Composition for coating uncoated portion of battery, method for coating uncoated portion of battery by using same, and electrode comprising composition for coating uncoated portion of battery

Abstract

The present invention relates to a composition for coating an uncoated portion of a battery, a method for coating an uncoated portion of a battery by using the composition for coating an uncoated portion of a battery, and an electrode comprising the composition for coating an uncoated portion of a battery. More particularly, the present invention relates to: a composition for coating an uncoated portion of a battery, having excellent heat resistance, excellent electrolyte stability, and excellent adhesive strength between an uncoated portion coating layer and an uncoated portion, thus enabling a stable coating layer to be formed; a method for coating an uncoated portion of a battery; and an electrode having an uncoated portion that has been coated.

Description

Composition for coating the non-conductive part of a battery, method for coating the non-conductive part of a battery using the same, and electrode comprising the composition for coating the non-conductive part of a battery

[0001] The present invention relates to a composition for coating the non-conductive part of a battery, a method for coating the non-conductive part of a battery using the composition for coating the non-conductive part of the battery, and an electrode comprising the composition for coating the non-conductive part of the battery. More specifically, the present invention relates to a composition for coating the non-conductive part of a battery having excellent heat resistance, preventing the occurrence of short circuits, and having electrolyte resistance.

[0002] Lithium secondary batteries have high energy density and are widely used in the electrical, electronic, communications, and computer industries. Their application areas are expanding from small lithium secondary batteries for portable electronic devices to high-capacity secondary batteries for hybrid and electric vehicles.

[0003] As applications expand, interest in the development of lithium secondary batteries is also growing. In particular, technologies are becoming increasingly integrated and sophisticated to improve the energy density of lithium secondary batteries.

[0004] In order to improve the lifespan and performance of secondary batteries, the cells within the battery must be stacked thinly and densely. However, when the battery is used for a long period of time at high output, there is a problem that internal short circuits or voids occur due to overcharge and discharge, or the stability of the battery is reduced due to dendritic growth.

[0005] Although the cathode and anode within the battery are physically insulated by a separator, the separator alone has limitations in ensuring battery stability, as a short circuit between the cathode and anode due to internal or external physical or chemical forces can cause overheating and explosion. In particular, a separator exposed to temperatures above approximately 130°C after a short circuit occurs can experience thermal shrinkage, and if the short circuit area expands, thermal runaway can occur.

[0006] While there are methods to improve heat resistance by applying a ceramic coating to a separator made of polyolefin, which has poor heat resistance, this method alone has limitations. Therefore, applying an insulating coating to the non-coated area of ​​the positive electrode plate, i.e., the uncoated area, was devised as a method to improve heat resistance.

[0007] The conventional method of applying a non-conductive insulating coating is to generally wind with insulating tape. However, the method of winding with insulating tape is complicated and has the problem of increasing the thickness of the battery. Therefore, research is needed on a composition that can form a stable coating layer.

[0008] [Prior Art Literature]

[0009] [Patent Document]

[0010] (Patent Document 1) Republic of Korea Patent No. 10-0982003

[0011] The present invention aims to provide a composition for coating the non-coated portion of a battery, which has excellent adhesion between the non-coated portion coating layer and the non-coated portion of an electrode, thereby forming a coating layer stably, has excellent heat resistance, and has excellent electrolyte stability by using a polymer that does not dissolve or swell in an electrolyte, a method for coating the non-coated portion of a battery using the composition, and an electrode including the composition for coating the non-coated portion of a battery.

[0012] However, the problems that the present invention seeks to solve are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0013] One aspect of our foundation is,

[0014] polymer;

[0015] inorganic particles; and

[0016] solvent; containing,

[0017] A composition for coating a non-conductive part of a battery is provided.

[0018]

[0019] Another aspect of the original is,

[0020] A step of coating a non-conductive coating composition of the above battery on the non-conductive part; including;

[0021] A method for coating a non-conductive part of a battery is provided.

[0022]

[0023] Another aspect of our company is,

[0024] Including a non-conductive coating layer including a composition for non-conductive coating of the above battery,

[0025] Provides electrodes.

[0026] As described above, the composition for coating the non-conductive portion of the battery of the present invention has excellent adhesion between the non-conductive portion coating layer and the non-conductive portion of the electrode, so that the coating layer can be stably formed.

[0027] In addition, since the composition for coating the non-conductive part of the battery of the present invention has excellent heat resistance and excellent electrolyte stability, an electrode coated on the non-conductive part using the composition for coating the non-conductive part of the battery of the present invention can effectively prevent the occurrence of a short circuit and improve the stability of the battery.

[0028] 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 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 to explain his or her own invention in the best way.

[0029] Accordingly, the configuration of the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical ideas of the present invention, so it should be understood that various equivalents and modified examples that can replace them may exist at the time of filing this application.

[0030] In this specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise," "include," or "have" should be understood to indicate the presence of a feature, number, step, component, or combination thereof, but not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0031] When various parameters are given in this specification as a range, a preferred range, or an enumeration of preferred upper and preferred lower values, it should be understood that this specifically discloses any range formed by any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether the ranges are separately disclosed.

[0032] When a range of numerical values ​​is mentioned herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range. The scope of the present invention is not intended to be limited to the specific values ​​mentioned when defining the range.

[0033] In this specification, “a to b” and “a~b” indicating a numerical range are defined as “a to” and “~” as ≥ a and ≤ b.

[0034]

[0035] A composition for coating the non-conductive portion of a battery according to one aspect of the present invention may include a polymer, inorganic particles, and a solvent.

[0036] The above-mentioned uncoated region refers to a portion of the electrode where the electrode active material is not coated. When coating the uncoated region of a battery using the composition for coating the uncoated region of the battery, an insulating film is formed at the boundary where the negative electrode and positive electrode face each other, thereby reducing the occurrence of short circuits due to physical contact between the positive and negative electrodes. In addition, the composition for coating the uncoated region of the battery includes a polymer with high electrolyte stability, thereby forming a stable insulating coating layer, thereby improving the stability of the battery.

[0037]

[0038] In one embodiment, the glass transition temperature (Tg) of the polymer may be 0°C or more and 230°C or less.

[0039]

[0040] *For example, the glass transition temperature (Tg) of the polymer may be 0°C or more, 4°C or less, 4°C or more, 15°C or less, 15°C or more, 25°C or less, 25°C or more, 35°C or less, 35°C or more, 45°C or less, 45°C or more, 55°C or less, 55°C or more, 75°C or less, 75°C or more, 95°C or less, 95°C or more, 115°C or less, 115°C or more, 135°C or less, 135°C or more, 155°C or less, 155°C or more, 175°C or less, 175°C or more, 195°C or less, 195°C or more, 210°C or less, or 210°C or more, 230°C or less.

