Pole winding and separation method

Abstract

The present application relates to a method for winding and separating an electrode, comprising the following steps: providing a reel and a heat shrink film, wherein the heat shrink film has opposite winding starting ends and winding ending ends; applying the winding starting end to the reel and being located on one side of a first surface, and then winding the heat shrink film along the circumference of the reel so that the winding ending end is wound back to one side of a second surface and applied to the reel; winding the electrode around the surface of the heat shrink film; heating the heat shrink film and shrinking the heat shrink film so that a separation gap is formed between the reel and the electrode; and removing the reel from the separation gap.

Description

Technical Field

[0001] The present application relates to the technical field of battery manufacturing, and in particular to a method for winding and separating pole pieces. Background Art

[0002] In the production process of battery electrodes, the electrodes are usually wound on a reel. However, during the production process of battery electrodes, due to reasons such as the adjustment of the production formula or the debugging of the production equipment, electrodes that do not meet the requirements may be produced. When these electrodes that do not meet the requirements wound on the reel need to be discarded, workers are usually required to use a utility knife to cut off the electrodes that do not meet the requirements wound on the reel to separate the electrodes that do not meet the requirements from the reel. However, when workers use the utility knife to cut the electrodes on the reel, the blade of the utility knife will inevitably scratch the reel, making the surface of the reel uneven. When the reel is used to rewind the electrodes, the electrodes located in the inner layer of the entire roll will be wrinkled and cause abnormal tension, resulting in waste of electrodes and increased production costs. Summary of the Invention

[0003] Based on this, it is necessary to provide a method for winding and separating electrodes to address the problem of high production costs caused by electrode waste.

[0004] The technical solution is as follows:

[0005] One embodiment provides a method for winding and separating a pole piece, wherein the pole piece has a connection end and a first surface and a second surface facing each other, comprising the following steps:

[0006] Providing a roll and a heat shrinkable film, wherein the heat shrinkable film has opposite winding start and winding end ends;

[0007] connecting the connecting end to the surface of the drum;

[0008] The winding start end is attached to the drum and positioned on one side of the first surface, and the heat shrink film is wound around the circumference of the drum so that the winding end is wound back to one side of the second surface and attached to the drum;

[0009] Winding the electrode sheet onto the surface of the heat shrinkable film;

[0010] heating the heat shrinkable film and shrinking the heat shrinkable film to form a separation gap between the roll and the pole piece;

[0011] The roll is removed from the separation gap.

[0012] The above-mentioned electrode sheet winding and separation method first connects the connection end of the electrode sheet to the surface of the reel, then applies the starting end of the heat shrink film to the reel and is located on one side of the first surface. The heat shrink film is then wound around the circumference of the reel so that the ending end of the heat shrink film is wound back to the side of the second surface and applied to the reel. Since the connection end of the electrode sheet is already connected to the surface of the reel, the electrode sheet is finally wound on the surface of the heat shrink film to complete the winding of the electrode sheet. If it is detected that the electrode sheet does not meet the requirements after winding, it is necessary to separate the electrode sheet from the reel. During separation, the heat shrink film is first heated and shrunk. After the heat shrink film shrinks, a separation gap is formed between the reel and the electrode sheet. Finally, the reel is removed from the separation gap to complete the separation between the electrode sheet and the reel. Compared with traditional technologies, the above-mentioned electrode winding and separation method does not require the use of a utility knife to cut the electrode on the reel when separating the electrode that does not meet the requirements, and will not cause scratches on the surface of the reel. It prevents the electrode from wrinkling due to the uneven scratches on the reel when the reel is rewound, resulting in abnormal electrode tension, thereby reducing the production cost of the electrode.

[0013] In one embodiment, the side surface of the heat shrinkable film facing the roll is the third surface, the side surface of the heat shrinkable film facing away from the roll is the fourth surface, and the winding starting end has a first transition surface connecting the third surface and the fourth surface, and the first transition surface is set at a first angle with the third surface, and the first angle is an acute angle.

[0014] The first transition surface of the heat shrink film is arranged at a first angle to the third surface, and the first angle is an acute angle, so that the electrode can more smoothly transition from the roll through the first transition surface to the surface of the heat shrink film at the beginning of winding, and then the electrode is further wound on the surface of the heat shrink film; such an arrangement can make the electrode more smoothly wound from the starting end of the winding of the heat shrink film, preventing the electrode from wrinkling and abnormal tension at the starting end of the winding, thereby causing damage to the electrode.

