Rolling device for manufacturing electrode and rolling method for manufacturing electrode

Abstract

A rolling device for manufacturing an electrode according to one embodiment of the present invention comprises: a rolling member for rolling an electrode base material when the electrode base material passes through; and an uncoated portion stretching member that additionally stretches the uncoated portion of the electrode substrate that has passed through the rolling member, in which the uncoated portion stretching member is configured such that a relative position of the uncoated portion stretching member with respect to the electrode substrate is adjusted in accordance with a state of the uncoated portion of the electrode substrate.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0002] This application claims the priority benefits of Korean Patent Application No. 10 - 2022 - 0165533, filed with the Korean Intellectual Property Office on December 1, 2022, and Korean Patent Application No. 10 - 2023 - 0159672, filed with the Korean Intellectual Property Office on November 17, 2023. The entire disclosures of the above - mentioned patent applications are incorporated herein by reference.

[0003] The present invention relates to a rolling device for manufacturing an electrode and a rolling method for manufacturing an electrode. More specifically, it relates to a rolling device for manufacturing an electrode and a rolling method for manufacturing an electrode that can precisely adjust the additional tension of the uncoated portion of an electrode substrate during the electrode rolling process. Background Art

[0004] In modern society, with the daily use of portable devices such as mobile phones, laptops, cameras, and digital cameras, the development of technologies in fields related to the above - mentioned mobile devices is actively carried out. In addition, rechargeable / dischargeable secondary batteries are used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug - in hybrid electric vehicles (P - HEVs), etc., in an attempt to solve problems such as air pollution caused by the use of fossil fuels in existing gasoline vehicles. Therefore, the demand for developing secondary batteries is increasing day by day.

[0005] Currently commercialized secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, and lithium secondary batteries, etc. Among these secondary batteries, lithium secondary batteries have attracted much attention due to their advantages. For example, compared with nickel - based secondary batteries, lithium secondary batteries hardly show a memory effect, so they can be freely charged and discharged, and have a very low self - discharge rate and high energy density.

[0006] The manufacturing process of such lithium secondary batteries is generally divided into an electrode process, an assembly process, and an activation process. The electrode process is divided into an active material mixing process, an electrode coating process, a rolling process, a cutting process, a winding process, etc. Among these processes, the rolling process is a process in which, after the coating process is completed, the thickness of the electrode substrate is reduced to improve the capacity density, and the electrode substrate is passed between a pair of rollers heated to a high temperature and compressed to the required thickness to increase the adhesion between the electrode current collector and the electrode active material.

[0007] On the other hand, when rolling the electrode substrate, the following problems exist: Due to the different stretchabilities between the coated portion 12 coated with the active material and the uncoated portion 11 not coated with the active material, phenomena such as swelling may occur in the uncoated portion 11 of the rolled electrode substrate. To improve this problem, referring to Figure 1 , the process is carried out in such a way that an additional stretch is applied to the uncoated portion 11 of the electrode substrate 10 passing between the rolling members 110 through the uncoated portion stretching member 120. However, depending on the pulling force applied by the uncoated portion stretching member 120 to the uncoated portion 11 of the electrode substrate, the swelling of the uncoated portion 11 may be improved, but in some cases, the swelling may deteriorate further.

[0008] Therefore, a method is needed to be able to more effectively improve the problem of swelling occurring in the uncoated portion 11 of the electrode substrate during the rolling process of the electrode substrate. Summary of the Invention

[0009] Technical Problem

[0010] The object of the present invention is to: during the rolling process of the electrode substrate, additionally stretch the uncoated portion 11, but adjust the stretching degree, so as to improve the problem of swelling occurring in the uncoated portion 11 of the electrode substrate.

[0011] However, the technical problems to be solved by the embodiments of the present invention are not limited to the above problems, and various expansions can be carried out within the scope of the technical idea included in the present invention.

[0012] Technical Solution

[0013] According to an embodiment of the present invention, there is provided a rolling device for manufacturing an electrode, the device comprising: rolling members for rolling the electrode substrate when the electrode substrate passes through; and an uncoated portion stretching member for additionally stretching the uncoated portion of the electrode substrate that has passed through the rolling members, wherein the uncoated portion stretching member is configured to adjust the relative position of the uncoated portion stretching member with respect to the electrode substrate according to the state of the uncoated portion of the electrode substrate.

[0014] The rolling device for manufacturing an electrode further includes a driving unit for adjusting the position of the uncoated portion stretching member, wherein the uncoated portion stretching member remains in place, or advances towards the electrode substrate, or retreats from the electrode substrate in the opposite direction, so that the position of the uncoated portion stretching member can be adjusted.

[0015] The rolling device for manufacturing an electrode further includes a monitoring unit that monitors the electrode substrate and determines the state of the uncoated portion of the electrode substrate. When the uncoated portion of the electrode substrate is in a normal state, the uncoated portion stretching member maintains its position unchanged. When the uncoated portion of the electrode substrate is in a predetermined first abnormal state, the uncoated portion stretching member advances toward the electrode substrate. And when the uncoated portion of the electrode substrate is in a predetermined second abnormal state, the uncoated portion stretching member can retreat from the electrode substrate.

[0016] The first abnormal state may be a state in which an expansion valley or an expansion peak of the uncoated portion appears in the length direction of the electrode substrate, and the second abnormal state may be a state in which an expansion valley or an expansion peak of the uncoated portion appears in the width direction of the electrode substrate.

[0017] When the angle between the direction of the expansion valley or expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 0 degrees or more and less than 45 degrees, it can be determined that the uncoated portion is in the first abnormal state; when the angle between the direction of the expansion valley or expansion peak of the uncoated portion and the advancing direction of the electrode substrate is greater than 45 degrees and 90 degrees or less, it can be determined that the uncoated portion is in the second abnormal state; and when the angle between the direction of the expansion valley or expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 45 degrees, it can be determined that the uncoated portion is in either the first abnormal state or the second abnormal state.

