Negative electrode, method for manufacturing same, and lithium secondary battery comprising same

Abstract

The present invention relates to a negative electrode comprising: a current collector; a negative electrode active material layer disposed on the current collector; and a solid electrolyte membrane precursor layer disposed on the negative electrode active material layer, wherein the negative electrode active material layer has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector, and the solid electrolyte membrane precursor layer is disposed so that the shape of the pattern grooves of the negative electrode active material layer is maintained.

Description

Negative electrode, method for manufacturing same, and lithium secondary battery comprising same Cross-citation with related applications This application claims the benefit of priority to Korean Patent Application No. 10-2023-0188709, dated December 21, 2023, the entire contents of which are incorporated herein by reference. Technical field The present invention relates to a negative electrode, a method for manufacturing the same, and a lithium secondary battery including the same. Secondary batteries are used in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, as well as in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices that store surplus generated power or renewable energy and as backup power storage devices. As mentioned above, as the application of lithium secondary batteries has recently expanded to large products requiring high output, development is being conducted to provide high energy density and excellent rapid charging performance of lithium secondary batteries. Meanwhile, in the past, electrodes were manufactured by applying a pattern electrode method that forms a certain shape on the electrode to improve the performance of rapid charging. However, when manufacturing an electrode by the pattern electrode method, a problem occurs in that energy density is lost compared to a general electrode due to the gap formed by the pattern. To compensate for this, there was a method of manufacturing the electrode pattern narrowly and deeply, but in this case, as shown in Fig. 1, since the exposed surface area of ​​the negative active material layer (10) arranged on the current collector (30) increases, there is a problem that the formation reaction of the SEI film (20) does not occur uniformly deep into the pattern groove. In addition, since a uniform SEI film is not formed deep into the pattern groove, the deterioration phenomenon in the deep pattern portion is accelerated, resulting in a problem that the life characteristics of the battery deteriorate. Therefore, in order to improve rapid charging performance, there is a need to develop a cathode that can form a uniform SEI film deep into the pattern while applying a pattern electrode. The present invention is intended to solve the above problems, and provides an anode having improved rapid charging performance and high-temperature storage characteristics by forming a uniform SEI film deep into a pattern, a method for manufacturing the same, and a lithium secondary battery including the same. The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned can be clearly understood by those skilled in the art from the description below. [1] The present invention provides an anode comprising: a current collector; a negative electrode active material layer disposed on the current collector; and a solid electrolyte film precursor layer disposed on the negative electrode active material layer; wherein the negative electrode active material layer has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector, and the solid electrolyte film precursor layer is disposed so as to maintain the shape of the pattern grooves of the negative electrode active material layer. [2] In the present invention, in the above [1], the average width of the line-shaped pattern groove may be 0.01 ㎛ to 500 ㎛. [3] In the present invention, in the above [1] or [2], the average depth of the line-shaped pattern groove may be 0.01 ㎛ or more. [4] In at least one of the above [1] to [3], the average spacing of the line-shaped pattern grooves may be 10 ㎛ to 500 ㎛. [5] In at least one of the above [1] to [4], the solid electrolyte membrane precursor layer may include a carbonate-based compound. [6] In at least one of the above [1] to [5], the solid electrolyte membrane precursor layer may include at least one selected from the group consisting of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and fluoroethylene carbonate (FEC). [7] In at least one of the above [1] to [6], the solid electrolyte membrane precursor layer may include vinylene carbonate (VC). [8] The present invention provides a method for manufacturing a negative electrode, comprising: a step of applying a first slurry including a negative electrode active material, a conductive material, and a binder, and a second slurry including a negative electrode active material, a conductive material, a binder, and a solid electrolyte membrane precursor onto a current collector; and a step of drying the first slurry and the second slurry applied onto the current collector; wherein the applying is performed by a nozzle printing method using a printing device having two or more nozzles, and a difference in the solid content of the first slurry and the second slurry is 10 wt% to 70 wt%. [9] In the present invention, in the above [8], the solid content of the first slurry may be 40 wt% to 80 wt%.

[0010] In the present invention, in the above [8] or [9], the solid content of the second slurry may be 10 wt% to 30 wt%.

[0011] In at least one of the above [8] to

[0010] , the solid electrolyte membrane precursor may include a carbonate-based compound, and the solid electrolyte membrane precursor may be included in an amount of 0.1 wt% to 5.0 wt% based on the total weight of solid content in the second slurry.

[0012] In at least one of the above [8] to

[0011] , the solid electrolyte membrane precursor may include a carbonate-based compound, and the solid electrolyte membrane precursor may be included in an amount of 0.2 wt% to 2.0 wt% based on the total weight of solid content in the second slurry.

