WO2024253469A1 - Dispositif électrochimique à haute densité d'énergie contenant du phosphate de fer et de lithium - Google Patents

Dispositif électrochimique à haute densité d'énergie contenant du phosphate de fer et de lithium Download PDF

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WO2024253469A1
WO2024253469A1 PCT/KR2024/007824 KR2024007824W WO2024253469A1 WO 2024253469 A1 WO2024253469 A1 WO 2024253469A1 KR 2024007824 W KR2024007824 W KR 2024007824W WO 2024253469 A1 WO2024253469 A1 WO 2024253469A1
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positive electrode
active material
electrochemical device
material layer
electrode active
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Korean (ko)
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김창현
최근호
김정환
조석규
이건희
조형민
이강택
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Ubatt Inc
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H01M4/623—Binders being polymers fluorinated polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a high energy density electrochemical device comprising lithium iron phosphate.
  • a thick-film positive electrode with such unevenness causes uneven flow characteristics of lithium ions, and causes problems such as uneven charge/discharge characteristics in the thickness direction and polarization.
  • the battery performance deteriorates due to the increase in the movement distance of lithium ions as the thickness of the positive electrode increases, and furthermore, such uneven flow characteristics of lithium ions further aggravate the problems of lithium metal precipitation and dendrite formation on the surfaces of lithium metal, graphite, and silicon negative electrodes, which not only shortens the life of the battery but also lowers the stability of the battery.
  • lithium iron phosphate is a promising cathode material that can be used in large-capacity secondary batteries because it is cheaper than other cathode active materials.
  • LFP lithium iron phosphate
  • it has a fatal disadvantage of low energy density compared to conventional lithium cobalt oxide (LCO) or ternary batteries such as NCM, NCA, and NCMA, despite its advantages in stability and cost-effectiveness.
  • an electrochemical device capable of simultaneously satisfying high energy density, excellent life characteristics, and stability is provided.
  • An electrochemical device comprises a cathode, an anode, and an electrolyte, wherein the cathode comprises a cathode current collector; and a cathode active material layer formed on the cathode current collector, the cathode active material layer comprising a porous binder scaffold and cathode active material particles, wherein the cathode active material particles comprise lithium iron phosphate particles having an olivine structure with respect to the total weight of the cathode active material layer.
  • the anode may have an electrode tortuosity ( ⁇ ) of 7 or less, calculated by the following relationship.
  • K electrolyte represents the ionic conductivity of the electrolyte
  • K electrode represents the ionic conductivity of the anode
  • Porosity represents the porosity of the anode
  • the negative electrode may include a negative electrode active material layer containing 50 wt% or more of a graphite-based active material.
  • the energy density of the electrochemical device may be 180 Wh/kg to 400 Wh/kg.
  • the negative electrode may include a negative electrode current collector, or a negative electrode current collector and lithium metal.
  • the metal salt may be included in an amount of 0.01 to 50 parts by weight based on 100 parts by weight of the positive electrode active material particles.
  • A may be lithium, sodium, zinc, copper, aluminum, silver, gold, cesium, indium, magnesium or calcium.
  • the electrolyte may have a ratio of the amount of electrolyte injected to the capacity of the electrochemical device (g/Ah) of less than 3.0.
  • the electrolyte may be included in a weight ratio of 15 to 30 parts per 100 parts by weight of the positive electrode.
  • a half-cell manufactured with the positive electrode may have a discharge capacity retention rate at 0.3 C of 70% or more compared to the discharge capacity at 0.1 C.
  • the electrochemical device may have a 0.1C discharge capacity realization ratio relative to the design capacity of 0.9 or more.
  • An electrochemical device comprises a cathode, a cathode and an electrolyte, wherein the cathode comprises a cathode current collector; And a cathode active material layer formed on the cathode current collector, comprising a binder, cathode active material particles, and a conductive material; wherein the cathode active material particles include lithium iron phosphate particles having an olivine structure, and the cathode is a thick-film cathode having a capacity per area of the cathode active material layer formed on one surface of the cathode current collector of 3.5 to 10 mAh/cm2, and when a cross-section of the cathode active material layer is analyzed by X-ray CT, a deviation of a conductive material concentration (C1) of a first active material layer corresponding to 1/3 of the thickness direction from the boundary between the cathode current collector and the cathode active material layer, a conductive material concentration (C2) of
  • the lithium iron phosphate particles may be included in an amount of 60 wt% or more with respect to the total weight of the positive electrode active material layer.
  • the conductive material may be one or a combination of two or more selected from the group consisting of carbon black, carbon nanotubes, and VGCF.
  • An electrochemical device can simultaneously satisfy high energy density, excellent life characteristics, and stability, despite containing lithium iron phosphate as a cathode material. Specifically, the electrochemical device can effectively suppress the occurrence of polarization phenomenon even though it employs a thick film type cathode, and can implement uniform charge/discharge characteristics.
  • Figure 1 shows the SEM analysis results of the anode surface manufactured in Comparative Example 1.
  • Figure 2 shows the results of SEM analysis of the surface of the anode manufactured in Example 1.
  • Units used herein, unless otherwise specified, are based on weight, and as an example, units of % or ratio mean weight% or weight ratio, and weight% means the weight % that any one component occupies in the composition among the entire composition, unless otherwise defined.
  • the numerical range used in this specification includes the lower and upper limits and all values within that range, the increments logically derived from the shape and width of the defined range, all doubly defined values, and all possible combinations of the upper and lower limits of the numerical range defined in different shapes. Unless otherwise specifically defined herein, values outside the numerical range that may arise due to experimental error or rounding of values are also included in the defined numerical range.
  • top ‘upper part’, ‘top surface’, ‘bottom’, ‘lower part’, ‘bottom’, and ‘side’ are based on the drawings, and may actually vary depending on the direction in which elements or components are arranged.
  • porous binder scaffold refers to a structure in which a mesh structure is uniformly formed three-dimensionally by a binder, in which the binder forms a framework and pores are abundantly developed within the framework.
  • the pores preferably have an open pore structure, and the porous mesh structure formed by the binder can act as a support in which positive electrode active material particles and a conductive material can be evenly distributed.
  • the pores may have a diameter of 0.1 ⁇ m to 50 ⁇ m, and specifically, may have a diameter of 0.5 ⁇ m to 10 ⁇ m.