[0015] In one embodiment, the winding end has a second transition surface connecting the third surface and the fourth surface, the second transition surface is set at a second angle with the fourth surface, and the angle of the second angle is equal to the angle of the first angle.

[0016] The second transition surface of the heat shrink film is set at a second angle to the third surface. In this way, since the second angle is equal to the first angle, when the heat shrink film is wound on the reel, the surface of the heat shrink film is smoother, and the connecting end of the electrode is attached between the first transition surface and the second transition surface. When the electrode is wound on the heat shrink film and passes through the docking position of the winding end end and the winding start end, it can pass through the docking position of the winding end end and the winding start end more smoothly and continue to be wound, thereby preventing the electrode from being wrinkled and causing abnormal tension, and then causing damage to the electrode.

[0017] In one embodiment, the first angle is greater than or equal to 30 degrees and less than or equal to 50 degrees.

[0018] The first angle is less than 50 degrees to allow the electrode to transition more smoothly from the roll through the first transition surface to the surface of the heat shrink film, preventing wrinkles and abnormal tension in the electrode at the starting end of winding in the initial stage; the first angle is greater than 30 degrees to ensure that the thickness of the heat shrink film meets the requirements, preventing the separation gap generated after heating from being too small, making it difficult to separate the electrode and the roll.

[0019] In one embodiment, the axial direction of the drum is set as a first direction, and the length of the drum along the first direction is greater than the width of the pole piece.

[0020] The length of the roll along the first direction is greater than the width of the electrode. In this way, after the electrode is rolled up, at least one end of the roll can protrude from the electrode in the width direction of the electrode. When the electrode needs to be separated from the roll, the heat shrink film is heated to form a separation gap between the roll and the electrode. At this time, it is only necessary to push or pull the end of the roll protruding from the electrode to move the roll relative to the electrode in the first direction, so that the electrode and the roll can be quickly separated. Such a setting can speed up the separation speed between the roll and the electrode at a low cost and improve production efficiency.

[0021] In one embodiment, the step of removing the roll from the separation gap further includes the following steps:

[0022] Fixing the pole piece, and applying an external force to one end of the drum to move the drum relative to the pole piece along the first direction;

[0023] The reel is separated from the pole piece.

[0024] The length of the drum along the first direction is greater than the length of the pole piece. Thus, when the pole piece needs to be separated from the drum, the pole piece is fixed and an external force is applied to one end of the drum. The drum moves along the first direction under the action of the external force to achieve rapid separation between the pole piece and the drum. In this way, the separation between the drum and the pole piece can be achieved efficiently and at low cost without damaging the drum.

[0025] In one embodiment, the step of removing the roll from the separation gap further includes the following steps:

[0026] placing the drum upright so that the pole piece moves relative to the drum under the action of gravity;

[0027] The reel is separated from the pole piece.

[0028] When the electrode piece needs to be separated from the reel, the reel is placed vertically. At this time, the electrode piece on the reel moves relative to the reel under the action of gravity, so that the electrode piece and the reel are quickly separated. This arrangement can achieve efficient and low-cost separation between the reel and the electrode piece without damaging the reel.

[0029] In one embodiment, the axial direction of the roll is set as a first direction, and the width of the heat shrinkable film along the first direction is greater than the width of the pole piece.

[0030] The width of the heat shrink film along the first direction is greater than the width of the electrode. In this way, when the electrode is wound on the heat shrink film, at least one side of the heat shrink film along the first direction will protrude from the electrode. When the heat shrink film needs to be heated, the part of the heat shrink film protruding from the electrode can better absorb heat and transfer the heat to the middle part of the heat shrink film, so that the heat shrink film shrinks faster and the separation speed and efficiency between the electrode and the reel are improved.

[0031] In one embodiment, the thickness of the heat shrinkable film is greater than or equal to 0.08 mm and less than or equal to 0.5 mm.

[0032] The thickness of the heat shrink film is greater than or equal to 0.08 mm, so that after the heat shrink film is heated, a wider separation gap can be formed between the reel and the electrode, facilitating the separation between the electrode and the reel; the thickness of the heat shrink film is less than or equal to 0.5 mm to reduce the heating time of the heat shrink film, save the raw materials of the heat shrink film, and reduce costs.

