Method for removing one-side electrode layer from double-side coated electrode

Abstract

The present invention provides a one-side electrode layer removal method for removing a one-side electrode layer from a double-side electrode, the one-side electrode layer removal method comprising the steps of: placing a plate assembly in an N-methyl-2-pyrrolidone (NMP) bath and applying ultrasonic waves thereto, the plate assembly has a structure in which a double-sided coated electrode is interposed between an upper plate and a lower plate, and the upper plate and the lower plate are coupled to each other with the double-sided coated electrode interposed therebetween, the upper plate being configured to have an opening communicating with a top and a bottom thereof, and the lower plate being configured to be open on one side thereof and have a closed recess on the other side thereof.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2022-0167845 filed on December 5, 2022, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0003] The present disclosure relates to a method for removing a one-side electrode layer from a double-side electrode. Background Art

[0004] As the use of fossil fuels is rapidly increasing, the demand for the use of alternative or clean energy is also increasing, and as part of this, the most active field of research is currently the field of power generation and power storage using electrochemistry.

[0005] Currently, secondary batteries are a representative example of electrochemical devices that utilize such electrochemical energy, and the scope of use thereof tends to be gradually expanded.

[0006] Recently, with the development of technology and the increase in demand for mobile devices such as portable computers, portable phones and cameras, the demand for secondary batteries as energy sources has increased rapidly. Among these secondary batteries, many studies have been conducted on lithium secondary batteries that show high charge / discharge characteristics, have a long cycle life and are environmentally friendly, and lithium secondary batteries have been commercialized and widely used.

[0007] Meanwhile, before, during, and after use of such lithium secondary batteries, they are disassembled to remove electrode layers from electrodes for various reasons and then recycled.

[0008] Figure 1 A conventional method of removing the electrode layer 12 from the electrode 10 is schematically shown as an example.

[0009] Reference Figure 1 Conventionally, only less damaging ultrasonic waves are used to peel the electrode layer 12 from the electrode current collector 11. Specifically, the following method is used: ultrasonic waves are applied to the surface of the electrode layer 12 using a device generating ultrasonic waves such as an ultrasonic horn 20 to form small bubbles and then the coating is destroyed by this, and no solvent is used.

[0010] In this regard, in the case of this method, all of the double-sided electrode layers 12 are destroyed, which makes it difficult to use as a single-sided electrode.

[0011] However, for example, it is difficult to analyze the potential of the positive electrode and the negative electrode in a typical full battery, so when an LTO electrode is inserted between the three-electrode battery to analyze the potential of the positive electrode and the negative electrode, a single-sided positive electrode and a single-sided negative electrode are used one by one in the three-electrode battery to reduce resistance and reduce the risk of developing capacity.

[0012] Therefore, the necessity of developing a method for removing one side electrode layer from a double-sided electrode is emerging.

[0013] However, when removing one electrode layer from a double-sided electrode to make a single-sided electrode, usually, an operator manually uses a solvent and a wafer towel. In this case, problems such as foil damage and solvent penetration into the used electrode surface may occur depending on the operator.

[0014] Therefore, there is an urgent need to develop a technology to address these issues and recycle the double-sided electrodes without damaging the surfaces used to make the single-sided electrodes. Summary of the invention

[0015] Technical issues

[0016] An object of the present disclosure is to provide a method for removing an electrode layer on one side of a double-sided electrode without damaging the electrode layer on the other side, while eliminating deviation caused by an operator.

[0017] Technical Solution

[0018] In order to achieve the above object, according to one embodiment of the present disclosure, a method for removing one side electrode layer from a double-sided electrode is provided, the method comprising the following steps:

[0019] A double-sided electrode is inserted between an upper plate and a lower plate, wherein the upper plate has a structure in which an opening portion communicating between the upper side and the lower side is formed, and the lower plate has a structure in which one side is open and the other side is formed with a sealed recessed portion; the plate assembly is placed in an NMP (N-methyl-2-pyrrolidone) water bath and ultrasonic waves are applied, the plate assembly having a structure in which the upper plate and the lower plate are connected to each other with the double-sided electrode inserted between the upper plate and the lower plate.

