WO2014156963A1 - Matériau actif d'électrode négative, feuille d'électrode négative l'utilisant et dispositif accumulateur d'électricité - Google Patents

Matériau actif d'électrode négative, feuille d'électrode négative l'utilisant et dispositif accumulateur d'électricité Download PDF

Info

Publication number
WO2014156963A1
WO2014156963A1 PCT/JP2014/057785 JP2014057785W WO2014156963A1 WO 2014156963 A1 WO2014156963 A1 WO 2014156963A1 JP 2014057785 W JP2014057785 W JP 2014057785W WO 2014156963 A1 WO2014156963 A1 WO 2014156963A1
Authority
WO
WIPO (PCT)
Prior art keywords
negative electrode
active material
electrode active
carbon
storage device
Prior art date
Application number
PCT/JP2014/057785
Other languages
English (en)
Japanese (ja)
Inventor
高橋　正史
実 成田
敦允 中川
三好　和弘
安部　浩司
Original Assignee
山石金属株式会社
宇部興産株式会社
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 山石金属株式会社, 宇部興産株式会社 filed Critical 山石金属株式会社
Priority to JP2015508418A priority Critical patent/JP6291479B2/ja
Publication of WO2014156963A1 publication Critical patent/WO2014156963A1/fr

Links

Images

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
    • H01M10/056—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
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/46—Metal oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H01G11/60—Liquid electrolytes characterised by the solvent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H01G11/62—Liquid electrolytes characterised by the solute, e.g. salts, anions or cations therein
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • 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
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries

