WO2015140992A1 - Nonaqueous-electrolyte secondary-battery positive electrode, nonaqueous-electrolyte secondary battery, and battery pack - Google Patents

Nonaqueous-electrolyte secondary-battery positive electrode, nonaqueous-electrolyte secondary battery, and battery pack Download PDF

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Publication number
WO2015140992A1
WO2015140992A1 PCT/JP2014/057800 JP2014057800W WO2015140992A1 WO 2015140992 A1 WO2015140992 A1 WO 2015140992A1 JP 2014057800 W JP2014057800 W JP 2014057800W WO 2015140992 A1 WO2015140992 A1 WO 2015140992A1
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positive electrode
negative electrode
electrolyte secondary
battery
secondary battery
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PCT/JP2014/057800
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French (fr)
Japanese (ja)
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岡本佳子
松野真輔
長田憲和
吉尾紗良
久保木貴志
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株式会社 東芝
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Priority to PCT/JP2014/057800 priority Critical patent/WO2015140992A1/en
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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
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M4/48—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
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/581—Devices or arrangements for the interruption of current in response to temperature
    • 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

  • Embodiments relate to a positive electrode for a nonaqueous electrolyte secondary battery, a nonaqueous electrolyte secondary battery, and a battery pack.
  • lithium secondary batteries having high capacity, high cycle characteristics, and light weight.
  • negative electrode materials for high-capacity lithium secondary batteries
  • a silicon oxide composite negative electrode in which silicon, silicon oxide, and carbon are mixed can be used.
  • Such a material does not have good negative electrode discharge efficiency (charge / discharge efficiency) with respect to the charge capacity.
  • the initial charge / discharge efficiency of a positive electrode material such as general LiCoO 2 or LiMn 2 O 4 is 90% or more, whereas the silicon oxide composite negative electrode is only about 60%.
  • Such an imbalance in charge and discharge efficiency means that the discharge reaction on the negative electrode side ends in spite of the stage where the discharge reaction on the positive electrode side has not been completed at the end of discharge, and the utilization rate of the positive electrode Is effectively reduced. Therefore, although the silicon oxide composite negative electrode has a discharge capacity per unit weight of about six times that of these positive electrode materials, it is difficult to increase the capacity of the secondary battery as a battery.
  • Lithium copper oxide has a charge capacity of about 400 mAh / g, which is twice or more that of a general positive electrode material.
  • lithium copper oxide can play the role of supplying lithium to the negative electrode at the first time, adding a small amount to the counterpart positive electrode of the silicon oxide composite negative electrode increases the utilization factor on the positive electrode side during discharge. This can contribute to higher battery capacity.
  • the lithium copper oxide dissolves the lithium copper oxide by an acid generated by the reaction of the supporting salt LiPF 6 in the electrolyte and moisture, specifically HF, and deposits metallic copper on the negative electrode.
  • Embodiment aims at increasing the capacity of a nonaqueous electrolyte secondary battery.
  • the positive electrode for a non-aqueous electrolyte secondary battery of the embodiment includes a current collector and a positive electrode mixture layer on the current collector.
  • the positive electrode mixture layer includes a composite metal lithium oxide, Li x Cu 1-y M1. at least one compound represented by the chemical formula of y O 2 and one or more compounds represented by the chemical formula of Cu 1-z M2 z O, wherein M1 and M2 are Mg, Ni, Co, It is at least one selected from Mn, Al, Zn, Cr, Ti, V and Zr.
  • the positive electrode of Embodiment 1 includes a current collector and a positive electrode mixture layer on the current collector.
  • the positive electrode mixture layer is formed on one side or both sides of the current collector.
  • FIG. 1 shows a conceptual cross-sectional view of the positive electrode.
  • a positive electrode 100 in FIG. 1 includes a current collector 101 and a positive electrode mixture layer 102.
  • the positive electrode mixture layer 102 is represented by a composite metal lithium oxide, at least one compound represented by a chemical formula of Li x Cu 1-y M1 y O 2, and a chemical formula of Cu 1-z M2 z O.
  • One or more compounds, a conductive agent, and a binder are included.
  • the current collector 101 of the embodiment is a conductive member that binds to the positive electrode mixture layer 102.
  • a conductive substrate having a porous structure or a non-porous conductive substrate can be used as the current collector 101. These conductive substrates can be formed from, for example, copper, stainless steel, or nickel.
  • the thickness of the current collector is preferably 5 ⁇ m or more and 20 ⁇ m or less. This is because within this range, the electrode strength and weight reduction can be balanced.
  • the positive electrode mixture layer 102 of the embodiment includes a composite metal lithium oxide, one or more compounds represented by a chemical formula of Li x Cu 1-y M1 y O 2, and a chemical formula of Cu 1-z M2 z O. It is a mixture of one or more compounds represented, a conductive agent, and a binder, and is bound to the current collector 101.
  • the composite metal lithium oxide refers to a composite metal lithium oxide containing a transition metal contained in the positive electrode mixture layer 102.
  • the composite metal lithium oxide functions as a positive electrode active material.
  • lithium manganese composite oxide for example, LiMn 2 O 4 or LiMnO 2
  • lithium nickel composite oxide for example, LiNiO 2
  • lithium cobalt composite oxide LiCoO 2
  • lithium iron phosphate compound LiFePO 4
  • lithium manganese cobalt composite oxide for example, LiMn 2- ⁇ 2 Co
  • a lithium composite phosphate compound for example, LiMn ⁇ 3 Fe 1- ⁇ 3 PO 4 , 0 ⁇ ⁇ 3 ⁇ 1).
  • lithium copper composite oxide represented by the chemical formula of Li x Cu 1-y M1 y O 2 contained in the positive electrode mixture layer 102 supply a large amount of lithium to the negative electrode during the initial charge. It is a compound that can be Taking a specific compound as an example, the lithium copper composite oxide Li 2 Cu 0.9 Ni 0.1 O 2 is about 1 of LiNi 1/3 Co 1/3 Mn 1/3 O 2 only at the first charge. .5 times or more of lithium can be supplied to the negative electrode. Therefore, it is suitable as a Li supply agent for improving the initial charge / discharge efficiency as described above.
  • y of the lithium cuprate complex preferably satisfies the relationship 0 ⁇ y.
  • Mg, Co, Mn, Al, Zn, Cr, Ti, V, Zr metal substitution, or combinations thereof were also effective, so M1 is Mg, Ni, Co, Mn, Al , Zn, Cr, Ti, and preferably one or more selected from the group consisting of V and Zr.
  • y exceeds 0.5, the same crystal structure as Li 2 CuO 2 is not obtained, and the effect of supplying lithium to the negative electrode at the first charge is lost. Even in an uncharged or charged state, that is, in a state of 1 ⁇ x ⁇ 2, if the range of y is 0 ⁇ y ⁇ 0.5, the Cu elution effect is obtained.
  • the Li 2 CuO 2 phase transitions to the LiCuO phase.
  • the positive electrode layer may or may not contain a LiCuO phase.
  • x exceeds 2, it does not have the same crystal structure as Li 2 CuO 2, and the effect of supplying lithium to the negative electrode at the first charge is lost.
  • Preferred ranges are 1 ⁇ x ⁇ 2 and 0 ⁇ y ⁇ 0.3.
  • At least one compound (copper composite oxide) represented by the chemical formula of Cu 1-z M2 z O is included.
  • Cu 1-z M2 z O When Li x Cu 1-y M1 y O 2 is charged for the first time, lithium is released and the volume changes greatly. Therefore, it is presumed that the strain tends to remain in the electrode and accelerates the elution reaction during battery storage. . Therefore, the presence of Cu 1-z M2 z O that is inert to the charge / discharge reaction has an effect of suppressing the volume expansion of Li x Cu 1-y M1 y O 2 .
  • M2 is preferably selected from one or more selected from the group consisting of Mg, Ni, Co, Mn, Al, Zn, Cr, Ti, V and Zr.
  • a preferable range of z is 0 ⁇ z ⁇ 0.5. When z exceeds 0.5, the crystal structure of CuO cannot be maintained, and the effect of suppressing volume expansion is reduced. When a different metal is substituted for Cu (z> 0), the effect of suppressing the volume expansion of Li x Cu 1-y M1 y O 2 becomes higher. If it is 0.3 or less, the crystallinity tends to be high, and the effect of suppressing volume expansion is high. Therefore, a preferable range is 0 ⁇ z ⁇ 0.3.
  • the Li x Cu 1-y M1 y O 2 and Cu 1-z M2 z O in the positive electrode mixture layer 102 preferably satisfy the following ratio.
  • the existence ratio can be defined.
  • the peak of the X-ray diffraction peak I (011) of Li x Cu 1-y M1 y O 2 occurs in the vicinity of 25 ° to 27 ° by X-ray diffraction measurement using CuK ⁇ rays.
  • the peak of the X-ray diffraction peak I (020) of Cu 1-z M2 z O occurs in the vicinity of 41 ° to 43 ° by X-ray diffraction measurement using CuK ⁇ rays. Note that a powder obtained by scraping the positive electrode mixture layer 102 as a whole is used as a measurement sample.
  • the peak intensity ratio I (011) / I (020) is 0.5 or more and 10 or less, the effect of supplying lithium to the negative electrode at the time of the initial charge to supplement the negative electrode initial irreversible capacity, and Cu 1 ⁇ z M2 z
  • the effect that the O phase suppresses the volume expansion of the Li x Cu 1-y M1 y O 2 phase is sufficiently obtained.
  • the ratio of Cu element present in the positive electrode mixture layer 102 is preferably 5 atom% or more and 30 atom% or less. If it is less than 5 atom% or more than 30 atom%, the elution of Cu is accelerated or the effect of supplying lithium to the negative electrode during the initial charge is reduced. A more preferable range is 5 atom% or more and 15 atom%.
  • the ratio of the Cu element present in the positive electrode mixture layer 102 can be calculated by inductively coupled plasma emission analysis (ICP-AES: Inductively Coupled Plasma Atomic Emission Spectroscopy).
  • ICP-AES Inductively Coupled Plasma Atomic Emission Spectroscopy
  • a solution obtained by dissolving the powder obtained by scraping the positive electrode mixture layer 102 as a whole with an acidic solution is analyzed.
  • Elements such as Cu, Ni, Mn, Li, F, C, O, M1, and M2 metal elements are observed in the positive electrode mixture layer 102.
  • it is preferably 5 atom% or more and 30 atom% or less.
  • Examples of the conductive agent contained in the positive electrode mixture layer 102 include acetylene black, carbon black, and graphite.
  • binder contained in the positive electrode mixture layer 102 examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, ethylene-butadiene rubber (SBR), polypropylene (PP), and polyethylene (PE). ), Carboxymethylcellulose (CMC), polyimide (PI), and polyacrylimide (PAI).
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • SBR ethylene-butadiene rubber
  • PP polypropylene
  • PE polyethylene
  • CMC Carboxymethylcellulose
  • PI polyimide
  • PAI polyacrylimide
  • An active material (a composite metal lithium oxide, at least one compound represented by a chemical formula of Li x Cu 1-y M1 y O 2 , and Cu 1-z M2 z O contained in the positive electrode mixture layer 102;
  • the preferable blending ratio of the one or more compounds represented by the chemical formula), the conductive agent and the binder is 80% by mass to 95% by mass of the active material, and 3% by mass to 20% by mass of the conductive agent.
  • the binder is 2 mass% or more and 7 mass% or less.
  • the nonaqueous electrolyte secondary battery according to the embodiment includes an exterior material, a positive electrode accommodated in the exterior material, and a negative electrode that is spatially separated from the positive electrode in the exterior material, for example, via a separator. And a non-aqueous electrolyte filled in the exterior material.
  • FIG. 2 is a conceptual cross-sectional view of a flat type nonaqueous electrolyte secondary battery 200 in which the exterior material 202 is made of a laminate film.
  • the flat wound electrode group 201 is housed in an exterior material 202 made of a laminate film in which an aluminum foil is interposed between two resin layers.
  • the flat wound electrode group 201 is laminated in the order of a negative electrode 203, a separator 204, a positive electrode 205, and a separator 204, as shown in FIG. And it is formed by winding the laminate in a spiral shape and press-molding it.
  • the electrode closest to the packaging material 202 is a negative electrode, and this negative electrode has no negative electrode mixture formed on the negative electrode current collector on the packaging material 202 side, and is only on one side of the negative electrode current collector on the battery inner surface side. It has the structure which formed the negative mix.
  • the other negative electrode 203 is configured by forming a negative electrode mixture on both surfaces of the negative electrode current collector.
  • the positive electrode 205 is configured by forming a positive electrode mixture layer on both surfaces of a positive electrode current collector.
  • the negative electrode terminal is electrically connected to the negative electrode current collector of the outermost negative electrode 203
  • the positive electrode terminal is electrically connected to the positive electrode current collector of the inner positive electrode 205.
  • the negative electrode terminal 206 and the positive electrode terminal 207 are extended from the opening of the exterior material 202 to the outside.
  • the quality non-aqueous electrolyte is injected from the opening of the exterior material 202.
  • the wound electrode group 201 and the quality non-aqueous electrolyte are sealed by heat-sealing the opening of the exterior material 202 with the negative electrode terminal 206 and the positive electrode terminal 207 interposed therebetween.
  • Examples of the negative electrode terminal 206 include aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu, and Si.
  • the negative electrode terminal 206 is preferably made of the same material as the negative electrode current collector in order to reduce the contact resistance with the negative electrode current collector.
  • the positive electrode terminal 207 can be made of a material having electrical stability and conductivity in the range of 3 to 4.25 V with respect to the lithium ion metal. Specifically, aluminum or an aluminum alloy containing an element such as Mg, Ti, Zn, Mn, Fe, Cu, or Si can be given.
  • the positive electrode terminal 207 is preferably made of the same material as the positive electrode current collector in order to reduce the contact resistance with the positive electrode current collector.
  • the exterior material 202, the positive electrode 205, the electrolyte, and the separator 204 which are constituent members of the nonaqueous electrolyte secondary battery 200, will be described in detail.
  • Exterior material 202 is formed from a laminate film having a thickness of 0.5 mm or less. Alternatively, a metal container having a thickness of 1.0 mm or less is used as the exterior material. The metal container is more preferably 0.5 mm or less in thickness.
  • the shape of the exterior material 202 can be selected from a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type.
  • the exterior material include, for example, an exterior material for a small battery that is loaded on a portable electronic device or the like, an exterior material for a large battery that is loaded on a two- to four-wheeled vehicle, etc., depending on the battery size.