[0033] In one embodiment, the heat shrinkable film is made of at least one of polypropylene, polyethylene, polyester, polyethylene terephthalate, polyvinyl chloride, and oriented polystyrene.

[0034] The heat shrinkable film is made of at least one of the above materials, which has good heat shrinkage performance and low cost, and can reduce costs while ensuring the separation effect between the reel and the pole piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 This is a flow chart of a method for winding and separating a pole piece in one embodiment of the present application;

[0037] Figure 2 This is a schematic diagram of the electrode after winding is completed in one embodiment of the present application;

[0038] Figure 3 This is a top view of the electrode after winding is completed in one embodiment of the present application;

[0039] Figure 4 This is a top view of the heat shrinkable film after being heated in one embodiment of the present application;

[0040] Figure 5 for Figure 3 Cross-sectional view of the middle BB surface;

[0041] Figure 6 This is a schematic diagram of a heat shrink film unfolded in one embodiment of the present application;

[0042] Figure 7 This is a top view of the heat shrink film when it is unfolded in one embodiment of the present application.

[0043] Description of the accompanying drawings:

[0044] 100, reel; 200, heat shrink film; 210, winding starting end; 211, first transition surface; 220, winding ending end; 221, second transition surface; 230, third surface; 240, fourth surface; 250, first angle; 260, second angle; 300, pole piece; 310, first surface; 320, second surface; 330, connection end; 400, separation gap. DETAILED DESCRIPTION

[0045] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0046] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does 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 cannot be understood as a limitation on this application.

[0047] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0048] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0050] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0051] See also Figures 1 to 4 One embodiment of the present application provides a method for rolling and separating a pole piece 300, wherein the pole piece 300 has a connecting end 330 and opposite first and second surfaces 310 and 320, including the following steps:

[0052] S100: providing a roll 100 and a heat shrinkable film 200, wherein the heat shrinkable film 200 has a winding start end 210 and a winding end end 220 opposite to each other;

[0053] S200: The winding start end 210 is attached to the roll 100 and positioned on one side of the first surface 310 , and the heat shrink film 200 is then wound around the circumference of the roll 100 so that the winding end 220 is wound back to one side of the second surface 320 and attached to the roll 100 ;

[0054] S300: Winding the pole piece 300 on the surface of the heat shrink film 200;

[0055] S400: heating the heat shrinkable film 200 and shrinking the heat shrinkable film 200 to form a separation gap 400 between the reel 100 and the pole piece 300;

[0056] S500 : taking the roll 100 out of the separation gap 400 .

[0057] The above-mentioned method for winding and separating the electrode 300 is to first connect the connecting end 330 of the electrode 300 to the surface of the reel 100, then apply the winding starting end 210 of the heat shrink film 200 to the reel 100 and be located on one side of the first surface 310, and continue to wind the heat shrink film 200 along the circumference of the reel 100 so that the winding ending end 220 of the heat shrink film 200 is wound back to one side of the second surface 320 and applied to the reel 100. Since the connecting end 330 of the electrode 300 has been connected to the surface of the reel 100, the electrode 300 is finally wound on the surface of the heat shrink film 200 to complete the winding of the electrode 300. If it is detected that the electrode piece 300 after winding does not meet the requirements, the electrode piece 300 that does not meet the requirements needs to be separated from the reel 100. During separation, the heat shrink film 200 is first heated and shrunk. After the heat shrink film 200 shrinks, a separation gap 400 is formed between the reel 100 and the electrode piece 300. Finally, the reel 100 is removed from the separation gap 400 to complete the separation between the electrode piece 300 and the reel 100. Compared with the conventional technology, the above-mentioned method for winding and separating the electrode piece 300 does not require the use of a utility knife to cut the electrode piece 300 on the reel 100 when separating the electrode piece 300 that does not meet the requirements on the reel 100, and will not cause scratches on the surface of the reel 100. This prevents the electrode piece 300 from wrinkling due to the uneven scratches on the reel 100 when the reel 100 is rewound, resulting in abnormal tension of the electrode piece 300, thereby reducing the production cost of the electrode piece 300.

[0058] In addition, in the traditional technology, using a utility knife to cut the pole piece 300 will not only cause scratches on the surface of the reel 100, but also generate fine dust and pollute the processing workshop during the cutting process. In this embodiment, the heat shrinkage property of the heat shrink film 200 is utilized to form a separation gap 400 between the reel 100 and the pole piece 300, and finally the reel 100 is removed from the separation gap 400. This method is not only convenient and low-cost, but also will not generate fine dust to pollute the processing workshop during the separation process, thereby protecting the health of the workshop workers.

