Electrode rolling machine

Abstract

The present invention provides an electrode rolling apparatus in which both the first and second rolling rollers can be used for rolling plain sections. [Solution] The present invention relates to an electrode rolling apparatus that applies pressure to the plain portion of an electrode.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0126836, filed on October 5, 2022, and includes all the contents disclosed in the document of the Korean Patent Application as part of this specification.

[0002] The present invention relates to an electrode rolling device, and more specifically, to an electrode rolling device that applies pressure to a non-patterned portion of an electrode.

Background Art

[0003] Secondary batteries are not only an energy source for mobile devices but have recently been realized as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), and their usage areas are also expanding to applications such as power assist power sources through grid connection.

[0004] The manufacturing process of such secondary batteries is roughly divided into three stages: an electrode process, an assembly process, and a formation process. The electrode process is further divided into an active material mixing process, an electrode coating process, a rolling process, a slitting process, a winding process, and the like.

[0005] Among these, the rolling process reduces the thickness of the electrode sheet after the electrode active material coating process to increase the capacity density and increases the adhesion and close adhesion between the electrode current collector and the electrode active material contained in the electrode active material. To do this, the electrode sheet is passed between two hot-rolled rollers and compressed to a desired thickness and density.

[0006] In such a rolling process, the thickness of the electrode sheet is determined by the rolling gap between the two rolling rollers. The rolling gap is calculated by operating a driving unit that controls the vertical position of the rolling rollers so as to compress and roll the electrode to a desired thickness. Generally, while one of the two rolling rollers is fixed, the position of the remaining one rolling roller is adjusted by the driving unit and the electrode is compressed and rolled based on the calculated rolling gap.

[0007] However, when the electrode sheet is rolled by rolling rollers, almost no pressure is applied to the plain areas where the electrode active material is not coated, compared to the maintenance areas where the electrode active material is coated. Due to the difference in stretching rates between the maintenance and plain areas, undulations or wrinkles occur in the plain areas.

[0008] Such undulations and wrinkles cause meandering and serious dimensional defects in the winding process that follows the rolling process, ultimately hindering the quality of electrodes for secondary batteries. Therefore, an additional step is required to roll the plain areas after the electrode sheet has been rolled.

[0009] Figure 1 is a cross-sectional view showing a conventional electrode rolling mill for rolling a plain portion. The conventional electrode rolling mill includes one rolling roll (10) and includes a central part (11), a first end (12), and a second end (13). Here, in the electrode rolling mill, the outer surface of the central part (11) extends from the first end (12) to the second end (13), and the first outer diameter (r1) of the central part (11) connected to the first end (12) is greater than the second outer diameter (r2) of the central part (11) connected to the second end (13). The plain portion (22) of the electrode (20) includes an insulating coated portion (23) and a non-insulating coated portion (24), and the first end (12) is located adjacent to the boundary between the insulating coated portion (23) and the non-insulating coated portion (24) of the electrode (20) and applies pressure to the insulating coated portion (23) and the non-insulating coated portion (24). Because the first outer diameter (r1) is larger than the second outer diameter (r2), even if there is a difference in thickness between the insulating coating portion (23) and the non-insulating coating portion (24), pressure is applied uniformly, and the deviation in the elongation rate can be reduced.

[0010] However, in the conventional electrode rolling apparatus, the plain portion (22) of the electrode (20) can only be rolled using the first end, which has a larger outer diameter, and the second end (13) cannot be used to roll the plain portion (22). Therefore, when the rolling roll (10) must be replaced due to wear of the first end (12), the second end (13) must also be discarded. This results in significant costs for rolling the plain portion (22), creating an economic problem that requires efforts to improve the situation. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Korean Published Patent No. 2019-0059210 [Patent Document 2] Korean Published Patent No. 2022-0067239 [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention aims to provide an electrode rolling apparatus in which both the first rolling roller and the second rolling roller can be used for rolling plain sections. [Means for solving the problem]

