[go: up one dir, main page]

WO2025205497A1 - Batterie secondaire aux ions lithium et module de batterie secondaire aux ions lithium - Google Patents

Batterie secondaire aux ions lithium et module de batterie secondaire aux ions lithium

Info

Publication number
WO2025205497A1
WO2025205497A1 PCT/JP2025/011219 JP2025011219W WO2025205497A1 WO 2025205497 A1 WO2025205497 A1 WO 2025205497A1 JP 2025011219 W JP2025011219 W JP 2025011219W WO 2025205497 A1 WO2025205497 A1 WO 2025205497A1
Authority
WO
WIPO (PCT)
Prior art keywords
ion secondary
secondary battery
active material
electrode active
negative electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/JP2025/011219
Other languages
English (en)
Japanese (ja)
Inventor
円花 藤原
佳麗 劉
哲志 小野
健宏 野口
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Envision AESC Japan Ltd
Original Assignee
AESC Japan Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AESC Japan Co Ltd filed Critical AESC Japan Co Ltd
Publication of WO2025205497A1 publication Critical patent/WO2025205497A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • 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
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • 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

  • ⁇ Method 2> The lithium ion secondary battery is placed in a thermostatic chamber at 25°C, and then the lithium ion secondary battery is charged and discharged in accordance with the ⁇ charge and discharge cycle> described below, and the first discharge capacity is measured. Next, the lithium ion secondary battery is repeatedly charged and discharged in accordance with the ⁇ charge and discharge cycle> described below until a total of 499 cycles have been reached. Next, the lithium ion secondary battery is charged and discharged in accordance with the ⁇ charge and discharge cycle> described below, and the discharge capacity is measured for the 500th cycle. Next, the capacity retention rate R25 is calculated using the following formula (2).
  • the lithium ion secondary battery of this embodiment has the above-described configuration, and thus can improve cycle characteristics.
  • a positive electrode tab 9 is connected to the positive electrode current collector 3, and a negative electrode tab 8 is connected to the negative electrode current collector 4.
  • the positive electrode tab 9 and the negative electrode tab 8 are extended outside the container.
  • An electrolyte solution is injected and sealed inside the container.
  • the container may also house an electrode group consisting of multiple electrode pairs stacked together.
  • the lithium ion secondary battery can be fabricated according to a known method.
  • the electrode can be, for example, a laminate or a wound body.
  • the exterior can be a metal exterior or an aluminum laminate exterior.
  • the battery may have any shape, such as a laminate, coin, button, sheet, cylindrical, rectangular, or flat shape, but a laminate battery is preferred.
  • the electrolytic solution contains an electrolyte and an organic solvent.
  • the electrolytic solution contains lithium bis(fluorosulfonyl)imide (hereinafter also referred to as LiFSI) as the electrolyte.
  • examples of electrolytes other than LiFSI include lithium hexafluorophosphate (LiPF 6 ), lithium difluorobis(oxalato)phosphate (LiDODFP), lithium difluorophosphate (LiPO 2 F 2 ), LiClO 4 , LiBF 4 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiB 10 Cl 10 , LiAlCl 4 , LiCl, LiBr, LiB(C 2 H 5 ) 4 , CH 3 SO 3 Li, LiC 4 F 9 SO 3 , and Li(CF 3 SO 2 ) 2 .
  • LiPF 6 lithium hexafluorophosphate
  • LiDODFP lithium difluorobis(oxalato)phosphate
  • LiPO 2 F 2 lithium difluorophosphate
  • LiClO 4 LiBF 4 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSb
  • the lithium salt of a lower fatty acid, a lower carboxylic acid, or a mixture thereof may contain one or more compounds selected from the group consisting of N, a lithium salt of a lower fatty acid, and a lithium salt of a lower carboxylic acid, and preferably contains one or more compounds selected from the group consisting of LiPF6 and LiCl, and more preferably contains LiPF6 .
  • the organic solvent is not particularly limited as long as it can dissolve the electrolyte.
  • organic solvents include carbonates such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and vinylene carbonate (VC); lactones such as ⁇ -butyrolactone and ⁇ -valerolactone; ethers such as trimethoxymethane, 1,2-dimethoxyethane, diethyl ether, 2-ethoxyethane, tetrahydrofuran, and 2-methyltetrahydrofuran; sulfoxides such as dimethyl sulfoxide; oxolanes such as 1,3-dioxolane and 4-methyl-1,3-dioxolane; and acetonitrile.
  • carbonates such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (
  • the solvent contains one or more solvents selected from the group consisting of nitrogen-containing solvents such as nitromethane, formamide, and dimethylformamide; organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; phosphate esters such as phosphate triesters; diglymes; triglymes; sulfolanes such as sulfolane and methylsulfolane; oxazolidinones such as 3-methyl-2-oxazolidinone; and sultones such as 1,3-propane sultone, 1,4-butane sultone, and naphtha sultone, preferably carbonates, and more preferably one or more solvents selected from the group consisting of EC and EMC.
  • nitrogen-containing solvents such as nitromethane, formamide, and dimethylformamide
  • organic acid esters such as
