode sheet 130. During the charging process of the lithium battery, the negative electrode sheet 110 can completely receive the lithium ions of the positive electrode sheet 130 and will not form lithium dendrites, thereby avoiding the situation where the continuous diaphragm 300 is pierced by the formation of lithium dendrites, resulting in a short circuit and causing thermal runaway, thereby improving the reliability of the battery.

[0077] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the distance between the outer contour of the projection of the positive electrode sheet 130 in the plane where the negative electrode sheet 110 is located and the corresponding side of the negative electrode sheet 110 is D1, where 0.5 mm ≤ D1 ≤ 3.5 mm. The value of D1 can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm or other unspecified values.

[0078] It can be understood that in the present embodiment, the positive electrode sheet 130 is a rectangle, the outer contour of the projection of the positive electrode sheet 130 in the plane where the negative electrode sheet 110 is located is a rectangle, the distance between the long side of the rectangle and the long side of the negative electrode sheet 110 and the distance between the wide side of the rectangle and the wide side of the negative electrode sheet 110 are both D1, and the size design is reasonable. On the premise of meeting the battery safety performance, it avoids waste of materials and increased costs due to excessive size.

[0079] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the projection of the negative electrode sheet 110 in the plane where the separator 120 is located completely falls into the separator 120 .

[0080] It can be understood that when the separator 120 is a film material of a single structure, the size of the separator 120 is larger than the size of the negative electrode sheet 110, and the projection of the size of the negative electrode sheet 110 on the separator 120 completely falls into the separator 120. When the separator 120 is a film material of a continuous structure and the negative electrode sheet 110 is a single structure, the size of the separator 121 of the separator 120 is larger than the size of the negative electrode sheet 110, and the projection of the size of the negative electrode sheet 110 on the separator 120 completely falls into the separator 121. When the separator 120 is a film material of a continuous structure and the negative electrode sheet 110 is a continuous structure, the size of the separator 120 is larger than the size of the negative electrode sheet 110, and the projection of the size of the negative electrode sheet 110 on the separator 120 completely falls into the separator 120.

[0081] The negative electrode sheet 110 and the positive electrode sheet 130 are separated by the separator 120. If the size of the separator 120 is smaller than that of the negative electrode sheet 110, the negative electrode sheet 110 and the positive electrode sheet 130 may directly contact each other, causing a short circuit and thermal runaway. The size of the separator 120 is designed to be larger than that of the positive electrode sheet 130 to meet the electrical safety requirements of the laminated battery cell and improve the reliability of the laminated battery cell.

[0082] In some embodiments, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the distance between the outer contour of the projection of the negative electrode sheet 110 in the plane where the diaphragm 120 is located and the corresponding side of the diaphragm 120 is D2, where 1mm≤D2≤4mm. The value of D2 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm or other unspecified values.

[0083] The sizes of the separator 120 and the negative electrode sheet 110 are designed reasonably to avoid waste of materials and increase of costs due to excessive sizes while meeting the battery safety performance.

[0084] When the separator 120 is a film material of a single structure, D2 refers to the distance between the side of the separator 120 and the side of the negative electrode sheet 110; when the separator 120 is a film material of a continuous structure and the negative electrode sheet 110 is a single structure, D2 refers to the distance between the side of the separating portion 121 of the separator 120 and the side of the negative electrode sheet 110; when the separator 120 is a film material of a continuous structure and the negative electrode sheet 110 is a continuous structure, D2 refers to the distance between the side or end of the separator 120 and the corresponding side or end of the negative electrode sheet 110. The above distances all refer to the distances between projections in the same plane.

[0085] The present application also provides a battery, comprising any one of the laminated cells described above. The battery is advantageous in simplifying production steps, improving production efficiency, and improving the alignment of the pole pieces in the battery.

[0086] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0088] The laminated cells and batteries provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A laminated battery cell, characterized in that: include: M first battery core units (100); N second battery cell units (200), the first battery cell unit (100) and the second battery cell unit (200) both comprise a negative electrode sheet (110), a separator (120) and a positive electrode sheet (130), the negative electrode sheets (110) and the positive electrode sheets (130) are alternately arranged along the thickness direction, and the negative electrode sheets (110) and the positive electrode sheets (130) are separated by the separator (120), the outermost sides of the first battery cell units (100) are the negative electrode sheets (110), and the outermost sides of the second battery cell units (200) are the positive electrode sheets (130), wherein M and N are both positive integers, and MN=1; The continuous separator (300) comprises a plurality of main bodies (310) and bending parts (320) which are arranged alternately and continuously. The first battery cell units (100) and the second battery cell units (200) are arranged alternately along the thickness direction. Adjacent first battery cell units (100) and second battery cell units (200) are separated by the main bodies (310).

2. The laminated battery cell according to claim 1, characterized in that: The negative electrode sheet (110) is a single-structure electrode sheet or a continuous-structure electrode sheet.

3. The laminated battery cell according to claim 1, characterized in that: The diaphragm is a membrane material with a monomer structure or a membrane material with a continuous structure.