[0013] The present invention provides a lithium secondary battery comprising at least one negative electrode among the above [1] to [7]. The negative electrode according to the present invention is characterized in that the negative electrode active material layer has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector, and the solid electrolyte film precursor layer is arranged so that the pattern shape of the negative electrode active material layer is maintained. The above-described line-shaped pattern groove can realize excellent rapid charging performance of the battery. In addition, since the solid electrolyte membrane precursor layer is arranged so that the pattern groove shape of the above-described negative electrode active material layer is maintained, an SEI film can be uniformly formed in the narrow and deep portion of the line-shaped pattern groove formed in the negative electrode active material layer arranged on the current collector, thereby enabling the implementation of a lithium secondary battery having excellent high-temperature storage characteristics and life characteristics. The drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the contents of the invention described above, serve to better understand the technical idea of ​​the present invention, so the present invention is not limited to the matters described in such drawings. Meanwhile, the shape, size, scale or ratio of elements in the drawings included in this specification may be exaggerated to emphasize a clearer explanation. Figure 1 is a schematic diagram showing that, in the case of a cathode manufactured according to conventional technology, an SEI film is not uniformly formed deep into a line-shaped pattern groove. FIG. 2 is a schematic diagram showing that, in the case of a cathode manufactured according to one embodiment of the present invention, an SEI film can be uniformly formed deep into a line-shaped pattern groove. FIGS. 3 and 4 are drawings showing the average width, average depth, average spacing, and preferred shape of the line-shaped pattern grooves in a cathode according to one embodiment of the present invention. FIG. 5 is a drawing showing a process of applying a first slurry and a second slurry using a printing device having two or more nozzles according to one embodiment of the present invention. FIG. 6 is a drawing showing a current collector to which a first slurry and a second slurry are applied before drying the negative electrode slurry discharged on the current collector according to one embodiment of the present invention. Hereinafter, the present invention will be described more preferably. The terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as having meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best manner. In the present invention, the MD direction (Machine Direction) means the longitudinal direction of the collector, and the TD direction (Transverse Direction) means the width direction of the collector. In the present invention, the average width, depth, and spacing of the line-shaped pattern grooves can be measured using a white light three-dimensional measuring device (optical profiler) or a laser microscope (CLSM, confocal laser scanning microscope). The present inventors have repeatedly developed a negative electrode in which an SEI film can be uniformly formed deep into the pattern when a negative electrode active material layer having a line-shaped pattern groove is applied, and as a result, they have found that when a solid electrolyte film precursor layer is arranged on a negative electrode active material layer having a line-shaped pattern groove so that the pattern groove shape can be maintained, an SEI film is uniformly formed deep into the pattern groove, and an negative electrode having excellent high-temperature storage characteristics and life characteristics can be manufactured, thereby completing the present invention. Hereinafter, the present invention will be described preferably. According to the present invention, the negative electrode, the method for manufacturing the same, and the lithium secondary battery including the same comprise at least one of the following disclosed configurations, and may comprise any combination between technically possible configurations among the following configurations. cathode Hereinafter, the cathode according to the present invention will be described. FIGS. 3 and 4 illustrate the average width, average depth, average spacing, and preferred shape of line-shaped pattern grooves in a cathode according to one embodiment of the present invention. Hereinafter, the cathode according to the present invention will be described with reference to FIGS. 3 and 4. Referring to FIGS. 3 and 4, a negative electrode according to the present invention includes a current collector (30); a negative electrode active material layer (10) disposed on the current collector (30); and a solid electrolyte film precursor layer (11) disposed on the negative electrode active material layer (10), wherein the negative electrode active material layer (10) has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector (30), and the solid electrolyte film precursor layer (11) is disposed such that the shape of the pattern grooves of the negative electrode active material layer (10) is maintained. According to the present invention, since the negative electrode active material layer (10) has two or more line-shaped pattern grooves formed in the longitudinal direction (MD) of the current collector (30), the surface area of ​​the negative electrode active material layer can be increased, so that a large amount of chemical reaction occurs between the negative electrode active material and the electrolyte, thereby improving the rapid charging performance. In addition, since the solid electrolyte film precursor layer (11) is arranged so that the shape of the pattern groove of the negative electrode active material layer (10) is maintained, while maintaining the effect of improving the rapid charging performance by the pattern groove, the SEI film can be uniformly formed deep into the pattern groove, thereby realizing excellent high-temperature storage characteristics and life characteristics. First, a preferred description will be given of the current collector (30) and the negative active material layer (10) disposed on the current collector (30). (entire house (30)) The current collector (30) is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. Preferably, the current collector (30) may be made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, an aluminum-cadmium alloy, or the like. The above-mentioned collector (30) can typically have a thickness of 3 to 500 μm. The above-mentioned current collector (30) may form fine irregularities on the surface to strengthen the bonding strength of the negative electrode active material. For example, the above-mentioned negative electrode current collector may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc. (Cathode active material layer (10)) The negative active material layer (10) disposed on the above current collector (30) has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector (30). The above two or more line-shaped pattern grooves are not particularly limited as long as they can be manufactured by a method that is usually used, but preferably, they can be manufactured by varying the solid content of the slurries applied on the current collector, and a detailed description will be given later. The cross-sectional shape of the above pattern home can be formed into various shapes such as a triangle, rectangle, or square, and is not particularly limited. The average width (41) of the above line-shaped pattern groove may be 0.01 ㎛ to 500 ㎛, preferably 10 ㎛ to 200 ㎛, and more preferably 30 ㎛ to 100 ㎛. When the above range is satisfied, the average width is not excessively