Electrode material, electrode, battery, and method for forming electrode material

Abstract

To provide an electrode material, an electrode, a battery, and a method for forming the electrode material.SOLUTION: An electrode material includes: an active particle; and a cladding layer partially or completely covering a surface of the active particle. The cladding layer includes: 5 to 70 parts by weight of a conductive additive; and 30 to 95 parts by weight of a first polymer. Therein a total weight of the first polymer and the conductive additive is 100 parts by weight. The first polymer is a product that is obtained by performing a polymerization reaction of a chemical compound having two acrylate groups and an ethylene / vinyl acetate polymer. The chemical compound having the two acrylate groups has a structure represented by a formula (I). (In the formula, A1 is a single bond, oxygen, -C(=O)-, -N=N-, -CH=CH- or the like, each R1 is independently hydrogen or a methyl group, and each R2 is independently hydrogen or a methyl group.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to electrode materials, electrodes, batteries, and methods for forming electrode materials. [Background technology]

[0002] Lithium batteries have already become the mainstream of commercial batteries, and efforts are being made to make them lighter, thinner, shorter, smaller, with higher energy density, longer lifespan, and greater safety. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] U.S. Patent No. 7883553B2 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] One of the key steps in lithium battery manufacturing is electrode formation. Conventional electrode formation steps include electrode slurry preparation, electrode coating, drying, and pressing. In the electrode slurry preparation step, electrode active material, binder (used to bind the powdered and granular electrode active material together and fix it to the current collector), and solvent (used to disperse the powdered and granular electrode active material and to ensure sufficient contact between the binder and the powdered and granular material) are mixed to prepare a fluid electrode slurry. Once the electrode slurry preparation is complete, the electrode slurry is coated onto the current collector, the solvent contained in the electrode slurry is removed, and the coating layer is pressed to a predetermined thickness. However, when the solvent in the electrode slurry is removed in the drying step, defects such as pinholes or cracks may occur in the previously formed electrode active layer. Also, because the evaporation rates of the solvents differ, differences in the degree of drying of the inside and outside of the coating layer formed from the electrode slurry can lead to the formation of gaps within the electrode, potentially reducing the quality of the resulting electrode.

[0005] To solve the problems arising from the production of electrodes using conventional electrode slurries, dry electrode process technologies that do not use any solvents have been proposed in the industry. This involves kneading a conductive material and an electrode active material using a fluorine-based binder (e.g., polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF)) and forming an electrode using a hot press process. However, when using a fluorine-based binder, it is necessary to perform a high-torque fibrillation treatment beforehand. Also, the dry electrode material of the fluorine-based binder requires a processing temperature of 200°C or higher during heating roll pressing. When the processing temperature is so high, wrinkles are likely to occur in the formed electrode, resulting in a decrease in the capacity, energy density, and stability of the electrode.

Means for Solving the Problems

[0006] According to an embodiment of the present disclosure, the present disclosure provides an electrode material, which includes active particles and a coating layer. The coating layer partially or completely covers the surface of the active particles. The coating layer may contain 5 to 70 parts by weight of a conductive additive and 30 to 95 parts by weight of a first polymer, and the total weight of the first polymer and the conductive additive is 100 parts by weight. The first polymer is a product obtained by polymerizing a compound having two acrylate groups and an ethylene / vinyl acetate copolymer, and the compound having two acrylate groups has a structure represented by formula (I).

[0007]

Chemical formula

[0008] In the formula, A is a single bond, oxygen,

Chemical formula

[0009] According to an embodiment of the present disclosure, the present disclosure provides an electrode, which may include a current collector layer and an active layer. The active layer is disposed on the current collector layer, and the active layer includes the electrode material according to the present disclosure.

[0010] According to an embodiment of the present disclosure, the present disclosure provides a battery, which includes a positive electrode, a separator, and a negative electrode. The negative electrode is separated from the positive electrode by the separator, and at least one of the positive electrode and the negative electrode is an electrode according to the present disclosure.

[0011] According to an embodiment of the present disclosure, the present disclosure provides a method for manufacturing an electrode material used for manufacturing the electrode material according to the present disclosure. The method for manufacturing the electrode material includes a step of preparing a composition, wherein the composition includes the active particles, the conductive additive, and the first polymer, and a step of subjecting the composition to a spray granulation process or a melt kneading process to obtain the electrode material.

Advantages of the Invention

[0012] This disclosure provides an electrode material applicable to electrode processes (e.g., dry electrode processes) and used as an electrode in a battery, such as the positive or negative electrode of a lithium battery. The electrode material according to this disclosure comprises active particles and a coating layer that partially or completely covers the surface of the active particles. The coating layer comprises a first polymer and a conductive additive. It should be noted that the first polymer has appropriate rheological properties, adhesiveness, and melting point, so that the conductive additive is uniformly dispersed in the coating layer by a spray granulation or melt kneading process, and the coating layer covers and adheres to the surface of the active particles, thereby enabling the production of the electrode material according to this disclosure. Furthermore, due to the specific composition and structure of the electrode material according to this disclosure, the electrode material according to this disclosure does not need to be prepared as an electrode slurry (i.e., it does not need to be dispersed in a solvent, nor does it need to be further mixed with a binder), so that an active layer made of the electrode material can be formed on the surface of the current collector layer using a dry process (e.g., a hot press process) at a relatively low operating temperature (below 200°C, and even below 150°C). As a result, the formed active layer has better mechanical strength and good adhesion (adhesion between the active layer and the current collector layer), as well as increased mass loading, compacted density, and stability of the active layer of the resulting electrode (i.e., problems such as uneven distribution and poor adhesion caused by wet electrode processes are overcome), thus increasing the capacity and energy density of the battery, and improving the life cycle, charge / discharge performance, and C-rate discharge ability in high-temperature / high-voltage operation.

[0013] This disclosure can be better understood by reading the following detailed description and embodiments while referring to the attached figures. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view of an electrode material according to one embodiment of the present disclosure. [Figure 2] This is a cross-sectional view of an electrode material according to another embodiment of the present disclosure. [Figure 3] This is a step flowchart of a method for producing an electrode material according to one embodiment of the present disclosure. [Figure 4] This is an explanatory diagram of an electrode according to one embodiment of the present disclosure. [Figure 5] This is an explanatory diagram of an electrode according to another embodiment of the present disclosure. [Figure 6] This is an explanatory diagram of a battery according to one embodiment of the present disclosure. [Figure 7] This is a scanning electron microscope (SEM) image of electrode material (1). [Figure 8] This is a scanning electron microscope (SEM) image of the electrode material (8). [Figure 9] This is a transmission electron microscopy (TEM) image of electrode material (1). [Modes for carrying out the invention]

[0015] Electrode materials, electrodes, batteries, methods for forming electrode materials, and methods for manufacturing them are described in the following detailed description. In the following detailed description, numerous specific details and embodiments are described for illustrative purposes so that the disclosure may be fully understood. Specific elements and configurations described in the following detailed description are shown to clearly illustrate the disclosure. However, the exemplary embodiments shown herein are for illustrative purposes only, and it is clear that the concepts of the invention may be embodied in various forms, not limited to these exemplary embodiments. In addition, in order to clearly illustrate the disclosure, similar numbers and / or corresponding numbers may be used in the figures of different embodiments to indicate similar and / or corresponding elements. However, the use of similar and / or corresponding numbers in the figures of different embodiments does not imply any correlation between different embodiments. Where used herein, the term “about” means adding or subtracting by an amount common and reasonable to those skilled in the art.

[0016] Furthermore, the use of ordinal numbers such as "first," "second," and "third" to modify elements in this disclosure does not in itself indicate priority, precedence, or temporal order in which one claim element is formed over another claim element, but is merely used as a marker to distinguish one claim element having a certain name from another claim element having the same name (except for the use of ordinal numbers), thereby distinguishing the claim elements from each other.

[0017] It should be noted that the elements or devices in the figures of this disclosure may exist in any form or configuration known to those skilled in the art. Furthermore, the expressions “layer overlapping another layer,” “layer positioned above another layer,” “layer positioned on another layer,” and “layer positioned on another layer” may refer to a layer that is in direct contact with another layer, or a layer that is not in direct contact with another layer, in which case one or more intermediate layers are positioned between the layer and the other layer.

[0018] This disclosure provides electrode materials used to form electrodes (e.g., negative or positive electrodes) used in batteries (e.g., lithium-ion batteries) or lithium secondary electrodes. Refer to Figure 1, a cross-sectional view of an electrode material according to one embodiment of this disclosure. The electrode material 10 may include active particles 12 and a cladding layer 14. According to an embodiment of this disclosure, as shown in Figure 1, the cladding layer 14 may be positioned on the surface of the active particles 12 and cover the entire surface of the active particles. In other words, the electrode material 10 has a core-shell structure, consisting of a core and a shell layer surrounding the core, the core being the active particles 12 and the shell layer being the cladding layer 14.

[0019] According to embodiments of the present disclosure, the particle size of the active particle 12 (for example, the maximum distance between any two points on the surface of the active particle) may be approximately 50 nm to 100 μm, for example, approximately 60 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or 80 μm. According to embodiments of the present disclosure, the active particle may have a circular, oval, polygonal, or nearly circular cross-section. According to embodiments of this disclosure, the thickness of the coating layer 14 (e.g., average thickness, or the shortest distance from the outer surface of the coating layer 14 to the surface of the active particles 12) may be from 10 nm to 5 μm, for example, about 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, or 4 μm. The particle size of the active particles and the thickness of the coating layer can be measured using an electron microscope.

[0020] According to embodiments of this disclosure, the electrode material according to this disclosure has a functional coating layer (as a protective layer and a conductive layer) on the surface of the active particles, and is formed by a spray granulation process or a melt kneading process. As a result, the volume swelling of the electrode made using the electrode material is reduced, water absorption is lowered, stability is increased, the elution of metallic components (e.g., manganese, iron, or nickel) from the active particles is suppressed, and the ion conduction / electron conduction performance can be improved.

[0021] According to embodiments of the present disclosure, as shown in Figure 2, the cladding layer 14 may be positioned on the surface of the active particles 12 to partially or completely cover the surface of the active particles. Here, partially covering the surface of the active particles by the cladding layer 14 means that 30% to 100% (for example, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, or 99.99%) of the surface of the active particles is covered by the cladding layer 14.

[0022] According to embodiments of this disclosure, the weight ratio of the coating layer to the active particles may be approximately 3:97 to 10:90, for example, 4:96, 5:95, 6:94, 7:93, 8:92, or 9:91. If the weight ratio of the coating layer to the active particles is excessively low, the surface area of ​​the active particles covered by the coating layer becomes excessively small, or the variation in the thickness of the coating layer becomes excessively large, which tends to reduce the structural toughness, stability, and adhesion of the electrode material, as well as the electrical performance of the electrode formed thereafter. If the weight ratio of the coating layer to the active particles is excessively high, both the mass loading and compacted density of the active layer decrease, and at the same time, the resistance of the electrode formed thereafter tends to increase, and the electrical properties, capacitance, and energy density tend to decrease.

[0023] According to embodiments of the present disclosure, the electrode material may comprise at least one coating layer according to the present disclosure. For example, the electrode material comprises active particles, a first coating layer, and a second coating layer, wherein the first coating layer covers the active particles and the second coating layer covers the first coating layer. The materials and compositions of the first and second coating layers may be the same or different. According to some embodiments, the electrode material may further comprise other coating layers, such as electrolyte-containing materials.

[0024] According to embodiments of this disclosure, the active particles may be a positive electrode active material or a negative electrode active material, and can be selected based on the electrical properties of the electrode to be formed. In other words, the electrode material according to this disclosure may be a positive electrode active material or a negative electrode active material.

