Electrode material, electrode, battery, and method for forming the 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] The present disclosure relates to an electrode material, an electrode, a battery, and a method of forming an electrode material.

Background Art

[0002] Lithium batteries have already become the mainstream of commercial batteries, and efforts are being made in the direction of making them lighter, thinner, shorter, smaller, increasing the energy density, extending the lifespan, and making them safer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One of the key steps in lithium battery manufacturing is the formation of the electrode. Conventional electrode formation steps include the steps of preparing an electrode slurry, applying the electrode, drying, and pressing. In the step of preparing the electrode slurry, an electrode active material, a binder (used to bind the powdered granular electrode active materials together and to fix them to the current collector), and a solvent (used to disperse the powdered granular electrode activity and to bring the binder into sufficient contact with the powdered granular) are mixed to prepare a fluid electrode slurry. Once the preparation of the electrode slurry is complete, the electrode slurry is applied to the current collector, the solvent contained in the electrode slurry is removed, and the coating layer is pressed to a predetermined thickness. However, when removing the solvent in the electrode slurry by a drying step, defects such as pinholes or cracks may occur in the previously formed electrode active layer. Also, since the evaporation rates of the solvents are different, a difference in the degree of drying inside and outside the coating layer formed from the electrode slurry may result in the formation of gaps in 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, a dry electrode process technology that does not use any solvents has 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 pressing process. However, when using a fluorine-based binder, it is necessary to perform a high-torque fibrillation treatment in advance. In addition, 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, and the electrode material includes active particles and a coating layer. The coating layer partially or completely covers the surface of the active particles. The coating layer may include 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 1 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, the composition including 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] The present disclosure is applicable to an electrode process (e.g., a dry electrode process) and provides an electrode material used for an electrode of a battery, such as a positive electrode or a negative electrode of a lithium battery. The electrode material according to the present disclosure includes active particles and a coating layer that partially or completely covers the surface of the active particles. The coating layer includes a first polymer and a conductive additive. Note that since the first polymer has appropriate rheological properties, adhesiveness, and a melting point, the conductive additive is uniformly dispersed in the coating layer by a spray granulation process or a melt-kneading process, and the coating layer covers and adheres to the surface of the active particles, so that the electrode material according to the present disclosure can be obtained. It should be noted that due to the specific composition and structure of the electrode material according to the present disclosure, there is a premise that the electrode material according to the present disclosure is not prepared as an electrode slurry (that is, it is not necessary to disperse the electrode material according to the present disclosure in a solvent and further add a binder to mix with the electrode material according to the present disclosure). Therefore, an active layer made of the electrode material can be formed on the surface of the current collector layer by using a dry process (e.g., a hot pressing process) at a relatively low operating temperature (less than 200 °C, and thus less than 150 °C). Thereby, the formed active layer has better mechanical strength and good adhesiveness (adhesiveness between the active layer and the current collector layer), and in addition, the mass loading, compacted density, and stability of the active layer of the obtained electrode are also increased (that is, problems such as non-uniform distribution and poor adhesion caused by the wet electrode process are overcome). Therefore, the capacity and energy density of the battery are increased, and the life cycle, charge / discharge performance, and C-rate discharge ability at high temperature / high voltage operation are improved.

[0013] The present disclosure can be more fully understood by reading the following detailed description and embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0015] An electrode material, an electrode, a battery, a method of forming an electrode material, and a method of manufacturing the same will be described in the following detailed description. In the following detailed description, numerous specific details and embodiments are set forth for purposes of explanation so that the present disclosure may be thoroughly understood. The specific elements and configurations described in the following detailed description are presented for the purpose of clarifying the present disclosure. However, it is clear that the exemplary embodiments shown herein are for illustrative purposes only and that the inventive concept may be embodied in various forms without being limited to these exemplary embodiments. In addition, for purposes of clarity in the present disclosure, like numbers and / or corresponding numbers may be used in the figures of different embodiments to indicate like elements and / or corresponding elements. However, the use of like and / or corresponding numbers in the figures of different embodiments does not imply any correlation between different embodiments. As used herein, the term "about" means plus or minus by an amount that is common and reasonable to one of ordinary skill in the art.

[0016] Furthermore, the use of ordinal numbers such as "first," "second," "third," etc. to modify elements in the present disclosure does not by itself indicate any priority, precedence, or temporal order of formation of one claim element over another claim element, but is merely used as a label to distinguish one claim element having a certain name from another claim element having the same name (except for the use of the ordinal number), and is only used to distinguish between claim elements.

[0017] It should be noted that the elements or devices in the figures of the present disclosure may exist in any form or configuration known to those of ordinary skill in the art. Also, the expressions "a layer overlapping another layer," "a layer is disposed above another layer," "a layer is disposed on top of another layer," and "a layer is disposed over another layer" may refer to a layer in direct contact with another layer or may refer to a layer not in direct contact, in which case one or more intermediate layers are disposed between the layer and the other layer.

[0018] The present disclosure provides an electrode material used to form a battery (e.g., a lithium-ion battery) or an electrode (e.g., a negative electrode or a positive electrode) used in a lithium secondary electrode. Refer to FIG. 1. It is a cross-sectional view of the electrode material according to an embodiment of the present disclosure. The electrode material 10 may include active particles 12 and a cladding layer 14. According to an embodiment of the present disclosure, as shown in FIG. 1, the cladding layer 14 is disposed on the surface of the active particles 12 and may cover the entire surface of the active particles. In other words, the electrode material 10 has a core-shell structure and is composed of a core and a shell layer that wraps the core. The core is the active particles 12, and the shell layer is the cladding layer 14.

[0019] According to an embodiment of the present disclosure, the particle size of the active particles 12 (e.g., the maximum distance between any two points on the surface of the active particles) may be from about 50 nm to 100 μm, such as about 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 an embodiment of the present disclosure, the active particles may have a circular, oval, polygonal, or cross-section close to circular shape. According to an embodiment of the present disclosure, the thickness of the cladding layer 14 (e.g., the average thickness, or the shortest distance from the outer surface of the cladding layer 14 to the surface of the active particles 12) may be from 10 nm to 5 μm, such as 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 cladding layer can be measured using an electron microscope.

[0020] According to an embodiment of the present disclosure, the electrode material according to the present disclosure is provided with a functional coating layer on the surface of active particles (as a protective layer and a conductive layer), and is formed by a spray granulation process or a melt kneading process. Therefore, the volume swelling of the electrode produced using the electrode material can be reduced, the water absorption can be lowered, the stability can be enhanced, the elution of the metal component (such as manganese, iron or nickel) of the active particles can be suppressed, and the ion conduction / electron conduction performance can be improved.

[0021] According to an embodiment of the present disclosure, as shown in FIG. 2, the cladding layer 14 may be disposed on the surface of the active particles 12 so as to partially or completely cover the surface of the active particles. Here, when the cladding layer 14 partially covers the surface of the active particles, it 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 an embodiment of the present disclosure, the weight ratio of the coating layer to the active particles may be from about 3:97 to 10:90, for example, 4:96, 5:95, 6:94, 7:93, 8:92, 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 will be excessively small, or the variation in the thickness of the coating layer will be excessively large, and the structural toughness, stability and adhesiveness of the electrode material, as well as the electrical performance of the electrode formed subsequently, are likely to deteriorate. If the weight ratio of the coating layer to the active particles is excessively high, both the mass loading and the compacted density of the active layer will decrease, and at the same time, the resistance of the electrode formed subsequently is likely to increase, and the electrical characteristics, capacity, and energy density are likely to deteriorate.

[0023] According to an embodiment of the present disclosure, the electrode material may include at least one coating layer according to the present disclosure. For example, the electrode material is composed of active particles, a first coating layer, and a second coating layer, the first coating layer covers the active particles, and the second coating layer covers the first coating layer. The components and compositions of the materials of the first coating layer and the second coating layer may be the same or different. According to some embodiments, the electrode material may further include other coating layers, and the other coating layers are, for example, electrolyte-containing materials.

[0024] According to an embodiment of the present disclosure, the active particles may be a positive electrode active material or a negative electrode active material, and may be selected based on the electrical characteristics of the electrode to be formed. In other words, the electrode material according to the present disclosure may be a positive electrode active material or a negative electrode active material.

[0025] According to an embodiment of the present disclosure, when the active particles are a cathode active material, the active particles may be sulfur, an organic sulfide, a sulfur-carbon composite, a metal-containing lithium oxide, a metal-containing lithium sulfide, a metal-containing lithium selenide, a metal-containing lithium telluride, a metal-containing lithium silicide, a metal-containing lithium boride, a metal-containing lithium phosphate, or a combination of the above, and 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 may be 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), lithium manganese iron phosphate (LMFP), or a combination of the above.