  • the laminate film a multilayer film in which a metal layer is interposed between resin layers is used.
  • the metal layer is preferably an aluminum foil or an aluminum alloy foil for weight reduction.
  • a polymer material such as polypropylene (PP), polyethylene (PE), nylon, polyethylene terephthalate (PET) can be used.
  • PP polypropylene
  • PE polyethylene
  • PET polyethylene terephthalate
  • the laminate film can be molded into the shape of an exterior material by sealing by heat sealing.
  • Metal containers are made from aluminum or aluminum alloy.
  • the aluminum alloy is preferably an alloy containing elements such as magnesium, zinc, and silicon.
  • transition metals such as iron, copper, nickel, and chromium are included in the alloy, the amount is preferably 100 ppm by mass or less.
  • Positive electrode 205 As the positive electrode 205, the positive electrode of Embodiment 1 is preferably used.
  • Negative electrode 203 has a current collector and a negative electrode mixture layer on the current collector.
  • the negative electrode mixture layer is formed on one side or both sides of the negative electrode current collector.
  • the negative electrode mixture layer includes at least a negative electrode active material.
  • the negative electrode mixture layer includes, for example, an active material, a conductive agent, and a binder.
  • the active material of the negative electrode 203 may be any material as long as it is used for the negative electrode.
  • a suitable negative electrode active material is dispersed in, for example, a carbonaceous material phase and a carbonaceous material phase.
  • Composite particles containing a silicon phase or tin phase and silicon oxide or tin oxide dispersed in a carbonaceous material phase.
  • a negative electrode having an active material having a discharge capacity larger than that of the graphite negative electrode as described above is advantageous because it can maximize the effects of the positive electrode of the embodiment.
  • the carbonaceous material of the negative electrode 203 one or more types selected from the group consisting of graphite, hard carbon, soft carbon, amorphous carbon, and acetylene black can be used.
  • the carbonaceous material gives strength to the negative electrode active material and forms the negative electrode active material.
  • a carbon material is usually used as the negative electrode conductive agent.
  • the carbon material only needs to have high alkali metal occlusion and conductivity.
  • Examples of the carbon material may include acetylene black or carbon black, and may be graphite having high crystallinity.
  • binder examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, ethylene-butadiene rubber (SBR), polypropylene (PP), polyethylene (PE), carboxymethyl cellulose (CMC), Includes polyimide (PI) and polyacrylimide (PAI).
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • SBR ethylene-butadiene rubber
  • PP polypropylene
  • PE polyethylene
  • CMC carboxymethyl cellulose
  • PI polyimide
  • PAI polyacrylimide
  • a preferable blending ratio of the active material, the conductive agent, and the binder contained in the negative electrode mixture layer is 70% by mass to 95% by mass of the negative electrode active material, and 0% by mass to 25% by mass of the conductive agent.
  • the binder is preferably 2% by mass or more and 10% by mass or less.
  • Nonaqueous electrolyte is prepared by dissolving an electrolyte in a nonaqueous solvent.
  • a nonaqueous solvent a known non-aqueous solvent for a lithium battery can be used.
  • non-aqueous solvents include cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC); mixed solvents of cyclic carbonate and a non-aqueous solvent having a viscosity lower than that of the cyclic carbonate (hereinafter referred to as second solvent). .
  • second solvents are linear carbonates such as dimethyl carbonate, methyl ethyl carbonate or diethyl carbonate; ⁇ -butyrolactone, acetonitrile, methyl propionate, ethyl propionate; cyclic ethers such as tetrahydrofuran or 2-methyltetrahydrofuran; Includes chain ethers such as dimethoxyethane or diethoxyethane.
  • Examples of the electrolyte include alkali salts, and lithium salts are particularly preferable.
  • Examples of lithium salts are lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluoroarsenide (LiAsF 6 ), lithium perchlorate (LiClO 4 ), or trifluorometa Lithium sulfonate (LiCF 3 SO 3 ) is included.
  • lithium hexafluorophosphate (LiPF 6 ) and lithium tetrafluoroborate (LiBF 4 ) are preferable.
  • the electrolyte is preferably dissolved at 0.5 to 2 mol / L in the non-aqueous solvent.
  • the separator is for preventing the positive electrode and the negative electrode from coming into contact, and is made of an insulating material. Furthermore, a shape in which the electrolyte can move between the positive electrode and the negative electrode is used. Specifically, for example, a synthetic resin nonwoven fabric, a polyethylene porous film, a polypropylene porous film, or a cellulose-based separator can be used.
  • the battery pack according to the third embodiment includes one or more non-aqueous electrolyte secondary batteries (that is, single cells) according to the second embodiment.
  • the single cells are electrically connected in series, parallel, or connected in series and parallel.
  • the battery pack 300 will be specifically described with reference to the conceptual diagram of FIG. 4 and the block diagram of FIG. In the battery pack 300 shown in FIG. 4, the flat type nonaqueous electrolyte battery 200 shown in FIG. 2 is used as the unit cell 301.
  • the plurality of single cells 301 are stacked such that the negative electrode terminal 302 and the positive electrode terminal 303 extending to the outside are aligned in the same direction, and are fastened with an adhesive tape 304 to constitute an assembled battery 305. These unit cells 301 are electrically connected to each other in series as shown in FIG.
  • the printed wiring board 306 is disposed to face the side surface of the unit cell 301 from which the negative electrode terminal 302 and the positive electrode terminal 303 extend.
  • a thermistor 307, a protection circuit 308, and a terminal 309 for energizing external devices are mounted on the printed wiring board 306, as shown in FIG. 5, as shown in FIG. 5, a thermistor 307, a protection circuit 308, and a terminal 309 for energizing external devices are mounted.
  • An insulating plate (not shown) is attached to the surface of the printed wiring board 306 facing the assembled battery 305 in order to avoid unnecessary connection with the wiring of the assembled battery 305.
  • the positive electrode side lead 310 is connected to the positive electrode terminal 303 located at the lowermost layer of the assembled battery 305, and the tip thereof is inserted into the positive electrode side connector 311 of the printed wiring board 306 and electrically connected thereto.
  • the negative electrode side lead 312 is connected to the negative electrode terminal 302 located on the uppermost layer of the assembled battery 305, and the tip thereof is inserted into and electrically connected to the negative electrode side connector 313 of the printed wiring board 306.
  • These connectors 311 and 313 are connected to the protection circuit 308 through wirings 314 and 315 formed on the printed wiring board 306.
  • the thermistor 307 is used to detect the temperature of the unit cell 305, and the detection signal is transmitted to the protection circuit 308.
  • the protection circuit 308 can cut off the plus-side wiring 316a and the minus-side wiring 316b between the protection circuit 308 and the terminal 309 for energizing external devices under a predetermined condition.
  • the predetermined condition is, for example, when the temperature detected by the thermistor 307 is equal to or higher than a predetermined temperature.
  • the predetermined condition is when an overcharge, overdischarge, overcurrent, or the like of the unit cell 301 is detected. This detection of overcharge or the like is performed for each single cell 301 or the entire single cell 301.
  • the battery voltage When detecting each single cell 301, the battery voltage may be detected, or the positive electrode potential or the negative electrode potential may be detected. In the latter case, a lithium electrode used as a reference electrode is inserted into each unit cell 301. 4 and 5, a voltage detection wiring 317 is connected to each single cell 301, and a detection signal is transmitted to the protection circuit 308 through the wiring 317.
  • Protective sheets 318 made of rubber or resin are disposed on the three side surfaces of the assembled battery 305 excluding the side surfaces from which the positive electrode terminal 303 and the negative electrode terminal 302 protrude.
  • the assembled battery 305 is stored in the storage container 319 together with each protective sheet 318 and the printed wiring board 306. That is, the protective sheet 318 is disposed on each of the inner side surface in the long side direction and the inner side surface in the short side direction of the storage container 319, and the printed wiring board 306 is disposed on the inner side surface on the opposite side in the short side direction.
  • the assembled battery 305 is located in a space surrounded by the protective sheet 318 and the printed wiring board 306.
  • the lid 320 is attached to the upper surface of the storage container 319.
  • a heat shrink tape may be used for fixing the assembled battery 305.
  • protective sheets are arranged on both side surfaces of the assembled battery, the heat shrinkable tape is circulated, and then the heat shrinkable tape is heat shrunk to bind the assembled battery.
  • a battery pack having excellent charge / discharge cycle performance can be provided by including the nonaqueous electrolyte secondary battery having excellent charge / discharge cycle performance in the second embodiment. .
  • the battery pack is preferably one that exhibits excellent cycle characteristics when a large current is taken out.
  • Specific examples include a power source for a digital camera, a vehicle for a two- to four-wheel hybrid electric vehicle, a two- to four-wheel electric vehicle, an assist bicycle, and the like.
  • a battery pack using a nonaqueous electrolyte secondary battery having excellent high temperature characteristics is suitably used for in-vehicle use. Specific examples will be given below and their effects will be described.
  • Example 1 Preparation of positive electrode> 80% by weight of lithium nickel manganese cobalt composite oxide (LiNi 1/3 Mn 1/3 Co 1/3 O 2 ) powder as an active material, 10% by weight of Li 2 Cu 0.9 Ni 0.1 O 2 powder, A slurry was prepared by adding 2% by weight of Cu 0.85 Ni 0.15 O powder, 3% by weight of acetylene black and 5% by weight of polyvinylidene fluoride (PVdF) to N-methylpyrrolidone and mixing them.
  • LiNi 1/3 Mn 1/3 Co 1/3 O 2 lithium nickel manganese cobalt composite oxide
  • Li 2 Cu 0.9 Ni 0.1 O 2 powder A slurry was prepared by adding 2% by weight of Cu 0.85 Ni 0.15 O powder, 3% by weight of acetylene black and 5% by weight of polyvinylidene fluoride (PVdF) to N-methylpyrrolidone and mixing them.
  • PVdF polyvinylidene fluoride
  • This slurry was applied to an aluminum foil (current collector) having a thickness of 15 ⁇ m, dried, and pressed to prepare a positive electrode having a positive electrode layer with a density of 3.2 g / cm 3 .
  • a positive electrode without adding a copper composite oxide and a lithium copper composite oxide was also produced while maintaining the amount of auxiliary members such as acetylene black and polyvinylidene fluoride that do not contribute to capacity.
  • This slurry was applied to a copper foil (current collector) having a thickness of 10 ⁇ m, dried, pressed, and copper was deposited in a vacuum atmosphere.
  • a negative electrode having a negative electrode layer with a density of 2.0 g / cm 3 was produced by heating at 500 ° C. for 8 hours in an argon gas containing 2 to 5% oxygen concentration.
  • Electrode group ⁇ Production of electrode group>
  • the positive electrode, a separator made of a polyethylene porous film, the negative electrode, and the separator were laminated in this order, and then wound in a spiral shape so that the negative electrode was located on the outermost periphery, thereby producing an electrode group.
  • Ethylene carbonate (EC) and methyl ethyl carbonate (MEC) were mixed at a volume ratio of 1: 2 to obtain a mixed solvent.
  • a nonaqueous electrolyte was prepared by dissolving 1.0 mol / L of lithium hexafluorophosphate (LiPF 6 ) in this mixed solvent.
  • the electrode group and the non-aqueous electrolyte were respectively housed in a stainless steel bottomed cylindrical container. Subsequently, one end of the negative electrode lead was connected to the negative electrode of the electrode group, and the other end was connected to a bottomed cylindrical container that also served as the negative electrode terminal.
  • an insulating sealing plate having a positive terminal fitted in the center was prepared. After connecting one end of the positive electrode lead to the positive electrode terminal and the other end to the positive electrode of the electrode group, the insulating sealing plate is caulked to the upper opening of the container to thereby form a cylindrical non-aqueous electrolyte having a capacity of 1.5 Ah. The next battery was assembled.
  • the obtained secondary battery was charged at 4.3 V in a 0.2 C rate and 25 ° C. environment, and discharged at a 0.2 C rate until 1.0 V was reached.
  • a secondary battery manufactured in the same process was disassembled in an argon box, and the positive electrode layer was analyzed.
  • the positive electrode layer was scraped out from the positive electrode with about 5 g with a spatula, and ICP emission analysis was performed. As a result, the ratio of Cu in all elements was 8 atom%.
  • Example 2 to 21 In accordance with the negative electrode, the lithium-copper composite oxide and the copper composite oxide in the positive electrode layer were appropriately adjusted so as to have the configurations shown in Tables 1 and 2, and the non-aqueous electrolyte secondary battery as in Example 1 was made.
  • Example 22 Due to the potential of the positive electrode, the produced secondary battery was charged at 3.6 V under a 0.2 C rate and 25 ° C. environment, and discharged at a 0.2 C rate until reaching 1.0 V.
  • the lithium copper composite oxide and the copper composite oxide in the positive electrode layer were appropriately adjusted so as to have the configurations shown in Tables 1 and 2, and the same procedures as in Examples 1 to 21 were performed.
  • Examples 1 to 21 and Comparative Example 1 were performed at a rate of 0.2 C in the range of 4.3 V to 2.0 V for both charging and discharging.
  • Examples 1 to 21 and Comparative Example 1 were performed at a rate of 0.2 C in the range of 4.3 V to 2.0 V for both charging and discharging.
  • charging and discharging were performed at a 0.2 C rate in the range of 3.6 V to 1.5 V.
  • Comparative Example 1 After battery storage, the capacity was greatly deteriorated and the amount of Cu eluted was large.
  • Comparative Example 2 the capacity deterioration after storage of the battery was large and the amount of elution of Cu was large, but the cycle retention rate tended to be high due to the effect of the copper composite oxide.
  • Comparative Example 3 the elution of Cu tended to be suppressed, but the cycle retention rate tended to be low.
  • Examples 1 to 22 it was confirmed that the performance was improved on the whole. The same tendency was obtained for the cycle test. Therefore, it is considered that the validity of the embodiment was shown from this result.
  • Electrode for nonaqueous electrolyte batteries 101 ... Negative electrode mixture layer, 102 ... Current collector, 103 ... Negative electrode active material, 104 ... Conductive material, 105 ... Binder, 200 ... Nonaqueous electrolyte secondary battery, 200 ... Winding electrode group, 202 ... exterior material, 203 ... negative electrode, 204 ... separator, 205 ... positive electrode, 300 ... battery pack, 301 ... single cell, 302 ... negative electrode terminal, 303 ... positive electrode terminal, 304 ... adhesive tape, 305 ...