[0025] According to embodiments of the present disclosure, when the active particles are a positive electrode active material, the active particles may be sulfur, organosulfides, sulfur-carbon composites, metal-containing lithium oxide, metal-containing lithium sulfide, metal-containing lithium selenide, metal-containing lithium telluride, metal-containing lithium silicide, metal-containing lithium boride, metal-containing lithium phosphate, or a combination of the above, wherein the metal may be at least one selected from the group consisting of aluminum, vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, and manganese.For example, the active particles include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt manganese oxide, lithium nickel cobalt oxide, lithium nickel manganese oxide, lithium nickel manganese cobalt oxide, lithium chromium-manganese oxide, lithium nickel vanadium oxide, lithium manganese-nickel oxide, lithium cobalt-vanadium oxide, lithium nickel-cobalt-aluminum oxide (NMC), lithium iron phosphate (LFP), and lithium manganese iron phosphate (lithium manganese iron It may be phosphate, LMFP, or any combination of the above.

[0026] According to embodiments of the present disclosure, when the active particles are a negative electrode active material, the active particles may be silicon, silicon-carbon, silicon-containing oxide, titanium-containing oxide, tin, tin-containing compound, silicon alloy, carbon material, lithium, lithium alloy, metal-containing lithium carbide, metal-containing lithium nitride, or a combination of the above, wherein the metal is at least one selected from the group consisting of aluminum, chromium, copper, iron, nickel, cobalt, and manganese. According to embodiments of the present disclosure, the carbon material may include metastable phase spherical carbon (MCMB), vapor-grown carbon fiber (VGCF), carbon nanotube (CNT), coke, carbon black, graphite, graphene, fluorocarbons, acetylene black, carbon fiber, vitreous carbon, or a combination thereof. According to embodiments of the present disclosure, the carbon nanotube may be a single-walled carbon nanotube (SWCNT), a double-walled carbon nanotube (DWCNT), a multi-walled carbon nanotube (MWCNT), or a combination thereof. According to embodiments of the present disclosure, the silicon-containing oxide may be, for example, silicon oxycarbide.According to embodiments of the present disclosure, the lithium alloy or metal-containing lithium nitride may be an aluminum-containing lithium alloy, a magnesium-containing lithium alloy alloy, a zinc-containing lithium alloy alloy, a bismuth-containing lithium alloy alloy, a cadmium-containing lithium alloy alloy, an antimony-containing lithium alloy alloy, a silicon-containing lithium alloy, a lead-containing lithium alloy alloy, a tin-containing lithium alloy, a lithium iron nitride, a lithium cobalt nitride, or a lithium copper nitride.

[0027] According to embodiments of the present disclosure, the coating layer may contain 5 to 70 parts by weight of a conductive additive (e.g., 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, or 65 parts by weight) and 30 to 95 parts by weight of a first polymer (e.g., 32, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 parts by weight). Here, the total weight of the first polymer and the conductive additive is 100 parts by weight. If the amount of the first polymer added is excessively low, the structural toughness, stability, adhesion, and electrode free-standing of the electrode material tend to decrease. If the amount of the first polymer added is excessively high, the mass loading, compacted density, electrical properties, capacity, and energy density of the subsequent electrode active layer tend to decrease.

[0028] According to embodiments of the present disclosure, the conductive additive is uniformly dispersed in the first polymer. According to embodiments of the present disclosure, the conductive additive may be a conductive additive, an ionic conductive additive, or a combination thereof. For example, the conductive additive may be a combination of a conductive additive and an ionic conductive additive. In this disclosure, a conductive additive means an additive that has conductivity. A conductive additive according to this disclosure may also have ionic conductivity. In cases where its conductivity is superior to its ionic conductivity (or where a person with ordinary skill in the art tends to recognize the material as a conductive material), it is also referred to as a conductive additive in this disclosure. In this disclosure, an ionic conductive additive means an additive that has ionic conductivity. An ionic conductive additive according to this disclosure may also have conductivity. In cases where its ionic conductivity is superior to its conductivity (or where a person with ordinary skill in the art tends to recognize the material as an ionic conductive material), it is also referred to as an ionic conductive additive in this disclosure.

[0029] According to embodiments of the present disclosure, the conductive additive may be a conductive polymer material, a conductive inorganic material, or a combination thereof. According to embodiments of the present disclosure, the conductivity of the conductive additive may be 10 S / cm or more (e.g., 15 S / cm, 20 S / cm, 25 S / cm, 30 S / cm, 35 S / cm, 40 S / cm, 45 S / cm, 50 S / cm, 55 S / cm, 60 S / cm, 65 S / cm, 70 S / cm, 75 S / cm, or 80 S / cm). According to embodiments of the present disclosure, the conductive polymer material may be polyacetylene, polydiacetylene, polyaniline, polypyrrole, polythiophene, or a combination thereof. The weight-average molecular weight of the conductive polymer material according to the present disclosure is not particularly limited and can be adjusted as needed by those with ordinary skill in the art. According to embodiments of the present disclosure, the weight-average molecular weight (Mw) of the conductive polymer material may range from about 10,000 (g / mol) to 5,000,000 (g / mol), for example, about 30,000 (g / mol), 50,000 (g / mol), 80,000 (g / mol), 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), 400,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2,000,000 (g / mol), 3,000,000 (g / mol), or 4,000,000 (g / mol). The weight-average molecular weight (Mw) of the aforementioned conductive polymer material can be measured by gel permeation chromatography (GPC) (a calibration curve was created using polystyrene as a standard).

[0030] According to embodiments of the present disclosure, the conductive inorganic material may be conductive carbon black, conductive graphite, fluorocarbon, reduced graphene oxide, nitrogen-doped graphite, nitrogen-doped graphene, carbon fiber, carbon nanotube, or a combination of the above. According to embodiments of the present disclosure, the conductive inorganic material may be granular. According to embodiments of the present disclosure, the value of the particle size distribution D90 of the conductive inorganic material may be from about 0.1 nm to 200 nm, such as about 0.2 nm, 0.5 nm, 1 nm, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 170 nm, or 190 nm. The particle size distribution D90 represents that the particle size of 90% of the total volume of the conductive inorganic material is smaller than the value defined by the D90. According to embodiments of the present disclosure, the particle size distribution D90 is measured according to the method defined in ISO13322-1:2004.

[0031] According to embodiments of the present disclosure, the ionic conductivity of the ionic conductive additive is 1×10 -6 S / cm to 9×10 -3 S / cm (such as 2×10 -6 S / cm, 5×10 -6 S / cm, 8×10 -6 S / cm, 1×10 <0000||0>S / cm, 2×10 -5 S / cm, 5×10 -5 S / cm, 8×10 -5 S / cm, 1×10 <00||0014>S / cm, 2×10 -4 S / cm, 5×10 -4 S / cm, 8×10 -4 S / cm, 1×10 -3 S / cm, 2×10 <00000||9>S / cm, 5×10-3 S / cm, or 8×10 -3 The ion-conducting additive may be a hyperbranched polymer, an ethyl cellulose resin, a lithium-ion-containing polythiophene polymer, a polymer having a lithium sulfonate group, a polymer having an organosilicon group, or a combination of the above.

[0032] According to embodiments of this disclosure, the hyperbranched polymer may be a nitrogen-containing hyperbranched polymer. The hyperbranched polymer may be obtained by polymerizing an imide compound. Furthermore, according to embodiments of this disclosure, the hyperbranched polymer may be obtained by copolymerizing an imide compound with barbituric acid. The imide compounds may be bismaleimide (e.g., N,N'-bismaleimide-4,4'-diphenylmethane), maleimide (e.g., phenylmethanemaleimide), or a combination of the above. For example, the nitrogen-containing hyperbranched polymer may be a copolymer of bismaleimide and barbituric acid, or a copolymer of a maleimide oligomer and barbituric acid. According to embodiments of this disclosure, Taiwan Patent No. I722747 can be used to describe the hyperbranched polymer and its preparation method. According to embodiments of this disclosure, the lithium-ion-containing polythiophene polymer may have repeating units of any of the following structures.

[0033]

change

[0034] In the formula, R ais a C6-C30 alkyl group. According to embodiments of this disclosure, Taiwan Patent No. I724715 can be referenced for lithium ion-containing polythiophene polymers and their preparation. According to embodiments of the present disclosure, polymers having a lithium sulfonate group include poly(2-acrylamido-2-methyl-1-propanesulfonic acid lithium salt), poly(styrenesulfonic acid lithium salt), poly(vinylsulfonic acid lithium salt), poly(perfluorosulfonic acid lithium salt), poly((methyl)acrylic acid lithium salt), poly(lithium maleate), poly(lithium fumarate), poly(lithium itaconate), and poly(lithium adipate). The adipate may be acrylonitrile / butadiene / lithium acrylate copolymer, tetrabutyl acrylate / ethyl acrylate / lithium methacrylate copolymer, ethylene / lithium acrylate copolymer, and methyl methacrylate / lithium methacrylate copolymer, or any combination thereof.According to embodiments of the present disclosure, the polymer having an organosilicon group may be a polyester-modified polysiloxane, a polyester-polysiloxane graft copolymer, or a combination thereof. According to embodiments of the present disclosure, Taiwan Patent No. I445739 can be used to refer to the preparation of the polymer having an organosilicon group.

[0035] The weight-average molecular weight of the ion-conducting polymers relating to this disclosure (i.e., hyperbranched polymers, ethyl cellulose resins, lithium ion-containing polythiophene polymers, polymers having lithium sulfonate groups, or polymers having organosilicon groups) is not particularly limited and can be adjusted as needed by persons with ordinary skill in the art while maintaining ionic conductivity. According to embodiments of the present disclosure, the weight-average molecular weight (Mw) of the ion-conducting polymer may range from about 10,000 (g / mol) to 5,000,000 (g / mol), for example, about 30,000 (g / mol), 50,000 (g / mol), 80,000 (g / mol), 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), 400,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2,000,000 (g / mol), 3,000,000 (g / mol), or 4,000,000 (g / mol). The weight-average molecular weight (Mw) of the aforementioned ion-conducting polymer material can be measured by gel permeation chromatography (GPC) (a calibration curve is created using polystyrene as a standard).

[0036] According to embodiments of the present disclosure, the coating layer may consist of the first polymer and the conductive additive. According to other embodiments of the present disclosure, the coating layer may consist substantially of the first polymer and the conductive additive, that is, the total weight of the first polymer and the conductive additive accounts for 95 wt% or more of the weight of the coating layer. If the coating layer contains other components, these other components may be additives used to form conventional electrodes. According to embodiments of the present disclosure, the electrode material according to the present disclosure does not contain fluorine-containing polymers. In other words, the active particles do not contain fluorine-containing polymers, and the coating layer does not contain fluorine-containing polymers.

[0037] According to embodiments of the present disclosure, in addition to the first polymer and the conductive additive, the coating layer may further contain 0.1 to 30 parts by weight (e.g., 0.5 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, or 25 parts by weight) of a second polymer, with the total weight of the first polymer and the conductive additive being 100 parts by weight. Here, the second polymer refers to a polymer added in a spray granulation or melt kneading process. Thus, the second polymer and the first polymer are mixed and exist independently in the coating layer (the second polymer does not react with the first polymer). According to embodiments of the present disclosure, the addition of the second polymer can be used to adjust the mechanical strength, corrosion resistance to electrolyte, wettability and permeability to electrolyte, electrochemical stability, safety protection, and adhesion of the coating layer. According to embodiments of the present disclosure, the first polymer and the second polymer are different.