[0041]

[0042] In one embodiment, the electrolyte swelling degree of the polymer at room temperature may be 30% or less.

[0043] For example, the electrolyte swelling degree of the polymer impregnated in an electrolyte at 25°C for 7 days may be 30% or less, 25% or less, 20% or less, or 15% or less. That is, the polymer of the present disclosure has excellent stability in an electrolyte even when impregnated in an electrolyte for a long period of time.

[0044] Additionally, the electrolyte swelling degree of the polymer impregnated in an electrolyte at 80°C for 2 hours may be, for example, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, or 5% or less.

[0045]

[0046] In one embodiment, the polymer may include an acrylamide copolymer, a styrene-butadiene rubber, an acrylate polymer, an acrylate copolymer, a methacrylate polymer, a methacrylate copolymer, an acrylic acid polymer, an acrylic acid copolymer, a vinyl alcohol polymer, a styrene polymer, or a combination thereof.

[0047] The acrylate polymer may be, for example, an acrylate homopolymer or an acrylate copolymer, the methacrylate polymer may be, for example, a methacrylate homopolymer or a methacrylate copolymer, and the acrylic acid polymer may be, for example, an acrylic acid homopolymer or an acrylic acid copolymer.

[0048] Acrylamide copolymers have strong hydrophilic functional groups (such as nitrile groups) and thus have low affinity for electrolytes, thereby satisfying the electrolyte swelling range of the present disclosure. Styrene-butadiene rubber has solvent resistance and is cross-linked, thereby satisfying the electrolyte swelling range of the present disclosure.

[0049] That is, when the above polymer is used, a composition for coating the non-conductive part of a battery having excellent stability in an electrolyte solution due to a low electrolyte swelling degree can be prepared.

[0050]

[0051] In one embodiment, the acrylamide copolymer may include a monomer unit of the acrylamide series and a monomer unit of the vinylpyrrolidone series, and the ratio of the number of moles of the monomer unit of the acrylamide series to the number of moles of the monomer unit of the vinylpyrrolidone series (number of moles of the monomer unit of the acrylamide series / number of moles of the monomer unit of the vinylpyrrolidone series) may be 1 or more and 3.5 or less.

[0052] For example, the ratio of the number of moles of the monomer unit of the acrylamide series to the number of moles of the monomer unit of the vinylpyrrolidone series (number of moles of the monomer unit of the acrylamide series / number of moles of the monomer unit of the vinylpyrrolidone series) may be 1.5 or more and 3.5 or less, 1.5 or more and 3.0 or less, 2.0 or more and 3.0 or less, or 2.0 or more and 2.5 or less.

[0053] If the ratio of the number of moles of the acrylamide series monomer unit to the number of moles of the vinylpyrrolidone series monomer unit (number of moles of acrylamide series monomer / number of moles of vinylpyrrolidone series monomer) falls below the range of the present disclosure, the adhesive strength with the substrate may be reduced, and if it exceeds the range of the present disclosure, the stability of the composition for coating the non-conductive part of the battery may be reduced.

[0054]

[0055] In one embodiment, the polymer may include the acrylamide copolymer and the styrene-butadiene rubber, and a ratio of the weight of the acrylamide copolymer to the weight of the styrene-butadiene rubber (weight of the acrylamide copolymer / weight of the styrene-butadiene rubber) may be 1 or more and 10 or less.

[0056] For example, the ratio of the weight of the acrylamide copolymer to the weight of the styrene-butadiene rubber (weight of acrylamide copolymer / weight of styrene-butadiene rubber) may be 1 or more and 9.5 or less, 1.5 or more and 9 or less, 2 or more and 8 or less, 2 or more and 7 or less, 2 or more and 6 or less, 2 or more and 5 or less, 2.5 or more and 5 or less, or 3 or more and 5 or less.

[0057] If the ratio of the weight of the acrylamide copolymer to the weight of the styrene-butadiene rubber (weight of acrylamide copolymer / weight of styrene-butadiene rubber) falls below the range of the present invention, the cohesive force with the inorganic particles may decrease, and if it exceeds the range of the present invention, the adhesive force with the substrate surface may decrease.

[0058]

[0059] In one embodiment, the polymer may include the acrylamide copolymer and the acrylate polymer, and the ratio of the weight of the acrylamide copolymer to the weight of the acrylate polymer (weight of the acrylamide copolymer / weight of the acrylate polymer) may be 2 or more and 6 or less.

[0060] For example, the ratio of the weight of the acrylamide copolymer to the weight of the acrylate polymer (weight of acrylamide copolymer / weight of acrylate polymer) can be 2.5 or more and 6 or less, 2.5 or more and 5.5 or less, 3 or more, 5.5 or less, 3 or more and 5 or less, 3.5 or more and 5 or less, or 3.5 or more and 4.5 or less.

[0061] If the ratio of the weight of the acrylamide copolymer to the weight of the acrylate polymer (weight of acrylamide copolymer / weight of acrylate polymer) falls below the range of the present invention, the cohesive force with the inorganic particles may decrease, and if it exceeds the range of the present invention, the adhesive force with the surface of the substrate may decrease.

[0062]

[0063] In one embodiment, the inorganic particles may include alumina, boehmite, or a combination thereof.

[0064] When the composition for coating the non-conductive part of a battery includes the above-mentioned inorganic particles, the composition can have excellent thermochemical stability and physical properties.

[0065]

[0066] In one embodiment, the composition for coating the non-conductive portion of the battery may have a ratio of the weight of the inorganic particles to the weight of the polymer (weight of the inorganic particles / weight of the polymer) of 5 or more and 20 or less.

[0067] For example, the ratio of the weight of the inorganic particles to the weight of the polymer (weight of the inorganic particles / weight of the polymer) may be 6 or more and 20 or less, 7 or more and 20 or less, 8 or more and 19 or less, 9 or more and 18 or less, 10 or more and 17 or less, or 11 or more and 16 or less.

[0068] If the ratio of the weight of the inorganic particles to the weight of the polymer (weight of the inorganic particles / weight of the polymer) is below the range of the present disclosure, the dispersibility of the composition for coating the non-conductive part of the battery may be reduced, resulting in reduced adhesiveness and coatability. If it exceeds the range of the present disclosure, the adhesiveness with the substrate may be reduced.