[0013] In order to achieve the aforementioned objective, The present invention relates to an electrode rolling apparatus that applies pressure to the plain portion of an electrode, comprising a maintenance portion coated with an electrode active material and a plain portion not coated with an electrode active material, wherein the plain portion includes an insulating coated portion and a non-insulating coated portion. The electrode rolling apparatus includes a first rolling roller and a second rolling roller, The first rolling roller includes a first central part and a first end located at one end of the first central part in the longitudinal direction. The second rolling roller includes a second central part and a second end located at one end of the second central part in the longitudinal direction. The other end cross-section of the first central part and the other end cross-section of the second central part are in contact with each other. The 1-1 outer diameter of the first central part connected to the first end is different from the 1-2 outer diameter of the first central part that is in contact with the other end cross section of the second central part. The outer diameter 2-1 of the second central part connected to the second end is different from the outer diameter 2-2 of the second central part tangent to the other end cross section of the first central part. The outer diameters 1-2 and 2-2 are the same. The present invention provides an electrode rolling apparatus in which the first or second end is adjacent to the boundary between the insulating coated portion and the non-insulating coated portion.

[0014] In one embodiment of the present invention, the outer diameter of the first-1 is smaller than the outer diameter of the first-2, and the outer diameter of the second-1 is smaller than the outer diameter of the second-2, or The 1-1 outer diameter may be larger than the 1-2 outer diameter, and the 2-1 outer diameter may be larger than the 2-2 outer diameter.

[0015] In one embodiment of the present invention, the lengths of the first central part and the second central part may be the same or different.

[0016] In one embodiment of the present invention, the lengths of the first central part and the second central part may be the same, and the outer diameters of the first-1 and the second-1 may be the same.

[0017] In one embodiment of the present invention, the lengths of the first central part and the second central part may be different from each other, and the outer diameters of the first-1 and the second-1 may be the same or different from each other.

[0018] In one embodiment of the present invention, the ratio of the lengths of the first central part to the second central part may be 3:5 to 5:3.

[0019] In one embodiment of the present invention, the outer diameter of the first-2 is 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the first-1, and the outer diameter of the second-2 may be 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the second-1.

[0020] In one embodiment of the present invention, the first end portion has a tapered shape in which the outer diameter gradually decreases from the first central portion toward the rear end portion, and the second end portion may have a tapered shape in which the outer diameter gradually decreases from the second central portion toward the rear end portion.

[0021] In one embodiment of the present invention, the tapered surfaces of the first end portion and the second end portion may include a curved tapered surface and a linear tapered surface extending from the curved tapered surface.

[0022] In one embodiment of the present invention, the taper angles of the first end portion and the second end portion may be the same as or different from each other.

[0023] In one embodiment of the present invention, the taper angles of the first end portion and the second end portion may be 20 to 30 degrees.

[0024] In one embodiment of the present invention, the materials of the first rolling roller and the second rolling roller may be the same as or different from each other, and the materials may be metal or polymer.

[0025] In one embodiment of the present invention, the insulating coating portion may include one or more selected from the group consisting of an insulating polymer material and an insulating ceramic material.

[0026] In one embodiment of the present invention, the material of the first rolling roller or the second rolling roller is metal, and the insulating coating portion may include an insulating polymer material.

[0027] In one embodiment of the present invention, the material of the first rolling roller or the second rolling roller is polymer, and the insulating coating portion may include an insulating ceramic material.

[0028] In one embodiment of the present invention, at least one of the first central part, first end, second central part, and second end outer surface may have grooves and protrusions alternately formed on the plain portion, parallel to the direction from the maintenance portion to the rear end of the plain portion.

[0029] In one embodiment of the present invention, the groove and the protrusion may have a cross-sectional shape similar to a triangle or a semicircle. [Effects of the Invention]

[0030] In the electrode rolling apparatus of the present invention, not only the first rolling roller but also the second rolling roller can be used for rolling the plain portion of the electrode. Specifically, even if the first rolling roller wears down due to continuous rolling of the plain portion, the plain portion can be rolled using the second rolling roller, thus eliminating the need to discard any components and demonstrating economic benefits.

