Winding type battery cell production line

Abstract

The utility model provides a winding type battery cell production line which comprises a positive electrode processing device, a negative electrode processing device and a winding device, the positive electrode processing device is used for conveying a positive electrode current collector and processing the positive electrode current collector into a positive plate, and the negative electrode processing device is used for conveying a negative electrode current collector and processing the negative electrode current collector into a negative plate; the winding device is used for winding the positive plate and the negative plate into a winding type battery cell; the positive pole processing device or the negative pole processing device comprises a rewinding mechanism, and pole pieces passing through the rewinding mechanism can be exchanged end to end. Due to the fact that the rewinding device is arranged, the production line can enable the feeding design of the winding device commonly used in the field to be suitable for the pole piece with the improved head and tail positions of the short film face.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a winding type battery core production line. Background Art

[0002] During the charging process of a battery cell, lithium ions are deintercalated from the positive electrode and intercalated into the negative electrode. However, if an abnormal condition occurs and the deintercalated lithium ions cannot be intercalated into the negative electrode, the lithium ions will precipitate onto the surface of the negative electrode, forming a gray layer of material known as lithium plating. Lithium plating not only affects the performance of the battery cell, such as reducing its capacity, but also affects its safety.

[0003] In order to increase the capacity of the battery cell, the existing positive and negative electrode sheets are usually double-sided coated structures, that is, the active material layer is coated on both sides of the current collector, and a long film surface and a short film surface are formed. In addition, after coating, there is often a phenomenon that the tail of the film surface is thin, especially when the negative electrode is double-layer coated, the thinness of the tail of the film surface is more serious. When the existing conventional winding process is used to make a wound battery cell, the tail of the short negative electrode film surface will correspond to the tail of the short positive electrode film surface. Since the tail of the film surface is difficult to be thinned, the unit area capacity of the anode (negative electrode) in the area near the short negative electrode film surface is smaller than the unit area capacity of the cathode (positive electrode), that is, the CB value is less than 1, which leads to lithium deposition at the tail of the anode.

[0004] Currently, it is possible to reduce the risk of lithium plating by changing the head and tail positions of the short film surface of the electrode. However, the winding device in the current battery industry generally adopts a design in which the misaligned end of the anode sheet (negative electrode sheet) enters the winding device first, and the aligned end of the cathode sheet (positive electrode sheet) enters the winding device first. For electrode sheets with improved head and tail positions of the short film surface, how to make such electrode sheets still suitable for the design of universal winding devices is a technical problem that needs to be solved urgently. Utility Model Content

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a wound cell production line that enables the feed design of the winding device commonly used in the field to be adapted to pole pieces with improved head and tail positions of the short film surface.

[0006] According to an embodiment of the present invention, the wound battery cell production line includes: a positive electrode processing device, the positive electrode processing device is used to transport the positive electrode current collector and process the positive electrode current collector into a positive electrode sheet, the positive electrode processing device includes a positive electrode coating mechanism, the positive electrode coating mechanism is used to process a positive electrode active material layer on the surface of the positive electrode current collector; a negative electrode processing device, the negative electrode processing device is used to transport the negative electrode current collector and process the negative electrode current collector into a negative electrode sheet; a winding device, the winding device is used to connect the positive electrode sheet output by the positive electrode processing device and the negative electrode The negative electrode sheet output by the processing device is wound into a wound battery cell; wherein, the positive electrode processing device also includes a rewinding mechanism, which is arranged downstream of the positive electrode coating mechanism and upstream of the winding device, and the rewinding mechanism includes a rewinding roller and a driving source, and the driving source is used to drive the rewinding roller to rotate, and the rewinding roller is used to rewind the positive electrode sheet from the upstream of the rewinding mechanism, and the rewinding roller is also used to unwind the positive electrode sheet to the downstream of the rewinding mechanism, so that the positive electrode sheet passing through the rewinding mechanism is reversed head to tail.

[0007] According to the embodiment of the utility model, the winding battery cell production line has at least the following beneficial effects: one of the "electrode sheets with improved head and tail positions of the short film surface" is a positive electrode sheet in which the positive electrode short head and the negative electrode short tail are correspondingly arranged and the positive electrode short tail and the positive electrode long head are aligned. For this positive electrode sheet, the positive electrode short head leaves the coating mechanism before the positive electrode short tail; accordingly, the misaligned end of the positive electrode sheet leaves the positive electrode coating mechanism before the aligned end of the positive electrode sheet. Assuming that no rewinding mechanism is provided, the misaligned end of the positive electrode sheet will enter the winding device before the aligned end of the positive electrode sheet, which does not conform to the common feeding method in the industry that "the aligned end of the positive electrode sheet (cathode) enters the winding device before the misaligned end of the positive electrode sheet", resulting in the winding device commonly used in this field being unsuitable for the above-mentioned positive electrode sheet. In the case where a rewinding mechanism is provided, under the head-to-tail reversal effect of the rewinding mechanism, the aligned end of the positive electrode will enter the winding device before the misaligned end of the positive electrode, so that the feeding design of the winding device commonly used in this field can be applied to the above-mentioned positive electrode sheet.

[0008] According to some embodiments of the present invention, the positive electrode processing device includes the positive electrode coating mechanism, the positive electrode laser cleaning mechanism, the positive electrode rolling mechanism and the positive electrode slitting mechanism arranged in sequence along the conveying direction of the positive electrode current collector; the rewinding mechanism is configured as follows: the rewinding mechanism is located downstream of the positive electrode coating mechanism and upstream of the positive electrode laser cleaning mechanism; or, the rewinding mechanism is located downstream of the positive electrode laser cleaning mechanism and upstream of the positive electrode rolling mechanism; or, the rewinding mechanism is located downstream of the positive electrode rolling mechanism and upstream of the positive electrode slitting mechanism; or, the rewinding mechanism is located downstream of the positive electrode slitting mechanism.

[0009] According to some embodiments of the present invention, the negative electrode processing device includes a negative electrode coating mechanism, a negative electrode rolling mechanism, a negative electrode stripping mechanism and a negative electrode laser cleaning mechanism, which are sequentially arranged along the conveying direction of the negative electrode current collector.

