Pole piece compounding device, naked battery cell winding equipment and naked battery cell winding method

Abstract

The invention belongs to the technical field of battery manufacturing, and particularly relates to a pole piece compounding device, naked battery cell winding equipment and a naked battery cell winding method. The pole piece compounding device comprises a first compounding roller assembly, a second compounding roller assembly and a third compounding roller assembly, the first compounding roller assembly comprises a first compounding roller and a second compounding roller, the first compounding roller and the second compounding roller are arranged oppositely, and the first compounding roller and the second compounding roller are used for sequentially compounding a first diaphragm, a first pole piece and a second diaphragm together in a stacked mode; and the side edge diaphragm composite assembly is used for compounding the part, exceeding the side edge of the first pole piece, of the first diaphragm with the part, exceeding the side edge of the first pole piece, of the second diaphragm. The technical scheme provided by the embodiment of the invention aims to solve the problem that the first diaphragm, the first pole piece, the second diaphragm and the second pole piece are easy to fold in the winding process of preparing the naked battery cell, so that the first pole piece and the second pole piece are overlapped.

Description

Technical Field

[0001] The present application belongs to the technical field of battery manufacturing, and in particular relates to a pole piece composite device, a bare cell winding device and a bare cell winding method. Background Art

[0002] In the related art, a first pole piece and a diaphragm are combined together by a composite roller to form a first composite material strip, and the edge areas on both sides of the diaphragm exceed the side edges of the first pole piece; a second pole piece and another diaphragm are also combined together by a composite roller to form a second composite material strip, and the edge areas on both sides of the diaphragm exceed the side edges of the second pole piece. Then, the first composite material strip and the second composite material strip are stacked and passed through a winding mechanism to be wound into a bare battery cell.

[0003] Since there is no restricting structure between the edge of the diaphragm extending beyond the side of the first pole piece and the edge of the diaphragm extending beyond the side of the second pole piece, during the process of winding the first composite material strip and the second composite material strip, the edge of the diaphragm extending beyond the side of the first pole piece and the edge of the diaphragm extending beyond the side of the second pole piece are prone to open away from each other. Subsequently, under the action of external force, the edge of the diaphragm extending beyond the side of the first pole piece and / or the edge of the diaphragm extending beyond the side of the second pole piece are prone to folding, resulting in overlapping of the first pole piece and the second pole piece in the wound bare cell, causing the positive second pole piece to short-circuit. If such a bare cell is assembled into a battery through subsequent manufacturing processes, it will cause a low voltage problem in the battery, affecting the product yield of the battery. Summary of the invention

[0004] The purpose of the present application is to provide a pole piece composite device, a bare cell winding device and a bare cell winding method, aiming to solve the problem that the first diaphragm, the first pole piece, the second diaphragm and the second pole piece are easily folded during the winding process of preparing the bare cell, resulting in the overlap of the first pole piece and the second pole piece.

[0005] To achieve the above purpose, the technical solution adopted in this application is: a pole piece composite device, comprising:

[0006] A first composite roller assembly includes a first composite roller and a second composite roller, wherein the first composite roller and the second composite roller are arranged opposite to each other, and the first composite roller and the second composite roller are used to laminate and composite the first diaphragm, the first pole piece and the second diaphragm in sequence;

[0007] The side diaphragm composite component is used to composite the portion of the first diaphragm that extends beyond the side of the first pole piece with the portion of the second diaphragm that extends beyond the side of the first pole piece.

[0008] The electrode composite device provided in the embodiment of the present application is used to perform a composite operation on the first diaphragm, the first electrode piece and the second diaphragm. Not only the first composite roller assembly is used to composite the first diaphragm, the first electrode piece and the second diaphragm together, but also the edge area of ​​the first diaphragm beyond one side of the first electrode piece is composited with the edge area of ​​the second diaphragm through the side diaphragm composite assembly, and the edge area of ​​the first diaphragm beyond the other side of the first electrode piece is composited with the edge area of ​​the second diaphragm, thereby obtaining a composite material strip in which the first diaphragm and the second diaphragm wrap the first electrode piece. In this way, when the composite material strip is in the subsequent process including but not limited to the winding process and other processes after winding, the problem of the first diaphragm and / or the second diaphragm loosening from the first electrode piece and causing the diaphragm to fold can be avoided, the situation of the first electrode piece and the second electrode piece overlapping can be eliminated, so that the first electrode piece and the second electrode piece are well insulated and separated by the first diaphragm or the second diaphragm, and the problem of low voltage of the battery caused by the overlapping of the first electrode piece and the second electrode piece can be eliminated, which is helpful to improve the product yield of the battery.

[0009] In the electrode assembly device of some embodiments of the present application, the side diaphragm assembly includes a first side roller and a second side roller, the first side roller corresponds to the first side of the first electrode without a pole ear, the second side roller corresponds to the second side of the first electrode with a pole ear, the first side roller is used to roll and laminate the first and second diaphragms together, and the second side roller is used to roll and laminate the first and second diaphragms together. In this way, in the composite material strip obtained by performing the composite operation, the first diaphragm and the second diaphragm wrap the first electrode, and when the composite material strip is wound in the subsequent winding process, the edge areas of the first diaphragm and the second diaphragm that exceed the two side edges of the first electrode will not overlap the first and second electrode due to the folding of the diaphragms even under the action of external force.

[0010] In the pole piece composite device of some embodiments of the present application, the first side roller and / or the second side roller includes a first gear roller and a load-bearing portion, and the first gear roller and the load-bearing portion are arranged opposite to each other. In the pole piece composite device of some embodiments of the present application, the load-bearing portion is arranged as a second gear roller, and the first gear roller and the second gear roller rotate synchronously, and during the rotation of the two, the convex teeth of the first gear roller and the convex teeth of the second gear roller correspond one by one to squeeze the first diaphragm and the second diaphragm. In the pole piece composite device of some embodiments of the present application, when the second side roller includes the first gear roller, the pitch between two adjacent convex teeth in the first gear roller is greater than or equal to the width of the pole ear, and the convex teeth of the first gear roller are used to roll and composite the first diaphragm and the second diaphragm located between two adjacent pole ears. The edge area of ​​the first diaphragm and the edge area of ​​the second diaphragm are composited together by the first gear roller and the load-bearing part, and the first diaphragm and the second diaphragm are composited through a plurality of spaced connection positions. In the manufactured battery, when the bare battery cell is immersed in the electrolyte, the electrolyte can penetrate through the gap between the first diaphragm and the second diaphragm without composite adhesion, thereby quickly soaking the first pole piece and the second pole piece, thereby improving the electrolyte wetting efficiency.

[0011] In the pole piece composite device of some embodiments of the present application, the side diaphragm composite assembly may be additionally provided with a gluing mechanism, the first side roller and / or the second side roller comprises a first round roller and a load-bearing portion, the first round roller and the load-bearing portion are arranged opposite to each other, the gluing mechanism is located upstream of the first round roller, and the gluing mechanism is used to apply glue between the first diaphragm and the second diaphragm portions that extend beyond the side of the first pole piece. In the pole piece composite device of some embodiments of the present application, the load-bearing portion is arranged as a second round roller, and the second round roller rotates synchronously with the first round roller. Glue is applied between the first diaphragm and the second diaphragm that extend beyond the side of the first pole piece by the gluing mechanism, and then the edge area of ​​the first diaphragm and the edge area of ​​the second diaphragm that extend beyond the side of the first pole piece are continuously rolled by the first round roller and the load-bearing portion, so that the edge area of ​​the first diaphragm and the edge area of ​​the second diaphragm are quickly glued and composited together.

[0012] In the pole piece composite device of some embodiments of the present application, the side diaphragm composite assembly may be additionally provided with an ultraviolet lamp, which is located downstream of the first round roller and is used to irradiate the glue-coated parts of the first diaphragm and the second diaphragm. The ultraviolet lamp irradiates the glue between the first diaphragm and the second diaphragm beyond the side of the first pole piece, which helps to increase the curing rate of the glue, thereby improving production efficiency.

[0013] In some embodiments of the electrode composite device of the present application, the electrode composite device further includes a first conveying roller, the first conveying roller is located upstream of one of the first composite roller and the second composite roller and is spaced therefrom, one of the first diaphragm and the second diaphragm is lapped on the first conveying roller to be obliquely conveyed between the first composite roller and the second composite roller; and / or, the electrode composite device further includes a second conveying roller, the second conveying roller is located upstream of the other of the first composite roller and the second composite roller and is spaced therefrom, the other of the first diaphragm and the second diaphragm is lapped on the second conveying roller to be obliquely conveyed between the first composite roller and the second composite roller. In this way, during the process of the first diaphragm, the first electrode piece and the second diaphragm being conveyed between the first composite roller and the second composite roller for stacking and performing the rolling composite operation, the conveying paths of the first diaphragm, the first electrode piece and the second diaphragm do not interfere with each other, so that the first diaphragm, the first electrode piece and the second diaphragm can all be conveyed smoothly.

