WO2017033316A1 - Nonaqueous electrolyte battery and battery pack - Google Patents

Nonaqueous electrolyte battery and battery pack Download PDF

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WO2017033316A1
WO2017033316A1 PCT/JP2015/074065 JP2015074065W WO2017033316A1 WO 2017033316 A1 WO2017033316 A1 WO 2017033316A1 JP 2015074065 W JP2015074065 W JP 2015074065W WO 2017033316 A1 WO2017033316 A1 WO 2017033316A1
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negative electrode
battery
active material
positive electrode
electrode active
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PCT/JP2015/074065
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French (fr)
Japanese (ja)
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高見　則雄
康宏 原田
一浩 安田
圭吾 保科
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株式会社 東芝
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Priority to PCT/JP2015/074065 priority Critical patent/WO2017033316A1/en
Priority to JP2016510840A priority patent/JP6054575B1/en
Publication of WO2017033316A1 publication Critical patent/WO2017033316A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • 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
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • 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
    • 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 of the present invention relate to a nonaqueous electrolyte battery and a battery pack.
  • Non-aqueous electrolyte batteries using lithium metal, lithium alloys, lithium compounds, or carbonaceous materials as negative electrodes are expected as high energy density batteries and are actively researched and developed. So far, lithium ion batteries including a positive electrode containing LiCoO 2 or LiMn 2 O 4 as an active material and a negative electrode containing a carbonaceous material that occludes and releases lithium have been widely put into practical use for portable devices.
  • the positive electrode because of the storage performance, cycle performance, high output long-term reliability of the non-aqueous electrolyte battery in a high temperature environment (for example, 45 ° C or higher),
  • a high temperature environment for example, 45 ° C or higher
  • a material excellent in chemical and electrochemical stability, strength, and corrosion resistance is required.
  • high performance is required even in a cold region, and high output performance and long life performance in a low temperature environment (for example, ⁇ 40 ° C.) are desired.
  • non-aqueous electrolytes non-volatile and non-flammable electrolytes are being developed from the viewpoint of improving safety performance, but they have not yet been put into practical use due to a decrease in output characteristics, low temperature performance, and long life performance. . Therefore, it is desired that the lithium ion battery mounted on the vehicle is excellent in high temperature durability and low temperature output performance.
  • Li 4/3 + x Ti 5/3 O 4 (0 ⁇ x ⁇ 1), monoclinic structure titanium dioxide (for example, the use of TiO 2 (B)) as a negative electrode active material has been studied.
  • a non-aqueous electrolyte battery including a negative electrode containing monoclinic titanium dioxide as a negative electrode active material has a problem that the battery swells under a high temperature environment of about 45 ° C. or higher, resulting in poor cycle performance.
  • a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided.
  • the negative electrode includes a negative electrode active material containing a titanium-containing oxide having a monoclinic structure and releasing 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C.
  • a battery pack including a non-aqueous electrolyte battery is provided.
  • FIG. 1 is a partially cutaway perspective view showing a nonaqueous electrolyte battery according to an embodiment.
  • FIG. 2 is an enlarged cross-sectional view of a part A in FIG.
  • FIG. 3 is a partially cutaway cross-sectional view of the nonaqueous electrolyte battery of the embodiment.
  • FIG. 4 is a side view of the battery of FIG.
  • FIG. 5 is a partially cutaway perspective view schematically showing the nonaqueous electrolyte battery of the embodiment.
  • FIG. 6 is a perspective view illustrating an example of an assembled battery used in the battery pack according to the embodiment.
  • FIG. 7 is a perspective view schematically showing an example of the battery pack according to the embodiment.
  • FIG. 8 is an exploded perspective view of another example of the battery pack according to the embodiment.
  • FIG. 9 is a block diagram showing an electric circuit of the battery pack of FIG. It is a figure which shows the thermogravimetric analysis result about the negative electrode active material of an Example and a comparative example.
  • a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided.
  • the negative electrode includes a negative electrode active material containing a titanium-containing oxide having a monoclinic structure that releases 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C.
  • the nonaqueous electrolyte battery contains moisture as an inevitable impurity.
  • water hydrolyzes LiPF 6 which is a lithium salt to generate protons (H + ).
  • a negative electrode active material containing a titanium-containing oxide having a monoclinic structure that releases 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C. is used in a high temperature environment of a nonaqueous electrolyte battery.
  • the cycle life performance can be greatly improved.
  • H 2 O released from a titanium-containing oxide having a monoclinic structure in a temperature range of 300 to 600 ° C. is not chemically or physically adsorbed on the particle surface of the titanium-containing oxide but contains titanium. Although it exists in the crystal
  • H 2 O is present in the crystal of the titanium-containing oxide.
  • Oxonium ions (H 3 + O) or protons (H + ) are taken into the particles, and as a result, hydrolysis reaction and gas generation caused by these cations are suppressed.
  • a more preferable range of the release amount of H 2 O is 0.02 to 0.3% by weight.
  • TG Thermogravimetry
  • MS Mass spectrometry
  • the specific measurement method is as follows.
  • a nonaqueous electrolyte battery having a battery voltage of 1.5 V or less is disassembled, and titanium-containing oxide particles having a monoclinic structure are taken out from the negative electrode.
  • the titanium-containing oxide particles taken out are sufficiently washed with water or the like to remove deposits (for example, non-aqueous electrolyte, lithium salt, conductive agent, binder) on the particle surface, and then the titanium-containing oxide particles are added to 100
  • deposits for example, non-aqueous electrolyte, lithium salt, conductive agent, binder
  • a titanium-containing oxide having a monoclinic structure can occlude and release lithium ions or sodium ions.
  • titanium dioxide can be obtained.
  • lithium titanium oxide can be obtained.
  • sodium titanium oxide can be taken. Therefore, the general formula of the titanium-containing oxide having a monoclinic structure is represented by Li x TiO 2 (0 ⁇ x ⁇ 1) or Na y TiO 2 (0 ⁇ y ⁇ 1).
  • the titanium-containing oxide having a monoclinic structure preferably has an intensity ratio (Ib / Ia) of 0 or more and 0.7 or less.
  • the intensity Ia is the intensity of the peak top (Pa) of the (002) plane where the diffraction angle (2 ⁇ ) appears at 27 deg to 29 deg in the powder X-ray diffraction method using a Cu—K ⁇ ray source, and the intensity Ib is Cu—K ⁇ .
  • it is 0 or more and 0.5 or less.
  • the intensity Ib is set to zero.
  • the titanium-containing oxide having a monoclinic structure preferably has a crystallite size in the range of 5 to 100 nm by X-ray diffraction. By being in this range, since the diffusion distance of lithium ions in the solid is shortened, the diffusibility of lithium ions in the solid is improved.
  • the crystallite size is preferably in the range of 10 to 30 nm. Thereby, it becomes possible to keep the content of H 2 O molecules in the crystal in an appropriate range.
  • a titanium-containing oxide having a monoclinic structure releasing 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C. can be produced by the following synthesis method.
  • This manufacturing method includes a step of obtaining an alkali titanate compound, a step of reacting an acid with the alkali titanate compound to proton exchange an alkali cation to obtain a titanate proton compound as a proton exchanger, and a proton exchanger (titanium Heat treating the acid proton compound) in a temperature range of 250 to 500 ° C. in a pressurized atmosphere.
  • a proton exchanger (a titanate proton compound) is added at 1.1 to 3 atm. It is preferable to perform heat treatment for a long time (for example, 5 hours or more) in a low temperature range of 200 to 350 ° C. in a pressurized atmosphere in the range. Alternatively, it is preferable to perform the heat treatment for a short time (for example, 1 hour or less) at a high temperature of 400 to 500 ° C. in a pressurized atmosphere in the range of 1.2 atmospheres to 5 atmospheres in a range in which anatase TiO 2 is not generated. . By setting the firing temperature to 500 ° C. or lower, it is possible to suppress the production of anatase TiO 2 .
  • alkali titanate compounds include K 2 Ti 2 O 5 , Na 2 T 3 O 7 , K 2 Ti 4 O 9 and Cs 2 Ti 5 O 12 .
  • the acid include hydrochloric acid, nitric acid, and sulfuric acid.
  • the concentration of the aqueous acid solution is preferably in the range of 0.5 to 2M.
