Electrode sheet rolling apparatus and methode

Abstract

The present invention provides an electrode sheet rolling apparatus (10) comprising a cylindrical first pressing roller (100) and a cylindrical second pressing roller (200) which: are arranged so as to face each other, with an electrode sheet (50) transferred therebetween in the lengthwise direction; come into contact with the electrode sheet (50) passing therebetween; and rotate about a first rotation axis (A1) and a second rotation axis (A2), respectively, the rotation axes extending in the widthwise direction. The second pressing roller (200) can contact the electrode sheet (50) along the circumference thereof in a first angle section (G1) centered around the second rotation axis (A2). The first angle section (G1) may include a first sub-section (U1) and a second sub-section (U2), the first sub-section (U1) being of at least the minimum angle of the first angle section (G1) and at most a first angle (L1) at which the first rotation axis (A1) is located relative to the second rotation axis (A2), and the second sub-section (U2) being of at least the first angle (L1) and at most the maximum angle of the first angle section (G1). The electrode sheet (50) may be apart from the first pressing roller (100) in at least a part of the first sub-section (U1) and at least a part of the second sub-section (U2).

Description

Electrode sheet rolling device and electrode sheet rolling method

[0001] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0029247, dated February 28, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an electrode sheet rolling device and an electrode sheet rolling method, and relates to an electrode sheet rolling device and an electrode sheet rolling method, which reduce the size of a continuous rolling device, the installation space, and the number of rolling rollers, reduce manufacturing, installation, and maintenance costs, and reduce or optimize the transport distance or transport path of an electrode sheet.

[0003] With technological developments and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. Recently, secondary batteries are being used as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs). Among these secondary batteries, lithium secondary batteries, which boast high energy density, high discharge voltage, and output stability, are in high demand.

[0004] In order to increase the energy density of lithium secondary batteries, it is essential to manufacture electrodes (positive or negative electrodes) with high rolling density.

[0005] Lithium secondary battery electrodes can be obtained as electrode sheets. For example, electrode sheets are manufactured by rolling and forming an electrode sheet coated with a composite layer containing an electrode active material using a rolling machine. Here, the electrode sheet is rolled while taking into account the desired density distribution, thickness, thickness distribution, and precision of the composite layer.

[0006] However, the electrode sheet has a problem in that it tends to return to its original state due to the stress accumulated in the powder of the electrode active material as it is rolled, that is, the spring-back phenomenon occurs severely, and the thickness of the composite layer containing the electrode active material becomes thicker than the desired thickness over time.

[0007] Accordingly, a continuous (Tandem) rolling device that rolls continuously multiple times is used. However, since the conventional continuous rolling device (1) arranges multiple rolling mills (5, 6, 7, 8) in a straight line as shown in Fig. 1, the size of the electrode sheet rolling device (1) is large. Therefore, spatial limitations of the continuous rolling device may occur, and the manufacturing, installation, and maintenance costs may increase. In addition, since the transport distance of the electrode sheet (50) becomes longer and the transport path becomes complicated, the electrode productivity may decrease.

[0008] Therefore, a method for reducing the size of a continuous rolling mill is required.

[0009] Prior art related to this is Korean Patent Publication No. 10-2018-0068520.

[0010] The present invention has been devised to solve the above-described problems, and aims to provide an electrode sheet rolling device and an electrode sheet rolling method in which the size of a continuous rolling device, installation space, and number of rolling rollers are reduced, manufacturing, installation, and maintenance costs are reduced, and the transport distance or transport path of the electrode sheet is reduced or optimized.

[0011] The purpose of the present invention is to provide an electrode sheet rolling device and an electrode sheet rolling method that improve the quality and extend the life of an electrode and a secondary battery even when the electrode sheet is rolled in a bent state.

[0012] The purpose of the present invention is to provide an electrode sheet rolling device and an electrode sheet rolling method in which a composite layer is stably, strongly, and uniformly adhered to an electrode current collector.

[0013] The purpose of the present invention is to provide an electrode sheet rolling device and an electrode sheet rolling method in which rolling is stably performed.

[0014] The purpose of the present invention is to provide an electrode sheet rolling device and an electrode sheet rolling method that can easily implement a continuous rolling device.

[0015]

[0016] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0017] In order to solve the above-described problem, the present invention provides an electrode sheet rolling device (10) that rolls an electrode sheet (50) in which a composite layer (54, 56) containing an electrode active material is formed on an electrode current collector (52) to a predetermined thickness, and includes a cylindrical first rolling roller (100) and a second rolling roller (200).

[0018] The first rolling roller (100) and the second rolling roller (200) can be arranged facing each other with the electrode sheet (50) being transported in the longitudinal direction interposed therebetween.

[0019] The first rolling roller (100) and the second rolling roller (200) can come into contact with the electrode sheet (50) passing therebetween.

[0020] The first rolling roller (100) and the second rolling roller (200) can each rotate around a first rotation axis (A1) and a second rotation axis (A2) extending in the width direction.

[0021] The second rolling roller (200) can come into contact with the electrode sheet (50) along the circumference at a first angular section (G1) centered on the second rotation axis (A2).

[0022] The above first angular section (G1) may include a first sub-section (U1) and a second sub-section (U2).

[0023] The above first sub-section (U1) may be an angular section that is equal to or greater than the minimum angle of the first angular section (G1) and equal to or less than the first angle (L1) at which the first rotation axis (A1) is located with respect to the second rotation axis (A2).

[0024] The above second sub-section (U2) may be an angular section that is greater than or equal to the first angle (L1) and less than or equal to the maximum angle of the first angular section (G1).

[0025] The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the first sub-section (U1) and at least a portion of the second sub-section (U2).

[0026] In one embodiment, the size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees.

[0027] The size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0028] In one embodiment, the size of the second sub-section (U2) may correspond to the size of the first sub-section (U1).

[0029] In one embodiment, it may include a guide (400) and a cylindrical third rolling roller (300).

[0030] The above guide (400) can come into contact with the electrode sheet (50) that has passed between the first rolling roller (100) and the second rolling roller (200).

[0031] The above guide (400) can change the transport direction of the electrode sheet (50).

[0032] The third rolling roller (300) can be placed facing the first rolling roller (100) with the electrode sheet (50) in between, the transport direction of which is changed by the guide (400).

