Binder composition for secondary batteries

Abstract

To provide a binder composition for a lithium ion battery and an electrode for a lithium ion battery, exhibiting excellent adhering capability and high electrochemical stability, keeping those characteristics, and contributing to the excellent battery electrochemical performance.SOLUTION: A binder composition for a lithium ion battery electrode includes a copolymer and a dispersant. The copolymer includes a structure unit (a) derived from a monomer containing a carboxylic acid group, a structure unit (b) derived from a monomer containing an amide group, and a structure unit (c) derived from a monomer containing a nitrile group, and has an improved bindability. The binder composition does not include a structure unit derived from a monomer containing an ester group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to the field of batteries. In particular, this invention relates to binder compositions for lithium-ion batteries. [Background technology]

[0002] Over the past several decades, lithium-ion batteries (LIBs) have become widely used in a variety of applications, particularly in consumer electronics, due to their superior energy density, long cycle life, and high discharge capacity. With the rapid market development of electric vehicles (EVs) and grid energy storage, high-performance, low-cost LIBs now offer one of the most promising options for large-scale energy storage devices.

[0003] Generally, lithium-ion battery electrodes are manufactured by casting an organic slurry onto a metal current collector. The slurry contains electrode active material, conductive carbon, and a binder in an organic solvent. The binder is electrochemically stable and binds the electrode active material together, allowing it to adhere to the current collector and produce the electrode. Polyvinylidene fluoride (PVDF) is one of the most commonly used binders in the commercial lithium-ion battery industry. However, PVDF is insoluble in water and only dissolves in certain flammable and toxic organic solvents such as N-methyl-2-pyrrolidone (NMP), requiring special handling.

[0004] To recover NMP vapor, it is necessary to install an NMP recovery device in the drying process. This requires a large capital investment, resulting in significant costs in the manufacturing process. Using a cheaper and more environmentally friendly solvent, such as an aqueous solvent, most commonly water, is preferable in this invention because it can reduce the large capital cost of the recovery system.

[0005] In light of these issues, attempts are being made to replace conventional PVDF with more environmentally friendly water-soluble binder materials, or to utilize the known advantages of PVDF as a binder for electrode slurries without using organic solvents that require specific recovery treatment during manufacturing.

[0006] Known aqueous binders such as carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) exhibit only poor adhesion and a poor cycle life. SBR, in particular, requires a thickener to adjust the binder viscosity. Furthermore, SBR has high expansion properties and exhibits undesirable cohesive characteristics, leading to uneven dispersion, increased electrode resistance, and reduced performance. Moreover, high voltage is applied to the cathode within a battery. Most rubbers, including SBR, are stable only at low anode voltages and decompose at high voltages. Therefore, their application, especially to cathodes, is somewhat limited.

[0007] EP Patent Application Publication No. 255293B1 discloses an aqueous electrode slurry for lithium-ion-containing electrochemical cells. This slurry consists of PVDF and SBR in aqueous solution, and at least one combination of polyacrylic acid (PAA) and CMC, and an electrochemically active material. The proposed invention seeks to combine PVDF with an aqueous slurry that allows for easier handling, reduced environmental pollution, and lower costs, while maintaining the known chemical and electrochemical advantages of PVDF as a binder, namely electrochemical stability, lifetime stability, and the fact that a reduced binder content allows for a higher C-rate. Despite the fact that an organic solvent-free slurry can be prepared based on the proposed invention, the slurry is nevertheless composed of a fluorine-containing binder material. PVDF is highly fluorinated and toxic when exposed to thermal decomposition, posing a risk to human health and the environment.

[0008] Therefore, in the preparation of cathode slurries, there is always a need for an aqueous binder composition for lithium-ion batteries that exhibits excellent adhesive ability and high electrochemical stability, maintains these properties, and contributes to excellent battery electrochemical performance. [Overview of the project]

[0009] The aforementioned needs are met by the various embodiments and models disclosed herein. Provided herein is a binder composition for secondary battery electrodes comprising a copolymer and a dispersion medium, wherein the copolymer consists of structural units (a) derived from a carboxylic acid group-containing monomer, structural units (b) derived from an amide group-containing monomer, and structural units (c) derived from a nitrile group-containing monomer, and is a binder with improved binding ability. Furthermore, a battery cell comprising a cathode prepared using the binder composition disclosed herein exhibits excellent electrochemical performance. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a flowchart of an embodiment showing the steps for preparing a binder composition. [Modes for carrying out the invention]

[0011] Provided herein is a binder composition for secondary battery electrodes comprising a copolymer and a dispersion medium, wherein the copolymer comprises structural units (a) derived from a carboxylic acid group-containing monomer, structural units (b) derived from an amide group-containing monomer, and structural units (c) derived from a nitrile group-containing monomer.

[0012] The term "electrode" refers to either the "cathode" or the "anode."

[0013] The term "negative electrode" is used interchangeably with "cathode." Similarly, the term "negative electrode" is used interchangeably with "anode."

[0014] The terms “binder,” “binder material,” or “binder composition” refer to a chemical compound, a mixture of compounds, or a polymer that forms a colloidal solution or colloidal dispersion in a dispersion medium such as water, and are used to hold electrode material and / or conductive agent in place and adhere to a conductive metal portion to form an electrode. In some embodiments, the electrode does not contain any conductive agent.

[0015] The term "conductive agent" refers to a material that is chemically inert and possesses good electrical conductivity. Therefore, conductive agents are often mixed with electrode active materials during electrode formation to improve the electrical conductivity of the electrodes.

[0016] The term "polymer" refers to a high-molecular-weight compound prepared by polymerizing the same or different types of monomers. The general term "polymer" encompasses not only "homopolymers" but also "copolymers."

[0017] The term "homopolymer" refers to a polymer prepared by the polymerization of the same type of monomer.

[0018] The term "copolymer" refers to a polymer prepared by the polymerization of two or more different types of monomers.

[0019] As used herein, the term "unsaturated" means a part having one or more unsaturated units.

[0020] The term "alkyl" or "alkyl group" refers to a compound of the general formula C obtained by removing a hydrogen atom from a saturated, unbranched, or branched aliphatic hydrocarbon. n H 2n+1This refers to a monovalent group having a t-butyl group, where n is an integer between 1 and 20, or an integer between 1 and 8. Examples of alkyl groups include (C1-C8) alkyl groups, but are not limited to these. Examples include methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. Long-chain alkyl groups include nonyl and decyl groups. The alkyl group may be unsubstituted or substituted with one or more suitable substituents. Furthermore, the alkyl group may be branched or unbranched. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0021] The term "cycloalkyl" or "cycloalkyl group" refers to a saturated or unsaturated cyclic non-aromatic hydrocarbon radical having a monocyclic or multiple fused rings. Examples of cycloalkyl groups include, but are not limited to, (C3-C7) cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, and saturated cyclic and dicyclic terpenes, and (C3-C7) cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl, and unsaturated cyclic and dicyclic terpenes. Cycloalkyl groups may be unsubstituted or substituted with one or two suitable substituents. Furthermore, cycloalkyl groups can be monocyclic or polycyclic. In some embodiments, cycloalkyl groups contain at least 5, 6, 7, 8, 9, or 10 carbon atoms.

[0022] The term "alkoxy" refers to an alkyl group, as defined above, that is bonded to the main carbon chain via an oxygen atom. Some non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, and butoxy. The alkoxy groups defined above may or may not be substituted, and the substituents may be, but are not limited to, deuterium, hydroxy, amino, halo, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, and similar groups.

[0023] The term "alkenyl" refers to an unsaturated linear, branched, or cyclic hydrocarbon radical containing one or more carbon-carbon double bonds. Examples of alkenyl groups include, but are not limited to, ethenyl, 1-propenyl, or 2-propenyl, which may optionally be substituted for one or more carbon atoms of the radical.

[0024] The term "aryl" or "aryl group" refers to an organic radical derived from monocyclic or polycyclic aromatic hydrocarbons by removing a hydrogen atom. Non-limiting examples of aryl groups include phenyl, naphthyl, benzyl, or tranyl groups, sexyphenylene, phenantrenyl, anthracenyl, coronenyl, and tranylphenyl. Aryl groups can be unsubstituted or substituted with one or more suitable substituents. Furthermore, aryl groups can be monocyclic or polycyclic. In some embodiments, aryl groups contain at least 6, 7, 8, 9, or 10 carbon atoms.

[0025] The term "aliphatic" refers to C1-C 30 Alkyl alkyl groups, C2-C 30 Alkenyl group, C2~C 30 Alkynyl group, C1~C 30 Alkylene group, C2~C 30 Alkenylene group, or C2-C 30 This refers to an alkylene group. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0026] The term "aromatic" refers to a group containing an aromatic hydrocarbon ring, which may optionally include a heteroatom or substituent. Examples of such groups include, but are not limited to, phenyl, tolyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthuryl, pyrenyl, triphenyl, and their derivatives.

[0027] The term "substituted" used to describe a compound or chemical moiety means that at least one hydrogen atom of that compound or chemical moiety is substituted at the second chemical moiety. Examples of substituents include halogens; alkyls; heteroalkyls; alkenyls; alkynyls; aryls, heteroaryls, hydroxyls; alkoxyls; aminos; nitros; thiols; thioethers; imines; cyanos; amides; phosphonates; phosphines; carboxyls; thiocarbonyls; sulfonyls; sulfonamides; acyls; formyls; acyloxys; alkoxycarbonyls; oxo; haloalkyls (e.g., trifluoromethyl); carbons that can be monocyclic or condensed or uncondensed polycyclic. Cycle cycloalkyls (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl) or heterocyclic cycloalkyls that may be monocyclic or condensed or uncondensed polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiadinyl); carbocyclic or heterocyclic, monocyclic or condensed or uncondensed polycyclic aryls (e.g., phenyl, naphthyl, pyrrolyl, indolyl, furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thia) Zolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, quinolinyl, isoquinolinyl, acridinyl, pyrazinyl, pyridadinyl, pyrimidinyl, benzoisodazolyl, benzotiphenyl or benzofuranyl); amino (primary, secondary or tertiary); o-lower alkyl; o-aryl, aryl; aryl-lower alkyl; -CO2CH3; -CONH2; -OCH2CONH2; -NH2; -SO2NH2; -OCHF2; -CF3; -OCF3; -NH(alkyl); -N (alkyl)2;-NH(aryl);-N(alkyl)(aryl);-N(aryl)2;-CHO;-CO(alkyl);-CO(aryl);-CO2(alkyl); and -CO2(aryl); and such moieties may also be optionally substituted by fused ring structures or bridges, e.g., -OCH2O-. These substituents may optionally be further substituted with substituents selected from such groups. All chemical groups disclosed herein may be substituted unless otherwise specified.

[0028] The term "halogen" or "halo" refers to F, Cl, Br, or I.

[0029] The term "monomer unit" refers to a constituent unit of a polymer structure that is contributed by a single monomer.

[0030] The term "structural unit" refers to all monomer units in a polymer that are contributed by the same monomer type.

[0031] The term "carboxylic acid base" refers to a carboxylic acid salt formed when a carboxylic acid reacts with a base. In some embodiments, the proton of the carboxylic acid is substituted with a metal cation. In some embodiments, the proton of the carboxylic acid is substituted with an ammonium ion.

[0032] The term "application" refers to the act of laying or spreading a substance on a surface.

[0033] The term "current collector" refers to any conductive substrate that is in contact with an electrode layer and capable of conducting the current flowing to the electrodes during the discharge or charge of a secondary battery. Some non-limiting examples of current collectors include a single conductive metal layer or substrate, and a single conductive metal layer or substrate having a conductive coating layer on top of it, such as a carbon black-based coating layer. The conductive metal layer or substrate may be in the form of a foil or porous body having a three-dimensional network structure, and may be a polymer material, a metallic material, or a metallized polymer. In some embodiments, the three-dimensional porous current collector is covered with a conformal carbon layer.

[0034] The term "electrode layer" refers to a layer containing an electrochemically active material that is in contact with the current collector. In some embodiments, the electrode layer is created by applying a coating to the current collector. In some embodiments, the electrode layer is located on the surface of the current collector. In other embodiments, a three-dimensional porous current collector is conformally coated with an electrode layer.

[0035] The term "room temperature" refers to an indoor temperature between approximately 18°C ​​and approximately 30°C, for example, an indoor temperature of 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30°C. In some embodiments, room temperature refers to a temperature of approximately 20°C ± 1°C, ± 2°C, or ± 3°C. In other embodiments, room temperature refers to a temperature of approximately 22°C or approximately 25°C.

[0036] "Particle size D50" refers to the volume-based cumulative 50% size (D50), which is the particle size at the 50% point on the cumulative curve when the entire volume is considered as 100% (i.e., the diameter of the particle representing 50% (median) of the particle's volume). Furthermore, with respect to the cathode active material of the present invention, particle size D50 refers to the volume-average particle size of secondary particles that can be formed by the mutual aggregation of primary particles, and if it consists only of primary particles, it refers to the volume-average particle size of the primary particles.

[0037] The term "polydispersion index" or "PDI" refers to the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn). It is a measure of the molecular weight distribution within a given binder composition sample.

[0038] The term "solids content" refers to the amount of non-volatile substances remaining after evaporation.

[0039] The term "average roughness depth" or "Rz" refers to the arithmetic mean of a single roughness depth over a continuous sampling length of the current collector.

[0040] The term "peel strength" refers to the magnitude of the force required to separate a current collector and an electrode active material coating that are bonded together. It is a measure of the bonding strength between such two materials and is usually expressed in N / cm.

[0041] The term "adhesion strength" refers to the magnitude of the force required to separate a current collector and a binder composition coating that are bonded together. It is a measure of the adhesive strength between two materials and is usually expressed in N / cm.

[0042] The term "swelling" means the volume change of the binder composition after immersion in the electrolyte or the uptake of the electrolyte due to the electrolyte-binder interaction.

[0043] The term "C-rate" means the charge or discharge rate of a cell or battery, expressed in terms of its total charge capacity (Ah or mAh). For example, a rate of 1C means using all of the stored energy in 1 hour, 0.1C means using 10% of the energy in 1 hour or all of the energy in 10 hours, and 5C means using all of the energy in 12 minutes.

[0044] The term "ampere-hour (Ah)" refers to the unit used to define the charge capacity of a battery. For example, a battery with a capacity of 1Ah can supply a current of 1A for 1 hour, or 0.5A for 2 hours, etc. Thus, 1Ah (ampere-hour) corresponds to a charge of 3,600 coulombs. Similarly, the term "milliampere-hour (mAh)" also means a unit of the charge capacity of a battery and is 1 / 1000 of 1 ampere-hour.

[0045] The term "battery cycle life" means the number of complete charge-discharge cycles that can be performed before the nominal capacity of the battery drops below 80% of its initial rated capacity.

[0046] The term "capacity" is a characteristic of an electrochemical cell that refers to the total amount of charge that the electrochemical cell, such as a battery, can hold. Capacity is usually expressed in units of ampere-hours. The term "specific capacity" refers to the capacity output of an electrochemical cell, such as a battery, per unit weight and is usually expressed in Ah / kg or mAh / g.

[0047] In the following description, all numerical values disclosed in this specification are approximate values, whether or not the words "about" or "approximate" are used in connection with them. They may vary by 1%, 2%, 5%, or in some cases 10 - 20%. The lower limit value R L and the upper limit value R UWhenever a numerical range having R is disclosed, any number that falls within that range is specifically disclosed. In particular, numbers within the following range are specifically disclosed: R = R L +k*(R U -R L ), where k is a variable in the range of 0 percent to 100 percent. Furthermore, any numerical range defined by the two numbers of R defined above is also specifically disclosed.

[0048] Currently, cathodes are often prepared by dispersing a cathode active material, binder material, and conductive agent in an organic solvent such as N-methyl-2-pyrrolidone (NMP) to form a cathode slurry, and then applying the cathode slurry onto a current collector and drying it.

[0049] In many cases, binders are considered electrochemically inert materials, and therefore their impact on cell performance is underestimated. The purpose of the binder is to bond active material particles and conductive agents together, forming a continuous electrical conduction path to the current collector. In addition to its bonding ability, the binder material should be able to facilitate electron and ion transport to reduce impedance between the current collector and electrode material, and should have sufficient elasticity to prevent electrode expansion due to volume expansion and contraction during charging and discharging.

[0050] Polyvinylidene fluoride (PVDF) is widely used as a binder material in the manufacture of lithium-ion batteries. However, PVDF only dissolves in certain organic solvents, such as flammable and toxic nanoparticles (NMP), requiring special handling. Furthermore, an NMP recovery system is necessary during the drying process to recover NMP vapors. This results in high energy consumption and manufacturing costs during the manufacturing process. Therefore, the search for new, environmentally friendly binder materials to replace PVDF has become essential in the development of binder materials for lithium-ion batteries.

[0051] Carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) are some of the representative aqueous binders already used in large-scale commercial applications. However, these binders have limitations in terms of binding strength and their ability to prevent electrode expansion. Furthermore, high voltages are applied to the cathode in batteries. Most rubbers, including SBR, are stable only at low anode voltages and decompose at high voltages. Therefore, their application, especially to cathodes, is somewhat limited.

[0052] Accordingly, the present invention provides a method for preparing an aqueous binder composition comprising a copolymer and a dispersion medium, wherein the copolymer comprises a structural unit (a) derived from a carboxylic acid group-containing monomer, a structural unit (b) derived from an amide group-containing monomer, and a structural unit (c) derived from a nitrile group-containing monomer. Figure 1 is a flowchart of an embodiment showing the steps of Method 100 for preparing the binder composition. The binder compositions described herein have been found to exhibit improved adhesiveness and flexibility, and at the same time have the unexpected effect of improving the capacity and electrochemical performance of the cathode formed therefrom.