[0059] For explanation, see Figures 3 and 4 In the above embodiment, the heat shrink film 200 is wound on the surface of the reel 100. After the pole piece 300 is rolled up, the heat shrink film 200 is located between the reel 100 and the pole piece 300. When the heat shrink film 200 needs to be separated from the reel 100, the heat shrink film 200 is heated. After heating, the length, width and thickness of the heat shrink film 200 will become smaller, thereby forming a gap between the pole piece 300 and the reel 100. This gap is the separation gap 400 in the above embodiment.

[0060] Furthermore, since there is a separation gap 400 between the reel 100 and the pole piece 300, the friction between the two is greatly reduced or even disappears. At this time, the reel 100 is taken out of the separation gap 400, which is faster and more labor-saving, and improves the separation efficiency between the reel 100 and the pole piece 300.

[0061] Furthermore, the connection end 330 of the pole piece 300 is connected to the surface of the reel 100. After the heat shrink film 200 is wound around the surface of the reel 100, the connection end 330 of the pole piece 300 is sandwiched between the winding start end 210 and the winding end end 220 of the heat shrink film 200. Then, the pole piece 300 is rolled up on the surface of the heat shrink film 200. Figure 3 and Figure 4 In the embodiment shown, the pole piece 300 is rolled in a clockwise direction. When the pole piece 300 is rolled on the surface of the heat shrink film 200 for the first week, the first surface 310 of the pole piece 300 is in contact with the side of the heat shrink film 200 away from the reel 100, and then the pole piece 300 is continued to be rolled in a clockwise direction to complete the rolling of the pole piece 300.

[0062] See also Figure 4 When the heat shrink film 200 is heated, not only will the thickness decrease, but the distance between the winding starting end 210 and the winding ending end 220 of the heat shrink film 200 will also decrease. At this time, the winding starting end 210 and the winding ending end 220 of the heat shrink film 200 wound on the reel 100 cannot be connected, and the heat shrink film 200 cannot be completely wound around the reel 100 (that is, the heat shrink film 200 can only cover a part of the reel 100). There is no heat shrink film 200 between the other part of the reel 100 and the pole piece 300. At this time, the separation gap 400 is larger, which helps to remove the reel 100 from the separation gap 400.

[0063] Optionally, the heat shrinkable film 200 may be baked with hot air using a hot air gun or a hair dryer, or may be baked in an oven, or heated by electric heating, so as to shrink the heat shrinkable film 200.

[0064] See also Figures 1 to 7 In one embodiment, in step S100, the following steps are further included:

[0065] The heat shrink film 200 is cut so that the distance between the winding start end 210 and the winding end 220 corresponds to the circumference of the cross section of the roll 100 .

[0066] Before the heat shrink film 200 is wound on the surface of the reel 100, the heat shrink film 200 is first cut so that the distance between the winding starting end 210 and the winding ending end 220 corresponds to the cross-sectional circumference of the reel 100, so that the heat shrink film 200 can be wound more flatly on the surface of the reel 100. The flat heat shrink film 200 can prevent the pole piece 300 wound on the surface of the heat shrink film 200 from generating abnormal tension, thereby avoiding damage to the innermost pole piece 300 in the entire roll of pole pieces 300 due to abnormal tension, preventing waste of the pole piece 300, and reducing production costs.

[0067] For explanation, in the above embodiment, the distance between the winding starting end 210 and the winding ending end 220 corresponds to the circumference of the cross section of the roll 100, which means that the distance between the winding starting end 210 and the winding ending end 220 is equal to or approximately equal to the circumference of the cross section of the roll 100, as long as it can be ensured that the heat shrink film 200 can cover the surface of the roll 100 after being wound on the roll 100.

[0068] See also Figures 3 to 7 In one embodiment, the side surface of the heat shrinkable film 200 facing the roll 100 is the third surface 230, and the side surface of the heat shrinkable film 200 facing away from the roll 100 is the fourth surface 240. The winding starting end 210 has a first transition surface 211 connecting the third surface 230 and the fourth surface 240. The first transition surface 211 is set at a first angle 250 with the third surface 230, and the first angle 250 is an acute angle.

