Pole piece coating method and coating device

Abstract

The invention discloses a coating method and a coating device of a pole piece, and the coating method of the pole piece comprises the following steps: controlling a coating die head to coat active slurry on a current collector at intervals along the length direction of the current collector so as to form a plurality of first active layers distributed at intervals and spacer regions located between any two adjacent first active layers; controlling the coating die head to coat the active slurry in the spacer region of the current collector so as to form a second active layer; a gap is formed between any end of the second active layer and the adjacent first active layer, the width of the gap is D1, and D1 is smaller than 13 mm. According to the invention, by controlling the length of the spacer region and the length of the second active layer, the active coatings with smaller intervals can be formed on the current collector, so that the empty foil region on the cut pole piece is shorter and does not need to be rolled into the innermost ring of a roll core, the internal space of the battery is prevented from being occupied, and the effects of improving the energy density and the performance of the battery are achieved.

Description

Technical Field

[0001] The present invention relates to the field of lithium batteries, and in particular to a coating method and a coating device for a pole piece. Background Art

[0002] In the production of lithium-ion batteries, the continuous coating process is widely used in the preparation of positive and negative electrode sheets. This process can achieve high-speed, continuous coating production, significantly improving production efficiency and output. In the traditional continuous coating process, the coating die is usually opened and closed at preset time intervals to form a coating on the foil and leave gaps between each coating. This process requires the die to respond quickly to the opening and closing instructions in order to accurately control the gap between the coatings.

[0003] However, it is difficult to quickly close and restart the existing coating die in a short time, resulting in a large coating gap (greater than 13 mm) formed on the electrode. This large gap forms a long empty foil area 111, i.e., an area without coating, during the subsequent cutting process. Figure 1 , Figure 2 As shown, part of the empty foil area 111 in the middle area of ​​the pole piece 110 is used to set the pole lug 120, and the empty foil area 111 at the end of the pole piece 110 is usually rolled into the innermost circle of the winding core 100 during the preparation process of the lithium battery. Since these empty foil areas 111 not only cannot provide any capacity for the winding core 100, but also occupy the internal space of the battery, the energy density of the battery is reduced, affecting the overall performance of the battery. Summary of the invention

[0004] The embodiments of the present invention provide a coating method and a coating device for a pole piece to solve the problem of a large coating gap, thereby reducing the length of an empty foil area and achieving the effect of improving the energy density of a battery.

[0005] Specifically, the present invention provides a coating method for a pole piece, comprising the following steps: Controlling the coating die head to coat the active slurry on the current collector at intervals along the length direction of the current collector to form a plurality of first active layers distributed at intervals and a spacing area between any two adjacent first active layers; Controlling the coating die to coat the active slurry in the spacer of the current collector to form a second active layer, wherein a gap exists between any end of the second active layer and the adjacent first active layer, and the width of the gap is D1, and D1 is less than 13 mm; Along the length direction parallel to the current collector, the length of the first active layer is L1, and the length of the second active layer is L2; ​​L1= L2, or L1≠L2; The area of ​​the current collector facing the gap is formed as an empty foil area, and at least a part of the empty foil area is used to provide a cutting position for cutting the electrode sheet.

[0006] Optionally, along the length direction of the current collector, the length of the spacing zone is L3, L3-L1=6mm~8mm.

[0007] Optionally, the width of the gap D1 is 2-9 mm.

[0008] Preferably, the width D1 of the gap is 3 mm to 4 mm.

[0009] Optionally, the coating die head includes a first sub-die head; the coating die head is controlled to coat the active slurry on the current collector at intervals along the length direction of the current collector, comprising: Controlling the current collector to move along a first direction, and controlling the first sub-die to start and close at a first preset time interval, so as to coat the active slurry on the current collector at intervals; Alternatively, the first sub-die head is controlled to move along the second direction, and the first sub-die head is controlled to start and close at a first preset time interval, so as to coat the active slurry on the current collector at intervals.