[0053] In some embodiments, the binder compositions described herein are produced by polymerization in which monomers, polymers, or monomer-polymer complexes are dispersed in an aqueous phase while generating free radicals with a water-soluble free radical initiator.

[0054] In some embodiments, the neutralizing solution is prepared by dissolving the neutralizing agent in water. In some embodiments, the first suspension is formed by adding the neutralizing solution to the dispersion medium in step 101. The addition of the neutralizing solution is intended to improve polymerization stability and provide a pH range in which initiators added in later steps can generate free radicals.

[0055] Establishing a desirable pH range for operation is particularly important in aqueous systems. Neutralizing agents are commonly used for pH adjustment. In some embodiments, the neutralizing agent includes an alkaline aqueous solution. In some embodiments, the neutralizing agent may be selected from the group consisting of ammonia, sodium bicarbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, magnesium hydroxide, calcium hydroxide, triethylamine, dimethylethanolamine (DMEA), sodium carbonate, lithium carbonate, lithium bicarbonate, and combinations thereof.

[0056] The dispersion medium is used as a solvent for free radical initiators, neutralizers, and other components. In some embodiments, the binder compositions disclosed herein are prepared by an aqueous treatment method in which water is used as the dispersion medium.

[0057] In some embodiments, the dispersion medium may further include a hydrophilic solvent selected from the group consisting of ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, dimethylacetamide (DMAc), dimethylformamide (DMF), N-methylpyrrolidone (NMP), methyl ethyl ketone (MEK), ethyl acetate (EA), butyl acetate (BA), and combinations thereof. In some embodiments, the dispersion medium is water, without ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, dimethylacetamide (DMAc), dimethylformamide (DMF), N-methylpyrrolidone (NMP), methyl ethyl ketone (MEK), ethyl acetate (EA), or butyl acetate (BA).

[0058] In some embodiments, the second suspension is formed in step 102 by adding a carboxylic acid group-containing monomer to the first suspension.

[0059] In other embodiments, a second suspension is formed by adding a carboxylic acid group-containing monomer solution to the first suspension. The carboxylic acid group-containing monomer solution can be prepared by dissolving the carboxylic acid group-containing monomer in water.

[0060] Structural unit (a) is derived from a carboxylic acid group-containing monomer. Any monomer having at least one carboxylic acid group may be used as a carboxylic acid group-containing monomer without particular limitation. In one embodiment, the carboxylic acid group-containing monomer is acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, or a combination thereof. In certain embodiments, the carboxylic acid group-containing monomers are 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angulic acid, tiglitic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butylacrylic acid, 2-butylacrylic acid, 2-pentylacrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propylacrylic acid, 2-ethyl-3-propyl These are acrylic acid, 2,3-diethylacrylic acid, 3,3-diethylacrylic acid, 3-methyl-3-hexylacrylic acid, 3-methyl-3-tert-butylacrylic acid, 2-methyl-3-pentylacrylic acid, 3-methyl-3-pentylacrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butylacrylic acid, 2,3-dimethyl-3-ethylacrylic acid, 3,3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-alyloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, or combinations thereof.In some embodiments, the carboxylic acid group-containing monomers are methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, or a combination thereof. In some embodiments, the carboxylic acid group-containing monomers are maleic anhydride, methyl maleate anhydride, dimethyl maleate anhydride, acrylic anhydride, methacrylic anhydride, metacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.

[0061] In some embodiments, the proportion of carboxylic acid group-containing monomers is approximately 40% to 70%, 40% to 68%, 40% to 66%, 40% to 65%, 40% to 64%, 40% to 63%, 40% to 62%, 40% to 61%, and 40% to 60% by weight, based on the total weight of monomers added in the preparation of the binder composition. These are approximately 40% to 59%, 40% to 58%, 40% to 57%, 40% to 56%, 40% to 55%, 41% to 55%, 42% to 55%, 43% to 55%, 44% to 55%, 45% to 55%, 43% to 58%, 47% to 53%, 47% to 57%, 45% to 58%, or 45% to 60%.

[0062] In some embodiments, the proportion of monomers containing carboxylic acid groups is less than 70%, less than 69%, less than 68%, less than 67%, less than 66%, less than 65%, less than 64%, less than 63%, less than 62%, less than 61%, less than 60%, less than 59%, less than 58%, less than 57%, less than 56%, less than 55%, less than 54%, less than 53%, less than 52%, less than 51%, less than 50%, less than 49%, less than 48%, less than 47%, less than 46%, less than 45%, less than 44%, less than 43%, or less than 42% by weight, based on the total weight of monomers added in the preparation of the binder composition. In some embodiments, the proportion of carboxylic acid group-containing monomers is more than 40%, more than 41%, more than 42%, more than 43%, more than 44%, more than 45%, more than 46%, more than 47%, more than 48%, more than 49%, more than 50%, more than 51%, more than 52%, more than 53%, more than 54%, more than 55%, more than 56%, more than 57%, more than 58%, more than 59%, more than 60%, more than 61%, more than 62%, more than 63%, more than 64%, more than 65%, more than 66%, more than 67%, or more than 68%, based on the total weight of monomers added during the preparation of the binder composition.

[0063] In some embodiments, the first suspension and the second suspension are stirred independently for a period of time of about 5 to 45 minutes, about 5 to 40 minutes, about 5 to 35 minutes, about 10 to 35 minutes, about 15 to 35 minutes, about 20 to 35 minutes, or about 25 to 35 minutes. In some embodiments, the first suspension and the second suspension are stirred independently for a period of time longer than 5 minutes, longer than 10 minutes, longer than 15 minutes, longer than 20 minutes, longer than 25 minutes, longer than 30 minutes, longer than 35 minutes, or longer than 40 minutes.

[0064] In some embodiments, the first suspension and the second suspension are each stirred independently at speeds of approximately 10 rpm to 600 rpm, approximately 10 rpm to 550 rpm, approximately 10 rpm to 500 rpm, approximately 10 rpm to 450 rpm, approximately 10 rpm to 400 rpm, approximately 10 rpm to 350 rpm, approximately 10 rpm to 300 rpm, approximately 10 rpm to 250 rpm, approximately 10 rpm to 200 rpm, approximately 10 rpm to 180 rpm, approximately 10 rpm to 160 rpm, approximately 10 rpm to 140 rpm, approximately 10 rpm to 120 rpm, approximately 10 rpm to 100 rpm, approximately 20 rpm to 100 rpm, approximately 30 rpm to 100 rpm, or approximately 40 rpm to 100 rpm. In some embodiments, the first suspension and the second suspension are independently stirred at speeds of less than 600 rpm, less than 550 rpm, less than 500 rpm, less than 450 rpm, less than 400 rpm, less than 350 rpm, less than 300 rpm, less than 250 rpm, less than 200 rpm, less than 150 rpm, less than 100 rpm, and less than 50 rpm. In some embodiments, the first suspension and the second suspension are independently stirred at speeds of faster than 10 rpm, faster than 50 rpm, faster than 100 rpm, faster than 150 rpm, faster than 200 rpm, faster than 250 rpm, faster than 300 rpm, faster than 350 rpm, faster than 400 rpm, faster than 450 rpm, faster than 500 rpm, or faster than 550 rpm.

[0065] In some embodiments, the temperature of the second suspension is approximately 20°C to 30°C, approximately 20°C to 29°C, approximately 20°C to 28°C, approximately 20°C to 27°C, approximately 20°C to 26°C, approximately 20°C to 25°C, approximately 21°C to 30°C, approximately 22°C to 30°C, approximately 23°C to 30°C, approximately 24°C to 30°C, approximately 25°C to 30°C, approximately 22°C to 26°C, or approximately 24°C to 28°C. In some embodiments, the temperature of the second suspension is less than 30°C, less than 29°C, less than 28°C, less than 27°C, less than 26°C, less than 25°C, less than 24°C, less than 23°C, less than 22°C, or less than 21°C. In some applications, the temperature of the second suspension is higher than 20°C, higher than 21°C, higher than 22°C, higher than 23°C, higher than 24°C, higher than 25°C, higher than 26°C, higher than 27°C, higher than 28°C, or higher than 29°C.

[0066] In some embodiments, in step 103, the third suspension is formed by adding an amide group-containing monomer to the second suspension.

[0067] In other embodiments, the third suspension is formed by adding an amide group-containing monomer solution to the second suspension. The amide group-containing monomer solution can be prepared by dissolving the amide group-containing monomer in water.

[0068] Structural unit (b) is derived from an amide group-containing monomer. Monomers having at least one amide group can be used as amide group-containing monomers without particular limitation. In some embodiments, the amide group-containing monomers are acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, isopropylacrylamide, Nn-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide These include crillamide, N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl methacrylamide, N,N-dimethylol methacrylamide, diaketone methacrylamide, diacetone acrylamide, methacryloylmorpholine, N-hydroxyl methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N,N'-methylene-bis-acrylamide (MBA), N-hydroxymethyl acrylamide, or combinations thereof.

[0069] In some embodiments, the amide group-containing monomer is present in the preparation of the binder composition in an amount of about 15% to about 35%, about 15% to about 34%, about 15% to about 33%, about 15% to about 32%, about 15% to about 31%, about 15% to about 30%, about 16% to about 30%, about 17% to about 30%, about 17% to about 29%, about 17% to about 28%, about 17% to about 27%, about 18% to about 27%, about 19% to about 27%, about 20% to about 27%, about 20% to about 25%, or about 15% to about 25%, based on the total weight of the monomers added.

[0070] In some embodiments, the proportion of amide group-containing monomers is less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, or less than 16% by weight, based on the total weight of monomers added in the preparation of the binder composition. In some embodiments, the proportion of amide group-containing monomers is more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 20%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, more than 28%, or more than 29% by weight, based on the total weight of monomers added in the preparation of the binder composition.

[0071] In some embodiments, the third suspension is stirred for a period of time of approximately 5 to 60 minutes, 5 to 55 minutes, 5 to 50 minutes, 10 to 50 minutes, 15 to 50 minutes, 20 to 50 minutes, 25 to 50 minutes, 30 to 50 minutes, or 35 to 50 minutes. In some embodiments, the third suspension is stirred for a period of less than 60 minutes, less than 55 minutes, less than 50 minutes, less than 45 minutes, less than 40 minutes, less than 35 minutes, less than 30 minutes, less than 25 minutes, less than 20 minutes, less than 15 minutes, or less than 10 minutes. In some embodiments, the third suspension is stirred for a time longer than 5 minutes, longer than 10 minutes, longer than 15 minutes, longer than 20 minutes, longer than 25 minutes, longer than 30 minutes, longer than 35 minutes, longer than 40 minutes, longer than 45 minutes, longer than 50 minutes, or longer than 55 minutes.

[0072] In some embodiments, the third suspension is stirred at speeds of approximately 10 rpm to 600 rpm, approximately 10 rpm to 550 rpm, approximately 10 rpm to 500 rpm, approximately 10 rpm to 450 rpm, approximately 10 rpm to 400 rpm, approximately 10 rpm to 350 rpm, approximately 10 rpm to 300 rpm, approximately 10 rpm to 250 rpm, approximately 10 rpm to 200 rpm, approximately 10 rpm to 180 rpm, approximately 10 rpm to 160 rpm, approximately 10 rpm to 140 rpm, approximately 10 rpm to 120 rpm, approximately 10 rpm to 100 rpm, approximately 20 rpm to 100 rpm, approximately 30 rpm to 100 rpm, or approximately 40 rpm to 100 rpm. In some embodiments, the third suspension is stirred at a speed of less than 600 rpm, less than 550 rpm, less than 500 rpm, less than 450 rpm, less than 400 rpm, less than 350 rpm, less than 300 rpm, less than 250 rpm, less than 200 rpm, less than 150 rpm, less than 100 rpm, or less than 50 rpm. In some embodiments, the third suspension is stirred at a speed faster than 10 rpm, faster than 50 rpm, faster than 100 rpm, faster than 150 rpm, faster than 200 rpm, faster than 250 rpm, faster than 300 rpm, faster than 350 rpm, faster than 400 rpm, faster than 450 rpm, faster than 500 rpm, or faster than 550 rpm.

[0073] In some embodiments, the temperature of the third suspension is raised to approximately 30°C to 70°C, approximately 32°C to 70°C, approximately 34°C to 70°C, approximately 36°C to 70°C, approximately 38°C to 70°C, approximately 40°C to 70°C, approximately 42°C to 70°C, approximately 44°C to 70°C, approximately 46°C to 70°C, approximately 48°C to 70°C, or approximately 50°C to 70°C.

[0074] In some embodiments, the temperature of the third suspension is raised to less than 70°C, less than 68°C, less than 66°C, less than 64°C, less than 62°C, less than 60°C, less than 58°C, less than 56°C, less than 54°C, less than 52°C, less than 50°C, less than 48°C, less than 46°C, less than 44°C, less than 42°C, less than 40°C, less than 38°C, less than 36°C, or less than 34°C. In some embodiments, the temperature of the third suspension is raised to more than 30°C, more than 32°C, more than 34°C, more than 36°C, more than 38°C, more than 40°C, more than 42°C, more than 44°C, more than 46°C, more than 48°C, more than 50°C, more than 52°C, more than 54°C, more than 56°C, more than 58°C, more than 60°C, more than 62°C, more than 64°C, or higher than 66°C.

[0075] In some embodiments, the fourth suspension is formed by adding a nitrile group-containing monomer to the third suspension in step 104.

[0076] In another embodiment, the fourth suspension is formed by adding a nitrile group-containing monomer solution to the third suspension. The nitrile group-containing monomer solution can be prepared by dissolving the nitrile group-containing monomer in water.

[0077] Structural unit (c) is derived from a nitrile group-containing monomer. Monomers having at least one nitrile group can be used as nitrile group-containing monomers without particular limitation. In some embodiments, the nitrile group-containing monomer includes α,β-ethylenically unsaturated nitrile monomers. In some embodiments, the nitrile group-containing monomer is acrylonitrile, α-halogenoacrylonitrile, α-alkylacrylonitrile, or a combination thereof. In some embodiments, the nitrile group-containing monomers are α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, or a combination thereof.

[0078] In a particular embodiment, the proportion of nitrile group-containing monomers is approximately 10% to 24% by weight, based on the total weight of monomers added in the preparation of the binder composition, approximately 10% to 24%, approximately 10.5% to 24%, approximately 11% to 24%, approximately 11.5% to 24%, approximately 12% to 24%, approximately 12.2% to 24%, approximately 12.4% to 24%, approximately 12.4% to 24%, approximately 12.6% to 24%, approximately 12.8% to 24%, approximately 13% to 24%, approximately 13.2% to 24%, approximately 13.4% to 24%, approximately 13.6% to 24%, approximately 13.8% to 24%, approximately 14% to 24%, and approximately 14.2% to 24%. 24%, approximately 14.4% to 24%, approximately 14.6% to 24%, approximately 14.8% to 24%, approximately 15% to 24%, approximately 15.2% to 24%, approximately 15.4% to 24%, approximately 15.6% to 24%, approximately 15.8% to 24%, approximately 16% to 24%, approximately 16.2% to 24%, 16.4% to 2 The percentages are 4%, approximately 16.6% to 24%, approximately 16.8% to 24%, approximately 17% to 24%, approximately 17% to 23.8%, approximately 17% to 23.6%, approximately 17% to 23.4%, approximately 17% to 23.2%, approximately 17% to 23%, approximately 16% to 23%, approximately 16% to 22%, or approximately 15% to 22%.

[0079] In some embodiments, the proportion of nitrile group-containing monomers is more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, or more than 23% by weight, based on the total weight of monomers added in the preparation of the binder composition. In some embodiments, the proportion of nitrile group-containing monomers is less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, or less than 11% by weight, based on the total weight of monomers added in the preparation of the binder composition.

[0080] In certain embodiments, combinations of carboxylic acid group-containing monomers, nitrile group-containing monomers, and amide group-containing monomers may be added to the first suspension to form a second suspension without forming a third and fourth suspension. In other embodiments, carboxylic acid group-containing monomers, nitrile group-containing monomers, amide group-containing monomers, or combinations thereof are added sequentially to the first suspension to form a second, third, or fourth suspension. Stirring or dispersion may be employed between these additions, which is advantageous as it can improve the dispersion of the materials. When monomer combinations are added sequentially, the formation of a third or fourth suspension can be omitted.

[0081] In some embodiments, the fourth suspension is stirred for a time of about 5 to 30 minutes, about 5 to 28 minutes, about 5 to 26 minutes, about 5 to 24 minutes, about 5 to 22 minutes, about 5 to 20 minutes, about 5 to 18 minutes, or about 5 to 15 minutes. In some embodiments, the fourth suspension is stirred for a time of less than 30 minutes, less than 28 minutes, less than 26 minutes, less than 24 minutes, less than 22 minutes, less than 20 minutes, less than 18 minutes, less than 16 minutes, less than 14 minutes, less than 12 minutes, less than 10 minutes, or less than 8 minutes. In some embodiments, the fourth suspension is stirred for a time longer than 5 minutes, longer than 7 minutes, longer than 10 minutes, longer than 12 minutes, longer than 14 minutes, longer than 16 minutes, longer than 18 minutes, longer than 20 minutes, longer than 22 minutes, longer than 24 minutes, longer than 26 minutes, or longer than 28 minutes.