[0018] When the uncoated portion of the electrode substrate is in the predetermined first abnormal state, the uncoated portion stretching member can advance toward the electrode substrate by a first predetermined value, and the operation of advancing the uncoated portion stretching member by the first predetermined value can be repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

[0019] When the uncoated portion of the electrode substrate is in the predetermined second abnormal state, the uncoated portion stretching member can retreat from the electrode substrate by a second predetermined value, and the operation of retreating the uncoated portion stretching member by the second predetermined value can be repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

[0020] The monitoring unit is located at the rear end of the uncoated portion stretching member and monitors the state of the uncoated portion of the electrode substrate that has passed through the uncoated portion stretching member, so that the position of the uncoated portion stretching member can be adjusted.

[0021] The monitoring unit is located between the rear end of the rolling member and the front end of the uncoated portion stretching member and monitors the state of the uncoated portion of the electrode substrate that has passed through the rolling member, so that the position of the uncoated portion stretching member can be adjusted.

[0022] The rolling member is a pair of rolling rolls that rotate in opposite directions around a rotation axis. The uncoated portion stretching member is an uncoated portion pressing roll, and the uncoated portion pressing roll includes a pressing portion. The pressing portion is provided at a position corresponding to the uncoated portion of the electrode substrate and may have a structure protruding from the outer peripheral surface of the uncoated portion pressing roll.

[0023] The drive unit may be an actuator connected to the uncoated portion pressing roll.

[0024] The rolling device for manufacturing an electrode may further include a guiding member that guides the movement of the electrode substrate.

[0025] The rolling device for manufacturing an electrode may further include an electrode rewinder that winds and recovers the electrode substrate.

[0026] According to another embodiment of the present invention, there is provided a rolling method for manufacturing an electrode, the method including the steps of: rolling an electrode substrate with a rolling member; additionally stretching the uncoated portion of the rolled electrode substrate with an uncoated portion stretching member; and monitoring the electrode substrate with a monitoring unit to determine the state of the uncoated portion of the electrode substrate. When the uncoated portion of the electrode substrate is in an abnormal state, the method further includes adjusting the relative position of the uncoated portion stretching member with respect to the electrode substrate.

[0027] When the uncoated portion of the electrode substrate is in a normal state, the uncoated portion stretching member may maintain its position unchanged.

[0028] Adjusting the relative position of the uncoated portion stretching member may include at least one of the following steps: when the uncoated portion of the electrode substrate is in a predetermined first abnormal state, moving the uncoated portion stretching member forward toward the electrode substrate; and when the uncoated portion of the electrode substrate is in a predetermined second abnormal state, moving the uncoated portion stretching member backward from the electrode substrate.

[0029] The first abnormal state may be a state in which an expansion valley or expansion peak of the uncoated portion appears in the length direction of the electrode substrate, and the second abnormal state may be a state in which an expansion valley or expansion peak of the uncoated portion appears in the width direction of the electrode substrate.

[0030] When the angle between the direction of the swelling valley or swelling peak of the uncoated portion and the advancing direction of the electrode substrate is 0 degrees or more and less than 45 degrees, it can be determined that the uncoated portion is in the first abnormal state; when the angle between the direction of the swelling valley or swelling peak of the uncoated portion and the advancing direction of the electrode substrate is greater than 45 degrees and 90 degrees or less, it can be determined that the uncoated portion is in the second abnormal state; and when the angle between the direction of the swelling valley or swelling peak of the uncoated portion and the advancing direction of the electrode substrate is 45 degrees, it can be determined that the uncoated portion is in one of the first abnormal state and the second abnormal state.

[0031] When the uncoated portion of the electrode substrate is in a predetermined first abnormal state, the uncoated portion stretching member can advance a first predetermined value toward the electrode substrate, and the advancing of the uncoated portion stretching member by the first predetermined value can be repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

[0032] When the uncoated portion of the electrode substrate is in a predetermined second abnormal state, the uncoated portion stretching member can retreat a second predetermined value from the electrode substrate, and the retreating of the uncoated portion stretching member by the second predetermined value can be repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

[0033] Advantageous Effects

[0034] According to the embodiment, in the rolling process of the electrode substrate, additional stretching is applied to the uncoated portion 11 and the degree of stretching is adjusted, so that the swelling problem occurring in the uncoated portion 11 of the electrode substrate can be improved. Therefore, the production efficiency of the electrode assembly can be maximized, and the quality of the produced electrode assembly can also be improved.

[0035] The effects obtainable by the present invention are not limited to the above effects, and those of ordinary skill in the art will clearly understand other effects not mentioned herein from the specification and the drawings. Description of the Drawings

[0036] Figure 1 Shows a rolling device for manufacturing an electrode according to the prior art.

[0037] Figure 2 Shows a rolling device for manufacturing an electrode according to an embodiment of the present invention.

[0038] Figure 3 Is a schematic diagram showing a part of the electrode substrate.

[0039] Figure 4 Shows Figure 2 The uncoated portion roll provided in the rolling device for manufacturing an electrode in

[0040] Figure 5 shows setting the forward and backward degrees of the uncoated portion of the stretching member in Figure 2 as the process variable of the wrap angle (θ).

[0041] Figure 6 and Figure 7 each show an example of an abnormal state of the uncoated portion of the electrode substrate.

[0042] Figure 8 shows Figure 2 a modification of the rolling device for manufacturing an electrode in

[0043] Figure 9 and Figure 10 shows a flowchart of a rolling method for manufacturing an electrode according to an embodiment of the present invention. Detailed Description of the Invention

[0044] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement these embodiments. The present invention can be modified in various different ways and is not limited to the embodiments described herein.

[0045] For clarity, descriptions of parts irrelevant to the specification will be omitted, and throughout the specification, the same reference numerals denote the same or similar elements.