[0010] According to some embodiments of the present invention, the positive electrode coating mechanism includes a back roller and a coating head, the coating head faces the back roller, the outer peripheral surface of the back roller is used to contact the positive electrode current collector and support the positive electrode current collector, and the coating head is used to spray out the positive electrode active material.

[0011] According to some embodiments of the present invention, the positive electrode laser cleaning mechanism includes multiple lasers, and the lasers emitted by the lasers are used to irradiate a part of the positive electrode active material layer. The multiple lasers are spaced apart along the width direction of the positive electrode sheet, and any two of the width direction, the thickness direction of the positive electrode current collector and the transport direction of the positive electrode current collector are perpendicular to each other.

[0012] According to some embodiments of the present invention, the positive electrode rolling mechanism includes a first pressing roller, a second pressing roller and a pressing roller drive source, the first pressing roller and the second pressing roller are used to clamp the positive electrode sheet, and the pressing roller drive source is used to drive at least one of the first pressing roller and the second pressing roller to move to change the distance between the first pressing roller and the second pressing roller.

[0013] According to some embodiments of the present invention, the positive electrode slitting mechanism includes multiple blades for cutting the positive electrode sheets, and the multiple blades are spaced apart along the width direction of the positive electrode collector, and any two of the width direction, the thickness direction of the positive electrode collector and the conveying direction of the positive electrode collector are perpendicular to each other.

[0014] According to some embodiments of the present invention, the wound battery cell production line includes: a positive electrode processing device, the positive electrode processing device is used to transport the positive electrode current collector and process the positive electrode current collector into a positive electrode sheet; a negative electrode processing device, the negative electrode processing device is used to transport the negative electrode current collector and process the negative electrode current collector into a negative electrode sheet, the negative electrode processing device includes a negative electrode coating mechanism, the negative electrode coating mechanism is used to process a negative electrode active material layer on the surface of the negative electrode current collector; a winding device, the winding device is used to process the positive electrode sheet output by the positive electrode processing device and the negative electrode processing device. The negative electrode sheet output by the processing device is wound into a wound battery cell; wherein the negative electrode processing device also includes a rewinding mechanism, which is arranged downstream of the negative electrode coating mechanism and upstream of the winding device, and the rewinding mechanism includes a rewinding roller and a driving source, and the driving source is used to drive the rewinding roller to rotate, and the rewinding roller is used to rewind the negative electrode sheet from the upstream of the rewinding mechanism, and the rewinding roller is also used to unwind the negative electrode sheet to the downstream of the rewinding mechanism, so that the negative electrode sheet passing through the rewinding mechanism is reversed head to tail.

[0015] According to the winding battery cell production line of the embodiment of the present invention, there are at least the following beneficial effects: one of the "electrode sheets with improved head and tail positions of the short film surface" is: a negative electrode sheet in which the positive electrode short head and the negative electrode short tail are arranged correspondingly and the negative electrode long tail and the negative electrode short head are aligned. For this negative electrode sheet, the negative electrode short head leaves the coating mechanism earlier than the negative electrode short tail. Correspondingly, the aligned end of the negative electrode sheet leaves the coating mechanism earlier than the misaligned end of the negative electrode sheet. Assuming that no rewinding mechanism is provided, the aligned end of the negative electrode sheet will enter the winding device earlier than the misaligned end of the negative electrode sheet. This does not conform to the common feeding method in the industry mentioned above that "the misaligned end of the negative electrode sheet (anode) enters the winding device earlier than the aligned end of the negative electrode sheet", resulting in the winding device commonly used in this field being unsuitable for the above-mentioned negative electrode sheet. In the case where a rewinding mechanism is provided, the aligned end of the negative electrode will enter the winding device before the misaligned end of the negative electrode due to the head-to-tail reversal of the rewinding mechanism, so that the feeding design of the winding device commonly used in this field can be applied to the above-mentioned negative electrode sheet.

[0016] According to some embodiments of the present invention, the negative electrode processing device includes the negative electrode coating mechanism, the negative electrode rolling mechanism, the negative electrode slitting mechanism and the negative electrode laser cleaning mechanism which are arranged in sequence along the conveying direction of the negative electrode current collector; the rewinding mechanism is configured as follows: the rewinding mechanism is located downstream of the negative electrode coating mechanism and upstream of the negative electrode rolling mechanism; or, the rewinding mechanism is located downstream of the negative electrode rolling mechanism and upstream of the negative electrode slitting mechanism; or, the rewinding mechanism is located downstream of the negative electrode slitting mechanism and upstream of the negative electrode laser cleaning mechanism; or, the rewinding mechanism is located downstream of the negative electrode laser cleaning mechanism.

[0017] According to some embodiments of the present invention, the positive electrode processing device includes the positive electrode coating mechanism, the positive electrode laser cleaning mechanism, the positive electrode rolling mechanism and the positive electrode stripping mechanism, which are sequentially arranged along the conveying direction of the positive electrode current collector.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 Schematic diagram of the positive electrode sheet and the negative electrode sheet of the battery cell in the prior art;

[0021] Figure 2 Schematic diagram of the positive electrode sheet and the negative electrode sheet of the battery cell in the first embodiment of the present utility model;

[0022] Figure 3 Schematic diagram of the positive electrode sheet and the negative electrode sheet of the battery cell in the second embodiment of the present utility model;

[0023] Figure 4 This is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic cross-sectional view of a battery cell according to another embodiment of the present invention;

[0025] Figure 6 Schematic diagram of a wound battery cell production line in one embodiment of the present invention;

[0026] Figure 7 A schematic diagram of a process in which a positive electrode sheet is transported to a winding device without being reversed end to end;

[0027] Figure 8 Schematic diagram of the process of transporting the positive electrode sheet to the winding device after being reversed end to end;

[0028] Figure 9 This is a schematic diagram of a wound battery cell production line in another embodiment of the present invention.

[0029] Figure 10 A schematic diagram of a process in which a negative electrode sheet is conveyed to a winding device without being reversed end to end;

[0030] Figure 11 Schematic diagram of the process when the negative electrode sheet is transported to the winding device after being reversed head to tail.

