Stacking jellyroll, stacking method therefor, and battery

Abstract

The present application provides a stacking jellyroll, a stacking method therefor, and a battery. In the thickness direction of the stacking jellyroll, the stacking jellyroll comprises a positive electrode sheet, a negative electrode sheet and a separator located therebetween; at least at one end of the positive electrode sheet, negative electrode sheet and separator, the edge of the separator is flush with the edge of the negative electrode sheet, and the edge of the separator exceeds the edge of the positive electrode sheet.

Description

Laminated core package, lamination method thereof, and battery

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 16, 2023, with application number 202321554850.7. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of lithium batteries, and in particular to laminated core packs and batteries. Background Art

[0003] The current production process for prismatic battery cores uses two methods: winding and lamination. Compared to winding, the lamination method offers advantages in structural stability and space utilization. SUMMARY OF THE INVENTION

[0004] However, the lamination process still has major defects. For example, in the related technology, the pole piece is made into a composite sheet with the diaphragm in advance and then the core package is made by winding. This process has very high requirements for the positioning of the composite sheet, which is prone to overhang dimensional problems, increasing the difficulty of manufacturing.

[0005] An embodiment of the present application provides a laminated core package, in which, in the thickness direction of the laminated core package, the core package includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive electrode sheet and the negative electrode sheet. At at least one end of the positive electrode sheet, the negative electrode sheet, and the separator, the edge of the separator is flush with the edge of the negative electrode sheet, and the edge of the separator exceeds the edge of the positive electrode sheet.

[0006] An embodiment of the present application provides a battery, comprising an electrolyte, a shell, and the above-mentioned laminated core package, wherein the shell is used to encapsulate the laminated core package and the electrolyte.

[0007] An embodiment of the present application provides a lamination method for a laminated core package, comprising the following steps:

[0008] Two layers of separators are placed on opposite sides of the negative electrode sheet, with the edges of the separators flush with the edges of the negative electrode sheet;

[0009] Cutting the positive electrode sheet coil to form positive electrode sheets;

[0010] The positive electrode sheet is arranged on one side of one of the two layers of separators, with the edge of the separator extending beyond the edge of the positive electrode sheet. The positive electrode sheet, the two layers of separators and the negative electrode sheet form a laminated unit.

[0011] Repeatedly manufacture multiple laminated units;

[0012] A stacking tool is used to stack multiple lamination units to complete the lamination of the lamination core package. Beneficial effects

[0013] In an embodiment of the present application, the laminated core package includes a core package, and in the thickness direction of the laminated core package, the laminated core package includes a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet; the negative electrode sheet and the separator are pre-compounded and cut so that the edge of the separator is flush with the edge of the negative electrode sheet, and there is no need to control the overhang size between the separator and the negative electrode sheet; in the process of compounding the positive electrode sheet and the negative electrode sheet, the overhang size between the separator and the positive electrode sheet is controlled so that the edge of the separator exceeds the edge of the positive electrode sheet, and in the stacking process, the stacked electrode sheets are clamped using stacking tooling, and there is no need to control the overhang size between the separator and the positive electrode sheet, which can achieve high-precision control and high-efficiency stacking, which is beneficial to improving the low positioning accuracy of the electrode sheets and avoiding poor overhang size. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 is a schematic diagram of a front view of a laminated core package provided in an embodiment of the present application;

[0015] FIG2 is a left-side structural schematic diagram of a laminated core package provided in an embodiment of the present application;

[0016] FIG3 is a schematic structural diagram of a lamination unit provided in an embodiment of the present application;

[0017] FIG4 is a flow chart of steps S1 to S3 in a lamination method of a laminated core package according to an embodiment of the present application;

[0018] FIG5 is another flow chart of steps S1 to S3 in the lamination method of the laminated core package provided in an embodiment of the present application;

[0019] FIG6 is a flow chart of steps S5 to S6 in the lamination method of the laminated core package provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0020] Please refer to Figures 1 and 2. An embodiment of the present application provides a laminated core package, including a laminated core package 1 including a positive electrode sheet 11, a negative electrode sheet 12, and a separator 13 located between the positive electrode sheet 11 and the negative electrode sheet 12 in the thickness direction of the laminated core package. At at least one end of the positive electrode sheet 11, the negative electrode sheet 12, and the separator 13, the edge of the separator 13 is flush with the edge of the negative electrode sheet 12, and the edge of the separator 13 exceeds the edge of the positive electrode sheet 11.