  • the porous binder scaffold may be a support including fibers formed by self-assembly of an organic binder and a conductive material as a unit structure, and including a thin inner wall structure formed by secondary self-assembly of the fibrous unit structure.
  • the binder scaffold is an open-cell foam formed by the inner wall structure, and the inner space can be partitioned by the inner wall structure.
  • the inner wall structure can be a porous inner wall, and the inner space can include a large number of pores compared to the pores formed in the inner wall structure.
  • Positive active material particles can be positioned in the inner space. More specifically, the positive active material particles can be positioned in the inner space and be fixed by contact with the porous inner wall structure.
  • the binder scaffold structure can form a conductive network superior to a fibrous mesh structure, and can have excellent adhesion to the positive active material particles.
  • An electrochemical device comprises a cathode, an anode, and an electrolyte, wherein the cathode comprises: a cathode current collector; and a cathode active material layer formed on the cathode current collector, the cathode active material layer comprising a porous binder scaffold and cathode active material particles; wherein the cathode active material particles are characterized in that they include lithium iron phosphate particles having an olivine structure with respect to the total weight of the cathode active material layer.
  • the porous binder scaffold means a mesh structure in which the binder forms a skeleton and pores are richly developed within the skeleton, and the porous mesh structure can serve as a support in which positive electrode materials such as positive electrode active material particles and conductive materials can be evenly distributed. That is, in the positive electrode according to one embodiment, cracks do not occur even when the positive electrode is thickened by making the binder component microporous, and the positive electrode material is very evenly distributed, so that excellent battery performance can be maintained.
  • an electrochemical device can realize a high energy density of 180 Wh/kg or more, or 180 Wh/kg to 400 Wh/kg, or 180 Wh/kg to 380 Wh/kg, despite containing lithium iron phosphate as a cathode material, and can satisfy both excellent life characteristics and stability.
  • the electrochemical device may include the cathode active material layer in an amount of 50 wt% or more, 55 wt% or more, or 60 wt% or more, or 95 wt% or less, or 90 wt% or less, or 88 wt% or less, or 50 to 90 wt%, or 60 to 90 wt%, or 60 to 85 wt%, based on the total weight.
  • the electrode tortuosity ( ⁇ ) calculated by the following relationship may be 10 or less, 8 or less, 7 or less, or 6 or less, and may be, but is not limited to, 1 or more.
  • the electrode tortuosity may be 1 to 10, 2 to 8, 3 to 7, 4 to 7, or 5 to 7.
  • K electrolyte represents the ionic conductivity of the electrolyte
  • K electrode represents the ionic conductivity of the anode
  • Porosity represents the porosity of the anode
  • An electrochemical device including such a cathode has excellent ion conductivity and can have excellent battery performance because the ion transfer path within the electrode is relatively short.
  • a half-cell manufactured with the positive electrode may have a discharge capacity retention rate at 0.3 C of 50% or more, or 60% or more, or 70% or more, or 74% or more, and may be from 60% to 99%, or from 70% to 98%, relative to the discharge capacity at 0.1 C.
  • the measurement of the discharge capacity retention rate at 0.1 C and 0.3 C may be, but is not limited to, the retention rate measured after 1 charge, after 5 charges, after 10 charges, or after 30 charges.
  • the electrochemical device may have a 0.1C discharge capacity implementation ratio relative to the design capacity of 0.8 or more, 0.85 or more, 0.9 or more, 0.95 or more, and may be from 0.8 to 1.0, or from 0.9 to 1.0, or from 0.95 to 1.0.
  • the design capacity means a theoretical value calculated from the total weight of positive active material particles included in the cell and the reversible discharge capacity of the positive active material particles.
  • the cathode active material layer according to one embodiment can implement excellent mechanical properties even using a small amount of binder since the binder forms a porous scaffold structure, and thus the content of cathode active material particles can be further increased, thereby implementing an even better energy density.
  • the porous binder scaffold may be included in an amount of 0.01 to 40 parts by weight, or 0.01 to 20 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 5 parts by weight, or 0.01 to 1 part by weight, relative to 100 parts by weight of the positive electrode active material particles.
  • the above positive electrode active material particles may include lithium iron phosphate particles represented by the following chemical formula.
  • M is at least one metal selected from the group consisting of Co, Ni, and Mn, and 0 ⁇ x ⁇ 1, 0.0.1 ⁇ x ⁇ 0.8, or 0.01 ⁇ x ⁇ 0.6.
  • the positive electrode active material particle may further include at least one known positive electrode active material.
  • the cathode active material particles may comprise less than 100 wt%, 99 wt% or less, 98 wt% or less, 97 wt% or less, 90 wt% or less, 80 wt% or less, and, but not limited to, 60 wt% or more of the lithium iron phosphate-based particles based on the total weight of the cathode active material.
  • the cathode active material particles may comprise 60 wt% or more and less than 100 wt%, 60 to 99 wt%, 65 to 99 wt%, 70 to 99 wt%, 80 to 99 wt%, 85 to 98 wt%, or 90 to 97 wt% of the lithium iron phosphate-based particles based on the total weight of the cathode active material particles.
  • the cathode active material particles may comprise 100 wt% of the lithium iron phosphate-based particles based on the total weight of the cathode active material particles.
  • a known positive electrode active material may be a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound).
  • a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used, and a specific example thereof may be a compound represented by one of the following chemical formulas.
  • Li a A 1-b B b D 2 (wherein 0.90 ⁇ a ⁇ 1.8, and 0 ⁇ b ⁇ 0.5); Li a E 1-b B b O 2-c D c (wherein 0.90 ⁇ a ⁇ 1.8, 0 ⁇ b ⁇ 0.5, 0 ⁇ c ⁇ 0.05); LiE 2-b B b O 4 -c D c (wherein 0 ⁇ b ⁇ 0.5, 0 ⁇ c ⁇ 0.05); Li a Ni 1-bc Co b B c D ⁇ (wherein 0.90 ⁇ a ⁇ 1.8, 0 ⁇ b ⁇ 0.5, 0 ⁇ c ⁇ 0.05, 0 ⁇ ⁇ ⁇ 2); Li a Ni 1-bc Co b B c O 2- ⁇ T ⁇ (in the above formula, 0.90 ⁇ a ⁇ 1.8, 0 ⁇ b ⁇ 0.5, 0 ⁇ c ⁇ 0.05, 0 ⁇ ⁇
  • the above porous binder scaffold may be any polymer binder commonly used in the relevant technical field, and either an aqueous polymer binder or a non-aqueous polymer binder may be used.
