Polyamide polymer, binder, slurry, electrode, separator, slurry composition for insulating coating of secondary battery blank area, and secondary battery

Abstract

The present invention relates to a polyamide polymer, a binder, a slurry, an electrode, a separator, a slurry composition for a secondary battery blank space insulating coating, and a secondary battery. The polyamide polymer includes a first monomer unit including an ether group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof. The binder of the present invention can improve electrochemical characteristics of a secondary battery due to exhibiting excellent binding characteristics, and can promote migration of lithium ions to improve internal resistance of the battery, thereby improving a capacity retention rate of the secondary battery.

Description

Technical Field

[0001] This invention relates to polyamide polymers for adhesives, adhesives, slurries, electrodes, separators, slurry compositions for insulating coatings in blank areas of secondary batteries, and secondary batteries. Background Technology

[0002] Lithium-ion batteries are widely used in the electrical, electronic, communications, and computer industries due to their high energy density. Their applications are expanding from small lithium-ion batteries for portable electronic devices to large-capacity batteries for hybrid vehicles, electric vehicles, and more.

[0003] To provide lithium secondary batteries with high energy density and excellent lifespan characteristics, it is preferable to increase the content of electrode active materials and conductive materials in the electrodes and reduce the content of binders.

[0004] However, if the binder content is reduced, the dispersibility, adhesion, and flexibility of the electrode active material and / or conductive material will decrease. Therefore, the electrode active material may detach from the current collector during charging and discharging, leading to a decline in cycle performance.

[0005] Therefore, there is a need for an adhesive that can ensure the dispersion of electrode active materials and / or conductive materials, electrode adhesion and electrode flexibility in a low amount.

[0006] For example, fluorinated binders such as polyvinylidene fluoride (PVDF), which do not contain polar groups, have low swelling in organic electrolytes, easily maintain electrode structure during battery operation, and can improve the dispersibility of active materials.

[0007] However, PVDF suffers from insufficient dispersion of conductive materials, inadequate electrode adhesion, and insufficient electrode flexibility. In particular, PVDF may exhibit reduced stability when exposed to alkaline conditions for extended periods, potentially generating HF gas.

[0008] In addition, although non-fluorinated adhesives such as hydrogenated acrylonitrile-butadiene adhesives improve the dispersion of conductive materials and the flexibility of the plates compared with fluorinated adhesives, the bonding strength is still insufficient.

[0009] Therefore, there is a need for an adhesive that can overcome the limitations of these previous technologies and simultaneously ensure improved adhesion and flexibility, excellent stability, and thus improve the lifespan characteristics of lithium secondary batteries.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Korean Patent Publication No. 10-2016-0040125 Summary of the Invention

[0013] The problem to be solved

[0014] Therefore, the object of the present invention is to provide a polyamide polymer for electrode adhesives, which improves the adhesive properties by applying a polyamide polymer containing a first monomer unit in an adhesive comprising a conventional polyamide polymer, thereby preventing electrode detachment due to lithium ion migration and improving the electrochemical and cycle characteristics of the secondary battery, wherein the first monomer unit comprises an ether group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof.

[0015] In addition, the objective is to provide an adhesive that improves the charging / discharging efficiency and lifespan of secondary batteries.

[0016] The present invention aims to provide a slurry composition that uses the aforementioned polyamide polymer for electrode binders to improve the characteristics of secondary batteries.

[0017] Furthermore, the present invention aims to provide electrodes, separators, and low-cost, high-performance secondary batteries incorporating the above-described slurry composition that exhibit excellent performance.

[0018] However, the problems that this application seeks to solve are not limited to those mentioned above, and those skilled in the art should be able to clearly understand other problems not mentioned based on the following description.

[0019] Methods for solving problems

[0020] One aspect of this application provides a polyamide polymer comprising a first monomer unit containing an ether group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof.

[0021] Another aspect of this application provides an adhesive comprising the aforementioned polyamide polymer.

[0022] Another aspect of this application provides a slurry comprising the above-mentioned binder and electrode active material.

[0023] Another aspect of this application provides an electrode comprising:

[0024] Current collector; and

[0025] An electrode active material layer containing the adhesive, a blank area insulating coating, or a combination thereof formed on the current collector.

[0026] Another aspect of this application provides a diaphragm comprising a porous substrate coated with a slurry composition comprising the aforementioned adhesive.

[0027] Another aspect of this application provides a slurry composition for an insulating coating of a blank area in a secondary battery, comprising the aforementioned adhesive.

[0028] Another aspect of this application provides a secondary battery comprising the aforementioned adhesive.

[0029] Invention Effects

[0030] The adhesive of the present invention exhibits excellent bonding properties, which can improve the electrochemical properties of the secondary battery and promote the migration of lithium ions to improve the internal resistance of the battery, thereby improving the capacity retention of the secondary battery.

[0031] In addition, the adhesive of the present invention can improve the charging / discharging efficiency and lifespan of secondary batteries.

[0032] Furthermore, the electrode adhesive of the present invention can reduce the amount of adhesive used while increasing the amount of active material and conductive agent due to improved adhesion, thus enabling the provision of high energy density lithium secondary batteries at low cost. Detailed Implementation

[0033] The following detailed description of the invention's function and effects will be provided through specific embodiments. However, these embodiments are merely illustrative and the scope of protection of the invention is not limited thereto.

[0034] Prior to this, the terms or words used in this specification and claims should not be interpreted as having their usual or dictionary meanings, but should be interpreted based on the principle that the inventor can appropriately define the concepts of the terms to best describe his own invention, and in accordance with the meanings and concepts consistent with the technical ideas of the present invention.

[0035] Therefore, the embodiments described in this specification are only one of the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. It should be understood that there may be many equivalents and modifications that can replace these embodiments when this application is filed.

[0036] In this specification, unless the context clearly specifies otherwise, singular expressions include plural expressions. It should be understood in this specification that terms such as “comprising,” “possessing,” or “having” are intended to specify the presence of the implemented features, numbers, steps, constituent elements, or combinations thereof, and do not presuppose the presence or additional possibilities of more than one other feature, number, step, constituent element, or combination thereof.

[0037] In this specification, the terms “a to b” and “a~b”, which represent numerical ranges, are defined as ≥ a and ≤ b.

[0038] One aspect of this application describes a polyamide polymer that may comprise a first monomer unit containing an ether group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof.

[0039] In one embodiment, the first monomer unit may comprise a structure represented by Formula 1, wherein the structure represented by Formula 1 comprises two aromatic rings connected to each other by straight-chain or branched hydrocarbon groups having 1 to 10 carbon atoms.

[0040] [Chemical Formula 1]

[0041]

[0042] R1 and R2 are each independently hydrogen, or straight-chain or branched hydrocarbon groups having 1 to 4 carbon atoms.

[0043] m ranges from 1 to 4.

[0044] For example, R1 and R2 can each independently be hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, or a combination thereof.

[0045] In one embodiment, the first monomer unit described above can be formed by polymerizing a first monomer represented by the following chemical formula 2.

[0046] [Chemical Formula 2]

[0047]

[0048] In the above chemical formula 2,

[0049] a+b+c is greater than 1 and less than 10.

[0050] X1, X2, and X3 are each independently an oxygen atom or a straight-chain or branched hydrocarbon group with 1 to 10 carbon atoms.

[0051] For example, X1, X2 and X3 can each independently be an ether group (-O-), a straight-chain or branched hydrocarbon group of the above chemical formula 1 with 1 to 10 carbon atoms connected to two aromatic rings, or a combination thereof.

