WO2024062862A1 - Électrode, élément de stockage d'énergie électrique et dispositif de stockage d'énergie électrique - Google Patents

Électrode, élément de stockage d'énergie électrique et dispositif de stockage d'énergie électrique Download PDF

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WO2024062862A1
WO2024062862A1 PCT/JP2023/031361 JP2023031361W WO2024062862A1 WO 2024062862 A1 WO2024062862 A1 WO 2024062862A1 JP 2023031361 W JP2023031361 W JP 2023031361W WO 2024062862 A1 WO2024062862 A1 WO 2024062862A1
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active material
power storage
positive electrode
mass
particles
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PCT/JP2023/031361
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English (en)
Japanese (ja)
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大輔 遠藤
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株式会社Ｇｓユアサ
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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
    • H01M4/13—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
    • 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
    • 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
    • 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 an electrode, a power storage element, and a power storage device.
  • Nonaqueous electrolyte secondary batteries represented by lithium ion nonaqueous electrolyte secondary batteries
  • a non-aqueous electrolyte secondary battery generally includes an electrode body having a pair of electrodes electrically isolated by a separator, and a non-aqueous electrolyte interposed between the electrodes, and transfers charge transport ions between the two electrodes.
  • the battery is configured to be charged and discharged by performing the following steps.
  • capacitors such as lithium ion capacitors and electric double layer capacitors are also widely used as power storage elements other than non-aqueous electrolyte secondary batteries.
  • Lithium transition metal compounds having a polyanion structure such as lithium iron phosphate
  • Patent Document 1 describes a non-aqueous electrolyte secondary battery including a positive electrode containing lithium iron phosphate as a positive electrode active material and a negative electrode containing graphite as a negative electrode active material.
  • a lithium transition metal compound having a polyanion structure is usually used in the form of granules coated with a carbon material from the viewpoint of electronic conductivity and the like.
  • the present invention was made based on the above circumstances, and an object of the present invention is to provide an electrode, a power storage element, and a power storage device that can increase the initial output.
  • the electrode according to one aspect of the present invention is a granular material in which particles containing a lithium transition metal compound having a polyanionic structure are coated with a carbon material, and the amount of change in particle size when pressurized from 20 mN to 100 mN is 1. .1 nm or less active material particles and a binder.
  • a power storage element includes the electrode.
  • a power storage device includes one or more power storage elements according to another aspect of the present invention, and includes two or more power storage elements.
  • an electrode, a power storage element, and a power storage device that have a high initial output.
  • FIG. 1 is a transparent perspective view showing one embodiment of a power storage element.
  • FIG. 2 is a schematic diagram showing an embodiment of a power storage device configured by collecting a plurality of power storage elements.
  • the electrode according to one aspect of the present invention is a granular material in which particles containing a lithium transition metal compound having a polyanionic structure are coated with a carbon material, and the particle size changes when pressurized from 20 mN to 100 mN.
  • the active material particles have an amount of 1.1 nm or less and a binder.
  • the electrode described in [1] above can increase the initial output. Although the reason for this is not certain, the following reasons are presumed. Particles containing lithium transition metal compounds with conventional polyanionic structures are relatively brittle. Therefore, when particles containing a lithium transition metal compound with a conventional polyanion structure are used, the particles are significantly deformed during pressing of the active material layer in the electrode manufacturing process, resulting in poor adhesion between the base material and the active material layer. As a result, the interfacial resistance between the base material and the active material layer becomes high, and the initial output of the electrode cannot be made sufficiently high.
  • the adhesion between the base material and the active material layer can be improved by pressing, and the initial stage of the electrode can be improved. It is assumed that the output can be increased.
  • the amount of change in particle size of active material particles is measured when the active material particles are incorporated into a power storage element as a positive electrode active material and are brought into a fully discharged state by the following method.
  • the electricity storage element is charged at a constant current of 0.05 C until it reaches the end-of-charge voltage during normal use, and is brought into a fully charged state.
  • constant current discharge is performed at a discharge current of 0.05C to the discharge end voltage (lower limit voltage) during normal use. It was dismantled, the positive electrode was taken out, and a test battery was assembled using a metal lithium electrode as a counter electrode. At a current value of 10 mA per 1 g of positive electrode mixture, the positive electrode potential was 2.0 V vs.
  • Constant current discharge is performed until Li/Li + , and the positive electrode is adjusted to a completely discharged state. Disassemble it again and take out the positive electrode. Using dimethyl carbonate, the electrolyte and the like adhering to the taken out positive electrode are thoroughly washed away, and after drying at room temperature for a day and night, the active material particles are collected. The collected active material particles are subjected to measurement. The work from dismantling the power storage element to collecting active material particles is performed in an argon atmosphere with a dew point of -60°C or lower. "Normal use” refers to the case where the energy storage element is used under the charging and discharging conditions recommended or specified for the energy storage element. Regarding the charging condition, for example, if a charger for the electricity storage element is prepared, the charger is used to use the electricity storage element.
  • the amount of change in particle size of the active material particles is measured by a microcompression test using a microcompression tester ("MCT-511" manufactured by Shimadzu Corporation).
  • MCT-511 manufactured by Shimadzu Corporation
  • the probe uses a diamond flat indenter with a diameter of 50 ⁇ m. Pressure is applied to one active material particle at a probe speed of 0.134 mN/sec, and the amount of displacement of the probe in the pressure range from 20 mN to 100 mN is defined as the amount of change in particle size when the pressure is applied from 20 mN to 100 mN. Further, the amount of change in particle size is measured for five active material particles, and the average value thereof is used.
  • the active material particles to be measured are selected from particles whose particle size is 1/2 or more and 2 times or less of the average particle size of the active material particles.
  • the "particle size" of each particle is the average value of the short axis and long axis.
  • the minor axis is the shortest diameter passing through the center of the smallest circumscribed circle of the particle, and the major axis is the diameter passing through the center and perpendicular to the minor axis. If there are two or more shortest diameters, the shortest diameter is the longest diameter orthogonal to the shortest diameter.
  • Average particle size is based on JIS-Z-8825 (2013), and is based on the particle size distribution measured by laser diffraction/scattering method on a diluted solution of particles diluted with a solvent. 2 (2001) at which the volume-based integrated distribution is 50%.
  • the binder may be a rubber-based binder.
  • the electrode described in [2] above can increase the initial output and improve the output retention rate after a charge/discharge cycle test.
  • the rate of change in particle size when the active material particles are pressurized from 20 mN to 100 mN may be 0.015% or less.
  • the electrode described in [3] above can provide a higher initial output.
  • the particle size deformation rate is defined as a percentage of the amount of change in particle size when the pressure is applied from 20 mN to 100 mN with respect to the average particle size of the active material particles.
