WO2012001840A1 - 非水電解質二次電池用負極およびその製造方法、ならびに非水電解質二次電池 - Google Patents
非水電解質二次電池用負極およびその製造方法、ならびに非水電解質二次電池 Download PDFInfo
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- WO2012001840A1 WO2012001840A1 PCT/JP2011/001113 JP2011001113W WO2012001840A1 WO 2012001840 A1 WO2012001840 A1 WO 2012001840A1 JP 2011001113 W JP2011001113 W JP 2011001113W WO 2012001840 A1 WO2012001840 A1 WO 2012001840A1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—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
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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
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
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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
- H01M4/139—Processes of manufacture
- H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/364—Composites as mixtures
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
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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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Definitions
- the present invention relates to a negative electrode for a non-aqueous electrolyte secondary battery, and more particularly to improvement of a negative electrode mixture layer containing graphite as an active material.
- a negative electrode current collector provided with a negative electrode active material mixture layer including a negative electrode active material
- a positive electrode current collector provided with a positive electrode current collector material mixture layer including a positive electrode active material.
- a positive electrode, a separator interposed between the negative electrode and the positive electrode, and a nonaqueous electrolyte are provided.
- a separator a polyolefin microporous film is mainly used.
- Various carbon materials such as graphite are used as the negative electrode active material.
- the negative electrode mixture layer is usually formed by rolling the coating film after forming the coating film of the negative electrode mixture in order to increase the energy density. Is done.
- the (002) plane or layer plane of graphite particles having a flake shape or the like is oriented in a direction parallel to the plane of the current collector.
- graphite has a layer structure, and during charge / discharge, lithium ions are inserted into or desorbed from the edge portion of each layer.
- the graphite layer surface is oriented in a direction parallel to the current collector surface. Lithium ions cannot be inserted efficiently from the edge of each layer of graphite. In addition, lithium ions are not easily desorbed during discharge. In particular, when charging and discharging with a large current, since the diffusion of lithium ions in the negative electrode mixture layer cannot catch up, the discharge capacity decreases.
- the magnetic layer is used to orient the graphite layer surface in a direction perpendicular to the current collector in the negative electrode mixture layer.
- graphite is oriented by applying a magnetic field to the coating film of the negative electrode mixture before rolling, and then the negative electrode mixture layer is compressed by rolling or the like. The orientation of is broken.
- battery capacity cannot be improved unless the negative electrode mixture layer is compressed.
- the strength of the mixture layer is lowered, and the negative electrode active material is dropped from the current collector or the mixture layer is peeled off, thereby increasing the possibility of an internal short circuit.
- An object of this invention is to provide the negative electrode which can improve a large-current characteristic, maintaining the battery capacity of a nonaqueous electrolyte secondary battery.
- One aspect of the present invention includes a sheet-like negative electrode current collector and a negative electrode mixture layer disposed on a surface of the negative electrode current collector. The negative electrode mixture layer is formed between graphite particles and the graphite particles.
- the present invention relates to a negative electrode for a nonaqueous electrolyte secondary battery including intervening ceramic particles.
- the average particle size of the ceramic particles is smaller than the average particle size of the graphite particles, and in the X-ray diffraction pattern of the negative electrode mixture layer, the peak intensity I 110 attributed to the (110) plane of the graphite particles and The ratio R: I 110 / I 002 with the peak intensity I 002 attributed to the (002) plane is 0.05 or more, and the density of the negative electrode mixture layer of the negative electrode mixture layer is 1.1. ⁇ 1.8 g / cm 3 .
- Another aspect of the present invention is a process for preparing a negative electrode slurry by dispersing graphite particles and ceramic particles having an average particle size smaller than the average particle size of the graphite particles in a liquid medium, A step of preparing a negative electrode current collector, a step of forming a coating film of a negative electrode mixture by applying the negative electrode slurry to a surface of the negative electrode current collector, introducing the coating film into a predetermined magnetic field, and The step of orienting the surface direction of the (002) plane of the graphite particles contained in the coating film toward the normal direction of the negative electrode current collector, and the surface direction of the (002) plane of the graphite particles. And rolling the coating film to form a negative electrode mixture layer having a density of 1.1 to 1.8 g / cm 3 after orientation, and a method for producing a negative electrode for a nonaqueous electrolyte secondary battery. .
- Still another aspect of the present invention relates to a non-aqueous electrolyte secondary battery including a positive electrode, the negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte.
- the orientation of the graphite particles can be prevented from being broken by the ceramic particles interposed between the graphite particles.
- the negative electrode for a nonaqueous electrolyte secondary battery of the present invention includes a sheet-like negative electrode current collector and a negative electrode mixture layer disposed on the surface of the negative electrode current collector.
- the negative electrode mixture layer contains graphite particles and ceramic particles interposed between the graphite particles.
- a graphite particle is a general term for particles including a region having a graphite structure.
- examples of graphite particles include natural graphite, artificial graphite, graphitized mesophase carbon, and the like.
- the graphite particles can be used singly or in combination of two or more.
- the graphite particles are preferably highly crystalline.
- the diffraction image of graphite particles measured by the wide-angle X-ray diffraction method has a peak attributed to the (101) plane and a peak attributed to the (100) plane.
- the ratio of the peak intensity I (101) attributed to the (101) plane and the peak intensity I (100) attributed to the (100) plane is 0.01 ⁇ I (101) / I. It is preferable to satisfy (100) ⁇ 0.25, and it is more preferable to satisfy 0.08 ⁇ I (101) / I (100) ⁇ 0.20.
- the peak intensity means the peak height.
- the average particle diameter of the graphite particles is, for example, 5 to 20 ⁇ m, preferably 7 to 17 ⁇ m, and more preferably 8 to 16 ⁇ m.
- the average particle diameter of the graphite particles means the median diameter (D50) in the volume-based particle size distribution of the graphite particles.
- the volume-based particle size distribution of the graphite particles can be measured by, for example, a commercially available laser diffraction particle size distribution measuring device.
- the average circularity of the graphite particles is preferably 0.90 to 0.95, more preferably 0.91 to 0.94.
- the average circularity is included in the above range, the slipping property of the graphite particles in the negative electrode mixture layer is improved, which is advantageous for improving the filling property of the graphite particles.
- the average circularity is represented by 4 ⁇ S / L 2 (where S is the area of the orthographic image of graphite particles, and L is the perimeter of the orthographic image).
- S is the area of the orthographic image of graphite particles
- L is the perimeter of the orthographic image
- the aspect ratio of the graphite particles is, for example, 1 to 20, preferably 2 or more (for example, 2 to 10), and more preferably 2 to 5.
