Automatic splicing device and automatic splicing method for electrodes

Abstract

One aspect of the present disclosure relates to an automatic splicing apparatus and method of electrode, and more particularly, to an automatic splicing apparatus and method of electrode capable of minimizing connection defects between a running electrode and a new electrode, in which the running electrode and the new electrode connected to the running electrode and supplied are aligned with their coated lines as a reference by using the automatic splicing apparatus.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0174586, filed on December 8, 2021, the entire contents of which are incorporated herein by reference.

[0002] One aspect of this disclosure relates to an auto splicing apparatus and method for supplying electrodes to a notching process using a roll-to-roll method during a secondary battery manufacturing process. Background Technology

[0003] In the secondary battery manufacturing process, the notching process refers to the process of cutting out the electrodes.

[0004] In the cutting process, the electrode to be cut is supplied while the coiled electrode is being unwound.

[0005] At this point, when the supply of one electrode wound into a roll ends, it needs to be replaced with another electrode. The process of automatically connecting the electrode to be replaced is called the auto splicing process. The electrode being supplied at this time can be called the running electrode, and the electrode that is replaced and continuously supplied after the running electrode can be called the new electrode. Specifically, the running electrode and the new electrode can be in the form of electrode sheets, which can be supplied to the cutting process and cut into individual electrodes.

[0006] The currently implemented automated splicing process suffers from electrode distortion and coating line positioning defects due to misalignment of the existing electrode and the new electrode during electrode replacement, resulting in electrode gaps at the electrode joints and causing problems such as overhang. In this case, overhang refers to a defect that occurs when the cathode, diaphragm, and anode are stacked in a post-cutting process, where the gap between the cathode, diaphragm, and anode exceeds specified dimensions.

[0007] Furthermore, there is a problem that cannot be corrected when misalignment occurs between the operating electrode and the new electrode.

[0008] Furthermore, although the two EPC (Edge Position Control) sensors sense the running electrode and the new electrode, because they sense different surfaces, dimensional defects may occur when the two electrodes are connected, and the process capability may be degraded accordingly.

[0009] As mentioned above, in conventional automated splicing processes, even if misalignment occurs between the running electrode and the new electrode during connection, it is difficult to correct the misalignment. Furthermore, due to limitations in the EPC sensor mounting position, gaps may arise between the running electrode and the new electrode. Consequently, coating line dimensional defects may occur before / after the connection between the manufactured electrodes, and process capability may deteriorate. Therefore, there is a need to develop a technology capable of addressing this problem.

[0010] [Existing technical documents]

[0011] [Patent Literature]

[0012] (Patent Document 1) Korean Patent No. 1479724 Summary of the Invention

[0013] Technical issues

[0014] The inventors of this invention conducted extensive research to address the aforementioned problems, and as a result, confirmed that in an automatic electrode splicing device, by setting the EPC sensor that senses the running electrode and the EPC sensor that senses the new electrodes continuously supplied after the running electrode to face the same direction, the coating lines formed on one surface of the running electrode and the coating lines formed on one surface of the new electrode can be sensed, thus preventing misalignment of the running electrode and the new electrode, and minimizing the formation of gaps at the connection between the running electrode and the new electrode. In this case, the one surface of the running electrode and the one surface of the new electrode sensed by the EPC sensor refer to the surfaces that are joined together as the same surface during connection.

[0015] Therefore, one aspect of this disclosure is to provide an automatic splicing apparatus and method for electrodes capable of correcting misalignment between spliced ​​electrodes and matching and connecting the coating lines of the electrodes.

[0016] Technical solution

[0017] Therefore, one aspect of this disclosure provides an automatic electrode splicing device, comprising: a first electrode conveying unit; a second electrode conveying unit; and an electrode supply unit.

[0018] The first electrode conveying unit includes: a first unwinding unit for unwinding the first electrode; a first conveying unit for conveying the unwound first electrode; and a first splicing unit for connecting the second electrode to the first electrode when the unwinding of the conveyed first electrode is completed.

[0019] The second electrode transfer unit includes: a second unwinding unit for unwinding the second electrode; a second transfer unit for transferring the unwound second electrode; and a second splicing unit for connecting the second electrode to the first electrode.

[0020] A first edge position control (EPC) sensor and a second EPC sensor are included on both sides of the first or second stitching unit.

