Electrode shape control method and electrode manufacturing method

Abstract

According to an embodiment of the present invention, there is provided an electrode shape control method and an electrode manufacturing method, which include a shaping step of irradiating a laser onto at least a portion of an electrode sheet on which an electrode slurry is applied, and moving the electrode slurry in the portion irradiated with the laser to an adjacent portion to shape the electrode slurry. The electrode shape control method and electrode manufacturing method according to the present invention have the advantage that the capacity loss can be minimized and the moving direction and the moving amount of the electrode slurry can be controlled to change the electrode shape.

Description

[Technical field]

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2022-0043367 filed on April 7, 2022 and Korean Patent Application No. 10-2023-0044807 filed on April 5, 2023.

[0002] The present invention relates to a method for controlling an electrode shape by coating an electrode with a slurry and then fluidizing a part of the slurry by irradiating the surface with a laser capable of transmitting heat, and a method for manufacturing an electrode. [Background technology]

[0003] In general, a secondary battery is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in the field of advanced electronic devices such as mobile phones, notebook computers, and camcorders.

[0004] The secondary batteries are classified into can-type secondary batteries and pouch-type secondary batteries, and the can-type secondary batteries include an electrode assembly, an electrolyte, a can that contains the electrode assembly and the electrolyte, and a cap assembly that is mounted on an opening of the can. The electrode assembly has a structure in which electrodes and separators are alternately stacked. The electrodes include a current collector and an electrode active material that is coated on the current collector.

[0005] One of the main research topics for such secondary batteries is to improve their quality and safety. This will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining problems with lithium secondary batteries according to the prior art.

[0006] 1, an electrode composite layer 2 is formed on an electrode current collector 1 by an electrode slurry coating method. The electrode composite layer 2 is formed by coating on both surfaces (upper and lower surfaces) of the electrode current collector 1.

[0007] In the case of a top coating formed on the upper surface of the electrode current collector 1, a phenomenon occurs in which the electrode slurry flows out from both ends of the electrode composite layer 2 due to the action of external forces such as gravity / centrifugal force. The region where the electrode slurry flows out is usually called a sliding region.

[0008] Such sliding regions cause capacity loss, making the battery capacity lower than the target value, and also cause the thickness of both ends of the electrode composite layer 2 to become thin, resulting in uneven contact with the separator S and separation (see symbol a in FIG. 1), which deteriorates the quality of the secondary battery overall.

[0009] In the case of a back coating formed on the lower surface of the electrode current collector 1, the electrode slurry flows out due to gravity before drying, causing both ends of the electrode mixture layer 2 to protrude downward (see symbol b in FIG. 1), and the protruding parts are subjected to high stress during the subsequent rolling process.

[0010] On the other hand, when the positive and negative electrodes face each other in a sliding region, the N / P ratio may differ from the design value. Furthermore, if the N / P ratio is reversed, problems may occur in which lithium is precipitated in the sliding region.

[0011] Korean Patent Publication No. 10-2017-0057953 discloses an electrode forming device that irradiates a laser beam onto the surface of an electrode to remove a portion of the electrode mixture layer. The technology disclosed in the above document can form the shape of the electrode surface, but a portion of the electrode mixture layer is removed, resulting in a capacity loss equivalent to the removed electrode mixture layer.

[0012] Therefore, there is a need to develop a technology for controlling the shape of an electrode after electrode coating, which can minimize the capacity loss while controlling the shape of the electrode. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Korean Patent Publication No. 10-2017-0057953 Summary of the Invention [Problem to be solved by the invention]

[0014] An object of the present invention is to provide a method for controlling the shape of an electrode and a method for manufacturing an electrode, which can minimize capacity loss while controlling the shape of the electrode after electrode coating. [Means for solving the problem]

[0015] According to an embodiment of the present invention, there is provided a method for controlling an electrode shape, comprising: irradiating a laser to at least a portion of an electrode sheet on which an electrode slurry is applied, and moving the electrode slurry in the portion irradiated with the laser to an adjacent portion to thereby shape the electrode slurry.

[0016] In an embodiment of the present invention, the electrode slurry of the electrode sheet may be in an unsolidified state.

[0017] In one embodiment of the invention, the laser may be an ultrashort near infrared laser.