4. The laminated battery cell according to claim 1, characterized in that: The first battery cell unit (100) is formed by stacking the negative electrode sheet (110), the separator (120), the positive electrode sheet (130), the separator (120) and the negative electrode sheet (110) in sequence in a single structure; And / or, the second battery cell unit (200) is formed by stacking the positive electrode sheet (130), the separator (120), the negative electrode sheet (110), the separator (120) and the positive electrode sheet (130) in sequence in a single structure.

5. The laminated battery cell according to claim 1, characterized in that: The first battery cell unit (100) is formed by stacking a negative electrode sheet (110) of a continuous structure, a separator (120) of a continuous structure, and a positive electrode sheet (130) of a single structure, wherein the negative electrode sheet (110) is attached to one side of the separator (120), the negative electrode sheet (110) and the separator (120) are bent, and the positive electrode sheet (130) is located in the bent space of the separator (120) and is attached to the separator (120) on both sides.

6. The laminated battery cell according to claim 1, characterized in that: The first battery cell unit (100) is formed by stacking a negative electrode sheet (110) of a continuous structure, two separators (120) of a continuous structure, and a plurality of positive electrode sheets (130) of a single structure, wherein the length of one separator (120) is smaller than the length of another separator (120), the negative electrode sheet (110) is composited between the two separators (120), and the composite structure formed by the negative electrode sheet (110) and the separator (120) is folded in a Z shape to form a plurality of first horizontal portions (122) and first connecting portions (123) that are alternately and continuously arranged, the outermost sides of the negative electrode sheets (110) on the first horizontal portions (122) on both sides are exposed, and along the thickness direction of the positive electrode sheet (130), the first horizontal portions (122) and the positive electrode sheets (130) are alternately arranged.

7. The laminated battery cell according to claim 1, characterized in that: The second battery cell unit (200) is formed by stacking a negative electrode sheet (110) with a single structure, a separator (120) with a continuous structure, and two positive electrode sheets (130) with a single structure, wherein the separator (120) is bent to form a separation portion (121), the negative electrode sheet (110) is located between the two positive electrode sheets (130), and the negative electrode sheet (110) and the positive electrode sheet (130) are separated by the separation portion (121).

8. The laminated battery cell according to claim 1, characterized in that: The second battery cell unit (200) is formed by stacking the negative electrode sheet (110) with a continuous structure, two separators (120) with a continuous structure, and a plurality of positive electrode sheets (130) with a single structure, wherein the negative electrode sheet (110) is compounded between the two separators (120), and the compound structure formed by the negative electrode sheet (110) and the separator (120) is folded in a Z shape to form a plurality of second horizontal portions (124) and second connecting portions (125) which are alternately and continuously arranged, and along the thickness direction of the positive electrode sheet (130), the positive electrode sheet (130) and the second horizontal portion (124) are alternately arranged.

9. The laminated battery cell according to claim 1, characterized in that: The negative electrode sheet (110) comprises a negative electrode current collector (111) and a negative electrode active layer (112), wherein the negative electrode active layer (112) covers two side surfaces of the negative electrode current collector (111).

10. The laminated battery cell according to claim 1, characterized in that: The outermost negative electrode sheets (110) in the first battery cell units (100) on both sides are bonded to the main body (310).

11. The laminated battery cell according to claim 1, characterized in that: The outermost negative electrode sheets (110) in the first battery cell units (100) on both sides include a negative electrode current collector (111) and a negative electrode active layer (112), and the negative electrode active layer (112) is provided on one side of the negative electrode current collector (111) close to the main body (310).

12. The laminated battery cell according to any one of claims 1 to 11, characterized in that: All of the first battery cell units (100) and all of the second battery cell units (200) form a stacking structure, and after the continuous separator (300) is folded in a Z-shape, the remaining continuous separator (300) wraps around the stacking structure for at least one cycle.

13. The laminated battery core according to any one of claims 1 to 11, characterized in that: The projection of the positive electrode sheet (130) within the plane where the negative electrode sheet (110) is located completely falls within the negative electrode sheet (110).

14. The laminated battery cell according to claim 13, characterized in that: The distance between the outer contour of the projection of the positive electrode sheet (130) in the plane where the negative electrode sheet (110) is located and the side edge corresponding to the negative electrode sheet (110) is D1, wherein 0.5 mm≤D1≤3.5 mm.

15. The laminated battery cell according to any one of claims 1 to 11, characterized in that: The projection of the negative electrode sheet (110) within the plane where the diaphragm (120) is located completely falls within the diaphragm (120).

16. The laminated battery cell according to claim 15, characterized in that: The distance between the outer contour of the projection of the negative electrode sheet (110) in the plane where the diaphragm (120) is located and the side edge corresponding to the diaphragm (120) is D2, wherein 1 mm≤D2≤4 mm.

17. A battery, characterized in that: include: A laminated battery cell as claimed in any one of claims 1 to 16.

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