  • the polymer binder may be a fluorine-based resin, a rubber-based material, a polyolefin-based resin, an acrylic resin, an imide-based resin, a cellulose-based resin, or the like.
  • the polymer binder is selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene, polyvinylpyrrolidone, polyacrylonitrile, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polymethyl methacrylate, polyvinylacetate, ethylene-co-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile styrene butadiene copolymer, polyimide, polyvinyl alcohol, carboxymethyl cellulose, acryl
  • the positive electrode active material layer may further include a conductive material, in which case the conductive material may be contained or adsorbed in the porous binder scaffold.
  • the above conductive material is not particularly limited as long as it is commonly used in the relevant technical field, but as a non-limiting example, it may be a carbon-based conductive material, and the carbon-based conductive material may include a point-shaped carbon-based conductive material, a linear carbon-based conductive material, a plate-shaped carbon-based conductive material, or a mixture thereof.
  • the point-shaped carbon-based conductive material may include acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, carbon black, etc.
  • the linear carbon-based conductive material may include carbon nanotubes, conductive carbon fibers, etc.
  • the plate-shaped carbon-based conductive material may include graphene, etc.
  • the above-described challenging material may be one or a combination of two or more selected from the group consisting of carbon black, carbon nanotubes, and VGCF (Vapor Grown Carbon Fiber, VGCF).
  • the positive electrode active material layer may further include a metal salt, and the metal salt may be contained in or surface-adsorbed at least one of the porous binder scaffold and the positive electrode active material particles.
  • the metal ion of the metal salt may be a metal ion (active ion) involved in an electrochemical reaction, and the metal salt may induce effective complexation of the carbon-based conductive material and the binder, and may remain contained in or surface-adsorbed at least one of the porous binder scaffold structure and the positive electrode active material, and may remain in a crystal phase unique to the salt.
  • the metal salt may be included in an amount of 0.01 to 50 parts by weight, or 0.01 to 30 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 1 part by weight, based on 100 parts by weight of the positive electrode active material particles.
  • the weight ratio of the binder: metal salt is not particularly limited, but may be 1:0.1 to 1, 1:0.1 to 0.8, or 1:0.2 to 0.6.
  • the above metal salt may be a metal salt containing a sulfonyl group, in which case it may remain in the positive electrode to further improve the electrochemical properties of the positive electrode and further improve wettability with respect to a liquid electrolyte.
  • the molecular weight (g/mole) of the above sulfonyl group-containing metal salt may be 1000 or less, specifically 500 or less, more specifically 400 or less, and may have a molecular weight of 20 or more, 50 or more, or 100 or more.
  • the number of anions per molecule of the above sulfonyl group-containing metal salt may be 1 to 4, specifically 1 to 3, more specifically 1 to 2.
  • the metal salt may be selected from the following chemical formula 1 or chemical formula 2, but is not limited thereto.
  • n 1 or 2;
  • A is a cation of valence n
  • R 1 to R 3 are each independently a fluoro(C1-C7) alkyl or a fluoro group.
  • R 1 to R 3 can each independently be F, CFH 2 , CF 2 H, CF 3 , C 2 F 5 , C 3 F 7 , C 4 F 9 or C 5 H 11 .
  • the above A is a monovalent cation or a divalent cation
  • the monovalent cation may be an alkali metal ion
  • the divalent cation may be an alkaline earth metal ion or a post-transition metal ion.
  • the A may be lithium, sodium, zinc, copper, aluminum, silver, gold, cesium, indium, magnesium or calcium.
  • the sulfonyl group-containing metal salt may be one or more selected from lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(perfluoroethanesulfonyl)imide, zinc trifluoromethanesulfonate, zinc di[bis(trifluoromethylsulfonyl)imide], and the like.
  • the deviation of the conductive material concentration (C 1 ) of the first active material layer corresponding to a point 1/3 of the thickness of the positive electrode active material layer from the boundary between the positive electrode current collector and the positive electrode active material layer, the conductive material concentration (C 2 ) of the second active material layer corresponding to a point from the point 1/3 to the point 2/3 of the thickness of the positive electrode active material layer, and the conductive material concentration (C 3 ) of the third active material layer from the point 2/3 of the thickness of the positive electrode active material layer to the surface may be 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, and, but not limited to, 1% or more. Specifically, the deviation may be 1 to 10%, 1 to 7%, or 1 to 5%.
  • the positive electrode active material layer is characterized by a positive electrode material such as a conductive material and positive electrode active material particles being very uniformly distributed in the thickness direction as the thickness of the positive electrode active material layer increases by forming a porous binder scaffold by microporousizing the binder component.
  • the above cathode is not particularly limited as long as it is commonly used in electrochemical devices.
  • the negative electrode includes a negative electrode active material layer containing a negative electrode active material
  • the negative electrode active material may be a material commonly used in a negative electrode of a lithium secondary battery.
  • the negative electrode active material may be a material capable of lithium intercalation.
  • the negative electrode active material may be one or more selected from, but is not limited to, lithium (metallic lithium), graphitizable carbon, non-graphitizable carbon, graphite, silicon, Sn alloy, Si alloy, Sn oxide, Si oxide, Ti oxide, Ni oxide, Fe oxide (FeO), lithium-titanium oxide (LiTiO 2 , Li 4 Ti 5 O 12 ), mixtures thereof, or composites thereof.
  • the negative electrode may include a negative electrode active material layer containing 50 wt% or more, 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, and not limited to 99 wt% or less of a graphite-based active material, specifically 50 to 99 wt%, 60 to 99 wt%, 70 to 99 wt%, 80 to 99 wt%, or 90 to 99 wt%.
  • the graphite-based active material may be artificial graphite or natural graphite.
  • the graphite-based active material may be natural graphite.
  • the negative electrode may include a negative current collector, or a negative current collector and lithium metal.
  • an electrochemical device may be a lithium metal battery including the above-described thick-film positive electrode; a negative electrode including a negative electrode current collector and lithium metal formed on the negative electrode current collector; and an electrolyte.
  • an electrochemical device may be an anode-free lithium battery including the above-described thick-film positive electrode; a negative electrode current collector; and an electrolyte.
  • the above positive and negative electrodes may be provided by forming the positive active material layer and the negative active material layer on a positive current collector and a negative current collector, respectively.