[0021] The first EPC sensor and the second EPC sensor are configured to face the same direction so as to sense one electrode surface of the first electrode and one electrode surface of the second electrode located on the same plane when the first electrode and the second electrode are connected.

[0022] The first EPC sensor senses the coating line formed on the electrode surface of the first electrode, and the second EPC sensor senses the coating line formed on the electrode surface of the second electrode.

[0023] The first electrode may include a first electrode surface and a second electrode surface, and the first electrode may be wound such that the first electrode surface faces the center of the roll and the second electrode surface faces the outside of the roll.

[0024] The second electrode may include a first electrode surface and a second electrode surface, and the second electrode may be wound such that the first electrode surface faces the center of the roll and the second electrode surface faces the outside of the roll.

[0025] The first EPC sensor can sense the coating line on the second electrode surface of the first electrode, and the second EPC sensor can sense the coating line on the second electrode surface of the second electrode.

[0026] The first electrode delivery unit and the second electrode delivery unit can remain separate from each other. When the unwinding of the first electrode is completed in the first electrode delivery unit, the first unwinding unit can be separated from the first splicing unit, and the first splicing unit and the second splicing unit can be joined to connect the first electrode and the second electrode and supply the first electrode and the second electrode to the electrode supply unit.

[0027] The electrode supply unit may include a third EPC sensor, which senses the second electrode surface of the first electrode and the second electrode surface of the second electrode connected above.

[0028] Furthermore, one aspect of this disclosure provides an automatic electrode splicing method, comprising the following steps: (a) unwinding a first electrode and supplying it to a cutting process; (b) cutting the lower end of the first electrode; (c) sensing and aligning the coating lines of the cut first electrode and the coating lines of a second electrode to be connected to the first electrode; and (d) connecting one end of the first electrode and one end of the second electrode by aligning with the sensed coating lines as a reference, wherein the coating lines formed on a surface of the first electrode and a surface of the second electrode located on the same plane are sensed and aligned by a first EPC sensor and a second EPC sensor, respectively.

[0029] When misalignment occurs between the first electrode and the second electrode, after stopping the first electrode, a correction can be performed to align the coating lines formed on one surface of the first electrode and the second electrode, which are located on the same plane.

[0030] Beneficial effects

[0031] According to one aspect of the present disclosure, an automatic electrode splicing apparatus and an automatic splicing method prevent gaps from forming at electrode joints by performing the electrode splicing process through coating lines of matching electrodes, and can correct misalignment even if misalignment occurs at the joints. Attached Figure Description

[0032] Figure 1 A schematic diagram showing the location of the coating lines in the electrode.

[0033] Figure 2a This is a schematic diagram of an automatic electrode splicing device according to one embodiment of one aspect of this disclosure. Figure 2b This is a schematic diagram of an automatic electrode splicing device according to another embodiment of one aspect of this disclosure.

[0034] Figure 3 This is a schematic diagram of a first electrode A1 and a second electrode A2 connected according to one aspect of the present disclosure.

[0035] Figure 4 This is a schematic diagram illustrating an automated electrode splicing process according to another aspect of this disclosure.

[0036] Figure 5a and Figure 5b This is a schematic diagram of the automated splicing process using a conventional automated splicing device. Detailed Implementation

[0037] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings, but this is for ease of understanding of the invention, and the scope of the invention is not limited thereto.

[0038] As used herein, the term coating line refers to the boundary between the retained portion and the uncoated portion, where the retained portion is the part of the electrode tab coated with the electrode active material and the uncoated portion is the part not coated with the electrode active material.

[0039] Figure 1 A schematic diagram showing the location of the coating lines in the electrode.

[0040] Reference Figure 1 Electrode 100 includes an electrode surface 110 and an electrode tab 120 protruding from the end of the electrode surface 110. The surface of electrode 100 may have an electrode coating layer coated with an electrode active material. The electrode coating layer can be formed on both surfaces of electrode 100. During electrode manufacturing, the electrode tab 120, formed by a notching process, includes a portion with an electrode coating layer and a portion without an electrode coating layer. In electrode 100, the portion with the electrode coating layer is referred to as a holding unit 130a, and the portion without the electrode coating layer is referred to as an uncoated unit 130b. The boundary of the holding unit 130a within the electrode tab 120, i.e., the portion with the electrode coating layer, is referred to as a shoulder line I, also known as a coating line I. When there is a difference in height between the coating lines formed on the two surfaces of the electrode, this is called a mismatch. Problems such as drooping can occur when the coating line deviates from its specified dimensions.