[0026] According to embodiments of the present disclosure, when the active particles are anode active materials, the active particles may be silicon, silicon-carbon, silicon-containing oxide, titanium-containing oxide, tin, tin-containing compounds, silicon alloys, carbon materials, lithium, lithium alloys, metal-containing lithium carbide, metal-containing lithium nitride, or a combination of the above, and 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 materials 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 of the above. 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 of the above. According to embodiments of the present disclosure, the silicon-containing oxide may be, for example, silicon oxycarbide.According to an embodiment of the present disclosure, the lithium alloy or metal-containing lithium nitride may be an aluminum-containing lithium alloy, a magnesium-containing lithium alloy, a zinc-containing lithium alloy, a bismuth-containing lithium alloy, a cadmium-containing lithium alloy, an antimony-containing lithium alloy, a silicon-containing lithium alloy, a lead-containing lithium alloy, a tin-containing lithium alloy, a lithium iron nitride, a lithium cobalt nitride, or a lithium copper nitride.

[0027] According to an embodiment of the present disclosure, the coating layer may contain 5 to 70 parts by weight (for example, 8 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, or 65 parts by weight) of a conductive additive and 30 to 95 parts by weight (for example, 32 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, or 90 parts by weight) of a first polymer. Here, the total weight of the first polymer and the conductive additive is 100 parts by weight. If the addition amount of the first polymer is excessively low, the structural toughness, stability, adhesiveness of the electrode material, and the electrode free-standing are likely to decrease. If the addition amount of the first polymer is excessively high, the mass loading, compacted density, electrical characteristics, capacity, and energy density of the active layer of the electrode formed subsequently are likely to decrease.

[0028] According to an embodiment of the present disclosure, the conductive additive is uniformly dispersed in the first polymer. According to an embodiment of the present disclosure, the conductive additive may be a conductive additive, an ion conductive additive, or a combination of the above. For example, the conductive additive may be a combination of a conductive additive and an ion conductive additive. In the present disclosure, the conductive additive refers to an additive having conductivity. The conductive additive according to the present disclosure may also have ion conductivity at the same time. Even when its conductivity is superior to the ion conductivity (or when a person having ordinary knowledge in the technical field tends to recognize the material as a conductive material), in the present disclosure, it is referred to as a conductive additive. Further, in the present disclosure, the ion conductive additive refers to an additive having ion conductivity. The ion conductive additive according to the present disclosure may also have conductivity at the same time. Even when its ion conductivity is superior to the conductivity (or when a person having ordinary knowledge in the technical field tends to recognize the material as an ion conductive material), in the present disclosure, it is referred to as an ion conductive additive.

[0029] According to an embodiment of the present disclosure, the conductive additive may be a conductive polymer material, a conductive inorganic material, or a combination of the above. According to an embodiment of the present disclosure, the conductivity of the conductive additive may be 10 S / cm or more (for example, 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 an embodiment of the present disclosure, the conductive polymer material may be polyacetylene, polydiacetylene, polyaniline, polypyrrole, polythiophene, or a combination of the above. There is no particular limitation on the weight average molecular weight of the conductive polymer material according to the present disclosure, and those having ordinary knowledge in the art can adjust it according to actual needs. According to an embodiment of the present disclosure, the weight average molecular weight (Mw) of the conductive polymer material is 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 conductive polymer material can be measured by gel permeation chromatography (using polystyrene as a standard to create a calibration curve).

[0030] According to an embodiment 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 an embodiment of the present disclosure, the conductive inorganic material may be granular. According to an embodiment 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, for example, 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 an embodiment of the present disclosure, the particle size distribution D90 is measured according to the method defined in ISO13322-1:2004.

[0031] According to an embodiment of the present disclosure, the ionic conductivity of the ionic conduction additive is 1×10 -6 S / cm to 9×10 -3 S / cm (for example, 2×10 -6 S / cm, 5×10 -6 S / cm, 8×10 -6 S / cm, 1×10 -5 S / cm, 2×10 -5 S / cm, 5×10 -5 S / cm, 8×10 -5 S / cm, 1×10 -4 S / cm, 2×10 -4 S / cm, 5×10 -4 S / cm, 8×10 -4 S / cm, 1×10 -3 S / cm, 2×10 -3 S / cm, 5×10-3 S / cm, or 8×10 -3 S / cm). According to an embodiment of the present disclosure, the ionic conduction 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 an embodiment of the present disclosure, the hyperbranched polymer according to the present disclosure may be a nitrogen-containing hyperbranched polymer. The hyperbranched polymer may be formed by polymerizing an imide compound. Further, according to an embodiment of the present disclosure, the hyperbranched polymer may be formed by copolymerizing an imide compound and barbituric acid. The imide compound may be bismaleimide (e.g., N,N'-bismaleimide-4,4'-diphenylmethane), maleimide (e.g., phenylmethane maleimide), 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 maleimide oligomer and barbituric acid. According to an embodiment of the present disclosure, reference may be made to Taiwan Patent No. I722747 for the hyperbranched polymer and its preparation method. According to an embodiment of the present disclosure, the lithium-ion-containing polythiophene polymer may have a repeating unit of any of the following structures.

[0033] [Chemistry]

[0034] In the formula, R ais a C6-C30 alkyl group. According to an embodiment of the present disclosure, reference can be made to Taiwan Patent No. I724715 regarding the lithium ion-containing polythiophene polymer and its preparation. According to an embodiment of the present disclosure, a polymer having a lithium sulfonate group may be 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), poly(lithium adipate), acrylonitrile / butadiene / lithium acrylate copolymer, tertbutyl acrylate / ethyl acrylate / lithium methacrylate copolymer, ethylene / lithium acrylate copolymer, and methyl methacrylate / lithium methacrylate copolymer, or a combination of the above.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 of the above. Regarding the polymer having an organosilicon group and its preparation according to embodiments of the present disclosure, reference can be made to Taiwan Patent No. I445739.

[0035] There is no particular limitation on the weight-average molecular weight of the ion-conductive polymer according to the present disclosure (i.e., hyperbranched polymer, ethyl cellulose resin, lithium ion-containing polythiophene polymer, polymer having a lithium sulfonate group, or polymer having an organosilicon group). Those with ordinary knowledge in the art can adjust it according to actual needs while maintaining the ionic conductivity. According to embodiments of the present disclosure, the weight-average molecular weight (Mw) of the ion-conductive polymer is 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 ion-conductive polymer material can be measured by gel permeation chromatography (GPC) (using polystyrene as a standard to create a calibration curve).

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

[0037] According to an embodiment 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 (for example, 0.5 part 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 the spray granulation process or the melt-kneading process. Therefore, 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 an embodiment of the present disclosure, by adding the second polymer, the mechanical strength, corrosion resistance to the electrolyte, wettability and permeability to the electrolyte, electrochemical stability, safety protection, and adhesiveness of the coating layer can be adjusted. According to an embodiment of the present disclosure, the first polymer and the second polymer are different.

[0038] According to an embodiment of the present disclosure, the weight average molecular weight of the first polymer may be from about 12,000 g / mol to 10,000,000 g / mol, such as about 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), 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), 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 an embodiment 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 an embodiment of the present disclosure, the first polymer is a product obtained by polymerizing a composition, and the composition includes a compound having two acrylate groups and the ethylene / vinyl acetate copolymer. According to an embodiment of the present disclosure, in addition to the compound having two acrylate groups and the ethylene / vinyl acetate copolymer, the composition may include a solvent, a reaction initiator, or a catalyst. According to some embodiments of the present disclosure, the components capable of proceeding with the polymerization reaction in the composition are only the compound having 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. 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 an embodiment of the present disclosure, when the composition has the solvent, the solid content of the composition may be from 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 solid 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 an embodiment of the present disclosure, the composition consists of a compound having two acrylate groups, the ethylene / vinyl acetate copolymer, a solvent, and a reaction initiator.

[0041] According to an embodiment of the present disclosure, the composition used to prepare the first polymer may further include a reaction monomer or a third polymer in addition to the compound having two acrylate groups and the ethylene / vinyl acetate copolymer, and the reaction monomer or the third polymer can react with the compound having two acrylate groups and / or the ethylene / vinyl acetate. In other words, the components capable of undergoing a polymerization reaction in the composition may be the compound having two acrylate groups, the ethylene / vinyl acetate copolymer, and the reaction monomer (or third polymer). According to an embodiment of the present disclosure, by adding the reaction monomer and / or third polymer, the structural toughness, adhesiveness, rheological properties, electrochemical stability, and processability of the resulting first polymer can be adjusted.