  • the positive current collector and the negative current collector may be any positive current collector or negative current collector used in a typical lithium secondary battery.
  • the positive current collector or the negative current collector may be any material that has excellent conductivity and is chemically stable during charge and discharge of the battery.
  • the positive current collector or the negative current collector may be any material that is conductive, such as graphite, graphene, titanium, copper, platinum, aluminum, nickel, silver, gold, aluminum, or carbon nanotubes, but the present invention is not limited thereto.
  • the above electrolyte may be a liquid electrolyte, a solid electrolyte or a combination thereof, and specifically may be a liquid electrolyte, and the liquid electrolyte may include a non-aqueous organic solvent and a lithium salt.
  • the non-aqueous organic solvent may be a mixed solvent of a cyclic carbonate solvent and a linear carbonate solvent, and a mixing volume ratio of the cyclic carbonate solvent: linear carbonate solvent may be mixed and used in a volume ratio of 1:1 to 9, or 1:1 to 4.
  • the lithium salt may be one or a mixture of two or more selected from the group consisting of LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 3 CF 3 ) 2 , LiC 4 F 9 SO 3 , LiAlO 4 , LiAlCl 4 , LiCl and LiI, but is not limited thereto.
  • the concentration of the lithium salt may be included in a range of 0.6 M to 2.0 M.
  • the liquid electrolyte may have a ratio of the amount of electrolyte injected to the capacity of the electrochemical device according to one embodiment (g/Ah) of less than 3.0, less than 2.0, less than 1.5, less than 1.2, or less than 1.1.
  • the liquid electrolyte may be included in a weight ratio of 15 to 30, or a weight ratio of 15 to 25, or a weight ratio of 15 to 20, with respect to 100 parts by weight of the positive electrode.
  • the positive electrode of the electrochemical device has excellent wettability with respect to the electrolyte, so that the amount of electrolyte used can be reduced while realizing a further improved energy density.
  • the electrochemical device may further include a separator, and the separator is not limited to one commonly used in the relevant technical field, but as a non-limiting example, for example, may be selected from glass fiber, polyester, polyethylene, polypropylene, polytetrafluoroethylene or a combination thereof, may be in the form of a non-woven fabric or a woven fabric, and may optionally be used in a single-layer or multi-layer structure.
  • a separator is not limited to one commonly used in the relevant technical field, but as a non-limiting example, for example, may be selected from glass fiber, polyester, polyethylene, polypropylene, polytetrafluoroethylene or a combination thereof, may be in the form of a non-woven fabric or a woven fabric, and may optionally be used in a single-layer or multi-layer structure.
  • an electrochemical device comprising a positive electrode, a negative electrode, and an electrolyte
  • the positive electrode comprises: a positive electrode current collector; and a positive electrode active material layer formed on the positive electrode current collector and comprising a binder, positive electrode active material particles, and a conductive material; wherein, when a cross-section of the positive electrode active material layer is analyzed by X-ray CT, a deviation of a conductive material concentration (C1) of a first active material layer corresponding to a point 1/3 of the thickness direction from a boundary between the positive electrode current collector and the positive electrode active material layer, a conductive material concentration (C2) of a second active material layer corresponding to a point 1/3 to 2/3 of the thickness direction of the positive electrode active material layer, and a conductive material concentration (C3) of a third active material layer from the point 2/3 of the thickness direction of the positive electrode active material layer to the surface is 10% or less.
  • the binder can form a porous binder scaffold structure forming a skeleton of a network structure in which pores are richly developed, and the porous network structure can serve as a support in which positive electrode materials such as positive electrode active material particles and conductive materials can be evenly distributed. That is, the positive electrode according to one embodiment can maintain excellent battery performance by making the binder component microporous so that the positive electrode material is very evenly distributed.
  • an electrochemical device can realize a high energy density of 180 Wh/kg or more, or 180 Wh/kg to 400 Wh/kg, or 180 Wh/kg to 380 Wh/kg, and can satisfy both excellent life characteristics and stability.
  • the electrochemical device may include the cathode active material layer in an amount of 50 wt% or more, 55 wt% or more, or 60 wt% or more, or 95 wt% or less, or 90 wt% or less, or 88 wt% or less, or 50 to 90 wt%, or 60 to 90 wt%, or 60 to 85 wt%, based on the total weight.
  • the positive electrode active material particles may be included in an amount of 70 to 99 wt%, 80 to 99 wt%, or 85 to 99 wt% with respect to the total weight of the positive electrode active material layer.
  • the above cathode active material particles may include 60 wt% or more, 70 wt% or more, 80 wt% or more, 90 wt% or more, 95 wt% or more, and, but not limited to, less than 100 wt% of the lithium iron phosphate-based particles based on the total weight of the cathode active material particles. Specifically, it may include 60 wt% or more and less than 100 wt%, 60 to 99 wt%, 65 to 99 wt%, 70 to 99 wt%, 80 to 99 wt%, 85 to 98 wt%, or 90 to 97 wt%. Alternatively, it goes without saying that the above cathode active material particles may include 100 wt% of the lithium iron phosphate-based particles based on the total weight of the cathode active material particles.
  • the positive electrode may have a positive electrode active material layer thickness of 50 ⁇ m or more, or 100 ⁇ m or more, or 200 ⁇ m or more, or 2,000 ⁇ m or less, or 1,500 ⁇ m or less, or 1,000 ⁇ m or less, and may be a thick-film positive electrode having a thickness of 150 to 2,000 ⁇ m, or 100 to 2,000 ⁇ m, or 100 to 1,000 ⁇ m, or 100 to 500 ⁇ m, or 200 to 500 ⁇ m.
  • the positive electrode may be a thick film positive electrode having a capacity per area of a positive electrode active material layer formed on one surface of a positive electrode current collector of 3.5 to 10 mAh/cm 2 , 3.5 to 9 mAh/cm 2 , or 3.8 to 8 mAh/cm 2 .
  • the positive electrode may be a thick-film positive electrode having a positive electrode active material layer composite density (g/cc) of 2.0 to 4.0, or 2.0 to 3.0, or 2.2 to 2.6.
  • g/cc positive electrode active material layer composite density
  • the electrode tortuosity ( ⁇ ) calculated by the following relationship may be 10 or less, 8 or less, 7 or less, or 6 or less, and may be, but is not limited to, 1 or more.