[0041] As used herein, the terms "first electrode" and "second electrode" refer to adjacent electrode sheets among a plurality of electrode sheets that are supplied continuously, and do not mean that only two electrodes are used in the automated splicing process according to the invention.

[0042] Automatic electrode splicing device

[0043] One aspect of this disclosure relates to an automated electrode splicing apparatus for supplying electrodes to a notching process using a roll-to-roll method during the manufacturing process of a secondary battery.

[0044] Figure 2a This is a schematic diagram of an automatic electrode splicing device according to one embodiment of one aspect of this disclosure. Figure 2b This is a schematic diagram of an automatic electrode splicing device according to another embodiment of one aspect of this disclosure.

[0045] like Figure 2aAs shown, the automatic electrode splicing device 1 according to one embodiment of one aspect of this disclosure includes a first electrode conveying unit 10, a second electrode conveying unit 20, and an electrode supply unit 30. At this time, when the electrode being supplied is called the running electrode, and after the running electrode is used up, the electrode connected to the running electrode and continuously supplied is called the new electrode, the first electrode A1 is the running electrode, and the second electrode A2 is the new electrode.

[0046] Furthermore, the first electrode transfer unit 10 includes: a first unwinding unit 11 for unwinding the first electrode A1; a first transfer unit 12 for transferring the unwound first electrode A1; and a first splicing unit 13 for connecting the second electrode A2 to the first electrode A1 when the unwinding of the transferred first electrode A1 is completed. At this time, the first unwinding unit 11 may include an unwinder (U / W).

[0047] Furthermore, the second electrode transfer unit 20 includes: a second unwinding unit 21 for unwinding the second electrode A2; a second transfer unit 22 for transferring the unwound second electrode A2; and a second splicing unit 23 for connecting the second electrode A2 to the first electrode A1. In this case, the second unwinding unit 21 may include an unwinder (U / W).

[0048] In addition, a first edge position control (EPC) sensor 40a and a second EPC sensor 40b are provided on both sides of the first splicing unit 13, which are arranged to face the same direction. The first EPC sensor 40a senses the first electrode A1, and the second EPC sensor 40b senses the second electrode A2.

[0049] The first electrode A1 includes a first electrode surface A1-1 and a second electrode surface A1-2. The first electrode surface A1-1 of the first electrode A1 is wound toward the center of the roll, and the second electrode surface A1-2 is wound toward the outside of the roll.

[0050] The second electrode A2 includes a first electrode surface A2-1 and a second electrode surface A2-2. The first electrode surface A2-1 of the second electrode A2 is wound toward the center of the roll, and the second electrode surface A2-2 is wound toward the outside of the roll.

[0051] At this time, when the first electrode A1 is unwound by the first unwinding unit 11, conveyed by the first conveying unit 12, and then supplied to the electrode supply unit 30 and used up, the second electrode A2 is connected to the first electrode A1 and continuously supplied. Depending on the process, electrodes such as the third electrode and the fourth electrode can also be continuously supplied.

[0052] Electrode coating layers are formed on the two surfaces of the first electrode A1 and the second electrode A2, respectively. The boundary line between the portion with the electrode coating layer and the uncoated portion without the electrode coating layer is called the coating line.

[0053] When the second electrode A2 is supplied continuously after the first electrode A1, the first electrode surface A1-1 of the first electrode A1 and the first electrode surface A2-1 of the second electrode A2 continue on the same surface, and the second electrode surface A1-2 of the first electrode A1 and the second electrode surface A2-2 of the second electrode A2 also continue on the same surface. At this time, since the second electrode surfaces A1-2 of the first electrode A1 and A2-2 of the second electrode A2 are aligned and connected with their respective coating lines as a reference, the error at the connection point can be minimized.

[0054] Therefore, during the process of unwinding and transferring the second electrode surface A1-2 of the first electrode A1 and the second electrode surface A2-2 of the second electrode A2, a device is needed that can sense these electrode surfaces to align the coating lines.