Definitions

  • the present invention relates to an alloy-based negative electrode active material capable of occluding and releasing lithium having high capacity and excellent cycle characteristics and charge storage characteristics, and a negative electrode sheet and an electricity storage device using the same.
  • lithium secondary batteries have been widely used in small electronic devices such as mobile phones and laptop computers, electric vehicles, and power storage applications.
  • Electronic devices equipped with lithium secondary batteries, such as smartphones and tablets, are becoming increasingly multifunctional and power consumption is increasing.
  • electricity in order to improve convenience, how to extend the cruising distance, that is, improvement of the energy density of the power storage device is the key to popularization.
  • the term lithium secondary battery is used as a concept including so-called lithium ion secondary batteries.
  • the theoretical capacity capable of occluding and releasing lithium includes silicon, tin, etc., which are much larger than the theoretical capacity of graphite, which is currently the most widely used negative electrode active material.
  • Alloy-based negative electrode active materials have been actively studied. However, these alloy-based materials have a problem that the volume of the material greatly expands when lithium is occluded, and the active material is cracked and pulverized, so that the current collecting property is lowered and the electrode is easily expanded.
  • the non-aqueous electrolyte is easily decomposed on the active new surface generated by the cracking of the active material, the decomposition product of the non-aqueous electrolyte is deposited on the surface of the active material to increase resistance, There is a problem that the battery tends to swell.
  • Patent Document 1 discloses that silicon (Si) synthesized by a single roll method or an atomizing method and copper (Cu), nickel (Ni), and cobalt (Co) are selected from the group consisting of It has been shown that the capacity retention rate after 50 cycles at 20 ° C. is improved by using a silicon alloy containing at least one metal element as a constituent element as the negative electrode material.
  • Patent Document 2 discloses a powder composed of a composite phase of an Si phase and an Si x Cu y phase composed of an Si x Cu y alloy which is an intermetallic compound of Si and Cu, and an Si x Cu y phase.
  • a composition of x ⁇ y, by using a Si alloy average hardness of the intermetallic compound phase consisting of Si x Cu y phase is equal to or less than 800HV a negative electrode material, 20 cycles at 25 ° C. It has been shown that the capacity retention after the improvement is improved.
  • JP 2004-362895 A Japanese Patent No. 4865105
  • An object of the present invention is to provide an alloy-based negative electrode active material which has a high capacity and is capable of occluding and releasing lithium, which is excellent in cycle characteristics and charge storage characteristics, and a negative electrode sheet and an electricity storage device using the same.
  • the present inventors have studied in detail the performance of the above-described conventional silicon alloy negative electrode. As a result, it was found that the silicon alloy negative electrodes of Patent Documents 1 and 2 do not necessarily have sufficient cycle characteristics, and further, a large amount of gas is generated when stored at a high temperature in a charged state, which poses a practical problem. Therefore, as a result of intensive studies to solve the above problems, the inventors have improved the cycle characteristics by including a very small amount of oxygen in an alloy containing at least silicon and copper as main components. The present inventors have found that the charge storage characteristics at high temperature can be improved, particularly that gas generation can be remarkably suppressed.
  • a silicon-copper alloy negative electrode active material containing a trace amount of oxygen represented by:
  • the negative electrode includes at least a negative electrode active material represented by the general formula (I).
  • a power storage device characterized.
  • an alloy-based negative electrode active material capable of occluding and releasing lithium having a high capacity and excellent cycle characteristics and charge storage characteristics, and a negative electrode sheet and an electricity storage device using the same.
  • the negative electrode active material of the present invention is a silicon-copper alloy negative electrode active material represented by the following general formula (I).
  • M is Be, B, Al, P, Zn, Ga, Ge, In, Sn, Sb And represents at least one element selected from Y, Zr, Nb, Mo, and W.
  • FIG. 1 shows an image diagram relating to one embodiment of the structure of the negative electrode active material of the silicon-copper alloy of the present invention.
  • Particle phase composed mainly of SiO x (A) of the SiCu 3 O y having the same crystal structure as SiCu 3 in a matrix phase as a main component (B) having the same crystal structure as silicon simple substance is embedded Is in a state.
  • x / y hereinafter referred to as oxygen distribution parameter
  • oxygen distribution parameter is 0.5 or less.
  • the silicon-copper alloy negative electrode active material of the present invention is excellent in cycle characteristics and charge storage characteristics.
  • a very small amount of oxygen can be contained therein, and as a result, the obtained negative electrode active material has the same crystal structure as SiCu 3 and the phase (A) mainly composed of SiO x having the same crystal structure as that of silicon alone.
  • the obtained negative electrode active material has the same crystal structure as SiCu 3 and the phase (A) mainly composed of SiO x having the same crystal structure as that of silicon alone.
  • a phase (B) containing SiCu 3 O y as a main component.
  • this slight oxygen atom is introduced to form a structure having such a phase (A) and a phase (B).
  • the cycle characteristics are remarkably improved because the bonding strength between the phase (A) and the phase (B) can be increased without lowering the electronic conductivity. Furthermore, since these slight oxygen atoms can suppress an electrochemical reaction with the non-aqueous electrolyte, it is considered that gas generation in a charged state can be remarkably suppressed.
  • M is Be, B, Al, P, Zn, Ga, Ge, In, Sn, Sb, It represents at least one element selected from Y, Zr, Nb, Mo, and W.
  • s representing the oxygen content (unit: atomic%) is 5 atomic% or less, the electronic conductivity of the active material and the electric capacity capable of inserting and extracting lithium are less likely to decrease, and 0.01 atomic% If it is above, since the intensity
  • the value of s is preferably 0.02 atomic% or more, more preferably 0.05 atomic% or more, still more preferably 0.1 atomic% or more, and the upper limit thereof is preferably 3 atomic% or less, more preferably 2 atomic% or less, and 1 atomic% or more. % Or less is more preferable.
  • the oxygen content in the negative electrode active material can be analyzed by a method such as an inert gas melting-infrared absorption method.
  • q (unit: atomic%) representing the copper content is 50 atomic% or less, there is little possibility that the electric capacity capable of occluding and releasing lithium decreases, and if it is 5 atomic% or more, the electronic conductivity of the active material is reduced. And the strength against expansion and contraction inside the active material are increased, and further, the reaction with the non-aqueous electrolyte is suppressed, so that the cycle characteristics and the charge storage characteristics are improved, which is preferable.
  • the value of q is more preferably 8 atomic% or more, more preferably 15 atomic% or more, particularly preferably 20 atomic% or more, and the upper limit thereof is more preferably 45 atomic% or less, still more preferably 40 atomic% or less, and particularly preferably 35 atomic% or less. preferable.
  • the silicon-copper alloy negative electrode active material of the present invention preferably contains an element M other than silicon, copper, and oxygen.
  • M include Be of Group IIA, Y, Zr, Nb, Mo of Groups IIIA to VIA, Inclusion of at least one element selected from W, IIB to VB group B, Al, P, Zn, Ga, Ge, In, Sn, and Sb increases the strength against expansion and contraction inside the active material. This is preferable because the characteristics and charge storage characteristics are improved.
  • at least one element selected from Be, Y, Zr, Nb, Zn, B, Al, P, Ge, In, and Sb is more preferable. From Be, Zr, Zn, B, Al, In, and Sb Particularly preferred are at least one element selected.
  • the negative electrode active material represented by the general formula (I) includes the element M, it is included in either the phase (A) or the phase (B), or the phase (A) or the phase (B). It may be included as another phase other than.
  • the average particle diameter of secondary particles of the powder is preferably 1 to 40 ⁇ m. If it is 40 ⁇ m or less, it can be applied uniformly when applied to the electrode, so there is no risk of failure such as peeling of the electrode sheet, and if it is 1 ⁇ m or more, the specific surface area of the powder is small. Therefore, the reaction with the non-aqueous electrolyte can be suppressed, and the cycle characteristics and the charge storage characteristics are improved.
  • the average particle diameter is more preferably 3 ⁇ m or more, further preferably 15 ⁇ m or more, particularly preferably 20 ⁇ m or more, and the upper limit thereof is more preferably 35 ⁇ m or less, further preferably 30 ⁇ m or less.
  • the average particle diameter of the secondary particles of the negative electrode active material powder can be measured with a particle size distribution meter using a laser diffraction / scattering method.
  • the average particle diameter can be measured as the 50% diameter of the volume cumulative particle size distribution, that is, the median diameter (D50).
  • the 5% diameter (D5) of the volume cumulative particle size distribution of the secondary particles is 0.2 ⁇ m or more. If 0.2 ⁇ m or more, the phase mainly composed of SiO x having the same crystal structure as the electrochemically active elemental silicon (A) is mainly composed of SiCu 3 O y having the same crystal structure as SiCu 3 Is sufficiently covered with the phase (B), which is preferable because the reaction with the non-aqueous electrolyte can be suppressed and the cycle characteristics and the charge storage characteristics are improved.
  • the 5% diameter (D5) of the volume cumulative particle size distribution is more preferably 1 ⁇ m or more, further preferably 5 ⁇ m or more, and particularly preferably 10 ⁇ m or more.
  • the average crystal grain size of the phase (A) is preferably 0.1 to 10 ⁇ m.
  • An average crystal grain size of the phase (A) of 10 ⁇ m or less is preferable because distortion due to volume change accompanying insertion and extraction of lithium is small, and cycle characteristics are improved.