[0018] In one embodiment of the present invention, the molding step may include a process of irradiating a laser using a laser module, and the laser module may include a laser oscillator that generates a laser, and a masking member coupled below the laser oscillator and having one or more openings that allow at least a portion of the laser generated from the laser oscillator to pass through.

[0019] In one embodiment of the present invention, the laser module may be configured to allow adjustment of the position and area of ​​the opening.

[0020] In an embodiment of the present invention, the laser module may be configured to allow the position of the opening to be adjusted based on a lateral direction (TD) of the electrode sheet.

[0021] In one embodiment of the present invention, the laser module can control the amount of movement of the electrode slurry by controlling one or more conditions among the vertical distance between the laser oscillator and the electrode sheet, the vertical distance between the masking member and the electrode sheet, the laser output, and the opening area of ​​the opening.

[0022] In an embodiment of the present invention, the laser module may control a moving direction of the electrode slurry by adjusting a position of the opening.

[0023] In one embodiment of the present invention, the masking member is a plate-like member having a plurality of through holes, and includes an opening / closing member slidably connected to one side plane of the plate-like member to open and close at least one of the plurality of through holes, and the through holes that are not covered by the opening / closing member may form the opening.

[0024] In one embodiment of the present invention, the masking member includes a number of plate-shaped blocks arranged in a row along the lateral direction of the electrode sheet, and a block driving unit that enables each of the number of plate-shaped blocks to move horizontally along the lateral direction of the electrode sheet, and the space between adjacent plate-shaped blocks may form the opening.

[0025] In one embodiment of the present invention, at least one of the laser oscillator and the masking member may be configured to be capable of reciprocating along a direction perpendicular to the plane of the electrode sheet.

[0026] According to another embodiment of the present invention, there is provided a method for manufacturing an electrode, including: a coating step of applying an electrode slurry onto a sheet-shaped current collector; a shaping step of irradiating a laser onto at least a portion of the electrode sheet on which the electrode slurry has been applied, and moving the electrode slurry in the laser-irradiated portion to an adjacent portion to shape the electrode slurry; and a drying step of drying the electrode sheet.

[0027] In an embodiment of the present invention, the electrode slurry of the electrode sheet may be in an unsolidified state.

[0028] In one embodiment of the present invention, the forming step may be performed prior to an initial drying step of the electrode sheet.

[0029] In one embodiment of the present invention, the forming step may be performed before a drying step of the electroded sheet. Effect of the Invention

[0030] The electrode shape control method and electrode manufacturing method according to the present invention can control the electrode shape without changing the coating conditions in the coating stage, thereby preventing the problem of deterioration of electrode quality due to changes in coating conditions.

[0031] In addition, there is an effect that the moving direction and the moving amount of the electrode slurry can be controlled by changing the electrode shape, and the loss of the electrode slurry can be minimized. [Brief description of the drawings]

[0032] [Figure 1] FIG. 13 shows an electrode shape where sliding regions occur after electrode coating. [Diagram 2] 4 is a flowchart illustrating an electrode shape control method according to an embodiment of the present invention. [Diagram 3] 1 is a diagram simply illustrating a method for controlling an electrode shape according to an embodiment of the present invention. [Figure 4] 4A to 4C are diagrams illustrating a process of controlling a position where a laser is irradiated on an electrode sheet and an amount of laser irradiation in accordance with an embodiment of the present invention. [Diagram 5] 4A to 4C are diagrams illustrating a process of controlling a position where a laser is irradiated on an electrode sheet and an amount of laser irradiation in accordance with an embodiment of the present invention. [Figure 6] 1 is a side view of an electrode shape forming device according to an embodiment of the present invention. [Figure 7] FIG. 7 is a top view of FIG. [Figure 8] 4 is a graph showing the results of measuring the thickness of each electrode slurry before and after laser irradiation according to an embodiment of the present invention. [Figure 9] 1 is a side view of a laser module according to a first embodiment of the present invention; [Figure 10] 5A to 5C are diagrams for explaining the operation of the masking member according to the first embodiment. [Figure 11] FIG. 11 is a side view of a laser module according to a second embodiment of the present invention. [Figure 12] 13A and 13B are diagrams for explaining the operation of the masking member according to the second embodiment. [Figure 13] 2 is a flowchart illustrating a method for manufacturing an electrode according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Since the present invention can be modified in various ways and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text, but it is not intended to limit the present invention to the specific disclosed forms, and it should be understood that the present invention includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0034] In this application, the terms "comprise" and "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in this application, being "on" may include not only the case where it is located on the top, but also the case where it is located on the bottom.