[0010] Optionally, controlling the coating die head to coat the active slurry in the spacer area of ​​the current collector comprises: Controlling the current collector to move along a first direction, and controlling the first sub-die to start and close at a second preset time interval, so as to apply the active slurry in the spaced area; Alternatively, the first sub-die head is controlled to move along a second direction, and the first sub-die head is controlled to start and close at a second preset time interval, so as to coat the active slurry in the spaced area.

[0011] Optionally, the coating die head further comprises a second sub-die head; The controlling the coating die head to coat the active slurry in the spacer area of ​​the current collector comprises: Controlling the current collector to move along a first direction, and controlling the second sub-die head to start and close at a third preset time interval, so as to apply the active slurry in the spacer area; Alternatively, the first sub-die head is controlled to move along the second direction, and the second sub-die head is controlled to start and close at a third preset time interval, so as to coat the active slurry in the spaced area.

[0012] Optionally, the discharge port of the second sub-die head and the discharge port of the first sub-die head are spaced apart in a length direction parallel to the current collector and the spacing is D2, D2-L1=D1; the current collector is controlled to move along the first direction, and the first sub-die head and the second sub-die head are controlled to be started and closed at intervals, so as to coat the active slurry on the current collector to form the first active layer and the second active layer; Alternatively, the first sub-die head and the second sub-die head are controlled to move synchronously along the second direction, and the first sub-die head and the second sub-die head are controlled to start and close at intervals, so as to coat the active slurry on the current collector to form the first active layer and the second active layer.

[0013] Optionally, the empty foil area is used to provide the cutting position; or, Part of the empty foil area is used to provide the cutting position, and part of the empty foil area is used to set the electrode ear.

[0014] Optionally, the electrode sheet is a positive electrode sheet, and the active slurry of the positive electrode sheet includes a ternary positive electrode material; Part of the empty foil area is used to provide a cutting position for cutting the electrode piece, and part of the empty foil area is used to set the electrode ear.

[0015] The present invention also provides a coating device, comprising: A coating die head, wherein the coating die head is used to coat the active slurry on the current collector; A feed pipe, the feed pipe is connected to the coating die head and is used to transport the active slurry to the coating die head; A coating valve, wherein the coating valve is disposed between the coating die head and the feed pipe; when the coating valve is in an open state, the coating die head is connected to the feed pipe; when the coating valve is in a closed state, the coating die head is disconnected from the feed pipe; A control device, the control device includes a memory, a processor and a machine executable program stored in the memory and running on the processor, and the processor implements the coating method of the electrode according to any one of the above items when executing the machine executable program.

[0016] Optionally, the coating die head includes a first sub-die head, and the first sub-die head is configured to be movable along the length direction of the current collector; the first sub-die head is connected to the coating valve.

[0017] Optionally, the coating die also includes a second sub-die, which is spaced apart from the first sub-die, and is configured to be movable along the length direction of the current collector; there are two coating valves, one coating valve is disposed between the first sub-die and the feed pipe, and the other coating valve is disposed between the second sub-die and the feed pipe.

[0018] Optionally, the coating device further includes a buffer tank, in which the active slurry is stored; the buffer tank is connected to the feed pipe.

[0019] Optionally, the coating device further comprises a feed return pipe and a feed return valve, wherein both ends of the feed return pipe are respectively connected to the buffer tank and the feed supply pipe; the feed return valve is arranged on the feed return pipe, and when the feed return valve is in an open state, the buffer tank is connected to the feed supply pipe; when the feed return valve is in a closed state, the buffer tank is disconnected from the feed supply pipe; When the coating valve is in an open state, the return valve and are in a closed state; when the coating valve is in a closed state, the return valve and are in an open state.