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

[0043]

Chemical formula

[0044] In the formula, A 1 may be a single bond, oxygen,

Chemical formula

[0045] According to an embodiment of the present disclosure, the compound having two acrylate groups may be any of the following.

[0046]

Chemical formula

Chem.

[0047] In the formula, R 1 、R 2 、and R 3 are defined in the same manner as described above.

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

[0049]

Chem.

[0050] The ratio of the number of the repeating unit represented by the formula (II) and the repeating unit represented by the 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 an embodiment of the present disclosure, the first repeating unit and the second repeating unit of the ethylene / vinyl acetate copolymer may repeat in a random form or a block form.

[0051] According to an embodiment of the present disclosure, the ethylene / vinyl acetate copolymer has n repeating units represented by the formula (II) and m repeating units represented by the formula (III), where n may be from 300 to 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, 90,000, 100,000, 150,000, 200,000, or 250,000), and m may be from 1,000 to 250,000 (e.g., 1500, 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 an embodiment of the present disclosure, the weight average molecular weight of the ethylene / vinyl acetate copolymer is from about 90,000 g / mol to 30,000,000 g / mol, such as about 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), 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) (using polystyrene as a standard to create a calibration curve). According to an embodiment of the present disclosure, during the copolymerization reaction process, the ethylene / vinyl acetate copolymer first dissociates into substances with relatively small molecular weights having reactivity.

[0053] According to an embodiment of the present disclosure, the melt index (MI) of the ethylene / vinyl acetate copolymer is from about 1 g / 10 min to 2,000 g / 10 min, for example, about 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. The higher the melt index, the better the fluidity, and it becomes easier to perform omnidirectional coating during the coating process. However, it becomes difficult to form a fibrillated structural morphology. Also, the lower the melt index, the lower the fluidity, and omnidirectional coating cannot be performed. However, under the action of shear force, a fibrillated structural morphology is relatively likely to occur. When the melt index of the ethylene / vinyl acetate copolymer is within the specific range described above, an electrode material with many merits such as the effect of omnidirectional coating, high adhesiveness, high structural toughness, and no use of a binder can be obtained. Also, the contact between the active particles and the conductive additive becomes closer, contributing to the improvement of the electrical properties of the electrode material. Therefore, lithium ions can be inserted and extracted more smoothly on the surface of the active material, the battery capacity increases, and the discharge rate performance improves. According to an embodiment of the present disclosure, the melt index of the ethylene / vinyl acetate copolymer is measured at about 190 °C under a load of about 2.16 kg by the method defined in ASTM D1238.

[0054] According to an embodiment of the present disclosure, the weight ratio of the compound having two acrylate groups to the ethylene / vinyl acetate copolymer is from 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 homopolymer of the compound having two acrylate groups is used instead of the first polymer to prepare the electrode material, the overall structure of the obtained electrode material becomes overly hard and brittle (i.e., insufficient flexibility and viscoelasticity), the electrochemical stability performance becomes lower, and cracks occur, making the structure of the electrical material easily collapse (when the processing temperature is overly high). Also, when the ethylene / vinyl acetate copolymer is used instead of the first polymer to prepare the electrode material, the structure of the obtained electrode material becomes overly soft and sparse, resulting in insufficient strength, being prone to deformation and aging, having lower heat resistance stability performance, and having an overly high processing temperature, and releasing 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 of the foregoing. According to embodiments of the present disclosure, the weight average molecular weight of the second polymer may be from about 2,000 g / mol to 3,000,000 g / mol, such as 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), 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 (using polystyrene as a standard to create a calibration curve).

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

[0057] According to an embodiment of the present disclosure, the third polymer may be polyacrylate, poly(acrylic acid), polyvinyl alcohol, sodium carboxymethyl cellulose, ethyl cellulose, polystyrene, styrene-butadiene rubber, polybutadiene, or a combination of the above. According to an embodiment of the present disclosure, the weight average molecular weight of the third polymer may be 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), 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 (using polystyrene as a standard to create a calibration curve).

[0058] According to an embodiment 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 a catalyst are added as necessary to obtain a composition. Then, the above composition is heated to react the compound having two acrylate groups with 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 necessary to obtain a composition. Then, the above composition is heated to react the compound having two acrylate groups with the ethylene / vinyl acetate copolymer to form the first polymer.

[0060] According to an embodiment of the present disclosure, referring to FIG. 3, the method 100 for manufacturing an electrode material according to the present disclosure may include the following steps. First, a composition used to manufacture the electrode material is prepared, and the composition includes the active particles, the conductive additive, and the first polymer (step 102). Next, a spray granulation process or a melt kneading process is performed on the composition to obtain the electrode material (step 104). According to an embodiment of the present disclosure, in the composition, the weight ratio of the conductive additive to the first polymer is from 5:95 to 70:30, for example 10:90, 20:80, 30:70, 40:60, 50:50, or 60:40. According to an embodiment of the present disclosure, the weight ratio of the total weight of the conductive additive and the first polymer to the active particles is from 4:96 to 10:90, for example from 5:95 to 70:30, for example 5:95, 6:94, 7:93, 8:92, or 9:91. Further, the composition further includes 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 an embodiment of the present disclosure, since the electrode material is formed from the composition used to manufacture the electrode material, 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 (or the total weight of the conductive additive, the first polymer, and the second polymer) to the active particles in the composition is approximately equal to the weight ratio of the coating layer to the active particles in the electrode material.

[0061] According to an embodiment of the present disclosure, the method for producing the electrode material according to the present disclosure may include the following steps. First, prepare a first composition used to produce the electrode material, where the first composition includes the active particles, the conductive additive, and the first polymer. Next, perform a spray granulation process on the first composition to obtain core-shell particles (composed of the active particles and the first coating layer). Next, mix the core-shell particles, the conductive additive, and the first polymer to obtain a second composition. Next, perform a spray granulation process on the first composition to obtain the electrode material according to the present disclosure.

[0062] According to an embodiment of the present disclosure, since the electrode material according to the present disclosure is formed by a spray granulation process or a melt-kneading process, the volume swelling of the electrode produced using the electrode material can be reduced, the water absorption can be lowered, the stability can be enhanced, the elution of the metal component (such as manganese, iron, or nickel) of the active particles can be suppressed, and the ion conduction / electron conduction performance can be enhanced.

[0063] According to an embodiment 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 performed using the slurry to obtain the electrode material. According to an embodiment of the present disclosure, the diameter of the atomizing nozzle, the atomizer frequency, the operating temperature, the inlet temperature, the outlet temperature, and the material supply flow rate used in the spray granulation process can be adjusted by those having ordinary knowledge in the art according to actual needs. For example, a closed inert gas circulation spray drying system (model CL-8) of Okawara Chemical Machinery Co., Ltd. and a centrifugal ceramic pin type atomizer disk (MC-50-8-14C) can be used. The rotation frequency of the atomizer can be from 20 Hz to 60 Hz, the operating temperature can be from 50 °C to 200 °C, the inlet temperature can be from 30 °C to 200 °C, the outlet temperature can be from 30 °C to 200 °C, and the material supply flow rate can be from 1 ml / min to 100 ml / min. Further, the spray granulation process may include a drying step for drying the product after granulating the slurry, and the temperature of the drying step can be adjusted, for example, from 50 °C to 200 °C according to the solvent used. For example, the spray granulation process can be performed 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 an embodiment of the present disclosure, when the electrode material is prepared using a melt-kneading process, the method for preparing the electrode material according to the present disclosure may include the following steps. First, the conductive additive, the active particles, and the first polymer (or further including the second polymer) are sufficiently mixed to obtain a mixture. Then, the electrode material is obtained by performing a melt-kneading process on the mixture. Here, the "melting" referred to in the present disclosure means that after heating to the melting point of the first polymer reactant or to a temperature above which the first polymer becomes deformable, it becomes a fluid state of matter. The "kneading" referred to in the present disclosure means the process of uniformly mixing the conductive additive, the active particles, and the polymer by the action of a machine (such as an extruder), and the kneading step can also be performed in a discontinuous or batch-wise manner. According to an embodiment of the present disclosure, since the present disclosure uses a specific polymer (i.e., the first polymer) to prepare the electrode material, the temperature of the melt-kneading process 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 an embodiment of the present disclosure, the present disclosure also provides an electrode (for example, a positive electrode or a negative electrode) for use in a battery (for example, a lithium ion battery or a lithium secondary electrode). According to an embodiment of the present disclosure, referring to FIG. 4, the electrode 200 according to the present disclosure may include a current collecting layer 202 and an active layer 204, and the active layer 204 is disposed on the current collecting layer 202. According to an embodiment of the present disclosure, the active layer 204 is directly disposed on the current collecting layer 202 so that the lower surface of the active layer 204 is in direct contact with the upper surface of the current collecting layer 202 (that is, there is no film layer or the like that separates (continuously or discontinuously) between the active layer 204 and the current collecting layer 202). For example, since there is good adhesion between the active layer 204 and the current collecting layer 202 of the electrode 200 according to the present disclosure, it is not necessary to further use a binder (or an adhesive layer) to fix the active layer 204 on the current collecting layer 202, or it is not necessary to mix an electrode material and a binder to form an active layer. According to an embodiment of the present disclosure, the electrode 200 according to the present disclosure is composed of the current collecting layer 202 and the active layer 204. According to an embodiment of the present disclosure, the active layer 204 according to the present disclosure is composed of the electrode material.

