WO2025211331A1 - Électrode négative pour élément de stockage d'énergie à électrolyte non aqueux, et élément de stockage d'énergie à électrolyte non aqueux - Google Patents

Électrode négative pour élément de stockage d'énergie à électrolyte non aqueux, et élément de stockage d'énergie à électrolyte non aqueux

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Publication number
WO2025211331A1
WO2025211331A1 PCT/JP2025/013220 JP2025013220W WO2025211331A1 WO 2025211331 A1 WO2025211331 A1 WO 2025211331A1 JP 2025013220 W JP2025013220 W JP 2025013220W WO 2025211331 A1 WO2025211331 A1 WO 2025211331A1
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WIPO (PCT)
Prior art keywords
negative electrode
active material
electrode active
material layer
mass
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Pending
Application number
PCT/JP2025/013220
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English (en)
Japanese (ja)
Inventor
泰幸 古谷
雄大 川副
理史 ▲高▼野
右京 針長
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GS Yuasa International Ltd
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GS Yuasa International Ltd
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Publication of WO2025211331A1 publication Critical patent/WO2025211331A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • 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
    • 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 negative electrode for a non-aqueous electrolyte storage element and a non-aqueous electrolyte storage element.
  • Nonaqueous electrolyte secondary batteries typified by lithium-ion secondary batteries
  • Nonaqueous electrolyte secondary batteries are widely used in electronic devices such as personal computers and communication terminals, as well as automobiles, due to their high energy density.
  • other nonaqueous electrolyte energy storage elements such as lithium-ion capacitors and electric double-layer capacitors, are also widely used.
  • Non-aqueous electrolyte storage elements typically include an electrode assembly in which a positive electrode containing a positive electrode active material and a negative electrode containing a negative electrode active material are stacked with a separator interposed between them. This electrode assembly is housed in a container together with a non-aqueous electrolyte to form a non-aqueous electrolyte storage element. Carbon materials such as graphite are widely used as negative electrode active materials (see Patent Documents 1 and 2).
  • Graphite used as a negative electrode active material is sometimes coated on the surface with non-graphitic carbon or the like to improve charge/discharge performance (e.g., discharge capacity).
  • charge/discharge performance e.g., discharge capacity
  • negative electrodes in which the density of the negative electrode active material layer has been increased by pressing or the like may have insufficient discharge capacity.
  • the object of the present invention is to provide a negative electrode for a nonaqueous electrolyte storage element having a sufficiently high density of the negative electrode active material layer and a large discharge capacity, and a nonaqueous electrolyte storage element equipped with such a negative electrode for a nonaqueous electrolyte storage element.
  • a negative electrode for a non-aqueous electrolyte storage element comprises a negative electrode active material layer containing coated graphite particles in which at least a portion of the surface of the graphite is coated with non-graphitic carbon, wherein the density of the negative electrode active material layer is 1.09 g/cm 3 or more, the ratio of the D10 particle size to the D90 particle size of the coated graphite particles (D10/D90) is 0.36 or more, the content of the non-graphitic carbon in the coated graphite particles is 10 mass % or more, and the BET specific surface area of the negative electrode active material layer is 4.0 m 2 /g or less.
  • a nonaqueous electrolyte storage element includes a negative electrode for a nonaqueous electrolyte storage element according to one aspect of the present invention.
  • discharging in the above half-cell refers to an oxidation reaction in which charge-transporting ions are released from the carbon material, which is the negative electrode active material.
  • the half-cell is disassembled, the negative electrode is removed, and after being thoroughly washed with dimethyl carbonate, it is dried under reduced pressure at room temperature.
  • the negative electrode active material layer containing the carbon material is then peeled from the negative electrode substrate, and the negative electrode active material layer is washed with a solvent that dissolves binders and other components to remove them.
  • the washed negative electrode active material layer is then immersed in an acid or alkaline solution to remove metals and SEI (solid electrolyte interface) coatings derived from the negative electrode substrate, followed by washing with water and drying under reduced pressure to obtain the carbon material.