[0069] The first transition surface 211 of the heat shrink film 200 is set at a first angle 250 with the third surface 230. The first angle 250 is an acute angle, so that the pole piece 300 can transition more smoothly from the roll 100 through the first transition surface 211 to the surface of the heat shrink film 200 at the starting stage of winding, and then the pole piece 300 is further wound on the surface of the heat shrink film 200; such a setting can make the pole piece 300 more smoothly wound from the winding starting end 210 of the heat shrink film 200, preventing the pole piece 300 from wrinkling and abnormal tension at the winding starting end 210, thereby causing damage to the pole piece 300.

[0070] Further, see Figures 3 and 4 In this embodiment, the pole piece 300 is wound on the surface of the heat shrink film 200 in a clockwise direction, and an acute angle is formed between the first transition surface 211 and the third surface 230, and the first transition surface 211 is inclined in the clockwise direction. When the pole piece 300 is wound from the winding starting end 210, the first transition surface 211 can provide a smooth transition surface for the pole piece 300, preventing the pole piece 300 from being wrinkled at the winding starting end 210 and causing damage to the pole piece 300.

[0071] See also Figures 3 to 7 In one embodiment, the winding end 220 has a second transition surface 221 connecting the third surface 230 and the fourth surface 240. The second transition surface 221 is set at a second angle 260 with the fourth surface 240, and the angle of the second angle 260 is equal to the angle of the first angle 250.

[0072] The second transition surface 221 of the heat shrink film 200 is set at a second angle 260 with the third surface 230. In this way, since the second angle 260 is equal to the first angle 250, when the heat shrink film 200 is wound on the reel 100, the surface of the heat shrink film 200 is smoother, and the connecting end 330 of the pole piece 300 is attached between the first transition surface 211 and the second transition surface 221. When the pole piece 300 is wound on the heat shrink film 200 and passes through the docking position of the winding end end 220 and the winding start end 210, it can pass through the docking position of the winding end end 220 and the winding start end 210 more smoothly and continue to be wound, thereby preventing the pole piece 300 from wrinkling and causing abnormal tension, and then causing damage to the pole piece 300.

[0073] For explanation, see Figure 3 The second transition surface 221 of the heat shrink film 200 is set at a second angle 260 with the third surface 230, and the second angle 260 is equal to the first angle 250. In this way, the second transition surface 221 of the winding end 220 of the heat shrink film 200 can match and splice with the first transition surface 211 of the winding starting end 210, and the splicing between the winding end 220 and the winding starting end 210 is smoother. The connecting end 330 of the pole piece 300 is clamped between the first transition surface 211 and the second transition surface 221. In this way, when the pole piece 300 is wound on the heat shrink film 200 and passes through the docking position of the winding end end 220 and the winding starting end 210, it can pass through the docking position of the winding end end 220 and the winding starting end 210 more smoothly and continue to be wound, thereby preventing the pole piece 300 from wrinkling.

[0074] See also Figures 3 to 7 In one embodiment, the first angle is greater than or equal to 30 degrees and less than or equal to 50 degrees.

[0075] The first angle is less than 50 degrees to allow the electrode 300 to transition more smoothly from the reel 100 to the surface of the heat shrink film 200 through the first transition surface 211, preventing the electrode 300 from generating wrinkles and abnormal tension at the winding starting end 210 in the initial stage of winding; the first angle is greater than 30 degrees to ensure that the thickness of the heat shrink film 200 meets the requirements, preventing the separation gap 400 generated after heating from being too small, making it difficult to separate the electrode 300 and the reel 100.

[0076] For explanation, if the first angle is too large, wrinkles will be generated on the pole piece 300 at the starting end 210 of the winding; when the first angle is too small, in order to make the thickness of the heat shrink film 200 meet the requirements, the length of the first transition surface 211 must be increased. Based on this, the first angle is set within the range of greater than or equal to 30 degrees and less than or equal to 50 degrees to improve the above problem.

[0077] See also Figure 2 and Figure 5 In one embodiment, the axis direction of the reel 100 is set to the first direction (ie Figure 2 (direction A in the figure), the length of the reel 100 along the first direction is greater than the width of the pole piece 300.