[0046] In addition, in the drawings, for convenience of description, the sizes and thicknesses of the respective elements are arbitrarily shown, and the present invention does not necessarily have to be limited to the sizes and thicknesses shown in the drawings. In the drawings, for clarity, the thicknesses of layers, regions, etc. are exaggerated. In the drawings, for convenience of description, the thicknesses of parts and regions are exaggerated.

[0047] In addition, it should be understood that when an element (such as a layer, film, region, or plate) is referred to as being "on" or "above" another element, it can be directly on the other element, or there may also be an intermediate element. In contrast, when an element is referred to as being "directly on" another element, it means that there are no other intermediate elements. In addition, a certain part being "above" or "on" a reference part means that the certain part is above or below the reference part, and does not particularly mean that the certain part is located "above" or "on" the reference part in the opposite direction of gravity.

[0048] In addition, throughout the specification, when a part is referred to as "including" or "containing" a certain component, unless otherwise specified, it means that the part may further include other components without excluding other components.

[0049] In addition, throughout the specification, when referred to as a "plane", it refers to the case when the target part is observed from the upper side; and when referred to as a "section", it refers to the case when the target part is observed from one side of a section vertically cut.

[0050] Now, reference will be made to Figures 2 to 5 describe a rolling device 100 for manufacturing an electrode according to an embodiment of the present invention.

[0051] Figure 2 The rolling device 100 for manufacturing an electrode in [[ ]] includes a rolling member 110, an uncoated portion stretching member 120, a monitoring unit 130, a guiding member 140, and an electrode winding member 150.

[0052] As [[ ]] Figure 3 shown, the electrode substrate 10 has such a structure: an electrode mixture is coated on one side or both sides of a current collector made of aluminum foil or the like, that is, a coated portion 12 (see [[ ]] Figure 3 ). The electrode substrate 10 is rolled when passing through the rolling member 110.

[0053] For example, the rolling member 110 can be a pair of rollers. Each roller rotates in opposite directions around the rotation axis in the longitudinal direction of each roller, and the rotation axis is located at the center of each roller in the pair of rollers. When the electrode substrate 10 passes between the rollers, the coated portion 12 is rolled.

[0054] At this time, swelling may occur in the uncoated portion 11 of the electrode substrate 10 that has passed through the rolling member 110.

[0055] Subsequently, the uncoated portion 11 of the electrode substrate 10 is stretched by the uncoated portion stretching member 120 disposed behind the rolling member 110. More specifically, as [[ ]] Figure 4 shown, for example, the uncoated portion stretching member 120 can be a pressure roller. In addition, in order to solve the problem of swelling occurring in the uncoated portion 11, a pressing portion 120a that only presses the uncoated portion 11 of the electrode substrate 10 can be included.

[0056] The pressing portion 120a of the uncoated portion stretching member 120 is formed at a position corresponding to the uncoated portion 11 of the electrode substrate 10. In addition, the pressing portion 120a has a structure protruding from the outer peripheral surface of the uncoated portion stretching member 120. Therefore, except for the coated portion 12 of the electrode substrate 10, only the uncoated portion 11 can be pressed by the pressing portion 120a of the uncoated portion stretching member 120.

[0057] The pressing portion 120a of the uncoated portion stretching member 120 can be integrally formed with the roller body of the uncoated portion stretching member 120, and can be attached to or detached from the outer peripheral surface of the uncoated portion stretching member 120 using a shrink fit method.

[0058] In addition, the pressing portion 120a can include heat rays for applying heat to the uncoated portion 11 to effectively roll the uncoated portion 11.

[0059] The width of the pressing portion 120a can be the same as or slightly smaller than the width of the uncoated portion 11 of the electrode substrate 10. For example, the width of the pressing portion 120a can be 90% to 100% of the width of the uncoated portion 11.

[0060] For example, the uncoated portion stretching member 120 is formed of any one of the following: a metal such as aluminum or its alloy, or a metal such as stainless steel, or an engineering plastic material having high strength and high hardness, or a plastic material having low hardness, or a plastic material made of rubber.

[0061] The uncoated portion stretching member 120 can rotate about a rotational axis in the longitudinal direction located at the center of the uncoated portion stretching member 120 in the advancing direction of the electrode substrate 10.

[0062] Meanwhile, both ends of the uncoated portion stretching member 120 are connected to a drive unit (not shown), and the drive unit can adjust the position of the uncoated portion stretching member 120. For example, the drive unit can be an actuator that adjusts the position of the uncoated portion stretching member 120. The drive unit can move the uncoated portion stretching member 120 forward (A1) toward the electrode substrate 10. However, conversely, it can also move it backward (A2) from the electrode substrate 10.

[0063] For example, in the direction of the rotational axis of the uncoated portion stretching member 120, bar-shaped support members are connected to both ends of the uncoated portion stretching member 120, and the uncoated portion stretching member 120 and the support members can move forward (A1) toward the electrode substrate 10 through the drive unit. However, conversely, they can also move backward (A2) from the electrode substrate 10.

[0064] The monitoring unit 130 monitors the state (e.g., the degree of improvement in swelling) of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120. For example, the monitoring unit 130 can be a visual unit that images the state of the uncoated portion 11 of the electrode substrate 10.

[0065] The monitoring unit 130 monitors the state of the uncoated portion 11 and uses the processor 130a to determine the state of the uncoated portion 11. The processor 130a is integrated with the monitoring unit 130 or provided separately and connected to the monitoring unit 130. For example, the monitoring unit 130 can determine whether the state of the uncoated portion 11 of the electrode substrate 10 is a normal state or an abnormal (non-normal) state.

[0066] The uncoated portion stretching member 120 is configured such that the relative position of the uncoated portion stretching member 120 with respect to the electrode substrate 10 can be adjusted according to the state of the uncoated portion 11 of the electrode substrate 10.