  • Negative electrode This negative electrode has a negative electrode current collector and a negative electrode active material-containing layer (negative electrode material layer) supported on one or both sides of the current collector and containing an active material, a conductive agent, and a binder.
  • the negative electrode active material only a monoclinic structure titanium-containing oxide may be used, but other negative electrode active materials may be included.
  • other negative electrode active materials include spinel-type lithium titanium oxide (for example, general formula Li 4/3 + x Ti 5/3 O 4 (0 ⁇ x ⁇ 1.1)), ramsdellite-type lithium titanium oxide Product (for example, Li 2 + x Ti 3 O 7 ( ⁇ 1 ⁇ x ⁇ 3)), Li 1 + x Ti 2 O 4 (0 ⁇ x ⁇ 1), Li 1.1 + x Ti 1.8 O 4 (0 ⁇ x ⁇ 1) ), Li 1.07 + x Ti 1.86 O 4 (0 ⁇ x ⁇ 1), niobium titanium oxide, and the like.
  • the ratio of the other negative electrode active material to the whole negative electrode active material is desirably 50% by weight or less.
  • niobium titanium oxide examples include Li a TiM b Nb 2 ⁇ ⁇ O 7 ⁇ ⁇ (0 ⁇ a ⁇ 5, 0 ⁇ b ⁇ 0.3, 0 ⁇ ⁇ ⁇ 0.3, 0 ⁇ ⁇ ⁇ 0.3).
  • M includes one represented by one or more elements selected from the group consisting of Fe, V, Mo, and Ta.
  • Examples of the conductive agent include acetylene black, carbon black, coke, carbon fiber, graphite, Li 4 Ti 5 O 12 , metal compound powder, and metal powder.
  • the type of the conductive agent can be one type or two or more types.
  • Examples of preferable conductive agents include coke having a heat treatment temperature of 800 ° C. to 2000 ° C. and an average particle size of 10 ⁇ m or less, graphite, acetylene black, metal compound powder (eg, TiO, TiC, TiN powder), metal powder (eg, Al, Ni, Cu, Fe powder).
  • Further preferable examples include graphite, carbon fiber having a fiber diameter of 1 ⁇ m or less, acetylene black, coke, and Li 4 Ti 5 O 12 .
  • electrode resistance can be reduced and cycle life performance can be improved. Further, by using carbon fibers having a fiber diameter of 1 ⁇ m or less and / or Li 4 Ti 5 O 12 as a conductive agent, it is possible to reduce electrode resistance and improve cycle life performance.
  • binder examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, acrylic rubber, styrene butadiene rubber, core shell binder, and polyimide.
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • fluorine rubber acrylic rubber
  • styrene butadiene rubber core shell binder
  • core shell binder examples include polyimide.
  • the kind of binder can be made into 1 type, or 2 or more types.
  • the compounding ratio of the negative electrode active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the negative electrode active material, 1 to 18% by weight of the conductive agent, and 2 to 7% by weight of the binder.
  • the porosity of the negative electrode (excluding the current collector) is preferably in the range of 20 to 50%. Thereby, it is possible to obtain a negative electrode having excellent affinity between the negative electrode and the non-aqueous electrolyte and a high density. A more preferable range of the porosity is 25 to 40%.
  • the negative electrode current collector is preferably an aluminum foil or an aluminum alloy foil.
  • the thickness of the aluminum foil and the aluminum alloy foil is 20 ⁇ m or less, more preferably 15 ⁇ m or less.
  • the purity of the aluminum foil is preferably 99.99% by weight or more.
  • As the aluminum alloy an aluminum alloy containing at least one element selected from the group consisting of magnesium, zinc and silicon is preferable.
  • transition metals such as iron, copper, nickel, and chromium are preferably 100 ppm by weight or less.
  • the negative electrode active material particles, the conductive agent and the binder are suspended in an appropriate solvent, and the suspension is applied to a current collector, dried, and subjected to a press (for example, a warming press). It is produced by this.
  • a press for example, a warming press
  • This positive electrode comprises a positive electrode current collector and a positive electrode active material-containing layer (positive electrode material layer) that is carried on one or both surfaces of the current collector and contains a positive electrode active material, a conductive agent, and a binder.
  • LiMn 1.5 Ni 0 .5 O 4 is preferred.
  • the potential of the positive electrode containing LiMn 1.5 Ni 0.5 O 4 can be as high as 4.7 (V vs. Li / Li + ).
  • a positive electrode containing LiMn 1.5 Ni 0.5 O 4 with a negative electrode it is preferable because a high voltage of 3.1 V can be obtained as the intermediate voltage of the battery (cell intermediate voltage). Further, gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
  • LiFeSO 4 F having a tabolite structure or a triplite structure LiFe 0.9 Mn 0.1 SO 4 F having a tabolite structure or a triplite structure is preferable.
  • the BET specific surface area of an active material particle can be 5 m ⁇ 2 > / g or more.
  • the intermediate voltage (cell intermediate voltage) of the battery can be set to 1.95V.
  • the intermediate voltage of the battery (cell intermediate voltage) can be set to 2.3V.
  • the specific surface area of the LiboSO 4 F of the tabolite structure or LiFe 0.9 Mn 0.1 SO 4 F of the triplite structure is set to 5 m 2 / g or more.
  • gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
  • the phosphate compound having an olivine structure represented by Li x Fe 1-yz Mn y M z PO 4 LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 and LiFePO 4 are preferable.
  • the BET specific surface area of an active material particle can be 8 m ⁇ 2 > / g or more.
  • the positive electrode containing LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 in the negative electrode containing a negative electrode active material according to the embodiment is an intermediate voltage of the battery (cell intermediate voltage) to 2.5V it can.
  • the battery intermediate voltage (cell intermediate voltage) can be 1.8V.
  • the specific surface area of the phosphate compound having an olivine structure represented by Li x Fe 1-yz Mn y M z PO 4 is set to 8 m 2 / g or more.
  • gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
  • the positive electrode containing a phosphate compound and / or a fluorinated sulfuric acid compound having an olivine structure may contain an oxide of at least one metal selected from the group consisting of cobalt, nickel and manganese. More preferable examples of the metal oxide include Li x CoO 2 (0 ⁇ x ⁇ 1), LiNi 1-e Co e Mn f O 2 (0 ⁇ e ⁇ 1, 0 ⁇ f ⁇ 1), Li x Mn 2 O 4 (0 ⁇ x ⁇ 1) and the like are included.
  • the addition amount of the metal oxide to the positive electrode active material-containing layer 30% by weight or less, the electrode density is increased and the volume specific capacity of the electrode is improved.
  • the average particle diameter (diameter) of the primary particles of the positive electrode active material is 1 ⁇ m or less, more preferably 0.05 to 0.5 ⁇ m. It is preferable that at least a part of the particle surface of the positive electrode active material is coated with a carbon material.
  • the carbon material may take the form of a layer structure, a particle structure, or an aggregate of particles.
  • Examples of the conductive agent include acetylene black, carbon black, graphite, carbon fiber and the like. Carbon fibers having a fiber diameter of 1 ⁇ m or less, particularly vapor-grown carbon fibers having a fiber diameter of 1 ⁇ m or less are preferred. By including a carbon fiber having a fiber diameter of 1 ⁇ m or less, the problem of large electron conduction resistance of the positive electrode can be improved by a network of carbon fibers having a small fiber diameter, and the positive electrode resistance can be effectively reduced. For this reason, the output performance of a positive electrode can be improved significantly.
  • the positive electrode may contain an oxide of at least one metal selected from the group consisting of cobalt, nickel and manganese. More preferable examples of the metal oxide include Li x CoO 2 (0 ⁇ x ⁇ 1), LiNi 1-e Co e Mn f O 2 (0 ⁇ e ⁇ 1, 0 ⁇ f ⁇ 1), Li x Mn 2 O 4 (0 ⁇ x ⁇ 1) and the like are included.
  • binder examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, acrylic acid, and the like.
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • fluorine-based rubber acrylic acid, and the like.
  • the kind of binder can be made into 1 type, or 2 or more types.
  • the compounding ratio of the positive electrode active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the positive electrode active material, 3 to 19% by weight of the conductive agent, and 1 to 7% by weight of the binder.
  • the current collector is preferably an aluminum foil or an aluminum alloy foil, and the thickness is desirably 20 ⁇ m or less, more preferably 15 ⁇ m or less.