- Use of graphite particles having an aspect ratio of 2 or more facilitates control of the orientation state of the graphite particles in the negative electrode mixture layer, which is advantageous for greatly improving the large current characteristics.
- the aspect ratio is the ratio of the maximum diameter to the minimum diameter of the graphite particles (maximum diameter / minimum diameter).
- Ceramic particles include inorganic oxides or composite oxides containing at least one element selected from titanium, aluminum, silicon, magnesium, and zirconium.
- ceramic particles for example, titania, alumina, silica, magnesia, zirconia, or the like may be used in consideration of hardness, chemical stability, cost, and the like. These ceramic particles can be used singly or in combination of two or more.
- the crystal structure of the ceramic particles may be, for example, spinel, perovskite, rutile, anatase, brookite, etc., depending on the type of element contained.
- the ceramic particles further include metal elements other than the above elements, for example, alkali metal elements such as Li, Na and K; alkaline earth metal elements such as Ca, Sr and Ba; V, Mo, W, Nb, Mn and Fe , Co, Ni, Cu, Zn, or other transition metal elements; B, Ga, or other periodic table group 13 elements, etc. may be used. These metal elements can be used singly or in combination of two or more. Of the metal elements, alkali metal elements such as lithium, alkaline earth metal elements, and the like are preferable.
- a preferable ceramic particle is a lithium titanium composite oxide having a spinel crystal structure.
- Such a composite oxide is advantageous in improving the capacity because lithium ions can be inserted and removed.
- lithium titanium composite oxide having a spinel crystal structure examples include lithium titanate represented by the formula: Li 4 Ti 5 O 12 , formula: Li x Ti 5- y My O 12 + z (3 ⁇ x ⁇ 5 , 0.005 ⁇ y ⁇ 1.5, ⁇ 1 ⁇ z ⁇ 1), and the like.
- M is an alkali metal such as Na; alkaline earth metal such as Mg, Ca, Sr, Ba; transition metal elements such as Zr, V, Mo, W, Nb, Mn, Fe, Co, Ni, Cu, Zn; It is at least one selected from the group consisting of Group 13 elements of the periodic table such as B, Al and Ga; Group 14 elements such as Bi.
- the average particle size of the ceramic particles needs to be smaller than the average particle size of the graphite particles in order to suppress the collapse of the orientation of the graphite particles when increasing the density of the mixture layer.
- the average particle size of the ceramic particles is, for example, 0.05 to 6 ⁇ m, preferably 0.1 to 5 ⁇ m, more preferably 0.1 to 2 ⁇ m, particularly 0.5 to 1.5 ⁇ m.
- the average particle diameter of the ceramic particles means the median diameter (D50) in the volume-based particle size distribution of the ceramic particles.
- the volume-based particle size distribution of the ceramic particles can be measured by, for example, a commercially available laser diffraction particle size distribution measuring apparatus.
- the ratio (W1 / W2) of the weight W1 of the ceramic particles contained in the negative electrode mixture layer to the weight W2 of the graphite particles is 0.01 to 1, preferably 0.03 to 0.6, more preferably 0.00. 05-0.4. Such a range is advantageous from the viewpoint of suppressing a decrease in energy density.
- the density of the negative electrode mixture layer is 1.1 to 1.8 g / cm 3 , preferably 1.2 to 1.7 g / cm 3 , more preferably 1.25 to 1.6 g / cm 3 . If the density is too small, the surface roughness of the negative electrode mixture layer increases and the separator may be damaged. If the density is too large, lithium ions may not be easily inserted into the negative electrode mixture layer, and the rate characteristics may deteriorate.
- the density of the negative electrode mixture layer can be adjusted by the degree of compression of the negative electrode mixture layer (compression pressure, number of times, etc.).
- the negative electrode mixture layer has a high density as described above, many graphite particles have a (002) plane that is the ab surface (layer surface) of the graphite particles in the negative electrode mixture layer. It is oriented toward the normal direction of the negative electrode current collector (direction perpendicular to the negative electrode current collector).
- the degree of orientation of the graphite particles depends on the peak intensity attributed to the (002) plane and the peak attributed to the (110) plane that is perpendicular to the (002) plane in the X-ray diffraction pattern of the negative electrode mixture layer. It can be expressed as a ratio to intensity. As the (002) plane is oriented in the direction perpendicular to the negative electrode current collector, the peak intensity attributed to the (002) plane decreases.
- the ratio R (I 110 / I 002 ) of the peak intensity I 110 attributed to the (110) plane and the peak intensity I 002 attributed to the (002) plane is 0.05 or more. Yes, preferably 0.1 or more, more preferably 0.15 or more, or 0.2 or more, or 0.25 or more.
- the upper limit of the intensity ratio R is not limited.
- the intensity ratio R is 1 or less, preferably 0.5 or less. More preferably, it may be 0.3 or less.
- FIG. 1 is a cross-sectional view schematically showing a negative electrode according to an embodiment of the present invention.
- the negative electrode 6 has a negative electrode current collector 6a and a negative electrode mixture layer 6b disposed on the surface of the negative electrode current collector 6a.
- the negative electrode mixture layer 6b includes flake-like graphite particles 21, and the graphite particles 21 are oriented in a direction substantially perpendicular to the surface of the negative electrode current collector 6a. Between the graphite particles 21, there are ceramic particles 22 having an average particle size smaller than that of the graphite particles 21.
- other components constituting the negative electrode mixture layer such as a binder are omitted.
- the negative electrode mixture layer can be formed on at least one surface of the negative electrode current collector, or may be formed on both surfaces.
- ceramic particles are interposed between graphite particles in the negative electrode mixture layer. Ceramic particles have a higher hardness than graphite particles. Therefore, even if the negative electrode mixture layer is compressed to the above density, it is possible to suppress the collapse of the orientation of the graphite particles.
- edge portions of the graphite particles on the surface of the negative electrode mixture layer, lithium ions can be occluded and desorbed in a direction substantially perpendicular to the surface of the negative electrode mixture layer.
- lithium ions can be smoothly inserted and desorbed, and the large current characteristics can be greatly improved.
- the negative electrode mixture layer contains graphite particles that are negative electrode active materials, ceramic particles, and a binder.
- the negative electrode mixture layer may further contain a thickener, a conductive material, and the like as necessary.
- binder examples include fluorine resins such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and vinylidene fluoride (VDF) -hexafluoropropylene (HFP) copolymer; polyolefin resins such as polyethylene and polypropylene; Polyamide resins such as aramid; Polyimide resins such as polyimide and polyamideimide; Acrylic resins such as polymethyl acrylate and ethylene-methyl methacrylate copolymer; Vinyl resins such as polyvinyl acetate and ethylene-vinyl acetate copolymer; Examples thereof include polyethersulfone; polyvinylpyrrolidone; rubbery materials such as styrene-butadiene rubber and acrylic rubber.