[0033] The third rolling roller (300) can come into contact with the electrode sheet (50) passing between the first rolling roller (100).

[0034] The third rolling roller (300) can rotate around a third rotation axis (A3) extending in the width direction.

[0035] In one embodiment, the third rolling roller (300) can contact the electrode sheet (50) along the circumference at a second angular section (G2) centered on the third rotation axis (A3).

[0036] The above second angle section (G2) may include a third sub-section (U3) and a fourth sub-section (U4).

[0037] The above third sub-section (U3) may be an angular section that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is located with the third rotation axis (A3) as the center.

[0038] The above fourth sub-section (U4) may be an angle section that is greater than or equal to the second angle (L2) and less than or equal to the maximum angle of the second angle section (G2).

[0039] The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4).

[0040] In one embodiment, the size of the third sub-section (U3) may be greater than or equal to 0 degrees and less than or equal to 90 degrees.

[0041] The size of the fourth sub-section (U4) may be greater than or equal to the size of the third sub-section (U3) and less than or equal to the value obtained by subtracting the size of the third sub-section (U3) from 180 degrees.

[0042] In one embodiment, the size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees.

[0043] The size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0044] In one embodiment, the size of the fourth sub-section (U4) may correspond to the size of the third sub-section (U3).

[0045] In one embodiment, the guide (400) may be a roller.

[0046] In one embodiment, by connecting the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) in an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) can be formed.

[0047] The above guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the bottom edge, but may be positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the bottom edge in a direction perpendicular to the bottom edge.

[0048] In one embodiment, the diameter of the first rolling roller (100) may be larger than the diameters of the second rolling roller (200) and the third rolling roller (300).

[0049] The above guide (400) can be located between the second rolling roller (200) and the third rolling roller (300).

[0050] In one embodiment, the diameter of the second rolling roller (200) may correspond to the diameter of the third rolling roller (300).

[0051] In one embodiment, by connecting the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) in an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) can be formed.

[0052] The above guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the bottom edge, but may be positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the bottom edge in a direction perpendicular to the bottom edge.

[0053] The diameter of the first rolling roller (100) may be larger than the diameters of the second rolling roller (200) and the third rolling roller (300).

[0054] The above guide (400) can be located between the second rolling roller (200) and the third rolling roller (300).

[0055] The sizes of the first sub-section (U1), the second sub-section (U2), the third sub-section (U3), and the fourth sub-section (U4) may each be 20 degrees or more and 40 degrees or less.

[0056] To solve the above-described problem, the present invention provides an electrode sheet rolling method (S500) including a rolling process (S510).

[0057] In the above rolling process (S510), the electrode sheet (50) transported in the longitudinal direction is rolled between the first rolling roller (100) and the second rolling roller (200) while contacting the circumference of the second rolling roller (200) at the first angle section (G1) with the second rotation axis (A2) as the center, and can be rolled at the first angle (L1) with the second rotation axis (A2) as the center.

[0058] Also, here, the electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the first sub-section (U1) before rolling and in at least a portion of the second sub-section (U2) after rolling.

[0059] In one embodiment, it may include a guide (400) and a cylindrical third rolling roller (300).

[0060] The above guide (400) can come into contact with the electrode sheet (50) that has passed between the first rolling roller (100) and the second rolling roller (200).

[0061] The above guide (400) can change the transport direction of the electrode sheet (50).

[0062] The third rolling roller (300) can be placed facing the first rolling roller (100) with the electrode sheet (50) in between, the transport direction of which is changed by the guide (400).

[0063] The third rolling roller (300) can come into contact with the electrode sheet (50) passing between the first rolling roller (100).

[0064] The third rolling roller (300) can rotate around a third rotation axis (A3) extending in the width direction.

[0065] The third rolling roller (300) can come into contact with the electrode sheet (50) along the circumference at the second angular section (G2) centered on the third rotation axis (A3).

[0066] The above second angle section (G2) may include a third sub-section (U3) and a fourth sub-section (U4).

[0067] The above third sub-section (U3) may be an angular section that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is located with the third rotation axis (A3) as the center.

[0068] The above fourth sub-section (U4) may be an angle section that is greater than or equal to the second angle (L2) and less than or equal to the maximum angle of the second angle section (G2).

[0069] The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4).

[0070] In the above rolling process (S510), the electrode sheet (50) whose transport direction has been changed by the guide (400) after being rolled between the first rolling roller (100) and the second rolling roller (200) is rolled between the first rolling roller (100) and the third rolling roller (300) while contacting the circumference of the third rolling roller (300) at the second angle section (G2) with the third rotation axis (A3) as the center, and can be rolled at the second angle (L2) with the third rotation axis (A3) as the center.

[0071] Also, here, the electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the third sub-section (U3) before rolling and in at least a portion of the fourth sub-section (U4) after rolling.

[0072] According to embodiments of the present invention, an electrode sheet rolling device (10) for rolling an electrode sheet (50) having a composite layer (54, 56) including an electrode active material formed on an electrode current collector (52) to a predetermined thickness may include a first cylindrical rolling roller (100) and a second rolling roller (200) that are arranged to face each other with the electrode sheet (50) being transported in the longitudinal direction therebetween, and that contact the electrode sheet (50) passing therebetween and rotate around a first rotation axis (A1) and a second rotation axis (A2) extending in the width direction, respectively. The second rolling roller (200) may contact the electrode sheet (50) along the circumference at a first angular section (G1) centered on the second rotation axis (A2). The first angular section (G1) may include a first sub-section (U1) that is equal to or greater than the minimum angle of the first angular section (G1) and equal to or less than the first angle (L1) at which the first rotation axis (A1) is positioned with respect to the second rotation axis (A2), and a second sub-section (U2) that is equal to or greater than the first angle (L1) and equal to or less than the maximum angle of the first angular section (G1). The electrode sheet (50) may be spaced apart from the first rolling roller (100) in at least a portion of the first sub-section (U1) and at least a portion of the second sub-section (U2).

