Pole piece coating method and pole piece coating device

Abstract

The invention belongs to the technical field of pole piece coating, and discloses a pole piece coating method and a pole piece coating device.In the pole piece coating method, a current collector is controlled to be conveyed in the length direction of the current collector; performing jump coating on the current collector along the length direction of the current collector to form a plurality of pole piece areas; wherein the pole piece area comprises two coating areas which are arranged at an interval along the length direction of the current collector, the area between the two coating areas is an uncoated jump coating area, and an uncoated pole piece interval area is arranged between any two adjacent pole piece areas; coating the jump coating area to form a supplementary coating area and an uncoated tab welding area; wherein the supplementary coating area and the tab welding area are sequentially arranged in the width direction of the current collector, so that after the current collector is subjected to jump coating, the jump coating area is coated again, the tab can be welded to the tab welding area, and the supplementary coating area can still serve as an effective coating area, so that the capacity loss of the battery cell is reduced.

Description

Technical Field

[0001] This invention relates to the field of electrode coating technology, and more particularly to electrode coating methods and apparatus. Background Technology

[0002] To improve battery charge / discharge rate performance, some solutions have begun to adopt a centrally located tab structure. Currently, there are generally two methods to achieve this: laser powder removal and gap coating. Laser powder removal is more complex, increasing electrode processing time and costs. Furthermore, the powder removal process requires strict dust control; otherwise, it can easily lead to poor K-value in the finished cell. For these reasons, related technologies mostly use gap coating. During gap coating, coating needs to stop at the tab welding area to leave space for tab welding. However, only a portion of the tab welding area is used for welding, leaving other empty foil areas unused, resulting in significant capacity loss in the cell. Summary of the Invention

[0003] According to one aspect of the present invention, an electrode coating method is provided to solve the problem in the prior art that other empty foil areas in the electrode tab welding area cannot be utilized, resulting in a large capacity loss in the battery cell.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] Electrode coating methods include:

[0006] S100: Drives the current collector to transport along its length;

[0007] S200: The current collector is applied in a skip coating along its length to form several electrode regions; wherein, each electrode region includes two coating regions spaced apart along the length of the current collector, the area between the two coating regions is an uncoated skip coating area, and the area between any two adjacent electrode regions is an uncoated electrode spacing area.

[0008] S300: Coating is applied to the skipped coating area to form a supplementary coating area and an uncoated tab welding area; wherein the supplementary coating area and the tab welding area are arranged sequentially along the width direction of the current collector.

[0009] As a preferred embodiment of the electrode coating method, step S300 includes:

[0010] S3001: Identify and recognize an unpainted blank area;

[0011] S3002: Determine that the identified blank area is the skipped painting area;

[0012] S3003: Coating is applied to the identified blank areas to form supplementary coating areas and uncoated tab welding areas.

[0013] As a preferred embodiment of the electrode coating method, step S3002 includes:

[0014] S30021: Obtain the dimension of the identified blank area along the length direction of the current collector;

[0015] S30022: Compare the size of the identified blank area along the length of the current collector with the size of a preset size;

[0016] If the size of the identified blank area along the length of the current collector is smaller than a preset size, then the identified blank area is determined to be the skip-paint area, and step S2003 is executed.

[0017] As a preferred embodiment of the electrode coating method, if the size of the identified blank area along the length direction of the current collector is not less than a preset size, then the identified blank area is determined to be the electrode spacing area, and the process returns to step S3001.

[0018] As a preferred embodiment of the electrode coating method, the following steps are also included after step S300:

[0019] S400: The current collector is cut to obtain several segmented current collectors; wherein each of the segmented current collectors includes one of the electrode regions.

[0020] As a preferred embodiment of the electrode coating method, in step S300, there are multiple supplementary coating areas and multiple electrode tab welding areas, and the multiple supplementary coating areas and the multiple electrode tab welding areas are staggered sequentially along the width direction of the current collector.

[0021] The electrode coating method further includes the following steps after step S400:

[0022] S500: The segmented current collector is cut to obtain multiple electrode sheets; wherein each of the electrode sheets includes a supplementary coating area and a tab welding area.

[0023] According to another aspect of the present invention, an electrode coating apparatus is provided for carrying out the above-described electrode coating method, the electrode coating apparatus comprising:

[0024] A conveying mechanism is used to convey the current collector along its length.

