Method of manufacturing electrode for secondary battery comprising pre-slitting process

Abstract

Disclosed herein is a method of manufacturing an electrode for a secondary battery, including: a process of continuously forming two or more slurry coated parts on one surface or both surfaces of metal foil in a second direction which is a longitudinal direction of the metal foil so that a non-coated part which an electrode slurry is not coated is positioned between the slurry coated parts coated with the electrode slurry including an electrode active material in a first direction which is a transverse direction of the metal foil; a process of forming mixture coated parts by drying the slurry coated parts and rolling by a roller; and a process of forming electrode strips by slitting the non-coated part in the second direction, wherein before continuously forming the slurry coated parts, while continuously forming the slurry coated parts, or between continuously forming the slurry coated parts and forming the mixture coated parts, the method further includes a process of forming non-continuous linear slits in the non-coated part of the metal foil in the second direction.

Claims

1. A method of manufacturing an electrode for a secondary battery, comprising: providing a metal foil, which is initially uncoated; a process of continuously forming two or more slurry coated parts on one surface or both surfaces of the metal foil in a second direction which is a longitudinal direction of the metal foil so that a non-coated part is positioned between the slurry coated parts coated with the electrode slurry, including an electrode active material, in a first direction which is a transverse direction of the metal foil; a process of forming non-continuous linear slits in the initially uncoated metal foil or in the non-coated part of the metal foil in the second direction, before forming mixture coated parts; a process of forming the mixture coated parts by drying the slurry coated parts and rolling by a roller; and a process of forming electrode strips by cutting along the non-continuous linear slits.

2. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein the metal foil is made of one or more selected from the group consisting of stainless steel, aluminum, copper, nickel, titanium, and an aluminum alloy.

3. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein the process of forming the non-continuous linear slits is performed before continuously forming the slurry coated parts.

4. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein the process of forming the non-continuous linear slits is performed while continuously forming the slurry coated parts.

5. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein the process of forming the non-continuous linear slits is performed between continuously forming the slurry coated parts and forming the mixture coated parts.

6. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein a length of each of the non-continuous linear slits is in a range of about 1 to 200 mm.

7. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein an interval between the non-continuous linear slits is in a range of about 1 to 1000 mm.

8. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein the non-continuous linear slits are formed perpendicular to the first direction.

9. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein, in the process of forming the electrode strips, the slitting of the non-coated part is performed by cutting between the non-continuous linear slits.

10. The method of manufacturing an electrode for a secondary battery according to claim 1, wherein, after the process of forming the electrode strips, a notching process of forming the electrode tab by partially cutting the slit non-coated part of the electrode strip is further included.

11. The method of manufacturing an electrode for a secondary battery according to claim 10, wherein, after the notching process, a cutting process of forming a unit electrode by cutting the electrode strip uniformly in the second direction is further included.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic plan view in which a roll press process is performed on an electrode-processed body to which an electrode mixture of the related art is applied.

(2) FIG. 2 is a schematic plan view illustrating a process of slitting an electrode-processed body of the related art.

(3) FIG. 3 is a schematic perspective view illustrating a process of forming an electrode tab in an electrode-processed body of the related art.

(4) FIG. 4 is a schematic plan view of an electrode-processed body having an electrode tab formed by a notching process of the related art.

(5) FIG. 5 is a flowchart illustrating a process of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(6) FIG. 6 is a schematic plan view of a metal foil before a process 110 is performed in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(7) FIG. 7 is a schematic plan view of a metal foil while a process 110 is being performed in a method of manufacturing an electrode for a secondary battery according to another exemplary embodiment of the present disclosure.

(8) FIG. 8 is a schematic plan view of a metal foil between a process 110 and a process 120 in a method of manufacturing an electrode for a secondary battery according to still another exemplary embodiment of the present disclosure.

(9) FIG. 9 is a schematic plan view illustrating a process 130 in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(10) FIG. 10 is a schematic plan view illustrating a notching process of forming an electrode tab in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(11) FIG. 11 is a schematic plan view illustrating a cutting process of forming a unit electrode in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the description provided herein is for a better understanding of the present disclosure, and the scope of the present disclosure is not limited thereto.

(13) FIG. 5 is a flowchart illustrating a process of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure, FIG. 6 is a schematic plan view of a metal foil before a process 110 is performed in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure, and FIG. 7 is a schematic plan view of a metal foil while the process 110 is performed in a method of manufacturing an electrode for a secondary battery according to another exemplary embodiment of the present disclosure.