[0078] The length of the reel 100 along the first direction is greater than the width of the pole piece 300. Thus, after the pole piece 300 is wound up, at least one end of the reel 100 can protrude from the pole piece 300 in the width direction of the pole piece 300. When the pole piece 300 needs to be separated from the reel 100, the heat shrink film 200 is heated to form a separation gap 400 between the reel 100 and the pole piece 300. At this time, it is only necessary to push or pull the end of the reel 100 protruding from the pole piece 300 to move the reel 100 relative to the pole piece 300 along the first direction, so that the pole piece 300 can be quickly separated from the reel 100. Such a setting can speed up the separation speed between the reel 100 and the pole piece 300 at a low cost, thereby improving production efficiency.

[0079] For explanation, in the above embodiment, “the width of the pole piece 300 ” refers to the width of the pole piece 300 along the axial direction (ie, the first direction) of the reel 100 when the pole piece 300 is wound on the reel 100 .

[0080] Furthermore, in one embodiment, when one end of the reel 100 protrudes from the pole piece 300 in the width direction of the pole piece 300 and the other end is located in the separation gap 400, the end of the reel 100 protruding from the pole piece 300 is pushed or pulled to move the reel 100 relative to the pole piece 300 and separate the reel 100; when both ends of the reel 100 protrude from the pole piece 300 in the width direction of the pole piece 300, it is sufficient to push or pull any one end of the reel 100, which is easy to operate and will not be repeated here.

[0081] See also Figure 2 In one embodiment, the step of removing the roll 100 from the separation gap 400 further includes the following steps:

[0082] Fix the pole piece 300 and apply an external force to one end of the reel 100 to move the reel 100 along a first direction relative to the pole piece 300;

[0083] The reel 100 is separated from the pole piece 300 .

[0084] The length of the reel 100 along the first direction is greater than the length of the pole piece 300. Thus, when the pole piece 300 needs to be separated from the reel 100, the pole piece 300 is fixed and an external force is applied to one end of the reel 100. The reel 100 moves along the first direction under the action of the external force to enable the pole piece 300 to be quickly separated from the reel 100. In this way, the separation between the reel 100 and the pole piece 300 can be achieved efficiently and at low cost without damaging the reel 100.

[0085] Furthermore, under normal circumstances, the connection end 330 of the pole piece 300 and the reel 100 are connected to each other by tape. When the reel 100 moves along the first direction relative to the pole piece 300 under the resistance of the unloading mechanism, the tape also loses its stickiness under the action of external force. At this time, the reel 100 is taken out from the separation gap 400 to achieve rapid separation between the pole piece 300 and the reel 100.

[0086] In one embodiment, a unloading mechanism (not shown in the figure) is provided. The unloading mechanism includes a grabbing unit, a resistance unit and a driving unit. The grabbing unit and the resistance unit are both connected to the driving unit. The driving unit is used to drive the grabbing unit to grab or release the wound pole piece 300. The driving unit is also used to drive the resistance unit to move back and forth along the axial direction of the reel 100. The resistance unit is used to resist the resistance end of the reel 100. When in use, the driving unit drives the grabbing unit to grab the wound pole piece 300, and then drives the resistance unit to resist the resistance end of the reel 100. The driving unit drives the resistance unit to move along the axial direction of the reel 100, so that the reel 100 moves in a first direction relative to the pole piece 300, thereby achieving rapid separation between the pole piece 300 and the reel 100.

[0087] In another embodiment, the step of removing the roll 100 from the separation gap 400 further includes the following steps:

[0088] The reel 100 is placed vertically so that the pole piece 300 moves relative to the reel 100 under the action of gravity;

[0089] The reel 100 is separated from the pole piece 300 .

[0090] When it is necessary to separate the pole piece 300 from the reel 100, the reel 100 is placed vertically. At this time, the pole piece 300 on the reel 100 moves relative to the reel 100 under the action of gravity, so that the pole piece 300 and the reel 100 are quickly separated. This arrangement can achieve the separation between the reel 100 and the pole piece 300 efficiently and at low cost without damaging the reel 100.

[0091] See also Figure 2 and Figure 7In one embodiment, the axial direction of the reel 100 is set as a first direction, and the width of the heat shrinkable film 200 along the first direction is greater than the width of the pole piece 300 .

[0092] The width of the heat shrink film 200 along the first direction is greater than the width of the electrode 300. In this way, when the electrode 300 is wound on the heat shrink film 200, at least one side of the heat shrink film 200 along the first direction will protrude from the electrode 300. When the heat shrink film 200 needs to be heated, the part of the heat shrink film 200 protruding from the electrode 300 can better absorb heat and transfer the heat to the middle part of the heat shrink film 200, so that the heat shrink film 200 shrinks faster, thereby improving the separation speed and separation efficiency between the electrode 300 and the reel 100.