[0038] According to embodiments of this disclosure, the weight-average molecular weight of the first polymer ranges from approximately 12,000 g / mol to 10,000,000 g / mol, for example, approximately 15,000 (g / mol), 20,000 (g / mol), 50,000 (g / mol), 80,000 (g / mol), 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), and 400 The weight-average molecular weight (Mw) of the first polymer can be 1,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2,000,000 (g / mol), 3,000,000 (g / mol), 4,000,000 (g / mol), 5,000,000 (g / mol), 8,000,000 (g / mol), or 9,000,000 (g / mol). The weight-average molecular weight (Mw) of the first polymer can be measured by gel permeation chromatography (GPC) (a calibration curve is created using polystyrene as a standard).

[0039] According to embodiments of the present disclosure, the first polymer may be a product obtained by polymerizing a compound having two acrylate groups with an ethylene / vinyl acetate copolymer.

[0040] According to embodiments of the present disclosure, the first polymer is a product obtained by polymerizing a composition, the composition comprising the compound having the two acrylate groups and the ethylene / vinyl acetate copolymer. According to embodiments of the present disclosure, in addition to the compound having the two acrylate groups and the ethylene / vinyl acetate copolymer, the composition may also contain a solvent, a reaction initiator, or a catalyst. According to some embodiments of the present disclosure, the only components in the composition that can undergo polymerization are the compound having the two acrylate groups and the ethylene / vinyl acetate copolymer. The solvent, reaction initiator, or catalyst may be a conventional solvent, reaction initiator, or catalyst used in olefin polymerization reactions. For example, the solvent may be N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), pyrrolidone, N-dodecylpyrrolidone, γ-butyrolactone, 1,2-propanediol monomethyl ether acetate, toluene, xylene, cyclopentanone, or a combination of the above. According to embodiments of the present disclosure, if the composition contains the solvent, the solids content of the composition may be about 1 wt% to 90 wt% (for example, about 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, or 85 wt%). Here, the solids content refers to the weight percentage of all components of the composition excluding the solvent, and is based on the total weight of the composition. According to embodiments of the present disclosure, the composition comprises the compound having the two acrylate groups, the ethylene / vinyl acetate copolymer, the solvent, and a reaction initiator.

[0041] According to embodiments of the present disclosure, the composition used to prepare the first polymer may further contain, in addition to the compound having two acrylate groups and the ethylene / vinyl acetate copolymer, a reaction monomer or a third polymer, the reaction monomer or the third polymer which can react with the compound having two acrylate groups and / or the ethylene / vinyl acetate. In other words, the components in the composition that can undergo polymerization reactions may be the compound having two acrylate groups, the ethylene / vinyl acetate copolymer, and the reaction monomer (or the third polymer). According to embodiments of the present disclosure, the addition of the reaction monomer and / or the third polymer can be used to adjust the structural toughness, adhesion, rheological properties, electrochemical stability, and processability of the resulting first polymer.

[0042] According to embodiments of the present disclosure, a compound having two acrylate groups may have the structure shown by formula (I).

[0043] [ka]

[0044] In the formula, A 1 is a single bond, oxygen, [ka] Alternatively, -CH=CH- may be the case, and each R 1 Each of these may independently be a hydrogen atom or a methyl group, and each R 2 Each of these may independently be a hydrogen atom or a methyl group, and each R 3 Each of these may independently be a hydrogen atom, a methyl group, or an ethyl group.

[0045] According to embodiments of this disclosure, the compound having the two acrylate groups may be any of the following:

[0046] [ka] [ka]

[0047] In the formula, R 1 , R 2 , and R 3 The definition is the same as above.

[0048] According to embodiments of the present disclosure, the ethylene / vinyl acetate copolymer may have repeating units represented by formula (II) and repeating units represented by formula (III).

[0049] [ka]

[0050] The ratio of the number of repeating units represented by formula (II) to the number of repeating units represented by formula (III) is from 1:1,250 to 300:1, for example, 1:1,000, 1:900, 1:800, 1:700, 1:500, 1:250, 1:100, 1:50, 1:25, 1:10, 1:8, 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, 5:1, 8:1, 10:1, 15:1, 20:1, 25:1, 80:1, 100:1, 150:1, 200:1, or 250:1. According to embodiments of the present disclosure, the first repeating unit of the ethylene / vinyl acetate copolymer and the second repeating unit may be repeated in a random or blocky form.

[0051] According to embodiments of the present disclosure, the ethylene / vinyl acetate copolymer has n repeating units represented by formula (II) and m repeating units represented by formula (III), where n is between 300 and 300,000 (e.g., 500, 1,000, 2,000, 3,000, 5,000, 8,000, 10,000, 10,000, 15,000, 20,000, 30,000, 50,000, 70,000, 80,000, 90 m may be 1,000, 100,000, 150,000, 200,000, or 250,000), and m may be 1,000 to 250,000 (for example, 1,500, 2,000, 3,000, 5,000, 8,000, 10,000, 10,000, 15,000, 20,000, 30,000, 50,000, 70,000, 80,000, 90,000, 100,000, 150,000, or 200,000).

[0052] According to embodiments of this disclosure, the weight-average molecular weight of the ethylene / vinyl acetate copolymer ranges from approximately 90,000 g / mol to 30,000,000 g / mol, for example, approximately 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), 400,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2 The weight-average molecular weight (Mw) of the ethylene / vinyl acetate copolymer can be 1,000,000 (g / mol), 3,000,000 (g / mol), 4,000,000 (g / mol), 5,000,000 (g / mol), 8,000,000 (g / mol), 10,000,000 (g / mol), 12,000,000 (g / mol), 15,000,000 (g / mol), 20,000,000 (g / mol), or 25,000,000 (g / mol). The weight-average molecular weight (Mw) of the ethylene / vinyl acetate copolymer can be measured by gel permeation chromatography (GPC) (a calibration curve is created using polystyrene as a standard). According to embodiments of this disclosure, the ethylene / vinyl acetate copolymer first dissociates during the copolymerization reaction to become a reactive substance with a relatively small molecular weight.

[0053] According to embodiments of this disclosure, the melt index (MI) of the ethylene / vinyl acetate copolymer ranges from approximately 1 g / 10 min to 2,000 g / 10 min, for example, approximately 200 g / 10 min, 300 g / 10 min, 400 g / 10 min, 500 g / 10 min, 800 g / 10 min, 1,000 g / 10 min, 1,200 g / 10 min, 1,500 g / 10 min, or 1,700 g / 10 min. A higher melt index results in better fluidity and easier omnidirectional coating during the coating process, but makes it more difficult for fibrillated structural morphologies to form. Conversely, a lower melt index results in reduced fluidity and makes omnidirectional coating impossible, but makes it relatively easier for fibrillated structural morphologies to form under the action of shear forces. When the melt index of the ethylene / vinyl acetate copolymer is within the specific range described above, an electrode material can be obtained that combines numerous advantages, such as omnidirectional coating effect, high adhesion, high structural toughness, and the absence of a binder. Furthermore, the contact between the active particles and the conductive additive becomes tighter, contributing to improved electrical properties of the electrode material. As a result, lithium ions can be inserted and extracted more smoothly from the active material surface, increasing battery capacity and improving discharge rate performance. According to the embodiments of this disclosure, the melt index of the ethylene / vinyl acetate copolymer is measured at approximately 190°C and under a load of approximately 2.16 kg by the method specified in ASTM D1238.

[0054] According to embodiments of the present disclosure, the weight ratio of the compound having the two acrylate groups to the ethylene / vinyl acetate copolymer may be about 1:99 to 99:1, for example, about 2:98, 3:97, 4:96, 5:95, 6:94, 7:93, 8:92, 9:91, 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, 91:9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, or 98:2. When the electrode material is prepared using a homopolymer of the compound having the two acrylate groups instead of the first polymer, the overall structure of the resulting electrode material becomes excessively hard and brittle (i.e., insufficient flexibility and viscoelasticity), has lower electrochemical stability, and is prone to cracking and collapse of the electrode material structure (when the processing temperature is excessively high). Furthermore, if the electrode material is prepared using the ethylene / vinyl acetate copolymer instead of the first polymer, the structure of the resulting electrode material becomes excessively soft and sparse, resulting in insufficient strength, susceptibility to deformation and aging, lower heat stability, and excessively high processing temperatures, leading to the release of corrosive decomposition products.

[0055] According to embodiments of the present disclosure, the second polymer may be polyamide, polyimide, polymaleimide, polybismaleimide, polyacrylate, poly(acrylic acid) , polyvinyl alcohol , sodium carboxymethyl cellulose , polystyrene , styrene-butadiene rubber , polyurethane , polyvinylpyrrolidone , polyvinyl chloride , polyacrylonitrile , polybutadiene , or a combination thereof. According to embodiments of this disclosure, the weight-average molecular weight of the second polymer ranges from approximately 2,000 g / mol to 3,000,000 g / mol, for example, approximately 3,000 (g / mol), 5,000 (g / mol), 8,000 (g / mol), 10,000 (g / mol), 12,000 (g / mol), 15,000 (g / mol), 20,000 (g / mol), 50,000 (g / mol). The weight-average molecular weight (Mw) of the second polymer can be 1 / mol, 80,000 (g / mol), 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), 400,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2,000,000 (g / mol), or 2,500,000 (g / mol). The weight-average molecular weight (Mw) of the second polymer can be measured by gel permeation chromatography (GPC) (a calibration curve is created using polystyrene as a standard).

[0056] According to embodiments of the present disclosure, the reaction monomer may be ethylene, propylene, isobutylene, 1-butene, ethyl acetate, acrylic acid, acrylic acid ester, vinyl aromatic monomer, maleimide, bismaleimide, barbituric acid, or a combination thereof.

[0057] According to embodiments of the present disclosure, the third polymer may be polyacrylate, poly(acrylic acid), polyvinyl alcohol, sodium carboxymethyl cellulose, ethyl cellulose, polystyrene, styrene-butadiene copolymer, polybutadiene, or a combination thereof. According to embodiments of the present disclosure, the weight-average molecular weight of the third polymer is from about 2,000 g / mol to 3,000,000 g / mol, for example, about 3,000 (g / mol), 5,000 (g / mol), 8,000 (g / mol), 10,000 (g / mol), 12,000 (g / mol), 15,000 (g / mol), 20,000 (g / mol), 50,000 (g / mol). The weight-average molecular weight (Mw) of the third polymer can be 1 / mol, 80,000 (g / mol), 100,000 (g / mol), 200,000 (g / mol), 300,000 (g / mol), 400,000 (g / mol), 500,000 (g / mol), 800,000 (g / mol), 1,000,000 (g / mol), 2,000,000 (g / mol), or 2,500,000 (g / mol). The weight-average molecular weight (Mw) of the third polymer can be measured by gel permeation chromatography (GPC) (a calibration curve is created using polystyrene as a standard).

[0058] According to embodiments of the present disclosure, the preparation of the first polymer according to the present disclosure may include the following steps: First, a compound having two acrylate groups and an ethylene / vinyl acetate copolymer are dispersed in the solvent, and an initiator and / or catalyst are added as necessary to obtain a composition. Next, the composition is heated to react the compound having two acrylate groups and the ethylene / vinyl acetate copolymer to form the first polymer.

[0059] According to other embodiments of the present disclosure, the preparation of the first polymer according to the present disclosure may include the following steps: First, a compound having two acrylate groups and an ethylene / vinyl acetate copolymer are dispersed in the solvent, and a reaction monomer, a third polymer, an initiator, and / or a catalyst are added as needed to obtain a composition. Next, the composition is heated to react the compound having two acrylate groups and the ethylene / vinyl acetate copolymer to form the first polymer.