[0020] The beneficial effects of the present invention are: In the coating method and coating device method of the pole piece provided by the present invention, due to the large gap coating method, the active slurry is coated on the current collector at intervals to form a first active layer and a spacing area between two first active layers, and the active slurry is coated in the spacing area to form a second active layer. There is also a large interval between two adjacent second active layers. Therefore, by controlling the length of the spacing area and the length of the second active layer, the coating die head does not need to be quickly closed and restarted in a short time to form an active coating layer (including the first active layer and the second active layer) with a smaller interval on the current collector, so that the empty foil area on the cut pole piece is shorter, and there is no need to be rolled into the innermost circle of the winding core, so as to avoid occupying the internal space of the battery, thereby achieving the effect of improving the energy density and performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0022] Figure 1 It is a schematic structural diagram of a winding core in the prior art; Figure 2 It is a schematic structural diagram of a pole piece in the prior art; Figure 3 is a schematic structural diagram of a winding core in one embodiment of the present invention; Figure 4 is a schematic flow chart of a coating method for a pole piece in one embodiment of the present invention; Figure 5 is a schematic structural diagram of a pole piece in one embodiment of the present invention; Figure 6It is a schematic structural diagram of a pole piece in one embodiment of the present invention.

[0023] In the figure: 100, winding core, 110, pole piece, 111, empty foil area, 120, pole ear; 200, winding core, 210, current collector, 211, empty foil area, 220, first active layer, 230, spacer area, 240, second active layer, 250, third active layer, 260, pole ear, 310, first sub-die head, 320, second sub-die head. DETAILED DESCRIPTION In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be glue injection inside two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Figure 3 is a schematic structural diagram of a winding core in one embodiment of the present invention, such as Figure 3 As shown, and refer to Figures 4 to 6 The embodiment of the present invention provides a coating method for a pole piece, comprising the following steps: Controlling the coating die head to coat the active slurry on the current collector 210 at intervals along the length direction of the current collector 210 to form a plurality of first active layers 220 distributed at intervals and a spacing area 230 located between any two adjacent first active layers 220; Controlling the coating die to coat the active slurry in the spacer 230 of the current collector 210 to form a second active layer 240 , wherein a gap is provided between any end of the second active layer 240 and the adjacent first active layer 220 , and the width of the gap is D1, and D1 is less than 13 mm; Along the length direction parallel to the current collector 210, the length of the first active layer is L1, and the length of the second active layer is L2; ​​L1= L2, or L1≠L2; The area of ​​the current collector 210 facing the gap is formed as an empty foil area 211, and at least a part of the empty foil area 211 is used to provide a cutting position for cutting the electrode sheet.

[0028] In the embodiment of the present invention, the active slurry is coated on the current collector 210 at intervals by adopting a large gap coating method to form a plurality of first active layers 220 distributed at intervals and a spacing area 230 located between any two adjacent first active layers 220, and the active slurry is coated in the spacing area 230 to form the second active layer 240, and there is also a large interval between two adjacent second active layers 240 (the length is greater than the length of the first active layer 220). Therefore, by controlling the length of the spacing area 230 and the length of the second active layer 240, the coating die head does not need to be quickly closed and restarted in a short time to coat an active coating with a smaller interval (including the first active layer 220 and the second active layer 240, and the gap between the first active layer 220 and the second active layer 240 is smaller) on the current collector 210, so that the empty foil area 211 on the cut electrode piece is shorter (not exceeding 13 mm), and does not need to be rolled into the innermost circle of the winding core 200, so as to avoid occupying the internal space of the battery, thereby achieving the effect of improving the energy density and performance of the battery.

[0029] In one embodiment of the present invention, the width D1 of the gap is 2-9 mm. If the width D1 of the gap is too large, the length of the empty foil area 211 on the electrode after cutting is too long, and the medicine is rolled into the innermost circle of the winding core 200; if the width D1 of the gap is too small, the cutting position during cutting is too close to the first active layer 220 or the second active layer 240, and powder is easily cut off. Specifically, the width D1 of the gap is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm or 9 mm. Preferably, the width D1 of the gap is 3 mm to 4 mm.

