Secondary battery manufacturing equipment and method for manufacturing secondary battery

Abstract

According to exemplary embodiments, a secondary battery manufacturing equipment is provided. The equipment comprises: an unwinder configured to unwind an electrode sheet from a first electrode roll; a rewinder configured to wind the electrode sheet onto a second electrode roll; a first die coater configured to form a first coating layer of the electrode sheet; a second die coater configured to form a second coating layer of the electrode sheet; and laser beam irradiators configured to partially etch the second coating layer.

Description

Secondary battery manufacturing equipment and method for manufacturing secondary batteries

[0001] The present invention relates to a secondary battery manufacturing facility and a method for manufacturing a secondary battery. This application claims the benefit of Korean Application No. 10-2024-0002193, filed January 5, 2024, which is incorporated herein by reference in its entirety.

[0002] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0003] Secondary batteries are manufactured through electrode processes, assembly processes, and activation processes. Among these, the electrode process is the most critical process in determining the yield and performance of the battery cell. The electrode process may include a coating process, a roll-pressing process, and a slitting process. In the coating process, active and insulating materials may be applied to the surface of the current collector. In the roll-pressing process, the electrode may be pressed by pressure rolls. The roll-pressing process may determine the density, performance, and surface quality of the electrode. In the slitting process, the electrode may be cut into multiple electrodes depending on the battery cell design.

[0004] The technical idea of ​​the present invention aims to solve a problem by providing a system for manufacturing a secondary battery with improved yield and productivity, and a method for manufacturing a secondary battery.

[0005] According to exemplary embodiments of the present invention for solving the above-described problem, a secondary battery manufacturing facility is provided. The facility includes an unwinder configured to unwind an electrode sheet from a first electrode roll; a rewinder configured to wind the electrode sheet onto a second electrode roll; a first die coater configured to form a first coating layer on the electrode sheet; a second die coater configured to form a second coating layer on the electrode sheet; and laser beam irradiators configured to partially etch the second coating layer.

[0006] A secondary battery manufacturing facility, characterized in that the transverse etching width of the second coating layer by the laser beam irradiators is in the range of 1 mm to 5 mm.

[0007] The etching depth of the second coating layer by the above laser beam irradiators is in the range of 1 μm to 5 μm.

[0008] The above laser beam emitters are configured to form a plurality of polished rails.

[0009] The above plurality of trimmed rails extend in the direction of progression of the electrode sheet.

[0010] The above laser beam irradiators are configured to scan the electrode sheet with the laser beam in the transverse direction.

[0011] The scanning speed of each of the above laser beam irradiators is in the range of 7000 mm / s to 50000 mm / s.

[0012] The pulse frequency of each of the above laser beam emitters is in the range of 10 kHz to 1000 kHz.

[0013] According to exemplary embodiments, a method for manufacturing a secondary battery is provided. The method comprises the steps of forming first and second coating layers on an electrode sheet moving in a forward direction; and partially etching the second coating layer by irradiating the electrode sheet with a laser beam.

[0014] A trimmed rail extending in the direction of travel of the electrode sheet is formed on the second coating layer by the laser beam.

[0015] The transverse width of the above-mentioned trimmed rail is in the range of 1 mm to 5 mm.

[0016] The depth of the above-mentioned trimmed rail is in the range of 1 μm to 5 μm.

[0017] The electrode sheet includes a retaining portion lane covered by the first and second coating layers and a non-retaining portion spaced apart from the first and second coating layers, and the trimmed rail is formed at an edge of the retaining portion lane.

[0018] According to exemplary embodiments of the present invention, by partially etching the coating layer of an electrode sheet, a performance degradation of a secondary battery manufactured from the electrode sheet can be prevented. Furthermore, since the partial etching of the coating layer is performed by an inline laser device, a reduction in the throughput of secondary battery manufacturing can be prevented despite the partial etching of the coating layer.

[0019] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0020] Figure 1 illustrates a secondary battery manufacturing facility according to exemplary embodiments.

[0021] Figure 2 illustrates processing of electrode sheets by secondary battery manufacturing equipment according to exemplary embodiments.