[0067] If the state of the uncoated portion 11 of the electrode substrate 10 corresponds to the normal state, the position of the uncoated portion stretching member 120 remains unchanged, and the pressing of the uncoated portion 11 also remains unchanged. Here, "the state of the uncoated portion 11 corresponds to the normal state" means that when the uncoated portion 11 of the electrode substrate is monitored by the monitoring unit 130, there is no swelling or the like in the uncoated portion 11, and the flatness of the coated portion 12 and the flatness of the uncoated portion 11 are the same or within the error range. The degree to which the coated portion 12 is stretched in the electrode substrate and the degree to which the uncoated portion 11 is stretched in the electrode substrate are within the error range. However, if the state of the uncoated portion 11 of the electrode substrate 10 corresponds to an abnormal (non-normal) state, the position of the uncoated portion stretching member 120 is adjusted by the driving unit.

[0068] If it is determined that the state of the uncoated portion 11 of the electrode substrate 10 corresponds to a predetermined first abnormal state among abnormal (non-normal) states, the driving unit advances the uncoated portion stretching member 120 toward the electrode substrate 10 (A1). Optionally, if it is determined that the state of the uncoated portion 11 of the electrode substrate 10 corresponds to a predetermined second abnormal state among abnormal (non-normal) states, the driving unit retracts the uncoated portion stretching member 120 from the electrode substrate 10 in the opposite direction (A2). That is, when swelling occurs in the uncoated portion 11 of the electrode substrate 10 between the rolling members 110, additional stretching of the uncoated portion 11 is performed using the uncoated portion stretching member 120, thereby being able to solve the problem of swelling occurring in the uncoated portion 11. At this time, the monitoring unit 130 is used during the process to monitor the state of the uncoated portion 11 of the electrode substrate 10, thereby adjusting the position of the uncoated portion stretching member 120 to adjust the degree to which the uncoated portion 11 is additionally stretched. Based on various process variables, such as the types of the electrode current collector and the electrode mixture, the transport speed of the electrode substrate 10, and the degree of rolling by the rolling members 110, when the uncoated portion stretching member 120 advances toward the electrode substrate 10 (A1), the degree of swelling of the uncoated portion 11 can be improved. In contrast, when the uncoated portion stretching member 120 retracts from the electrode substrate 10 (A2) to reduce the degree of stretching applied to the uncoated portion 11, the degree of swelling of the uncoated portion 11 can be improved.

[0069] That is, according to various environments in which the present invention is implemented, a predetermined first abnormal state, a predetermined second abnormal state, and a normal state are preset, and the position of the uncoated portion stretching member 120 can be adjusted accordingly.

[0070] In addition, according to various environments in which the present invention is implemented, the degree of advancement (A1) and / or retraction (A2) of the uncoated portion stretching member 120 is preset in detail, and the position of the uncoated portion stretching member 120 can also be precisely adjusted.

[0071] On the other hand, regarding the uncoated portion 11 of the electrode substrate 10, the present invention is not limited to Figure 3 the uncoated portion shown, and similarly, the uncoated portion stretching member 120 is not limited to Figure 4 the uncoated portion stretching member shown. Regarding the uncoated portion 11 of the electrode substrate 10 and the uncoated portion stretching member 120, various modifications and changes can be made to the present invention based on various environments and circumstances in which the present invention is implemented, so as to apply and implement the present invention. In some cases, the degree of advancement (A1) and / or retraction (A2) of the uncoated portion stretching member 120 is set as a process variable of the wrap angle (θ) to adjust the degree of this angle. As Figure 5As shown, the wrap angle refers to the angle around a part of the uncoated tensile member 120 when the electrode substrate 10 contacts the uncoated tensile member 120.

[0072] Figure 6 and Figure 7 Each shows an example of an abnormal (non-normal) state of the uncoated portion 11. They respectively show a top view, a side view, and a cross-sectional view of the electrode substrate 10 by magnifying the portion indicated by the dashed line of the electrode substrate 10 shown in Figure 3 The arrow indicates the advancing direction of the electrode substrate 10 during the process. The arrow does not necessarily mean that the advancing direction is upward in the drawing, and depending on the various environments in which the present invention is applied, it is sufficient if the electrode substrate 10 advances in the length direction of the electrode substrate 10.

[0073] First, an example of a predetermined first abnormal state is a case where an expansion of the uncoated portion 11 is formed along the advancing direction of the electrode substrate 10, as Figure 6 exemplarily shown in. In this case, an extension line extending along the expansion valley (in the direction of the expansion valley) and / or an extension line extending along the expansion peak (in the direction of the expansion peak) are formed along the advancing direction of the electrode substrate 10.

[0074] This occurs when the degree of stretching of the uncoated portion 11 is less than the degree of stretching of the coated portion 12. That is, even when the uncoated portion 11 is stretched by the uncoated tensile member 120, when it fails to be stretched sufficiently to the degree of stretching of the coated portion 12, the expanded uncoated portion 11 forms an expansion in the advancing direction of the electrode substrate 10.

[0075] In addition, based on the relative stretching degree of the uncoated portion 11 with respect to the coated portion 12, the expansion valley becomes deeper or shallower. When the difference between the stretching degree of the uncoated portion 11 and the stretching degree of the coated portion 12 (i.e., the absolute value of the value obtained by subtracting the stretching degree of the coated portion 12 from the stretching degree of the uncoated portion 11) is small, the expansion valley becomes shallower, and when the stretching degree of the coated portion 12 and the stretching degree of the uncoated portion 11 become equal within the error range, the expansion of the uncoated portion 11 will disappear.

[0076] On the other hand, based on the type of the electrode substrate and the process environment, in addition to the case where the direction of the expansion valley and / or the expansion peak of the uncoated portion 11 matches the advancing direction of the electrode substrate 10, the direction of the expansion valley and / or the expansion peak of the uncoated portion 11 may have an oblique angle with respect to the advancing direction of the electrode substrate 10. Therefore, the angle between the direction of the expansion valley and / or the expansion peak of the uncoated portion 11 and the advancing direction of the electrode substrate 10 can be formed within a range of 0 degrees or more and 45 degrees or less.