[0060] According to embodiments of the present disclosure, please refer to Figure 3, the method 100 for producing an electrode material according to the present disclosure may include the following steps: First, a composition to be used to produce an electrode material is prepared, the composition comprising the active particles, the conductive additive, and the first polymer (step 102). Next, the composition is subjected to a spray granulation step or a melt kneading step to obtain the electrode material (step 104). According to embodiments of the present disclosure, the weight ratio of the conductive additive to the first polymer in the composition is 5:95 to 70:30, for example 10:90, 20:80, 30:70, 40:60, 50:50, or 60:40. According to embodiments of the present disclosure, the weight ratio of the total weight of the conductive additive and the first polymer to the active particles is 4:96 to 10:90, for example 5:95 to 70:30, for example 5:95, 6:94, 7:93, 8:92, or 9:91. The composition further comprises a second polymer, and the weight ratio of the total weight of the conductive additive, the first polymer, and the second polymer to the active particles is from 3:97 to 10:90, for example, 4:96, 5:95, 6:94, 7:93, 8:92, or 9:91. According to embodiments of the present disclosure, the electrode material is formed from the composition used to produce the electrode material, so that the weight ratio of the conductive additive to the first polymer in the composition is approximately equal to the weight ratio of the conductive additive to the first polymer in the coating layer, and the weight ratio of the total weight of the conductive additive and the first polymer in the composition (or the total weight of the conductive additive, the first polymer, and the second polymer) to the active particles is approximately equal to the weight ratio of the coating layer to the active particles in the electrode material.

[0061] According to embodiments of the present disclosure, a method for producing an electrode material according to the present disclosure may include the following steps: First, a first composition to be used to produce an electrode material is prepared, the first composition comprising the active particles, the conductive additive, and the first polymer. Next, a spray granulation step is performed on the first composition to obtain core-shell particles (consisting of active particles and a first coating layer). Next, the core-shell particles, the conductive additive, and the first polymer are mixed to obtain a second composition. Next, a spray granulation step is performed on the first composition to obtain an electrode material according to the present disclosure.

[0062] According to embodiments of this disclosure, the electrode material is formed by a spray granulation process or a melt kneading process, thereby reducing the volume swelling of the electrode made using the electrode material, lowering water absorption, increasing stability, suppressing the elution of metallic components (e.g., manganese, iron, or nickel) of the active particles, and improving ion conduction / electron conduction performance.

[0063] According to embodiments of the present disclosure, when the electrode material is produced by a spray granulation process, the method for producing the electrode material according to the present disclosure may include the following steps: First, the conductive additive is uniformly dispersed in a solvent to obtain a first solution. Next, the active particles are added to the first solution and uniformly dispersed to obtain a second solution. Next, the first polymer (or a combination of the second polymer and the first polymer) is added to the second solution and uniformly mixed to obtain a slurry. Next, the spray granulation process is carried out using the slurry to obtain the electrode material. According to embodiments of the present disclosure, the diameter of the atomizing nozzle used in the spray granulation process, the atomizer frequency, the operating temperature, the inlet temperature, the outlet temperature, and the material supply flow rate can be adjusted by a person with ordinary skill in the art as needed. For example, a closed-type inert gas circulation spray drying system (model CL-8) and a centrifugal ceramic pin type atomizer disc (MC-50-8-14C) from Okawara Chemical Machinery Co., Ltd. can be used. The atomizer's rotation frequency can be set from 20 Hz to 60 Hz, its operating temperature from 50°C to 200°C, its inlet temperature from 30°C to 200°C, its outlet temperature from 30°C to 200°C, and its material supply flow rate from 1 ml / min to 100 ml / min. The spray granulation process may also include a drying step for drying the product after granulation in the slurry, and the temperature of the drying step can be adjusted, for example, from 50°C to 200°C depending on the solvent used. For example, the spray granulation process can be carried out by a spray drying system.For example, the solvent may be N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), pyrrolidone, N-dodecylpyrrolidone, γ-butyrolactone, 1,2-propanediol monomethyl ether acetate, toluene, xylene, cyclopentanone, or a combination of the above.

[0064] According to embodiments of the present disclosure, when the electrode material is prepared using a melt-kneading step, the method for preparing the electrode material according to the present disclosure may include the following steps: First, the conductive additive, active particles, and a first polymer (or further including the second polymer) are thoroughly mixed to obtain a mixture. Next, the electrode material is obtained by performing a melt-kneading step on the mixture. Here, "melting" as used in the present disclosure refers to heating to the melting point of the first polymer reactant, or heating to a temperature above which the first polymer becomes deformable, and then becoming a fluid substance. "Kneading" as used in the present disclosure refers to the process of uniformly mixing the conductive additive, active particles, and polymer by the action of a machine (e.g., an extruder), and the kneading step can be performed in a discontinuous or batch manner. According to embodiments of the present disclosure, since the electrode material is prepared using a specific polymer (i.e., the first polymer), the temperature of the melt-mixing step can be from 60°C to 200°C, for example, about 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or 190°C.

[0065] According to embodiments of the present disclosure, the present disclosure also provides electrodes (e.g., positive or negative electrodes) for use in batteries (e.g., lithium-ion batteries or lithium secondary electrodes). According to embodiments of the present disclosure, see Figure 4, the electrode 200 according to the present disclosure may include a current collector layer 202 and an active layer 204, wherein the active layer 204 is placed on the current collector layer 202. According to embodiments of the present disclosure, the active layer 204 is placed directly on the current collector layer 202 so that the lower surface of the active layer 204 and the upper surface of the current collector layer 202 are in direct contact (i.e., there is no film layer or the like separating the active layer 204 and the current collector layer 202 (continuously or discontinuously)). For example, since there is good adhesion between the active layer 204 and the current collector layer 202 of the electrode 200 according to this disclosure, it is not necessary to further use a binder (or adhesive layer) to fix the active layer 204 on the current collector layer 202, or to mix the electrode material and the binder to form the active layer. According to an embodiment of this disclosure, the electrode 200 according to this disclosure consists of the current collector layer 202 and the active layer 204. According to an embodiment of this disclosure, the active layer 204 according to this disclosure consists of the electrode material.

[0066] According to embodiments of the present disclosure, the electrode 200 according to the present disclosure may include two active layers (i.e., a first active layer 204 and a second active layer 206) and one current collector layer 202, wherein the current collector layer 202 is positioned between the two active layers 204. Here, the first active layer 204 is positioned directly on the current collector layer 202 so that the lower surface of the first active layer 204 and the upper surface of the current collector layer 202 are in direct contact, and the current collector layer 202 is positioned directly on the second active layer 206 so that the lower surface of the current collector layer 202 and the upper surface of the second active layer 206 are in direct contact.

[0067] According to embodiments of the present disclosure, the electrode according to the present disclosure can be used as the positive electrode of a battery, and the active particles of the electrode material used in the active layer are the positive electrode active material. According to embodiments of the present disclosure, the electrode according to the present disclosure can be used as the negative electrode of a battery, and the active particles of the electrode material used in the active layer are the negative electrode active material.

[0068] According to embodiments of the present disclosure, the thickness of the active layer is not particularly limited and can be adjusted as needed by a person with ordinary skill in the art. For example, the thickness of the active layer may be about 50 μm to 500 μm (e.g., about 70 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, or 450 μm).

[0069] According to embodiments of the present disclosure, the current collector layer may be a conductive carbon-based material, a metal foil (e.g., nickel foil, aluminum foil, copper foil, carbon-coated aluminum foil, or stainless steel foil), or a porous metal material, such as carbon cloth, carbon felt, or carbon paper, nickel mesh, copper mesh, molybdenum mesh, foamed nickel, foamed copper, or foamed molybdenum. According to embodiments of the present disclosure, the porosity of the porous metal material may be about 10% to 99.9% (e.g., 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%). According to embodiments of the present disclosure, the thickness of the current collector layer is not particularly limited and can be adjusted as needed by a person with ordinary skill in the art. For example, the thickness of the current collector layer may be approximately 5 μm to 50 μm (for example, approximately 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or 45 μm).

[0070] According to embodiments of the present disclosure, the method for manufacturing an electrode according to the present disclosure may include the following steps: Prepare the electrode material and current collector layer according to the present disclosure. Next, place the electrode material on the current collector layer, and perform a hot pressing process on the electrode material to make the electrode material an active layer, thereby obtaining the electrode. The active layer is in direct contact with the current collector layer. According to embodiments of the present disclosure, the hot pressing process may be, for example, a hot roll press or hot rolling. Since each particle of the electrode material according to the present disclosure is provided with the coating layer, and the coating layer has the first polymer according to the present disclosure, the active particles, conductive additives, and the first polymer naturally satisfy the requirement of uniform mixing. Furthermore, due to its specific chemical structure, the first polymer according to the present disclosure has a suitable melting point, rheological properties, and adhesiveness, allowing the hot pressing process to be performed at a relatively low temperature. According to embodiments of the present disclosure, the operating temperature of the hot pressing process may be approximately 80°C to 200°C, for example, approximately 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or 190°C. According to embodiments of the present disclosure, the pressure applied in the hot pressing process can be adjusted as needed by a person with ordinary skill in the art. For example, the pressure applied in the hot pressing process may be 100 psi or more. The electrodes according to the present disclosure can avoid problems arising from the further use of binders and can improve the uniformity of the mixing of the active material and the conductive material, thereby increasing the mass loading, compacted density, and stability of the active layer of the resulting electrode (i.e., overcoming problems associated with wet electrode processes).

[0071] According to embodiments of the present disclosure, the method for manufacturing an electrode according to the present disclosure may include the following steps: Prepare an electrode material and a current collector layer according to the present disclosure. Next, perform a hot pressing process on the electrode material to obtain an electrode material film. Next, place the electrode material film on the current collector layer and perform a hot pressing process on the electrode material to make the electrode material film an active layer to obtain the electrode. The active layer is in direct contact with the current collector layer. According to embodiments of the present disclosure, the hot pressing process may be, for example, a thermal rolling process or a thermal milling process.

[0072] According to embodiments of the present disclosure, the method for manufacturing an electrode according to the present disclosure may include the following steps: Prepare a composition and a current collector to be used to manufacture an electrode material, wherein the composition comprises the active particles, the conductive additive, and the first polymer according to the present disclosure. Next, introduce the composition into a spray granulation step and use the current collector to support the electrode material to be formed (i.e., directly form the electrode material on the current collector by a spray granulation step). Next, perform a hot press step on the electrode material to make the electrode material an active layer and obtain the electrode.

[0073] According to embodiments of the present disclosure, the method for manufacturing an electrode according to the present disclosure may include the following steps: Prepare a composition and a current collector to be used to manufacture the electrode material, wherein the composition comprises the active particles, the conductive additive, and the first polymer. Next, introduce the composition into a melt-kneading step and coat the extruded electrode material directly onto the current collector. Next, perform a thermal pressing step on the electrode material to make the electrode material an active layer and obtain the electrode.

[0074] According to embodiments of the present disclosure, see Figure 5, the present disclosure also provides a battery 300, for example, a lithium battery, a lithium-ion battery, or a lithium secondary battery. The battery 300 includes a positive electrode 302, a separator 304, and a negative electrode 306, wherein the negative electrode 306 is separated from the positive electrode 302 by the separator 304. According to embodiments of the present disclosure, at least one of the positive electrode 302 or the negative electrode 306 is an electrode according to the present disclosure. If the positive electrode 302 is an electrode according to the present disclosure, in the positive electrode 302, the active particles of the electrode material used in the active layer are positive electrode active material. If the negative electrode 306 is an electrode according to the present disclosure, in the negative electrode 306, the active particles of the electrode material used in the active layer are negative electrode active material.

[0075] According to embodiments of this disclosure, if the positive electrode is not an electrode according to this disclosure, the positive electrode may be a conventional positive electrode used in a battery (e.g., a lithium battery). For example, the positive electrode may include a positive electrode active layer (including a positive electrode active material) and a positive electrode current collector layer. According to embodiments of this disclosure, if the negative electrode is not an electrode according to this disclosure, the negative electrode may be a conventional negative electrode used in a battery (e.g., a lithium battery). For example, the negative electrode may include a negative electrode active layer (including a negative electrode active material) and a negative electrode current collector layer. According to embodiments of this disclosure, the definitions of the positive electrode current collector layer and the negative electrode current collector layer may be the same as those of the current collector layers according to this disclosure.