[0020] At this time, when the double-sided electrode is inserted between the upper plate and the lower plate, the area of ​​the opening portion and the recessed portion is smaller than the area of ​​the double-sided electrode excluding the joint so as to cover both the opening portion of the upper plate and the recessed portion of the lower plate. Specifically, the area of ​​the opening portion and the recessed portion can be 90% to 98% of the area of ​​the double-sided electrode excluding the joint.

[0021] In one embodiment, an inner side surface of the upper plate facing the lower plate includes a groove having a shape corresponding to a frame shape of the upper plate, and a rubber ring may be installed in the groove.

[0022] Here, when the double-sided electrodes are coupled, the rubber ring may press the entire edge of the double-sided electrodes.

[0023] In another embodiment, the upper plate and the lower plate can be mechanically coupled and detached, and specifically, the upper plate and the lower plate can be coupled by fastening bolts inserted into fastening holes.

[0024] Meanwhile, when the plate assembly is placed in an NMP (N-methylpyrrolidone) water bath, no NMP solvent may exist between the double-sided electrode and the lower plate.

[0025] In one embodiment, the temperature of the NMP solvent in the NMP water bath may be between 25 degrees Celsius and 60 degrees Celsius, and two or more ultrasonic horns are formed in the NMP water bath.

[0026] In one embodiment, the plate assembly can be subjected to ultrasonic waves while being completely immersed in the NMP solvent. At this time, ultrasonic waves can be applied at a frequency of 10 kHz to 500 kHz for 5 minutes to 30 minutes.

[0027] Furthermore, the method for removing one-side electrode layer may include the step of drying the single-side electrode from which the one-side electrode layer has been removed after applying the ultrasonic wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram showing, as an example, a conventional method of removing an electrode layer from a double-sided electrode.

[0029] Figure 2 is an exploded perspective view of a plate used in a method for removing one surface electrode layer according to an embodiment of the present disclosure.

[0030] Figure 3 is a top view of a plate assembly according to an embodiment of the present disclosure.

[0031] Figure 4 is along Figure 3 Cross-sectional view of the plate assembly cut along line L in FIG.

[0032] Figure 5 Schematic diagram of the inner surface of the upper plate of the embodiment of the present disclosure.

[0033] Figure 6 is a schematic diagram of a method for removing an electrode layer according to an embodiment of the present disclosure.

[0034] Figure 7 Schematic diagram of the mechanism of removing one electrode layer from a double-sided electrode. DETAILED DESCRIPTION

[0035] Hereinafter, for a better understanding of the present disclosure, specific embodiments will be described in more detail.

[0036] The terms or words used in the specification and the appended claims should not be construed as being limited to the ordinary or dictionary meanings, and the present disclosure should be interpreted with meanings and concepts consistent with the technical ideas of the present disclosure based on the principle that inventors can appropriately define the concepts of the terms to appropriately describe their own inventions in the best manner.

[0037] The terms used herein are used to describe the embodiments but are not intended to limit the concepts of the present disclosure. Unless the context clearly indicates otherwise, the singular includes the plural.

[0038] Furthermore, throughout the description, when a part is referred to as “including” or “comprising” a certain component, it means that the part may further include other components, rather than excluding the other components, unless otherwise specified.

[0039] According to an embodiment of the present disclosure,

[0040] A method for removing one-side electrode layer from a double-sided electrode is provided, the method comprising the following steps: inserting the double-sided electrode between an upper plate and a lower plate, wherein the upper plate has a structure in which an opening portion communicating between the upper side and the lower side is formed, and the lower plate has a structure in which one side is open and the other side is formed with a sealed recessed portion; placing a plate assembly having a structure in which the upper plate and the lower plate are connected to each other with the double-sided electrode inserted between the upper plate and the lower plate in an NMP (N-methyl-2-pyrrolidone) water bath and applying ultrasonic waves.

[0041] Now, the method for removing one electrode layer according to an embodiment of the present disclosure will be described in more detail with reference to the accompanying drawings. However, the following description of the accompanying drawings is based on one embodiment, and the scope of the present disclosure is not limited thereto.

[0042] first, Figures 2 to 4 A plate assembly used in the present disclosure is schematically shown.