[0073] Accordingly, since the electrode sheet (50) is in contact with the circumference of the second rolling roller (200) in the first angle section (G1), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the size of the continuous (Tandem) rolling device (10) that continuously rolls multiple times and the number of rolling rollers can be reduced. That is, the transport direction of the electrode sheet (50) is straight, and therefore, the size of the rolling device and the number of rolling rollers can be reduced compared to the conventional continuous rolling device that requires multiple rolling mills to be arranged in a straight line. When the size of the continuous rolling device and the number of rolling rollers are reduced, the installation space is reduced, so the manufacturing, installation, and maintenance costs of the continuous rolling device can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0074] In addition, since the electrode sheet (50) is in contact along the circumference of the second rolling roller (200) in each of the first sub-section (U1) and the second sub-section (U2), the electrode sheet (50) can be maintained in a consistently bent state along the circumference of the second rolling roller (200) during rolling (e.g., first rolling) and before and after rolling. Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling. Therefore, even if the composite layers (54, 56) are repeatedly contracted and relaxed due to repeated charging and discharging, the resistance does not increase, so an abnormal heating phenomenon may not occur, and the capacity of the battery may not decrease. That is, even if the electrode sheet (50) is rolled in a bent state, the quality of the electrode and secondary battery can be improved and the lifespan can be extended.

[0075] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the second rolling roller (200), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0076] According to embodiments of the present invention, the size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees. The size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0077] Accordingly, the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the second sub-section (U2) may be greater than or equal to the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the first sub-section (U1). Accordingly, the electrode sheet (50) can be prevented from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during rolling (e.g., primary rolling).

[0078] In addition, since the electrode sheet (50) can be in contact along the circumference of the second rolling roller (200) in the second sub-section (U2), the electrode sheet (50) can be maintained in a state of being evenly bent along the circumference of the second rolling roller (200) during and after rolling (e.g., first rolling). Accordingly, since the electrode sheet (50) does not quickly change to a state of not being evenly bent or straightened after rolling (e.g., first rolling), the composite layer (54, 56) can be stably, strongly, and uniformly bonded to the electrode current collector (52).

[0079] According to embodiments of the present invention, the size of the second sub-section (U2) may correspond to the size of the first sub-section (U1).

[0080] Accordingly, the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the first sub-section (U1) and the second sub-section (U2) can be balanced. Accordingly, rolling (e.g., primary rolling) can be performed stably.

[0081] According to embodiments of the present invention, a guide (400) that comes into contact with the electrode sheet (50) that passes between the first rolling roller (100) and the second rolling roller (200) and changes the transport direction of the electrode sheet (50), and a cylindrical third rolling roller (300) that is arranged facing the first rolling roller (100) with the electrode sheet (50) whose transport direction has been changed by the guide (400) interposed therebetween, comes into contact with the electrode sheet (50) that passes between the first rolling roller (100), and rotates around a third rotation axis (A3) that extends in the width direction.

[0082] Accordingly, a continuous rolling mill that performs two consecutive rolling cycles can be easily implemented with three rolling rollers. This reduces the size of the continuous rolling mill and the number of rolling rollers. Consequently, the installation space of the continuous rolling mill can be reduced, and manufacturing, installation, and maintenance costs can be reduced. Furthermore, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0083] According to embodiments of the present invention, the third rolling roller (300) can contact the electrode sheet (50) along the circumference in a second angular section (G2) centered on the third rotation axis (A3). The second angular section (G2) can include a third sub-section (U3) that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is positioned centered on the third rotation axis (A3), and a fourth sub-section (U4) that is equal to or greater than the second angle (L2) and equal to or less than the maximum angle of the second angular section (G2). The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4).

[0084] Accordingly, since the electrode sheet (50) is brought into contact along the circumference of the third rolling roller (300) in the second angle section (G2), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the transport direction of the electrode sheet (50) exiting the continuous (Tandem) rolling device (10) can be appropriately adjusted, so that the installation and maintenance costs of the electrode sheet rolling device (10) can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved. In addition, the conventional continuous rolling device can be easily replaced.

[0085] In addition, since the electrode sheet (50) is in contact along the circumference of the third rolling roller (300) in each of the third sub-section (U3) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being constantly bent along the circumference of the third rolling roller (300) before and after rolling (e.g., secondary rolling). Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly bonded to the electrode collector (52) after rolling.

[0086] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the third rolling roller (300), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0087] According to embodiments of the present invention, the size of the third sub-section (U3) may be greater than or equal to 0 degrees and less than or equal to 90 degrees. The size of the fourth sub-section (U4) may be greater than or equal to the size of the third sub-section (U3) and less than or equal to the value obtained by subtracting the size of the third sub-section (U3) from 180 degrees.

[0088] Accordingly, the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the fourth sub-section (U4) may be greater than or equal to the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the third sub-section (U3). Accordingly, the electrode sheet (50) can be prevented from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during rolling (e.g., secondary rolling).

[0089] In addition, since the electrode sheet (50) can be in contact with the circumference of the third rolling roller (300) in the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being evenly bent along the circumference of the third rolling roller (300) during and after rolling (e.g., secondary rolling). Accordingly, since the electrode sheet (50) does not quickly change to a state of not being evenly bent or straightened after rolling (e.g., secondary rolling), the composite layer (54, 56) can be stably, strongly, and uniformly bonded to the electrode current collector (52).

[0090] According to embodiments of the present invention, the size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees. The size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0091] Accordingly, it is possible to reliably prevent the electrode sheet (50) from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during the first and second rolling.

[0092] In addition, since the electrode sheet (50) can be in contact along the circumference of the second rolling roller (200) and the third rolling roller (300) in the second sub-section (U2) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being consistently bent along the circumference of the second rolling roller (200) and the third rolling roller (300) during and after the first and second rolling. Accordingly, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling.

[0093] According to embodiments of the present invention, the size of the fourth sub-section (U4) may correspond to the size of the third sub-section (U3).

[0094] Accordingly, the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the third sub-section (U3) and the fourth sub-section (U4) can be balanced. Accordingly, rolling (e.g., secondary rolling) can be performed stably.

[0095] According to embodiments of the present invention, the guide (400) may be a roller.

[0096] Accordingly, a continuous rolling device can be easily implemented with three rolling rollers and a guide roller.

[0097] According to embodiments of the present invention, when the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) are connected in an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) can be formed. The guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the base, but may be positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the base in a direction perpendicular to the base.

[0098] Accordingly, the installation space of the continuous rolling device and the transport path of the electrode sheet (50) can be reduced.

[0099] According to embodiments of the present invention, the diameter of the first rolling roller (100) may be larger than the diameters of the second rolling roller (200) and the third rolling roller (300). The guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300).