Abstract

[Problem] The purpose of one embodiment is to increase the capacity of a nonaqueous-electrolyte secondary battery. [Solution] A nonaqueous-electrolyte secondary-battery positive electrode in one embodiment is characterized by comprising a collector and a positive-electrode mixture layer on top of said collector, wherein: said positive-electrode mixture layer contains a complex metal/lithium oxide, at least one compound that can be represented by the chemical formula LixCu1 − yM1yO2, and at least one compound that can be represented by the chemical formula Cu1 − zM2zO; and M1 and M2 each represent one or more elements selected from among magnesium, nickel, cobalt, manganese, aluminum, zinc, chromium, titanium, vanadium, and zirconium.

Description

非水電解質二次電池用正極、非水電解質二次電池および電池パックNon-aqueous electrolyte secondary battery positive electrode, non-aqueous electrolyte secondary battery, and battery pack
　実施形態は、非水電解質二次電池用正極、非水電解質二次電池および電池パックに関する。 Embodiments relate to a positive electrode for a nonaqueous electrolyte secondary battery, a nonaqueous electrolyte secondary battery, and a battery pack.
　近年、高容量、高サイクル特性、且つ軽量なリチウム二次電池の需要が高まっている。それに伴い、電極材料をはじめ、電池構成材料の新規開発が加速している。高容量リチウム二次電池の負極材料のひとつとして、シリコンとシリコン酸化物とカーボンとが混合した酸化シリコン複合負極などが挙げられる。このような材料は、充電容量に対する負極放電の効率（充放電効率）が芳しくない。一般的なＬｉＣｏＯ２、ＬｉＭｎ２Ｏ４といった正極材料の初回充放電効率は９０％以上示すのに対し、酸化シリコン複合負極は６０％程度でしかない。このような充放電効率のアンバランスは、放電末期時に正極側の放電反応が終了しきっていない段階にもかかわらず、負極側の放電反応が終了してしまうということを意味し、正極の利用率を事実上下げることにつながる。従って酸化シリコン複合負極はこれらの正極材料の６倍程度の単位重量あたりの放電容量を持つにもかかわらず、電池として二次電池の高容量化させることを難しくする。 In recent years, there is an increasing demand for lithium secondary batteries having high capacity, high cycle characteristics, and light weight. Along with this, new development of battery components, including electrode materials, is accelerating. As one of negative electrode materials for high-capacity lithium secondary batteries, a silicon oxide composite negative electrode in which silicon, silicon oxide, and carbon are mixed can be used. Such a material does not have good negative electrode discharge efficiency (charge / discharge efficiency) with respect to the charge capacity. The initial charge / discharge efficiency of a positive electrode material such as general LiCoO 2 or LiMn 2 O 4 is 90% or more, whereas the silicon oxide composite negative electrode is only about 60%. Such an imbalance in charge and discharge efficiency means that the discharge reaction on the negative electrode side ends in spite of the stage where the discharge reaction on the positive electrode side has not been completed at the end of discharge, and the utilization rate of the positive electrode Is effectively reduced. Therefore, although the silicon oxide composite negative electrode has a discharge capacity per unit weight of about six times that of these positive electrode materials, it is difficult to increase the capacity of the secondary battery as a battery.
　正極の初回充放電効率と負極の初回効率のアンバランスを解決させるために、種々の提案がなされている。特に正極材料にリチウム銅酸化物（例えばＬｉ２ＣｕＯ２）を適宜加える提案がなされている。リチウム銅酸化物は、充電容量が４００ｍＡｈ／ｇ程度、一般的な正極材料の２倍以上の容量を示す。一方で放電容量はほとんど存在せず、２回目以降は殆ど充放電容量をもたない。従って、リチウム銅酸化物は初回時に負極にリチウムを供給するだけの役割を果たすことができるため、酸化シリコン複合負極の相手側正極に少量添加すると、放電時に正極側の利用率が高くなるため、電池の高容量化に寄与できる。
　一方で、リチウム銅酸化物は電解質中の支持塩ＬｉＰＦ６と水分などの反応により生じる酸、具体的にはＨＦ、により、リチウム銅酸化物が溶解し、負極上に金属銅を析出させてしまう欠点があった。 Various proposals have been made to solve the imbalance between the initial charge / discharge efficiency of the positive electrode and the initial efficiency of the negative electrode. In particular, proposals have been made to appropriately add lithium copper oxide (for example, Li 2 CuO 2 ) to the positive electrode material. Lithium copper oxide has a charge capacity of about 400 mAh / g, which is twice or more that of a general positive electrode material. On the other hand, there is almost no discharge capacity, and there is almost no charge / discharge capacity after the second time. Therefore, since lithium copper oxide can play the role of supplying lithium to the negative electrode at the first time, adding a small amount to the counterpart positive electrode of the silicon oxide composite negative electrode increases the utilization factor on the positive electrode side during discharge. This can contribute to higher battery capacity.
On the other hand, the lithium copper oxide dissolves the lithium copper oxide by an acid generated by the reaction of the supporting salt LiPF 6 in the electrolyte and moisture, specifically HF, and deposits metallic copper on the negative electrode. There were drawbacks.
特開２００１－１６０３９５号公報JP 2001-160395 A
　実施形態は、非水電解質二次電池の高容量化を目的とする。 Embodiment aims at increasing the capacity of a nonaqueous electrolyte secondary battery.
　実施形態の非水電解質二次電池用正極は、集電体と、集電体上に正極合剤層を含み、正極合剤層は、複合金属リチウム酸化物と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物とを少なくとも含み、Ｍ１とＭ２は、Ｍｇ、Ｎｉ、Ｃｏ、Ｍｎ、Ａｌ、Ｚｎ、Ｃｒ、Ｔｉ、ＶとＺｒから選ばれる少なくとも１種以上であることを特徴とする。 The positive electrode for a non-aqueous electrolyte secondary battery of the embodiment includes a current collector and a positive electrode mixture layer on the current collector. The positive electrode mixture layer includes a composite metal lithium oxide, Li x Cu 1-y M1. at least one compound represented by the chemical formula of y O 2 and one or more compounds represented by the chemical formula of Cu 1-z M2 z O, wherein M1 and M2 are Mg, Ni, Co, It is at least one selected from Mn, Al, Zn, Cr, Ti, V and Zr.
実施形態の正極の概念図である。It is a conceptual diagram of the positive electrode of embodiment. 実施形態の非水電解質二次電池の概念図である。It is a conceptual diagram of the nonaqueous electrolyte secondary battery of embodiment. 実施形態の非水電解質二次電池の拡大概念図である。It is an expansion conceptual diagram of the nonaqueous electrolyte secondary battery of an embodiment. 実施形態の電池パックの概念図である。It is a conceptual diagram of the battery pack of embodiment. 電池パックの電気回路を示すブロック図である。It is a block diagram which shows the electric circuit of a battery pack.
（実施形態１）
　実施形態１の正極は、集電体と、集電体上に正極合剤層を含む。正極合剤層は、集電体の片面または両面に形成される。図１に正極の断面概念図を示す。図１の正極１００は、集電体１０１と、正極合剤層１０２を有する。正極合剤層１０２は、複合金属リチウム酸化物と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物と、導電剤と、結着剤とを含む。 (Embodiment 1)
The positive electrode of Embodiment 1 includes a current collector and a positive electrode mixture layer on the current collector. The positive electrode mixture layer is formed on one side or both sides of the current collector. FIG. 1 shows a conceptual cross-sectional view of the positive electrode. A positive electrode 100 in FIG. 1 includes a current collector 101 and a positive electrode mixture layer 102. The positive electrode mixture layer 102 is represented by a composite metal lithium oxide, at least one compound represented by a chemical formula of Li x Cu 1-y M1 y O 2, and a chemical formula of Cu 1-z M2 z O. One or more compounds, a conductive agent, and a binder are included.
　実施形態の集電体１０１は、正極合剤層１０２と結着する導電性の部材である。集電体１０１としては、多孔質構造の導電性基板か、あるいは無孔の導電性基板を用いることができる。これら導電性基板は、例えば、銅、ステンレスまたはニッケルから形成することができる。集電体の厚さは５μｍ以上２０μｍ以下であることが望ましい。この範囲内であると電極強度と軽量化のバランスがとれるからである。 The current collector 101 of the embodiment is a conductive member that binds to the positive electrode mixture layer 102. As the current collector 101, a conductive substrate having a porous structure or a non-porous conductive substrate can be used. These conductive substrates can be formed from, for example, copper, stainless steel, or nickel. The thickness of the current collector is preferably 5 μm or more and 20 μm or less. This is because within this range, the electrode strength and weight reduction can be balanced.
　実施形態の正極合剤層１０２は、複合金属リチウム酸化物と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物と、導電剤と、結着剤との混合物であって、集電体１０１と結着している。 The positive electrode mixture layer 102 of the embodiment includes a composite metal lithium oxide, one or more compounds represented by a chemical formula of Li x Cu 1-y M1 y O 2, and a chemical formula of Cu 1-z M2 z O. It is a mixture of one or more compounds represented, a conductive agent, and a binder, and is bound to the current collector 101.
　複合金属リチウム酸化物は、正極合剤層１０２に含まれる遷移金属を含有する複合金属リチウム酸化物を指す。複合金属リチウム酸化物は、正極活物質として機能する。例をあげると、リチウムマンガン複合酸化物（例えばＬｉＭｎ２Ｏ４またはＬｉＭｎＯ２）、リチウムニッケル複合酸化物（例えばＬｉＮｉＯ２）、リチウムコバルト複合酸化物（ＬｉＣｏＯ２）、リチウム鉄リン酸化合物（ＬｉＦｅＰＯ４）、遷移金属部分を他金属で置換したような、リチウムニッケルコバルトマンガン複合酸化物（例えばＬｉＮｉα１Ｃｏβ１Ｍｎγ１Ｏ２、α１＋β１＋γ１＝１）、リチウムマンガンコバルト複合酸化物（例えばＬｉＭｎ２－α２Ｃｏα２Ｏ４、０≦α≦１）、リチウム複合リン酸化合物（例えばＬｉＭｎα３Ｆｅ１－α３ＰＯ４、０≦α３≦１）を含む。 The composite metal lithium oxide refers to a composite metal lithium oxide containing a transition metal contained in the positive electrode mixture layer 102. The composite metal lithium oxide functions as a positive electrode active material. For example, lithium manganese composite oxide (for example, LiMn 2 O 4 or LiMnO 2 ), lithium nickel composite oxide (for example, LiNiO 2 ), lithium cobalt composite oxide (LiCoO 2 ), lithium iron phosphate compound (LiFePO 4). ), Lithium nickel cobalt manganese composite oxide (for example, LiNi α1 Co β1 Mn γ1 O 2 , α1 + β1 + γ1 = 1), lithium manganese cobalt composite oxide (for example, LiMn 2-α2 Co) α2 O 4 , 0 ≦ α ≦ 1), and a lithium composite phosphate compound (for example, LiMn α3 Fe 1-α3 PO 4 , 0 ≦ α3 ≦ 1).
　正極合剤層１０２に含まれるＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物（リチウム銅複合酸化物）は、初回充電時に負極に多くのリチウムを供給することのできる化合物である。具体的な化合物を例にとり説明すると、リチウム銅複合酸化物Ｌｉ２Ｃｕ０．９Ｎｉ０．１Ｏ２は、初回充電時のみＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２の約１．５倍以上のリチウムを負極に対して供給することができる。したがって、上述したように初回充放電効率を向上させるためのＬｉ供給剤として好適である。 One or more compounds (lithium copper composite oxide) represented by the chemical formula of Li x Cu 1-y M1 y O 2 contained in the positive electrode mixture layer 102 supply a large amount of lithium to the negative electrode during the initial charge. It is a compound that can be Taking a specific compound as an example, the lithium copper composite oxide Li 2 Cu 0.9 Ni 0.1 O 2 is about 1 of LiNi 1/3 Co 1/3 Mn 1/3 O 2 only at the first charge. .5 times or more of lithium can be supplied to the negative electrode. Therefore, it is suitable as a Li supply agent for improving the initial charge / discharge efficiency as described above.