  • the positive electrode is produced, for example, by suspending a positive electrode active material, a conductive agent, and a binder in a suitable solvent, applying the suspension to a current collector, drying, and pressing.
  • the specific surface area by the BET method of the positive electrode active material-containing layer is preferably in the range of 0.1 to 10 m 2 / g.
  • Non-aqueous electrolyte is a liquid, gel-like, solid electrolyte having lithium ion conductivity, and may contain an organic electrolyte containing a lithium salt, an ionic liquid, a polymer solid electrolyte, and an inorganic solid electrolyte. preferable. Further, it is a liquid, gel, or solid electrolyte having sodium ion conductivity, and may contain an organic electrolyte containing sodium salt, an ionic liquid, a polymer solid electrolyte, or an inorganic solid electrolyte.
  • non-aqueous electrolytes examples include a liquid organic electrolyte prepared by dissolving an electrolyte in an organic solvent, a gel organic electrolyte obtained by combining a liquid organic solvent and a polymer material, lithium metal oxide, lithium metal Examples thereof include solid nonaqueous electrolytes in which a sulfide or lithium salt electrolyte and a polymer material are combined. Moreover, you may use the normal temperature molten salt (ionic melt) containing lithium ion as a non-aqueous electrolyte.
  • the polymer material examples include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), and the like.
  • a liquid non-aqueous electrolyte is prepared by dissolving a lithium salt electrolyte in an organic solvent at a concentration of 0.5 to 2.5 mol / L.
  • lithium salt electrolytes examples include LiBF 4 , LiPF 6 , LiAsF 6 , LiClO 4 , LiCF 3 SO 3 , LiN (FSO 2 ) 2 , LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ). 2 , Li (CF 3 SO 2 ) 3 C, LiB [(OCO) 2 ] 2 and the like.
  • the type of electrolyte used can be one type or two or more types. Among them, LiPF 6, LiBF 4, LiN (FSO 2) preferably comprises one or more selected from the group consisting of 2. Thereby, the chemical stability of the organic solvent is increased, the film resistance on the negative electrode can be reduced, and the low temperature performance and cycle life performance can be greatly improved.
  • a sodium salt electrolyte in which lithium ions are replaced with sodium ions can be used.
  • organic solvent examples include cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC), chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC), dimethoxyethane ( DME) and chain ethers such as diethoxyethane (DEE), cyclic ethers such as tetrahydrofuran (THF) and dioxolane (DOX), ⁇ -butyrolactone (GBL), 2-methyl- ⁇ -butyrolactone (MBL), acetonitrile (AN) ), 3-methoxypropiononitrile (MOPN), sulfolane (SL), and the like.
  • cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC)
  • chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC)
  • DME dim
  • organic solvents can be used alone or in the form of a mixture of two or more.
  • the main component is one or more selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), and ⁇ -butyrolactone (GBL), and the boiling point becomes 200 ° C. or higher, resulting in high thermal stability. .
  • ⁇ -butyrolactone GBL
  • 2-methyl- ⁇ -butyrolactone MBL
  • 3-methoxypropiononitrile MOPN
  • GBL ⁇ -butyrolactone
  • MBL 2-methyl- ⁇ -butyrolactone
  • MOPN 3-methoxypropiononitrile
  • the lithium ion concentration at the interface between the positive electrode and the non-aqueous electrolyte is rapidly reduced during discharge with a large current, and the output may be significantly reduced.
  • the concentration exceeds 3 mol / L the viscosity of the non-aqueous electrolyte increases, and the migration rate of lithium ions may decrease, resulting in a significant decrease in output.
  • the room temperature molten salt (ionic melt) is preferably composed of lithium ions or sodium ions, an organic cation, and an organic anion.
  • the room temperature molten salt is preferably liquid at room temperature or lower.
  • an electrolyte containing a room temperature molten salt will be described.
  • Room temperature molten salt refers to a salt that is at least partially liquid at room temperature
  • room temperature refers to a temperature range in which the power supply is assumed to normally operate.
  • the temperature range in which the power supply is assumed to operate normally has an upper limit of about 120 ° C., in some cases about 60 ° C., and a lower limit of about ⁇ 40 ° C., in some cases about ⁇ 20 ° C. In particular, a range of ⁇ 20 ° C. or more and 60 ° C. or less is suitable.
  • ionic melt composed of lithium ions, organic cations and anions.
  • the ionic melt is preferably in a liquid state even at room temperature or lower.
  • organic cation examples include alkyl imidazolium ions and quaternary ammonium ions having a skeleton shown in Chemical Formula 1 below.
  • alkyl imidazolium ion a dialkyl imidazolium ion, a trialkyl imidazolium ion, a tetraalkyl imidazolium ion and the like are preferable.
  • dialkylimidazolium 1-methyl-3-ethylimidazolium ion (MEI + ) and the like are preferable.
  • trialkylimidazolium ion 1,2-diethyl-3-propylimidazolium ion (DMPI + ) and the like are preferable.
  • tetraalkylimidazolium ion 1,2-diethyl-3,4 (5) -dimethylimidazolium ion and the like are preferable.
  • quaternary ammonium ions tetraalkylammonium ions, cyclic ammonium ions and the like are preferable.
  • tetraalkylammonium ion dimethylethylmethoxyethylammonium ion, dimethylethylmethoxymethylammonium ion, dimethylethylethoxyethylammonium ion, and trimethylpropylammonium ion are preferable.
  • the melting point can be made 100 ° C. or lower, more preferably 20 ° C. or lower. Furthermore, the reactivity with the negative electrode can be lowered.
  • the concentration of lithium ions is preferably 20 mol% or less. A more preferred range is from 1 to 10 mol%. By setting it within the above range, a liquid room temperature molten salt can be easily formed even at a low temperature of 20 ° C. or lower. Further, the viscosity can be lowered even at room temperature or lower, and the ionic conductivity can be increased.
  • at least one anion selected from (CF 3 SO 2 ) 2 ⁇ , N (C 2 F 5 SO 2 ) 2 ⁇ , (CF 3 SO 2 ) 3 C ⁇ and the like coexists.
  • More preferred anions include BF 4 ⁇ , (FSO 2 ) 2 N ⁇ , CF 3 SO 3 ⁇ , CF 3 COO ⁇ , CH 3 COO ⁇ , CO 3 2 ⁇ , N (CF 3 SO 2 ) 2 ⁇ , N (C 2 F 5 SO 2 ) 2 ⁇ and (CF 3 SO 2 ) 3 C ⁇ .
  • These anions make it easier to form a room temperature molten salt at 0 ° C. or lower.
  • the nonaqueous electrolyte battery may include a separator and an exterior member in addition to the positive electrode, the negative electrode, and the nonaqueous electrolyte.
  • a separator and an exterior member in addition to the positive electrode, the negative electrode, and the nonaqueous electrolyte.
  • a separator can be disposed between the positive electrode and the negative electrode.
  • the separator include a synthetic resin nonwoven fabric, a porous film, and a cellulose nonwoven fabric.
  • a porous film can be formed from polyolefin, such as polyethylene and a polypropylene, for example.
  • the separator is preferably a non-woven fabric or a porous membrane containing cellulose and / or polyolefin having a thickness of 30 ⁇ m or less and a porosity of 50% or more. It is preferable to use a cellulose fiber separator having a porosity of 60% or more. The fiber diameter is preferably 10 ⁇ m or less. Examples of the separator include non-woven fabric, film, and paper. Cellulose fiber separators with a porosity of 60% or more have good nonaqueous electrolyte impregnation properties, and can provide high output performance from low to high temperatures. A more preferable range of the porosity is 62% to 80%.
  • the negative electrode containing the negative electrode active material of the embodiment does not react with a separator made of cellulose fiber having a porosity of 60% or more even during long-term charge storage, float charge or overcharge, and the negative electrode formed by lithium metal dendride precipitation No short circuit with the positive electrode occurs. Furthermore, by making the fiber diameter 10 ⁇ m or less, the affinity between the separator and the non-aqueous electrolyte is improved, and the battery resistance can be reduced. A more preferable fiber diameter range is 3 ⁇ m or less.
  • the separator preferably has a thickness of 20 to 100 ⁇ m and a density of 0.2 to 0.9 g / cm 3 . Within this range, it is possible to balance the mechanical strength and the battery resistance reduction, and it is possible to provide a battery that is high in output and hardly shorts internally. Moreover, there is little heat shrinkage in a high temperature environment, and good high temperature storage performance can be obtained.