- a binder can be used individually by 1 type or in combination of 2 or more types. The ratio of the binder is, for example, 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight with
- a conductive material such as a carbon material or a metal material different from the graphite particles can be used.
- Specific examples include carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers and metal fibers; and carbon fluoride.
- a conductive material can be used individually by 1 type or in combination of 2 or more types.
- the proportion of the conductive material is not particularly limited, and is, for example, 0 to 5 parts by weight, preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of graphite particles.
- the thickener examples include cellulose derivatives such as carboxymethyl cellulose (CMC); poly C 2-4 alkylene glycol such as polyethylene glycol and ethylene oxide-propylene oxide copolymer; polyvinyl alcohol; solubilized modified rubber and the like. .
- a thickener can be used individually by 1 type or in combination of 2 or more types.
- the ratio of the thickener is not particularly limited, and is, for example, 0 to 10 parts by weight, preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the graphite particles.
- the negative electrode current collector may be a non-porous conductive substrate (metal foil, metal sheet, etc.), or a porous conductive substrate (punching sheet, expanded metal, etc.) having a plurality of through holes. Good.
- the metal material forming the negative electrode current collector include stainless steel, nickel, copper, and copper alloy. Of these, copper or a copper alloy is preferable.
- the thickness of the negative electrode current collector can be selected, for example, from the range of 3 to 50 ⁇ m, preferably 5 to 30 ⁇ m, more preferably 5 to 20 ⁇ m.
- the negative electrode of the present invention can be produced through the following steps (i) to (v).
- steps (i) to (v). a step of preparing a negative electrode slurry by dispersing graphite particles and ceramic particles in a liquid medium;
- introducing the coating film into a predetermined magnetic field and orienting the surface direction of the (002) plane of the graphite particles contained in the coating film in the magnetic field toward the normal direction of the negative electrode current collector a step of orienting the plane direction of the (002) plane of the graphite particles and then rolling the coating film to form a negative electrode mixture layer having a density of 1.1 to 1.8 g / cm 3 .
- the liquid medium (dispersion medium) used for the negative electrode slurry is not particularly limited.
- water alcohol such as ethanol, ether such as tetrahydrofuran, amide such as dimethylformamide, N-methyl- Examples include 2-pyrrolidone (NMP) or a mixture thereof.
- NMP 2-pyrrolidone
- the negative electrode slurry usually contains constituent components dissolved or dispersed in a dispersion medium.
- the negative electrode slurry can be prepared by a method using a conventional mixer or kneader.
- the negative electrode slurry can be applied to the surface of the current collector by a conventional coating method, for example, a coating method using various coaters such as a blade coater, a knife coater, and a gravure coater.
- the coating film is introduced into a predetermined magnetic field.
- the coating film is introduced into the magnetic field so that the direction of the magnetic flux of the magnetic field is substantially perpendicular (for example, 80 to 90 °) with respect to the surfaces of the coating film and the negative electrode current collector.
- the coating film is introduced into the magnetic field before the liquid medium (such as a dispersion medium) is completely volatilized. Thereby, the surface direction of the (002) plane of the graphite particles can be oriented toward the normal direction of the negative electrode current collector.
- the magnetic field can be applied, for example, by arranging a magnet in the vicinity of the negative electrode current collector on which the coating film is formed.
- the magnetic flux density of the magnetic field is, for example, 0.1 to 3T, preferably 0.2 to 2.5T, and more preferably 0.3 to 2T.
- the application time of the magnetic field depends on the magnitude of the magnetic flux density, but is, for example, 0.1 second to 5 minutes, preferably 0.1 second to 1 minute, and more preferably 0.5 to 30 seconds.
- the coating film is preferably introduced into the magnetic field before removing a liquid medium (such as a dispersion medium) from the coating film, or introduced into the magnetic field while removing the dispersion medium from the coating film. That is, the coating film is dried after orienting the plane direction of the (002) plane of the graphite particles, or dried while orienting the graphite particles.
- the coating is solidified by drying, and the graphite particles are fixed in a state in which the surface direction of the (002) plane is oriented toward the normal direction of the negative electrode current collector. Drying may be natural drying or may be performed under heating or under reduced pressure. If necessary, drying may be performed while blowing air.
- the density of the negative electrode mixture layer is increased by compressing the coating film (usually, a dried coating film).
- the negative electrode mixture layer can be formed by rolling the coating film using a pair of rollers.
- the rolling pressure is a linear pressure of 500 to 2,500 N / cm, preferably 800 to 2,000 N / cm, and more preferably 1,000 to 1,800 N / cm.
- the thickness of the negative electrode mixture layer is, for example, 10 to 60 ⁇ m, preferably 12 to 50 ⁇ m, and more preferably 15 to 35 ⁇ m.
- ceramic particles having an average particle size smaller than that of the graphite particles are used together with the graphite particles. Therefore, ceramic particles having relatively high hardness enter between the graphite particles, and when the negative electrode mixture layer is compressed, the orientation of the (002) plane of the graphite particles changes from the normal direction of the negative electrode current collector to the plane direction. Suppresses excessive collapse toward the. Therefore, the orientation of the graphite particles can be maintained even after compression, and at the same time, the density of the negative electrode mixture layer can be increased. Further, since the negative electrode mixture layer can be compressed, the strength of the negative electrode mixture layer can be increased, the surface roughness can be reduced, the dropping of the mixture layer can be suppressed, and the internal short circuit associated therewith can be suppressed.
- the nonaqueous electrolyte secondary battery of the present invention includes the above negative electrode, a positive electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte.
- a non-aqueous electrolyte secondary battery has an electrode group in which a positive electrode, a negative electrode, and a separator that separates them are wound. Usually, an electrode group and a non-aqueous electrolyte are accommodated in a battery case. ing.
- the nonaqueous electrolyte secondary battery of FIG. 2 includes an electrode group 4 in which a long strip-shaped positive electrode 5, a long strip-shaped negative electrode 6, and a separator 7 interposed between the positive electrode 5 and the negative electrode 6 are wound.
- an electrode group 4 in which a long strip-shaped positive electrode 5, a long strip-shaped negative electrode 6, and a separator 7 interposed between the positive electrode 5 and the negative electrode 6 are wound.
- a non-aqueous electrolyte (not shown) is accommodated.
- the electrode group 4 is produced by winding a positive electrode 5, a negative electrode 6, and a separator 7 separating them in a spiral shape using a wick. The wick may be removed if necessary.