  • the electrode tortuosity may be 1 to 10, 2 to 8, 3 to 7, 4 to 7, or 5 to 7.
  • K electrolyte represents the ionic conductivity of the electrolyte
  • K electrode represents the ionic conductivity of the anode
  • Porosity represents the porosity of the anode
  • An electrochemical device including such a cathode has excellent ion conductivity and can have excellent battery performance because the ion transfer path within the electrode is relatively short.
  • a half-cell manufactured with the positive electrode may have a discharge capacity retention rate at 0.3 C of 50% or more, or 60% or more, or 70% or more, or 74% or more, and may be from 60% to 99%, or from 70% to 98%, relative to the discharge capacity at 0.1 C.
  • the measurement of the discharge capacity retention rate at 0.1 C and 0.3 C may be, but is not limited to, the retention rate measured after 1 charge, after 5 charges, after 10 charges, or after 30 charges.
  • the electrochemical device may have a 0.1C discharge capacity implementation ratio relative to the design capacity of 0.8 or more, 0.85 or more, 0.9 or more, 0.95 or more, and may be from 0.8 to 1.0, or from 0.9 to 1.0, or from 0.95 to 1.0.
  • the design capacity means a theoretical value calculated from the total weight of the positive active material included in the cell and the reversible discharge capacity of the positive active material.
  • the positive electrode active material layer does not generate cracks at all even though it is high-density/high-loaded, and the positive electrode material can be very evenly distributed in the thickness direction, and the uniform flow characteristics of lithium ions and uniform charge/discharge characteristics in the thickness direction can be effectively maintained.
  • the cathode active material layer according to one embodiment can implement excellent mechanical properties even using a small amount of binder since the binder forms a porous scaffold structure, and thus the cathode active material content can be further increased, thereby implementing an even better energy density.
  • the porous binder scaffold may be included in an amount of 0.01 to 40 parts by weight, or 0.01 to 20 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 5 parts by weight, or 0.01 to 1 part by weight, relative to 100 parts by weight of the positive electrode active material particles.
  • the positive electrode active material layer may further include a metal salt, and the metal salt may be contained in or surface-adsorbed in at least one of the porous binder scaffold and the positive electrode active material particles.
  • the metal salt may be included in an amount of 0.01 to 50 parts by weight, or 0.01 to 30 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 10 parts by weight, or 0.01 to 1 part by weight, based on 100 parts by weight of the positive electrode active material particles. Since a description of the type of the metal salt is as described above, it is omitted.
  • the ratio (g/Ah) of the electrolyte injection amount to the capacity of the electrochemical device may be less than 2.0, less than 1.5, less than 1.2, or less than 1.1.
  • the liquid electrolyte may be included in a weight ratio of 10 to 30, or a weight ratio of 10 to 25, or a weight ratio of 15 to 25 with respect to 100 parts by weight of the positive electrode.
  • the positive electrode of the electrochemical device has excellent wettability with respect to the electrolyte, so that the amount of electrolyte used can be reduced while realizing a further improved energy density.
  • the means for forming a porous binder scaffold by microporousing the binder component is not particularly limited, but may be, for example, using a pore former when preparing a cathode material slurry, and the pore former may be, for example, a mixed solvent of two or more having different solubility parameters, a metal salt, or a combination thereof.
  • the above mixed solvent may be, specifically, a mixed solvent of a first solvent and a second solvent having different solubility parameters, and the first solvent and the second solvent may have different solubilities with respect to the binder due to the different solubility parameters. Due to the different solubilities between the solvents, solidification of the binder may occur in a state where the solvent remains during the drying process of the cathode material slurry, and porosity of the binder component may occur in the cathode due to volatilization of the residual solvent during and/or after solidification of the binder.
  • the difference in the solubility parameters between the first solvent and the second solvent may be 0.1 to 20, or 0.1 to 10, or 0.1 to 5, or 1 to 5, and specifically, may be 0.5 or more, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 15 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, or 5 or less.
  • the solubility parameter (based on 25°C) may be based on a known value through the Hansen solubility parameter for each substance (e.g., Charles Hansen, "Hansen Solubility Parameters: A User's Handbook” CRC Press (2007), “The CRC Handbook and Solubility Parameters and Cohesion Parameters,” Allan F. M. Barton (1999)), etc.) or a value calculated by commercial software such as Molecular Modeling Pro or Dynacomp Software, and the Hansen solubility parameter for each substance is a value that is already known to those skilled in the art or can be easily calculated.
  • Hansen solubility parameter for each substance e.g., Charles Hansen, "Hansen Solubility Parameters: A User's Handbook” CRC Press (2007), “The CRC Handbook and Solubility Parameters and Cohesion Parameters,” Allan F. M. Barton (1999)), etc.
  • commercial software such as Molecular Modeling Pro or Dynacomp Software
  • the second solvent can act as a pore former, and the degree of porosity of the binder can be controlled by controlling the relative amounts of the first solvent and the second solvent.
  • the weight ratio of the first solvent to the second solvent can be 1:0.1 to 10, 1:0.1 to 5, 1:0.1 to 1, or 1:0.1 to 0.5, but is not necessarily limited thereto.
  • a method for manufacturing an electrochemical device comprising: a positive electrode, an negative electrode, and an electrolyte; wherein the positive electrode comprises: a positive electrode current collector; and a positive electrode active material layer formed on the positive electrode current collector, the positive electrode active material layer comprising a porous binder scaffold and positive electrode active material particles; wherein the positive electrode active material particles comprise lithium iron phosphate particles having an olivine structure with respect to the total weight of the positive electrode active material layer.
  • the method for manufacturing the electrochemical device includes the steps of manufacturing a positive electrode including a current collector and a positive electrode active material layer on the current collector; the step of manufacturing a negative electrode; the step of assembling the positive electrode and the negative electrode; and the step of injecting an electrolyte. Since the positive electrode, the negative electrode, and the electrolyte are the same as those described above, a detailed description thereof will be omitted.
  • the step of manufacturing the positive electrode may include a step of applying a positive electrode slurry including the positive electrode active material particles, a conductive material, a binder, and a metal salt as described above onto a current collector; and a step of drying the applied positive electrode slurry.
  • the application of the cathode slurry may be performed by one or more methods selected from spin coating, roll coating, spray coating, dip coating, flow coating, doctor blade, dispensing, inkjet printing, offset printing, stencil printing, screen printing, pad printing, gravure printing, reverse gravure printing, gravure offset printing, flexography printing, stencil printing, imprinting, xerography, slot die coating, bar coating, and roll-to-roll coating, but is not limited thereto.