[0014] In some embodiments of the electrode composite device of the present application, the electrode composite device also includes a first cutting mechanism, the first cutting mechanism is located upstream of the first composite roller assembly, and the first cutting mechanism is used to cut off the first electrode. In some embodiments of the electrode composite device of the present application, the electrode composite device also includes a first detection mechanism, the first detection mechanism is located between the first cutting mechanism and the first composite roller assembly, the first detection mechanism is electrically connected to the first cutting mechanism, and the first detection mechanism is used to detect the conveying length of the first electrode. The first detection mechanism and the first cutting mechanism realize the automatic cutting function of the first electrode, improve the degree of automation, and improve production efficiency.

[0015] According to another aspect of an embodiment of the present application, a bare cell winding device is provided, comprising:

[0016] The aforementioned pole piece composite device outputs a composite material strip formed by sequentially stacking and composited the first diaphragm, the first pole piece and the second diaphragm;

[0017] A second composite roller assembly is located downstream of the electrode sheet composite device, and the second composite roller assembly includes a third composite roller and a fourth composite roller, and the third composite roller and the fourth composite roller are arranged opposite to each other, and the third composite roller and the fourth composite roller are used to composite the second electrode sheet on one of the first diaphragm and the second diaphragm to output the battery core strip;

[0018] The winding mechanism is located downstream of the second composite roller assembly and is used to wind the battery core material strip into a bare battery core.

[0019] In the bare cell winding device provided in the embodiment of the present application, the pole piece composite device provided in the embodiment of the present application is used to perform a composite operation on the first diaphragm, the first pole piece and the second diaphragm, and not only the first diaphragm, the first pole piece and the second diaphragm are composited together through the first composite roller assembly, but also the edge area of ​​the first diaphragm that exceeds one side of the first pole piece is composited with the edge area of ​​the second diaphragm through the side diaphragm composite assembly, and the edge area of ​​the first diaphragm that exceeds the other side of the first pole piece is composited with the edge area of ​​the second diaphragm, thereby obtaining a composite material strip in which the first diaphragm and the second diaphragm wrap the first pole piece. The second pole piece is then rolled and composited on the first diaphragm or the second diaphragm of the composite material strip through the second composite roller assembly, and then the winding operation is performed to wind up the bare cell. In the subsequent processes including but not limited to the winding process and other processes after winding, the first diaphragm and / or the second diaphragm can be prevented from loosening from the first pole piece and causing the diaphragm folding problem, and the overlapping of the first pole piece and the second pole piece can be eliminated, thereby eliminating the overlapping of the first pole piece and the second pole piece in the wound bare battery cell, so that the first pole piece and the second pole piece are well insulated and separated by the first diaphragm or the second diaphragm, eliminating the low voltage problem of the battery caused by the overlapping of the first pole piece and the second pole piece, which helps to improve the product yield of the battery.

[0020] In some embodiments of the present application, the bare cell winding device further includes a second detection mechanism and a pressing mechanism, the second detection mechanism is located upstream of the second composite roller assembly, the second detection mechanism is electrically connected to the pressing mechanism, and the pressing mechanism is used to press the end of the second pole piece against one of the first diaphragm and the second diaphragm. Through the cooperation of the second detection mechanism and the pressing mechanism, the end of the second pole piece can be accurately and quickly pressed against the composite material strip, so that the center distance between the first pole ear of the first pole piece and the second pole ear of the second pole piece is accurately determined, thereby improving production efficiency.

[0021] In some embodiments of the bare cell winding device of the present application, the bare cell winding device further includes a second cutting mechanism, the second cutting mechanism is located upstream of the pressing mechanism, the second cutting mechanism is electrically connected to the second detection mechanism, and the second cutting mechanism is used to cut the second electrode piece when the second detection mechanism detects the predetermined conveying length of the second electrode piece. In this way, the accuracy of cutting the second electrode piece is improved, and the product quality of the bare cell is improved.

[0022] In some embodiments of the bare cell winding device of the present application, the bare cell winding device also includes a third conveying roller, which is located upstream of the second cutting mechanism. The second pole piece is wrapped around the third conveying roller so that the second pole piece is conveyed obliquely to the pressing mechanism, so that the second pole piece can always be smoothly conveyed, thereby improving production efficiency.

[0023] In the bare cell winding equipment of some embodiments of the present application, the bare cell winding equipment may be additionally provided with a film stripping guide roller, which is located downstream of the second composite roller assembly. The film stripping guide roller is used to peel off the release film of the electrostatic protective film composited to the second pole piece, thereby realizing a rapid peeling operation of the release film and improving production efficiency.

[0024] According to another aspect of the embodiments of the present application, a bare cell winding method is provided, comprising the following steps:

[0025] The first diaphragm, the first pole piece and the second diaphragm are laminated together in sequence;

[0026] Compounding the second pole piece on one of the first diaphragm and the second diaphragm to form a battery core strip;

[0027] The battery cell strip is wound to form a bare battery cell.

[0028] The bare cell winding method provided in the embodiment of the present application is used to wind the bare cell. Since the first diaphragm, the first pole piece, the second diaphragm and the second pole piece are compounded to form a cell strip through steps S10 and S20, and then the winding operation is performed, that is to say, the ends of the cell strip formed by the first diaphragm, the first pole piece, the second diaphragm and the second pole piece are fixed on the winding mechanism at one time. Compared with the winding operation of the related art, the problem of the second composite material strip swinging its head and tail is eliminated, which not only greatly improves the winding work efficiency, but also improves the winding quality of the bare cell, and significantly improves the product yield of the bare cell.

[0029] In the bare cell winding method of some embodiments of the present application, before executing the step of "winding the cell material strip into a bare cell", the bare cell winding method also includes the steps of: compounding the first diaphragm that extends beyond one side of the first pole piece with the second diaphragm; compounding the first diaphragm that extends beyond the other side of the first pole piece with the second diaphragm. In this way, in subsequent processes including but not limited to the winding process and other processes after winding, it is possible to avoid the first diaphragm and / or the second diaphragm from loosening from the first pole piece and causing the diaphragm to fold, eliminate the overlap of the first pole piece and the second pole piece, thereby eliminating the overlap of the first pole piece and the second pole piece in the wound bare cell, so that the first pole piece and the second pole piece are well insulated and separated by the first diaphragm or the second diaphragm, eliminate the problem of low voltage of the battery caused by the overlap of the first pole piece and the second pole piece, and help to improve the product yield of the battery.

[0030] In the bare cell winding method of some embodiments of the present application, when executing the step of "combining the first diaphragm, the first electrode sheet and the second diaphragm in layers in sequence", the bare cell winding method further includes the steps of: detecting the first predetermined length of the first electrode sheet, and cutting the first electrode sheet according to the first predetermined length; and when executing the step of "combining the second electrode sheet on one of the first diaphragm and the second diaphragm to form a cell strip", the bare cell winding method further includes the steps of: detecting the second predetermined length of the second electrode sheet, and cutting the second electrode sheet according to the second predetermined length. In this way, the automation process of winding the bare cell is greatly improved, and the production efficiency of the bare cell can be greatly improved.

[0031] In the bare cell winding method of some embodiments of the present application, the first predetermined length is greater than the second predetermined length, and both end ends of the cut first pole piece exceed both end ends of the second pole piece, thus meeting the standard requirement that the first pole piece in the production of bare cells is longer than the second pole piece.

[0032] In the bare cell winding method of some embodiments of the present application, before executing the step of "combining the first diaphragm, the first pole piece and the second diaphragm in layers in sequence", the bare cell winding method further includes the step of: fixing the end of the first pole piece on one of the first diaphragm and the second diaphragm. By positioning the end of the first pole piece, the frequency of the first pole piece offset relative to the first diaphragm and the second diaphragm is reduced or even eliminated during the composite molding of the composite material strip, thereby improving the composite work efficiency and the composite quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 It is a structural schematic diagram of equipment for compounding process and winding process in the related art;

[0035] Figure 2 It is a structural schematic diagram of the equipment of the winding process in the related art;

[0036] Figure 3 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 1 ;

[0037] Figure 4 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 2 ;

[0038] Figure 5 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 3 ;

[0039] Figure 6 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 4 ;

[0040] Figure 7 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 5 ;

[0041] Figure 8 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 6 ;

[0042] Fig. 9 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 7 ;

[0043] Fig.10 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 8 ;

[0044] Fig.11 The structure of the electrode composite device of the embodiment of the present application is shown in FIG. Figure 9 ;

[0045] Fig.12 This is a schematic structural diagram of a bare cell winding device according to an embodiment of the present application;

[0046] Fig.13 The process flow chart of the bare cell winding method of the embodiment of the present application is as follows: Figure 1 ;

[0047] Fig.14 The process flow chart of the bare cell winding method of the embodiment of the present application is as follows: Figure 2 .