[0069] The content of the polymer may be more than 1 part by weight and less than 10 parts by weight per 300 parts by weight of the solvent. For example, the content of the polymer may be more than 2 parts by weight and less than 10 parts by weight, more than 3 parts by weight and less than 10 parts by weight, more than 4 parts by weight and less than 10 parts by weight, or more than 5 parts by weight and less than 10 parts by weight per 300 parts by weight of the solvent. If the content of the polymer is below the range of the present disclosure, the adhesive strength with the substrate may be reduced, and if it exceeds the range of the present disclosure, the dispersibility of the composition for coating the non-conductive portion of the battery may be reduced, thereby reducing the adhesive strength and coatability.

[0070] In addition, the content of the inorganic particles may be 90 parts by weight or more and 95 parts by weight or less per 300 parts by weight of the solvent. For example, the content of the inorganic particles may be 90 parts by weight or more and 94.5 parts by weight or less, 90.5 parts by weight or more and 94.5 parts by weight or less, 90.5 parts by weight or more and 94 parts by weight or less, 91 parts by weight or more and 94 parts by weight or less, 91 parts by weight or more and 93.5 parts by weight or less, 91.5 parts by weight or more and 93.5 parts by weight or less, 91.5 parts by weight or more and 93 parts by weight or less, or 92 parts by weight or more and 93 parts by weight or less, per 300 parts by weight of the solvent.

[0071] The composition for coating the non-conductive portion of the battery may have a ratio of the weight of the solvent to the sum of the weight of the polymer and the weight of the inorganic particles (weight of the solvent / sum of the weight of the polymer and the weight of the inorganic particles) of 2 or more and 4 or less. For example, the ratio of the weight of the solvent to the sum of the weight of the polymer and the weight of the inorganic particles (weight of the solvent / sum of the weight of the polymer and the weight of the inorganic particles) may be 2.2 or more and 4 or less, 2.2 or more and 3.8 or less, 2.4 or more and 3.8 or less, 2.4 or more and 3.6 or less, 2.6 or more and 3.6 or less, 2.8 or more and 3.6 or less, or 2.8 or more and 3.5 or less. If the ratio of the weight of the solvent to the sum of the weight of the polymer and the weight of the inorganic particles (the weight of the solvent / the sum of the weight of the polymer and the weight of the inorganic particles) is below the range of the present disclosure, the viscosity of the composition for coating the non-coated portion of the battery may increase, thereby deteriorating dispersibility and coating stability. If the ratio of the weight of the solvent to the sum of the weight of the polymer and the weight of the inorganic particles (the weight of the solvent / the sum of the weight of the polymer and the weight of the inorganic particles) exceeds the range of the present disclosure, the surface tension of the composition for coating the non-coated portion of the battery may become excessively high, requiring the addition of an additional leveling agent, thereby deteriorating the adhesion with the substrate.

[0072]

[0073] In one embodiment, the composition for coating the non-conductive portion of the battery may further include a dispersant and a leveling agent, and the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) may be 0.1 or more and 0.3 or less.

[0074] For example, the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) may be 0.2 or more and 0.3 or less.

[0075] Preferably, when the polymer is an acrylamide copolymer and a styrene-butadiene rubber, the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) may be 0.1 or more and 0.3 or less, and when the polymer is an acrylamide copolymer, the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) may be 0.2 or more and 0.3 or less.

[0076] If the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) is below the range of the present invention, the surface tension of the composition for coating the non-conductive part of the battery may become excessively high, thereby reducing the coating property, and if it exceeds the range of the present invention, the adhesive mechanism of the polymer acting as a binder may be reduced.

[0077]

[0078] In one embodiment, the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) may be 0.005 or more and 0.015 or less, and the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) may be 0.01 or more and 0.5 or less.

[0079] For example, the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) may be 0.007 or more, 0.013 or less, or 0.009 or more, 0.011 or less, and the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) may be 0.02 or more, 0.45 or less, 0.03 or more, 0.40 or less, or 0.04 or more, 0.35 or less.

[0080] Preferably, when the polymer is an acrylamide copolymer and a styrene-butadiene rubber, the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) may be 0.005 or more and 0.015 or less, and the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) may be 0.01 or more and 0.5 or less. In addition, when the polymer is an acrylamide copolymer, preferably, the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) may be 0.05 or more and 0.015 or less, and the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) may be 0.02 or more and 0.45 or less.

[0081] If the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) is below the range of the present disclosure, the dispersibility of the slurry composition may deteriorate, resulting in a significant decrease in the stability and coatability of the slurry composition. If it exceeds the range, the adhesive strength between the non-coated portion and the coating layer may deteriorate. In addition, if the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) is below the range of the present disclosure, the surface tension of the slurry composition may become excessively high, resulting in a deterioration in the coatability. If it exceeds the range, the adhesive mechanism of the polymer acting as a binder may deteriorate.

[0082]

[0083] A method for coating a non-conductive part of a battery according to another aspect of the present invention may include a step of coating a composition for coating a non-conductive part of the battery on the non-conductive part.

[0084]

[0085] In one embodiment, the coating may be, but is not limited to, doctor blade coating, dip coating, gravure coating, slit die coating, spin coating, comma coating, bar coating, reverse roll coating, screen coating, or cap coating.

[0086]

[0087] In one embodiment, the method for coating the non-conductive portion of the battery may additionally include a primary drying step after the coating step.

[0088] In the above first drying step, the drying temperature may be 50°C or higher and 80°C or lower, and the drying time may be 5 minutes or higher and 15 minutes or lower.

[0089] If the drying temperature exceeds the range of the present disclosure, the composition for coating the non-conductive portion of the battery may not be sufficiently wetted, which may result in reduced adhesion to the substrate. If it falls below the range, the time required for drying may increase, which may result in deterioration of processability. In addition, if the drying time exceeds the range of the present disclosure, the processability may deteriorate, and if it falls below the range, the moisture content of the coating layer may increase, which may result in deterioration of the battery performance.

[0090]

[0091] In one embodiment, the method for coating the non-conductive portion of the battery may additionally include a second drying step after the first drying step.

[0092] In the above secondary drying step, the drying temperature may be 100°C or higher and 150°C or lower, and the drying time may be 5 minutes or higher and 15 minutes or lower.

[0093] If the drying temperature exceeds the range of the present invention, the polymer's physical properties may change, and if it falls below the range, the processability may deteriorate. In addition, if the drying time exceeds the range of the present invention, the processability may deteriorate, and if it falls below the range, the moisture content of the coating layer may increase, which may deteriorate the battery's performance.

[0094]

[0095] In one embodiment, the first and second drying may be, but are not limited to, warm air drying, hot air drying, vacuum drying, or infrared drying, and may be dried using a drying method commonly known in the art.

[0096]

[0097] According to another aspect of the present invention, an electrode may include a non-coating layer including a composition for coating the non-coating portion of the battery.