[0031] Furthermore, the materials of the first and second rolling rollers, the ratio of the first-to-second outer diameter to the first-to-first outer diameter, the ratio of the second-to-second outer diameter to the second-to-first outer diameter, or the ratio of the lengths of the first and second centers can be easily changed by the material of the insulating coating portion, the width of the plain portion, etc., making it possible to manufacture electrodes of various forms. [Brief explanation of the drawing]

[0032] [Figure 1] This is a cross-sectional view showing a conventional electrode rolling mill. [Figure 2] This is a cross-sectional view of the electrode. [Figure 3] This is a cross-sectional view showing an electrode rolling apparatus used for the plain portion of an electrode according to one embodiment of the present invention. [Figure 4] This is a cross-sectional view showing an electrode rolling apparatus used for the plain portion of an electrode according to one embodiment of the present invention. [Figure 5] This is a cross-sectional view showing an electrode rolling apparatus used for the plain portion of an electrode according to one embodiment of the present invention. [Figure 6] This is a cross-sectional view showing an electrode rolling apparatus used for the plain portion of an electrode according to one embodiment of the present invention. [Figure 7] This is a photograph of an electrode whose plain portion has been rolled using an electrode rolling apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0033] The present invention will be described in detail below, based on the attached drawings, so that it can be easily implemented by a person with ordinary skill in the art to which the invention pertains. However, the present invention can be embodied in various different forms and is not limited to the embodiments described herein.

[0034] To clearly illustrate the present invention, irrelevant parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0035] Furthermore, the terms and words used in this specification and the claims shall not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner and concept consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0036] Figure 2 is a side cross-sectional view of the electrode (20) that is rolled in the electrode rolling apparatus (100) of the present invention.

[0037] Referring to Figure 2, the electrode (20) includes a maintenance portion (21) on both sides of a rectangular plate-shaped current collector, where electrode active material is coated. The portion where the electrode active material is not coated is a plain portion (22), and the plain portion (22) may be a current collector. An insulating coating portion (23) is included at the boundary between the plain portion (22) and the maintenance portion (21). Specifically, the insulating coating portion (23) may be positioned so that its upper or lower surface is in contact with the plain portion (22) and its side surface is in contact with the maintenance portion (21). The portion of the plain portion (22) where the insulating coating portion (23) is not formed is a non-insulating coating portion (24), and the plain portion (22) may include both the insulating coating portion (23) and the non-insulating coating portion (24). Therefore, the non-insulating coating portion (24) may be a current collector.

[0038] Furthermore, as shown in Figure 2, in this embodiment, the height of the insulating coating portion (23) when it is adhered to the surface of the retaining portion (21) can be configured to be the same as the height of the retaining portion (21), or slightly lower.

[0039] The present invention relates to an electrode rolling apparatus that applies pressure to the plain portion (22) of an electrode (20), comprising a maintenance portion (21) coated with an electrode active material and a plain portion (22) not coated with an electrode active material, wherein the plain portion (22) includes an insulating coated portion (23) and a non-insulating coated portion (24). The electrode rolling apparatus (100) includes a first rolling roller (110); and a second rolling roller (120), The first rolling roller (110) includes a first central part (111) and a first end part (112) located at one end of the first central part in the longitudinal direction. The second rolling roller (120) includes a second central part (121) and a second end part (122) located at one end of the second central part in the longitudinal direction. The other end cross-section of the first central part (111) and the other end cross-section of the second central part (121) are in contact with each other. The first outer diameter (r1-1) of the first central part (111) connected to the first end (112) is different from the first outer diameter (r1-2) of the first central part (111) that is in contact with the other end cross section of the second central part (121). The second outer diameter (r2-1) of the second central part (121) connected to the second end (122) is different from the second outer diameter (r2-2) of the second central part (121) that is in contact with the other end cross section of the first central part (111). The aforementioned outer diameters 1-2 (r1-2) and 2-2 (r2-2) are the same. The first end (112) or the second end (122) relates to an electrode rolling apparatus (100) adjacent to the boundary between the insulating coated portion (23) and the non-insulating coated portion (24).

[0040] The first rolling roller (110) may include a first center (111) and a first end (112) located at one end of the first center (111), and the first center (111) and the first end (112) may be integrated. That is, the first end (112) may extend from one end of the first center (111). For example, the first rolling roller (110) may be manufactured by processing the first end (112) through an additional process with respect to the first center (111). Alternatively, the first center (111) and the first end (112) may be manufactured separately and joined together by an additional process, but are not limited to this, and the first rolling roller (110) can be manufactured in various ways.

[0041] The second rolling roller (120) may include a second center (121) and a second end (122) located at one end of the second center (121), and the second center (121) and the second end (122) may be integrated. That is, the second end (122) may extend from one end of the second center (121). For example, the second rolling roller (120) may be manufactured by processing the second end (122) through an additional process with respect to the second center (121). Alternatively, the second center (121) and the second end (122) may be manufactured separately and joined together by an additional process, but are not limited to this, and the second rolling roller (120) can be manufactured in various ways.