small, so the process difficulty may not be difficult, and the excellent rapid charging characteristics of the pattern electrode may be exhibited, and the desirable N / P ratio may be implemented, which is preferable. The average width (41) of the above line-shaped pattern groove is an average value of the widths of multiple pattern grooves. The above width can be measured as the width of the pattern formed on the surface of the negative electrode active material layer (10). The average depth (43) of the above-described line-shaped pattern groove may be 0.01 ㎛ or more, preferably 0.1 ㎛ or more, 1 ㎛ or more, 5 ㎛ or more, 6 ㎛ or more, 10 ㎛ or more, or 20 ㎛ or more, and may be equal to or less than the thickness of the negative electrode active material layer, 100 ㎛ or less, 70 ㎛ or less, or 50 ㎛ or less. More preferably, it may be 0.01 ㎛ to the thickness of the negative electrode active material layer, and more preferably 20 ㎛ to 50 ㎛. When the above range is satisfied, the tortuosity within the electrode decreases, so that the movement path of lithium ions moving to the electrode is reduced, thereby reducing the overall resistance and implementing excellent rapid charging characteristics. The average spacing (42) of the above-mentioned line-shaped pattern grooves may be 10 ㎛ to 500 ㎛, preferably 50 ㎛ to 400 ㎛, and more preferably 50 ㎛ to 200 ㎛. The average spacing (42) of the above-mentioned line-shaped pattern grooves may be measured as the distance between the outermost side of the widest width of a specific pattern groove and the adjacent part of the widest width of the adjacent pattern groove of the specific pattern groove. When the above range is satisfied, the N / P ratio is appropriately controlled, and excellent electrolyte impregnation property can be implemented, so that the life characteristics of the battery can be improved. The number of the above-mentioned line-shaped pattern grooves may be 2 or more, and it is preferable that the line-shaped pattern grooves are formed throughout the negative electrode active material layer (10). Specifically, the number of the above-mentioned line-shaped pattern grooves may be appropriately controlled depending on the width (TD direction) of the negative electrode active material layer, but it is preferable that the number of pattern grooves formed throughout the negative electrode active material layer (10) be such that the average spacing (42) of the line-shaped pattern grooves is within the range of the line-shaped pattern grooves. When the above-mentioned condition is satisfied, the number of pattern grooves is appropriate, so that excellent energy density and rapid charging characteristics can be implemented. Hereinafter, the negative electrode active material, conductive material, and binder that may be included in the negative electrode active material layer are preferably described. The above negative active material layer may include a negative active material. The above negative active material is a material capable of reversibly inserting / de-inserting lithium ions, and may include at least one selected from the group consisting of a carbon-based active material, a silicon-based active material, and lithium metal, and preferably may include at least one selected from a carbon-based active material and a silicon-based active material. The above carbon-based active material may include at least one selected from the group consisting of graphite, hard carbon, soft carbon, carbon black, graphene, and fibrous carbon, and preferably may include graphite. The graphite may include, for example, at least one selected from the group consisting of artificial graphite and natural graphite. When the carbon-based active material is included, it may be preferable in that the rapid charging performance can be maximized through a short lithium ion movement path by the line-shaped pattern groove. The average particle diameter (D) of the above carbon-based active material 50 ) may be 10 ㎛ to 30 ㎛, preferably 15 ㎛ to 25 ㎛, in order to ensure structural stability during charging and discharging and reduce side reactions with the electrolyte. The above silicon-based active material is SiO x It may include a compound represented by (0≤x<2). In the case of SiO2, since it does not react with lithium ions and thus cannot store lithium, it is preferable that x is within the above range, and more preferably, the silicon-based active material may include SiO. In the case of including the silicon-based active material, it may be preferable in that the line-shaped pattern groove can play a buffering role for the silicon-based active material with a large volume change, thereby maximizing the life characteristics. The average particle diameter (D) of the above silicon-based active material 50 ) may be 1 ㎛ to 30 ㎛, preferably 2 ㎛ to 15 ㎛, in order to reduce side reactions with the electrolyte while ensuring structural stability during charge and discharge. The above negative active material may be included in the negative active material layer in an amount of 60 to 99 wt%, preferably 75 to 95 wt%. The above negative electrode active material layer may further include a binder and / or a conductive material together with the negative electrode active material. The above binder is used to improve the performance of the battery by improving the adhesion between the negative electrode active material layer and the negative electrode current collector, and may include, for example, at least one selected from the group consisting of polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber (SBR), fluororubber, and materials in which hydrogens of these are substituted with Li, Na or Ca, etc., and also may include various copolymers thereof. may include: The above binder may be included in the negative electrode active material layer in an amount of 0.5 wt% to 10 wt%, preferably 1 wt% to 5 wt%. The conductive material is not particularly limited as long as it is conductive and does not cause a chemical change in the battery, and for example, graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, paneth black, lamp black, thermal black, etc.; conductive fibers such as carbon fibers or metal fibers; conductive tubes such as carbon nanotubes; fluorocarbon; metal powder such as aluminum or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc. can be used. The above-mentioned conductive agent may be included in the negative electrode active material layer in an amount of 0.5 wt% to 10 wt%, preferably 1 wt% to 5 wt%. The thickness of the above negative active material layer may be 10 µm to 100 µm, preferably 40 µm to 80 µm. Next, the solid electrolyte membrane precursor layer (11) disposed on the negative active material layer (10) will be preferably described. (Solid electrolyte membrane precursor layer (11)) According to one embodiment of the present invention, the solid electrolyte membrane precursor layer (11) may include a carbonate-based compound. Typically, a portion of the carbonate-based compound included in the electrolyte of a lithium secondary battery reacts with the electrode to form an SEI film. This SEI film prevents further decomposition reaction of the electrolyte and has high lithium ion conductivity, so it can function as a separator. However, in the case of a negative electrode on which a patterned electrode is formed, there may be a problem that the SEI film is not uniformly formed deep into the pattern. Therefore, when the solid electrolyte membrane precursor layer includes a carbonate-based compound, the carbonate-based compound may be present deep into the line-shaped pattern groove, so that the SEI film is uniformly formed deep into the pattern groove, which is preferable in that excellent high-temperature storage characteristics and life characteristics can be implemented. According to one embodiment of the present invention, the solid electrolyte