[0077] In summary, the monitoring unit 130 monitors the direction of the swelling valley and / or swelling peak of the uncoated portion 11, and if it is formed along the advancing direction of the electrode substrate 10, it is determined as the first abnormal state.

[0078] More specifically, when the angle between the direction of the swelling valley and / or swelling peak of the uncoated portion 11 and the advancing direction of the electrode substrate 10 is 0 degrees or more and 45 degrees or less, the meaning that the direction of the swelling valley and / or swelling peak of the uncoated portion 11 is formed along the advancing direction of the electrode substrate 10 is determined as the first abnormal state.

[0079] When it is determined that the state of the uncoated portion 11 of the electrode substrate 10 is in the first abnormal state, the uncoated portion stretching member 120 advances toward the electrode substrate 10.

[0080] In addition, an example of the second predetermined abnormal state is the case where swelling of the uncoated portion 11 is formed along the width direction of the electrode substrate 10 (the direction perpendicular to the advancing direction of the electrode substrate 10), as Figure 7 schematically shown. In this case, an extension line extending along the swelling valley (the direction of the swelling valley) and / or an extension line extending along the swelling peak (the direction of the swelling peak) are formed along the width direction of the electrode substrate 10.

[0081] This occurs when the degree of stretching of the uncoated portion 11 is greater than the degree of stretching of the coated portion 12. That is, if the uncoated portion 11 is stretched by the uncoated portion stretching member 120, but the uncoated portion 11 is stretched more than the coated portion 12 is stretched, swelling will be formed in the uncoated portion 11 with a relatively longer length in the width direction of the electrode substrate 10.

[0082] In addition, based on the relative stretching degree of the uncoated portion 11 with respect to the coated portion 12, the swelling valley will become deeper or shallower. When the difference between the stretching degree of the uncoated portion 11 and the stretching degree of the coated portion 12 (i.e., the absolute value obtained by subtracting the stretching degree of the coated portion 12 from the stretching degree of the uncoated portion 11) is small, the swelling valley will become shallower, and when the stretching degree of the coated portion 12 and the stretching degree of the uncoated portion 11 become equal within the error range, the swelling of the uncoated portion 11 will disappear.

[0083] On the other hand, based on the type of the electrode substrate and the process environment, except for the case where the direction of the expansion valley and / or expansion peak of the uncoated portion 11 is perpendicular to the advancing direction of the electrode substrate 10, the direction of the expansion valley and / or expansion peak of the uncoated portion 11 may also have an oblique angle with the direction perpendicular to the advancing direction of the electrode substrate 10. Therefore, the angle between the direction of the expansion valley and / or expansion peak of the uncoated portion 11 and the advancing direction of the electrode substrate 10 can be formed within the range of 45 degrees or more and 90 degrees or less.

[0084] In summary, the monitoring unit 130 monitors the direction of the expansion valley and / or expansion peak of the uncoated portion 11, and if it is formed along the width direction of the electrode substrate 10, it is determined as the second abnormal state.

[0085] More specifically, when the angle between the direction of the expansion valley and / or expansion peak of the uncoated portion 11 and the advancing direction of the electrode substrate 10 is 45 degrees or more and 90 degrees or less, the meaning that the direction of the expansion valley and / or expansion peak of the uncoated portion 11 is formed along the width direction of the electrode substrate 10 is determined as the second abnormal state.

[0086] When it is determined that the state of the uncoated portion 11 of the electrode substrate 10 is in the second abnormal state, the uncoated portion stretching member 120 retracts from the electrode substrate 10.

[0087] As a reference, when the expansion valley and / or expansion peak of the uncoated portion 11 is at 45 degrees with the advancing direction of the electrode substrate 10, whether the uncoated portion stretching member 120 advances (A1) or retracts (A2) is preset according to various factors such as the type of the electrode current collector and the electrode mixture, the transport speed of the electrode substrate 10, and the degree of rolling by the rolling member 110 according to the relevant environment. That is, when the angle between the direction of the expansion valley and / or expansion peak of the uncoated portion 11 and the advancing direction of the electrode substrate 10 is 45 degrees, it is determined by any one of the first abnormal state and the second abnormal state based on the type of the electrode substrate 10, the process environment, etc. according to the environment for implementing the present invention.

[0088] On the other hand, the degree to which the uncoated portion stretching member 120 advances when the state of the uncoated portion 11 of the electrode substrate 10 is determined to be in the first abnormal state, and the degree to which the uncoated portion stretching member 120 retracts when the state of the uncoated portion 11 of the electrode substrate 10 is determined to be in the second abnormal state can be respectively predetermined based on the type of the electrode substrate 10 and / or the corresponding process environment. More specifically, the degree to which the uncoated portion stretching member 120 advances and the degree to which it retracts are respectively predetermined as a first predetermined value and a second predetermined value.

[0089] When the state of the uncoated portion 11 of the electrode substrate 10 monitored by the monitoring unit 130 is determined to be the first abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, so that the uncoated portion stretching member 120 advances toward the electrode substrate 10 by a first predetermined value.

[0090] In the monitoring unit 130, the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 after the forward movement / backward movement of the uncoated portion stretching member 120 is monitored by the monitoring unit 130. Optionally, in any case, the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 can be continuously monitored by the monitoring unit 130.

[0091] When it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has advanced by the first predetermined value is still the first abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, and the uncoated portion stretching member 120 advances toward the electrode substrate 10 by the first predetermined value again.

[0092] When it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has advanced by the first predetermined value is the normal state, the uncoated portion stretching member 120 does not advance or retreat, but remains in place.

[0093] On the contrary, when it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has advanced by the first predetermined value is the second abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, and the uncoated portion stretching member 120 retreats from the electrode substrate 10 by a second predetermined value.

[0094] The above process is repeated until it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 is in the normal state.

[0095] Similarly, if the state of the uncoated portion 11 of the electrode substrate 10 monitored by the monitoring unit 130 is determined to be in the second abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, so that the uncoated portion stretching member 120 retreats from the electrode substrate 10 by a second predetermined value.