　ｘ＝２、ｙ＝０である無置換のＬｉ２ＣｕＯ２も同様にＬｉ供給の効果があるが、発明者らが調査した結果、電池充電時に６５℃環境下で保存試験を実施すると、無置換のＬｉ２ＣｕＯ２から、大量のＣｕが溶出し、負極側に析出することが分かった。ＣｕにＮｉを置換した結果、このＣｕの溶出を大幅に抑制させる効果があることが確認された。したがって、リチウム銅酸複合化物のｙは、０＜ｙの関係を満たすことが好ましい。その他、列挙したようにＭｇ、Ｃｏ、Ｍｎ、Ａｌ、Ｚｎ、Ｃｒ、Ｔｉ、Ｖ、Ｚｒの金属の置換、あるいはこれらの組み合わせも効果があったため、Ｍ１は、Ｍｇ、Ｎｉ、Ｃｏ、Ｍｎ、Ａｌ、Ｚｎ、Ｃｒ、Ｔｉ、ＶとＺｒからなる群から選ばれる１種以上であることが好ましい。ｙが０．５を超えると、Ｌｉ２ＣｕＯ２と同じ結晶構造を持たなくなり、初回充電時にリチウムを負極に供給する効果が失われる。未充電、あるいは充電された状態、すなわち１＜ｘ≦２の状態でも、ｙの範囲が０＜ｙ≦０．５であればＣｕの溶出効果は得られる。 Unsubstituted Li 2 CuO 2 in which x = 2 and y = 0 is also effective in supplying Li. However, as a result of investigations by the inventors, when a storage test is performed in a 65 ° C. environment during battery charging, there is no effect. It was found that a large amount of Cu was eluted from the substituted Li 2 CuO 2 and deposited on the negative electrode side. As a result of substituting Ni for Cu, it was confirmed that there was an effect of greatly suppressing the elution of Cu. Therefore, y of the lithium cuprate complex preferably satisfies the relationship 0 <y. In addition, as listed, Mg, Co, Mn, Al, Zn, Cr, Ti, V, Zr metal substitution, or combinations thereof were also effective, so M1 is Mg, Ni, Co, Mn, Al , Zn, Cr, Ti, and preferably one or more selected from the group consisting of V and Zr. When y exceeds 0.5, the same crystal structure as Li 2 CuO 2 is not obtained, and the effect of supplying lithium to the negative electrode at the first charge is lost. Even in an uncharged or charged state, that is, in a state of 1 <x ≦ 2, if the range of y is 0 <y ≦ 0.5, the Cu elution effect is obtained.
　ｘが１以下の場合、Ｌｉ２ＣｕＯ２相はＬｉＣｕＯ相に相転移する。ＬｉＣｕＯ相は、調査の結果、初回充放電容量と銅の溶出に関して正極に何ら影響をもたらさないことが確認された。正極層にＬｉＣｕＯ相が含まれていても、含まれていなくてもかまわない。また、ｘが２を超えるとＬｉ２ＣｕＯ２と同じ結晶構造を持たなくなり、初回充電時にリチウムを負極に供給する効果が失われる。好ましい範囲は、１＜ｘ≦２、かつ０＜ｙ≦０．３である。 When x is 1 or less, the Li 2 CuO 2 phase transitions to the LiCuO phase. As a result of the investigation, it was confirmed that the LiCuO phase had no influence on the positive electrode with respect to the initial charge / discharge capacity and the elution of copper. The positive electrode layer may or may not contain a LiCuO phase. Moreover, when x exceeds 2, it does not have the same crystal structure as Li 2 CuO 2, and the effect of supplying lithium to the negative electrode at the first charge is lost. Preferred ranges are 1 <x ≦ 2 and 0 <y ≦ 0.3.
　ＬｉｘＣｕ１－ｙＭ１ｙＯ２の他に、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物（銅複合酸化物）が含まれることが好ましい。ＬｉｘＣｕ１－ｙＭ１ｙＯ２の初回充電反応時、リチウムが抜けるとともに、体積が大きく変化するため、電極内に歪みが残りやすく、電池貯蔵時に溶出反応を加速させる要因になると推察される。そこで充放電反応に不活性なＣｕ１－ｚＭ２ｚＯが存在すると、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の体積膨張を抑制させる効果がもたらされる。Ｍ２は、Ｍｇ、Ｎｉ、Ｃｏ、Ｍｎ、Ａｌ、Ｚｎ、Ｃｒ、Ｔｉ、ＶとＺｒからなる群から選ばれる１種以上選ばれることが好ましい。ｚの好ましい範囲は、０≦ｚ≦０．５である。ｚが０．５を超えると、ＣｕＯの結晶構造を維持できなくなり、体積膨張を抑制させる効果が薄れる。Ｃｕに対して異種金属が置換されている（ｚ＞０）と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の体積膨張を抑制させる効果がより高くなる。０．３以下であれば結晶性が高くなる傾向があるため、体積膨張を抑制させる効果が高い。したがって、好ましい範囲は、０＜ｚ≦０．３である。 In addition to Li x Cu 1-y M1 y O 2 , it is preferable that at least one compound (copper composite oxide) represented by the chemical formula of Cu 1-z M2 z O is included. When Li x Cu 1-y M1 y O 2 is charged for the first time, lithium is released and the volume changes greatly. Therefore, it is presumed that the strain tends to remain in the electrode and accelerates the elution reaction during battery storage. . Therefore, the presence of Cu 1-z M2 z O that is inert to the charge / discharge reaction has an effect of suppressing the volume expansion of Li x Cu 1-y M1 y O 2 . M2 is preferably selected from one or more selected from the group consisting of Mg, Ni, Co, Mn, Al, Zn, Cr, Ti, V and Zr. A preferable range of z is 0 ≦ z ≦ 0.5. When z exceeds 0.5, the crystal structure of CuO cannot be maintained, and the effect of suppressing volume expansion is reduced. When a different metal is substituted for Cu (z> 0), the effect of suppressing the volume expansion of Li x Cu 1-y M1 y O 2 becomes higher. If it is 0.3 or less, the crystallinity tends to be high, and the effect of suppressing volume expansion is high. Therefore, a preferable range is 0 <z ≦ 0.3.
　正極合剤層１０２中のＬｉｘＣｕ１－ｙＭ１ｙＯ２とＣｕ１－ｚＭ２ｚＯは、以下の比率を満たすことが好ましい。ＬｉｘＣｕ１－ｙＭ１ｙＯ２のＸ線回折ピークＩ（０１１）のピーク強度と、Ｃｕ１－ｚＭ２ｚＯのＸ線回折ピークＩ（０２０）のピーク強度比により、それぞれの相の存在割合を規定することができる。なお、ＬｉｘＣｕ１－ｙＭ１ｙＯ２のＸ線回折ピークＩ（０１１）のピークはＣｕＫα線を用いたＸ線回折測定にて２５°～２７°付近に生じる。Ｃｕ１－ｚＭ２ｚＯのＸ線回折ピークＩ（０２０）のピークはＣｕＫα線を用いたＸ線回折測定にて４１°～４３°付近に生じる。なお、測定試料には、正極合剤層１０２を全体的に削って得た粉末を用いる。ピーク強度比Ｉ（０１１）／Ｉ（０２０）が０．５以上１０以下であれば、初回充電時にリチウムを負極に供給し、負極初回不可逆容量を補填する効果、かつ、Ｃｕ１－ｚＭ２ｚＯ相がＬｉｘＣｕ１－ｙＭ１ｙＯ２相の体積膨張を抑え込む効果が十分に得られる。一方で、ピーク強度比Ｉ（０１１）／Ｉ（０２０）が０．５未満の場合は、初回充電時にリチウムを負極に供給する効果が殆どない。また、ピーク強度比Ｉ（０１１）／Ｉ（０２０）が１０を超えると、体積膨張が大きくなり、電池貯蔵時にＣｕの溶出が加速される。上記理由から、より好ましい範囲は、０．５以上５以下である。 The Li x Cu 1-y M1 y O 2 and Cu 1-z M2 z O in the positive electrode mixture layer 102 preferably satisfy the following ratio. Depending on the peak intensity ratio of the X-ray diffraction peak I (011) of Li x Cu 1-y M1 y O 2 and the X-ray diffraction peak I (020) of Cu 1-z M2 z O, The existence ratio can be defined. The peak of the X-ray diffraction peak I (011) of Li x Cu 1-y M1 y O 2 occurs in the vicinity of 25 ° to 27 ° by X-ray diffraction measurement using CuKα rays. The peak of the X-ray diffraction peak I (020) of Cu 1-z M2 z O occurs in the vicinity of 41 ° to 43 ° by X-ray diffraction measurement using CuKα rays. Note that a powder obtained by scraping the positive electrode mixture layer 102 as a whole is used as a measurement sample. When the peak intensity ratio I (011) / I (020) is 0.5 or more and 10 or less, the effect of supplying lithium to the negative electrode at the time of the initial charge to supplement the negative electrode initial irreversible capacity, and Cu 1−z M2 z The effect that the O phase suppresses the volume expansion of the Li x Cu 1-y M1 y O 2 phase is sufficiently obtained. On the other hand, when the peak intensity ratio I (011) / I (020) is less than 0.5, there is almost no effect of supplying lithium to the negative electrode during the initial charge. On the other hand, when the peak intensity ratio I (011) / I (020) exceeds 10, volume expansion increases and Cu elution is accelerated during battery storage. For the above reason, a more preferable range is 0.5 or more and 5 or less.
　正極合剤層１０２内に存在するＣｕ元素比率は、５ａｔｏｍ％以上３０ａｔｏｍ％以下であることが好ましい。５ａｔｏｍ％未満、あるいは３０ａｔｏｍ％を超えると、Ｃｕの溶出が加速されたり、初回充電時にリチウムを負極に供給したりする効果が薄れる。さらに好ましい範囲は５ａｔｏｍ％以上１５ａｔｏｍ％である。 The ratio of Cu element present in the positive electrode mixture layer 102 is preferably 5 atom% or more and 30 atom% or less. If it is less than 5 atom% or more than 30 atom%, the elution of Cu is accelerated or the effect of supplying lithium to the negative electrode during the initial charge is reduced. A more preferable range is 5 atom% or more and 15 atom%.
　正極合剤層１０２内に存在するＣｕ元素比率は、誘導結合プラズマ発光分析（ＩＣＰ－ＡＥＳ：Ｉｎｄｕｃｔｉｖｅｌｙ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ　Ａｔｏｍｉｃ　Ｅｍｉｓｓｉｏｎ　Ｓｐｅｃｔｒｏｓｃｏｐｙ）により算出することができる。なお、正極合剤層１０２を全体的に削りとって得た粉末を酸性溶液で溶解処理した溶液を分析する。正極合剤層１０２にはＣｕをはじめ、Ｎｉ、Ｍｎ、Ｌｉ、Ｆ、Ｃ、Ｏ、Ｍ１およびＭ２の金属元素などの元素が観測される。これら全元素中におけるＣｕ元素比率を算出した結果、５ａｔｏｍ％以上３０ａｔｏｍ％以下であることが好ましい。 The ratio of the Cu element present in the positive electrode mixture layer 102 can be calculated by inductively coupled plasma emission analysis (ICP-AES: Inductively Coupled Plasma Atomic Emission Spectroscopy). A solution obtained by dissolving the powder obtained by scraping the positive electrode mixture layer 102 as a whole with an acidic solution is analyzed. Elements such as Cu, Ni, Mn, Li, F, C, O, M1, and M2 metal elements are observed in the positive electrode mixture layer 102. As a result of calculating the Cu element ratio in all these elements, it is preferably 5 atom% or more and 30 atom% or less.
　正極合剤層１０２に含まれる導電剤は、例えば、アセチレンブラック、カーボンブラック、黒鉛が挙げられる。 Examples of the conductive agent contained in the positive electrode mixture layer 102 include acetylene black, carbon black, and graphite.
　正極合剤層１０２に含まれる結着剤は、例えば、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン（ＰＶｄＦ）、フッ素系ゴム、エチレン-ブタジエンゴム（ＳＢＲ）、ポリプロピレン（ＰＰ）、ポリエチレン（ＰＥ）、カルボキシメチルセルロース（ＣＭＣ）、ポリイミド（ＰＩ）、ポリアクリルイミド（ＰＡＩ）が挙げられる。 Examples of the binder contained in the positive electrode mixture layer 102 include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, ethylene-butadiene rubber (SBR), polypropylene (PP), and polyethylene (PE). ), Carboxymethylcellulose (CMC), polyimide (PI), and polyacrylimide (PAI).
　正極合剤層１０２に含まれる、活物質（複合金属リチウム酸化物と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物の合計）、導電剤および結着剤の好ましい配合割合は、活物質が８０質量％以上９５質量％以下であり、導電剤が３質量％以上２０質量％以下であり、結着剤が２質量％以上７質量％以下である。 An active material (a composite metal lithium oxide, at least one compound represented by a chemical formula of Li x Cu 1-y M1 y O 2 , and Cu 1-z M2 z O contained in the positive electrode mixture layer 102; The preferable blending ratio of the one or more compounds represented by the chemical formula), the conductive agent and the binder is 80% by mass to 95% by mass of the active material, and 3% by mass to 20% by mass of the conductive agent. The binder is 2 mass% or more and 7 mass% or less.
（実施形態２）
　実施形態２に係る非水電解質二次電池を説明する。
　第実施形態に係る非水電解質二次電池は、外装材と、外装材内に収納された正極と、外装材内に正極と空間的に離間して、例えばセパレータを介在して収納された負極と、外装材内に充填された非水電解質とを具備する。 (Embodiment 2)
A nonaqueous electrolyte secondary battery according to Embodiment 2 will be described.
The nonaqueous electrolyte secondary battery according to the embodiment includes an exterior material, a positive electrode accommodated in the exterior material, and a negative electrode that is spatially separated from the positive electrode in the exterior material, for example, via a separator. And a non-aqueous electrolyte filled in the exterior material.
　実施形態に係る非水電解質二次電池２００の一例を示した図２の概念図を参照してより詳細に説明する。図２は、外装材２０２がラミネートフィルムからなる扁平型非水電解質二次電池２００の断面概念図である。 A more detailed description will be given with reference to the conceptual diagram of FIG. 2 showing an example of the non-aqueous electrolyte secondary battery 200 according to the embodiment. FIG. 2 is a conceptual cross-sectional view of a flat type nonaqueous electrolyte secondary battery 200 in which the exterior material 202 is made of a laminate film.