[0082] In some embodiments, the fourth suspension is stirred at speeds of approximately 10 rpm to 600 rpm, approximately 10 rpm to 550 rpm, approximately 10 rpm to 500 rpm, approximately 10 rpm to 450 rpm, approximately 10 rpm to 400 rpm, approximately 10 rpm to 350 rpm, approximately 10 rpm to 300 rpm, approximately 10 rpm to 250 rpm, approximately 10 rpm to 200 rpm, approximately 10 rpm to 180 rpm, approximately 10 rpm to 160 rpm, approximately 10 rpm to 140 rpm, approximately 10 rpm to 120 rpm, approximately 10 rpm to 100 rpm, approximately 20 rpm to 100 rpm, approximately 30 rpm to 100 rpm, or approximately 40 rpm to 100 rpm. In some embodiments, the fourth suspension is stirred at a speed of less than 600 rpm, less than 550 rpm, less than 500 rpm, less than 450 rpm, less than 400 rpm, less than 350 rpm, less than 300 rpm, less than 250 rpm, less than 200 rpm, less than 150 rpm, less than 100 rpm, or less than 50 rpm. In some embodiments, the fourth suspension is stirred at a speed faster than 10 rpm, faster than 50 rpm, faster than 100 rpm, faster than 150 rpm, faster than 200 rpm, faster than 250 rpm, faster than 300 rpm, faster than 350 rpm, faster than 400 rpm, faster than 450 rpm, faster than 500 rpm, or faster than 550 rpm.

[0083] In some embodiments, copolymers are obtained by polymerization of the composition. In some embodiments, the composition comprises a carboxylic acid base-containing monomer, a carboxylic acid group-containing monomer, a nitrile group-containing monomer, and an amide group-containing monomer. In some embodiments, the formation of the carboxylic acid base-containing monomer is due to the neutralization of the carboxylic acid group-containing monomer by the neutralizing agent added in step 101.

[0084] In one embodiment, the carboxylate base-containing monomer is acrylate, methacrylate, crotonate, 2-butylcrotonate, cinnamate, maleate, maleic anhydride, fumarate, itaconate, itaconic anhydride, tetraconate, or a combination thereof. In a specific embodiment, the carboxylic acid base-containing monomer is 2-ethylacrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelicaate, tiglicate, 3,3-dimethylacrylate, 3-propylacrylate, trans-2-methyl-3-ethylacrylate, cis-2-methyl-3-ethylacrylate, 3-isopropylacrylate, trans-3-methyl-3-ethylacrylate, cis-3-methyl-3-ethylacrylate, 2-isopropylacrylate, trimethylacrylate, 2-methyl-3,3-diethylacrylate, 3-butyl Acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propyl acrylate, 2-ethyl-3-propyl acrylate, 2,3-diethyl acrylate, 3,3-diethyl acrylate, 3-methyl-3-hexyl acrylate, 3-methyl-3-tert-butyl acrylate, 2-methyl-3-pentyl acrylate, 3-methyl-3-pentyl acrylate, 4-methyl-2-hexenoate, 4-ethyl-2-hexenoate, 3-methyl-2-ethyl-2-hexenoate, 3-tert-butyl acrylate. These include 2,3-dimethyl-3-ethyl acrylate, 3,3-dimethyl-2-ethyl acrylate, 3-methyl-3-isopropyl acrylate, 2-methyl-3-isopropyl acrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxyacrylate, β-trans-alyloxyacrylate, α-chloro-β-E-methoxyacrylate, or a combination thereof.In some embodiments, the carbone base-containing monomer is methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloro maleate, dichloro maleate, fluoro maleate, difluoro maleate, or a combination thereof.

[0085] In some embodiments, the carboxylic acid base-containing monomer is an alkali metal carboxylic acid base-containing monomer. Examples of alkali metals that form alkali metal carboxylates include lithium, sodium, and potassium. In some embodiments, the carboxylic acid base-containing monomer is an ammonium carboxylic acid base-containing monomer.

[0086] In some embodiments, the molar ratio of carboxylic acid group-containing monomers to carboxylic acid base-containing monomers in the composition is approximately 0 to approximately 0.8, approximately 0 to approximately 0.78, approximately 0 to approximately 0.76, approximately 0 to approximately 0.74, approximately 0 to approximately 0.72, approximately 0 to approximately 0.7, approximately 0 to approximately 0.68, approximately 0 to approximately 0.66, approximately 0 to approximately 0.64, approximately 0 to approximately 0.62, approximately 0 to approximately 0.6, approximately 0 to approximately 0.58, approximately 0 to approximately 0.56, approximately 0 to approximately 0.54, approximately 0 to approximately 0. The ranges are approximately 0.52, 0 to 0.5, 0 to 0.48, 0 to 0.46, 0 to 0.44, 0 to 0.42, 0 to 0.4, 0 to 0.38, 0 to 0.36, 0 to 0.34, 0 to 0.32, 0 to 0.3, 0.02 to 0.3, 0.04 to 0.3, 0.06 to 0.3, 0.08 to 0.3, 0.1 to 0.3, 0.05 to 0.5, or 0.05 to 0.4.

[0087] In some embodiments, the molar ratio of carboxylic acid group-containing monomers to carboxylic acid base-containing monomers in the composition is less than 0.8, less than 0.75, less than 0.7, less than 0.65, less than 0.6, less than 0.55, less than 0.5, less than 0.45, less than 0.4, less than 0.35, less than 0.3, less than 0.25, less than 0.2, less than 0.15, less than 0.1, or less than 0.05. In some embodiments, the molar ratio of carboxylic acid group-containing monomers to carboxylic acid base-containing monomers in the composition is greater than 0, greater than 0.05, greater than 0.1, greater than 0.15, greater than 0.2, greater than 0.25, greater than 0.3, greater than 0.35, greater than 0.4, greater than 0.45, greater than 0.5, greater than 0.55, greater than 0.6, greater than 0.65, greater than 0.7, or greater than 0.75.

[0088] In some embodiments, the proportion of monomers containing carboxylic acid groups is approximately 0% to 30%, 0% to 29%, 0% to 28%, 0% to 27.5%, 0% to 27%, 0% to 26.5%, 0% to 26%, 0% to 25%, 0% to 24%, 0% to 23%, and 0% to 22%, based on the total number of moles of monomers in the composition. The percentages are approximately 0% to 21%, 0% to 20%, 0% to 19%, 0% to 18%, 0% to 17%, 0% to 16%, 0% to 15%, 1% to 15%, 2% to 15%, 3% to 15%, 4% to 15%, 5% to 15%, 6% to 15%, 6% to 14%, 6% to 13%, 5% to 20%, or 5% to 25%.

[0089] In some embodiments, the proportion of monomers containing carboxylic acid groups is less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11%, less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, or less than 2%, based on the total number of moles of monomers in the composition. In some embodiments, the proportion of carboxylic acid group-containing monomers is more than 0%, more than 1%, more than 2%, more than 3%, more than 4%, more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, or more than 28%, based on the total number of moles of monomers in the composition.

[0090] In some embodiments, the proportion of carboxylic acid base-containing monomers is approximately 25% to 45%, 25.5% to 45%, 26% to 45%, 26.5% to 45%, 27% to 45%, 27.5% to 45%, 28% to 45%, 28.5% to 45%, 29% to 45%, and approximately, based on the total number of moles of monomers in the composition. The percentages are approximately 29.5% to 45%, approximately 30% to 45%, approximately 30% to 44.5%, approximately 30% to 44%, approximately 30% to 43.5%, approximately 30% to 43%, approximately 30% to 42.5%, approximately 30% to 42%, approximately 30% to 41.5%, approximately 30% to 41%, approximately 30% to 40.5%, approximately 30% to 40%, approximately 25% to 35%, or approximately 35% to 40%.

[0091] In some embodiments, the proportion of carboxylic acid base-containing monomers is less than 45%, less than 44%, less than 43%, less than 42%, less than 41%, less than 40%, less than 39%, less than 38%, less than 37%, less than 36%, less than 35%, less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, or less than 26%, based on the total number of moles of monomers in the composition. In some embodiments, the proportion of carboxylic acid base-containing monomers is more than 25%, more than 26%, more than 27%, more than 28%, more than 29%, more than 30%, more than 31%, more than 32%, more than 33%, more than 34%, more than 35%, more than 36%, more than 37%, more than 38%, or more than 39%, based on the total number of moles of monomers in the composition.

[0092] In some embodiments, the proportion of nitrile group-containing monomers is approximately 10% to 30%, 11% to 30%, 12% to 30%, 13% to 30%, 14% to 30%, 15% to 30%, 16% to 30%, 17% to 30%, 18% to 30%, 19% to 30%, and 20% based on the total number of moles of monomers contained in the composition. The percentages are approximately 30%, 20% to 29%, 20% to 28%, 20% to 27%, 20% to 26%, 20% to 25%, 11% to 25%, 12% to 25%, 13% to 25%, 14% to 25%, 15% to 25%, 16% to 27%, 17% to 27%, 18% to 27%, 19% to 27%, or 10% to 27%.

[0093] In some embodiments, the proportion of nitrile group-containing monomers is less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, or less than 12%, based on the total number of moles of monomers in the composition. In some embodiments, the proportion of nitrile group-containing monomers is more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, or more than 28%, based on the total number of moles of monomers in the composition.

[0094] In some embodiments, the proportion of amide group-containing monomers is approximately 10% to 35%, 10% to 34%, 10% to 33%, 10% to 32%, 10% to 31%, 10% to 30%, 11% to 30%, 12% to 30%, 13% to 30%, 14% to 30%, 15% to 30%, 16% to 30%, 17% to 30%, 18% to 30%, 19% to 30%, 20% to 30%, 20% to 29%, 20% to 28%, 15% to 35%, or 20% to 35%, based on the total number of moles of monomers in the composition.

[0095] In some embodiments, the proportion of amide group-containing monomers is less than 35%, less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 18%, less than 16%, less than 14%, or less than 12%, based on the total number of moles of monomers in the composition. In some embodiments, the proportion of amide group-containing monomers is more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, more than 28%, more than 29%, more than 30%, more than 32%, or more than 34%, based on the total number of moles of monomers in the composition.

[0096] In some embodiments, the initiator solution is prepared by dissolving the initiator in water. In some embodiments, the fifth suspension is formed by adding the initiator solution to the fourth suspension in step 105.

[0097] In other embodiments, the fifth suspension is formed by sequentially adding a portion of the initiator solution to the fourth suspension. Stirring or dispersion may be employed during the addition.

[0098] The polymerization occurring in this invention follows a radical mechanism in which an initiator acts to generate free radicals, which then propagate the polymer chain. The free radicals used herein can be generated using thermal decomposition or redox reactions. The free radical initiators(s) disclosed herein are water-soluble.

[0099] Water-soluble free radical initiators provide radicals that can be thermally decomposed in the aqueous phase to initiate polymerization. In some embodiments, the water-soluble initiator can be selected from the group consisting of persulfate initiators such as ammonium persulfate, sodium persulfate, and potassium persulfate; azo initiators such as azobis(isobutyl-amidine hydrochloride) (AIBA), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, bis[2-(4'-sulfophenyl)alkyl]-2,2'-azodisobutyrate ammonium salt, and 2,2'-azobis(N-2'-methylpropanoyl-2-aminoalkyl-1)-sulfonic acid; and peroxide initiators such as hydrogen peroxide, t-butyl hydroperoxide, succinic acid peroxide, and combinations thereof.

[0100] In some embodiments, a water-soluble free radical initiator can be used together with a reducing agent to establish a redox initiator system. This enables the generation of free radicals by oxidation-reduction reactions at relatively low temperatures, thereby promoting an improvement in the polymerization rate.

[0101] In some embodiments, the reducing agent solution is prepared by dissolving the reducing agent in water. In some embodiments, the reducing agent can be selected from the group consisting of sodium bisulfite, sodium metabisulfite, sodium sulfite, sodium thiosulfate, thiourea dioxide, ferrous sulfate, ferrous chloride, ascorbic acid, citric acid, tartaric acid, erythorbic acid, glucose, formaldehyde sulfoxylate metal salts, burgolite FF6M, and combinations thereof.

[0102] In some embodiments, when a redox initiator system is selected as the initiator, the molar ratio of the water-soluble free radical initiator to the reducing agent is approximately 0.2 to 10, approximately 0.2 to 9, approximately 0.2 to 8, approximately 0.2 to 7, approximately 0.2 to 6, approximately 0.2 to 5, approximately 0.3 to 5, approximately 0.4 to 5, approximately 0.5 to 5, approximately 0.6 to 5, approximately 0.7 to 5, approximately 0.8 to 5, approximately 0.9 to 5, approximately 1 to 5, approximately 0.5 to 4.5, approximately 0.5 to 4, approximately 0.6 to 3.5, approximately 0.6 to 0.3, approximately 0.8 to 3, or approximately 0.2 to 1.

[0103] In some embodiments, when a redox initiator system is selected as the initiator, the molar ratio of the water-soluble free radical initiator to the reducing agent is less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 3, less than 2.8, less than 2.6, less than 2.4, less than 2.2, less than 2, less than 1.8, less than 1.6, less than 1.4, less than 1.2, less than 1, less than 0.8, less than 0.6, or less than 0.4. In some embodiments, when a redox initiator system is selected as the initiator, the molar ratio of the water-soluble free radical initiator to the reducing agent is greater than 0.2, greater than 0.4, greater than 0.6, greater than 0.8, greater than 1, greater than 1.2, greater than 1.4, greater than 1.6, greater than 1.8, greater than 2, greater than 2.2, greater than 2.4, greater than 2.6, greater than 2.8, greater than 3, greater than 3.2, greater than 3.4, greater than 3.6, greater than 3.8, greater than 4, greater than 4.2, greater than 4.4, greater than 4.6, greater than 4.8, greater than 5, greater than 6, greater than 7, greater than 8, or greater than 9.

[0104] The polymerization temperature depends on the type of initiator applied. In some embodiments, the polymerization reaction temperature is approximately 50°C to 90°C, approximately 50°C to 85°C, approximately 50°C to 80°C, approximately 50°C to 75°C, approximately 50°C to 70°C, approximately 55°C to 75°C, approximately 55°C to 80°C, approximately 55°C to 85°C, approximately 60°C to 80°C, approximately 60°C to 75°C, approximately 60°C to 70°C, or approximately 55°C to 70°C. When the polymerization reaction temperature is within the above range, higher reaction stability may be achieved, and the binder composition may exhibit better overall bonding performance.

[0105] In some embodiments, the polymerization reaction temperature is less than 90°C, less than 88°C, less than 86°C, less than 84°C, less than 82°C, less than 80°C, less than 78°C, less than 76°C, less than 74°C, less than 72°C, less than 70°C, less than 68°C, less than 66°C, less than 64°C, less than 62°C, less than 60°C, less than 58°C, less than 56°C, or less than 54°C. In some embodiments, the polymerization reaction temperature is higher than 50°C, higher than 52°C, higher than 54°C, higher than 56°C, higher than 58°C, higher than 60°C, higher than 62°C, higher than 64°C, higher than 66°C, higher than 68°C, higher than 70°C, higher than 72°C, higher than 74°C, higher than 76°C, higher than 78°C, higher than 80°C, higher than 82°C, higher than 84°C, or higher than 86°C.

[0106] In some embodiments, the total polymerization reaction time is approximately 20 to 28 hours, approximately 20 to 27.5 hours, approximately 20 to 27 hours, approximately 20 to 26.5 hours, approximately 20 to 26 hours, approximately 20.5 to 26 hours, approximately 21 to 26 hours, approximately 21.5 to 26 hours, approximately 22 to 26 hours, approximately 22 to 25.5 hours, approximately 22 to 25 hours, approximately 22.5 to 25 hours, approximately 23 to 25 hours, approximately 23.5 to 25 hours, or approximately 23.5 to 24.5 hours.

[0107] In some embodiments, the total reaction time for polymerization is less than 28 hours, less than 27.5 hours, less than 27 hours, less than 26.5 hours, less than 26 hours, less than 25.5 hours, less than 25 hours, less than 24.5 hours, less than 24 hours, less than 23.5 hours, less than 23 hours, less than 22.5 hours, less than 22 hours, less than 21.5 hours, less than 21 hours, or less than 20.5 hours. In some embodiments, the total reaction time for polymerization is longer than 20 hours, longer than 20.5 hours, longer than 21 hours, longer than 21.5 hours, longer than 22 hours, longer than 22.5 hours, longer than 23 hours, longer than 23.5 hours, longer than 24 hours, longer than 24.5 hours, longer than 25 hours, longer than 25.5 hours, longer than 26 hours, longer than 26.5 hours, longer than 27 hours, or longer than 27.5 hours.

[0108] In some embodiments, the fifth suspension is administered for approximately 20 to 28 hours, approximately 20.25 to 28 hours, approximately 20.5 to 28 hours, approximately 20.75 to 28 hours, approximately 21 to 28 hours, approximately 21 to 27.75 hours, approximately 21 to 27.5 hours, approximately 21 to 27.25 hours, approximately 21 to 27 hours, approximately 21.25 to 27 hours, approximately 21.5 to 27 hours, and approximately 21.75 to 27 hours. The mixture is stirred for approximately 21.25 to 27 hours, 21.5 to 27 hours, 21.75 to 27 hours, 22 to 27 hours, 22 to 26.75 hours, 22 to 26.5 hours, 22 to 26.25 hours, 22 to 26 hours, 22.25 to 26 hours, 22.5 to 26 hours, 22.75 to 26 hours, 23 to 26 hours, 23 to 25.75 hours, 23 to 25.5 hours, 23 to 25.25 hours, or 23 to 25 hours.