  • a step of drying the slurry application (the applied cathode slurry) can be performed.
  • the drying can be performed by applying energy, or can be performed through natural drying or vacuum drying without separately applying energy.
  • the applied energy can be thermal energy, light energy, or thermal and light energy, and the application of thermal and light energy can include sequential application or simultaneous application.
  • the light can be near-infrared light, which is a heat ray.
  • the above drying can be performed in a multi-stage manner, and the drying method of each stage can be the same or different.
  • hot air drying can be performed first, followed by vacuum drying second.
  • the above drying temperature is not particularly limited as long as it is a temperature capable of drying the cathode material slurry.
  • the drying temperature may be performed at a temperature of 90 to 180° C., 100 to 160° C., 100 to 140° C., or 100 to 130° C.
  • the drying time may be appropriately adjusted in proportion to the amount of the cathode material slurry applied.
  • the cathode material slurry can be prepared by mixing the cathode active material particles, the conductive material, the organic binder, and the ionic material described above in the mixed solvent described above.
  • the order of adding the cathode active material particles, the conductive material, the organic binder, and the ionic material is not particularly limited.
  • the cathode material slurry can be prepared by simultaneously adding and mixing the cathode active material particles, the conductive material, the organic binder, and the ionic material to the solvent.
  • the cathode material slurry can be prepared by first adding the cathode active material particles to a mixture in which the conductive material, the organic binder, and the ionic material are mixed.
  • the cathode material slurry prepared in this way can form a more stable porous binder scaffold structure when dried later to form a cathode active material layer.
  • the cathode material slurry preparation step may include a step of preparing an active material mixture by mixing an ionic material (metal salt) and cathode active material particles, a step of mixing the active material mixture, a conductive material, and a binder into the cathode material mixture described above in the mixed solvent.
  • the step of preparing the above active material mixture may include a step of mixing an ionic material and positive electrode active material particles and then calcining them.
  • the above mixing may mean mechanical mixing through a stirring device such as a rotary mixer, and the mixing speed (rpm) and mixing time may be appropriately adjusted according to the amount of ionic material and positive electrode active material particles introduced.
  • the above-mentioned calcination can be performed at a temperature below the melting point of the ionic material, and is not particularly limited as long as it is a temperature higher than room temperature (20 ⁇ 5°C) and a temperature below the melting point (MP) of the ionic material.
  • the temperature of the above-mentioned calcination may be 0.5 (MP) or more and less than 1 (MP), 0.5 (MP) to 0.9 (MP), or 0.6 (MP) to 0.8 (MP) with respect to the melting point (MP) of the ionic material.
  • the above-mentioned calcination can be performed at a temperature of 150 to 300°C, 160 to 250°C, or 180 to 220°C.
  • the heating rate during the firing may be, but is not limited to, 1 to 30°C/min, 1 to 15°C/min, 1 to 10°C/min, or 3 to 7°C/min.
  • the time for which the above-mentioned calcination is performed can be appropriately adjusted depending on the amount of the active material mixture introduced, and can be performed for, but not limited to, 10 to 180 minutes, 20 to 150 minutes, or 30 to 90 minutes.
  • a cathode material was prepared by mixing 94 wt% of lithium iron phosphate (LiFePO 4 ) active material having an olivine structure and an average particle size of 7 ⁇ m, 2 wt% of carbon black (Super-P) having an average particle size of 40 nm as a conductive material, 3 wt% of polyvinylidene fluoride as a binder, and 1 wt% of lithium trifluoromethanesulfonate as a salt ionic material (total 100 wt%).
  • LiFePO 4 lithium iron phosphate
  • Super-P carbon black
  • the cathode material was added to a mixed solvent of 32.5 wt% of N-methyl-2-pyrrolidone and 7.5 wt% of propylene carbonate to an amount of 60 wt% to prepare a cathode material slurry.
  • the above cathode material slurry was applied to a 20 ⁇ m thick aluminum film using a doctor blade, dried with hot air at 100 °C, vacuum dried at 130 °C for 24 hours, and rolled using a roll press to manufacture a cathode including a 121 ⁇ m thick cathode active material layer in which cathode active material particles are evenly distributed within a porous binder scaffold structure.
  • the positive electrode active material loading of the above positive electrode was 29.2 mg/cm2, and the composite density was 2.4 g/cc.
  • the anode material slurry was prepared by adding 60 wt% of the above anode material to 40 wt% of distilled water.
  • the above anode material slurry was applied to a 20 ⁇ m thick copper thin film using a doctor blade, dried with hot air at 100 ° C., vacuum dried at 130 ° C. for 24 hours, and rolled using a roll press to prepare an anode including a 74 ⁇ m thick anode active material layer.
  • the negative active material loading of the above negative electrode was 13.7 mg/cm2, and the composite density was 1.65 g/cc.
  • the manufactured positive and negative electrodes and separator were laminated to manufacture a battery assembly, and an aluminum battery tab (0.1 T ⁇ 7 mm) was ultrasonically welded to the non-coated portion of the positive electrode assembly, and a nickel battery tab (0.1 T ⁇ 7 mm) was welded to the non-coated portion of the negative electrode assembly, respectively. Then, the battery assembly was placed in a formed battery pouch film (153 ⁇ m, DNP) and sealed. Thereafter, an electrochemical device was manufactured by injecting 2.72 g/Ah of a liquid electrolyte containing 1 mol of LiPF 6 dissolved in a solvent containing ethylene carbonate and dimethyl carbonate in a volume ratio of 1:1.
  • An electrochemical device was manufactured in the same manner as in Example 1, except that poly(1-ethyl-3-methylimidazolium)bis(trifluoromethanesulfonyl)imide (PVIm[TFSI]) was used instead of lithium trifluoromethanesulfonate as the salt ionic material in the manufacture of the positive electrode.
  • PVm[TFSI] poly(1-ethyl-3-methylimidazolium)bis(trifluoromethanesulfonyl)imide
  • An electrochemical device was manufactured in the same manner as in Example 1, except that a mixture of trimethylolpropane ethoxylate triacrylate and lithium trifluoromethanesulfonate in a 50:50 mass% ratio was used instead of lithium trifluoromethanesulfonate as the salt ionic material in the manufacture of the positive electrode.