membrane precursor layer (11) may include at least one selected from the group consisting of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and fluoro ethylene carbonate (FEC). Preferably, the solid electrolyte membrane precursor layer (11) may include vinylene carbonate (VC). When the above condition is satisfied, a stable SEI film can be formed through rapid reduction in an electrolyte solvent, additional electrolyte decomposition can be suppressed, and electrode expansion can be prevented, thereby implementing excellent high-temperature storage characteristics and life characteristics. The above negative electrode can be manufactured by coating a negative electrode slurry including a negative electrode active material, a binder, a conductive agent and / or a solvent for forming a negative electrode slurry on at least one surface of a current collector, and then drying and rolling. The solvent for forming the negative electrode slurry may include at least one selected from the group consisting of distilled water, NMP (N-methyl-2-pyrrolidone), ethanol, methanol, and isopropyl alcohol, preferably distilled water, in order to facilitate dispersion of the negative electrode active material, binder, and / or conductive agent. The solid content of the negative electrode slurry may be 10 wt% to 80 wt%. Method for manufacturing cathode Hereinafter, a method for manufacturing a cathode according to the present invention will be described. FIGS. 5 and 6 illustrate a shape in which a first slurry and a second slurry are applied onto a current collector in a printing device having two or more nozzles before drying the negative electrode slurry discharged onto a current collector according to one embodiment of the present invention. Hereinafter, a negative electrode according to the present invention will be described with reference to FIGS. 5 and 6. Referring to FIGS. 5 and 6, a method for manufacturing a negative electrode according to the present invention includes a step of applying a first slurry (101) including a negative electrode active material, a conductive material, and a binder, and a second slurry (102) including a negative electrode active material, a conductive material, a binder, and a solid electrolyte membrane precursor (111) onto a current collector (30); and a step of drying the first slurry (101) and the second slurry (102) applied onto the current collector (30); wherein the applying is performed by a nozzle printing method using a printing device having two or more nozzles (400), and a difference in the solid content of the first slurry (101) and the second slurry (102) is 10 wt% to 70 wt%. According to one embodiment of the present invention, the difference in solid content between the first slurry (101) and the second slurry (102) is 10 wt% to 70 wt%. At this time, since the slurry having the low solid content contains a negative electrode active material, a conductive material, and a binder in a smaller weight compared to the weight of the solvent contained in the slurry, a thin negative electrode active material layer can be generated when the solvent is evaporated in the drying step. In contrast, the slurry having the high solid content contains a negative electrode active material, a conductive material, and a binder in a larger weight compared to the weight of the solvent contained in the slurry, and therefore a thick negative electrode active material layer can be generated when the solvent is evaporated in the drying step. That is, one feature of the present invention is to form two or more line-shaped pattern grooves by applying different slurries having a solid content difference of 10 wt% to 70 wt% by a nozzle printing method using a printing device having two or more nozzles. In addition, according to one embodiment of the present invention, the two or more line-shaped pattern grooves may be formed by arranging the solid content (110) in the first slurry and the second slurry contained in the solvent (not shown) of the slurry in which the first slurry and the second slurry are mixed so as to have the pattern grooves, as illustrated in FIG. 6. Accordingly, according to the present invention, the slurry arranged as illustrated in FIG. 6 may be dried and / or rolled to manufacture the negative electrode as illustrated in FIG. 3 and FIG. 4. The solid content in the above slurry may mean a solid contained in the slurry, and preferably may mean a negative electrode active material, a conductive material, and a binder, and the content of the solid content in the slurry may be calculated as a percentage of the weight of the negative electrode active material, the conductive material, and the binder with respect to the total weight of the negative electrode active material, the conductive material, the binder, and the solvent. In addition, according to one embodiment of the present invention, since the second slurry (102) contains a solid electrolyte film precursor (111), the solid electrolyte film precursor (111) is arranged deep in the pattern groove and on the slope of the pattern groove. The solid electrolyte film precursor (111) arranged in this way enables the SEI film to be uniformly formed deep in the pattern groove and on the slope of the pattern groove when the electrode and the electrolyte react later to form an SEI film, thereby implementing excellent high-temperature storage characteristics. Hereinafter, a method for manufacturing a cathode according to the present invention will be described step by step. First, a first slurry (101) containing a negative electrode active material, a conductive material, and a binder, and a second slurry (102) containing a negative electrode active material, a conductive material, a binder, and a solid electrolyte membrane precursor (111) are applied on a current collector (30). As the above-mentioned collector (30), negative electrode active material, conductive material, and binder have been described above, their description is omitted. The above first slurry (101) and second slurry (102) may each independently include the aforementioned negative electrode active material, binder, conductive material, and solvent for forming the negative electrode slurry. The solvent for forming the negative electrode slurry may include at least one selected from the group consisting of distilled water, NMP (N-methyl-2-pyrrolidone), ethanol, methanol, and isopropyl alcohol, preferably distilled water, in order to facilitate dispersion of the negative electrode active material, binder, and / or conductive agent. According to one embodiment of the present invention, the application is performed by a nozzle printing method using a printing device having two or more nozzles (400). Preferably, the number of nozzles may be five or more. Specifically, the number of nozzles may be controlled so as to form the number of line-type pattern grooves described above. According to one embodiment of the present invention, the nozzle printing method may be performed by a printing device in which the nozzles (400) are composed of the first nozzle (400a) to the fifth nozzle (400e), as disclosed in FIG. 5. When the above range is satisfied, the number of line-type pattern grooves is appropriate, so that the energy density and rapid charging characteristics may be excellent. According to one embodiment of the present invention, the difference in the solid content of the first slurry (101) and the second slurry (102) is 10 wt% to 70 wt%. Preferably, it may be 20 wt% to 60 wt%, and more preferably 30 wt% to 50%. When the difference in the solid content is less than 10 wt%, when the first slurry (101) and the second slurry (102) are applied on the current collector, the respective solids in the first slurry (101) and the second slurry (102) overlap each other at the interface and cannot form a pattern groove, thereby deteriorating the rapid charging