[0098]

[0099] In one embodiment, the coating layer may be formed on one side or both sides of the non-conductive portion of the electrode, and the thickness of the coating layer may be 4 μm or more and 10 μm or less.

[0100] If the thickness of the coating layer falls below the range of the present invention, the adhesive strength between the non-coated coating layer and the non-coated portion and the heat resistance characteristics of the composition for coating the non-coated portion of the battery may be significantly reduced, and if it exceeds the range of the present invention, the thickness of the non-coated coating layer may be too thick, which may increase the thickness of the battery itself, and the adhesive strength between the non-coated coating layer and the non-coated portion may be reduced.

[0101]

[0102] In one embodiment, the adhesive strength between the non-woven portion and the non-woven portion coating layer may be 200 N / m or more.

[0103] For example, the adhesive strength between the non-coated portion and the non-coated portion coating layer may be 210 N / m or more, 220 N / m or more, 230 N / m or more, 240 N / m or more, or 250 N / m or more.

[0104] If the adhesive strength between the above-mentioned plain portion and the above-mentioned plain portion coating layer falls below the range of the present invention, it may be difficult to maintain a stable coating layer on the plain portion.

[0105]

[0106] In one embodiment, the electrode may be a cathode or an anode, and preferably, the electrode may be an anode.

[0107]

[0108] The present invention can provide a secondary battery including the positive electrode, the negative electrode, and a separator interposed between the positive electrode and the negative electrode.

[0109] The positive electrode may include a positive electrode active material and a positive electrode current collector, and the negative electrode may include a negative electrode active material and a negative electrode current collector.

[0110]

[0111] In one embodiment, the positive electrode active material may be any positive electrode active material available in the art. Specific examples of such positive electrode active materials include lithium metal; lithium cobalt oxides such as LiCoO2; Li 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxides such as Li2CuO2; vanadium oxides such as LiV3O8, V2O5, Cu2V2O7; LiNi 1-x M x Lithium nickel oxide represented by O2 (wherein, M=Co, Mn, Al, Cu, Fe, Mg, B or Ga and x=0.01 to 0.3); LiMn 2-x M xLithium manganese composite oxide represented by O2 (wherein, M=Co, Ni, Fe, Cr, Zn or Ta, and x=0.01 to 0.1) or Li2Mn3MO8 (wherein, M=Fe, Co, Ni, Cu or Zn); Li(Ni a Co b Mn c )O2 (wherein, 0<a<1, 0<b<1, 0<c<1, a+b+c=1); lithium-nickel-manganese-cobalt oxides; sulfur or disulfide compounds; phosphates such as LiFePO4, LiMnPO4, LiCoPO4, and LiNiPO4; Fe2(MoO4)3, but are not limited to these.

[0112]

[0113] In one embodiment, the positive electrode current collector may be any positive electrode current collector available in the art. Specific examples of such positive electrode current collectors include, but are not limited to, aluminum foil, aluminum mesh, copper foil, and the like.

[0114]

[0115] In one embodiment, the negative electrode active material may be any negative electrode active material available in the art, and specifically, carbon-based negative electrode active materials such as crystalline carbon, amorphous carbon, or carbon composites may be used alone or in combination of two or more, but is not limited thereto. In addition, the negative electrode current collector may be any negative electrode current collector available in the art, and specific examples of such negative electrode current collectors include, but are not limited to, copper.

[0116]

[0117] In one embodiment, the separator must be an insulator capable of separating the anode and cathode, and must provide a path through which only lithium ions can move. To achieve this, it must have good wettability to the electrolyte, and a porous polymer film such as PE / PP, a porous non-woven fabric, etc. may be used. To prevent battery short-circuits, a coated separator coated with ceramics for enhanced heat resistance and mechanical strength may be used, and the coating may be single-layer or multi-layered.

[0118] The above separator may be formed of a porous substrate. Any porous substrate commonly used in electrochemical devices may be used as the porous substrate. For example, a polyolefin porous membrane or non-woven fabric may be used, but is not particularly limited thereto.

[0119] The above separation membrane may be a porous substrate made of one selected from the group consisting of polyethylene, polypropylene, polybutylene, polypentene, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylene sulfide, and polyethylene naphthalate, or a mixture of two or more thereof.

[0120]

[0121] In one embodiment, the secondary battery can be manufactured by laminating and stacking a separator and electrodes and folding processes in addition to the typical winding process. Furthermore, the case housing the battery may be cylindrical, square, pouch-shaped, or coin-shaped. Furthermore, such a lithium secondary battery can be used in small to medium-sized devices such as automobiles and electronic devices.

[0122] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples.

[0123]

[0124] [Examples and Comparative Examples: Preparation of a Composition for Coating the Non-Positive Surface of a Battery]

[0125] When manufacturing a composition for coating the non-conductive part of a battery, the polymers used were Hansol Chemical's SP-230 acrylamide copolymer solution (polymer A), Hansol Chemical's A-200 styrene-butadiene rubber (polymer B), another company's Y-123 acrylic emulsion (polymer C), and Hansol Chemical's SP-30 polyvinylalcohol solution (polymer D).

[0126] The acrylamide copolymer of polymer A used a mole ratio of acrylamide series monomer units and vinylpyrrolidone series monomer units of 7:3.

[0127]

[0128] Examples 1-1 to 1-5, Comparative Examples 1-1 and 1-2

[0129] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 0.5 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0130] Then, 5.0 parts by weight of acrylamide copolymer solution (polymer A) of Hansol Chemical was added to the first slurry and dispersed to prepare a second slurry.

[0131] Afterwards, 0.1 part by weight of polyether-modified silicon as a leveling agent and 0.1 part by weight of polyvinyl alcohol with a saponification value of 80% as a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Example 1-1.

[0132] The compositions for coating the non-conductive portion of the batteries of Examples 1-2 to 1-5 and Comparative Examples 1-1 and 1-2 were prepared in the same manner as the composition for coating the non-conductive portion of the battery of Example 1-1, except that the content of the polymer was changed. The content of the polymer used is shown in Table 1 below.

[0133]

[0134] Composition for coating the non-conductive part of the battery Content of polymer A (parts by weight) Example 1-13.0 Example 1-25.0 Example 1-36.0 Example 1-47.0 Example 1-58.0 Comparative Example 1-11.0 Comparative Example 1-210.0

[0135]

[0136] In the above Table 1, polymer A refers to Hansol Chemical's acrylamide copolymer solution.