[0100] Accordingly, the installation space of the continuous rolling device can be minimized and the transport path of the electrode sheet (50) can be optimized.

[0101] According to embodiments of the present invention, the diameter of the second rolling roller (200) may correspond to the diameter of the third rolling roller (300).

[0102] Accordingly, the first and second rolling can be performed stably.

[0103] According to embodiments of the present invention, when the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) are connected on an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) can be formed. The guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the base, but may be positioned on the other side than the first rotation axis (A1) and the first rolling roller (100), which are positioned on one side of the base in a direction perpendicular to the base. The diameter of the first rolling roller (100) may be larger than the diameters of the second rolling roller (200) and the third rolling roller (300). The above guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300). The sizes of the first sub-section (U1), the second sub-section (U2), the third sub-section (U3), and the fourth sub-section (U4) may each be 20 degrees or more and 40 degrees or less.

[0104] Accordingly, the installation space of the continuous rolling device can be minimized and the transport path of the electrode sheet (50) can be optimized.

[0105] According to embodiments of the present invention, the electrode sheet rolling method (S500) may include a rolling process (S510) in which the electrode sheet (50) transported in the longitudinal direction is rolled between the first rolling roller (100) and the second rolling roller (200) while coming into contact along the circumference of the second rolling roller (200) in the first angular section (G1) with the second rotation axis (A2) as the center, and is rolled at the first angle (L1) with the second rotation axis (A2) as the center, and the electrode sheet (50) is spaced from the first rolling roller (100) in at least a portion of the first sub-section (U1) before rolling and in at least a portion of the second sub-section (U2) after rolling.

[0106] Accordingly, since the electrode sheet (50) is in contact with the circumference of the second rolling roller (200) in the first angle section (G1), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the size of the continuous (Tandem) rolling device (10) that continuously rolls multiple times and the number of rolling rollers can be reduced. That is, the transport direction of the electrode sheet (50) is straight, and therefore, the size of the rolling device and the number of rolling rollers can be reduced compared to the conventional continuous rolling device that requires multiple rolling mills to be arranged in a straight line. When the size of the continuous rolling device and the number of rolling rollers are reduced, the installation space is reduced, so the manufacturing, installation, and maintenance costs of the continuous rolling device can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0107] In addition, since the electrode sheet (50) is in contact along the circumference of the second rolling roller (200) in each of the first sub-section (U1) and the second sub-section (U2), the electrode sheet (50) can be maintained in a consistently bent state along the circumference of the second rolling roller (200) during rolling (e.g., first rolling) and before and after rolling. Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling. Therefore, even if the composite layers (54, 56) are repeatedly contracted and relaxed due to repeated charging and discharging, the resistance does not increase, so an abnormal heating phenomenon may not occur, and the capacity of the battery may not decrease. That is, even if the electrode sheet (50) is rolled in a bent state, the quality of the electrode and secondary battery can be improved and the lifespan can be extended.

[0108] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the second rolling roller (200), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0109] According to embodiments of the present invention, a guide (400) that comes into contact with the electrode sheet (50) that passes between the first rolling roller (100) and the second rolling roller (200) and changes the transport direction of the electrode sheet (50), and a cylindrical third rolling roller (300) that is arranged facing the first rolling roller (100) with the electrode sheet (50) of which the transport direction is changed by the guide (400) interposed therebetween, comes into contact with the electrode sheet (50) that passes between the first rolling roller (100), and rotates around a third rotational axis (A3) that extends in the width direction. The third rolling roller (300) can come into contact with the electrode sheet (50) along the circumference at a second angular section (G2) with the third rotational axis (A3) as the center. The second angular section (G2) may include a third sub-section (U3) that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is positioned with respect to the third rotation axis (A3), and a fourth sub-section (U4) that is equal to or greater than the second angle (L2) and equal to or less than the maximum angle of the second angular section (G2). In at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4), the electrode sheet (50) may be spaced apart from the first rolling roller (100). In the above rolling process (S510), the electrode sheet (50) whose transport direction has been changed by the guide (400) after being rolled between the first rolling roller (100) and the second rolling roller (200) is rolled between the first rolling roller (100) and the third rolling roller (300) while coming into contact along the circumference of the third rolling roller (300) at the second angle section (G2) with the third rotation axis (A3) as the center, and is rolled at the second angle (L2) with the third rotation axis (A3) as the center, and the electrode sheet (50) can be spaced from the first rolling roller (100) in at least a portion of the third sub-section (U3) before rolling and in at least a portion of the fourth sub-section (U4) after rolling.

[0110] Accordingly, a continuous rolling mill that performs two consecutive rolling cycles can be easily implemented with three rolling rollers. This reduces the size of the continuous rolling mill and the number of rolling rollers. Consequently, the installation space of the continuous rolling mill can be reduced, and manufacturing, installation, and maintenance costs can be reduced. Furthermore, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0111] In addition, since the electrode sheet (50) is in contact with the circumference of the third rolling roller (300) in the second angle section (G2), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the (transport) direction of the electrode sheet (50) exiting the continuous (Tandem) rolling device (10) can be appropriately adjusted, so that the installation and maintenance costs of the electrode sheet rolling device (10) can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved. In addition, the conventional continuous rolling device can be easily replaced.

[0112] In addition, since the electrode sheet (50) is in contact along the circumference of the third rolling roller (300) in each of the third sub-section (U3) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being constantly bent along the circumference of the third rolling roller (300) before and after rolling (e.g., secondary rolling). Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly bonded to the electrode collector (52) after rolling.

[0113] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the third rolling roller (300), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0114] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0115] Figure 1 is a side view schematically showing a continuous rolling device as a conventional electrode sheet rolling device.

[0116] FIG. 2 is a side view schematically showing a continuous rolling device as an electrode sheet rolling device according to one embodiment of the present invention.

[0117] Fig. 3 is an enlarged view of a portion of the electrode sheet rolling device of Fig. 2.

[0118] Figure 4 is a flow chart of an electrode sheet rolling method according to one embodiment of the present invention.