[0043] Specifically, Figure 2 shows an exploded perspective view of a plate used in a method for removing a one-side electrode layer according to an embodiment of the present disclosure, Figure 3 A top view of a plate assembly showing a double-sided electrode coupled to the plate, and Figure 4 is a cross-sectional view of the plate assembly.

[0044] Reference Figures 2 to 4, the plate assembly 100 has a structure in which a double-sided electrode 130 is interposed between an upper plate 110 and a lower plate 120 .

[0045] Specifically, the upper plate 110 has a structure in which an opening portion 111 communicating between the upper side and the lower side is formed, and the lower plate 120 has a structure in which one side is open and the other side is formed with a sealed recessed portion. Here, the opening portion 111 of the upper plate 110 and the recessed portion 121 of the lower plate 120 have the same area, and when they are coupled with the double-sided electrode 130, the opening portion 111 is coupled with the recessed portion 121 so that they are located at the same position.

[0046] Here, the upper plate 110 and the lower plate 120 may be mechanically coupled and detached, whereby the double-sided electrode 130 may be inserted between the upper plate 110 and the lower plate 120 and removed.

[0047] At this time, the method of mechanical coupling and detachment is not limited as long as it can be repeatedly performed, but for example, the plates may be coupled by the fastening bolts 140 inserted into the fastening holes 113 and 123. In the case of this structure, the plates 110 and 120 may be repeatedly used.

[0048] Specifically, the upper plate 110 and the lower plate 120 may include fastening holes 113 and 123. In a state where the double-sided electrode 130 is inserted between the opening portion 111 and the recessed portion 121 so that the electrode layer 133 is exposed, the fastening bolts 140 are inserted into the fastening holes 113 and 123 so that the double-sided electrode 130 can be inserted therebetween to manufacture the plate assembly 100.

[0049] In addition, after removing one side electrode layer 133, the fastening bolts 140 are removed from the fastening holes 113 and 123 again, so that the upper plate 110 and the lower plate 120 can be separated, and the single-sided electrode with one side electrode layer 133 removed can be separated and removed from the plate assembly 100.

[0050] Here, the fastening holes 113 and 123 may be formed at positions communicating with each other so that they may be coupled at one time by one fastening bolt 140 .

[0051] On the other hand, the double-sided electrode 130 must be inserted and fixed between the upper plate 110 and the lower plate 120. Therefore, when the double-sided electrode 130 is inserted between the upper plate 110 and the lower plate 120, the area S of the opening portion 111 and the recessed portion 121 is 1 Smaller than the area S of the double-sided electrode 130 excluding the joints 131 and 132 2 , so as to cover both the opening portion 111 of the upper plate 110 and the recessed portion 121 of the lower plate 120 .

[0052] Specifically, the area S of the opening portion 111 and the recessed portion 121 is 1 The area S of the double-sided electrode 130 excluding the joints 131 and 132 may be 2 90% to 98%, specifically 92% to 98%, more specifically 92% to 95%.

[0053] If the size of the opening portion 111 and the recessed portion 121 is too small (outside the above range), it is likely that the electrode layer 133 will not be removed. If the size of the opening portion 111 and the recessed portion 121 is too large, the double-sided electrode 130 may not be inserted and fixed between the upper plate 110 and the lower plate 120, which is not preferred.

[0054] In addition, in order to ensure that the double-sided electrode 130 is fixed more firmly so that it does not move between the upper plate 110 and the lower plate 120, a groove is formed in the inner surface of the upper plate 110 facing the lower plate 120 in a form corresponding to the frame shape of the upper plate 110, and a rubber ring can be installed in the groove.

[0055] To explain this, Figure 5 Schematically showing the inner surface of the upper plate 110.

[0056] Reference Figure 5 The upper plate 110 is formed such that an opening portion 111 communicates between the upper side and the lower side and has a frame shape. A rubber ring 112 is mounted on a groove (not shown) having a shape corresponding to the frame shape.