[0048] Among them, the reference numerals in the figure are:

[0049] 100. Pole piece composite device;

[0050] 10. battery core strip; 11. first diaphragm; 12. first pole piece; 121. first pole ear; 13. second diaphragm; 14. composite strip; 15. second pole piece; 16. release film;

[0051] 20. First composite roller assembly; 21. First composite roller; 22. Second composite roller;

[0052] 30. Side diaphragm composite assembly; 31. Side roller assembly; 311. First side roller; 312. Second side roller; 313. First gear roller; 314. First convex tooth; 315. Load bearing part; 316. Second convex tooth; 317. First round roller; 32. Gluing mechanism; 33. Ultraviolet lamp;

[0053] 41. First conveying roller; 42. Second conveying roller; 43. Third conveying roller; 44. First cutting mechanism; 45. First detecting mechanism;

[0054] 50. second composite roller assembly; 51. third composite roller; 52. fourth composite roller;

[0055] 61. Winding mechanism; 62. Second detection mechanism; 63. Pressing mechanism; 64. Second cutting mechanism; 65. De-filming guide roller; 66. Positioning tape; 67. Positioning adhesive;

[0056] 300, composite roller; 301, first composite material strip; 302, second composite material strip. DETAILED DESCRIPTION

[0057] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0058] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] At present, from the perspective of market development, the application of power batteries, especially lithium batteries, is becoming more and more extensive. Lithium batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as police equipment, military equipment and aerospace and other fields. With the continuous expansion of the application field of lithium batteries, its market demand is also constantly expanding.

[0062] In the process of preparing lithium batteries, a series of steps are required, which include but are not limited to compounding step, winding step, shaping step, battery cell assembly step, welding step, etc. in the production order.

[0063] The composite process refers to compositely molding the first pole piece, the diaphragm and the second pole piece into a cell material strip for winding the bare cell.

[0064] The winding process refers to winding the composite-molded battery cell material strip to form a bare battery cell semi-finished product. At this time, the bare battery cell semi-finished product formed by winding is in a fluffy state, the shape contour of the bare battery cell is not fixed, and the first electrode piece and the second electrode piece in the bare battery cell are easy to slip and difficult to assemble.

[0065] The shaping process refers to the use of hot pressing or cold pressing technology to clamp and press the fluffy bare battery cell semi-finished products to fix the shape contour of the bare battery cell, thereby solving the problem that the first and second pole pieces in the fluffy bare battery cell are easy to slip and difficult to assemble, which is beneficial to improving the assembly accuracy and efficiency of the subsequent battery cell assembly process.

[0066] The process of assembling battery cells refers to assembling the shaped bare cells, current collectors, shells, shell covers and other components into battery cells.

[0067] The welding process refers to welding components such as the shell, shell cover and electrode terminals, so that the shell and the shell cover are sealed and the electrode terminals are electrically connected to the bare battery cells.

[0068] In the related art, the compounding process and the winding process are generally combined and operated together. Figure 1As shown, the first pole piece and a diaphragm are compounded together by a compound roller 300 to form a first composite material strip 301, and the edge areas on both sides of the diaphragm exceed the side edges of the first pole piece; the second pole piece and another diaphragm are also compounded together by another compound roller 300 to form a second composite material strip 302, and the edge areas on both sides of the diaphragm exceed the side edges of the second pole piece. Then, the first composite material strip 301 and the second composite material strip 302 are stacked and passed through the winding mechanism 61, so as to be wound into a bare battery cell. When the first composite material strip 301 and the second composite material strip 302 are stacked, the first pole piece and the second pole piece are insulated and separated by one of the diaphragms, and then the winding operation is performed. Since there is no limiting structure between the edge of the diaphragm beyond the side of the first pole piece and the edge of the diaphragm beyond the side of the second pole piece, during the process of winding the first composite material strip 301 and the second composite material strip 302, the edge of the diaphragm beyond the side of the first pole piece and the edge of the diaphragm beyond the side of the second pole piece are prone to opening away from each other, and then, when winding around the roller, the diaphragm is prone to folding, resulting in the overlap of the first pole piece and the second pole piece. That is to say, in the subsequent process of the wound bare cell, the diaphragm is subjected to external forces (such as the force of air conditioning wind sweeping, and the interference of the positioning block for correcting the deviation of the material strip, etc.), and the edge of the diaphragm beyond the side of the positive pole piece and / or the edge of the diaphragm beyond the side of the negative pole piece are prone to folding, resulting in the overlap of the first pole piece and the second pole piece in the wound bare cell. If such a bare cell is assembled into a battery through subsequent manufacturing processes, it will cause the battery to have a low voltage problem, affecting the product yield of the battery.

[0069] Based on the above considerations, in order to solve the technical problems existing in the related art, namely: when the first pole piece, the second pole piece and the two diaphragms are compounded and wound to form a bare cell, the edge of the diaphragm beyond the side of the first pole piece and / or the edge of the diaphragm beyond the side of the second pole piece are prone to folding, resulting in overlapping of the first pole piece and the second pole piece in the wound bare cell, resulting in low voltage problems in the assembled battery. Therefore, the embodiment of the present application is designed to provide a pole piece compound device 100, a bare cell winding device and a bare cell winding method. The pole piece compound device 100, the bare cell winding device and the bare cell winding method provided in the embodiment of the present application are compounded when the first pole piece, the second pole piece and the two diaphragms are compounded, so that one of the first pole piece and the second pole piece is wrapped by the two diaphragms, and then the other of the first pole piece and the second pole piece is compounded on one of the diaphragms, and then wound to form a bare cell. In this way, during the process of winding the composite battery cell strip into a bare battery cell, the folding of the diaphragm edge that exceeds the side of the first pole piece and / or the diaphragm edge that exceeds the side of the second pole piece can be eliminated, so that the first pole piece and the second pole piece are well insulated and separated by the diaphragm, thereby eliminating the problem of low voltage of the battery caused by overlapping the first pole piece and the second pole piece, which helps to improve the product yield of the battery.

[0070] In the embodiment of the present application, the two diaphragms are respectively a first diaphragm 11 and a second diaphragm 13. Furthermore, one of the first pole piece and the second pole piece is a first pole piece 12, and the other of the first pole piece and the second pole piece is a second pole piece 15. In the following, the positive pole piece is the first pole piece 12, and the negative pole piece is the second pole piece 15 for description.

[0071] like Figure 3 and Figure 4As shown, the electrode sheet composite device 100 provided in the embodiment of the present application includes a first composite roller assembly 20 and a side diaphragm composite assembly 30, wherein the first composite roller assembly 20 includes a first composite roller 21 and a second composite roller 22. The first composite roller 21 and the second composite roller 22 are arranged opposite to each other, and the first composite roller 21 and the second composite roller 22 rotate synchronously, and the first composite roller 21 and the second composite roller 22 rotate in opposite directions. The first composite roller 21 and the second composite roller 22 are used to laminate the first diaphragm 11, the first electrode sheet 12 and the second diaphragm 13 in sequence, that is, the first diaphragm 11, the first electrode sheet 12 and the second diaphragm 13 are laminated in sequence, and then rolled by the first composite roller 21 and the second composite roller 22, so that the first diaphragm 11, the first electrode sheet 12 and the second diaphragm 13 are laminated together to obtain a composite material strip 14. In the composite material strip 14, the edge areas on both sides of the first diaphragm 11 and the edge areas on both sides of the second diaphragm 13 exceed the side edges of the first electrode sheet 12. Then, the side membrane composite assembly 30 composites the edge area of ​​the first membrane 11 and the edge area of ​​the second membrane 13 beyond one side of the first electrode piece 12, and the side membrane composite assembly 30 composites the edge area of ​​the first membrane 11 and the edge area of ​​the second membrane 13 beyond the other side of the first electrode piece 12, so that the first membrane 11 and the second membrane 13 wrap the first electrode piece 12. In this way, in the subsequent processes including but not limited to the winding process and other processes after winding, the problem of the first membrane and / or the second membrane loosening from the first electrode piece and causing the membrane to fold can be avoided, and the overlap of the first electrode piece and the second electrode piece can be eliminated.