[0052] In one embodiment, the first monomer may be 4,4'-diaminodiphenyl ether (4,4'-Oxydianiline, ODA), 3,4'-methylenedianilne (3,4'-MDA), 1,3-bis(3-aminophenoxy)benzene (APB), 1,4-bis(4-aminophenoxy)benzene (1,4-Bis(4-aminophenoxy)benzene), 1,3-bis(4-aminophenoxy)benzene (1,3-Bis(4-aminophenoxy)benzene), or 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene (1,3- Bis[2-(4-aminophenyl)-2-propyl]benzene), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-isopropylidenebis[(4-aminophenoxy)benzene], 4,4'-(1,4-phenylenediisopropylidene)bisaniline, or combinations thereof.

[0053] In one embodiment, the polyamide polymer may further comprise a second monomer unit containing at least one aromatic ring.

[0054] At least one aromatic ring can be used to form part of the backbone of the polyamide polymer. That is, the polyamide polymer can contain an aromatic ring within its backbone.

[0055] The monomer unit containing at least one aromatic ring must be capable of polymerizing with a diamine monomer to form a polyamide polymer, and may contain substituents for this purpose.

[0056] In one embodiment, the polyamide polymer may further comprise a third monomer unit containing sulfone, a fourth monomer unit containing carboxylic acid, or a combination thereof.

[0057] The aforementioned sulfone-containing third monomer unit may also contain an aromatic ring. The sulfone, or sulfone and aromatic ring, of the aforementioned sulfone-containing third monomer unit can be used to form part of the main chain of the polyamide polymer. That is, the aforementioned polyamide polymer may contain sulfone, or sulfone and aromatic ring, within its main chain.

[0058] The aforementioned sulfone-containing third monomer unit can help improve the bonding properties of polyamide polymers. Furthermore, it can significantly improve battery characteristics.

[0059] In addition, the aforementioned third monomer unit containing sulfone can also help improve the initial efficiency of the battery.

[0060] The fourth monomer unit containing carboxylic acid may contain more than one carboxylic acid, and the carboxylic acid may be a substituent of an aromatic ring.

[0061] When the fourth monomer unit containing carboxylic acid is used in an appropriate amount, the adhesion of the polyamide polymer can be improved, and the performance of the battery can be enhanced.

[0062] In one embodiment, the above-mentioned polyamide polymer can be formed by polymerizing bis[4-(4-aminophenoxy)phenyl] sulfone (BAPS), 4,4'-diaminodiphenyl ether (ODA), isophthaloyl chloride (IPC), and terephthaloyl chloride (TPC).

[0063] In one embodiment, the above-mentioned polyamide polymer can be formed by polymerizing bis[4-(4-aminophenoxy)phenyl] sulfone (BAPS), 3,4'-methylenedianilne (3,4'-MDA), isophthaloyl chloride (IPC), and terephthaloyl chloride (TPC).

[0064] In one embodiment, the above-mentioned polyamide polymer can be formed by polymerizing bis[4-(4-aminophenoxy)phenyl] sulfone (BAPS), 1,3-bis(3-aminophenoxy)benzene (APB), isophthaloyl chloride (IPC), and terephthaloyl chloride (TPC).

[0065] In one embodiment, the second monomer formed by polymerizing the second monomer unit containing at least one aromatic ring may be a terephthaloyl chloride monomer, an isophthaloyl chloride monomer, an phthalic acid monomer, an isophthalic acid monomer, a terephthalic acid monomer, or a combination thereof.

[0066] In one embodiment, based on a total content of 100 mol% of the terephthaloyl chloride and isophthaloyl chloride used in the polymerization of the polyamide polymer, the molar ratio of the terephthaloyl chloride to the isophthaloyl chloride (mol% of the terephthaloyl chloride: mol% of the isophthaloyl chloride) can be 100:0 to 0:100.

[0067] For example, the molar ratio of terephthaloyl chloride to isophthaloyl chloride (mol% of terephthaloyl chloride:mol% of isophthaloyl chloride) can be 90:10~10:90, 80:20~20:80, 75:25~25:75, 70:30~30:70, 50:50~90:10, 50:50~80:20, 50:50~70:30, 60:40~75:25, 60:40~70:30, or 70:30.

[0068] That is, for the polymerization of the polyamide polymer of this application, terephthaloyl chloride and isophthaloyl chloride can be used simultaneously.

[0069] In one embodiment, the third monomer formed by polymerizing the aforementioned sulfone-containing third monomer unit may be bis[4-(4-aminophenoxy)phenyl]sulfone, bis(4-aminophenyl)sulfone, bis(3-aminophenyl)sulfone, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, or 1,3-bis(3-aminophenyl)sulfone. 1,3-bis(3-aminophenyl)sulfone), 1,3-bis(4-aminophenylsulfone), 1,4-bis(4-aminophenylsulfone), bis[3-(3-aminophenoxy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]sulfone, bis[3-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, or combinations thereof.

[0070] In particular, the bonding properties of polyamide polymers can be significantly improved when using bis[4-(4-aminophenoxy)phenyl]sulfone. Furthermore, it can greatly contribute to improving the characteristics of batteries using anodes with bis[4-(4-aminophenoxy)phenyl]sulfone (e.g., initial efficiency characteristics of the battery).

[0071] In one embodiment, the fourth monomer formed by polymerizing the above-mentioned fourth monomer unit containing carboxylic acid can be 5,5'-methylenebis(2-aminobenzoic acid) (MBAA), 3,5-diaminobenzoic acid (DABA), or a combination thereof.

[0072] The carboxylic acid of 5,5'-methylenebis(2-aminobenzoic acid) or 3,5-diaminobenzoic acid can help improve the adhesion to aluminum current collectors.

[0073] In one embodiment, in the polyamide polymer, based on a total content of 100 mol% of the third monomer unit and the first monomer unit, the molar ratio of the third monomer unit to the first monomer unit (mol% of the third monomer unit: mol% of the first monomer unit) can be 90:10 to 1:99.

[0074] That is, the molar ratio (mol% of the third monomer to mol% of the first monomer) of the third monomer formed by polymerizing the third monomer unit can be 90:10 to 1:99.

[0075] For example, the molar ratio of the third monomer to the first monomer (mol% of the third monomer: mol%) can be 90:10~5:95, 90:10~10:90, 80:20~1:99, 80:20~5:95, 80:20~10:90, 70:30~10:90, or 70:30~20:80.

[0076] If the content of the first monomer unit containing the aforementioned ether group, a straight-chain or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof is higher than the content in this application, then the first monomer unit containing the aforementioned ether group, a straight-chain or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof has a lower molecular weight than the aforementioned diamine monomer containing sulfone. Therefore, it may exhibit reduced adhesion due to limited increase in molecular weight, and the performance of the battery may decrease.

[0077] On the other hand, if the content of the diamine monomer containing the first monomer unit having an ether group, a straight-chain or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof is lower than that in this application, the adhesion may be reduced and the battery performance may decrease.

[0078] In one embodiment, the polyamide polymer described above may contain a monomer repeating unit represented by the following chemical formula 3.

[0079] [Chemical Formula 3]

[0080]

[0081] In the above chemical formula 3,

[0082] Y1 comprises at least one aromatic ring substituted with a halogen element, hydrogen, hydroxyl group, carboxyl group, a straight-chain or branched hydrocarbon group having 1 to 4 carbon atoms, or a combination thereof.

[0083] Y2 comprises two aromatic rings linked together by -SO2-; an aromatic ring substituted with at least one carboxyl group; two aromatic rings linked together by straight-chain or branched hydrocarbon groups having 1 to 10 carbon atoms; or combinations thereof.

[0084] The two aromatic rings linked by -SO2- can be substituted by halogens, hydrogen, hydroxyl groups, carboxyl groups, straight-chain or branched hydrocarbon groups with 1 to 4 carbon atoms, substituted or unsubstituted by halogens, or combinations thereof.