　扁平状の捲回電極群２０１は、２枚の樹脂層の間にアルミニウム箔を介在したラミネートフィルムからなる外装材２０２内に収納されている。扁平状の捲回電極群２０１は、一部を抜粋した概念図である図３に示すように、負極２０３、セパレータ２０４、正極２０５、セパレータ２０４の順で積層されている。そして積層物を渦巻状に捲回し、プレス成型することにより形成されたものである。外装材２０２に最も近い電極は負極であり、この負極は、外装材２０２側の負極集電体には、負極合剤が形成されておらず、負極集電体の電池内面側の片面のみに負極合剤を形成した構成を有する。その他の負極２０３は、負極集電体の両面に負極合剤を形成して構成されている。正極２０５は、正極集電体の両面に正極合剤層を形成して構成されている。 The flat wound electrode group 201 is housed in an exterior material 202 made of a laminate film in which an aluminum foil is interposed between two resin layers. The flat wound electrode group 201 is laminated in the order of a negative electrode 203, a separator 204, a positive electrode 205, and a separator 204, as shown in FIG. And it is formed by winding the laminate in a spiral shape and press-molding it. The electrode closest to the packaging material 202 is a negative electrode, and this negative electrode has no negative electrode mixture formed on the negative electrode current collector on the packaging material 202 side, and is only on one side of the negative electrode current collector on the battery inner surface side. It has the structure which formed the negative mix. The other negative electrode 203 is configured by forming a negative electrode mixture on both surfaces of the negative electrode current collector. The positive electrode 205 is configured by forming a positive electrode mixture layer on both surfaces of a positive electrode current collector.
　捲回電極群２０１の外周端近傍において、負極端子は最外殻の負極２０３の負極集電体に電気的に接続され、正極端子は内側の正極２０５の正極集電体に電気的に接続されている。これらの負極端子２０６及び正極端子２０７は、外装材２０２の開口部から外部に延出されている。例えば質状非水電解質は、外装材２０２の開口部から注入されている。外装材２０２の開口部を負極端子２０６及び正極端子２０７を挟んでヒートシールすることにより捲回電極群２０１及び質状非水電解質を密封している。 In the vicinity of the outer peripheral end of the wound electrode group 201, the negative electrode terminal is electrically connected to the negative electrode current collector of the outermost negative electrode 203, and the positive electrode terminal is electrically connected to the positive electrode current collector of the inner positive electrode 205. ing. The negative electrode terminal 206 and the positive electrode terminal 207 are extended from the opening of the exterior material 202 to the outside. For example, the quality non-aqueous electrolyte is injected from the opening of the exterior material 202. The wound electrode group 201 and the quality non-aqueous electrolyte are sealed by heat-sealing the opening of the exterior material 202 with the negative electrode terminal 206 and the positive electrode terminal 207 interposed therebetween.
　負極端子２０６は、例えばアルミニウムまたはＭｇ、Ｔｉ、Ｚｎ、Ｍｎ、Ｆｅ、Ｃｕ、Ｓｉ等の元素を含むアルミニウム合金が挙げられる。負極端子２０６は、負極集電体との接触抵抗を低減するために、負極集電体と同様の材料であることが好ましい。
　正極端子２０７は、リチウムイオン金属に対する電位が３～４．２５Ｖの範囲における電気的安定性と導電性とを備える材料を用いることができる。具体的には、アルミニウムまたはＭｇ、Ｔｉ、Ｚｎ、Ｍｎ、Ｆｅ、Ｃｕ、Ｓｉ等の元素を含むアルミニウム合金が挙げられる。正極端子２０７は、正極集電体との接触抵抗を低減するために、正極集電体と同様の材料であることが好ましい。 Examples of the negative electrode terminal 206 include aluminum or an aluminum alloy containing elements such as Mg, Ti, Zn, Mn, Fe, Cu, and Si. The negative electrode terminal 206 is preferably made of the same material as the negative electrode current collector in order to reduce the contact resistance with the negative electrode current collector.
The positive electrode terminal 207 can be made of a material having electrical stability and conductivity in the range of 3 to 4.25 V with respect to the lithium ion metal. Specifically, aluminum or an aluminum alloy containing an element such as Mg, Ti, Zn, Mn, Fe, Cu, or Si can be given. The positive electrode terminal 207 is preferably made of the same material as the positive electrode current collector in order to reduce the contact resistance with the positive electrode current collector.
　以下、非水電解質二次電池２００の構成部材である外装材２０２、正極２０５、電解質、セパレータ２０４について詳細に説明する。 Hereinafter, the exterior material 202, the positive electrode 205, the electrolyte, and the separator 204, which are constituent members of the nonaqueous electrolyte secondary battery 200, will be described in detail.
１）外装材２０２
　外装材２０２は、厚さ０．５ｍｍ以下のラミネートフィルムから形成される。或いは、外装材は厚さ１．０ｍｍ以下の金属製容器が用いられる。金属製容器は、厚さ０．５ｍｍ以下であることがより好ましい。 1) Exterior material 202
The exterior material 202 is formed from a laminate film having a thickness of 0.5 mm or less. Alternatively, a metal container having a thickness of 1.0 mm or less is used as the exterior material. The metal container is more preferably 0.5 mm or less in thickness.
　外装材２０２の形状は、扁平型（薄型）、角型、円筒型、コイン型、及びボタン型から選択できる。外装材の例には、電池寸法に応じて、例えば携帯用電子機器等に積載される小型電池用外装材、二輪乃至四輪の自動車等に積載される大型電池用外装材などが含まれる。 The shape of the exterior material 202 can be selected from a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type. Examples of the exterior material include, for example, an exterior material for a small battery that is loaded on a portable electronic device or the like, an exterior material for a large battery that is loaded on a two- to four-wheeled vehicle, etc., depending on the battery size.
　ラミネートフィルムは、樹脂層間に金属層を介在した多層フィルムが用いられる。金属層は、軽量化のためにアルミニウム箔若しくはアルミニウム合金箔が好ましい。樹脂層は、例えばポリプロピレン（ＰＰ）、ポリエチレン（ＰＥ）、ナイロン、ポリエチレンテレフタレート（ＰＥＴ）等の高分子材料を用いることができる。ラミネートフィルムは、熱融着によりシールを行って外装材の形状に成形することができる。 As the laminate film, a multilayer film in which a metal layer is interposed between resin layers is used. The metal layer is preferably an aluminum foil or an aluminum alloy foil for weight reduction. For the resin layer, for example, a polymer material such as polypropylene (PP), polyethylene (PE), nylon, polyethylene terephthalate (PET) can be used. The laminate film can be molded into the shape of an exterior material by sealing by heat sealing.
　金属製容器は、アルミニウムまたはアルミニウム合金等から作られる。アルミニウム合金は、マグネシウム、亜鉛、ケイ素等の元素を含む合金が好ましい。合金中に鉄、銅、ニッケル、クロム等の遷移金属が含まれる場合、その量は１００質量ｐｐｍ以下にすることが好ましい。 Metal containers are made from aluminum or aluminum alloy. The aluminum alloy is preferably an alloy containing elements such as magnesium, zinc, and silicon. When transition metals such as iron, copper, nickel, and chromium are included in the alloy, the amount is preferably 100 ppm by mass or less.
２）正極２０５
　正極２０５には、実施形態１の正極を用いることが好ましい。 2) Positive electrode 205
As the positive electrode 205, the positive electrode of Embodiment 1 is preferably used.
３）負極２０３
　負極２０３は、集電体と集電体上に負極合剤層とを有する。負極合剤層は、負極集電体の片面または両面に形成される。負極合剤層は、少なくとも負極活物質を含む。負極合剤層は、例えば、活物質と、導電剤と、結着剤とを有する。負極２０３の活物質は、負極に用いられるものであればよいが、上述の初期充電効率の観点から、好適な負極の活物質は、例えば、炭素質物相と、炭素質物相中に分散されたシリコン相またはスズ相と、炭素質物相中に分散されたシリコン酸化物またはスズ酸化物を含む複合粒子である。 3) Negative electrode 203
The negative electrode 203 has a current collector and a negative electrode mixture layer on the current collector. The negative electrode mixture layer is formed on one side or both sides of the negative electrode current collector. The negative electrode mixture layer includes at least a negative electrode active material. The negative electrode mixture layer includes, for example, an active material, a conductive agent, and a binder. The active material of the negative electrode 203 may be any material as long as it is used for the negative electrode. However, from the viewpoint of the initial charging efficiency described above, a suitable negative electrode active material is dispersed in, for example, a carbonaceous material phase and a carbonaceous material phase. Composite particles containing a silicon phase or tin phase and silicon oxide or tin oxide dispersed in a carbonaceous material phase.
　上述のようなグラファイト負極よりも放電容量が大きくなる活物質を有する負極は、実施形態の正極の効果を最も引き出すことができるため好都合である。 A negative electrode having an active material having a discharge capacity larger than that of the graphite negative electrode as described above is advantageous because it can maximize the effects of the positive electrode of the embodiment.
　負極２０３の炭素質物は、炭素質物としては、グラファイト、ハードカーボン、ソフトカーボン、アモルファス炭素とアセチレンブラックからなる群から選ばれる１種類以上を用いることができる。炭素質物は、負極活物質に強度を与え、負極活物質を形作る。 As the carbonaceous material of the negative electrode 203, one or more types selected from the group consisting of graphite, hard carbon, soft carbon, amorphous carbon, and acetylene black can be used. The carbonaceous material gives strength to the negative electrode active material and forms the negative electrode active material.
　負極導電剤は、通常、炭素材料が使用される。炭素材料は、アルカリ金属の吸蔵性と導電性との両特性の高いものがあればよい。炭素材料の例は、アセチレンブラックまたはカーボンブラックを含み、結晶性の高いグラファイトでも構わない。 As the negative electrode conductive agent, a carbon material is usually used. The carbon material only needs to have high alkali metal occlusion and conductivity. Examples of the carbon material may include acetylene black or carbon black, and may be graphite having high crystallinity.
　結着剤の例は、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン（ＰＶｄＦ）、フッ素系ゴム、エチレン-ブタジエンゴム（ＳＢＲ）、ポリプロピレン（ＰＰ）、ポリエチレン（ＰＥ）、カルボキシメチルセルロース（ＣＭＣ）、ポリイミド（ＰＩ）、ポリアクリルイミド（ＰＡＩ）を含む。 Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, ethylene-butadiene rubber (SBR), polypropylene (PP), polyethylene (PE), carboxymethyl cellulose (CMC), Includes polyimide (PI) and polyacrylimide (PAI).
　負極合剤層に含まれる、活物質、導電剤および結着剤の好ましい配合割合は、負極活物質が７０質量％以上９５質量％以下であり、導電剤が０質量％以上２５質量％以下であり、結着剤が２質量％以上１０質量％以下であることが好ましい。 A preferable blending ratio of the active material, the conductive agent, and the binder contained in the negative electrode mixture layer is 70% by mass to 95% by mass of the negative electrode active material, and 0% by mass to 25% by mass of the conductive agent. And the binder is preferably 2% by mass or more and 10% by mass or less.
４）非水電解質
　非水電解質は、非水溶媒に電解質を溶解することにより調製される。
　非水溶媒は、リチウム電池で公知の非水溶媒を用いることができる。非水溶媒の例は、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）のような環状カーボネート；環状カーボネートとこの環状カーボネートより低粘度の非水溶媒（以下第２の溶媒）との混合溶媒を含む。 4) Nonaqueous electrolyte A nonaqueous electrolyte is prepared by dissolving an electrolyte in a nonaqueous solvent.
As the non-aqueous solvent, a known non-aqueous solvent for a lithium battery can be used. Examples of non-aqueous solvents include cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC); mixed solvents of cyclic carbonate and a non-aqueous solvent having a viscosity lower than that of the cyclic carbonate (hereinafter referred to as second solvent). .
　第２の溶媒の例は、ジメチルカーボネート、メチルエチルカーボネートまたはジエチルカーボネートのような鎖状カーボネート；γ-ブチロラクトン、アセトニトリル、プロピオン酸メチル、プロピオン酸エチル；テトラヒドロフランまたは２－メチルテトラヒドロフランのような環状エーテル；ジメトキシエタンまたはジエトキシエタンのような鎖状エーテルを含む。 Examples of second solvents are linear carbonates such as dimethyl carbonate, methyl ethyl carbonate or diethyl carbonate; γ-butyrolactone, acetonitrile, methyl propionate, ethyl propionate; cyclic ethers such as tetrahydrofuran or 2-methyltetrahydrofuran; Includes chain ethers such as dimethoxyethane or diethoxyethane.