[0119] [Explanation of symbols]

[0120] 10: Electrode sheet rolling device

[0121] 50: Electrode sheet 52: Electrode current collector

[0122] 54, 56: Combined layer

[0123] 100: First rolling roller A1: First rotation axis

[0124] 200: Second rolling roller A2: Second rotating shaft

[0125] G1: First angle section L1: First angle

[0126] U1: First subsection U2: Second subsection

[0127] 300: Third rolling roller A3: Third rotating shaft

[0128] G2: First angle section L2: Second angle

[0129] U3: Third subsection U4: Fourth subsection

[0130] 400: Guide

[0131] 512: Intake

[0132] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0133] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0134] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0135] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0136] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0137] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0138]

[0139] Fig. 1 is a side view schematically illustrating a continuous rolling device as a conventional electrode sheet rolling device. Fig. 2 is a side view schematically illustrating a continuous rolling device as an electrode sheet rolling device according to an embodiment of the present invention. Fig. 3 is an enlarged view of a portion of the electrode sheet rolling device of Fig. 2. Fig. 4 is a flowchart of an electrode sheet rolling method according to an embodiment of the present invention.

[0140]

[0141] [Electrode sheet rolling device]

[0142] Referring to FIGS. 2 and 3, an electrode sheet rolling device (10) according to one embodiment may include a first rolling roller (100) and a second rolling roller (200). The electrode sheet rolling device (10) may include a third rolling roller (300). The electrode sheet rolling device (10) may include a guide (400).

[0143] The electrode sheet rolling device (10) can roll the electrode sheet (50) to a predetermined thickness. Here, the electrode sheet (50) may be a sheet-shaped electrode in which a composite layer (54, 56) containing an electrode active material is formed on an electrode current collector (52). However, unlike the drawing, the composite layer (54, 56) may be formed on only one side of the electrode current collector (52) rather than both sides.

[0144]

[0145] [1st rolling roller, 2nd rolling roller]

[0146] The first rolling roller (100) and the second rolling roller (200) may be cylindrical. The first rolling roller (100) and the second rolling roller (200) may be arranged to face each other with an electrode sheet (50) that is transported in the longitudinal direction therebetween. The first rolling roller (100) and the second rolling roller (200) may be in contact with the electrode sheet (50) passing therebetween. The first rolling roller (100) and the second rolling roller (200) may rotate about a first rotation axis (A1) and a second rotation axis (A2) that extend in the width direction, respectively (Fig. 3). Here, the length direction and the width direction may be the length direction and the width direction of the electrode sheet (50), respectively.

[0147] The second rolling roller (200) can contact the electrode sheet (50) along the circumference at the first angular section (G1) centered on the second rotation axis (A2) (Fig. 3).

[0148] The first angular section (G1) may be an angular section that is greater than or equal to a predetermined minimum angle and less than or equal to a predetermined maximum angle. The first angular section (G1) may include a first sub-section (U1) and a second sub-section (U2).

[0149] The first sub-section (U1) may be an angular section that is equal to or greater than the minimum angle of the first angular section (G1) and equal to or less than the first angle (L1) at which the first rotation axis (A1) is located about the second rotation axis (A2).

[0150] The second sub-section (U2) may be an angular section that is greater than or equal to the first angle (L1) and less than or equal to the maximum angle of the first angular section (G1).

[0151] The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the first sub-section (U1) and at least a portion of the second sub-section (U2).

[0152] Accordingly, since the electrode sheet (50) is in contact with the circumference of the second rolling roller (200) in the first angle section (G1), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the size of the continuous (Tandem) rolling device (10) that continuously rolls multiple times and the number of rolling rollers can be reduced. That is, the transport direction of the electrode sheet (50) is straight, and therefore, the size of the rolling device and the number of rolling rollers can be reduced compared to the conventional continuous rolling device that requires multiple rolling mills to be arranged in a straight line. When the size of the continuous rolling device and the number of rolling rollers are reduced, the installation space is reduced, so the manufacturing, installation, and maintenance costs of the continuous rolling device can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0153] In addition, since the electrode sheet (50) is in contact along the circumference of the second rolling roller (200) in each of the first sub-section (U1) and the second sub-section (U2), the electrode sheet (50) can be maintained in a consistently bent state along the circumference of the second rolling roller (200) during rolling (e.g., first rolling) and before and after rolling. Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling. Therefore, even if the composite layers (54, 56) are repeatedly contracted and relaxed due to repeated charging and discharging, the resistance does not increase, so an abnormal heating phenomenon may not occur, and the capacity of the battery may not decrease. That is, even if the electrode sheet (50) is rolled in a bent state, the quality of the electrode and secondary battery can be improved and the lifespan can be extended.

[0154] In contrast, if the electrode sheet (50) does not contact the circumference of the second rolling roller (200) in the first sub-section (U1) or the second sub-section (U2), the electrode sheet (50) may be rolled in a state in which it is not evenly bent, and thus the composite layer (54, 56) may be unevenly and weakly adhered to the electrode current collector (52). In addition, if the electrode sheet (50) does not contact the circumference of the second rolling roller (200) in the second sub-section (U2), the electrode sheet (50) may quickly change to a state in which it is not evenly bent or a state in which it is straightened after rolling, and thus the composite layer (54, 56) may be unevenly and weakly adhered to the electrode current collector (52).

[0155] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the second rolling roller (200), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0156] Meanwhile, the present invention can also be applied to a general rolling mill that performs a single-rolling operation, rather than a continuous rolling mill. Furthermore, the aforementioned effects can also occur when the present invention is applied to a general rolling mill that performs a single-rolling operation, rather than a continuous rolling mill.

[0157] The size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees. In this case, the size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0158] Accordingly, the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the second sub-section (U2) may be greater than or equal to the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the first sub-section (U1). Accordingly, the electrode sheet (50) can be prevented from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during rolling (e.g., primary rolling).

[0159] In addition, since the electrode sheet (50) can be in contact along the circumference of the second rolling roller (200) in the second sub-section (U2), the electrode sheet (50) can be maintained in a state of being evenly bent along the circumference of the second rolling roller (200) during and after rolling (e.g., first rolling). Accordingly, since the electrode sheet (50) does not quickly change to a state of not being evenly bent or straightened after rolling (e.g., first rolling), the composite layer (54, 56) can be stably, strongly, and uniformly bonded to the electrode current collector (52).

[0160] The size of the second sub-section (U2) can correspond to the size of the first sub-section (U1). That is, the first rotation axis (A1) can be located at the middle angle of the first angular section (G1) with respect to the second rotation axis (A2).