[0031] Reference numerals:

[0032] 100-battery cell, 101-positive electrode sheet, 102-negative electrode sheet, 103-insulating separator;

[0033] 201 - positive electrode current collector, 202 - second positive electrode active material layer, 203 - first positive electrode active material layer, 204 - positive electrode long end, 205 - positive electrode long tail, 206 - positive electrode short end, 207 - positive electrode short tail, 208 - positive electrode ear welding groove, 209 - first surface, 210 - second surface;

[0034] 301 - negative electrode current collector, 302 - second negative electrode active material layer, 303 - first negative electrode active material layer, 304 - negative electrode long head, 305 - negative electrode long tail, 306 - negative electrode short head, 307 - negative electrode short tail, 308 - negative electrode ear welding groove, 309 - third surface;

[0035] 400-production line, 401-positive electrode processing device, 402-negative electrode processing device, 403-winding device, 404-positive electrode coating mechanism, 405-positive electrode rolling mechanism, 406-positive electrode slitting mechanism, 407-positive electrode laser cleaning mechanism, 408-rewinding mechanism, 409-rewinding roller, 410-coating head, 411-back roller, 412-laser, 413-blade, 414-first pressing roller, 415-second pressing roller, 416-negative electrode coating mechanism, 417-negative electrode slitting mechanism, 418-negative electrode laser cleaning mechanism, 419-negative electrode rolling mechanism, 420-positive electrode alignment end, 421-positive electrode misalignment end, 422-negative electrode alignment end, 423-negative electrode misalignment end. DETAILED DESCRIPTION

[0036] The following describes embodiments of the present invention in detail. 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 only to explain the present invention and are not to be construed as limiting the present invention.

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention 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. Therefore, they cannot be understood as limitations on the present invention.

[0038] In the description of this utility model, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of the terms "first" and "second" is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0039] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0040] The following first introduces the terms mentioned in this application and the common designs in electrode or battery production.

[0041] (1) Short membrane surface: Among the two active material layers of the electrode, the shorter active material layer is the short membrane surface.

[0042] (2) Long film surface: Among the two active material layers of the electrode, the longer active material layer is the long film surface.

[0043] (3) Alignment end of the electrode: At the alignment end of the electrode, the short membrane surface and the long membrane surface are aligned with each other. For example, for Figure 2 In the positive electrode sheet 101 shown, the left end of the short film surface (first positive electrode active material layer 203) and the left end of the long film surface (second positive electrode active material layer 202) are aligned, and the aligned end of the positive electrode sheet 101 is the left end of the positive electrode sheet 101. Figure 2 In the negative electrode sheet 102 shown, the right end of the short film surface (first negative electrode active material layer 303 ) and the right end of the long film surface (second negative electrode active material layer 302 ) are aligned, and the aligned end of the negative electrode sheet 102 is the right end of the negative electrode sheet 102 .

[0044] (4) Displacement end of the pole piece: At the displaced end of the pole piece, the short film surface and the long film surface are staggered. For example, Figure 2 In the positive electrode sheet 101 shown, the right end of the short film surface and the right end of the long film surface are staggered, and the staggered end of the positive electrode sheet 101 is the right end of the positive electrode sheet 101. Figure 2 In the negative electrode sheet 102 shown, the left end of the short film surface and the left end of the long film surface are aligned, and the offset end of the negative electrode sheet 102 is the left end of the negative electrode sheet 102 .

[0045] (5) The commonly used order of double-sided coating of the electrode is: first, the active material is coated on one side of the current collector to form a long film surface, and then the active material is coated on the other side of the current collector to form a short film surface.

[0046] (6) Common feeding method of the winding device: the misaligned end of the negative electrode sheet 102 (anode) enters the winding device 403 before the aligned end of the negative electrode sheet 102, and the aligned end of the positive electrode sheet 101 (cathode) enters the winding device 403 before the misaligned end of the positive electrode sheet 101. Accordingly, for a wound battery cell that has been processed, the misaligned end of the negative electrode sheet 102 and the aligned end of the positive electrode sheet 101 are at the center of the wound battery cell, and the aligned end of the negative electrode sheet 102 and the misaligned end of the positive electrode sheet 101 are at the periphery of the wound battery cell.

[0047] The above-mentioned order of double-sided coating of the electrode sheet and the feeding method of the winding device are both common designs in the prior art. This application does not change these designs, and this application does not require changing the structure of the coating mechanism and the winding device 403. In order to make the improved electrode sheet still suitable for the common coating equipment and winding device 403 in the prior art, this application adds a rewinding mechanism 408 on the basis of the existing technology. In this application, the current collector that has passed through the coating mechanism and is coated with the active material layer is called a electrode sheet.

[0048] To facilitate the introduction of the wound battery cell production line of the present application, the following first introduces the pole pieces in the prior art and the pole pieces that need to be processed and handled by the wound battery cell production line of the present application.

[0049] Figure 1 The figure shows the positive electrode sheet 101 and negative electrode sheet 102 of a battery cell 100 in the prior art. The positive electrode sheet 101 includes a positive electrode current collector 201 and two positive electrode active material layers extending in the same direction. The two positive electrode active material layers are a second positive electrode active material layer 202 and a first positive electrode active material layer 203. The positive electrode current collector 201 includes a first surface 209 and a second surface 210 facing each other. The second positive electrode active material layer 202 is disposed on the first surface 209, and the first positive electrode active material layer 203 is disposed on the second surface 210. The length of the second positive electrode active material layer 202 is greater than that of the first positive electrode active material layer 203. The second positive electrode active material layer 202 and the first positive electrode active material layer 203 are provided with positive electrode tab welding grooves 208, which are used to accommodate positive electrode tabs (not shown). The negative electrode sheet 102 includes a negative electrode current collector 301 and two negative electrode active material layers extending in the same direction. The two negative electrode active material layers include a second negative electrode active material layer 302 and a first negative electrode active material layer 303. The negative electrode current collector 301 includes a third surface 309 and a fourth surface 310 facing each other. The second negative electrode active material layer 302 is disposed on the third surface 309, and the first negative electrode active material layer 303 is disposed on the fourth surface 310. The second negative electrode active material layer 302 and the first negative electrode active material layer 303 are provided with negative electrode tab welding grooves 308 for accommodating negative electrode tabs (not shown).

[0050] It should be noted that Figures 1 to 3The battery cell 100 shown is actually a wound battery cell, but Figures 1 to 3 The positive electrode sheet 101 and the negative electrode sheet 102 are in a state before being wound, and both the positive electrode sheet 101 and the negative electrode sheet 102 are in a flattened state.