  • SEI solid electrolyte interface
  • the "content of non-graphitic carbon in coated graphite particles” and the "D90 particle size,” “D10 particle size,” and “D50 particle size” of coated graphite particles are measured on the coated graphite particles before assembly into the negative electrode, if such particles can be prepared. If the coated graphite particles to be measured are prepared from the negative electrode of an assembled non-aqueous electrolyte storage element, measurements are performed on coated graphite particles prepared according to the procedure for preparing the carbon material (coated graphite particles) to be subjected to X-ray diffraction from the assembled non-aqueous electrolyte storage element described above.
  • the "density of the negative electrode active material layer” is the value obtained by dividing the mass of the negative electrode active material layer by the apparent volume (volume including voids) of the negative electrode active material layer. That is, the density of the negative electrode active material layer is a density that takes into account the volume of voids in the negative electrode active material layer.
  • the density of the negative electrode active material layer is calculated from the area, average thickness, and mass of the negative electrode active material layer.
  • the average thickness is the average value of thicknesses measured at any five points. The same applies to the average thicknesses of layers other than the negative electrode active material layer.
  • the BET specific surface area of the negative electrode active material layer is 2.0 m 2 /g or more and 3.8 m 2 /g or less, and the discharge capacity is large.
  • the ratio of the D10 particle size to the D90 particle size (D10/D90) of the coated graphite particles may be 0.36 or more and 0.50 or less.
  • the ratio of the D10 particle size to the D90 particle size (D10/D90) of the coated graphite particles is 0.36 or more and 0.50 or less, thereby better demonstrating the above-mentioned effects.
  • the nonaqueous electrolyte storage element described in [5] above has a large discharge capacity because it includes the negative electrode for a nonaqueous electrolyte storage element described in any one of [1] to [4] above.
  • the negative electrode for a nonaqueous electrolyte storage element, the nonaqueous electrolyte storage element, the method for manufacturing a nonaqueous electrolyte storage element, the storage device, and other embodiments according to one embodiment of the present invention are described in detail below.
  • the thickness of the negative electrode is set appropriately depending on the application of the non-aqueous electrolyte storage element, etc.
  • the average thickness of the negative electrode may be, for example, 30 ⁇ m or more and 1,000 ⁇ m or less.
  • the lower limit of the average thickness of the negative electrode may be 50 ⁇ m, 100 ⁇ m, or 200 ⁇ m.
  • the upper limit of the average thickness of the negative electrode may be 500 ⁇ m, 400 ⁇ m, 300 ⁇ m, 200 ⁇ m, or 100 ⁇ m.
  • the average thickness of the negative electrode is the average thickness of the portion where the negative electrode active material layer is laminated onto the negative electrode substrate directly or via an intermediate layer.
  • the negative electrode substrate has both a portion where the negative electrode active material layer is laminated onto both sides and a portion where the negative electrode active material layer is laminated onto only one side, the average thickness of the portion where the negative electrode active material layer is laminated onto both sides of the negative electrode substrate is used.
  • Materials for the negative electrode substrate include metals such as copper, nickel, iron, and alloys thereof (such as stainless steel), as well as carbon materials. Of these, copper or copper alloys are preferred.
  • the negative electrode substrate has a shape such as a sheet, plate, or strip.
  • Examples of the negative electrode substrate include foil, vapor-deposited film, mesh, and porous material, with foil being preferred.
  • the negative electrode substrate may also be, for example, copper foil or copper alloy foil.
  • the average thickness of the negative electrode substrate may be, for example, 2 ⁇ m or more and 35 ⁇ m or less.
  • the lower limit of the average thickness of the negative electrode substrate may be 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, or 10 ⁇ m.
  • the upper limit of the average thickness of the negative electrode substrate may be 30 ⁇ m, 20 ⁇ m, 15 ⁇ m, or 10 ⁇ m.
  • the intermediate layer is a layer disposed between the negative electrode substrate and the negative electrode active material layer.
  • the intermediate layer contains, for example, a conductive agent and a binder. When the intermediate layer contains a conductive agent, the contact resistance between the negative electrode substrate and the negative electrode active material layer can be reduced.
  • conductive agents and binders used in the intermediate layer include the same conductive agents and binders used in the negative electrode active material layer described below.
  • the negative electrode active material layer contains coated graphite particles.
  • the negative electrode active material layer may contain optional components such as other negative electrode active materials besides the coated graphite particles, conductive agents, binders, thickeners, and fillers, as necessary.
  • the negative electrode active material layer may be formed from a negative electrode mixture containing a negative electrode active material and other optional components.
