Dam slurry for electrodes, electrodes using the same, and methods for manufacturing electrodes

Abstract

The present invention relates to an electrode dam slurry containing a hydrophobic additive, wherein the electrode dam slurry allows for control of the electrode sliding shape and suppression of fat edge formation.

Description

[Technical Field]

[0001] This application claims priority under Korean Patent Application No. 10-2023-0142321 dated October 23, 2023, and all content disclosed in the documents of said Korean Patent Application is incorporated herein as part of this specification.

[0002] This invention relates to a dam slurry for electrodes, an electrode for a secondary battery using the same, and a method for manufacturing the electrode using the same. [Background technology]

[0003] As technological development and demand for mobile devices increase, the demand for rechargeable batteries as an energy source is rapidly rising, and consequently, much research is being conducted on batteries that can meet diverse requirements.

[0004] One of the main challenges in such secondary batteries is improving safety. The main cause of battery safety-related accidents is the arrival of abnormal high temperatures due to short circuits between the positive and negative electrodes. That is, under normal conditions, a separator membrane is located between the positive and negative electrodes to maintain electrical insulation, but under abnormal conditions such as overcharging or over-discharging of the battery, or dendritic growth of the electrode material, the existing separator membrane shows its limitations. Various methods have been attempted to reduce the possibility of short circuits of the electrodes under such external shocks or high-temperature conditions. For example, methods have been proposed to attach insulating tape to the boundary region between the plain and textured parts of the electrode, or to form an insulating layer by insulating liquid coating.

[0005] However, research into forming insulating layers on electrodes has primarily focused on the positive electrode. Therefore, technological development is needed to improve the safety of the negative electrode. [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the object of the present invention is to provide a dam slurry that is applicable as an insulating layer for electrodes while having excellent processability, an electrode for a secondary battery using the same, and a method for manufacturing the electrode. [Means for solving the problem]

[0007] To solve the above-mentioned problems, an electrode dam slurry according to one embodiment of the present invention comprises inorganic particles, a binder, a hydrophobic additive, and an aqueous solvent. The hydrophobic additive has a specific surface area (BET) of 500 m². 2 The particles are in particulate form, with a concentration of 1g or more. Furthermore, the content of the hydrophobic additive is in the range of 0.03 to 35 parts by weight, based on 100 parts by weight of the total solid content.

[0008] In a specific embodiment, the dam slurry contains 60 to 90 parts by weight of inorganic particles, 5 to 20 parts by weight of a binder, and 0.03 to 35 parts by weight of a hydrophobic additive, based on 100 parts by weight of total solid content.

[0009] In one embodiment, the hydrophobic additive has a specific surface area (BET) of 700 m². 2 / g~3,000m 2 It is within the range of / g. In a specific embodiment, the hydrophobic additive is a carbon-based additive. For example, the carbon-based additive is activated carbon.

[0010] In a specific embodiment, the carbon-based additive has a specific surface area of ​​700 m². 2 / g~1500m 2 A first additive in the range of / g, and a specific surface area of ​​1,500m 2 / g~3,000m 2 It contains one or more second additives within the range of / g. For example, the first additive may be large-diameter activated carbon, and the second additive may be relatively small-diameter activated carbon.

[0011] In one embodiment, the binder is an aqueous binder, and may be in the form of one type or a mixture of two or more types. For example, the binder includes carboxymethyl cellulose (CMC) and styrene butadiene rubber (SBR) binder in a weight ratio of 1:1 to 1:3.

[0012] In another embodiment, the inorganic particles are one or more selected from boehmite (AlOOH) and alumina (Al₂O₃). For example, the inorganic particles are boehmite.

[0013] In one embodiment, the dam slurry has a volume resistance of 1,000 Ω·cm or more. Specifically, the dam slurry has a volume resistance in the range of 1,000 Ω·cm to 5,000 Ω·cm and is substantially electrically insulating.

[0014] In another embodiment, the dam slurry has a surface tension of 70 mN / m or more. Specifically, the dam slurry has a surface tension in the range of 70 mN / m to 85 mN / m.

[0015] The present invention provides an electrode for a secondary battery to which the above-described dam slurry for an electrode is applied. The present invention also provides a secondary battery to which the above electrode is applied.