[0030] In one embodiment of the present invention, the length of the spacer is L3 along the length direction of the current collector 210, L3-L1=6mm-8mm. During coating, after the active slurry is coated in the center of the spacer 230 to form the second active layer 240, the width D1 of the gap between any end of the second active layer 240 and the adjacent first active layer 220 can be 3mm-4mm.

[0031] like Figure 4 As shown, in one embodiment of the present invention, the coating die head includes a first sub-die head 310; the coating die head is controlled to coat the active slurry on the current collector 210 at intervals along the length direction of the current collector 210, including: Controlling the current collector 210 to move along a first direction, and controlling the first sub-die head 310 to start and close at a first preset time interval, so as to coat the active slurry on the current collector 210 at intervals; Alternatively, the first sub-die head 310 is controlled to move along the second direction, and the first sub-die head 310 is controlled to start and close at a first preset time interval, so as to coat the active slurry on the current collector 210 at intervals.

[0032] This embodiment provides a variety of solutions for moving the first sub-die head 310 relative to the current collector 210 to accommodate different coating devices; and, by controlling the first sub-die head 310 to start and close at a first preset time interval, the first sub-die head 310 can coat the active slurry and form the first active layer 220 when it is turned on, and leave a spacer area 230 on the current collector 210 when the first sub-die head 310 is closed.

[0033] Furthermore, the controlling the coating die head to coat the active slurry in the spacer 230 of the current collector 210 comprises: Controlling the current collector 210 to move along a first direction, and controlling the first sub-die head 310 to start and close at a second preset time interval, so as to apply the active slurry in the spacer 230; Alternatively, the first sub-die head 310 is controlled to move along the second direction, and the first sub-die head 310 is controlled to start and close at a second preset time interval, so as to apply the active slurry in the spacer area 230 .

[0034] After the first active layer 220 is formed, the first sub-die 310 is controlled to perform secondary coating in the spacer 230, so as to form the second active layer 240 in the spacer 230. Similarly, this embodiment provides a variety of solutions for moving the first sub-die 310 relative to the current collector 210 during secondary coating to adapt to different coating devices.

[0035] like Figure 5 As shown, in an alternative embodiment of the present invention, the coating die head further includes a second sub-die head 320; the controlling the coating die head to coat the active slurry in the spacer 230 of the current collector 210 includes: Controlling the current collector 210 to move along a first direction, and controlling the second sub-die head 320 to start and close at a third preset time interval, so as to apply the active slurry in the spacer 230; Alternatively, the first sub-die head 310 is controlled to move along the second direction, and the second sub-die head 320 is controlled to start and close at a third preset time interval, so as to apply the active slurry in the spacer area 230 .

[0036] In this embodiment, the second sub-die 320 is provided so that the second sub-die 320 is turned on / off at a third preset time interval during coating to form the second active layer 240 ; compared with the second coating by the first sub-die 310 , the process can be saved.

[0037] Further, the discharge port of the second sub-die head 320 and the discharge port of the first sub-die head 310 are arranged in a longitudinal direction parallel to the current collector 210 at intervals of D2, and D2-L1=D1; the current collector 210 is controlled to move along the first direction, and the first sub-die head 310 and the second sub-die head 320 are controlled to be started and closed at intervals, so as to coat the active slurry on the current collector 210 to form the first active layer 220 and the second active layer 240; Alternatively, the first sub-die head 310 and the second sub-die head 320 are controlled to move synchronously along the second direction, and the first sub-die head 310 and the second sub-die head 320 are controlled to start and close at intervals to coat the active slurry on the current collector 210 to form the first active layer 220 and the second active layer 240 .