  • the average crystal grain size of the phase (A) is 0.1 ⁇ m or more, the reaction with the non-aqueous electrolyte is suppressed, so that the cycle characteristics and the charge storage characteristics are improved, which is preferable.
  • the average crystal grain size of the phase (A) is more preferably from 0.3 to 5 ⁇ m, particularly preferably from 1 to 4 ⁇ m.
  • the average crystal grain size of the phase (A) is determined from, for example, a photograph in which a cross-sectional sample is prepared by embedding a negative electrode active material in a resin and polishing, and observed with a scanning electron microscope (SEM). It can be obtained by performing image analysis.
  • SEM scanning electron microscope
  • Negative electrode active material represented by the general formula (I) composed mainly of SiCu 3 O y having the same crystal structure phase mainly composed of SiO x having the same crystal structure as elemental silicon (A) and SiCu 3
  • the oxygen atom in the negative electrode active material represented by the general formula (I) is contained in the phase (B) more than the phase (A)
  • Bond strength at the interface with the phase (A) is increased, strength against expansion and contraction inside the active material is increased, and further, reaction with the non-aqueous electrolyte is suppressed, so that cycle characteristics and charge storage characteristics are improved. This is preferable.
  • the value of y is preferably larger than the value of x, and the oxygen distribution parameter x / y is more preferably 0.5 or less, and further preferably 0.1 or less.
  • a negative electrode active material is prepared using a focused ion beam (FIB) apparatus or the like, and a thin sample is prepared, and energy dispersive X-ray spectroscopy attached to a transmission electron microscope (TEM) is used. It can be measured using an analyzer (EDS).
  • FIB focused ion beam
  • TEM transmission electron microscope
  • This negative electrode active material can be produced, for example, using a single roll method or an atomizing method as follows.
  • a raw material ingot of a silicon alloy is mixed at a predetermined ratio, and after being dissolved by high frequency induction heating in an atmosphere in which oxygen is slightly introduced into argon gas, A silicon-copper alloy flake is obtained by spraying on a rotating roll. Next, after pulverizing the silicon-copper alloy flakes and classifying as necessary, a negative electrode active material can be obtained.
  • a raw material ingot of a silicon-copper alloy is mixed in a predetermined ratio, and this is mixed in an argon gas atmosphere or an atmosphere in which oxygen is slightly introduced into the argon gas.
  • the molten metal is obtained by melting by high frequency induction heating.
  • the molten metal is injected into a tank under an argon gas atmosphere or an atmosphere in which oxygen is slightly introduced into the argon gas, while argon gas or argon gas into which oxygen is slightly introduced is sprayed toward the sample being sprayed.
  • a silicon-copper alloy powder is obtained.
  • a negative electrode active material can be obtained by classifying as needed.
  • the atomizing method is not limited to the gas atomizing method described here.
  • the introduction of oxygen can be performed in any step, and it may be introduced in at least one of the steps, but the oxygen concentration is preferably about 1 ppm to 3000 ppm, more preferably 100 ppm to 2000 ppm.
  • the oxygen concentration is particularly preferable to contain about 1 ppm to 3000 ppm of oxygen in the argon gas ejected toward the sample being sprayed.
  • the oxygen distribution parameter x / y can be adjusted by introducing oxygen in two or more steps of each step and adding light / dark to the oxygen concentration in each step.
  • the oxygen distribution parameter x / y can be adjusted by making the oxygen concentration relatively high.
  • the average particle diameter of the secondary particles of the negative electrode active material powder can be adjusted by adjusting the diameter of the atomizing nozzle, the pressure of argon gas jetted toward the sample being sprayed, or by adjusting the oxygen concentration as appropriate.
  • the average crystal grain size of phase (A) can be controlled.
  • pulverization and classification can be performed to adjust the secondary particle diameter, but it is preferable not to perform pulverization because cycle characteristics and charge storage characteristics are improved.
  • the negative electrode sheet of the present invention is a sheet-like formed body formed of a negative electrode mixture comprising the silicon-copper alloy negative electrode active material of aspect 1, a carbon material, and a binder, and the silicon-copper alloy of aspect 1
  • a negative electrode active material, a carbon material, a binder, and a high boiling point solvent such as 1-methyl-2-pyrrolidone are kneaded to form a slurry, which is then applied to a copper foil of a current collector and dried. After the pressure molding, it can be produced by heat treatment at a temperature of about 50 ° C. to 350 ° C. for about 2 hours under reduced pressure or in an inert atmosphere.
  • the carbon material acts as a conductive agent or an active material.
  • the amount of the silicon-copper alloy negative electrode active material is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, as a mass in the negative electrode mixture, in order to increase the capacity. From the viewpoint of improving characteristics, it is preferably 80% by mass or less, more preferably 65% by mass or less, and further preferably 45% by mass or less.
  • the ratio of the silicon-copper alloy negative electrode active material to the carbon material is the number of electrons generated by mixing the carbon material.
  • the ratio of the total mass of the carbon material to the total mass of the silicon-copper alloy negative electrode active material in the negative electrode mixture is preferably 0.2 or more, and preferably 1 or more More preferably, it is more preferably 5 or more.
  • the ratio of the total mass of the carbon material to the total mass of the silicon-copper alloy negative electrode active material is preferably 95 or less, more preferably 70 or less, and even more preferably 45 or less.
  • the silicon-copper alloy negative electrode active material of the present invention has good electrical contact with the carbon material due to the effect of the high electronic conductivity of the phase (B), and has a specific surface area in order to ensure conductivity. There is an effect that the use of a large conductive auxiliary agent can be reduced.
  • Examples of the carbon material include carbon materials that can occlude and release lithium [graphitizable carbon, non-graphitizable carbon with a (002) plane spacing of 0.37 nm or more, and (002) plane spacing.
  • Graphite of 0.34 nm or less] and carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, etc. can be used as the conductive auxiliary agent. Therefore, the amount of the conductive aid used can be 20% by mass or less, more preferably 10% by mass or less, based on the mass of the negative electrode mixture.
  • the fibrous carbon powder has a graphite mesh surface composed of only carbon atoms, forming a bell-shaped structural unit having a closed top portion and a trunk portion having an open bottom, and the bell-shaped structural unit is In some cases, 2-30 pieces are stacked by sharing a central axis to form an aggregate, and the aggregate is composed of fine carbon fibers that are connected to form a fiber in a head-to-tail manner. Particularly preferred.
  • the bell-shaped structure body portion gradually spreads toward the open end, and as a result, the busbar of the body portion is slightly inclined with respect to the central axis of the bell-shaped structure unit, and the angle ⁇ formed by both is from 15 °.
  • the number of bell-shaped structural unit stacks is preferably 2 to 25, and more preferably 2 to 15.
  • the outer diameter D of the trunk portion of the aggregate is 5 to 40 nm, preferably 5 to 30 nm, and more preferably 5 to 20 nm. If D is 40 nm or less, the fiber diameter is not too large, and an excessive addition amount is not required to form a conductive path with the negative electrode active material, which is preferable. On the other hand, if D is 5 nm or more, it is preferable because the fiber diameter becomes thin and the aggregation of fibers becomes strong and it is not difficult to disperse in the negative electrode mixture.
  • the inner diameter d of the aggregate body is 3 to 30 nm, preferably 3 to 20 nm, more preferably 3 to 10 nm.
  • the aspect ratio (L / D) calculated from the length L of the aggregate and the body outer diameter D is 2 to 150, preferably 2 to 50, more preferably 2 to 30, and still more preferably 2 to 20. .
  • the aspect ratio is large, the structure of the formed fiber approaches a cylindrical tube shape, and the conductivity in the fiber axis direction of one fiber is improved.
  • the open end of the graphite network surface constituting the structural unit body is a fiber. Since the frequency of exposure to the outer peripheral surface is reduced, the conductivity between adjacent fibers is deteriorated.
  • the aspect ratio is small, the open end of the graphite mesh surface constituting the structural unit body portion is more frequently exposed to the outer peripheral surface of the fiber, so that the conductivity between adjacent fibers is improved.
  • the amount of the fibrous carbon powder is preferably 1 to 10% by mass, more preferably 2 to 5% by mass as the mass in the negative electrode mixture.
  • graphite having a specific surface area of 0.5 to 10 m 2 / g and d002 of 0.335 to 0.337 nm is particularly preferable.
  • a mechanical action such as compression force, friction force, shear force, etc. is repeatedly applied to artificial graphite particles having a massive structure in which a plurality of flat graphite fine particles are assembled or bonded non-parallel to each other, for example, scaly natural graphite particles,
  • the peak intensity I (110) of the (110) plane and the peak intensity I (004) of the (004) plane of the graphite crystal obtained from the X-ray diffraction measurement of the negative electrode sheet are obtained.
  • the ratio I (110) / I (004) is 0.01 or more, cycle characteristics and charge storage characteristics are improved, more preferably 0.05 or more, and further preferably 0.1 or more. preferable. Moreover, since it may process too much and crystallinity may fall and the discharge capacity of a battery may fall, 0.5 or less is preferable and the upper limit of I (110) / I (004) is 0.3 or less more preferable.
  • the silicon-copper alloy negative electrode active material of the present invention is The effect of the high electronic conductivity of phase (B) suppresses the reaction between the non-aqueous electrolyte and the negative electrode sheet without impairing the electrical contact between the silicon-copper alloy negative electrode active material and the carbon material. Therefore, the cycle characteristics and the charge storage characteristics are further improved, which is preferable.