  • a power storage element according to another aspect of the present invention includes the electrode according to any one of [1] to [3] above. Since the electricity storage element described in [4] above includes the electrode described in any one of [1] to [3], the initial output can be increased.
  • a power storage device includes one or more power storage elements described in [4] above, and includes two or more power storage elements. Since the power storage device according to [5] above includes one or more power storage elements according to [4] above, the initial output can be increased.
  • each component (each component) used in each embodiment may be different from the name of each component (each component) used in the background art.
  • An electrode according to an embodiment of the present invention is a granular material in which particles containing a lithium transition metal compound having a polyanionic structure are coated with a carbon material, and the amount of change in particle size when pressurized from 20 mN to 100 mN is
  • the device includes active material particles having a size of 1.1 nm or less and a binder.
  • the active material particles included in the electrode according to one embodiment of the present invention are granules in which particles containing a lithium transition metal compound having a polyanion structure are coated with a carbon material.
  • a lithium transition metal compound having a polyanion structure includes an oxoacid anion (PO 4 3- , SO 4 2- , SiO 4 4- , BO 3 3- , VO 4 3-, etc.), a lithium ion, and a transition metal ion. Examples include compounds containing.
  • the oxoacid anion may be a condensed anion (P 2 O 7 4- , P 3 O 10 5- , etc.).
  • the lithium transition metal compound having a polyanion structure may have an olivine crystal structure.
  • the lithium transition metal compound having a polyanion structure is typically a polyanion compound containing a lithium element and a transition metal element, and may further contain other elements (for example, a halogen element, etc.).
  • the transition metal element contained in the lithium transition metal compound having a polyanion structure iron element, manganese element, nickel element and cobalt element are preferable, and iron element is more preferable.
  • a phosphate anion (PO 4 3- ) is preferable.
  • the lithium transition metal compound having a polyanion structure is preferably a compound represented by the following formula (1).
  • M is at least one transition metal element.
  • A is at least one selected from B, Al, Si, P, S, Cl, Ti, V, Cr, Mo, and W.
  • X is at least one halogen element.
  • a, b, c, d, and e are numbers satisfying 0 ⁇ a ⁇ 3, 0 ⁇ b ⁇ 2, 2 ⁇ c ⁇ 4, 1 ⁇ d ⁇ 3, and 0 ⁇ e ⁇ 1.
  • a, b, c, d, and e may all be integers or decimals.
  • any one of Fe, Mn, Ni, and Co, or a combination of any two of these is preferable.
  • Fe, Mn, or a combination thereof is further preferable, and Fe is more preferable.
  • the content of Fe in M is preferably 50 mol% or more, more preferably 70 mol% or more, 90 mol% or more, or 99 mol% or more.
  • A P is preferable.
  • lithium transition metal compounds having a polyanion structure include, for example, LiFePO 4 , LiCoPO 4 , LiFe 0.5 Co 0.5 PO 4 , LiMnPO 4 , LiNiPO 4 , LiMn 0.5 Fe 0.5 PO 4 , LiCrPO 4 , LiFeVO 4 , Li 2 FeSiO 4 , Li 2 Fe 2 (SO 4 ) 3 , LiFeBO 3 , LiFePO 3.9 F 0.2 , Li 3 V 2 (PO 4 ) 3 , Li 2 MnSiO 4 , Li 2 CoPO Examples include 4F .
  • the atoms or polyanions in these lithium transition metal compounds having a polyanion structure may be partially substituted with other atoms or anion species.
  • the lithium transition metal compounds having a polyanion structure may be used alone or in combination of two or more.
  • the content of the lithium transition metal compound having a polyanionic structure in the particles containing the lithium transition metal compound having a polyanionic structure may be 60% by mass or more, 80% by mass or more, and 90% by mass or more.
  • the amount may be 95% by mass or more or 99% by mass or more.
  • Particles containing a lithium transition metal compound having a polyanion structure may be formed by a plurality of primary particles existing independently without aggregation (single particle), but may be formed by aggregation of a plurality of primary particles. Preferably, they are secondary particles.
  • the particles are, for example, secondary particles of a lithium transition metal compound having a polyanionic structure.
  • Carbon material Particles containing a lithium transition metal compound having a polyanion structure are coated with a carbon material to constitute active material particles included in an electrode according to an embodiment of the present invention.
  • a part of the carbon material may be present inside the particles containing the lithium transition metal compound having a polyanionic structure.
  • the active material particles may have a portion that is not covered with the carbon material (for example, a portion where a lithium transition metal compound having a polyanion structure is exposed).
  • the carbon material coats the particles containing the lithium transition metal compound having a polyanion structure, so that the active material particles can exhibit sufficient electronic conductivity between particles.
  • the carbon material is, for example, a material with a carbon element content of 80% by mass or more and 100% by mass or less.
  • the carbon element content in the carbon material may be 90% by mass or more, or may be 95% by mass.
  • elements other than the carbon element that may be contained in the carbon material include oxygen, hydrogen, and nitrogen.
  • Examples of carbon materials include graphite and non-graphitic carbon.
  • the content of carbon material in the active material particles is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.2% by mass or more and 10% by mass or less, and 0.3% by mass or more and 5% by mass or less. is more preferable, and particularly preferably 0.5% by mass or more and 2% by mass or less.
  • the content of the carbon material in the active material particles is equal to or higher than the lower limit, electronic conductivity can be improved.
  • the content of the carbon material in the active material particles is below the above upper limit, the content of the lithium transition metal compound having a polyanion structure can be increased, and the discharge capacity per volume of the active material layer can be increased. Can be done.
  • the total content of the lithium transition metal compound having a polyanion structure and the carbon material in the active material particles is preferably 90% by mass or more and 100% by mass or less, 95% by mass or more, 98% by mass or more, 99% by mass or more, or It may be 99.9% by mass or more.
  • the lower limit of the ratio of the specific surface area of the carbon material to the total specific surface area of the lithium transition metal compound having a polyanion structure and the carbon material is preferably 5%, more preferably 10%.
  • the upper limit is preferably 60%, more preferably 50%.
  • the "specific surface area” is determined by immersing the sample to be measured in liquid nitrogen, supplying nitrogen gas to physically adsorb nitrogen molecules on the particle surface, and measuring the pressure and adsorption amount at that time. BET specific surface area.
  • the nitrogen adsorption amount [m 2 ] for the sample is determined by a single point method.
  • the value obtained by dividing the obtained nitrogen adsorption amount by the mass [g] of the sample is defined as the BET specific surface area [m 2 /g].
  • the ratio of the specific surface area of the carbon material to the total specific surface area of the lithium transition metal compound having a polyanion structure and the carbon material is determined by the following procedure.
  • a positive electrode was taken out by disassembling a non-aqueous electrolyte storage element that had been brought into a fully discharged state by the same method as in the measurement of the amount of change in particle size of active material particles described above, and the positive electrode was collected after being washed and dried as described above.