[0096] When it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has retreated by the second predetermined value is still the second abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, and the uncoated portion stretching member 120 advances from the electrode substrate 10 by the second predetermined value again.

[0097] When it is determined that the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has retracted by a second predetermined value is in a normal state, the uncoated portion stretching member 120 does not advance or retract, but remains in place.

[0098] Conversely, when it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 that has retracted by a second predetermined value is in a first abnormal state, the corresponding result is fed back to the uncoated portion stretching member 120, and the uncoated portion stretching member 120 advances toward the electrode substrate 10 by a first predetermined value.

[0099] The above process is repeated until it is determined that the state of the uncoated portion 11 of the electrode substrate 10 stretched by the uncoated portion stretching member 120 is in a normal state.

[0100] In addition, each of the first predetermined value and the second predetermined value can be preset in various ways according to the environment based on the type of the electrode substrate 10 and the process environment for implementing the present invention (various process variables such as the types of the electrode current collector and the electrode mixture, the transport speed of the electrode substrate 10, and the degree of rolling by the rolling member 110, etc.).

[0101] Figure 8 Shows Figure 2 A modification of the rolling device for manufacturing an electrode in

[0102] First, in Figure 2 's case, the monitoring unit 130 is located at the rear end of the uncoated portion stretching member 120. Therefore, the monitoring unit 130 monitors the electrode substrate 10 that has passed through the uncoated portion stretching member 120, and adjusts the position of the uncoated portion stretching member 120, thereby adjusting the degree of expansion of the uncoated portion 11 of the electrode substrate 10 entering the uncoated portion stretching member 120.

[0103] In Figure 8 's case, the monitoring unit 130 is located between the rear end of the rolling member 110 and the front end of the uncoated portion stretching member 120. Therefore, it monitors the electrode substrate 10 that has passed through the rolling member 110, and adjusts the position of the uncoated portion stretching member 120.

[0104] As described above Figure 2 In the method of monitoring the electrode substrate 10 to adjust the position of the uncoated portion stretching member 120, a predetermined first abnormal state, a predetermined second abnormal state, and a normal state can be preset according to various environments for implementing the present invention, and the position of the uncoated portion stretching member 120 can be adjusted accordingly.

[0105] Next, reference will be made to Figure 9 AndFigure 10 To describe a rolling method for manufacturing an electrode according to an embodiment of the present invention.

[0106] Referring to Figure 9 , a rolling method for manufacturing an electrode according to an embodiment of the present invention includes: a step (S110) of rolling an electrode substrate with a rolling member 110; a step (S120) of additionally stretching an uncoated portion 11 of the rolled electrode substrate 10 with an uncoated portion stretching member 120; and a step (S130) of monitoring the electrode substrate with a monitoring unit 130 to determine the state of the uncoated portion of the electrode substrate. In Figure 2 's embodiment, step S130 is performed after step S120. Optionally, in Figure 8 's embodiment, step S120 can be performed after step S130 is executed. Next, will mainly refer to Figure 10 to describe Figure 2 's embodiment of the device.

[0107] In step S130, it is determined whether the state of the uncoated portion is normal. If it is determined that the state of the uncoated portion is abnormal, step S130 includes step S131: determining whether the state of the uncoated portion is a first abnormal state or a second abnormal state. When it is determined that the state of the uncoated portion is abnormal, step S131 determines whether the direction of expansion of the uncoated portion is formed in the advancing direction of the electrode substrate or in the width direction of the electrode substrate, etc. For a more detailed description of determining whether the state of the uncoated portion is a first abnormal state or a second abnormal state, since it repeats the content described in the above Figures 1 to 7 , please refer to the above content.

[0108] Based on the state of the uncoated portion 11 of the electrode substrate monitored by the monitoring unit, the method includes a step (S140) of using a driving unit to adjust the relative position of the uncoated portion stretching member with respect to the electrode substrate.

[0109] In step S130, if it is determined that the uncoated portion of the electrode substrate is in a normal state, the uncoated portion stretching member maintains its position unchanged.

[0110] If it is determined in step S130 (step S131) that the uncoated portion of the electrode substrate is in a predetermined first abnormal state, then step S140 includes step (S141): in this step, the uncoated portion stretching member advances a first predetermined value toward the electrode substrate. Further, if it is determined in S130 (step S131) that the uncoated portion of the electrode substrate is in a predetermined second abnormal state, then step S140 includes step (S141): in this step, the uncoated portion stretching member retreats a second predetermined value from the electrode substrate. The step (S140) of adjusting the relative position of the uncoated portion stretching member is repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

[0111] In one embodiment, the electrode refers to the positive electrode and / or negative electrode of a lithium secondary battery.

[0112] The positive electrode has a structure in which two layers of positive electrode active material layers are laminated on a positive electrode current collector. In one example, the positive electrode active material layer includes a positive electrode active material, a conductive material, and a binder polymer, and may further include a positive electrode additive commonly used in the art if necessary.

[0113] The positive electrode active material may be a lithium-containing oxide, and may be the same or different. As the lithium-containing oxide, a lithium-containing transition metal oxide may be used.