[0022] Figure 3 is a cross-sectional view taken along the cutting line 2I-2I' of Figure 2.

[0023] Figure 4 is a cross-sectional view taken along the cutting line 2II-2II' of Figure 2.

[0024] Fig. 5 is a plan view showing a beam trace on the electrode sheet.

[0025] FIG. 6 is a flowchart illustrating a method for manufacturing a secondary battery according to exemplary embodiments.

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0027] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0028] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0029] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0030]

[0031] (Example 1)

[0032] FIG. 1 illustrates a secondary battery manufacturing facility (100) according to exemplary embodiments.

[0033] FIG. 2 illustrates processing of electrode sheets by secondary battery manufacturing equipment (100) according to exemplary embodiments.

[0034] Figure 3 is a cross-sectional view taken along the cutting line 2I-2I' of Figure 2.

[0035] Figure 4 is a cross-sectional view taken along the cutting line 2II-2II' of Figure 2.

[0036] Referring to FIGS. 1 to 4, the secondary battery manufacturing facility (100) may include an unwinder (111), a rewinder (113), a first die coater (121), a second die coater (123), an oven (125), and a plurality of laser beam irradiators (127_1, 127_2, 127_3, 127_4, 127_5, 127_6, 127_7, 127_8, 127_9, 127_10, 127_11, 127_12, 127_13, 127_14, 127_15, 127_16, hereinafter referred to as 127_1 to 127_16).

[0037] A first electrode roll (ER1) can be loaded onto an unwinder (111). The unwinder (111) can be configured to unwind an electrode sheet (ES) from the first electrode roll (ER1). A rewinder (113) can be configured to wind the electrode sheet (ES) onto a second electrode roll (ER2). The electrode sheet (ES) can be wound onto the second electrode roll (ER2) and, after reaching a predetermined winding length, cut and separated. Accordingly, the electrode sheet (ES) can be moved between the unwinder (111) and the rewinder (113).

[0038] The first die coater (121) may be configured to apply a first electrode slurry containing an active material onto an electrode sheet (ES). A first coating layer (CL1) may be formed by the first die coater (121).

[0039] The second die coater (123) may be configured to apply a second electrode slurry containing an active material onto the electrode sheet (ES). A second coating layer (CL2) may be formed by the second die coater (123). The second coating layer (CL2) may cover the first coating layer (CL1).

[0040] In FIGS. 3 and 4, examples are shown in which first and second coating layers (CL1, CL2) are applied to the first surface of the current collector (EP) of the electrode sheet (ES) by the secondary battery manufacturing equipment (100). A person skilled in the art will easily be able to arrive at an example in which the secondary battery manufacturing equipment (100) applies the first and second coating layers (CL1, CL2) to the second surface of the current collector (EP) of the electrode sheet (ES).

[0041] The first and second electrode slurries may include an electrode active material, a conductive agent, a binder, and a solvent. The electrode slurry may be prepared by dissolving the electrode active material, the conductive agent, the binder, and the like in a solvent. The solvent may disperse the electrode active material and the like. The solvent may be an aqueous solvent or a non-aqueous solvent. The solvent may include any one of dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, and mixtures thereof. The amount of the solvent used may be determined based on the target viscosity of the slurry. Parameters determining the amount of the solvent used include the coating thickness of the slurry, the manufacturing yield, and the workability.

[0042] The first electrode slurry and the second electrode slurry may have different compositions. For example, the composition ratio of natural graphite in the first electrode slurry may be different from the composition ratio of natural graphite in the second electrode slurry. The composition ratio of natural graphite in the first electrode slurry may be greater than the composition ratio of natural graphite in the second electrode slurry. In another example, for example, the composition ratio of artificial lead in the first electrode slurry may be different from the composition ratio of artificial graphite in the second electrode slurry. The composition ratio of artificial graphite in the second electrode slurry may be greater than the composition ratio of artificial graphite in the first electrode slurry.