  • the negative electrode active material layer may be provided on only one side or on both sides of a negative electrode substrate having a shape such as a sheet.
  • Coated graphite particles are a component that functions as a negative electrode active material.
  • Coated graphite particles contain graphite as a base material and non-graphitic carbon that coats at least a portion of the surface of the graphite.
  • the non-graphitic carbon may coat the entire surface of the graphite. Alternatively, the non-graphitic carbon may be contained within the graphite. Coating the graphite base material with non-graphitic carbon can be achieved, for example, by coating the surface of graphite particles with pitch and then firing the particles.
  • the coated graphite particles may be particles consisting essentially of graphite and non-graphitic carbon.
  • the total content of graphite and non-graphitic carbon in the coated graphite particles is preferably 90% by mass or less and 100% by mass or less, and may be 99% by mass or more and 100% by mass or less. Note that the content of each component in the coated graphite particles does not include moisture. In other words, the mass of the coated graphite particles excluding moisture (the mass of the coated graphite particles in a dry state) is used as the reference (100% by mass).
  • the graphite that is the base material of the coated graphite particles may be either artificial graphite or natural graphite, but natural graphite is preferred.
  • natural graphite include flake graphite, lump graphite (flake graphite), and amorphous graphite.
  • Graphite may also be obtained by spheroidizing flake graphite and subjecting it to a compaction treatment.
  • the content of coated graphite particles in the negative electrode active material layer is preferably 60% by mass or more and 99.5% by mass or less, and more preferably 90% by mass or more and 99% by mass or less.
  • the lower limit of the content of coated graphite particles in the negative electrode active material layer may be 95% by mass or 97% by mass.
  • a conductive agent is typically a component made of a material that is electrically conductive. Even if the volume resistivity of a conductive agent cannot be directly measured, a conductive agent made of a material known to have a volume resistivity of 10 ⁇ 2 ⁇ cm or less is considered a conductive agent.
  • Examples of conductive agents include carbon materials, metals, and conductive ceramics.
  • a carbon material refers to a material whose main constituent element is carbon.
  • a main constituent element refers to the element that is most abundant on a mass basis. For example, the carbon content in a carbon material may be 80% by mass or more, 90% by mass or more, 95% by mass, 99% by mass, or 99.9% by mass or more.
  • the content of the conductive agent in the negative electrode active material layer is preferably 1% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 9% by mass or less.
  • the content of the conductive agent in the negative electrode active material layer may be 5% by mass or less, or may be 2% by mass or less, 1% by mass or less, 0.5% by mass or less, or 0.1% by mass or less.
  • the technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer does not contain a conductive agent.
  • aqueous binders examples include polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polytetrafluoroethylene, styrene-butadiene rubber, polyethylene, polypropylene, nitrile-butadiene rubber, and cellulose.
  • the content of the binder in the negative electrode active material layer is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.5% by mass or more and 8% by mass or less.
  • the content of the binder in the negative electrode active material layer may be 5% by mass or less, or may be 2% by mass or less.
  • the technology disclosed herein can also be implemented in an embodiment in which the negative electrode active material layer does not contain a binder.
  • the negative electrode active material layer may further contain other components in addition to the coated graphite particles, other negative electrode active materials other than the coated graphite particles, conductive agents, binders, thickeners, and fillers. These other components include those unintentionally generated in the negative electrode active material layer.
  • the negative electrode active material layer may also contain unintentionally contained impurities as the other components, as long as the effects of the present invention are achieved.
  • the upper limit of the content of the other components in the negative electrode active material layer may be 10% by mass, or may be 5%, 2%, 1%, 0.1%, or 0.01% by mass.
  • the upper limit of the content of unintentionally generated components in the negative electrode active material layer may be 10% by mass, or may be 5%, 2%, 1%, 0.1%, or 0.01% by mass.
  • the upper limit of the content of unintentionally contained impurities in the negative electrode active material layer may be 10% by mass, or may be 5%, 2%, 1%, 0.1%, or 0.01% by mass.
  • the lower limit of the density of the negative electrode active material layer is 1.09 g/cm 3 , and may be 1.10 g/cm 3 , 1.13 g/cm 3 , 1.15 g/cm 3 , 1.17 g/cm 3 , 1.18 g/cm 3 , 1.19 g/cm 3 , or 1.20 g/cm 3 .