[0055] The first EPC sensor 40a and the second EPC sensor 40b, located on both sides of the first splicing unit 13, respectively sense the first electrode A1 and the second electrode A2. Specifically, the first EPC sensor 40a senses the second electrode surface A1-2 of the first electrode A1 unwound from the first unwinding unit 11, and the second EPC sensor 40b senses the second electrode surface A2-2 of the second electrode A2. Therefore, since the correct position of the coating line is sensed by the first EPC sensor 40a and the second EPC sensor 40b, and the aligned second electrode surfaces A1-2 and A-2 are connected, thereby connecting the first electrode A1 and the second electrode A2, the gap caused by their mismatch can be minimized.

[0056] Alternatively, the first EPC sensor 40a and the second EPC sensor 40b may be disposed on both sides of the second splicing unit 23 (not shown). The first EPC sensor 40a and the second EPC sensor 40b may be positioned in the same direction to sense the electrode surface in which the coating lines of the first electrode and the coating lines of the second electrode are aligned.

[0057] Furthermore, if misalignment occurs during the connection of the first electrode A1 and the second electrode A2, it can be corrected by performing an alignment adjustment of the coating lines of the first electrode A1 and the second electrode A2 before splicing them together.

[0058] For example, the first electrode A1, i.e., the running electrode, stops and its lower end is cut off. After sensing the coating lines of the first electrode A1 and the second electrode A2 using the first EPC sensor 40a and the second EPC sensor 40b, the first electrode and the second electrode are moved and connected such that one end of the first electrode A1 is joined to one end of the second electrode A2 connected to one end of the first electrode A1, and the two electrodes are connected such that the coating lines of the first electrode A1 and the second electrode A2 are aligned on a single line to perform automatic splicing, thereby correcting misalignment.

[0059] Furthermore, the electrode supply unit 30 supplying the connected first electrode A1 and second electrode A2 may include a third EPC sensor 40c. In this case, the connected first electrode A1 and second electrode A2 can be supplied to a notching process for cutting out individual electrodes.

[0060] Similar to the first EPC sensor 40a and the second EPC sensor 40b, the third EPC sensor 40c continuously senses the second electrode surface A1-2 of the first electrode and the second electrode surface A2-2 of the second electrode, and checks whether the alignment of their coating lines is maintained and does not deviate from the specified specifications during the cutting process, so that correction can be performed when misalignment occurs.

[0061] Furthermore, the first electrode transfer unit 10 and the second electrode transfer unit 20 remain separate from each other.

[0062] When the unwinding of the first electrode is completed in the first electrode conveying unit 10, the first unwinding unit 11 and the first conveying unit 12 are separated from the first splicing unit 13, and the first splicing unit 13 and the second splicing unit 23 are joined. Then the first electrode A1 and the second electrode A2 can be connected and supplied to the electrode supply unit 30.

[0063] Figure 2b This illustrates a scenario where the second electrode A2 is the operating electrode and the first electrode A1 is the new electrode. The driving principle is based on... Figure 2a The implementation method is the same.

[0064] Figure 3 This is a schematic diagram of a first electrode A1 and a second electrode A2 connected according to one aspect of this disclosure. In this case, the first electrode A1 can be a running electrode, and the second electrode A2 can be a new electrode.

[0065] like Figure 3 As shown, the first electrode A1 and the second electrode A2 can be connected with reference to the coating line I aligned with the first EPC sensor and the second EPC sensor.

[0066] For example, the electrode surfaces sensed by the first EPC sensor and the second EPC sensor can be the second electrode surface A1-2 of the first electrode A1 and the second electrode surface A2-2 of the second electrode A2.

[0067] Automatic electrode splicing method

[0068] Another aspect of this disclosure relates to an automated method for splicing electrodes used in a notching process during the manufacturing process of a secondary battery using a roll-to-roll method.

[0069] Figure 4 This is a schematic diagram illustrating an automated electrode splicing process according to another aspect of this disclosure.