[0072] The electrode composite device 100 provided in the embodiment of the present application performs a composite operation on the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13. Not only are the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 composited together through the first composite roller assembly 20, but also, through the operation of the side diaphragm composite assembly 30, the edge area of ​​the first diaphragm 11 that extends beyond one side of the first electrode piece 12 is composited with the edge area of ​​the second diaphragm 13, and the edge area of ​​the first diaphragm 11 that extends beyond the other side of the first electrode piece 12 is composited with the edge area of ​​the second diaphragm 13, thereby obtaining a composite material strip 14 in which the first diaphragm 11 and the second diaphragm 13 wrap the first electrode piece 12. In this way, when the composite material strip 14 is wound in the subsequent winding process, the edge areas of the first diaphragm 11 and the second diaphragm 13 that extend beyond the two side edges of the first pole piece 12 are not easy to fold even under the action of external force, or even if they are folded, the first pole piece and the second pole piece will not be exposed, and the first pole piece and the second pole piece will not overlap, thereby eliminating the overlap of the first pole piece 12 and the second pole piece 15 in the wound bare battery cell, so that the first pole piece 12 and the second pole piece 15 are well insulated and separated by the first diaphragm 11 or the second diaphragm 13, eliminating the problem of low voltage of the battery caused by the overlap of the first pole piece 12 and the second pole piece 15, and helping to improve the product yield of the battery.

[0073] In some embodiments of the present application, the side diaphragm composite assembly 30 may be located downstream of the first composite roller assembly 20. That is, after the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 are stacked in sequence, a rolling operation is first performed to composite the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 together, and then the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 beyond the two sides of the first pole piece 12 are composited.

[0074] Alternatively, in some other embodiments of the present application, the side diaphragm composite assembly 30 is located upstream of the first composite roller assembly 20. That is, after the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 are stacked in sequence, the edge areas of the first diaphragm 11 and the edge areas of the second diaphragm 13 that extend beyond the two sides of the first pole piece 12 are composited first, and then a rolling operation is performed to composite the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 together.

[0075] In some embodiments of the present application, the first composite roller 21 and / or the second composite roller 22 are heated and then roll-pressed on the first diaphragm 11, the first pole piece 12, and the second diaphragm 13, i.e., hot pressing composite. Alternatively, the first composite roller 21 and / or the second composite roller 22 are configured to transmit ultrasonic energy and ultrasonically roll-press the first diaphragm 11, the first pole piece 12, and the second diaphragm 13, i.e., ultrasonic composite. Alternatively, the first composite roller 21 and / or the second composite roller 22 roll-press the first diaphragm 11, the first pole piece 12, and the second diaphragm 13 at room temperature, i.e., cold pressing composite.

[0076] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the side diaphragm composite assembly 30 includes an edge roller assembly 31, and the edge areas of the first diaphragm 11 and the edge areas of the second diaphragm 13 that extend beyond the two side edges of the first pole piece 12 are rolled separately by the edge roller assembly 31, thereby rolling and compounding the edge areas of the first diaphragm 11 and the second diaphragm 13 together.

[0077] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, the edge roller assembly 31 includes a first edge roller 311, and the first edge roller 311 corresponds to the side of the first pole piece 12 where the pole ear is not provided. In the process of performing a composite operation on the first diaphragm 11, the first pole piece 12, and the second diaphragm 13, the first edge roller 311 is used to roll and composite the first diaphragm 11 and the second diaphragm 13 that exceed the side of the first pole piece 12. In addition, the edge roller assembly 31 also includes a second edge roller 312, and the second edge roller 312 corresponds to the side of the first pole piece 12 where the pole ear is provided. In the process of performing a composite operation on the first diaphragm 11, the first pole piece 12, and the second diaphragm 13, the second edge roller 312 is used to roll and composite the first diaphragm 11 and the second diaphragm 13 that exceed the side of the first pole piece 12. In this way, in the composite material strip 14 obtained after the composite operation is completed, the first diaphragm 11 and the second diaphragm 13 wrap the first pole piece 12. When the composite material strip 14 is wound in the subsequent winding process, the edge areas of the first diaphragm 11 and the second diaphragm 13 that extend beyond the two side edges of the first pole piece 12 are not easy to fold even under the action of external force, or even if they are folded, the first pole piece and the second pole piece will not be exposed, and the first pole piece and the second pole piece will not overlap.

[0078] like Figures 3 to 5As shown, in some embodiments of the present application, only the first side roller 311 includes the first gear roller 313 and the bearing portion 315, and the first gear roller 313 and the bearing portion 315 are arranged opposite to each other. The bearing portion 315 supports the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 that extend beyond the side of the first pole piece 12, and then the tooth top of the first convex tooth 314 of the first gear roller 313 presses the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 against the bearing portion 315, thereby combining the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 together. At this time, the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 are discontinuous, and the first diaphragm 11 and the second diaphragm 13 are combined through multiple spaced connection positions. Furthermore, there is a position without composite adhesion between two adjacent connection positions. In the manufactured battery, when the bare cell is immersed in the electrolyte, the electrolyte can penetrate through the gap between the first diaphragm 11 and the second diaphragm 13 without composite adhesion, thereby quickly wetting the first pole piece 12 and the second pole piece 15, thereby improving the electrolyte wetting efficiency.

[0079] like Figure 3 and Figure 4 As shown, in some embodiments of the present application, only the second side roller 312 includes the first gear roller 313 and the bearing portion 315, and the first gear roller 313 and the bearing portion 315 are arranged opposite to each other. The bearing portion 315 supports the edge area of ​​the first diaphragm 11, the edge area of ​​the second diaphragm 13, and each first pole lug 121 beyond the side of the first pole piece 12, and then the tooth top of the first convex tooth 314 presses the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 between two adjacent first pole lugs 121 against the bearing portion 315, thereby compounding the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 together. At this time, the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 corresponding to the first pole lug 121 are not compound-adhered to the first pole lug 121, so that the electrolyte can pass through to infiltrate the first pole piece 12 and the second pole piece 15, thereby improving the electrolyte infiltration efficiency.

[0080] like Figures 3 to 5 As shown, in some embodiments of the present application, in order to further improve the wetting efficiency of the electrolyte in the first pole piece 12 and the second pole piece 15 , the first side roller 311 and the second side roller 312 both include a first gear roller 313 and a load-bearing portion 315 .

[0081] In some embodiments of the present application, the load-bearing portion 315 may be, but is not limited to, set as a second gear roller, a bearing workbench, etc. When the load-bearing portion 315 is set as a second gear roller, the first gear roller 313 and the second gear roller rotate synchronously, the first gear roller 313 and the second gear roller rotate in opposite directions, and the synchronous rotation of the first gear roller 313 and the second gear roller can also provide a driving force for the composite material strip 14 to move backward, thereby improving the composite work efficiency. In the process of synchronous rotation of the first gear roller 313 and the second gear roller, the first convex teeth 314 of the first gear roller 313 and the second convex teeth 316 of the second gear roller squeeze the first diaphragm 11 and the second diaphragm 13 one by one.

[0082] In some embodiments of the present application, the second side roller 312 includes a first gear roller 313, and the pitch between two adjacent first convex teeth 314 in the first gear roller 313 is greater than or equal to the width of the first pole ear 121 of the first pole piece 12. The first convex teeth 314 of the first gear roller 313 are used to roll and laminate the first diaphragm 11 and the second diaphragm 13 located between the two adjacent first pole ears 121. Correspondingly, when the load-bearing portion 315 is set as a second gear roller, the pitch between two adjacent second convex teeth 316 in the second gear roller is greater than or equal to the width of the first pole ear 121 of the first pole piece 12, and during the rotation of the first gear roller 313 and the second gear roller, the center of each first convex tooth 314 and the center of each second convex tooth 316 can be arranged opposite to each other in a one-to-one correspondence. Since the pitch between two adjacent first protruding teeth 314 is greater than or equal to the width of the first pole ear 121 of the first pole piece 12, and the pitch between two adjacent second protruding teeth 316 is greater than or equal to the width of the first pole ear 121 of the first pole piece 12, the first protruding teeth 314 and the second protruding teeth 316 can avoid the first pole ears 121 of the first pole piece 12, avoiding the first pole ears 121 from being squeezed and deformed or even broken. Moreover, when the first protruding teeth 314 and the second protruding teeth 316 avoid the first pole ears 121, the first diaphragm 11 and the second diaphragm 13 opposite to the first pole ears 121 are not composited on the first pole ears 121. That is, there is a gap between the first pole ear 121 and the first diaphragm 11 corresponding thereto, and there is a gap between the first pole ear 121 and the second diaphragm 13 corresponding thereto. In the manufactured battery, when the bare cell is immersed in the electrolyte, the electrolyte can penetrate through these gaps, thereby quickly wetting the first pole piece 12 and the second pole piece 15, thereby improving the electrolyte wetting efficiency. Optionally, the pitch between two adjacent second convex teeth 316 in the second gear roller is equal to the pitch between two adjacent first convex teeth 314 in the first gear roller 313.