  • the density of the negative electrode active material layer may be greater than 1.20 g/cm 3 . According to this configuration, even when a high-density negative electrode active material layer is formed that is equal to or greater than the lower limit, cracking of the coated graphite particles is unlikely to occur. Therefore, it is possible to increase the volume-based energy density while maintaining a large discharge capacity.
  • the upper limit of the density of the negative electrode active material layer is, for example, 1.40 g/cm 3 , and may be 1.30 g/cm 3 , 1.25 g/cm 3 , 1.23 g/cm 3 , or 1.20 g/cm 3 .
  • the density of the negative electrode active material layer may be equal to or greater than any of the above-mentioned lower limits and equal to or less than any of the above-mentioned upper limits.
  • the density of the negative electrode active material layer can be adjusted by the particle size of the coated graphite particles, whether or not pressing is performed during production, the pressing pressure, etc.
  • the BET specific surface area of the negative electrode active material layer may be not less than any of the above lower limits and not more than any of the above upper limits.
  • the BET specific surface area of the negative electrode active material layer can be adjusted by the content of non-graphitic carbon in the coated graphite particles, the particle size of the coated graphite particles, whether or not pressing is performed during production, the pressing pressure, etc.
  • the lower limit of the value ((D10/D90)/BET specific surface area) obtained by dividing the ratio of the D10 particle size to the D90 particle size of the coated graphite particles (D10/D90) by the BET specific surface area of the negative electrode active material layer is preferably 0.10 g/m 2.
  • this value ((D10/D90)/BET specific surface area) is 0.10 g/m 2 or more (e.g., 0.10 g/m 2 or more and 0.20 g/m 2 or less)
  • the porosity of the negative electrode active material layer may be, for example, 30% or more and 70% or less.
  • the lower limit of the porosity of the negative electrode active material layer may be 35%, 40%, or 45%.
  • the upper limit of the porosity of the negative electrode active material layer may be 60%, 55%, or 50%.
  • the porosity of the negative electrode active material layer may be equal to or greater than any of the above-mentioned lower limits and equal to or less than any of the above-mentioned upper limits.
  • the "porosity (%)" of the negative electrode active material layer and the positive electrode active material layer described below is calculated by the formula ( 1 -V2/V1) x 100, where V1 is the apparent volume (volume including voids) of the negative (positive) electrode active material layer and V2 is the sum of the actual volumes of the materials constituting the negative ( positive ) electrode active material layer.
  • V1 is the apparent volume (volume including voids) of the negative (positive) electrode active material layer
  • V2 is the sum of the actual volumes of the materials constituting the negative ( positive ) electrode active material layer.
  • the sum V2 of the actual volumes of the materials constituting the negative (positive) electrode active material layer can be calculated from the content of each material in the negative (positive) electrode active material layer and the true density of each material.
  • the thickness of the negative electrode active material layer is appropriately set depending on the type of negative electrode active material, the application of the non-aqueous electrolyte storage element, etc.
  • the average thickness of one negative electrode active material layer may be, for example, 5 ⁇ m or more and 1,000 ⁇ m or less.
  • the lower limit of the average thickness of one negative electrode active material layer may be 10 ⁇ m, 20 ⁇ m, 30 ⁇ m, 40 ⁇ m, 50 ⁇ m, 60 ⁇ m, or 100 ⁇ m.
  • the upper limit of the average thickness of one negative electrode active material layer may be 800 ⁇ m, 500 ⁇ m, 200 ⁇ m, 100 ⁇ m, 80 ⁇ m, 60 ⁇ m, or 40 ⁇ m.
  • the mass per unit area of one negative electrode active material layer may be, for example, 2 mg/cm 2 or more and 50 mg/cm 2 or less.
  • the lower limit of the mass per unit area of one negative electrode active material layer may be 3 mg/cm 2 , 4 mg/cm 2 , 5 mg/cm 2 , or 6 mg/cm 2 .
  • the upper limit of the mass per unit area of one negative electrode active material layer may be 30 mg/cm 2 , 20 mg/cm 2 , 15 mg/cm 2 , 12 mg/cm 2 or 10 mg/cm 2 .