[0016] In one embodiment, the electrode for a secondary battery includes a current collector, an active material layer formed on one or both surfaces of the current collector, and a dam insulating layer formed on a side surface in the width direction of the active material layer. Specifically, the dam insulating layer includes inorganic particles, a binder, and a hydrophobic additive. The hydrophobic additive has a specific surface area (BET) of 500 m 2 / g or more and has a particulate shape. The content of the hydrophobic additive is in the range of 0.03 parts by weight to 35 parts by weight based on 100 parts by weight of the entire dam insulating layer.

[0017] In another embodiment, the electrode for a secondary battery according to the present invention satisfies the following Mathematical Formula 1.

[0018] [Mathematical Formula 1] 75≦(H edge / H ever )×100≦110

[0019] In the above Mathematical Formula 1, H ever represents the average height (mm) of the flat portion of the active material layer, H edge represents the maximum height (mm) observed at the edge portion of the active material layer.

[0020] In a specific example, the above electrode is a negative electrode.

[0021] The present invention also provides a method for producing an electrode using the dam slurry for electrode described above. In one embodiment, the method for producing an electrode according to the present invention comprises: an electrode coating step of discharging an electrode slurry and the dam slurry described above onto a current collector; and a step of drying the electrode coated with the electrode slurry and the dam slurry.

[0022] In a specific embodiment, in the electrode coating step, the electrode slurry is discharged onto the current collector to form a coated area. Further, the dam slurry is discharged onto a non-coated area where the electrode slurry is not discharged.

[0023] In another specific embodiment, the electrode coating step is performed by simultaneously discharging the electrode slurry and the dam slurry onto the current collector using a slot die. [Effects of the Invention]

[0024] The dam slurry for electrode according to the present invention enables control of electrode profile shape and suppression of fat edge occurrence. [Brief Description of the Drawings]

[0025] [Figure 1] It is a result showing the thickness profile of an electrode specimen according to one embodiment of the present invention. [Figure 2]This result shows the thickness profile of an electrode specimen according to one comparative example of the present invention. [Modes for carrying out the invention]

[0026] Since the present invention can be modified in various ways and has a variety of embodiments, specific embodiments will be described in detail in the detailed description.

[0027] However, this is not intended to limit the present invention to any particular embodiment, but rather should be understood to include all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0028] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof as described in the specification, and do not preemptively exclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Furthermore, in this invention, when a part such as a layer, film, region, or plate is described as being "on top" of another part, this includes not only the case where it is "directly above" the other part, but also the case where another part is located in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is located in between. Also, in this application, being "placed on top" may include being placed not only at the top but also at the bottom.

[0030] The present invention will be described in more detail below.

[0031] The present invention provides an electrode dam slurry containing a hydrophobic additive. In one embodiment, the electrode dam slurry according to the present invention comprises inorganic particles, a binder, a hydrophobic additive, and an aqueous solvent. The hydrophobic additive has the effect of increasing the surface tension of the electrode dam slurry and reducing the occurrence of fat edges. The hydrophobic additive has a measured specific surface area (BET) of 500 m². 2 The hydrophobic additive is in particulate form of 1g or more, and its content is in the range of 0.03 to 35 parts by weight, based on 100 parts by weight of the total solid content.

[0032] In this invention, by applying a hydrophobic additive, the viscosity, surface tension, and adhesive strength of the electrode dam slurry are increased, thereby minimizing the occurrence of fat edges.

[0033] In one embodiment, the dam slurry contains 60 to 90 parts by weight of inorganic particles, 5 to 20 parts by weight of a binder, and 0.03 to 35 parts by weight of a hydrophobic additive, based on 100 parts by weight of total solids. The content of the hydrophobic additive is in the range of 0.03 to 30 parts by weight, 0.05 to 20 parts by weight, 0.5 to 25 parts by weight, or 1 to 20 parts by weight. By controlling the content of the hydrophobic additive within the above range, surface tension can be improved while minimizing the fat edge phenomenon.

[0034] In one embodiment, the hydrophobic additive has a specific surface area (BET) of 700 m². 2 / g~3,000m 2 It is within the range of / g. For example, the specific surface area (BET) of the above hydrophobic additive is 950m². 2 / g~3,000m 2 Range of / g, 950m 2 / g~2,500m 2 Range of / g, 700m 2 / g~1,500m 2 Range of / g, or 1,500m 2 / g~3,000m 2 It is within the range of / g. If the specific surface area of ​​the above hydrophobic additive is lower than the above range, the fat edge reduction effect is insufficient.