[0083] In addition, in some other embodiments of the present application, the tooth width of the second convex teeth 316 is greater than the tooth width of the first convex teeth 314, and the tooth pitch between two adjacent second convex teeth 316 in the second gear roller is less than the tooth pitch between two adjacent first convex teeth 314 in the first gear roller 313. Moreover, during the rotation of the first gear roller 313 and the second gear roller, the center of each first convex tooth 314 and the center of each second convex tooth 316 can be arranged in a one-to-one correspondence. In this way, the first convex teeth 314 and the second convex teeth 316 not only roll and compositely bond the first diaphragm 11 and the second diaphragm 13 between two adjacent first pole tabs 121 together, but also, compared with the situation that the tooth pitch between two adjacent first convex teeth 314 is equal to the tooth pitch between two adjacent second convex teeth 316 and the tooth width of the first convex teeth 314 is equal to the tooth width of the second convex teeth 316, the spacing distance between two adjacent composite bonding positions can be increased, that is, the spacing opening for electrolyte immersion is increased, so that the electrolyte can quickly infiltrate the first pole piece 12, and the electrolyte infiltration efficiency is improved.

[0084] Alternatively, in some other embodiments of the present application, the tooth width of the second convex teeth 316 is smaller than the tooth width of the first convex teeth 314, and the tooth pitch between two adjacent second convex teeth 316 in the second gear roller is larger than the tooth pitch between two adjacent first convex teeth 314 in the first gear roller 313. Moreover, during the rotation of the first gear roller 313 and the second gear roller, the center of each first convex tooth 314 and the center of each second convex tooth 316 can be arranged in a one-to-one correspondence. In this way, the first convex teeth 314 and the second convex teeth 316 not only roll and compositely bond the first diaphragm 11 and the second diaphragm 13 between two adjacent first pole tabs 121 together, but also, compared with the situation that the tooth pitch between two adjacent first convex teeth 314 is equal to the tooth pitch between two adjacent second convex teeth 316 and the tooth width of the first convex teeth 314 is equal to the tooth width of the second convex teeth 316, the spacing distance between two adjacent composite bonding positions can be increased, that is, the spacing opening for electrolyte immersion is increased, so that the electrolyte can quickly infiltrate the first pole piece 12, and the electrolyte infiltration efficiency is improved.

[0085] In some embodiments of the present application, the first gear roller 313 and the bearing part 315 are heated and then roll-pressed on the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13, which is hot pressing compounding. Alternatively, the first gear roller 313 and the bearing part 315 are configured to transmit ultrasonic energy, and ultrasonically roll-press the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13, which is ultrasonic compounding. Alternatively, the first gear roller 313 and the bearing part 315 roll-press the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 at room temperature, which is cold pressing compounding.

[0086] In some embodiments of the present application, the first gear roller 313 and the load-bearing part 315 are replaced by round rollers, and the edge areas of the first diaphragm 11 and the second diaphragm 13 that extend beyond the side of the first pole piece 12 are continuously rolled, so that the electrolyte can pass through the micropores of the first diaphragm 11 and the second diaphragm 13, and then the electrolyte can infiltrate the first pole piece 12, so that the electrochemical reaction can be carried out normally to generate electrical energy.

[0087] like Fig.11 As shown, in some embodiments of the present application, the side diaphragm composite assembly 30 further includes a glue coating mechanism 32, and the glue coating mechanism 32 is used to apply glue between the first diaphragm 11 and the second diaphragm 13 beyond the side of the first pole piece 12. Figure 3-4 and Fig.11 As shown, the first side roller 311 and / or the second side roller 312 include a first round roller 317 and a bearing portion 315, and the first round roller 317 and the bearing portion 315 are arranged opposite to each other, and the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 beyond the side of the first electrode piece 12 are continuously rolled by the first round roller 317 and the bearing portion 315, so that the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 are quickly bonded and compounded together. At this time, the electrolyte can pass through the micropores of the first diaphragm 11 and the second diaphragm 13, and then the electrolyte can infiltrate the first electrode piece 12, so that the electrochemical reaction is carried out normally to generate electric energy.

[0088] When the side diaphragm composite assembly 30 is located downstream of the first composite roll assembly 20, as shown in FIG. Figure 4 As shown, the glue coating mechanism 32 is located between the first round roller 317 and the first composite roller assembly 20; when the side diaphragm composite assembly 30 is located upstream of the first composite roller assembly 20, as shown in FIG. Figure 3 As shown, the glue coating mechanism 32 is located on the side of the first round roller 317 away from the first composite roller assembly 20. In the following, the side diaphragm composite assembly 30 is located downstream of the first composite roller assembly 20 as an example.

[0089] In some embodiments of the present application, only the first side roller 311 includes the first round roller 317 and the load-bearing portion 315. On the side of the first pole piece 12 where the first pole ear 121 is not provided, the load-bearing portion 315 supports the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 that extend beyond the side of the first pole piece 12. Since glue has been applied between the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13, and the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 are continuously rolled by the first round roller 317, the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 are continuously rolled and bonded together by the composite glue.

[0090] In some embodiments of the present application, only the second side roller 312 includes the first round roller 317 and the load-bearing portion 315. On the side of the first pole piece 12 where the first pole ear 121 is provided, the load-bearing portion 315 supports the edge area of ​​the first diaphragm 11, the edge area of ​​the second diaphragm 13, and each first pole ear 121 beyond the side of the first pole piece 12, and the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 beyond the first pole piece 12 between two adjacent first pole ears 121 have been coated with glue, and are continuously rolled by the first round roller 317, so that the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 are continuously rolled and bonded together by the composite glue.

[0091] In some embodiments of the present application, the first side roller 311 and the second side roller 312 both include a first round roller 317 and a load-bearing portion 315, which can simplify the coordination layout of the first side roller 311 and the second side roller 312 and reduce the overall cost of the pole piece composite device.

[0092] In some embodiments of the present application, the force bearing part 315 can be, but is not limited to, set as a second round roller, a bearing workbench, etc. When the force bearing part 315 is set as a second round roller, the second round roller rotates synchronously with the first round roller 317, and the first round roller 317 rotates in opposite directions to the second round roller. In addition, the synchronously moving first round roller 317 and second round roller can also provide a driving force for the composite material strip 14 to move backward, thereby improving the composite work efficiency.

[0093] like Fig.11 As shown, in some embodiments of the present application, the side diaphragm composite assembly 30 further includes an ultraviolet lamp 33, which is located downstream of the first circular roller 317. Accordingly, ultraviolet curing UV glue (UV is the abbreviation of Ultra-Violet ray, which refers to ultraviolet light) is applied between the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 beyond the side of the first pole piece 12. After the glue between the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 beyond the side of the first pole piece 12 is rolled by the first circular roller 317 and the second circular roller, the glue between the first diaphragm 11 and the second diaphragm 13 beyond the side of the first pole piece 12 is irradiated by the ultraviolet lamp 33, which helps to increase the curing rate of the glue, so as to improve production efficiency.

[0094] like Figures 6 to 10As shown, in some embodiments of the present application, the electrode composite device 100 further includes a first conveying roller 41, which is located upstream of one of the first composite roller 21 and the second composite roller 22 and is spaced therefrom; and / or, the electrode composite device 100 further includes a second conveying roller 42, which is located upstream of the other of the first composite roller 21 and the second composite roller 22 and is spaced therefrom. Hereinafter, the electrode composite device 100 is described by taking "the electrode composite device 100 is provided with a first conveying roller 41 and a second conveying roller 42 at the same time; the first conveying roller 41 is located upstream of the first composite roller 21 and is spaced therefrom, and the second conveying roller 42 is located upstream of the second composite roller 22 and is spaced therefrom" as an example, and the remaining embodiments are described in combination with the example description. The first diaphragm 11 is lapped around the first conveying roller 41 to be obliquely conveyed between the first composite roller 21 and the second composite roller 22. The second diaphragm 13 is lapped around the second conveying roller 42 to be obliquely conveyed between the first composite roller 21 and the second composite roller 22. The first electrode piece 12 is horizontally conveyed between the first diaphragm 11 and the second diaphragm 13 between the first composite roller 21 and the second composite roller 22. The first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 are rolled and compounded together by the rolling action of the first composite roller 21 and the second composite roller 22. In this way, when the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 are conveyed between the first composite roller 21 and the second composite roller 22 for stacking and rolling compounding, the conveying paths of the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 do not interfere with each other, so that the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 can be conveyed smoothly.

[0095] like Fig.12 As shown, in some embodiments of the present application, the electrode composite device 100 further includes a first cutting mechanism 44, which is located upstream of the first composite roller assembly 20, and the first cutting mechanism 44 is used to cut the first electrode 12. In each wound bare cell, the length of the first electrode 12 is a calculated first predetermined length, so the first electrode 12 is cut by the first cutting mechanism 44 after being conveyed to the first predetermined length. After the first electrode 12 is cut by the first cutting mechanism 44, the first electrode 12 stops conveying for a period of time, and the first diaphragm 11 and the second diaphragm 13 are always conveyed, thereby obtaining a blank section where the first diaphragm 11 and the second diaphragm 13 are directly rolled and composited (that is, there is no first electrode 12 in the blank section), and the length of the blank section is also a calculated preset length. Then, the first electrode 12 continues to be conveyed, and the first composite roller 21 and the second composite roller 22 continue to roll and composite to obtain the composite material strip 14.