  • the concentration of LiFSI in the electrolyte during production of the lithium ion secondary battery is preferably 0.7% by mass or more and 4.8% by mass or less, more preferably 0.8% by mass or more and 4.5% by mass or less, even more preferably 0.9% by mass or more and 4.0% by mass or less, even more preferably 1.0% by mass or more and 3.5% by mass or less, and even more preferably 1.0% by mass or more and 3.2% by mass or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the concentration of LiPF6 in the electrolyte solution during production of the lithium ion secondary battery is preferably 1.0 mass% or more, more preferably 5.0 mass% or more, even more preferably 10.0 mass% or more, still more preferably 10.5 mass% or more, still more preferably 11.0 mass% or more, and still more preferably 11.5 mass% or more, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the LiPF6 concentration (at the time of manufacture) is preferably 20.0 mass % or less, more preferably 18.0 mass % or less, even more preferably 15.0 mass % or less, still more preferably 14.0 mass % or less, still more preferably 13.0 mass % or less, and still more preferably 12.5 mass % or less, from the viewpoint of reducing corrosion of the battery components.
  • the LiPF6 concentration (at the time of production) is preferably 1.0 mass % or more and 20.0 mass % or less, more preferably 5.0 mass % or more and 18.0 mass % or less, even more preferably 10.0 mass % or more and 15.0 mass % or less, still more preferably 10.5 mass % or more and 14.0 mass % or less, still more preferably 11.0 mass % or more and 13.0 mass % or less, and still more preferably 11.5 mass % or more and 12.5 mass % or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery and reducing corrosion of the battery components.
  • the content of the electrolyte in the lithium ion secondary battery is preferably 15 parts by mass or more and 60 parts by mass or less, more preferably 20 parts by mass or more and 55 parts by mass or less, even more preferably 25 parts by mass or more and 50 parts by mass or less, and even more preferably 30 parts by mass or more and 45 parts by mass or less, when the total content of the negative electrode active material and the positive electrode active material in the lithium ion secondary battery is taken as 100 parts by mass, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the negative electrode of this embodiment includes a negative electrode active material layer. From the viewpoint of further improving the battery performance of the lithium ion secondary battery, the negative electrode of this embodiment preferably includes a negative electrode current collector and the negative electrode active material layer of this embodiment.
  • the negative electrode active material contained in the negative electrode active material layer has an SEI (Solid Electrolyte Interphase) film on at least a part of its surface, and preferably has an SEI film on its entire surface.
  • the SEI film is formed by decomposition of the electrolyte on the surface of the negative electrode during initial charge/discharge.
  • the SEI film is a film formed on at least a portion of the surface of the negative electrode active material by decomposition products of the electrolyte and electrolyte additives.
  • the SEI film functions to insert or extract lithium ions into or from the negative electrode, while also functioning to reduce further decomposition of the electrolyte on the surface of the negative electrode.
  • an SEI film can be formed on at least a portion of the surface of the negative electrode (negative electrode active material) by the method described in the "Initial Charging and Discharging of Lithium-Ion Secondary Battery" section in the Examples.
  • the lithium-ion secondary battery of this embodiment has an SEI film on at least a portion of the surface of the negative electrode active material contained in the negative electrode active material layer, and is therefore a lithium-ion secondary battery after at least initial charging and discharging.
  • the negative electrode active material layer of the present embodiment preferably contains the negative electrode active material of the present embodiment and a binder, and more preferably contains the negative electrode active material of the present embodiment, a binder, and a conductive additive.
  • the thickness of the negative electrode active material layer in this embodiment is preferably 10 ⁇ m or more and 250 ⁇ m or less, more preferably 15 ⁇ m or more and 200 ⁇ m or less, even more preferably 20 ⁇ m or more and 100 ⁇ m or less, and even more preferably 25 ⁇ m or more and 75 ⁇ m or less.
  • the density of the negative electrode active material layer of this embodiment is preferably 0.50 g/ cm3 or more and 3.00 g/ cm3 or less, more preferably 1.00 g/ cm3 or more and 2.50 g/cm3 or less , and even more preferably 1.30 g/ cm3 or more and 2.00 g/ cm3 or less.
  • the negative electrode active material of the present embodiment preferably contains one or more materials selected from the group consisting of a carbon material, a lithium-based metal material, a Si-based material, and a conductive polymer material, more preferably contains one or more materials selected from the group consisting of a carbon material and a Si-based material, and even more preferably contains both a carbon material and a Si-based material.
  • Examples of the carbon material of the present embodiment include graphite powder, hard carbon, soft carbon, and any mixture thereof, and graphite powder is preferred.