[0114] For example, the lithium-containing transition metal oxide may be any one or a mixture of two or more of those selected from the group consisting of Li x CoO 2 (0.5 < x < 1.3), Li x NiO 2 (0.5 < x < 1.3), Li x MnO 2 (0.5 < x < 1.3), Li x Mn 2 O 4 (0.5 < x < 1.3), Li x (Ni a Co b Mn c )O 2 (0.5 < x < 1.3, 0 < a < 1, 0 < b < 1, 0 < c < 1, a + b + c = 1), Li x Ni 1-y Co y O 2 (0.5 < x < 1.3, 0 < y < 1), Li x Co 1-y Mn y O 2(0.5 < x < 1.3, 0 ≤ y < 1), Li x Ni 1-y Mn y O 2 (0.5 < x < 1.3, 0 ≤ y < 1), Li x (Ni a Co b Mn c )O 4 (0.5 < x < 1.3, 0 < a < 2, 0 < b < 2, 0 < c < 2, a + b + c = 2), Li x Mn 2-z Ni z O 4 (0.5 < x < 1.3, 0 < z < 2), Li x Mn 2-z Co z O 4 (0.5 < x < 1.3, 0 < z < 2), Li x CoPO 4 (0.5 < x < 1.3) and Li x FePO 4 (0.5 < x < 1.3). The lithium-containing transition metal oxide can be coated with a metal or metal oxide, such as aluminum (Al). In addition, in addition to the lithium-containing transition metal oxide, one or more types selected from the group consisting of sulfides, selenides, and halides can also be used.

[0115] In the positive electrode active material layer, the content of the positive electrode active material can be in the range of 94.0% to 98.5% by weight. When the content of the positive electrode active material satisfies the above range, it is advantageous in terms of manufacturing a high-capacity battery and providing sufficient positive electrode conductivity or adhesion between the electrode materials.

[0116] The current collector for the positive electrode is a metal with high conductivity, and can be used without limitation as long as the positive electrode active material slurry can easily adhere and there is no reactivity within the voltage range of the electrochemical device. Specifically, non-limiting examples of the positive electrode current collector include foils made of aluminum, nickel, or a combination thereof.

[0117] The positive electrode active material layer further includes a conductive material. Based on the total weight of the mixture including the positive electrode active material, the addition amount of the conductive material is generally 1% to 30% by weight. There is no particular limitation on such a conductive material as long as it has conductivity without causing chemical changes in the secondary battery. The conductive material may include one or more selected from the group consisting of: graphite, such as natural graphite or artificial graphite; carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal crack carbon black; conductive fibers, such as carbon fibers and metal fibers; fluorocarbons; metal powders, such as aluminum powder and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and polyphenylene derivatives, etc.

[0118] The negative electrode has such a structure that two layers of negative electrode active material layers are laminated on the negative electrode current collector. In one example, the negative electrode active material layer includes a negative electrode active material, a conductive material, a binder polymer, etc., and if necessary, may further include negative electrode additives commonly used in the art.

[0119] The negative electrode active material may include a carbon material, lithium metal, silicon, tin, etc. When using a carbon material as the negative electrode active material, both low-crystalline carbon and high-crystalline carbon can be used. Typical examples of low-crystalline carbon include soft carbon and hard carbon, and typical examples of high-crystalline carbon include one or more types of high-temperature calcined carbon selected from the group consisting of: natural graphite, kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, mesocarbon microbead, mesophase pitches and petroleum, or coal tar pitch derived cokes.

[0120] Non-limiting examples of the current collector used in the negative electrode include foils made of copper, gold, nickel, or copper alloy or combinations thereof. In addition, substrates made by laminating the above materials can be used as the current collector.

[0121] In addition, the negative electrode may include conductive materials and binders commonly used in the art.

[0122] Meanwhile, according to an embodiment of the present invention, a rolling device 100 for manufacturing an electrode includes a guiding member 140 that guides the movement of an electrode substrate 10. For example, the guiding member 140 may be a conveying roller. The guiding member 140 can adjust the curvature or the tension of the electrode substrate 10. Finally, the electrode substrate 10 is wound by an electrode winding member 150.

[0123] The electrode manufactured by applying the control method of the rolling device for manufacturing an electrode according to the above embodiment of the present invention can be included in a secondary battery, and the plurality of secondary batteries can be assembled together to form a battery module. The battery module can be installed together with various control and protection systems (such as a BMS (Battery Management System) and a cooling system) to form a battery pack.

[0124] The above secondary battery, battery module, and battery pack can be applied to various devices. Such devices can be applied to transportation means such as electric bicycles, electric vehicles, or hybrid vehicles, but the present disclosure is not limited thereto, and can be applied to various devices that can use secondary batteries.

[0125] Although the present invention has been described in detail with reference to the preferred embodiments of the present invention, the scope of the present invention is not limited thereto, and those of ordinary skill in the art can make various modifications and improvements using the basic concept of the present invention, and these modifications and improvements are defined in the appended claims and also fall within the scope of the present invention.

[0126] Description of Reference Numerals

[0127] 10: Electrode substrate

[0128] 11: Uncoated portion

[0129] 12: Coated portion

[0130] 100: Rolling device for manufacturing an electrode

[0131] 110: Rolling member

[0132] 120: Uncoated portion stretching member

[0133] 120a: Pressing portion

[0134] 130: Monitoring unit

[0135] 130a: Processor

[0136] 140: Guiding member

[0137] 150: Electrode winding member

Claims

1. A rolling device for manufacturing an electrode, the device comprising: a rolling member that rolls the electrode substrate when the electrode substrate passes through; and an uncoated portion stretching member that additionally stretches the uncoated portion of the electrode substrate that has passed through the rolling member, wherein the uncoated portion stretching member is configured to adjust the relative position of the uncoated portion stretching member with respect to the electrode substrate according to the state of the uncoated portion of the electrode substrate.

2. The rolling device for manufacturing an electrode according to claim 1, further comprising a driving unit that adjusts the position of the uncoated portion stretching member, wherein, the uncoated portion stretching member maintains its position unchanged, or advances toward the electrode substrate, or retreats from the electrode substrate in the opposite direction, thereby adjusting the position of the uncoated portion stretching member.

3. The rolling device for manufacturing an electrode according to claim 2, further comprising a monitoring unit that monitors the electrode substrate and determines the state of the uncoated portion of the electrode substrate, wherein, when the uncoated portion of the electrode substrate is in a normal state, the uncoated portion stretching member maintains its position unchanged, wherein when the uncoated portion of the electrode substrate is in a predetermined first abnormal state, the uncoated portion stretching member advances toward the electrode substrate, and wherein when the uncoated portion of the electrode substrate is in a predetermined second abnormal state, the uncoated portion stretching member retreats from the electrode substrate.