[0035] <Electrode shape control method> FIG. 2 is a flowchart illustrating a method for controlling an electrode shape according to an embodiment of the present invention, and FIG. 3 is a diagram simply illustrating a method for controlling an electrode shape according to an embodiment of the present invention.

[0036] Referring to FIG. 2, an electrode shape control method according to an embodiment of the present invention may include a coating step (S10) of applying an electrode slurry onto a sheet-shaped current collector, and a shaping step (S20) of irradiating a laser onto at least a portion of the electrode sheet on which the electrode slurry has been applied, thereby moving the electrode slurry in the laser-irradiated portion to an adjacent portion to shape the shape of the electrode slurry.

[0037] The electrode shape control method according to an embodiment of the present invention may include a process of irradiating a laser onto the surface of the electrode slurry in the forming step (S20). The light energy of the laser is absorbed by the electrode slurry during interaction with the electrode slurry and converted into thermal energy, and the heat generated at this time is transferred to the surroundings.

[0038] The temperature of the electrode slurry portion irradiated with the laser and its surroundings increases due to this thermal energy, and the viscosity of the electrode slurry decreases due to the increase in temperature, making it easier to move to adjacent portions. Since the laser can penetrate to the lower layer of the electrode sheet, not only the surface of the electrode slurry but also the electrode slurry adjacent to the current collector can be made to flow by the laser. This allows the operator to easily control the electrode shape to a desired shape.

[0039] According to an embodiment of the present invention, the electrode slurry of the electrode sheet is preferably in an unsolidified state, because when the electrode slurry is completely dried and solidified, no or only a small amount of solvent component is present in the electrode slurry, so the electrode slurry is not easily moved even when irradiated with a laser, and the light energy of the laser may deteriorate the solidified electrode slurry and cause the electrode slurry to be detached.

[0040] The electrode slurry of the electrode sheet in the early stage of the electrode sheet coating step or the electrode sheet drying step may be in a non-solid state. Here, the early stage of the drying step may be a section in which the drying step is advanced so that 30% or more, 50% or more, or 60% or more of the solvent remains in the electrode slurry based on the total amount of the solvent removed from the electrode slurry by the drying step.

[0041] Therefore, the electrode shape control method according to this embodiment differs from the conventional method of etching and removing a portion of the electrode slurry with a laser, in that a laser is irradiated to the area requiring shape deformation to move the electrode slurry to the periphery, and therefore may have the advantage of causing almost no capacity loss.

[0042] The coating step (S10) may be a step of applying an electrode slurry onto a sheet-shaped current collector. In the present invention, the electrode slurry may be a concept including both an electrode-forming slurry containing an electrode active material and an electrode mixture layer formed by applying the electrode-forming slurry. In addition, the electrode slurry may be a concept including, in addition to the above-mentioned electrode-forming slurry and electrode mixture layer, an insulating coating layer composition applied around the portion where the electrode slurry is applied to prevent short circuits, and an insulating coating layer formed by applying the insulating coating layer composition.

[0043] Specifically, the coating step (S10) may include preparing an electrode-forming slurry by mixing / stirring an electrode active material in a solvent, and applying the slurry to a current collector to form an electrode mixture layer. The electrode-forming slurry may further include at least one material selected from a binder, a conductive material, and other additives in addition to the solvent and the electrode active material. The electrode mixture layer is formed by applying the electrode-forming slurry.

[0044] The insulating coating layer can be formed by applying an insulating coating layer composition, which is prepared by mixing / stirring an insulating polymer and inorganic particles in a solvent, onto a current collector. The insulating coating layer composition can be applied around the edge of the electrode mixture layer and can also overlap a part of the edge of the electrode mixture layer.