[0021] It can be understood that the laminated core package 1 provided in the embodiment of the present application is pre-compounded and cut by the negative electrode sheet 12 and the diaphragm 13, so that the edge of the diaphragm 13 is flush with the edge of the negative electrode sheet 12, and there is no need to control the overhang size H1 between the diaphragm 13 and the negative electrode sheet 12; during the compounding process of the positive electrode sheet 11 and the negative electrode sheet 12, the overhang size H2 between the diaphragm 13 and the positive electrode sheet 11 is controlled, so that the edge of the diaphragm 13 exceeds the edge of the positive electrode sheet 11, and the stacking tool 3 is used to clamp the stacked electrode sheets during the stacking process. There is no need to control the overhang size H2 between the diaphragm 13 and the positive electrode sheet 11, which can achieve high-precision control and high-efficiency stacking, which is beneficial to improving the low positioning accuracy of the electrode sheets and avoiding poor overhang size.

[0022] In one embodiment, referring to Figure 3, the laminate core package 1 includes a plurality of laminate units 14 stacked together, each laminate unit 14 includes a positive electrode sheet 11 and a negative electrode diaphragm composite sheet 15, the negative electrode diaphragm composite sheet 15 includes a negative electrode sheet 12 and two layers of diaphragms 13 located on opposite sides of the negative electrode sheet 12; wherein, one of the two layers of diaphragms 13 is located between the positive electrode sheet 11 and the negative electrode sheet 12, and the other layer of the two layers of diaphragms 13 is located between the negative electrode sheet 12 and the positive electrode sheet 11 in the adjacent laminate unit 14.

[0023] In the laminated core pack of the present embodiment, the opposite sides of the negative electrode sheet 12 are bonded to two layers of separator 13 to form a negative electrode separator composite sheet 15. The positive electrode sheet 11 is then laminated with the negative electrode separator composite sheet 15 to form a laminate unit 14. The laminated core pack 1 is laminated using the laminate unit 14 as the basic unit. Simply put, the negative electrode sheet 12 and the two layers of separator 13 are continuously laminated to form the negative electrode separator composite sheet 15, while the positive electrode sheet 11 and the negative electrode separator composite sheet 15 are laminated intermittently. The basic structure of the laminate unit 14 is separator 13 - negative electrode sheet 12 - separator 13 - positive electrode sheet 11.

[0024] It can be understood that in the embodiment of the present application, since the positive electrode sheet 11 is directly positioned on one of the layers of the diaphragm 13 of the negative electrode diaphragm composite sheet 15 after cutting and slicing, there is no need to paste the positive electrode sheet 11 and the diaphragm 13, which reduces the transfer of the positive and negative electrode sheets 12 and the diaphragm 13, helps to reduce the risk of folding of the electrode sheet and the diaphragm 13, greatly improves the efficiency of battery production, and also reduces the cost of battery production.

[0025] In one embodiment, the edge of the separator 13 extends beyond the edge of the positive electrode sheet 11 by more than 0.1 mm and less than 5 mm.

[0026] The edge of the separator 13 extends beyond the edge of the positive electrode sheet 11 by more than 1 mm and less than 3 mm.

[0027] In one embodiment, referring to FIG2 , the laminated core package 1 further includes an insulating layer 2 , which covers at least two sides of the laminated core package 1 to improve the electronic insulation and ion insulation between the laminated core package 1 and the shell, thereby improving the corrosion resistance of the shell.

[0028] In the embodiment of the present application, the laminated core package 1 is square. The laminated core package 1 includes a first side surface 16 and a second side surface 17 that are perpendicular to each other. The first side surface 16 is formed by the end surfaces of the positive electrode sheet 11, the separator 13, and the negative electrode sheet 12. The first side surface 16 is parallel to the stacking direction of the laminated unit 14. The second side surface 17 is parallel to the planar direction of the positive electrode sheet 11, the separator 13, and the negative electrode sheet 12, and is perpendicular to the first side surface 16.

[0029] Correspondingly, the insulating layer 2 includes an integrated first insulating portion 21 and a second insulating portion 22 . The first insulating portion 21 covers the first side surface 16 . The second insulating portion 22 is formed by bending the first insulating portion 21 inward. The second insulating portion 22 covers at least a portion of the second side surface 17 .

[0030] In the thickness direction of the laminated core package 1, the dimension H3 of the area where the insulating layer 2 covers the laminated core package 1 is greater than 3 mm, and the dimension of the area where the insulating layer 2 covers the laminated core package 1 is less than the thickness of the laminated core package 1. In other words, the dimension of the area where the second insulating portion 22 covers the second side surface 17 is greater than 3 mm, and the dimension of the area where the second insulating portion 22 covers the second side surface 17 is less than the length of the second side surface 17.