　電解質は、アルカリ塩が挙げられる、特にリチウム塩が好ましい。リチウム塩の例は、六フッ化リン酸リチウム（ＬｉＰＦ６）、四フッ化硼酸リチウム（ＬｉＢＦ４）、六フッ化ヒ素リチウム（ＬｉＡｓＦ６）、過塩素酸リチウム（ＬｉＣｌＯ４）、またはトリフルオロメタスルホン酸リチウム（ＬｉＣＦ３ＳＯ３）を含む。特に、六フッ化リン酸リチウム（ＬｉＰＦ６）、四フッ化硼酸リチウム（ＬｉＢＦ４）が好ましい。電解質は、非水溶媒に対して０．５～２モル／Ｌ溶解することが好ましい。 Examples of the electrolyte include alkali salts, and lithium salts are particularly preferable. Examples of lithium salts are lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluoroarsenide (LiAsF 6 ), lithium perchlorate (LiClO 4 ), or trifluorometa Lithium sulfonate (LiCF 3 SO 3 ) is included. In particular, lithium hexafluorophosphate (LiPF 6 ) and lithium tetrafluoroborate (LiBF 4 ) are preferable. The electrolyte is preferably dissolved at 0.5 to 2 mol / L in the non-aqueous solvent.
　セパレータは、正極および負極が接触するのを防止するためのものであり、絶縁性材料で構成される。さらに、正極および負極の間を電解質が移動可能な形状のものが使用される。具体的には、例えば合成樹脂製不織布、ポリエチレン多孔質フィルム、ポリプロピレン多孔質フィルム、またはセルロース系のセパレータを用いることができる。 The separator is for preventing the positive electrode and the negative electrode from coming into contact, and is made of an insulating material. Furthermore, a shape in which the electrolyte can move between the positive electrode and the negative electrode is used. Specifically, for example, a synthetic resin nonwoven fabric, a polyethylene porous film, a polypropylene porous film, or a cellulose-based separator can be used.
（実施形態３）
　次に、実施形態３に係る電池パックを説明する。
　実施形態３に係る電池パックは、上記実施形態２に係る非水電解質二次電池（即ち、単電池）を一以上有する。電池パックに複数の単電池が含まれる場合、各単電池は、電気的に直列、並列、或いは、直列と並列に接続して配置される。
　図４の概念図及び図５のブロック図を参照して電池パック３００を具体的に説明する。図４に示す電池パック３００では、単電池３０１として図２に示す扁平型非水電解質電池２００を使用している。 (Embodiment 3)
Next, the battery pack according to Embodiment 3 will be described.
The battery pack according to the third embodiment includes one or more non-aqueous electrolyte secondary batteries (that is, single cells) according to the second embodiment. When the battery pack includes a plurality of single cells, the single cells are electrically connected in series, parallel, or connected in series and parallel.
The battery pack 300 will be specifically described with reference to the conceptual diagram of FIG. 4 and the block diagram of FIG. In the battery pack 300 shown in FIG. 4, the flat type nonaqueous electrolyte battery 200 shown in FIG. 2 is used as the unit cell 301.
　複数の単電池３０１は、外部に延出した負極端子３０２及び正極端子３０３が同じ向きに揃えられるように積層され、粘着テープ３０４で締結することにより組電池３０５を構成している。これらの単電池３０１は、図５に示すように互いに電気的に直列に接続されている。 The plurality of single cells 301 are stacked such that the negative electrode terminal 302 and the positive electrode terminal 303 extending to the outside are aligned in the same direction, and are fastened with an adhesive tape 304 to constitute an assembled battery 305. These unit cells 301 are electrically connected to each other in series as shown in FIG.
　プリント配線基板３０６は、負極端子３０２及び正極端子３０３が延出する単電池３０１側面と対向して配置されている。プリント配線基板３０６には、図５に示すようにサーミスタ３０７、保護回路３０８及び外部機器への通電用端子３０９が搭載されている。なお、組電池３０５と対向するプリント配線基板３０６の面には組電池３０５の配線と不要な接続を回避するために絶縁板（図示せず）が取り付けられている。 The printed wiring board 306 is disposed to face the side surface of the unit cell 301 from which the negative electrode terminal 302 and the positive electrode terminal 303 extend. On the printed wiring board 306, as shown in FIG. 5, a thermistor 307, a protection circuit 308, and a terminal 309 for energizing external devices are mounted. An insulating plate (not shown) is attached to the surface of the printed wiring board 306 facing the assembled battery 305 in order to avoid unnecessary connection with the wiring of the assembled battery 305.
　正極側リード３１０は、組電池３０５の最下層に位置する正極端子３０３に接続され、その先端はプリント配線基板３０６の正極側コネクタ３１１に挿入されて電気的に接続されている。負極側リード３１２は、組電池３０５の最上層に位置する負極端子３０２に接続され、その先端はプリント配線基板３０６の負極側コネクタ３１３に挿入されて電気的に接続されている。これらのコネクタ３１１、３１３は、プリント配線基板３０６に形成された配線３１４、３１５を通して保護回路３０８に接続されている。 The positive electrode side lead 310 is connected to the positive electrode terminal 303 located at the lowermost layer of the assembled battery 305, and the tip thereof is inserted into the positive electrode side connector 311 of the printed wiring board 306 and electrically connected thereto. The negative electrode side lead 312 is connected to the negative electrode terminal 302 located on the uppermost layer of the assembled battery 305, and the tip thereof is inserted into and electrically connected to the negative electrode side connector 313 of the printed wiring board 306. These connectors 311 and 313 are connected to the protection circuit 308 through wirings 314 and 315 formed on the printed wiring board 306.
　サーミスタ３０７は、単電池３０５の温度を検出するために用いられ、その検出信号は保護回路３０８に送信される。保護回路３０８は、所定の条件で保護回路３０８と外部機器への通電用端子３０９との間のプラス側配線３１６ａ及びマイナス側配線３１６ｂを遮断できる。所定の条件とは、例えばサーミスタ３０７の検出温度が所定温度以上になったときである。また、所定の条件とは単電池３０１の過充電、過放電、過電流等を検出したときである。この過充電等の検出は、個々の単電池３０１もしくは単電池３０１全体について行われる。個々の単電池３０１を検出する場合、電池電圧を検出してもよいし、正極電位もしくは負極電位を検出してもよい。後者の場合、個々の単電池３０１中に参照極として用いるリチウム電極が挿入される。図４及び図５の場合、単電池３０１それぞれに電圧検出のための配線３１７を接続し、これら配線３１７を通して検出信号が保護回路３０８に送信される。 The thermistor 307 is used to detect the temperature of the unit cell 305, and the detection signal is transmitted to the protection circuit 308. The protection circuit 308 can cut off the plus-side wiring 316a and the minus-side wiring 316b between the protection circuit 308 and the terminal 309 for energizing external devices under a predetermined condition. The predetermined condition is, for example, when the temperature detected by the thermistor 307 is equal to or higher than a predetermined temperature. The predetermined condition is when an overcharge, overdischarge, overcurrent, or the like of the unit cell 301 is detected. This detection of overcharge or the like is performed for each single cell 301 or the entire single cell 301. When detecting each single cell 301, the battery voltage may be detected, or the positive electrode potential or the negative electrode potential may be detected. In the latter case, a lithium electrode used as a reference electrode is inserted into each unit cell 301. 4 and 5, a voltage detection wiring 317 is connected to each single cell 301, and a detection signal is transmitted to the protection circuit 308 through the wiring 317.
　正極端子３０３及び負極端子３０２が突出する側面を除く組電池３０５の三側面には、ゴムもしくは樹脂からなる保護シート３１８がそれぞれ配置されている。
　組電池３０５は、各保護シート３１８及びプリント配線基板３０６と共に収納容器３１９内に収納される。すなわち、収納容器３１９の長辺方向の両方の内側面と短辺方向の内側面それぞれに保護シート３１８が配置され、短辺方向の反対側の内側面にプリント配線基板３０６が配置される。組電池３０５は、保護シート３１８及びプリント配線基板３０６で囲まれた空間内に位置する。蓋３２０は、収納容器３１９の上面に取り付けられている。 Protective sheets 318 made of rubber or resin are disposed on the three side surfaces of the assembled battery 305 excluding the side surfaces from which the positive electrode terminal 303 and the negative electrode terminal 302 protrude.
The assembled battery 305 is stored in the storage container 319 together with each protective sheet 318 and the printed wiring board 306. That is, the protective sheet 318 is disposed on each of the inner side surface in the long side direction and the inner side surface in the short side direction of the storage container 319, and the printed wiring board 306 is disposed on the inner side surface on the opposite side in the short side direction. The assembled battery 305 is located in a space surrounded by the protective sheet 318 and the printed wiring board 306. The lid 320 is attached to the upper surface of the storage container 319.
　なお、組電池３０５の固定には粘着テープ３０４に代えて、熱収縮テープを用いてもよい。この場合、組電池の両側面に保護シートを配置し、熱収縮テープを周回させた後、熱収縮テープを熱収縮させて組電池を結束させる。 In addition, instead of the adhesive tape 304, a heat shrink tape may be used for fixing the assembled battery 305. In this case, protective sheets are arranged on both side surfaces of the assembled battery, the heat shrinkable tape is circulated, and then the heat shrinkable tape is heat shrunk to bind the assembled battery.
　図４、図５では単電池３０１を直列接続した形態を示したが、電池容量を増大させるためには並列に接続しても、または直列接続と並列接続を組み合わせてもよい。組み上がった電池パックをさらに直列、並列に接続することもできる。
　以上記載した本実施形態によれば、上記実施形態２における優れた充放電サイクル性能を有する非水電解質二次電池を備えることにより、優れた充放電サイクル性能を有する電池パックを提供することができる。 4 and 5 show the configuration in which the unit cells 301 are connected in series, but in order to increase the battery capacity, they may be connected in parallel, or a combination of series connection and parallel connection may be used. The assembled battery packs can be further connected in series and in parallel.
According to this embodiment described above, a battery pack having excellent charge / discharge cycle performance can be provided by including the nonaqueous electrolyte secondary battery having excellent charge / discharge cycle performance in the second embodiment. .
　なお、電池パックの態様は用途により適宜変更される。電池パックの用途は、大電流を取り出したときに優れたサイクル特性を示すものが好ましい。具体的には、デジタルカメラの電源用や、二輪乃至四輪のハイブリッド電気自動車、二輪乃至四輪の電気自動車、アシスト自転車等の車載用が挙げられる。特に、高温特性の優れた非水電解質二次電池を用いた電池パックは車載用に好適に用いられる。
　以下に具体的な実施例を挙げ、その効果について述べる。 In addition, the aspect of a battery pack is changed suitably by a use. The battery pack is preferably one that exhibits excellent cycle characteristics when a large current is taken out. Specific examples include a power source for a digital camera, a vehicle for a two- to four-wheel hybrid electric vehicle, a two- to four-wheel electric vehicle, an assist bicycle, and the like. In particular, a battery pack using a nonaqueous electrolyte secondary battery having excellent high temperature characteristics is suitably used for in-vehicle use.
Specific examples will be given below and their effects will be described.
　以下、実施形態の実施例について説明する。
（実施例１）
　＜正極の作製＞
　活物質であるリチウムニッケルマンガンコバルト複合酸化物（ＬｉＮｉ１／３Ｍｎ１／３Ｃｏ１／３Ｏ２）粉末８０重量％と、Ｌｉ２Ｃｕ０．９Ｎｉ０．１Ｏ２粉末１０重量％、Ｃｕ０．８５Ｎｉ０．１５Ｏ粉末２重量％、アセチレンブラック３重量％とポリフッ化ビニリデン（ＰＶｄＦ）５重量％とをＮ－メチルピロリドンに加えて混合してスラリーを調製した。このスラリーを厚さ１５μｍのアルミニウム箔（集電体）に塗布し、乾燥後、プレスすることにより密度３．２ｇ／ｃｍ３の正極層を有する正極を作製した。
　一方、比較のためにアセチレンブラック、ポリフッ化ビニリデンなど容量に寄与しない副部材量をそのままに、銅複合酸化物およびリチウム銅複合酸化物を加えない正極もあわせて作製した。 Examples of the embodiment will be described below.
Example 1
<Preparation of positive electrode>
80% by weight of lithium nickel manganese cobalt composite oxide (LiNi 1/3 Mn 1/3 Co 1/3 O 2 ) powder as an active material, 10% by weight of Li 2 Cu 0.9 Ni 0.1 O 2 powder, A slurry was prepared by adding 2% by weight of Cu 0.85 Ni 0.15 O powder, 3% by weight of acetylene black and 5% by weight of polyvinylidene fluoride (PVdF) to N-methylpyrrolidone and mixing them. This slurry was applied to an aluminum foil (current collector) having a thickness of 15 μm, dried, and pressed to prepare a positive electrode having a positive electrode layer with a density of 3.2 g / cm 3 .