[0042] Furthermore, the other end cross-sections of the first central part (111) and the other end cross-sections of the second central part (121) may be in contact with each other. Therefore, the first rolling roller (110) and the second rolling roller (120) may be integrated, and the first-to-second outer diameter (r1-2) of the first central part and the second-to-second outer diameter (r2-2) of the second central part may be the same.

[0043] The electrode rolling apparatus (100) of the present invention is highly economical because both the first rolling roller (110) and the second rolling roller (120) can be used to roll the plain portion (22) of the electrode (20). In the present invention, the meaning that the first rolling roller (110) and the second rolling roller (120) can roll the plain portion (22) of the electrode (20) does not mean that the first rolling roller (110) and the second rolling roller (120) roll the plain portion (22) of the electrode (20) simultaneously, but rather that the first rolling roller (110) and the second rolling roller (120) each roll the plain portion (22) of the electrode (20). More specifically, the first rolling roller (110) is preferentially used for rolling the plain portion (22) of the electrode (20), and if the first rolling roller (110) cannot be used due to wear or other reasons, the second rolling roller (120) can be used to roll the plain portion (22) of the electrode (20). Alternatively, the first rolling roller (110) and the second rolling roller (120) can be manufactured with different shapes and materials, and by selecting the first rolling roller (110) or the second rolling roller (120) that is suitable for the shape and material of the electrode (20), the plain portion (22) can be rolled at the same level as the maintenance portion (21).

[0044] The outer surface of the first central part (111) may extend from the first end (112) to the second central part (121), and the outer surface of the second central part (121) may extend from the second end (122) to the first central part (111).

[0045] The first-first outer diameter (r1-1) may be smaller than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be smaller than the second-second outer diameter (r2-2). Alternatively, the first-first outer diameter (r1-1) may be larger than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be larger than the second-second outer diameter (r2-2).

[0046] Furthermore, the outer diameter of the first-second outer diameter (r1-2) may be 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the first-first outer diameter (r1-1), and the outer diameter of the second-second outer diameter (r2-2) may be 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the second-first outer diameter (r2-1).

[0047] The lengths of the first central part (L1) and the second central part (L2) may be the same or different. Preferably, the ratio of the lengths of the first central part (L1) and the second central part (L2) may be 3:5 to 5:3, and preferably 3:4 to 4:3.

[0048] The lengths of the first center (L1) and the second center (L2) may be the same, in which case the first-1 outer diameter (r1-1) and the second-1 outer diameter (r2-1) may be the same or different from each other.

[0049] The lengths of the first center (L1) and the second center (L2) may be different from each other, in which case the first-1 outer diameter (r1-1) and the second-1 outer diameter (r2-1) may be the same or different from each other.

[0050] The first end (112) may have a tapered shape in which the outer diameter gradually decreases from the first center (111) towards the rear end, and the second end (122) may have a tapered shape in which the outer diameter gradually decreases from the second center (121) towards the rear end.

[0051] Furthermore, the tapered surfaces of the first end (112) and the second end (122) may include a curved tapered surface (R) and a linear tapered surface (L) extending from the curved tapered surface (R). If the tapered surface is formed only of a linear tapered surface (L), there is a possibility of wire breakage occurring when rolling the plain portion (22) of the electrode (20). Therefore, by curving the tapered surface to form a curved tapered surface (R), the plain portion (22) can be rolled without damaging the electrode (20).

[0052] Therefore, the first end (112) and the second end (122) may have a taper angle, and the taper angles of the first end (112) and the second end (122) may be the same or different. In one embodiment, the taper angles of the first end (112) and the second end (122) may be 20 to 30 degrees.

[0053] The electrode rolling apparatus (100) according to the present invention can roll the plain portion (22) of the electrode (20) with the first rolling roller (110) or the second rolling roller (120), so that the first end (112) or the second end (122) can be adjacent to the boundary between the maintenance portion (21) and the plain portion (22). Preferably, it can be adjacent to the boundary between the insulating coated portion (23) and the non-insulating coated portion (24). Figures 3 and 4 illustrate an electrode rolling apparatus (100) according to one embodiment of the present invention.