[0085] c+d=1.

[0086] (Where, Y2 must contain two aromatic rings connected to each other by straight-chain or branched hydrocarbon groups having 1 to 10 oxygen or carbon atoms.)

[0087] In the above chemical formula 3, c and d represent the mole fraction.

[0088] The halogen element in the above chemical formula 3 may not include fluorine.

[0089] The monomer unit corresponding to Y1 in the above chemical formula 3 is equivalent to a monomer unit containing at least one aromatic ring.

[0090] For example, the monomer formed by polymerizing the monomer unit corresponding to Y1 of the above chemical formula 3 can be a terephthaloyl chloride monomer, an isophthaloyl chloride monomer, an phthalic acid monomer, an isophthalic acid monomer, a terephthalic acid monomer, or a combination thereof.

[0091] In addition, the monomer formed by polymerizing the monomer unit corresponding to Y2 of the above chemical formula 3 can be a diamine monomer containing sulfone and at least one aromatic ring, a diamine monomer containing carboxylic acid, a diamine monomer containing oxygen atom and a straight-chain or branched hydrocarbon with 1 to 10 carbon atoms or a combination thereof, or a combination thereof.

[0092] For example, a diamine monomer containing a sulfone and at least one aromatic ring, formed by polymerizing the monomer unit corresponding to Y2 of the above chemical formula 3, can be bis[4-(4-aminophenoxy)phenyl]sulfone, bis(4-aminophenyl)sulfone, bis(3-aminophenyl)sulfone, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 1,3- Bis(3-aminophenyl sulfone)benzene (1,3-bis(3-aminophenyl)sulfone), 1,3-bis(4-aminophenyl sulfone)benzene (1,3-bis(4-aminophenyl)sulfone), 1,4-bis(4-aminophenyl sulfone)benzene (1,4-bis(4-aminophenyl)sulfone), bis[3-(3-aminophenoxy)phenyl]sulfone (bis[3-(3-aminophenoxy)phenyl]sulfone), bis[3-(4-aminophenoxy)phenyl]sulfone (bis[3-(4-aminophenoxy)phenyl]sulfone), bis[4-(3-aminophenoxy)phenyl]sulfone (bis[4-(3-aminophenoxy)phenyl]sulfone) or combinations thereof.

[0093] In addition, the diamine monomer containing carboxylic acid formed by polymerizing the monomer unit corresponding to Y2 of the above chemical formula 3 can be 5,5'-methylenebis(2-aminobenzoic acid) (MBAA), 3,5-diaminobenzoic acid (DABA) or a combination thereof.

[0094] Additionally, for example, the diamine monomer formed by polymerizing the monomer unit corresponding to Y2 of the above chemical formula 3, containing oxygen atoms, straight-chain or branched hydrocarbon groups having 1 to 10 carbon atoms, or combinations thereof, can be 4,4'-diaminodiphenyl ether (4,4'-Oxydianiline, ODA), 3,4'-methylenedianilne (3,4'-MDA), 1,3-bis(3-aminophenoxy)benzene (APB), 1,4-bis(4-aminophenoxy)benzene (1,4-Bis(4-aminophenoxy)benzene), 1,3-bis(4-aminophenoxy)benzene (1,3-Bis(4-aminophenoxy)benzene), 1, 3-Bis[2-(4-aminophenyl)-2-propyl]benzene, 4,4'-Diaminodiphenylmethane, 4,4'-Diaminodiphenylethane, 4,4'-Isopropylidenebis[(4-aminophenoxy)benzene], 4,4'-(1,4-Phenylenediisopropylidene)bisaniline, or combinations thereof.

[0095] In one embodiment, the weight-average molecular weight of the polyamide polymer can be more than 50,000 and less than 1,000,000.

[0096] Within the range of weight-average molecular weight of the polyamide polymers in this application, the higher the weight-average molecular weight, the higher the adhesive strength of the polyamide polymer can become.

[0097] When the weight-average molecular weight of the aforementioned polyamide polymer is less than 50,000, the electrolyte stability of the electrode binder containing the polyamide polymer may decrease. Additionally, the stability of the electrode slurry containing a binder containing a polyamide polymer may also decrease.

[0098] On the other hand, if the weight-average molecular weight of the aforementioned polyamide polymer is higher than 1,000,000, the viscosity may become high during slurry production, making slurry coating difficult.

[0099] Another aspect of the adhesive in this application may comprise the aforementioned polyamide polymer.

[0100] Another aspect of the slurry of this application may include the aforementioned binder and electrode active material.

[0101] In one embodiment, the slurry may contain organic solvents such as carboxymethyl cellulose, NMP (N-methylpyrrolidone), DMF (dimethylformamide), acetone, and dimethylacetamide, or water as a solvent; carboxymethyl cellulose is preferred. Furthermore, the slurry may contain more than one solvent.

[0102] The degree of substitution of the hydroxyl group (-OH) based on carboxymethyl (-CH2CO2H) in the above-mentioned carboxymethyl cellulose can be 0.7 to 1.2, the molecular weight (Mn) can be 500,000 to 900,000, and the pH can be 6.5 to 8.0.

[0103] In addition, the above slurry may contain electrode active materials capable of lithium-ion intercalation and deintercalation with carboxymethyl cellulose (CMC).

[0104] For example, the aforementioned slurry can be an anode slurry, a cathode slurry, or a combination thereof.

[0105] The electrode active material used in the electrode formation of the present invention can be any electrode active material available in the art.

[0106] In one embodiment, the aforementioned electrode active material is a substance capable of initiating an electrochemical reaction and is used to manufacture cathode and anode slurries. Depending on the type of electrode, there are cathode active materials and anode active materials.

[0107] The aforementioned cathode active material can be one or more selected from the group consisting of carbon and graphite materials capable of lithium-ion intercalation and deintercalation, Si-based materials, metals and compounds capable of forming alloys with lithium, complexes of metals and their compounds with carbon and graphite materials, and lithium-containing nitrides.

[0108] As carbon and graphite materials, there are natural graphite, artificial graphite, expanded graphite, carbon fiber, non-graphitizable carbon, carbon black, carbon nanotubes, fullerenes, activated carbon, hard carbon, and soft carbon. As Si-based materials, there are Si and SiO. x(0 < x < 2), S-based compounds such as Si-Y alloys (where Y is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element, transition metal, rare earth element, or a combination thereof), Si-C composites, or combinations thereof. As metals and elements capable of forming alloys with lithium, there are Al, Si, Sn, Ag, Bi, Mg, Zn, In, Ge, Pb, Pd, Pt, Ti, etc. The above cathode paste may contain the above cathode active material in a content of 20 to 80 parts by weight based on 100 parts by weight of the above cathode paste.

[0109] Specific examples of the above anode active material include: lithium metal; lithium cobalt-based oxides such as LiCoO2; Li 1+x Mn 2-x O4 (where x is from 0 to 0.33), lithium manganese-based oxides such as LiMnO3, LiMn2O3, LiMnO2; lithium copper oxides such as Li2CuO2; vanadium oxides such as LiV3O8, V2O5, Cu2V2O7; LiNi 1-x M x O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, x = 0.01 to 0.3) represented by lithium nickel-based oxides; LiMn 2-x M x O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, x = 0.01 to 0.1) or lithium manganese composite oxides represented by Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); Li(Ni a Co b Mn c )O2 (where 0 < a < 1, 0 < b < 1, 0 < c < 1, a + b + c = 1) represented by lithium-nickel-manganese-cobalt-based oxides; sulfur or disulfide compounds; phosphates such as LiFePO4, LiMnPO4, LiCoPO4, LiNiPO4; Fe2(MoO4)3, etc., but not limited to these.