[0051] like Figure 1 As shown, the first positive electrode active material layer 203 and the first negative electrode active material layer 303 are arranged opposite each other. The starting end of coating the first positive electrode active material layer 203 is the positive electrode short head 206, and the ending end of coating the first positive electrode active material layer 203 is the positive electrode short tail 207. The starting end of coating the first negative electrode active material layer 303 is the negative electrode short head 306, and the ending end of coating the first negative electrode active material layer 303 is the negative electrode short tail 307. The positive electrode short head 206 and the negative electrode short head 306 are arranged in correspondence, and the positive electrode short tail 207 and the negative electrode short tail 307 are arranged in correspondence.

[0052] The coating starting end of the active material layer refers to the position where the active material slurry used to form the active material layer first falls on the positive electrode current collector 201. The coating ending end of the active material layer refers to the position where the active material slurry used to form the active material layer last falls on the positive electrode current collector 201. From another perspective, since the coating of the active material slurry is achieved through a coating head, the coating starting end of the active material layer can also be understood as the position where the active material layer first passes through the coating head. Similarly, the coating ending end of the active material layer can also be understood as the position where the active material layer last passes through the coating head.

[0053] The applicant has found that compared with the thickness of the active material layer at the coating starting end, the thickness of the active material layer at the coating ending end is more difficult to control within a preset thickness range. During the coating process of the electrode, the thinning of the coating starting end can be controlled by parameters such as the gasket of the coating head, the pump speed of the pump for conveying the slurry, and the distance between the coating head and the electrode, but the thinning of the coating ending end cannot be controlled by these parameters. When the coating head reaches the coating ending end, the slurry at the coating head will stop flowing out, and then under the action of the gravity of the slurry itself, the slurry at the coating ending end will flow to the surroundings. The randomness of the leveling effect is relatively large, which makes the thickness of the coating ending end difficult to control. Therefore, the thickness of the negative electrode short tail 307 and the positive electrode short tail 207 is actually not easy to be controlled within the preset size.

[0054] To reduce the risk of lithium plating, the ratio of the negative electrode active material to the positive electrode active material in the battery cell 100 needs to be maintained within an appropriate range (usually between 1 and 1.05). The amount of active material layer is related to the thickness of the active material layer. Difficulty controlling the thickness at the coating end means that the amount of active material near the coating end is also difficult to control. Figure 1The negative electrode short tail 307 and the positive electrode short tail 207 are set correspondingly. In fact, the thickness of the negative electrode short tail 307 and the positive electrode short tail 207 is not easy to be controlled within the preset size. Therefore, near the negative electrode short tail 307 ( Figure 1 In the middle A area), the ratio of negative electrode active material to positive electrode active material is difficult to control, and this ratio is likely to exceed a reasonable range, resulting in a higher risk of lithium plating near the negative electrode short tail 307.

[0055] Figure 2 The battery cell 100 of the first embodiment of the present invention is shown in FIG. 1 , which is beneficial for solving the above-mentioned technical problems. Figure 2 As shown, in the first embodiment, the negative electrode short head 306 is correspondingly provided with the positive electrode short tail 207, and the negative electrode short tail 307 is correspondingly provided with the positive electrode short head 206. In the present invention, the corresponding provision of the negative electrode short head 306 and the positive electrode short tail 207 means that the negative electrode short head 306 and the positive electrode short tail 207 are both located on the same side of the positive electrode tab welding groove 208 (for example, both located on the left side), and the corresponding provision of the negative electrode short tail 307 and the positive electrode short head 206 means that the negative electrode short tail 307 and the positive electrode short head 206 are both located on the same side of the positive electrode tab welding groove 208 (for example, both located on the right side); and the negative electrode short head 306 and the negative electrode short tail 307 are respectively located on different sides of the negative electrode tab welding groove 308, and the positive electrode short head 206 and the positive electrode short tail 207 are respectively located on different sides of the positive electrode tab welding groove 208.

[0056] In addition, if Figure 2 As shown, in the first embodiment, the positive electrode long end 204 is aligned with the positive electrode short tail 207, and the negative electrode long end 304 is aligned with the negative electrode short tail 307. The coating start end of the second positive electrode active material layer 202 is the positive electrode long end 204, and the coating end end of the second positive electrode active material layer 202 is the positive electrode long tail 205. The coating start end of the second negative electrode active material layer 302 is the negative electrode long end 304, and the coating end end of the second negative electrode active material layer 302 is the negative electrode long tail 305.

[0057] In the prior art (such as Figure 1 As shown in the A area of ​​the negative electrode, since the negative electrode short tail 307 corresponds to the positive electrode short tail 207, the amount of the positive electrode active material and the amount of the negative electrode active material near the negative electrode short tail 307 are not easy to control. In the first embodiment, the negative electrode short tail 307 corresponds to the positive electrode short head 206, and near the negative electrode short tail 307 ( Figure 2 The amount of the positive electrode active material can be easily controlled within the required range, and this embodiment reduces the uncontrollable factors at the negative electrode short tail 307. Figure 1Compared with the prior art shown in FIG, this embodiment enhances the controllability of the amount of positive electrode active material near the negative electrode short tail 307 by changing the positions of the positive electrode short head 206 and the positive electrode short tail 207, thereby reducing the uncontrollability of the ratio of the negative electrode active material to the positive electrode active material near the negative electrode short tail 307, and further reducing the risk of lithium plating at the negative electrode short tail 307.