  • Exterior member examples include a laminate film container and a metal container.
  • the shape of the container depends on the form of the nonaqueous electrolyte battery.
  • the nonaqueous electrolyte battery examples include a flat battery, a square battery, a cylindrical battery, a coin battery, a button battery, a sheet battery, a stacked battery, a large battery mounted on an electric vehicle, and the like.
  • the preferable range of the thickness of the laminate film is 0.5 mm or less. A more preferable range is 0.2 mm or less. Moreover, it is desirable that the lower limit value of the thickness of the laminate film be 0.01 mm.
  • the more preferable range of the plate thickness of the metal container is 0.5 mm or less. Further, the lower limit value of the plate thickness of the metal container is desirably 0.05 mm.
  • the laminate film examples include a multilayer film including a metal layer and a resin layer covering the metal layer.
  • the metal layer is preferably an aluminum foil or an aluminum alloy foil.
  • the resin layer is for reinforcing the metal layer, and can be formed of a polymer such as polypropylene (PP), polyethylene (PE), nylon, polyethylene terephthalate (PET).
  • a laminate film container can be obtained, for example, by laminating a laminate film by heat fusion.
  • the metal container is preferably formed from aluminum or an aluminum alloy.
  • the strength is increased by a metal container made of an aluminum alloy, and sufficient mechanical strength can be ensured even if the thickness of the container is reduced. Thereby, since the heat dissipation of a container can be improved, the raise of battery temperature can be suppressed. Further, the energy density can be improved to reduce the weight and size of the battery.
  • the aluminum alloy an alloy containing at least one element selected from the group consisting of magnesium, zinc and silicon is preferable.
  • the content of transition metals such as iron, copper, nickel, and chromium in aluminum and aluminum alloy is 100 ppm or less.
  • the metal container can be sealed with a laser. For this reason, the volume of a sealing part can be decreased compared with the container made from a laminate film, and an energy density can be improved.
  • the non-aqueous electrolyte battery of the embodiment can be applied to various forms of non-aqueous electrolyte batteries such as a square, cylindrical, flat, thin, coin type, etc. Examples include a rectangular battery or a cylindrical battery using a manufactured exterior member, and a thin battery using a laminated film exterior member. An example of the nonaqueous electrolyte battery will be described with reference to FIGS.
  • FIG. 1 and FIG. 2 show an example of a nonaqueous electrolyte battery using a laminate film exterior member.
  • the laminated electrode group 1 is housed in a bag-like container 2 made of a laminate film in which a metal layer is interposed between two resin films.
  • the stacked electrode group 1 has a structure in which positive electrodes 3 and negative electrodes 4 are alternately stacked with separators 5 interposed therebetween.
  • a plurality of negative electrodes 4 are present, each including a current collector 4a and a negative electrode active material-containing layer 4b formed on both surfaces of the current collector 4a.
  • One side of the current collector 4 a of each negative electrode 4 protrudes from the positive electrode 3.
  • the protruding current collector 4 a is electrically connected to the strip-shaped negative electrode terminal 6.
  • the tip of the strip-like negative electrode terminal 6 is drawn out from the container 2 to the outside.
  • the current collector 3a of the positive electrode 3 has a side protruding from the negative electrode 4 on the side opposite to the protruding side of the current collector 4a.
  • the current collector 3 a protruding from the negative electrode 4 is electrically connected to the belt-like positive electrode terminal 7.
  • the tip of the strip-like positive electrode terminal 7 is located on the opposite side to the negative electrode terminal 6 and is drawn out from the side of the container 2 to the outside.
  • 3 and 4 show an example of a nonaqueous electrolyte battery using a metal container.
  • the electrode group 11 is housed in a rectangular cylindrical metal container 12.
  • the electrode group 11 has a structure in which a positive electrode 13 and a negative electrode 14 are wound in a spiral shape so that a flat shape is formed with a separator 15 interposed therebetween.
  • a nonaqueous electrolyte (not shown) is held by the electrode group 11.
  • a strip-like positive electrode lead 16 is electrically connected to each of a plurality of locations at the end of the positive electrode 13 located on the end face of the electrode group 1.
  • a strip-like negative electrode lead 17 is electrically connected to each of a plurality of locations at the end of the negative electrode 14 located on this end face.
  • the plurality of positive electrode leads 16 are electrically connected to the positive electrode conductive tab 18 in a bundled state.
  • a positive electrode terminal is constituted by the positive electrode lead 16 and the positive electrode conductive tab 18.
  • the negative electrode lead 17 is connected to the negative electrode conductive tab 19 in a bundled state.
  • the negative electrode lead 17 and the negative electrode conductive tab 19 constitute a negative electrode terminal.
  • the metal sealing plate 20 is fixed to the opening of the metal container 12 by welding or the like.
  • the positive electrode conductive tab 18 and the negative electrode conductive tab 19 are each drawn out from an extraction hole provided in the sealing plate 20.
  • the inner peripheral surface of each extraction hole of the sealing plate 20 is covered with an insulating member 21 in order to avoid a short circuit due to contact with the positive electrode conductive tab 18 and the negative electrode conductive tab 19.
  • FIG. 5 shows another example of a nonaqueous electrolyte battery using a metal container.
  • the flat or thin nonaqueous electrolyte battery shown in FIG. 5 is a rectangular parallelepiped aluminum alloy container 22, an electrode group 23 housed in the container 22, and housed in the container 22 and held by the electrode group 23.
  • Non-aqueous electrolyte (not shown).
  • the electrode group 23 has a structure in which a positive electrode 24 and a negative electrode 25 are wound in a spiral shape so that a flat shape is formed with a separator 26 interposed therebetween.
  • the electrode group 23 is produced, for example, by winding a positive electrode 24 and a negative electrode 25 in a spiral shape with a separator 26 interposed therebetween, and then applying a heat press.
  • the strip-like positive electrode lead 27 is electrically connected to the positive electrode 24.
  • the strip-shaped negative electrode lead 28 is electrically connected to the negative electrode 25.
  • the positive electrode lead 27 is electrically connected to the container 22, and the negative electrode lead 28 is electrically connected to a negative electrode terminal 29 that is insulated from the container 22.
  • the assembled battery which uses a nonaqueous electrolyte battery as a unit cell, and the battery pack containing this assembled battery can be provided.
  • the nonaqueous electrolyte of the first embodiment can be used for the nonaqueous electrolyte battery.
  • Examples of the assembled battery include a plurality of unit cells electrically connected in series or in parallel as a constituent unit, a unit composed of a plurality of unit cells electrically connected in series, or electrically connected in parallel Examples include a unit including a unit composed of a plurality of unit cells.
  • Examples of a form in which a plurality of non-aqueous electrolyte batteries are electrically connected in series or in parallel include those in which a plurality of batteries each having an exterior member are electrically connected in series or in parallel, and are accommodated in a common housing.
  • a plurality of electrode groups electrically connected in series or in parallel are included.
  • the positive terminals and the negative terminals of a plurality of nonaqueous electrolyte batteries are connected by a metal bus bar (for example, aluminum, nickel, copper).
  • a plurality of electrode groups are accommodated in a single casing in an electrochemically insulated state by partition walls, and these electrode groups are electrically connected in series.
  • a metal can made of aluminum alloy, iron, stainless steel, a plastic container, or the like can be used. Further, the plate thickness of the container is desirably 0.5 mm or more.
  • Assembled battery 31 shown in FIG. 6 includes a plurality non-aqueous electrolyte battery of the square according to the first embodiment (e.g. FIG. 3, FIG. 4) 32 1 to 32 5 as a unit cell.
  • a battery 32 1 of the positive electrode conductive tab 18, a negative electrode conductive tab 19 of the battery 32 2 located next to it, are electrically connected by a lead 33.
  • a negative electrode conductive tab 19 of the battery 32 3 positioned positive electrode conductive tab 18 of the battery 32 2 next to it are electrically connected by a lead 33. In this way, the batteries 32 1 to 32 5 are connected in series.
  • the battery pack 40 includes an assembled battery composed of the nonaqueous electrolyte battery shown in FIGS.
  • the battery pack 40 includes a housing 41 and an assembled battery 42 accommodated in the housing 41.
  • Battery pack 42 is to nonaqueous electrolyte battery 43 1-43 5 a plurality (e.g. five) are electrically connected in series.