[0076] According to embodiments of the present disclosure, the positive electrode 302 may be in direct contact with the separator 304, and / or the negative electrode 306 may be in direct contact with the separator 304. According to embodiments of the present disclosure, the positive electrode 302 may be at a certain distance from the separator 304, and / or the negative electrode 306 may be at a certain distance from the separator 304. According to embodiments of the present disclosure, the battery 300 may further contain an electrolyte 308, which is placed between the positive electrode 302 and the negative electrode 306. In other words, the interlayer structure of the positive electrode 302, separator 304, and negative electrode 306 is immersed in the electrolyte 308. That is, the electrolyte is dispersed throughout the entire battery 300.

[0077] According to some embodiments of the present disclosure, the positive electrode active layer according to the present disclosure may be located between the separator 304 and the positive electrode current collector layer. According to embodiments of the present disclosure, the negative electrode active layer according to the present disclosure may be located between the separator 304 and the negative electrode current collector layer.

[0078] According to embodiments of the present disclosure, the separator 304 may include an insulating material such as polyethylene (PE), polypropylene (PP), polytetrafluoroethylene film, polyamide film, polyvinyl chloride film, polyvinylidene fluoride film, polyaniline film, polyimide film, nonwoven fabric, polyethylene terephthalate, polystyrene (PS), cellulose, or a combination thereof. For example, the separator 304 may be a PE / PP / PE multilayer composite structure. According to embodiments of the present disclosure, the separator may have a porous structure; that is, the voids in the separator are uniformly distributed throughout the separator. According to embodiments of the present disclosure, there are no particular limitations on the thickness of the separator, and it can be adjusted as needed by a person with ordinary skill in the art. For example, the thickness of the separator can be approximately 1 μm to 100 μm (for example, approximately 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm).

[0079] According to embodiments of the present disclosure, the electrolyte 308 may contain a solvent and a lithium salt (or lithium compound). According to embodiments of the present disclosure, the concentration of the lithium salt in the solvent is about 0.8 M to 1.6 M, for example, about 0.9 M, 1.0 M, 1.1 M, 1.2 M, 1.3 M, 1.4 M, or 1.5 M. According to embodiments of the present disclosure, the solvent may be an organic solvent, for example, an ester solvent, a ketone solvent, a carbonate solvent, an ether solvent, an alkane solvent, an amide solvent, or a combination thereof. According to embodiments of the present disclosure, the solvent is 1,2-diethoxyethane, 1,2-dimethoxyethane, 1,2-dibutoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), methyl acetate, ethyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate, propyl acetate (PA), γ-butyrolactone (GBL), ethylene carbonate (EC), propylene carbonate (propylene Carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (dimethyl carbonate,This may be DMC, vinylene carbonate, butylene carbonate, dipropyl carbonate, or any combination thereof. According to embodiments of the present disclosure, the lithium salt is lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), bis(fluorosulfonyl)imide lithium (LiN(SO2F)2) (LiFSI), lithium difluoro(oxalato)borate (LiBF2(C2O4)) (LiDFOB), lithium tetrafluoroborate (LiBF4), lithium trifluoromethanesulfonate (LiSO3CF3), bis(trifluoromethane)sulfonimide lithium (LiN(SO2CF3)2) (LiTFSI), lithium bis perfluoroethanesulfonimide (lithium bis Perfluoroethanesulfonimide (LiN(SO2CF2CF3)2), lithium hexafluoroarsenate (LiAsF6), lithium hexafluoroantimonate (LiSbF6), lithium tetrachloroaluminate (LiAlCl4), lithium tetrachlorogallate (LiGaCl4), lithium nitrate (LiNO3), tris(trifluoromethanesulfonyl)methyllithium (LiC(SO2CF3)3), lithium thiocyanate hydrate (LiSCN), LiO3SCF2CF3, LiC6F5SO3, LiO2CCF3, lithium fluorosulfonateLiSO3F), lithium tetrakis(pentafluorophenyl)borate (Lithium tetrakis(pentafluorophenyl)borate, LiB(C6H5)4), lithium bis(oxalato)borate (LiB(C2O4)2) (LiBOB), or any combination thereof.

[0080] According to embodiments of the present disclosure, the battery according to the present disclosure may use a solid electrolyte and may not contain an electrolyte solution. For example, the battery according to the disclosure may include a solid electrolyte membrane (not shown) provided between the positive electrode and the negative electrode. According to embodiments of the present disclosure, the solid electrolyte may be provided on top of the separator to form a composite separator. Alternatively, the battery according to the present disclosure may use a solid electrolyte membrane instead of the separator.

[0081] Hereinafter, exemplary embodiments will be described in detail so as to be easily understood by those with ordinary skill in the art. The concept of the present invention can be embodied in various forms, but is not limited to these exemplary embodiments described herein.

[0082] Preparation of compounds having two acrylate groups Preparation Example 1 1 mol of 4-hydroxyacetophenone, 1.2 mol of methacrylic anhydride, and 0.1 mol of sodium bicarbonate were added to a reaction bottle. The reaction bottle was purged with nitrogen gas and heated to 80°C. After reacting for 2 hours, 700 ml of 2M aqueous sodium hydroxide solution was added to the reaction bottle. The reaction was allowed to proceed for 8 hours, the resulting mixture was filtered, the solid was collected, washed with water, and then heated and dried to obtain compound (1) (yield approximately 97%). The reaction equation for the above reaction is shown below.

[0083] [ka]

[0084] Compound (1) (0.97 mol), hydrazine sulfate (0.49 mol), triethylamine (NEt3) (0.49 mol), and ethanol (200 g) were added to a reaction bottle. The reaction bottle was then heated and refluxed. After reacting for 5 hours, the reaction bottle was cooled to room temperature, and the product precipitated. The product was then washed with ethanol and deionized water, and dried by heating to obtain compound (1) having two acrylate groups. The reaction equation for the above reaction is shown below.

[0085] [ka]

[0086] Compound (1) containing two acrylate groups was analyzed by nuclear magnetic resonance spectroscopy. The obtained spectral information is as follows. 1 H NMR (400MHz,d6-DMSO): 7.97(d,4H,J=8.0Hz), 7.26(d,4H,J=8.0Hz), 6.30(s,2H), 5.91(s,202H), 2.29(s,6H), 2.01(s,6H).

[0087] Polymer preparation Preparation Example 2 95 parts by weight of ethylene-vinyl acetate copolymer (EVA) (product number UE647-04, purchased from Taiwan Juhe Co., Ltd., VA content 28%, MI value 800), 5 parts by weight of compound (1) having two acrylate groups, and toluene were added to a reaction bottle. The reaction bottle was then heated to 105°C. After reacting for 6 hours, the solvent was removed from the resulting mixture by rotary evaporation to obtain polymer (1). The decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (1) were then evaluated. The results are shown in Table 1.

[0088] The decomposition temperature (Td) of the polymers relating to this disclosure was analyzed using a thermogravimetric analyzer (TGA). The melt flow rate (MFR) of the polymers relating to this disclosure was measured using a melt flow indexer at 230°C with a test weight of 2.16 kg, according to the method specified in ASTM D 1238-A. The melting point of the polymers relating to this disclosure could be measured using a differential scanning calorimetry (DSC) (model number Discovery DAS 25, manufactured by TA Instruments, Inc.). The surface resistivity of the polymers relating to this disclosure was measured using a four-probe resistivity meter (model number DU-5211Ohm Meter, purchased from DELTA UNITED INSTRUMENT CO. LTD). The measurement method included the following steps: The sample was placed on the four-probe resistivity meter. The probe was brought into contact with the sample surface at a pressure of 0.07 MPa. After contact, it was left to stand for 3 seconds, and the resistance value (in ohms) of the instrument was read. The volume resistivity of the polymers according to this disclosure was measured according to the method specified in IEC 62788-1-2. The flame retardancy grade of the polymers according to this disclosure was tested and classified using the UL 94 method (Underwriter Laboratories).

[0089] Preparation Example 3 Polymer (2) was obtained by following the method described in Preparation Example 2, except that the weight ratio of the ethylene / vinyl acetate copolymer to compound (1) having two acrylate groups was adjusted from 95:5 to 20:80. The decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (2) were then evaluated. The results are shown in Table 1.

[0090] Preparation Example 4 Polymer (3) was obtained by following the method described in Preparation Example 2, except that the weight ratio of the ethylene / vinyl acetate copolymer to compound (1) having two acrylate groups was adjusted from 95:5 to 90:10 in Preparation Example 4. The decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (3) were then evaluated. The results are shown in Table 1.

[0091] Preparation Example 5 Preparation Example 5 was carried out according to the method described in Preparation Example 2, except that the weight ratio of the ethylene / vinyl acetate copolymer to compound (1) having two acrylate groups was adjusted from 95:5 to 5:95, to obtain polymer (4). Next, the decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (4) were evaluated. The results are shown in Table 1.

[0092] Preparation Example 6 95 parts by weight of ethylene-vinyl acetate copolymer (EVA) (product number UE630, purchased from Taiwan Juhe Co., Ltd., VA content 16%, MI value 1.5 g / 10 min), 5 parts by weight of compound (1) having two acrylate groups, and 200 parts by weight of toluene (as solvent) were added to a reaction bottle. The reaction bottle was then heated to 105°C. After reacting for 6 hours, the solvent was removed from the resulting product by rotary evaporation to obtain polymer (5). The decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (5) were then evaluated. The results are shown in Table 1.

[0093] Preparation Example 7 84 grams of polymer (6) (polyvinylidene fluoride, purchased from Kynar, product number PVDF-HVS900) were dissolved in 616 grams of N-methylpyrrolidone (NMP) to prepare a PVDF-HVS900 solution with a solid content of 12 wt%. This solution was applied to a glass plate using a blade with a 200 μm gap to form a wet film, which was then heated and dried in an oven at 180°C to obtain a polymer (6) film. The decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (6) were evaluated. The results are shown in Table 1.

[0094] [Table 1]

[0095] As can be seen from Table 1, the compounds having two acrylate groups according to this disclosure and polymers prepared from ethylene / vinyl acetate have high thermal decomposition temperatures, moderate melting points (which may be less than 150°C), and high melt flow rates.

[0096] Next, using a rheometer (TA ARES-G2), the rheological properties of polymers (1), (3) to (6) (the diameter of the evaluation samples was 20 mm) were evaluated (test conditions: shear rate 10¹ / s, and heating rate 5.0°C / min). It was found that polymers (1), (3) to (6) have good meltability.

[0097] Next, polymers (1) and (3) were tested using cyclic voltammetry to evaluate their activity and reaction kinetics, while simultaneously observing their stability and durability. The test conditions were set to a voltage range of 0 to 4.8V, and polymer (1) and (3) films were introduced into Taiwan Plastics' lithium iron phosphate battery. The results showed that polymers (1) and (3) possessed high electrochemical stability and hardly reacted with the electrolyte.