[0070] like Figure 4 As shown, the automatic splicing process of the electrode according to another aspect of this disclosure includes the following steps: (a) unwinding the first electrode and supplying it to the cutting process (step 1); (b) cutting the lower end of the first electrode (step 2); (c) sensing and aligning the coating lines of the cut first electrode and the coating lines of the second electrode to be connected to the first electrode (step 3); and (d) connecting one end of the first electrode and one end of the second electrode by aligning with the sensed coating lines as a reference (step 4), wherein the coating lines formed on one surface of the first electrode and one surface of the second electrode located on the same plane can be sensed and aligned by the first EPC sensor and the second EPC sensor, respectively.

[0071] Furthermore, the first EPC sensor and the second EPC sensor sense whether the alignment between the coating lines formed on one surface of the first electrode and the coating lines formed on one surface of the second electrode is maintained. If misalignment occurs due to the coating lines being offset from the reference line, the automatic splicing operation can be performed again after a correction operation to align the coating lines of the first electrode and the coating lines of the second electrode is performed.

[0072] Furthermore, after the automatic splicing process is completed by connecting the first and second electrodes, a cutting process can be performed by the electrode supply unit. At this time, a third EPC sensor located in the electrode supply unit can continuously sense whether the alignment of the coating lines of the first and second electrodes is maintained. The third EPC sensor can sense the coating lines on the same electrode surface as those sensed by the first and second EPC sensors.

[0073] Figure 5a and Figure 5b This is a comparative embodiment of an automated splicing process using a conventional automated splicing device, which is another aspect of this disclosure.

[0074] Figure 5a This is a schematic diagram of the automatic splicing process of replacing the running electrode A1 with a new electrode A2. The automatic splicing device 1 includes a first electrode transfer unit 10, a second electrode transfer unit 20, and an electrode supply unit 30.

[0075] In addition, the first electrode transfer unit 10 includes: a first unwinding unit 11 for unwinding the first electrode A1; a first transfer unit 12 for transferring the unwound first electrode A1; and a first splicing unit 13 for connecting the second electrode A2 to the first electrode A1 when the unwinding of the transferred first electrode A1 is completed.

[0076] In addition, the second electrode transfer unit 20 includes: a second unwinding unit 21 for unwinding the second electrode A2; a second transfer unit 22 for transferring the unwound second electrode A2; and a second splicing unit 23 for connecting the second electrode A2 to the first electrode A1.

[0077] Furthermore, a first edge position control (EPC) sensor 40a is located in the first splicing unit 13, and a second EPC sensor 40b is located in the second splicing unit 23. The first EPC sensor 40a senses the second electrode surface A1-2 of the first electrode, and the second EPC sensor 40b senses the first electrode surface A2-1 of the second electrode.

[0078] When the first electrode and the second electrode are connected, the first electrode surface A1-1 of the first electrode A1 and the first electrode surface A2-1 of the second electrode A2 are located on the same surface, and the second electrode surface A1-2 of the first electrode and the second electrode surface A2-2 of the second electrode A2 are located on the same surface.

[0079] However, as described above, since the first EPC sensor 40a senses the second electrode surface A1-2 of the first electrode A1 and the second EPC sensor senses the first electrode surface A2-1 of the second electrode A2, thus sensing electrode surfaces that are not located on the same surface and aligning their coating lines, defects may occur at the connection site when these electrodes are connected.

[0080] Figure 5b This is a schematic diagram of the automatic splicing process where the new electrode A1 replaces the running electrode A2. This process will result in... Figure 5a The same problem as the automatic splicing process.

[0081] According to the automated splicing process using the aforementioned conventional automated splicing device, misalignment of the running electrode and the new electrode during electrode replacement can cause electrode distortion. Furthermore, poor positioning of the electrode coating lines can create gaps at the connection between the running and new electrodes, leading to overhang problems. In this case, misalignment refers to the running or new electrode shifting relative to the path line, and even if misalignment occurs, it cannot be corrected.

[0082] Furthermore, since the operating electrode is sensed on the second electrode surface by the first EPC sensor, while the new electrode is sensed on the first electrode surface, different surfaces of the electrodes are sensed. It is difficult to accurately match the coating lines of the operating electrode and the coating lines of the new electrode, and a gap may be generated between the operating electrode and the new electrode during the automatic splicing process.

[0083] Figure 5b This is a schematic diagram of the automatic splicing process where the new electrode A1 is used to replace the running electrode A2. Figure 5a Compared to the change in the position of the running electrode and the new electrode, what will happen? Figure 5a The same problem as the automatic splicing process.