  • the BET specific surface area of a particulate material formed by coating particles containing a lithium transition metal compound having a polyanion structure with a carbon material is measured.
  • the carbon material is removed by baking the granular material at 350° C. for 4 hours in an air atmosphere. Thereafter, the BET specific surface area of particles containing a lithium transition metal compound having a polyanion structure from which the carbon material has been removed is measured.
  • the BET specific surface area Bp 1 [m 2 /g] of the carbon material is the BET specific surface area of the granular material Bp [m 2 /g], and the particle containing a lithium transition metal compound having a polyanionic structure from which the carbon material has been removed
  • Bp 1 Bp - Bp 2 ...1
  • the upper limit of the amount of change in particle size when the active material particles are pressurized from 20 mN to 100 mN is 1.1 nm, preferably 1.0 nm, more preferably 0.9 nm, 0.7 nm or 0.5 nm. More preferably 0.4 nm or 0.2 nm.
  • the amount of change in particle size is equal to or less than the above upper limit, the adhesion between the base material and the active material layer can be improved, and the initial output of the electrode can be increased.
  • the lower limit of the amount of change in particle size may be, for example, 0.001 nm, 0.01 nm, or 0.1 nm.
  • the amount of change in the particle size may be greater than or equal to any of the lower limits described above and less than or equal to any of the upper limits described above.
  • the upper limit of the rate of change in particle size when the active material particles are pressurized from 20 mN to 100 mN is preferably 0.015%, more preferably 0.013%, 0.010%, 0.008%, 0.015%, and more preferably 0.013%. 0.006% or 0.004% is more preferred.
  • the rate of change in particle size is equal to or less than the above upper limit, the density of the active material layer can be further increased, and the discharge capacity per volume of the active material layer can be further increased.
  • the lower limit of the rate of change in particle size may be, for example, 0.0001%, 0.001%, or 0.002%.
  • the rate of change in particle size may be greater than or equal to any of the lower limits described above and less than or equal to any of the upper limits described above.
  • the average particle diameter of the active material particles is preferably 0.5 ⁇ m or more and 30 ⁇ m or less, more preferably 1 ⁇ m or more and 20 ⁇ m or less, still more preferably 2 ⁇ m or more and 15 ⁇ m or less, 4 ⁇ m or more and 10 ⁇ m or less, or 6 ⁇ m or more and 8 ⁇ m or less.
  • the average particle size of the active material particles is within the above range, the density of the active material layer can be further increased, and the discharge capacity per volume of the active material layer can be further increased.
  • a pulverizer, classifier, etc. are used to obtain the active material particles with a predetermined average particle size.
  • Examples of the pulverization method include methods using a mortar, a ball mill, a sand mill, a vibrating ball mill, a planetary ball mill, a jet mill, a counter jet mill, a swirling jet mill, a sieve, and the like.
  • wet pulverization in which water or an organic solvent such as hexane is present can also be used.
  • a sieve, a wind classifier, etc. may be used, both dry and wet, as necessary.
  • binder examples of the binder included in the electrode according to an embodiment of the present invention include fluororesins (polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.), thermoplastic resins such as polyethylene, polypropylene, polyacrylic, polyimide, etc.; - Rubber binders such as propylene-diene rubber (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, and gum arabic; polysaccharide polymers, and the like.
  • EPDM propylene-diene rubber
  • SBR sulfonated EPDM
  • SBR styrene-butadiene rubber
  • fluororubber examples of the binder included in the electrode according to an embodiment of the present invention include fluororesins (polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), etc.), thermoplastic resins such as
  • SBR is a copolymer of styrene and butadiene.
  • SBR may be copolymerized with monomers other than styrene and butadiene.
  • monomers other than styrene and butadiene For example, carboxy-modified SBR, acrylic acid-modified SBR (including those containing fluorine), methyl methacrylic acid-modified SBR, etc. may be used.
  • One type of these SBRs may be used alone or two or more types may be used in combination.
  • the blending ratio of styrene and butadiene is preferably about 1:2 to 2:1.
  • the total amount of styrene and butadiene accounts for 50% by mass or more (typically 75% by mass or more, for example 90% by mass or more) of the total amount of monomers.
  • SBR can preferably be used in the form of an aqueous emulsion (latex) dispersed in an aqueous solvent (typically water).
  • an SBR in which a carboxyl group is introduced into the polymer can be preferably employed.
  • the binder has a functional group that reacts with lithium or the like, this functional group may be deactivated in advance by methylation or the like.
  • the active material particles provided in the electrode according to one embodiment of the present invention can be efficiently obtained by adjusting the pH of the reaction solution using an aqueous ammonia solution or the like when producing the hydroxide precursor in a method using a hydroxide precursor, a lithium source, and a carbon source.
  • active material particles that are spherical and whose particle shape is not easily deformed even when pressed can be obtained.
  • the production method will be described in detail below.
  • the active material particles provided in the present invention are not limited to those produced by the following production method.
  • a hydroxide precursor is obtained by a precipitation reaction between transition metal ions and hydroxide ions in water.
  • a hydroxide precursor transition metal hydroxide
  • the transition metal salt may be any salt that contains the transition metal element constituting the target lithium transition metal compound and is water-soluble, such as iron sulfate, iron chloride, cobalt sulfate, manganese sulfate, nickel sulfate, etc. be able to.
  • a potassium hydroxide aqueous solution or the like can be used instead of the sodium hydroxide aqueous solution.
  • reaction liquid When dropping a transition metal salt aqueous solution, a sodium hydroxide aqueous solution, etc. into water, an ammonia aqueous solution or the like is further dropped into the reaction liquid in order to maintain the pH of the water (reaction liquid) into which these aqueous solutions are dropped within a predetermined range.
  • the pH of the reaction solution is preferably in the range of 8.5 to 10.5. If the pH of the reaction solution is outside the above range, or if an ammonia aqueous solution or the like is not added dropwise to the reaction solution even if the pH of the reaction solution is within the above range, the final active material particles obtained will The amount of change in particle size tends to be large.
  • the concentration of the ammonia aqueous solution to be dropped can be, for example, about 0.3 mol/dm 3 or more and 1 mol/dm 3 or less.
  • the pH of the reaction solution can be adjusted by adjusting the concentration, amount, etc. of the ammonia aqueous solution, sodium hydroxide aqueous solution, etc. to be added dropwise.
  • Another alkaline aqueous solution such as a hydrazine aqueous solution may be added dropwise together with the ammonia aqueous solution.
  • the pH of the reaction solution can also be adjusted by adjusting the amount of other alkaline aqueous solution added dropwise.
  • the obtained hydroxide precursor, a lithium source, and a carbon source are mixed and fired in an inert atmosphere (for example, a nitrogen atmosphere) to produce active material particles according to an embodiment of the present invention.
