Coating sheet, coating device, coating method, splitting method, and pole sheet

Abstract

The invention discloses a coating piece, a coating device, a coating method, a slitting method and a pole piece, the coating piece comprises a current collector, and at least one side of the current collector is provided with a coating area or is provided with a plurality of coating areas arranged at intervals along a first direction; the multiple coating areas comprise at least one first coating area and at least one second coating area which are alternately arranged in the second direction; the pole piece smear further comprises an active material layer coated on the first coating area and the second coating area; the first coating area is provided with a plurality of uncoated sections which are arranged at intervals in the first direction; a thinning section is arranged at the end, close to the uncoated section, of the active material layer of the first coating area, and the thickness of the thinning section is decreased in the direction close to the uncoated section. Therefore, the pole piece provided by the embodiment of the invention has the characteristics of improving the production efficiency of the battery, reducing the production cost of the battery and reducing the volume energy density of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of battery pole piece manufacturing, and in particular to a coating sheet, a coating device, a coating method, a slitting method and a pole piece. Background Art

[0002] In the related art, the coating sheet used for battery production usually has at least a slot for welding the pole lug and a protective slot corresponding to the slot for welding the pole lug, that is, the coating area of ​​the pole sheet used for battery production will be provided with two types of slots.

[0003] In the related art, a foaming process, a scraper process, a laser cleaning process, etc. are usually used to make grooves on the electrode after coating. For example, Foam glue process: Before coating the pole piece, apply foam glue to the preset position where the groove is required on the current collector, and then coat it. After coating, bake the pole piece to expand the foam glue on the pole piece and lift up the coating layer to make the groove. Then use a brush to sweep away the foam glue and coating layer paint in the groove, and then use a laser to further clean the edge of the groove; Scraping process: After the electrode is coated, a scraper is used to scrape off the coating layer at the position where the groove is required on the electrode to make the groove, and then the edge of the groove is further cleaned by laser; Laser cleaning process: After the electrode is coated, the laser cleaning equipment is used to laser clean the position where the slot is required on the electrode to make the slot, and then the laser is used to further clean the edge of the slot; The above-mentioned processes are all based on the coating process, and other processing techniques are required to produce grooves on the coating area of ​​the pole piece. There are many processing steps, and there are problems of low production efficiency and high production cost. Summary of the invention

[0004] In view of the problem of low efficiency in existing electrode production, the present invention provides a coating sheet, a coating device, a coating method and a slitting method.

[0005] The coating sheet described in the embodiment of the present invention is used for cutting to form positive and negative electrode sheets.

[0006] The coating sheet comprises a current collector, at least one side of the current collector has a coating area or is provided with a plurality of coating areas spaced apart along a first direction, the plurality of coating areas comprising at least one first coating area and at least one second coating area alternately arranged along a second direction; The electrode coating also includes an active material layer coated on the first coating area and the second coating area; the first coating area has a plurality of uncoated sections spaced apart along a first direction; The active material layer in the first coating area is provided with a thinned section at an end portion adjacent to the uncoated section, and the thickness of the thinned section decreases in a direction approaching the uncoated section.

[0007] The coating sheet of the embodiment of the present invention has a plurality of uncoated sections arranged at intervals along the length direction of the current collector on the first coating area. A groove that can be directly used in the subsequent battery production process can be formed on the coating sheet only through a coating process, and there is no need to perform other processes on the coating sheet to make the groove. Therefore, the coating sheet of the embodiment of the present invention can be directly used in the subsequent battery production process after the pole pieces are formed by cutting, thereby greatly improving the production efficiency of the battery and greatly reducing the production cost of the battery.

[0008] At the same time, by arranging a thinning section at the end of the uncoated section adjacent to the active material layer in the first coating area, a bonding basis can be provided for the insulating protective tape in the subsequent battery assembly process, and the thickness of the electrode sheet can be avoided without increasing the exposure of the uncoated electrode sheet, thereby improving the volume energy density of the battery.

[0009] Therefore, the pole piece of the embodiment of the present invention has the characteristics of being able to improve battery production efficiency, reduce battery production cost and battery volume energy density.

[0010] In some embodiments, the coating zone includes a plurality of first coating zones and a plurality of second coating zones; The area located outside the coating area in the second direction is the first coating area and / or the second coating area.

[0011] In some embodiments, the widths of the plurality of first coating regions located on the same side of the current collector are the same, and the widths of the plurality of second coating regions located on the same side of the current collector are the same.

[0012] In some embodiments, the area located outside the coating area in the second direction is the second coating area; The widths of the plurality of first coating regions located on the same side of the current collector are the same; Among the plurality of second coating regions located on the same side of the current collector, at least the plurality of second coating regions spaced between the plurality of first coating regions have the same width.

[0013] In some embodiments, there are two uncoated segments, and the two uncoated segments are respectively a first uncoated segment and a second uncoated segment; The dimension L1 of the first uncoated section in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the first uncoated section in the first direction is 8 mm to 12 mm; The dimension L2 of the second uncoated section in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the second uncoated section in the first direction is 8 mm to 12 mm; The thinned section adjacent to the first uncoated section is a first thinned section, and the thinned section adjacent to the second uncoated section is a second thinned section; The dimension L3 of the first thinning section in the first direction is 2 mm to 6 mm; The dimension L4 of the second thinned section in the first direction is 4 mm-15 mm.

[0014] In some embodiments, both sides of the current collector have a plurality of the coating regions; The uncoated segment located on one side of the current collector is arranged in one-to-one correspondence with the uncoated segment located on the other side of the current collector; the projections of the two corresponding uncoated segments in the thickness direction of the coating sheet at least partially overlap.

[0015] In some embodiments, the number of uncoated sections on the first coating area is two; One of the uncoated sections on the first coated area on one side of the current collector is used to form a pole lug groove on the pole piece, and the other uncoated section is used to form a first alignment groove on the pole piece; the pole lug groove is used to accommodate the pole lug; the first alignment groove is aligned with the pole lug groove, the first alignment groove is used to accommodate the insulating protective adhesive tape, or the open end of the first alignment groove is used to cover the insulating protective adhesive tape; The two uncoated sections on the first coated area on the other side of the current collector are used to form a second alignment groove on the pole piece; the second alignment groove is used to align with the pole ear on the pole piece of the other polarity, and the second alignment groove is used to accommodate the insulating protective tape, or the open end of the second alignment groove is used to cover the insulating protective tape.