  • the crystallinity of the carbon material for covering the core material can be confirmed by TEM.
  • the average particle diameter of graphite that is, the 50% diameter (D50) of the volume cumulative particle size distribution is preferably 10 ⁇ m to 50 ⁇ m, more preferably 10 ⁇ m to 30 ⁇ m, and still more preferably 15 ⁇ m to 25 ⁇ m. If D50 is 10 ⁇ m or more, the bulk density does not become too low and the specific surface area does not become too high. Therefore, when the negative electrode sheet is formed by a coating method, its coatability is lowered or charge / discharge efficiency is lowered. There is no fear. On the other hand, if D50 is 50 ⁇ m or less, there is no possibility that streaking occurs during electrode coating, which is preferable.
  • the ratio of the average particle size of graphite to the average particle size of silicon-copper alloy is 0.6 to 1.9, since the electrical contact with each other is good even during the charge / discharge cycle and the cycle characteristics are improved. 0.8 to 1.4 is more preferable.
  • the amount of graphite is preferably 5% by mass or more, more preferably 20% by mass or more, still more preferably 55% by mass or more from the viewpoint of improving cycle characteristics, as the mass in the negative electrode mixture. 95 mass% or less is preferable, 85 mass% or less is more preferable, and 70 mass% or less is still more preferable.
  • a conductive auxiliary other than the carbon material may be blended in the negative electrode mixture, and as such a conductive auxiliary, a metal such as copper, nickel, titanium or the like should be used. Can do. For example, after producing an electrode sheet, these metals can be imparted with conductivity using plating or vapor deposition.
  • binders polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene / butadiene copolymer (SBR), acrylonitrile / butadiene copolymer (NBR), carboxymethylcellulose (CMC), ethylene Polyimide, aromatic tetracarboxylic acid and / or derivative thereof and diamine compound obtained from propylene diene terpolymer, polyvinyl pyrrolidone, polyacrylic acid, sodium polyacrylate, aromatic tetracarboxylic acid and / or derivative thereof and diamine compound And polyamide imide obtained from diisocyanate are preferable.
  • PTFE polytetrafluoroethylene
  • PVDF polyvinylidene fluoride
  • SBR styrene / butadiene copolymer
  • NBR acrylonitrile / butadiene copolymer
  • CMC carboxymethylcellulose
  • ethylene Polyimide aromatic
  • polyvinylpyrrolidone, polyacrylic acid, sodium polyacrylate, aromatic which is a polymer containing any of carboxyl group, amide group and imide group
  • At least one selected from polyimides obtained from tetracarboxylic acids and / or derivatives thereof and diamine compounds, and polyamideimides obtained from aromatic tetracarboxylic acids and / or derivatives thereof, diamine compounds and diisocyanates is silicon of the present invention.
  • -It is preferable because the affinity with the phase (B) present on the surface of the copper alloy negative electrode active material is high, the binding force is increased, and the cycle characteristics and the storage characteristics are further enhanced.
  • a polyimide obtained from an aromatic tetracarboxylic acid and / or a derivative thereof and a diamine compound is preferable.
  • the content of the binder is preferably 0.5% by mass to 50% by mass with respect to the total mass of the negative electrode active material, the carbon material, and the binder. If the content of the binder is 0.5% by mass or more, there is no fear that the moldability of the electrode is lowered, and if it is 50% by mass or less, the decrease in the energy density of the electrode is small, which is preferable.
  • the content of the binder is more preferably 2% by mass to 15% by mass.
  • the density of the portion excluding the current collector of the negative electrode is usually 0.8 g / cm 3 or more, and is preferably 1.0 g / cm 3 or more, more preferably 1.2 g in order to further increase the capacity of the battery. / Cm 3 or more, more preferably 1.5 g / cm 3 or more.
  • the upper limit is 6 g / cm 3 or less, more preferably 5 g / cm 3 or less, and still more preferably 4 g / cm 3 or less.
  • An electricity storage device of the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte solution in which an electrolyte salt is dissolved in a non-aqueous solvent.
  • the negative electrode includes at least the negative electrode active material of Aspect 1, or the negative electrode of Aspect 2 A sheet is used.
  • Non-aqueous electrolyte In the electricity storage device of the present invention, by combining the negative electrode active material of aspect 1 or the negative electrode sheet of aspect 2 with the nonaqueous electrolyte described below, the electricity storage device cycle characteristics and charge storage characteristics can be improved, and gas It exhibits a unique effect of suppressing the occurrence.
  • Nonaqueous solvent examples of the nonaqueous solvent used in the nonaqueous electrolytic solution of the present invention include cyclic carbonates, chain esters, lactones, ethers, and amides, and it is preferable that both cyclic carbonates and chain esters are included.
  • chain ester is used as a concept including chain carbonate and chain carboxylic acid ester.
  • Cyclic carbonates include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 4-fluoro-1,3-dioxolan-2-one (FEC), trans or Cis-4,5-difluoro-1,3-dioxolan-2-one (hereinafter collectively referred to as “DFEC”), vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and 4-ethynyl-1 , 3-dioxolan-2-one (EEC), ethylene carbonate, propylene carbonate, 4-fluoro-1,3-dioxolan-2-one, vinylene carbonate and 4-ethynyl- One selected from 1,3-dioxolan-2-one (EEC) Or two or more is more preferable.
  • the cycle characteristics and charge storage characteristics of the electricity storage device are further improved.
  • the cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond is more preferably VC, VEC or EEC, and the cyclic carbonate having a fluorine atom is FEC, DFEC is more preferable, and it is more preferable to include both a cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond and a carbon-carbon triple bond and a cyclic carbonate having a fluorine atom.
  • the content of the cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond is preferably 0.07% by volume or more, more preferably 0.8%, based on the total volume of the nonaqueous solvent.
  • the content of the cyclic carbonate having a fluorine atom is preferably 0.07% by volume or more, more preferably 4% by volume or more, still more preferably 7% by volume or more, based on the total volume of the nonaqueous solvent.
  • the upper limit is preferably 35% by volume or less, more preferably 25% by volume or less, and still more preferably 15% by volume or less, because the stability of the coating increases and the cycle characteristics and charge storage characteristics of the electricity storage device are improved.
  • the non-aqueous solvent contains both a cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond and a carbon-carbon triple bond and a cyclic carbonate having a fluorine atom
  • the carbon content relative to the content of the cyclic carbonate having a fluorine atom is preferably 0.2% or more, more preferably 3% or more, and further preferably 7% or more. Is preferably 40% or less, more preferably 30% or less, and even more preferably 15% or less, because the stability of the coating is increased and the cycle characteristics and charge storage characteristics of the electricity storage device are improved.
  • the non-aqueous solvent contains ethylene carbonate and / or propylene carbonate
  • the resistance of the film formed on the electrode is reduced, and the content of ethylene carbonate and / or propylene carbonate is preferably equal to the total volume of the non-aqueous solvent.
  • it is preferably 3% by volume or more, more preferably 5% by volume or more, further preferably 7% by volume or more, and the upper limit thereof is preferably 45% by volume or less, more preferably 35% by volume or less, further Preferably it is 25 volume% or less.
  • solvents may be used alone, and when two or more types are used in combination, the cycle characteristics and charge storage characteristics of the electricity storage device are further improved, and three or more types should be used in combination. Is particularly preferred.
  • Preferred combinations of these cyclic carbonates include EC and PC, EC and VC, PC and VC, VC and FEC, EC and FEC, PC and FEC, FEC and DFEC, EC and DFEC, PC and DFEC, VC and DFEC , VEC and DFEC, VC and EEC, EC and EEC, EC and PC and VC, EC and PC and FEC, EC and VC and FEC, EC and VC and VEC, EC and VC and EEC, EC and EEC and FEC, PC And VC and FEC, EC and VC and DFEC, PC and VC and DFEC, EC and PC and VC and FEC, EC and PC and VC and FEC, EC and PC and VC and DF
  • chain esters examples include asymmetric chain carbonates such as methyl ethyl carbonate (MEC), methyl propyl carbonate (MPC), methyl isopropyl carbonate (MIPC), methyl butyl carbonate, and ethyl propyl carbonate, dimethyl carbonate (DMC), and diethyl carbonate ( DEC), symmetrical linear carbonates such as dipropyl carbonate and dibutyl carbonate, pivalate esters (MPV) such as methyl pivalate, ethyl pivalate, propyl pivalate, methyl propionate (MP), ethyl propionate (EP),
  • Preferable examples include chain carboxylic acid esters such as methyl acetate (MA), ethyl acetate (EA), and n-propyl acetate (PA).
  • asymmetric chain carbonate is preferable because the cycle characteristics and charge storage characteristics of the electricity storage device are improved and the amount of gas generation tends to be reduced.
  • solvents may be used alone or in combination of two or more, since the cycle characteristics and charge storage characteristics of the electricity storage device are improved and the amount of gas generated is reduced.
  • the content of the chain ester is not particularly limited, but it is preferably used in the range of 60 to 90% by volume with respect to the total volume of the nonaqueous solvent. If the content is 60% by volume or more, the effect of reducing the viscosity of the non-aqueous electrolyte is sufficiently obtained, and if it is 90% by volume or less, the electrical conductivity of the non-aqueous electrolyte is sufficiently increased, and the cycle of the electricity storage device The above range is preferable because the characteristics and the charge storage characteristics are improved.
  • chain carbonate when using chain carbonate, it is preferable to use 2 or more types. Further, it is more preferable that both a symmetric chain carbonate and an asymmetric chain carbonate are contained, and it is more preferable that the content of the symmetric chain carbonate is more than that of the asymmetric chain carbonate.