[0066] According to an embodiment of the present disclosure, the electrode 200 according to the present disclosure may include two of the active layers (that is, a first active layer 204 and a second active layer 206) and one current collecting layer 202, and the current collecting layer 202 is disposed between the two active layers 204. Here, the first active layer 204 is directly disposed on the current collecting layer 202 so that the lower surface of the first active layer 204 is in direct contact with the upper surface of the current collecting layer 202, and the current collecting layer 202 is directly disposed on the second active layer 206 so that the lower surface of the current collecting layer 202 is in direct contact with the upper surface of the second active layer 206.

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

[0068] According to an embodiment of the present disclosure, the thickness of the active layer is not particularly limited and can be adjusted by those having ordinary knowledge in the art according to actual needs. For example, the thickness of the active layer may be from about 50 μm to 500 μm (for example, 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 an embodiment of the present disclosure, the current collector layer may be a conductive carbon-based material, a metal foil (for example, nickel foil, aluminum foil, copper foil, carbon-coated aluminum foil, or stainless steel foil), or a metal material having a porous structure, such as carbon cloth, carbon felt, or carbon paper, nickel mesh, copper mesh, molybdenum mesh, foamed nickel, foamed copper, or foamed molybdenum. According to an embodiment of the present disclosure, the porosity of the metal material having a porous structure may be from about 10% to 99.9% (for example, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%). According to an embodiment of the present disclosure, the thickness of the current collector layer is not particularly limited and can be adjusted by those having ordinary knowledge in the art according to actual needs. For example, the thickness of the current collector layer may be from about 5 μm to 50 μm (for example, about 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 an embodiment of the present disclosure, the method for fabricating 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, place the electrode material on the current collector layer, and perform a hot pressing process on the electrode material to form the electrode material into an active layer, thereby obtaining the electrode. The active layer is in direct contact with the current collector layer. According to an embodiment of the present disclosure, the hot pressing process may be, for example, hot roll pressing 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, the conductive additive, and the first polymer will each satisfy the requirement of uniform mixing. Also, due to its specific chemical structure, the first polymer according to the present disclosure has appropriate melting point, rheological properties, and adhesiveness, enabling the hot pressing process to be performed at a relatively low temperature. According to an embodiment of the present disclosure, the operating temperature of the hot pressing process may be from about 80°C to 200°C, for example, about 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 an embodiment of the present disclosure, the pressure applied in the hot pressing process can be adjusted by those with ordinary knowledge in the art according to actual needs. For example, the pressure applied in the hot pressing process may be 100 psi or more. The electrode according to the present disclosure can avoid the problems caused by further using a binder and can improve the mixing uniformity of the active material and the conductive material, thereby enhancing the mass loading, compacted density, and stability of the active layer of the obtained electrode (that is, the problems caused by the wet electrode process can be overcome).

[0071] According to an embodiment of the present disclosure, the method for fabricating the electrode according to the present disclosure may include the following steps. Prepare the electrode material and the 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, dispose the electrode material film on the current collector layer, and perform a hot pressing process on the electrode material to form the electrode material film into an active layer, thereby obtaining the electrode. The active layer is in direct contact with the current collector layer. According to an embodiment of the present disclosure, the hot pressing process may be, for example, a thermal rolling process or a thermal milling process.

[0072] According to an embodiment of the present disclosure, the method for fabricating the electrode according to the present disclosure may include the following steps. Prepare the composition used to fabricate the electrode material and the current collector layer, where the composition includes the active particles, the conductive additive, and the first polymer according to the present disclosure. Next, introduce the composition into a spray granulation process, and use the current collector layer to carry the formed electrode material (i.e., directly form the electrode material on the current collector layer by the spray granulation process). Next, perform a hot pressing process on the electrode material to form the electrode material into an active layer, thereby obtaining the electrode.

[0073] According to an embodiment of the present disclosure, the method for fabricating the electrode according to the present disclosure may include the following steps. Prepare the composition used to fabricate the electrode material and the current collector layer, where the composition includes the active particles, the conductive additive, and the first polymer. Next, introduce the composition into a melt-kneading process, and directly apply the extruded electrode material to the current collector layer. Next, perform a thermal pressing process on the electrode material to form the electrode material into an active layer, thereby obtaining the electrode.

[0074] According to an embodiment of the present disclosure, referring to FIG. 5, the present disclosure also provides a battery 300, such as 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, and the negative electrode 306 is separated from the positive electrode 302 by the separator 304. According to an embodiment 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. When 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 for the active layer are positive electrode active materials. When 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 for the active layer are negative electrode active materials.

[0075] According to an embodiment of the present disclosure, when the positive electrode is not an electrode according to the present disclosure, the positive electrode may be a conventional positive electrode used in a battery (such as 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 an embodiment of the present disclosure, when the negative electrode is not an electrode according to the present disclosure, the negative electrode may be a conventional negative electrode used in a battery (such as 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 an embodiment of the present disclosure, the definitions of the positive electrode current collector layer and the negative electrode current collector layer may be the same as the current collector layer according to the present disclosure.

[0076] According to an embodiment 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 an embodiment of the present disclosure, the positive electrode 302 may be separated from the separator 304 by a certain distance, and / or the negative electrode 306 may be separated from the separator 304 by a certain distance. According to an embodiment of the present disclosure, the battery 300 may further include an electrolyte 308, and the electrolyte is disposed between the positive electrode 302 and the negative electrode 306. In other words, the mutually laminated structure of the positive electrode 302, the separator 304, and the negative electrode 306 is immersed in the electrolyte 308. That is, the electrolyte is dispersed throughout the interior of the battery 300.

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

[0078] According to an embodiment 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, non-woven fabric, polyethylene terephthalate, polystyrene (PS), cellulose, or a combination of the above. For example, the separator 304 may be, for example, a PE / PP / PE multilayer composite structure. According to an embodiment of the present disclosure, the separator may have a porous structure. That is, the voids of the separator are uniformly distributed throughout the separator. According to an embodiment of the present disclosure, the thickness of the separator is not particularly limited and can be adjusted by those having ordinary knowledge in the art according to actual needs. For example, the thickness of the separator can be about 1 μm to 100 μm (for example, about 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 an embodiment of the present disclosure, the electrolytic solution 308 may contain a solvent and a lithium salt (or a lithium compound). According to an embodiment of the present disclosure, the concentration of the lithium salt in the solvent is from 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 an embodiment of the present disclosure, the solvent may be an organic solvent, such as an ester-based solvent, a ketone-based solvent, a carbonate-based solvent, an ether-based solvent, an alkane-based solvent, an amide-based solvent, or a combination of the above. According to an embodiment 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 (PC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), dimethyl carbonate,DMC), vinylene carbonate, butylene carbonate, dipropyl carbonate, or a combination of the above may be used. According to an embodiment 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 (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 fluorosulfonate,(LiSO3F), lithium tetrakis(pentafluorophenyl)borate (LiB(C6H5)4), lithium bis(oxalato)borate (LiBOB), or a combination thereof may be used.

[0080] According to an embodiment of the present disclosure, the battery according to the present disclosure may use a solid electrolyte and does not include the 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 an embodiment of the present disclosure, the solid electrolyte may be provided on the separator to form a composite separator. Further, 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 that those of ordinary skill in the art can easily understand them. The inventive concept can be embodied in various forms without being limited to these exemplary embodiments described herein.

[0082] Preparation of a compound having two acrylate groups Preparation Example 1 4-Hydroxyacetophenone (1 mol), methacrylic anhydride (1.2 mol), and sodium bicarbonate (0.1 mol) were added to a reaction flask. The reaction flask was purged with nitrogen gas and heated to 80°C. Then, after reacting for 2 hours, 700 milliliters of an aqueous sodium hydroxide solution (2M) was added to the reaction flask. After reacting for 8 hours, the resulting product was filtered, the solid was collected, washed with water, and then dried by heating to obtain Compound (1) (yield was approximately 97%). The reaction formula for the above reaction is as shown below.