[0096] like Fig.12As shown, in some embodiments of the present application, the electrode composite device 100 also includes a first detection mechanism 45, which is located between the first cutting mechanism 44 and the first composite roller assembly 20. The first detection mechanism 45 is used to detect the conveying length of the first electrode 12, that is, the first detection mechanism 45 detects the first electrode 12 of the first predetermined length. The first detection mechanism 45 is electrically connected to the first cutting mechanism 44. Therefore, when the first detection mechanism 45 detects the first predetermined length of the first electrode 12, the first detection mechanism 45 sends a signal, and the first cutting mechanism 44 cuts the first electrode 12 according to the signal, thereby cutting off the first electrode 12 of the first predetermined length. The first detection mechanism 45 and the first cutting mechanism 44 realize the automatic cutting function of the first electrode 12, improve the degree of automation, and improve production efficiency.

[0097] According to another aspect of the embodiment of the present application, a bare cell winding device is provided, such as Fig.12 As shown. The bare cell winding device includes a pole piece composite device, a second composite roller assembly 50 and a winding mechanism 61. Specifically, the pole piece composite device is the aforementioned pole piece composite device 100 of the present application. The pole piece composite device 100 outputs a composite material strip 14. The second composite roller assembly 50 is located downstream of the pole piece composite device. The second composite roller assembly 50 includes a third composite roller 51 and a fourth composite roller 52. The third composite roller 51 and the fourth composite roller 52 are arranged opposite to each other, and the third composite roller 51 and the fourth composite roller 52 rotate synchronously. The third composite roller 51 and the fourth composite roller 52 rotate in opposite directions. The third composite roller 51 and the fourth composite roller 52 are used to composite the second pole piece 15 on one of the first diaphragm 11 and the second diaphragm 13 to output the battery cell strip 10. The winding mechanism 61 is located downstream of the second composite roller assembly 50. The winding mechanism 61 winds the battery cell strip 10 into a bare cell.

[0098] The electrode composite device 100 provided by the embodiment of the present application performs a composite operation on the first diaphragm 11, the first electrode 12 and the second diaphragm 13, not only the first composite roller assembly 20 composites the first diaphragm 11, the first electrode 12 and the second diaphragm 13 together, but also the side diaphragm composite assembly 30 works to composite the edge area of ​​the first diaphragm 11 beyond one side of the first electrode 12 with the edge area of ​​the second diaphragm 13, and the edge area of ​​the first diaphragm 11 beyond the other side of the first electrode 12 with the edge area of ​​the second diaphragm 13 together, thereby obtaining a composite material strip 14 in which the first diaphragm 11 and the second diaphragm 13 wrap the first electrode 12. Then, the second electrode 15 is rolled and composited on the first diaphragm 11 or the second diaphragm 13 of the composite material strip 14 by the second composite roller assembly 50, and then a winding operation is performed to wind up a bare battery cell. During the winding process, the edge areas of the first diaphragm 11 and the second diaphragm 13 that extend beyond the two side edges of the first pole piece 12 will no longer fold over even under the action of external force, thereby eliminating the overlap of the first pole piece 12 and the second pole piece 15 in the wound bare battery cell, so that the first pole piece 12 and the second pole piece 15 are well insulated and separated by the first diaphragm 11 or the second diaphragm 13, eliminating the low voltage problem of the battery caused by the overlap of the first pole piece 12 and the second pole piece 15, which helps to improve the product yield of the battery.

[0099] like Fig.12 As shown, in some embodiments of the present application, the bare cell winding device also includes a second detection mechanism 62 and a pressing mechanism 63. The second detection mechanism 62 is located upstream of the second composite roller assembly 50, and the second detection mechanism 62 can be used to detect the preset length of the end of the first pole piece 12 passing through the pressing mechanism 63. The second detection mechanism 62 is electrically connected to the pressing mechanism 63. When the second detection mechanism 62 detects that the end of the first pole piece 12 has passed a preset length relative to the pressing mechanism 63, the second detection mechanism 62 sends a signal to the pressing mechanism 63, and the pressing mechanism 63 presses the end of the second pole piece 15 against the first diaphragm 11 or the second diaphragm 13 of the composite material strip 14 according to the signal. Through the cooperation of the second detection mechanism 62 and the pressing mechanism 63, the end of the second pole piece 15 can be accurately and quickly pressed against the composite material strip 14, so that the center distance between the first pole ear 121 of the first pole piece 12 and the second pole ear of the second pole piece 15 is accurately determined, thereby improving production efficiency.

[0100] Furthermore, after the second pole piece 15 is composited on the composite material strip 14, the center distance between the first pole tab 121 and the second pole tab is fixed. Even during the winding process, the center distance between the first pole tab 121 and the second pole tab does not change. This improves the product quality of the bare cell, and then improves the product quality of the produced battery.

[0101] In some related technologies, such as Figure 1 As shown, the first pole piece and a diaphragm are compounded together by a compound roller 300 to form a first composite material strip 301, and the edge areas on both sides of the diaphragm exceed the side edges of the first pole piece; the second pole piece and another diaphragm are also compounded together by another compound roller 300 to form a second composite material strip 302, and the edge areas on both sides of the diaphragm exceed the side edges of the second pole piece. Then, the first composite material strip 301 and the second composite material strip 302 are stacked through the winding mechanism 61, so as to be wound into a bare battery cell. However, during the winding process, when the running length of the first composite material strip 301 reaches a predetermined length, the first pole piece of the first composite material strip 301 will be cut off but the diaphragm will not be cut off, the winding mechanism 61 will continue to rotate, and the diaphragm will continue to be transported, and the first pole piece will stop being transported for a period of time so that the head end of the first pole piece of the next section is spaced from the tail end of the first pole piece of the previous section by one end. At this time, the blank section of the diaphragm is stretched and deformed by the pulling of the winding mechanism 61. Similarly, when the running length of the second composite material strip 302 reaches a predetermined length, the second pole piece will be cut off, and the blank section of the diaphragm will also be stretched and deformed by being pulled by the winding mechanism 61. When the elongation of the blank section of the diaphragm of the first composite material strip 301 and the elongation of the blank section of the diaphragm of the second composite material strip 302 are not equal, the center distance between the subsequent pole ear of the first pole piece and the pole ear of the second pole piece will be offset and changed, and the center distance cannot be kept consistent.

[0102] like Fig.12 As shown, in some embodiments of the present application, the bare cell winding device further includes a second cutting mechanism 64, which is located upstream of the pressing mechanism 63, and the second cutting mechanism 64 is located downstream of the second detection mechanism 62 (i.e., the second cutting mechanism 64 is located between the second detection mechanism 62 and the pressing mechanism 63). In each wound bare cell, the length of the second pole piece 15 is a calculated second predetermined length, so the second pole piece 15 is cut off by the second cutting mechanism 64 when the second detection mechanism 62 detects the predetermined conveying length (i.e., the second predetermined length) of the second pole piece 15. The second cutting mechanism 64 is electrically connected to the second detection mechanism 62, that is, when the second detection mechanism 62 detects the second predetermined length of the second pole piece 15, the second detection mechanism 62 sends a signal to the second cutting mechanism 64, and then the second cutting mechanism 64 cuts off the second pole piece 15 according to the signal. After the second pole piece 15 is cut by the second cutting mechanism 64, the second pole piece 15 stops conveying for a period of time to correspond to the blank section where the first diaphragm 11 and the second diaphragm 13 are directly compounded.

[0103] Furthermore, the second detection mechanism 62 is electrically connected to the first detection mechanism 45. When the first detection mechanism 45 detects the first predetermined length of the first electrode piece 12 and sends a signal to the first cutting mechanism 44, the first detection mechanism 45 also sends a signal to the second detection mechanism 62 that the first cutting mechanism 44 performs a cutting operation, thereby interactively communicating with the second detection mechanism 62 to determine that the previous process is being performed normally and correctly, and then the second detection mechanism 62 sends a signal to the second cutting mechanism 64 when the second predetermined length of the second electrode piece 15 is detected. When the first detection mechanism 45 does not send a signal to the second detection mechanism 62 for a long time, the second detection mechanism 62 predicts that the first detection mechanism 45 has a fault, thereby issuing an alarm to prompt the staff to perform maintenance on the first detection mechanism 45. Furthermore, the second cutting mechanism 64 is electrically connected to the first detection mechanism 45, so that the first detection mechanism 45 serves as a backup for the second detection mechanism 62. When the second detection mechanism 62 fails (that is, the second detection mechanism 62 does not send a signal to the first detection mechanism 45 within the predetermined time), the first detection mechanism 45 predicts that the second detection mechanism 62 has failed. At this time, the first detection mechanism 45 sends an alarm to prompt the staff to inspect and maintain the second detection mechanism 62, and the first detection mechanism 45 sends a signal to the second cutting mechanism 64. The second cutting mechanism 64 cuts off the second pole piece 15 according to the signal sent by the first detection mechanism 45, thereby obtaining a second pole piece 15 of a second predetermined length.