  • Si-based material of the present embodiment examples include silicon oxide particles and Si-C composite particles containing silicon and a carbon material (hereinafter also referred to as Si-C composite particles), and preferably contains Si-C composite particles from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the content of the negative electrode active material in the negative electrode active material layer of this embodiment when the total amount of the negative electrode active material layer is taken as 100.0 parts by mass, is preferably 50.0 parts by mass or more and 100.0 parts by mass or less, more preferably 75.0 parts by mass or more and 99.0 parts by mass or less, even more preferably 85.0 parts by mass or more and 98.5 parts by mass or less, even more preferably 90.0 parts by mass or more and 98.0 parts by mass or less, and even more preferably 95.0 parts by mass or more and 97.5 parts by mass or less.
  • the negative electrode active material of this embodiment preferably includes a negative electrode active material (A) and a negative electrode active material (B) of a type different from the negative electrode active material (A), from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the negative electrode active material (A) preferably contains a carbon material, more preferably contains graphite powder, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the volume-based median diameter D50 of the negative electrode active material (A) as measured by a laser diffraction scattering method is preferably 3.0 ⁇ m or more and 30.0 ⁇ m or less, more preferably 5.0 ⁇ m or more and 27.5 ⁇ m or less, even more preferably 7.5 ⁇ m or more and 22.5 ⁇ m or less, still more preferably 8.0 ⁇ m or more and 15.5 ⁇ m or less, and still more preferably 9.0 ⁇ m or more and 12.0 ⁇ m or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the graphite powder of this embodiment preferably contains graphite powder (A1) and a type of graphite powder (A1') different from the graphite powder (A1).
  • the graphite powder of this embodiment more preferably contains graphite powder (A1) and graphite powder (A2) having a volume-based median diameter D50 measured by a laser diffraction scattering method different from that of the graphite powder (A1), and the median diameter D50 of the graphite powder (A1) is larger than the median diameter D50 of the graphite powder (A2).
  • the ratio of D2 to D1 , D2 / D1 is preferably 0.40 or more and less than 1.0, more preferably 0.45 or more and 0.90 or less, even more preferably 0.50 or more and 0.80 or less, even more preferably 0.55 or more and 0.75 or less, and still more preferably 0.60 or more and 0.70 or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the volume-based median diameter D50 of the negative electrode active material (B) as measured by a laser diffraction scattering method is preferably 1.0 ⁇ m or more and 20.0 ⁇ m or less, more preferably 1.5 ⁇ m or more and 19.0 ⁇ m or less, even more preferably 2.5 ⁇ m or more and 17.0 ⁇ m or less, even more preferably 3.5 ⁇ m or more and 11.0 ⁇ m or less, and still more preferably 4.0 ⁇ m or more and 9.0 ⁇ m or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the binder in the negative electrode active material layer of this embodiment preferably contains one or more types selected from the group consisting of fluororesin, polycarboxylic acid polymer, and synthetic rubber, more preferably contains one or more types selected from the group consisting of PVDF, polycarboxylic acid polymer, and SBR, even more preferably contains a polycarboxylic acid polymer, and even more preferably contains poly(meth)acrylic acid.
  • the conductive additive in the negative electrode active material layer of this embodiment includes, for example, one or more selected from the group consisting of carbon materials such as carbon fibers such as carbon nanofibers, carbon blacks such as acetylene black and ketjen black, activated carbon, mesoporous carbon, fullerenes, and carbon nanotubes.
  • the conductive additive in the negative electrode active material layer of this embodiment preferably includes a carbon material, more preferably includes carbon nanotubes, and even more preferably includes single-walled carbon nanotubes, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the negative electrode current collector of this embodiment includes, for example, one or more selected from the group consisting of copper, stainless steel, nickel, titanium, and alloys thereof.
  • the negative electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh.
  • the thickness of the negative electrode current collector is not particularly limited, but is, for example, 1 ⁇ m or more and 50 ⁇ m or less.
  • the method for producing the negative electrode is not particularly limited and can be carried out according to a generally known method, for example, the method described in the Examples.
  • the positive electrode of this embodiment includes a positive electrode active material layer. From the viewpoint of further improving the battery performance of the lithium ion secondary battery, the positive electrode of this embodiment preferably includes a positive electrode current collector and the positive electrode active material layer of this embodiment.
  • the positive electrode active material layer of the present embodiment preferably contains the positive electrode active material of the present embodiment and a binder, and more preferably contains the positive electrode active material of the present embodiment, a binder, and a conductive additive.