[0098] Fabrication of electrode materials

[0099] Example 1 2,500 grams of lithium iron phosphate (LFP) (purchased from Taiwan Plastics Lithium Iron Technology Co., Ltd., product number LFP-3005E), hyperbranch polymer / ethyl cellulose resin solution (solids content 6 wt%) (ethyl cellulose resin purchased from Dow Chemical, product number ETHOCEL STD 100) (The hyperbranch structure is a polymer structure obtained by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermal polymerization. By introducing ethyl cellulose during the process of forming the hyperbranch polymer molecular structure, it is incorporated into the hyperbranch structure and interwoven, forming a polyhyperbranch linear interpenetrating combined polymer structure. The weight ratio of hyperbranch polymer bismaleimide to ethyl cellulose resin is 2:1) (Used as an ion-conducting additive. Ionic conductivity is 3.4 x 10⁻⁶. -4Composition (1) was obtained by mixing 62.50 grams of lithium iron phosphate (S / cm), 178.57 grams of carbon nanotube dispersion (product number CNT-SP, purchased from Beijing Tiannai, used as a conductive additive) (solid content 4.2 wt%, dispersed in N-methylpyrrolidone (NMP)), 601.65 grams of polymer solution (120.33 grams of polymer (1) dissolved in toluene), and 706 g of toluene. Composition (1) was obtained by mixing these together (solid content 65%). In composition (1), the weight ratio of the ion-conducting additive, conductive additive, and polymer (1) was 2.85:5.70:91.45, and the ratio of the weight of lithium iron phosphate to the total weight of the ion-conducting additive, conductive additive, and polymer (1) was 95:5. Next, a spray granulation process was performed on composition (1) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the resulting material was collected to obtain powdered electrode material (1). The conditions for the spray granulation process were as follows: (1) A centrifugal ceramic pin-type atomizer disc (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 130°C and 80°C, respectively. (3) The circulation fan frequency was 35Hz. (4) The atomizer frequency was 40Hz. (5) The material supply rate was 10.030 ml / min.

[0100] Example 2 1,500 grams of lithium iron phosphate (LFP) (purchased from Shiojo Shinzai Co., Ltd., product number LFP-GF19), 37.50 grams of hyperbranch polymer / ethylcellulose resin solution (purchased from Dow Chemical, product number ETHOCEL STD 100) (The hyperbranch structure is a polymer structure obtained by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermal polymerization. By introducing ethylcellulose during the process of forming the hyperbranch polymer molecular structure, it is incorporated into the hyperbranch structure and interwoven, forming a polyhyperbranch linear interpenetrating combination polymer structure. The weight ratio of hyperbranch polymer bismaleimide to ethylcellulose resin is 2:1) (Used as an ion-conducting additive. Ionic conductivity is 3.4 x 10⁻⁶). -4Composition (2) was obtained by mixing 107.14 grams of a carbon nanotube dispersion (product number CNT-SP, purchased from Beijing Tiannai, used as a conductive additive) (solid content 4.2 wt%, dispersed in N-methylpyrrolidone (NMP)), 360.99 grams of a polymer solution (120.33 grams of polymer (1) dissolved in toluene), and 424 grams of toluene (toluene) (solid content 65%). In composition (2), the weight ratio of the ion-conducting additive, conductive additive, and polymer (1) was 3:6:91, and the ratio of the weight of lithium iron phosphate to the total weight of the ion-conducting additive, conductive additive, and polymer (1) was 95:5. Next, a spray granulation process was performed on composition (2) using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the obtained material was collected to obtain powdered electrode material (2). The conditions for the spray granulation process were as follows. (1) Use a centrifugal ceramic pin-type atomizer disc (MC-50-8-14C). (2) Set the inlet temperature and outlet temperature to 145°C and 110°C, respectively. (3) Circulation fan frequency: 35Hz. (4) Atomizer frequency: 30Hz. (5) Material supply rate: 12.070ml / min.

[0101] Example 3 1,500 grams of lithium iron phosphate (LFP) (purchased from Shiojo Shinzai Co., Ltd., product number LFP-GF19), 37.47 grams of hyperbranch polymer / ethylcellulose resin solution (solid content 6 wt%) (ethylcellulose resin purchased from Dow Chemical, product number ETHOEL STD 100) (The hyperbranch structure is a polymer structure obtained by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermal polymerization. By introducing ethylcellulose during the process of forming the hyperbranch polymer molecular structure, it is incorporated into the hyperbranch structure and interwoven to form a polyhyperbranch linear interpenetrating combination polymer structure. The weight ratio of hyperbranch polymer bismaleimide to ethylcellulose resin is 2:1) (Used as an ion-conducting additive. Ionic conductivity is 3.4 x 10⁻⁶. -4Composition (3) was obtained by mixing 375.94 grams of a carbon nanotube dispersion (product number CNT-SP, purchased from Beijing Tiannai, used as a conductive additive) (solid content 4.2 wt%, dispersed in N-methylpyrrolidone (NMP)), 607.89 grams of a polymer solution (60.79 grams of polymer (3) dissolved in toluene), and 50 grams of toluene (toluene) (solid content 61.36%). In composition (3), the weight ratio of the ion-conducting additive, conductive additive, and polymer (3) was 3:20:77, and the ratio of the weight of lithium iron phosphate to the total weight of the ion-conducting additive, conductive additive, and polymer (3) was 95:5. Next, a spray granulation process was performed on composition (3) using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the obtained material was collected to obtain powdered electrode material (3). The conditions for the spray granulation process were as follows. (1) Use a centrifugal ceramic pin-type atomizer disc (MC-50-8-14C). (2) Set the inlet temperature and outlet temperature to 145°C and 110°C, respectively. (3) Circulation fan frequency: 50Hz. (4) Atomizer frequency: 30Hz. (5) Material supply rate: 12.070ml / min.

[0102] Example 4 2,000 grams of lithium iron phosphate (LFP) (purchased from Shiojo Shinzai Co., Ltd., product number LFP-GF19), 106.38 grams of hyperbranch polymer / ethylcellulose resin solution (solid content 6 wt%) (ethylcellulose resin purchased from Dow Chemical, product number ETHOEL STD 100) (The hyperbranch structure is a polymer structure obtained by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermal polymerization. By introducing ethylcellulose during the process of forming the hyperbranch polymer molecular structure, it is incorporated into the hyperbranch structure and interwoven, forming a polyhyperbranch linear interpenetrating combined polymer structure. The weight ratio of hyperbranch polymer bismaleimide to ethylcellulose resin is 2:1) (Used as an ion-conducting additive. Ionic conductivity is 3.4 x 10⁻⁶ -4Composition (4) was obtained by mixing 506.59 grams of a carbon nanotube dispersion (product number CNT-SP, purchased from Beijing Tiannai, used as a conductive additive) (solid content 4.2 wt%, dispersed in N-methylpyrrolidone (NMP)), 666.67 grams of a polymer solution (100.00 grams of polymer (3) dissolved in toluene), and 975.68 grams of N-methylpyrrolidone (NMP) (solid content 61.36%) in composition (4). In composition (4), the weight ratio of the ion conductive additive, conductive additive, and polymer (3) was 5:16.67:78.33, and the ratio of the weight of lithium iron phosphate to the total weight of the ion conductive additive, conductive additive, and polymer (3) was 94:6. Next, a spray granulation process was performed on composition (4) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the obtained material was collected to obtain powdered electrode material (4). The conditions for the spray granulation process were as follows: (1) A centrifugal ceramic pin-type atomizer disc (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 140°C and 120°C, respectively. (3) The circulation fan frequency was 45Hz. (4) The atomizer frequency was 25Hz. (5) The material supply rate was 25.160 ml / min.

[0103] Example 5 1,800 grams of lithium iron phosphate (LFP) (purchased from Shiojo Shinzai Co., Ltd., product number LFP-GF19), 157.89 grams of hyperbranch polymer / ethylcellulose resin solution (solid content 6 wt%) (ethylcellulose resin purchased from Dow Chemical, product number ETHOEL STD 100) (The hyperbranch structure is a polymer structure obtained by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermal polymerization. By introducing ethylcellulose during the process of forming the hyperbranch polymer molecular structure, it is incorporated into the hyperbranch structure and interwoven, forming a polyhyperbranch linear interpenetrating combined polymer structure. The weight ratio of hyperbranch polymer bismaleimide to ethylcellulose resin is 2:1) (Used as an ion-conducting additive. Ionic conductivity is 3.4 x 10⁻⁶ -4Composition (5) was obtained by mixing 451.13 grams of lithium iron phosphate (S / cm), a carbon nanotube dispersion (product number CNT-SP, purchased from Beijing Tiannai, used as a conductive additive) (solid content 4.2 wt%, dispersed in N-methylpyrrolidone (NMP)), 442.11 grams of polymer solution (100.00 grams of polymer (3) dissolved in toluene), and 306.77 grams of N-methylpyrrolidone (NMP) (solid content 60.00%). In composition (5), the weight ratio of the ion-conducting additive, conductive additive, and polymer (3) was 1:2:7, and the ratio of the weight of lithium iron phosphate to the total weight of the ion-conducting additive, conductive additive, and polymer (3) was 95:5. Next, a spray granulation process was performed on composition (5) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the obtained material was collected to obtain powdered electrode material (5). The conditions for the spray granulation process were as follows. (1) Use a centrifugal ceramic pin-type atomizer disc (MC-50-8-14C). (2) Set the inlet temperature and outlet temperature to 110°C and 70°C, respectively. (3) Circulation fan frequency: 45Hz. (4) Atomizer frequency: 25Hz. (5) Material supply rate: 10.030ml / min.

[0104] Example 6 Composition (6) was obtained by mixing 6,000 grams of lithium iron phosphate (LFP) (purchased from Wanrun Technology, product number LFP-A8-4E), 64.17 grams of graphite (product number KS6, purchased from TIMCAL Taiwan Wave Co., Ltd., used as a conductive additive), 160.435 grams of conductive carbon powder (product number Super-P, purchased from TIMCAL Taiwan Wave Co., Ltd., used as a conductive additive), and 192.51 grams of polymer (3). A melt-kneading process was performed on composition (6) using a Banbury mixer (manufactured by Lina Machinery Industry Co., Ltd., KD-3-7.5) (temperature 120°C, mixing time 1 hour in a closed-type mixer) to obtain powdered electrode material (6). In composition (6), the weight ratio of KS6, Super-P, and polymer (3) was 2:5:6, and the ratio of the weight of lithium iron phosphate to the total weight of the conductive additive and polymer (3) was 93.5:6.5.

[0105] Example 7 Composition (7) was obtained by mixing 1,800 grams of lithium iron phosphate (LFP) (purchased from Wan Run Technology, product number LFP-A8-4E), 19.25 grams of graphite (product number KS6, purchased from Taiwan Wave Ltd, used as a conductive additive), 48.13 g of conductive carbon powder (product number Super-P, purchased from Taiwan Wave Ltd, used as a conductive additive), 57.75 grams of polymer (5), and 1036.61 grams of toluene (toluene) (solid content 65.00%). In composition (7), the weight ratio of KS6, Super-P, and polymer (5) was 1:2.5:3, and the ratio of the weight of lithium iron phosphate to the total weight of KS6, Super-P, and polymer (5) was 93.5:6.5. Next, a spray granulation process was performed on composition (7) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the resulting material was collected to obtain powdered electrode material (7). The conditions for the spray granulation process were as follows: (1) A centrifugal ceramic pin-type atomizer disc (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 120°C and 70°C, respectively. (3) The circulation fan frequency was 35Hz. (4) The atomizer frequency was 35Hz. (5) The material supply rate was 50.150 ml / min.

[0106] Example 8 Composition (8) was obtained by mixing 1,800 grams of lithium iron phosphate (LFP) (purchased from Wan Run Technology, product number LFP-A8-4E), 19.25 grams of graphite (product number KS6, purchased from Taiwan Wave Ltd, used as a conductive additive), 48.13 g of conductive carbon powder (product number Super-P, purchased from Taiwan Wave Ltd, used as a conductive additive), 28.9 g of polymer (3), 28.9 g of polymer (5), and 1036.61 grams of toluene (toluene) (solid content 65.00%). In composition (8), the weight ratio of KS6, Super-P, polymer (3), and polymer (5) was 1:2.5:1.5:1.5, and the ratio of the weight of lithium iron phosphate to the total weight of KS6, Super-P, polymer (3), and polymer (5) was 93.5:6.5. Next, a spray granulation process was performed on composition (8) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the resulting material was collected to obtain powdered electrode material (8). The conditions for the spray granulation process were as follows: (1) A centrifugal ceramic pin-type atomizer disc (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 120°C and 70°C, respectively. (3) The circulation fan frequency was 35Hz. (4) The atomizer frequency was 35Hz. (5) The material supply rate was 25.160 ml / min.