- a positive electrode lead 9 is electrically connected to the positive electrode 5, and a negative electrode lead 10 is electrically connected to the negative electrode 6.
- the positive electrode lead 9 for example, an aluminum plate can be used, and as the negative electrode lead 10, for example, a nickel plate, a copper plate, or the like can be used.
- the electrode group 4 is housed in the battery case 1 together with the lower insulating ring 8b with the positive electrode lead 9 led out.
- the end of the positive electrode lead 9 is welded to the sealing plate 2, and the positive electrode 5 and the sealing plate 2 are electrically connected.
- the lower insulating ring 8 b is disposed between the bottom surface of the electrode group 4 and the negative electrode lead 10 led out from the electrode group 4.
- the negative electrode lead 10 is welded to the inner bottom surface of the battery case 1, and the negative electrode 6 and the battery case 1 are electrically connected.
- An upper insulating ring 8 a is mounted on the upper surface of the electrode group 4.
- the electrode group 4 is held in the battery case 1 by an inwardly protruding step 11 formed on the upper side surface of the battery case 1 above the upper insulating ring 8a.
- a sealing plate 2 having a resin gasket 3 on the periphery is placed, and the opening end of the battery case 1 is caulked and sealed inward.
- the positive electrode current collector may be a non-porous conductive substrate (metal foil, metal sheet, etc.), or a porous conductive substrate (punching sheet, expanded metal, etc.) having a plurality of through holes. Good.
- the metal material used for the positive electrode current collector include stainless steel, titanium, aluminum, and an aluminum alloy.
- the thickness of the positive electrode current collector can be selected, for example, from the range of 3 to 50 ⁇ m, preferably 5 to 30 ⁇ m, more preferably 5 to 20 ⁇ m.
- a positive electrode mixture layer is attached to the surface of the positive electrode current collector.
- the positive electrode mixture layer may be formed on one side of the positive electrode current collector or on both sides.
- the positive electrode mixture layer contains a positive electrode active material and a binder.
- the positive electrode mixture layer may further contain a thickener, a conductive material, and the like as necessary.
- the positive electrode active material examples include transition metal oxides commonly used in the field of non-aqueous electrolyte secondary batteries, such as lithium-containing transition metal oxides.
- the lithium-containing transition metal oxide preferably has a layered or hexagonal crystal structure or a spinel structure.
- the positive electrode active material is usually used in a particulate form.
- transition metal element contained in the transition metal oxide examples include Co, Ni, and Mn.
- the transition metal may be partially substituted with a different element.
- the surface of the lithium-containing transition metal oxide particles may be coated with a different element.
- the different elements include Na, Mg, Sc, Y, Cu, Zn, Al, Cr, Pb, Sb, and B.
- a positive electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type.
- M Li x Mn 2-y M y O 4
- the thickener and the conductive material used in the positive electrode mixture layer the same thickener and conductive material as exemplified in the negative electrode mixture layer can be used.
- the proportion of the thickener is not particularly limited, and is, for example, 0 to 10 parts by weight, preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the positive electrode active material.
- the ratio of the conductive material is, for example, 0 to 15 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the positive electrode active material.
- the positive electrode can be formed by preparing a positive electrode slurry containing a positive electrode active material and a binder and applying it to the surface of the positive electrode current collector.
- the positive electrode slurry usually contains a dispersion medium, and a thickener and / or a conductive material may be added.
- the coating film formed on the surface of the positive electrode current collector is usually dried and further rolled.
- the positive electrode mixture layer may be rolled at a relatively high pressure.
- the rolling pressure may be linear pressure, for example, 1 to 30 kN / cm, preferably 5 to 25 kN / cm, more preferably 10 to 22 kN / cm.
- the separator examples include a porous film (porous film) containing resin and a nonwoven fabric.
- the resin constituting the separator include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer.
- the porous film may contain inorganic oxide particles as necessary.
- the thickness of the separator is, for example, 5 to 100 ⁇ m, preferably 7 to 50 ⁇ m, and more preferably 10 to 25 ⁇ m.
- the nonaqueous electrolyte includes a nonaqueous solvent and a lithium salt dissolved in the nonaqueous solvent.
- Nonaqueous solvents include, for example, cyclic carbonates, chain carbonates, cyclic carboxylic acid esters, and the like.
- the cyclic carbonate include ethylene carbonate (EC) and propylene carbonate (PC).
- the chain carbonate include diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC).
- Examples of the cyclic carboxylic acid ester include ⁇ -butyrolactone (GBL) and ⁇ -valerolactone (GVL).
- a non-aqueous solvent may be used individually by 1 type, and may be used in combination of 2 or more type.
- the lithium salt for example, a lithium salt of a fluorine-containing acid (LiPF 6 , LiBF 4 , LiCF 3 SO 3 and the like), a lithium salt of a fluorine-containing acid imide (LiN (CF 3 SO 2 ) 2 and the like), and the like can be used.
- a lithium salt can be used individually by 1 type or in combination of 2 or more types.
- the concentration of the lithium salt in the nonaqueous electrolyte is 0.5 to 2 mol / L.
- the non-aqueous electrolyte may contain a known additive, for example, vinylene carbonate, cyclohexylbenzene, diphenyl ether and the like, if necessary.
- the electrode group is not limited to a wound one, but may be a laminated one or a folded one.
- the shape of the electrode group may be a cylindrical shape and a flat shape having an oval end surface perpendicular to the winding axis, depending on the shape of the battery or battery case.
- the battery case may be made of a laminate film, but is usually made of metal from the viewpoint of pressure strength.
- a material for the battery case aluminum, an aluminum alloy (such as an alloy containing a trace amount of a metal such as manganese or copper), a steel plate, or the like can be used.
- the battery case may be plated by nickel plating or the like, if necessary.
- the shape of the battery case may be a cylindrical shape, a square shape, or the like depending on the shape of the electrode group.
- Example 1 The nonaqueous electrolyte secondary battery shown in FIG. 2 was produced by the following procedure. (1) Preparation of positive electrode An appropriate amount of lithium nickelate (LiNiO 2 ) as an active material, acetylene black as a conductive material, and polyvinylidene fluoride (PVDF) as a binder in a weight ratio of 100: 5: 4 NMP was added. The obtained mixture was kneaded with a planetary mixer to obtain a slurry-like positive electrode mixture (positive electrode slurry).
- LiNiO 2 lithium nickelate
- acetylene black as a conductive material
- PVDF polyvinylidene fluoride
- a positive electrode slurry was applied to both surfaces of a positive electrode current collector made of an aluminum foil (thickness 15 ⁇ m, width 100 mm), and air-dried at 80 ° C. for 20 minutes.