[0045] Such an electrode-forming slurry and an insulating coating layer composition can be coated on a current collector by a conventionally known coating device such as a coating die, a coating roll, or a slide slot, and the electrode-forming slurry and the insulating coating layer composition can be coated in any form, without being limited thereto.

[0046] The coating device including the coating die may have a structure including: a coating die having an outlet slot through which the electrode-forming slurry flows out toward the current collector; and a coater roll that is spaced a predetermined distance from the outlet slot of the coating die and transports the current collector by rotation so that the electrode active material slurry can be applied to the current collector by the coating die.

[0047] In such a coating device, the electrode shape can also be controlled by controlling factors such as the distance (Gap) between the coating die and the current collector, the viscosity of the electrode forming slurry or the viscosity of the insulating coating layer composition, the rotation speed of the coater roll, the discharge pressure of the coating die, etc., but when such factors are controlled, the electrode loading amount also changes. The electrode shape control method of the present invention has the advantage that it is not necessary to change such coating control factors.

[0048] According to an embodiment, the forming step (S20) may include a process of irradiating a laser onto the electrode sheet using a laser module, and the laser module is not limited in shape as long as it is capable of irradiating a laser onto the electrode slurry.

[0049] Referring to FIG. 3, in one embodiment, the laser module 110 may include a laser oscillator 111 that generates a laser and a masking member 112.

[0050] As long as the laser oscillator 111 can generate a laser that is irradiated to at least a part of the electrode sheet 10, the specific embodiment thereof is not particularly limited.

[0051] In one embodiment, the laser generated from the laser oscillator 111 may be an ultrashort near-infrared laser. The ultrashort near-infrared laser has a short wavelength and can reach the lower part of the electrode sheet in the thickness direction, which is preferable because it allows the electrode slurry adjacent to the current collector to move to the adjacent part.

[0052] Such an ultrashort near-infrared laser may have a wavelength of 500 nm to 1500 nm, preferably 600 nm to 1300 nm, and most preferably 700 nm to 1100 nm. When the wavelength of the laser satisfies the above range, the laser can reach the lower part of the electrode sheet without damaging the electrode slurry, which is preferable.

[0053] The output of the laser generated from the laser oscillator 111 can be adjusted by a controller (not shown), and the amount of movement of the electrode slurry can be controlled by adjusting the output of the laser.

[0054] In one embodiment, the masking member 112 may be coupled below the laser oscillator 111 and may include one or more openings 112a that allow at least a portion of the laser generated from the laser oscillator 111 to pass therethrough.

[0055] The masking member 112 may be positioned below the laser oscillator 111 based on the vertical direction (z direction) on the plane of the electrode sheet, and the masking member 112 may serve to block the laser generated from the laser oscillator 111 from reaching the electrode sheet 10 below.

[0056] The masking member 112 may be provided with at least one opening 112a, and the laser generated from the laser oscillator 111 may be irradiated onto the electrode sheet below only through the opening 112a.

[0057] In one embodiment, the laser module 110 may be configured to adjust the position and opening area of ​​the opening 112a. The masking member 112 according to this embodiment may adjust the position where the laser is irradiated on the electrode sheet and the amount of laser irradiation.

[0058] Since the position of the opening 112a can be adjusted, the position of the portion of the electrode slurry where the laser passes through the opening 112a and is irradiated can be adjusted. Since the electrode slurry can move from the portion of the electrode slurry where the laser is irradiated first to the portion of the electrode slurry where the laser is irradiated later, it may be possible to control the movement direction of the electrode slurry by adjusting the position of the opening 112a.

[0059] In addition, the opening area of ​​the opening 112a can be adjusted, so that the amount of movement of the electrode slurry can be controlled. That is, the larger the opening area, the larger the total amount of light energy of the irradiated laser, and therefore the larger the amount of movement of the electrode slurry can be, and conversely, the smaller the opening area, the smaller the total amount of light energy of the irradiated laser, and therefore the smaller the amount of movement of the electrode slurry can be.

[0060] In one embodiment, the laser module 110 may be configured to allow for position adjustment of the aperture relative to the transverse direction (TD) of the electrode sheet.