  • the volume ratio of the symmetric chain carbonate in the chain carbonate is preferably 51% by volume or more, and more preferably 55% by volume or more. As an upper limit, 95 volume% or less is more preferable, and it is still more preferable in it being 85 volume% or less. It is particularly preferable that diethyl carbonate is contained in the symmetric chain carbonate. Moreover, it is especially preferable that the asymmetric chain carbonate includes methyl ethyl carbonate. The above case is preferable because the cycle characteristics and charge storage characteristics of the electricity storage device are further improved.
  • the ratio between the cyclic carbonate and the chain carbonate is preferably 10:90 to 45:55 in terms of the cyclic carbonate: chain carbonate (volume ratio) from the viewpoint of improving electrochemical characteristics when the electricity storage device is used at a high temperature. 85 to 40:60 is more preferable, and 20:80 to 35:65 is particularly preferable.
  • additives include (A) Trimethyl phosphate, triethyl phosphate, tris (2,2,2-trifluoroethyl) phosphate, ethyl 2- (diethoxyphosphoryl) acetate, 2-propynyl 2- (diethoxyphosphoryl) acetate, etc.
  • Nitriles such as acetonitrile, propionitrile, succinonitrile, 2-ethylsuccinonitrile, glutaronitrile, 2-methylglutaronitrile, adiponitrile, pimelonitrile, and sebacononitrile
  • Containing compounds Containing compounds, (D) a chain carboxylic acid anhydride such as acetic anhydride and propionic anhydride, a cyclic acid anhydride such as succinic anhydride, maleic anhydride, glutaric anhydride, itaconic anhydride, 3-sulfo-propionic anhydride, (E) diisocyanate compounds such as 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, One type or two or more types selected from among these are preferably mentioned.
  • a chain carboxylic acid anhydride such as acetic anhydride and propionic anhydride
  • a cyclic acid anhydride such as succinic anhydride, maleic anhydride, glutaric anhydride, itaconic anhydride, 3-sulfo-propionic an
  • the content of the additives (a) to (e) is preferably 0.001 to 5% by mass in the non-aqueous electrolyte. In this range, the coating film is sufficiently formed without becoming too thick, and the effect of improving the cycle characteristics and charge storage characteristics of the electricity storage device is enhanced.
  • the content is more preferably 0.005% by mass or more, more preferably 0.01% by mass or more, particularly preferably 0.03% by mass or more in the non-aqueous electrolyte, and the upper limit is 3% by mass or less. More preferred is 2% by mass or less, and particularly preferred is 1.5% by mass or less.
  • a phosphate ester one or more selected from ethyl 2- (diethoxyphosphoryl) acetate and 2-propynyl 2- (diethoxyphosphoryl) acetate are more preferable.
  • nitriles one or more selected from succinonitrile, 2-ethylsuccinonitrile, glutaronitrile, 3-methylglutaronitrile, adiponitrile, and pimelonitrile are more preferable.
  • diisocyanate compounds 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, and 1,7-diisocyanatoheptane are more preferable.
  • Electrolyte salt Preferred examples of the electrolyte salt used in the present invention include the following lithium salts.
  • lithium salt examples include inorganic lithium salts such as LiPF 6 , LiBF 4 , and LiClO 4 , LiN (SO 2 F) 2 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 C 2 F 5 ) 2 , LiCF 3 SO 3 , LiC (SO 2 CF 3 ) 3 , LiPF 4 (CF 3 ) 2 , LiPF 3 (C 2 F 5 ) 3 , LiPF 3 (CF 3 ) 3 , LiPF 3 (iso-C 3 F 7 ) 3 , LiPF 5 Lithium salts containing a chain-like fluorinated alkyl group such as (iso-C 3 F 7 ), (CF 2 ) 2 (SO 2 ) 2 NLi, (CF 2 ) 3 (SO 2 ) 2 NLi, etc.
  • inorganic lithium salts such as LiPF 6 , LiBF 4 , and LiClO 4 , LiN (SO 2 F) 2 , LiN (SO 2 CF 3
  • a lithium salt having a cyclic fluorinated alkylene chain lithium bis (oxalato) borate (LiBOB), lithium tetrafluoro (oxalato) phosphate (LiTFOP), and Lithium salts having at least one oxalic acid skeleton selected from lithium difluoro (oxalato) phosphate (LiDFOP), lithium having at least one phosphate backbone selected from LiPO 2 F 2 and Li 2 PO 3 F, etc.
  • Lithium salt having at least one sulfonic acid skeleton selected from a salt, lithium trifluoro ((methanesulfonyl) oxy) borate (LiTFMSB), lithium pentafluoro ((methanesulfonyl) oxy) phosphate (LiPFMSP), and FSO 3 Li
  • LiTFMSB lithium trifluoro ((methanesulfonyl) oxy) borate
  • LiPFMSP lithium pentafluoro ((methanesulfonyl) oxy) phosphate
  • FSO 3 Li Lithium salt having at least one sulfonic acid skeleton selected from a salt, lithium trifluoro ((methanesulfonyl) oxy) borate (LiTFMSB), lithium pentafluoro ((methanesulfonyl) oxy) phosphate (LiPFMSP), and FSO 3 Li
  • at least one lithium salt selected from these is
  • the concentration of the lithium salt is usually preferably 0.3 M or more, more preferably 0.7 M or more, and further preferably 1.1 M or more with respect to the non-aqueous solvent.
  • the upper limit is preferably 2.5M or less, more preferably 2.0M or less, and still more preferably 1.6M or less.
  • LiPF 6 is included, and LiBF 4 , LiN (SO 2 CF 3 ) 2 , LiN (SO 2 F) 2 , lithium bis (oxalato) borate (LiBOB), lithium Tetrafluoro (oxalato) phosphate (LiTFOP), lithium difluorobis (oxalato) phosphate (LiDFOP), LiPO 2 F 2 , lithium trifluoro ((methanesulfonyl) oxy) borate (LiTFMSB), lithium pentafluoro ((methanesulfonyl) oxy ) It is preferable that at least one lithium salt selected from phosphate (LiPFMSP) and FSO 3 Li is contained in the non-aqueous electrolyte, and the proportion of the lithium salt other than LiPF 6 in the non-aqueous solvent is 0.
  • the effect of improving the cycle characteristics and charge storage characteristics of the electricity storage device is easily exhibited, and when it is 0.005 M or less, there is less concern that the effect of improving the cycle characteristics and charge storage characteristics of the electricity storage device is reduced.
  • it is 0.01M or more, Especially preferably, it is 0.03M or more, Most preferably, it is 0.04M or more.
  • the upper limit is preferably 0.4M or less, particularly preferably 0.2M or less.
  • the non-aqueous electrolyte used in the present invention can be obtained, for example, by mixing the non-aqueous solvent and adding a predetermined additive to the electrolyte salt and the non-aqueous electrolyte. .
  • the compound added to the non-aqueous solvent and the non-aqueous electrolyte to be used is one that is purified in advance and has as few impurities as possible within a range that does not significantly reduce the productivity.
  • the non-aqueous electrolyte used in the present invention can be used in the following first and second electricity storage devices, and as the non-aqueous electrolyte, not only a liquid but also a gelled one is used. obtain. Furthermore, the non-aqueous electrolyte used in the present invention can also be used for a solid polymer electrolyte. In particular, it is preferably used for a first electricity storage device (ie, for a lithium battery) or a second electricity storage device (ie, for a lithium ion capacitor) using a lithium salt as an electrolyte salt, and is used for a lithium battery. More preferably, it is most suitable for use as a lithium secondary battery.
  • the lithium battery of the present invention is a generic term for a lithium primary battery and a lithium secondary battery.
  • the term lithium secondary battery is used as a concept including a so-called lithium ion secondary battery.
  • a lithium battery according to the present invention includes a positive electrode, a negative electrode, and the non-aqueous electrolyte solution in which an electrolyte salt is dissolved in a non-aqueous solvent.
  • the negative electrode includes at least the negative electrode active material of Aspect 1, or Aspect 2 A negative electrode sheet is used.
  • the positive electrode active material for a lithium secondary battery a composite metal oxide with lithium containing one or more selected from cobalt, manganese and nickel is used.
  • lithium composite metal oxides include LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , LiCo 1-x Ni x O 2 (0.01 ⁇ x ⁇ 1), LiCo 1/3 Ni 1/3.
  • LiCoO 2 and LiMn 2 O 4, LiCoO 2 and LiNiO 2 may be used in combination as LiMn 2 O 4 and LiNiO 2.
  • a part of the lithium composite metal oxide is replaced with another element.
  • a part of cobalt, manganese, nickel is replaced with at least one element such as Sn, Mg, Fe, Ti, Al, Zr, Cr, V, Ga, Zn, Cu, Bi, Mo, La,
  • a part of O can be substituted with S or F, or a compound containing these other elements can be coated.
  • lithium composite metal oxides such as LiCoO 2 , LiMn 2 O 4 , and LiNiO 2 that can be used at a charged potential of the positive electrode in a fully charged state of 4.3 V or more on the basis of Li are preferable, and LiCo 1-x M x O 2 (where M is one or more elements selected from Sn, Mg, Fe, Ti, Al, Zr, Cr, V, Ga, Zn, and Cu, 0.001 ⁇ x ⁇ 0.
  • LiCo 1/3 Ni 1/3 Mn 1/3 O 2 LiNi 0.5 Mn 0.3 Co 0.2 O 2 , LiNi 0.85 Co 0.10 Al 0.05 O 2 , LiNi 1 / 2 Mn 3/2 O 4 , Li 2 MnO 3 and LiMO 2 (M is a transition metal such as Co, Ni, Mn, Fe, etc.)
  • Lithium composite metal oxide usable at 4.4 V or higher like a solid solution Things are more preferred .
  • the secondary battery is preferable because it can suppress the deterioration of the electrochemical characteristics.
  • lithium-containing olivine-type phosphate can also be used as the positive electrode active material.
  • lithium-containing olivine-type phosphate containing one or more selected from iron, cobalt, nickel and manganese is preferable. Specific examples thereof include one or more selected from LiFePO 4 , LiCoPO 4 , LiNiPO 4 , and LiMnPO 4 .
  • Some of these lithium-containing olivine-type phosphates may be substituted with other elements, and some of iron, cobalt, nickel, and manganese are replaced with Co, Mn, Ni, Mg, Al, B, Ti, V, and Nb.
  • LiFePO 4 or LiMnPO 4 is preferable.
  • mold phosphate can also be mixed with the said positive electrode active material, for example, and can be used.
  • the positive electrode for lithium primary battery CuO, Cu 2 O, Ag 2 O, Ag 2 CrO 4, CuS, CuSO 4, TiO 2, TiS 2, SiO 2, SnO, V 2 O 5, V 6 O 12 , VO x , Nb 2 O 5 , Bi 2 O 3 , Bi 2 Pb 2 O 5 , Sb 2 O 3 , CrO 3 , Cr 2 O 3 , MoO 3 , WO 3 , SeO 2 , MnO 2 , Mn 2 O 3 , Fe 2 O 3 , FeO, Fe 3 O 4 , Ni 2 O 3 , NiO, CoO 3 , or CoO, one or more metal element oxides or chalcogen compounds, SO 2 , SOCl 2, etc.
  • Examples thereof include sulfur compounds, and fluorocarbons (fluorinated graphite) represented by the general formula (CF x ) n .
  • fluorocarbons fluorinated graphite represented by the general formula (CF x ) n .
  • MnO 2, V 2 O 5 , fluorinated graphite and the like are preferable.
  • the pH of the supernatant obtained when 10 g of the positive electrode active material is dispersed in 100 ml of distilled water is 10.0 to 12.5, it is preferable because the effect of improving the cycle characteristics and the charge storage characteristics can be easily obtained. Furthermore, the case of 10.5 to 12.0 is preferable. Further, when Ni is contained as an element in the positive electrode, since there is a tendency that impurities such as LiOH in the positive electrode active material tend to increase, the effect of improving the cycle characteristics and the charge storage characteristics is more easily obtained.