[0058] In addition, the ratio of the capacity of the negative electrode short head 306 to the capacity of the positive electrode short tail 207 is greater than 1, and the ratio of the capacity of the negative electrode short tail 307 to the capacity of the positive electrode short head 206 is greater than 1. In this way, the amount of lithium ions that the negative electrode can absorb is greater than the amount of lithium ions that can be released by the positive electrode, and lithium deposition is less likely to occur at the negative electrode. Among them, the capacity of the positive electrode short head 206 is P1, the capacity of the positive electrode short tail 207 is P2, the capacity of the negative electrode short head 306 is N1, and the capacity of the negative electrode short tail 307 is N2, N1 / P2>1, N2 / P1>1. At the positive electrode short head 206, the product of the gram capacity of the positive electrode active material, the density of the positive and negative electrode active materials, and the positive electrode active material content ratio is equal to P1; at the positive electrode short tail 207, the product of the gram capacity of the positive electrode active material, the density of the positive and negative electrode active materials, and the positive electrode active material content ratio is equal to P2. At the negative electrode short end 306, the product of the gram capacity of the negative electrode active material, the density of the negative electrode active material, and the negative electrode active material content ratio is equal to N1. At the negative electrode short end 307, the product of the gram capacity of the negative electrode active material, the density of the negative electrode active material, and the negative electrode active material content ratio is equal to N2. Furthermore, to prevent excessive cathode (positive electrode) capacity from causing material waste and cathode instability, the above capacity ratios can also meet the following requirements: 1 < N1 / P2 < 1.1, and 1 < N2 / P1 < 1.1.

[0059] Figure 3 The figure shows the positive electrode sheet 101 and the negative electrode sheet 102 of the battery cell 100 of the second embodiment of the present invention. In the first embodiment, the positive electrode short tail 207, the negative electrode short head 306, the positive electrode short head 206 and the negative electrode short tail 307 are spaced from left to right in sequence; in the second embodiment, the positive electrode short head 206, the negative electrode short tail 307, the positive electrode short tail 207 and the negative electrode short head 306 are spaced from left to right in sequence. In addition, as shown in FIG. Figure 3 As shown, in the second embodiment, the positive electrode short head 206 is aligned with the positive electrode long tail 205, and the negative electrode long tail 305 is aligned with the negative electrode short head 306. The second embodiment also satisfies the following requirements: the negative electrode short head 306 is arranged correspondingly with the positive electrode short tail 207, and the negative electrode short tail 307 is arranged correspondingly with the positive electrode short head 206. Similar to the principles of the first embodiment, the battery cell 100 of the second embodiment has a lower risk of lithium plating.

[0060] The state of the electrode and the insulating separator 103 of the first embodiment after being wound into the battery cell 100 is as follows Figure 4 As shown. Figure 4As shown, the negative electrode long tail 305 and the negative electrode short head 306 are both located in the center of the battery cell 100, and the positive electrode long tail 205 and the positive electrode short head 206 are both located at the periphery of the battery cell 100. Figure 2 and Figure 4 It can be determined that for Figure 4 In the battery cell 100 shown, the misaligned end of the negative electrode sheet 102 and the aligned end of the positive electrode sheet 101 are located at the center of the battery cell 100 , and the aligned end of the negative electrode sheet 102 and the misaligned end of the positive electrode sheet 101 are located at the periphery of the battery cell 100 .

[0061] The state of the electrode and the insulating separator 103 of the second embodiment after being wound into the battery cell 100 is as follows Figure 5 As shown. Figure 5 As shown, the negative electrode long head 304 and the negative electrode short tail 307 are both located in the center of the battery cell 100, and the positive electrode long head 204 and the positive electrode short tail 207 are both located at the periphery of the battery cell 100. Figure 3 and Figure 5 It can be determined that for Figure 5 In the battery cell 100 shown, the misaligned end of the negative electrode sheet 102 and the aligned end of the positive electrode sheet 101 are located at the center of the battery cell 100 , and the aligned end of the negative electrode sheet 102 and the misaligned end of the positive electrode sheet 101 are located at the periphery of the battery cell 100 .

[0062] Please refer to Figure 1 and Figure 2 Compared with the prior art, the first embodiment mainly improves the positive electrode sheet 101. The first embodiment swaps the positions of the positive electrode short head 206 and the positive electrode short tail 207. Figure 1 and Figure 3 Compared to the prior art, the second embodiment primarily improves the negative electrode sheet 102 by swapping the positions of the negative electrode short head 306 and the negative electrode short tail 307. In this application, the positive electrode sheet 101 of the first embodiment and the negative electrode sheet 102 of the second embodiment are "electrode sheets with improved head and tail positions of the short film surface."

[0063] Figure 6 4 shows a wound cell production line (hereinafter referred to as the production line, corresponding to the reference numeral "400") according to an embodiment of the present application. Figure 6 The production line 400 shown is suitable for winding the positive electrode sheet 101 and the negative electrode sheet 102 of the first embodiment into Figure 4 The battery cell 100 is shown.

[0064] like Figure 6As shown, the production line 400 includes a positive electrode processing device 401, a negative electrode processing device 402 and a winding device 403. The positive electrode processing device 401 is used to transport the positive electrode collector 201 and process the positive electrode collector 201 into a positive electrode sheet 101. The negative electrode processing device 402 is used to transport the negative electrode collector 301 and process the negative electrode collector 301 into a negative electrode sheet 102. The winding device 403 is used to wind the positive electrode sheet 101 output by the positive electrode processing device 401 and the negative electrode sheet 102 output by the negative electrode processing device 402 into a wound battery cell. It can be seen that the winding device 403 is located both downstream of the positive electrode processing device 401 and downstream of the negative electrode processing device 402. The negative electrode sheet 102 processed by the negative electrode sheet 102 processing device is as shown in FIG. Figure 2 shown.

[0065] The positive electrode processing device 401 includes a positive electrode coating mechanism 404, which is used to process a positive electrode active material layer on the surface of the positive electrode current collector 201. Specifically, the positive electrode coating mechanism 404 is used to process a first positive electrode active material layer 203 and a second positive electrode active material layer 202 on the surface of the positive electrode current collector 201. Figure 2 As shown, the second positive electrode active material layer 202 and the first positive electrode active material layer 203 are respectively arranged on the two side surfaces of the positive electrode current collector 201 that are back to back with each other, the length of the second positive electrode active material layer 202 is greater than the length of the first positive electrode active material layer 203, and the coating starting end of the second positive electrode active material layer 202 (positive electrode long head 204) and the coating ending end of the first positive electrode active material layer 203 (positive electrode short tail 207) are aligned.

[0066] like Figure 6 As shown, the positive electrode coating mechanism 404 may include a back roller 411 and a coating head 410. The coating head 410 faces the back roller 411. The outer peripheral surface of the back roller 411 is used to contact and support the positive electrode current collector 201. The coating head 410 is used to spray the positive electrode active material, so that the positive electrode active material adheres to the surface of the positive electrode current collector 201. The positive electrode coating mechanism 404 may include only one coating head 410, so that the two side surfaces of the positive electrode current collector 201 are successively directed toward the coating head 410, thereby successively forming two positive electrode active material layers.