[0083] [Chemical formula]

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

[0085]

Chemical formula

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

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

[0088] The decomposition temperature (Td) of the polymer according to the present disclosure was analyzed using a thermogravimetric analyzer (TGA). Regarding the melt flow rate (MFR) of the polymer according to the present disclosure, measurement was carried out using a melt flow indexer in accordance with the method defined in ASTM D 1238-A at 230 °C with a test weight of 2.16 kg. The melting point of the polymer according to the present 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 polymer according to the present disclosure was measured using a four-probe probe resistance meter (number DU-5211 Ohm Meter, purchased from DELTA UNITED INSTRUMENT CO., LTD). The measurement method includes the following steps. The sample was placed on the four-probe probe resistance meter. The probe was brought into contact with the sample surface at a pressure of 0.07 MPa. After contact, it was left stationary for 3 seconds, and the resistance value (unit: ohm) of the instrument was read. The volume resistivity of the polymer according to the present disclosure was measured according to the method defined in IEC 62788-1-2. The flame retardant grade of the polymer according to the present disclosure was tested and classified by the UL 94 measurement method (Underwriter Laboratories).

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

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

[0092] Preparation Example 6 95 parts by weight of ethylene-vinyl acetate copolymer (EVA) (product number UE630, purchased from Taiwan Polymer Co., 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 a solvent) were added into a reaction flask. Subsequently, the reaction flask was heated to 105 °C. After reacting for 6 hours, the solvent was removed from the obtained product by rotary evaporation to obtain polymer (5). Next, the decomposition temperature (Td), melt flow rate (MFR), melting point (Tm), surface resistivity, and volume resistivity of the obtained polymer (5) were evaluated. The results are as shown in Table 1.

[0093] Preparation Example 7 84 grams of polymer (6) (polyvinylidene fluoride, purchased from Kynar, product number PVDF-HVS900) was dissolved in 616 grams of N-methylpyrrolidone (NMP) to prepare a PVDF-HVS900 solution with a solid content of 12 wt%. It was applied onto a glass plate with a blade having a gap of 200 μm to form a wet film, and then placed in an oven at 180 °C for heating and drying 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 as shown in Table 1.

[0094]

Table 1

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

[0096] Next, using a rheometer (TA ARES-G2), the rheological properties of polymers (1), (3) to (6) (the diameter of the evaluation sample was 20 mm) were evaluated (test conditions: shear rate 10 1 / s, and heating rate 5.0 °C / min). As a result, it was found that polymers (1), (3) to (6) have good meltability.

[0097] Next, polymers (1) and (3) were tested by cyclic voltammetry to evaluate the activity and reaction kinetics of the materials, and at the same time, the stability and durability of the materials were observed. The test conditions were in the voltage range of 0 to 4.8 V, and polymers (1) and (3) films were introduced into a lithium iron phosphate battery of Formosa Plastics. From the results, it was found that polymers (1) and (3) have high electrochemical stability and hardly react with the electrolyte.

[0098] Fabrication of Electrode Materials

[0099] Example 1 2,500 grams of lithium iron phosphate (LFP) (purchased from Taiwan Plastic Lithium Iron Technology Co., product number LFP-3005E), hyperbranched polymer / ethyl cellulose resin solution (solid content 6 wt%) (ethyl cellulose resin was purchased from Dow Chemical Co., product number ETHOCEL STD 100) (the hyperbranched structure is a polymer structure formed by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermally polymerizing it, and introducing ethyl cellulose during the process of forming its hyperbranched polymer molecular structure, incorporating and intertwining it into the hyperbranched structure to form a polyhyperbranched-linear interpenetrating combined polymer structure. The weight ratio of the hyperbranched polymer bismaleimide to the ethyl cellulose resin is 2:1) (used as an ionic conduction additive. The ionic conductivity is 3.4x10 -462.50 grams of ionic conduction additive, 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 (dissolving 120.33 grams of polymer (1) in toluene), and 706 g of toluene were mixed to obtain Composition (1) (solid content 65%). In Composition (1), the weight ratio of the ionic conduction additive, the 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 ionic conduction additive, the conductive additive, and polymer (1) was 95:5. Next, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (1), and the obtained product was collected to obtain a powdery electrode material (1). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (MC-50-8-14C) was used. (2) The inlet temperature and the outlet temperature were set to 130°C and 80°C, respectively. (3) The circulation fan frequency was 35 Hz. (4) The atomizer frequency was 40 Hz. (5) The material supply rate was 10.030 ml / min.

[0100] Example 2 1,500 grams of lithium iron phosphate (LFP) (purchased from Yancheng Core Material Co., Ltd., product number: LFP-GF19), 37.50 grams of hyperbranched polymer / ethyl cellulose resin solution (solid content: 6 wt%) (ethyl cellulose resin purchased from Dow Chemical, product number: ETHOCEL STD 100) (the hyperbranched structure is a polymer structure formed by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermally polymerizing it. During the process of forming its hyperbranched polymer molecular structure, ethyl cellulose is introduced and incorporated into the hyperbranched structure to form a polyhyperbranched-linear interpenetrating combined polymer structure by intertwining. The weight ratio of the hyperbranched polymer bismaleimide to the ethyl cellulose resin is 2:1) (used as an ionic conduction additive. The ionic conductivity is 3.4x10 -4Ionic conduction additive (lithium bis(trifluoromethanesulfonyl)imide, LiTFSI, with a conductivity of 1.0 S / cm), 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)) 107.14 grams, polymer solution (dissolving 120.33 grams of polymer (1) in toluene) 360.99 grams, and toluene 424 grams were mixed to obtain Composition (2) (solid content 65%). In Composition (2), the weight ratio of the ionic conduction 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 ionic conduction additive, conductive additive, and polymer (1) was 95:5. Subsequently, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (2), and the obtained product was collected to obtain a powdery electrode material (2). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 145 °C and 110 °C, respectively. (3) The circulation fan frequency was 35 Hz. (4) The atomizer frequency was 30 Hz. (5) The material supply rate was 12.070 ml / min.

[0101] Example 3 1,500 grams of lithium iron phosphate (LFP) (purchased from Yancheng Core Material Co., Ltd., product number: LFP-GF19), 37.47 grams of hyperbranched polymer / ethyl cellulose resin solution (solid content: 6 wt%) (ethyl cellulose resin purchased from Dow Chemical, product number: ETHOEL STD 100) (the hyperbranched structure is a polymer structure formed by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and subjecting it to thermal polymerization. During the process of forming its hyperbranched polymer molecular structure, ethyl cellulose is introduced and incorporated into the hyperbranched structure to form a polyhyperbranched-linear interpenetrating combined polymer structure by intertwining. The weight ratio of hyperbranched polymer bismaleimide to ethyl cellulose resin is 2:1) (used as an ionic conduction additive. The ionic conductivity is 3.4x10 -4S / cm), 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)) 375.94 grams, polymer solution (dissolved 60.79 grams of polymer (3) in toluene) 607.89 grams, and toluene 50 grams were mixed to obtain Composition (3) (solid content 61.36%). In Composition (3), the weight ratio of the ion conduction 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 conduction additive, conductive additive, and polymer (3) was 95:5. Subsequently, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (3), and the obtained product was collected to obtain a powdery electrode material (3). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 145°C and 110°C, respectively. (3) The circulation fan frequency was 50 Hz. (4) The atomizer frequency was 30 Hz. (5) The material supply rate was 12.070 ml / min.

[0102] Example 4 2,000 grams of lithium iron phosphate (LFP) (purchased from Yancheng Core Materials Co., Ltd., product number: LFP-GF19), 106.38 grams of hyperbranched polymer / ethyl cellulose resin solution (solid content: 6 wt%) (ethyl cellulose resin was purchased from Dow Chemical, product number: ETHOEL STD 100) (the hyperbranched structure is a polymer structure formed by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and subjecting it to thermal polymerization. During the process of forming its hyperbranched polymer molecular structure, ethyl cellulose was introduced and incorporated into the hyperbranched structure. By intertwining, it was formed into a polyhyperbranched-linear interpenetrating combined polymer structure. The weight ratio of the hyperbranched polymer bismaleimide to the ethyl cellulose resin is 2:1) (used as an ionic conduction additive. The ionic conductivity is 3.4x10 -4Ionic conduction additive (conductivity 1.0 S / cm), 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)) 506.59 grams, polymer solution (100.00 grams of polymer (3) dissolved in toluene) 666.67 grams, and N-methylpyrrolidone (NMP) 975.68 grams were mixed to obtain Composition (4) (solid content 61.36%). In Composition (4), the weight ratio of the ionic conduction 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 ionic conduction 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 number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), and the obtained product was collected to obtain a powdery electrode material (4). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (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 45 Hz. (4) The atomizer frequency was 25 Hz. (5) The material supply rate was 25.160 ml / min.