[0035] In specific embodiments, the hydrophobic additive is a carbon-based additive. For example, the hydrophobic additive is formed from graphite, such as activated carbon. The activated carbon is composed of graphite and has a structure linked by carbon-carbon bonds, forming a porous structure. The activated carbon has a porous structure with a large specific surface area, and even a small amount can adsorb SBR binders and the like into the pores, thereby achieving high surface tension.

[0036] In one embodiment, the carbon-based additive has a specific surface area of ​​700 m². 2 / g~1500m 2 The first additive in the range of / g, and the specific surface area of ​​1500m 2 / g~3000m 2 It contains one or more of the second additives in the range of / g. Specifically, the first additive has a specific surface area of ​​700m 2 / g~1,500m 2 It is in the range of / g and the average particle size (D50) is in the range of 25μm to 60μm. For example, the first additive described above has a specific surface area of ​​1,000m². 2 / g~1,250m 2 It is within the range of / g, and the average particle size (D50) is in the range of 35μm to 45μm. In addition, the above second additive has a specific surface area of ​​1,500m². 2 / g~2,200m 2 It is within the range of / g, and the average particle size (D50) is in the range of 2μm to 10μm. For example, the second additive described above has a specific surface area of ​​1,600m². 2 / g~2,100m 2 It is within the range of / g, and the average particle size (D50) is in the range of 3μm to 6μm.

[0037] In the present invention, carbon-based additives can be used as hydrophobic additives, and various methods are possible for increasing the hydrophobicity of carbon-based additives. First, one method is to use activated carbon with a high specific surface area. Second, the hydrophobicity of activated carbon can be increased by heat treatment, for example, heat treatment at the 500°C level. In addition, the hydrophobicity of activated carbon can also be increased by acid or base treatment. The present invention includes any of the hydrophobic additives to which the above methods have been applied.

[0038] In one embodiment, the binder may be an aqueous binder. For example, the binder may be one or more selected from the group consisting of carboxymethylcellulose, styrene-butadiene rubber, acrylate-styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber, acrylic rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene propylene copolymer, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, hydroxypropyl methylcellulose, hydroxypropyl cellulose, and diacetylcellulose.

[0039] Specifically, the above binder contains one or more of carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR). For example, the above binder may have a composition containing carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) binder in a weight ratio of 1:1 to 1:3.

[0040] Furthermore, the inorganic particles may be one or more selected from the group consisting of AlOOH, Al2O3, γ-AlOOH, Al(OH)3, Mg(OH)2, Ti(OH)4, MgO, CaO, Cr2O3, MnO2, Fe2O3, Co3O4, NiO, ZrO2, BaTiO3, SnO2, CeO2, Y2O3, SiO2, silicon carbide (SIC), and boron nitride (BN). In a specific example, the inorganic particles may be one or more selected from the group consisting of AlOOH, Al2O3, γ-AlOOH, and Al(OH)3. For example, the inorganic particles may be one or more of boehmite (AlOOH) and alumina (Al2O3), or AlOOH.

[0041] The average particle size of the inorganic particles can be 0.1 μm to 100 μm, 0.5 μm to 80 μm, 1 μm to 50 μm, 2 μm to 30 μm, 3 μm to 20 μm, or 5 μm to 10 μm. In this invention, by providing a dam slurry containing inorganic particles, the insulating properties are enhanced and a more uniform insulating layer can be formed.

[0042] The solvent mentioned above can be an aqueous solvent; for example, the solvent is water (H2O).

[0043] In one embodiment, the dam slurry is substantially non-electrically conductive. For example, the dam slurry has a resistance of 1,000 Ω·cm or more, or in the range of 1,000 Ω·cm to 5,000 Ω·cm, based on the volume resistance of the powder.

[0044] In another embodiment, the dam slurry has a surface tension of 70 mN / m or more. The dam slurry according to the present invention has a high surface tension by containing an appropriate amount of hydrophobic additive. For example, the surface tension of the dam slurry is in the range of 70 mN / m to 100 mN / m or 70 mN / m to 75 mN / m.

[0045] Furthermore, the present invention provides an electrode for a secondary battery having a dam insulating layer formed using the above-described electrode dam slurry.

[0046] In one embodiment, the electrode for the secondary battery includes a current collector, an active material layer formed on one or both sides of the current collector, and a dam insulating layer formed on the widthwise side surface of the active material layer. Here, the dam insulating layer includes inorganic particles, a binder, and a hydrophobic additive. The hydrophobic additive has a specific surface area (BET) of 500 m². 2 The particles are in particulate form and exceed 1g / g. Furthermore, the content of the hydrophobic additive is in the range of 0.03 to 35 parts by weight, based on 100 parts by weight of the entire dam insulating layer. Specifically, the dam insulating layer can be applied as an insulating layer that insulates the boundary region between plain and textured areas, and as a dam that defines the width of the textured area.