[0107] Here, taking electrode material (1) as an example, its morphology was evaluated as follows. The particle size distribution, tap density of the powder, and BET specific surface area (BET) of the lithium iron phosphate (i.e., active particles) used to prepare electrode material (1) were evaluated. The results are shown in Table 2. The particle size distribution was measured according to the method specified in ISO 13322-1:2004. The specific surface area was measured using a specific surface area measuring device (Micromeritics Instrument Corporation ASAP2400). The tap density of the powder was measured using a tap density measuring device according to the method specified in ISO 3953.

[0108] [Table 2]

[0109] The original lithium iron phosphate had a relatively broad overall particle size distribution. After modification, the granules with relatively small particle sizes aggregate and become spherical during the spray drying process, resulting in a decrease in their specific area. This increases the particle size, uniformity of particle size distribution, and tap density of the electrode material (1) according to this disclosure, which is advantageous for increasing the density of the active layer during the subsequent hot pressing process. Furthermore, it was shown that after modification, the specific surface area of ​​the electrode material (1) decreases, and the contour of the electrode material (1) tends to become more spherical. Furthermore, when a separate lithium nickel-cobalt-manganate ternary cathode material (NMC / Ges Technology Co.) was subjected to the surface modification and spray granulation described above, similar results to those above were obtained. Small and large structures were relatively few (for example, the proportion of structures smaller than 1 μm decreased from 0.5% to 0%, and the proportion of structures larger than 25 μm decreased from 3.5% to 1.6%), the structural size was more uniform (for example, the proportion of structures between 1 and 25 μm increased from 96.0% to 98.4%), and the powder granules tended to be more spherical. All of these factors are advantageous for increasing the density of the active layer during the subsequent hot pressing process. These results are shown in Table 2.

[0110] Next, electrode materials (1) and (8) obtained by scanning electron microscope (SEM) were observed. The results are shown in Figures 7 and 8, respectively. As can be seen from Figures 7 and 8, electrode material (1) consists of spherical granules, and the particle size distribution is relatively uniform, with no granules larger than 30 μm observed. Next, electrode material (1) obtained by focused ion beam (FIB) transmission electron microscope (TEM) was observed. The results are shown in Figure 9. As can be seen from Figure 9, the thickness of the coating layer of electrode material (1) is approximately 40 nm to 60 nm. Based on the above, the electrode material according to this disclosure consists of spherical granules and may have a core-shell structure.

[0111] Comparative Example 1 Composition (9) was obtained by mixing 1,800 grams of lithium iron phosphate (LFP) (purchased from Wan Run Technology, product number LFP-A8-4E), 19.25 g of graphite (product number KS6, purchased from Taiwan Wave Ltd, used as a conductive additive), 48.13 g of conductive carbon powder (product number Super-P, purchased from Taiwan Wave Ltd, used as a conductive additive), 57.75 g of polymer (6) (purchased from Kynar, HSV900), and 1036.61 g of N-methylpyrrolidone (NMP) (solid content 65.00%). In composition (9), the weight ratio of the conductive additive to polymer (6) was 7:6, and the ratio of the weight of lithium iron phosphate to the total weight of the ion conductive additive and polymer (6) was 93.5:6.5. Next, a spray granulation process was performed on the composition (9) using a spray drying system (model CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the resulting material was collected to obtain powdered electrode material (9). The conditions for the spray granulation process were as follows: (1) A centrifugal ceramic pin-type atomizer disc (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 1350°C and 100°C, respectively. (3) The circulation fan frequency was 40 Hz. (4) The atomizer frequency was 45 Hz. (5) The material supply rate was 10.030 ml / min.

[0112] Dry electrode film process

[0113] Example 9 Method I: Using a tabletop tablet press system (Retsch PP35, 35 tons pressure), electrode material (1) was placed in a 40 mm tablet mold set (equipped with an automatic ejection function), and the dry electrode composition powder was pressed at room temperature. The pressure was increased from 5 tons to 25 tons, and after the film was discharged, a dry electrode film was obtained (1-I). The weight (cut to an area of ​​3 cm x 3 cm), thickness, basis weight of the electrode active material, and compressive density of the electrode material of the dry electrode film (1-I) are shown in Table 3.

[0114] Method II: Electrode material (1) was placed in a modified small extruder equipped with a homogenization supply module, preheating and mixing / homogenization were performed, and quantitative feeding was carried out by a conveyor screw (the temperature (i.e., preheating temperature) of the three sections before, in the middle, and after the conveyor screw pipeline was all 90°C, the screw rotation speed was 1100 rpm, and the extrusion rate was 46.8 kg / hr). Then, after the electrode material (1) was homogenized and weighed out of the extruder, the powder material was homogenized and conveyed by a flat die head (the width can reach 145 mm), and sent to a heated roll press module system (the linear pressure control value of the rollers was 200 N / mm, and the heating temperature (i.e., roller temperature) of the two rollers was 90°C) to produce a dry electrode film (1-II). The weight (cut to an area of ​​3 cm x 3 cm), thickness, basis weight of the electrode active material, and compressed density of the electrode material of the dry electrode film are shown in Table 3.

[0115] Method II was repeated, but the process parameters were changed according to Table 3 to obtain dry electrode films (1-III).

[0116] Examples 10-16 Examples 10 to 16 were carried out based on methods I and II described in Example 9, except that electrode material (1) was replaced with electrode materials (2) to (8), and process parameters were changed according to Table 3 to obtain dry electrode films (2-I) to (8-II), respectively. The weight of the dry electrode films (2-I) to (8-II), the thickness of the electrode film, the basis weight of the electrode active material, and the compressed density of the electrode material are shown in Table 3.

[0117] Comparative Example 2 Except for replacing electrode material (1) with electrode material (9) (Comparative Example 1), Comparative Example 2 was carried out based on methods I and II described in Example 9, and process parameters were changed according to Table 3 to obtain dry electrode films (9-I) and (9-II). The weight of the dry electrode films (9-I) and (9-II), the thickness of the electrode film, the basis weight of the electrode active material, and the compressed density of the electrode material are as shown in Table 3.

[0118] Comparative Example 3 The method for producing a wet process positive electrode plate is as follows: Lithium iron phosphate active material, super P conductive additive, KS-6 conductive additive, and an appropriate amount of solvent, such as N-methylpyrrolidone (NMP), were stirred and mixed for 3 hours. Then, an NMP solution containing PVDF-HSV900 binder (containing 10 wt% PVDF) was added, and the mixture was stirred and mixed for another 3 hours to obtain a lithium iron phosphate positive electrode slurry with a solid content of 65 wt%. The solid composition was lithium iron phosphate active material (93.5 wt%), PVDF-HSV900 binder (3 wt%), super P conductive additive (2.5 wt%), and KS-6 conductive additive (1 wt%). The positive electrode slurry was applied to a current collector (e.g., aluminum metal foil), heated to 150°C to dry the applied layer, and then rolled to form a 100 micrometer thick positive electrode active layer on the metal foil, obtaining an electrode film (10).

[0119] Electrode film (10) was transported and fed into a hot roll press module system (with a controlled linear pressure of 200 N / mm for the rollers and a heating temperature of 90°C for the two rollers) to produce electrode film (11). The weight (cut to a 3cm x 3cm area), thickness, basis weight of electrode active material, and compressed density of electrode material were measured for both electrode film (10) and electrode film (11). The results are shown in Table 3.

[0120] [Table 3-1] [Table 3-2]

[0121] As can be seen from Table 3, in typical wet processes, it is necessary to evaporate the NMP solvent as much as possible to remove any residue. Therefore, the basis weight of lithium iron phosphate active material in the electrode film is usually 15-25 mg / cm³. 2 In that case, 25 mg / cm³ 2It is almost impossible to exceed this limit, and therefore it is not easy to significantly increase the capacity. If the basis weight of the active material becomes excessively large, the thickness of the electrode film increases, making it difficult for the solvent to completely evaporate and dry, resulting in residue. Moreover, the excess amount of solvent destabilizes the negative electrode material structure, adversely affecting subsequent electrode and battery performance, particularly reducing capacity and cycle life. Furthermore, as the solvent evaporates upward, the binder often becomes distributed in a gradient layer within the electrode structure, which can also affect the structural stability, adhesive strength, and cycle performance of the electrode film. In addition, the structure of the electrode film obtained through the coating and heat drying process is relatively soft and sparse, and does not have very good adhesive properties. Therefore, it is necessary to compress it densely using high roll press pressure to increase the compressive density and adhesive strength of the electrode film structure. However, excessively high roll press pressure causes the electrode active material (which has relatively high hardness) to be embedded more deeply into the relatively soft aluminum foil structure, leading to strain-induced tearing or cracking of the aluminum foil, and ultimately causing structural fracture or breakage of the electrode film. Therefore, the compressed density of lithium iron phosphate electrode film is typically 2.3 to 2.5 g / cm³. 3 It is controlled to 2.5 g / cm³. 3It is rare for it to exceed this value. Using the electrode material composition of this disclosure, dry electrode films and dry electrodes can be directly manufactured by hot roll pressing, eliminating the need for wet coating and heat drying. This significantly reduces the need for solvent use and VOC emissions in the manufacturing process, and provides an eco-friendly production model. As shown in the test and measurement results of the basis weight of the active material and the compressed density of the electrode film obtained by manufacturing dry electrode films using Method I or Method II from the electrode compositions in each example in Table 3, the dry electrode composition of this disclosure possesses structural toughness and elasticity, as well as adhesive properties, and can withstand high roll pressing forces and high shear forces. Therefore, when the film thickness needs to be increased (e.g., 150 μm or more), the resulting dry electrode film is hard and relatively less likely to break or fold. Thus, the electrode film manufactured according to this disclosure has an active material basis weight of 30 mg / cm². 2 (and consequently 45 mg / cm³) 2 It can be adjusted to a value exceeding 2.2 g / cm³, and the initial compression density before laminating the electrode film with aluminum foil and performing roll pressing is 2.2 g / cm³. 3 (and therefore 2.4 g / cm³) 3 It can be adjusted to a value exceeding [a certain value]. A high initial compressive density of the electrode film can enhance structural stability and reduce expansion deformation, which can further improve the weather resistance and manufacturing processability of the electrode film.

[0122] Single-sided dry electrode The aforementioned electrode films (1-II), (2-II), (3-II), (4-II), (5-II), (6-II), (7-II), (8-II), (9-II), and electrode film (11) were further laminated to an aluminum foil substrate (purchased from BLUEGLOWNANO, 12 μm thick) using a roll press machine (purchased from Tokyo, model: ONO 2RM-350DRR), and the films were compressed, with a roll press pressure of 0-30 kgf / cm². 2The pressure and roll press speed (1 m / min) were adjusted to obtain (9) and electrode (10) from the roll-pressed single-sided dry electrode (1). The compression densities of the corresponding electrodes are shown in Table 4.