[0137]

[0138] Examples 2-1 to 2-5

[0139] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 0.5 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0140] Then, 4.0 parts by weight of acrylamide copolymer solution (polymer A) of Hansol Chemical and 1.0 parts by weight of A-200 styrene-butadiene rubber (polymer B) of Hansol Chemical were added to the first slurry and dispersed to prepare a second slurry.

[0141] Afterwards, 0.1 part by weight of a leveling agent and 0.1 part by weight of a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Example 2-1.

[0142] The compositions for coating the non-conductive portion of the batteries of Examples 2-2 to 2-5 were prepared in the same manner as the composition for coating the non-conductive portion of the batteries of Example 2-1, except that the contents of polymer A and polymer B were changed. The contents of the polymers used are shown in Table 2 below.

[0143]

[0144] Composition for non-conductive coating of battery Content of polymer A (parts by weight) Content of polymer B (parts by weight) Total content of polymer (parts by weight) Example 2-14.01.05.0 Example 2-26.30.77.0 Example 2-35.61.47.0 Example 2-44.92.17.0 Example 2-54.22.87.0

[0145]

[0146] In Table 2 above, polymer A refers to Hansol Chemical's acrylamide copolymer solution, and polymer B refers to Hansol Chemical's A-200 styrene-butadiene rubber.

[0147]

[0148] Examples 3-1, 3-2 and Comparative Examples 3-1 to 3-5

[0149] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 0.5 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0150] Then, 4.9 parts by weight of Hansol Chemical's acrylamide copolymer solution (polymer A) and 2.1 parts by weight of a third-party's acrylic emulsion (polymer C) were added to the first slurry and dispersed to prepare a second slurry.

[0151] Afterwards, 0.1 part by weight of a leveling agent and 0.1 part by weight of a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Example 3-1.

[0152] The compositions for coating the non-conductive portion of the batteries of Example 3-2 and Comparative Examples 3-1 to 3-5 were prepared in the same manner as the composition for coating the non-conductive portion of the battery of Example 3-1, except that the contents of polymer A and polymer C were changed. The contents of the polymers used are shown in Table 3 below.

[0153]

[0154] Composition for non-conductive coating of battery Content of polymer A (parts by weight) Content of polymer C (parts by weight) Total content of polymer (parts by weight) Example 3-14.9 2.17.0 Example 3-25.6 1.47.0 Comparative Example 3-14.5 0.5 5.0 Comparative Example 3-24.0 1.0 5.0 Comparative Example 3-33.5 1.5 5.0 Comparative Example 3-43.0 2.0 5.0 Comparative Example 3-54.2 2.8 7.0

[0155]

[0156] In Table 3 above, polymer A refers to Hansol Chemical's acrylamide copolymer solution, and polymer C refers to another company's acrylic emulsion.

[0157]

[0158] Example 4-1, Comparative Examples 4-1 and 4-2

[0159] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 1.0 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0160] Then, 7.0 parts by weight of Hansol Chemical's acrylamide copolymer solution (polymer A) was added to the first slurry and dispersed to prepare a second slurry.

[0161] Afterwards, 0.1 part by weight of a leveling agent and 0.1 part by weight of a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Example 4-1.

[0162] The compositions for coating the non-conductive portion of the batteries of Comparative Examples 4-1 and 4-2 were prepared in the same manner as the composition for coating the non-conductive portion of the batteries of Example 4-1, except that the content of the leveling agent was changed. The content of the leveling agent used is shown in Table 4 below, and the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) is also shown in Table 4.

[0163]

[0164] Leveling agent content (weight parts) of composition for non-conductive coating of battery Leveling agent content / dispersant content Example 4-10.3 0.3 Comparative Example 4-10.10.1 Comparative Example 4-20.2 0.2

[0165]

[0166] Examples 5-1 to 5-3

[0167] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 1.0 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0168] Then, 5.6 parts by weight of acrylamide copolymer solution (polymer A) of Hansol Chemical and 1.4 parts by weight of A-200 styrene-butadiene rubber (polymer B) of Hansol Chemical were added to the first slurry and dispersed to prepare a second slurry.

[0169] Afterwards, 0.1 part by weight of a leveling agent and 0.1 part by weight of a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Example 5-1.

[0170] The compositions for coating the non-conductive portion of the batteries of Examples 5-2 and 5-3 were prepared in the same manner as the composition for coating the non-conductive portion of the batteries of Example 5-1, except that the content of the leveling agent was changed. The content of the leveling agent used is shown in Table 5 below, and the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) is also shown in Table 5.

[0171]

[0172] Leveling agent content (weight parts) of composition for non-conductive coating of battery Leveling agent content / dispersant content Example 5-10.10.1 Example 5-20.20.2 Example 5-30.30.3

[0173]

[0174] Comparative examples 6 to 8

[0175] A primary slurry was prepared by mixing 92.3 parts by weight of boehmite (average particle size: 0.15 μm) as an inorganic particle, 0.5 parts by weight of ammonium polyacrylate (product name: HDA) from Hansol Chemical as a dispersant, and 300 parts by weight of ultra pure water, and dispersing using a ball mill method or a mechanical stirrer.

[0176] Then, 5.0 parts by weight of Hansol Chemical's A-200 styrene-butadiene rubber (polymer B) was added to the first slurry and dispersed to prepare a second slurry.

[0177] Afterwards, 0.1 part by weight of a leveling agent and 0.1 part by weight of a wetting agent were added to the secondary slurry and dispersed to prepare a composition for coating the non-conductive portion of the battery of Comparative Example 6.

[0178] Comparative Example 7 was prepared in the same manner as the battery non-coating composition of Comparative Example 6, except that the type of polymer was changed from polymer B to an acrylic emulsion (polymer C) from another company.

[0179] Comparative Example 8 was prepared in the same manner as the composition for coating the non-conductive part of a battery of Comparative Example 6, except that the type of polymer was changed from Polymer B to Hansol Chemical's polyvinyl alcohol solution (Polymer D).

[0180]

[0181] [Evaluation Example 1: Measurement of the glass transition temperature (Tg) of a polymer]

[0182] 10 to 20 mg of polymer A (acrylamide copolymer solution of Hansol Chemical) was placed in a 40 μl aluminum pan, and the glass transition temperature (Tg) of polymer A was measured by checking the thermal behavior using a differential scanning calorimeter (DSC).

[0183] The glass transition temperatures (Tg) of polymer B (Hansol Chemical's A-200 styrene-butadiene rubber), polymer C (an acrylic emulsion from another company), and polymer D (Hansol Chemical's polyvinyl alcohol solution) were also measured using the same method.

[0184] The measured glass transition temperature (Tg) is shown in Table 6 below.