[0110] As the secondary battery adhesive, in addition to the adhesive containing a polyamide polymer containing monomer units with an aromatic ring of the present application, any one or two or more of the following compounds can be selected and used together: poly(meth)acrylic acid, poly(meth)acrylamide, carboxymethyl cellulose, polyvinylidene fluoride, copolymer of polyhexafluoropropylene - polyvinylidene fluoride (P(VdF / HFP)), poly(vinyl acetate), polyvinyl alcohol, poly(ethylene oxide), polyvinylpyrrolidone, alkylated poly(ethylene oxide), poly(ethylene ether), poly(methyl methacrylate), poly(ethyl acrylate), polytetrafluoroethylene, polyvinyl chloride, polyacrylonitrile, polyvinylpyridine, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and their copolymers.

[0111] The content of the aforementioned binder in the slurry composition, based on the solid content, is preferably 0.3 wt% to 10 wt%, more preferably 0.7 wt% to 8 wt%. If the content is less than 0.3 wt%, it is difficult to expect sufficient bonding force within the current collector and electrode composition. When the content is greater than 10 wt%, the binder ratio in the electrode slurry composition increases, which may reduce the battery capacity.

[0112] The electrode of another aspect of this application may include: a current collector; and an electrode active material layer containing the adhesive of this application, a non-coated portion insulating coating, or a combination thereof formed on the current collector.

[0113] For example, the electrodes described above can be anodes, cathodes, or a combination thereof.

[0114] In one embodiment of this application, the current collector is the portion in which electron migration occurs during the electrochemical reaction of the active material. Depending on the type of electrode, there are cathode current collectors and anode current collectors. The current collector may also have minute irregularities formed on its surface to enhance the bonding force of the electrode active material, and it can be used in various forms such as films, sheets, foils, meshes, porous bodies, foams, and nonwoven fabrics.

[0115] The aforementioned cathode current collector can generally be formed with a thickness of 5 μm to 30 μm. There are no particular restrictions on such a cathode current collector as long as it does not cause a chemical change in the corresponding cell and is conductive. For example, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, or combinations thereof can be used.

[0116] The aforementioned anode current collector can generally be formed with a thickness ranging from 3 μm to 500 μm. There are no particular restrictions on the anode current collector as long as it does not cause chemical changes in the corresponding battery and has high conductivity. For example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel, aluminum-cadmium alloys with surface treatments such as carbon, nickel, titanium, and silver can be used.

[0117] The electrode described above can be manufactured by the following steps: (a) manufacturing a composition for forming an electrode active material layer comprising an electrode active material and the binder of this application; and (b) coating the current collector with the composition for forming an electrode active material layer and then drying it.

[0118] The above-mentioned composition for forming the electrode active material layer can be mixed using a conventional mixer, such as a high-speed shear mixer or a homogenizer, by stirring in a conventional manner.

[0119] Step (b) above is a step of manufacturing an electrode for a lithium secondary battery by coating the electrode active material layer formation composition manufactured in step (a) onto the current collector and then drying it.

[0120] At this time, there is no limitation on the method of forming the electrode active material layer by coating the above-mentioned slurry. For example, it can be manufactured by implementing doctor blade coating, dip coating, gravure coating, slit die coating, spin coating, comma coating, bar coating, reverse roll coating, screen coating, cap coating, etc.

[0121] After coating and drying, electrodes for secondary batteries (especially lithium secondary batteries) with electrode active material layers can be manufactured.

[0122] The aforementioned current collectors can be used as long as they are conductive and do not chemically react with the electrode forming paste. Representative examples include aluminum foil and copper foil. Current collectors with a thickness between 3 and 50 micrometers can be selected.

[0123] At this point, in addition to the electrode active material, the aforementioned electrode active material layer may further contain dispersants, conductive materials, fillers, and other additives.

[0124] The content of the aforementioned electrode active material, based on the solid component content, can be 90-99% by weight. If the content of active material is low, the battery may not be able to achieve high capacity; if the content of active material is too high, the content of binders, conductive materials, etc., will be relatively low, and thus the electrode adhesion and conductivity may be reduced.

[0125] There are no particular restrictions on the conductive materials mentioned above, and they can be selected appropriately according to the type of battery and capacitor. For example, in the case of lithium-ion secondary batteries, carbon such as graphite and activated carbon can be used, while in the case of nickel-metal hydride secondary batteries, cobalt oxide can be used, and the cathode can be made of nickel powder, cobalt oxide, titanium oxide, carbon, etc.

[0126] Examples of carbon species mentioned above include acetylene black, furnace black, graphite, carbon fiber, fullerenes, and carbon nanotubes.

[0127] The amount of the conductive material used is typically 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the electrode active material.

[0128] By reducing the amount of conductive material and increasing the amount of electrode active material, the energy density of the secondary battery can be improved. Therefore, it is important to show high efficiency when using the same amount of conductive material.

[0129] The smaller and more uniformly the conductive material is dispersed in the slurry used in secondary batteries, the higher the conductivity and the lower the internal resistance of the battery, resulting in improved output and lifespan characteristics. Conversely, if the dispersion is large and uneven, even with the same quantity, the binding properties and conductivity will decrease, adversely affecting the battery's lifespan and output characteristics. Furthermore, if the dispersion has a low viscosity, the solids content of the slurry can be increased to improve electrode production speed.

[0130] Another aspect of the diaphragm of this application may comprise a porous substrate coated with a slurry composition comprising the adhesive of this application.

[0131] The separator must be an insulator capable of separating the cathode and anode, and must provide a pathway for lithium ions to migrate only. Therefore, it must have good wettability with the electrolyte, and porous polymer membranes such as PE / PP or porous nonwoven fabrics can be used. To prevent battery short circuits, separators coated with ceramics or other materials that enhance heat resistance and mechanical strength can be used, and can be coated in single or multiple layers.

[0132] The aforementioned diaphragm can be made of a porous substrate. Any porous substrate commonly used in electrochemical devices can be used, such as polyolefin porous membranes or nonwoven fabrics, but it is not particularly limited to these.

[0133] The aforementioned diaphragm may be a porous substrate formed from any one or more mixtures selected from the group consisting of: polyethylene, polypropylene, polybutene, polypentene, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene ether, polyphenylene sulfide, and polyethylene naphthalate.

[0134] The above-mentioned slurry composition may contain inorganic particles. These inorganic particles can be used without limitation as long as they are insulating particles, and preferably are high dielectric constant insulating particles.

[0135] Specific examples of the aforementioned inorganic particles include Al2O3, AlOOH, SiO2, TiO2, ZrO2, ZnO, NiO, CaO, SnO2, Y2O3, MgO, BaTiO3, CaTiO3, SrTiO3, SiC, Li3PO4, Pb(Zr,Ti)O3(PZT), (Pb,La)(Zr,Ti)O3(PLZT), and mixtures thereof.

[0136] There is no particular limitation on the size of the inorganic particles. For example, the average particle size can be from 0.01 μm to 30 μm, more preferably from 0.1 μm to 10 μm. If the average particle size of the inorganic particles is lower than the above-mentioned preferred range, the dispersibility may deteriorate. If it is higher than the above-mentioned preferred range, the thickness of the coated layer may become thicker, resulting in a decrease in mechanical properties.

[0137] In addition, there are no particular restrictions on the shape of the aforementioned inorganic particles; for example, they can be spherical, plate-shaped, elliptical, or irregular in shape.

[0138] A diaphragm can be manufactured by coating the above-mentioned slurry composition onto at least one side of a porous substrate membrane or by forming the above-mentioned slurry composition into a membrane and attaching it to a porous substrate membrane.