  • an inert atmosphere for example, a nitrogen atmosphere
  • the lithium source compounds having a polyanion structure and containing the lithium element, such as LiH 2 PO 4 , Li 3 PO 4 , LiHSO 4 , etc., can be suitably used.
  • LiOH, lithium halide, etc. can be used as the lithium source.
  • the lithium source used is not a compound having a polyanion structure, a compound having a polyanion structure is further mixed and firing is performed.
  • Compounds having a polyanion structure include ammonium cations and polyanions such as NH 4 H 2 PO 4 , (NH 4 ) 3 PO 4 , (NH 4 ) 2 HPO 4 , (NH 4 ) 2 SO 4 , and NH 4 VO 3 . Salts and the like can be suitably used.
  • the carbon source organic substances such as sucrose, lactose, maltose, sucrose, polyvinyl alcohol, and ascorbic acid can be used.
  • the firing temperature can be, for example, 500°C or higher and 800°C or lower.
  • a power storage element includes an electrode body having a positive electrode, a negative electrode, and a separator, an electrolyte, and a container housing the electrode body and the electrolyte.
  • the electrode body is usually a laminated type in which a plurality of positive electrodes and a plurality of negative electrodes are laminated with a separator in between, or a wound type in which a positive electrode and a negative electrode are laminated with a separator in between and are wound.
  • the electrolyte exists in the positive electrode, negative electrode, and separator.
  • the electrolyte may be a non-aqueous electrolyte.
  • a non-aqueous electrolyte secondary battery hereinafter also simply referred to as a "secondary battery" in which the electrolyte is a non-aqueous electrolyte will be described.
  • the positive electrode of the electric storage element can be the electrode described above according to one embodiment of the present invention.
  • the positive electrode has a positive electrode substrate and a positive electrode active material layer disposed on the positive electrode substrate directly or via an intermediate layer.
  • the positive electrode base material has electrical conductivity. Whether or not it has “conductivity” is determined using a volume resistivity of 10 ⁇ 2 ⁇ cm as a threshold value, which is measured in accordance with JIS-H-0505 (1975).
  • the material of the positive electrode base material metals such as aluminum, titanium, tantalum, stainless steel, or alloys thereof are used. Among these, aluminum or aluminum alloy is preferred from the viewpoint of potential resistance, high conductivity, and cost.
  • Examples of the positive electrode base material include foil, vapor deposited film, mesh, porous material, etc., and foil is preferable from the viewpoint of cost. Therefore, aluminum foil or aluminum alloy foil is preferable as the positive electrode base material. Examples of aluminum or aluminum alloy include A1085, A3003, A1N30, etc. specified in JIS-H-4000 (2014) or JIS-H-4160 (2006).
  • the average thickness of the positive electrode base material is preferably 3 ⁇ m or more and 50 ⁇ m or less, more preferably 5 ⁇ m or more and 40 ⁇ m or less, even more preferably 8 ⁇ m or more and 30 ⁇ m or less, and particularly preferably 10 ⁇ m or more and 25 ⁇ m or less.
  • the intermediate layer is a layer disposed between the positive electrode substrate and the positive electrode active material layer.
  • the intermediate layer contains a conductive agent such as carbon particles to reduce the contact resistance between the positive electrode substrate and the positive electrode active material layer.
  • the composition of the intermediate layer is not particularly limited, and may include, for example, a binder and a conductive agent.
  • the positive electrode active material layer includes the active material particles and the binder.
  • the positive electrode active material layer contains optional components such as a positive electrode active material other than the active material particles, a conductive agent, a thickener, and a filler, as necessary.
  • the content of the active material particles in the positive electrode active material layer is preferably 50% by mass or more and 99% by mass or less, more preferably 70% by mass or more and 98% by mass or less, and even more preferably 80% by mass or more and 95% by mass or less.
  • the positive electrode active material layer may further contain a positive electrode active material other than the active material particles.
  • a positive electrode active material other positive electrode active materials
  • various conventionally known positive electrode active materials can be used.
  • the content of the active material particles with respect to all the positive electrode active materials (total of the active material particles and other positive electrode active materials) contained in the positive electrode active material layer is preferably 90% by mass or more, and 99% by mass or more. More preferably, 100% by mass is even more preferred.
  • the conductive agent is not particularly limited as long as it is a material that has conductivity.
  • Examples of such conductive agents include carbon materials, metals, conductive ceramics, and the like.
  • Examples of the carbon material include graphite, non-graphitic carbon, graphene-based carbon, and the like.
  • Examples of non-graphitic carbon include carbon nanofibers, pitch-based carbon fibers, carbon black, and the like.
  • Examples of carbon black include furnace black, acetylene black, Ketjen black, and the like.
  • Examples of graphene-based carbon include graphene, carbon nanotubes (CNT), and fullerene.
  • Examples of the shape of the conductive agent include powder, fiber, and the like.
  • the conductive agent one type of these materials may be used alone, or two or more types may be used in combination. Further, these materials may be used in combination.
  • a composite material of carbon black and CNT may be used.
  • carbon black is preferred from the viewpoint of electronic conductivity and coatability, and acetylene black is particularly preferred.
  • the content of the conductive agent in the positive electrode active material layer is preferably 1% by mass or more and 10% by mass or less, more preferably 3% by mass or more and 9% by mass or less.
  • the content of the conductive agent does not include the carbon material (the carbon material that coats the particles containing the lithium transition metal compound having a polyanion structure) contained in the active material particles according to one embodiment of the present invention.
  • the content of the binder in the positive electrode active material layer is preferably 1% by mass or more and 10% by mass or less, more preferably 3% by mass or more and 9% by mass or less.
  • the thickener examples include polysaccharide polymers such as carboxymethylcellulose (CMC) and methylcellulose.
  • CMC carboxymethylcellulose
  • the content of the thickener in the positive electrode active material layer can be, for example, 0.1% by mass or more and 8% by mass or less, and 5% by mass or less or 1% by mass or less. You can also do it.
  • the technology disclosed herein can be preferably implemented in an embodiment in which the positive electrode active material layer does not contain a thickener.
  • the filler is not particularly limited.
  • the filler include polyolefins such as polypropylene and polyethylene, inorganic oxides such as silicon dioxide, alumina, titanium dioxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide, and aluminosilicate, hydroxides such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide, carbonates such as calcium carbonate, poorly soluble ion crystals such as calcium fluoride, barium fluoride, and barium sulfate, nitrides such as aluminum nitride and silicon nitride, mineral resource-derived substances such as talc, montmorillonite, boehmite, zeolite, apatite, kaolin, mullite, spinel, olivine, sericite, bentonite, and mica, and artificial products thereof.