[0103] Example 5 1,800 grams of lithium iron phosphate (LFP) (purchased from Yancheng Core Materials Co., Ltd., product number LFP-GF19), 157.89 grams of hyperbranched polymer / ethyl cellulose resin solution (solid content is 6 wt%) (ethyl cellulose resin is purchased from Dow Chemical, product number ETHOEL STD 100) (the hyperbranched structure is a polymer structure formed by dissolving bismaleimide monomer in N-methyl-2-pyrrolidone (NMP) and thermally polymerizing it. During the process of forming its hyperbranched polymer molecular structure, ethyl cellulose is introduced and incorporated into the hyperbranched structure, and by intertwining, it forms a polyhyperbranched-linear interpenetrating combined polymer structure. The weight ratio of the hyperbranched polymer bismaleimide to the ethyl cellulose resin is 2:1) (used as an ionic conduction additive. The ionic conductivity is 3.4x10 -4S / cm), 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)) 451.13 grams, polymer solution (100.00 grams of polymer (3) dissolved in toluene) 442.11 grams, and N-methylpyrrolidone (NMP) 306.77 grams were mixed to obtain Composition (5) (solid content 60.00%). In Composition (5), the weight ratio of the ion conductive 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 conductive additive, conductive additive, and polymer (3) was 95:5. Subsequently, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (5), and the obtained product was collected to obtain a powdery electrode material (5). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 110 °C and 70 °C, respectively. (3) The circulation fan frequency was 45 Hz. (4) The atomizer frequency was 25 Hz. (5) The material supply rate was 10.030 ml / min.

[0104] Example 6 6,000 grams of lithium iron phosphate (LFP) (purchased from Wanrun Technology Co., Ltd., product number LFP-A8-4E), 64.17 grams of graphite (product number KS6, purchased from TIMCAL Taiwan Co., Ltd., used as a conductive additive), 160.435 grams of conductive carbon powder (product number Super-P, purchased from TIMCAL Taiwan Co., Ltd., used as a conductive additive), and 192.51 grams of polymer (3) were mixed to obtain Composition (6). Using a Banbury mixer (manufactured by Lina Machinery Industry Co., Ltd., KD-3-7.5), a melt-kneading process was performed on Composition (6) (temperature: 120 °C, mixing time: 1 hour by closed kneading) to obtain a powdery 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 1,800 grams of lithium iron phosphate (LFP) (purchased from Wanrun Technology Co., Ltd., product number: LFP-A8-4E), 19.25 grams of graphite (product number: KS6, purchased from Taiwan Bolv Co., Ltd., used as a conductive additive), 48.13 g of conductive carbon powder (product number: Super-P, purchased from Taiwan Bolv Co., Ltd., used as a conductive additive), 57.75 grams of polymer (5), and 1,036.61 grams of toluene were mixed to obtain Composition (7) (solid content: 65.00%). In Composition (7), the weight ratio of the 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 the KS6, Super-P, and polymer (5) was 93.5:6.5. Next, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (7), and the obtained product was collected to obtain a powdery electrode material (7). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (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 35 Hz. (4) The atomizer frequency was 35 Hz. (5) The material supply rate was 50.150 ml / min.

[0106] Example 8 1,800 grams of lithium iron phosphate (LFP) (purchased from Wanrun Technology Co., Ltd., product number LFP-A8-4E), 19.25 grams of graphite (product number KS6, purchased from Taiwan Bolyu Co., used as a conductive additive), 48.13 g of conductive carbon powder (product number Super-P, purchased from Taiwan Bolyu Co., used as a conductive additive), 28.9 g of polymer (3), 28.9 g of polymer (5), and 1,036.61 grams of toluene were mixed to obtain Composition (8) (solid content: 65.00%). In Composition (8), the weight ratio of the 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 the KS6, Super-P, polymer (3), and polymer (5) was 93.5:6.5. Next, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (8), and the obtained product was collected to obtain a powdery electrode material (8). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (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 35 Hz. (4) The atomizer frequency was 35 Hz. (5) The material supply rate was 25.160 ml / min.

[0107] Here, taking the electrode material (1) as an example, the evaluation of its morphology was carried out as follows. The particle size distribution, tap density of the powder, and BET specific surface area of the lithium iron phosphate (i.e., the active particles) used to prepare the electrode material (1) and the electrode material (1) were evaluated. The results are as shown in Table 2. The particle size distribution was measured according to the method specified in ISO13322-1:2004. The measurement of the specific surface area could be carried out 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 ISO3953.

[0108]

Table 2

[0109] The overall particle size distribution of the original lithium iron phosphate was relatively wide. After modification, particles with a relatively small particle size diameter agglomerate and become spherical during the spray drying process, resulting in a phenomenon that the specific surface area decreases. Therefore, the particle size, uniformity of the particle size distribution, and tap density of the electrode material (1) according to the present disclosure increase, which is advantageous for increasing the density of the active layer during the formation of the active layer by the subsequent hot pressing process. In addition, after modification, it was shown that the specific surface area of the electrode material (1) decreased and the profile of the electrode material (1) tended to be more spherical. Furthermore, separately taking the lithium nickel cobalt manganese ternary cathode material (NMC / Geshi Technology Co., Ltd.) and performing the above-mentioned surface modification and spray granulation, the same results as above can be obtained, with relatively few small and large structures (for example, the proportion of those less than 1 μm decreased from 0.5% to 0%, and the proportion of those larger than 25 μm decreased from 3.5% to 1.6%), the size of the structure is more uniform (for example, the proportion of those between 1 and 25 μm increased from 96.0% to 98.4%), and the powder particles tend to be more spherical, all of which are advantageous for increasing the density of the active layer during the formation of the active layer by the subsequent hot pressing process. This is as shown in Table 2.

[0110] Next, the electrode materials (1) and (8) obtained with a scanning electron microscope (SEM) were observed. The results are shown in FIGS. 7 and 8, respectively. As can be seen from FIGS. 7 and 8, the electrode material (1) is spherical type particles, and the particle size distribution has relatively uniformity, and particles exceeding 30 μm were not observed. Next, the electrode material (1) obtained with a focused ion beam (FIB) transmission electron microscope (TEM) was observed. The result is as shown in FIG. 9. As can be seen from FIG. 9, the thickness of the coating layer of the electrode material (1) is about 40 nm to 60 nm. Based on the above, the electrode material according to the present disclosure is spherical type particles and may have a core-shell structure.

[0111] Comparative Example 1 1,800 grams of lithium iron phosphate (LFP) (purchased from Wanrun Technology Co., Ltd., product number LFP-A8-4E), 19.25 g of graphite (product number KS6, purchased from Taiwan Bolyu Co., used as a conductive additive), 48.13 g of conductive carbon powder (product number Super-P, purchased from Taiwan Bolyu Co., used as a conductive additive), 57.75 g of polymer (6) (purchased from Kynar HSV900), and 1,036.61 g of N-methylpyrrolidone (NMP) were mixed to obtain Composition (9) (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, using a spray drying system (model number CL-8, manufactured by Okawara Chemical Machinery Co., Ltd.), a spray granulation process was performed on Composition (9), and the obtained product was collected to obtain a powdery electrode material (9). The conditions of the spray granulation process were as follows. (1) A centrifugal ceramic pin type atomizer disk (MC-50-8-14C) was used. (2) The inlet temperature and outlet temperature were set to 1,350 °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 (Retsch PP35, pressure 35 tons) system, Electrode Material (1) was placed in a 40 mm tablet mold set (equipped with an automatic ejection function), and a room temperature pressing operation of the dry electrode composition powder was performed. 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, electrode active material areal density, and electrode material compression density of the dry electrode film (1-I) are as shown in Table 3.