[0123] Peel strength The peel strength between the current collector layer and the active layer of dry electrodes (1) to (9) and electrode (10) was measured. The results are shown in Table 4. The peel strength was measured using a universal tensile testing machine (purchased from SHIMADZU, model: AG-X PLIS), referencing the 180-degree peel strength test specified in ASTM D903-98. The roll-pressed single-sided dry electrode pieces described above were cut into 120 mm x 25 mm rectangular strips to obtain the test electrode samples. An 18mm x 35mm insulating tape was applied to the upper edge of the stainless steel plate, and a 30mm x 100mm double-sided tape was applied to one side of the stainless steel plate with the insulating tape and to the front surface of the single-sided dry electrode piece composite layer on the other side. The backing paper of the double-sided tape was cut into a 30mm x 30mm rectangular strip and applied to the underside of the electrode piece, and a rectangular strip of 30mm x 50mm double-sided tape backing paper was applied to the upper surface of the electrode piece. Using a 2kg rubber roller, the roller press was passed back and forth twice on the electrode piece covered with backing paper. The free end of the electrode piece was fixed to the upper grip of the tensioning machine, and the bottom edge of the stainless steel plate was fixed to the lower grip of the tensioning machine. The parameters of the tensile force measuring device were set to a peel length of 40mm and a width of 18mm, and the tensioning device was started to perform a 180° peel test at a peeling speed of 50mm / min, obtaining the peel strength shown in Table 4.

[0124] [Table 4]

[0125] Electrode films with relatively high compressive density have numerous advantages and benefits, particularly in battery technology, including increased energy density, improved conductivity (reduced internal resistance), enhanced battery charge / discharge performance, increased structural stability, longer cycle life, reduced battery expansion and deformation (improved safety), and improved thermal conductivity (improved thermal management performance). As can be seen from Table 4, dry electrodes (1) to (8) in the examples all have a compressive density of 2.35 g / cm³. 3 It exceeds (and consequently 2.50 g / cm³) 3 (Having reached the above level), it has more advantages and benefits compared to wet process electrodes.

[0126] Electrode peel strength is one of the important indicators for evaluating the stability and reliability of a battery during its use, and it reflects the adhesion between the electrode composition material and the metal foil. Insufficient peel strength can cause problems such as electrode detachment and interruption of current transmission during battery use. Higher peel strength can guarantee performance in terms of battery performance, cycle life, and safety. As can be seen from Table 4, when the compressed density of the electrodes is similar (e.g., 2.3-2.4 g / cm³), 3 The peel strength of dry electrodes is higher than that of wet-process electrodes, and the peel strength of the electrode increases as the compressive density of the electrode increases.

[0127] Evaluation of electrode performance using half-cells

[0128] Example 17 Electrode (4) was prepared as the positive electrode plate, a polypropylene separator (product number 2320, purchased from Celgard, thickness approximately 20 μm) was prepared, an electrolyte for lithium iron phosphate batteries (purchased from Taiwan Plastics Industry Co., Ltd., model number: LE) was prepared, and lithium metal was used as the negative electrode plate.

[0129] Next, the negative electrode plate / separator / positive electrode plate were arranged in that order (so that the active layer of the positive electrode faces the separator), and electrolyte (purchased from Taiwan Plastics Industry Co., Ltd., product number FPC-401) was injected between the positive and negative electrode plates so that the separator was positioned in the electrolyte. The assembly was then made into a CR2032 button cell (size: 3.2 mm (thickness) x 20 mm (width) x 20 mm (length)) to obtain button cell (1). After standing for one day to allow the electrolyte to diffuse and permeate the positive and negative electrode plates, button cell (1) was placed in the test module of a button cell charge / discharge device (MACCOR SERIER4000), charged to 3.75 V with a current of 0.1 C, and discharged to 2.5 V with a current of 0.1 C (cut-off = 0.01 C). The chemical conversion process was completed by repeating the charge-discharge cycle three times, and the electrical characteristics of the button-type battery (1) were measured and recorded. The results are shown in Table 5.

[0130] Example 18 Electrode (7) was prepared as the positive electrode plate, a polypropylene separator (product number 2320, purchased from Celgard, thickness approximately 20 μm) was prepared, an electrolyte for lithium iron phosphate batteries (purchased from Taiwan Plastics Industry Co., Ltd., model number: LE) was prepared, and lithium metal was used as the negative electrode plate.

[0131] Next, the negative electrode plate / separator / positive electrode plate were arranged in that order (so that the active layer of the positive electrode faces the separator), and the electrolyte (purchased from Taiwan Plastics Industry Co., Ltd., lithium iron phosphate electrolyte, product number FPC-401) was injected between the positive and negative electrode plates so that the separator was positioned in the electrolyte. The CR2032 button cell was then assembled (size: 3.2 mm (thickness) x 20 mm (width) x 20 mm (length)) to obtain button cell (2). After standing for one day to allow the electrolyte to diffuse and permeate the positive and negative electrode plates, button cell (2) was placed in the test module of a button cell charge / discharge device (MACCOR SERIER4000), charged to 3.75 V with a current of 0.1 C, and discharged to 2.5 V with a current of 0.1 C (cut-off = 0.01 C). The chemical conversion process was completed by repeating the charge-discharge cycle three times, and the electrical characteristics of the button-type battery (2) were measured and recorded. The results are shown in Table 5.

[0132] Comparative Example 4 Electrode (9) was prepared as the positive electrode plate, a polypropylene separator (product number 2320, purchased from Celgard, thickness approximately 20 μm) was prepared, an electrolyte for lithium iron phosphate batteries (purchased from Taiwan Plastics Industry Co., Ltd., model number: LE) was prepared, and lithium metal was used as the negative electrode plate.

[0133] Next, the negative electrode plate / separator / positive electrode plate were arranged in that order (so that the active layer of the positive electrode faces the separator), and electrolyte (purchased from Taiwan Plastics Industry Co., Ltd., product number FPC-401) was injected between the positive and negative electrode plates so that the separator was positioned in the electrolyte. The assembly was then made into a CR2032 button cell (size: 3.2 mm (thickness) x 20 mm (width) x 20 mm (length)) to obtain button cell (3). After standing for one day to allow the electrolyte to diffuse and permeate the positive and negative electrode plates, button cell (3) was placed in the test module of a button cell charge / discharge device (MACCOR SERIER4000), charged to 3.75 V with a current of 0.1 C, and discharged to 2.5 V with a current of 0.1 C (cut-off = 0.01 C). The chemical conversion process was completed by repeating the charge-discharge cycle three times, and the electrical characteristics of the button-type battery (3) were measured and recorded. The results are shown in Table 5.

[0134] Comparative Example 5 Electrode (10) was prepared as the positive electrode plate, a polypropylene separator (product number 2320, purchased from Celgard, thickness approximately 20 μm) was prepared, an electrolyte for lithium iron phosphate batteries (purchased from Taiwan Plastics Industry Co., Ltd., model number: LE) was prepared, and lithium metal was used as the negative electrode plate.

[0135] Next, the negative electrode plate / separator / positive electrode plate were arranged in that order (so that the active layer of the positive electrode faces the separator), and electrolyte (purchased from Taiwan Plastics Industry Co., Ltd., product number FPC-401) was injected between the positive and negative electrode plates so that the separator was positioned in the electrolyte. The assembly was then made into a CR2032 button cell (size: 3.2 mm (thickness) x 20 mm (width) x 20 mm (length)) to obtain button cell (4). After standing for one day to allow the electrolyte to diffuse and permeate the positive and negative electrode plates, button cell (4) was placed in the test module of a button cell charger / discharger (MACCOR SERIER4000), charged to 3.75 V with a current of 0.1 C, and discharged to 2.5 V with a current of 0.1 C (cut-off = 0.01 C). The chemical conversion process was completed by repeating the charge-discharge cycle three times, and the electrical characteristics of the button-type battery (4) were measured and recorded. The results are shown in Table 5.

[0136] [Table 5-1] [Table 5-2]

[0137] As can be seen from Table 5, the half-cells fabricated from the dry electrodes according to this disclosure have a post-formation resistance of only about 7-9 Ω, which is lower than batteries containing electrodes formed using a wet process (resistance of about 21-23 Ω). This improves energy efficiency, enhances battery performance, extends battery life, increases stability and safety, and improves discharge stability.

[0138] In summary, according to the electrode material having a specific structure and composition according to the present disclosure, the electrode material according to the present disclosure can be formed as an active layer on the surface of a current collector layer at a relatively low operating temperature by utilizing an electrode process (e.g., a dry electrode process). Therefore, the formed active layer not only has more desirable mechanical strength and good adhesion, but the mass loading, compacted density, and stability of the active layer of the resulting electrode can be increased, thereby improving the charge / discharge capacity and energy density of the battery, significantly reducing internal resistance, increasing energy efficiency, improving battery performance, extending battery life, enhancing stability and safety, and increasing discharge stability.

[0139] It will be apparent that various modifications and changes can be made to the methods and materials of this disclosure. This specification and embodiments are intended to be illustrative only, and the true scope of this disclosure is shown by the following claims and equivalents. [Explanation of Symbols]

[0140] 10...Electrode material 12…Active particles 14…Covering layer 200...electrode 202...Collector layer 204...First active layer 206...Second active layer 300...battery 302...Positive electrode 304... Separator 306...Negative electrode 308...Electrolyte

Claims

1. Electrode material, Active particles and A coating layer that partially or completely covers the surface of the active particles, Includes, The aforementioned coating layer 5 to 70 parts by weight of conductive additive, The first polymer is contained in 30 to 95 parts by weight, An electrode material wherein the total weight of the first polymer and the conductive additive is 100 parts by weight, the first polymer is a product obtained by polymerizing a compound having two acrylate groups with an ethylene / vinyl acetate copolymer, and the compound having two acrylate groups has the structure shown in formula (I). 【Chemistry 1】 (In the formula, A １ is a single bond, oxygen, 【Chemistry 2】 Alternatively, -CH=CH-, and each R １ Each is independently either a hydrogen atom or a methyl group, and each R ２ Each is independently either a hydrogen atom or a methyl group, and each R ３ Each of these is independently a hydrogen atom, a methyl group, or an ethyl group.

2. The electrode material according to claim 1, wherein the weight ratio of the compound having the two acrylate groups to the ethylene / vinyl acetate copolymer is 1:99 to 99:

1.

3. The ethylene / vinyl acetate copolymer has repeating units represented by formula (II) and repeating units represented by formula (III), 【Transformation 3】 The electrode material according to claim 1, wherein the ratio of the number of repeating units represented by formula (II) to the number of repeating units represented by formula (III) is from 1:1250 to 300:

1.

4. The aforementioned coating layer The electrode material according to claim 1, further comprising 0.1 to 30 parts by weight of a second polymer, wherein the second polymer is polyamide, polyimide, polymaleimide, polybismaleimide, polyacrylate, polyacrylic acid, polyvinyl alcohol, sodium carboxymethylcellulose, polystyrene, polystyrene-butadiene copolymer, polyurethane, polyvinylpyrrolidone, polyvinyl chloride, polyacrylonitrile, polybutadiene, or a combination thereof.

5. The electrode material according to claim 1, wherein the weight ratio of the coating layer to the active particles is 3:97 to 10:

90.

6. The electrode material according to claim 1, wherein the electrode material has a core-shell structure composed of a core and a shell layer covering the core, the core being the active particle and the shell layer being the coating layer.

7. An electrode, Current collector layer, The active layer disposed in the current collector layer, Includes, An electrode comprising the electrode material described in claim 1 for the active layer.

8. It is a battery, Positive electrode and, Separator and, The negative electrode and, Includes, A battery in which the negative electrode is separated from the positive electrode by the separator, and at least one of the positive electrode and the negative electrode is the electrode described in claim 7.

9. A method for producing an electrode material, which is used to produce the electrode material described in claim 1, A step of preparing a composition comprising the active particles, the conductive additive, and the first polymer, The steps include: obtaining the electrode material by performing a spray granulation step or a melt kneading step on the composition; A method for preparing electrode materials containing [specific material].

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