[0067] like Figure 6As shown, the positive electrode processing device 401 also includes a rewinding mechanism 408, which is arranged downstream of the positive electrode coating mechanism 404 and upstream of the winding device 403. The rewinding mechanism 408 is used to reverse the positive electrode sheet 101 passing through the rewinding mechanism 408. The rewinding mechanism 408 includes a rewinding roller 409 and a driving source. The driving source is not shown. The driving source can be a motor. The driving source is used to drive the rewinding roller 409 to rotate, so that the rewinding roller 409 can be wound and unwound. The rewinding roller 409 is used to rewind the positive electrode sheet 101 from the upstream of the rewinding mechanism 408. After the rewinding roller 409 completes the winding, the rewinding roller 409 is also used to unwind the wound positive electrode sheet 101 to the downstream of the rewinding mechanism 408.

[0068] The user can first connect the head end of the positive electrode sheet 101 to the rewinding roller 409, and the coated positive electrode sheet 101 is gradually rewound to the outer periphery of the rewinding roller 409. After the rewinding roller 409 completes the rewinding, for this roll of positive electrode sheet 101 on the rewinding roller 409, the tail end of the positive electrode sheet 101 is at the outermost layer of the positive electrode sheet 101, and the head end of the positive electrode sheet 101 is at the innermost layer of the positive electrode sheet 101. Subsequently, the user can connect the tail end of the positive electrode sheet 101 to the remaining mechanisms downstream of the rewinding mechanism 408, and the rewinding mechanism 408 unwinds. The tail end of the positive electrode sheet 101 is first conveyed to the remaining mechanisms downstream of the rewinding mechanism 408, and the head end of the positive electrode sheet 101 is finally conveyed to the remaining mechanisms downstream of the rewinding mechanism 408. In this way, the head and tail of the positive electrode sheet 101 passing through the rewinding mechanism 408 are reversed. If the leading end of the positive electrode sheet 101 is the misaligned end of the positive electrode sheet 101 , then the trailing end of the positive electrode sheet 101 is the aligned end of the positive electrode sheet 101 .

[0069] Since the short film surface is formed after the long film surface is formed, and the coating tail of the short film surface leaves the coating mechanism last, Figure 2 In the positive electrode sheet 101 shown, the positive electrode short head 206 leaves the coating mechanism before the positive electrode short tail 207. Accordingly, the misaligned end of the positive electrode sheet 101 leaves the positive electrode coating mechanism 404 before the aligned end of the positive electrode sheet 101.

[0070] like Figure 7 As shown, assuming that the rewinding mechanism 408 is not provided, then since the other mechanisms of the positive electrode processing device 401 do not have the function of reversing the end of the positive electrode sheet 101, the misaligned end of the positive electrode sheet 101 (positive electrode misaligned end 421) will enter the winding device 403 before the aligned end of the positive electrode sheet 101 (positive electrode aligned end 420). This does not conform to the common feeding method mentioned above, that is, "the aligned end of the positive electrode sheet 101 (cathode) enters the winding device 403 before the misaligned end of the positive electrode sheet 101", resulting in the winding device 403 commonly used in the art being unsuitable for the positive electrode sheet 101 of the first embodiment.

[0071] And as Figure 8 As shown, when a rewinding mechanism 408 is provided, under the head-to-tail reversal action of the rewinding mechanism 408, the positive electrode alignment end 420 will enter the winding device 403 before the positive electrode misalignment end 421, so that the winding device 403 commonly used in this field can be applied to the positive electrode sheet 101 of the first embodiment.

[0072] like Figure 6 As shown, the positive electrode processing device 401 includes a positive electrode coating mechanism 404, a positive electrode laser cleaning mechanism 407, a positive electrode rolling mechanism 405, and a positive electrode slitting mechanism 406, which are arranged in sequence along the conveying direction of the positive electrode current collector 201. The rewinding mechanism 408 is located downstream of the positive electrode coating mechanism 404 and upstream of the positive electrode laser cleaning mechanism 407. To adapt to the positive electrode sheet 101 of the first embodiment, in some embodiments not shown, the rewinding mechanism 408 can also be configured as follows: the rewinding mechanism 408 is located downstream of the positive electrode laser cleaning mechanism 407 and upstream of the positive electrode rolling mechanism 405; or the rewinding mechanism 408 is located downstream of the positive electrode rolling mechanism 405 and upstream of the positive electrode slitting mechanism 406; or the rewinding mechanism 408 is located downstream of the positive electrode slitting mechanism 406. The rewinding mechanism 408 only needs to be located downstream of the positive electrode coating mechanism 404 and upstream of the winding device 403.

[0073] The positive electrode laser cleaning mechanism 407 includes a plurality of lasers 412 ( Figure 6 Not all lasers 412 are shown. The laser light emitted by the laser 412 is used to irradiate a portion of the positive electrode active material layer. Multiple lasers 412 are spaced apart along the width direction of the positive electrode current collector 201. Any two of the width direction, the thickness direction of the positive electrode current collector 201, and the transport direction of the positive electrode current collector 201 are perpendicular to each other. The laser light emitted by the laser 412 can remove a portion of the positive electrode active material layer, thereby processing certain grooves on the positive electrode active material layer, such as Figure 2 The positive tab welding groove 208 is shown.

[0074] like Figure 6 As shown, the positive electrode rolling mechanism 405 includes a first rolling roller 414, a second rolling roller 415, and a rolling roller drive source (the rolling roller drive source is not shown). The first rolling roller 414 and the second rolling roller 415 are used to clamp the positive electrode sheet 101. The rolling roller drive source can be an air cylinder, an oil cylinder, etc. The rolling roller drive source is used to drive at least one of the first rolling roller 414 and the second rolling roller 415 to move, thereby changing the distance between the first rolling roller 414 and the second rolling roller 415. The positive electrode rolling mechanism 405 is used to roll the positive electrode sheet 101, thereby controlling the thickness of the positive electrode active material layer within a preset range.