[0109] In some embodiments, the fifth suspension is stirred for a time of less than 28 hours, less than 27.5 hours, less than 27 hours, less than 26.5 hours, less than 26 hours, less than 25.5 hours, less than 25 hours, less than 24.5 hours, less than 24 hours, less than 23.5 hours, less than 23 hours, less than 22.5 hours, less than 22 hours, less than 21.5 hours, less than 21 hours, or less than 20.5 hours. In some embodiments, the fifth suspension is stirred for a time longer than 20 hours, longer than 20.5 hours, longer than 21 hours, longer than 21.5 hours, longer than 22 hours, longer than 22.5 hours, longer than 23 hours, longer than 23.5 hours, longer than 24 hours, longer than 24.5 hours, longer than 25 hours, longer than 25.5 hours, longer than 26 hours, longer than 26.5 hours, longer than 27 hours, or longer than 27.5 hours.

[0110] In some embodiments, the fifth suspension is stirred at speeds of approximately 20 rpm to 300 rpm, approximately 20 rpm to 280 rpm, approximately 20 rpm to 260 rpm, approximately 20 rpm to 240 rpm, approximately 20 rpm to 220 rpm, approximately 20 rpm to 200 rpm, approximately 20 rpm to 180 rpm, approximately 20 rpm to 160 rpm, approximately 40 rpm to 160 rpm, approximately 60 rpm to 160 rpm, approximately 60 rpm to 140 rpm, approximately 80 rpm to 140 rpm, approximately 80 rpm to 120 rpm, approximately 50 rpm to 150 rpm, or approximately 50 rpm to 200 rpm.

[0111] In some embodiments, the fifth suspension is stirred at a speed of less than 300 rpm, less than 280 rpm, less than 260 rpm, less than 240 rpm, less than 220 rpm, less than 200 rpm, less than 180 rpm, less than 160 rpm, less than 140 rpm, less than 120 rpm, less than 100 rpm, less than 80 rpm, less than 60 rpm, or less than 40 rpm. In some embodiments, the fifth suspension is stirred at a speed faster than 20 rpm, faster than 40 rpm, faster than 60 rpm, faster than 80 rpm, faster than 100 rpm, faster than 120 rpm, faster than 140 rpm, faster than 160 rpm, faster than 180 rpm, faster than 200 rpm, faster than 220 rpm, faster than 240 rpm, faster than 260 rpm, or faster than 280 rpm.

[0112] In some embodiments, the proportion of water-soluble free radical initiator is approximately 0.005% to 0.05%, 0.0075% to 0.05%, 0.01% to 0.05%, 0.01% to 0.048%, 0.01% to 0.046%, 0.01% to 0.044%, 0.01% to 0.042%, 0.01% to 0.04%, 0.01% to 0.038%, 0.01% to 0.036%, and 0.0. The ranges are approximately 0.01% to 0.034%, approximately 0.01% to 0.032%, approximately 0.01% to 0.03%, approximately 0.012% to 0.03%, approximately 0.014% to 0.03%, approximately 0.016% to 0.03%, approximately 0.01% to 0.028%, approximately 0.016% to 0.026%, approximately 0.018% to 0.026%, or approximately 0.02% to 0.026%. When the proportion of water-soluble initiators in the total weight of monomers added during the preparation of the binder composition falls within the above ranges, a higher monomer conversion rate can be achieved, and the binder composition can exhibit better overall binding performance.

[0113] In some embodiments, the proportion of the water-soluble free radical initiator is less than 0.05%, less than 0.048%, less than 0.046%, less than 0.044%, less than 0.042%, less than 0.04%, less than 0.038%, less than 0.036%, less than 0.034%, less than 0.032%, less than 0.03%, less than 0.028%, less than 0.026%, less than 0.024%, less than 0.022%, less than 0.02%, less than 0.018%, less than 0.016%, less than 0.014%, less than 0.012%, less than 0.01%, less than 0.008%, or less than 0.006% by weight, based on the total weight of monomers added in the preparation of the binder composition. In some embodiments, the proportion of the water-soluble free radical initiator is, based on the total weight of the monomers added in the preparation of the binder composition, more than 0.005%, more than 0.0075%, more than 0.01%, more than 0.012%, more than 0.014%, more than 0.016%, more than 0.018%, more than 0.02%, more than 0.022%, more than 0.024%, more than 0.026%, more than 0.028%, more than 0.03%, more than 0.032%, more than 0.034%, more than 0.036%, more than 0.038%, more than 0.04%, more than 0.042%, more than 0.044%, more than 0.046%, or more than 0.048% by weight.

[0114] In some embodiments, the proportion of the reducing agent is approximately 0.001% to 0.03% by weight, based on the total weight of monomers added in the preparation of the binder composition, approximately 0.001% to 0.03%, approximately 0.0025% to 0.03%, approximately 0.005% to 0.03%, approximately 0.005% to 0.029%, approximately 0.005% to 0.028%, approximately 0.005% to 0.027%, approximately 0.005% to 0.026%, approximately 0.005% to 0.025%, approximately 0.005% to 0.024%, and approximately 0.005% by weight. The percentages are approximately 0.023%, 0.005% to 0.022%, 0.005% to 0.021%, 0.005% to 0.02%, 0.005% to 0.019%, 0.005% to 0.018%, 0.005% to 0.017%, 0.005% to 0.016%, 0.005% to 0.015%, 0.006% to 0.015%, 0.007% to 0.015%, 0.007% to 0.02%, or 0.007% to 0.025%.

[0115] In some embodiments, the proportion of the reducing agent is less than 0.03%, less than 0.029%, less than 0.028%, less than 0.027%, less than 0.026%, less than 0.025%, less than 0.024%, less than 0.023%, less than 0.022%, less than 0.021%, less than 0.02%, less than 0.019%, less than 0.018%, less than 0.017%, less than 0.016%, less than 0.015%, less than 0.014%, less than 0.013%, less than 0.012%, less than 0.011%, less than 0.01%, less than 0.008%, less than 0.006%, or less than 0.004% by weight, based on the total weight of monomers added in the preparation of the binder composition. In some embodiments, the proportion of the reducing agent is more than 0.001%, more than 0.0025%, more than 0.005%, more than 0.006%, more than 0.007%, more than 0.008%, more than 0.009%, more than 0.01%, more than 0.011%, more than 0.012%, more than 0.013%, more than 0.014%, more than 0.015%, and 0. More than 0.016%, more than 0.017%, more than 0.018%, more than 0.019%, more than 0.02%, more than 0.021%, more than 0.022%, more than 0.023%, more than 0.024%, more than 0.025%, more than 0.026%, more than 0.027%, or more than 0.028%.

[0116] In some embodiments, the neutralizing solution is prepared by dissolving the neutralizing agent in water. In some embodiments, the sixth suspension is formed by adding the neutralizing solution dropwise to the fifth suspension in step 106. The neutralizing agent described above in step 101 may be selected. In some embodiments, the neutralizing agent applied in step 101 may correspond to the neutralizing agent used in step 106. In some embodiments, the neutralizing agents applied in steps 101 and 106 may not be the same.

[0117] In some embodiments, the temperature of the fifth suspension is lowered to about 20°C to about 40°C, about 20°C to about 39°C, about 20°C to about 38°C, about 20°C to about 37°C, about 20°C to about 36°C, about 20°C to about 35°C, about 20°C to about 34°C, about 20°C to about 33°C, about 20°C to about 32°C, about 20°C to about 31°C, about 20°C to about 30°C, about 21°C to about 35°C, about 22°C to about 35°C, about 23°C to about 35°C, about 24°C to about 35°C, or about 25°C to about 35°C before adding the neutralizing solution to form the sixth suspension. In some embodiments, the temperature of the fifth suspension is lowered to less than 40°C, less than 39°C, less than 38°C, less than 37°C, less than 36°C, less than 35°C, less than 34°C, less than 33°C, less than 32°C, less than 31°C, less than 30°C, less than 29°C, less than 28°C, less than 27°C, less than 26°C, less than 25°C, less than 24°C, less than 23°C, less than 22°C, or less than 21°C before the neutralizing solution is added to form the sixth suspension. In some embodiments, the temperature of the fifth suspension is lowered to above 20°C, above 21°C, above 22°C, above 23°C, above 24°C, above 25°C, above 26°C, above 27°C, above 28°C, above 29°C, above 30°C, above 31°C, above 32°C, above 33°C, above 34°C, above 35°C, above 36°C, above 37°C, above 38°C, or above 39°C before adding the neutralizing solution to form the sixth suspension.

[0118] In some embodiments, the total proportion of the neutralizing agent is approximately 35% to 68%, 35% to 66%, 35% to 64%, 35% to 62%, 35% to 60%, 35% to 59%, 35% to 58%, 35% to 57%, and 3% in moles, based on the total number of moles of monomer units in the copolymer of the binder composition. The percentages are approximately 5% to 56%, 35% to 55%, 35% to 54%, 35% to 53%, 35% to 52%, 35% to 51%, 35% to 50%, 36% to 50%, 37% to 50%, 38% to 50%, 39% to 50%, 40% to 50%, 35% to 45%, or 42% to 52%.

[0119] In some embodiments, the total proportion of the neutralizing agent is less than 68%, less than 66%, less than 64%, less than 62%, less than 60%, less than 58%, less than 56%, less than 54%, less than 52%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 38%, or less than 36%, based on the total number of moles of monomer units in the copolymer in the binder composition. In some embodiments, the total proportion of the neutralizing agent is more than 35%, more than 37%, more than 40%, more than 42%, more than 44%, more than 46%, more than 48%, more than 50%, more than 52%, more than 54%, more than 56%, more than 58%, more than 60%, more than 62%, more than 64%, or more than 66%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0120] In some embodiments, the neutralizing solution is added dropwise to the fifth suspension for a period of time of approximately 15 to 120 minutes, 20 to 120 minutes, 30 to 120 minutes, 30 to 110 minutes, 30 to 100 minutes, 30 to 90 minutes, 40 to 90 minutes, 40 to 80 minutes, 45 to 80 minutes, 45 to 75 minutes, 50 to 75 minutes, 50 to 70 minutes, 55 to 70 minutes, or 55 to 65 minutes. In some embodiments, the neutralizing solution is added dropwise to the fifth suspension for a period of time of less than 120 minutes, less than 110 minutes, less than 100 minutes, less than 90 minutes, less than 80 minutes, less than 70 minutes, less than 60 minutes, less than 50 minutes, less than 40 minutes, less than 30 minutes, or less than 20 minutes. In some embodiments, the neutralizing solution is added dropwise to the fifth suspension for a period of time longer than 15 minutes, longer than 20 minutes, longer than 30 minutes, longer than 40 minutes, longer than 50 minutes, longer than 60 minutes, longer than 70 minutes, or longer than 80 minutes.

[0121] In some embodiments, the fifth suspension is stirred for about 1 to 6 hours, about 1 to 5.75 hours, about 1 to 5.5 hours, about 1 to 5.25 hours, about 1 to 5 hours, about 1 to 4.75 hours, about 1 to 4.5 hours, about 1 to 4.25 hours, about 1 to 4 hours, about 1.25 to 4 hours, about 1.5 to 4 hours, about 1.75 to 4 hours, about 2 to 4 hours, about 2.25 to 4 hours, about 2.5 to 4 hours, about 2.5 to 3.75 hours, 2.5 to 3.5 hours, 2.5 to 4 hours, or about 2 to 3.5 hours while the neutralizing solution is added and neutralization takes place.

[0122] In some embodiments, the fifth suspension is stirred for a period of less than 6 hours, less than 5.75 hours, less than 5.5 hours, less than 5.25 hours, less than 5 hours, less than 4.75 hours, less than 4.5 hours, less than 4.25 hours, less than 4 hours, less than 3.75 hours, less than 3.5 hours, less than 3.25 hours, less than 3 hours, less than 2.75 hours, less than 2.5 hours, less than 2.25 hours, less than 2 hours, less than 1.75 hours, or less than 1.5 hours while the neutralizing solution is added and neutralization takes place. In some embodiments, the fifth suspension is stirred for a period of time longer than 1 hour, longer than 1.25 hours, longer than 1.5 hours, longer than 1.75 hours, longer than 2 hours, longer than 2.25 hours, longer than 2.5 hours, longer than 2.75 hours, longer than 3 hours, longer than 3.25 hours, longer than 3.5 hours, longer than 3.75 hours, longer than 4 hours, longer than 4.25 hours, longer than 4.5 hours, longer than 4.75 hours, longer than 5 hours, longer than 5.25 hours, or longer than 5.5 hours while the neutralizing solution is added and neutralization takes place.

[0123] In some embodiments, the fifth suspension is stirred at speeds of approximately 20 rpm to 300 rpm, approximately 20 rpm to 280 rpm, approximately 20 rpm to 260 rpm, approximately 20 rpm to 240 rpm, approximately 20 rpm to 220 rpm, approximately 20 rpm to 200 rpm, approximately 20 rpm to 180 rpm, approximately 20 rpm to 160 rpm, approximately 40 rpm to 160 rpm, approximately 60 rpm to 160 rpm, approximately 60 rpm to 140 rpm, approximately 80 rpm to 140 rpm, approximately 80 rpm to 120 rpm, approximately 50 rpm to 150 rpm, or approximately 50 rpm to 200 rpm.

[0124] In some embodiments, the fifth suspension is stirred at a speed of less than 300 rpm, less than 280 rpm, less than 260 rpm, less than 240 rpm, less than 220 rpm, less than 200 rpm, less than 180 rpm, less than 160 rpm, less than 140 rpm, less than 120 rpm, less than 100 rpm, less than 80 rpm, less than 60 rpm, or less than 40 rpm. In some embodiments, the fifth suspension is stirred at a speed faster than 20 rpm, faster than 40 rpm, faster than 60 rpm, faster than 80 rpm, faster than 100 rpm, faster than 120 rpm, faster than 140 rpm, faster than 160 rpm, faster than 180 rpm, faster than 200 rpm, faster than 220 rpm, faster than 240 rpm, faster than 260 rpm, or faster than 280 rpm.

[0125] In some embodiments, the binder composition is formed by filtering the sixth suspension in step 107.

[0126] The addition of neutralizing agents in steps 101 and 106 is intended to neutralize the carboxylic acid group-containing monomer added in step 102 and to produce a binder composition that is inherently weakly alkaline. Exposing the binder composition to acidic conditions is undesirable because it may disrupt the dispersion of the binder composition.

[0127] In some embodiments, structural unit (a) derived from a carboxylic acid group-containing monomer contains a carboxylic acid base. In some embodiments, the carboxylic acid base is a salt of a carboxylic acid group. In some embodiments, structural unit (a) derived from a carboxylic acid group-containing monomer contains a combination of a carboxylic acid base and a carboxylic acid group. In some embodiments, structural unit (a) contains an alkali metal carboxylic acid base. Examples of alkali metals that form alkali metal carboxylic acid salts include lithium, sodium, and potassium. In some embodiments, structural unit (a) contains an ammonium carboxylic acid base.

[0128] In some embodiments, the molar ratio of carboxylic acid groups to carboxylic acid bases in the copolymer is about 0 to about 0.2, about 0 to about 0.19, about 0 to about 0.18, about 0 to about 0.17, about 0 to about 0.16, about 0 to about 0.15, about 0 to about 0.14, about 0 to about 0.13, about 0 to about 0.16, about 0 to about 0.15, about 0 to about 0.14, about 0 to about 0.13, about 0 to about 0.12, about 0 to about 0.11, about 0 to about 0.1, about 0 to about 0.09, about 0 to about 0.08, about 0 to about 0.07, about 0 to about 0.06, about 0 to about 0.05, about 0.01 to about 0.1, about 0.02 to about 0.12, or about 0.01 to about 0.15.

[0129] In some embodiments, the molar ratio of carboxylic acid groups to carboxylic acid bases in the copolymer is less than 0.2, less than 0.19, less than 0.18, less than 0.17, less than 0.16, less than 0.15, less than 0.14, less than 0.13, less than 0.12, less than 0.11, less than 0.1, less than 0.09, less than 0.08, less than 0.07, less than 0.06, less than 0.05, less than 0.04, less than 0.03, or less than 0.02. In some embodiments, the molar ratio of carboxylic acid groups to carboxylic acid bases in the copolymer is greater than 0, greater than 0.01, greater than 0.02, greater than 0.03, greater than 0.04, greater than 0.05, greater than 0.06, greater than 0.07, greater than 0.08, greater than 0.09, greater than 0.1, greater than 0.11, greater than 0.12, greater than 0.13, greater than 0.14, greater than 0.15, greater than 0.16, greater than 0.17, or greater than 0.18.

[0130] In some embodiments, the proportion of structural units (a) in the copolymer is approximately 33% to 70%, 33% to 69%, 33% to 68%, 33% to 67%, 33% to 66%, 33% to 65%, 33% to 64%, 33% to 63%, 33% to 62%, 33% to 61%, 33% to 60%, and 33% to 5% in moles, based on the total number of moles of monomer units in the copolymer in the binder composition. The percentages are 9%, approximately 33%-58%, approximately 33%-57%, approximately 33%-56%, approximately 33%-55%, approximately 33%-54%, approximately 33%-53%, approximately 33%-52%, approximately 33%-51%, approximately 33%-50%, approximately 34%-50%, approximately 35%-50%, approximately 36%-50%, approximately 37%-50%, approximately 38%-50%, approximately 39%-50%, approximately 40%-50%, approximately 35%-60%, or approximately 40%-55%.