- the positive electrode current collector having the obtained coating film was rolled with a roller at a linear pressure of 2000 kgf / cm (19.6 kN / cm). This obtained the positive electrode 5 in which the positive mix layer was formed on both surfaces of the positive electrode collector.
- the thickness of the positive electrode mixture layer was 40 ⁇ m, and the thickness of the positive electrode 5 was 95 ⁇ m.
- the positive electrode 5 was cut into a strip shape having a width of 50 mm and a length of 1000 mm.
- the positive electrode mixture layer was not formed at a predetermined portion of the positive electrode 5, and a portion (not shown) where the positive electrode current collector was exposed was provided.
- a copper foil (thickness 20 ⁇ m) was used for the negative electrode current collector.
- a neodymium magnet is installed on the lower side of the negative electrode current collector, and the magnetic field generated by the magnet (magnetic flux density 300 mT) is applied.
- the graphite particles were oriented by application so as to be perpendicular to the surface of the body. Next, it was blown and dried at 80 ° C. for 20 minutes.
- a dried coating film in which graphite particles were oriented was formed on the other surface of the negative electrode current collector.
- the obtained negative electrode current collector having a coating film on both sides was rolled once with a pair of rollers at a linear pressure of 150 kgf / cm (1470 N / cm) to obtain a negative electrode 6.
- the density of the negative electrode mixture layer was 1.4 g / cm 3 .
- the thickness of the negative electrode mixture layer was 50 ⁇ m, and the total thickness of the negative electrode 6 was 120 ⁇ m.
- the negative electrode 6 was cut into a strip shape having a width of 55 mm and a length of 1100 mm. A predetermined portion of the negative electrode 6 was provided with a portion (not shown) where the negative electrode mixture layer was not formed and the negative electrode current collector was exposed.
- the electrode group 4 was sandwiched between the upper insulating ring 8a and the lower insulating ring 8b, and the other end of the negative electrode lead 10 was welded to the inner bottom surface of the battery case 1.
- the other end of the positive electrode lead 9 was welded to the lower surface of the sealing plate 2.
- the electrode group 4 was accommodated in a cylindrical battery case 1 having an outer diameter of 18 mm and a length of 65 mm.
- a non-aqueous electrolyte was injected into the battery case 1 and the electrode group 4 was impregnated with the non-aqueous electrolyte by a reduced pressure method.
- the battery case 1 was caulked and sealed with the sealing plate 2 through the gasket 3 to produce a cylindrical lithium ion secondary battery A1.
- Comparative Example 1 A negative electrode was produced in the same manner as in Example 1 except that alumina particles were not used. The density of the negative electrode mixture layer was 1.4 g / cm 3 . Using the obtained negative electrode, a battery B1 was obtained in the same manner as in Example 1.
- Example 2 A negative electrode was produced in the same manner as in Example 1 except that the linear pressure during rolling was 100 kgf / cm (980 N / cm). The density of the negative electrode mixture layer was 1.2 g / cm 3 . Using the obtained negative electrode, a battery A2 was obtained in the same manner as in Example 1.
- Example 3 A negative electrode was produced in the same manner as in Example 1 except that the number of rolling was changed to 2. The density of the negative electrode mixture layer was 1.6 g / cm 3 . Using the obtained negative electrode, a battery A3 was obtained in the same manner as in Example 1.
- Examples 4 to 6 A negative electrode was produced in the same manner as in Example 1 except that the ratio of the alumina particles to 100 parts by weight of the graphite particles was changed. Batteries A4, A5 and A6 were obtained by the same method as in Example 1 using the obtained negative electrode.
- Example 7 and Comparative Example 2 A negative electrode was produced in the same manner as in Example 1 except that the aspect ratio of the graphite particles as the negative electrode active material was changed. Using this negative electrode, batteries A7 and B2 were obtained in the same manner as in Example 1.
- Examples 8 to 11 A negative electrode was produced in the same manner as in Example 1 except that the average particle size of the alumina particles as ceramic particles was changed. Using this negative electrode, batteries A8 to A11 were obtained in the same manner as in Example 1.
- Examples 12 to 15 A negative electrode was produced in the same manner as in Example 1 except that silica particles, magnesia particles, zirconia particles, or lithium titanium composite oxide particles (Li 4 Ti 5 O 12 ) were used in place of the alumina particles. . Using this negative electrode, batteries A12 to A15 were obtained in the same manner as in Example 1. In Table 1, lithium titanium composite oxide particles are described as “LiTi-based”.
- the particle diameter is the average particle diameter
- the density is the density of the negative electrode mixture layer after rolling.
- the batteries A1 to A15 of Examples 1 to 15 exhibited excellent high output characteristics as compared with the battery B3 of Comparative Example 3 in which no magnetic field was applied.
- the mixture density after the rolling was 1.1 to 1.8 g, compared with the battery B1 of Comparative Example 1 using a negative electrode containing no ceramic particles.
- I 110 / I 002 was 0.05 or more, and high output characteristics could be improved.
- the batteries A1 to A15 obtained excellent battery capacity and high output characteristics even when compared with the battery B2 in which I 110 / I 002 after rolling was 0.03.
- graphites having different aspect ratios were used, that is, when the battery A1, the battery A7, and the battery B2 were respectively compared, particularly when the aspect ratio was 2 or more, a higher effect was obtained with high output characteristics.
- the negative electrode of the present invention is advantageous in providing a non-aqueous electrolyte secondary battery having high capacity and excellent large current characteristics.
- the nonaqueous electrolyte secondary battery of the present invention is suitably used as a drive source for electronic devices such as notebook computers, mobile phones, and digital still cameras, as well as power storage devices and electric vehicles that require high output.