[0061] Referring to FIG. 3, the opening 112a of the masking member 112 may be configured to be horizontally movable along the lateral direction (TD, y direction) of the electrode sheet 10, thereby enabling movement of the electrode slurry from the end of the electrode slurry toward the center of the electrode slurry.

[0062] Hereinafter, a process for controlling the position and dose of laser irradiation on an electrode sheet will be described according to an embodiment of the present invention.

[0063] 4 and 5 are diagrams illustrating a process of controlling the position where a laser is irradiated on an electrode sheet and the amount of laser irradiation, according to one embodiment of the present invention.

[0064] 4, the electrode sheet 10 includes a coated portion 12 to which the electrode slurry is applied and a non-coated portion 11 to which the electrode slurry is not applied, and an opening 112a of a masking member 112 may be opened to a size corresponding to the width length of the coated portion in the lateral direction (y direction). Thus, a laser (dotted arrow) generated from a laser oscillator 111 may pass through the opening 112a and be irradiated to the entire area along the lateral direction (y axis direction) of the electrode slurry.

[0065] 5, the coating portion 12 to which the electrode slurry is applied may be divided into a center portion 12a and edge portions 12b around both edges of the electrode coating portion in the lateral direction (y direction). The opening 112a of the masking member 112 may be opened to a size corresponding to the width of the edge portion 12b. Thus, the laser (dotted arrow) generated from the laser oscillator 111 may pass through the opening 112a and be irradiated only to the edge portion 12b of the electrode coating portion 12.

[0066] In this way, the electrode shape control method of the present invention is configured to enable adjustment of the position and opening area of ​​the opening in the masking member through which a laser passes, and can control the position and / or area of ​​the laser irradiation region.

[0067] FIG. 6 is a side view of an electrode shape forming device according to an embodiment of the present invention, and FIG. 7 is a top view of FIG.

[0068] Referring to these drawings, an electrode shape control device 100 according to one embodiment of the present invention may include a laser module 110, a laser module driving unit 120, a frame 130, a transport unit 140, and a controller (not shown).

[0069] The laser module 110 has been described above, so a duplicated description will be omitted.

[0070] The laser module driver 120 is coupled to one side of the laser module 110 and serves to drive the laser module 110 movably along one or more of the longitudinal direction (x direction) of the electrode sheet 10, the lateral direction (y direction) of the electrode sheet 10, and the direction perpendicular to the plane of the electrode sheet (z direction).

[0071] In one embodiment, the laser module driving unit 120 may be configured to independently drive each of the laser oscillator 111 and the masking member 112. That is, the laser module driving unit 120 may include a first driving unit that drives the laser oscillator 111 and a second driving unit that drives the masking member.

[0072] In one embodiment, the first driving unit can drive the laser oscillator 111 to be able to move back and forth along a direction perpendicular to the plane of the electrode sheet (z direction) in order to adjust the vertical distance between the laser oscillator 111 and the electrode sheet 10.

[0073] In addition, in one embodiment, the second driving unit may drive the masking member 112 to be reciprocally movable along a direction perpendicular to the plane of the electrode sheet (z direction) in order to adjust the vertical distance between the masking member 112 and the electrode sheet 10. The second driving unit may also drive the masking member 112 to be reciprocally movable along the lateral direction (TD, y direction) of the electrode sheet in order to adjust the position of the opening 112a of the masking member 112.

[0074] The electrode shape control method of this embodiment can suitably control the amount of movement of the electrode slurry by configuring at least one of the laser oscillator 111 and the masking member 112 to be capable of reciprocating movement along a direction perpendicular to the plane of the electrode sheet 10.

[0075] The frame 130 may serve as a support for mounting the laser module 110 above the electrode sheet 10 .

[0076] The conveying unit 140 may serve to convey the electrode sheet 10 in a traveling direction (x direction). The conveying unit 140 may include a conveying roller that conveys the electrode sheet in one direction by a rotational motion, and a motor (not shown) that imparts a rotational force to the conveying roller.

[0077] The controller (not shown) may serve to control the operation of the various components of the electrode shape control device 100 .

[0078] That is, a controller (not shown) can control the position of the opening 112a and can play a role in controlling one or more of the following conditions: the vertical distance between the laser oscillator 111 and the electrode sheet 10, the vertical distance between the masking member 112 and the electrode sheet 10, the laser output generated from the laser oscillator 111, and the opening area of ​​the opening 112a.