4. The rolling device for manufacturing an electrode according to claim 3, wherein: the first abnormal state is a state in which an expansion valley or an expansion peak of the uncoated portion appears in the longitudinal direction of the electrode substrate, and the second abnormal state is a state in which an expansion valley or an expansion peak of the uncoated portion appears in the width direction of the electrode substrate.

5. The rolling device for manufacturing an electrode according to claim 3, wherein: when the angle between the direction of the expansion valley or expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 0 degrees or more and less than 45 degrees, it is determined that the uncoated portion is in the first abnormal state, when the angle between the direction of the expansion valley or the expansion peak of the uncoated portion and the advancing direction of the electrode substrate is greater than 45 degrees and 90 degrees or less, it is determined that the uncoated portion is in the second abnormal state, and when the angle between the direction of the expansion valley or the expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 45 degrees, it is determined that the uncoated portion is in one of the first abnormal state and the second abnormal state.

6. The rolling device for manufacturing an electrode according to claim 3, wherein: when the uncoated portion of the electrode substrate is in the predetermined first abnormal state, the uncoated portion stretching member advances toward the electrode substrate by a first predetermined value, and Repeat the process of advancing the uncoated portion stretching member by the first predetermined value until it is determined that the uncoated portion of the electrode substrate is in a normal state.

7. The rolling device for manufacturing an electrode according to claim 3, wherein: When the uncoated portion of the electrode substrate is in the predetermined second abnormal state, the uncoated portion stretching member retreats from the electrode substrate by a second predetermined value, Repeat the process of retreating the uncoated portion stretching member by the second predetermined value until it is determined that the uncoated portion of the electrode substrate is in a normal state.

8. The rolling device for manufacturing an electrode according to claim 3, wherein: The monitoring unit is located at the rear end of the uncoated portion stretching member and monitors the state of the uncoated portion of the electrode substrate that has passed through the uncoated portion stretching member, thereby adjusting the position of the uncoated portion stretching member.

9. The rolling device for manufacturing an electrode according to claim 3, wherein: The monitoring unit is located between the rear end of the rolling member and the front end of the uncoated portion stretching member and monitors the state of the uncoated portion of the electrode substrate that has passed through the rolling member, thereby adjusting the position of the uncoated portion stretching member.

10. The rolling device for manufacturing an electrode according to claim 1, wherein: The rolling member is a pair of rollers that rotate in opposite directions around a rotation axis, The uncoated portion stretching member is an uncoated portion pressing roller, and the uncoated portion pressing roller includes a pressing portion, and The pressing portion is provided at a position corresponding to the uncoated portion of the electrode substrate and has a structure that protrudes from the outer peripheral surface of the uncoated portion pressing roller.

11. The rolling device for manufacturing an electrode according to claim 10, wherein, The drive unit is an actuator connected to the uncoated portion pressing roller.

12. The rolling device for manufacturing an electrode according to claim 1, further includes a guiding member that guides the movement of the electrode substrate.

13. The rolling device for manufacturing an electrode according to claim 1, further includes an electrode winding member that winds and recovers the electrode substrate.

14. A rolling method for manufacturing an electrode, the method comprises the following steps: Rolling an electrode substrate with a rolling member; Using an uncoated portion stretching member to additionally stretch the uncoated portion of the rolled electrode substrate; and Monitoring the electrode substrate with a monitoring unit to determine the state of the uncoated portion of the electrode substrate, wherein when the uncoated portion of the electrode substrate is in an abnormal state, the method further includes adjusting the relative position of the uncoated portion stretching member with respect to the electrode substrate.

15. The rolling method for manufacturing an electrode according to claim 14, wherein: When the uncoated portion of the electrode substrate is in a normal state, the uncoated portion stretching member remains in position.

16. The rolling method for manufacturing an electrode according to claim 14, wherein: Adjusting the relative position of the uncoated portion stretching member includes at least one of the following steps: When the uncoated portion of the electrode substrate is in a predetermined first abnormal state, advancing the uncoated portion stretching member toward the electrode substrate; And When the uncoated portion of the electrode substrate is in a predetermined second abnormal state, retracting the uncoated portion stretching member from the electrode substrate.

17. The rolling method for manufacturing an electrode according to claim 14, Wherein: The first abnormal state is a state in which an expansion valley or an expansion peak of the uncoated portion appears in the length direction of the electrode substrate, and The second abnormal state is a state in which an expansion valley or an expansion peak of the uncoated portion appears in the width direction of the electrode substrate.

18. The rolling method for manufacturing an electrode according to claim 14, Wherein: When the angle between the direction of the expansion valley or expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 0 degrees or more and less than 45 degrees, it is determined that the uncoated portion is in the first abnormal state, When the angle between the direction of the expansion valley or the expansion peak of the uncoated portion and the advancing direction of the electrode substrate is greater than 45 degrees and 90 degrees or less, it is determined that the uncoated portion is in the second abnormal state, and When the angle between the direction of the expansion valley or the expansion peak of the uncoated portion and the advancing direction of the electrode substrate is 45 degrees, it is determined that the uncoated portion is in one of the first abnormal state and the second abnormal state.

19. The rolling method for manufacturing an electrode according to claim 14, Wherein: When the uncoated portion of the electrode substrate is in the predetermined first abnormal state, the uncoated portion stretching member advances a first predetermined value toward the electrode substrate, and The operation of advancing the uncoated portion stretching member by the first predetermined value is repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

20. The rolling method for manufacturing an electrode according to claim 14, Wherein: When the uncoated portion of the electrode substrate is in the predetermined second abnormal state, the uncoated portion stretching member retracts a second predetermined value from the electrode substrate, and The operation of retracting the uncoated portion stretching member by the second predetermined value is repeated until it is determined that the uncoated portion of the electrode substrate is in a normal state.

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