[0075] like Figure 6As shown, the positive electrode stripping mechanism 406 includes a plurality of blades 413 ( Figure 6 Not all blades 413 are shown), and multiple blades 413 are spaced apart along the width direction of the positive electrode sheet 101. The positive electrode slitting mechanism 406 is used to cut the positive electrode sheet 101 into a size suitable for being wound into a battery cell 100. The positive electrode sheet 101 before being cut by the positive electrode slitting mechanism 406 is a "wide positive electrode sheet", and the positive electrode sheet 101 after being cut is a "narrow positive electrode sheet". The width of the wide positive electrode sheet is more than n times the width of the narrow positive electrode sheet (n is an integer not less than 2). The positive electrode sheet 101 that finally enters the winding device 403 is a narrow positive electrode sheet, and the negative electrode sheet 102 that finally enters the winding device 403 is a narrow negative electrode sheet. A wound battery cell includes a narrow positive electrode sheet and a narrow negative electrode sheet.

[0076] like Figure 6 As shown, in some embodiments, the negative electrode processing device 402 includes a negative electrode coating mechanism 416, a negative electrode rolling mechanism 419, a negative electrode slitting mechanism 417, and a negative electrode laser cleaning mechanism 418, which are arranged in sequence along the conveying direction of the negative electrode current collector 301. The negative electrode processing device 402 does not need to reverse the coated negative electrode sheet 102 end to end, so the negative electrode processing device 402 does not include a rewinding mechanism 408. The specific configuration of the negative electrode coating mechanism 416, the negative electrode rolling mechanism 419, the negative electrode slitting mechanism 417, and the negative electrode laser cleaning mechanism 418 can be referred to one-to-one with the positive electrode coating mechanism 404, the positive electrode rolling mechanism 405, the positive electrode slitting mechanism 406, and the positive electrode laser cleaning mechanism 407, and will not be repeated here.

[0077] It should be noted that the negative electrode processing device 402 first slits the negative electrode sheet 102 and then performs laser cleaning on the negative electrode sheet 102 because the negative electrode laser cleaning mechanism 418 is generally configured to clean narrow negative electrode sheets 102. The positive electrode processing device 401 first laser cleans the positive electrode sheet 101 and then slits the positive electrode sheet 101 because the negative electrode laser cleaning mechanism 418 is generally configured to clean wide positive electrode sheets 101.

[0078] Figure 9 The production line 400 of another embodiment of the present application is shown. The production line 400 is suitable for winding the positive electrode sheet 101 and the negative electrode sheet 102 of the second embodiment into Figure 5The battery cell 100 shown in FIG. The production line 400 includes a positive electrode processing device 401, a negative electrode processing device 402, and a winding device 403. The negative electrode processing device 402 includes a negative electrode coating mechanism 416, which is used to process a negative electrode active material layer on the surface of the negative electrode current collector 301. The positive electrode processing device 401 is used to transport the positive electrode current collector 201 and process the positive electrode current collector 201 into a positive electrode sheet 101. More specifically, the positive electrode sheet 101 processed by the positive electrode processing device 401 is as follows: Figure 3 As shown. The positive electrode processing device 401 includes a positive electrode coating mechanism 404, a positive electrode laser cleaning mechanism 407, a positive electrode rolling mechanism 405, and a positive electrode slitting mechanism 406, which are arranged in sequence along the conveying direction of the positive electrode current collector 201. The positive electrode processing device 401 in this embodiment does not include a rewinding mechanism 408. The negative electrode processing device 402 also includes a rewinding mechanism 408. The rewinding mechanism 408 is arranged downstream of the negative electrode coating mechanism 416 and upstream of the winding device 403. The rewinding mechanism 408 includes a rewinding roller 409 and a driving source, and the driving source is used to drive the rewinding roller 409 to rotate. The rewinding roller 409 is used to rewind the negative electrode sheet 102 from the upstream of the rewinding mechanism 408. The rewinding roller 409 is also used to unwind the negative electrode sheet 102 to the downstream of the rewinding mechanism 408, so that the negative electrode sheet 102 passing through the rewinding mechanism 408 is reversed head to tail.

[0079] Since the short film surface is formed after the long film surface is formed, and the coating tail of the short film surface leaves the coating mechanism last, Figure 3 In the negative electrode sheet 102 shown, the negative electrode short head 306 leaves the coating mechanism earlier than the negative electrode short tail 307. Accordingly, the aligned end of the negative electrode sheet 102 leaves the coating mechanism earlier than the misaligned end of the negative electrode sheet 102.

[0080] like Figure 10 As shown, assuming that the rewinding mechanism 408 is not provided, then since the other mechanisms of the negative electrode processing device 402 do not have the function of reversing the end of the negative electrode sheet 102, the aligned end of the negative electrode sheet 102 (negative electrode aligned end 422) will enter the winding device 403 before the misaligned end of the negative electrode sheet 102 (negative electrode misaligned end 423). This does not conform to the common feeding method mentioned above, that is, "the misaligned end of the negative electrode sheet 102 (anode) enters the winding device 403 before the aligned end of the negative electrode sheet 102", resulting in the winding device 403 commonly used in the art being unsuitable for the negative electrode sheet 102 of the second embodiment.

[0081] And as Figure 11 As shown, when a rewinding mechanism 408 is provided, under the head-to-tail reversal action of the rewinding mechanism 408 , the negative electrode aligned end 422 will enter the winding device 403 before the negative electrode misaligned end 423 , thereby making the winding device 403 commonly used in the art applicable to the negative electrode sheet 102 of the second embodiment.

[0082] The negative electrode processing device 402 includes a negative electrode coating mechanism 416, a negative electrode rolling mechanism 419, a negative electrode slitting mechanism 417, and a negative electrode laser cleaning mechanism 418, which are arranged in sequence along the conveying direction of the negative electrode current collector 301. The rewinding mechanism 408 can be configured as follows: the rewinding mechanism 408 is located downstream of the negative electrode coating mechanism 416 and upstream of the negative electrode rolling mechanism 419; or the rewinding mechanism 408 is located downstream of the negative electrode rolling mechanism 419 and upstream of the negative electrode slitting mechanism 417; or the rewinding mechanism 408 is located downstream of the negative electrode slitting mechanism 417 and upstream of the negative electrode laser cleaning mechanism 418; or the rewinding mechanism 408 is located downstream of the negative electrode laser cleaning mechanism 418. The rewinding mechanism 408 only needs to be located downstream of the negative electrode coating mechanism 416 and upstream of the winding device 403.