  • a nonaqueous electrolyte battery 43 1-43 5 are stacked in the thickness direction.
  • the housing 41 has an opening 44 on each of the upper part and the four side surfaces. Side nonaqueous electrolyte battery 43 1-43 5 of the positive and negative electrode terminals 6 and 7 are protruded is exposed to the opening 44 of the housing 41.
  • Output positive terminal of the assembled battery 42 45 form a strip, one end is electrically connected to the 6 one of the positive terminal of the nonaqueous electrolyte battery 43 1-43 5, and the other end of the housing 41 opening 44 protrudes from the upper portion of the housing 41.
  • the output negative terminal 46 of the assembled battery 42 without a band, one end of which is connected one of the negative electrode terminal 7 and electrically non-aqueous electrolyte battery 43 1-43 5, and the other end of the housing 41 It protrudes from the opening 44 and protrudes from the upper part of the housing 41.
  • a plurality of unit cells 51 composed of a flat type non-aqueous electrolyte battery are stacked so that the negative electrode terminal 52 and the positive electrode terminal 53 extending to the outside are aligned in the same direction, and are assembled by fastening with an adhesive tape 54.
  • a battery 55 is configured.
  • the printed wiring board 56 is disposed to face the side surface of the unit cell 51 from which the negative electrode terminal 52 and the positive electrode terminal 53 extend. As shown in FIG. 9, a thermistor 57, a protection circuit 58, and a terminal 59 for energizing an external device are mounted on the printed wiring board 56. An insulating plate (not shown) is attached to the surface of the printed wiring board 56 facing the assembled battery 55 in order to avoid unnecessary connection with the wiring of the assembled battery 55.
  • the positive electrode lead 60 is connected to the positive electrode terminal 53 located at the lowermost layer of the assembled battery 55, and the tip thereof is inserted into the positive electrode connector 61 of the printed wiring board 56 and electrically connected thereto.
  • the negative electrode lead 62 is connected to the negative electrode terminal 52 located on the uppermost layer of the assembled battery 55, and the tip thereof is inserted into and electrically connected to the negative electrode side connector 63 of the printed wiring board 56.
  • These connectors 61 and 63 are connected to the protection circuit 58 through wirings 64 and 65 formed on the printed wiring board 56.
  • the thermistor 57 detects the temperature of the unit cell 51, and the detection signal is transmitted to the protection circuit 58.
  • the protection circuit 58 can cut off the plus wiring 66a and the minus wiring 66b between the protection circuit 58 and the energization terminal 59 to the external device under a predetermined condition.
  • the predetermined condition is, for example, when the temperature detected by the thermistor 57 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 51 is detected. This detection of overcharge or the like is performed for each unit cell 51 or the assembled battery 55.
  • 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 51. 8 and 9, a voltage detection wiring 67 is connected to each unit cell 51, and a detection signal is transmitted to the protection circuit 58 through the wiring 67.
  • Protective sheets 68 made of rubber or resin are arranged on the three side surfaces of the assembled battery 55 excluding the side surfaces from which the positive electrode terminal 53 and the negative electrode terminal 52 protrude.
  • the assembled battery 55 is stored in a storage container 69 together with each protective sheet 68 and the printed wiring board 56. That is, the protective sheet 68 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 69, and the printed wiring board 56 is disposed on the inner side surface on the opposite side in the short side direction.
  • the assembled battery 55 is located in a space surrounded by the protective sheet 68 and the printed wiring board 56.
  • the lid 70 is attached to the upper surface of the storage container 69.
  • a heat shrink tape may be used in place of the adhesive tape 54 for fixing the assembled battery 55.
  • 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.
  • the mode of the battery pack is appropriately changed depending on the application.
  • a use of the battery pack one in which charging / discharging with a large current is desired is preferable.
  • 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.
  • the vehicle-mounted one is suitable.
  • Example 1 LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles having an olivine structure were prepared.
  • These particles contain secondary particles, and the average particle size of the primary particles was 50 nm.
  • the BET specific surface area was 25 m 2 / g.
  • Carbon fine particles having an average particle diameter of 5 nm were attached to the surface of LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles.
  • the amount of carbon fine particles attached to the LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles was 0.1% by weight.
  • the positive electrode active material thus obtained, 3% by weight of vapor-grown carbon fiber having a fiber diameter of 0.1 ⁇ m as a conductive agent, 5% by weight of graphite powder, and 5% by weight of graphite powder as a conductive agent. 5% by weight of PVdF was mixed and dispersed in an n-methylpyrrolidone (NMP) solvent to prepare a slurry. The obtained slurry was applied to both sides of a 15 ⁇ m thick aluminum alloy foil (purity 99% by weight), dried, and subjected to a pressing process. The thickness of the positive electrode active material-containing layer on one side was 43 ⁇ m, and the electrode density was 2.2 g. A positive electrode of / cm 3 was produced. The specific surface area of the positive electrode active material-containing layer was 8 m 2 / g. After producing the positive electrode, vacuum drying at 90 ° C. was performed for 24 hours.
  • NMP n-methylpyrrolidone
  • a negative electrode active material was produced by the following method. Spherical secondary particles of potassium titanate (K 2 Ti 2 O 5 ) having an average particle size of 10 ⁇ m were obtained by spray drying. Proton exchange was performed by adding potassium titanate particles in 1 M sulfuric acid solution and stirring at 25 ° C. for 2 weeks. The resulting proton exchanger is H 2 Ti 4 O 9 . The proton exchanger powder was washed with pure water and then washed until the pH of the washing solution was in the range of 6-7.
  • K 2 Ti 2 O 5 potassium titanate having an average particle size of 10 ⁇ m
  • the proton exchanger (H 2 Ti 4 O 9 ) was baked in an electric furnace at a temperature of 320 ° C. for 6 hours.
  • the atmosphere in the electric furnace was changed to a pressurized atmosphere by increasing the water vapor pressure.
  • Table 1 shows the atmospheric pressure. After heating, it was quickly removed from the electric furnace and rapidly cooled in the atmosphere.
  • the fired product was stored in a vacuum at 100 ° C. to remove adsorbed water and dried to obtain a sample of a titanium dioxide compound.
  • This sample was subjected to powder X-ray diffraction measurement using Cu—K ⁇ rays as a radiation source, and it was confirmed from the obtained diffraction rays that the titanium dioxide had a monoclinic structure belonging to the space group C2 / m.
  • the intensity ratio (Ib / Ia) was 0.43.
  • the intensity Ia is the intensity of the peak top (Pa) of the (002) plane where the diffraction angle (2 ⁇ ) in the powder X-ray diffraction method using a Cu—K ⁇ ray source appears as 27 deg to 29 deg
  • the intensity Ib is the diffraction angle ( 2 ⁇ ) is the intensity of the peak top (Pb) appearing at 29 deg to 32 deg.
  • the crystallite size by X-ray diffraction was 100 nm.
  • the obtained titanium dioxide particles have a 0.15 wt% H 2 O generated in the temperature range of 300 ° C. to 600 ° C. and a specific surface area of 20 m 2 / g by the BET method by N 2 adsorption. Met.
  • the average particle diameter of the primary particles was 0.3 ⁇ m, and the average particle diameter of the secondary particles was 10 ⁇ m.
  • a method for measuring the weight percentage of H 2 O will be described. With respect to 20 mg of titanium dioxide particles, TG measurement and MS measurement were performed under the condition of increasing the temperature from room temperature to 600 ° C. (temperature increase rate: 5 ° C./min). In MS measurement, He was used as a carrier gas. MS measurement revealed that the gas generated in the temperature range of 300 ° C.
  • Particles of titanium dioxide compound, acetylene black powder as a conductive agent, graphite powder having an average particle diameter of 6 ⁇ m, and PVdF as a binder are blended in a weight ratio of 85: 6: 5: 4, and n ⁇
  • a slurry was prepared by dispersing in a methylpyrrolidone (NMP) solvent and using a ball mill with stirring at a rotational speed of 1000 rpm and a stirring time of 2 hours.
  • NMP methylpyrrolidone
  • the obtained slurry was applied to an aluminum alloy foil (purity: 99.3% by weight) having a thickness of 15 ⁇ m, dried, and subjected to a heat press process, whereby the thickness of the negative electrode active material-containing layer on one side was 59 ⁇ m, and the electrode density Produced a negative electrode of 2.8 g / cm 3 .