[0016] The present invention also provides a coating device for making the coating sheet described in the above embodiment, characterized in that it comprises a die assembly and a material conveying assembly matched with the die assembly and used for conveying the current collector; The die assembly comprises a first die and a second die disposed at intervals and a coating gasket disposed between the first die and the second die; A plurality of first flow channels spaced apart along a second direction are provided between the coating gasket and the first die head, a plurality of second flow channels spaced apart along the second direction are provided between the coating gasket and the second die head, and the first flow channels and the second flow channels are alternately arranged along the second direction; One of the first flow channel and the second flow channel is used to discharge material to a first coating area to coat the first coating area, and the other is used to discharge material to a second coating area to coat the second coating area; The first die head has a first feed port connected to the first flow channel, and the first feed port is connected to one end of a first branch for conveying active material slurry; The second die head has a second feed port connected to the second flow channel, and the second feed port is connected to one end of a second branch for conveying active material slurry.

[0017] In some embodiments, the first die head further has a first chamber, and the first chamber is connected to the first flow channel and the first feed port; The second die head also has a second chamber, and the second chamber is connected with the second flow channel and the second feed port.

[0018] In some embodiments, the feeding device of the embodiment of the present invention further includes a feeding assembly, which includes a storage tank, the other end of the first branch is connected to the storage tank, and the other end of the second branch is connected to the storage tank.

[0019] The coating device according to claim 3 is characterized in that a first valve body is provided on the first branch line, and a second valve body is provided on the second branch line.

[0020] In some embodiments, the first branch of the feeding device of the embodiment of the present invention is further provided with a first reflux valve, and the first reflux valve is located upstream of the first valve body in the feeding direction of the first branch; The second branch line is also provided with a second reflux valve, which is located upstream of the second valve body in the material supply direction of the second branch line.

[0021] In some embodiments, the first branch of the feeding device of the embodiment of the present invention is further provided with a first pump body, and the first pump body is located upstream of the first reflux valve in the feeding direction of the first branch; The second branch line is also provided with a second pump body, and the second pump body is located upstream of the second reflux valve in the material supply direction of the second branch line.

[0022] The present invention further provides a coating method for making the coating sheet described in the above embodiment using the coating device described in the above embodiment, characterized in that it comprises the following steps: During the coating process of a single coating zone: The second flow channel is continuously opened until the coating of the first coating area on a single coating area is completed, and then the second flow channel is closed; the die assembly is continuously coated on the second coating area to form a continuously distributed active material layer on the second coating area; The first flow channel is opened and closed alternately, and the first flow channel is closed at least twice at intervals during the coating process until the first flow channel is closed when the coating of the first coating area on the single coating area is completed; the die head assembly performs intermittent coating on the first coating area to form an active material layer with intervals on the first coating area, and the area of ​​the first coating area exposed from the active material layer with intervals is the uncoated section.

[0023] In some embodiments, the coating method of the present invention comprises the following steps: Step S100: opening the first flow channel and the second flow channel simultaneously to coat the current collector; Step S200: Repeat closing and opening the first flow channel at least once to coat the current collector to form a plurality of uncoated sections in the first coating area, and extend the travel time of closing and opening the first flow channel to form a thinned section at the end of the active material layer adjacent to the uncoated section; Step S300: Closing the first flow channel and the second flow channel simultaneously to coat the current collector; Repeat the above steps to coat the current collector.

[0024] In some embodiments, in step S100, the first valve body and the second valve body are opened, and the first return valve and the second return valve are closed.

[0025] In some embodiments, in step S200, the first valve body is repeatedly closed and opened at least once, and the first reflux valve is repeatedly opened and closed at least once.

[0026] In some embodiments, in step S300, the first valve body and the second valve body are closed, and the first return valve and the second return valve are opened.

[0027] In some embodiments, in step S200, the moving speed of the current collector is V, the size of the thinning section in the first direction is L, and the travel time of closing and opening of the first valve body is T=L / V.

[0028] The embodiment of the present invention further provides a method for cutting the coated sheet described in the above embodiment into electrode sheets, comprising the following steps: Cutting the coated sheet along the second direction; the cutting line of cutting the coated sheet along the second direction is a first cutting line, and the first cutting line is located at the end of the coating area or between adjacent coating areas; Cutting the coated sheet along a first direction; wherein: A slitting line for slitting the coated sheet along the second direction is a second slitting line, and the second slitting line is located between the first coating area and the second coating area, or is located at an edge of the first coating area adjacent to the second coating area; or, The cutting line that cuts the coated sheet along the second direction is a third cutting line, which is located on the middle plane of the first coated areas spaced between the second coated areas and located on the middle plane of the second coated areas spaced between the first coated areas.

[0029] An embodiment of the present invention also provides a pole piece obtained by slitting the coated sheet described in the above embodiment using the slitting method described in the above embodiment, the pole piece having a plurality of uncoated sections spaced apart along a first direction, insulating protective tape being provided at positions on the pole piece corresponding to the uncoated sections, the two ends of the insulating protective tape being respectively connected to the thinned sections adjacent to the uncoated sections.

[0030] In some embodiments, the insulating protective tape corresponding to the first uncoated section is the first insulating protective tape, and the dimension L5 of the first insulating protective tape in the first direction satisfies L1<L5≤L1+2L3-2L3h1 / H, wherein H is the thickness of the active material layer, and h1 is the thickness of the first insulating protective tape.

[0031] In some embodiments, the insulating protective tape corresponding to the second uncoated section is the second insulating protective tape, and the dimension L6 of the second insulating protective tape in the first direction satisfies L2<L6≤L2+2L4-2L4h2 / H, wherein H is the thickness of the active material layer, and h2 is the thickness of the insulating protective tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] 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.

[0033] Figure 1 is a schematic structural diagram of a coating device according to an embodiment of the present invention; Figure 2 is an enlarged view of a die assembly of a coating device according to an embodiment of the present invention; Figure 3 is a schematic structural diagram of a coating gasket of a coating device according to an embodiment of the present invention, which is adjacent to a first die head; Figure 4 is a schematic structural diagram of a coating gasket of a coating device according to an embodiment of the present invention, which is adjacent to a second die head; Figure 5 is a cross-sectional view of a coating pad of a coating device according to an embodiment of the present invention; Figure 6 1 is a schematic structural diagram of a coated sheet according to an embodiment of the present invention; Figure 7 Schematic diagram of slitting according to the slitting method of an embodiment of the present invention; Figure 8 is a slitting schematic diagram of a slitting method according to another embodiment of the present invention; Fig. 9 is a cross-sectional view of a thinned section of an embodiment of the present invention; Fig.10 4 is a cross-sectional view of the insulating protective tape according to an embodiment of the present invention.

[0034] In the figure: 100. Coated sheet; 1. Coating area; 101, first coating area; 102, second coating area; 2. The first uncoated section; 3. The second uncoated section; 4. Die head assembly; 401, first die head; 4011, first chamber; 4012, first feed port; 402, second die head; 4021, second chamber; 4022, second feed port; 403, coating gasket; 4031, first flow channel; 4032, second flow channel; 5. Conveying components; 6. Feeding components; 601, first branch; 6011, first valve body; 6012, first reflux valve; 6013, first pump body; 602, second branch; 6021, second valve body; 6022, second reflux valve; 6023, second pump body; 603. Storage tank; 7. Current collector; 8. The first thinning section; 9. Welding groove; 10. The second thinning section; 11. The first insulating protective tape; 12. Second insulating protective tape; 131, first cutting line; 132, second cutting line; 133, third cutting line; 134, fourth cutting line; 14. Active material layer. DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] 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.