[0139] On the other hand, the above-mentioned separator can be used as a separator for secondary batteries, for example, it can be used as a separator for lithium secondary batteries.

[0140] As an example of membrane manufacturing, it may include: (a) dissolving or dispersing the above-mentioned adhesive in a solvent to produce a polymer solution; (b) adding and mixing inorganic particles in the polymer solution of step (a); and (c) coating and drying the mixture of step (b) on one or more regions selected from the group consisting of the surface of a polyolefin membrane substrate and a portion of the pore portion of the substrate.

[0141] First, 1) dissolve or disperse the above-mentioned adhesive in a suitable solvent to manufacture and prepare it in the form of a polymer solution.

[0142] As a solvent, a solvent with a solubility index similar to that of the aforementioned copolymer used as a binder and a low boiling point is preferred. This is for uniform mixing and easy solvent removal afterwards. Non-limiting examples of solvents that can be used include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone (NMP), cyclohexane, water, or mixtures thereof. More preferably, it can be used in a state of dispersion in water.

[0143] 2) Add inorganic particles to the polymer solution and disperse them to produce a mixture of inorganic particles and polymer.

[0144] The preferred method is to perform a dispersion process involving the polymer solution and inorganic particles. In this case, a dispersion time of 1 to 50 hours is suitable. Conventional methods can be used as the dispersion method, with ball milling being particularly preferred.

[0145] The composition of the mixture of inorganic particles and polymers is not significantly restricted, but the thickness, pore size and porosity of the organic / inorganic composite porous membrane of the present invention can be adjusted accordingly.

[0146] That is, as the ratio of inorganic particles (I) to polymers (P) increases (ratio = I / P), the porosity of the membrane increases, resulting in a greater membrane thickness for the same solid content (weight of inorganic particles + weight of polymers). Furthermore, it increases the likelihood of pore formation between inorganic particles, leading to an increase in pore size. In this case, the larger the size (particle diameter) of the inorganic particles, the greater the interstitial distance between them, thus increasing the pore size.

[0147] 3) The mixture of inorganic particles and polymers is coated onto the prepared polyolefin membrane substrate and then dried to obtain the membrane of the present invention.

[0148] At this point, the method for coating the mixture of inorganic particles and polymers onto the polyolefin-based separator substrate can employ conventional coating methods known in the art, such as dip coating, die coating, roll coating, comma coating, or a combination thereof. Furthermore, when coating the mixture of inorganic particles and polymers onto the polyolefin-based separator substrate, both sides of the separator substrate can be coated, or only one side can be coated.

[0149] Another aspect of this application is that the slurry composition for the insulating coating of the blank area of ​​a secondary battery may contain the adhesive of this application.

[0150] In addition, the above-mentioned slurry composition for insulating coating in the blank area of ​​the secondary battery may further contain inorganic particles, which may be AlOOH, Al2O3, γ-AlOOH, Al(OH)3, SiO2, silicon carbide (SiC), boron nitride (BN) or a combination thereof.

[0151] The above-mentioned slurry composition for insulating coating of the blank area of ​​the secondary battery may contain 5% to 30% of the above-mentioned adhesive and 70% to 95% of the above-mentioned inorganic particles, based on 100% of the total weight of the above-mentioned adhesive and inorganic particles.

[0152] On the other hand, the solid content of the above-mentioned slurry composition for insulating coating of the blank area of ​​the secondary battery can be more than 10% by weight and less than 45% by weight.

[0153] For example, the insulating coating for the blank area of ​​the secondary battery electrode can be manufactured by applying the above-mentioned slurry composition for the insulating coating of the blank area to the electrode current collector and then drying it.

[0154] Another aspect of the secondary battery of this application may include the adhesive of this application.

[0155] For example, the aforementioned secondary battery may include an anode, cathode, separator, or a combination thereof containing the adhesive of this application.

[0156] The aforementioned secondary battery may include an anode, a cathode, a separator between the anode and the cathode, and an electrolyte.

[0157] The aforementioned secondary battery can be manufactured according to conventional methods known in the art. As one embodiment, the electrodes can be assembled with a separator in between, and then an electrolyte can be injected into the assembly.

[0158] On the other hand, the electrolyte of the aforementioned secondary battery is a non-aqueous electrolyte containing lithium salt, consisting of lithium salt and solvent. The solvent used includes non-aqueous organic solvents, organic solid electrolytes, and inorganic solid electrolytes.

[0159] The lithium salts mentioned above are substances that are readily soluble in the aforementioned non-aqueous electrolytes. For example, LiCl, LiBr, LiI, LiClO4, LiBF4, and LiB can be used. 10 Cl 10 LiPF6, LiAsF6, LiSbF6, LiAlCl4, LiSCN, LiC4BO8, LiCF3CO2, LiCH3SO3, LiCF3SO3, LiN(SO2CF3)2, LiN(SO2F)2, LiN(SO2C2F5)2, LiC4F9SO3, LiC(CF3SO2)3, (CF3SO2)·2Nli, lithium chloroborane, lower aliphatic carboxylic acids, lithium 4-phenylboronic acid imide, etc.

[0160] Non-aqueous organic solvents such as N-methyl-2-pyrrolidone, propylene carbonate, ethylene carbonate, butenyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydroxyfranc, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,3-dioxolane, 4-methyl-1,3-diepoxyethylene, diethyl ether, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, triphosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ethers, methyl propionate, ethyl propionate, and other non-protic organic solvents can be used.

[0161] As the aforementioned organic solid electrolyte, for example, polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate polymers, agitation lysine, polyester sulfides, polyvinyl alcohol, polyvinylidene fluoride, polymers containing secondary dissociation groups, etc., can be used.

[0162] As the aforementioned inorganic solid electrolytes, for example, nitrides, halides, and sulfates of Li such as Li3N, LiI, Li5NI2, Li3N-LiI-LiOH, LiSiO4, LiSiO4-LiI-LiOH, Li2SiS3, Li4SiO4, Li4SiO4-LiI-LiOH, and Li3PO4-Li2S-SiS2 can be used.

[0163] In addition, non-aqueous electrolytes may contain other additives for purposes such as improving charging / discharging characteristics and flame retardancy. Examples of such additives include pyridine, triethyl phosphite, triethanolamine, cyclic ethers, ethylenediamine, n-glycol dimethyl ether (glyme), triammonium hexaphosphate, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolides, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, aluminum trichloride, fluoroethylene carbonate (FEC), propenesulfonyl lactone (PRS), and vinylene carbonate (VC).

[0164] In addition to the conventional winding process, the lithium secondary battery of the present invention can also undergo lamination stacking and folding processes for the separator and electrodes. Furthermore, the battery casing can be cylindrical, square, pouch-shaped, or coin-shaped, etc.

[0165] In one embodiment, the initial discharge capacity of a secondary battery (cell) containing the adhesive described above can be 190 mAh / g or higher.

[0166] For example, it can be above 193mAh / g, above 195mAh / g, or above 196mAh / g.

[0167] At this point, the initial discharge capacity can be initialized as follows: In CC / CV mode, charge to 4.2V at a rate of 0.1C, then discharge to 2.8V at a rate of 0.1C, then charge to 4.2V at a rate of 0.2C, then discharge to 2.8V at a rate of 0.2C, then charge to 4.2V at a rate of 0.5C, then discharge to 2.8V at a rate of 0.5C. The chamber temperature can be set to 25℃.

[0168] In the above initialization, the discharge capacity when discharged at a rate of 0.1C to 2.8V can be measured as the initial discharge capacity.

[0169] In one embodiment, the initial efficiency of a secondary battery (cell) containing the adhesive described above can be 85% or higher.

[0170] For example, it can be above 86%, above 87%, or above 87.15%.