[0025] The first extrusion die is used to apply the current collector in a skip coating along the length of the current collector to form several electrode areas;

[0026] The second extrusion die is located downstream of the first extrusion die along the conveying direction of the current collector. The second extrusion die is used to coat the skipped coating area to form a supplementary coating area and an uncoated tab welding area.

[0027] As a preferred embodiment of the electrode coating apparatus, it further includes an identification device located between the first extrusion die and the second extrusion die along the conveying direction of the current collector; the identification device is capable of acquiring the size of the identified blank area along the length direction of the current collector.

[0028] As a preferred embodiment of the electrode coating apparatus, the distance between the identification device and the second extrusion die is a preset distance. The second extrusion die is configured to determine that the identified blank area is the skipped coating area, and after a preset time, coat the skipped coating area to form a supplementary coating area and an uncoated electrode tab welding area.

[0029] The preset distance and the preset time satisfy the following:

[0030] ;

[0031] Where L is the preset distance, v is the conveying speed of the current collector, and Δt is the preset time.

[0032] As a preferred embodiment of the electrode coating apparatus, a drying chamber is also included, located downstream of the second extrusion die along the conveying direction of the current collector, and the drying chamber is used to dry the coated current collector.

[0033] The beneficial effects of this invention are:

[0034] This invention provides an electrode coating method. In this method, a current collector is controlled to be transported along its length direction; the current collector is subjected to skip coating along its length direction to form several electrode regions; wherein each electrode region includes two coating regions spaced apart along the length direction of the current collector, the area between the two coating regions is an uncoated skip coating area, and the area between any two adjacent electrode regions is an uncoated electrode gap area; the skip coating area is coated to form a supplementary coating area and an uncoated tab welding area; wherein the supplementary coating area and the tab welding area are arranged sequentially along the width direction of the current collector, so that after the current collector is skip coated, the skip coating area between the two coating regions is coated again to form a supplementary coating area and an uncoated tab welding area. Subsequently, the tab can be welded to the tab welding area, and the supplementary coating area can still be used as an effective coating area, thereby reducing the capacity loss of the battery cell.

[0035] The present invention also provides an electrode coating apparatus for implementing the above-described electrode coating method. The electrode coating apparatus includes a conveying mechanism, a first extrusion die, and a second extrusion die. The conveying mechanism is used to convey the current collector along the length direction of the current collector. The first extrusion die is used to perform skip coating on the current collector along the length direction of the current collector to form several electrode areas. Along the conveying direction of the current collector, the second extrusion die is located downstream of the first extrusion die. The second extrusion die is used to coat the skip coating areas to form supplementary coating areas and uncoated tab welding areas. Thus, by conveying the current collector along the length direction of the current collector through the conveying mechanism, performing skip coating on the current collector along the length direction of the current collector through the first extrusion die to form several electrode areas, and then coating the skip coating areas through the second extrusion die to form supplementary coating areas and uncoated tab welding areas, the capacity loss of the battery cell can be reduced. Attached Figure Description

[0036] Figure 1 This is a first flowchart of the electrode coating method in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the first structure of the current collector in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the second structure of the current collector in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the third structure of the current collector in an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the fourth structure of the current collector in an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the fifth structure of the current collector in an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the first structure of the electrode sheet in an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the second structure of the electrode sheet in an embodiment of the present invention;

[0044] Figure 9 This is a second flowchart of the electrode coating method in an embodiment of the present invention;

[0045] Figure 10 This is a schematic diagram of the electrode coating device in an embodiment of the present invention.

[0046] In the picture:

[0047] 100. Current collector; 101. Electrode; 200. Conveying mechanism; 300. First extrusion die; 400. Second extrusion die; 500. Identification device; 600. Drying oven;

[0048] 1. Electrode area; 11. Coating area; 12. Skip coating area; 121. Replenishment coating area; 122. Tab welding area;

[0049] 2. Electrode spacing area. Detailed Implementation

[0050] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0051] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0054] Example 1

[0055] To achieve center-mounted tabs, the relevant technology uses a gap coating method. During gap coating, coating needs to be stopped in the tab welding area to leave a certain space for tab welding. However, the area used for welding tabs is only a part of the tab welding area, and other empty foil areas in the tab welding area cannot be utilized, resulting in a large capacity loss in the cell.