[0047] In one embodiment, the electrode for a secondary battery according to the present invention satisfies the following formula 1.

[0048] [Formula 1] 75≦(H edge / H ever ) × 100 ≤ 110

[0049] In the above formula 1, H ever This represents the average height (mm) of the flat portion of the active material layer. H edge This represents the maximum height (mm) observed at the edge of the active material layer.

[0050] The value calculated by formula 1 above is 110 or less, specifically satisfying the ranges of 75-110, 80-110, 85-100, or 85-95. Through iterative and diverse experiments, the inventors have confirmed that the above numerical range can be controlled by adjusting the content and specific surface area of ​​the hydrophobic additive. For example, when the content of the hydrophobic additive is adjusted to 0.5 parts by weight or more, the value calculated by formula 1 above is controlled to the range of 85-100. To suppress the occurrence of fat edges in secondary battery electrodes, it is advantageous to control the value calculated by formula 1 above to 100 or less.

[0051] In the present invention, "flat portion of the active material layer" means the region in which the active material layer formed on the electrode current collector forms a flat surface, and more specifically, it means the region of the active material layer excluding the edge portion.

[0052] Furthermore, in this invention, the "edge portion of the active material layer" refers to the region located at the boundary between the textured portion and the untextured portion of the active material layer formed on the electrode current collector. For example, the edge portion of the active material layer refers to the region at the left and right ends where the thickness of the active material layer is reduced, with reference to the width direction of the active material, and means the portion coated with the dam insulating layer.

[0053] In another embodiment, the dam insulating layer has an average thickness (D ave ) is in the range of 10 μm to 100 μm. For example, the average thickness of the above dam insulating layer (D ave ) are in the range of 10 μm to 60 μm or 30 μm to 50 μm.

[0054] In one embodiment, the electrode is the negative electrode. Conventionally, techniques have been studied to form an insulating layer on the positive electrode to ensure the safety of the electrode. The present invention provides a negative electrode to which a dam insulating layer is applied, which simultaneously serves as such an insulating layer and also acts as a dam that defines the coating area of ​​the active material layer.

[0055] Furthermore, the present invention provides a method for manufacturing electrodes using the dam slurry described above. In one embodiment, the method for manufacturing electrodes according to the present invention includes an electrode coating step of discharging electrode slurry and dam slurry onto a current collector, and a step of drying the electrode coated with electrode slurry and dam slurry. The dam slurry is as described above.

[0056] The drying step described above can be carried out in an average temperature range of 50°C to 300°C. The drying step of the electrode slurry and dam slurry can be carried out by drying methods commonly known in the art, and will remove the solvent contained in the electrode slurry and dam slurry. In specific examples, the drying step can be applied by changing the method, such as hot air, direct heating, or induction heating, at a temperature at which all the solvent evaporates, and is not limited thereto. In this case, the drying temperature can be in the temperature range of 50°C to 300°C, in the range of 60°C to 200°C, or in the range of 70°C to 150°C. A rolling step may be further included after the drying step described above.

[0057] The electrode slurry is discharged and dried to form an active material layer, and the dam slurry is discharged and dried to form a dam insulating layer. In this invention, the region on the current collector where an active material layer is formed is called the surface area, and the region on the current collector where no active material layer is formed is called the surface area.

[0058] In one embodiment, the electrode coating step involves discharging electrode slurry onto the current collector to form a surface area, and the dam slurry is discharged onto the surface area where electrode slurry is not discharged. Specifically, the dam slurry is discharged onto the widthwise side surface of the area where electrode slurry has been discharged.

[0059] In one embodiment, the electrode coating step is performed by simultaneously discharging electrode slurry and dam slurry onto a current collector using a slot die. The electrode slurry is discharged via the slot die. The slot die includes a first block and a second block, and the electrode slurry is discharged through a slot located between the first block and the second block. A coating shim is placed in the slot located between the first block and the second block to control the discharge width of the electrode slurry. For example, the coating shim may have an electrode slurry discharge line formed thereon, with dam slurry discharge lines formed on the left and right sides of the electrode slurry discharge line.

[0060] The present invention will be described in more detail below with reference to examples and experimental examples. However, the following examples and experimental examples are illustrative of the present invention, and the content of the present invention is not limited to the following examples and experimental examples.