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Abstract
Description
本発明の一局面は、シート状の負極集電体と、前記負極集電体の表面に配した負極合剤層とを含み、前記負極合剤層は、黒鉛粒子と、前記黒鉛粒子間に介在するセラミックス粒子とを含む非水電解質二次電池用負極に関する。前記セラミックス粒子の平均粒径は、前記黒鉛粒子の平均粒径よりも小さく、前記負極合剤層のX線回折パターンにおいて、前記黒鉛粒子の(110)面に帰属されるピークの強度I110と、(002)面に帰属されるピークの強度I002との比R:I110/I002は、0.05以上であり、前記負極合剤層の負極合剤層の密度は、1.1~1.8g/cm3である。
黒鉛粒子とは、黒鉛構造を有する領域を含む粒子の総称である。よって、黒鉛粒子としては、天然黒鉛、人造黒鉛、黒鉛化メソフェーズカーボンなどが挙げられる。黒鉛粒子は、一種を単独でまたは二種以上を組み合わせて使用できる。黒鉛粒子は高結晶性のものが好ましい。
セラミックス粒子の結晶構造は、含有する元素の種類などに応じて、例えば、スピネル、ペロブスカイト、ルチル、アナターゼ、ブルカイトなどであってもよい。
Mは、Naなどのアルカリ金属;Mg、Ca、Sr、Baなどのアルカリ土類金属;Zr、V、Mo、W、Nb、Mn、Fe、Co、Ni、Cu、Znなどの遷移金属元素;B、Al、Gaなどの周期表13族元素;Biなどの14族元素よりなる群から選択された少なくとも1種である。
セラミックス粒子の平均粒径は、例えば、0.05~6μm、好ましくは0.1~5μm、さらに好ましくは0.1~2μm、特に0.5~1.5μmである。セラミックス粒子の平均粒径が、黒鉛粒子の平均粒径よりも大きくなると、負極合剤層中の黒鉛粒子の割合を大きくすることが難しくなり、エネルギー密度が低下する場合がある。セラミックス粒子の平均粒径とは、セラミックス粒子の体積基準の粒度分布におけるメジアン径(D50)を意味する。セラミックス粒子の体積基準の粒度分布は、例えば、市販のレーザー回折式の粒度分布測定装置により測定することができる。
負極合剤層の密度は、1.1~1.8g/cm3、好ましくは1.2~1.7g/cm3、さらに好ましくは1.25~1.6g/cm3である。密度が小さすぎると、負極合剤層の表面粗さが大きくなり、セパレータが破損する場合がある。密度が大きすぎると、負極合剤層に、リチウムイオンが挿入しにくくなり、レート特性が低下する場合がある。負極合剤層の密度は、負極合剤層の圧縮の程度(圧縮の圧力、回数など)により調整できる。
負極合剤層は、負極集電体の少なくとも一方の表面に形成でき、両面に形成してもよい。
結着剤の割合は、黒鉛粒子100重量部に対して、例えば、0.01~10重量部、好ましくは0.05~5重量部である。
導電材の割合は、特に制限されず、例えば、黒鉛粒子100重量部に対して0~5重量部、好ましくは0.01~3重量部である。
増粘剤の割合は、特に制限されず、例えば、黒鉛粒子100重量部に対して0~10重量部、好ましくは0.01~5重量部である。
負極集電体の厚みは、例えば、3~50μmの範囲から選択でき、好ましくは5~30μm、さらに好ましくは5~20μmである。
(i)黒鉛粒子と、セラミックス粒子とを、液状の媒体に分散させて負極スラリーを調製する工程、
(ii)シート状の負極集電体を準備する工程、
(iii)負極スラリーを負極集電体の表面に塗布することにより、負極合剤の塗膜を形成する工程、
(iv)塗膜を所定の磁場に導入し、磁場中で、塗膜に含まれる前記黒鉛粒子の(002)面の面方向を、前記負極集電体の法線方向に向かって配向させる工程、
(v)前記黒鉛粒子の(002)面の面方向を配向させた後、前記塗膜を圧延し、密度が1.1~1.8g/cm3である負極合剤層を形成する工程。
結着剤、導電材および/または増粘剤を使用する場合、通常、負極スラリーに添加される。負極スラリーは、通常、構成成分を、分散媒に溶解または分散させた状態で含有する。
負極スラリーは、慣用の混合機または混練機などを用いる方法により調製できる。
磁場は、例えば、塗膜を形成した負極集電体の近傍に磁石を配置することで印加することができる。
磁場の印加時間は、磁束密度の大きさにも依存するが、例えば、0.1秒~5分、好ましくは0.1秒~1分、さらに好ましくは0.5~30秒である。
圧延の圧力は、線圧で、500~2,500N/cm、好ましくは800~2,000N/cm、さらに好ましくは1,000~1,800N/cmである。
負極合剤層の厚みは、例えば、10~60μm、好ましくは12~50μm、さらに好ましくは15~35μmである。
また、負極合剤層を圧縮できるため、負極合剤層の強度を高めるとともに、表面粗さを低減することができ、合剤層の脱落などを抑制でき、これに伴う内部短絡を抑制できる。
図2の非水電解質二次電池は、長尺帯状の正極5と、長尺帯状の負極6と、正極5と負極6との間に介在するセパレータ7とが捲回された電極群4を有する。有底円筒型の金属製の電池ケース1内には、電極群4とともに、図示しない非水電解質が収容されている。
図2において、電極群4は、正極5と、負極6と、これらを隔離するセパレータ7とを、捲芯を用いて渦捲状に捲回することにより作製される。捲芯は、必要により、抜き取ってもよい。
電極群4は、正極リード9を導出した状態で、下部絶縁リング8bとともに電池ケース1に収納される。正極リード9の端部は封口板2に溶接され、正極5と封口板2とは電気的に接続されている。
(正極)
正極集電体は、無孔の導電性基板(金属箔、金属シートなど)であってもよく、複数の貫通孔を有する多孔性の導電性基板(パンチングシート、エキスパンドメタルなど)であってもよい。正極集電体に使用される金属材料としては、ステンレス鋼、チタン、アルミニウム、アルミニウム合金などが例示できる。
正極集電体の表面には、正極合剤層が付着している。正極合剤層は、正極集電体の片面に形成してもよく、両面に形成してもよい。
正極合剤層は、正極活物質と、結着剤とを含有する。正極合剤層は、必要に応じて、さらに増粘剤、導電材などを含有してもよい。
増粘剤の割合は、特に制限されず、例えば、正極活物質100重量部に対して0~10重量部、好ましくは0.01~5重量部である。
導電材の割合は、例えば、正極活物質100重量部に対して0~15重量部、好ましくは1~10重量部である。
セパレータの厚みは、例えば、5~100μm、好ましくは7~50μm、さらに好ましくは10~25μmである。
非水溶媒は、例えば環状炭酸エステル、鎖状炭酸エステル、環状カルボン酸エステルなどを含む。環状炭酸エステルとしては、エチレンカーボネート(EC)、プロピレンカーボネート(PC)などが挙げられる。鎖状炭酸エステルとしては、ジエチルカーボネート(DEC)、エチルメチルカーボネート(EMC)、ジメチルカーボネート(DMC)などが挙げられる。環状カルボン酸エステルとしては、γ-ブチロラクトン(GBL)、γ-バレロラクトン(GVL)などが挙げられる。非水溶媒は、一種を単独で用いてもよく、二種以上を組み合わせて用いてもよい。
非水電解質は、必要により、公知の添加剤、例えば、ビニレンカーボネート、シクロヘキシルベンゼン、ジフェニルエーテルなどを含有してもよい。
電池ケースの形状は、電極群の形状に応じて、円筒型、角型などであってもよい。
以下の手順により、図2に示す非水電解質二次電池を作製した。
(1)正極の作製
活物質としてニッケル酸リチウム(LiNiO2)、導電材としてアセチレンブラック、および結着剤としてポリフッ化ビニリデン(PVDF)を100:5:4の重量比で含む混合物に、適量のNMPを加えた。得られた混合物を、プラネタリーミキサーで混練し、スラリー状の正極合剤(正極スラリー)を得た。