[0161] Accordingly, the frictional force acting between the electrode sheet (50) and the second rolling roller (200) in the first sub-section (U1) and the second sub-section (U2) can be balanced. Accordingly, rolling (e.g., primary rolling) can be performed stably.

[0162]

[0163] [Third rolling roller]

[0164] The third rolling roller (300) may be cylindrical. The third rolling roller (300) may be positioned facing the first rolling roller (100) with an electrode sheet (50) in between, the transport direction of which is changed by a guide (400) described later. The third rolling roller (300) may be in contact with the electrode sheet (50) passing between the third rolling roller (300) and the first rolling roller (100). The third rolling roller (300) may rotate around a third rotation axis (A3) extending in the width direction.

[0165] Accordingly, a continuous rolling mill that performs two consecutive rolling cycles can be easily implemented with three rolling rollers. This reduces the size of the continuous rolling mill and the number of rolling rollers. Consequently, the installation space of the continuous rolling mill can be reduced, and manufacturing, installation, and maintenance costs can be reduced. Furthermore, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0166] The third rolling roller (300) can come into contact with the electrode sheet (50) along the circumference at the second angular section (G2) centered on the third rotation axis (A3).

[0167] The second angular section (G2) may be an angular section that is greater than or equal to a predetermined minimum angle and less than or equal to a predetermined maximum angle. The second angular section (G2) may include a third sub-section (U3) and a fourth sub-section (U4).

[0168] The third sub-section (U3) may be an angular section that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is located about the third rotation axis (A3).

[0169] The fourth sub-section (U4) may be an angle section that is greater than or equal to the second angle (L2) and less than or equal to the maximum angle of the second angle section (G2).

[0170] The electrode sheet (50) can be spaced apart from the first rolling roller (100) in at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4).

[0171] Accordingly, since the electrode sheet (50) is brought into contact along the circumference of the third rolling roller (300) in the second angle section (G2), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the transport direction of the electrode sheet (50) exiting the continuous (Tandem) rolling device (10) can be appropriately adjusted, so that the installation and maintenance costs of the electrode sheet rolling device (10) can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved. In addition, the conventional continuous rolling device can be easily replaced.

[0172] In addition, since the electrode sheet (50) is in contact along the circumference of the third rolling roller (300) in each of the third sub-section (U3) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being constantly bent along the circumference of the third rolling roller (300) before and after rolling (e.g., secondary rolling). Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly bonded to the electrode collector (52) after rolling.

[0173] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the third rolling roller (300), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0174] The size of the third subsection (U3) may be greater than or equal to 0 degrees and less than or equal to 90 degrees. In this case, the size of the fourth subsection (U4) may be greater than or equal to the size of the third subsection (U3) and less than or equal to the value obtained by subtracting the size of the third subsection (U3) from 180 degrees.

[0175] Accordingly, the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the fourth sub-section (U4) may be greater than or equal to the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the third sub-section (U3). Accordingly, the electrode sheet (50) can be prevented from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during rolling (e.g., secondary rolling).

[0176] In addition, since the electrode sheet (50) can be in contact with the circumference of the third rolling roller (300) in the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being evenly bent along the circumference of the third rolling roller (300) during and after rolling (e.g., secondary rolling). Accordingly, since the electrode sheet (50) does not quickly change to a state of not being evenly bent or straightened after rolling (e.g., secondary rolling), the composite layer (54, 56) can be stably, strongly, and uniformly bonded to the electrode current collector (52).

[0177] At this time, as described above, the size of the first sub-section (U1) may be greater than or equal to 0 degrees and less than or equal to 90 degrees, and the size of the second sub-section (U2) may be greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

[0178] Accordingly, it is possible to reliably prevent the electrode sheet (50) from being pushed in the opposite direction to the transport direction of the electrode sheet (50) during the first and second rolling.

[0179] In addition, since the electrode sheet (50) can be in contact along the circumference of the second rolling roller (200) and the third rolling roller (300) in the second sub-section (U2) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being consistently bent along the circumference of the second rolling roller (200) and the third rolling roller (300) during and after the first and second rolling. Accordingly, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling.

[0180] The size of the fourth sub-section (U4) can correspond to the size of the third sub-section (U3). That is, the first rotation axis (A1) can be located at the middle angle of the second angular section (G2) with respect to the third rotation axis (A3).

[0181] Accordingly, the frictional force acting between the electrode sheet (50) and the third rolling roller (300) in the third sub-section (U3) and the fourth sub-section (U4) can be balanced. Accordingly, rolling (e.g., secondary rolling) can be performed stably.

[0182]

[0183] [guide]

[0184] The guide (400) can come into contact with the electrode sheet (50) that has passed between the first rolling roller (100) and the second rolling roller (200). The guide (400) can change the transport direction of the electrode sheet (50).

[0185] The guide (400) may be a roller.

[0186] Accordingly, a continuous rolling device can be easily implemented with three rolling rollers and a guide roller.

[0187] Meanwhile, when the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) are connected on an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) can be formed. At this time, the guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the base, but may be positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the base in a direction perpendicular to the base.

[0188] Accordingly, the installation space of the continuous rolling device and the transport path of the electrode sheet (50) can be reduced.

[0189] At this time, the diameter of the first rolling roller (100) may be larger than the diameters of the second rolling roller (200) and the third rolling roller (300), and the guide (400) may be positioned between the second rolling roller (200) and the third rolling roller (300).

[0190] Accordingly, the installation space of the continuous rolling device can be minimized and the transport path of the electrode sheet (50) can be optimized.

[0191] As described above, in the case where a triangle is formed by connecting the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) on an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) and having a base connecting the second rotation axis (A2) and the third rotation axis (A3), the diameter of the second rolling roller (200) can correspond to the diameter of the third rolling roller (300).

[0192] Accordingly, the first and second rolling can be performed stably.

[0193] As described above, a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) is formed by connecting the first rotation axis (A1), the second rotation axis (A2) and the third rotation axis (A3) in an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2) and the third rotation axis (A3), and the guide (400) is positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the base, but is positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the base in a direction perpendicular to the base, and the diameter of the first rolling roller (100) is larger than the diameters of the second rolling roller (200) and the third rolling roller (300), and the guide (400) is positioned between the second rolling roller (200) and the third rolling roller (300). When positioned between the third rolling rollers (300), the sizes of the first sub-section (U1), the second sub-section (U2), the third sub-section (U3), and the fourth sub-section (U4) may each be 20 degrees or more and 40 degrees or less.