[0038] The following is based on the attached Figure 1-10 A coating sheet 100 according to an embodiment of the present invention is described.

[0039] like Figure 6 As shown, the coated sheet 100 of the embodiment of the present invention includes a current collector 7, at least one side of the current collector 7 has a coating area or has a plurality of coating areas 1 arranged at intervals along a first direction, and the plurality of coating areas 1 include at least one first coating area 101 and at least one second coating area 102 arranged alternately in a second direction; the coated sheet 100 also includes an active material layer 9 coated on the first coating area 101 and the second coating area 102; the first coating area 101 has a plurality of uncoated sections arranged at intervals along the first direction.

[0040] It can be understood that the first direction is the length direction of the current collector 7 and the second direction is the width direction of the current collector 7 . Similarly, the first direction may also be the length direction of the coating sheet 100 and the second direction may also be the width direction of the coating sheet 100 .

[0041] Meanwhile, one side of the current collector 7 refers to one side of the current collector in the thickness direction thereof.

[0042] like Figure 6As shown, a plurality of coating regions 1 are provided on the current collector 7 at intervals along the length direction of the current collector 7 , and the plurality of coating regions 1 include at least a first coating region 101 and at least a second coating region 102 alternately arranged in the width direction of the current collector 7 .

[0043] It can be understood that at least one first coating area 101 and at least one second coating area 102 are alternately arranged in the width direction of the current collector 7, which means that the first coating area 101 and the second coating area 102 are alternately arranged in the width direction of the current collector.

[0044] Meanwhile, the first coating area 101 has a plurality of uncoated sections spaced apart along the length direction of the current collector 7 , and the plurality of uncoated sections can be used as slots in subsequent battery production processes.

[0045] The coated sheet 100 of the embodiment of the present invention is provided with a plurality of uncoated sections spaced apart along the length direction of the current collector 7 on the first coating area 101. A groove that can be directly used in the subsequent battery production process can be formed on the coated sheet 100 only through a coating process, and no other process is required to make the groove on the coated sheet 100. Therefore, the coated sheet 100 of the embodiment of the present invention can be directly used in the subsequent battery production process after the pole pieces are formed by cutting, thereby greatly improving the production efficiency of the battery and greatly reducing the production cost of the battery.

[0046] like Fig.10 As shown, the active material layer in the first coating area is provided with a thinned section at the end adjacent to the uncoated section, and the thickness of the thinned section decreases in a direction approaching the uncoated section.

[0047] The coated sheet 100 of the embodiment of the present invention can provide a bonding basis for the insulating protective tape in the subsequent battery assembly process by setting a thinning section at the end of the uncoated section adjacent to the active material layer in the first coating area 101, and can avoid exposing the uncoated section of the electrode without increasing the thickness of the electrode, thereby improving the volume energy density of the battery.

[0048] Therefore, the pole piece of the embodiment of the present invention has the characteristics of being able to improve battery production efficiency, reduce battery production cost and battery volume energy density.

[0049] In some embodiments, the coating zone 1 includes a plurality of first coating zones 101 and a plurality of second coating zones 102; The outermost area of ​​the coating zone 1 in the second direction is the first coating zone 101 and / or the second coating zone 102 .

[0050] In some embodiments, the widths of the plurality of first coating regions 101 located on the same side of the current collector 7 are the same, and the widths of the plurality of second coating regions 102 located on the same side of the current collector 7 are the same.

[0051] In some embodiments, the outermost area of ​​the coating area 1 in the second direction is the second coating area 102; The widths of the plurality of first coating regions 101 located on the same side of the current collector 7 are the same; Among the plurality of second coating regions 102 located on the same side of the current collector 7 , at least the plurality of second coating regions 102 spaced between the plurality of first coating regions 101 have the same width.

[0052] In some embodiments, there are two uncoated segments, and the two uncoated segments are respectively a first uncoated segment 2 and a second uncoated segment 3; The dimension L1 of the first uncoated section 2 in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the first uncoated section 2 in the first direction is 8 mm to 12 mm; The dimension L2 of the second uncoated section 3 in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the second uncoated section 3 in the first direction is 8 mm to 12 mm; The thinning section adjacent to the first uncoated section 2 is the first thinning section, and the thinning section adjacent to the second uncoated section 3 is the second thinning section; The dimension L3 of the first thinning section in the first direction is 2 mm to 6 mm; The dimension L4 of the second thinned section in the first direction is 4 mm-15 mm.

[0053] In some embodiments, both sides of the current collector 7 have a plurality of coating regions 1; The uncoated segment on one side of the current collector 7 is arranged one-to-one with the uncoated segment on the other side of the current collector 7; the projections of the two corresponding uncoated segments in the thickness direction of the coating sheet at least partially overlap.

[0054] In some embodiments, there are two uncoated sections on the first coating area 101; An uncoated section on the first coating area 101 on one side of the current collector 7 is used to form a pole ear groove on the pole piece, and another uncoated section is used to form a first alignment groove on the pole piece; the pole ear groove is used to accommodate the pole ear; the first alignment groove is aligned with the pole ear groove, and the first alignment groove is used to accommodate the insulating protective adhesive tape, or the open end of the first alignment groove is used to cover the insulating protective adhesive tape; The two uncoated sections on the first coating area 101 on the other side of the current collector 7 are used to form a second alignment groove on the pole piece; the second alignment groove is used to align with the pole ear on the pole piece of the other polarity, and the second alignment groove is used to accommodate the insulating protective tape, or the open end of the second alignment groove is used to cover the insulating protective tape.

[0055] The embodiment of the present invention further provides a coating device for manufacturing the coating sheet 100 as described in the above embodiment.

[0056] The following is combined with Figure 1-5 A coating device according to an embodiment of the present invention is described.

[0057] like Figure 1 As shown, the coating device of the embodiment of the present invention includes a die assembly 4 and a conveying assembly matched with the die assembly 4 and used for conveying the current collector 7 .

[0058] The die assembly 4 includes a first die 401 and a second die 402 that are spaced apart and a coating gasket 403 that is disposed between the first die 401 and the second die 402 .

[0059] A plurality of first flow channels 4031 are provided at intervals along the second direction on one side of the coating gasket 403 corresponding to the first die head 401 , and a plurality of second flow channels 4032 are provided at intervals along the second direction on one side of the coating gasket 403 corresponding to the second die head 402 .