  • polyolefins such as polypropylene and polyethylene
  • inorganic oxides such as silicon dioxide, alumina, titanium dioxide, calcium
  • the content of the filler in the positive electrode active material layer can be, for example, 0.1% by mass or more and 8% by mass or less, and can also be 5% by mass or less, or 1% by mass or less.
  • the technology disclosed herein can be preferably implemented in an embodiment in which the positive electrode active material layer does not contain a filler.
  • the positive electrode active material layer is made of typical nonmetallic elements such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, K, Ca, Zn, Ga, Ge, Sn, Sr, Ba, etc.
  • Typical metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Nb, W and other transition metal elements, active material particles, other positive electrode active materials, conductive agents, It may be contained as a component other than the binder, thickener, and filler.
  • the lower limit of the density of the positive electrode active material layer is preferably 1.8 g/cm 3 , more preferably 1.9 g/cm 3 , further preferably 2.0 g/cm 3 , and particularly preferably 2.1 g/cm 3.
  • the upper limit of the density of the positive electrode active material layer may be 2.6 g/cm 3 , 2.5 g/cm 3 , 2.4 g/cm 3 , or 2.3 g/cm 3.
  • the density of the positive electrode active material layer may be equal to or greater than any of the lower limits and equal to or less than any of the upper limits.
  • the density of the positive electrode active material layer can be adjusted by the type of active material particles, the strength of the press when manufacturing the positive electrode, and the like.
  • the density of the positive electrode active material layer is obtained by dividing the mass per unit area of one positive electrode active material layer by the average thickness of one positive electrode active material layer.
  • the mass per unit area of one positive electrode active material layer is preferably 0.3 g/cm 2 or more and 3 g/cm 2 or less, more preferably 0.5 g/cm 2 or more and 2 g/cm 2 or less, and 0.7 g/cm 2 or less. cm 2 or more and 1.5 g/cm 2 or less is more preferable.
  • the mass per unit area of one positive electrode active material layer is within the above range, the discharge capacity of the electricity storage element can be increased.
  • the positive electrode can be produced by, for example, applying a positive electrode mixture paste to the positive electrode base material and drying it to laminate a positive electrode active material layer along at least one surface of the positive electrode base material.
  • the positive electrode mixture paste includes, for example, each component constituting the positive electrode active material layer and a dispersion medium. It is preferable to press after applying and drying the positive electrode mixture paste. By pressing, a high-density positive electrode active material layer can be obtained.
  • the negative electrode includes a negative electrode base material and a negative electrode active material layer disposed on the negative electrode base material directly or via an intermediate layer.
  • the configuration of the intermediate layer is not particularly limited, and can be selected from, for example, the configurations exemplified for the positive electrode.
  • the negative electrode base material has electrical conductivity.
  • metals such as copper, nickel, stainless steel, nickel-plated steel, aluminum, alloys thereof, carbon materials, etc. are used. Among these, copper or copper alloy is preferred.
  • the negative electrode base material include foil, vapor deposited film, mesh, porous material, etc. Foil is preferred from the viewpoint of cost. Therefore, copper foil or copper alloy foil is preferable as the negative electrode base material. Examples of copper foil include rolled copper foil, electrolytic copper foil, and the like.
  • the average thickness of the negative electrode base material is preferably 2 ⁇ m or more and 35 ⁇ m or less, more preferably 3 ⁇ m or more and 30 ⁇ m or less, even more preferably 4 ⁇ m or more and 25 ⁇ m or less, and particularly preferably 5 ⁇ m or more and 20 ⁇ m or less.
  • the negative electrode active material layer contains a negative electrode active material.
  • the negative electrode active material layer contains optional components such as a conductive agent, a binder, a thickener, and a filler as necessary.
  • the optional components such as a conductive agent, a binder, a thickener, and a filler can be appropriately selected from known components, and may be selected from the materials exemplified for the positive electrode.
  • the negative electrode active material layer is made of typical nonmetallic elements such as B, N, P, F, Cl, Br, I, Li, Na, Mg, Al, K, Ca, Zn, Ga, Ge, Sn, Sr, Ba, etc. Typical metal elements of It may be contained as a component other than the adhesive and filler.
  • the negative electrode active material can be appropriately selected from known negative electrode active materials.
  • the negative electrode active material for lithium ion secondary batteries a material capable of absorbing and releasing lithium ions is usually used.
  • the negative electrode active material include metal Li; metals or semimetals such as Si and Sn; metal oxides or semimetal oxides such as Si oxide, Ti oxide, and Sn oxide; titanium-containing oxides such as Li 4 Ti 5 O 12 , LiTiO 2, and TiNb 2 O 7 ; polyphosphate compounds; silicon carbide; carbon materials such as graphite and non-graphitic carbon (easily graphitized carbon or non-graphitizable carbon). Among these materials, graphite and non-graphitic carbon are preferred. In the negative electrode active material layer, one of these materials may be used alone, or two or more may be mixed and used.
  • Graphite refers to a carbon material having an average lattice spacing (d 002 ) of the (002) plane determined by X-ray diffraction before charging and discharging or in a discharged state of 0.33 nm or more and less than 0.34 nm.
  • Examples of graphite include natural graphite and artificial graphite. Artificial graphite is preferred from the viewpoint of obtaining a material with stable physical properties.
  • Non-graphitic carbon refers to a carbon material whose average lattice spacing (d 002 ) of the (002) plane is 0.34 nm or more and 0.42 nm or less, as determined by X-ray diffraction before charging and discharging or in a discharge state.
  • Examples of non-graphitic carbon include non-graphitizable carbon and easily graphitizable carbon.
  • Examples of the non-graphitic carbon include resin-derived materials, petroleum pitch or petroleum pitch-derived materials, petroleum coke or petroleum coke-derived materials, plant-derived materials, alcohol-derived materials, and the like.
  • discharged state refers to a state in which the carbon material that is the negative electrode active material is discharged such that lithium ions that can be intercalated and released are sufficiently released during charging and discharging.
  • the open circuit voltage is 0.7 V or more.
  • Non-graphitizable carbon refers to a carbon material in which the above d 002 is 0.36 nm or more and 0.42 nm or less.
  • Graphitizable carbon refers to a carbon material in which the above d 002 is 0.34 nm or more and less than 0.36 nm.
  • the negative electrode active material is usually particles (powder).
  • the average particle size of the negative electrode active material can be, for example, 1 nm or more and 100 ⁇ m or less.
  • the negative electrode active material is a carbon material, a titanium-containing oxide, or a polyphosphoric acid compound, the average particle size thereof may be 1 ⁇ m or more and 100 ⁇ m or less.
  • the negative electrode active material is Si, Sn, Si oxide, Sn oxide, or the like, the average particle size thereof may be 1 nm or more and 1 ⁇ m or less.
  • the electronic conductivity of the negative electrode active material layer is improved.
  • a pulverizer, classifier, etc. are used to obtain powder with a predetermined particle size.