On the other hand, for comparison, a positive electrode without adding a copper composite oxide and a lithium copper composite oxide was also produced while maintaining the amount of auxiliary members such as acetylene black and polyvinylidene fluoride that do not contribute to capacity.
　＜負極の作製＞
　シリコン（Ｓｉ）粉末２５重量％、シリコン酸化物（ＳｉＯ）粉末３０重量％、とハードカーボン粉末２０重量％とグラファイト粉末２０重量％とポリイミド（ＰＩ）５重量％をＮＭＰに加えて混合してスラリーを調製した。このスラリーを厚さ１０μｍの銅箔（集電体）に塗布し、乾燥し、プレスし、真空雰囲気下にて銅の蒸着を実施した。その後、酸素濃度２～５％含まれるアルゴンガス中にて５００℃、８時間加熱することにより密度２．０ｇ／ｃｍ３の負極層を有する負極を作製した。 <Production of negative electrode>
A slurry prepared by adding 25% by weight of silicon (Si) powder, 30% by weight of silicon oxide (SiO) powder, 20% by weight of hard carbon powder, 20% by weight of graphite powder and 5% by weight of polyimide (PI) to NMP and mixing them. Was prepared. This slurry was applied to a copper foil (current collector) having a thickness of 10 μm, dried, pressed, and copper was deposited in a vacuum atmosphere. Then, a negative electrode having a negative electrode layer with a density of 2.0 g / cm 3 was produced by heating at 500 ° C. for 8 hours in an argon gas containing 2 to 5% oxygen concentration.
　＜電極群の作製＞
　前記正極、ポリエチレン製多孔質フィルムからなるセパレータ、前記負極および前記セパレータをそれぞれこの順序で積層した後、前記負極が最外周に位置するように渦巻状に捲回して電極群を作製した。 <Production of electrode group>
The positive electrode, a separator made of a polyethylene porous film, the negative electrode, and the separator were laminated in this order, and then wound in a spiral shape so that the negative electrode was located on the outermost periphery, thereby producing an electrode group.
　＜非水電解質の調製＞
　エチレンカーボネート（ＥＣ）とメチルエチルカーボネート（ＭＥＣ）とを体積比で１：２になるように混合して混合溶媒とした。この混合溶媒に六フッ化リン酸リチウム（ＬｉＰＦ６）を１．０モル／Ｌ溶解して非水電解質を調製した。
　前記電極群および前記非水電解質をステンレス製の有底円筒状容器内にそれぞれ収納した。つづいて、負極リードの一端を電極群の負極に接続し、その他端を負極端子を兼ねる有底円筒状容器に接続した。ひきつづき、中央に正極端子が嵌着された絶縁封口板を用意した。正極リードの一端を正極端子に、その他端を電極群の正極に接続した後、絶縁封口板を容器の上部開口部にかしめ加工することにより、１．５Ａｈの容量を持つ円筒形非水電解質二次電池を組み立てた。 <Preparation of non-aqueous electrolyte>
Ethylene carbonate (EC) and methyl ethyl carbonate (MEC) were mixed at a volume ratio of 1: 2 to obtain a mixed solvent. A nonaqueous electrolyte was prepared by dissolving 1.0 mol / L of lithium hexafluorophosphate (LiPF 6 ) in this mixed solvent.
The electrode group and the non-aqueous electrolyte were respectively housed in a stainless steel bottomed cylindrical container. Subsequently, one end of the negative electrode lead was connected to the negative electrode of the electrode group, and the other end was connected to a bottomed cylindrical container that also served as the negative electrode terminal. Subsequently, an insulating sealing plate having a positive terminal fitted in the center was prepared. After connecting one end of the positive electrode lead to the positive electrode terminal and the other end to the positive electrode of the electrode group, the insulating sealing plate is caulked to the upper opening of the container to thereby form a cylindrical non-aqueous electrolyte having a capacity of 1.5 Ah. The next battery was assembled.
　得られた二次電池を、０．２Ｃレート、２５℃環境下にて、４．３Ｖで充電し、１．０Ｖに達するまで０．２Ｃレートで放電した。同様のプロセスで作製した二次電池を、アルゴンボックスで解体し、正極層の分析を実施した。 The obtained secondary battery was charged at 4.3 V in a 0.2 C rate and 25 ° C. environment, and discharged at a 0.2 C rate until 1.0 V was reached. A secondary battery manufactured in the same process was disassembled in an argon box, and the positive electrode layer was analyzed.
　正極層をメチルエチルカーボネート（ＭＥＣ）で３０分間洗浄した後、不活性雰囲気下でＸ線回折測定をＣｕＫα線を用いて実施した。スキャン速度は１°／ｍｉｎで実施した。その結果、正極層内に存在する、ＬｉＮｉ１／３Ｍｎ１／３Ｃｏ１／３Ｏ２と、Ｌｉ２Ｃｕ０．９Ｎｉ０．１Ｏ２と、Ｃｕ０．８５Ｎｉ０．１５Ｏ由来の各種ピークを確認できた。ピークの帰属を実施し、ピークトップの値から、Ｌｉ２Ｃｕ０．９Ｎｉ０．１Ｏ２と、Ｃｕ０．８５Ｎｉ０．１５Ｏの強度比率を算出したところ、Ｉ（０１１）／Ｉ（０２０）は１．３を示した。 After the positive electrode layer was washed with methyl ethyl carbonate (MEC) for 30 minutes, X-ray diffraction measurement was performed using CuKα rays in an inert atmosphere. The scan speed was 1 ° / min. As a result, LiNi 1/3 Mn 1/3 Co 1/3 O 2 , Li 2 Cu 0.9 Ni 0.1 O 2 , and Cu 0.85 Ni 0.15 O are present in the positive electrode layer. Various peaks were confirmed. The assignment of peaks was performed, and the intensity ratio of Li 2 Cu 0.9 Ni 0.1 O 2 and Cu 0.85 Ni 0.15 O was calculated from the peak top value, and I (011) / I (020) showed 1.3.
　また、正極の電極から約５ｇ程度スパチュラで正極層を掻き出し、ＩＣＰ発光分析を実施した。その結果、全元素に占めるＣｕの割合は、８ａｔｏｍ％であった。 Further, the positive electrode layer was scraped out from the positive electrode with about 5 g with a spatula, and ICP emission analysis was performed. As a result, the ratio of Cu in all elements was 8 atom%.
（実施例２～２１）
　負極電極にあわせて、正極層内のリチウム銅複合酸化物ならびに銅複合酸化物を表１と表２の構成になるように適宜調整しながら、実施例１と同じように非水電解質二次電池を作製した。 (Examples 2 to 21)
In accordance with the negative electrode, the lithium-copper composite oxide and the copper composite oxide in the positive electrode layer were appropriately adjusted so as to have the configurations shown in Tables 1 and 2, and the non-aqueous electrolyte secondary battery as in Example 1 Was made.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
（実施例２２）
　正極の電位の関係上、作製した二次電池を、０．２Ｃレート、２５℃環境下にて、３．６Ｖで充電し、１．０Ｖに達するまで０．２Ｃレートで放電したこと以外は、負極電極にあわせて、正極層内のリチウム銅複合酸化物ならびに銅複合酸化物を表１と表２の構成になるように適宜調整しながら、実施例１～２１と同様に実施した。 (Example 22)
Due to the potential of the positive electrode, the produced secondary battery was charged at 3.6 V under a 0.2 C rate and 25 ° C. environment, and discharged at a 0.2 C rate until reaching 1.0 V. In accordance with the negative electrode, the lithium copper composite oxide and the copper composite oxide in the positive electrode layer were appropriately adjusted so as to have the configurations shown in Tables 1 and 2, and the same procedures as in Examples 1 to 21 were performed.
（比較例１～３）
　正極および負極電極を表１と表２の構成になるように適宜調整しながら、実施例１と同じように非水電解質二次電池を作製した。 (Comparative Examples 1 to 3)
A nonaqueous electrolyte secondary battery was produced in the same manner as in Example 1 while appropriately adjusting the positive electrode and the negative electrode to have the configurations shown in Tables 1 and 2.
　実施例１～２２および、比較例１～２の電池について、容量確認を実施した。容量確認においては、実施例１～２１および比較例１については４．３Ｖ～２．０Ｖの範囲にて充放電ともに０．２Ｃレートで実施した。一方、実施例２２については、３．６Ｖ～１．５Ｖの範囲にて充放電ともに０．２Ｃレートで実施した。 The capacity of the batteries of Examples 1 to 22 and Comparative Examples 1 and 2 was confirmed. In the capacity confirmation, Examples 1 to 21 and Comparative Example 1 were performed at a rate of 0.2 C in the range of 4.3 V to 2.0 V for both charging and discharging. On the other hand, for Example 22, charging and discharging were performed at a 0.2 C rate in the range of 3.6 V to 1.5 V.
　実施例１～２２、比較例１については、銅複合酸化物およびリチウム銅複合酸化物を加えなかった場合の容量を同時に測定して、それらを１とした場合の銅複合酸化物およびリチウム銅複合酸化物を加えた電池の容量を表３と表４に示した。 For Examples 1 to 22 and Comparative Example 1, the capacities when the copper composite oxide and the lithium copper composite oxide were not added were measured at the same time. Tables 3 and 4 show the battery capacities to which oxides were added.
　その後、実施例１～２１および比較例１の電池をそれぞれ４．３Ｖに充電し、実施例２２の電池を３．６Ｖに充電し、それぞれ６５℃の環境下に１か月間貯蔵した。その後２５℃に電池温度を下げて、再び０．２Ｃレートで容量確認を実施した。貯蔵後の容量確認した結果を表３と表４に示す。なお表３と表４には、貯蔵前の容量をそれぞれ１として表記した。
容量確認後、不活性雰囲気内にて電池を解体し、電解質中に含まれるＣｕイオンの量をＩＣＰ発光分析にて確認した。その結果を表３と表４に示す。 Thereafter, the batteries of Examples 1 to 21 and Comparative Example 1 were each charged to 4.3 V, the battery of Example 22 was charged to 3.6 V, and each was stored in an environment of 65 ° C. for 1 month. Thereafter, the battery temperature was lowered to 25 ° C., and the capacity was confirmed again at a 0.2 C rate. Tables 3 and 4 show the results of confirming the capacity after storage. In Tables 3 and 4, the capacity before storage is shown as 1.
After confirming the capacity, the battery was disassembled in an inert atmosphere, and the amount of Cu ions contained in the electrolyte was confirmed by ICP emission analysis. The results are shown in Tables 3 and 4.
　また同条件で作製した電池を容量確認で実施した充放電範囲にて１Ｃレートにて５００回２５℃環境下でサイクル試験を実施した。その後、０．２Ｃレートで再び容量確認を実施して、サイクル試験前との容量を比較し、維持率を算出した。結果を表３と表４にあわせて示す。 In addition, a cycle test was performed 500 times at a 1C rate in a 25 ° C. environment in a charge / discharge range in which the battery manufactured under the same conditions was confirmed by capacity check. Thereafter, the capacity was confirmed again at a 0.2 C rate, the capacity before the cycle test was compared, and the maintenance rate was calculated. The results are shown in Table 3 and Table 4.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　比較例１では電池貯蔵後、容量劣化が大きく、かつＣｕの溶出量が大きかった。比較例２では、電池貯蔵後の容量劣化が大きく、Ｃｕの溶出量が大きかったが、銅複合酸化物の効果にて、サイクル維持率は高い傾向があった。比較例３では、Ｃｕの溶出が抑制される傾向があったが、サイクル維持率は低い傾向があった。実施例１～２２については、軒並み改善することが確認された。サイクル試験についても同様な傾向を得た。したがって本結果より、実施形態の妥当性が示されたと考えられる。 In Comparative Example 1, after battery storage, the capacity was greatly deteriorated and the amount of Cu eluted was large. In Comparative Example 2, the capacity deterioration after storage of the battery was large and the amount of elution of Cu was large, but the cycle retention rate tended to be high due to the effect of the copper composite oxide. In Comparative Example 3, the elution of Cu tended to be suppressed, but the cycle retention rate tended to be low. In Examples 1 to 22, it was confirmed that the performance was improved on the whole. The same tendency was obtained for the cycle test. Therefore, it is considered that the validity of the embodiment was shown from this result.
　以上、本発明の実施の形態を説明したが、本発明はこれらに限られず、特許請求の範囲に記載の発明の要旨の範疇において様々に変更可能である。また、本発明は、実施段階ではその要旨を逸脱しない範囲で種々に変形することが可能である。さらに、上記実施形態に開示されている複数の構成要素を適宜組み合わせることにより種々の発明を形成できる。 Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the gist of the invention described in the claims. In addition, the present invention can be variously modified without departing from the scope of the invention in the implementation stage. Furthermore, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment.
１００…非水電解質電池用電極、１０１…負極合剤層、１０２…集電体、１０３…負極活物質、１０４…導電材、１０５…結着剤、２００…非水電解質二次電池、２００…捲回電極群、２０２…外装材、２０３…負極、２０４…セパレータ、２０５…正極、３００…電池パック、３０１…単電池、３０２…負極端子、３０３…正極端子、３０４…粘着テープ、３０５…組電池、３０６…プリント配線基板、３０７…サーミスタ、３０８…保護回路、３０９…通電用端子、３１０…正極側リード、３１１…正極側コネクタ、３１２…負極側リード、３１３…負極側コネクタ、３１４…配線、３１５…配線、３１６ａ…プラス側配線、３１６ｂ…マイナス側配線、３１７…配線、３１８…保護シート、３１９…収納容器、３２０…蓋
 