[0038] In this embodiment, the first active layer 220 and the second active layer 240 are formed at the same time; that is, the distance L1 that the first sub-die head 310 moves relative to the current collector 210 when it is closed is the same as the distance L2 that the second sub-die head 320 moves relative to the current collector 210 when it is closed, and both are greater than the length of the second active layer 240 or the first active layer 220; therefore, by controlling the interval between the first sub-die head 310 and the second sub-die head 320, the interval between the formed first active layer 220 and the second active layer 240 can be made smaller, thereby reducing the length of the empty foil area 211 on the pole piece, and improving the energy density of the core 200 and the performance of the battery.

[0039] like Figure 6 As shown, in one embodiment of the present invention, the empty foil area is used to provide the cutting position so that the current collector can be cut off in the empty foil area to obtain a pole piece; or, part of the empty foil area is used to provide the cutting position, and part of the empty foil area is used to set the pole ear 260. This setting can directly reserve the position for setting the pole ear 260 during coating without etching the pole ear groove, thereby simplifying the processing of the pole piece.

[0040] In one embodiment of the present invention, the electrode sheet is a positive electrode sheet, and the active slurry of the positive electrode sheet includes a ternary positive electrode material; part of the empty foil area is used to provide a cutting position for cutting the electrode sheet, and part of the empty foil area is used to set the electrode ear 260, avoiding the production of the electrode ear groove through other processes, thereby simplifying the processing of the electrode sheet.

[0041] The positive electrode sheet is usually made of aluminum foil. The melting point of the ternary positive electrode material is higher than that of the lithium cobalt oxide system, and the specific heat capacity is lower than that of the lithium cobalt oxide system and is closer to that of the aluminum foil. If a laser cleaning process is selected to clean part of the active material on the positive electrode sheet to form a tab groove, the laser cleaning window of the ternary material is narrower than that of the lithium cobalt oxide material, and it is easy to damage the aluminum foil. Therefore, when the positive electrode sheet including the ternary positive electrode material in the industry adopts the tab center, the tab groove is generally realized by large gap coating, and the width of the tab groove is greater than 13mm. The present application forms a plurality of first active layers 220 and a plurality of first active layers 220 located at intervals by coating the active slurry on the current collector 210 at intervals. In the manner of a spacer 230 between any two adjacent first active layers 220, the active slurry is coated in the spacer 230 of the current collector 210 to form a second active layer 240, and a gap is provided between any end of the second active layer 240 and the adjacent first active layer 220, and the width of the gap is D1, where D1 is the width of the tab groove. This avoids the tab groove width being too large when the tab is placed in the center of the positive electrode sheet including the ternary positive electrode material, greatly reduces the tab groove width, and can even accurately control the tab groove width within 4 mm, thereby improving the energy density of the battery.

[0042] Specifically, the empty foil area for providing the cutting position and the empty foil area for setting the pole ear 260 are alternately arranged in sequence, so that the cut pole piece simultaneously contains the second active layer 240, the first active layer 220 and an empty foil area for setting the pole ear 260, so that the pole ear 260 can be directly welded on the empty foil area.

[0043] The present invention also provides a coating device, including a coating die, a feeding pipe, a coating valve and a control device, wherein the coating die is used to coat an active slurry on a current collector 210; the feeding pipe is connected to the coating die, and is used to convey the active slurry to the coating die; the coating valve is arranged between the coating die and the feeding pipe; when the coating valve is in an open state, the coating die is connected to the feeding pipe; when the coating valve is in a closed state, the coating die is disconnected from the feeding pipe; the control device includes a memory, a processor and a machine executable program stored in the memory and running on the processor, and when the processor executes the machine executable program, it implements the coating method of the electrode according to any of the above embodiments.

[0044] In one embodiment of the present invention, the coating die head includes a first sub-die head 310, and the first sub-die head 310 is configured to be movable along the length direction of the current collector 210; the first sub-die head 310 is connected to the coating valve. Specifically, the first sub-die head 310 is fixedly arranged, and the current collector 210 is movable along the first direction; or, the current collector 210 is fixedly arranged, and the first sub-die head 310 is movable along the second direction; or, the current collector 210 is movable along the first direction, and the first sub-die head 310 is movable along the second direction.