[0061] <Examples 1-18>

[0062] Dam slurry was prepared by mixing boehmite, CMC (carboxymethylcellulose), SBR (styrene-butadiene rubber, ZEON BM451B product), and a hydrophobic additive with water as the solvent. Activated carbon was used as the hydrophobic additive. The specific composition and content for each example are shown in Table 1 below.

[0063] The specific surface area of ​​the hydrophobic additive was measured using the BET (Branuer-Emmett-Teller) method, specifically calculated by the amount of nitrogen gas adsorbed using liquid nitrogen.

[0064] [Table 1]

[0065] Referring to Table 1, Examples 1-7 use large-particle activated carbon as the hydrophobic additive, while Examples 8-12 use relatively small-particle activated carbon. Furthermore, Examples 13-15 control the CMC content, and Examples 16-18 control the solid content.

[0066] <Comparative Examples 1-6>

[0067] Dam slurry was prepared by mixing boehmite, CMC (carboxymethylcellulose), SBR (styrene-butadiene rubber, ZEON BM451B product), and a hydrophobic additive with water as the solvent. Activated carbon was used as the hydrophobic additive. The specific composition and content for each example are shown in Table 1 below.

[0068] [Table 2]

[0069] Referring to Table 2, Comparative Examples 1 and 2 use C65 (carbon black) as a hydrophobic additive. Comparative Examples 3 and 4 do not use a hydrophobic additive, and Comparative Examples 5 and 6 use activated carbon as a hydrophobic additive, but with its content controlled to the 0.01 wt% level.

[0070] <Example of experiment>

[0071] Viscosity, surface tension, adhesion, fat edge, and powder resistance were measured for each manufactured electrode specimen. The measurement methods are as follows:

[0072] Evaluation of surface tension

[0073] - DCA-200 (Dynamic Contract Angle System, SEO Corporation) product was used as the surface tension measuring instrument.

[0074] - Motor speed:15 / Probe type:Ring / Immersion Depth:4 / Surface Detact Weight:0.005 / Stabilization Time:5

[0075] Evaluation of adhesive strength

[0076] - Evaluate the adhesive strength of electrode specimens cut to a size of 150 mm in length and 20 mm in width.

[0077] - Attach the electrode specimen with double-sided tape, with the coated side facing a 75mm long and 25mm wide glass slide.

[0078] - The sample is passed through a laminator (temperature unset, 9 speed settings) to ensure even adhesion of the double-sided tape, and the evaluation sample is prepared.

[0079] - The portion of the electrode specimen attached to the glass slide is fixed to the sample stage, while the remaining half of the electrode specimen that is not attached to the glass slide is connected to the load cell of the UTM instrument.

[0080] - The load cell was moved up to 50 mm while the load was measured under the conditions of a speed of 100 mN / min and a force of 90.

[0081] - The average value of the load measured in the 20mm to 40mm section of the running distance was calculated, and this was repeated a total of 5 times. The average value was then evaluated using the adhesive strength (gf / 20mm) of each electrode specimen.

[0082] Step height measurement and fat edge evaluation

[0083] - After keeping the electrode specimen flat, set the laser microscope camera magnification to 25x (×25) and focus to perform 3D measurement of the electrode.

[0084] - The thickness of the coated electrode active material layer (based on a flat surface), the thickness of the dam slurry, and the thickness (mm) of the edge between the electrode active material layer and the dam slurry were measured, with the zero point aligned to the thickness of the current collector foil.

[0085] - Fat edge is calculated as (edge ​​thickness) / (thickness of electrode active material layer) × 100

[0086] Measurement of powder volume resistance

[0087] - Place the powder to be measured into a cylinder with a diameter of 2 cm and a height of 5 cm.

[0088] - The input powder is pressurized from 200 kgf to 2,000 kgf.

[0089] - After measuring the electrical conductivity of the powder for every 200 kgf of pressure, it was converted to the powder's volume resistance.

[0090] - If the powder resistance value is 1000 Ω·cm or higher, it will be labeled as having no conductivity.

[0091] [Table 3]

[0092] Referring to Table 3, the electrode specimens of Examples 1 to 18 had a surface tension of 70 (mN / m) or higher and an adhesive strength of 130 (gf / 20mm) or higher. Furthermore, it was confirmed that the calculated fat edge did not exceed 10⁶.