  • the negative electrode according to one embodiment of the present invention can be manufactured, for example, by applying a paste-like negative electrode mixture (negative electrode mixture paste) to a negative electrode substrate directly or via an intermediate layer, and then drying the mixture to form a negative electrode active material layer. After drying, the negative electrode active material layer may be pressed, for example.
  • the negative electrode mixture paste contains the components that make up the negative electrode active material layer, such as coated graphite particles and an optional binder.
  • the negative electrode mixture paste typically further contains a dispersion medium. Water is preferred as the dispersion medium used in the negative electrode mixture paste.
  • a nonaqueous electrolyte storage element comprises a positive electrode, a negative electrode, a nonaqueous electrolyte, and a container for accommodating these.
  • the nonaqueous electrolyte storage element may further comprise a separator interposed between the positive electrode and the negative electrode to electrically insulate the positive electrode from the negative electrode.
  • the positive electrode, the negative electrode, and any separator typically constitute an electrode assembly. At least a portion of the nonaqueous electrolyte typically exists in a state of being impregnated into the electrode assembly.
  • the nonaqueous electrolyte storage element according to one embodiment of the present invention may further comprise other components.
  • the nonaqueous electrolyte storage element 1 shown in FIG. 1 comprises an electrode assembly 2, a nonaqueous electrolyte (not shown), and a rectangular parallelepiped container 3 that houses these.
  • the nonaqueous electrolyte storage element 1 in FIG. 1 further comprises a positive electrode lead 4, a positive electrode external terminal 5, a negative electrode lead 6, and a negative electrode external terminal 7.
  • the positive electrode lead 4 and the negative electrode lead 6 are housed in the container 3 together with the electrode assembly 2, etc.
  • the positive electrode external terminal 5 and the negative electrode external terminal 7 are provided outside the container 3.
  • the positive electrode constituting the electrode assembly 2 is electrically connected to the positive electrode external terminal 5 via the positive electrode lead 4.
  • the negative electrode constituting the electrode assembly 2 is electrically connected to the negative electrode external terminal 7 via the negative electrode lead 6.
  • the positive electrode has a positive electrode substrate and a positive electrode active material layer laminated on the positive electrode substrate directly or via an intermediate layer. Usually, the positive electrode has a portion where the positive electrode substrate is exposed. This exposed portion of the positive electrode substrate is usually connected to the above-mentioned positive electrode lead.
  • the positive electrode may have a shape such as a sheet, plate, or strip.
  • Chalcogen compounds include titanium disulfide, molybdenum disulfide, and molybdenum dioxide.
  • a chain carbonate refers to a carbonate that does not have a ring structure containing a carbonate group.
  • chain carbonates include diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, diphenyl carbonate, trifluoroethyl methyl carbonate, and bis(trifluoroethyl) carbonate.
  • the chain carbonate may be a saturated chain carbonate such as dimethyl carbonate, or an unsaturated chain carbonate such as diphenyl carbonate. As the chain carbonate, a saturated chain carbonate is preferred, and ethyl methyl carbonate is more preferred.
  • the content of the electrolyte salt in the non-aqueous electrolyte solution at 20°C and 1 atmosphere is preferably 0.1 mol/dm3 or more and 2.5 mol/dm3 or less , more preferably 0.3 mol/ dm3 or more and 2.0 mol/dm3 or less , even more preferably 0.5 mol/dm3 or more and 1.7 mol/dm3 or less, and particularly preferably 0.7 mol/ dm3 or more and 1.5 mol/dm3 or less.
  • the solid electrolyte can be selected from any material that has ionic conductivity of lithium, sodium, calcium, etc. and is solid at room temperature (e.g., 20°C).
  • Examples of the solid electrolyte include sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, halide solid electrolytes, and polymer solid electrolytes.
  • One or more types of solid electrolytes can be used.
  • the container accommodates the electrode assembly and the non-aqueous electrolyte in its internal space.
  • the container may be made of a metal material such as aluminum or stainless steel, or a resin material. Metal materials are preferred from the viewpoint of strength, etc. Composite materials of metal and resin may also be used.
  • the shape of the container is not particularly limited, but can be cylindrical, rectangular (square), disk-shaped, etc.
  • the container may also be in the shape of a sheet formed from a metal-resin composite film.
  • the shape of the nonaqueous electrolyte storage element is not particularly limited, and may be, for example, a cylindrical battery, a prismatic battery, a flat battery, a coin battery, a button battery, or the like.