  • the thickness of the positive electrode active material layer in this embodiment is preferably 10 ⁇ m or more and 250 ⁇ m or less, more preferably 15 ⁇ m or more and 200 ⁇ m or less, even more preferably 20 ⁇ m or more and 100 ⁇ m or less, and even more preferably 25 ⁇ m or more and 75 ⁇ m or less.
  • the density of the positive electrode active material layer of this embodiment is preferably 1.0 g/cm or more and 6.0 g/cm or less, more preferably 2.0 g/cm or more and 5.0 g/cm or less , and even more preferably 2.5 g/cm or more and 4.5 g/cm or less .
  • Examples of composite oxides of lithium and transition metals include lithium-nickel-cobalt-manganese composite oxide, lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-manganese composite oxide, lithium-manganese-nickel composite oxide, and lithium-nickel-cobalt-aluminum composite oxide.
  • Examples of transition metal sulfides include TiS 2 , FeS, and MoS 2 .
  • Examples of transition metal oxides include MnO, V 2 O 5 , V 6 O 13 , and TiO 2 .
  • the content of the positive electrode active material in the positive electrode active material layer of this embodiment when the entire positive electrode active material layer is taken as 100.0 parts by mass, is preferably 50.0 parts by mass or more and 99.9 parts by mass or less, more preferably 75.0 parts by mass or more and 99.5 parts by mass or less, even more preferably 85.0 parts by mass or more and 99.0 parts by mass or less, even more preferably 90.0 parts by mass or more and 98.5 parts by mass or less, and even more preferably 95.0 parts by mass or more and 98.0 parts by mass or less.
  • the positive electrode active material contained in the positive electrode active material layer preferably contains particles (C) containing one or more kinds selected from particles (C1) constituted by a single crystal of a lithium-nickel-cobalt-manganese composite oxide and particles (C2) constituted by a polycrystal of a lithium-nickel-cobalt-manganese composite oxide.
  • the content of nickel in particles (C) is preferably 80 mol or more, more preferably 80 mol or more and 99 mol or less, even more preferably 82 mol or more and 99 mol or less, even more preferably 84 mol or more and 98 mol or less, even more preferably 85 mol or more and 96 mol or less, even more preferably 86 mol or more and 95 mol or less, and even more preferably 88 mol or more and 94 mol or less, when the total content of nickel, cobalt, and manganese in particles (C) is taken as 100 mol.
  • the content of cobalt in particles (C) is preferably 0.5 mol or more and 10 mol or less, more preferably 1 mol or more and 10 mol or less, even more preferably 2 mol or more and 10 mol or less, even more preferably 2.5 mol or more and 10 mol or less, even more preferably 3 mol or more and 8 mol or less, and even more preferably 4 mol or more and 6 mol or less, when the total content of nickel, cobalt, and manganese in particles (C) is taken as 100 mol.
  • the manganese content in particles (C) is preferably 0.5 mol or more and 10 mol or less, more preferably 1 mol or more and 10 mol or less, even more preferably 2 mol or more and 10 mol or less, even more preferably 2.5 mol or more and 10 mol or less, even more preferably 3 mol or more and 8 mol or less, and even more preferably 4 mol or more and 6 mol or less, when the total content of nickel, cobalt, and manganese in particles (C) is taken as 100 mol.
  • the ratio mN/(mC+mM) of the number of moles of nickel mN to the sum of the number of moles of cobalt mC and the number of moles of manganese mM is preferably 4 or more and 50 or less, more preferably 4.5 or more and 25 or less, even more preferably 5 or more and 16 or less, even more preferably 7 or more and 12 or less, and even more preferably 8 or more and 11 or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the binder in the positive electrode active material layer of this embodiment includes, for example, one or more selected from the group consisting of fluororesins such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyhexafluoropropylene (PHFP), polyvinyl fluoride (PVF), and copolymers of vinylidene fluoride and hexafluoropropylene; polycarboxylic acid polymers such as poly(meth)acrylic acid; conductive polymers such as polyanilines, polythiophenes, polyacetylenes, and polypyrroles; synthetic rubbers such as styrene butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), isoprene rubber (IR), and acrylonitrile butadiene rubber (NBR); and polysaccharides such as carboxymethyl cellulose (CMC), xant
  • the binder in the positive electrode active material layer of this embodiment preferably contains one or more types selected from the group consisting of fluororesin, polycarboxylic acid polymer, and synthetic rubber, more preferably contains one or more types selected from the group consisting of PVDF, polycarboxylic acid polymer, and SBR, and even more preferably contains PVDF.
  • the content of the binder in the positive electrode active material layer of this embodiment is preferably 0.05 parts by mass or more and 10.0 parts by mass or less, more preferably 0.1 parts by mass or more and 5.0 parts by mass or less, even more preferably 0.2 parts by mass or more and 2.5 parts by mass or less, and even more preferably 0.5 parts by mass or more and 2.0 parts by mass or less, when the total amount of the positive electrode active material layer is taken as 100.0 parts by mass.