[0060] One of the first flow channel 4031 and the second flow channel 4032 is used to discharge material to the first coating area 101 for coating the first coating area 101, and the other is used to discharge material to the second coating area 102 for coating the second coating area 102. A plurality of first flow channels 4031 and a plurality of second flow channels 4032 are alternately arranged along the second direction.

[0061] like Figure 5 As shown, the cross-sectional shapes of the first flow channel 4031 and the second flow channel 4032 are both rectangular, and the end surface of the first flow channel 4031 away from the first die head 401 and the end surface of the second flow channel 4032 away from the second die head 402 are located on the same plane.

[0062] It can be understood that by arranging a coating gasket 403 with a first flow channel 4031 and a second flow channel 4032 on both sides between the first die head 401 and the second die head 402, the current collector 7 wound around the feed assembly 5 can be coated according to the coating needs. For example, the first flow channel 4031 corresponds to the first coating area 101, and the second flow channel 4032 corresponds to the second coating area 102. When both the first coating area 101 and the second coating area 102 need to be coated, The first flow channel 4031 and the second flow channel 4032 are opened; when the first coating area 101 needs to be coated and the second coating area 102 does not need to be coated, the first flow channel 4031 is opened and the second flow channel 4032 is closed; when the first coating area 101 does not need to be coated and the second coating area 102 needs to be coated, the first flow channel 4031 and are closed; when both the first coating area 101 and the second coating area 102 do not need to be coated, the first flow channel 4031 and the second flow channel 4032 are closed.

[0063] The first die head 401 has a first feed port 4012 connected to the first flow channel 4031, and the second die head 402 has a second feed port 4022 connected to the second flow channel 4032; the first feed port 4012 is connected to one end of a first branch 601 for conveying active material slurry, and a first valve body 6011 is provided on the first branch 601, and the second feed port 4022 is connected to one end of a second branch 602 for conveying active material slurry, and a second valve body 6021 is provided on the second branch 602.

[0064] The working mode of the first flow channel 4031 and the second flow channel 4032 of the coating device of an embodiment of the present invention will be described below in conjunction with the accompanying drawings and taking as an example a coating sheet 100 in which the first coating area 101 has two uncoated sections, namely a first uncoated section 2 and a second uncoated section 3, which are spaced apart along the length direction of the current collector 7.

[0065] When coating to the first uncoated section 2 or the second uncoated section 3, the first flow channel 4031 is closed and the second flow channel 4032 is opened, so that the first coating area 101 corresponding to the first flow channel 4031 stops coating, and as the conveying component drives the current collector 7 to move, the first uncoated section 2 or the second uncoated section 3 is formed on the first coating area 101; When coating to the gap between two adjacent coating areas 1, the first flow channel 4031 and the second flow channel 4032 are both closed, so that the first coating area 101 and the second coating area 102 corresponding to the first flow channel 4031 and the second flow channel 4032 stop coating, and as the feeding component 5 drives the current collector 7 to rotate, an empty foil area is formed on the current collector 7, that is, an empty foil area located between two adjacent coating areas 1 is formed on the current collector 7; When coating to other areas except the above-mentioned areas, the first flow channel 4031 and the second flow channel 4032 are opened at the same time, so as to coat the first coating area 101 and the second coating area 102 at the same time.

[0066] It can be understood that when coating the current collector 7 having the first uncoated section 2 and the second uncoated section 3 spaced apart along the length direction of the current collector 7 in the second coating area 102 , a coating method similar to the above can also be adopted.

[0067] Therefore, the coating device of the embodiment of the present invention can coat the current collector 7 wound around the feed assembly 5 according to coating needs by arranging a coating gasket 403 with a first flow channel 4031 and a second flow channel 4032 on both sides between the first die head 401 and the second die head 402, and can directly form the first uncoated section 2 and the second uncoated section 3 on the current collector 7 during the coating process, without the need to perform other processes on the coating sheet 100 to make grooves, so that the coating sheet 100 formed by the coating device of the embodiment of the present invention can be directly used in the subsequent battery production process after the pole pieces are cut to form, thereby greatly improving the production efficiency of the battery and greatly reducing the production cost of the battery.

[0068] Therefore, the coating device according to the embodiment of the present invention has the characteristics of being able to improve battery production efficiency and reduce battery production costs.

[0069] In some embodiments, the first die head 401 has a first chamber 4011 , which is connected to the first flow channel 4031 and the first feed port 4012 ; the second die head 402 has a second chamber 4021 , which is connected to the second flow channel 4032 and the second feed port 4022 .

[0070] Furthermore, the first chamber 4011 and the second chamber 4021 are both hemispherical, and the openings of the first chamber 4011 and the second chamber 4021 are both facing the coating gasket 403 .

[0071] Preferably, the diameters of the first chamber 4011 and the second chamber 4021 are both 3-15 mm.

[0072] Furthermore, the first chamber 4011 of the first die 401 and the second chamber 4021 of the second die 402 are symmetrically arranged, thereby ensuring that the distance between the first feed port 4012 and the first flow channel 4031 and the distance between the second feed port 4022 and the second flow channel 4032 are equal, so as to facilitate the control of the pressure of the first chamber 4011 and the second chamber 4021.

[0073] In some embodiments, the coating device of the embodiment of the present invention further includes a feeding assembly 6, which includes a storage tank 603, the other end of the first branch 601 is connected to the storage tank 603, and the other end of the second branch 602 is connected to the storage tank 603.

[0074] The coating device of the embodiment of the present invention is provided with a feeding component 6, and uses the first branch 601 and the second branch 602 to connect the storage tank 603 and the first feed port 4012, as well as the storage tank 603 and the second feed port 4022, respectively, so as to facilitate the control of the feeding of the first feed port 4012 and the second feed port 4022. For example, when the first feed port 4012 needs to be fed or the feeding is stopped, it is only necessary to control the opening and closing of the first valve body 6011. Similarly, when the second feed port 4022 needs to be fed or the feeding is stopped, it is only necessary to control the opening and closing of the second valve body 6021, thereby greatly improving the convenience of controlling the feeding component 6.

[0075] In some embodiments, a first return valve 6012 is further provided on the first branch 601, and the first return valve 6012 is located upstream of the first valve body 6011 in the supply direction of the first branch 601; a second return valve 6022 is further provided on the second branch 602, and the second return valve 6022 is located upstream of the second valve body 6021 in the supply direction of the second branch 602.

[0076] It can be understood that when the first valve body 6011 is closed, opening the first return valve 6012 can facilitate the coating slurry in the first branch 601 to flow back into the storage tank 603, thereby preventing the coating slurry from clogging the first branch 601 for a long time. Similarly, when the second valve body 6021 is closed, opening the second return valve 6022 can facilitate the coating slurry in the second branch 602 to flow back into the storage tank 603, thereby preventing the coating slurry from clogging the second branch 602 for a long time.