[0131] In some embodiments, the proportion of structural units (a) in the copolymer is less than 70%, less than 68%, less than 66%, less than 64%, less than 62%, less than 60%, less than 58%, less than 56%, less than 54%, less than 52%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 38%, less than 36%, or less than 34%, based on the total number of moles of monomer units in the copolymer in the binder composition. In some embodiments, the proportion of structural units (a) in the copolymer is more than 33%, more than 34%, more than 36%, more than 38%, more than 40%, more than 42%, more than 44%, more than 46%, more than 48%, more than 50%, more than 52%, more than 54%, more than 56%, more than 58%, more than 60%, more than 62%, more than 64%, or more than 66%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0132] In some embodiments, the proportion of structural units (b) in the copolymer is approximately 10% to 35%, 10% to 34%, 10% to 33%, 10% to 32%, 10% to 31%, 10% to 30%, 11% to 30%, 12% to 30%, and 1 The percentages are approximately 3% to 30%, 14% to 30%, 15% to 30%, 16% to 30%, 17% to 30%, 18% to 30%, 19% to 30%, 20% to 30%, 20% to 29%, 20% to 28%, 20% to 27%, 20% to 26%, 20% to 25%, 15% to 28%, or 15% to 34%.

[0133] In some embodiments, the proportion of structural units (b) in the copolymer is less than 35%, less than 34%, less than 33%, less than 32%, less than 31%, less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, or less than 12%, based on the total number of moles of monomer units in the copolymer in the binder composition. In some embodiments, the proportion of structural units (b) in the copolymer is more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, more than 28%, more than 29%, more than 30%, more than 31%, more than 32%, or more than 33%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0134] In some embodiments, the proportion of structural units (c) in the copolymer is approximately 10% to 30%, 11% to 30%, 12% to 30%, 13% to 30%, 14% to 30%, 15% to 30%, 16% to 30%, 17% to 30%, 18% to 30%, and 19% to 30%, based on the total number of moles of monomer units in the copolymer in the binder composition. The percentages are 0%, approximately 20% to 30%, approximately 20% to 29%, approximately 20% to 28%, approximately 20% to 27%, approximately 20% to 26%, approximately 20% to 25%, approximately 11% to 25%, approximately 12% to 25%, approximately 13% to 25%, approximately 14% to 25%, approximately 15% to 25%, approximately 16% to 27%, approximately 17% to 27%, approximately 18% to 27%, approximately 19% to 27%, or approximately 10% to 27%.

[0135] In some embodiments, the proportion of structural units (c) in the copolymer is less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21%, less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, or less than 12%, based on the total number of moles of monomer units in the copolymer in the binder composition. In some embodiments, the proportion of structural units (c) in the copolymer is more than 10%, more than 11%, more than 12%, more than 13%, more than 14%, more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24%, more than 25%, more than 26%, more than 27%, or more than 28%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0136] In some embodiments, the total proportion of structural unit (a) and structural unit (c) in the copolymer is approximately 65% ​​to 90%, 65% to 89%, 65% to 88%, 65% to 87%, 65% to 86%, 65% to 85%, 65% to 84%, 65% to 83%, 65% to 82%, 65% to 81%, 65% to 80%, 66% to 80%, 67% to 80%, 68% to 80%, 69% to 80%, 70% to 80%, 65% to 75%, or 70% to 85%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0137] In some embodiments, the total proportion of structural units (a) and structural units (c) in the copolymer is less than 90%, less than 88%, less than 86%, less than 84%, less than 82%, less than 80%, less than 78%, less than 76%, less than 74%, less than 72%, less than 70%, less than 68%, or less than 66%, based on the total number of moles of monomer units in the copolymer in the binder composition. In some embodiments, the total proportion of structural units (a) and structural units (c) in the copolymer is more than 65%, more than 67%, more than 70%, more than 72%, more than 74%, more than 76%, more than 78%, more than 80%, more than 82%, more than 84%, more than 86%, or more than 88%, based on the total number of moles of monomer units in the copolymer in the binder composition.

[0138] In some embodiments, the molar ratio of the total structural unit (a) and structural unit (c) to structural unit (b) in the copolymer is about 1 to about 7, about 1 to about 6.8, about 1 to about 6.6, about 1 to about 6.4, about 1 to about 6.2, about 1 to about 6, about 1 to about 5.8, about 1 to about 5.6, about 1 to about 5.4, about 1 to about 5.2, about 1 to about 5, about 1 to about 4.8, about 1 to about 4.6, about 1 to about 4.4, about 1 to about 4.2, about 1 to about 4, about 1 to about 3.8, about 1.2 to about 3.8, about 1.4 to about 3.8, about 2 to about 6, about 2 to about 4, about 3 to about 5, or about 3 to about 7.

[0139] In some embodiments, the molar ratio of the total structural unit (a) and structural unit (c) to structural unit (b) in the copolymer is less than 7, less than 6.8, less than 6.6, less than 6.4, less than 6.2, less than 6, less than 5.8, less than 5.6, less than 5.4, less than 5.2, less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 2.8, less than 2.6, less than 2.4, less than 2.2, less than 2, less than 1.8, less than 1.6, less than 1.4, or less than 1.2. In some embodiments, the molar ratio of the total structural unit (a) and structural unit (c) to structural unit (b) in the copolymer is greater than 1, greater than 1.2, greater than 1.4, greater than 1.6, greater than 1.8, greater than 2, greater than 2.2, greater than 2.4, greater than 2.6, greater than 2.8, greater than 3, greater than 3.2, greater than 3.4, greater than 3.6, greater than 3.8, greater than 4, greater than 4.2, greater than 4.4, greater than 4.6, greater than 4.8, greater than 5, greater than 5.2, greater than 5.4, greater than 5.6, greater than 5.8, greater than 6, greater than 6.2, greater than 6.4, greater than 6.6, or greater than 6.8.

[0140] In some embodiments, structural units (a) and (b) constitute the hydrophilic portion of the copolymer. In some embodiments, structural unit (c) constitutes the hydrophobic portion of the copolymer.

[0141] In some embodiments, the molar ratio of the total structural unit (a) and structural unit (b) to structural unit (c) in the copolymer is about 1 to about 7, about 1 to about 6.8, about 1 to about 6.6, about 1 to about 6.4, about 1 to about 6.2, about 1 to about 6, about 1 to about 5.8, about 1 to about 5.6, about 1 to about 5.4, about 1 to about 5.2, about 1 to about 5, about 1 to about 4.8, about 1 to about 4.6, about 1 to about 4.4, about 1 to about 4.2, about 1 to about 4, about 1 to about 3.8, about 1 to about 3.6, about 1 to about 3.4, about 1.2 to about 3.4, about 1.4 to about 3.4, about 1.5 to about 6.7, about 1.5 to about 5, about 1.5 to about 4.8, or about 1.5 to about 4.

[0142] In some embodiments, the molar ratio of the total structural unit (a) and structural unit (b) to structural unit (c) in the copolymer is less than 7, less than 6.8, less than 6.6, less than 6.4, less than 6.2, less than 6, less than 5.8, less than 5.6, less than 5.4, less than 5.2, less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 2.8, less than 2.6, less than 2.4, less than 2.2, less than 2, less than 1.8, less than 1.6, less than 1.4, or less than 1.2. In some embodiments, the molar ratio of the total structural unit (a) and structural unit (b) to structural unit (c) in the copolymer is greater than 1, greater than 1.2, greater than 1.4, greater than 1.6, greater than 1.8, greater than 2, greater than 2.2, greater than 2.4, greater than 2.6, 2.8, greater than 3, greater than 3.2, greater than 3.4, greater than 3.6, greater than 3.8, greater than 4, greater than 4.2, greater than 4.4, greater than 4.6, 4.8, greater than 5, greater than 5.2, greater than 5.4, greater than 5.6, 5.8, greater than 6, greater than 6.2, greater than 6.4, greater than 6.6, or greater than 6.8.

[0143] The addition of ester group-containing monomers in the preparation of the binder compositions disclosed herein has been found to result in a deterioration of electrochemical performance. In some embodiments, the binder compositions do not have structural units derived from ester group-containing monomers. In some embodiments, the ester group-containing monomers are C1-C 20 Alkyl acrylates, C1-C 20The monomers are alkyl (meth)acrylates, cycloalkyl acrylates, or combinations thereof. In some embodiments, the ester group-containing monomers are methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, pentyl acrylate, hesyl acrylate, heptyl acrylate, octyl acrylate, 3,3,5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, perfluorooctyl acrylate, stearyl acrylate, or combinations thereof. In some embodiments, the ester group-containing monomer is cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, or a combination thereof. In some embodiments, the ester group-containing monomers are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, stearyl methacrylate, 2,2,2-trifluoroethyl methacrylate, phenyl methacrylate, benzyl methacrylate, or a combination thereof.

[0144] In some embodiments, the binder composition does not contain structural units derived from conjugated diene group-containing monomers. Examples of conjugated diene group-containing monomers include aliphatic conjugated diene monomers such as 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and 2-chloro-1,3-butadiene, as well as substituted linear conjugated pentadienes and substituted side-chain conjugated hexadienes.

[0145] In some embodiments, the binder composition does not contain structural units derived from aromatic vinyl group-containing monomers. Examples of aromatic vinyl group-containing monomers include styrene, α-methylstyrene, vinyltoluene, and divinylbenzene.

[0146] In some embodiments, the pH of the binder composition is about 7 to about 9, about 7 to about 8.9, about 7 to about 8.8, about 7 to about 8.7, about 7 to about 8.6, about 7 to about 8.5, about 7 to about 8.4, about 7 to about 8.3, about 8 to about 8.2, about 7 to about 8.1, about 7 to about 8, about 7.1 to about 9, about 7.2 to about 9, about 7.3 to about 9, about 7.4 to about 9, about 7.5 to about 9, about 7.6 to about 9, about 7.7 to about 9, about 7.8 to about 9, about 7.9 to about 9, or about 8 to about 9.

[0147] In certain embodiments, the pH of the binder composition is less than 9, less than 8.9, less than 8.8, less than 8.7, less than 8.6, less than 8.5, less than 8.4, less than 8.3, less than 8.2, less than 8.1, less than 8, less than 7.9, less than 7.8, less than 7.7, less than 7.6, less than 7.5, less than 7.4, less than 7.3, or less than 7.2. In certain embodiments, the pH of the binder composition is greater than 7, greater than 7.1, greater than 7.2, greater than 7.3, greater than 7.4, greater than 7.5, greater than 7.6, greater than 7.7, greater than 7.8, greater than 7.9, greater than 8, greater than 8.1, greater than 8.2, greater than 8.3, greater than 8.4, greater than 8.5, greater than 8.6, greater than 8.7, or greater than 8.8.

[0148] In some embodiments, the viscosity of the binder composition is approximately 10,000 mPa·s to approximately 50,000 mPa·s, approximately 10,000 mPa·s to approximately 47,500 mPa·s, approximately 10,000 mPa·s to approximately 45,000 mPa·s, approximately 10,000 mPa·s to approximately 42,500 mPa·s, and approximately 10,000 mPa·s to approximately 4000 mPa·s. 0mPa·s, 10,000mPa·s~approx. 3,7500mPa·s, 10,000mPa·s~approx. 35,000mPa·s, 10,000mPa·s~approx. 32,5 00mPa·s, 10,000mPa·s~approx. 30,000mPa·s, 10,000mPa·s~approx. 29,000mPa·s, approx. 10,000mPa·s~approx. 28, 000mPa·s, approximately 10,000mPa·s~approx. 27,000mPa·s, approximately 10,000mPa·s~approximately 26,000mPa·s, approximately 10,000mPa·s~ Approx. 25,000mPa s, Approx. 10,000mPa s~Approx. 24,000mPa s, Approx. 10,000mPa s~Approx. 23,000mPa s, Approx. 10,000mPa The pressure ranges are approximately 22,000 mPa·s for 10,000 mPa·s and 21,000 mPa·s for 10,000 mPa·s and 20,000 mPa·s for 15,000 mPa·s and 30,000 mPa·s for 15,000 mPa·s and 25,000 mPa·s for 15,000 mPa·s and 35,000 mPa·s for 15,000 mPa·s.

[0149] In some embodiments, the viscosity of the binder composition is less than 50,000 mPa·s, less than 47,500 mPa·s, less than 45,000 mPa·s, less than 42,500 mPa·s, less than 40,000 mPa·s, less than 37,500 mPa·s, less than 35,000 mPa·s, less than 32,500 mPa·s, less than 30,000 mPa·s, less than 27,500 mPa·s, less than 25,000 mPa·s, less than 22,500 mPa·s, less than 20,000 mPa·s, less than 17,500 mPa·s, less than 15,000 mPa·s, or less than 12,500 mPa·s. In some embodiments, the viscosity of the binder composition is greater than 10,000 mPa·s, greater than 12,500 mPa·s, greater than 15,000 mPa·s, greater than 17,500 mPa·s, greater than 20,000 mPa·s, greater than 22,500 mPa·s, greater than 25,000 mPa·s, greater than 27,500 mPa·s, greater than 30,000 mPa·s, greater than 32,500 mPa·s, greater than 35,000 mPa·s, greater than 37,500 mPa·s, greater than 40,000 mPa·s, greater than 42,500 mPa·s, greater than 45,000 mPa·s, and greater than 47,500 mPa·s.

[0150] In some embodiments, the solids content of the binder composition is approximately 5% to 10%, 5% to 9.9%, 5% to 9.8%, 5% to 9.7%, 5% to 9.6%, 5% to 9.5%, 5% to 9.4%, 5% to 9.3%, 5% to 9.2%, 5% to 9.1%, 5% to 9.9%, 5.1% to 9%, 5.2% to 9%, 5.3% to 9%, 5.4% to 9%, and 5% to 9% by weight, based on the total weight of the binder composition. The percentages are approximately 0.5% to 9%, approximately 5.6% to 9%, approximately 5.7% to 9%, approximately 5.8% to 9%, approximately 5.9% to 9%, approximately 6% to 9%, approximately 6% to 8.9%, approximately 6% to 8.8%, approximately 6% to 8.7%, approximately 6% to 8.6%, approximately 6% to 8.5%, approximately 6% to 8.4%, approximately 6% to 8.3%, approximately 6% to 8.2%, approximately 6% to 8.1%, approximately 6% to 8%, approximately 6% to 9.8%, approximately 6% to 9.6%, approximately 6% to 9.4%, or approximately 6% to 9.2%.

[0151] In some embodiments, the solid content of the binder composition is less than 10%, less than 9.8%, less than 9.6%, less than 9.4%, less than 9.2%, less than 9%, less than 8.8%, less than 8.6%, less than 8.4%, less than 8.2%, less than 8%, less than 7.8%, less than 7.6%, less than 7.4%, less than 7.2%, less than 7%, less than 6.8%, less than 6.6%, less than 6.4%, less than 6.2%, less than 6%, less than 5.8%, less than 5.6%, less than 5.4%, or less than 5.2% by weight, based on the total weight of the binder composition. In some embodiments, the solids content of the binder composition is more than 5%, more than 5.2%, more than 5.4%, more than 5.6%, more than 5.8%, more than 6%, more than 6.2%, more than 6.4%, more than 6.6%, more than 6.8%, more than 7%, more than 7.2%, more than 7.4%, more than 7.6%, more than 7.8%, more than 8%, more than 8.2%, more than 8.4%, more than 8.6%, more than 8.8%, more than 9%, more than 9.2%, more than 9.4%, more than 9.6%, or more than 9.8% by weight, based on the total weight of the binder composition.

[0152] In some embodiments, the weight-average molecular weight of the binder composition is approximately 50,000 g / mol to approximately 200,000 g / mol, approximately 55,000 g / mol to approximately 200,000 g / mol, approximately 60,000 g / mol to approximately 200,000 g / mol, and approximately 65. 000g / mol~about 200,000g / mol, about 70,000g / mol~about 200,000g / mol, about 75,000g / mol~about 200,000g / mol, about 80,000g / mol~about 200,000g / mol, about 85,0 00g / mol~about 200,000g / mol, about 90,000g / mol~about 200,000g / mol, about 90,000g / mol~about 190,000g / mol, about 90,000g / mol~about 180,000g / mol, about 90,000 The weight-average molecular weight ranges from approximately g / mol to 170,000 g / mol, approximately 90,000 g / mol to 160,000 g / mol, approximately 95,000 g / mol to 160,000 g / mol, approximately 100,000 g / mol to 160,000 g / mol, approximately 100,000 g / mol to 155,000 g / mol, approximately 100,000 g / mol to 150,000 g / mol, approximately 100,000 g / mol to 145,000 g / mol, or approximately 100,000 g / mol to 140,000 g / mol. When the weight-average molecular weight of the binder composition is not greater than the above upper limit, the coatability of the binder composition is ensured and the adhesive strength of the binder composition can be improved, thus enabling the creation of a smooth binder composition layer. On the other hand, if the weight-average molecular weight of the binder composition is not below the lower limit specified above, the bonding properties of the binder composition can be ensured, and the adhesive strength and secondary battery cycle characteristics of the binder composition can be improved.