[0057] When the double-sided electrode 130 is then inserted between the rubber ring 112 and the lower plate 120, the rubber ring 112 can press the entire edge of the double-sided electrode 130. Therefore, the edge of the double-sided electrode 130 can be more firmly grasped, thereby preventing the movement of the double-sided electrode 130 and subsequently preventing the NMP solvent from being transferred to the electrode layer on the other side. Therefore, in the process of removing the electrode layer 133 on one side, damage to the electrode layer on the other side can be effectively prevented.

[0058] Therefore, a method of removing one surface electrode layer 133 using the plate assembly 100 will be described below.

[0059] Figure 6 A schematic diagram showing a method for removing an electrode layer on one side according to an embodiment of the present disclosure is shown. Figure 7 Schematic diagram showing the mechanism of removing one electrode layer.

[0060] Reference Figure 6 and Figure 7 as well as Figure 3 and Figure 4, the board assembly 100 is configured such that one side electrode layer 133 of the double-sided electrode 130 is exposed to the outside through the opening portion 111 of the upper board 110 , and the other side electrode layer 134 is sealed by the lower board 120 .

[0061] and Figure 4 different, Figure 6 The plate assembly 100 shown does not have a shape in which the electrode layer 133 is exposed as a side view rather than a cross-sectional view, and when viewed from above, as shown in FIG. Figure 3 As shown, one side of the electrode layer 133 is inserted into the NMP water bath 150 with it exposed.

[0062] Therefore, when the plate assembly 100 is inserted into the NMP water bath 150 and contacts the NMP solvent 151, the electrode layer 133 of the double-sided electrode 130, which is only exposed through the opening portion 111 of the upper plate 110, contacts the NMP solvent 151, while the electrode layer 134 facing the lower plate 120 is sealed by the lower plate 120 and does not contact the NMP solvent 151. That is, the NMP solvent 151 does not exist between the double-sided electrode 130 and the lower plate 120.

[0063] At this time, the temperature of the NMP solvent 151 in the NMP water bath 150 may be between 25 degrees Celsius and 60 degrees Celsius, specifically between 30 degrees Celsius and 60 degrees Celsius, and more specifically between 45 degrees Celsius and 50 degrees Celsius.

[0064] If the temperature is too high (outside the above range), the temperature may be transferred to the other side of the double-sided electrode 130, and oxidation of the current collector may occur, which is not preferred.

[0065] Subsequently, the plate assembly 100 is placed in the NMP water bath 150, and ultrasonic waves are applied to remove the one-side electrode layer 133. At this time, since the one-side electrode layer 133 must be completely in contact with the NMP solvent 151, ultrasonic waves can be applied to the plate assembly 100 while being completely immersed in the NMP solvent 151.

[0066] Therefore, two or more ultrasonic horns 152 may be formed in the NMP water bath 150 , and ultrasonic waves may be applied to the NMP solvent 151 through the ultrasonic horns 152 .

[0067] Here, the ultrasonic wave may be applied at a frequency of 10 kHz to 500 kHz for 5 to 30 minutes. Specifically, the ultrasonic wave may be applied at a frequency of 20 kHz to 50 kHz for 10 to 20 minutes.

[0068] If the ultrasonic waves are applied for too short a time or at too low a frequency (outside the above range), the single-sided electrode layer 133 may not be cleanly removed, and if the ultrasonic waves are applied for too long a time or at too high a frequency, they may affect the surface of the current collector 135, which is not preferred.

[0069] When ultrasound is applied in this way, it is similar to the ultrasonic cleaning principle, such as Figure 7 As shown, fine cavitations are formed in the NMP solvent 151. As the cavitations explode and form gaps between the electrode layers 133, the cavitations then penetrate into the gaps again and explode, thereby removing the electrode layers 133.

[0070] At this time, through the plate assembly 100 according to the present invention, only the electrode layer 133 formed on one side of the current collector 133 in the double-sided electrode 130 contacts the NMP solvent, and the NMP solvent cannot contact the electrode layer 134 formed on the other side, so that only the electrode layer 133 on one side is removed, while the electrode layer 134 on the other side remains intact. Therefore, it is easier to manufacture a single-sided electrode.

[0071] Furthermore, since the operator does not manually remove the one-side electrode layer 133 , only the one-side electrode layer 133 can be removed without any deviation according to the operator.