[0077] At the same time, when the first valve body 6011 is opened, closing the first return valve 6012 can make the coating slurry in the first branch 601 flow in one direction, that is, flow from the storage tank 603 to the first feed port 4012, thereby avoiding the problem of backflow of the coating slurry in the first branch 601. Similarly, when the second valve body 6021 is opened, closing the second return valve 6022 can make the coating slurry in the second branch 602 flow in one direction, that is, flow from the storage tank 603 to the second feed port 4022, thereby avoiding the problem of backflow of the coating slurry in the second branch 602.

[0078] The coating device of the embodiment of the present invention can prevent the coating slurry from blocking the first branch 601 and the second branch 602 by setting the first reflux valve 6012 and the second reflux valve 6022 on the one hand; on the other hand, it can prevent the coating slurry in the first branch 601 and the second branch 602 from flowing back.

[0079] In some embodiments, a first pump body 6013 is further provided on the first branch 601, and the first pump body 6013 is located upstream of the first reflux valve 6012 in the supply direction of the first branch 601; a second pump body 6023 is further provided on the second branch 602, and the second pump body 6023 is located upstream of the second reflux valve 6022 in the supply direction of the second branch 602.

[0080] It can be understood that by setting the first pump body 6013 on the first branch 601, the parameters such as the feed pressure and the feed speed of the coating slurry in the first branch 601 can be more accurately controlled. Similarly, by setting the second pump body 6023 on the second branch 602, the parameters such as the feed pressure and the feed speed of the coating slurry in the second branch 602 can be more accurately controlled, thereby further improving the accuracy and convenience of feed control.

[0081] The embodiment of the present invention further provides a coating method for making the coating sheet of the above embodiment using the coating device of the above embodiment, comprising the following steps: During coating in a single coating zone 1: The second flow channel 4032 is continuously opened until the coating of the second coating area 102 on the single coating area 1 is completed, and then the second flow channel 4032 is closed; so that the die assembly 4 continuously coats the second coating area 102, thereby forming a continuously distributed active material layer on the second coating area 102; The first flow channel 4031 is opened and closed alternately, and is closed at least twice at intervals during the coating process until the first coating area 101 on the single coating area 1 is coated with the first coating area 101; so that the die head assembly 4 performs intermittent coating on the first coating area 101, thereby forming an intermittently distributed active material layer on the first coating area 101, and the area of ​​the first coating area 101 exposed from the intermittently distributed active material layer is an uncoated section.

[0082] In some embodiments, the coating method of the present invention comprises the following steps: Step S100: opening the first flow channel 4031 and the second flow channel 4032 simultaneously to coat the current collector 7; Step S200: repeatedly closing and opening the first flow channel 4031 at least once, coating the current collector 7, so as to form a plurality of uncoated sections in the first coating area 101; Step S300: closing the first flow channel 4031 and the second flow channel 4032 at the same time to stop coating the current collector 7; Repeat the above steps to coat the current collector 7 .

[0083] The coating method of the embodiment of the present invention can form multiple uncoated sections as grooves on the first coating area 101 simply by controlling the opening and closing of the first flow channel 4031 during the coating process of the electrode, without performing other processes on the coating sheet 100 to make the grooves, so that the coating sheet 100 formed by the coating method of the embodiment of the present invention can be directly used in the subsequent battery production process after the electrode is cut, thereby greatly improving the production efficiency of the battery and greatly reducing the production cost of the battery.

[0084] At the same time, the coating method of the embodiment of the present invention prolongs the travel time of closing and opening the first flow channel, and coats a thinned section at the end of the active material layer in the first coating area adjacent to the uncoated section, which can provide a bonding basis for the insulating protective tape in the subsequent battery assembly process, and can avoid exposing the uncoated section of the electrode without increasing the thickness of the electrode, thereby improving the volume energy density of the battery.

[0085] The following is combined with Figure 1 The coating method of the embodiment of the present invention is described by taking a coating sheet 100 in which the first coating area 101 has two uncoated sections, namely a first uncoated section 2 and a second uncoated section 3, spaced apart along the length direction of the current collector 7 as an example.

[0086] The coating method comprises the following steps: Step S10: Open the first flow channel 4031 and the second flow channel 4032 simultaneously to coat the current collector 7; Step S20: closing the first flow channel 4031 and opening the second flow channel 4032 to coat the current collector 7, and extending the travel time of closing the first flow channel to form one of the first thinning sections; Step S30: opening the first flow channel 4031 and the second flow channel 4032 at the same time to coat the current collector 7, and extending the travel time of opening the first flow channel to form another first thinning section; Step S40: closing the first flow channel 4031 and opening the second flow channel 4032 to coat the current collector 7, and extending the travel time of closing the first flow channel to form one of the second thinning sections; Step S50: opening the first flow channel 4031 and the second flow channel 4032 at the same time to coat the current collector 7, and extending the opening time of the first flow channel to form another second thinning section; Step S60: close the first flow channel 4031 and the second flow channel 4032 to coat the current collector 7; Repeat the above steps to coat the current collector 7 .

[0087] Figure 1The first stage in the process is the coating stage of step S10. When the coating reaches the first stage, the first flow channel 4031 and the second flow channel 4032 are opened at the same time to coat the current collector 7. Figure 1 The second stage in step S20 is the coating stage. When coating reaches the second stage, the first flow channel 4031 is closed and the second flow channel 4032 is opened to coat the current collector 7 to form a first uncoated section 2, and the travel time of opening the first flow channel is extended to form another first thinning section. Figure 1 The third stage in step S30 is the coating stage. When coating reaches the third stage, the first flow channel 4031 and the second flow channel 4032 are opened at the same time to coat the current collector 7, and the travel time of opening the first flow channel is extended to form another first thinning section. Figure 1 The fourth stage in step S40 is the coating stage. In the fourth coating stage, the first flow channel 4031 is closed and the second flow channel 4032 is opened to coat the current collector 7 to form a second uncoated section 3, and the travel time of closing the first flow channel is extended to form one of the second thinning sections. Figure 1 The fifth stage in step S50 is the coating stage. During the coating fifth stage, the first flow channel 4031 and the second flow channel 4032 are opened at the same time to coat the current collector 7, and the travel time of opening the first flow channel is extended to form another second thinning section. Figure 1 The sixth stage in the step S60 is the coating stage. When coating the sixth stage, the first flow channel 4031 and the second flow channel 4032 are closed to coat the current collector 7 to form an empty foil area between adjacent coating areas.

[0088] When coating the subsequent current collector 71 , the above steps can be repeated.