  • An electrochemical device was manufactured in the same manner as in Example 1, except that cesium bis(trifluoromethanesulfonyl)imide was used instead of lithium trifluoromethanesulfonate as the salt ionic material in the manufacture of the positive electrode.
  • Example 1 an electrochemical device was manufactured in the same manner as in Example 1, except that the positive electrode material was manufactured by mixing the active material mixture, conductive material, and binder after manufacturing the active material mixture during the manufacture of the positive electrode.
  • the active material mixture was manufactured by pre-mixing lithium trifluoromethanesulfonate and lithium iron phosphate active material using a rotary mixer at 2000 rpm for 3 minutes, placing the mixture in a furnace, heating it to 200 °C at a heating rate of 5 °C/min, maintaining it at that temperature for 1 hour, and then firing it. The fired product was then naturally cooled to room temperature (25 ⁇ 5 °C).
  • Example 1 an electrochemical device was manufactured in the same manner as in Example 1, except that a silicon composite cathode manufactured by the following method was used instead of the cathode of Example 1.
  • the above-mentioned negative electrode slurry was applied onto a 20 ⁇ m thick copper thin film using a doctor blade, dried with hot air at 100 °C, vacuum-dried at 130 °C for 24 hours, and rolled using a roll press to prepare a silicon composite negative electrode including a 50 ⁇ m thick negative electrode active material layer.
  • Example 1 an electrochemical device was manufactured in the same manner as in the above Example 1, except that 94 wt% of lithium iron phosphate (LiFePO 4 ) active material was used as a positive electrode active material, 2 wt% of carbon black (Super-P) having an average particle size of 40 nm was used as a conductive material, and 4 wt% of polyvinylidene fluoride was used as a binder to manufacture a positive electrode slurry.
  • LiFePO 4 lithium iron phosphate
  • Super-P carbon black
  • 4 wt% of polyvinylidene fluoride was used as a binder to manufacture a positive electrode slurry.
  • the energy density was calculated by dividing the unit cell energy (Wh) of the electrochemical devices of the examples and comparative examples by the total weight (Kg) of the electrochemical devices.
  • energy density refers to a non-patent literature (Park, S.-H. et al. High areal capacity battery electrodes enabled by segregated nanotube networks. Nat. Energy 4, 560-567 (2019).).
  • the total weight of the electrochemical device means the weight of the final electrochemical device product including the weight of all auxiliary materials such as pouches and tabs, and the unit cell energy was measured by integrating the 0.05 C discharge graph. The results are shown in Table 1 below.
  • the electrochemical devices of the examples and comparative examples were charged at 0.1 C-rate to 3.6 V under constant current/constant voltage (CC/CV) conditions at 25°C and then cut-off. Thereafter, they were discharged at 0.1 C-rate to 2.8 V (CC conditions).
  • the capacity implementation rate was evaluated as a percentage of the discharge capacity divided by the design capacity.
  • the design capacity means a value calculated from the total weight of the positive electrode active material included in the cell and the reversible discharge capacity of the positive electrode active material. The results are shown in Table 1 below.
  • the electrochemical device according to the embodiment can simultaneously implement high energy density and excellent capacity retention. That is, it can be seen that the electrochemical device according to the present invention can implement high energy density while maintaining excellent life characteristics even when employing a thick-film anode.
  • the appearance of the surfaces of the positive electrodes manufactured in Example 1 and Comparative Example 1 was evaluated using a scanning electron microscope (SEM) analysis.
  • SEM analysis results of the positive electrodes according to Comparative Example 1 and Example 1 are shown in FIGS. 1 and 2, respectively.
  • FIGS. 1 and 2 in the case of the positive electrode manufactured in Comparative Example 1, it was confirmed that numerous cracks occurred in the electrode appearance due to uneven distribution of the conductive agent/binder during slurry coating and drying.
  • the positive electrode active material coating layer was evenly applied on the current collector without mechanical deformation and a uniform binder scaffold structure was formed in the direction of the entire electrode thickness, so that no cracks occurred in the electrode appearance.
  • the cross-sections of the positive electrodes manufactured in Example 1 and Comparative Example 1 were X-ray CT scanned to analyze the distribution of the conductive material, carbon black, in the thickness direction. It was confirmed that the positive electrode of Comparative Example 1 had an uneven distribution of the conductive material in the thickness direction. On the other hand, the positive electrode of Example 1 had a uniform distribution of the conductive material in the first active material layer corresponding to 1/3 of the thickness direction from the boundary between the positive electrode current collector and the positive electrode active material layer, the second active material layer from 1/3 to 2/3 of the thickness direction, and the third active material layer from 2/3 to the surface.
  • the distribution of the conductive material content (vol%) in the first active material layer, the second active material layer, and the third active material layer according to the X-ray CT scan results was quantified, and the results are shown in Table 2 below.
  • the positive electrode according to Example 1 showed a very low value of about 5% or less in the deviation of the conductive material concentration according to Equation 1 below, and through this, it was confirmed that the positive electrode active material layer of Example 1 had the conductive material very uniformly distributed.
  • C 0 is the average concentration (vol%) of the conductive material throughout the positive electrode active material layer
  • C n is the conductive material concentration (vol%) of the nth active material layer.
  • a symmetric cell was manufactured using the positive electrodes manufactured in the Examples and Comparative Examples, and a liquid electrolyte containing 1 mol of LiPF 6 dissolved in a solvent containing ethylene carbonate (EC) and diethyl carbonate (DEC) in a 1:1 volume ratio was injected to manufacture a cell for measuring ionic conductivity.
  • the ionic resistance was measured through impedance analysis of the cell for measuring ionic conductivity, and the ionic conductivity value inside the positive electrode was calculated. The results are shown in Table 3 below.
  • N m MacMullin number
  • K electrolyte refers to the ionic conductivity of the liquid electrolyte
  • K electrode refers to the ionic conductivity of the anode according to the examples and comparative examples measured at 25 °C.
  • the liquid electrolyte was prepared by adding 1 M LiPF 6 to a cosolvent containing ethylene carbonate (EC)/diethyl carbonate (DEC) in a volume ratio of 1:1.
  • the ionic conductivity of the anode was calculated by measuring the conductivity in the thickness direction of the electrode after filling the anode with a 1 M LiPF 6 EC/DEC solution.