正極5を、幅50mmおよび長さ1000mmの帯状に切り出した。なお、正極5の所定箇所には、正極合剤層が形成されず、正極集電体が露出した部分(図示せず)を設けた。
活物質として平均粒径15μmの人造黒鉛(アスペクト比2)、結着剤としてスチレン-ブタジエン共重合体ゴム粒子分散体(固形分40重量%)、増粘剤としてカルボキシメチルセルロース、およびアルミナ粒子(平均粒径1μm)を、100:2.5:1:10の重量比で含む混合物に、適量の水を加えた。得られた混合物をプラネタリーミキサーで混練し、スラリー状の負極合剤(負極スラリー)を得た。
なお、負極6の所定箇所には、負極合剤層が形成されず、負極集電体が露出した部分(図示せず)を設けた。
正極5の正極集電体が露出した部分には、アルミニウム製の正極リード9の一端を溶接した。負極6の負極集電体が露出した部分には、ニッケル製の負極リード10の一端を溶接した。その後、上記で得られた正極5、負極6、およびこれらを隔離するセパレータ7を重ね合わせて捲回し、渦巻状の電極群4を構成した。セパレータ7としては、ポリエチレン製多孔膜(厚み20μm)を用いた。
電極群4を上部絶縁リング8aおよび下部絶縁リング8bで挟み、負極リード10の他端を電池ケース1の内底面に溶接した。正極リード9の他端を封口板2の下面に溶接した。電極群4を、外径18mm、長さ65mmの円筒型の電池ケース1に収容した。
ガスケット3を介して電池ケース1を封口板2でかしめ封口し、円筒型リチウムイオン二次電池A1を作製した。
アルミナ粒子を用いない以外は、実施例1と同様に、負極を作製した。負極合剤層の密度は、1.4g/cm3であった。得られた負極を用いて、実施例1と同様の方法により、電池B1を得た。
圧延の際の線圧を100kgf/cm(980N/cm)とする以外は、実施例1と同様に、負極を作製した。負極合剤層の密度は、1.2g/cm3であった。得られた負極を用いて、実施例1と同様の方法により、電池A2を得た。
圧延の回数を2回に変更する以外は、実施例1と同様に、負極を作製した。負極合剤層の密度は、1.6g/cm3であった。得られた負極を用いて、実施例1と同様の方法により、電池A3を得た。
黒鉛粒子100重量部に対するアルミナ粒子の割合を変更する以外は、実施例1と同様に、負極を作製した。得られた負極を用いて、実施例1と同様の方法により、電池A4、A5およびA6を得た。
負極活物質である黒鉛粒子のアスペクト比を変更する以外は、実施例1と同様の方法により、負極を作製した。この負極を用いて、実施例1と同様の方法により電池A7およびB2を得た。
セラミックス粒子であるアルミナ粒子の平均粒径を変更する以外は、実施例1と同様の方法により、負極を作製した。この負極を用いて、実施例1と同様の方法により電池A8~A11を得た。
アルミナ粒子に代えて、シリカ粒子、マグネシア粒子、ジルコニア粒子、またはリチウムチタン複合酸化物粒子(Li4Ti5O12)を用いたこと以外は、実施例1と同様の方法により、負極を作製した。この負極を用いて、実施例1と同様の方法により電池A12~A15を得た。
なお、表1中では、リチウムチタン複合酸化物粒子を、「LiTi系」と記載した。
負極合剤を負極集電体表面に塗布した後、磁界を印加しない以外は、実施例1と同様の方法により、負極を作製した。この負極を用いて、実施例1と同様の方法により電池B3を得た。
実施例および比較例で得られた各電池について、以下の評価を行った。
(A)電池容量
25℃の環境下において、電池の閉路電圧が4.2Vに達するまで0.7Cで充電した後、電流値が0.1Aに減衰するまで4.2Vで充電した。その後、電池の閉路電圧が2.5Vに達するまで、0.2Cで放電した。そのときの容量を電池容量として表1に示す。
(B)高出力特性
25℃の環境下において、電池の閉路電圧が4.2Vに達するまで0.7Cで充電した後、電流値が0.1Aに減衰するまで4.2Vで充電した。その後、電池の閉路電圧が2.5Vに達するまで、5Cで放電した。0.2Cでの放電容量に対する5Cでの放電容量の比率(%)を算出した。この比率(%)を表1に示す。
表1に示されるように、実施例1~15の電池A1~A15は、磁場を印加しない比較例3の電池B3と比べて、優れた高出力特性を示した。さらに負極合剤層中にセラミックス粒子を含む負極を用いた場合、セラミックス粒子を含まない負極を用いた比較例1の電池B1と比較して、圧延後に合剤密度が1.1~1.8g/cm3と高いにもかかわらず、I110/I002が0.05以上であり、高出力特性を向上できた。また、電池A1~A15は、圧延後のI110/I002が0.03である電池B2に比較しても、優れた電池容量および高出力特性が得られた。異なるアスペクト比の黒鉛を用いた場合、すなわち電池A1と、電池A7と、電池B2とを、それぞれ比べると、特にアスペクト比が2以上の場合、高出力特性でより高い効果が得られた。
2 封口板
3 ガスケット
4 電極群
5 正極
6 負極
6a 負極集電体
6b 負極合剤層
7 セパレータ
8a 上部絶縁リング
8b 下部絶縁リング
9 正極リード
10 負極リード
11 段部
21 黒鉛粒子
22 セラミックス粒子
Claims (10)
- シート状の負極集電体と、前記負極集電体の表面に配した負極合剤層とを含み、
前記負極合剤層は、黒鉛粒子と、前記黒鉛粒子間に介在するセラミックス粒子とを含み、
前記セラミックス粒子の平均粒径は、前記黒鉛粒子の平均粒径よりも小さく、
前記負極合剤層のX線回折パターンにおいて、前記黒鉛粒子の(110)面に帰属されるピークの強度I110と、(002)面に帰属されるピークの強度I002との比R:I110/I002が、0.05以上であり、
前記負極合剤層の密度が、1.1~1.8g/cm3である、非水電解質二次電池用負極。 - 前記黒鉛粒子の平均粒径が、5~20μmであり、前記セラミックス粒子の平均粒径が、0.1~2μmである、請求項1記載の非水電解質二次電池用負極。
- 前記黒鉛粒子の平均粒径が、7~17μmであり、前記セラミックス粒子の平均粒径が、0.5~1.5μmである、請求項1または2記載の非水電解質二次電池用負極。
- 前記黒鉛粒子のアスペクト比が、2以上である、請求項1~3のいずれか1項に記載の非水電解質二次電池用負極。
- 前記負極合剤層に含まれる前記セラミックス粒子の重量W1と、前記黒鉛粒子の重量W2との比:W1/W2が、0.05~0.4である、請求項1~4のいずれか1項に記載の非水電解質二次電池用負極。
- 前記セラミックス粒子が、チタニア、アルミナ、シリカ、マグネシアおよびジルコニアよりなる群から選択される少なくとも1種である、請求項1~5のいずれか1項に記載の非水電解質二次電池用負極。
- 前記セラミックス粒子が、スピネル型結晶構造を有するリチウムチタン複合酸化物である、請求項1~5のいずれか1項に記載の非水電解質二次電池用負極。
- 黒鉛粒子と、前記黒鉛粒子の平均粒径よりも小さい平均粒径を有するセラミックス粒子とを、液状の媒体に分散させて負極スラリーを調製する工程、
シート状の負極集電体を準備する工程、
前記負極スラリーを前記負極集電体の表面に塗布することにより、負極合剤の塗膜を形成する工程、
前記塗膜を所定の磁場に導入し、前記磁場中で、前記塗膜に含まれる前記黒鉛粒子の(002)面の面方向を、前記負極集電体の法線方向に向かって配向させる工程、