[0089] It can be understood that the opening and closing of the first flow channel 4031 and the second flow channel 4032 in the coating method of the embodiment of the present invention refers to whether the coating slurry flows out of the first flow channel 4031 and the second flow channel 4032. For example, the opening of the first flow channel 4031 means that the slurry flows out of the first flow channel 4031, and the closing of the first flow channel 4031 means that the slurry stops flowing out of the first flow channel 4031. Similarly, the opening of the second flow channel 4032 means that the slurry flows out of the second flow channel 4032, and the closing of the second flow channel 4032 means that the slurry stops flowing out of the second flow channel 4032.

[0090] The coating method of the embodiment of the present invention can form a first uncoated section 2 and a second uncoated section 3 on the first coating area 101 or the second coating area 102 by controlling the opening and closing of the first flow channel 4031 and the second flow channel 4032 during the coating process of the coating sheet 100, so that the coated coating sheet 100 can be directly used in battery production after being cut into pole pieces, which can greatly improve the production efficiency of the battery.

[0091] At the same time, a thinned section is coated on the end of the active material layer adjacent to the uncoated section in the first coating area, which can provide a bonding basis for the insulating protective tape in the subsequent battery assembly process, and can avoid exposing the uncoated section of the pole piece without increasing the thickness of the pole piece, thereby improving the volume energy density of the battery.

[0092] In some embodiments, in step S100 , the first valve body 6011 and the second valve body 6021 are opened, and the first return valve 6012 and the second return valve 6022 are closed.

[0093] The coating method of the embodiment of the present invention can avoid the problem of backflow of the coating slurry in the first branch 601 and the second branch 602 on the basis of supplying the coating slurry to the first feed port 4012 and the second feed port 4022 by opening the first valve body 6011 and the second valve body 6021 in step S100 and closing the first return valve 6012 and the second return valve 6022.

[0094] In some embodiments, in step S200, the first valve body 6011 is repeatedly closed and opened at least once, and the first return valve 6012 is repeatedly opened and closed at least once.

[0095] The coating method of the embodiment of the present invention can form multiple uncoated sections on the first coating area 101 without affecting the coating of the second coating area 102 by repeatedly closing and opening the first valve body 6011 at least once and repeatedly opening and closing the first return valve 6012 at least once in step S200.

[0096] In some embodiments, in step S300 , the first valve body 6011 and the second valve body 6021 are closed, and the first return valve 6012 and the second return valve 6022 are opened.

[0097] The coating method of the embodiment of the present invention can form an empty foil area between two adjacent coating areas 1 on the collector 7 by closing the first valve body 6011 and the second valve body 6021 in step S300, and opening the first return valve 6012 and the second return valve 6022 at the same time can avoid the problem of clogging of the coating slurry in the first branch 601 and the second branch 602.

[0098] The method according to claim 19 is characterized in that, in step S200, the moving speed of the current collector 7 is V, the size of the thinning section in the first direction is L, and the travel time of closing and opening of the first valve body is T=L / V.

[0099] For example, in step S20 , the moving speed of the current collector 7100 is V, and the closing stroke time of the first valve body 6011 is T1=L3 / V.

[0100] For example, in step S30, the moving speed of the current collector 7100 is V, and the opening travel time of the first valve body 6011 is T2=L3 / V.

[0101] For example, in step S40 , the moving speed of the pole piece 100 is V, and the closing stroke time of the first valve body 6011 is T1=L4 / V.

[0102] For example, in step S50, the moving speed of the pole piece 100 is V, and the opening stroke time of the first valve body 6011 is T2=L4 / V.

[0103] The coating method of the embodiment of the present invention can form the first thinning section 8 and the second thinning section 10 at the ends of the active material layer adjacent to the first uncoated section 2 and the second uncoated section 3 respectively by extending the closing time and the opening time of the first valve body 6011.

[0104] The embodiment of the present invention further provides a method for cutting the coated sheet 100 described in the above embodiment into pole pieces.

[0105] The slitting method of the embodiment of the present invention comprises the following steps: The coated sheet 100 is cut along the second direction; the cutting line of the coated sheet 100 is a first cutting line 81, and the first cutting line 81 is located at the end of the coating area 1 or between adjacent coating areas 1; The coated sheet 100 is cut along a first direction; wherein: The slitting line for slitting the coated sheet 100 along the first direction is the second slitting line 82, and the second slitting line 82 is located between the first coating area 101 and the second coating area 102, or located at an edge of the first coating area 101 adjacent to the second coating area 102; or, The cutting line for cutting the coated sheet 100 along the first direction is the third cutting line 83, and the third cutting line 83 is located on the middle dividing plane of the first coating area 101 between the second coating areas 102, or is located on the middle dividing plane of the second coating area 102 between the first coating areas 101; specifically, when there are multiple first coating areas 101 and second coating areas 102, the middle dividing planes of the first coating areas 101 between the second coating areas 102 are all used as the cutting positions, and the middle dividing planes of the second coating areas 102 between the first coating areas 101 are all used as the cutting positions.

[0106] In one embodiment, if Figure 7 As shown, a method for cutting a coating sheet (100) for cutting into a negative electrode sheet (i.e., a negative electrode sheet) comprises the following steps: The coated sheet 100 is cut along the second direction; the cutting line for cutting the coated sheet 100 along the second direction is a first cutting line 81, and the first cutting line is located between the adjacent coating areas 1; in order to reduce the length of the empty foil segment of the current collector of the negative electrode sheet, the sheet can be cut along two first cutting lines 81 between the adjacent coating areas 1, and the empty foil segment of the current collector between the two first cutting lines 81 is cut off; The coated sheet 100 is cut along a first direction; wherein: A cutting line that cuts the coated sheet 100 along the second direction is a second cutting line, and the second cutting line is located at an edge of the first coating area 101 adjacent to the second coating area 102 .

[0107] Preferably, the outermost area of ​​the coating area 1 in the second direction is the second coating area 102; when the width of the second coating area 102 located at the outermost side of the coating area 1 in the second direction on the pole piece exceeds the requirement, the second coating area 102 located at the outermost side of the coating area 1 in the second direction can be cut along the first direction, and the cutting line for cutting the second coating area 102 located at the outermost side of the coating area 1 in the second direction is the fourth cutting line 84.

[0108] In one embodiment, if Figure 8 As shown, a method for cutting a coating sheet (100) for cutting into a negative electrode sheet (i.e., a negative electrode sheet) comprises the following steps: The coated sheet 100 is cut along the second direction; the cutting line for cutting the coated sheet 100 along the second direction is a first cutting line 81, and the first cutting line is located between the adjacent coating areas 1; in order to reduce the length of the empty foil segment of the current collector of the negative electrode sheet, the sheet can be cut along two first cutting lines 81 between the adjacent coating areas 1, and the empty foil segment of the current collector between the two first cutting lines 81 is cut off; The coated sheet 100 is cut along a first direction; wherein: The cutting line that cuts the coated sheet 100 along the first direction is the third cutting line 83, part of the third cutting line 83 is located on the middle plane of the first coating area 101 between the second coating areas 102, and the remaining third cutting line 83 is located on the middle plane of the second coating area 102 between the first coating areas 101.