[0114] Method II: The electrode material (1) was put into a mini-extruder with a redesigned structure equipped with a homogenizing supply module, and preheating, mixing, and homogenizing operations were performed. Quantitative supply was carried out by a conveying screw (the temperatures in the three sections before, in the middle, and after the conveying screw pipeline, i.e., the preheating temperature, were all 90°C, the screw rotation speed was 1100 rpm, and the extrusion amount was 46.8 kg / hr). Then, after the electrode material (1) became uniform and was metered and discharged from the extruder, the powder material was homogenized and conveyed by a flat die head (the width can reach 145 mm), and sent to a heating roll press module system (the control value of the linear pressure of the rollers was 200 N / mm, and the heating temperatures of the two rollers, i.e., the roller temperatures, were 90°C), and a dry electrode film (1-II) was produced. The weight (cut into an area of 3 cm x 3 cm), thickness, areal density of the electrode active material, and compression density of the electrode material of the said dry electrode film are as shown in Table 3.

[0115] Method II was repeated. However, the process parameters were changed according to Table 3, and a dry electrode film (1-III) was obtained.

[0116] Examples 10 - 16 Examples 10 - 16 were carried out based on Method I and Method II described in Example 9, except that the electrode material (1) was replaced with electrode materials (2) - (8) respectively, and the process parameters were changed according to Table 3, and dry electrode films (2-I) to (8-II) were obtained respectively. The weights, thicknesses of the electrode films, areal densities of the electrode active materials, and compression densities of the electrode materials of the said dry electrode films (2-I) to (8-II) are as shown in Table 3.

[0117] Comparative Example 2 Comparative Example 2 was carried out based on Method I and Method II described in Example 9, except that the electrode material (1) was replaced with the electrode material (9) (Comparative Example 1), and the process parameters were changed according to Table 3, and dry electrode films (9-I) and (9-II) were obtained. The weights, thicknesses of the electrode films, areal densities of the electrode active materials, and compression densities of the electrode materials of the said dry electrode films (9-I) and (9-II) are as shown in Table 3.

[0118] Comparative Example 3 The method for producing the wet-process positive electrode plate is as follows. After stirring and mixing lithium iron phosphate active material, super P conductive additive, KS-6 conductive additive, and an appropriate amount of a solvent, such as N-methylpyrrolidone (NMP), for 3 hours, an NMP solution containing PVDF-HSV900 binder (containing 10 wt% PVDF) was added, and stirring and mixing were continued for 3 hours to obtain a lithium iron phosphate positive electrode slurry with a solid content of 65 wt%. The composition of the solid is 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%). After applying the positive electrode slurry to a current collector (for example, aluminum metal foil), it was heated to 150°C to dry the coating layer, rolled, and a positive electrode active layer with a thickness of 100 micrometers was formed on the metal foil to obtain an electrode film (10).

[0119] The electrode film (10) was conveyed and fed into a hot roll press module system (the control value of the line pressure of the rollers was 200 N / mm, and the heating temperature of the two rollers (i.e., the roller temperature) was 90°C) to produce an electrode film (11). The weights (cut into an area of 3 cm x 3 cm), thicknesses, electrode active material areal weights, and electrode material compression densities of the electrode film (10) and the electrode film (11) were measured. The results were as shown in Table 3.

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

[0121] As can be seen from Table 3, in a general wet process, since it is necessary to evaporate and dry the NMP solvent as much as possible so that no residue remains, the areal weight of the lithium iron phosphate active material in the electrode film is usually 15 to 25 mg / cm 2 at, 25 mg / cm 2It is almost impossible to exceed this, so it is not easy to significantly increase the capacity. As the areal amount 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, an excessive amount of solvent destabilizes the negative electrode material structure, subsequently affecting the electrode and battery performance, particularly reducing the capacity and cycle life. Also, during the process of the solvent evaporating upward, the binder often becomes distributed in a gradient layer pattern within the electrode structure, which can also affect the structural stability, adhesion strength, and cycle performance of the electrode film. Furthermore, the structure of the electrode film obtained through the processes of coating and heat drying is relatively soft, porous, and not very adhesive. Therefore, it is necessary to compress it tightly under the action of a high roll press pressure to increase the compression density and adhesion strength of the electrode film structure. However, an excessively high roll press pressure causes the electrode active material (relatively high hardness) to be embedded deeper into the relatively soft aluminum foil structure, resulting in the aluminum foil being distorted or cut, or cracks occurring, causing structural fractures or breaks in the electrode film. Therefore, the compression density of the lithium iron phosphate electrode film is usually controlled to be 2.3~2.5 g / cm 3 to 2.5 g / cm 3It is rare to exceed this value. By using the electrode material composition of the present disclosure, it is possible to directly produce a dry electrode film and a dry electrode by thermal roll pressing, eliminating the need for wet coating and heat drying operations. As a result, the necessity of solvent use and the VOC emission amount in the manufacturing process can be significantly reduced, and an eco-friendly production model can be provided. As shown in the test and measurement results of the areal amount of the active material and the compression density of the electrode film of the dry electrode film produced from the electrode composition in each example of Table 3 using Method I or Method II, the dry electrode composition of the present disclosure has structural toughness and elasticity, as well as adhesion, and can withstand high roll pressing force and high shear force. Therefore, when the resulting dry electrode film needs to have a thick film thickness (for example, 150 μm or more), it is relatively difficult to break, fold, or crack due to its hardness. Thus, the electrode film produced according to the present disclosure can adjust the areal amount of the active material to 30 mg / cm 2 or more (and thus a value exceeding 45 mg / cm 2 ), and can adjust the initial compression density before roll pressing by laminating with an aluminum foil of the electrode film to 2.2 g / cm 3 or more (and thus a value exceeding 2.4 g / cm 3 ). When the initial compression density of the electrode film is high, the structural stability can be enhanced, the expansion deformation can be reduced, and furthermore, the weather resistance storage property and the manufacturing processability of the electrode film can be improved.

[0122] Single-sided dry electrode The above-mentioned electrode films (1-II), (2-II), (3-II), (4-II), (5-II), (6-II), (7-II), (8-II), (9-II), and the electrode film (11) were further used with a roll press (purchased from TOKYO, model: ONO 2RM-350DRR) to perform roll press lamination and film compression with an aluminum foil substrate (purchased from BLUEGLOWNANO, thickness 12 μm), and the roll press pressure (0 - 30 kgf / cm 2) The roll press speed (1 m / min) was adjusted to obtain the single-sided dry electrodes (1) to (9) and the electrode (10) that had been roll press compressed. The compression density of the corresponding electrodes is as shown in Table 4.

[0123] Peeling strength The peeling strength between the current collector layer and the active layer of the dry electrodes (1) to (9) and the electrode (10) was measured. The results are as shown in Table 4. The measurement of the peeling strength was carried out using a universal tensile testing machine (purchased from SHIMADZU, model: AG-X PLIS), referring to the 180-degree peeling strength test defined in ASTM D903-98. The above-mentioned roll pressed single-sided dry electrode piece was cut into a rectangular strip of 120 mm × 25 mm to obtain a test electrode piece sample. An insulating tape with a specification of 18 mm × 35 mm was pasted on the upper end of the stainless steel plate, and a double-sided tape with a specification of 30 mm × 100 mm was pasted on one side to the stainless steel plate with the insulating tape, and on the other side to the front surface of the single-sided dry electrode piece composite layer. The backing paper of the double-sided tape was cut into a rectangular strip with a specification of 30 mm × 30 mm and pasted on the lower side of the electrode piece, and a rectangular strip of the backing paper of the double-sided tape with a specification of 30 mm × 50 mm was pasted on the upper surface of the electrode piece. A rubber roller with a weight of 2 kg was used to perform 2 reciprocations of roll pressing on the electrode piece covered with the backing paper. The free end of the electrode piece was fixed to the upper grip of the tensile machine, and the bottom end of the stainless steel plate was fixed to the lower grip of the tensile machine. The parameter settings of the tensile force measuring device were carried out, with the peeling length set to 40 mm and the width set to 18 mm. The tensile device was started to perform a 180° peeling test at a peeling speed of 50 mm / min, and the peeling strength as shown in Table 4 was obtained.

[0124]

Table 4

[0125] Electrode films with relatively high compression density have numerous advantages and merits. Especially in battery technology, the energy density increases, the conductivity is improved (the internal resistance is reduced), the charge-discharge performance of the battery is enhanced, the structural stability is enhanced, the cycle life is enhanced, the expansion and deformation of the battery are reduced (safety is improved), and the thermal conductivity of the battery is improved (the thermal management performance is improved), etc. As can be seen from Table 4, the dry electrodes (1) to (8) in the examples all have a compression density exceeding 2.35 g / cm 3 and (subsequently reaching 2.50 g / cm 3 or more), and have more advantages and merits compared to wet-process electrodes.