[0043] A cathode active material is a material capable of causing an electrochemical reaction. The cathode active material may be a lithium transition metal oxide. Examples of the cathode active material include layered compounds such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2) substituted with one or more transition metals; lithium manganese oxide substituted with one or more transition metals; chemical formula LiNi 1-y M y Lithium nickel oxide expressed as O2 (wherein, M is any one of Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn, and Ga, and 0.01≤y≤0.7); Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, Li 1+zN i 0.4 Mn 0.4 Co 0.2 Li like O2 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e(wherein, -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1, M is any one of Al, Mg, Cr, Ti, Si, and Y, and A is any one of F, P, and Cl) lithium nickel cobalt manganese composite oxide; and chemical formula Li 1+x M 1-y M' y PO 4-z X z (wherein, M is a transition metal, more specifically, one of Fe, Mn, Co, and Ni, M' is one of Al, Mg, and Ti, X is one of F, S, and N, -0.5≤x≤+0.5, 0≤y≤0.5, and 0≤z≤0.1) and may include one of the olivine-based lithium metal phosphates.

[0044] The negative active material may include carbon, such as non-graphitizable carbon, graphitic carbon, etc. The negative active material may include, for example, Li x Fe2O3(0≤x≤1), LixWO2(0≤x≤1), Sn x Me 1-x Me' y O z(wherein Me is any one of Mn, Fe, Pb and Ge, and Me' is any one of Al, B, P, Si, elements of group 1, 2 and 3 of the periodic table and halogens; 0 <x≤1 이고; 1≤y≤3 이며; 1≤z≤8) 등의 금속 복합 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 리튬 금속; 리튬 합금; 규소계 합금; 및 주석계 합금 중 어느 하나를 포함할 수 있다. 음극 활물질은, 예컨대, SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4및 Bi2O5등의 금속 산화물을 포함할 수 있다. 음극 활물질은, 예컨대, 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni 계 재료 등을 포함할 수도 있다.

[0045] The conductive material can be conductive without causing a chemical change in the secondary battery to be ultimately manufactured. The conductive material may include, for example, graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fiber or metal fiber; metal powders such as fluorocarbon, aluminum, and nickel powder; conductive whiskey such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and polyphenylene derivatives.

[0046] The binder can enhance the bonding between the active material and the conductive material and the bonding strength to the current collector. The binder can include, for example, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluoroelastomer, various copolymers, and the like.

[0047] The thickness of the current collector (EP) may range from about 3 ㎛ to about 500 ㎛. The current collector (EP) may not cause chemical changes in the secondary battery to be ultimately manufactured and may have high conductivity. The surface of both current collectors (EP) may include a micro-roughened structure to increase the adhesion of the active material. The shape of the current collector (EP) may include any one of a film, a sheet, a foil, a net, a porous material, a foam, and a non-woven fabric.

[0048] When the current collector (EP) is for the positive electrode, the current collector (EP) may include any one of stainless steel, aluminum, nickel, titanium, calcined carbon, and aluminum. When the current collector (EP) is for the negative electrode, the current collector (EP) may include any one of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and an aluminum-cadmium alloy.

[0049] A plurality of holding portion lanes (L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12, L13, L14, L15, L16, hereinafter referred to as L1 to L16) can be formed by the first and second die coaters (121, 123). The plurality of holding portion lanes (L1 to L16) are portions of the electrode sheet (ES) coated with the first and second coating layers (CL1, CL2).

[0050] The retention lanes (L1, L2) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L3, L4) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L5, L6) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L7, L8) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L9, L10) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L11, L12) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L13, L14) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other. The retention lanes (L15, L6) can be formed from the same slits of the first and second die coaters (121, 123) and can be connected to each other.

[0051] The sustaining lanes (L1, L2), sustaining lanes (L3, L4), sustaining lanes (L5, L6), sustaining lanes (L7, L8), sustaining lanes (L9, L10), sustaining lanes (L11, L12), sustaining lanes (L13, L14), and sustaining lanes (L15, L16) can be separated in a slitting process. As a non-limiting example, the slitting process can be performed in two steps. That is, the electrode sheet (ES) including 16 sustaining lanes (L1 to L16) can be separated into electrode sheets including 8 sustaining lanes (L1 to L8), and then separated again into a plurality of separated electrode sheets each including only one of the plurality of sustaining lanes (L1 to L16).