[0056] In response, this embodiment provides an electrode coating method to solve the problem in the prior art that other empty foil areas in the electrode tab welding area cannot be utilized, resulting in a large capacity loss in the battery cell. This method can be used in the field of electrode coating technology.

[0057] Reference Figure 1 The electrode coating method includes the following steps.

[0058] S100: Drives the current collector 100 to transport along its length.

[0059] Specifically, the current collector 100 can be conveyed by a conveying mechanism.

[0060] S200: The current collector 100 is subjected to a skip coating along its length to form several electrode regions 1; wherein, the electrode region 1 includes two coating regions 11 spaced apart along the length of the current collector 100, the area between the two coating regions 11 is an uncoated skip coating region 12, and the area between any two adjacent electrode regions 1 is an uncoated electrode spacing region 2.

[0061] After the coating process in step S200, the structure of current collector 1 is as follows: Figures 2-4 As shown. Along the length of the current collector 1, the arrangement order of the various parts of the current collector 1 is as follows: electrode spacer region 2, electrode region 1, electrode spacer region 2, electrode region 1, ..., electrode spacer region 2, electrode region 1, electrode spacer region 2. In any electrode region 1 and its two adjacent electrode spacer regions 2, one electrode spacer region 2, one coating region 11 of electrode region 1, the skip coating region 12 between the two coating regions 11, the other coating region 11 of electrode region 1, and the other electrode spacer region 2 are arranged sequentially along the length of the current collector 100.

[0062] S300: Coating is applied to the skipped coating area 12 to form a supplementary coating area 121 and an uncoated tab welding area 122; wherein, the supplementary coating area 121 and the tab welding area 122 are arranged sequentially along the width direction of the current collector 100.

[0063] After the coating process in step S200, the structure of current collector 1 is as follows: Figures 5-6As shown. After the current collector 1 is applied by skip coating, the skip coating area 12 between the two coating areas 11 is coated again to form a supplementary coating area 121 and an uncoated tab welding area 122. The tab can then be welded to the tab welding area 122, while the supplementary coating area 121 can still be used as an effective coating area, thereby reducing the capacity loss of the cell.

[0064] Furthermore, it is understandable that both surfaces of the current collector 1 need to be coated. Figure 3 as well as Figure 5 One of the surfaces of current collector 1 is shown. Figure 4 as well as Figure 6 The other surface of the current collector 1 is shown. Each time the electrode coating method is performed, only one side of the current collector 1 is coated, and the coating method for both surfaces is the same, so it will not be described again.

[0065] Example 2

[0066] This embodiment provides another electrode coating method, which is a specific modification of the electrode coating method in Embodiment 1. (Refer to...) Figure 7 The electrode coating method includes the following steps.

[0067] S100: Drives the current collector 100 to transport along its length.

[0068] S200: The current collector 100 is subjected to a skip coating along its length to form several electrode regions 1; wherein, the electrode region 1 includes two coating regions 11 spaced apart along the length of the current collector 100, the area between the two coating regions 11 is an uncoated skip coating region 12, and the area between any two adjacent electrode regions 1 is an uncoated electrode spacing region 2.

[0069] S300: Coating is applied to the skipped coating area 12 to form a supplementary coating area 121 and an uncoated tab welding area 122; wherein, the supplementary coating area 121 and the tab welding area 122 are arranged sequentially along the width direction of the current collector 100.

[0070] Step S300 includes steps S3001-S3003.

[0071] S3001: Identified an unpainted blank area.

[0072] Specifically, identification can be performed using recognition devices such as visual CCD cameras.

[0073] S3002: The identified blank area is determined to be the skip-paint area 12.

[0074] Step S3002 includes steps S30021-S30022.

[0075] S30021: Obtain the dimensions of the identified blank area along the length of the current collector 100.

[0076] The dimensions of the identified blank area along the length of the current collector 100 can also be obtained by a recognition device such as a visual CCD camera.

[0077] S30022: Compare the size of the identified blank area along the length of the current collector 100 with the preset size.

[0078] If the size of the identified blank area along the length of the current collector 100 is smaller than the preset size, then the identified blank area is determined to be the skip coating area 12, and the subsequent coating operation continues, i.e., step S2003 is executed.

[0079] If the size of the identified blank area along the length of the current collector 100 is not less than the preset size, then the identified blank area is determined to be the electrode spacing area 2, and the process returns to step S3001, and it is determined whether the next identified uncoated blank area is the skip coating area 12.