  • the atomic concentration of Ni is more preferably 5 to 25 atomic%, and particularly preferably 8 to 21 atomic%.
  • the positive electrode conductive agent is not particularly limited as long as it is an electron conductive material that does not cause a chemical change.
  • graphite such as natural graphite (scaly graphite, etc.), graphite such as artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, and one or more carbon blacks selected from thermal black It is done. Further, graphite and carbon black may be appropriately mixed and used.
  • the addition amount of the conductive agent to the positive electrode mixture is preferably 1 to 10% by mass, and particularly preferably 2 to 5% by mass.
  • the positive electrode is composed of a conductive agent such as acetylene black and carbon black, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), a copolymer of styrene and butadiene (SBR), acrylonitrile and butadiene.
  • a conductive agent such as acetylene black and carbon black, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), a copolymer of styrene and butadiene (SBR), acrylonitrile and butadiene.
  • PTFE polytetrafluoroethylene
  • PVDF polyvinylidene fluoride
  • SBR styrene and butadiene
  • SBR styrene and butadiene
  • acrylonitrile and butadiene acrylonitrile and butadiene.
  • binder such as copolymer (NBR), carb
  • this positive electrode mixture was applied to a current collector aluminum foil, a stainless steel lath plate, etc., dried and pressure-molded, and then subjected to vacuum at a temperature of about 50 ° C. to 250 ° C. for about 2 hours. It can be manufactured by heat treatment.
  • the density of the part except the collector of the positive electrode is usually at 1.5 g / cm 3 or more, for further increasing the capacity of the battery, is preferably 2 g / cm 3 or more, more preferably 3 g / cm 3 or more More preferably, it is 3.6 g / cm 3 or more.
  • the upper limit is preferably 4 g / cm 3 or less.
  • the structure of the lithium battery is not particularly limited, and a coin-type battery, a cylindrical battery, a square battery, a laminated battery, or the like having a single-layer or multi-layer separator can be applied. Although it does not restrict
  • the lithium secondary battery according to the present invention has excellent electrochemical characteristics even when the end-of-charge voltage of the positive electrode with respect to lithium metal is 4.2 V or higher, particularly 4.3 V or higher, and further has excellent characteristics even at 4.4 V or higher. is there.
  • the current value is not particularly limited, but is usually used in the range of 0.1 to 30C.
  • the lithium battery in the present invention can be charged / discharged at ⁇ 40 to 100 ° C., preferably ⁇ 10 to 80 ° C.
  • a method of providing a safety valve on the battery lid or cutting a member such as a battery can or a gasket can be employed.
  • the battery lid can be provided with a current interruption mechanism that senses the internal pressure of the battery and interrupts the current.
  • a 2nd electrical storage device is an electrical storage device which stores energy using the lithium ion intercalation to carbon materials, such as a graphite which is a negative electrode. It is called a lithium ion capacitor (LIC).
  • the 2nd electrical storage device of this invention contains the negative electrode active material of aspect 1 in this negative electrode.
  • Examples of the positive electrode include those using an electric double layer between an activated carbon electrode and an electrolytic solution, and those using a ⁇ -conjugated polymer electrode doping / dedoping reaction.
  • the electrolyte contains at least a lithium salt such as LiPF 6 .
  • Examples 1 to 25, Comparative Examples 1 and 2 [Preparation of silicon-copper alloy negative electrode active material]
  • the silicon-copper alloys (A-1 to A-25, C-1, C-2) used in Examples 1 to 25 and Comparative Examples 1 and 2 were prepared by mixing raw material ingots of silicon-copper alloys at a predetermined ratio. Then, it is melted by high-frequency induction heating in an argon gas atmosphere (oxygen concentration of less than 1 ppm) or in an atmosphere in which oxygen is slightly introduced into the argon gas (oxygen concentration of about 1 ppm to 3000 ppm) to obtain a molten metal.
  • this molten metal is injected into a tank in an argon gas atmosphere (oxygen concentration of less than 1 ppm) or an atmosphere in which oxygen is slightly introduced into the argon gas (oxygen concentration of about 1 ppm to 3000 ppm), while argon is directed toward the sample being sprayed.
  • Gas (oxygen concentration of less than 1 ppm) or argon gas with a slight introduction of oxygen (oxygen concentration of about 1 ppm to 3000 ppm) is ejected to obtain silicon-copper alloy powder. Then, it produced by classifying as needed.
  • the oxygen distribution parameter x / y was adjusted by adding light and shade to the oxygen concentration in each step.
  • LiNi 1/3 Mn 1/3 Co 1/3 O 2 the positive electrode active material, the pH of the supernatant liquid when 10 g of the positive electrode active material is dispersed in 100 ml of distilled water is 10.8; 94% by mass, acetylene black ( Conductive agent); 3% by mass was mixed, and PVDF (binder); 3% by mass was added to and mixed with a solution in which 3% by mass was previously dissolved in 1-methyl-2-pyrrolidone to prepare a positive electrode mixture paste. .
  • This positive electrode mixture paste was applied to one side of an aluminum foil (current collector), dried and pressurized, punched out to a predetermined size, and a positive electrode sheet was produced.
  • the density of the portion excluding the current collector of the positive electrode was 3.6 g / cm 3 .
  • This negative electrode mixture paste was applied to one side of a copper foil (current collector), dried and pressurized, and punched into a predetermined size to produce a negative electrode sheet.
  • the ratio of the peak intensity I (110) of the (110) plane of the graphite crystal to the peak intensity I (004) of the (004) plane [I (110) / I (004) )] was 0.1.
  • EC / FEC / VC / MEC / DEC 25/3/2/30/40 volume obtained by laminating a positive electrode sheet, a microporous polyethylene film separator, and a negative electrode sheet in this order and dissolving 1M LiPF 6 as an electrolytic solution. Ratio) non-aqueous electrolyte was added to prepare a 2032 type coin battery.
  • the power storage device characteristics are shown in Table 1.
  • Capacity retention rate (%) (discharge capacity at 100th cycle / initial discharge capacity) ⁇ 100
  • the negative electrode active materials (A-1 to A-25) of the present invention correspond to the silicon-copper alloy negative electrode active material of the prior art.
  • First-time charge / discharge of an electricity storage device produced using these negative electrode active materials, rather than a negative electrode active material (C-1) containing almost no oxygen and a negative electrode active material (C-2) that is excessively oxidized and has a high oxygen content The efficiency (that is, a measure that does not waste charging energy), the capacity maintenance rate after 100 cycles, and the gas suppression effect after storage after charging are all significantly improved, and it is considered preferable to eliminate oxygen as much as possible. It has been found that the technical idea for the conventional silicon-copper alloy negative electrode active material has an unexpected effect.
  • a coin battery was prepared in the same manner as in Example 3 except that the number of bell-shaped structural units was about 10) (Example 30).
  • PVDF aromatic tetracarboxylic acid and U-varnish-A (registered trademark, manufactured by Ube Industries, Ltd.), which is a 1-methyl-2-pyrrolidone solution of polyamic acid obtained from a diamine compound (precursor of polyimide)
  • a coin battery was manufactured in the same manner as in Example 30 (Example 31) except that the negative electrode active material C-1 was used instead of the negative electrode active material A-3.
  • Table 2 shows the results of measuring power storage device characteristics using coin batteries that were produced in the same manner (Comparative Example 3 and Comparative Example 4). In Table 2, the results of Example 3 and Comparative Examples 1 and 2 described above are also shown.
  • Examples 3 and 26 to 31 which are examples of the negative electrode sheet of the invention of aspect 2 and the electricity storage device of the invention of aspect 3 using the same, electricity storage using the negative electrode sheet of examples 3 and 26 to 31 of the present invention
  • the device uses a negative electrode active material (C-1) substantially free of oxygen corresponding to a silicon-copper alloy negative electrode active material of the prior art or a negative electrode active material (C-2) that is excessively oxidized and has a high oxygen content.
  • the initial charge / discharge efficiency of the electricity storage device that is, a measure that does not waste the charging energy
  • the capacity retention rate after 100 cycles, and the gas suppression effect after charge storage are all significant. It has been found that a significant synergistic effect that cannot be seen in a negative electrode sheet using a conventional silicon-copper alloy that has been considered to be preferable to eliminate oxygen as much as possible is exhibited. It was.
  • Table 3 also shows the results of producing a coin battery and measuring the characteristics of the electricity storage device in the same manner as in Example 3 except that the nonaqueous electrolytic solution shown in Table 3 was used. In Table 3, the results of Example 3 and Comparative Examples 1 and 2 are also shown.
  • the electricity storage device using the non-aqueous electrolyte of various compositions using the silicon-copper alloy of the present invention is a silicon-copper alloy of the prior art.
  • the negative electrode active material (C-1) which does not substantially contain oxygen corresponding to the negative electrode active material and the negative electrode active material (C-2) which is excessively oxidized and has a high oxygen content Compared to the negative electrode active material (C-1) which does not substantially contain oxygen corresponding to the negative electrode active material and the negative electrode active material (C-2) which is excessively oxidized and has a high oxygen content, The initial charge / discharge efficiency (that is, a measure that does not waste charge energy), the capacity retention rate after 100 cycles, and the gas suppression effect after charge storage are all significantly improved, and it is preferable to eliminate oxygen as much as possible. It was found that a remarkable synergistic effect that is not seen in the conventional silicon-copper alloy negative electrode active material that was considered to be
  • the lithium secondary battery using the non-aqueous electrolyte of the present invention is useful as a power storage device such as a lithium secondary battery having excellent electrochemical characteristics in a wide temperature range.