[0084] Those skilled in the art can make various applications and modifications within the scope of this invention based on the above content.

[0085] Although the invention has been described with reference to limited embodiments and accompanying drawings, the invention is not limited thereto. Needless to say, those skilled in the art to which this invention pertains can make various modifications and variations within the scope of the inventive concept and the equivalents of the claims described below.

[0086] [Description of reference markers]

[0087] 1: Automatic splicing device

[0088] 10: First Electrode Transfer Unit

[0089] 11: First unwinding unit

[0090] 12: First Transmission Unit

[0091] 13: First splicing unit

[0092] 20: Second electrode transmission unit

[0093] 21: Second unwinding unit

[0094] 22: Second Transmission Unit

[0095] 23: Second splicing unit

[0096] 30: Electrode supply unit

[0097] 40a: First EPC sensor

[0098] 40b: Second EPC sensor

[0099] 40c: Third EPC sensor

[0100] A1: First electrode

[0101] A2: Second electrode

[0102] 100: Electrode

[0103] 110: Electrode surface

[0104] I: Coating line.

Claims

1. An automatic electrode splicing device, comprising: First electrode transfer unit; Second electrode transfer unit; and electrode supply unit, The first electrode conveying unit includes: a first unwinding unit for unwinding the first electrode; a first conveying unit for conveying the unwound first electrode; and a first splicing unit for connecting the second electrode to the first electrode when the unwinding of the conveyed first electrode is completed. The second electrode transfer unit includes: a second unwinding unit for unwinding the second electrode; a second transfer unit for transferring the unwound second electrode; and a second splicing unit for connecting the second electrode to the first electrode. A first edge position control sensor and a second edge position control sensor are included on both sides of the first splicing unit or the second splicing unit. The first edge position control sensor and the second edge position control sensor are configured to face the same direction to sense an electrode surface of the first electrode and an electrode surface of the second electrode located on the same plane when the first electrode and the second electrode are connected. The first edge position control sensor senses the coating line formed on the electrode surface of the first electrode, and the second edge position control sensor senses the coating line formed on the electrode surface of the second electrode. The electrode supply unit includes a third edge position control sensor that senses whether the alignment of the coating lines of the connected first and second electrodes is maintained.

2. The automatic electrode splicing device according to claim 1, wherein the first electrode includes a first electrode surface and a second electrode surface, and the first electrode is wound such that the first electrode surface faces the center of the roll, and the second electrode surface faces the outside of the roll.

3. The automatic electrode splicing device according to claim 2, wherein the second electrode includes a first electrode surface and a second electrode surface, and the second electrode is wound such that the first electrode surface faces the center of the roll and the second electrode surface faces the outside of the roll.

4. The automatic electrode splicing device according to claim 3, wherein the first edge position control sensor senses the coating line on the second electrode surface of the first electrode, and the second edge position control sensor senses the coating line on the second electrode surface of the second electrode.

5. The automatic electrode splicing device according to claim 4, wherein the first electrode conveying unit and the second electrode conveying unit remain separate from each other, and when the unwinding of the first electrode is completed in the first electrode conveying unit, the first unwinding unit separates from the first splicing unit, and the first splicing unit and the second splicing unit engage to connect the first electrode and the second electrode and supply the first electrode and the second electrode to the electrode supply unit.

6. An automatic electrode splicing method, comprising the following steps: (a) Unwind the first electrode and supply it to the cutting process; (b) Cut the lower end of the first electrode; (c) Sensing and aligning the cut coating lines of the first electrode and the coating lines of the second electrode to be connected to the first electrode; as well as (d) Connect one end of the first electrode and one end of the second electrode by aligning with the sensed coating line as a reference. The coating lines formed on one surface of the first electrode and one surface of the second electrode, located on the same plane, are sensed and aligned by a first edge position control sensor and a second edge position control sensor, respectively. The automatic splicing method for the electrodes further includes the following steps: sensing whether the alignment of the coating lines of the first and second electrodes being connected is maintained by a third edge position control sensor.

7. The automatic electrode splicing method according to claim 6, When misalignment occurs between the first electrode and the second electrode, After stopping the first electrode, a correction is performed to align the coating lines formed on one surface of the first electrode and one surface of the second electrode, which are located on the same plane.

Images