  • vacuum drying at 90 ° C. was performed for 24 hours.
  • the BET specific surface area of the negative electrode active material-containing layer (surface area per 1 g of the negative electrode active material-containing layer) was 8 m 2 / g.
  • the porosity of the negative electrode excluding the current collector was 40%.
  • a plurality of positive electrodes and a plurality of negative electrodes were laminated with a separator made of a polyethylene porous film having a thickness of 12 ⁇ m interposed therebetween, to produce an electrode group.
  • a strip-shaped positive electrode terminal was electrically connected to the aluminum foil current collector of each of the plurality of positive electrodes, and a strip-shaped negative electrode terminal was electrically connected to the aluminum foil current collector of each of the plurality of negative electrodes.
  • This electrode group was accommodated in a laminate film container (exterior member) having a thickness of 6 mm, a width of 70 mm, and a height of 110 mm.
  • a liquid nonaqueous electrolyte was prepared by dissolving 1.5 mol / L of a lithium salt made of LiPF 6 in an organic solvent made of propylene carbonate (PC).
  • the obtained nonaqueous electrolyte was poured into a container to produce a thin nonaqueous electrolyte secondary battery having the structure shown in FIG.
  • the method for measuring the particles of the negative electrode active material is shown below.
  • a laser diffraction distribution measuring device Shiadzu SALD-300.
  • Electrode active material, and a BET specific surface area by N 2 adsorption of the negative electrode was measured under the following conditions.
  • Two pieces of 1 g of powdered negative electrode active material or 2 ⁇ 2 cm 2 negative electrodes were cut out and used as samples.
  • a BET specific surface area measuring apparatus manufactured by Yuasa Ionics was used, and nitrogen gas was used as an adsorption gas.
  • the specific surface area of the positive electrode active material-containing layer was measured by the same method as the BET specific surface area by N 2 adsorption of the negative electrode.
  • the porosity of the negative electrode is determined by comparing the volume of the negative electrode active material-containing layer with the volume of the negative electrode active material-containing layer when the porosity is 0%, and the volume of the negative electrode active material-containing layer when the porosity is 0%. This is calculated by regarding the increase in the volume as the pore volume.
  • the volume of the negative electrode active material-containing layer is the sum of the volumes of the negative electrode active material-containing layers on both sides when the negative electrode active material-containing layer is formed on both sides of the current collector.
  • Examples 2 to 15 and Comparative Examples 1 to 2 and 5 The type of positive electrode active material, the specific surface area of the positive electrode active material-containing layer (m 2 / g), the type of negative electrode active material, the pressure of the heat treatment atmosphere in the production of the negative electrode active material, released from the negative electrode active material at 300 to 600 ° C.
  • a nonaqueous electrolyte secondary battery was fabricated in the same manner as described in Example 1 except that the H 2 O amount (% by weight) was set as shown in Table 1 below.
  • Comparative Example 3 A nonaqueous electrolyte secondary battery was produced in the same manner as described in Example 1 except that the negative electrode active material produced by the following method was used.
  • the particles of the obtained lithium titanate (Li 4/3 Ti 5/3 O 4) is, 300 °C ⁇ H 2 O wt% of which occurred in the temperature range of 600 ° C. is 0 wt%, BET by N 2 adsorption
  • the specific surface area determined by the method was 8 m 2 / g.
  • the average particle diameter of the primary particles was 0.3 ⁇ m, and the average particle diameter of the secondary particles was 5 ⁇ m.
  • a nonaqueous electrolyte secondary battery was produced in the same manner as described in Example 1 except that the negative electrode active material described below was used.
  • anatase titanium dioxide (TiO 2 ) were used as the negative electrode active material.
  • the particles of anatase titanium dioxide (TiO 2 ) had 0% by weight of H 2 O generated in the temperature range of 300 ° C. to 600 ° C., and the specific surface area by the BET method by N 2 adsorption was 5 m 2 / g. It was.
  • the average particle diameter of the primary particles was 0.3 ⁇ m, and the average particle diameter of the secondary particles was 5 ⁇ m.
  • the nonaqueous electrolyte secondary battery is the same as described in Comparative Example 3 except that the type of the positive electrode active material and the specific surface area (m 2 / g) of the positive electrode active material-containing layer are set as shown in Table 1 below. Was made.
  • the nonaqueous electrolyte secondary battery is the same as described in Comparative Example 4 except that the type of the positive electrode active material and the specific surface area (m 2 / g) of the positive electrode active material-containing layer are set as shown in Table 1 below. Was made.
  • Examples 1 to 15 and Comparative Examples 1 to 7 were at a constant current of 1 C (1 hour rate) at 25 ° C. After charging to 3 V in 90 minutes, the discharge capacity (Ah) when discharged at 1 C to 1.5 V and the open circuit voltage (V) with a discharge rate of 50% were measured.
  • the 50 ° C high-temperature cycle test repeats the cycle of charging to 3V at a constant current of 3C in a 50 ° C environment, and then discharging at 3C to 1.5V, and the number of cycles and battery when the capacity reaches 80% of the initial capacity. The thickness change was measured.
  • Example 6 to 11 and Comparative Example 5 discharge capacity (Ah) when charging at a constant current of 1 C (1 hour rate) at 25 ° C. to 2.8 V in 90 minutes and then discharging to 1.2 V at 1 C Then, an open circuit voltage (V) with a discharge rate of 50% was measured.
  • the 50 ° C high-temperature cycle test repeats a cycle of charging to 2.8V at a constant current of 3C in a 50 ° C environment and then discharging at 3C to 1.2V, and the number of cycles when the capacity reaches 80% of the initial capacity. The battery thickness change was measured.
  • Example 12 to 15 and Comparative Examples 6 to 7 the discharge capacity when charging at a constant current of 1 C (1 hour rate) at 25 ° C. to 3.7 V in 90 minutes and then discharging to 2.5 V at 1 C ( Ah) and an open circuit voltage (V) with a discharge rate of 50%.
  • the 50 ° C high-temperature cycle test repeats a cycle of charging to 3.7V at a constant current of 3C in a 50 ° C environment and then discharging at 3C to 2.5V, and the number of cycles when the capacity reaches 80% of the initial capacity.
  • the battery thickness change was measured.
  • the nonaqueous electrolyte secondary batteries of Examples 1 to 15 are superior to Comparative Examples 1 to 7 in the balance of battery capacity, 50 ° C. high-temperature cycle life performance, and battery swelling.
  • Examples 8 and 9 having a H 2 O release amount of 0.02 to 0.3% by weight are compared with Example 10, Compared to 11, the battery capacity, 50 ° C high-temperature cycle life performance, and battery swelling are excellent.
  • Examples 12 and 13 having a H 2 O release amount of 0.02 to 0.3% by weight are compared with Examples 14 and 13, respectively.
  • the battery capacity, 50 ° C. high-temperature cycle life performance and battery swelling are excellent.
  • Example 6 using LiFePO 4 as the positive electrode active material has a battery capacity, 50 ° C. high-temperature cycle life performance, and battery swelling. The balance is excellent.
  • FIG. 10 shows the temperature change of the weight reduction rate of the negative electrode active material in the TG measurement of the negative electrode active material of Example 3 and Comparative Example 1.
  • the weight reduction rate up to 300 ° C. is smaller than that in Comparative Example 1, and the weight reduction rate increases when the temperature range is 300 to 600 ° C. If the temperature exceeds °C, there is almost no change in the weight loss rate.
  • the weight reduction rate up to 300 ° C. is larger than that in Example 3, and a slight weight reduction is observed in the temperature range exceeding 600 ° C.
  • the weight loss up to 300 ° C. is considered to be adsorbed water or crystal water of TiO 2 particles.
  • FIG. 11 shows the results of MS measurement of the negative electrode active materials of Example 3 and Comparative Example 1.
  • a negative electrode containing a monoclinic structure titanium-containing oxide that releases 0.01 to 0.5 wt% of H 2 O in a temperature range of 300 to 600 ° C. Since it contains an active material, it is possible to provide a nonaqueous electrolyte battery in which swelling under a high temperature environment is suppressed and cycle life performance is improved.