  • the negative electrode active material is a metal such as metal Li
  • the negative electrode active material layer may be in the form of a foil.
  • the content of the negative electrode active material in the negative electrode active material layer is preferably 60% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 98% by mass or less.
  • the separator can be appropriately selected from known separators.
  • a separator consisting of only a base material layer, a separator in which a heat resistant layer containing heat resistant particles and a binder is formed on one or both surfaces of the base material layer, etc.
  • Examples of the shape of the base material layer of the separator include woven fabric, nonwoven fabric, and porous resin film. Among these shapes, a porous resin film is preferred from the viewpoint of strength, and a nonwoven fabric is preferred from the viewpoint of liquid retention of the nonaqueous electrolyte.
  • polyolefins such as polyethylene and polypropylene are preferred from the viewpoint of shutdown function, and polyimide, aramid, etc. are preferred from the viewpoint of oxidative decomposition resistance.
  • a composite material of these resins may be used as the base material layer of the separator.
  • the heat-resistant particles contained in the heat-resistant layer preferably have a mass loss of 5% or less when the temperature is raised from room temperature to 500°C in an air atmosphere of 1 atm, and the mass loss when the temperature is raised from room temperature to 800°C. is more preferably 5% or less.
  • Inorganic compounds are examples of materials whose mass loss is less than a predetermined value. Examples of inorganic compounds include oxides such as iron oxide, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, calcium oxide, strontium oxide, barium oxide, magnesium oxide, and aluminosilicate; nitrides such as aluminum nitride and silicon nitride.
  • carbonates such as calcium carbonate
  • sulfates such as barium sulfate
  • poorly soluble ionic crystals such as calcium fluoride, barium fluoride, barium titanate
  • covalent crystals such as silicon and diamond
  • talc montmorillonite, boehmite
  • examples include substances derived from mineral resources such as zeolite, apatite, kaolin, mullite, spinel, olivine, sericite, bentonite, and mica, or artificial products thereof.
  • these substances may be used alone or in combination, or two or more types may be used in combination.
  • silicon oxide, aluminum oxide, or aluminosilicate is preferable from the viewpoint of safety of the electricity storage element.
  • the porosity of the separator is preferably 80% by volume or less from the viewpoint of strength, and preferably 20% by volume or more from the viewpoint of discharge performance.
  • porosity is a value based on volume, and means a value measured with a mercury porosimeter.
  • a polymer gel composed of a polymer and a non-aqueous electrolyte may be used as the separator.
  • the polymer include polyacrylonitrile, polyethylene oxide, polypropylene oxide, polymethyl methacrylate, polyvinyl acetate, polyvinylpyrrolidone, polyvinylidene fluoride, and the like.
  • Use of polymer gel has the effect of suppressing liquid leakage.
  • a separator a porous resin film or nonwoven fabric as described above and a polymer gel may be used in combination.
  • Nonaqueous electrolyte The non-aqueous electrolyte can be appropriately selected from known non-aqueous electrolytes.
  • a non-aqueous electrolyte may be used as the non-aqueous electrolyte.
  • the nonaqueous electrolyte includes a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent.
  • the non-aqueous solvent can be appropriately selected from known non-aqueous solvents.
  • the non-aqueous solvent include cyclic carbonates, chain carbonates, carboxylic esters, phosphoric esters, sulfonic esters, ethers, amides, nitriles, and the like.
  • compounds in which some of the hydrogen atoms contained in these compounds are replaced with halogens may be used.
  • cyclic carbonates examples include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), vinylethylene carbonate (VEC), chloroethylene carbonate, fluoroethylene carbonate (FEC), and difluoroethylene carbonate. (DFEC), styrene carbonate, 1-phenylvinylene carbonate, 1,2-diphenylvinylene carbonate, and the like. Among these, EC is preferred.
  • chain carbonates examples include diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), diphenyl carbonate, trifluoroethylmethyl carbonate, bis(trifluoroethyl) carbonate, and the like. Among these, EMC is preferred.
  • the nonaqueous solvent it is preferable to use a cyclic carbonate or a chain carbonate, and it is more preferable to use a cyclic carbonate and a chain carbonate together.
  • a cyclic carbonate it is possible to promote the dissociation of the electrolyte salt and improve the ionic conductivity of the non-aqueous electrolyte.
  • chain carbonate By using chain carbonate, the viscosity of the non-aqueous electrolyte can be kept low.
  • the volume ratio of the cyclic carbonate to the chain carbonate is preferably in the range of, for example, 5:95 to 50:50.
  • the electrolyte salt can be appropriately selected from known electrolyte salts.
  • electrolyte salts include lithium salts, sodium salts, potassium salts, magnesium salts, onium salts, and the like. Among these, lithium salts are preferred.
  • lithium salt examples include inorganic lithium salts such as LiPF6 , LiPO2F2 , LiBF4 , LiClO4 , and LiN( SO2F ) 2 ; lithium oxalate salts such as lithium bis (oxalate)borate (LiBOB), lithium difluorooxalateborate (LiFOB), and lithium bis(oxalate)difluorophosphate ( LiFOP ) ; and lithium salts having a halogenated hydrocarbon group such as LiSO3CF3 , LiN ( SO2CF3 ) 2 , LiN ( SO2C2F5 ) 2 , LiN ( SO2CF3 ) ( SO2C4F9 ), LiC( SO2CF3 ) 3 , and LiC( SO2C2F5 ) 3 .
  • inorganic lithium salts are preferred, and LiPF6 is more preferred.
  • the content of the electrolyte salt in the nonaqueous electrolyte is preferably 0.1 mol/dm 3 or more and 2.5 mol/dm 3 or less, and 0.3 mol/dm 3 or more and 2.0 mol/dm at 20° C. and 1 atmosphere. It is more preferably 3 or less, even more preferably 0.5 mol/dm 3 or more and 1.7 mol/dm 3 or less, particularly preferably 0.7 mol/dm 3 or more and 1.5 mol/dm 3 or less.
  • the non-aqueous electrolyte may contain additives in addition to the non-aqueous solvent and electrolyte salt.
  • additives include halogenated carbonate esters such as fluoroethylene carbonate (FEC) and difluoroethylene carbonate (DFEC); lithium bis(oxalate)borate (LiBOB), lithium difluorooxalateborate (LiFOB), and lithium bis(oxalate).
  • Oxalates such as difluorophosphate (LiFOP); Imide salts such as lithium bis(fluorosulfonyl)imide (LiFSI); biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene , t-amylbenzene, diphenyl ether, dibenzofuran and other aromatic compounds; 2-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene and other aromatic compounds such as partial halides; 2,4-difluoroanisole, 2 , 5-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole and other halogenated anisole compounds; vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, succinic an
  • the content of the additives contained in the non-aqueous electrolyte is preferably 0.01% by mass to 10% by mass, more preferably 0.1% by mass to 7% by mass, even more preferably 0.2% by mass to 5% by mass, and particularly preferably 0.3% by mass to 3% by mass.