  • the porosity was measured using a mercury porosimeter (Mercury Porosimet, AutoPore V, Micromeritics) according to ASTM D 4284-83. Specifically, a pre-weighed anode sample was placed in a mercury porosimeter cell, and the cell was filled with mercury up to a given pressure range (30 psia to 60,000 psia) to measure the pore volume inside the anode. The final curvature was calculated from the measured porosity and McMullin number. The measured electrode curvature is shown in Table 3 below.
  • the positive electrode according to the embodiment had improved curvature within the electrode compared to the positive electrode according to the comparative example.
  • the curvature of the electrode is affected by the pore structure formed within the electrode, and when the conductive agent and the binder are unevenly distributed, a high curvature value is measured, which can be expected to result in a longer ion transfer path within the electrode and a decrease in battery performance.
  • Comparative Example 1 it can be confirmed that the uneven distribution of the conductive agent and binder became more severe due to the high electrode loading, and the curvature of the electrode significantly increased.
  • the electrode manufactured according to the embodiment evenly distributes the positive electrode active material within the uniformly formed porous binder scaffold structure by inducing interaction between the conductive agent, binder, and metal salt to suppress the unbalanced movement of the conductive agent and binder that occurs during electrode drying, and it can be confirmed that the curvature within the electrode does not significantly increase even with high electrode loading.
  • the cathode of the embodiment it was confirmed that by controlling the timing of adding the metal salt during the slurry preparation, the interaction between the conductive agent, binder and metal salt can be more easily induced, thereby further improving the structural characteristics of the porous binder scaffold.
  • a half cell was manufactured using the positive electrode manufactured in Example 1, and the capacity was measured under 0.1 C/0.1 C charge/discharge conditions and 0.1 C/0.3 C charge/discharge conditions, respectively, and the discharge capacity retention rate according to the rate (C-rate) was evaluated.
  • the half cell was manufactured in the same manner as the method for manufacturing the electrochemical device, except that a 200 ⁇ m thick lithium metal was used as the negative electrode.
  • the above half-cell was charged to 3.6 V at 0.1 C-rate under constant current/constant voltage (CC/CV) conditions at 25 °C and then cut-off. Thereafter, it was discharged to 2.8 V at 0.1 C-rate (CC conditions) and the discharge capacity under 0.1 C/0.1 C charge/discharge conditions was measured. In addition, the C-rate was changed to 0.3 C and the discharge capacity under 0.1 C/0.3 C charge/discharge conditions was measured.
  • the relative discharge capacity at 0.3 C was defined as the value obtained by dividing the measured discharge capacity at 0.1 C by the discharge capacity at 0.3 C, and the discharge capacity retention rate was calculated by multiplying the relative discharge capacity at 0.3 C by 100. The results are shown in Table 4 below.
  • the measurement results show that the half cell of the positive electrode according to Example 1 effectively maintains the discharge capacity even when the rate increases. That is, the positive electrode according to one embodiment has uniform lithium ion flow characteristics and excellent output characteristics even when the thickness increases.
  • the positive electrode according to Example 1 was confirmed to have a capacity per area of 4 mAh/cm2 under 0.1 C/0.1 C conditions and a voltage range of 2.8-3.6 V.

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Abstract

La présente invention concerne un dispositif électrochimique à haute densité d'énergie contenant du phosphate de fer et de lithium. Le dispositif électrochimique selon la présente invention comprend une cathode, une anode et un électrolyte, la cathode comprenant un collecteur de courant de cathode et une couche de matériau actif de cathode, qui est formée sur le collecteur de courant de cathode et comprend un échafaudage de liant poreux et des particules de matériau actif de cathode, et les particules de matériau actif de cathode comprennent des particules à base de phosphate de fer et de lithium à structure d'olivine sur la base du poids total de la couche de matériau actif de cathode.
PCT/KR2024/007824 2023-06-07 2024-06-07 Dispositif électrochimique à haute densité d'énergie contenant du phosphate de fer et de lithium Ceased WO2024253469A1 (fr)

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Cited By (1)

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CN120341240A (zh) * 2025-05-12 2025-07-18 宁德时代新能源科技股份有限公司 电池单体、电池装置、用电装置以及储能装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003132877A (ja) * 2001-10-23 2003-05-09 Sony Corp 正極及び固体電解質電池、並びに正極の製造方法
JP2009043514A (ja) * 2007-08-08 2009-02-26 Toyota Motor Corp 電極材料、電極板、二次電池、及び電極材料の製造方法
KR20190007419A (ko) * 2016-05-13 2019-01-22 니폰 제온 가부시키가이샤 전기 화학 소자 전극용 바인더 입자 집합체, 전기 화학 소자 전극용 슬러리 조성물, 및 그들의 제조 방법, 그리고, 전기 화학 소자용 전극 및 전기 화학 소자
CN112133921A (zh) * 2020-09-30 2020-12-25 蜂巢能源科技有限公司 适用于全固态电池的正极材料层、其制备方法、正极片和全固态电池
CN116130807A (zh) * 2023-01-12 2023-05-16 楚能新能源股份有限公司 补锂膜及其制备方法、复合补锂隔膜和锂离子电池

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070094156A (ko) 2006-03-16 2007-09-20 주식회사 엘지화학 고용량 특성을 갖는 전극 및 이의 제조방법

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003132877A (ja) * 2001-10-23 2003-05-09 Sony Corp 正極及び固体電解質電池、並びに正極の製造方法
JP2009043514A (ja) * 2007-08-08 2009-02-26 Toyota Motor Corp 電極材料、電極板、二次電池、及び電極材料の製造方法
KR20190007419A (ko) * 2016-05-13 2019-01-22 니폰 제온 가부시키가이샤 전기 화학 소자 전극용 바인더 입자 집합체, 전기 화학 소자 전극용 슬러리 조성물, 및 그들의 제조 방법, 그리고, 전기 화학 소자용 전극 및 전기 화학 소자
CN112133921A (zh) * 2020-09-30 2020-12-25 蜂巢能源科技有限公司 适用于全固态电池的正极材料层、其制备方法、正极片和全固态电池
CN116130807A (zh) * 2023-01-12 2023-05-16 楚能新能源股份有限公司 补锂膜及其制备方法、复合补锂隔膜和锂离子电池

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120341240A (zh) * 2025-05-12 2025-07-18 宁德时代新能源科技股份有限公司 电池单体、电池装置、用电装置以及储能装置

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