[0104] like Fig.12 As shown, in some embodiments of the present application, the bare cell winding device further includes a third conveyor roller 43, and the third conveyor roller 43 is located upstream of the second detection mechanism 62. The second pole piece 15 is wrapped around the third conveyor roller 43, so that the second pole piece 15 is obliquely conveyed to the pressing mechanism 63, so that the second pole piece 15 can always be smoothly conveyed, thereby improving production efficiency. In addition, the incoming material position of the second pole piece 15 (i.e., the placement position for storing the second pole piece 15) is reasonably arranged through the third conveyor roller 43, thereby optimizing the utilization of the plant space.

[0105] like Fig.12As shown, in some embodiments of the present application, the bare cell winding device also includes a stripping guide roller 65, which is located downstream of the second composite roller assembly 50, and the stripping guide roller 65 is used to peel off the release film 16 of the electrostatic protective film composited on the second pole piece 15. In the process of composite the second pole piece 15 on the first diaphragm 11 or the second diaphragm 13 of the composite material strip 14, the electrostatic protective film is composited on the second pole piece 15 at the same time. Among them, the electrostatic protective film is attached to the release film 16. The side of the electrostatic protective film facing away from the release film 16 is fixed on the second pole piece 15, and then fixed on the pressing mechanism 63. At this time, the release film 16, the electrostatic protective film and the second pole piece 15 are stacked on the pressing mechanism 63 in sequence. After the release film 16 passes through the third composite roller 51 and the fourth composite roller 52, the release film 16 is wrapped around the stripping guide roller 65, so that the release film 16 is separated from the electrostatic protective film upward, and the release film 16 is quickly peeled off, thereby improving production efficiency.

[0106] According to another aspect of the embodiments of the present application, a bare cell winding method is provided, such as Fig.13 The bare cell winding method includes the following core steps:

[0107] Step S10: laminating the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 in sequence, thereby obtaining a composite material strip 14;

[0108] Step S20: Compounding the second pole piece 15 on one of the first diaphragm 11 and the second diaphragm 13 of the composite material strip 14 to form the battery core material strip 10. At this time, the center distance between the first pole tab 121 of the first pole piece 12 on the battery core material strip 10 and the second pole tab of the second pole piece 15 is fixed;

[0109] Step S40: The battery cell strip 10 is wound to form a bare battery cell. Since the center distance between the first pole ear 121 of the first pole sheet 12 and the second pole ear of the second pole sheet 15 on the battery cell strip 10 is fixed, the center distance between the first pole ear 121 and the second pole ear of the battery cell strip 10 will no longer be offset and enlarged during the winding process, thereby effectively improving the product quality of the bare battery cell.

[0110] In the related art, the compounding process and the winding process are combined and operated together, such as Figure 1As shown, the first electrode sheet and a diaphragm are combined together by a composite roller to form a first composite material strip, and the edge areas on both sides of the diaphragm exceed the side edges of the first electrode sheet; the second electrode sheet and another diaphragm are also combined together by a composite roller to form a second composite material strip. After the first composite material strip is wound by the winding mechanism, the starting end of the second composite material strip is then conveyed to the winding mechanism. Since the starting end of the second composite material strip is in a free state for a period of time before being conveyed to the winding mechanism (at this time, the starting end of the second composite material strip becomes the free end A, as shown in FIG. Figure 2 As shown). Therefore, the free end A of the second composite material strip may be swung by the external force during this period (such as the swung free end A caused by the external force of winding correction), resulting in the inability to quickly deliver the free end A to the winding mechanism, thereby affecting the winding work efficiency. In serious cases, the free end A may not be accurately delivered to the winding mechanism, resulting in the scrapping of the wound bare cell, affecting the product quality and production yield of the bare cell. The bare cell winding method provided in the embodiment of the present application is used to wind and form a bare cell. The first diaphragm 11, the first electrode piece 12, the second diaphragm 13 and the second electrode piece 15 are compounded to form a cell strip 10 through steps S10 and S20, and then the winding operation is performed. That is to say, the end of the cell strip 10 formed by the first diaphragm 11, the first electrode piece 12, the second diaphragm 13 and the second electrode piece 15 is fixed on the winding mechanism 61 at one time. Compared with the winding operation of the related art, the problem that the free end A of the second composite material strip is swung under the action of external force, resulting in the free end A cannot be accurately transported to the winding mechanism and accurately aligned with the first composite material strip for winding is eliminated. Not only the winding work efficiency is greatly improved, but also the winding quality of the bare cell is improved, and the product yield of the bare cell is significantly improved.

[0111] like Fig.14As shown, in some embodiments of the present application, before executing step S40, that is, before executing "winding the battery cell strip 10 into a bare battery cell", the bare battery cell winding method also includes step S30: compounding the first diaphragm 11 and the second diaphragm 13 that extend beyond one side of the first pole piece 12; compounding the first diaphragm 11 and the second diaphragm 13 that extend beyond the other side of the first pole piece 12. By compounding the edge area of ​​the first diaphragm 11 that exceeds one side of the first pole sheet 12 with the edge area of ​​the second diaphragm 13, and compounding the edge area of ​​the first diaphragm 11 that exceeds the other side of the first pole sheet 12 with the edge area of ​​the second diaphragm 13, the first diaphragm 11 and the second diaphragm 13 wrap the first pole sheet 12. In this way, when the battery core strip 10 is wound, the edge area of ​​the first diaphragm 11 and the edge area of ​​the second diaphragm 13 that exceed the two side edges of the first pole sheet 12 are not easy to fold even under the action of external force, or even if they are folded, the first and second pole sheets will not be exposed, and the first and second pole sheets will not overlap, thereby eliminating the overlap of the first and second pole sheets 12 and 15 in the wound bare battery cell, so that the first and second pole sheets 12 and 15 are well insulated and separated by the first diaphragm 11 or the second diaphragm 13, eliminating the low voltage problem of the battery caused by the overlap of the first and second pole sheets 12 and 15, which helps to improve the product yield of the battery.

[0112] Wherein: step S30 can be performed after step S20 is completed; or, step S30 can be performed after step S10 is completed and before step S20 is performed, which is a better solution. Fig.14 As shown; alternatively, step S30 can be performed before executing step S10.

[0113] In fact, the bare cell winding method provided by the embodiment design of the present application can be but is not limited to being performed by the above-mentioned bare cell winding equipment provided by the embodiment design of the present application, thereby manufacturing a shaped bare cell, which not only improves the production efficiency of the bare cell, but also improves the product quality and product yield of the bare cell.

[0114] like Fig.12 and Fig.14As shown, in some embodiments of the present application, when executing step S10, that is, when "combining the first diaphragm 11, the first electrode sheet 12 and the second diaphragm 13 in sequence in layers", the bare cell winding method further includes step S11: detecting the first predetermined length of the first electrode sheet 12, and cutting the first electrode sheet 12 according to the first predetermined length. And, when executing step S20, that is, when "combining the second electrode sheet 15 on one of the first diaphragm 11 and the second diaphragm 13 to form the battery strip 10", the bare cell winding method further includes step S21: detecting the second predetermined length of the second electrode sheet 15, and cutting the second electrode sheet 15 according to the second predetermined length. Among them, the first predetermined length is greater than the second predetermined length, and the two end ends of the cut first electrode sheet 12 are both beyond the two end ends of the second electrode sheet 15, which meets the standard requirement that the first electrode sheet is longer than the second electrode sheet in the production of bare cells. The first predetermined length of the first pole piece 12 is detected by the first detection mechanism 45 of the bare cell winding device, and then the first pole piece 12 is cut by the first cutting mechanism 44, so as to obtain the first pole piece 12 of the first predetermined length; and the second predetermined length of the second pole piece 15 is detected by the second detection mechanism 62 of the bare cell winding device, and then the second pole piece 15 is cut by the second cutting mechanism 64, so as to obtain the second pole piece 15 of the second predetermined length. In this way, the automation process of winding the bare cell is greatly improved, and the production efficiency of the bare cell can be greatly improved.

[0115] like Figure 9-10 and Fig.14 As shown, in some embodiments of the present application, before executing step S10, that is, before executing "stacking the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 in sequence", the bare cell winding method also includes step 01: fixing the end of the first pole piece 12 on one of the first diaphragm 11 and the second diaphragm 13.