[0054] Referring to Figure 3, the first-first outer diameter (r1-1) may be smaller than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be smaller than the second-second outer diameter (r2-2). Also, the length of the first central part (L1) is the same as the length of the second central part (L2), and the first-first outer diameter (r1-1) and the second-first outer diameter (r2-1) may be the same as each other.

[0055] Referring to Figure 4, the first-first outer diameter (r1-1) may be larger than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be larger than the second-second outer diameter (r2-2). Also, the length of the first central part (L1) is the same as the length of the second central part (L2), and the first-first outer diameter (r1-1) and the second-first outer diameter (r2-1) may be the same as each other.

[0056] In other words, the electrode rolling apparatus (100) shown in Figures 3 and 4 may have a symmetrical configuration of the first rolling roller (110) and the second rolling roller (120).

[0057] The retaining portion (21) of the electrode (20) may have the same or different widths of the electrode active material coated on its upper surface (tab) and lower surface (bottom). Therefore, the widths of the upper and lower surfaces of the plain portion (22) formed thereby may be the same or different.

[0058] An electrode rolling apparatus (100) shown in Figures 3 and 4 according to one embodiment of the present invention has a symmetrical configuration for the first rolling roller (110) and the second rolling roller (120), and is therefore preferably used for rolling electrodes where the width of the upper and lower surfaces of the blank portion (22) are the same. That is, in the electrode rolling apparatus (100) shown in Figures 3 and 4, both the first rolling roller (110) and the second rolling roller (120) can be used to roll the blank portion (22) of the electrode (20), and even if the first rolling roller (110) wears out, the blank portion (22) can be rolled using the second rolling roller (120). Furthermore, the electrode rolling apparatus (100) shown in Figures 3 and 4 can achieve a rolling effect on the blank portion (22) at an equivalent level.

[0059] Figures 3 and 4 show that the first end (112) and the second end (122) of the electrode (20) are located at the boundary between the insulating coated portion (23) and the non-insulating coated portion (24). However, this does not mean that the first rolling roller (110) and the second rolling roller (120) roll the plain portion (22) of the electrode (20) simultaneously, but rather that the first rolling roller (110) and the second rolling roller (120) each roll the plain portion (22) of the electrode (20).

[0060] Figures 5 and 6 illustrate an electrode rolling apparatus (100) according to one embodiment of the present invention.

[0061] Referring to Figure 5, the first-first outer diameter (r1-1) may be smaller than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be smaller than the second-second outer diameter (r2-2). Also, the length of the first center (L1) is different from the length of the second center (L2), and the first-first outer diameter (r1-1) and the second-first outer diameter (r2-1) may be the same as each other.

[0062] Referring to Figure 6, the first-first outer diameter (r1-1) may be larger than the first-second outer diameter (r1-2), and the second-first outer diameter (r2-1) may be larger than the second-second outer diameter (r2-2). Also, the length of the first center (L1) is different from the length of the second center (L2), and the first-first outer diameter (r1-1) and the second-first outer diameter (r2-1) may be the same as each other.

[0063] In other words, the electrode rolling apparatus (100) shown in Figures 5 and 6 may have an asymmetrical configuration of the first rolling roller (110) and the second rolling roller (120).

[0064] An electrode rolling apparatus (100) shown in Figures 5 and 6 according to one embodiment of the present invention has an asymmetrical configuration for the first rolling roller (110) and the second rolling roller (120). Therefore, it can preferably be used for rolling electrodes in which the widths of the upper and lower surfaces of the blank portion (22) are different. That is, the electrode rolling apparatus (100) shown in Figures 5 and 6 can be used for rolling the blank portion (22) of the electrode (20) using both the first rolling roller (110) and the second rolling roller (120).

[0065] The electrode rolling apparatus (100) shown in Figures 5 and 6 indicates that the length of the first central part (L1) is shorter than the length of the second central part (L2). Furthermore, the electrode (20) indicates that the upper surface (tab) of the plain section (22) is narrower than the lower surface (bottom). Therefore, the upper surface (tab) of the narrow plain section (22) can be positioned on the first rolling roller (110), and the lower surface (bottom) of the wide plain section (22) can be positioned on the second rolling roller (120).

[0066] In other words, in the electrode rolling apparatus (100) according to one embodiment of the present invention, since the rolling rollers that can roll the electrode (20) can be selected according to the shape of the electrode (20), both the first rolling roller (110) and the second rolling roller (120) can be used to roll the electrode (20).

