Method for removing one electrode layer from a double-sided electrode.

Abstract

The present invention provides a method for removing one side of an electrode layer of a double-sided electrode, which comprises interposing a double-sided electrode between an upper plate having an opening communicating with the top and bottom and a lower plate having a recessed portion that is open on one side and closed on the other side, placing the plate assembly, in which the upper plate and the lower plate are joined together with the double-sided electrode interposed, in an NMP (N-methyl-2-pyrrolidone) water bath and applying ultrasonic waves to the plate assembly.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0167845 filed on December 5, 2022, and all the contents disclosed in the documents of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a method for removing an electrode layer from one side of a double - sided electrode.

Background Art

[0003] Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative energy and clean energy has been increasing. As part of this, the fields of power generation and power storage using electrochemistry are the most actively studied.

[0004] Currently, as a typical example of an electrochemical device that uses such electrochemical energy, a secondary battery can be cited, and its usage area is expanding more and more.

[0005] Recently, with the increase in technology development and demand for portable devices such as portable computers, mobile phones, and cameras, the demand for secondary batteries as an energy source has been rapidly increasing. Among such secondary batteries, various studies have been conducted on lithium secondary batteries that exhibit high charge - discharge characteristics and long - life characteristics and are environmentally friendly, and they have also been commercialized and widely used.

[0006] On the other hand, before, during, and after the use of such lithium secondary batteries, for various reasons, they are disassembled to remove the electrode layer from the electrodes and recycled.

[0007] In FIG. 1, as an example, a conventional method for removing the electrode layer 12 from the electrode 10 is schematically shown.

[0008] Referring to Figure 1, conventionally, to separate only the electrode layer 12 from the electrode current collector 11, a less damaging ultrasonic method was used. Specifically, a device that generates ultrasonic waves, such as an ultrasonic horn 20, was used to apply ultrasonic waves to the surface of the electrode layer 12, creating small bubbles, which then destroyed the coating. No solvent was used.

[0009] However, with this method, the entire double-sided electrode layer 12 was destroyed, making it difficult to use it as a single-sided electrode.

[0010] However, in a typical full cell, for example, it is difficult to analyze the potential of the positive and negative electrodes. When inserting LTO electrodes between three electrode cells to analyze the potential of the positive and negative electrodes, one positive electrode on one side and one negative electrode on the other were used in each of the three electrode cells to reduce the risk of resistance reduction and capacitance loss.

[0011] In response to this, the need arose for a method to remove one electrode layer from a double-sided electrode. However, when removing one electrode layer from a double-sided electrode to manufacture a single-sided electrode, it is generally done manually by an operator using a solvent and a wafer towel. In this case, problems such as damage to the foil and penetration of the solvent into the electrode surface can occur due to the operator.

[0012] Therefore, there is an urgent need to develop technology that can solve these problems and manufacture single-sided electrodes by recycling double-sided electrodes without damaging the working surface. [Overview of the project] [Problems that the invention aims to solve]

[0013] The problem that this invention aims to solve is to provide a method for removing one electrode layer from a double-sided electrode without damaging the electrode layer on the other side, while simultaneously eliminating deviations caused by the operator. [Means for solving the problem]

[0014] A method for removing a single-sided electrode layer according to one embodiment of the present invention to achieve such objectives is a method for removing a single-sided electrode layer of a double-sided electrode, characterized in that a double-sided electrode is interposed between an upper plate having an opening that communicates vertically and a lower plate having a recessed portion that is open on one side and sealed on the other side, and with the double-sided electrode interposed, the plate assembly having a structure in which the upper plate and the lower plate are joined together is placed in an NMP (N-methyl-2-pyrrolidone) water tank and ultrasonic waves are applied.

[0015] In this case, when the double-sided electrode is interposed between the upper plate and the lower plate, the area of ​​the opening in the upper plate and the recessed area of ​​the lower plate are smaller than the area of ​​the double-sided electrode excluding the tab, and more specifically, may be 90% to 98% of the area of ​​the double-sided electrode excluding the tab.

[0016] In one specific example, the inner surface of the upper plate facing the lower plate may include a groove having a shape corresponding to the frame shape of the upper plate, and a rubber ring may be fitted into the groove.

[0017] Here, the rubber ring may apply pressure to the entire edge of the double-sided electrodes when the double-sided electrodes are joined together.

[0018] Furthermore, in one specific example, the upper plate and the lower plate may be mechanically connectable and detachable, and more specifically, the upper plate and the lower plate may be connected by fastening bolts inserted into fastening holes.

[0019] On the other hand, when the plate assembly is placed in an NMP (N-methylpyrrolidone) aqueous bath, the NMP solvent may not be present between the double-sided electrodes and the lower plate.

[0020] In one specific example, the temperature of the NMP solvent in the NMP water tank may be 25 to 60 degrees Celsius, and two or more ultrasonic horns may be formed in the NMP water tank.