[0031] Optionally, the insulating layer 2 includes an insulating tape.

[0032] Referring to FIG. 4 to FIG. 6 , the present application also provides a lamination method for a laminated core package, comprising the following steps:

[0033] S1, placing two layers of separators 13 on opposite sides of the negative electrode sheet 12, with the edges of the separators 13 flush with the edges of the negative electrode sheet 12;

[0034] S2, cutting the positive electrode sheet roll to form a positive electrode sheet 11;

[0035] S3, placing the positive electrode sheet 11 on one side of one of the two separators 13, with the edge of the separator 13 extending beyond the edge of the positive electrode sheet 11. The positive electrode sheet 11, the two separators 13, and the negative electrode sheet 12 form a laminate unit 14;

[0036] S4, repeating steps S1-S3 to form a plurality of laminated units 14;

[0037] S5, stacking the plurality of lamination units 14 using the stacking tool 3 to complete the lamination of the laminated core package 1; and

[0038] S6 , covering at least two side surfaces of the laminated core package 1 with the insulating layer 2 .

[0039] It can be understood that the embodiment of the present application pre-compounds and cuts the negative electrode sheet 12 and the diaphragm 13 so that the edge of the diaphragm 13 is flush with the edge of the negative electrode sheet 12, and there is no need to control the overhang size H1 between the diaphragm 13 and the negative electrode sheet 12; during the compounding process of the positive electrode sheet 11 and the negative electrode sheet 12, the overhang size H2 between the diaphragm 13 and the positive electrode sheet 11 is controlled so that the edge of the diaphragm 13 exceeds the edge of the positive electrode sheet 11, and the stacking tool 3 is used to clamp the stacked electrode sheets during the stacking process. There is no need to control the overhang size H2 between the diaphragm 13 and the positive electrode sheet 11, which can achieve high-precision control and high-efficiency stacking, which is beneficial to improving the low positioning accuracy of the electrode sheets and avoiding poor overhang size.

[0040] In step S2 , the positive electrode sheet roll is cut by a cutting unit to form positive electrode sheets 11 having a required size.

[0041] In step S5, as shown in FIG6 , the stacking tool 3 may be a robot, which clamps the stacking units 14 in stages for stacking. In the embodiment of the present application, the clamping width of the robot is the same as the width of the negative electrode sheet 12 .

[0042] In one embodiment, as shown in FIG4 , after the negative electrode diaphragm composite sheet 15 is formed, the negative electrode diaphragm composite sheet 15 is first cut, and then it is combined with the positive electrode sheet 11 to form a laminate unit 14 , and then multiple laminate units 14 are stacked and finally wrapped with tape.

[0043] In step S1 , two layers of separator 13 are respectively arranged on opposite sides of the negative electrode sheet roll to form a negative electrode separator composite sheet 15 , and the negative electrode separator composite sheet 15 is cut; in step S3 , the cut negative electrode separator composite sheet 15 is stacked with the positive electrode sheet 11 to form a laminated unit 14 .

[0044] In step S1, the negative electrode sheet and two layers of separator 13 are passed through a heated pressing roller, thereby bonding and fixing the negative electrode sheet 12 to the separator 13. The heated pressing roller applies a temperature during the pressing process. In this embodiment, a heating unit is also provided to heat the negative electrode sheet and separator 13. Of course, flat rollers, patterned rollers, or smooth rollers can also be used for pressing, and this application does not limit this.

[0045] In one embodiment, as shown in FIG5 , after the negative electrode separator composite sheet 15 is formed, the positive electrode sheet 11 and the negative electrode separator composite sheet 15 are first composited, and then the composite structure is cut to form a laminated unit 14 , and then multiple laminated units 14 are stacked and finally wrapped with tape.

[0046] In step S1 , two layers of separators 13 are respectively disposed on opposite sides of a negative electrode sheet roll to form a negative separator composite sheet 15 ; in step S3 , the negative separator composite sheet 15 and the positive electrode sheet 11 are stacked and cut to form a laminate unit 14 .

[0047] An embodiment of the present application further provides a battery, which includes an electrolyte, a shell, and a laminated core package 1, wherein the shell is used to encapsulate the laminated core package 1 and the electrolyte.

[0048] In the embodiment of the present application, the battery is a square shell battery.