[0109] Preferably, the outermost area of ​​the coating area 1 in the second direction is the second coating area 102; when the width of the second coating area 102 located at the outermost side of the coating area 1 in the second direction on the pole piece exceeds the requirement, the second coating area 102 located at the outermost side of the coating area 1 in the second direction can be cut along the first direction, and the cutting line for cutting the second coating area 102 located at the outermost side of the coating area 1 in the second direction is the fourth cutting line 84.

[0110] In one embodiment, the method for cutting the coated sheet 100 for cutting to form the positive electrode sheet (i.e., the positive electrode sheet) can refer to the steps of the aforementioned embodiment of the method for cutting the coated sheet 100 for cutting to form the negative electrode sheet (i.e., the negative electrode sheet).

[0111] Preferably, the first cutting line is located at the end of the coating area 1, so that the end of the current collector of the positive electrode sheet is also coated with the dressing, and the empty foil section of the excess current collector is removed.

[0112] The embodiment of the present invention further provides a pole piece produced by slitting the coating sheet 100 described in the above embodiment using the slitting method described in the above embodiment.

[0113] The pole piece of the embodiment of the present invention has a plurality of uncoated sections arranged at intervals along the first direction, and insulating protective tape is provided at positions corresponding to the uncoated sections on the pole piece, and both ends of the insulating protective tape are respectively connected to thinned sections adjacent to adjacent uncoated sections.

[0114] Furthermore, the insulating protective tape corresponding to the first uncoated section 2 is the first insulating protective tape, the two ends of the first insulating protective tape are respectively connected to the two first thinned sections, a space for the thermally heated pole ear is defined between the first insulating protective tape and the pole piece, and a dimension L5 of the first insulating protective tape in the first direction satisfies L1<L5≤L1+2L3-2L3h1 / H, wherein H is the thickness of the active material layer, and h1 is the thickness of the first insulating protective tape.

[0115] At the same time, if Figure 5 and 6As shown, a welding groove 913 for accommodating the pole ear is provided on the first uncoated section 2. It can be understood that by providing a welding groove 9 for accommodating the pole ear on the first uncoated section 2, a sinking area can be formed in the first uncoated section 2, thereby preventing the pole ear from protruding from the surface of the coating area 1 after welding, thereby reducing the possibility of interference between the pole ear and the external structure.

[0116] Furthermore, the insulating protective tape corresponding to the second uncoated section 3 is the second insulating protective tape 12, and the dimension L6 of the second insulating protective tape 12 in the first direction satisfies L2<L6≤L2+2L4-2L4h2 / H, wherein H is the thickness of the active material layer, and h2 is the thickness of the insulating protective tape.

[0117] The electrode of the embodiment of the present invention is provided with a second insulating protective tape on the second uncoated section 3. When manufacturing the battery cell, the second insulating protective tape of the second uncoated section 3 can correspond to the first insulating protective tape of the first uncoated section 2, which can further reduce the possibility of exposure of the first uncoated section 2 and the second uncoated section 3, and can further improve the safety of the battery.

[0118] 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 sheet for cutting to form positive and negative electrode sheets, characterized in that: The coating sheet (100) comprises a current collector (7), wherein at least one side of the current collector (7) has a coating area (1) or is provided with a plurality of coating areas (1) arranged at intervals along a first direction, wherein the plurality of coating areas (1) comprise at least one first coating area (101) and at least one second coating area (102) arranged alternately along a second direction; The electrode coating further comprises an active material layer (14) coated on the first coating area (101) and the second coating area (102); the first coating area (101) has a plurality of uncoated sections arranged at intervals along a first direction; The active material layer (14) of the first coating area (101) is provided with a thinning section at the end adjacent to the uncoated section, and the thickness of the thinning section decreases in a direction approaching the uncoated section.

2. A coated sheet according to claim 1, characterized in that: The coating area (1) comprises a plurality of first coating areas (101) and a plurality of second coating areas (102); The area located outside the coating area (1) in the second direction is the first coating area (101) and / or the second coating area (102).

3. A coated sheet according to claim 2, characterized in that: The widths of the plurality of first coating regions (101) located on the same side of the current collector (7) are the same, and the widths of the plurality of second coating regions (102) located on the same side of the current collector (7) are the same.

4. A coated sheet according to claim 2, characterized in that: An area located outside the coating area (1) in the second direction is the second coating area (102); The widths of the plurality of first coating regions (101) located on the same side of the current collector (7) are the same; Among the plurality of second coating regions (102) located on the same side of the current collector (7), at least the plurality of second coating regions (102) spaced between the plurality of first coating regions (101) have the same width.

5. A coated sheet according to claim 1, characterized in that: There are two uncoated sections, which are a first uncoated section (2) and a second uncoated section (3); The dimension L1 of the first uncoated section (2) in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the first uncoated section (2) in the first direction is 8 mm to 12 mm; The dimension L2 of the second uncoated section (3) in the first direction is 5 mm to 15 mm; Preferably, the dimension L1 of the second uncoated section (3) in the first direction is 8 mm to 12 mm; The thinned section adjacent to the first uncoated section (2) is a first thinned section, and the thinned section adjacent to the second uncoated section (3) is a second thinned section; The dimension L3 of the first thinning section in the first direction is 2 mm to 6 mm; The dimension L4 of the second thinned section in the first direction is 4 mm-15 mm.

6. A coated sheet according to claim 1, characterized in that: Both sides of the current collector (7) are provided with a plurality of coating areas (1); The uncoated segment located on one side of the current collector (7) is arranged in one-to-one correspondence with the uncoated segment located on the other side of the current collector (7); the projections of the two correspondingly arranged uncoated segments in the thickness direction of the coating sheet at least partially overlap.

7. A coated sheet according to claim 6, characterized in that: The number of uncoated sections on the first coating area (101) is set to be two; One of the uncoated sections on the first coating area (101) located on one side of the current collector (7) is used to form a pole lug groove on the pole piece, and the other uncoated section is used to form a first alignment groove on the pole piece; the pole lug groove is used to accommodate the pole lug; the first alignment groove is aligned with the pole lug groove, the first alignment groove is used to accommodate the insulating protective adhesive tape, or the open end of the first alignment groove is used to cover the insulating protective adhesive tape; The two uncoated sections on the first coating area (101) located on the other side of the current collector (7) are used to form a second alignment groove on the pole piece; the second alignment groove is used to align with the pole ear on the pole piece of the other polarity, and the second alignment groove is used to accommodate the insulating protective tape, or the open end of the second alignment groove is used to cover the insulating protective tape.