[0185]

[0186] Polymer glass transition temperature (Tg, ℃)Polymer A203~206Polymer B0~3Polymer C5~10Polymer D60~70

[0187]

[0188] In the above Table 6, polymer A refers to Hansol Chemical's acrylamide copolymer solution, polymer B refers to Hansol Chemical's A-200 styrene-butadiene rubber, polymer C refers to another company's acrylic emulsion, and polymer D refers to Hansol Chemical's polyvinyl alcohol solution.

[0189]

[0190] [Evaluation Example 2: Measurement of the swelling degree of a polymer electrolyte]

[0191] Polymer A (acrylamide copolymer solution of Hansol Chemical) was dried in a 5 cm x 2 cm square frame at 60 ℃ for 24 hours to produce a specimen.

[0192] Specimens of polymer B (Hansol Chemical's A-200 styrene-butadiene rubber), polymer C (an acrylic emulsion from another company), and polymer D (Hansol Chemical's polyvinyl alcohol solution) were also prepared using the same method.

[0193] The fabricated specimen was immersed in an electrolyte (EC:DEC=3:7 99 wt%+VC 1 wt%, 1.6M LiPF6) and left at a temperature of 80°C for 2 hours. The weight of the changed specimen was measured to calculate the weight change rate. EC refers to ethylene carbonate, DEC refers to diethyl carbonate, and VC refers to vinylene carbonate.

[0194] For polymer A and polymer B, the electrolyte swelling degree was additionally measured over a long period of time by changing the impregnation temperature and increasing the impregnation time to 7 days.

[0195] The electrolyte swelling degrees of polymer A, polymer B, polymer C, and polymer D, measured after leaving at a temperature of 80°C for 2 hours, are shown in Table 7 below. In addition, the electrolyte swelling degrees of polymer A and polymer B, measured at an impregnation temperature and with an impregnation period of 7 days, are shown in Table 8 below.

[0196]

[0197] Polymer electrolyte swelling ratio (%) Polymer A3 Polymer B30 Polymer C38 Polymer D20 (discoloration)

[0198]

[0199] As a result of the measurement, the swelling degree of polymer C impregnated in an electrolyte at 80°C for 2 hours exceeded 30%, confirming that polymer C has low stability in the electrolyte. In addition, the swelling degree of polymer D impregnated in an electrolyte at 80°C for 2 hours was 20%, satisfying the electrolyte swelling degree range of the present invention, but it was discolored, confirming that polymer D has low stability in the electrolyte.

[0200] On the other hand, the electrolyte swelling degree of polymer A impregnated in an electrolyte at 80°C for 2 hours was 3%, and the electrolyte swelling degree of polymer B was 30%, satisfying the electrolyte swelling degree range of the present invention, and it was confirmed that the stability in the electrolyte was high.

[0201]

[0202] Electrolyte Swelling (%) Impregnation Temperature (℃) Polymer A Polymer B 2 5 1 3 2 0 6 0 3 9 4 0 8 0 4 3 5 2

[0203]

[0204] As a result of the measurement, the electrolyte swelling degree of polymer A impregnated in an electrolyte at 25°C for 7 days was 13%, and the electrolyte swelling degree of polymer B was 20%, satisfying the electrolyte swelling degree range of the present invention of 30% or less, and it was confirmed that polymer A and polymer B also have excellent electrolyte stability for a long period of time.

[0205]

[0206] [Evaluation Example 3: Measurement of adhesive strength of a composition for coating the non-conductive part of a battery]

[0207] After applying the composition for coating the non-coated portion of the battery of the examples and comparative examples to aluminum foil, primary drying was performed at a temperature ranging from 50 to 80°C for 5 to 15 minutes. Then, secondary drying was performed for 5 to 15 minutes by increasing the temperature to 100 to 120°C to form a non-coated portion coating layer. At this time, the thickness of the formed non-coated portion coating layer was 4 to 10 μm.

[0208] The aluminum foil on which the non-coated layer was formed was cut into pieces of 25 mm in width and 50 mm in length and prepared. A 3M double-sided tape cut into pieces of 18 mm in width and 70 mm in length was evenly attached onto the non-coated layer of the prepared aluminum foil and pressed three times without gaps using a rubber roll press to prepare a specimen.

[0209] The above specimen was mounted on a universal testing machine (UTM) (1-3 kg load cell), one side of the aluminum foil was fixed to the upper clip of the tensile strength tester, and the double-sided tape was fixed to the lower clip, and the 180° peel strength was measured at a speed of 1.33 mm / sec.

[0210] Five or more specimens of aluminum foil on which the above-mentioned non-coated layer was formed were produced per sample, measured, and the average value was calculated to be used as the adhesive strength.

[0211]

[0212] Adhesion of the composition for coating the non-conductive part of the batteries of Examples 1-2, 2-1, Comparative Examples 3-2 and 6 to 8

[0213] The adhesion between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the batteries of Examples 1-2, 2-1, Comparative Examples 3-2 and 6 to 8 is shown in Table 9 below.

[0214]

[0215] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 1-2159.5 Comparative Example 637.4 Comparative Example 725.4 Comparative Example 8115.9 Example 2-1194.5 Comparative Example 3-2152.9

[0216]

[0217] As a result of the measurement, it was confirmed that when the composition for coating the non-coated region of Example 1-2 containing only polymer A was used, an electrode having a higher adhesive strength between the non-coated region coating layer and the non-coated region could be manufactured than when the composition for coating the non-coated region of Comparative Example 6 containing only polymer B, the composition for coating the non-coated region of Comparative Example 7 containing only polymer C, and the composition for coating the non-coated region of Comparative Example 8 containing only polymer D were used.

[0218] In addition, it was confirmed that when the composition for coating the non-coated region of Comparative Example 3-2 containing both polymer A and polymer C was used, an electrode having a higher adhesive strength between the non-coated region coating layer and the non-coated region could be manufactured than when the composition for coating the non-coated region of Comparative Example 6 containing only polymer B, the composition for coating the non-coated region of Comparative Example 7 containing only polymer C, and the composition for coating the non-coated region of Comparative Example 8 containing only polymer D were used.

[0219] In addition, it was confirmed that when the composition for coating the non-coated region of Example 2-1 containing both polymer A and polymer B was used, an electrode having a higher adhesive strength between the non-coated region coating layer and the non-coated region could be manufactured than when the composition for coating the non-coated region of Example 1-2 containing only polymer A, the composition for coating the non-coated region of Comparative Example 6 containing only polymer B, the composition for coating the non-coated region of Comparative Example 7 containing only polymer C, the composition for coating the non-coated region of Comparative Example 8 containing only polymer D, and the composition for coating the non-coated region of Comparative Example 3-2 containing both polymer A and polymer C were used.