  • the conductive additive in the positive electrode active material layer of this embodiment includes, for example, one or more selected from the group consisting of carbon materials such as carbon fibers such as carbon nanofibers, carbon blacks such as acetylene black and ketjen black, activated carbon, mesoporous carbon, fullerenes, and carbon nanotubes.
  • the conductive additive in the positive electrode active material layer of this embodiment preferably includes a carbon material, more preferably includes carbon nanotubes, and even more preferably includes single-walled carbon nanotubes, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the content of the conductive additive in the positive electrode active material layer of this embodiment is preferably 0.05 parts by mass or more and 10.0 parts by mass or less, more preferably 0.1 parts by mass or more and 5.0 parts by mass or less, even more preferably 0.2 parts by mass or more and 2.5 parts by mass or less, and even more preferably 0.5 parts by mass or more and 2.0 parts by mass or less, when the total amount of the positive electrode active material layer is taken as 100.0 parts by mass.
  • the positive electrode current collector of this embodiment includes, for example, one or more selected from the group consisting of aluminum, stainless steel, nickel, titanium, and alloys thereof.
  • the positive electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh.
  • the thickness of the positive electrode current collector is not particularly limited, but is, for example, 1 ⁇ m or more and 50 ⁇ m or less.
  • the method for producing the positive electrode is not particularly limited and can be carried out according to a generally known method, for example, the method described in the Examples.
  • the lithium ion secondary battery of this embodiment includes an electrolyte, a positive electrode, and a negative electrode, and preferably further includes a separator.
  • the separator is not particularly limited as long as it can be used in lithium ion secondary batteries, and generally known separators can be used.
  • the separator preferably includes a substrate and a ceramic layer provided on at least one surface of the substrate, from the viewpoints of improving heat resistance and reducing thermal shrinkage of the separator.
  • the substrate may be, for example, a porous polyolefin film made of polyethylene, polypropylene, or a laminate of these.
  • the ceramic layer can be formed, for example, by applying a ceramic layer-forming material to a substrate and drying it.
  • the ceramic layer-forming material can be, for example, a material obtained by dispersing or dissolving an inorganic filler and a binder in a solvent.
  • the inorganic filler and binder are not particularly limited as long as they are known materials used in separators for lithium-ion secondary batteries.
  • the concentration of LiFSI in the electrolyte solution by ⁇ Method 1> is 0.6 mass % or more, preferably 0.7 mass % or more, more preferably 0.8 mass % or more, even more preferably 0.9 mass % or more, still more preferably 1.0 mass % or more, still more preferably 1.1 mass % or more, still more preferably 1.2 mass % or more, still more preferably 1.3 mass % or more, and still more preferably 1.4 mass % or more, from the viewpoint of improving the cycle characteristics of the lithium ion secondary battery.
  • the concentration of LiFSI in the electrolyte by ⁇ Method 1> is preferably 0.6 mass % or more and 5.0 mass % or less, more preferably 0.7 mass % or more and 4.0 mass % or less, even more preferably 0.8 mass % or more and 3.0 mass % or less, even more preferably 0.9 mass % or more and 3.0 mass % or less, even more preferably 1.0 mass % or more and 3.0 mass % or less, even more preferably 1.1 mass % or more and 3.0 mass % or less, even more preferably 1.2 mass % or more and 3.0 mass % or less, even more preferably 1.3 mass % or more and 3.0 mass % or less, and even more preferably 1.4 mass % or more and 2.7 mass % or less, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery.
  • the capacity retention rate R25 at 25°C is, from the viewpoint of further improving the cycle characteristics of the lithium ion secondary battery, preferably 87.0% or more, more preferably 87.5% or more, even more preferably 88.0% or more, even more preferably 88.5% or more, even more preferably 89.0% or more, even more preferably 89.5% or more, even more preferably 90.0% or more, even more preferably 90.5% or more, even more preferably 91.0% or more, even more preferably 91.5% or more, and even more preferably 92.0% or more.
  • the upper limit of the capacity retention rate R 25 at 25° C. is not particularly limited, but is, for example, less than 100%, and may be 99.0% or less, 98.0% or less, or 95.0% or less.
  • the lithium ion secondary battery is charged at 30 mA until it reaches an upper limit voltage of 4.25 V. After the upper limit voltage of 4.25 V is reached, the lithium ion secondary battery is charged at a constant voltage until 2.5 hours have elapsed since the start of charging. The lithium ion secondary battery is then discharged at a constant current of 30 mA until it reaches a lower limit voltage of 2.5 V.
  • the lithium-ion secondary battery module of this embodiment includes the lithium-ion secondary battery of this embodiment.
  • the lithium-ion secondary battery module of this embodiment preferably includes two or more lithium-ion secondary batteries of this embodiment connected in series or parallel.