characteristic. If the difference in the above solid content exceeds 70 wt%, there is a problem that the inlet of the nozzle (400) that discharges the slurry is blocked or slurry coating is difficult because the solid content of one of the slurries is too high and the viscosity of the slurry is excessively high, and on the other hand, there is a problem that the solid content of one of the slurries is too low and the viscosity of the slurry is excessively low, making it difficult to coat by flowing down on the current collector. Accordingly, when the above range is satisfied, two or more line-shaped pattern homes can be easily formed, so that the fairness can be excellent, and accordingly, excellent rapid charging characteristics can be implemented. According to one embodiment of the present invention, the solid content of the first slurry (101) may be 40 wt% to 80 wt%, preferably 45 wt% to 65 wt%, and more preferably 45 wt% to 55 wt%. When the above range is satisfied, the contents of the negative active material, conductive material, and binder contained in the slurry are appropriate, so that excellent energy density can be implemented, and the solid content may be appropriate for implementing the pattern groove shape. According to one embodiment of the present invention, the solid content of the second slurry (102) may be 10 wt% to 30 wt%, preferably 10 wt% to 20 wt%, and more preferably 10 wt% to 15 wt%. When the above range is satisfied, the viscosity of the slurry may be appropriate while maintaining the pattern groove shape, thereby improving processability. According to one embodiment of the present invention, the solid electrolyte membrane precursor (111) includes a carbonate-based compound, and the solid electrolyte membrane precursor (111) may be included in an amount of 0.1 wt% to 5.0 wt% based on the total weight of the solid content in the second slurry (102), preferably 0.1 wt% to 3.5 wt%, and more preferably 0.2 wt% to 2.0 wt%. When the above range is satisfied, an SEI film can be uniformly formed deep into the pattern groove, so that rapid charging characteristics, high-temperature storage characteristics, and lifespan characteristics can be excellent. According to one embodiment of the present invention, the solid electrolyte membrane precursor (111) may include at least one selected from the group consisting of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and fluoro ethylene carbonate (FEC). Preferably, the solid electrolyte membrane precursor (111) may include vinylene carbonate (VC). When the above condition is satisfied, a stable SEI film can be formed through rapid reduction in an electrolyte solvent, additional electrolyte decomposition can be suppressed, and electrode expansion can be prevented, thereby implementing excellent high-temperature storage characteristics and life characteristics. Next, a step of drying the first slurry and the second slurry applied on the entire body is performed to manufacture a negative electrode. The drying serves to dry the solvent contained in the first slurry and the second slurry, leaving only the solid content in the slurry. The drying can be performed at 40°C to 180°C, preferably 40°C to 140°C, more preferably 40°C to 100°C, and even more preferably 40°C to 70°C. Lithium secondary battery Hereinafter, a lithium secondary battery according to the present invention will be described. A lithium secondary battery according to the present invention includes an anode according to the present invention, an anode, a separator interposed between the anode and the cathode, and an electrolyte. (anode) The above anode can be opposed to the above cathode. The above positive electrode may include a positive electrode current collector; and a positive electrode active material layer positioned on at least one surface of the positive electrode current collector. The positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. Preferably, the positive electrode current collector may include at least one selected from the group consisting of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and an aluminum-cadmium alloy, and preferably may include aluminum. The above positive electrode current collector may typically have a thickness of 3 to 500 μm. The above-mentioned positive electrode current collector may form fine irregularities on the surface to strengthen the bonding strength of the negative electrode active material. For example, the above-mentioned positive electrode current collector may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a non-woven fabric, etc. The above positive electrode active material layer may include a positive electrode active material. The above positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and may preferably include a lithium-transition metal composite oxide comprising lithium and at least one transition metal selected from nickel, cobalt, manganese, and aluminum, and preferably a lithium-transition metal composite oxide comprising lithium and a transition metal selected from nickel, cobalt, and manganese. More preferably, the lithium transition metal composite oxide is a lithium-manganese oxide (e.g., LiMnO2, LiMn2O4, etc.), a lithium-cobalt oxide (e.g., LiCoO2, etc.), a lithium-nickel oxide (e.g., LiNiO2, etc.), a lithium-nickel-manganese oxide (e.g., LiNi 1-Y Mn Y O2(here, 0 <Y<1), LiMn 2-z Ni z O4 (wherein, 0<Z<2) etc.), lithium-nickel-cobalt oxides (e.g., LiNi 1-Y1 Co Y1 O2(here, 0 <Y1<1) 등), 리튬-망간-코발트계 산화물(예를 들면, LiCo 1-Y2 Mn Y2O2(here, 0 <Y2<1), LiMn 2-z1 Co z1 O4 (wherein, 0<Z1<2) etc.), lithium-nickel-manganese-cobalt oxides (e.g., Li(Ni p Co q Mn r1 )O2(where, 0<p<1, 0<q<1, 0<r1<1, p+q+r1=1) or Li(Ni p1 Co q1 Mn r2 )O4 (wherein, 0<p1<2, 0<q1<2, 0<r2<2, p1+q1+r2=2) etc.), or lithium-nickel-cobalt-transition metal (M) oxide (e.g., Li(Ni p2 Co q2 Mn r3 M S2 )O2(wherein, M is selected from the group consisting of Al, Fe, V, Cr, Ti, Ta, Mg and Mo, and p2, q2, r3 and s2 are atomic fractions of independent elements, 0<p2<1, 0<q2<1, 0<r3<1, 0<s2<1, p2+q2+r3+s2=1), etc.), and one or more compounds of these may be included. Among these, the lithium transition metal composite oxide may be LiCoO2, LiMnO2, LiNiO2, lithium nickel-manganese-cobalt oxide (for example, Li(Ni 0.6 Mn 0.2 Co 0.2 )O2, Li(Ni 0.5 Mn 0.3 Co 0.2 )O2, Li(Ni 0.7 Mn 0.15 Co 0.15 )O2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O2, etc.), or lithium nickel cobalt aluminum oxide (e.g., Li(Ni 0.8 Co 0.15 Al 0.05)O2, etc.), and considering the remarkable improvement effect according to the control of the type and content ratio of the constituent elements forming the lithium transition metal composite oxide, the lithium transition metal composite oxide may be Li(Ni 0.6 Mn 0.2 Co 0.2 )O2, Li(Ni 0.5 Mn 0.3 Co 0.2 )O2, Li(Ni 0.7 Mn 0.15 Co 0.15 )O2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O2, etc., and one or a mixture of two or more of these may be used. The above-mentioned positive electrode active material may be included in the positive electrode active material layer at 80 to 99 wt%, preferably 92 to 98.5 wt%, taking into account sufficient capacity of the positive electrode active material. The above-described positive electrode active material layer may further include a binder and / or a conductive material together with the above-described positive electrode active material. The above binder is a component that assists in the binding of the active material and the conductive material and the binding to the current collector, and preferably includes at least one selected from the group consisting of polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, and fluororubber, and preferably includes polyvinylidene fluoride. The above binder may be included in the positive electrode active material layer at 1 to 20 wt%, preferably 1.2 to 10 wt%, in order to sufficiently secure binding force between components such