[0220] That is, by combining polymer A, which has strong cohesion with inorganic matter, with polymer B or C, which has high permeability to aluminum foil, in an appropriate ratio, a composition for coating the non-coated portion of a battery having excellent adhesion between the non-coated portion and the non-coated portion can be obtained.

[0221]

[0222] Adhesive strength of compositions for coating the non-conductive part of batteries of Examples 1-1 to 1-5 and Comparative Examples 1-1 and 1-2

[0223] The adhesive strength between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the battery of Examples 1-1 to 1-5 and Comparative Examples 1-1 and 1-2 is shown in Table 10 below.

[0224]

[0225] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 1-1 101.3 Example 1-2 159.5 Example 1-3 274.9 Example 1-4 288.9 Example 1-5 295.3 Comparative Example 1-1 33.0 Comparative Example 1-255.9

[0226]

[0227] As a result of the measurement, when using a composition for coating a non-coated area containing only polymer A, the adhesive strength between the non-coated area coating layer and the non-coated area increased as the content of polymer A increased, but when the content of polymer A exceeded the range of the present invention by reaching 10 parts by weight (Comparative Example 1-2), it was confirmed that the adhesive strength decreased rapidly.

[0228] In addition, when the content of polymer A was 1 part by weight (Comparative Example 1-1), 3 parts by weight (Example 1-1), and 5 parts by weight (Example 1-2), the adhesive force between the coating layer on the non-coated part and the non-coated part was less than 250 N / m, and it was confirmed that it was difficult to maintain a stable coating layer on the non-coated part.

[0229] On the other hand, when the content of polymer A was 6 parts by weight (Example 1-3), 7 parts by weight (Example 1-4), and 8 parts by weight (Example 1-5), the adhesive force between the coating layer on the uncoated part and the uncoated part was 250 N / m or more, so that a stable coating layer could be maintained on the uncoated part. Therefore, when using a composition for coating the uncoated part containing polymer A alone, it was confirmed that it is preferable that the content of polymer A be more than 5 parts by weight and less than 10 parts by weight.

[0230]

[0231] Adhesive strength of composition for coating the non-conductive part of batteries in Examples 2-1 to 2-5

[0232] The adhesive strength between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the battery of Examples 2-1 to 2-5 is shown in Table 11 below.

[0233]

[0234] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 2-1 194.5 Example 2-2 288.7 Example 2-3 305.5 Example 2-4 285.4 Example 2-5 301.1

[0235]

[0236] As a result of the measurement, when using a composition for coating a non-coated area containing both polymer A and polymer B, it was confirmed that a higher adhesive strength was achieved between the non-coated area coating layer and the non-coated area when the sum of the contents of polymer A and polymer B was 7 parts by weight (Examples 2-2 to 2-5) than when the sum of the contents of polymer A and polymer B was 5 parts by weight (Example 2-1).

[0237] In addition, when the sum of the content of polymer A and the content of polymer B was 7 parts by weight (Examples 2-2 to 2-5), the adhesive force between the coating layer on the uncoated part and the uncoated part was 250 N / m or more, so that a stable coating layer could be maintained on the uncoated part. Therefore, when using a composition for coating the uncoated part containing both polymer A and polymer B, it was confirmed that it is preferable that the total weight of the polymer exceeds 5 parts by weight.

[0238] In addition, it was confirmed that when the composition for coating the non-woven fabric of Example 2-2, which satisfies the range of the present invention with a ratio of the weight of polymer A to the weight of polymer B (weight of polymer A / weight of polymer B) of 4, was used, it had a higher adhesive strength.

[0239]

[0240] Adhesive strength of compositions for coating the non-conductive part of batteries of Examples 3-1, 3-2 and Comparative Examples 3-1 to 3-5

[0241] The adhesive strength between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the battery of Examples 3-1, 3-2 and Comparative Examples 3-1 to 3-5 is shown in Table 12 below.

[0242]

[0243] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 3-1191.1 Example 3-2271.8 Comparative Example 3-1154.0 Comparative Example 3-2152.9 Comparative Example 3-3160.3 Comparative Example 3-4161.7 Comparative Example 3-5172.9

[0244]

[0245] As a result of the measurement, when a composition for coating a non-coated area containing both polymer A and polymer C was used, a higher adhesive strength was exhibited between the non-coated area coating layer and the non-coated area when the sum of the contents of polymer A and polymer C was 7 parts by weight (Examples 3-1, 3-2 and Comparative Example 3-5) than when the sum of the contents of polymer A and polymer C was 5 parts by weight (Comparative Examples 3-1 to 3-4). Therefore, it was confirmed that when a composition for coating a non-coated area containing both polymer A and polymer C is used, it is preferable that the total content of polymers be more than 5 parts by weight.

[0246] In addition, when using 7 parts by weight of a non-coating composition containing both polymer A and polymer C, when using the non-coating composition of Example 3-2 in which the ratio of the weight of polymer A to the weight of polymer C (weight of polymer A / weight of polymer C) was 4, a high adhesive strength of 250 N / m or more was exhibited, and it was confirmed that it is preferable that the ratio of the weight of polymer A to the weight of polymer C (weight of polymer A / weight of polymer C) be 3 or more and 6 or less.

[0247]

[0248] Adhesive strength of compositions for coating the non-conductive part of batteries of Example 4-1, Comparative Examples 4-1 and 4-2

[0249] The adhesive strength between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the batteries of Example 4-1, Comparative Examples 4-1 and 4-2 is shown in Table 13 below.

[0250]

[0251] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 4-1300.4 Comparative Example 4-1129.5 Comparative Example 4-236.4

[0252]

[0253] As a result of the measurement, in the case of a composition for coating the uncoated portion of a battery (Comparative Example 4-1) containing 0.1 part by weight of a leveling agent and 1.0 part by weight of a dispersant, and having a ratio of the weight of the leveling agent to the weight of the dispersant (weight of leveling agent / weight of dispersant) of 0.1, it was confirmed that the adhesive force between the coating layer on the uncoated portion and the uncoated portion was less than 250 N / m, making it difficult to maintain a stable coating layer on the uncoated portion.

[0254] On the other hand, in the case of using a composition for coating the uncoated part of a battery (Example 1-4) containing 0.1 part by weight of a leveling agent and 0.5 part by weight of a dispersant, and having a ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) of 0.2, the adhesive strength between the uncoated part coating layer and the uncoated part was 288.9 N / m, which was 250 N / m or more, and in the case of using a composition for coating the uncoated part of a battery (Example 4-1) containing 0.3 part by weight of a leveling agent and 1.0 part by weight of a dispersant, and having a ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) of 0.3, the adhesive strength between the uncoated part coating layer and the uncoated part was also 250 N / m or more, so that a stable coating layer could be maintained on the uncoated part. The ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) of 0.2 or more and the ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant) It was confirmed that the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) is preferably 0.05 or more and 0.015 or less, and that the ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) is preferably 0.02 or more and 0.45 or less.