[0116] The end of the first electrode 12 can be positioned on one of the first diaphragm 11 and the second diaphragm 13 by means of a positioning tape 66. Fig. 9 As shown, one end of the positioning tape 66 is adhered to the end of the first electrode piece 12, and then the other end of the positioning tape 66 is adhered to one of the first diaphragm 11 and the second diaphragm 13, so that the end of the first electrode piece 12 can be positioned. Then, the first diaphragm 11, the first electrode piece 12 and the second diaphragm 13 are sequentially stacked through the first composite roller 21 and the second composite roller 22 to obtain the composite material strip 14 after composite.

[0117] Alternatively, the end of the first electrode 12 may also be positioned on one of the first diaphragm 11 and the second diaphragm 13 by means of the positioning adhesive 67. Fig.10As shown, a positioning adhesive 67 (i.e., glue) is coated on one of the first diaphragm 11 and the second diaphragm 13, and then the end of the first pole piece 12 is adhered and fixed to one of the first diaphragm 11 and the second diaphragm 13 by the positioning adhesive 67, so that the end of the first pole piece 12 can be positioned, and then, the first diaphragm 11, the first pole piece 12 and the second diaphragm 13 are sequentially stacked through the first composite roller 21 and the second composite roller 22, so as to obtain the composite material strip 14 after compounding.

[0118] By positioning the end of the first pole piece 12, the frequency of the first pole piece 12 shifting relative to the first diaphragm 11 and the second diaphragm 13 is reduced or even eliminated during the composite molding of the composite material strip 14, thereby improving the composite work efficiency and the composite quality.

[0119] The bare cell prepared by the pole piece composite device, bare cell winding equipment and bare cell winding method provided by the embodiment design of the present application is applied to battery manufacturing. The prepared lithium battery can be used for but not limited to mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles and spacecrafts, etc.

[0120] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A pole piece composite device, characterized in that: include: A first composite roller assembly, comprising a first composite roller and a second composite roller, wherein the first composite roller and the second composite roller are arranged opposite to each other, and the first composite roller and the second composite roller are used to laminate and composite the first diaphragm, the first pole piece and the second diaphragm in sequence; The side diaphragm composite component is used to composite the portion of the first diaphragm extending beyond the side of the first pole piece with the portion of the second diaphragm extending beyond the side of the first pole piece.

2. The pole piece composite device according to claim 1, characterized in that: The side diaphragm composite assembly includes a first side roller and a second side roller, the first side roller corresponds to the first side of the first pole piece where no pole ear is provided, and the second side roller corresponds to the second side of the first pole piece where the pole ear is provided, the first side roller is used to roll and composite the first diaphragm and the second diaphragm together with their portions exceeding the first side, and the second side roller is used to roll and composite the first diaphragm and the second diaphragm together with their portions exceeding the second side.

3. The pole piece composite device according to claim 2, characterized in that: The first side roller and / or the second side roller comprises a first gear roller and a load-bearing portion, and the first gear roller and the load-bearing portion are arranged opposite to each other.

4. The pole piece composite device according to claim 3, characterized in that: The load-bearing portion is configured as a second gear roller, and the first gear roller and the second gear roller are configured such that during rotation, the convex teeth of the first gear roller and the convex teeth of the second gear roller press the first diaphragm and the second diaphragm in a one-to-one correspondence.

5. The pole piece composite device according to claim 3 or 4, characterized in that: The second side roller comprises a first gear roller, the pitch between two adjacent protruding teeth of the first gear roller is greater than or equal to the width of the pole lug, and the protruding teeth of the first gear roller are used to roll and laminate the first diaphragm and the second diaphragm parts located between two adjacent pole lugs.

6. The pole piece composite device according to claim 2, characterized in that: The side diaphragm composite assembly may be additionally provided with a glue coating mechanism, the first side roller and / or the second side roller comprises a first round roller and a load-bearing part, the first round roller and the load-bearing part are arranged opposite to each other, the glue coating mechanism is located upstream of the first round roller, and the glue coating mechanism is used to apply glue between the parts of the first diaphragm and the second diaphragm that extend beyond the side of the first pole piece.

7. The pole piece composite device according to claim 6, characterized in that: The load-bearing part is configured as a second circular roller, and the second circular roller rotates synchronously with the first circular roller.

8. The pole piece composite device according to claim 6 or 7, characterized in that: The side diaphragm composite assembly may be additionally provided with an ultraviolet lamp, which is located downstream of the first round roller and is used to irradiate the glue-coated parts of the first diaphragm and the second diaphragm.

9. The pole piece composite device according to any one of claims 1 to 8, characterized in that: The electrode composite device further includes a first conveying roller, the first conveying roller is located upstream of one of the first composite roller and the second composite roller and is spaced therefrom, and one of the first diaphragm and the second diaphragm is wrapped around the first conveying roller to be obliquely conveyed between the first composite roller and the second composite roller; And / or, the electrode composite device also includes a second conveying roller, which is located upstream of the other of the first composite roller and the second composite roller and is spaced apart from it, and the other of the first diaphragm and the second diaphragm is wrapped around the second conveying roller to be conveyed obliquely between the first composite roller and the second composite roller.

10. The pole piece composite device according to any one of claims 1 to 9, characterized in that: The pole piece composite device further includes a first cutting mechanism, which is located upstream of the first composite roller assembly and is used to cut off the first pole piece.

11. The pole piece composite device according to claim 10, characterized in that: The electrode sheet composite device further includes a first detection mechanism, which is located between the first cutting mechanism and the first composite roller assembly, and is electrically connected to the first cutting mechanism, and is used to detect the conveying length of the first electrode sheet.

12. A bare cell winding device, characterized in that: include: The pole piece composite device according to any one of claims 1 to 11, wherein the pole piece composite device outputs a composite material strip formed by sequentially stacking and composited the first diaphragm, the first pole piece, and the second diaphragm; A second composite roller assembly, located downstream of the electrode sheet composite device, is used to composite the second electrode sheet onto one of the first diaphragm and the second diaphragm to output the battery core strip; The winding mechanism is located downstream of the second composite roller assembly and is used for winding the battery core material strip to form a bare battery core.

13. The bare cell winding device according to claim 12, characterized in that: The second composite roller assembly includes a third composite roller and a fourth composite roller, the third composite roller and the fourth composite roller are arranged opposite to each other, and the third composite roller and the fourth composite roller are used to composite the second pole piece on one of the first diaphragm and the second diaphragm.

14. The bare cell winding device according to claim 12 or 13, characterized in that: The bare cell winding device also includes a second detection mechanism and a pressing mechanism. The second detection mechanism is located upstream of the second composite roller assembly. The second detection mechanism is electrically connected to the pressing mechanism. The pressing mechanism is used to press the end of the second pole piece against one of the first diaphragm and the second diaphragm.

15. The bare cell winding device according to claim 14, characterized in that: The bare cell winding device also includes a second cutting mechanism, which is located upstream of the pressing mechanism. The second cutting mechanism is electrically connected to the second detection mechanism, and the second cutting mechanism is used to cut off the second pole piece when the second detection mechanism detects a predetermined conveying length of the second pole piece.

16. The bare cell winding device according to claim 15, characterized in that: The bare cell winding device also includes a third conveying roller, which is located upstream of the second cutting mechanism. The second pole piece is wrapped around the third conveying roller so that the second pole piece is conveyed to the pressing mechanism at an angle.

17. The bare cell winding device according to any one of claims 13 to 16, characterized in that: The bare cell winding device may be additionally provided with a film stripping guide roller, wherein the film stripping guide roller is located downstream of the second composite roller assembly, and the film stripping guide roller is used to peel off the release film composited to the second pole piece.

18. A bare cell winding method, characterized in that: The following steps are involved: The first diaphragm, the first pole piece and the second diaphragm are laminated together in sequence; Compounding a second pole piece on one of the first diaphragm and the second diaphragm to form a battery core strip; The battery core material strip is wound to form a bare battery core.

19. The bare cell winding method according to claim 18, characterized in that: Before "winding the battery core material strip into a bare battery core", the bare battery core winding method further includes: combining the first diaphragm and the second diaphragm together at a portion extending beyond the side of the first pole piece.

20. The bare cell winding method according to claim 18 or 19, characterized in that: In the step of “combining the first diaphragm, the first pole piece and the second diaphragm in a stacked manner”, the running length of the first pole piece is detected, and the first pole piece is cut off when the running length reaches a first predetermined length; Furthermore, in the step of "combining the second pole piece on one of the first diaphragm and the second diaphragm to form a battery core strip", the running length of the second pole piece is detected, and the second pole piece is cut off when the running length is a second predetermined length.

21. The bare cell winding method according to claim 20, characterized in that: The first predetermined length is greater than the second predetermined length, and both ends of the first pole piece obtained by cutting are beyond both ends of the second pole piece.

22. The bare cell winding method according to any one of claims 18 to 21, characterized in that: Before the step of "combining the first diaphragm, the first pole piece and the second diaphragm in sequence by stacking them together", the bare cell winding method further includes the step of: fixing the end of the first pole piece on one of the first diaphragm and the second diaphragm.

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