Landscapes

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

Abstract

La présente invention concerne : un matériau actif d'électrode négative à base d'alliage qui est un matériau actif d'électrode négative en alliage silicium-cuivre représenté par la formule générale (I) et contenant une légère quantité d'oxygène, et qui peut absorber et désorber le lithium, tout en ayant une capacité élevée, d'excellentes caractéristiques de cycle et d'excellentes caractéristiques d'entreposage chargé ; une feuille d'électrode négative utilisant ce matériau actif d'électrode négative à base d'alliage ; et un dispositif accumulateur d'électricité. Le matériau actif d'électrode négative représenté par la formule générale (I) est composé d'une phase (A) qui est principalement composée de SiOx qui a la même structure cristalline que le silicium élémentaire et une phase (B) qui est principalement composée de SiCu3Oy qui a la même structure cristalline que le SiCu3. SipCuqMrOs (I) (Dans la formule, p + q + r + s = 100 ; s est compris entre 0,01 et 5 ; q est compris entre 5 et 50 ; r est compris entre 0 et 10 ; et M représente au moins un élément sélectionné parmi Be, B, Al, P, Zn, Ga, Ge, In, Sn, Sb, Y, Zr, Nb, Mo et W.)
PCT/JP2014/057785 2013-03-25 2014-03-20 Matériau actif d'électrode négative, feuille d'électrode négative l'utilisant et dispositif accumulateur d'électricité WO2014156963A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2015508418A JP6291479B2 (ja) 2013-03-25 2014-03-20 負極活物質、それを用いた負極シート及び蓄電デバイス