  DESCRIPTION OF SYMBOLS 100 ... Electrode for nonaqueous electrolyte batteries, 101 ... Negative electrode mixture layer, 102 ... Current collector, 103 ... Negative electrode active material, 104 ... Conductive material, 105 ... Binder, 200 ... Nonaqueous electrolyte secondary battery, 200 ... Winding electrode group, 202 ... exterior material, 203 ... negative electrode, 204 ... separator, 205 ... positive electrode, 300 ... battery pack, 301 ... single cell, 302 ... negative electrode terminal, 303 ... positive electrode terminal, 304 ... adhesive tape, 305 ... set Battery: 306: Printed circuit board, 307: Thermistor, 308: Protection circuit, 309: Terminal for energization, 310: Positive electrode lead, 311: Positive electrode connector, 312: Negative electrode lead, 313: Negative electrode connector, 314: Wiring 315 ... wiring, 316a ... plus side wiring, 316b ... minus side wiring, 317 ... wiring, 318 ... protective sheet, 319 ... storage container, 320 ... lid

Claims (8)

  1. 　集電体と、
    　前記集電体上に正極合剤層を含み、
    　前記正極合剤層は、複合金属リチウム酸化物と、ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物とを少なくとも含み、
    　前記Ｍ１とＭ２は、Ｍｇ、Ｎｉ、Ｃｏ、Ｍｎ、Ａｌ、Ｚｎ、Ｃｒ、Ｔｉ、ＶとＺｒから選ばれる少なくとも１種以上であることを特徴とする非水電解質二次電池用正極。     A current collector,
    A positive electrode mixture layer on the current collector;
    The positive electrode mixture layer is represented by a composite metal lithium oxide, at least one compound represented by a chemical formula of Li x Cu 1-y M1 y O 2, and a chemical formula of Cu 1-z M2 z O. Including at least one or more compounds,
    M1 and M2 are at least one selected from Mg, Ni, Co, Mn, Al, Zn, Cr, Ti, V, and Zr. A positive electrode for a nonaqueous electrolyte secondary battery.
  2. 　前記ＬｉｘＣｕ１－ｙＭ１ｙＯ２の化学式で表される１種以上の化合物のＸ線回折ピーク（０１１）のピーク強度と、Ｃｕ１－ｚＭ２ｚＯの化学式で表される１種以上の化合物のＸ線回折ピーク（０２０）のピーク強度比Ｉ（０１１）／Ｉ（０２０）が０．５以上１０以下であることを特徴とする請求項１に記載の非水電解質二次電池用正極。 The peak intensity of the X-ray diffraction peak (011) of one or more compounds represented by the chemical formula of Li x Cu 1-y M1 y O 2 and one species represented by the chemical formula of Cu 1-z M2 z O 2. The nonaqueous electrolyte secondary battery according to claim 1, wherein a peak intensity ratio I (011) / I (020) of an X-ray diffraction peak (020) of the compound is 0.5 or more and 10 or less. Positive electrode.
  3. 　前記正極合剤層内に存在するＣｕ元素比率は、５ａｔｏｍ％以上３０ａｔｏｍ％以下であることを特徴とする請求項１に記載の非水電解質二次電池用正極。 2. The positive electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein a ratio of Cu element present in the positive electrode mixture layer is 5 atom% or more and 30 atom% or less.
  4. 　前記、ｘ、ｙとｚは、１＜ｘ≦２、０＜ｙ≦０．３と０≦ｚ≦０．５の関係を満たすことを特徴とする請求項１に記載の非水電解質二次電池用正極。 2. The nonaqueous electrolyte secondary according to claim 1, wherein x, y, and z satisfy a relationship of 1 <x ≦ 2, 0 <y ≦ 0.3 and 0 ≦ z ≦ 0.5. Battery positive electrode.
  5. 　外装材と、
    　前記外装材内に収納された前記請求項１ないし４のいずれか１項に記載の正極と、
    　前記外装材内に前記正極と空間的に離間して、セパレータを介在して収納された負極と、
    　前記外装材内に充填された非水電解質とを具備することを特徴とする非水電解質二次電池。     An exterior material,
    The positive electrode according to any one of claims 1 to 4 housed in the exterior material;
    A negative electrode that is spatially separated from the positive electrode in the exterior material, and is housed via a separator;
    A non-aqueous electrolyte secondary battery comprising: a non-aqueous electrolyte filled in the exterior material.
  6. 　前記負極は、集電体と、前記集電体上に負極活物質を少なくとも含む負極合剤層を有し
    　前記負極活物質は、炭素質物相と、炭素質物相中に分散されたシリコン相またはスズ相と、炭素質物相中に分散されたシリコン酸化物またはスズ酸化物を含む複合粒子であることを特徴とする請求項５に記載の非水電解質二次電池。     The negative electrode has a current collector and a negative electrode mixture layer containing at least a negative electrode active material on the current collector. The negative electrode active material includes a carbonaceous material phase and a silicon phase dispersed in the carbonaceous material phase or The nonaqueous electrolyte secondary battery according to claim 5, wherein the nonaqueous electrolyte secondary battery is a composite particle containing a tin phase and silicon oxide or tin oxide dispersed in a carbonaceous material phase.
  7. 　前記請求項５に記載の非水電解質二次電池を一以上有することを特徴とする電池パック。 A battery pack comprising one or more of the nonaqueous electrolyte secondary batteries according to claim 5.
  8. 　前記非水電解質二次電池の負極は、集電体と、前記集電体上に負極活物質を少なくとも含む負極合剤層を有し、前記負極活物質は、炭素質物相と、炭素質物相中に分散されたシリコン相またはスズ相と、炭素質物相中に分散されたシリコン酸化物またはスズ酸化物を含む複合粒子であることを特徴とする請求項７に記載の電池パック。

          The negative electrode of the non-aqueous electrolyte secondary battery has a current collector and a negative electrode mixture layer including at least a negative electrode active material on the current collector. The negative electrode active material includes a carbonaceous material phase and a carbonaceous material phase. 8. The battery pack according to claim 7, wherein the battery pack is a composite particle comprising a silicon phase or tin phase dispersed therein and silicon oxide or tin oxide dispersed in a carbonaceous material phase.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017168255A (en) * 2016-03-15 2017-09-21 株式会社東芝 Nonaqueous electrolyte secondary battery, battery pack, and vehicle

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0422066A (en) * 1990-05-17 1992-01-27 Asahi Chem Ind Co Ltd Nonaqueous secondary battery
JPH05174817A (en) * 1991-12-19 1993-07-13 Matsushita Electric Ind Co Ltd Positive electrode active material for nonaqueous electrolyte battery and nonaqueous electrolyte battery using this material
JPH06243869A (en) * 1993-02-12 1994-09-02 Sanyo Electric Co Ltd Nonaqueous secondary battery
JP2001160395A (en) * 1999-12-03 2001-06-12 Mitsubishi Chemicals Corp Material for positive electrode of lithium secondary battery
JP2001167766A (en) * 1999-12-13 2001-06-22 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001223009A (en) * 1999-11-29 2001-08-17 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001273899A (en) * 1999-08-27 2001-10-05 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001357847A (en) * 2000-06-12 2001-12-26 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery
JP2006127911A (en) * 2004-10-28 2006-05-18 Canon Inc Lithium secondary battery
JP2008532224A (en) * 2005-04-01 2008-08-14 エルジー・ケム・リミテッド Electrode for lithium secondary battery containing electrode additive and lithium secondary battery containing the electrode
JP2012138313A (en) * 2010-12-28 2012-07-19 Hitachi Ltd Positive electrode for lithium ion secondary battery, lithium ion secondary battery, and vehicle and power storage system mounting the lithium ion secondary battery
JP2014017210A (en) * 2012-07-11 2014-01-30 Nippon Telegr & Teleph Corp <Ntt> Lithium cuprate positive electrode material, method for producing the same, and lithium secondary battery including the positive electrode material as positive electrode active material

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0422066A (en) * 1990-05-17 1992-01-27 Asahi Chem Ind Co Ltd Nonaqueous secondary battery
JPH05174817A (en) * 1991-12-19 1993-07-13 Matsushita Electric Ind Co Ltd Positive electrode active material for nonaqueous electrolyte battery and nonaqueous electrolyte battery using this material
JPH06243869A (en) * 1993-02-12 1994-09-02 Sanyo Electric Co Ltd Nonaqueous secondary battery
JP2001273899A (en) * 1999-08-27 2001-10-05 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001223009A (en) * 1999-11-29 2001-08-17 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001160395A (en) * 1999-12-03 2001-06-12 Mitsubishi Chemicals Corp Material for positive electrode of lithium secondary battery
JP2001167766A (en) * 1999-12-13 2001-06-22 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery
JP2001357847A (en) * 2000-06-12 2001-12-26 Mitsubishi Chemicals Corp Positive electrode material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery
JP2006127911A (en) * 2004-10-28 2006-05-18 Canon Inc Lithium secondary battery
JP2008532224A (en) * 2005-04-01 2008-08-14 エルジー・ケム・リミテッド Electrode for lithium secondary battery containing electrode additive and lithium secondary battery containing the electrode
JP2012138313A (en) * 2010-12-28 2012-07-19 Hitachi Ltd Positive electrode for lithium ion secondary battery, lithium ion secondary battery, and vehicle and power storage system mounting the lithium ion secondary battery
JP2014017210A (en) * 2012-07-11 2014-01-30 Nippon Telegr & Teleph Corp <Ntt> Lithium cuprate positive electrode material, method for producing the same, and lithium secondary battery including the positive electrode material as positive electrode active material

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017168255A (en) * 2016-03-15 2017-09-21 株式会社東芝 Nonaqueous electrolyte secondary battery, battery pack, and vehicle

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