[0194] Accordingly, the installation space of the continuous rolling device can be minimized and the transport path of the electrode sheet (50) can be optimized.

[0195]

[0196] [Electrode sheet rolling method]

[0197] Referring to FIG. 4, the electrode sheet rolling method according to one embodiment of the present invention may include a rolling process (S510).

[0198] In the rolling process (S510), the electrode sheet (50) being transported in the longitudinal direction is rolled between the first rolling roller (100) and the second rolling roller (200) while coming into contact with the circumference of the second rolling roller (200) at the first angle section (G1) centered on the second rotation axis (A2), and is rolled at the first angle (L1) centered on the second rotation axis (A2), and the electrode sheet (50) can be spaced from the first rolling roller (100) in at least a part of the first sub-section (U1) before rolling and in at least a part of the second sub-section (U2) after rolling.

[0199] Accordingly, since the electrode sheet (50) is in contact with the circumference of the second rolling roller (200) in the first angle section (G1), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the size of the continuous (Tandem) rolling device (10) that continuously rolls multiple times and the number of rolling rollers can be reduced. That is, the transport direction of the electrode sheet (50) is straight, and therefore, the size of the rolling device and the number of rolling rollers can be reduced compared to the conventional continuous rolling device that requires multiple rolling mills to be arranged in a straight line. When the size of the continuous rolling device and the number of rolling rollers are reduced, the installation space is reduced, so the manufacturing, installation, and maintenance costs of the continuous rolling device can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0200] In addition, since the electrode sheet (50) is in contact along the circumference of the second rolling roller (200) in each of the first sub-section (U1) and the second sub-section (U2), the electrode sheet (50) can be maintained in a consistently bent state along the circumference of the second rolling roller (200) during rolling (e.g., first rolling) and before and after rolling. Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly adhered to the electrode current collector (52) after rolling. Therefore, even if the composite layers (54, 56) are repeatedly contracted and relaxed due to repeated charging and discharging, the resistance does not increase, so an abnormal heating phenomenon may not occur, and the capacity of the battery may not decrease. That is, even if the electrode sheet (50) is rolled in a bent state, the quality of the electrode and secondary battery can be improved and the lifespan can be extended.

[0201] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the second rolling roller (200), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0202] Meanwhile, the present invention can also be applied to a general rolling method that involves a single rolling process, rather than a continuous rolling process. Furthermore, the aforementioned effects can also occur when the present invention is applied to a general rolling method that involves a single rolling process, rather than a continuous rolling process.

[0203] In addition, in the rolling process (S510), the electrode sheet (50) that has been rolled between the first rolling roller (100) and the second rolling roller (200) and then has its transport direction changed by the guide (400) is rolled between the first rolling roller (100) and the third rolling roller (300) while contacting the circumference of the third rolling roller (300) in the second angular section (G2) centered on the third rotation axis (A3), but is rolled at the second angle (L2) centered on the third rotation axis (A3), and the electrode sheet (50) can be spaced from the first rolling roller (100) in at least a part of the third sub-section (U3) before rolling and at least a part of the fourth sub-section (U4) after rolling.

[0204] Accordingly, a continuous rolling mill that performs two consecutive rolling cycles can be easily implemented with three rolling rollers. This reduces the size of the continuous rolling mill and the number of rolling rollers. Consequently, the installation space of the continuous rolling mill can be reduced, and manufacturing, installation, and maintenance costs can be reduced. Furthermore, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved.

[0205] In addition, since the electrode sheet (50) is in contact with the circumference of the third rolling roller (300) in the second angle section (G2), the transport direction of the electrode sheet (50) can be sufficiently changed. Accordingly, the (transport) direction of the electrode sheet (50) exiting the continuous (Tandem) rolling device (10) can be appropriately adjusted, so that the installation and maintenance costs of the electrode sheet rolling device (10) can be reduced. In addition, since the transport distance of the electrode sheet (50) can be shortened and the transport path can be simplified, electrode productivity can be improved. In addition, the conventional continuous rolling device can be easily replaced.

[0206] In addition, since the electrode sheet (50) is in contact along the circumference of the third rolling roller (300) in each of the third sub-section (U3) and the fourth sub-section (U4), the electrode sheet (50) can be maintained in a state of being constantly bent along the circumference of the third rolling roller (300) before and after rolling (e.g., secondary rolling). Accordingly, even if the electrode sheet (50) is rolled in a bent state, the composite layers (54, 56) can be stably, strongly, and uniformly bonded to the electrode collector (52) after rolling.

[0207] In addition, since the electrode sheet (50) is rolled in a state in which it is bent evenly along the circumference of the third rolling roller (300), the composite layer (54, 56) can be adhered to the electrode collector (52) in a state in which the surface area of ​​the electrode collector (52) and the composite layer (54, 56) is increased. Accordingly, the composite layer (54, 56) can be adhered to the electrode collector (52) more stably, strongly, and uniformly than in the past.

[0208]

[0209] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0210] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. An electrode sheet rolling device (10) that rolls an electrode sheet (50) having a composite layer (54, 56) containing an electrode active material formed on an electrode current collector (52) to a predetermined thickness. It includes a cylindrical first rolling roller (100) and a second rolling roller (200) that are arranged facing each other with the electrode sheet (50) being transported in the longitudinal direction therebetween and that are in contact with the electrode sheet (50) passing therebetween and that rotate around a first rotation axis (A1) and a second rotation axis (A2) that extend in the width direction, respectively. The second rolling roller (200) is in contact with the electrode sheet (50) along the circumference at the first angular section (G1) centered on the second rotation axis (A2), The above first angular section (G1) includes a first sub-section (U1) that is equal to or greater than the minimum angle of the first angular section (G1) and equal to or less than the first angle (L1) at which the first rotation axis (A1) is located with respect to the second rotation axis (A2), and a second sub-section (U2) that is equal to or greater than the first angle (L1) and equal to or less than the maximum angle of the first angular section (G1). In at least a part of the first sub-section (U1) and at least a part of the second sub-section (U2), the electrode sheet (50) is spaced apart from the first rolling roller (100). Electrode sheet rolling device.