  • the lithium-ion secondary battery module of this embodiment more preferably further includes a housing capable of accommodating two or more lithium-ion secondary batteries of this embodiment connected in series or parallel.
  • the lithium-ion secondary battery module of this embodiment more preferably further includes one or more devices selected from the group consisting of a protection circuit that protects the lithium-ion secondary battery from overcurrent, a balancing circuit that equalizes the voltage between the electrodes of the lithium-ion secondary battery, a controller that controls the lithium-ion secondary battery, a cooler that can cool the lithium-ion secondary battery, and a heater that can heat the lithium-ion secondary battery.
  • a protection circuit that protects the lithium-ion secondary battery from overcurrent
  • a balancing circuit that equalizes the voltage between the electrodes of the lithium-ion secondary battery
  • a controller that controls the lithium-ion secondary battery
  • a cooler that can cool the lithium-ion secondary battery
  • a heater that can heat the lithium-ion secondary battery.
  • the lithium-ion secondary battery module of this embodiment can be used in a battery system comprising two or more electrically connected lithium-ion secondary battery modules and a battery control system.
  • battery systems include battery packs, stationary storage battery systems, automotive power storage battery systems, automotive auxiliary storage battery systems, and emergency power storage battery systems.
  • the negative electrode active material (A) was a combination of the following graphite powder (A1) and graphite powder (A2).
  • Graphite powder (A1) As the graphite powder (A1), artificial graphite particles containing amorphous carbon on the surface were used. As the graphite powder (A1), the following graphite powder 1 was used. Graphite powder 1 (artificial graphite particles containing amorphous carbon on the surface, median diameter D 50 : 14.0 ⁇ m)
  • the negative electrode active material (B) used was the following Si—C composite particles (hereinafter also referred to as Si/C particles).
  • the Si--C composite particles used were the following Si/C particles 1.
  • Si/C particles 1 (median diameter D 50 : 4.8 ⁇ m, particles prepared according to the ⁇ Preparation of Si/C particles 1> below)
  • the positive electrode active material used was the following positive electrode active material 1.
  • Solvent 1 Ethylene carbonate (hereinafter also referred to as EC)
  • Solvent 2 Ethyl methyl carbonate (hereinafter also referred to as EMC)
  • Electrolyte Lithium hexafluorophosphate (LiPF 6 )
  • Electrolyte Lithium bis(fluorosulfonyl)imide (LiFSI)
  • Separator 10 ⁇ m thick microporous polyethylene film with ceramic coating on both sides
  • Negative electrode current collector copper foil (thickness: 8 ⁇ m)
  • Binder Polyacrylic acid (hereinafter referred to as PAA)
  • Conductive additive single-walled carbon nanotubes (hereinafter also referred to as CNTs)
  • Solvent Pure water
  • Positive electrode current collector aluminum foil (thickness: 12 ⁇ m)
  • Binder Polyvinylidene fluoride (hereinafter also referred to as PVDF)
  • Conductive additive single-walled carbon nanotubes (hereinafter also referred to as CNTs)
  • Solvent N-methyl-2-pyrrolidone (hereinafter also referred to as NMP)
  • ⁇ Method for measuring particle diameters of positive electrode active material and negative electrode active material> Using a laser diffraction particle size distribution analyzer (Shimadzu Corporation, model number: SALD-2300), the volume-based median diameter D 50 of each of the positive electrode active material and the negative electrode active material was measured by laser diffraction scattering.
  • the median diameter D 50 of the positive electrode active material was measured after suspending the positive electrode active material in a dispersion medium (0.1% by mass sodium hexametaphosphate aqueous solution) and ultrasonically dispersing it.
  • the median diameter D 50 of the negative electrode active material was measured after suspending the negative electrode active material in a dispersion medium (0.1% by mass sodium hexametaphosphate aqueous solution) and ultrasonically dispersing it. The measurement was performed five times, and the average value was taken as the median diameter D 50 .
  • the electrolyte solutions to be used in the lithium ion secondary batteries of each example were prepared according to the following procedure. Ethylene carbonate and ethyl methyl carbonate were mixed in a mass ratio of 30:70 (EC:EMC) to obtain a mixed solvent. Lithium hexafluorophosphate (LiPF 6 ) was dissolved in the obtained mixed solvent to a content of 12 mass%. Furthermore, lithium bis(fluorosulfonyl)imide (LiFSI) was dissolved in the mixed solvent to obtain the LiFSI concentration (at the time of preparation) shown in Table 1, thereby preparing the electrolyte solutions of each example.
  • LiPF 6 Lithium hexafluorophosphate
  • LiFSI lithium bis(fluorosulfonyl)imide
  • the positive electrodes to be used in the lithium ion secondary batteries of each example were fabricated in the following manner.
  • the positive electrode slurry was applied to a 12 ⁇ m thick aluminum foil positive electrode current collector in an amount such that the initial charge capacity per unit area was 4.0 mAh/cm 2.
  • the applied positive electrode slurry was then dried to obtain a positive electrode laminate.
  • the positive electrode laminate was pressed with a pressure such that the density of the positive electrode active material layer was 3.5 g/cm 3 , to produce each positive electrode of each example.