[0080] Since the electrode region 1 and its two adjacent electrode spacing regions 2 are arranged as follows: one electrode spacing region 2, one coating region 11 of electrode region 1, a skip coating region 12 between the two coating regions 11, another coating region 11 of electrode region 1, and another electrode spacing region 2, the identified blank areas are generally alternating between electrode spacing region 2 and skip coating region 12. Therefore, as an alternative, the identified blank areas can also be counted. When the count is a single count, the identified blank area is determined to be electrode spacing region 2, and when the count is double count, the identified blank area is determined to be skip coating region 12.

[0081] S3003: Coating is applied to the identified blank areas to form a supplementary coating area 121 and an uncoated tab welding area 122.

[0082] S400: The current collector 100 is cut to obtain several segmented current collectors; wherein each segmented current collector includes an electrode region 1.

[0083] The segmented current collector includes an electrode region 1 and a portion of the two adjacent electrode spacing regions 2.

[0084] Optionally, in step S300, multiple supplementary coating areas 121 and multiple electrode welding areas 122 are formed, and the multiple supplementary coating areas 121 and multiple electrode welding areas 122 are staggered sequentially along the width direction of the current collector 100. This results in the current collector 100 having multiple supplementary coating areas 121 and multiple electrode welding areas 122 along its width direction, enabling the cutting of multiple electrode sheets 101.

[0085] The electrode coating method also includes step S500, which is located after step S400.

[0086] S500: The segmented current collector is cut to obtain multiple electrode sheets 101; wherein each electrode sheet 101 includes a supplementary coating area 121 and an electrode tab welding area 122.

[0087] The electrode 101 obtained after cutting is as follows Figures 8-9 As shown in the figure, Figure 8 One surface of electrode 101 is shown. Figure 9 Another surface of electrode 101 is shown.

[0088] Example 3

[0089] This embodiment provides an electrode coating apparatus for implementing the electrode coating method in any of the above embodiments.

[0090] Reference Figure 10 The electrode coating apparatus includes a conveying mechanism 200, a first extrusion die 300, and a second extrusion die 400. The conveying mechanism 200 is used to convey the current collector 100 along its length. The first extrusion die 300 is used to perform skip coating on the current collector 100 along its length to form several electrode regions 1. Along the conveying direction of the current collector 100, the second extrusion die 400 is located downstream of the first extrusion die 300 and is used to coat the skip coating regions 12. The current collector 100 is conveyed along the length of the current collector 100 by the conveying mechanism 200, and the current collector 100 is subjected to skip coating along the length of the current collector 100 by the first extrusion die 300 to form several electrode areas 1. Subsequently, the skip coating areas 12 are coated by the second extrusion die 400 to form the supplementary coating area 121 and the uncoated electrode welding area 122, which can reduce the capacity loss of the battery cell.

[0091] Continue to refer to Figure 10The electrode coating apparatus also includes an identification device 500, located between the first extrusion die 300 and the second extrusion die 400 along the conveying direction of the current collector 100. The identification device 500 can acquire the size of the identified blank area along the length direction of the current collector 100, and is also used to determine whether the identified area is a coated area 11 that has been coated or an uncoated blank area. In this embodiment, the identification device 500 is specifically a CCD vision camera.

[0092] Understandably, the response time between the identification device 500 identifying the skipped coating area 12 and the second extrusion die 400 starting to coat is extremely short. However, there is still a certain distance between the identification device 500 and the second extrusion die 400. Therefore, after the identification device 500 identifies the skipped coating area 12, the time for the second extrusion die 400 to start coating needs to be adjusted.

[0093] In this regard, we will continue to refer to Figure 10 The distance between the identification device 500 and the second extrusion die 400 is a preset distance. The second extrusion die 400 is configured to identify the blank area as the skip coating area 12 and, after a preset time, coat the skip coating area 12 to form a supplementary coating area 121 and an uncoated tab welding area 122.

[0094] The preset distance and preset time satisfy the following formula.

[0095] .

[0096] Where L is the preset distance, v is the conveying speed of the current collector 100 (the conveying speed of the current collector 100 remains constant), and Δt is the preset time.

[0097] With this configuration, after the identification device 500 identifies the skipped coating area 12, the current collector 100 continues to move forward. After a preset time interval, the second extrusion die 400 begins to coat. At this time, the current collector 100 has just moved a preset distance, so that the second extrusion die 400 can start coating from the skipped coating area 12.