前記黒鉛粒子の(002)面の面方向を配向させた後、前記塗膜を圧延し、密度が1.1~1.8g/cm3である負極合剤層を形成する工程、を有する、非水電解質二次電池用負極の製造方法。 - 前記黒鉛粒子の(002)面の面方向を配向させる工程を、前記塗膜から前記液状の媒体を除去する前または除去しながら行う、請求項8記載の非水電解質二次電池用負極の製造方法。
- 正極、請求項1~7のいずれか1項に記載の負極、前記正極と前記負極との間に介在するセパレータ、および非水電解質を含む、非水電解質二次電池。
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JP2011548715A JP5073105B2 (ja) | 2010-06-30 | 2011-02-25 | 非水電解質二次電池用負極およびその製造方法、ならびに非水電解質二次電池 |
US13/394,499 US20120164530A1 (en) | 2010-06-30 | 2011-02-25 | Negative electrode for nonaqueous electrolyte secondary battery, method for producing same, and nonaqueous electrolyte secondary battery |
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---|---|---|---|---|
JP2012069488A (ja) * | 2010-09-27 | 2012-04-05 | Mitsubishi Chemicals Corp | 非水電解液二次電池 |
WO2013088540A1 (ja) * | 2011-12-14 | 2013-06-20 | トヨタ自動車株式会社 | 非水電解質二次電池と二次電池用負極の製造方法 |
WO2013099138A1 (ja) * | 2011-12-28 | 2013-07-04 | パナソニック株式会社 | リチウムイオン二次電池用負極及びリチウムイオン二次電池用負極を有するリチウムイオン二次電池 |
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JP2014137879A (ja) * | 2013-01-16 | 2014-07-28 | Toyota Motor Corp | 二次電池 |
WO2014157419A1 (ja) * | 2013-03-26 | 2014-10-02 | 日産自動車株式会社 | 非水電解質二次電池 |
EP2814095A4 (en) * | 2012-02-10 | 2015-07-08 | Panasonic Ip Man Co Ltd | NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM-ION BATTERIES, AND METHOD FOR MANUFACTURING THE SAME |
JP2016522961A (ja) * | 2013-04-16 | 2016-08-04 | エーテーハー チューリヒ | 電極の製造方法及び当該方法を用いて作製された電極 |
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US11594784B2 (en) | 2021-07-28 | 2023-02-28 | EnPower, Inc. | Integrated fibrous separator |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003197182A (ja) * | 2001-12-21 | 2003-07-11 | Samsung Sdi Co Ltd | 黒鉛含有組成物並びにリチウム二次電池用の負極及びリチウム二次電池 |
JP2006083030A (ja) * | 2004-09-17 | 2006-03-30 | Sony Corp | 黒鉛粉末および非水電解質二次電池 |
JP2007305545A (ja) * | 2006-05-15 | 2007-11-22 | Sony Corp | リチウムイオン電池 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4150516B2 (ja) * | 2001-12-21 | 2008-09-17 | 三星エスディアイ株式会社 | リチウム二次電池の負極用の黒鉛含有組成物の製造方法並びにリチウム二次電池用の負極の製造方法及びリチウム二次電池の製造方法 |
KR20140108697A (ko) * | 2004-01-16 | 2014-09-12 | 히타치가세이가부시끼가이샤 | 리튬 이차전지용 음극 및 리튬 이차전지 |
CN101515640B (zh) * | 2008-02-22 | 2011-04-20 | 比亚迪股份有限公司 | 一种负极和包括该负极的锂离子二次电池 |
-
2011
- 2011-02-25 US US13/394,499 patent/US20120164530A1/en not_active Abandoned
- 2011-02-25 KR KR1020127006106A patent/KR20120048007A/ko not_active Application Discontinuation
- 2011-02-25 JP JP2011548715A patent/JP5073105B2/ja not_active Expired - Fee Related
- 2011-02-25 CN CN2011800036794A patent/CN102484244A/zh active Pending
- 2011-02-25 WO PCT/JP2011/001113 patent/WO2012001840A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003197182A (ja) * | 2001-12-21 | 2003-07-11 | Samsung Sdi Co Ltd | 黒鉛含有組成物並びにリチウム二次電池用の負極及びリチウム二次電池 |
JP2006083030A (ja) * | 2004-09-17 | 2006-03-30 | Sony Corp | 黒鉛粉末および非水電解質二次電池 |
JP2007305545A (ja) * | 2006-05-15 | 2007-11-22 | Sony Corp | リチウムイオン電池 |
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US9966605B2 (en) | 2013-03-26 | 2018-05-08 | Nissan Motor Co., Ltd. | Non-aqueous electrolyte secondary battery |
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JPWO2012001840A1 (ja) | 2013-08-22 |
KR20120048007A (ko) | 2012-05-14 |
JP5073105B2 (ja) | 2012-11-14 |
US20120164530A1 (en) | 2012-06-28 |
CN102484244A (zh) | 2012-05-30 |
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