  • the negative electrodes to be used in the lithium ion secondary batteries of each example were fabricated in the following manner.
  • the negative electrode slurry was applied to an 8 ⁇ m thick copper foil negative electrode current collector in an amount such that the initial charge capacity per unit area was 4.3 mAh/cm 2.
  • the applied negative electrode slurry was then dried to obtain a negative electrode laminate.
  • the negative electrode laminate was pressed at a pressure such that the density of the negative electrode active material layer was 1.65 g/cm 3 , to produce each negative electrode of each example.
  • the lithium ion secondary batteries of each example were fabricated in the following manner.
  • One double-sided coated positive electrode and two single-sided coated negative electrodes were arranged with the coated surfaces facing each other through a separator, and stacked in the following order: negative electrode, separator, positive electrode, separator, negative electrode.
  • the stack thus produced was then wrapped in a laminated outer casing formed by processing a film primarily composed of aluminum.
  • the aluminum foil and copper foil cut out for current collection protruded from the laminated film.
  • the edge containing the protruding current collection foil and the other two edges were then heat-sealed to produce a laminated cell with only one edge open.
  • a predetermined amount of the electrolyte solution prepared above was poured into the opening of the laminated cell, and the laminated cell was then sealed under reduced pressure to produce a laminated lithium ion secondary battery.
  • the amount of the electrolyte solution to be injected was set so that the amount of the electrolyte solution was 30 parts by mass when the total amount of the positive electrode active material and the negative electrode active material was 100 parts by mass.
  • the lithium ion secondary battery of each example was initially charged and discharged under the following conditions to form an SEI film on the surface of the negative electrode active material, thereby obtaining the lithium ion secondary battery of each example after initial charge and discharge.
  • the charge and discharge of the lithium ion secondary battery was performed using a charge and discharge device in an environment at a temperature of 25°C.
  • the lithium ion secondary battery of each example was charged at a charging current of 0.05 C up to a battery voltage of 3.2 V, and then left to stand for 12 hours to perform pre-charging. Next, constant current charging was performed at a charging current of 0.05 C until the battery voltage reached 4.25 V.
  • the lithium-ion secondary battery was returned to an environment at a temperature of 25°C and constant current discharge was performed at a discharge current of 1 C until the battery voltage reached 2.5 V.
  • constant current discharge was performed at a discharge current of 0.33 C until the battery voltage reached 2.5 V.
  • the battery was left for 10 minutes.
  • constant current charging was performed at a charging current of 0.33 C until the battery voltage reached 4.25 V.
  • constant voltage charging was performed until the current value decreased to 0.05 C.
  • 10 minutes after the end of charging constant current discharging was performed at a discharge current of 1 C until the battery voltage reached 2.5 V.
  • constant current discharging was performed at a discharge current of 0.33 C until the battery voltage reached 2.5 V. After the battery voltage reached 2.5 V, the battery was left to stand for 10 minutes. Next, constant current charging was performed at a charging current of 0.33 C until the battery voltage reached 4.25 V. After the battery voltage reached 4.25 V, constant voltage charging was performed until the current value decreased to 0.05 C. The battery was then left for 10 minutes. Thereafter, constant current discharging was performed at a discharging current of 0.33 C until the battery voltage reached 2.5 V.
  • LiFSI concentration after initial charge/discharge For the lithium ion secondary battery of each example after the initial charge and discharge, the LiFSI concentration after the initial charge and discharge was measured by the following method.
  • the lithium-ion secondary battery after initial charge and discharge in each example was decomposed in an inert gas atmosphere at a temperature of 25°C and a relative humidity of 3% or less.
  • 0.2 g of the electrolyte solution collected from the decomposed lithium-ion secondary battery was dissolved in 1.0 g of deuterated acetonitrile to prepare a first sample.
  • 0.002 g of hexafluorobenzene was added to the first sample as a reference material to prepare a second sample.
  • LiFSI concentration in the electrolyte (Amount of LiFSI in the first sample) / (Amount of electrolyte solution collected from the disassembled lithium-ion secondary battery) ⁇ 100
  • ⁇ Charge/discharge cycle> The lithium ion secondary battery was charged at 30 mA until the upper limit voltage reached 4.25 V. After the upper limit voltage of 4.25 V was reached, the lithium ion secondary battery was charged at a constant voltage until 2.5 hours had elapsed since the start of charging. The lithium ion secondary battery was then discharged at a constant current of 30 mA until the lower limit voltage of 2.5 V was reached.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