[0079] The controller can control the direction of movement of the electrode slurry by adjusting the position of the opening 112a.

[0080] The controller can also control the amount of movement of the electrode slurry by controlling one or more conditions among the vertical distance between the laser oscillator 111 and the electrode sheet 10, the vertical distance between the masking member 112 and the electrode sheet 10, the laser output generated from the laser oscillator 111, and the opening area of ​​the opening 112a.

[0081] FIG. 8 is a graph showing the results of measuring the thickness of each electrode slurry before and after laser irradiation according to one embodiment of the present invention.

[0082] 8, the thickness of the electrode slurry before the laser irradiation gradually decreases from about 8 mm of the coating width corresponding to the x-axis to about 2 mm of the coating width, and then decreases rapidly. When the laser is irradiated to the area of ​​about 1 mm to about 5 mm of the coating width corresponding to the x-axis according to the embodiment of the present invention, the temperature of the electrode slurry increases due to the light energy of the irradiated laser, making it easy to flow, and it moves in the direction of the arrow. As a result, the thickness of the electrode mixture layer in the area of ​​about 4 mm to about 1 mm of the coating width decreases, and the thickness of the electrode mixture layer in the area of ​​about 8 mm to 4 mm increases.

[0083] In this way, the electrode shape control method according to the present invention has the advantage that the electrode shape can be easily formed as intended by the operator by irradiating a laser to a position where the operator wants to form the electrode. Also, since the electrode shape is changed by a method of moving the electrode slurry using a laser, there is almost no loss of the electrode slurry, and the shape can be changed in the sliding region, flat portion, or all of these regions of the electrode active material coating portion.

[0084] (First embodiment) FIG. 9 is a side view of the laser module according to the first embodiment of the present invention, and FIG. 10 is a diagram for explaining the operation of the masking member according to the first embodiment of FIG.

[0085] Referring to these drawings, the laser module 110 according to the first embodiment includes a masking member 112, which is a plate-like member having a number of through-holes 112a, and may include an opening / closing member 113 slidably coupled to one side of the plate-like member 112 in order to open and close at least one of the number of through-holes. The through-holes 112a that are not covered by the opening / closing member 113 may form the opening.

[0086] The opening / closing member 113 is configured to be capable of blocking a part or the whole of the opening formed by the through-hole 112a, and the opening position and / or the opening area of ​​the opening can be controlled by the operation of the opening / closing member 113.

[0087] The masking member 112 may be a plate-like member having a predetermined thickness d. The masking member 112 may be located between the laser oscillator 111 and the electrode sheet 10 with respect to the direction perpendicular to the plane of the electrode sheet (z direction).

[0088] The opening / closing member 113 may be attached to one side plane of the plate-shaped masking member 112. In Figures 9 and 10, the opening / closing member 113 is illustrated as being attached to the lower surface of the masking member 112, but this is not limited to this and it may also be attached to the upper surface of the masking member 112.

[0089] The opening / closing member 113 may be a plate-like member, and one opening / closing member may slide to cover all or a part of the through-hole 112a that needs to be covered, or, as shown in Figures 9 and 10, two or more plate-like members may be assembled to form one opening / closing member 113, and the multiple opening / closing members may be configured to be able to slide independently. When there are two or more opening / closing members 113, it may be easier to select the position of the through-hole 112a to be covered.

[0090] The through-hole 112a is formed by passing through a plate-shaped masking member 112 from one surface to the other surface, and a laser generated by a laser oscillator 111 may be irradiated onto the electrode sheet through the through-hole 112a. That is, the through-hole 112a may form an opening.

[0091] The portions of the masking member 112 where no through-holes are formed can block the laser generated from the laser oscillator 111 .

[0092] 9 and 10, a number of through holes 112a are formed in the masking member 112, and the opening / closing member 113 slides to the position of the through holes 112a that need to be shielded from the laser, and the opening / closing member 113 can block some or all of the through holes to prevent the laser from being irradiated onto the electrode sheet.

[0093] By selecting the through-hole to be blocked by the opening / closing member 113, it is possible to adjust the position where the laser generated by the laser oscillator 111 is irradiated on the electrode sheet. This makes it possible to control the moving direction of the electrode slurry.