[0093] For explanation, in the above embodiment, the “width of the heat shrink film 200 ” refers to the width of the heat shrink film 200 along the axial direction (i.e., the first direction) of the reel 100 when the heat shrink film 200 is wound on the reel 100 , and the “width of the pole piece 300 ” refers to the width of the pole piece 300 along the axial direction (i.e., the first direction) of the reel 100 when the pole piece 300 is wound on the reel 100 .

[0094] Preferably, the width of the heat shrink film 200 along the first direction is 10 mm to 20 mm greater than the width of the pole piece 300. In this way, the heat shrink film 200 can effectively absorb heat and prevent the heat shrink film 200 from being too wide, resulting in low heating efficiency and waste of the heat shrink film 200.

[0095] In one embodiment, the thickness of the heat shrinkable film 200 is greater than or equal to 0.08 mm and less than or equal to 0.5 mm.

[0096] The thickness of the heat shrink film 200 is greater than or equal to 0.08 mm, so that after the heat shrink film 200 is heated, a wider separation gap 400 can be formed between the reel 100 and the pole piece 300, which facilitates the separation between the pole piece 300 and the reel 100; the thickness of the heat shrink film 200 is less than or equal to 0.5 mm, so as to reduce the heating time of the heat shrink film 200, save the raw materials of the heat shrink film 200, and reduce costs.

[0097] In one embodiment, the heat shrinkable film 200 is made of at least one of polypropylene, polyethylene, polyester, polyethylene terephthalate, polyvinyl chloride, and oriented polystyrene.

[0098] The heat shrink film 200 is made of at least one of the above materials. The above materials have good heat shrinkage performance and low cost, and can reduce costs while ensuring the separation effect between the reel 100 and the pole piece 300.

[0099] Furthermore, when the polymer chains inside the heat-shrinkable film 200 are heated, the "thawed" chain segments are stimulated to move (memory effect), and curl up through the internal rotation of the single bonds in the polymer chains. They will spontaneously move from the stretched state to the direction of increasing entropy, that is, the polymer chains transform into a curled state, which manifests as a heat shrinkage phenomenon on a macro scale.

[0100] Table 1 Shrinkage rate and separation effect of heat shrink film 200 under different conditions

[0101]

[0102] Please refer to Table 1, wherein D is the thickness of the heat shrinkable film 200, α is the first angle 250 of the heat shrinkable film 200, H is the heating temperature of the heat shrinkable film 200, T is the heating time of the heat shrinkable film 200, MD is the longitudinal shrinkage rate of the heat shrinkable film 200, and TD is the transverse shrinkage rate of the heat shrinkable film 200.

[0103] By way of explanation, MD is calculated as follows:

[0104]

[0105] TD is calculated as follows:

[0106]

[0107] Among them, D1 is the distance between the winding end 220 and the winding starting end 210 of the heat shrinkable film 200 before heating, D2 is the distance between the winding end 220 and the winding starting end 210 of the heat shrinkable film 200 after heating; D3 is the width of the heat shrinkable film 200 in the first direction before heating; D4 is the width of the heat shrinkable film 200 along the first direction after heating.

[0108] It can be seen from Examples 1 to 5 in Table 1 that for heat shrinkable films 200 with different thicknesses D, α, heating temperature H, and heating time T are all the same, and MD ≥ 50% and TD ≥ 40% must be satisfied before the pole piece 300 and the reel 100 can be separated from each other; if the heating time T is insufficient or the thickness D of the heat shrinkable film 200 is too large, MD and TD will not meet the requirements, and the pole piece 300 and the reel 100 will not be able to be separated from each other.

[0109] It can be seen from Examples 6 to 10 in Table 1 that, under the conditions that the thickness D and α of the heat shrinkable film 200 are the same, increasing the heating temperature H can shorten the heating time T. After heating, the heat shrinkable film 200 can meet MD ≥ 50% and TD ≥ 40%, and the pole piece 300 and the roll 100 can be separated from each other.

[0110] It can be seen from Examples 11 to 14 in Table 1 that, under the conditions that the thickness D of the heat shrinkable film 200 is the same, α is the same, and the heating temperature H is the same, extending the heating time T has a very limited effect on improving MD and TD, and instead reduces the separation efficiency between the pole piece 300 and the roll 100.