  • the use of the nonaqueous electrolyte energy storage element according to one embodiment of the present invention is not particularly limited.
  • the nonaqueous electrolyte energy storage element can be used, for example, as a power source for automobiles such as electric vehicles, hybrid vehicles, and plug-in hybrid vehicles; as a power source for electronic devices such as personal computers and communication terminals; and as a power source for power storage.
  • the nonaqueous electrolyte storage element of the present invention may be used singly or in multiples. When the required output and voltage are small, the nonaqueous electrolyte storage element may be used singly. On the other hand, when at least one of the required output and voltage is large, the nonaqueous electrolyte storage element may be used as a storage device in combination with other nonaqueous electrolyte storage elements. In a storage device in which multiple nonaqueous electrolyte storage elements are combined, at least one of the nonaqueous electrolyte storage elements included in the storage device may be a nonaqueous electrolyte storage element according to one embodiment of the present invention. Storage devices will be described in more detail below.
  • the container may be constrained so as to maintain a constant thickness, or may not be constrained in this way.
  • the container may be constrained so as to apply a constant load. If the container is constrained, expansion of the container due to charge/discharge cycles, etc., may be suppressed, and a decrease in charge/discharge performance may be suppressed. If the container is constrained, a load may or may not be applied to the electrode body within the container.
  • a constraining member that performs such constraining may be provided in the nonaqueous electrolyte storage element or the energy storage device.
  • Preparing a positive electrode may mean manufacturing a positive electrode.
  • the positive electrode can be manufactured by the method described above.
  • Preparing a negative electrode may mean manufacturing a negative electrode.
  • the negative electrode can be manufactured by the method described above.
  • Preparing a non-aqueous electrolyte may mean preparing a non-aqueous electrolyte.
  • the non-aqueous electrolyte can be prepared, for example, by dissolving an electrolyte salt in a non-aqueous solvent.
  • the positive electrode, negative electrode, separator, non-aqueous electrolyte, etc. may be prepared by purchasing them, etc.
  • the nonaqueous electrolyte storage element according to one embodiment of the present invention may be manufactured by other methods.
  • the nonaqueous electrolyte storage element according to one embodiment of the present invention is an all-solid-state battery, it may be manufactured by pressing the materials forming the positive electrode, separator, and negative electrode individually or all at once.
  • an electrode assembly in which a separator is interposed between the positive electrode and the negative electrode is described, but the electrode assembly does not have to include a separator.
  • the positive electrode and the negative electrode may be in direct contact with each other, with a non-conductive layer formed on the active material layer of the positive electrode or the negative electrode.
  • the positive electrode and the negative electrode may further include layers other than the substrate, intermediate layer, and active material layer.
  • the positive electrode and the negative electrode do not have to have a layered structure.
  • Natural graphite (coated graphite particles: particles A) at least partially coated with non-graphitic carbon was prepared as a negative electrode active material.
  • the coated graphite particles (particles A) had a D10 particle size of 5.0 ⁇ m, a D50 particle size of 8.2 ⁇ m, and a D90 particle size of 13.3 ⁇ m, a ratio (D10/D90) of 0.376, and a non-graphitic carbon content of 12.5 mass%.
  • a negative electrode mixture paste was prepared using the coated graphite particles, styrene-butadiene rubber (SBR) as a binder, carboxymethyl cellulose (CMC) as a thickener, and water as a dispersion medium.
  • the mass ratio of the coated graphite particles, binder, and thickener was 98.5:1.0:0.5 in terms of solid content.
  • the negative electrode mixture paste was applied to both sides of copper foil as a negative electrode substrate so that the mass per unit area (mass of solid content) was 4 mg/cm 2 and dried. Then, roll pressing was performed to obtain a negative electrode in which a negative electrode active material layer was laminated on both sides of the negative electrode substrate.
  • the BET specific surface area of the negative electrode active material layer in the obtained negative electrode was 3.50 m 2 /g, the density was 1.19 g/cm 3 , and the porosity was 45%.
  • a positive electrode mixture paste was prepared using LiNi 1/3 Mn 1/3 Co 1/3 O 2 as a positive electrode active material, acetylene black (AB) as a conductive agent, polyvinylidene fluoride (PVDF) as a binder, and N-methylpyrrolidone (NMP) as a dispersion medium.