[0171] At this point, the initial efficiency mentioned above can be calculated using the following mathematical formula 1.

[0172] <Mathematical Formula 1>

[0173] Initial efficiency [%] = [Initial discharge capacity / Initial charge capacity] × 100

[0174] In one embodiment, the DC-IR resistance of the secondary battery (cell) containing the adhesive described above can be 23.5 mΩ or less.

[0175] For example, it can be below 23.4mΩ, below 23.3mΩ, below 23.2mΩ, below 23.1mΩ, below 23mΩ, below 21mΩ, or below 19.4mΩ.

[0176] In one embodiment, the capacity retention rate (CycleStability), calculated by measuring the capacity of a secondary battery (cell) containing the adhesive described above after 100 cycles relative to its initial capacity (capacity in the first cycle), can be 95% or higher.

[0177] For example, it can be above 95.5%, above 96%, or above 96.3%.

[0178] To determine the capacity retention rate mentioned above, the chamber can be charged to 4.2V at a 1C rate and then discharged to 2.8V at a 1C rate in CC / CV mode, with the chamber temperature set to 25°C.

[0179] The "C" above refers to the battery's discharge rate, which is the value obtained by dividing the battery's total capacity by the total discharge time.

[0180] The battery can be charged / discharged under these conditions to perform cycle analysis. A cycle consists of one charge and one discharge.

[0181] The battery capacity retention rate after 100 cycles can be calculated using the following mathematical formula 1.

[0182] <Mathematical Formula 1>

[0183] Capacity retention (%) = (Capacity at 100th cycle / Initial capacity) × 100

[0184] The present application will now be described in more detail using examples, but the present application is not limited thereto.

[0185] Manufacturing Example 1. Manufacturing of Polymers for Adhesives

[0186] [Example 1]

[0187] In a 500 ml four-necked flask under a nitrogen atmosphere, N-methyl-2-pyrrolidone (NMP), monomers 4,4'-Oxydianiline (ODA) and (bis[4-(4-aminophenoxy)phenyl]sulfone Bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), and 5,5'-methylenebis(2-aminobenzoic acid) (MBAA) containing a carboxylic acid were added and stirred.

[0188] Based on a total molar percentage of 100 mol% for the polyamide copolymer used in adhesives, the amount of MBAA is fixed at 5 mol%, and the molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 4,4'-diaminodiphenyl ether is 7:3.

[0189] Then, after lowering the internal temperature of the reactor to below 5°C, isophthaloyl chloride (IPC), a monomeric unit containing an aromatic ring, is added and reacted.

[0190] Add terephthaloyl chloride (TPC), a monomer that forms a monomer unit containing an aromatic ring, and stir for a sufficient time.

[0191] The molar ratio of the above-mentioned isophthaloyl chloride to the above-mentioned terephthaloyl chloride is 3:7.

[0192] An olefinic neutralizing agent is added to a solution whose viscosity has increased to a certain extent, and the solution is stirred to remove the HCl generated during the synthesis process.

[0193] The final product is a polyamide copolymer solution for adhesives with a solid component concentration of 10% by weight.

[0194] [Example 2]

[0195] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 4,4'-diaminodiphenyl ether was changed to 5:5, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 1.

[0196] [Example 3]

[0197] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 4,4'-diaminodiphenyl ether was changed to 3:7, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 1.

[0198] [Example 4]

[0199] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 4,4'-diaminodiphenyl ether was changed to 1:9, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 1.

[0200] [Example 5]

[0201] In a 500 ml four-necked flask under a nitrogen atmosphere, N-methyl-2-pyrrolidone (NMP), 3,4'-methylenedianilne (3,4'-MDA) and (bis[4-(4-aminophenoxy)phenyl]sulfone Bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), and 5,5'-methylenebis(2-aminobenzoic acid) (MBAA) containing a carboxylic acid were added and stirred.

[0202] Based on a total molar percentage of 100 mol% for the polyamide copolymer used in adhesives, the amount of MBAA is fixed at 5 mol%, and the molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl]sulfone to the above-mentioned 3,4'-methylenediphenylamine is 7:3.

[0203] Then, after lowering the internal temperature of the reactor to below 5°C, isophthaloyl chloride (IPC), a monomeric unit containing an aromatic ring, is added and reacted.

[0204] Add terephthaloyl chloride (TPC), a monomer that forms a monomer unit containing an aromatic ring, and stir for a sufficient time.

[0205] The molar ratio of the above-mentioned isophthaloyl chloride to the above-mentioned terephthaloyl chloride is 3:7.

[0206] An olefinic neutralizing agent is added to a solution whose viscosity has increased to a certain extent, and the solution is stirred to remove the HCl generated during the synthesis process.

[0207] The final product is a polyamide copolymer solution for adhesives with a solid component concentration of 10% by weight.

[0208] [Example 6]

[0209] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 3,4'-methylenediphenylamine was changed to 5:5, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 5.

[0210] [Example 7]

[0211] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 3,4'-methylenediphenylamine was changed to 3:7, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 5.

[0212] [Example 8]

[0213] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 3,4'-methylenediphenylamine was changed to 1:9, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 5.

[0214] [Example 9]

[0215] In a 500 ml four-necked flask under a nitrogen atmosphere, N-methyl-2-pyrrolidone (NMP), monomers 1,3-Bis(3-aminophenoxy)benzene (APB) and (bis[4-(4-aminophenoxy)phenyl]sulfone Bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), and 5,5'-methylenebis(2-aminobenzoic acid) (MBAA) containing a carboxylic acid were added and stirred.

[0216] Based on a total molar percentage of 100 mol% for the polyamide copolymer used in adhesives, the amount of MBAA is fixed at 5 mol%, and the molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl]sulfone to the above-mentioned 1,3-bis(3-aminophenoxy)benzene is 7:3.

[0217] Then, after lowering the internal temperature of the reactor to below 5°C, isophthaloyl chloride (IPC), a monomeric unit containing an aromatic ring, is added and reacted.

[0218] Add terephthaloyl chloride (TPC), a monomer that forms a monomer unit containing an aromatic ring, and stir for a sufficient time.

[0219] The molar ratio of the above-mentioned isophthaloyl chloride to the above-mentioned terephthaloyl chloride is 3:7.

[0220] An olefinic neutralizing agent is added to a solution whose viscosity has increased to a certain extent, and the solution is stirred to remove the HCl generated during the synthesis process.

[0221] The final product is a polyamide copolymer solution for adhesives with a solid component concentration of 10% by weight.

[0222] [Example 10]

[0223] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl]sulfone to the above-mentioned 1,3-bis(3-aminophenoxy)benzene was changed to 5:5, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 9.

[0224] [Example 11]

[0225] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl]sulfone to the above-mentioned 1,3-bis(3-aminophenoxy)benzene was changed to 3:7, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 9.

[0226] [Example 12]

[0227] The molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 1,3-bis(3-aminophenoxy)benzene was changed to 2:8, and the polyamide copolymer solution for adhesive was prepared in the same manner as in Example 9.

[0228] [Comparative Example 1]

[0229] The polyamide copolymer solution for adhesives was prepared in the same manner as in Example 1, except that 4,4'-diaminodiphenyl ether was not added (the molar ratio of the above-mentioned bis[4-(4-aminophenoxy)phenyl] sulfone to the above-mentioned 4,4'-diaminodiphenyl ether was 10:0).

[0230] The monomer composition and the molar ratios of BAPS with ODA, BAPS with 3,4'-MDA, and BAPS with APB in Examples 1 to 12 and Comparative Example 1 are shown in Table 1 below.