2. In claim 1, The size of the above first sub-section (U1) is greater than or equal to 0 degrees and less than or equal to 90 degrees, An electrode sheet rolling device, wherein the size of the second sub-section (U2) is greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

3. In claim 2, An electrode sheet rolling device in which the size of the second sub-section (U2) corresponds to the size of the first sub-section (U1).

4. In any one of claims 1 to 3, A guide (400) that comes into contact with the electrode sheet (50) that passes between the first rolling roller (100) and the second rolling roller (200) and changes the transport direction of the electrode sheet (50); An electrode sheet rolling device, comprising a cylindrical third rolling roller (300) that is positioned facing the first rolling roller (100) with the electrode sheet (50) having its transport direction changed by the guide (400) interposed therebetween, and that contacts the electrode sheet (50) passing between the first rolling roller (100) and rotates around a third rotation axis (A3) extending in the width direction.

5. In claim 4, The third rolling roller (300) is in contact with the electrode sheet (50) along the circumference at the second angular section (G2) centered on the third rotation axis (A3), The above second angular section (G2) includes a third sub-section (U3) that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is located with respect to the third rotation axis (A3), and a fourth sub-section (U4) that is equal to or greater than the second angle (L2) and equal to or less than the maximum angle of the second angular section (G2). In at least a part of the third sub-section (U3) and at least a part of the fourth sub-section (U4), the electrode sheet (50) is spaced apart from the first rolling roller (100). Electrode sheet rolling device.

6. In claim 5, The size of the third sub-section (U3) above is greater than or equal to 0 degrees and less than or equal to 90 degrees, An electrode sheet rolling device, wherein the size of the fourth sub-section (U4) is greater than or equal to the size of the third sub-section (U3) and less than or equal to the value obtained by subtracting the size of the third sub-section (U3) from 180 degrees.

7. In claim 6, The size of the above first sub-section (U1) is greater than or equal to 0 degrees and less than or equal to 90 degrees, An electrode sheet rolling device, wherein the size of the second sub-section (U2) is greater than or equal to the size of the first sub-section (U1) and less than or equal to the value obtained by subtracting the size of the first sub-section (U1) from 180 degrees.

8. In claim 6, An electrode sheet rolling device in which the size of the fourth sub-section (U4) corresponds to the size of the third sub-section (U3).

9. In any one of claims 4 to 8, The above guide (400) is a roller, electrode sheet rolling device.

10. In any one of claims 4 to 9, When the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) are connected on an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) is formed. The above guide (400) is an electrode sheet rolling device, which is positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the bottom edge, but is positioned on the other side of the first rotation axis (A1) and the first rolling roller (100) located on one side of the bottom edge in a direction perpendicular to the bottom edge.

11. In claim 10, The diameter of the first rolling roller (100) is larger than the diameters of the second rolling roller (200) and the third rolling roller (300), The above guide (400) is an electrode sheet rolling device located between the second rolling roller (200) and the third rolling roller (300).

12. In claim 10 or claim 11, An electrode sheet rolling device in which the diameter of the second rolling roller (200) corresponds to the diameter of the third rolling roller (300).

13. In any one of claims 5 to 8, When the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3) are connected on an imaginary plane perpendicular to the first rotation axis (A1), the second rotation axis (A2), and the third rotation axis (A3), a triangle having a base connecting the second rotation axis (A2) and the third rotation axis (A3) is formed. The above guide (400) is positioned between the second rolling roller (200) and the third rolling roller (300) in the extension direction of the bottom side, but is positioned on the other side than the first rotation axis (A1) and the first rolling roller (100) located on one side of the bottom side in a direction perpendicular to the bottom side, The diameter of the first rolling roller (100) is larger than the diameters of the second rolling roller (200) and the third rolling roller (300), The above guide (400) is located between the second rolling roller (200) and the third rolling roller (300), An electrode sheet rolling device, wherein the sizes of the first sub-section (U1), the second sub-section (U2), the third sub-section (U3), and the fourth sub-section (U4) are each 20 degrees or more and 40 degrees or less.

14. In the electrode sheet rolling method (S500) using the electrode sheet rolling device (10) of any one of claims 1 to 3, The electrode sheet (50) transported in the longitudinal direction is rolled between the first rolling roller (100) and the second rolling roller (200) while contacting the circumference of the second rolling roller (200) in the first angle section (G1) with the second rotation axis (A2) as the center, and is rolled at the first angle (L1) with the second rotation axis (A2) as the center, and the electrode sheet (50) is spaced from the first rolling roller (100) in at least a part of the first sub-section (U1) before rolling and in at least a part of the second sub-section (U2) after rolling. Electrode sheet rolling method.

15. In claim 14, A guide (400) that comes into contact with the electrode sheet (50) that passes between the first rolling roller (100) and the second rolling roller (200) and changes the transport direction of the electrode sheet (50); A cylindrical third rolling roller (300) is disposed facing the first rolling roller (100) with the electrode sheet (50) in the transport direction changed by the guide (400) interposed therebetween, and is in contact with the electrode sheet (50) passing between the first rolling roller (100) and rotates around a third rotation axis (A3) extending in the width direction. The third rolling roller (300) is in contact with the electrode sheet (50) along the circumference at the second angular section (G2) centered on the third rotation axis (A3), The above second angular section (G2) includes a third sub-section (U3) that is equal to or greater than the minimum angle of the second angular section (G2) and equal to or less than the second angle (L2) at which the first rotation axis (A1) is located with respect to the third rotation axis (A3), and a fourth sub-section (U4) that is equal to or greater than the second angle (L2) and equal to or less than the maximum angle of the second angular section (G2). In at least a portion of the third sub-section (U3) and at least a portion of the fourth sub-section (U4), the electrode sheet (50) is spaced apart from the first rolling roller (100). In the above rolling process (S510), the electrode sheet (50) whose transport direction has been changed by the guide (400) after being rolled between the first rolling roller (100) and the second rolling roller (200) is rolled between the first rolling roller (100) and the third rolling roller (300) while coming into contact along the circumference of the third rolling roller (300) in the second angle section (G2) with the third rotation axis (A3) as the center, and is rolled at the second angle (L2) with the third rotation axis (A3) as the center, and the electrode sheet (50) is spaced from the first rolling roller (100) in at least a part of the third sub-section (U3) before rolling and at least a part of the fourth sub-section (U4) after rolling. Electrode sheet rolling method.

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