[0045] In one embodiment of the present invention, the coating die head further includes a second sub-die head 320, which is spaced apart from the first sub-die head 310, and the second sub-die head 320 is configured to be movable along the length direction of the current collector 210; there are two coating valves, one of which is disposed between the first sub-die head 310 and the feed pipe, and the other coating valve is disposed between the second sub-die head 320 and the feed pipe. By disposing the second sub-die head 320, the second sub-die head 320 is started / closed synchronously with the first sub-die head 310 during coating, so that the first active layer 220 and the second active layer 240 can be formed simultaneously, reducing the number of coating times and improving coating efficiency.

[0046] In one embodiment of the present invention, the coating device also includes a circulation pump and a buffer tank, in which the active slurry is stored; the buffer tank is connected to the feed pipe, and the circulation pump is arranged between the buffer tank and the feed pipe to provide power for the transportation of the active slurry.

[0047] Furthermore, the coating device also includes a return pipe and a return valve, and both ends of the return pipe are connected to the buffer tank and the supply pipe respectively; the return valve is arranged on the return pipe, and when the return valve is in an open state, the buffer tank is connected to the supply pipe; when the return valve is in a closed state, the buffer tank is disconnected from the supply pipe; when the coating valve is in an open state, the return valve is in a closed state; when the coating valve is in a closed state, the return valve is in an open state.

[0048] In this embodiment, a return pipe and a return valve are provided so that when the coating valve is in a closed state, the return valve is in an open state, so that the active slurry returns to the buffer tank through the reflux pipe, avoiding frequent opening and closing of the circulation pump, so that the circulation pump can provide stable conveying power.

[0049] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A coating method for a pole piece, characterized in that: The following steps are involved: Controlling the coating die head to coat the active slurry on the current collector (210) at intervals along the length direction of the current collector (210) to form a plurality of first active layers (220) distributed at intervals and a spacing region (230) located between any two adjacent first active layers (220); Controlling the coating die to coat the active slurry in the spacer (230) of the current collector (210) to form a second active layer (240), wherein a gap exists between any end of the second active layer (240) and the adjacent first active layer (220), and the width of the gap is D1, and D1 is less than 13 mm; Along a length direction parallel to the current collector (210), the length of the first active layer (220) is L1, and the length of the second active layer (240) is L2; ​​L1= L2, or L1≠L2; The area of ​​the current collector (210) facing the gap is formed as an empty foil area, and at least part of the empty foil area is used to provide a cutting position for cutting the electrode sheet.

2. The electrode coating method according to claim 1, characterized in that: Along the length direction of the current collector (210), the length of the spacer is L3, where L3-L1=6 mm to 8 mm.

3. The coating method of the pole piece according to claim 1, characterized in that: The width D1 of the gap is 2-9 mm.

4. The coating method of the pole piece according to claim 3, characterized in that: The width D1 of the gap is 3 mm to 4 mm.

5. The electrode coating method according to claim 1, characterized in that: The coating die head comprises a first sub-die head (310); the coating die head is controlled to coat the active slurry on the current collector (210) at intervals along the length direction of the current collector (210), comprising: Controlling the current collector (210) to move along a first direction, and controlling the first sub-die head (310) to start and stop at a first preset time interval, so as to coat the active slurry on the current collector (210) at intervals; Alternatively, the first sub-die head (310) is controlled to move along the second direction, and the first sub-die head (310) is controlled to start and close at a first preset time interval, so as to coat the active slurry on the current collector (210) at intervals.

6. The coating method of the pole piece according to claim 5, characterized in that: The controlling the coating die head to coat the active slurry in the spacer area (230) of the current collector (210) comprises: Controlling the current collector (210) to move along a first direction, and controlling the first sub-die head (310) to start and close at a second preset time interval, so as to apply the active slurry in the spacer area (230); Alternatively, the first sub-die head (310) is controlled to move along a second direction, and the first sub-die head (310) is controlled to start and close at a second preset time interval, so as to apply the active slurry in the spacer area (230).