[0153] In some embodiments, the weight-average molecular weight of the binder composition is less than 200,000 g / mol, less than 195,000 g / mol, less than 190,000 g / mol, less than 185,000 g / mol, less than 180,000 g / mol, less than 175,000 g / mol, less than 170,000 g / mol, less than 165,000 g / mol, less than 160,000 g / mol, and 1 The values ​​are less than 55,000 g / mol, less than 150,000 g / mol, less than 145,000 g / mol, less than 140,000 g / mol, less than 135,000 g / mol, less than 130,000 g / mol, less than 125,000 g / mol, less than 120,000 g / mol, less than 115,000 g / mol, less than 110,000 g / mol, less than 105,000 g / mol, less than 100,000 g / mol, less than 95,000 g / mol, less than 90,000 g / mol, less than 85,000 g / mol, less than 80,000 g / mol, less than 75,000 g / mol, less than 70,000 g / mol, less than 65,000 g / mol, or less than 60,000 g / mol. In some embodiments, the weight-average molecular weight of the binder composition is greater than 50,000 g / mol, greater than 55,000 g / mol, greater than 60,000 g / mol, greater than 65,000 g / mol, greater than 70,000 g / mol, greater than 75,000 g / mol, greater than 80,000 g / mol, greater than 85,000 g / mol, greater than 90,000 g / mol, greater than 95,000 g / mol, greater than 10,000 g / mol, greater than 105,000 g / mol, greater than 110,000 g / mol, greater than 115,000 g / mol, and 120,000 g / mol. More than g / mol, more than 125,000 g / mol, more than 130,000 g / mol, more than 135,000 g / mol, more than 140,000 g / mol, more than 145,000 g / mol, more than 150,000 g / mol, more than 155,000 g / mol, more than 160,000 g / mol, more than 165,000 g / mol, more than 170,000 g / mol, more than 175,000 g / mol, more than 180,000 g / mol, more than 185,000 g / mol, more than 190,000 g / mol, or more than 195,000 g / mol.

[0154] In some embodiments, the number-average molecular weight of the binder composition is approximately 10,000 g / mol to approximately 100,000 g / mol, approximately 15,000 g / mol to approximately 100,000 g / mol, approximately 20,000 g / mol to approximately 100,000 g / mol, approximately 25,000 g / mol to approximately 100,000 g / mol, approximately 30,000 g / mol to approximately 100,000 g / mol, approximately 35,000 g / mol to approximately 100,000 g / mol, approximately 40,000 g / mol to approximately 100,000 g / mol, and approximately 45,000 g / mol to approximately 100,000 g / mol. The ranges are mol, approximately 50,000 g / mol to approximately 100,000 g / mol, approximately 50,000 g / mol to approximately 95,000 g / mol, approximately 50,000 g / mol to approximately 90,000 g / mol, approximately 50,000 g / mol to approximately 85,000 g / mol, approximately 50,000 g / mol to approximately 80,000 g / mol, approximately 55,000 g / mol to approximately 80,000 g / mol, approximately 60,000 g / mol to approximately 80,000 g / mol, approximately 65,000 g / mol to approximately 75,000 g / mol, or approximately 60,000 g / mol to approximately 90,000 g / mol.

[0155] In some embodiments, the number-average molecular weight of the binder composition is less than 100,000 g / mol, less than 95,000 g / mol, less than 90,000 g / mol, less than 85,000 g / mol, less than 80,000 g / mol, less than 75,000 g / mol, less than 70,000 g / mol, less than 65,000 g / mol, less than 60,000 g / mol, less than 55,000 g / mol, less than 50,000 g / mol, less than 45,000 g / mol, less than 40,000 g / mol, less than 35,000 g / mol, less than 30,000 g / mol, less than 25,000 g / mol, less than 20,000 g / mol, or less than 15,000 g / mol. In some embodiments, the number-average molecular weight of the binder composition is greater than 10,000 g / mol, greater than 15,000 g / mol, greater than 20,000 g / mol, greater than 25,000 g / mol, greater than 30,000 g / mol, greater than 35,000 g / mol, greater than 40,000 g / mol, greater than 45,000 g / mol, greater than 50,000 g / mol, greater than 55,000 g / mol, greater than 60,000 g / mol, greater than 65,000 g / mol, greater than 70,000 g / mol, greater than 75,000 g / mol, greater than 80,000 g / mol, greater than 85,000 g / mol, greater than 90,000 g / mol, or greater than 95,000 g / mol.

[0156] In some embodiments, the polydispersity index (PDI) of the binder composition is about 1 to about 5, about 1 to about 4.8, about 1 to about 4.6, about 1 to about 4.4, about 1 to about 4.2, about 1 to about 4, about 1 to about 3.8, about 1 to about 3.6, about 1 to about 3.4, about 1 to about 3.2, about 1 to about 3, about 1.1 to about 3, about 1.2 to about 3, about 1.3 to about 3, about 1.4 to about 3, about 1.5 to about 3, about 1.6 to about 3, about 1.6 to about 2.8, about 1.6 to about 2.6, about 1.8 to about 2.6, or about 1.8 to about 2.8. When the polydispersity index of the binder composition is within the above range, the stability of the binder composition can be further improved.

[0157] In some embodiments, the polydispersity index of the binder composition is less than 5, less than 4.8, less than 4.6, less than 4.4, less than 4.2, less than 4, less than 3.8, less than 3.6, less than 3.4, less than 3.2, less than 3, less than 2.8, less than 2.6, less than 2.4, less than 2.2, less than 2, less than 1.8, less than 1.6, less than 1.4, or less than 1.2. In some embodiments, the polydispersity index of the binder composition is greater than 1, greater than 1.2, greater than 1.4, greater than 1.6, greater than 1.8, greater than 2, greater than 2.2, greater than 2.4, greater than 2.6, greater than 2.8, greater than 3, greater than 3.2, greater than 3.4, greater than 3.6, greater than 3.8, greater than 4, greater than 4.2, greater than 4.4, greater than 4.6, or greater than 4.8.

[0158] The binder composition of the present invention exhibits strong adhesion to the current collector. The good adhesive strength of the binder composition to the current collector is important in the fabrication of battery electrodes to promote the bonding force of the electrode layer to the current collector, prevent separation, and improve the mechanical stability of the electrode. In some embodiments, the adhesive strength between the binder composition and the current collector is approximately 2 N / cm to 4 N / cm, approximately 2.1 N / cm to 4 N / cm, approximately 2.2 N / cm to 4 N / cm, approximately 2.3 N / cm to 4 N / cm, approximately 2.4 N / cm to 4 N / cm, approximately 2.5 N / cm to 4 N / cm, approximately 2.6 N / cm to 4 N / cm, approximately 2.7 N / cm to 4 N / cm, approximately 2.8 N / cm to 4 N / cm, approximately 2.9 N / cm to 4 N / cm, approximately 3 N / cm to 4 N / cm, and approximately 2 N / cm to 3.9 N / cm. N / cm, about 2N / cm to about 3.8N / cm, about 2N / cm to about 3.7N / cm, about 2N / cm to about 3.6N / cm, about 2N / cm to about 3.5N / cm, about 2N / cm to about 3.4N / cm, about 2N / cm to about 3.3N / cm, about 2N / cm to about 3.2N / cm, about 2N / cm to about 3.1N / cm, about 2N / cm to about 3N / cm, about 2.5N / cm to about 3.5N / cm, about 2.3N / cm to about 3.7N / cm, about 2.5N / cm to about 3N / cm, or about 3N / cm to about 3.5N / cm.

[0159] In some embodiments, the adhesive strength between the binder composition and the current collector is less than 4 N / cm, less than 3.9 N / cm, less than 3.8 N / cm, less than 3.7 N / cm, less than 3.6 N / cm, less than 3.5 N / cm, less than 3.4 N / cm, less than 3.3 N / cm, less than 3.2 N / cm, less than 3.1 N / cm, less than 3 N / cm, less than 2.9 N / cm, less than 2.8 N / cm, less than 2.7 N / cm, less than 2.6 N / cm, less than 2.5 N / cm, less than 2.4 N / cm, less than 2.3 N / cm, or less than 2.2 N / cm. In some embodiments, the adhesive strength between the binder composition and the current collector is greater than 2 N / cm, greater than 2.1 N / cm, greater than 2.2 N / cm, greater than 2.3 N / cm, greater than 2.4 N / cm, greater than 2.5 N / cm, greater than 2.6 N / cm, greater than 2.7 N / cm, greater than 2.8 N / cm, greater than 2.9 N / cm, greater than 3 N / cm, greater than 3.1 N / cm, greater than 3.2 N / cm, greater than 3.3 N / cm, greater than 3.4 N / cm, greater than 3.5 N / cm, greater than 3.6 N / cm, greater than 3.7 N / cm, or greater than 3.8 N / cm.

[0160] In another embodiment, provided herein is an electrode for a secondary battery, comprising an electrode active material, a current collector, and a binder composition prepared by the method described above. In another embodiment, the electrode further comprises a conductive agent.

[0161] In some embodiments, the electrode active material is a cathode active material, and the cathode active material is LiCoO2, LiNiO2, LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiLiLi x Co y Al zThe cathode active material is selected from the group consisting of O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, Li2MnO3, LiFeO2, LiFePO4 and combinations thereof, where each x is independently 0.2 to 0.9, each y is independently 0.1 to 0.45, and each z is independently 0 to 0.2. In certain embodiments, the cathode active material is LiCoO2, LiNiO2, LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2(NMC), LiNi x Co y Al z The cathode active material is selected from the group consisting of O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, LiFePO4 and combinations thereof, where each x is independently 0.4 to 0.6, each y is independently 0.2 to 0.4, and each z is independently 0 to 0.1. In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, or LiFePO4. In a further embodiment, the cathode active material is LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2, or LiNi x Co y Al z Instead of O2, each x is independently 0.2 to 0.9, each y is independently 0.1 to 0.45, and each z is independently 0 to 0.2. In certain embodiments, the cathode active material is Li 1+x Ni a Mn b Co c Al (1-a-b-c) It is O2, and -0.2≦x≦0.2, 0≦a<1, 0≦b<1, 0≦c<1, and a+b+c≦1. In some embodiments, the cathode active material is Li 1+x Ni a Mnb Co c Al (1-a-b-c) It has O2 and satisfies 0.33≦a≦0.92, 0.33≦a≦0.9, 0.33≦a≦0.8, 0.5≦a≦0.92, 0.5≦a≦0.9, 0.5≦a≦0.8, 0.6≦a≦0.92, or 0.6≦a≦0.9; 0≦b≦0.5, 0≦b≦0.3, 0.1≦b≦0.5, 0.1≦b≦0.4, 0.1≦b≦0.3, 0.1≦b≦0.2, or 0.2≦b≦0.5; 0≦c≦0.5, 0≦c≦0.3, 0.1≦c≦0.5, 0.1≦c≦0.4, 0.1≦c≦0.3, 0.1≦c≦0.2, or 0.2≦c≦0.5.

[0162] In certain embodiments, the cathode active material is doped with a dopant selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the dopant is not Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge. In certain embodiments, the dopant is not Al, Sn, or Zr.

[0163] In some embodiments, the cathode active material is LiNi 0.33 Mn 0.33 Co 0.33 O2 (NMC333), LiNi 0.4 Mn 0.4 Co 0.2 O2, LiLiLi 0.5 Mn 0.3 Co 0.2 O2 (NMC532), LiNi 0.6 Mn 0.2 Co 0.2 O2 (NMC622), LiNi 0.7 Mn 0.15 Co 0.15 O2, LiLiLi 0.8 Mn 0.1 Co 0.1 O2 (NMC811), LiNi 0.92 Mn 0.04 Co 0.04 O2, LiLiLi 0.8 Co 0.15 Al 0.05O2(NCA), LiNiO2 (LNO), and combinations thereof.

[0164] In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiMnO2, LiMn2O4, or Li2MnO3. In further embodiments, the cathode active material is LiNi 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​The material comprises lithium transition metal oxides selected from the group consisting of these combinations, where -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1. In other embodiments, the core and shell each independently comprise two or more lithium transition metal oxides. In some embodiments, one of the core or shell comprises only one lithium transition metal oxide, while the other comprises two or more lithium transition metal oxides. The lithium transition metal oxides or oxides of the core and shell may be the same, or they may be different or partially different. In some embodiments, the two or more lithium transition metal oxides are uniformly distributed on the core. In certain embodiments, the two or more lithium transition metal oxides are not uniformly distributed on the core. In some embodiments, the cathode active material is not a core-shell composite.

[0166] In some embodiments, each of the lithium transition metal oxides of the core and shell is independently doped with a dopant selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In certain embodiments, the core and shell each independently contain two or more doped lithium transition metal oxides. In some embodiments, the two or more doped lithium transition metal oxides are uniformly distributed on the core and / or shell. In certain embodiments, the two or more doped lithium transition metal oxides are not uniformly distributed on the core and / or shell.

[0167] In some embodiments, the cathode active material comprises or is a core-shell composite comprising a core containing a lithium transition metal oxide and a shell containing a transition metal oxide. In certain embodiments, the lithium transition metal oxide is Li 1+x Ni a Mn b Co c Al (1-a-b-c)O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 The transition metal oxide is selected from the group consisting of LiV2O5, LiTiS2, LiMoS2, and combinations thereof, where -0.2≦x≦0.2, 0≦a<1, 0≦b<1, 0≦c<1, and a+b+c≦1. In some embodiments, the transition metal oxide is selected from the group consisting of Fe2O3, MnO2, Al2O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2, and combinations thereof. In certain embodiments, the shell comprises lithium transition metal oxide and transition metal oxide.

[0168] In some embodiments, the core diameter is approximately 1 μm to 15 μm, approximately 3 μm to 15 μm, approximately 3 μm to 10 μm, approximately 5 μm to 10 μm, approximately 5 μm to 45 μm, approximately 5 μm to 35 μm, approximately 5 μm to 25 μm, approximately 10 μm to 45 μm, approximately 10 μm to 40 μm, or approximately 10 μm to 35 μm, approximately 10 μm to 25 μm, approximately 15 μm to 45 μm, approximately 15 μm to 30 μm, approximately 15 μm to 25 μm, approximately 20 μm to 35 μm, or approximately 20 μm to 30 μm. In certain embodiments, the shell thickness is approximately 1 μm to 45 μm, approximately 1 μm to 35 μm, approximately 1 μm to 25 μm, approximately 1 μm to 15 μm, approximately 1 μm to 10 μm, approximately 1 μm to 5 μm, approximately 3 μm to 15 μm, approximately 3 μm to 10 μm, approximately 5 μm to 10 μm, approximately 10 μm to 35 μm, approximately 10 μm to 20 μm, approximately 15 μm to 30 μm, approximately 15 μm to 25 μm, or approximately 20 μm to 35 μm. In certain embodiments, the core to shell diameter or thickness ratio is 15:85 to 85:15, 25:75 to 75:25, 30:70 to 70:30, or 40:60 to 60:40. In certain embodiments, the volume or weight ratio of the core to the shell is 95:5, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, or 30:70.

[0169] A current collector acts to collect electrons generated by the electrochemical reaction of the cathode active material, or to supply electrons necessary for the electrochemical reaction. In some embodiments, the current collector may be in the form of a foil, sheet, or film. In certain embodiments, the current collector is stainless steel, titanium, nickel, aluminum, copper, or an alloy thereof, or an electrically conductive resin. In certain embodiments, the current collector has a two-layer structure including an outer layer and an inner layer, the outer layer comprising a conductive material, and the inner layer comprising an insulating material or another conductive material, such as aluminum attached with a conductive resin layer, or a polymer insulating material coated with an aluminum film. In some embodiments, the current collector has a three-layer structure including an outer layer, an intermediate layer, and an inner layer, the outer and inner layers comprising a conductive material, and the intermediate layer comprising an insulating material or another conductive material, such as a plastic substrate coated with a metal film on both sides. In certain embodiments, each of the outer layer, intermediate layer, and inner layer is independently stainless steel, titanium, nickel, aluminum, copper, or an alloy thereof, or a conductive resin. In some embodiments, the insulating material is a polymer material selected from the group consisting of polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane, polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, oxidized polyphenyl, cellulose polymer, and combinations thereof. In certain embodiments, the current collector has three or more layers. In some embodiments, the current collector is coated with a protective coating. In certain embodiments, the protective coating contains a carbon-containing material. In some embodiments, the current collector is not coated with a protective coating.

[0170] The thickness of the current collector affects the volume it occupies within the battery, the amount of electrode active material required, and the capacity of the battery. In some embodiments, the current collector has a thickness of about 5 μm to about 30 μm. In certain embodiments, the current collector has a thickness of about 5 μm to about 20 μm, about 5 μm to about 15 μm, about 10 μm to about 30 μm, about 10 μm to about 25 μm, or about 10 μm to about 20 μm.

[0171] In some embodiments, the current collector has a thickness of less than 30 μm, less than 28 μm, less than 26 μm, less than 24 μm, less than 22 μm, less than 20 μm, less than 18 μm, less than 16 μm, less than 14 μm, less than 12 μm, less than 10 μm, less than 8 μm, or 6 μm. In some embodiments, the current collector has a thickness greater than 5 μm, greater than 7 μm, greater than 10 μm, greater than 12 μm, greater than 14 μm, greater than 16 μm, greater than 18 μm, greater than 20 μm, greater than 22 μm, greater than 24 μm, greater than 26 μm, or greater than 28 μm.

[0172] Conductive agents are used to improve the electrical conductivity of electrodes. Any suitable material can act as a conductive agent. In some embodiments, the conductive agent is a carbonaceous material. Some non-limiting examples include carbon, carbon black, graphite, expanded graphite, graphene, graphene nanoplatelets, carbon fibers, carbon nanofibers, graphitized carbon flakes, carbon tubes, activated carbon, Super P, 0-dimensional KS6, 1-dimensional vapor-grown carbon fibers (VGCF), mesoporous carbon, and combinations thereof.