[0094] In addition, the area of ​​the through-holes shielded by the opening / closing member 113 can also be adjusted. That is, the entire area of ​​one through-hole can be shielded, or a portion of one through-hole can be shielded. By adjusting the area of ​​the through-holes shielded by the opening / closing member, the amount of laser irradiated to the electrode sheet 10 can also be adjusted. And, by adjusting the amount of laser irradiated to the electrode sheet, the amount of movement of the electrode slurry can be controlled.

[0095] In the electrode shape control method according to the embodiment described above, in order to irradiate a laser to a portion for which the electrode shape is to be controlled, the opening position of the masking member can be freely selected by suitably moving the shielding member 113, and the amount of laser irradiation can be suitably controlled by suitably adjusting the opening area of ​​the opening. Therefore, the operator can freely select the laser irradiation area along the lateral direction of the coating portion to which the electrode slurry is applied. For example, when there are protruding portions (fat edges) at both side edges in the lateral direction (y direction) of the coating portion to which the electrode slurry is applied, the opening position and opening area of ​​the opening of the masking member can be adjusted to selectively irradiate the laser only to the protruding portion, thereby controlling the electrode shape to a desired shape.

[0096] Second embodiment FIG. 11 is a side view of a laser module according to a second embodiment of the present invention, and FIG. 12 is a diagram for explaining the operation of a masking member according to the second embodiment.

[0097] Referring to these drawings, the laser module according to the second embodiment includes a masking member 212, which may include a number of plate-shaped blocks 212-1, 212-2, 212-3, and 212-4 arranged in a row along the lateral direction of the electrode sheet 10, and a block driving unit (not shown) that allows each of the number of plate-shaped blocks 212-1, 212-2, 212-3, and 212-4 to move horizontally along the lateral direction of the electrode sheet. The interval spaces 212a between the adjacent plate-shaped blocks may form the openings.

[0098] A number of plate-shaped blocks 212-1, 212-2, 212-3, and 212-4 are assembled to form a masking member 212, and a laser generated from a laser oscillator 211 can reach the electrode sheet 10 underneath through the mutually spaced spaces between the plate-shaped blocks.

[0099] In order to adjust the position and area of ​​the electrode sheet where the laser is irradiated, the multiple plate-shaped blocks 212-1, 212-2, 212-3, and 212-4 may be structured to be independently movable. As shown in Fig. 12, the position and area of ​​the electrode sheet where the laser is irradiated may be adjusted according to the movement of the multiple plate-shaped blocks 212-1, 212-2, 212-3, and 212-4.

[0100] <Electrode manufacturing method> FIG. 13 is a flowchart illustrating a method for manufacturing an electrode according to an embodiment of the present invention.

[0101] Referring to FIG. 13, a method for manufacturing an electrode according to an embodiment of the present invention may include a coating step (S110) of applying an electrode slurry onto a sheet-shaped current collector, a shaping step (S120) of irradiating a laser onto at least a portion of the electrode sheet on which the electrode slurry has been applied, and moving the electrode slurry in the laser irradiated portion to an adjacent portion to shape the electrode slurry, and a drying step (S130) of the electrode sheet.

[0102] According to an embodiment of the present invention, in the forming step (S120), the electrode slurry of the electrode sheet is preferably in an unsolidified state because the electrode slurry is completely dried and solidified, and therefore no or only a small amount of solvent component is present in the electrode slurry, so the electrode slurry is not easily moved even when irradiated with a laser, and the light energy of the laser may deteriorate the solidified electrode slurry, causing the electrode slurry to be detached.

[0103] The coating step (S110) and the molding step (S120) have been described in detail above, so a duplicated description will be omitted.

[0104] The drying step (S130) may be a step of removing a solvent from the electrode slurry by using a hot air supplying means and / or a radiant heat supplying means to the electrode sheet. The drying step (S130) may be performed according to a technique generally known in the technical field of electrodes for lithium secondary batteries.

[0105] According to an embodiment of the present invention, the forming step (S120) may be performed prior to an initial stage of the drying step (S130) of the electrode sheet.