  • Nonaqueous electrolyte battery 33 ... Lead, 40 ... Battery pack , 41 ... housing, 42 ... assembled battery, 44 ... opening, 45 ... output positive terminal, 46 ... output negative terminal, 51 ... unit cell, 55 ... assembled battery, 56 ... printed wiring board, 57 ... thermistor, 58 .. protection circuit, 59... Terminal for energizing external equipment.

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Abstract

One embodiment of the present invention provides a nonaqueous electrolyte battery which comprises a positive electrode 3, a negative electrode 4 and a nonaqueous electrolyte. The negative electrode contains a negative electrode active material containing a titanium-containing oxide which has a monoclinic crystal structure and discharges 0.01-0.5% by weight of H2O within the temperature range of 300-600°C.

Description

非水電解質電池及び電池パックNonaqueous electrolyte battery and battery pack
　本発明の実施形態は、非水電解質電池及び電池パックに関する。 Embodiments of the present invention relate to a nonaqueous electrolyte battery and a battery pack.
　リチウム金属、リチウム合金、リチウム化合物または炭素質物を負極に用いた非水電解質電池は、高エネルギー密度電池として期待され、盛んに研究開発が進められている。これまでに、活物質としてＬｉＣｏＯ2またはＬｉＭｎ2Ｏ4を含む正極と、リチウムを吸蔵・放出する炭素質物を含む負極と具備したリチウムイオン電池が、携帯機器用に広く実用化されている。 Non-aqueous electrolyte batteries using lithium metal, lithium alloys, lithium compounds, or carbonaceous materials as negative electrodes are expected as high energy density batteries and are actively researched and developed. So far, lithium ion batteries including a positive electrode containing LiCoO 2 or LiMn 2 O 4 as an active material and a negative electrode containing a carbonaceous material that occludes and releases lithium have been widely put into practical use for portable devices.
　一方、自動車、電車などの車両に非水電解質電池を搭載する場合、非水電解質電池の高温環境下（例えば４５℃以上）での貯蔵性能、サイクル性能、高出力の長期信頼性などから正極、負極の構成材料には、化学的、電気化学的な安定性、強度、耐腐食性の優れた材料が求められる。さらに、寒冷地でも高い性能が要求され、低温環境下（例えば－４０℃）での高出力性能、長寿命性能が望まれている。一方、非水電解質として、安全性能向上の観点から不揮発性、不燃性電解液の開発が進められているが、出力特性、低温性能、長寿命性能の低下を伴うことからいまだ実用化されていない。
　よって、車両に搭載されるリチウムイオン電池は、高温耐久性、低温出力性能が優れていることが望まれる。 On the other hand, when a non-aqueous electrolyte battery is mounted on a vehicle such as an automobile or a train, the positive electrode, because of the storage performance, cycle performance, high output long-term reliability of the non-aqueous electrolyte battery in a high temperature environment (for example, 45 ° C or higher), As a constituent material of the negative electrode, a material excellent in chemical and electrochemical stability, strength, and corrosion resistance is required. Furthermore, high performance is required even in a cold region, and high output performance and long life performance in a low temperature environment (for example, −40 ° C.) are desired. On the other hand, as non-aqueous electrolytes, non-volatile and non-flammable electrolytes are being developed from the viewpoint of improving safety performance, but they have not yet been put into practical use due to a decrease in output characteristics, low temperature performance, and long life performance. .
Therefore, it is desired that the lithium ion battery mounted on the vehicle is excellent in high temperature durability and low temperature output performance.
　このような二次電池では、高容量化を図るために負極を薄くして高密度化すると、集電体の強度が十分でないため、電池容量、出力性能、サイクル寿命、信頼性で大きな制約を受ける恐れがある。また、負極を薄くする代わりに負極活物質の粒子径を大きくすると、電極の界面抵抗の増大を伴いますます高性能を引き出すことが困難になる。 In such a secondary battery, if the negative electrode is thinned and densified to increase the capacity, the current collector strength is not sufficient, so there are significant restrictions on battery capacity, output performance, cycle life, and reliability. There is a risk of receiving. Further, if the particle size of the negative electrode active material is increased instead of making the negative electrode thinner, it becomes difficult to obtain higher performance with an increase in the interfacial resistance of the electrode.
　また、高出力化する観点から電極薄膜化する検討はなされているが、活物質の粒子径が数μｍ～数十μｍと大きい場合、高出力を引き出すことは困難である。特に、低温環境下（－２０℃以下）では、活物質の利用率が低下して放電することが困難になる。 Also, studies have been made to reduce the thickness of the electrode from the viewpoint of higher output, but it is difficult to obtain high output when the particle diameter of the active material is as large as several μm to several tens of μm. In particular, in a low-temperature environment (−20 ° C. or lower), the utilization factor of the active material is lowered and it becomes difficult to discharge.
　一方、非水電解質電池の寿命を改善するため、Ｌｉ4/3+xＴｉ5/3Ｏ4（０＜ｘ＜１）で表わされるチタン酸リチウム（ＬＴＯ）、単斜晶構造の二酸化チタン（例えば、ＴｉＯ２（Ｂ））を負極活物質として用いることが検討されている。単斜晶構造の二酸化チタンを負極活物質に含む負極を備えた非水電解質電池には、４５℃程度またはそれ以上の高温環境下で電池が膨れてサイクル性能に劣るという課題がある。 On the other hand, in order to improve the lifetime of the nonaqueous electrolyte battery, lithium titanate (LTO) represented by Li 4/3 + x Ti 5/3 O 4 (0 <x <1), monoclinic structure titanium dioxide ( For example, the use of TiO 2 (B)) as a negative electrode active material has been studied. A non-aqueous electrolyte battery including a negative electrode containing monoclinic titanium dioxide as a negative electrode active material has a problem that the battery swells under a high temperature environment of about 45 ° C. or higher, resulting in poor cycle performance.
特表２０１４－５１１３３５号公報Special table 2014-511335 gazette 米国公開公報２０１４／００３８０５８Ａ１US Publication 2014 / 0038058A1 特開２０１０－１４０８６３号公報JP 2010-140863 A 米国公開公報２０１０／０１５１３２７Ａ１US Publication No. 2010 / 0151327A1
　実施形態によれば、高温環境下でのサイクル性能が改善された非水電解質電池及び電池パックを提供することができる。 According to the embodiment, it is possible to provide a nonaqueous electrolyte battery and a battery pack with improved cycle performance under a high temperature environment.
　実施形態によれば、正極と、負極と、非水電解質とを含む非水電解質電池が提供される。負極は、３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出し、かつ単斜晶構造を有するチタン含有酸化物を含有する負極活物質を含む。 According to the embodiment, a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided. The negative electrode includes a negative electrode active material containing a titanium-containing oxide having a monoclinic structure and releasing 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C.
　また、実施形態によれば、非水電解質電池を含む電池パックが提供される。 Moreover, according to the embodiment, a battery pack including a non-aqueous electrolyte battery is provided.
図１は、実施形態の非水電解質電池を示す部分切欠斜視図である。FIG. 1 is a partially cutaway perspective view showing a nonaqueous electrolyte battery according to an embodiment. 図２は、図１のＡ部の拡大断面図である。FIG. 2 is an enlarged cross-sectional view of a part A in FIG. 図３は、実施形態の非水電解質電池の部分切欠断面図である。FIG. 3 is a partially cutaway cross-sectional view of the nonaqueous electrolyte battery of the embodiment. 図４は、図３の電池についての側面図である。FIG. 4 is a side view of the battery of FIG. 図５は、実施形態の非水電解質電池を模式的に示す部分切欠斜視図である。FIG. 5 is a partially cutaway perspective view schematically showing the nonaqueous electrolyte battery of the embodiment. 図６は、実施形態の電池パックに用いられる組電池の一例を示す斜視図である。FIG. 6 is a perspective view illustrating an example of an assembled battery used in the battery pack according to the embodiment. 図７は、実施形態に係る電池パックの一例を模式的に示す斜視図である。FIG. 7 is a perspective view schematically showing an example of the battery pack according to the embodiment. 図８は、実施形態に係る電池パックの他の例の分解斜視図である。FIG. 8 is an exploded perspective view of another example of the battery pack according to the embodiment. 図９は、図８の電池パックの電気回路を示すブロック図である。FIG. 9 is a block diagram showing an electric circuit of the battery pack of FIG. 実施例及比較例の負極活物質についての熱重量分析結果を示す図である。It is a figure which shows the thermogravimetric analysis result about the negative electrode active material of an Example and a comparative example.