[0173] Furthermore, cathodes prepared using the binder composition of the present invention exhibit strong adhesion between the electrode layer and the current collector. The electrode layer having good peel strength against the current collector is important to prevent electrode peeling or separation, which significantly affects the mechanical stability of the electrode and the battery's cycle life. Therefore, the electrode needs to have sufficient peel strength to withstand the rigors of battery manufacturing.

[0174] In some embodiments, the peel strength between the current collector and the electrode layer is approximately 1.0 N / cm to 8.0 N / cm, approximately 1.0 N / cm to 6.0 N / cm, approximately 1.0 N / cm to 5.0 N / cm, approximately 1.0 N / cm to 4.0 N / cm, approximately 1.0 N / cm to 3.0 N / cm, approximately 1.0 N / cm to 2.5 N / cm, approximately 1.2 N / cm to 3.0 N / cm, approximately 1.2 N / cm to 2.5 N / cm, approximately 1.2 N / cm to 2.0 N / cm, approximately 1.5 N / cm to 3.0 N / cm, and 1.5 The ranges are approximately N / cm to 2.5 N / cm, 1.5 N / cm to 2.0 N / cm, 1.8 N / cm to 3.0 N / cm, 1.8 N / cm to 2.5 N / cm, 2.0 N / cm to 6.0 N / cm, 2.0 N / cm to 5.0 N / cm, approximately 2.0 N / cm to 3.0 N / cm, approximately 2.0 N / cm to 2.5 N / cm, approximately 2.2 N / cm to 3.0 N / cm, approximately 2.5 N / cm to 3.0 N / cm, approximately 3.0 N / cm to 8.0 N / cm, approximately 3.0 N / cm to 6.0 N / cm, or approximately 4.0 N / cm to 6.0 N / cm.

[0175] In some embodiments, the peel strength between the current collector and the electrode layer is 1.0 N / cm or more, 1.2 N / cm or more, 1.5 N / cm or more, 2.0 N / cm or more, 2.2 N / cm or more, 2.5 N / cm or more, 3.0 N / cm or more, 3.5 N / cm or more, 4.5 N / cm or more, 5.0 N / cm or more, or 5.5 N / cm or more. In some embodiments, the peel strength between the current collector and the electrode layer is less than 6.5 N / cm, less than 6.0 N / cm, less than 5.5 N / cm, less than 5.0 N / cm, less than 4.5 N / cm, less than 4.0 N / cm, less than 3.5 N / cm, less than 3.0 N / cm, less than 2.8 N / cm, less than 2.5 N / cm, less than 2.2 N / cm, less than 2.0 N / cm, less than 1.8 N / cm, or less than 1.5 N / cm.

[0176] The degree of swelling of a binder composition due to electrolyte incorporation in a secondary battery provides insights into the crystallinity of the binder composition, the way the binder composition interacts with the electrolyte, and the flexibility of the binder composition. On the one hand, binder compositions with high crystallinity exhibit low swelling behavior, which can act as a barrier to solvent penetration, shortening the ion transport pathway and thus reducing internal resistance, and, more importantly, altering the mechanical properties of the swollen polymer, which is essential for stable battery performance. On the other hand, binder compositions with low crystallinity have more amorphous regions that allow more electrolyte to penetrate the binder composition and ensure good ion transport without the binder composition decomposing when subjected to swelling. The semi-crystalline binder compositions disclosed herein benefit from both influencing factors and therefore exhibit outstanding electrochemical performance.

[0177] In some embodiments, the electrolyte swelling of the binder composition is approximately 7% to 10%, 7% to 9.9%, 7% to 9.8%, 7% to 9.7%, 7% to 9.6%, 7% to 9.5%, 7% to 9.4%, 7% to 9.3%, 7% to 9.2%, 7% to 9.1%, 7% to 9%, 7% to 8.9%, 7% to 8.8%, 7% to 8.7%, 7% to 8.6%, 7% to 8.5%, and 7% to 8.8%. The percentages are approximately 0.4%, 7% to 8.3%, 7% to 8.2%, 7% to 8.1%, 7% to 8%, 7.1% to 10%, 7.2% to 10%, 7.3% to 10%, 7.4% to 10%, 7.5% to 10%, 7.6% to 10%, 7.7% to 10%, 7.8% to 10%, 7.9% to 10%, 8% to 10%, 7.5% to 9.5%, 7.5% to 9%, 8% to 9%, or 8% to 9.5%.

[0178] In some embodiments, the electrolyte swelling of the binder composition is less than 10%, less than 9.9%, less than 9.8%, less than 9.7%, less than 9.6%, less than 9.5%, less than 9.4%, less than 9.3%, less than 9.2%, less than 9.1%, less than 9%, less than 8.9%, less than 8.8%, less than 8.7%, less than 8.6%, less than 8.5%, less than 8.4%, less than 8.3%, less than 8.2%, less than 8.1%, less than 8%, less than 7.9%, less than 7.8%, less than 7.7%, less than 7.6%, less than 7.5%, less than 7.4%, less than 7.3%, less than 7.2%, or less than 7.1%. In some embodiments, the electrolyte swelling of the binder composition is more than 7%, more than 7.1%, more than 7.2%, more than 7.3%, more than 7.4%, more than 7.5%, more than 7.6%, more than 7.7%, more than 7.8%, more than 7.9%, more than 8%, more than 8.1%, more than 8.2%, more than 8.3%, more than 8.4%, more than 8.5%, more than 8.6%, more than 8.7%, more than 8.8%, more than 8.9%, more than 9%, more than 9.1%, more than 9.2%, more than 9.3%, more than 9.4%, more than 9.5%, more than 9.6%, more than 9.7%, more than 9.8%, or more than 9.9%.

[0179] The method disclosed herein has the advantage of saving processing time and equipment because it allows the use of aqueous solvents in the manufacturing process, and also improving safety because there is no need to handle or recycle hazardous organic solvents. Furthermore, the overall process is simplified, resulting in cost reduction. Therefore, this method is particularly suitable for industrial processes because it is low-cost and easy to handle.

[0180] The following embodiments are provided to illustrate embodiments of the present invention, but are not intended to limit the invention to any specific embodiment defined. Unless otherwise indicated, all parts and percentages are by weight. All numerical values ​​are approximate. Where numerical ranges are given, it should be understood that embodiments outside the range described may still fall within the scope of the invention. Specific details described in each embodiment should not be construed as essential features of the invention. Examples

[0181] The pH value of the binder composition was measured using an electrode-type pH meter (ION2700, manufactured by U-Tech Instruments).

[0182] The viscosity of the binder composition was measured at 25°C using a rotational viscometer (NDJ-5S, Shanghai JT Electronics Technology Co., Ltd., China).

[0183] The adhesive strength of the dried binder composition layer was measured using a tensile testing machine (DZ-106A, Dongguan Zonghao Test Equipment Co., Ltd., China). This test measures the average force in Newtons required to peel the binder composition layer from the current collector at a 180° angle. The average roughness depth (Rz) of the current collector was 2 μm. The binder composition was applied to the current collector and dried to obtain a binder composition layer with a thickness of 10 μm to 12 μm. Next, the coated current collector was placed in a constant temperature environment of 25°C and 50% to 60% humidity for 30 minutes. A strip of adhesive tape (3M; USA, model number 810) with a width of 18 mm and a length of 20 mm was attached to the surface of the binder composition layer. The binder composition strip was placed in the testing machine, the tape was folded 180 degrees over itself, placed in the movable jaws, and pulled at a peeling speed of 300 mm per minute at room temperature. The measured maximum peeling force was defined as the adhesive strength. The measurement was repeated three times, and the average value was calculated.

[0184] The electrolyte swelling of the binder composition measures the degree of mass change of the binder composition before and after immersion in the electrolyte. A test specimen of a dried binder composition strip, 50 mm to 60 mm in length and 1 mm in width, was prepared. This dried binder composition strip was further dried at 80°C for 1 to 2 hours to completely remove moisture from the strip. The weight of the dried binder composition strip was measured, and after cooling, it was placed in a sealed container with the electrolyte. The binder composition strip was immersed in the electrolyte at 25°C for 3 days. After removing the binder composition strip from the container with the electrolyte, the electrolyte on the surface of the strip was absorbed with oil-absorbing paper. The weight of the immersed binder composition strip was measured. The ratio of the weight change of the strip before and after immersion in the electrolyte to the weight of the strip before immersion was defined as electrolyte swelling. The measurement was repeated three times, and the average value was calculated.

[0185] The solid content of the binder composition was determined by measuring the degree of mass change of the binder composition before and after drying. Approximately 1 g of the binder composition was weighed into a weighing bottle and dried in a vacuum dryer at 110 ± 5°C and -0.09 MPa for more than 5 hours. After cooling the binder composition in a desiccator for approximately 15 minutes, its mass was measured. The mass difference of the binder composition before and after drying was determined, and the solid content (%) of the binder composition was calculated using the following formula.

[0186]

number

[0187] The weight-average molecular weight and number-average molecular weight of the binder composition were measured by gel permeation chromatography (GPC). First, the binder composition was dissolved in dimethylformamide at room temperature. Once the binder composition was dissolved, the solution was carefully filtered through a 0.45 μm filter to prepare the sample for measurement. A calibration curve was created using standard polystyrene so that the weight-average molecular weight and number-average molecular weight could be calculated as standard material equivalent values. The molecular weight distribution in the binder composition is expressed by the polydispersity index (PDI), which is the ratio of the weight-average molecular weight to the number-average molecular weight. The obtained sample for measurement was analyzed under the following conditions.

[0188] Column: Agilent PLgel 5um MIXED-C column

[0189] Eluent: Dimethylformamide

[0190] Flow rate: 1ml / min

[0191] Sample weight: 2 mg

[0192] Detector: Waters 2414 refractive index (RI) detector

[0193] Detection temperature: 35℃

[0194] Standard material: Polystyrene Example 1 A) Preparation of binder composition

[0195] 80 g of a neutralizing agent (sodium hydroxide, NaOH) was added to a round-bottom flask containing 1500 g of distilled water. This mixture was stirred at 80 rpm for 30 minutes to obtain the first suspension.

[0196] 180 g of acrylic acid (AA) was dissolved in 200 g of pure water to form an AA solution. Then, 380 g of the AA solution was added to the first suspension. This mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0197] 94 g of acrylamide (AM) was dissolved in 200 g of pure water to form an AM solution. Then, 294 g of the AM solution was added to the second suspension. This mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0198] 66 g of acrylonitrile (AN) was dissolved in 50 g of pure water to form an AN solution. Then, 116 g of the AN solution was added to the third suspension. This mixture was further stirred at 80 rpm at 55°C for 10 minutes to obtain the fourth suspension.

[0199] Furthermore, 0.075 g of a water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industries, China) was dissolved in 15 g of pure water, and 0.0375 g of a reducing agent (sodium bisulfite; obtained from Tianjin Cannabis Chemical Reagent Factory, China) was dissolved in 7.5 g of pure water. 15.075 g of the APS solution and 7.5375 g of the sodium bisulfite solution were added to the fourth suspension. This mixture was stirred at 200 rpm at 55°C for 24 hours to obtain the fifth suspension.

[0200] After the reaction was complete, the temperature of the fifth suspension was lowered to 25°C. 19.12 g of NaOH was dissolved in 3300 g of pure water. Then, 3319.12 g of sodium hydroxide solution was added dropwise to the fifth suspension over 1 hour to adjust the pH to 7.59 and form the sixth suspension. The binder composition was prepared by filtration using 200 mesh filter paper. The solid content of the binder composition was 6.77 wt.%. The weight-average molecular weight of the binder composition was 125,031 g / mol, the number-average molecular weight was 55,437 g / mol, and the polydispersity index was 2.26. The components and their respective proportions of the binder composition of Example 1 are shown in Table 1 below. In addition, the pH, solid content, viscosity, adhesive strength, and electrolyte swelling of the binder composition of Example 1 were measured and are shown in Table 2 below. B) Fabrication of the positive electrode

[0201] The first mixture was prepared by dispersing 0.9 g of conductive agent (SuperP; obtained from Timcal Ltd, Bodio, Switzerland) and 6 g of binder composition (solids content 6.77 wt.%) in deionized water while stirring with an overhead stirrer (R20, manufactured by IKA). After addition, the first mixture was further stirred at 25°C and a rotation speed of 1200 rpm for approximately 30 minutes.

[0202] Subsequently, 28.2 g of NMC622 (Shandong Tianqiao New Energy Co., Ltd., China) was added to the first mixture at 25°C while stirring with an overhead stirrer to prepare the second mixture. Next, the second mixture was degassed under a pressure of approximately 10 kPa for 1 hour. Then, the second mixture was further stirred at 25°C for approximately 60 minutes at a rotation speed of 1,200 rpm to form a homogenized slurry.

[0203] This homogenized slurry was applied to one side of a 14 μm thick aluminum foil, which would serve as the current collector, using a doctor blade coater. The slurry film applied to the aluminum foil was dried in a hot air dryer (DHG 10H, Huyue Equipment Co. Ltd., China) at approximately 85°C for 120 minutes to form the cathode electrode layer. Next, the electrode was pressed to reduce the thickness of the cathode electrode layer to 27 μm, and the surface density was 5.2 mg / cm². 2 That was the case. C) Preparation of the negative electrode

[0204] A slurry for the anode was prepared by mixing 90 wt.% hard carbon (BTR New Energy Materials Inc., Shenzhen, Guangdong Province, China), 1.5 wt.% carboxymethylcellulose (CMC, BSH-12, DKS Corporation, Japan), 3.5 wt.% SBR (AL-2001, Nippon A&L Co., Ltd., Japan) as a binder, and 5 wt.% carbon black as a conductive agent in deionized water. The solid content of the anode slurry was 50 wt.%. This slurry was applied to one side of an 8 μm thick copper foil using a doctor blade coater. The coating film on the copper foil was dried in a hot air dryer at approximately 85°C for 120 minutes to obtain the anode. Subsequently, the electrode was pressed to reduce the thickness of the coating film to 18 μm. D) Assembly of coin cell battery

[0205] A CR2032 coin-type lithium battery was assembled in an argon-filled glove box. The coated cathode and anode plates were cut into disc-shaped positive and negative electrodes, and the cathode and anode electrode plates were stacked alternately to form an electrode assembly, which was then housed in a CR2032-type stainless steel case. The cathode and anode electrode plates were separated by a separator. The separator was a ceramic-coated nonwoven microporous membrane (MPM, Japan) with a thickness of approximately 25 μm. Next, the electrode assembly was dried under vacuum in a box-type resistance oven (DZF-6020, Shenzhen Kejing Star Technology Co. Ltd., China) at 105°C for approximately 16 hours.

[0206] Next, under a high-purity argon atmosphere with moisture and oxygen content of 3 ppm or less, the electrolyte was injected into the case holding the filled electrodes. The electrolyte was a solution of LiPF6 (1M) mixed with ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1. After filling with the electrolyte, the coin cell was vacuum sealed and mechanically pressed using a standard circular punch die. E) Electrochemical measurements

[0207] Coin cells were analyzed in constant current mode using a multi-channel battery tester (BTS-4008-5V10mA, Neware Electronics Co. Ltd, obtained from China). After completing one cycle at C / 20, charging and discharging were performed at a rate of C / 2. Charge-discharge cycle tests were performed on the cells under conditions of 3.0~4.3V, current density C / 2, and 25℃, and the discharge capacity was determined. The electrochemical performance of the coin cell of Example 1 was measured and is shown in Table 2 below. Preparation of the binder composition of Example 2

[0208] 16 g of NaOH was added to a round-bottom flask containing 380 g of distilled water. This mixture was stirred at 80 rpm for 30 minutes to obtain the first suspension.

[0209] 35.80 g of AA was added to the first suspension. This mixture was further stirred at 80 rpm for 30 minutes to obtain the second suspension.

[0210] 18.70 g of AM was dissolved in 10 g of pure water to form an AM solution. Then, 28.70 g of the AM solution was added to the second suspension. This mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0211] 13.50 g of AN was added to the third suspension. This mixture was further stirred at 80 rpm for 10 minutes to obtain the fourth suspension.

[0212] Furthermore, 0.015 g of APS was dissolved in 3 g of pure water, and 0.0075 g of sodium bisulfite was dissolved in 1.5 g of pure water. 3.015 g of the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. This mixture was stirred at 200 rpm and 55°C for 24 hours to obtain the fifth suspension.

[0213] After the reaction was complete, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of pure water. Then, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension over 1 hour to adjust the pH to 7.31 and form the sixth suspension. The mixture was filtered using 200-mesh filter paper to prepare the binder composition. The solids content of the binder composition was 9.00 wt.%.

[0214] Example 3: A binder composition was prepared in the same manner as in Example 2, except that 36.04 g of AA was added in the preparation of the second suspension, 17.0 g of AM was added in the preparation of the third suspension, and 14.96 g of AN was added in the preparation of the fourth suspension.

[0215] Example 4: The binder composition was prepared in the same manner as in Example 2, except that 37.4 g of AA was added in the preparation of the second suspension, 17.0 g of AM was added in the preparation of the third suspension, and 13.6 g of AN was added in the preparation of the fourth suspension.

[0216] Example 5: The binder composition was prepared in the same manner as in Example 2, except that 40.8 g of AA was added in the preparation of the second suspension, 17.0 g of AM was added in the preparation of the third suspension, 10.2 g of AN was added in the preparation of the fourth suspension, and 5.33 g of NaOH was added in the preparation of the sixth suspension.

[0217] Example 6: The binder composition was prepared in the same manner as in Example 2, except that 44.2 g of AA was added in the preparation of the second suspension, 17.0 g of AM was added in the preparation of the third suspension, 6.8 g of AN was added in the preparation of the fourth suspension, and 6.23 g of NaOH was added in the preparation of the sixth suspension.