as the positive electrode active material. The conductive material can be used to assist and improve conductivity in a lithium secondary battery, and is not particularly limited as long as it has conductivity without causing a chemical change. Preferably, the conductive material may include at least one selected from the group consisting of graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, paneth black, lamp black, thermal black; conductive fibers such as carbon fibers or metal fibers; conductive tubes such as carbon nanotubes; fluorocarbon; metal powder such as aluminum or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and polyphenylene derivatives, and preferably, the conductive material may include carbon black in terms of improving conductivity. The above-mentioned conductive agent may be included in the positive electrode active material layer at 1 wt% to 20 wt%, preferably 1.2 wt% to 10 wt%, in order to sufficiently secure electrical conductivity. The thickness of the above positive electrode active material layer may be 30 ㎛ to 400 ㎛, preferably 50 ㎛ to 110 ㎛. The above positive electrode can be manufactured by coating a positive electrode slurry including a positive electrode active material and optionally a binder, a conductive material, and a solvent for forming a positive electrode slurry on the positive electrode current collector, and then drying and rolling. The solvent for forming the positive electrode slurry may include an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that provides a desirable viscosity when including the positive electrode active material, and optionally a binder and a conductive material. For example, the solvent for forming the positive electrode slurry may be included in the positive electrode slurry such that the concentration of the solid content including the positive electrode active material, and optionally a binder and a conductive material is 50 wt% to 95 wt%, preferably 70 wt% to 90 wt%. (Separator) The above separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move. If it is a separator commonly used in lithium secondary batteries, it can be used without special restrictions, and in particular, it is preferable that it has low resistance to ion movement of the electrolyte and excellent electrolyte moisture retention capacity. Preferably, a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, and an ethylene / methacrylate copolymer, or a laminated structure of two or more layers thereof, can be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc. may be used. In addition, a coated separator containing a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure. (electrolyte) In addition, the electrolyte used in the present invention may include, but is not limited to, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, a molten inorganic electrolyte, etc. that can be used in the manufacture of a lithium secondary battery. Preferably, the electrolyte may include an organic solvent and a lithium salt. As the organic solvent, any solvent that can act as a medium through which ions involved in the electrochemical reaction of the battery can move may be used without particular limitation. Preferably, the organic solvent includes ester solvents such as methyl acetate, ethyl acetate, gamma-butyrolactone, and ε-caprolactone; ether solvents such as dibutyl ether or tetrahydrofuran; ketone solvents such as cyclohexanone; aromatic hydrocarbon solvents such as benzene and fluorobenzene; carbonate solvents such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); alcohol solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (R is a C2 to C20 linear, branched, or cyclic hydrocarbon group, which may include a double-bonded aromatic ring or an ether bond); Amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes can be used. Among these, a carbonate solvent is preferable, and a mixture of a cyclic carbonate (e.g., ethylene carbonate or propylene carbonate) having high ionic conductivity and high dielectric constant, which can improve the charge / discharge performance of the battery, and a low-viscosity linear carbonate compound (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate) is more preferable. In this case, when the cyclic carbonate and the chain carbonate are mixed and used in a volume ratio of about 1:1 to about 1:9, the performance of the electrolyte can be excellent. The lithium salt may be used without any particular limitation as long as it is a compound capable of providing lithium ions used in a lithium secondary battery. Preferably, the lithium salt may be LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiCl, LiI, or LiB(C2O4)2. It is preferable to use the concentration of the lithium salt within the range of 0.1 to 2.0 M. When the concentration of the lithium salt is within the above range, the electrolyte can exhibit excellent electrolyte performance because it has appropriate conductivity and viscosity, and lithium ions can move effectively. The above lithium secondary battery can be manufactured by injecting an electrolyte after interposing a separator between the negative electrode and positive electrode described above according to a conventional lithium secondary battery manufacturing method. There is no particular limitation on the external shape of the lithium secondary battery according to the present invention, but it may be in the shape of a cylinder, a square, a pouch, or a coin using a can. In addition, since the lithium secondary battery according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, it is useful in portable devices such as mobile phones, notebook computers, and digital cameras, and electric vehicles such as hybrid electric vehicles (HEVs). Accordingly, according to another embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided. The above battery module or battery pack can be used as a power source for one or more medium- to large-sized devices, including power tools; electric vehicles including electric vehicles (EVs), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEVs); or power storage systems. Hereinafter, the present invention will be described in more detail through specific examples. However, the following examples are merely examples to help understand the present invention and do not limit the scope of the present invention. It will be obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present description, and it is natural that such changes and modifications fall within the scope of the appended patent claims. Examples and Comparative Examples Example 1: Preparation of cathode A first slurry was prepared by adding negative active material (artificial graphite), conductive material (carbon black), and binder (SBR-CMC) in a ratio of 96 wt%: 1.5 wt%: 2.5 wt% to a solvent (distilled water). A negative active material (artificial graphite), a conductive agent (carbon black), and a binder (SBR-CMC) were each added to a solvent (distilled water) at a ratio of 96 wt%: 1.5 wt%: 2.5 wt%, and 0.2 wt% of vinylene carbonate (VC) was added based on the total weight of the solids (negative active material, conductive agent, and binder) to prepare a second slurry. At this time, the solids content of the first slurry was 55 wt%, and the solids content of the second slurry was 15 wt%. In a printing device having nine nozzles, the first slurry was injected into nozzles 1, 3, 5, 7, and 9, and the second slurry was injected into nozzles 2, 4, 6, and 8, and then the first slurry and the second slurry were applied to one surface of a negative current collector (copper, 15 μm) along the collector longitudinal direction (MD) so as to form a line-shaped pattern groove. After that, drying and roll pressing were performed to manufacture the cathode. Example 2: Preparation of cathode A negative electrode was manufactured in the same manner as in Example 1, except that