[0083] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Claims

1. The wound battery cell production line is characterized by: include: A positive electrode processing device, the positive electrode processing device is used to transport the positive electrode current collector and process the positive electrode current collector into a positive electrode sheet, the positive electrode processing device includes a positive electrode coating mechanism, the positive electrode coating mechanism is used to process a positive electrode active material layer on the surface of the positive electrode current collector; A negative electrode processing device, the negative electrode processing device is used to transport the negative electrode current collector and process the negative electrode current collector into a negative electrode sheet; A winding device, configured to wind the positive electrode sheet outputted from the positive electrode processing device and the negative electrode sheet outputted from the negative electrode processing device into a wound battery cell; In which, the positive electrode processing device also includes a rewinding mechanism, which is arranged downstream of the positive electrode coating mechanism and upstream of the winding device. The rewinding mechanism includes a rewinding roller and a driving source. The driving source is used to drive the rewinding roller to rotate. The rewinding roller is used to rewind the positive electrode sheet from the upstream of the rewinding mechanism. The rewinding roller is also used to unwind the positive electrode sheet to the downstream of the rewinding mechanism, so that the positive electrode sheet passing through the rewinding mechanism is reversed head to tail.

2. The wound battery cell production line according to claim 1, characterized in that: The positive electrode processing device includes the positive electrode coating mechanism, the positive electrode laser cleaning mechanism, the positive electrode rolling mechanism and the positive electrode stripping mechanism, which are sequentially arranged along the conveying direction of the positive electrode current collector; The rewinding mechanism is configured as follows: The rewinding mechanism is located downstream of the positive electrode coating mechanism and upstream of the positive electrode laser cleaning mechanism; Alternatively, the rewinding mechanism is located downstream of the positive electrode laser cleaning mechanism and upstream of the positive electrode rolling mechanism; Alternatively, the rewinding mechanism is located downstream of the positive electrode rolling mechanism and upstream of the positive electrode slitting mechanism; Alternatively, the rewinding mechanism is located downstream of the positive electrode slitting mechanism.

3. The wound battery cell production line according to claim 1, characterized in that: The negative electrode processing device comprises a negative electrode coating mechanism, a negative electrode rolling mechanism, a negative electrode stripping mechanism and a negative electrode laser cleaning mechanism which are sequentially arranged along the conveying direction of the negative electrode current collector.

4. The wound battery cell production line according to claim 1, characterized in that: The positive electrode coating mechanism includes a back roller and a coating head. The coating head faces the back roller. The outer peripheral surface of the back roller is used to contact the positive electrode current collector and support the positive electrode current collector. The coating head is used to spray positive electrode active material.

5. The wound battery cell production line according to claim 2, characterized in that: The positive electrode laser cleaning mechanism includes multiple lasers, and the lasers emitted by the lasers are used to irradiate a part of the positive electrode active material layer. The multiple lasers are distributed at intervals along the width direction of the positive electrode sheet, and any two of the width direction, the thickness direction of the positive electrode collector, and the transport direction of the positive electrode collector are perpendicular to each other.

6. The wound battery cell production line according to claim 2, characterized in that: The positive electrode rolling mechanism includes a first pressing roller, a second pressing roller and a pressing roller driving source. The first pressing roller and the second pressing roller are used to clamp the positive electrode sheet. The pressing roller driving source is used to drive at least one of the first pressing roller and the second pressing roller to move to change the distance between the first pressing roller and the second pressing roller.

7. The wound battery cell production line according to claim 2, characterized in that: The positive electrode stripping mechanism includes a plurality of blades for cutting the positive electrode sheet, and the plurality of blades are spaced apart along the width direction of the positive electrode collector, and any two of the width direction, the thickness direction of the positive electrode collector and the conveying direction of the positive electrode collector are perpendicular to each other.

8. The wound battery cell production line is characterized by: include: A positive electrode processing device, the positive electrode processing device is used to transport the positive electrode current collector and process the positive electrode current collector into a positive electrode sheet; A negative electrode processing device, the negative electrode processing device is used to transport the negative electrode current collector and process the negative electrode current collector into a negative electrode sheet, the negative electrode processing device includes a negative electrode coating mechanism, the negative electrode coating mechanism is used to process a negative electrode active material layer on the surface of the negative electrode current collector; a winding device for winding the positive electrode sheet outputted by the positive electrode processing device and the negative electrode sheet outputted by the negative electrode processing device into a wound battery cell; Among them, the negative electrode processing device also includes a rewinding mechanism, which is arranged downstream of the negative electrode coating mechanism and upstream of the winding device. The rewinding mechanism includes a rewinding roller and a driving source. The driving source is used to drive the rewinding roller to rotate. The rewinding roller is used to rewind the negative electrode sheet from the upstream of the rewinding mechanism. The rewinding roller is also used to unwind the negative electrode sheet to the downstream of the rewinding mechanism, so that the negative electrode sheet passing through the rewinding mechanism is reversed head to tail.

9. The wound battery cell production line according to claim 8, characterized in that: The negative electrode processing device includes the negative electrode coating mechanism, the negative electrode rolling mechanism, the negative electrode stripping mechanism and the negative electrode laser cleaning mechanism which are sequentially arranged along the conveying direction of the negative electrode current collector; The rewinding mechanism is configured as follows: The rewinding mechanism is located downstream of the negative electrode coating mechanism and upstream of the negative electrode rolling mechanism; Alternatively, the rewinding mechanism is located downstream of the negative electrode rolling mechanism and upstream of the negative electrode slitting mechanism; Alternatively, the rewinding mechanism is located downstream of the cathode slitting mechanism and upstream of the cathode laser cleaning mechanism; Alternatively, the rewinding mechanism is located downstream of the cathode laser cleaning mechanism.

10. The wound battery cell production line according to claim 8, characterized in that: The positive electrode processing device comprises a positive electrode coating mechanism, a positive electrode laser cleaning mechanism, a positive electrode rolling mechanism and a positive electrode stripping mechanism which are sequentially arranged along the conveying direction of the positive electrode current collector.

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