[0021] In one specific example, the plate assembly applies ultrasonic waves in a state of being completely immersed in the NMP solvent. At this time, the ultrasonic waves may be applied at a frequency of 10 kHz to 500 kHz for 5 to 30 minutes.

[0022] Furthermore, the method for removing the one-sided electrode layer may include a process of drying the one-sided electrode from which the one-sided electrode layer has been removed after the application of the ultrasonic waves.

Brief Description of the Drawings

[0023] [Figure 1] It is an example of a schematic diagram showing a conventional method for removing an electrode layer from both-sided electrodes. [Figure 2] It is an exploded perspective view of a plate used in the method for removing a one-sided electrode layer according to an embodiment of the present invention. [Figure 3] It is a top view of a plate assembly according to an embodiment of the present invention. [Figure 4] It is a side view of a plate assembly cut along the reference L in FIG. 3. [Figure 5] It is a schematic inner surface view of the top plate according to an embodiment of the present invention. [Figure 6] It is a schematic diagram related to the method for removing a one-sided electrode layer according to an embodiment of the present invention. [Figure 7] It is a schematic diagram of the mechanism by which the one-sided electrode layer is removed from both-sided electrodes.

Modes for Carrying Out the Invention

[0024] The terms and words used in this specification and in the claims should not be interpreted in a manner limited to their conventional or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0025] The terms used herein are for illustrative purposes only and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0026] Furthermore, throughout this specification, when a part "includes" a certain component, unless otherwise stated, it means that it may include other components rather than excluding them.

[0027] According to one embodiment of the present invention, a method for removing a single-sided electrode layer is provided, in which a plate assembly having a structure in which a double-sided electrode is interposed between an upper plate having an opening that is connected vertically and a lower plate having a recessed portion that is open on one side and sealed on the other side, and the upper plate and lower plate are joined together with the double-sided electrode interposed, is placed in an NMP (N-methyl-2-pyrrolidone) water tank and ultrasonic waves are applied.

[0028] The method for removing a single-sided electrode layer according to an embodiment of the present invention will be described in more detail below with reference to the drawings. However, the description of the drawings below is based on one embodiment and does not limit the scope of the present invention thereto.

[0029] First, Figures 2 to 4 schematically show the plate assembly used in the present invention.

[0030] Specifically, the drawings show an exploded perspective view of a plate used in a single-sided electrode layer removal method according to one embodiment of the present invention, Figure 3 shows a top view of a plate assembly in which double-sided electrodes are bonded to the plate, and Figure 4 shows a single-sided view of the plate assembly.

[0031] Referring to Figures 2 to 4, the plate assembly 100 has a structure in which a double-sided electrode 130 is interposed between the upper plate 110 and the lower plate 120.

[0032] Specifically, the upper plate 110 has a structure in which an opening 111 is formed that communicates vertically, and the lower plate 120 has a structure in which a recessed portion 121 is formed that is open on one side and sealed on the other side. Here, the opening 111 of the upper plate 110 and the recessed portion 121 of the lower plate 120 have the same area, and when the double-sided electrode 130 is connected to them, the opening 111 and the recessed portion 121 are connected so that they are located at the same position relative to each other.

[0033] Here, the upper plate 110 and the lower plate 120 are mechanically connected and detachable, thereby allowing the double-sided electrodes 130 to be interposed and removed between the upper plate 110 and the lower plate 120.

[0034] At this time, the method of mechanically joining and separating the plates is not limited as long as it can be repeated, but for example, they can be joined by fastening bolts 140 inserted into fastening holes 113 and 123. In such a structure, plates 110 and 120 can be reused repeatedly.

[0035] Specifically, the upper plate 110 and the lower plate 120 may include fastening holes 113 and 123, and the plate assembly 100 can be manufactured by inserting fastening bolts 140 into the fastening holes 113 and 123 with the double-sided electrodes 130 interposed between them such that the electrode layer 133 is exposed in the opening 111 and recessed portion 121.

[0036] Furthermore, after removing the single-sided electrode layer 133, the upper plate 110 and the lower plate 120 can be separated by again removing the fastening bolts 140 from the fastening holes 113 and 123, and the single-sided electrode from which the single-sided electrode layer 133 has been removed can be separated and removed from the plate assembly 100.

[0037] Here, the fastening holes 113 and 123 may be formed in positions that communicate with each other so that they can be joined at once by a single fastening bolt 140.

[0038] On the other hand, since the double-sided electrode 130 must be interposed and fixed between the upper plate 110 and the lower plate 120, when the double-sided electrode 130 is interposed between the upper plate 110 and the lower plate 120, the area (S1) of the opening 111 of the upper plate 110 and the recessed portion 121 of the lower plate 120 is smaller than the area (S2) of the double-sided electrode 130 excluding the tabs 131 and 132, so as to completely cover the opening 111 of the upper plate 110 and the recessed portion 121 of the lower plate 120.