[0106] Here, the initial stage of the drying step may be a section in which the drying step is carried out so that 30% or more, 50% or more, or 60% or more of the solvent remains in the electrode slurry based on the total amount of the solvent removed from the electrode slurry by the drying step.

[0107] In the initial drying stage, since a considerable amount of solvent still remains in the electrode slurry, the electrode slurry is also in a state where it is easy to move, so that the operator can shape the electrode into a desired shape by irradiating the laser according to the present invention.

[0108] According to an embodiment of the present invention, the forming step (S120) may be performed before the drying step (S130) of the electrode sheet. That is, the drying step (S120) may be performed after the forming step (S120) of the present invention is performed on the electrode sheet that has been subjected to the coating step (S110).

[0109] The present invention is not limited to the above-described embodiments, and the scope of application is diverse. It goes without saying that anyone having ordinary knowledge in the field to which the present invention pertains can make various modifications without departing from the gist of the present invention as claimed in the claims. [Explanation of symbols]

[0110] 100: Electrode shape forming device 110: Laser module 111, 211: Laser oscillator 112, 212: Masking material 112a: Opening 113: Opening and closing parts 120, 220: Laser module drive unit 130: Frame 140:Transfer section 10: Electrode sheet 12: Electrode slurry (coating part) 11: Current collector (plain area)

Claims

1. An electrode shape control method comprising a shaping step of irradiating with a laser at least a portion of an electrode sheet on which electrode slurry has been applied, and moving the electrode slurry in the portion irradiated with the laser to an adjacent portion to shape the electrode slurry.

2. The electrode shape control method according to claim 1 , wherein the electrode slurry of the electrode sheet is in an unsolidified state.

3. The electrode shape control method according to claim 1 , wherein the laser is an ultrashort near-infrared laser.

4. The forming step includes a step of irradiating a laser using a laser module, The laser module includes: A laser oscillator for generating a laser; The electrode shape control method according to claim 1 , further comprising: a masking member coupled below the laser oscillator and having one or more openings through which at least a portion of the laser generated from the laser oscillator passes.

5. The laser module includes: The electrode shape control method according to claim 4 , wherein the position and area of ​​the opening can be adjusted.

6. The laser module includes: The electrode shape control method according to claim 4 , wherein the position of the opening can be adjusted based on a lateral direction of the electrode sheet.

7. The laser module includes:

5. The electrode shape control method according to claim 4, wherein the amount of movement of the electrode slurry is controlled by controlling one or more conditions among the vertical distance between the laser oscillator and the electrode sheet, the vertical distance between the masking member and the electrode sheet, the laser output, and the opening area of ​​the opening.

8. The laser module includes: The electrode shape control method according to claim 4 , further comprising controlling a moving direction of the electrode slurry by adjusting the position of the opening.

9. the masking member is a plate-like member having a number of through holes; an opening / closing member slidably coupled to one side of the plate-like member to open and close at least one of the through-holes; The electrode shape control method according to claim 4 , wherein a through-hole that is not blocked by the opening / closing member forms the opening.

10. The masking member is A number of plate-shaped blocks are arranged in a row along the lateral direction of the electrode sheet; a block driving unit that enables each of the plurality of plate-shaped blocks to move horizontally along a lateral direction of the electrode sheet, The electrode shape control method according to claim 4 , wherein a space between adjacent plate-like blocks forms the opening.

11. The electrode shape control method according to claim 4 , wherein at least one of the laser oscillator and the masking member is configured to be capable of reciprocating movement along a direction perpendicular to a plane of the electrode sheet.

12. A coating step of applying an electrode slurry onto a sheet-shaped current collector; a forming step of irradiating a laser onto at least a portion of the electrode sheet on which the electrode slurry has been applied, and moving the electrode slurry from the portion irradiated with the laser to an adjacent portion to form a shape of the electrode slurry; and drying the electrode sheet.

13. A method for manufacturing an electrode as described in claim 12, wherein, during the molding step, the electrode slurry of the electrode sheet is in an unsolidified state.

14. The method for manufacturing an electrode according to claim 12 , wherein the forming step is performed before an initial stage of a drying step of the electrode sheet.

15. The method of claim 12, wherein the forming step is performed before a step of drying the electrode sheet.

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