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2013-062200 2013-03-25
JP2013062200 2013-03-25
JP2013269235 2013-12-26
JP2013-269235 2013-12-26

Publications (1)

Publication Number Publication Date
WO2014156963A1 true WO2014156963A1 (fr) 2014-10-02

Family

ID=51623942

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/057785 WO2014156963A1 (fr) 2013-03-25 2014-03-20 Matériau actif d'électrode négative, feuille d'électrode négative l'utilisant et dispositif accumulateur d'électricité

Country Status (2)

Country Link
JP (1) JP6291479B2 (fr)
WO (1) WO2014156963A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015065146A (ja) * 2013-03-30 2015-04-09 国立大学法人東北大学 リチウムイオン二次電池用負極活物質およびその製造方法並びに負極および電池
JP2016035825A (ja) * 2014-08-01 2016-03-17 国立大学法人東北大学 リチウムイオン二次電池用負極活物質およびその製造方法並びに負極および電池
JP2018514070A (ja) * 2015-12-18 2018-05-31 シェンヂェン キャプケム テクノロジー カンパニー リミテッドＳｈｅｎｚｈｅｎ Ｃａｐｃｈｅｍ Ｔｅｃｈｎｏｌｏｇｙ Ｃｏ．， Ｌｔｄ． リチウムイオン電池用電解液及びリチウムイオン電池

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001297766A (ja) * 2000-04-14 2001-10-26 Sumitomo Metal Ind Ltd 非水電解質二次電池とその負極材料および該材料の製法
JP2003077534A (ja) * 2001-08-31 2003-03-14 Hitachi Maxell Ltd 非水二次電池
JP2010238575A (ja) * 2009-03-31 2010-10-21 Ube Ind Ltd リチウムイオン電池用電極およびその製造方法
WO2012063762A1 (fr) * 2010-11-08 2012-05-18 古河電気工業株式会社 Nanoparticules utilisées dans une électrode négative pour batterie secondaire au lithium-ion et procédé de fabrication s'y rapportant
JP2012233177A (ja) * 2011-04-19 2012-11-29 Ube Industries Ltd ポリイミド前駆体組成物、並びにそれを用いた電極合剤ペースト、電極および塗料
JP2013161785A (ja) * 2012-02-07 2013-08-19 Samsung Sdi Co Ltd リチウム２次電池用負極活物質、その製造方法、およびこれを含むリチウム２次電池

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8432786B2 (en) * 2007-07-10 2013-04-30 Qualcomm Incorporated Control channel design to support one-to-one, many-to-one, and one-to-many peer-to-peer communications
JP2009297766A (ja) * 2008-06-16 2009-12-24 Kobe Steel Ltd 取鍋の上部構造、取鍋の上部の耐火物施工方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001297766A (ja) * 2000-04-14 2001-10-26 Sumitomo Metal Ind Ltd 非水電解質二次電池とその負極材料および該材料の製法
JP2003077534A (ja) * 2001-08-31 2003-03-14 Hitachi Maxell Ltd 非水二次電池
JP2010238575A (ja) * 2009-03-31 2010-10-21 Ube Ind Ltd リチウムイオン電池用電極およびその製造方法
WO2012063762A1 (fr) * 2010-11-08 2012-05-18 古河電気工業株式会社 Nanoparticules utilisées dans une électrode négative pour batterie secondaire au lithium-ion et procédé de fabrication s'y rapportant
JP2012233177A (ja) * 2011-04-19 2012-11-29 Ube Industries Ltd ポリイミド前駆体組成物、並びにそれを用いた電極合剤ペースト、電極および塗料
JP2013161785A (ja) * 2012-02-07 2013-08-19 Samsung Sdi Co Ltd リチウム２次電池用負極活物質、その製造方法、およびこれを含むリチウム２次電池

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015065146A (ja) * 2013-03-30 2015-04-09 国立大学法人東北大学 リチウムイオン二次電池用負極活物質およびその製造方法並びに負極および電池
JP2016035825A (ja) * 2014-08-01 2016-03-17 国立大学法人東北大学 リチウムイオン二次電池用負極活物質およびその製造方法並びに負極および電池
JP2018514070A (ja) * 2015-12-18 2018-05-31 シェンヂェン キャプケム テクノロジー カンパニー リミテッドＳｈｅｎｚｈｅｎ Ｃａｐｃｈｅｍ Ｔｅｃｈｎｏｌｏｇｙ Ｃｏ．， Ｌｔｄ． リチウムイオン電池用電解液及びリチウムイオン電池

Also Published As

Publication number Publication date
JP6291479B2 (ja) 2018-03-14

Similar Documents

Publication Publication Date Title
JP6138490B2 (ja) リチウム二次電池
JP6191454B2 (ja) 二次電池および電解液
US9123955B2 (en) Negative active material, lithium battery including the material, and method for manufacturing the material
JP6070540B2 (ja) 二次電池および電解液
JP5757148B2 (ja) リチウムイオン二次電池用負極活物質及びその負極活物質を用いたリチウムイオン二次電池
JP6079770B2 (ja) リチウム二次電池
JP6222106B2 (ja) 非水電解液及びそれを用いた蓄電デバイス
EP3252853B1 (fr) Électrode négative pour pile rechargeable au lithium-ion, et pile rechargeable au lithium-ion
US10044072B2 (en) Lithium secondary battery pack, as well as electronic device, charging system, and charging method using said pack
WO2014021272A1 (fr) Électrolyte non aqueux et dispositif de stockage d'énergie utilisant celui-ci
JP2010531041A (ja) 導電性が優れたアノード材料及びそれを使用する高出力二次バッテリー
JP6380377B2 (ja) リチウムイオン二次電池
KR101728753B1 (ko) 음극 활물질, 이를 채용한 음극과 리튬 전지, 및 상기 음극 활물질의 제조방법
WO2013161774A1 (fr) Batterie secondaire au lithium
US9356287B2 (en) Negative active material, negative electrode and lithium battery including the negative active material, and method of preparing the negative active material
KR102494419B1 (ko) 리튬 이차전지용 비수전해액 첨가제, 이를 포함하는 리튬 이차전지용 비수전해액 및 리튬 이차전지
KR20170039924A (ko) 음극 활물질 및 이를 채용한 음극 및 리튬 전지
JP6291479B2 (ja) 負極活物質、それを用いた負極シート及び蓄電デバイス
JP2010033830A (ja) 非水電解質二次電池用負極およびそれを用いた非水電解質二次電池
JPWO2014156963A1 (ja) 負極活物質、それを用いた負極シート及び蓄電デバイス
WO2014103893A1 (fr) Batterie secondaire au lithium et son procédé de sélection
WO2014171518A2 (fr) Batterie secondaire lithium-ion
WO2019111958A1 (fr) Solution électrolytique pour batterie à électrolyte non aqueux, et batterie à électrolyte non aqueux mettant en œuvre celui-ci
JP6258180B2 (ja) リチウム二次電池用電解液の添加剤及びそれを用いたリチウム二次電池用電解液、リチウム二次電池
WO2024150400A1 (fr) Matériau d'électrode négative pour batteries secondaires au lithium-ion, électrode négative pour batteries secondaires au lithium-ion et batterie secondaire au lithium-ion

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: 14772606

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2015508418

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14772606

Country of ref document: EP

Kind code of ref document: A1