[0111] It can be seen from Comparative Example 1 in Table 1 that if the thickness D of the heat shrinkable film 200 is too small, after the heat shrinkable film 200 is heated, the separation gap 400 will be too small, and even if MD ≥ 50% and TD ≥ 40% are satisfied, the pole piece 300 and the roll 100 will be difficult to separate.

[0112] It can be seen from Comparative Example 2 in Table 1 that since the material of the reel 100 is mainly acrylonitrile-butadiene-styrene plastic (ABS), the normal operating temperature range of the reel 100 is between -40°C and 100°C. If the heating temperature H is too high, the surface of the reel 100 will soften and deform, thereby causing irreversible damage to the reel 100. Even if MD ≥ 50% and TD ≥ 40% are met, the pole piece 300 and the reel 100 cannot be separated.

[0113] It can be seen from Comparative Example 3 in Table 1 that if α is too large, even if MD ≥ 50% and TD ≥ 40% are satisfied, wrinkles will appear on the surface of the pole piece 300 at the winding starting end 210, resulting in abnormal tension, reducing the effective utilization rate of the pole piece 300 and causing waste of the pole piece 300.

[0114] It can be seen from the embodiments and comparative examples in Table 1 that, preferably, in the present application, the thickness D of the heat shrinkable film 200 is between 0.08 mm and 0.5 mm, the α of the heat shrinkable film 200 is between 30 degrees and 50 degrees, the heating temperature H of the heat shrinkable film 200 is between 75°C and 90°C, and the heating time T of the heat shrinkable film 200 is between 90s and 300s.

[0115] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for winding and separating a pole piece, wherein the pole piece has a connection end and a first surface and a second surface opposite to each other, characterized in that: The steps include: Providing a roll and a heat shrinkable film, wherein the heat shrinkable film has opposite winding start and winding end ends; connecting the connecting end to the surface of the drum; The winding start end is attached to the drum and positioned on one side of the first surface, and the heat shrink film is wound around the circumference of the drum so that the winding end is wound back to one side of the second surface and attached to the drum; Winding the electrode sheet onto the surface of the heat shrinkable film; heating the heat shrinkable film and shrinking the heat shrinkable film to form a separation gap between the roll and the pole piece; The roll is removed from the separation gap.

2. The electrode winding and separation method according to claim 1, characterized in that: The side surface of the heat shrinkable film facing the roll is the third surface, the side surface of the heat shrinkable film facing away from the roll is the fourth surface, and the winding starting end has a first transition surface connecting the third surface and the fourth surface, and the first transition surface is arranged at a first angle with the third surface, and the first angle is an acute angle.

3. The electrode winding and separation method according to claim 2, characterized in that: The winding end has a second transition surface connecting the third surface and the fourth surface. The second transition surface is arranged at a second angle with the fourth surface, and the angle of the second angle is equal to the angle of the first angle.

4. The electrode winding and separation method according to claim 3, characterized in that: The first angle is greater than or equal to 30 degrees and less than or equal to 50 degrees.

5. The electrode winding and separation method according to claim 1, characterized in that: The axis direction of the drum is set as a first direction, and the length of the drum along the first direction is greater than the width of the pole piece.

6. The electrode winding and separation method according to claim 5, characterized in that: The step of removing the roll from the separation gap further includes the following steps: Fixing the pole piece, and applying an external force to one end of the drum to move the drum relative to the pole piece along the first direction; The reel is separated from the pole piece.

7. The electrode winding and separation method according to claim 5, characterized in that: The step of removing the roll from the separation gap further includes the following steps: placing the drum upright so that the pole piece moves relative to the drum under the action of gravity; The reel is separated from the pole piece.

8. The electrode winding and separation method according to claim 1, characterized in that: The axis direction of the roll is set as a first direction, and the width of the heat shrinkable film along the first direction is greater than the width of the pole piece.

9. The electrode winding and separation method according to claim 1, characterized in that: The thickness of the heat shrinkable film is greater than or equal to 0.08 mm and less than or equal to 0.5 mm.

10. The electrode winding and separation method according to claim 1, characterized in that: The heat shrinkable film is made of at least one of polypropylene, polyethylene, polyester, polyethylene terephthalate, polyvinyl chloride, and oriented polystyrene.

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