[0039] More specifically, the area (S1) of the opening 111 and recessed portion 121 may be 90% to 98% of the area (S2) obtained by subtracting the tabs 131 and 132 from the double-sided electrode 130, more specifically, 92% to 98%, and more specifically, 92% to 95%.

[0040] If the size of the opening 111 and the recessed portion 121 is too small beyond the aforementioned range, an unremoved electrode layer 133 is likely to occur. If the size of the opening 111 and the recessed portion 121 is too large, the double-sided electrode 130 may not be interposed and fixed between the upper plate 110 and the lower plate 120, which is undesirable.

[0041] Furthermore, in order to more firmly fix the double-sided electrodes 130 so as not to move between the upper plate 110 and the lower plate 120, grooves are formed on the inner surface of the upper plate 110 facing the lower plate 120 in a shape corresponding to the frame shape of the upper plate 110, and rubber rings can be fitted into these grooves.

[0042] To illustrate this, Figure 5 schematically shows the inner surface of the upper plate 110.

[0043] Referring to Figure 5, the upper plate 110s is formed such that the opening 111 is vertically connected, and has a frame shape. A rubber ring 112 is fitted onto a groove (not shown) with a shape corresponding to this frame shape.

[0044] The rubber ring 112 can then apply pressure to the edges of the double-sided electrode 130 when the double-sided electrode 130 is interposed between it and the lower plate 120. Therefore, the edges of the double-sided electrode 130 can be held more firmly, preventing movement of the double-sided electrode 130, and subsequently preventing the NMP solvent from burning and transferring to the electrode layer, and effectively preventing damage to the other electrode layer during the removal process of one electrode layer 133.

[0045] Therefore, a method for removing the single-sided electrode layer 133 using such a plate assembly 100 will be described below.

[0046] Figure 6 shows a schematic diagram of a method for removing a single-sided electrode layer according to one embodiment of the present invention, and Figure 7 schematically shows the mechanism by which the single-sided electrode layer is removed.

[0047] Referring to Figures 6 and 7 in conjunction with Figures 3 and 4, the plate assembly 100 has one electrode layer 133 of the double-sided electrode 130 exposed to the outside through an opening 111 in the upper plate 110, while the other electrode layer 134 is sealed by the lower plate 120.

[0048] Unlike Figure 4, the plate assembly 100 shown in Figure 6 is a side view rather than a cross-sectional view, and the shape in which the electrode layer 133 is exposed is not visible. When viewed from above, it is inserted into the NMP tank 150 in a form in which one surface of the electrode layer 133 is exposed, as shown in Figure 3.

[0049] Therefore, when the plate assembly 100 is inserted into the NMP water tank 150 and comes into contact with the NMP solvent 151, only the electrode layer 133 on one side of the double-sided electrode 130, exposed through the opening 111 of the upper plate 110, comes into contact with the NMP solvent 151, while the electrode layer 134 on the other side facing the lower plate 120 is sealed by the lower plate 120 and does not come into contact with the NMP solvent 151. In other words, there is no NMP solvent 151 between the double-sided electrode 130 and the lower plate 120.

[0050] At this time, the temperature of the NMP solvent 151 in the NMP tank 150 can be between 25 and 60 degrees Celsius, more specifically between 30 and 60 degrees Celsius, and more specifically between 45 and 50 degrees Celsius.

[0051] If the temperature exceeds the aforementioned range and is too high, the heat may be transferred to the other side of the double-sided electrode 130, potentially causing oxidation of the current collector, which is undesirable.

[0052] Subsequently, the plate assembly 100 is placed in the NMP water tank 150, and ultrasonic waves are applied to remove the electrode layer 133 on one side. At this time, since the electrode layer 133 on one side must be in complete contact with the NMP solvent 151, ultrasonic waves can be applied to the plate assembly 100 while it is completely immersed in the NMP solvent 151.

[0053] Therefore, two or more ultrasonic horns 152 may be formed in the NMP water tank 150, and ultrasonic waves can be applied to the NMP solvent 151 by the ultrasonic horns 152.

[0054] Here, ultrasound can be applied at frequencies of 10kHz to 500kHz for 5 to 30 minutes, or more specifically, at frequencies of 20kHz to 50kHz for 10 to 20 minutes.

[0055] If the current is applied for a very short time or at a frequency that exceeds the aforementioned range, the single-surface electrode layer 133 may not be completely removed, and if it is applied for a very long time or at a frequency that exceeds the aforementioned range, it may also affect the surface of the current collector 135, which is undesirable.

[0056] As described above, when ultrasound is applied, as shown in Figure 7, fine cavities (cavitations) are formed in the NMP solvent 151, similar to the principle of ultrasonic cleaning. These cavities explode, creating gaps between the electrode layers 133, and then the cavities penetrate these gaps again and explode, removing the electrode layers 133.