[0067] Figures 5 and 6 show that the first end (112) and the second end (122) of the electrode (20) are located at the boundary between the insulating coated portion (23) and the non-insulating coated portion (24). However, this does not mean that the first rolling roller (110) and the second rolling roller (120) roll the plain portion (22) of the electrode (20) simultaneously, but rather that the first rolling roller (110) and the second rolling roller (120) each roll the plain portion (22) of the electrode (20).

[0068] The insulating coating portion (23) may include one or more materials selected from the group consisting of insulating polymer materials and insulating ceramic materials. The insulating polymer material is not particularly limited in type as long as it is used in the industry, but preferably includes one or more materials selected from the group consisting of polyvinylidene fluoride, polyimide, polyethylene terephthalate, polyurethane, polyacrylate, epoxy, and silicone. The insulating ceramic material is not particularly limited in type as long as it is used in the industry, but may include a mixture of an insulating polymer and one or more materials selected from the group consisting of aluminum oxide, silicon oxide, silicon nitride, iron oxide, and glass.

[0069] The first rolling roller (110) and the second rolling roller (120) may be made of the same or different materials, and the materials may be metal or polymer. The metal may include one or more oxides selected from the group consisting of aluminum, tin, and zinc, and preferably aluminum. The polymer may include one or more selected from the group consisting of polyether ether ketone, polyolefin resin, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, polycarbonate, polyimide, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalene, and preferably polyether ether ketone.

[0070] If the first rolling roller (110) and the second rolling roller (120) are made of the same material, the first rolling roller (110) and the second rolling roller (120) may be integrated into a single unit.

[0071] Depending on the type of material forming the insulating coating portion (23), the materials of the first rolling roller (110) and the second rolling roller (120) can be determined. In one embodiment, if the material forming the insulating coating portion (23) is an insulating ceramic material, the material of the first rolling roller (110) or the second rolling roller (120) that rolls the plain portion (22) of the electrode (20) may be a polymer. If the material is a metal, both the ceramic and the metal are strong, and wear may occur quickly at the first end (112) or the second end (122) of the metal material that comes into contact with the ceramic. In another embodiment, if the material forming the insulating coating portion (23) is an insulating polymer material, the material of the first rolling roller (110) or the second rolling roller (120) that rolls the plain portion (22) of the electrode (20) may be a metal. If the material is a polymer, both the insulating polymer material and the polymer may have low strength, which could prevent proper rolling of the plain portion (22).

[0072] Furthermore, the electrode rolling apparatus (100) can alternately form grooves and protrusions on at least one of the outer circumferential surfaces of the first central part (111), first end (112), second central part (121), and second end (122) of the plain part (22) to form a number of wrinkles parallel to the direction from the maintenance part (21) to the rear end of the plain part (22). The grooves and protrusions may have a cross-sectional shape similar to a triangle or a semicircle.

[0073] The electrode rolling apparatus (100) of the present invention can not only roll the plain portion (22) of the electrode (20) with the first rolling roller (110), but can also roll the plain portion (22) with the second rolling roller (120). Therefore, it can have an economic effect. Furthermore, even if the shape and material of the electrode (20) differ, such as the width of the plain portion (22) and the type of material forming the insulating coating portion (23), by changing the material of the first rolling roller (110) and the second rolling roller (120), the ratio of the first-2 outer diameter (r1-2) to the first-1 outer diameter (r1-1), the ratio of the second-2 outer diameter (r2-2) to the second-1 outer diameter (r2-1), or the ratio of the lengths of the first and second centers (L1 / L2), it is possible to achieve a rolling effect of the plain portion (22) equivalent to that of the maintenance portion (21).

[0074] Furthermore, the first rolling roller (110) and the second rolling roller (120) of the present invention may integrally form a single press roll, and the press roll may include a press roll fixing part (not shown) that rotatably fixes the press roll.