[0052] The plurality of maintenance lanes (L1 to L16) can extend in the machine direction (MD) of the electrode sheet (ES). The plurality of maintenance lanes (L1 to L16) can be spaced apart in the transverse direction (TD) of the electrode sheet (ES).

[0053] Each of the uncoated portions (U1, U2, U3, U4, U5, U6, U7, U8, U9, U10, U11, U12, U13, U14, U15, U16, hereinafter referred to as U1 to U16) may be a portion of the electrode sheet (ES) that is not coated with an active material (i.e., the current collector (EP) is exposed). The uncoated portions (U1, U16) may be at both ends of the electrode sheet (ES) in the transverse direction (TD). The uncoated portions (U2, U3) may be between the holding portion lanes (L2, L3). The uncoated portions (U4, U5) may be between the holding portion lanes (L4, L5). The uncoated portions (U6, U7) may be between the holding portion lanes (L6, L7). The unlined portions (U8, U9) may be between the maintenance portion lanes (L8, L9). The unlined portions (U10, U11) may be between the maintenance portion lanes (L10, L11). The unlined portions (U12, U13) may be between the maintenance portion lanes (L12, L13). The unlined portions (U14, U15) may be between the maintenance portion lanes (L14, L15).

[0054] The uncoated portion (U1) corresponds to the maintenance portion lane (L1), and the uncoated portion (U1) and the maintenance portion lane (L1) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U2) corresponds to the maintenance portion lane (L2), and the uncoated portion (U2) and the maintenance portion lane (L2) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U3) corresponds to the maintenance portion lane (L3), and the uncoated portion (U3) and the maintenance portion lane (L3) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U4) corresponds to the maintenance portion lane (L4), and the uncoated portion (U4) and the maintenance portion lane (L4) can be included in the same electrode roll after the slitting process is completed. The plain region (U5) corresponds to the maintenance region lane (L5), and the plain region (U5) and the maintenance region lane (L5) can be included in the same electrode roll after the slitting process is completed. The plain region (U6) corresponds to the maintenance region lane (L6), and the plain region (U6) and the maintenance region lane (L6) can be included in the same electrode roll after the slitting process is completed. The plain region (U7) corresponds to the maintenance region lane (L7), and the plain region (U7) and the maintenance region lane (L7) can be included in the same electrode roll after the slitting process is completed. The plain region (U8) corresponds to the maintenance region lane (L8), and the plain region (U8) and the maintenance region lane (L8) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U9) corresponds to the maintenance portion lane (L9), and the uncoated portion (U9) and the maintenance portion lane (L9) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U10) corresponds to the maintenance portion lane (L10), and the uncoated portion (U10) and the maintenance portion lane (L10) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U11) corresponds to the maintenance portion lane (L11), and the uncoated portion (U11) and the maintenance portion lane (L11) can be included in the same electrode roll after the slitting process is completed. The uncoated portion (U12) corresponds to the maintenance portion lane (L12), and the uncoated portion (U12) and the maintenance portion lane (L12) can be included in the same electrode roll after the slitting process is completed.The plain region (U13) corresponds to the maintenance region lane (L13), and the plain region (U13) and the maintenance region lane (L13) can be included in the same electrode roll after the slitting process is completed. The plain region (U14) corresponds to the maintenance region lane (L14), and the plain region (U14) and the maintenance region lane (L14) can be included in the same electrode roll after the slitting process is completed. The plain region (U15) corresponds to the maintenance region lane (L15), and the plain region (U15) and the maintenance region lane (L15) can be included in the same electrode roll after the slitting process is completed. The plain region (U16) corresponds to the maintenance region lane (L16), and the plain region (U16) and the maintenance region lane (L16) can be included in the same electrode roll by the slitting process.

[0055] The oven (125) may be configured to dry the electrode sheet (ES). The moisture content of the electrode sheet (ES) may be limited to a set numerical range by the oven (125).