[0218] Example 7: The binder composition was prepared in the same manner as in Example 2, except that 47.6 g of AA was added in the preparation of the second suspension, 10.2 g of AM was added in the preparation of the third suspension, 10.2 g of AN was added in the preparation of the fourth suspension, and 8.18 g of NaOH was added in the preparation of the sixth suspension.

[0219] Example 8: The binder composition was prepared in the same manner as in Example 2, except that 28.56 g of AA was added in the preparation of the second suspension, 23.12 g of AM was added in the preparation of the third suspension, and 16.32 g of AN was added in the preparation of the fourth suspension.

[0220] Example 9: A binder composition was prepared in the same manner as in Example 2, except that 34.0 g of AA was added in the preparation of the second suspension, 23.8 g of AM was added in the preparation of the third suspension, and 10.2 g of AN was added in the preparation of the fourth suspension.

[0221] Example 10: The binder composition was prepared in the same manner as in Example 2, except that 9.50 g of NaOH was added to the fifth suspension to adjust the pH to 8.23 ​​in the preparation of the sixth suspension.

[0222] Example 11: In preparing the sixth suspension, the binder composition was prepared in the same manner as in Example 2, except that 10.93 g of NaOH was added to the fifth suspension to adjust the pH to 8.51. Preparation of binder compositions for Examples 12-14

[0223] The binder compositions of Examples 12 to 14 were prepared in the same manner as in Example 2.

[0224] Example 15: In preparing the fifth suspension, the binder composition was prepared in the same manner as in Example 2, except that 0.0204 g of APS was dissolved in 3 g of pure water and 0.0102 g of sodium bisulfite was dissolved in 1.5 g of pure water, so that 3.0204 g of APS solution and 1.5102 g of sodium bisulfite solution were added. The weight-average molecular weight of the binder composition was 78,528 g / mol, the number-average molecular weight was 33,523 g / mol, and the polydispersity index was 2.34.

[0225] Example 16: In preparing the fifth suspension, a binder composition was prepared in the same manner as in Example 2, except that 0.0068 g of APS was dissolved in 3 g of pure water and 0.0034 g of sodium bisulfite was dissolved in 1.5 g of pure water, so that 3.0068 g of APS solution and 1.5034 g of sodium bisulfite solution were added. The weight-average molecular weight of the binder composition was 175,432 g / mol, the number-average molecular weight was 82,640 g / mol, and the polydispersity index was 2.12. Comparative Example 1

[0226] The binder composition was prepared in the same manner as in Example 2, except that 30.6 g of AA was added in the preparation of the second suspension, 10.2 g of AM was added in the preparation of the third suspension, and 27.2 g of AN was added in the preparation of the fourth suspension. Comparative Example 2

[0227] The binder composition was prepared in the same manner as in Example 2, except that 44.2 g of AA was added in the preparation of the second suspension, 20.4 g of AM was added in the preparation of the third suspension, 3.4 g of AN was added in the preparation of the fourth suspension, and 6.5 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 3

[0228] The binder composition was prepared in the same manner as in Example 2, except that 51.0 g of AA was added in the preparation of the second suspension, 10.2 g of AM was added in the preparation of the third suspension, 6.8 g of AN was added in the preparation of the fourth suspension, and 10.42 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 4

[0229] The binder composition was prepared in the same manner as in Example 2, except that 46.92 g of AA was added in the preparation of the second suspension, 5.44 g of AM was added in the preparation of the third suspension, 15.64 g of AN was added in the preparation of the fourth suspension, and 8.23 ​​g of NaOH was added in the preparation of the sixth suspension. Comparative Example 5

[0230] The binder composition was prepared in the same manner as in Example 2, except that 30.6 g of AA was added in the preparation of the second suspension, 30.6 g of AM was added in the preparation of the third suspension, and 6.8 g of AN was added in the preparation of the fourth suspension. Comparative Example 6

[0231] The binder composition was prepared in the same manner as in Example 2, except that 8 g of NaOH was added in the preparation of the first suspension, 20.4 g of AA was added in the preparation of the second suspension, 31.96 g of AM was added in the preparation of the third suspension, 15.64 g of AN was added in the preparation of the fourth suspension, and 3.21 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 7

[0232] The binder composition was prepared in the same manner as in Example 2, except that 5 g of NaOH was added in the preparation of the first suspension, 13.6 g of AA was added in the preparation of the second suspension, 27.2 g of AM was added in the preparation of the third suspension, 27.2 g of AN was added in the preparation of the fourth suspension, and 2.1 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 8

[0233] The binder composition was prepared in the same manner as in Example 2, except that 57.8 g of AA was added in the preparation of the second suspension, 6.8 g of AM was added in the preparation of the third suspension, 3.4 g of AN was added in the preparation of the fourth suspension, and 13.5 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 9

[0234] The binder composition was prepared in the same manner as in Example 2, except that 34.0 g of AA and 6.8 g of methyl acrylate (MA) were added in the preparation of the second suspension, 13.6 g of AM was added in the preparation of the third suspension, 13.6 g of AN was added in the preparation of the fourth suspension, and 3.72 g of NaOH was added in the preparation of the sixth suspension. Comparative Example 10

[0235] The inder composition was prepared in the same manner as in Example 2, except that 34.0 g of AA was added in the preparation of the second suspension, 14.96 g of AM was added in the preparation of the third suspension, and 19.04 g of AN was added in the preparation of the fourth suspension. Preparation of positive electrodes for Examples 2-11, 15-16 and Comparative Examples 1-10

[0236] The positive electrodes for Examples 2-11, 15-16, and Comparative Examples 1-10 were prepared using the same method as in Example 1. Preparation of the positive electrode in Example 12

[0237] The positive electrode of Example 12 was prepared in the same manner as in Example 1, except that 28.2 g of NMC622 was replaced with the same weight of NMC532 (obtained from Tianjin Bomao Technology Co., Ltd., China). Fabrication of the positive electrode in Example 13

[0238] The positive electrode of Example 13 was prepared in the same manner as in Example 1, except that 28.2 g of NMC622 was replaced with the same weight of LiCoO2 (obtained from Tianjin Bamao Technology Co., Ltd., China). Preparation of the positive electrode of Example 14

[0239] The positive electrode of Example 14 was prepared in the same manner as in Example 1, except that 28.2 g of NMC622 was replaced with the same weight of LiFePO4 (obtained from Xiamen Tungsten Industry Co., Ltd., China). Preparation of the negative electrodes of Examples 2 to 16 and Comparative Examples 1 to 10

[0240] The negative electrodes of Examples 2 to 16 and Comparative Examples 1 to 10 were prepared in the same manner as in Example 1. Assembly of coin cells of Examples 2 to 16 and Comparative Examples 1 to 10

[0241] The coin cells of Examples 2 to 16 and Comparative Examples 1 to 10 were assembled in the same manner as in Example 1. Electrochemical measurements of Examples 2 to 16 and Comparative Examples 1 to 10

[0242] The electrochemical performance of the coin cells of Examples 2 to 16 and Comparative Examples 1 to 10 was measured in the same manner as in Example 1, and the test results are shown in Table 2 below.

Table 1

Table 2

[0243] The present invention has been described with reference to a limited number of embodiments, but the specific features of one embodiment should not be attributed to other embodiments of the present invention. In some embodiments, the method can include a number of steps not mentioned herein. In other embodiments, the method does not include, or substantially does not include, any steps not listed herein. There are variations and modifications from the described embodiments. The appended claims are intended to cover all such modifications and variations as being within the scope of the present invention. The invention described in the original claims of this application is listed below. [1] A binder composition for secondary battery electrodes comprising a copolymer and a dispersion medium, wherein the copolymer comprises a structural unit (a) derived from a carboxylic acid group-containing monomer, a structural unit (b) derived from an amide group-containing monomer, and a structural unit (c) derived from a nitrile group-containing monomer. [2] The carboxylic acid group-containing monomers are acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglitic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl- 3,3-Diethylacrylic acid, 3-Butylacrylic acid, 2-Butylacrylic acid, 2-Pentylacrylic acid, 2-Methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-Methyl-3-Propylacrylic acid, 2-Ethyl-3-Propylacrylic acid, 2,3-Diethylacrylic acid, 3,3-Diethylacrylic acid, 3-Methyl-3-Hexylacrylic acid, 3-Methyl-3-Tert-Butylacrylic acid, 2-Methyl-3-Pentylacrylic acid, 3-Methyl-3-Pentylacrylic acid, 4-Methyl-2-Hexenoic acid, 4-Ethyl-2-Hexenoic acid, 3-Methyl-2-Ethyl-2-Hexenoic acid, 3-Tert-Butylacrylic acid, 2,3-Dimethyl-3-Ethylacrylic acid, 3,A binder composition according to [1], selected from the group consisting of 3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-alyloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleic anhydride, methyl maleate anhydride, dimethyl maleate anhydride, acrylic anhydride, methacrylic anhydride, metacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof. [3] The binder composition according to [1], wherein the proportion of the structural unit (a) derived from the carboxylic acid group-containing monomer in the copolymer is about 33% to about 70% in moles, based on the total number of moles of monomer units of the copolymer in the binder composition. [4] The amide group-containing monomer is selected from the group consisting of methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, Nn-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylmethacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylolmethacrylamide, diacetone methacrylamide, methacryloylmorpholine, and combinations thereof, as described in [1]. [5] The binder composition according to [1], wherein the proportion of structural unit (b) derived from the amide group-containing monomer in the copolymer is about 10% to about 35% in moles, based on the total number of moles of monomer units in the copolymer in the binder composition. [6] The nitrile group-containing monomer is selected from the group consisting of acrylonitrile, α-halogenoacrylonitrile, α-alkylacrylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, and combinations thereof, as described in [1], for the binder composition. [7] The binder composition according to [1], wherein the proportion of structural units (c) derived from nitrile group-containing monomers in the copolymer is about 10% to about 30% in moles, based on the total number of moles of monomer units in the copolymer in the binder composition. [8] The binder composition according to [1], wherein the dispersion medium is water. [9] The binder composition according to claim 8, wherein the dispersion medium further comprises a hydrophilic solvent selected from the group consisting of ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, dimethylacetamide (DMAc), dimethylformamide (DMF), N-methylpyrrolidone (NMP), methyl ethyl ketone (MEK), ethyl acetate (EA), butyl acetate (BA), and combinations thereof.

[10] The binder composition according to [1], wherein the total proportion of structural units (a) derived from carboxylic acid group-containing monomers and structural units (c) derived from nitrile group-containing monomers in the copolymer is approximately 65% ​​to approximately 90% in moles, based on the total number of moles of monomer units in the copolymer of the binder composition.

[11] The binder composition according to [1], wherein the molar ratio of the total structural unit (a) derived from a carboxylic acid group-containing monomer and the structural unit (c) derived from a nitrile group-containing monomer to the structural unit (b) derived from an amide group-containing monomer in the copolymer is about 1 to about 7.

[12] The binder composition according to [1], wherein the molar ratio of the total structural units (a) derived from a carboxylic acid group-containing monomer and the structural units (b) derived from an amide group-containing monomer to the structural units (c) derived from a nitrile group-containing monomer in the copolymer is about 1 to about 7.

[13] The binder composition according to [1], wherein the pH of the binder composition is about 7 to about 9.

[14] The binder composition according to [1], wherein the viscosity of the binder composition is about 10,000 mPa·s to about 50,000 mPa·s.

[15] The binder composition according to [1], wherein the electrolyte swelling of the binder composition is about 7% to about 10%.

[16] The binder composition according to [1], wherein the adhesive strength between the binder composition and the current collector is approximately 2 N / cm to approximately 4 N / cm.

[17] The binder composition according to [1], wherein the solid content of the binder composition is approximately 5% to approximately 10% by weight, based on the total weight of the binder composition.

[18] An electrode for a secondary battery comprising an electrode active material, a conductive agent, and the binder composition described in [1].

[19] The electrode for a secondary battery as described in

[18] , wherein the peel strength between the current collector and the electrode layer is in the range of approximately 1.0 N / cm to approximately 8.0 N / cm.

Claims

1. A binder composition for lithium-ion battery electrodes comprising a copolymer, wherein the copolymer comprises structural units (a) derived from a carboxylic acid group-containing monomer, structural units (b) derived from an amide group-containing monomer, and structural units (c) derived from a nitrile group-containing monomer, wherein the proportion of structural units (a) derived from the carboxylic acid group-containing monomer in the copolymer is 33% to 70% in moles based on the total number of moles of monomer units of the copolymer in the binder composition, the proportion of structural units (b) derived from the amide group-containing monomer in the copolymer is 10% to 35% in moles based on the total number of moles of monomer units in the copolymer in the binder composition, and the proportion of structural units (c) derived from the nitrile group-containing monomer in the copolymer is 10% to 30% in moles based on the total number of moles of monomer units in the copolymer in the binder composition, and the binder composition does not contain structural units derived from an ester group-containing monomer.

2. The aforementioned carboxylic acid group-containing monomers are acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglitic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl- 3,3-Diethylacrylic acid, 3-Butylacrylic acid, 2-Butylacrylic acid, 2-Pentylacrylic acid, 2-Methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-Methyl-3-Propylacrylic acid, 2-Ethyl-3-Propylacrylic acid, 2,3-Diethylacrylic acid, 3,3-Diethylacrylic acid, 3-Methyl-3-Hexylacrylic acid, 3-Methyl-3-Tert-Butylacrylic acid, 2-Methyl-3-Pentylacrylic acid, 3-Methyl-3-Pentylacrylic acid, 4-Methyl-2-Hexenoic acid, 4-Ethyl-2-Hexenoic acid, 3-Methyl-2-Ethyl-2-Hexenoic acid, 3-Tert-Butylacrylic acid, 2,3-Dimethyl-3-Ethylacrylic acid, 3,A binder composition according to claim 1, selected from the group consisting of 3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-alyloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleic anhydride, methyl maleate anhydride, dimethyl maleate anhydride, acrylic anhydride, methacrylic anhydride, metacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.

3. The binder composition according to claim 1, wherein the amide group-containing monomer is selected from the group consisting of methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, Nn-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylolmethacrylamide, diacetone methacrylamide, methacryloylmorpholine, and combinations thereof.

4. The binder composition according to claim 1, wherein the nitrile group-containing monomer is selected from the group consisting of acrylonitrile, α-halogenoacrylonitrile, α-alkylacrylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, and combinations thereof.

5. The binder composition according to claim 1, wherein the proportion of the structural unit (c) derived from the nitrile group-containing monomer in the copolymer is 10% to less than 30% in moles, based on the total number of moles of monomer units in the copolymer of the binder composition.

6. The binder composition according to claim 1, wherein the carboxylic acid group-containing monomer comprises a combination of a carboxylic acid base and a carboxylic acid group, and the molar ratio of the carboxylic acid group to the carboxylic acid base in the copolymer is 0 to 0.

2.

7. The binder composition according to claim 1, wherein the total proportion of structural units (a) derived from carboxylic acid group-containing monomers and structural units (c) derived from nitrile group-containing monomers in the copolymer is 65% to 90% in moles, based on the total number of moles of monomer units in the copolymer of the binder composition.

8. The binder composition according to claim 1, wherein the molar ratio of the total structural unit (a) derived from a carboxylic acid group-containing monomer and the structural unit (c) derived from a nitrile group-containing monomer to the structural unit (b) derived from an amide group-containing monomer in the copolymer is 1 to 7.

9. The binder composition according to claim 1, wherein the molar ratio of the total structural units (a) derived from a carboxylic acid group-containing monomer and the structural units (b) derived from an amide group-containing monomer to the structural units (c) derived from a nitrile group-containing monomer in the copolymer is 1 to 7.

10. The binder composition according to claim 1, wherein the adhesive strength between the binder composition and the current collector is 2 N / cm to 4 N / cm.

11. The binder composition according to claim 1, further comprising a dispersion medium selected from the group consisting of water, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, dimethylacetamide (DMAc), dimethylformamide (DMF), N-methylpyrrolidone (NMP), methyl ethyl ketone (MEK), ethyl acetate (EA), butyl acetate (BA), and combinations thereof.

12. The binder composition according to claim 11, wherein the pH of the binder composition is 7 to 9.

13. The binder composition according to claim 11, wherein the viscosity of the binder composition is 10,000 mPa·s to 50,000 mPa·s.

14. The binder composition according to claim 11, wherein the solid content of the binder composition is 5% to 10% by weight, based on the total weight of the binder composition.

15. An electrode for a lithium-ion battery comprising an electrode active material, a conductive agent, and the binder composition described in claim 1.

16. The electrode according to claim 15, wherein the peel strength between the current collector and the electrode layer is in the range of 1.0 N / cm to 8.0 N / cm.

17. The electrode active material includes LiCoO 2 , LiNiO 2 , LiNi x Mn y O 2 , Li 1+z Ni x Mn y Co 1-xy O 2 , LiNi x Co y Al z O 2 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiMnO 2 , LiCrO 2 , LiMn 2 O 4 , Li 2 MnO 3 , LiFeO 2 , LiFePO 4 , Li 4 Ti 5 O 12 , LiNi 0.92 Mn 0.04 Co 0.04 O 2 , Li 1+d Ni a Mn b Co c Al (1-abc) O 2 The electrode according to claim 15, selected from the group consisting of , and combinations thereof, wherein each x is independently 0.2 to 0.9, each y is independently 0.1 to 0.45, and each z is independently 0 to 0.2, with -0.2 ≤ d ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1.

Images