(14) Referring to FIG. 5 to FIG. 7, a method 100 of manufacturing an electrode for a secondary battery according to the present disclosure may include a process 110 of continuously forming three slurry coated parts 220, 221, and 222 on one surface or both surfaces of a metal foil 200 in a second direction D.sub.2, which is a longitudinal direction of the metal foil 200, so that a non-coated part 230, which is not coated with an electrode slurry, is positioned between the slurry coated parts 220, 221, and 222 coated with an electrode slurry 225 including an electrode active material in a first direction D.sub.1, which is a transverse direction of the metal foil 200, a process 120 of forming mixture coated parts 204 (FIG. 9) by rolling and drying the slurry coated parts 220, 221, and 222 by a roller, and a process 130 of forming electrode strips 260 (FIG. 10) by slitting the non-coated part 230 in the second direction D.sub.2.

(15) In particular, the metal foil 200 may be made of aluminum when a positive electrode current collector is manufactured, and copper may be used as the metal foil 200 when a negative electrode current collector is manufactured.

(16) Referring to FIG. 5 and FIG. 6, a process 140 of forming non-continuous linear slits 210 in the non-coated part 230 of the metal foil 200 in the second direction D.sub.2 by a cutter member 310 may be performed before the process 110 of coating the metal foil 200 with the electrode slurry (not shown) including the electrode active material.

(17) In addition, the non-continuous linear slits 210 may be formed perpendicular to the first direction D.sub.1, and the non-continuous linear slits 210 may also be formed in a direction coinciding with the second direction D.sub.2 of slitting in the process 130.

(18) Further, a length L.sub.1 of each of the non-continuous linear slits 210 may be in a range of about 1 to 200 mm, and an interval L.sub.2 between the non-continuous linear slits 210 may be in a range of about 1 to 1,000 mm.

(19) Referring to FIG. 5 and FIG. 7, in the process of forming the non-continuous linear slits 210, the process 140 of forming non-continuous linear slits 210 in the non-coated part 230 of the metal foil 200 in the second direction D.sub.2 by a cutter member 310 may be performed during the process 110 of coating the metal foil 200 with the electrode slurry 225 including the electrode active material by a discharge member 400.

(20) FIG. 8 is a schematic plan view of a metal foil between the process 110 and the process 120 in a method of manufacturing an electrode for a secondary battery according to still another exemplary embodiment of the present disclosure.

(21) Referring to FIG. 5 and FIG. 8, the process 140 of forming the non-continuous linear slits 210 in the non-coated part 230 of the metal foil 200 in the second direction D.sub.2 may be performed between the process 110 of coating the metal foil 200 with the electrode slurry 225 including the electrode active material and the process 120 of performing a roll press process of rolling and drying the slurry coated parts 220, 221 and 222 by rollers 501 and 502.

(22) FIG. 9 is a schematic plan view illustrating the process 130 in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(23) Referring to FIGS. 5 and 9, in the process 130, the slitting of the non-coated part 230 may be performed by cutting between the non-continuous linear slits 210 by a cutter 300 for slitting moving in the second direction D.sub.2, which is the longitudinal direction of the metal foil 200.

(24) FIG. 10 is a schematic plan view illustrating a notching process of forming an electrode tab in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(25) Referring to FIGS. 5, 9 and 10, in the method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure, after the process 130, a notching process of forming electrode tabs 232 by partially cutting the slit non-coated part 230 of the electrode strip 260 using a metal mold 600 is further performed.

(26) FIG. 11 is a schematic plan view illustrating a cutting process of forming a unit electrode in a method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure.

(27) Referring to FIG. 10 and FIG. 11, in the method of manufacturing an electrode for a secondary battery according to an exemplary embodiment of the present disclosure, a cutting process of forming a unit electrode 700 by cutting the electrode strip 260 uniformly in the first direction D.sub.1 using a cutter 330 is further performed after the notching process of FIG. 10.

(28) As described above, the method of manufacturing an electrode for a secondary battery according to the present disclosure can prevent wrinkles or wave patterns, which are generated when a shear force is applied to a non-coated part by a cutter during a slitting process, from being further lengthened or deepened by performing a process of forming non-continuous linear slits in the non-coated part of a metal foil in a second direction before a process of continuously forming slurry coated parts, during a process of continuously forming the slurry coated parts, or between the processes of continuously forming the slurry coated parts and forming the slurry coated parts, thereby reducing defects due to folding of the non-coated part or an electrode tab by the wrinkles or wave patterns.