[0126] The peel strength of the electrode is one of the important indicators for evaluating its stability and reliability during the battery use process, and reflects the adhesion between the electrode composition material and the metal foil. Insufficient peel strength may cause problems such as the electrode peeling off and the current transmission being interrupted during the battery use process. The higher the peel strength, the more guaranteed the performance in terms of battery performance, cycle life, and safety, etc. As can be seen from Table 4, when the compression density of the electrodes is at the same level (for example, 2.3 - 2.4 g / cm 3 ), the peel strength of the dry electrode is higher than that of the wet-process electrode, and the higher the compression density of the electrode, the higher the peel strength of the electrode.

[0127] Evaluation of Electrode Performance by Half-Cell

[0128] Example 17 Prepare electrode (4) as the positive electrode plate, prepare a polypropylene separator (product number is 2320, purchased from Celgard, thickness about 20 μm), prepare an electrolyte for lithium iron phosphate battery (purchased from Taiwan Plastic Industry Co., Ltd., model number: LE), and use lithium metal as the negative electrode plate.

[0129] Next, arrange them in the order of negative electrode plate / separator / positive electrode plate (make the active layer of the positive electrode face the separator side), inject an electrolytic solution (purchased from Taiwan Plastic Industry Co., Ltd., product number is FPC-401) between the positive electrode plate and the negative electrode plate so that the separator is positioned in the electrolytic solution, and assemble it into a CR2032 button-type battery (size: 3.2 mm (thickness) × 20 mm (width) × 20 mm (length)) to obtain a button-type battery (1). Leave it standing for one day to allow the electrolytic solution to diffuse and penetrate into the positive electrode plate and the negative electrode plate. Then, place the button-type battery (1) in the test module of a button-type battery charge and discharge device (MACCOR SERIER4000), charge it to 3.75 V at a current of 0.1C, and discharge it to 2.5 V at a current of 0.1C (cut-off = 0.01C). Repeat the charge and discharge for 3 cycles to complete the formation process, and measure and record the electrical characteristics of the button-type battery (1). The results are as shown in Table 5.

[0130] Example 18 Prepare an electrode (7) as the positive electrode plate, prepare a polypropylene separator (product number is 2320, purchased from Celgard, thickness is about 20 μm), prepare an electrolytic solution for a lithium iron phosphate battery (purchased from Taiwan Plastic Industry Co., Ltd., model number: LE), and use lithium metal as the negative electrode plate.

[0131] Next, arrange them in the order of negative electrode plate / separator / positive electrode plate (make the active layer of the positive electrode face the separator side), inject an electrolytic solution (purchased from Taiwan Plastic Industry Co., Ltd., lithium iron phosphate electrolytic solution, product number is FPC-401) between the positive electrode plate and the negative electrode plate so that the separator is positioned in the electrolytic solution, and assemble it into a CR2032 button-type battery (size: 3.2 mm (thickness) × 20 mm (width) × 20 mm (length)) to obtain a button-type battery (2). Leave it standing for one day to allow the electrolytic solution to diffuse and penetrate into the positive electrode plate and the negative electrode plate. Then, place the button-type battery (2) in the test module of a button-type battery charge and discharge device (MACCOR SERIER4000), charge it to 3.75 V at a current of 0.1C, and discharge it to 2.5 V at a current of 0.1C (cut-off = 0.01C). Repeat the charge and discharge for 3 cycles to complete the formation process, and measure and record the electrical characteristics of the button-type battery (2). The results are as shown in Table 5.

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

[0133] Next, they were arranged in the order of negative electrode plate / separator / positive electrode plate (so that the active layer of the positive electrode faced the separator side), and an electrolyte (purchased from Taiwan Plastics Industry Co., Ltd., product number FPC-401) was injected between the positive electrode plate and the negative electrode plate so that the separator was positioned in the electrolyte, and it was assembled into a CR2032 button-type battery (size: 3.2 mm (thickness) × 20 mm (width) × 20 mm (length)) to obtain a button-type battery (3). It was left standing for one day to allow the electrolyte to diffuse and penetrate into the positive electrode plate and the negative electrode plate. Then, the button-type battery (3) was placed in the test module of a button-type battery charge-discharge device (MACCOR SERIER4000), charged to 3.75 V at a current of 0.1C, and discharged to 2.5 V at a current of 0.1C (cut-off = 0.01C). The charge-discharge was repeated 3 cycles to complete the formation process, and the electrical characteristics of the button-type battery (3) were measured and recorded. The results are as shown in Table 5.

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

[0135] Next, arrange them in the order of negative electrode plate / separator / positive electrode plate (make the active layer of the positive electrode face the separator side), inject an electrolytic solution (purchased from Taiwan Plastic Industry Co., Ltd., product number is FPC-401) between the positive electrode plate and the negative electrode plate so that the separator is located in the electrolytic solution, and assemble it into a CR2032 button-type battery (size: 3.2 mm (thickness) × 20 mm (width) × 20 mm (length)) to obtain a button-type battery (4). Let it stand for one day to diffuse the electrolytic solution and penetrate it into the positive electrode plate and the negative electrode plate. Then, place the button-type battery (4) in the test module of a button-type battery charge and discharge device (MACCOR SERIER4000), charge it to 3.75 V at a current of 0.1C, and discharge it to 2.5 V at a current of 0.1C (cut-off = 0.01C). Repeat the charge and discharge for 3 cycles to complete the formation process, and measure and record the electrical characteristics of the button-type battery (4). The results are as shown in Table 5.

[0136]

Table 5-1

Table 5-2

[0137] As can be seen from Table 5, the half-cell fabricated from the dry electrode according to the present disclosure has a resistance value of only about 7-9 Ω after formation, which is lower than that of a battery including an electrode formed using a wet process (the resistance value is about 21-23 Ω). It can enhance the energy efficiency, improve the battery performance, extend the battery life, enhance the stability and safety, and increase the discharge stability.

[0138] In summary, according to the electrode material having the specific structure and composition according to the present disclosure, by using an electrode process (for example, a dry electrode process), the electrode material according to the present disclosure can be formed as an active layer on the surface of the current collector layer at a relatively low operating temperature. Therefore, the formed active layer not only has more preferable mechanical strength and good adhesiveness, but also can increase the mass loading, compacted density, and stability of the active layer of the obtained electrode. As a result, the charge-discharge capacity and energy density of the battery are improved, the internal resistance is significantly reduced, the energy efficiency is increased, the battery performance is improved, the battery life is extended, the stability and safety are enhanced, and the discharge stability can be increased.

[0139] It will be apparent that various modifications and changes can be added to the methods and materials of the present disclosure. The present specification and embodiments are intended to be regarded merely as examples, and the true scope of the present disclosure is indicated by the following claims and their equivalents.

Explanation of Reference Numerals

[0140] 10... Electrode material 12... Active particles 14... Coating layer 200... Electrode 202... Current collector layer 204... First active layer 206... Second active layer 300... Battery 302... Positive electrode 304... Separator 306... Negative electrode 308... Electrolyte

Claims

1. An electrode material comprising: active particles; and a coating layer that partially or completely covers the surface of the active particles, wherein the coating layer contains 5 to 70 parts by weight of a conductive additive and 30 to 95 parts by weight of a first polymer, wherein the total weight of the first polymer and the conductive additive is 100 parts by weight, and 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).

2. 【Chemical 1】 (wherein, A １ is a single bond, oxygen, 【Chemical 2】 or -CH=CH-, and each R １ is independently hydrogen or a methyl group, and each R ２ is independently hydrogen or a methyl group, and each R ３ is independently hydrogen, a methyl group, or an ethyl group.) The electrode material according to claim 1, wherein the weight ratio of the compound having two acrylate groups to the ethylene / vinyl acetate copolymer is from 1:99 to 99:

1.

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

1. 【Chemical Formula 3】

4. The electrode material according to claim 1, wherein the coating layer further contains 0.1 to 30 parts by weight of a second polymer, and the second polymer is polyamide, polyimide, polymaleimide, polybismaleimide, polyacrylate, polyacrylic acid, polyvinyl alcohol, sodium carboxymethyl cellulose, 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 from 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 is the active particles, and the shell layer is the coating layer.

7. An electrode comprising: a current collector layer; and an active layer disposed on the current collector layer, wherein the active layer contains the electrode material according to claim 1.

8. A battery comprising: a positive electrode; a separator; and a negative electrode, wherein 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 according to claim 7.

9. ​ ​ ​ ​ A method for producing an electrode material, which is used for producing the electrode material according to claim 1, preparing a composition containing the active particles, the conductive additive, and the first polymer; performing a spray granulation process or a melt kneading process on the composition to obtain the electrode material; A method for producing an electrode material, comprising the steps of:

Images