  • the mass ratio of the positive electrode active material, conductive agent, and binder was 93:5:2 in terms of solid content.
  • the positive electrode mixture paste was applied to both sides of aluminum foil as a positive electrode substrate so that the mass per unit area (mass of solid content) was 6 mg/cm 2 and dried. Thereafter, roll pressing was performed to obtain a positive electrode in which a positive electrode active material layer was laminated on both sides of the positive electrode substrate.
  • LiPF6 was dissolved at a concentration of 1.2 mol/ dm3 in a solvent in which ethylene carbonate and ethyl methyl carbonate were mixed in a volume ratio of 30:70 to obtain a non-aqueous electrolyte.
  • the nonaqueous electrolyte storage elements of Examples 1 to 4 which used coated graphite particles having a D10 particle size to D90 particle size ratio (D10/D90) of 0.36 or more and a non-graphitic carbon content of 10 mass% or more, had a discharge capacity (relative value) of 99.7% or more, indicating a large discharge capacity. Furthermore, in the nonaqueous electrolyte storage elements of Examples 1 to 4, the density of the negative electrode active material layer was 1.09 g/cm or more , indicating a sufficiently high density of the negative electrode active material layer.
  • the present invention can be applied to nonaqueous electrolyte storage elements used as power sources for electronic devices such as personal computers and communication terminals, as well as for automobiles and industrial applications.

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  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
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Abstract

Une électrode négative pour un élément de stockage d'énergie à électrolyte non aqueux selon un aspect de la présente invention comprend une couche de matériau actif d'électrode négative contenant des particules de graphite enrobées dans lesquelles au moins une partie de la surface du graphite est revêtue de carbone non graphitique. La densité de la couche de matériau actif d'électrode négative est de 1,09 g/cm3 ou plus. Le rapport (D10/D90) du diamètre de particule D10 au diamètre de particule D90 des particules de graphite revêtues est de 0,36 ou plus. La teneur en carbone non graphitique des particules de graphite revêtues est de 10 % en masse ou plus, et la surface spécifique BET de la couche de matériau actif d'électrode négative est de 4,0 m2/g ou moins.
PCT/JP2025/013220 2024-04-03 2025-03-31 Électrode négative pour élément de stockage d'énergie à électrolyte non aqueux, et élément de stockage d'énergie à électrolyte non aqueux Pending WO2025211331A1 (fr)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014191924A (ja) * 2013-03-26 2014-10-06 Mitsubishi Chemicals Corp 非水系二次電池用炭素材の製造方法及びその製造方法によって得られた炭素材
JP2016189319A (ja) * 2015-03-27 2016-11-04 三菱化学株式会社 炭素材、及び、非水系二次電池
WO2020141607A1 (fr) * 2019-01-04 2020-07-09 日立化成株式会社 Matériau d'électrode négative pour batterie secondaire au lithium-ion ainsi que procédé de fabrication de celui-ci, électrode négative pour batterie secondaire au lithium-ion, et batterie secondaire au lithium-ion
US20220077451A1 (en) * 2019-01-14 2022-03-10 Lg Energy Solution, Ltd. Negative electrode and secondary battery including the negative electrode
JP7444322B1 (ja) * 2023-07-12 2024-03-06 株式会社レゾナック リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極及びリチウムイオン二次電池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014191924A (ja) * 2013-03-26 2014-10-06 Mitsubishi Chemicals Corp 非水系二次電池用炭素材の製造方法及びその製造方法によって得られた炭素材
JP2016189319A (ja) * 2015-03-27 2016-11-04 三菱化学株式会社 炭素材、及び、非水系二次電池
WO2020141607A1 (fr) * 2019-01-04 2020-07-09 日立化成株式会社 Matériau d'électrode négative pour batterie secondaire au lithium-ion ainsi que procédé de fabrication de celui-ci, électrode négative pour batterie secondaire au lithium-ion, et batterie secondaire au lithium-ion
US20220077451A1 (en) * 2019-01-14 2022-03-10 Lg Energy Solution, Ltd. Negative electrode and secondary battery including the negative electrode
JP7444322B1 (ja) * 2023-07-12 2024-03-06 株式会社レゾナック リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極及びリチウムイオン二次電池

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