[0056] A plurality of laser beam emitters (127_1 to 127_16) may be configured to process the electrode sheet (ES). A plurality of laser beam emitters (127_1 to 127_16) may be configured to process the second surface of the electrode sheet (ES).

[0057] A plurality of laser beam emitters (127_1 to 127_16) may be arranged downstream of the oven (125). That is, the electrode sheet (ES) processed by the oven (125) may be processed by the plurality of laser beam emitters (127_1 to 127_16). The electrode sheet (ES) discharged from the outlet (Outfeed) of the oven (125) may be processed by the plurality of laser beam emitters (127_1 to 127_16). The plurality of laser beam emitters (127_1 to 127_16) may be interposed between the oven (125) and the rewinder (113). The oven (125) may be interposed between the second die coater (123) and the plurality of laser beam emitters (127_1 to 127_16).

[0058] The first and second electrode slurries may be fluid materials. Accordingly, when forming the first and second coating layers (CL1, CL2), a slide, which is a change in the thickness of the first and second coating layers (CL1, CL2) in the transverse direction (TD), may be formed by the transverse direction (TD) flow of the first and second electrode slurries. The slide may be an inclination of the profile of the first and second coating layers (CL1, CL2) at the edges of the plurality of holding lanes (L1 to L16). Here, the profile is an outline on a transverse direction (TD) cross-sectional view of the first and second coating layers (CL1, CL2) of the electrode sheet (ES).

[0059] The flow of the first and second electrode slurries may cause undesirable thickness variations of the first and second coating layers (CL1, CL2), such as fat edges. The fat edges may be portions of the plurality of retention lanes (L1-L16) having increased thickness. The fat edges may interfere with the winding of the second electrode roll (ER2) and may cause lithium precipitation, which degrades the performance of the finished battery cell.

[0060] According to exemplary embodiments, the plurality of laser beam emitters (127_1 to 127_16) may etch only the second coating layer (CL2). That is, while the second coating layer (CL2) is etched, the first coating layer (CL1) may not be etched. The plurality of laser beam emitters (127_1 to 127_16) may also be configured to etch the first and second coating layers (CL1, CL2).

[0061] A plurality of laser beam emitters (127_1 to 127_16) can be configured to remove fat edges. Accordingly, the thickness of the electrode sheet (ES) in the transverse direction (TD) can be uniformized, and the electrode sheet (ES) can be easily wound onto the second electrode roll (ER2).

[0062] A plurality of laser beam emitters (127_1 to 127_16) may be configured to emit laser beams onto the electrode sheet (ES). A plurality of laser beam emitters (127_1 to 127_16) may be configured to emit laser beams continuously (or intermittently) onto the electrode sheet (ES).

[0063] A plurality of laser beam emitters (127_1 to 127_16) may be configured to partially etch the second coating layer (CL2). The plurality of laser beam emitters (127_1 to 127_16) may be configured to form a plurality of trimmed rails (TR) on the electrode sheet (ES). Each of the plurality of trimmed rails (TR) may extend in the traveling direction (MD).