the vinylene carbonate (VC) was included in an amount of 0.5 wt% based on the total weight of the solid content in the second slurry. Example 3: Preparation of cathode A negative electrode was manufactured in the same manner as in Example 1, except that the vinylene carbonate (VC) was included in an amount of 1.0 wt% based on the total weight of the solid content in the second slurry. Comparative Example 1: Manufacturing of cathode A first slurry was prepared by adding negative active material (artificial graphite), conductive material (carbon black), and binder (SBR-CMC) in a ratio of 96 wt%: 1.5 wt%: 2.5 wt% to a solvent (distilled water). At this time, the solid content of the first slurry was 55 wt%. After applying the above first slurry to one side of a negative electrode collector (copper, 15 μm), drying and roll pressing were performed to manufacture a negative electrode. Comparative Example 2: Manufacturing of cathode A negative electrode was prepared in the same manner as in Example 1, except that vinylene carbonate (VC) was not included. Comparative Example 3: Manufacturing of cathode A negative electrode was manufactured in the same manner as in Comparative Example 1, except that 0.2 wt% of vinylene carbonate (VC) was applied based on the total weight of the solid components (negative active material, conductive agent, and binder) on the first slurry. Comparative Example 4: Manufacturing of cathode A negative electrode was manufactured in the same manner as in Example 1, except that the solid content of the first slurry was 55 wt% and the solid content of the second slurry was 50 wt%. Comparative Example 5: Manufacturing of cathode An attempt was made to manufacture a negative electrode in the same manner as in Example 1, except that the solid content of the first slurry was 85 wt% and the solid content of the second slurry was 15 wt%. At this time, the difference in solid content between the first slurry and the second slurry was excessive, so the first slurry was not discharged from the nozzle, making it impossible to manufacture the cathode. First slurrySecond slurryLine-like patternHome formationSolid content (weight %)VC content (weight %)Solid content (weight %)VC content (weight %)Example 1550.0150.2OExample 2550.0150.5OExample 3550.0151.0OComparative Example 1550.0--XComparative Example 2550.0150.0OComparative Example 3550.2--XComparative Example 4550.0500.2OComparative Example 5850.0150.2- Pattern groove average width (㎛)Pattern groove average spacing (㎛)Pattern groove average depth (㎛)Example 17520045Example 27520045Example 37520045Comparative example 1---Comparative example 27520045Comparative example 3---Comparative example 4352205Comparative example 5--- Experimental Example 1: Rapid charging performance evaluation (Lithium secondary battery manufacturing) An electrode assembly was manufactured by interposing a porous separator (polyethylene (PE)) between each of the negative electrodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 5 and the positive electrode as described below, and then positioning this inside a case, and then injecting an electrolyte to manufacture lithium secondary batteries. At this time, the positive electrode is Li as the positive electrode active material. 1.0 [Ni 0.8 Co 0.1 Mn 0.1 ]O2 as a conductive agent, carbon nanotubes (CNTs) as a binder, and polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 97:1.5:1.5 in an N-methylpyrrolidone (NMP) solvent to prepare a composition for forming a cathode, which was then applied to one surface of an aluminum current collector, dried at 60°C, and then rolled to produce the composition. The above electrolyte was prepared by dissolving LiPF61M and vinylene carbonate (VC) in an organic solvent having a volume ratio of 30:70 (ethylene carbonate (EC) / ethyl methyl carbonate (EMC)) at 2 wt% based on the total weight of the organic solvent. (Measuring fast charging time) For the above-mentioned manufactured lithium secondary batteries, the time required to charge them to 80% SOC (State Of Charge) using an electrochemical charger / discharger was measured to evaluate the rapid charging characteristics. Specifically, the lithium secondary batteries were subjected to an activation process, and then charged at a constant current / constant voltage (CC / CV) of 3C at 25°C to 4.2 V (0.05C cut-off) to reach a SOC (State Of Charge) of 80%. The time required to charge was measured, and the charging time for each lithium secondary battery was expressed as a percentage based on the lithium secondary battery including the negative electrode manufactured in Comparative Example 1 in [Table 3] below. Experimental Example 2: Evaluation of High Temperature Storage Characteristics The high-temperature storage characteristics were evaluated for each of the lithium secondary batteries manufactured in Experimental Example 1 above. Specifically, the lithium secondary batteries were charged to 4.2 V at a constant current / constant voltage (CC / CV) at a 0.33 C rate at 25°C (0.05 C cut-off) so that the SOC (State of Charge) reached 100%, and then stored at 60°C for 8 weeks. Before preservation, the capacity of the fully charged lithium secondary battery was measured and set as the capacity of the initial lithium secondary battery. After 8 weeks, the capacity retention rate was measured for the preserved lithium secondary batteries compared to the initial capacity before preservation. The capacity retention rate after 8 weeks was derived by calculating the percentage ratio of the capacity of the lithium secondary battery after preservation to the capacity of the initial lithium secondary battery. The results are shown in [Table 3] below. Experimental Example 3: Evaluation of Gas Generation Amount The amount of gas generation was evaluated for each lithium secondary battery manufactured in Experimental Example 1 above. Specifically, the lithium secondary batteries were subjected to an activation process, and then charged at 25°C at a constant current / constant voltage (CC / CV) to 4.2 V at a 0.33 C rate (0.05 C cut-off), and discharged at a constant current (CC) to 2.5 V at a 0.33 C rate for 1 cycle. The same charge / discharge was repeated 300 cycles to measure the amount of gas generated. The above gas generation amount was analyzed using a GC-TCD (gas chromatography-thermal conductivity detector) for the gas captured in the pouch after 300 cycles, and when the gas generation amount measured in Comparative Example 1 was set as 100%, the relative gas generation amount of each battery was calculated and shown in [Table 3]. Rapid charging time (%) Capacity retention rate during high temperature storage (%) Gas generation (%) Example 172.588.184.1 Example 274.391.781.8 Example 375.792.078.6 Comparative example 110092.2100 Comparative example 272.185.7102.4 Comparative example 3110.292.492.6 Comparative example 495.891.791.2 Comparative example 5--- Referring to Table 3 above, it can be seen that Examples 1 to 3 have a superior rapid charging time than Comparative Examples 1, 3, and 4, and a superior capacity retention rate during high-temperature storage than Comparative Example 2. Additionally, in the case of Examples 1 to 3, it can be confirmed that the amount of gas generated is significantly reduced compared to Comparative Examples 1 to 4. [Explanation of symbols] 10: Negative active material layer 11: Solid electrolyte membrane precursor layer 20: SEI film 30: Whole house 41: Average width of line-shaped pattern home 42: Average spacing of line-shaped pattern grooves 43: Average depth of line-shaped pattern home 101: 1st slurry 102: Second slurry 110: Solid content in first slurry and second slurry 111: Solid electrolyte membrane precursor 400: Nozzle 400a: Nozzle 1 400b: 2nd nozzle 400c: 3rd nozzle 400d: 4th nozzle 400e: 5th nozzle MD: Lengthwise direction of the entire house TD: Width direction of the entire house