L'invention concerne une batterie secondaire aux ions lithium (10) pourvue d'une électrode positive qui comprend une couche de matériau actif d'électrode positive (1), une électrode négative qui comprend une couche de matériau actif d'électrode négative (2), et un électrolyte, le matériau actif d'électrode négative inclus dans la couche de matériau actif d'électrode négative (2) comportant un film SEI sur au moins une partie de sa surface ; l'électrolyte contenant du bis(fluorosulfonyl)imide de lithium ; et la concentration de bis(fluorosulfonyl)imide de lithium dans l'électrolyte déterminée à l'aide d'un procédé prescrit étant d'au moins 0,6 % en masse.
PCT/JP2025/011219 2024-03-29 2025-03-21 Batterie secondaire aux ions lithium et module de batterie secondaire aux ions lithium Pending WO2025205497A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2024-057082 2024-03-29
JP2024057082A JP2025154209A (ja) 2024-03-29 2024-03-29 リチウムイオン二次電池およびリチウムイオン二次電池モジュール

Publications (1)

Publication Number Publication Date
WO2025205497A1 true WO2025205497A1 (fr) 2025-10-02

Family

ID=97217298

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2025/011219 Pending WO2025205497A1 (fr) 2024-03-29 2025-03-21 Batterie secondaire aux ions lithium et module de batterie secondaire aux ions lithium

Country Status (2)

Country Link
JP (1) JP2025154209A (fr)
WO (1) WO2025205497A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023008177A1 (fr) * 2021-07-30 2023-02-02 パナソニックＩｐマネジメント株式会社 Électrode négative pour batterie secondaire, et batterie secondaire
WO2023171564A1 (fr) * 2022-03-09 2023-09-14 パナソニックエナジ－株式会社 Batterie secondaire à solution électrolytique non aqueuse

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023008177A1 (fr) * 2021-07-30 2023-02-02 パナソニックＩｐマネジメント株式会社 Électrode négative pour batterie secondaire, et batterie secondaire
WO2023171564A1 (fr) * 2022-03-09 2023-09-14 パナソニックエナジ－株式会社 Batterie secondaire à solution électrolytique non aqueuse

Also Published As

Publication number Publication date
JP2025154209A (ja) 2025-10-10

Similar Documents

Publication Publication Date Title
JP5150966B2 (ja) 非水電解液二次電池用正極およびそれを用いた非水電解液二次電池
JP5582587B2 (ja) リチウムイオン二次電池
JP7321932B2 (ja) 電力機器を始動するためのバッテリーモジュール
CN101060182B (zh) 锂离子二次电池
WO2014010526A1 (fr) Batterie rechargeable à électrolyte non aqueux
US20140315089A1 (en) Positive active material, method of preparing the same, and rechargeable lithium battery including the same
KR20170080104A (ko) 양극 활물질 및 상기 양극 활물질을 채용한 양극과 리튬 전지
JP7556779B2 (ja) 負極活物質、負極、及び二次電池
WO2013024621A1 (fr) Pile au lithium-ion
CN104868168A (zh) 非水电解质二次电池
CN113346140A (zh) 一种电解液及其应用
JP2012084426A (ja) 非水電解質二次電池
CN118402106A (zh) 锂离子电池和用电装置
JP5207282B2 (ja) リチウム二次電池
US20160190562A1 (en) Negative electrode for lithium ion secondary battery, and lithium ion secondary battery
JP2020077576A (ja) リチウムイオン二次電池
EP4539185A1 (fr) Batterie secondaire, son procédé de fabrication et appareil électrique
JP5573875B2 (ja) 非水電解質溶液およびリチウムイオン二次電池
JP2017204334A (ja) 電極の製造方法、ならびに非水電解質二次電池および蓄電ユニット
JP2025510855A (ja) 非水電解質およびそれを含むリチウム二次電池
WO2014115322A1 (fr) Matériau actif d'électrode négative pour cellule secondaire au lithium-ion et cellule secondaire au lithium-ion obtenue en utilisant celle-ci
WO2025205497A1 (fr) Batterie secondaire aux ions lithium et module de batterie secondaire aux ions lithium
WO2025205494A1 (fr) Batterie rechargeable au lithium-ion et module de batterie rechargeable au lithium-ion
JP2025154206A (ja) リチウムイオン二次電池およびリチウムイオン二次電池モジュール
JP2025154205A (ja) リチウムイオン二次電池およびリチウムイオン二次電池モジュール

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 25775315

Country of ref document: EP

Kind code of ref document: A1