[0064] The laser beam irradiator (127_1) may be configured to irradiate a laser beam to the maintenance lane (L1) so as to form a trimmed rail (TR) in the maintenance lane (L1). The laser beam irradiator (127_2) may be configured to irradiate a laser beam to the maintenance lane (L2) so as to form a trimmed rail (TR) in the maintenance lane (L2). The laser beam irradiator (127_3) may be configured to irradiate a laser beam to the maintenance lane (L3) so as to form a trimmed rail (TR) in the maintenance lane (L3). The laser beam irradiator (127_4) may be configured to irradiate a laser beam to the maintenance lane (L4) so ​​as to form a trimmed rail (TR) in the maintenance lane (L4). The laser beam irradiator (127_5) may be configured to irradiate a laser beam to the maintenance lane (L5) to form a trimmed rail (TR) on the maintenance lane (L5). The laser beam irradiator (127_6) may be configured to irradiate a laser beam to the maintenance lane (L6) to form a trimmed rail (TR) on the maintenance lane (L6). The laser beam irradiator (127_7) may be configured to irradiate a laser beam to the maintenance lane (L7) to form a trimmed rail (TR) on the maintenance lane (L7). The laser beam irradiator (127_8) may be configured to irradiate a laser beam to the maintenance lane (L8) to form a trimmed rail (TR) on the maintenance lane (L8). The laser beam irradiator (127_9) may be configured to irradiate a laser beam to the maintenance lane (L9) so as to form a trimmed rail (TR) in the maintenance lane (L9). The laser beam irradiator (127_10) may be configured to irradiate a laser beam to the maintenance lane (L10) so as to form a trimmed rail (TR) in the maintenance lane (L10). The laser beam irradiator (127_11) may be configured to irradiate a laser beam to the maintenance lane (L11) so as to form a trimmed rail (TR) in the maintenance lane (L11).The laser beam irradiator (127_12) may be configured to irradiate a laser beam to the maintenance lane (L12) so as to form a trimmed rail (TR) in the maintenance lane (L12). The laser beam irradiator (127_13) may be configured to irradiate a laser beam to the maintenance lane (L13) so as to form a trimmed rail (TR) in the maintenance lane (L13). The laser beam irradiator (127_14) may be configured to irradiate a laser beam to the maintenance lane (L14) so ​​as to form a trimmed rail (TR) in the maintenance lane (L14). The laser beam irradiator (127_15) may be configured to irradiate a laser beam to the maintenance lane (L15) so as to form a trimmed rail (TR) in the maintenance lane (L15). The laser beam irradiator (127_16) can be configured to irradiate a laser beam to the maintenance lane (L16) so as to form a trimmed rail (TR) on the maintenance lane (L16).

[0065] A plurality of trimmed rails (TR) may be formed on the transverse (TD) edges of the plurality of maintenance lanes (L1 to L16). More specifically, the plurality of trimmed rails (TR) may be formed on the transverse (TD) edges of each of the plurality of maintenance lanes (L1 to L16) adjacent to the uncoated portions (U1 to U16).

[0066] According to exemplary embodiments, the transverse width (TRW) of each of the plurality of trimmed rails (TR) may be about 1 mm or more. According to exemplary embodiments, the transverse width (TRW) of each of the plurality of trimmed rails (TR) may be about 5 mm or less. According to exemplary embodiments, the transverse width (TRW) of each of the plurality of trimmed rails (TR) may be about 4 mm or less. According to exemplary embodiments, the transverse width (TRW) of each of the plurality of trimmed rails (TR) may be about 3 mm or less.

[0067] According to exemplary embodiments, the depth (TRD) of each of the plurality of trimmed rails (TR) may be about 1 μm or more. According to exemplary embodiments, the depth (TRD) of each of the plurality of trimmed rails (TR) may be about 2 μm or more. According to exemplary embodiments, the depth (TRD) of each of the plurality of trimmed rails (TR) may be about 5 μm or less. According to exemplary embodiments, the depth (TRD) of each of the plurality of trimmed rails (TR) may be about 4 μm or less.

[0068] Fig. 5 is a plan view showing a beam trace (BT) on the first lane (L1) of the electrode sheet (ES). The beam trace (BT) indicates the path of a laser beam irradiated by a laser beam irradiator (127_1).

[0069] Referring to FIGS. 1 and 5, the laser beam emitter (127_1) may be configured to scan the laser beam in the transverse direction (TD) along the first lane (L1). While the laser beam scans the first lane (L1) in the transverse direction (TD), the electrode sheet (ES) moves in the traveling direction (MD), so that the beam trace (BT) may have a zigzag shape. According to exemplary embodiments, the scanning speed of the laser beam by the laser beam emitter (127_1) may be in a range of about 7000 mm / s to about 50000 mm / s.