[0098] Continue to refer to Figure 10 The electrode coating apparatus also includes a drying chamber 600. Along the conveying direction of the current collector 100, the drying chamber 600 is located downstream of the second extrusion die 400. The drying chamber 600 is used to dry the coated current collector 100 so that the current collector 100 can be further processed.

[0099] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method of coating an electrode sheet, characterized by, Comprising: S100: driving the current collector (100) to transport along the length direction thereof; S200: performing skip coating on the current collector (100) along the length direction thereof to form a plurality of tab regions (1); wherein the tab region (1) comprises two coating regions (11) arranged at intervals along the length direction of the current collector (100), the region between the two coating regions (11) is a non-coated skip coating region (12), and the region between any two adjacent tab regions (1) is a non-coated tab interval region (2); S300: coating the skip coating region (12) to form a supplementary coating region (121) and a non-coated tab lug welding region (122); wherein the supplementary coating region (121) and the tab lug welding region (122) are sequentially arranged along the width direction of the current collector (100).

2. The pole piece coating method according to claim 1, characterized by, Step S300 comprises: S3001: determining that a non-coated blank region is identified; S3002: determining that the identified blank region is the skip coating region (12); S3003: coating the identified blank region to form a supplementary coating region (121) and a non-coated tab lug welding region (122).

3. The pole piece coating method according to claim 2, characterized by, Step S3002 comprises: S30021: obtaining the size of the identified blank region along the length direction of the current collector (100); S30022: comparing the size of the identified blank region along the length direction of the current collector (100) with a preset size; If the size of the identified blank region along the length direction of the current collector (100) is less than the preset size, it is determined that the identified blank region is the skip coating region (12), and step S2003 is performed.

4. The pole piece coating method according to claim 3, characterized by If the size of the identified blank region along the length direction of the current collector (100) is not less than the preset size, it is determined that the identified blank region is the tab interval region (2), and step S3001 is returned.

5. The pole piece coating method according to claim 1, characterized by, Further comprising after step S300: S400: cutting the current collector (100) to obtain a plurality of segmented current collectors; wherein any segmented current collector comprises one tab region (1).

6. The pole piece coating method according to claim 5, characterized by In step S300, the supplementary coating region (121) and the tab lug welding region (122) are both a plurality of regions, and the plurality of supplementary coating regions (121) and the plurality of tab lug welding regions (122) are sequentially and staggered arranged along the width direction of the current collector (100); The tab coating method further comprises after step S400: S500: cutting the segmented current collector to obtain a plurality of tabs (101); wherein any tab (101) comprises one supplementary coating region (121) and one tab lug welding region (122).

7. An electrode sheet coating device characterized by comprising: The tab coating device is used to implement the tab coating method according to any one of claims 1-6, and the tab coating device comprises: A conveying mechanism (200) is configured to convey the current collector (100) along a length direction of the current collector (100); A first extrusion die (300) is configured to perform skip coating on the current collector (100) along the length direction of the current collector (100) to form a plurality of pole piece regions (1); A second extrusion die (400) is located downstream of the first extrusion die (300) along a conveying direction of the current collector (100), and the second extrusion die (400) is configured to perform coating on the skip coating region (12) to form a supplementary coating region (121) and an uncoated tab welding region (122).

8. The pole piece coating apparatus of claim 7, wherein Further comprising an identification device (500) located between the first extrusion die (300) and the second extrusion die (400) along the conveying direction of the current collector (100), and the identification device (500) is configured to obtain a size of an identified blank region along the length direction of the current collector (100).

9. The pole piece coating apparatus of claim 8, wherein A distance between the identification device (500) and the second extrusion die (400) is a preset distance, and the second extrusion die (400) is configured to perform coating on the skip coating region (12) to form the supplementary coating region (121) and the uncoated tab welding region (122) after a preset time when it is determined that the identified blank region is the skip coating region (12); The preset distance and the preset time satisfy: ； wherein L is the preset distance, v is a conveying speed of the current collector (100), and Δt is the preset time.

10. The pole piece coating apparatus of claim 7, wherein Further comprising a drying box (600) located downstream of the second extrusion die (400) along the conveying direction of the current collector (100), and the drying box (600) is configured to dry the coated current collector (100).

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