[0075] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, using the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of symbols]

[0076] 10: Rolling roll 11: Center 20: Electrode 21: Maintenance part 22: Plain section 23: Insulating coated section 24: Non-insulating coated section 100: Electrode rolling machine 110: First rolling roller 111: First center 12, 112: First end 120: Second rolling roller 121: Second center part 13, 122: Second end part r1: 1st outer diameter r2: 2nd outer diameter r1-1: No. 1-1 outer diameter r1-2: No. 1-2 outer diameter r2-1: No. 2-1 outer diameter r2-2: No. 2-2 outer diameter L1: Length of the first center L2: Length of the second center

Claims

1. An electrode rolling apparatus that applies pressure to the uncoated portion of an electrode, comprising a maintenance portion coated with an electrode active material and a plain portion not coated with an electrode active material, wherein the plain portion includes an insulating coated portion and a non-insulating coated portion. The electrode rolling apparatus includes a first rolling roller and a second rolling roller, The first rolling roller includes a first central part and a first end located at one end of the first central part in the longitudinal direction. The second rolling roller includes a second central part and a second end located at one end of the second central part in the longitudinal direction. The other end cross-section of the first central part and the other end cross-section of the second central part are in contact with each other. The first-1 outer diameter of the first central part connected to the first end is different from the first-2 outer diameter of the first central part that is in contact with the other end cross section of the second central part. The second-1 outer diameter of the second central part connected to the second end is different from the second-2 outer diameter of the second central part that is in contact with the other end cross section of the first central part. The outer diameters of the first and second 2 are the same. An electrode rolling apparatus in which the first end or the second end is adjacent to the boundary between the insulating coated portion and the non-insulating coated portion.

2. The outer diameter of the first-first is smaller than the outer diameter of the first-second, and the outer diameter of the second-first is smaller than the outer diameter of the second-second, or The electrode rolling apparatus according to claim 1, wherein the outer diameter of the first-first is larger than the outer diameter of the first-second, and the outer diameter of the second-first is larger than the outer diameter of the second-second.

3. The electrode rolling apparatus according to claim 2, wherein the lengths of the first central part and the second central part are the same or different from each other.

4. The lengths of the first central part and the second central part are the same. The electrode rolling apparatus according to claim 3, wherein the 1-1 outer diameter and the 2-1 outer diameter are the same or different from each other.

5. The lengths of the first central part and the second central part are different from each other. The electrode rolling apparatus according to claim 3, wherein the 1-1 outer diameter and the 2-1 outer diameter are the same or different from each other.

6. The electrode rolling apparatus according to claim 3, wherein the ratio of the lengths of the first central part to the second central part is 3:5 to 5:

3.

7. The outer diameter of the first-2 is 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the first-1. The electrode rolling apparatus according to claim 1, wherein the outer diameter of the second-second part is 0.8 to 0.99 times or 1.01 to 1.2 times the outer diameter of the second-first part.

8. The first end has a tapered shape in which the outer diameter gradually decreases from the first center to the rear end. The electrode rolling apparatus according to claim 1, wherein the second end has a tapered shape in which the outer diameter gradually decreases from the second center to the rear end.

9. The electrode rolling apparatus according to claim 8, wherein the tapered surfaces of the first end and the second end include a curved tapered surface and a linear tapered surface extending from the curved tapered surface.

10. The electrode rolling apparatus according to claim 8, wherein the taper angles of the first end and the second end are the same or different from each other.

11. The electrode rolling apparatus according to claim 10, wherein the taper angles of the first end and the second end are 20 to 30 degrees.

12. The materials of the first rolling roller and the second rolling roller are either the same or different. The electrode rolling apparatus according to claim 1, wherein the material is a metal or a polymer.

13. The electrode rolling apparatus according to claim 1, wherein the insulating coating portion includes one or more materials selected from the group consisting of insulating polymer materials and insulating ceramic materials.

14. The material of the first rolling roller or the second rolling roller is metal. The electrode rolling apparatus according to claim 1, wherein the insulating coating portion includes an insulating polymer material.

15. The material of the first rolling roller or the second rolling roller is a polymer. The electrode rolling apparatus according to claim 1, wherein the insulating coating portion includes an insulating ceramic material.

16. The electrode rolling apparatus according to any one of claims 1 to 15, wherein at least one of the outer circumferential surfaces of the first central part, the first end, the second central part, and the second end has grooves and protrusions alternately formed on the plain portion for forming a number of wrinkles parallel to the direction from the maintenance portion to the rear end of the plain portion.

17. The electrode rolling apparatus according to claim 16, wherein the groove and the protrusion have a cross-sectional shape similar to a triangle or a semicircle.

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