[0072] In addition, since the operation is performed using the NMP solvent 151 and ultrasonic waves, the surface of the current collector 135 of the electrode layer 133 to be removed is not damaged, and the NMP solvent 151 has the effect of removing impurities, thereby having excellent quality, which is conducive to obtaining a single-sided electrode.

[0073] Meanwhile, although not shown in the drawings, since the method for removing one side electrode layer according to the embodiment of the present disclosure uses NMP solvent, it may include a process of drying the single-sided electrode from which the one side electrode layer is removed after applying ultrasonic waves.

[0074] Thus, the NMP solvent was evaporated, and finally a reusable single-sided electrode could be obtained.

[0075] Although exemplary embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

[0076] Industrial Applicability

[0077] As described above, according to the present disclosure, when making a single-sided electrode from a double-sided electrode, it is possible to eliminate deviation caused by an operator that occurs when a manual operation is conventionally performed while removing an electrode layer on one side without damaging the electrode layer on the other side.

[0078] Therefore, since the single-sided electrode manufactured in this manner has little damage to its surface during use, when the single-sided electrode manufactured subsequently is used, the effects of accurately displaying the capacity and reducing the deviation can be achieved.

Claims

1. A method for removing one-sided electrode layer, which is used to remove the one-sided electrode layer from a double-sided electrode. This method for removing the one-sided electrode layer comprises the following steps: Insert the double-sided electrode between the upper plate and the lower plate, where the upper plate has a structure with an opening part formed to communicate between the upper side and the lower side, and the lower plate has a structure with an opening on one side and a sealed recessed part formed on the other side; Place the plate assembly in an NMP (N-methyl-2-pyrrolidone) water bath and apply ultrasonic waves. The plate assembly has a structure in which the upper plate and the lower plate are connected to each other when the double-sided electrode is inserted between the upper plate and the lower plate.

2. The method for removing one-sided electrode layer according to claim 1, wherein: When the double-sided electrode is inserted between the upper plate and the lower plate, the areas of the opening part and the recessed part are smaller than the area of the double-sided electrode except for the joint, so as to cover both the opening part of the upper plate and the recessed part of the lower plate.

3. The method for removing one-sided electrode layer according to claim 2, wherein: The areas of the opening part and the recessed part are 90% to 98% of the area of the double-sided electrode except for the joint.

4. The method for removing one-sided electrode layer according to claim 1, wherein: The inner surface of the upper plate facing the lower plate includes a groove having a shape corresponding to the frame shape of the upper plate, and a rubber ring is installed in the groove.

5. The method for removing one-sided electrode layer according to claim 4, wherein: When the double-sided electrode is connected, the rubber ring presses the entire edge of the double-sided electrode.

6. The method for removing one-sided electrode layer according to claim 1, wherein: The upper plate and the lower plate can be mechanically connected and disassembled.

7. The method for removing one-sided electrode layer according to claim 6, wherein: The upper plate and the lower plate are connected by a fastening bolt inserted into a fastening hole.

8. The method for removing one-sided electrode layer according to claim 1, wherein: When the plate assembly is placed in an NMP (N-methylpyrrolidone) water bath, there is no NMP solvent between the double-sided electrode and the lower plate.

9. The method for removing one-sided electrode layer according to claim 1, wherein: The temperature of the NMP solvent in the NMP water bath is between 25 degrees Celsius and 60 degrees Celsius.

10. The method for removing one-sided electrode layer according to claim 1, wherein: Two or more ultrasonic horns are formed in the NMP water bath.

11. The method for removing one-sided electrode layer according to claim 1, wherein: The plate assembly can apply ultrasonic waves in a state of being completely immersed in the NMP solvent.

12. The method for removing one-sided electrode layer according to claim 1, wherein: The ultrasonic waves are applied for 5 minutes to 30 minutes.

13. The method for removing one-sided electrode layer according to claim 1, wherein: The ultrasonic waves are applied at a frequency of 10 kHz to 500 kHz.

14. The method for removing one-sided electrode layer according to claim 1, wherein, The method for removing one-sided electrode layer further comprises the following steps: Dry the single-sided electrode from which the one-sided electrode layer has been removed after applying the ultrasonic wave.

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