[0070] According to exemplary embodiments, the laser beam emitter (127_1) may be configured to emit a pulsed fine laser beam. According to exemplary embodiments, the pulse frequency (e.g., chopping frequency) of the laser beam emitted by the laser beam emitter (127_1) may be in a range of about 10 kHz to about 1000 kHz. According to exemplary embodiments, the laser beam emitter (127_1) may also be configured to emit a continuous fine laser beam.

[0071] The laser irradiation method by the laser beam irradiator (127_2, 127_3, 127_4, 127_5, 127_6, 127_7, 127_8, 127_9, 127_10, 127_11, 127_12, 127_13, 127_14, 127_15, 127_16) is substantially the same as that of the laser beam irradiator (127_1), so a duplicate description thereof is omitted.

[0072]

[0073] (Example 2: Method)

[0074] Figure 6 is a flowchart illustrating an exemplary secondary battery manufacturing method.

[0075] Referring to FIGS. 1, 2, 3, and 6, first and second coating layers (CL1, CL2) can be formed at P110. The first coating layer (CL1) can be formed by a first die coater (121), and the second coating layer (CL2) can be formed by a second die coater (123).

[0076] Referring to FIGS. 1 to 4 and 6, at P130, the second coating layer (CL2) may be partially etched. The partial etching of the second coating layer (CL2) may include irradiating a laser beam to the edges of a plurality of support lanes (L1 to L16) of the electrode sheet (ES). By irradiating the laser beam, trimmed rails (TR) may be formed. The mechanism of the partial etching by the laser may be, but is not limited to, sublimation. The processes of P110 and P120 may be performed simultaneously, but may be performed on different portions of the electrode sheet (ES).

[0077] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. An unwinder configured to unwind an electrode sheet from a first electrode roll; A rewinder configured to wind the electrode sheet onto a second electrode roll; A first die coater configured to form a first coating layer of the electrode sheet; a second die coater configured to form a second coating layer of the electrode sheet; and A secondary battery manufacturing facility comprising laser beam irradiators configured to partially etch the second coating layer.

2. In paragraph 1, A secondary battery manufacturing facility, characterized in that the transverse etching width of the second coating layer by the laser beam irradiators is in the range of 1 mm to 5 mm.

3. In paragraph 1, A secondary battery manufacturing facility, characterized in that the etching depth of the second coating layer by the laser beam irradiators is in the range of 1 μm to 5 μm.

4. In paragraph 1, A secondary battery manufacturing facility characterized in that the above laser beam irradiators are configured to form a plurality of trimmed rails.

5. In paragraph 4, A secondary battery manufacturing facility, characterized in that the plurality of trimmed rails extend in the direction in which the electrode sheet advances.

6. In paragraph 1, A secondary battery manufacturing facility, characterized in that the above laser beam irradiators are configured to scan the electrode sheet with the laser beam in the transverse direction.

7. In paragraph 6, A secondary battery manufacturing facility, characterized in that each of the above laser beam irradiators has a scanning speed in a range of 7,000 mm / s to 50,000 mm / s.

8. In paragraph 1, A secondary battery manufacturing facility, characterized in that each of the above laser beam irradiators has a pulse frequency in the range of 10 kHz to 1000 kHz.

9. A step of forming first and second coating layers on an electrode sheet moving in the direction of travel; and A method for manufacturing a secondary battery, comprising the step of partially etching the second coating layer by irradiating the electrode sheet with a laser beam.

10. In paragraph 9, A method for manufacturing a secondary battery, characterized in that a trimmed rail extending in the progress direction of the electrode sheet is formed on the second coating layer by the laser beam.

11. In paragraph 10, A method for manufacturing a secondary battery, characterized in that the transverse width of the above-mentioned trimmed rail is in a range of 1 mm to 5 mm.

12. In paragraph 10, A method for manufacturing a secondary battery, characterized in that the depth of the above-mentioned trimmed rail is in the range of 1 μm to 5 μm.

13. In paragraph 10, The electrode sheet comprises a maintenance portion lane covered by the first and second coating layers and a non-conductive portion spaced from the first and second coating layers, and A method for manufacturing a secondary battery, characterized in that the above-mentioned trimmed rail is formed on the edge of the above-mentioned maintenance lane.

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