[0231] [Table 1]

[0232]

[0233] Manufacturing Example 2. Manufacturing of Anode Slurry and Anode

[0234] An anode active material slurry composition with a solid content of 65% by weight was prepared by mixing 97.5% by weight of NCM811 as the electrode active material, 1.5% by weight of the binder polymer of Examples 1 to 12 and Comparative Example 1, 1% by weight of CNT dispersion, and the balance of NMP.

[0235] That is, an anode active material slurry composition with a solid content of 65% by weight was prepared by using 97.5% by weight of NCM811 as the electrode active material, 1.5% by weight of the binder polymer of Examples 1 to 12 and Comparative Example 1, 1% by weight of CNT dispersion, and NMP as the remainder.

[0236] On the other hand, the aforementioned anolyte slurry composition may comprise 96% to 98% by weight of the aforementioned electrode active material, 1.5% to 2% by weight of the aforementioned binder polymer, and 0.7% to 0.8% by weight of CNT dispersion. Furthermore, the solid content of the aforementioned anolyte slurry composition may be 60% to 70% by weight.

[0237] The prepared anode slurry composition was coated onto a 20 μm thick aluminum (Al) foil serving as the anode current collector using a coater. After drying in a 110°C circulating oven for 1 hour, the dried anode was rolled using a roll press to manufacture the anode.

[0238] Manufacturing Example 3. Battery Manufacturing

[0239] A non-aqueous electrolyte containing 1% by weight of 1M LiPF6, fluoroethylene carbonate (FEC), 1% by weight of propylene sulfide (PS), and 1% by weight of LiPO2F2 was used as the electrolyte. After sandwiching a polyolefin separator between the anode and cathode of the anode plate of Examples 1 to 12 and Comparative Example 1, which were manufactured using the adhesive polymer of Manufacturing Example 2 described above, a lithium secondary battery of 2032 button cell type was manufactured without distinguishing its shape.

[0240] Evaluation Example 1. Adhesion Strength Measurement

[0241] The anode manufactured by Example 2 was dried at 130°C for 1 hour and then cut into 15 x 2.5 cm pieces.

[0242] Then, the anode-coated side is bonded to an acrylic sheet with adhesive tape on both sides, and pressed 3-4 times with a rubber roller to produce an adhesion test (peel-off test) sample.

[0243] The prepared sample was placed on a UTM capable of measuring adhesive strength to perform a 2.5cm, 180° peel test, and the load value (gf / 25mm) was measured to calculate the adhesive force of the anode.

[0244] The calculated adhesion strength of the anode is shown in Table 2 below.

[0245] [Table 2]

[0246]

[0247] As shown in Table 2 above, the adhesive polymers of Examples 1 to 12 exhibited an adhesive strength of 90.59 gf / 25 mm or higher.

[0248] It can be confirmed that the adhesive polymers of Examples 1 to 12 have significantly improved adhesive strength compared to the polyamide adhesive polymer of Comparative Example 1, which does not use ODA as a monomer.

[0249] On the other hand, it can be confirmed that the anodic adhesion of the adhesive polymers in Examples 1 to 4 is improved due to the increased content of ODA in the molar ratio of BAPS to ODA (mol% of BAPS:mol%) of ODA.

[0250] Furthermore, it can be confirmed that the anodic adhesion of the adhesive polymers in Examples 5 to 8 is improved due to the increased content of 3,4'-MDA in the molar ratio of BAPS to 3,4'-MDA (mol% of BAPS:mol%) of 3,4'-MDA.

[0251] Furthermore, it can be confirmed that the anodic adhesion of the adhesive polymers in Examples 9 to 12 is improved due to the increased content of APB in the molar ratio of BAPS to APB (mol% of BAPS:mol%).

[0252] The results confirm that the adhesive of this application, which contains polyamide polymers with appropriately adjusted molar ratios of BAPS to ODA, BAPS to 3,4'-MDA, and BAPS to APB, exhibits excellent adhesive properties.

[0253] Evaluation Example 2. Battery Performance Measurement

[0254] A battery manufactured according to Manufacturing Example 3, using an anode plate made with the adhesive polymer of Examples 1 to 12 and Comparative Example 1, was charged to 4.2V at a rate of 0.1C in CC / CV mode, then discharged to 2.8V at a rate of 0.1C, followed by charging to 4.2V at a rate of 0.2C, then discharging to 2.8V at a rate of 0.2C, then charging to 4.2V at a rate of 0.5C, and then discharging to 2.8V at a rate of 0.5C (initialization). The chamber temperature was 25°C. Here, "C" represents the battery discharge rate, calculated by dividing the total battery capacity by the total discharge time.

[0255] The results of measuring the initial discharge capacity and initial efficiency of the battery manufactured according to Manufacturing Example 3 using the anode plate of the adhesive polymer of Examples 1 to 12 and Comparative Example 1 are shown in Table 3 below.

[0256] During initialization, the discharge capacity at a rate of 0.1C to 2.8V is measured as the initial discharge capacity, and the initial efficiency is calculated using the following mathematical formula 1.

[0257] <Mathematical Formula 1>

[0258] Initial efficiency [%] = [Initial discharge capacity / Initial charge capacity] × 100

[0259] [Table 3]

[0260]

[0261] As shown in Table 3 above, the battery manufactured according to Manufacturing Example 3 using an anode plate with an adhesive polymer from Examples 1 to 12 exhibits an initial discharge capacity of 196.01 mAh / g or more and an initial efficiency of 87.15% or more.

[0262] It can be confirmed that when comparing the battery manufactured according to Manufacturing Example 3 using an anode plate made with the adhesive polymer of Examples 1 to 12 and the battery manufactured according to Manufacturing Example 3 using an anode plate made with the polyamide adhesive polymer of Comparative Example 1 without using ODA as a monomer, the initial discharge capacity and initial efficiency both showed the same or improved results.

[0263] Furthermore, when using an electrode adhesive containing the polyamide polymer of this application (Examples 1 to 12), compared with the case of using an electrode adhesive containing the polymer of Comparative Example 1, the improved bonding properties can prevent electrode detachment caused by lithium ion migration, thereby presumably improving the electrochemical characteristics of the secondary battery.

[0264] Evaluation Example 3. DC-IR Resistance Measurement

[0265] The battery manufactured according to Manufacturing Example 3, using an anode plate made with the adhesive polymer of Examples 1 to 12 and Comparative Example 1, was charged to 4.2V at a 1C rate in CC / CV mode and then discharged to 2.8V at a 1C rate.

[0266] The DC-IR resistance value was measured when the discharged battery reached 50% of its remaining State of Charge (SoC).

[0267] At this point, the chamber temperature is 25°C. The "C" above represents the battery's discharge rate, calculated by dividing the battery's total capacity by the total discharge time.

[0268] The DC-IR resistance values ​​of the batteries manufactured according to Manufacturing Example 3 using the anode plates of the adhesive polymers of Examples 1 to 12 and Comparative Example 1 are shown in Table 4 below.

[0269] [Table 4]

[0270]

[0271] As shown in Table 4 above, the DC-IR resistance values ​​of the batteries manufactured according to Manufacturing Example 3 using the anode plates of the adhesive polymers of Examples 1 to 12 show resistance values ​​of less than 23.1 mΩ.

[0272] In particular, the DC-IR resistance value of the battery manufactured according to Manufacturing Example 3 using the anode plate of the adhesive polymer of Examples 5 to 12 showed a resistance value of less than 19.4 mΩ.

[0273] That is, it can be confirmed that the battery manufactured according to Manufacturing Example 3 using an anode plate with an adhesive polymer of Examples 5 to 12 has a lower resistance value than the battery manufactured according to Manufacturing Example 3 using an anode plate with a polyamide adhesive polymer of Comparative Example 1 that does not use ODA as a monomer.