[0255]

[0256] Adhesive strength of composition for coating the non-conductive part of batteries in Examples 5-1 to 5-3

[0257] The adhesive strength between the non-coated coating layer and the non-coated portion of the electrode formed using the composition for coating the non-coated portion of the battery of Examples 5-1 to 5-3 is shown in Table 14 below.

[0258]

[0259] Composition for coating the non-conductive part of the battery Adhesion (N / m) Example 5-1531.9 Example 5-2479.8 Example 5-3411.9

[0260]

[0261] As a result of the measurement, in the case of using a composition for coating the uncoated portion of a battery (Example 5-1) containing 0.1 part by weight of a leveling agent and 1.0 part by weight of a dispersant so that the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) was 0.1, a composition for coating the uncoated portion of a battery (Example 5-2) containing 0.2 part by weight of a leveling agent and 1.0 part by weight of a dispersant so that the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) was 0.2, or a composition for coating the uncoated portion of a battery (Example 5-3) containing 0.3 part by weight of a leveling agent and 1.0 part by weight of a dispersant so that the ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) was 0.3, the adhesive force between the uncoated portion coating layer and the uncoated portion was 250 N / m or more, so that a stable coating layer could be maintained on the uncoated portion. It was confirmed that it is preferable that the weight ratio of the dispersant (weight of the dispersant / weight of the inorganic particles) is 0.1 or more, the weight ratio of the dispersant (weight of the dispersant / weight of the inorganic particles) is 0.005 or more and 0.015 or less, and the weight ratio of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) is 0.01 or more and 0.5 or less.

[0262]

[0263] The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0264]

[0265] As described above, the composition for coating the non-conductive portion of the battery of the present invention has excellent adhesion between the non-conductive portion coating layer and the non-conductive portion of the electrode, so that the coating layer can be stably formed.

[0266] In addition, since the composition for coating the non-conductive part of the battery of the present invention has excellent heat resistance and excellent electrolyte stability, an electrode having the non-conductive part coated using the composition for coating the non-conductive part of the battery of the present invention can effectively prevent the occurrence of a short circuit and improve the stability of the battery.

Claims

1. Polymer; inorganic particles; and solvent; containing, A composition for coating the non-conductive part of a battery.

2. In paragraph 1, The glass transition temperature (Tg) of the above polymer is 0 ℃ or more and 230 ℃ or less, A composition for coating the non-conductive part of a battery.

3. In paragraph 1, The electrolyte swelling degree of the above polymer at room temperature is 30% or less, A composition for coating the non-conductive part of a battery.

4. In paragraph 1, The polymer comprises an acrylamide copolymer, a styrene-butadiene rubber, an acrylate polymer, an acrylate copolymer, a methacrylate polymer, a methacrylate copolymer, an acrylic acid polymer, an acrylic acid copolymer, a vinyl alcohol polymer, a styrene polymer, or a combination thereof. A composition for coating the non-conductive part of a battery.

5. In paragraph 4, The above acrylamide copolymer contains a monomer unit of the acrylamide series and a monomer unit of the vinylpyrrolidone series, The ratio of the number of moles of the monomer unit of the acrylamide series to the number of moles of the monomer unit of the vinylpyrrolidone series (number of moles of the monomer unit of the acrylamide series / number of moles of the monomer unit of the vinylpyrrolidone series) is 1 or more and 3.5 or less, A composition for coating the non-conductive part of a battery.

6. In paragraph 4, The polymer comprises the acrylamide copolymer and the styrene-butadiene rubber. A composition for coating the non-conductive part of a battery.

7. In paragraph 6, The ratio of the weight of the acrylamide copolymer to the weight of the styrene-butadiene rubber (weight of acrylamide copolymer / weight of styrene-butadiene rubber) is 1 or more and 10 or less, A composition for coating the non-conductive part of a battery.

8. In paragraph 4, The polymer comprises the acrylamide copolymer and the acrylate polymer. A composition for coating the non-conductive part of a battery.

9. In paragraph 8, The ratio of the weight of the acrylamide copolymer to the weight of the acrylate polymer (weight of the acrylamide copolymer / weight of the acrylate polymer) is 2 or more and 6 or less, A composition for coating the non-conductive part of a battery.

10. In paragraph 1, The above inorganic particles include alumina, boehmite, or a combination thereof. A composition for coating the non-conductive part of a battery.

11. In paragraph 1, The ratio of the weight of the inorganic particles to the weight of the polymer (weight of the inorganic particles / weight of the polymer) is 5 or more and 20 or less, A composition for coating the non-conductive part of a battery.

12. In paragraph 1, dispersant; and In addition, it includes a leveling agent; The ratio of the weight of the leveling agent to the weight of the dispersant (weight of the leveling agent / weight of the dispersant) is 0.1 or more and 0.3 or less, A composition for coating the non-conductive part of a battery.

13. In paragraph 1, dispersant; and In addition, it includes a leveling agent; The ratio of the weight of the dispersant to the weight of the inorganic particles (weight of the dispersant / weight of the inorganic particles) is 0.005 or more and 0.015 or less, The ratio of the weight of the leveling agent to the weight of the polymer (weight of the leveling agent / weight of the polymer) is 0.01 or more and 0.5 or less, A composition for coating the non-conductive part of a battery.

14. A step of coating a non-conductive part of a battery with a composition for coating a non-conductive part of any one of claims 1 to 13; including; Method for coating the non-conductive part of a battery.

15. In paragraph 14, The above coating is doctor blade coating, dip coating, gravure coating, slit die coating, spin coating, comma coating, bar coating, reverse roll coating, screen coating, or cap coating. Method for coating the non-conductive part of a battery.

16. In paragraph 14, A primary drying step after the above coating step; additionally comprising; Method for coating the non-conductive part of a battery.

17. In paragraph 16, A second drying step after the first drying step; additionally comprising; Method for coating the non-conductive part of a battery.

18. A non-coating layer comprising a composition for coating the non-coating portion of a battery according to any one of claims 1 to 13, electrode.

19. In paragraph 18, The coating layer is formed on one side or both sides of the non-coated portion of the electrode, The thickness of the above coating layer is 4 μm or more and 10 μm or less, electrode.

20. In paragraph 18, The adhesive strength between the plain part and the plain part coating layer is 200 N / m or more, electrode.