[0057] In this case, with the plate assembly 100 according to the present invention, only the electrode layer 133 formed on one side of the current collector 133 of the double-sided electrode 130 comes into contact with the NMP solvent, and the electrode layer 134 formed on the other side cannot come into contact with the NMP solvent. As a result, only the electrode layer 133 on one side is removed, while the electrode layer 134 on the other side remains. Therefore, single-sided electrodes can be manufactured more easily.

[0058] Furthermore, since the worker does not manually remove the electrode layer 133 from one surface, there is no deviation due to the worker, and only the electrode layer 133 from one surface can be removed.

[0059] Furthermore, because the process uses NMP solvent 151 and ultrasound, there is no surface damage to the current collector 135 of the electrode layer 133 being removed, and the NMP solvent 151 also has an impurity removal effect, which is advantageous for obtaining a single-sided electrode of excellent quality.

[0060] On the other hand, although not shown in the drawings, the method for removing the single-sided electrode layer according to one embodiment of the present invention uses an NMP solvent, and therefore may include a step of drying the single-sided electrode from which the single-sided electrode layer has been removed after the application of ultrasound.

[0061] This allows the NMP solvent to evaporate, and consequently, a reusable single-sided electrode can be obtained.

[0062] Anyone with ordinary skill in the art to which this invention belongs will be able to make various applications and modifications within the scope of this invention based on the above. Potential for Industrial Use

[0063] As described above, according to the present invention, when manufacturing a single-sided electrode from a double-sided electrode, deviations caused by the operator that occur when the process is performed manually in the past can be eliminated, and at the same time, the electrode layer on one side can be removed without damaging the electrode layer on the other side.

[0064] Therefore, since single-sided electrodes manufactured in this way show almost no damage to the working surface, there is an effect of reducing the accuracy of capacitance expression and deviation when using single-sided electrodes manufactured in this way in the future. [Explanation of symbols]

[0065] 10 electrodes 11 Electrode current collector 12 Electrode layer 20 Ultrasonic Horns 100 Plate Assembly 110 Top plate 111 Opening 112 Rubber rings 113 Conclusion Hall 120 Bottom Plate 121 Sinkhole 123 Fastening Hall 130 Double-sided electrodes 131, 132 tabs 133, 134 Electrode layer 135 Current collector 140 fastening bolts 150 aquariums 151 NMP solvent 152 Ultrasonic Horn

Claims

1. A method for removing one electrode layer from a double-sided electrode, A method for removing a single-sided electrode layer, comprising interposing double-sided electrodes between an upper plate with an opening formed thereon and a lower plate with a recessed portion formed thereon, which is open on one side and sealed on the other side, and then placing the plate assembly, in an NMP (N-methyl-2-pyrrolidone) water tank with the double-sided electrodes interposed and joining the upper plate and lower plate plates together, and applying ultrasonic waves.

2. The method for removing a single-sided electrode layer according to claim 1, wherein when the double-sided electrode is interposed between the upper plate and the lower plate, the area of ​​the opening in the upper plate and the recessed area of ​​the lower plate are smaller than the area of ​​the double-sided electrode excluding the tab.

3. The method for removing a single-sided electrode layer according to claim 2, wherein the size of the opening and the recessed portion is 90% to 98% of the size of the double-sided electrode excluding the tab.

4. The method for removing a single-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 fitted in the groove.

5. The method for removing a single electrode layer according to claim 4, wherein the rubber ring applies pressure to the edges of the double-sided electrodes when the double-sided electrodes are joined together.

6. The method for removing a single-sided electrode layer according to claim 1, wherein the upper plate and the lower plate are mechanically connectable and detachable.

7. The method for removing a single-sided electrode layer according to claim 6, wherein the upper plate and the lower plate are joined by fastening bolts inserted into fastening holes.

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

9. The method for removing a single-sided electrode layer according to claim 1, wherein the NMP solvent temperature in the NMP water tank is 25 to 60 degrees Celsius.

10. The method for removing a single-sided electrode layer according to claim 1, wherein two or more ultrasonic horns are formed in the NMP water tank.

11. The method for removing a single electrode layer according to claim 1, wherein the plate assembly is completely immersed in an NMP solvent and ultrasonic waves are applied to it.

12. The method for removing a single electrode layer according to claim 1, wherein the ultrasonic waves are applied for 5 to 30 minutes.

13. The method for removing a single-sided electrode layer according to claim 1, wherein the ultrasonic wave is applied at a frequency of 10 kHz to 500 kHz.

14. The method for removing a single-sided electrode layer according to claim 1, further comprising the step of drying the single-sided electrode from which the single-sided electrode layer has been removed after applying ultrasonic waves.

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