  • a solid electrolyte may be used as the non-aqueous electrolyte, or a non-aqueous electrolyte and a solid electrolyte may be used together.
  • the solid electrolyte can be selected from any material that has ionic conductivity, such as lithium, sodium, and calcium, and is solid at room temperature (for example, 15° C. to 25° C.).
  • Examples of the solid electrolyte include sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, polymer solid electrolytes, and the like.
  • Examples of the sulfide solid electrolyte in the case of a lithium ion secondary battery include Li 2 SP 2 S 5 , LiI-Li 2 SP 2 S 5 , Li 10 Ge-P 2 S 12 , and the like.
  • the shape of the power storage element of this embodiment is not particularly limited, and examples include a cylindrical battery, a square battery, a flat battery, a coin battery, a button battery, and the like.
  • FIG. 1 shows a power storage element 1 as an example of a square battery. Note that this figure is a perspective view of the inside of the container.
  • An electrode body 2 having a positive electrode and a negative electrode wound together with a separator in between is housed in a rectangular container 3.
  • the positive electrode is electrically connected to the positive electrode terminal 4 via a positive electrode lead 41.
  • the negative electrode is electrically connected to the negative electrode terminal 5 via a negative electrode lead 51.
  • the power storage element of this embodiment can be used as a power source for automobiles such as an electric vehicle (EV), a hybrid vehicle (HEV), or a plug-in hybrid vehicle (PHEV), a power source for electronic devices such as a personal computer or a communication terminal, or a power source for power storage. etc., it can be mounted as a power storage unit (battery module) configured by collecting a plurality of power storage elements.
  • the technology of the present invention may be applied to at least one power storage element included in the power storage unit.
  • a power storage device according to an embodiment of the present invention includes one or more power storage elements according to the embodiment of the present invention, and includes two or more power storage elements (hereinafter referred to as "second embodiment").
  • the technology according to an embodiment of the present invention may be applied to at least one power storage element included in the power storage device according to the second embodiment, and the power storage element according to the embodiment of the present invention may be applied to the power storage device according to the second embodiment.
  • the battery may include one or more power storage elements that are not related to the embodiment of the present invention, or may include two or more power storage elements that are not related to the embodiment of the present invention.
  • FIG. 2 shows an example of a power storage device 30 according to the second embodiment in which a power storage unit 20 in which two or more electrically connected power storage elements 1 are assembled is further assembled.
  • the power storage device 30 may include a bus bar (not shown) that electrically connects two or more power storage elements 1, a bus bar (not shown) that electrically connects two or more power storage units 20, etc. good.
  • the power storage unit 20 or the power storage device 30 may include a state monitoring device (not shown) that monitors the state of one or more power storage elements.
  • a method for manufacturing the electricity storage element of this embodiment can be appropriately selected from known methods.
  • the manufacturing method includes, for example, preparing an electrode body, preparing an electrolyte, and accommodating the electrode body and the electrolyte in a container.
  • Preparing the electrode body includes preparing a positive electrode and a negative electrode, and forming the electrode body by laminating or winding the positive electrode and the negative electrode with a separator in between.
  • Storing the electrolyte in a container can be appropriately selected from known methods.
  • the injection port may be sealed after the non-aqueous electrolyte is injected through an injection port formed in the container.
  • the active material particles, electrodes, and power storage elements of the present invention are not limited to the embodiments described above, and various changes may be made without departing from the gist of the present invention.
  • the configuration of one embodiment can be added to the configuration of another embodiment, and a part of the configuration of one embodiment can be replaced with the configuration of another embodiment or a known technique.
  • some of the configurations of certain embodiments may be deleted.
  • well-known techniques can be added to the configuration of a certain embodiment.
  • the electricity storage element is used as a chargeable/dischargeable non-aqueous electrolyte secondary battery (for example, a lithium ion secondary battery) has been described, but the type, shape, size, capacity, etc. of the electricity storage element are arbitrary. .
  • the present invention can also be applied to capacitors such as various secondary batteries, electric double layer capacitors, and lithium ion capacitors.
  • the power storage element of the present invention may be a power storage element other than a non-aqueous electrolyte power storage element.
  • an electrode body in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween has been described, but the electrode body does not need 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 electrode of the present invention is a positive electrode
  • the electrode of the present invention may be a negative electrode.
  • the electrode of the present invention can also be used as a negative electrode by combining with a positive electrode using an appropriate positive electrode active material.
  • Example 1 preparation of active material particles
  • active material particles in which secondary particles of lithium iron phosphate were coated with a carbon material were obtained.
  • a 1 mol/dm 3 FeSO 4 aqueous solution was dropped at a constant rate into a 2 dm 3 reaction vessel containing 750 cm 3 of ion-exchanged water, while maintaining the pH of the reaction solution at a constant value of 8.5 ⁇ 0.1.
  • a 4 mol/dm 3 aqueous NaOH solution, a 0.5 mol/dm 3 aqueous NH 3 solution, and a 0.5 mol/dm 3 NH 2 NH 2 aqueous solution were added dropwise to produce a Fe(OH) 2 precursor.
  • the temperature of the reaction vessel was set at 50°C ⁇ 2°C.
  • the produced Fe(OH) 2 precursor was taken out from the reaction vessel and mixed in a solid phase with 116 parts by mass of LiH 2 PO 4 and 10 parts by mass of sucrose powder per 100 parts by mass of the Fe(OH) 2 precursor. did.
  • the obtained mixture was fired at a firing temperature of 650° C. in a nitrogen atmosphere to form active material particles of Example 1 in which particles of LiFePO 4 , which is a lithium transition metal compound having a polyanion structure, were coated with a carbon material. I got it.
  • the content of carbon material in the obtained active material particles of Example 1 was 1.0% by mass.
  • the average particle diameter of the active material particles of Example 1 measured by the method described above was 7.5 ⁇ m.
  • the amount of change in particle size measured by the method described above was 0.2 nm, and the rate of change in particle size was 0.003%.
  • the coating amount of the positive electrode mixture paste was 1.0 g/cm 2 in terms of solid content, the pressure of the roll press was 320 kgf/cm, the temperature of the roll was 120° C., and the speed was 2.0 m/min.
  • the density of the positive electrode active material layer measured by the method described above was 2.2 g/cm 3 .
  • a negative electrode mixture paste was prepared by mixing graphite as a negative electrode active material, styrene butadiene rubber (SBR) as a binder, carboxymethyl cellulose (CMC) as a thickener, and water as a dispersion medium.
  • SBR styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • This negative electrode mixture paste was applied to a copper foil serving as a negative electrode base material, dried, and roll pressed to form a negative electrode active material layer to obtain a negative electrode.