[0093] Specifically, Examples 1-7 use large-particle activated carbon as the hydrophobic additive, while Examples 8-12 use small-particle activated carbon as the hydrophobic additive. Compared in particular to Example 8, Example 6 has relatively lower surface tension but superior adhesive strength, and the fat edge is at a comparable level.

[0094] Furthermore, it was confirmed that the electrode specimens of Examples 1 to 5 exhibited superior overall performance. The electrode specimens of Examples 1 to 5 contained hydrophobic additives in the range of 0.5 wt% to 20 wt%.

[0095] Figure 1 below shows the measurement results of the thickness profile of the electrode specimen according to Example 11. Referring to Figure 1, the fat edge is ((0.174 / 0.179) × 100).

[0096] [Table 4]

[0097] Referring to Table 4, it can be seen that the specimens of Comparative Examples 1-6 had a surface tension less than 69 (mN / m) and an adhesive strength not exceeding 150 (gf / 20mm). In particular, the calculated fat edge value was confirmed to be 117 or higher.

[0098] Figure 2 below shows the measurement results of the thickness profile of the electrode specimen related to Comparative Example 6. Referring to Figure 2, the fat edge is 117 ((0.200 / 0.171) × 100).

Claims

1. It comprises inorganic particles, a binder, a hydrophobic additive, and an aqueous solvent. The hydrophobic additive has a specific surface area (BET) of 500 m². ２ The particulate shape is greater than / g, An electrode dam slurry wherein the content of the hydrophobic additive is in the range of 0.03 parts by weight to 35 parts by weight, based on 100 parts by weight of the total solid content.

2. The electrode dam slurry is based on a total solid content of 100 parts by weight, 60 parts by weight to 90 parts by weight of inorganic particles, Binder 5 to 20 parts by weight, and The electrode dam slurry according to claim 1, comprising 0.03 to 35 parts by weight of a hydrophobic additive.

3. The specific surface area (BET) of the hydrophobic additive is 700 m². ２ / g to 3,000m ２ An electrode dam slurry according to claim 1, which is in the range of / g.

4. The electrode dam slurry according to claim 1, wherein the hydrophobic additive is a carbon-based additive.

5. The carbon-based additive is Specific surface area (BET) of 700 m ２ / g to 1500m ２ A first additive in the range of / g, Specific surface area (BET) of 1,500 m ２ / g to 3,000m ２ The electrode dam slurry according to claim 4, comprising one or more of a second additive in the range of / g.

6. The electrode dam slurry according to claim 1, wherein the binder comprises carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) binder in a weight ratio of 1:1 to 1:

3.

7. The inorganic particles are one or more of boehmite (AlOOH) and alumina (Al ２ O ３ ), the dam slurry for an electrode according to claim 1.

8. The electrode dam slurry according to claim 1, wherein the powder resistance of the electrode dam slurry is 1,000 Ω·cm or more.

9. The electrode dam slurry according to claim 1, wherein the surface tension of the electrode dam slurry is 70 mN / m or more.

10. Current collector, An active material layer formed on one or both sides of the current collector, and The active material layer includes a dam insulating layer formed on the widthwise side surface of the active material layer, The dam insulating layer comprises inorganic particles, a binder, and a hydrophobic additive. The hydrophobic additive has a specific surface area (BET) of 500 m². ２ The particulate shape is greater than / g, The content of the hydrophobic additive is in the range of 0.03 parts by weight to 35 parts by weight, based on 100 parts by weight of the entire dam insulating layer, for a secondary battery electrode.

11. The following equation 1 is satisfied, [Formula 1] 75≦(H ｅｄｇｅ / H ｅｖｅｒ )×100≦110 In the above formula 1, H ｅｖｅｒ This represents the average height (mm) of the flat portion of the active material layer. H ｅｄｇｅ The electrode for a secondary battery according to claim 10, wherein represents the maximum height (mm) observed at the edge of the active material layer.

12. The secondary battery electrode according to claim 10, wherein the electrode for the secondary battery is a negative electrode.

13. An electrode coating step of discharging an electrode slurry and the dam slurry described in claim 1 onto a current collector, A method for manufacturing an electrode, comprising the steps of drying an electrode coated with an electrode slurry and a dam slurry.

14. In the electrode coating step, An electrode slurry is discharged onto the current collector to form a textured area. The method for manufacturing an electrode according to claim 13, wherein the dam slurry is discharged onto a plain area where electrode slurry is not discharged.

15. The electrode manufacturing method according to claim 13, wherein the electrode coating step is performed by simultaneously discharging an electrode slurry and a dam slurry onto a current collector using a slot die.

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