[0274] Furthermore, it can be confirmed that the battery manufactured according to Manufacturing Example 3 using an anode plate made with the adhesive polymer of Examples 1 to 4 and a battery manufactured according to Manufacturing Example 3 using an anode plate made with the polyamide adhesive polymer of Comparative Example 1, which does not use ODA as a monomer, exhibits the same level of resistance value.

[0275] Evaluation Example 4. Battery Capacity Retention Measurement

[0276] The charging / discharging and chamber temperature conditions were set to analyze the capacity retention (Cycle Stability) of the battery manufactured according to Manufacturing Example 3 using an anode plate made with the adhesive polymer of Examples 1 to 4 and Comparative Examples 1 to 3.

[0277] In CC / CV mode, the battery is charged to 4.2V at a 1C rate and then discharged to 2.8V at a 1C rate. At this time, the chamber temperature is 25°C. The "C" above refers to the battery's discharge rate, which is the value obtained by dividing the battery's total capacity by the total discharge time.

[0278] The battery is charged and discharged under these conditions to perform a cycle analysis. One cycle consists of one charge and one discharge, and a total of 100 cycles are performed. At the end of the 100th cycle, the battery capacity is measured relative to the initial capacity (capacity in the first cycle) to determine how much capacity remains after cycling.

[0279] The capacity retention rate of the battery manufactured according to Manufacturing Example 3 using the anode plate of the adhesive polymer of Examples 1 to 12 and Comparative Example 1 is shown in Table 5 below.

[0280] The battery capacity retention rate after 100 cycles is calculated using the following mathematical formula 1.

[0281] <Mathematical Formula 1>

[0282] Capacity retention (%) = (Capacity at 100th cycle / Initial capacity) × 100

[0283] [Table 5]

[0284]

[0285] As shown in Table 5 above, the battery manufactured according to Manufacturing Example 3 using an anode plate utilizing the adhesive polymer of Examples 1 to 12 showed a capacity retention rate of over 96.33%.

[0286] It can be confirmed that the battery manufactured according to Manufacturing Example 3 using an anode plate with an adhesive polymer of Examples 1 to 12 showed the same or improved capacity retention rate compared to the battery manufactured according to Manufacturing Example 3 using an anode plate with a polyamide adhesive polymer of Comparative Example 1 that did not use ODA as a monomer.

[0287] The battery capacity retention rate measurement results show a similar trend to the DC-IR resistance value measurement results, suggesting that the reduction in DC-IR resistance value also has a positive impact on battery capacity retention rate.

[0288] The results confirm that the binder of this application, which contains polyamide polymers with appropriately adjusted molar ratios of BAPS to ODA, BAPS to 3,4'-MDA, and BAPS to APB, exhibits excellent effects in improving battery internal resistance and enhancing battery capacity retention.

[0289] Furthermore, it can be confirmed that the characteristics of the secondary battery are improved when an adhesive containing the polyamide polymer of this application is used.

[0290] The scope of this invention is embodied in the claims described below rather than in the foregoing detailed description, and all modifications or alterations derived from the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of this invention.

Claims

1. A polyamide polymer comprising a first monomer unit, the first monomer unit containing an ether group, a linear or branched hydrocarbon group having 1 to 10 carbon atoms, or a combination thereof.

2. The polyamide polymer according to claim 1, wherein the first monomer unit comprises a structure represented by chemical formula 1, wherein the structure represented by chemical formula 1 comprises two aromatic rings connected to each other by straight-chain or branched hydrocarbon groups having 1 to 10 carbon atoms. Chemical Formula 1 R1 and R2 are each independently hydrogen, or straight-chain or branched hydrocarbon groups having 1 to 4 carbon atoms. m ranges from 1 to 4.

3. The polyamide polymer according to claim 1, wherein the first monomer unit is formed by polymerization of a first monomer represented by the following chemical formula 2. Chemical formula 2 In the chemical formula 2, a+b+c is greater than 1 and less than 10. X1, X2, and X3 are each independently an oxygen atom or a straight-chain or branched hydrocarbon group with 1 to 10 carbon atoms.

4. The polyamide polymer according to claim 3, wherein the first monomer is 4,4'-diaminodiphenyl ether (ODA), 3,4'-methylenediphenylamine (3,4'-MDA), 1,3-bis(3-aminophenoxy)benzene (APB), 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-isopropylidene bis[(4-aminophenoxy)benzene], 4,4'-(1,4-phenylene diisopropylidene)bisaniline, or a combination thereof.

5. The polyamide polymer according to claim 1, further comprising a second monomer unit containing at least one aromatic ring.

6. The polyamide polymer according to claim 1, further comprising a third monomer unit containing sulfone, a fourth monomer unit containing carboxylic acid, or a combination thereof.

7. The polyamide polymer according to claim 5, wherein the second monomer formed by polymerizing the second monomer unit is a terephthaloyl chloride monomer, an isophthaloyl chloride monomer, an phthalic acid monomer, an isophthalic acid monomer, a terephthalic acid monomer, or a combination thereof.

8. The polyamide polymer according to claim 6, wherein the third monomer formed by polymerizing the third monomer unit is bis[4-(4-aminophenoxy)phenyl]sulfone, bis(4-aminophenyl)sulfone, bis(3-aminophenyl)sulfone, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 1,3-bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, bis[3-(3-aminophenoxy)phenylsulfone, bis[3-(4-aminophenoxy)phenylsulfone, bis[4-(3-aminophenoxy)phenylsulfone, or a combination thereof.

9. The polyamide polymer according to claim 6, wherein the fourth monomer formed by polymerizing the fourth monomer unit is 5,5'-methylenebis(2-aminobenzoic acid) i.e., MBAA, 3,5-diaminobenzoic acid i.e., DABA, or a combination thereof.

10. The polyamide polymer according to claim 6, wherein, based on a total content of 100 mol% of the third monomer unit and the first monomer unit, the molar ratio of the third monomer unit to the first monomer unit, i.e., the mol% of the third monomer unit: the mol% of the first monomer unit, is 90:10 to 1:

99.

11. The polyamide polymer according to claim 1, wherein the polyamide polymer comprises a monomer repeating unit represented by the following chemical formula 3, Chemical formula 3 In the chemical formula 3 Y1 comprises at least one aromatic ring substituted with a halogen element, hydrogen, hydroxyl group, carboxyl group, a straight-chain or branched hydrocarbon group having 1 to 4 carbon atoms, or a combination thereof. Y2 comprises two aromatic rings linked together by -SO2-; an aromatic ring substituted with at least one carboxyl group; two aromatic rings linked together by straight-chain or branched hydrocarbon groups having 1 to 10 carbon atoms; or combinations thereof. The two aromatic rings linked by -SO2- can be substituted by halogen elements, hydrogen, hydroxyl groups, carboxyl groups, straight-chain or branched hydrocarbon groups with 1 to 4 carbon atoms that are substituted or not substituted by halogen elements, or combinations thereof. c+d=1, in, The Y2 must contain two aromatic rings connected to each other by straight-chain or branched hydrocarbon groups consisting of 1 to 10 oxygen atoms or carbon atoms.

12. An adhesive comprising the polyamide polymer according to any one of claims 1 to 11.

13. A slurry comprising: The adhesive according to claim 12; and Electrode active material.

14. An electrode comprising: Current collector; and An electrode active material layer comprising the adhesive of claim 12, a blank area insulating coating, or a combination thereof, formed on the current collector.

15. A diaphragm comprising a porous substrate coated with a slurry composition comprising the adhesive of claim 12.

16. A slurry composition for an insulating coating of a blank area in a secondary battery, comprising the adhesive of claim 12.

17. A secondary battery comprising the adhesive of claim 12.

Images