8. A coating device for producing a coating sheet as claimed in any one of claims 1 to 7, characterized in that: It comprises a die assembly (4) and a material conveying assembly matched with the die assembly (4) and used for conveying a current collector (7); The die assembly (4) comprises a first die (401) and a second die (402) which are arranged at an interval, and a coating gasket (403) arranged between the first die (401) and the second die (402); A plurality of first flow channels (4031) spaced apart and distributed along a second direction are provided between the coating gasket (403) and the first die head (401); a plurality of second flow channels (4032) spaced apart and distributed along the second direction are provided between the coating gasket (403) and the second die head (402); the first flow channels (4031) and the second flow channels (4032) are alternately arranged along the second direction; One of the first flow channel (4031) and the second flow channel (4032) is used to discharge material to the first coating area (101) so as to coat the first coating area (101), and the other is used to discharge material to the second coating area (102) so as to coat the second coating area (102); The first die head (401) has a first feed port (4012) connected to the first flow channel (4031), and the first feed port (4012) is connected to one end of a first branch (601) for conveying active material slurry; The second die head (402) has a second feed port (4022) connected to the second flow channel (4032), and the second feed port (4022) is connected to one end of a second branch (602) for conveying active material slurry.

9. The coating device according to claim 8, characterized in that: The first die head (401) further comprises a first chamber (4011), wherein the first chamber (4011) is connected to the first flow channel (4031) and the first feed port (4012); The second die head (402) further comprises a second chamber (4021), and the second chamber (4021) is connected to the second flow channel (4032) and the second feed port (4022).

10. The coating device according to claim 8, characterized in that: It also comprises a material supply assembly (6), the material supply assembly (6) comprising a material storage tank (603), the other end of the first branch (601) being connected to the material storage tank (603), and the other end of the second branch (602) being connected to the material storage tank (603).

11. The coating device according to claim 8, characterized in that: The first branch (601) is provided with a first valve body (6011), and the second branch (602) is provided with a second valve body (6021).

12. The coating device according to claim 11, characterized in that: A first reflux valve (6012) is also provided on the first branch (601), and the first reflux valve (6012) is located upstream of the first valve body (6011) in the material supply direction of the first branch (601); A second reflux valve (6022) is also provided on the second branch (602), and the second reflux valve (6022) is located upstream of the second valve body (6021) in the material supply direction of the second branch (602).

13. The coating device according to claim 12, characterized in that: A first pump body (6013) is also provided on the first branch line (601), and the first pump body (6013) is located upstream of the first reflux valve (6012) in the material supply direction of the first branch line (601); A second pump body (6023) is also provided on the second branch (602), and the second pump body (6023) is located upstream of the second reflux valve (6022) in the material supply direction of the second branch (602).

14. A coating method for producing a coating sheet according to any one of claims 1 to 4 using a coating device according to any one of claims 8 to 13, characterized in that: The steps include: During the coating process of a single coating zone (1): The second flow channel (4032) is continuously opened until the coating of the first coating area (101) on a single coating area (1) is completed, and then the second flow channel (4032) is closed; the die assembly (4) is enabled to continuously coat the second coating area (102), so as to form a continuously distributed active material layer on the second coating area (102); The first flow channel (4031) is opened and closed alternately, and the first flow channel (4031) is closed at least twice at intervals during the coating process until the first flow channel (4031) is closed when the coating of the first coating area (101) on a single coating area (1) is completed; the die head assembly (4) performs intermittent coating on the first coating area (101) to form an active material layer distributed at intervals on the first coating area (101), and the area of ​​the first coating area (101) exposed from the active material layer distributed at intervals is the uncoated section.

15. A method according to claim 14, characterized in that: The steps include: Step S100: opening the first flow channel (4031) and the second flow channel (4032) simultaneously to coat the current collector (7); Step S200: Repeat closing and opening the first flow channel (4031) at least once, coating the current collector (7) to form a plurality of uncoated sections in the first coating area (101), and at the same time prolonging the travel time of closing and opening the first flow channel (4031) to form a thinned section at the end of the active material layer (14) adjacent to the uncoated section; Step S300: Closing the first flow channel (4031) and the second flow channel (4032) simultaneously to coat the current collector (7); Repeat the above steps to coat the current collector (7).

16. The method according to claim 15, characterized in that In step S100, the first valve body (6011) and the second valve body (6021) are opened, and the first return valve (6012) and the second return valve (6022) are closed.

17. The method according to claim 15, characterized in that In step S200, the first valve body (6011) is repeatedly closed and opened at least once, and the first return valve (6012) is repeatedly opened and closed at least once.

18. The method according to claim 15, characterized in that In step S300, the first valve body (6011) and the second valve body (6021) are closed, and the first return valve (6012) and the second return valve (6022) are opened.

19. The method according to claim 15, characterized in that In step S200, the moving speed of the current collector (7) is V, the size of the thinning section in the first direction is L, and the travel time of closing and opening of the first valve body (6011) is T=L / V.

20. A method for cutting the coated sheet according to any one of claims 1 to 7 into electrode sheets, characterized in that: The steps include: The coated sheet (100) is cut along a second direction; the cutting line for cutting the coated sheet (100) along the second direction is a first cutting line (81), and the first cutting line (81) is located at an end of the coating area (1) or between adjacent coating areas (1); The coated sheet (100) is cut along a first direction; wherein: A slitting line for slitting the coated sheet (100) along the first direction is a second slitting line (82), and the second slitting line (82) is located between the first coating area (101) and the second coating area (102), or is located at an edge of the first coating area (101) adjacent to the second coating area (102); or, A cutting line that cuts the coated sheet (100) along the first direction is a third cutting line (83), and the third cutting line (83) is located on a mid-plane of the first coated areas (101) spaced between the second coated areas (102), or is located on a mid-plane of the second coated areas (102) spaced between the first coated areas (101).

21. A pole piece obtained by slitting the coated sheet according to any one of claims 1 to 7 using the slitting method according to claim 20, characterized in that: The pole piece has a plurality of uncoated sections spaced apart along a first direction, and insulating protective adhesive tape is provided at positions on the pole piece corresponding to the uncoated sections, and two ends of the insulating protective adhesive tape are respectively connected to the thinned sections adjacent to the uncoated sections.

22. A pole piece according to claim 21, characterized in that: The insulating protective tape corresponding to the first uncoated section (2) is the first insulating protective tape, and the dimension L5 of the first insulating protective tape in the first direction satisfies L1<L5≤L1+2L3-2L3h1 / H, wherein H is the thickness of the active material layer (14), and h1 is the thickness of the first insulating protective tape (11).

23. A pole piece according to claim 21, characterized in that: The insulating protective tape corresponding to the second uncoated section (3) is the second insulating protective tape, and the dimension L6 of the second insulating protective tape in the first direction satisfies L2<L6≤L2+2L4-2L4h2 / H, wherein H is the thickness of the active material layer (14), and h2 is the thickness of the insulating protective tape.

Images