[0049] The beneficial effects are as follows: in an embodiment of the present application, the laminated core package includes a core package, and in the thickness direction of the laminated core package, the laminated core package includes a positive electrode sheet, a negative electrode sheet and a separator located between the positive electrode sheet and the negative electrode sheet; the negative electrode sheet and the separator are pre-compounded and cut so that the edge of the separator is flush with the edge of the negative electrode sheet, and there is no need to control the overhang size between the separator and the negative electrode sheet; in the process of compounding the positive electrode sheet and the negative electrode sheet, the overhang size between the separator and the positive electrode sheet is controlled so that the edge of the separator exceeds the edge of the positive electrode sheet, and in the stacking process, stacking tooling is used to clamp the stacked electrode sheets, and there is no need to control the overhang size between the separator and the positive electrode sheet, which can achieve high-precision control and high-efficiency stacking, which is beneficial to improving the low positioning accuracy of the electrode sheets and avoiding poor overhang size.

Claims

1. A laminated core package (1), comprising, in a thickness direction of the laminated core package (1), a positive electrode sheet (11), a negative electrode sheet (12), and a separator (13) located between the positive electrode sheet (11) and the negative electrode sheet (12), wherein at least one end of the positive electrode sheet (11), the negative electrode sheet (12), and the separator (13), an edge of the separator (13) is flush with an edge of the negative electrode sheet (12), and an edge of the separator (13) exceeds an edge of the positive electrode sheet (11).

2. The laminated core package (1) according to claim 1, wherein the laminated core package (1) comprises a plurality of laminated units (14) stacked together, each of the laminated units (14) comprising one of the positive electrode sheets (11) and one of the negative electrode diaphragm composite sheets (15), and the negative electrode diaphragm composite sheet (15) comprising one of the negative electrode sheets (12) and two layers of diaphragms (13) located on opposite sides of the negative electrode sheet (12); in, One of the two layers of separator (13) is located between the positive electrode sheet (11) and the negative electrode sheet (12), and the other of the two layers of separator (13) is located between the negative electrode sheet (12) and the positive electrode sheet (11) in the adjacent laminate unit (14).

3. The laminated core package (1) according to claim 2, wherein: The dimension by which the edge of the separator (13) exceeds the edge of the positive electrode sheet (11) is greater than 0.1 millimetres and less than 5 millimetres.

4. The laminated core package (1) according to claim 3, wherein: The dimension by which the edge of the separator (13) exceeds the edge of the positive electrode sheet (11) is greater than 1 millimeter and less than 3 millimeters.

5. The laminated core package (1) according to any one of claims 1 to 4, further comprising an insulating layer (2), wherein the insulating layer (2) covers at least two side surfaces of the laminated core package (1).

6. The laminated core package (1) according to claim 5, wherein: In the thickness direction of the laminated core package (1), the size of the area where the insulating layer (2) covers the laminated core package (1) is greater than 3 millimeters.

7. The laminated core package (1) according to claim 5, wherein: In the thickness direction of the laminated core package (1), the size of the area where the insulating layer (2) covers the laminated core package (1) is smaller than the thickness of the laminated core package (1).

8. The laminated core package (1) according to claim 5, wherein: The insulating layer (2) comprises an insulating tape.

9. A battery, comprising an electrolyte, a shell, and the laminated core package (1) according to any one of claims 1 to 8, wherein the shell is used to encapsulate the laminated core package (1) and the electrolyte.

10. The battery according to claim 9, wherein The battery is a square-shell battery.

11. A lamination method for a laminated core package, comprising the following steps: Disposing two layers of separators (13) on opposite sides of the negative electrode sheet (12), respectively, with the edge of the separator (13) being flush with the edge of the negative electrode sheet (12); Cutting the positive electrode sheet coil to form a positive electrode sheet (11); The positive electrode sheet (11) is arranged on one side of one of the two layers of the separator (13), the edge of the separator (13) exceeds the edge of the positive electrode sheet (11), and the positive electrode sheet (11), the two layers of the separator (13) and the negative electrode sheet (12) form a laminated unit (14); Repeatedly manufacturing a plurality of the lamination units (14); A plurality of the lamination units (14) are stacked using a stacking tool (3) to complete the lamination of the lamination core package (1).

12. The lamination method according to claim 11, wherein: The step of arranging the two layers of separator (13) on opposite sides of the negative electrode sheet (12) comprises: arranging the two layers of separator (13) on opposite sides of the negative electrode sheet roll to form a negative electrode separator composite sheet (15), and cutting the negative electrode separator composite sheet (15); The method of arranging the positive electrode sheet (11) on one side of one of the two layers of the separator (13) comprises: stacking the cut negative electrode separator composite sheet (15) and the positive electrode sheet (11).

13. The lamination method according to claim 11 or 12, characterized in that: After stacking the plurality of lamination units (14) using the stacking tool (3), the lamination method further comprises: The insulating layer (2) covers at least two side surfaces of the laminated core package (1).

Images