7. The coating method of the pole piece according to claim 5, characterized in that: The coating die also includes a second sub-die (320); The controlling the coating die head to coat the active slurry in the spacer area (230) of the current collector (210) comprises: Controlling the current collector (210) to move along a first direction, and controlling the second sub-die head (320) to start and stop at a third preset time interval, so as to apply the active slurry in the spacer area (230); Alternatively, the first sub-die head (310) is controlled to move along the second direction, and the second sub-die head (320) is controlled to start and close at a third preset time interval, so as to apply the active slurry in the spacer area (230).

8. The electrode coating method according to claim 7, characterized in that: The discharge port of the second sub-die head (320) and the discharge port of the first sub-die head (310) are arranged in a longitudinal direction parallel to the current collector (210) at an interval of D2, and D2-L1=D1; the current collector (210) is controlled to move in a first direction, and the first sub-die head (310) and the second sub-die head (320) are controlled to start and close at intervals, so as to coat the active slurry on the current collector (210) to form the first active layer (220) and the second active layer (240); Alternatively, the first sub-die head (310) and the second sub-die head (320) are controlled to move synchronously along the second direction, and the first sub-die head (310) and the second sub-die head (320) are controlled to start and close at intervals, so as to coat the active slurry on the current collector (210) to form the first active layer (220) and the second active layer (240).

9. The coating method of the pole piece according to claim 1, characterized in that: The empty foil area is used to provide the cutting position; or, Part of the empty foil area is used to provide the cutting position, and part of the empty foil area is used to set the electrode ear (260).

10. The electrode coating method according to claim 1, characterized in that: The electrode sheet is a positive electrode sheet, and the active slurry of the positive electrode sheet includes a ternary positive electrode material; Part of the empty foil area is used to provide a cutting position for cutting the electrode piece, and part of the empty foil area is used to set the electrode ear (260).

11. A coating device, characterized in that: include: A coating die head, the coating die head is used to coat the active slurry on the current collector (210); A feed pipe, the feed pipe is connected to the coating die head and is used to transport the active slurry to the coating die head; A coating valve, wherein the coating valve is disposed between the coating die head and the feed pipe; when the coating valve is in an open state, the coating die head is connected to the feed pipe; when the coating valve is in a closed state, the coating die head is disconnected from the feed pipe; A control device, the control device comprising a memory, a processor and a machine executable program stored in the memory and running on the processor, and the processor implements the coating method of the electrode according to any one of claims 1 to 10 when executing the machine executable program.

12. The coating device according to claim 11, characterized in that: The coating die head comprises a first sub-die head (310), wherein the first sub-die head (310) is arranged to be movable along the length direction of the current collector (210); the first sub-die head (310) is connected to the coating valve.

13. The coating device according to claim 12, characterized in that: The coating die head further comprises a second sub-die head (320), the second sub-die head (320) being spaced apart from the first sub-die head (310), and the second sub-die head (320) being arranged to be movable along the length direction of the current collector (210); the number of the coating valves is two, one coating valve being arranged between the first sub-die head (310) and the feed pipe, and the other coating valve being arranged between the second sub-die head (320) and the feed pipe.

14. The coating device according to claim 11, characterized in that: The coating device further comprises a buffer tank, in which the active slurry is stored; the buffer tank is connected to the feed pipe; The coating device further comprises a feed return pipe and a feed return valve, wherein both ends of the feed return pipe are respectively connected to the buffer tank and the feed supply pipe; the feed return valve is arranged on the feed return pipe, and when the feed return valve is in an open state, the buffer tank is connected to the feed supply pipe; when the feed return valve is in a closed state, the buffer tank is disconnected from the feed supply pipe; When the coating valve is in an open state, the return valve and are in a closed state; when the coating valve is in a closed state, the return valve and are in an open state.

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