Claims

1. A current collector; a negative electrode active material layer disposed on the current collector; and a solid electrolyte film precursor layer disposed on the negative electrode active material layer; An anode, wherein the negative electrode active material layer has two or more line-shaped pattern grooves formed in the longitudinal direction of the current collector, and the solid electrolyte membrane precursor layer is arranged so as to maintain the shape of the pattern grooves of the negative electrode active material layer.

2. In claim 1, A cathode, wherein the average width of the line-shaped pattern groove is 0.01 ㎛ to 500 ㎛.

3. In claim 1, A cathode, wherein the average depth of the line-shaped pattern groove is 0.01㎛ or more.

4. In claim 1, A cathode, wherein the average spacing of the above line-shaped pattern grooves is 10 ㎛ to 500 ㎛.

5. In claim 1, A cathode, wherein the solid electrolyte membrane precursor layer comprises a carbonate compound.

6. In claim 1, A cathode, wherein the solid electrolyte membrane precursor layer comprises at least one selected from the group consisting of vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and fluoro ethylene carbonate (FEC).

7. In claim 1, A cathode, wherein the solid electrolyte membrane precursor layer comprises vinylene carbonate (VC).

8. A step of applying a first slurry containing a negative electrode active material, a conductive material, and a binder on a current collector, and a second slurry containing a negative electrode active material, a conductive material, a binder, and a solid electrolyte membrane precursor; and A step of drying the first slurry and the second slurry applied on the entire body; The above application is performed by nozzle printing using a printing device with two or more nozzles. A method for manufacturing a cathode, wherein the difference in solid content between the first slurry and the second slurry is 10 wt% to 70 wt%.

9. In claim 8, A method for manufacturing a cathode, wherein the solid content of the first slurry is 40 wt% to 80 wt%.

10. In claim 8, A method for manufacturing a cathode, wherein the solid content of the second slurry is 10 wt% to 30 wt%.

11. In claim 8, The above solid electrolyte membrane precursor comprises a carbonate compound, A method for manufacturing a cathode, wherein the solid electrolyte membrane precursor is included in an amount of 0.1 wt% to 5.0 wt% based on the total weight of solid content in the second slurry.

12. In claim 8, The above solid electrolyte membrane precursor comprises a carbonate compound, A method for manufacturing a cathode, wherein the solid electrolyte membrane precursor is included in an amount of 0.2 wt% to 2.0 wt% based on the total weight of solid content in the second slurry.

13. The cathode of claim 1; anode; A separator interposed between the positive and negative electrodes; and A lithium secondary battery comprising an electrolyte.

Images