  • Nonaqueous electrolyte LiPF 6 was dissolved at a concentration of 1.1 mol/dm 3 in a solvent containing ethylene carbonate (EC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) mixed at a volume ratio of 30:35:35. A water electrolyte was obtained.
  • EC ethylene carbonate
  • DEC diethyl carbonate
  • EMC ethyl methyl carbonate
  • the positive electrode, negative electrode, and separator were laminated to produce an electrode body.
  • the obtained electrode body was placed in a container, and then the non-aqueous electrolyte was poured into the container and the container was sealed, thereby obtaining the electricity storage element of Example 1.
  • Example 2 In the production of active material particles, Example 2 was carried out in the same manner as in Example 1, except that the pH of the reaction solution and the concentration of the NH 3 aqueous solution when producing the Fe(OH) 2 precursor were as shown in Table 1. 5 and Comparative Examples 1 to 3, positive electrodes, and power storage elements were obtained. The pH of the reaction solution was adjusted by changing the amount of each aqueous solution added dropwise. Note that in Comparative Example 3, the NH 3 aqueous solution was not dropped.
  • Comparative example 4 Active material particles, a positive electrode, and a power storage element of Comparative Example 4 were obtained in the same manner as in Example 1 except that the active material particles were produced by the solid phase method described below. Li 2 CO 3 , FePO 4 , and sucrose powders were mixed in a solid phase at a molar ratio of 1:2:1. The resulting mixture was fired in a nitrogen atmosphere at a firing temperature of 650°C to obtain active material particles of Comparative Example 4 in which particles of LiFePO 4 , a lithium transition metal compound having a polyanionic structure, were coated with a carbon material. Ta.
  • Examples 6 to 10, Comparative Examples 5 to 8 A positive electrode mixture paste was prepared by using polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (NMP) as the binder and dispersion medium, respectively, and setting the mass ratio of active material particles, AB, and PVDF to 90:5:5 in terms of solid content. Except for the above, electricity storage elements of Examples 6 to 10 and Comparative Examples 5 to 8 were obtained in the same manner as Examples 1 to 5 and Comparative Examples 1 to 4, respectively.
  • PVDF polyvinylidene fluoride
  • NMP N-methylpyrrolidone
  • the amount of change in particle size (amount of particle size change) when each of the obtained active material particles is pressurized from 20 mN to 100 mN and the rate of change in particle size at this time (rate of particle size change), measured by the above method. are shown in Table 1.
  • each power storage element was charged at a constant current of 1.0 C at 25° C. to bring the SOC to 50%. Subsequently, a current of 0.2C, 0.5C, or 1.0C was discharged for 30 seconds, respectively. After each discharge, constant current charging was performed at a current of 1.0 C to bring the SOC to 50%.
  • the relationship between the current in each discharge and the voltage 10 seconds after the start of discharge was plotted, and the direct current resistance was determined from the slope of the straight line obtained from the three points plotted.
  • the output 10 seconds after the start of discharge was calculated from the determined DC resistance, and was taken as the initial output. The results are shown in Table 1.
  • each of the power storage elements of Examples 1 to 10 using active material particles in which the change in particle size when a predetermined pressure is applied is 1.1 nm or less
  • the initial output was improved compared to each of the power storage elements of Comparative Examples 1 to 8 in which active material particles having an amount exceeding 1.1 nm were used.
  • the power storage elements of Examples 1 to 5 using SBR as the positive electrode binder have improved output retention rates compared to the power storage elements of Examples 6 to 10 using PVDF as the positive electrode binder. I found out that there is.
  • the present invention is suitably used as power storage elements such as non-aqueous electrolyte secondary batteries used as power sources for electronic devices such as personal computers and communication terminals, and automobiles.

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Abstract

Une électrode selon un mode de réalisation de la présente invention comprend : des particules de matériau actif qui sont un matériau granulaire obtenu en recouvrant des particules qui contiennent un composé de métal de transition de lithium ayant une structure polyanionique avec un matériau carboné, lesdites particules de matériau actif présentant une quantité de changement du diamètre de particule inférieur ou égal à 1,1 nm lorsqu'elles sont mises sous pression de 20 mN à 100 mN ; et un liant.
PCT/JP2023/031361 2022-09-20 2023-08-30 Électrode, élément de stockage d'énergie électrique et dispositif de stockage d'énergie électrique WO2024062862A1 (fr)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11250937A (ja) * 1998-02-27 1999-09-17 Fuji Film Celltec Kk 非水電解液二次電池
JP2009081002A (ja) * 2007-09-26 2009-04-16 Furukawa Battery Co Ltd:The リチウム二次電池用正極活物質の製造法、正極活物質及びリチウム二次電池
WO2010134156A1 (fr) * 2009-05-19 2010-11-25 トヨタ自動車株式会社 Matière de substance active de cathode en poudre destinée à un accumulateur au lithium-ion
JP2016525265A (ja) * 2013-06-21 2016-08-22 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニア 電池性能増強のための全体論的アプローチを用いた長寿命ハイレートリチウム／硫黄電池
JP2018156724A (ja) * 2017-03-15 2018-10-04 日立化成株式会社 リチウムイオン二次電池
JP2022073197A (ja) * 2020-10-30 2022-05-17 株式会社Ｇｓユアサ 蓄電素子用正極活物質合剤、蓄電素子用正極及び蓄電素子
JP2022075345A (ja) * 2020-11-06 2022-05-18 株式会社Ｇｓユアサ 蓄電素子用正極及び蓄電素子

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11250937A (ja) * 1998-02-27 1999-09-17 Fuji Film Celltec Kk 非水電解液二次電池
JP2009081002A (ja) * 2007-09-26 2009-04-16 Furukawa Battery Co Ltd:The リチウム二次電池用正極活物質の製造法、正極活物質及びリチウム二次電池
WO2010134156A1 (fr) * 2009-05-19 2010-11-25 トヨタ自動車株式会社 Matière de substance active de cathode en poudre destinée à un accumulateur au lithium-ion
JP2016525265A (ja) * 2013-06-21 2016-08-22 ザ リージェンツ オブ ザ ユニバーシティ オブ カリフォルニア 電池性能増強のための全体論的アプローチを用いた長寿命ハイレートリチウム／硫黄電池
JP2018156724A (ja) * 2017-03-15 2018-10-04 日立化成株式会社 リチウムイオン二次電池
JP2022073197A (ja) * 2020-10-30 2022-05-17 株式会社Ｇｓユアサ 蓄電素子用正極活物質合剤、蓄電素子用正極及び蓄電素子
JP2022075345A (ja) * 2020-11-06 2022-05-18 株式会社Ｇｓユアサ 蓄電素子用正極及び蓄電素子

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