（第一の実施形態）
　第一の実施形態によれば、正極と、負極と、非水電解質とを含む非水電解質電池が提供される。負極は、３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出し、単斜晶構造を有するチタン含有酸化物を含有する負極活物質を含む。 (First embodiment)
According to the first embodiment, a nonaqueous electrolyte battery including a positive electrode, a negative electrode, and a nonaqueous electrolyte is provided. The negative electrode includes a negative electrode active material containing a titanium-containing oxide having a monoclinic structure that releases 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C.
　非水電解質電池は、不可避不純物として水分を含む。水分は非水電解質内で、例えばリチウム塩のＬｉＰＦ６を加水分解してプロトン（Ｈ＋）を生成する。 The nonaqueous electrolyte battery contains moisture as an inevitable impurity. In the non-aqueous electrolyte, for example, water hydrolyzes LiPF 6 which is a lithium salt to generate protons (H + ).
　３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出し、単斜晶構造を有するチタン含有酸化物を含む負極活物質は、非水電解質電池の高温環境下でのサイクル寿命性能を大幅に改善することができる。単斜晶構造を有するチタン含有酸化物が、３００～６００℃の温度範囲で放出するＨ２Ｏは、チタン含有酸化物の粒子表面に化学的又は物理的に吸着されたものではなく、チタン含有酸化物の結晶中に存在しているが、６００℃よりも高い温度（例えば９００℃）で放出される結晶水とも異なる。約４５℃またはそれ以上の高温環境下において電池内に水分やプロトン（Ｈ＋）が存在していても、チタン含有酸化物の結晶中にＨ２Ｏが存在しているためにチタン含有酸化物粒子中にオキソニウムイオン（Ｈ３ ＋Ｏ）又はプロトン（Ｈ＋）が取り込まれ、その結果、これらのカチオンが原因で生じる加水分解反応とガス発生が抑制される。Ｈ２Ｏの放出量が上記範囲を逸脱すると、高温環境下でガス発生が顕著となりサイクル寿命が大幅に低下する。Ｈ２Ｏの放出量のより好ましい範囲は、０．０２～０．３重量％である。 A negative electrode active material containing a titanium-containing oxide having a monoclinic structure that releases 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C. is used in a high temperature environment of a nonaqueous electrolyte battery. The cycle life performance can be greatly improved. H 2 O released from a titanium-containing oxide having a monoclinic structure in a temperature range of 300 to 600 ° C. is not chemically or physically adsorbed on the particle surface of the titanium-containing oxide but contains titanium. Although it exists in the crystal | crystallization of an oxide, it differs also from the crystal water discharge | released at the temperature higher than 600 degreeC (for example, 900 degreeC). Even if moisture and protons (H + ) are present in the battery in a high temperature environment of about 45 ° C. or higher, the titanium-containing oxide is present because H 2 O is present in the crystal of the titanium-containing oxide. Oxonium ions (H 3 + O) or protons (H + ) are taken into the particles, and as a result, hydrolysis reaction and gas generation caused by these cations are suppressed. When the amount of released H 2 O deviates from the above range, gas generation becomes remarkable under a high temperature environment, and the cycle life is significantly reduced. A more preferable range of the release amount of H 2 O is 0.02 to 0.3% by weight.
　３００～６００℃の温度範囲でチタン含有酸化物から放出されるＨ２Ｏを検出して重量を測定する方法を説明する。例えば、ＴＧ（Ｔｈｅｒｍｏｇｒａｖｉｍｅｔｒｙ：熱重量分析）及びＭＳ（Ｍａｓｓ　ｓｐｅｃｔｒｏｍｅｔｒｙ：質量分析）を用いることができる。ＴＧは、加熱による試料（チタン含有酸化物）の重量変化を測定する。また、ＭＳは、試料（チタン含有酸化物）から発生したガスがＨ２Ｏであることを同定する。 A method for measuring the weight by detecting H 2 O released from the titanium-containing oxide in the temperature range of 300 to 600 ° C. will be described. For example, TG (Thermogravimetry) and MS (Mass spectrometry) can be used. TG measures the change in weight of a sample (titanium-containing oxide) due to heating. MS also identifies that the gas generated from the sample (titanium-containing oxide) is H 2 O.
　具体的な測定方法は以下の通りである。電池電圧が１．５Ｖ以下の非水電解質電池を分解して負極から単斜晶構造を有するチタン含有酸化物の粒子を取り出す。取り出したチタン含有酸化物粒子を十分に水等で洗浄して粒子表面の付着物（例えば、非水電解質、リチウム塩、導電剤、結着剤）を除去した後、チタン含有酸化物粒子を１００℃で真空乾燥後、上記ＴＧ及びＭＳにより３００～６００℃の温度範囲で放出するＨ２Ｏを検出すると共に、チタン含有酸化物の重量変化を測定することができる。 The specific measurement method is as follows. A nonaqueous electrolyte battery having a battery voltage of 1.5 V or less is disassembled, and titanium-containing oxide particles having a monoclinic structure are taken out from the negative electrode. The titanium-containing oxide particles taken out are sufficiently washed with water or the like to remove deposits (for example, non-aqueous electrolyte, lithium salt, conductive agent, binder) on the particle surface, and then the titanium-containing oxide particles are added to 100 After vacuum drying at 0 ° C., H 2 O released in the temperature range of 300 to 600 ° C. can be detected by the above TG and MS, and the weight change of the titanium-containing oxide can be measured.
　単斜晶構造を有するチタン含有酸化物は、リチウムイオンまたはナトリウムイオンを吸蔵放出し得る。リチウムイオンもナトリウムイオンも吸蔵されていない合成時が二酸化チタンで、充電等によりリチウムイオンが吸蔵されるとリチウムチタン酸化物を取り得る。また、充電等によりナトリウムイオンが吸蔵されるとナトリウムチタン酸化物を取り得る。よって、単斜晶構造を有するチタン含有酸化物の一般式は、ＬｉｘＴｉＯ２（０≦ｘ≦１）またはＮａｙＴｉＯ２（０≦ｙ≦１）で表される。 A titanium-containing oxide having a monoclinic structure can occlude and release lithium ions or sodium ions. At the time of synthesis in which neither lithium ions nor sodium ions are occluded, titanium dioxide can be obtained. When lithium ions are occluded by charging or the like, lithium titanium oxide can be obtained. Further, when sodium ions are occluded by charging or the like, sodium titanium oxide can be taken. Therefore, the general formula of the titanium-containing oxide having a monoclinic structure is represented by Li x TiO 2 (0 ≦ x ≦ 1) or Na y TiO 2 (0 ≦ y ≦ 1).
　単斜晶構造を有する二酸化チタンは、空間群Ｃ２／ｍで表すことができる。 Titanium dioxide having a monoclinic structure can be represented by a space group C2 / m.
　単斜晶構造を有するチタン含有酸化物は、強度比（Ｉｂ／Ｉａ）が０以上０．７以下であることが好ましい。強度Ｉａは、Ｃｕ－Ｋα線源とする粉末Ｘ線回折法において回折角（２θ）が２７ｄｅｇ～２９ｄｅｇに現れる（００２）面のピークトップ（Ｐａ）の強度であり、強度Ｉｂは、Ｃｕ－Ｋα線源とする粉末Ｘ線回折法において回折角（２θ）が２９ｄｅｇ～３２ｄｅｇに現れるピークトップ（Ｐｂ）の強度である。この範囲を満たすことにより、高温環境下でのガス発生を減少させてサイクル寿命性能を向上することができる。より好ましくは、０以上０．５以下である。ただしＰａとＰｂのピークが重なる場合は、強度Ｉｂを０とする。 The titanium-containing oxide having a monoclinic structure preferably has an intensity ratio (Ib / Ia) of 0 or more and 0.7 or less. The intensity Ia is the intensity of the peak top (Pa) of the (002) plane where the diffraction angle (2θ) appears at 27 deg to 29 deg in the powder X-ray diffraction method using a Cu—Kα ray source, and the intensity Ib is Cu—Kα. In the powder X-ray diffraction method using a radiation source, the intensity of the peak top (Pb) where the diffraction angle (2θ) appears at 29 deg to 32 deg. By satisfying this range, gas generation under a high temperature environment can be reduced and cycle life performance can be improved. More preferably, it is 0 or more and 0.5 or less. However, when the peaks of Pa and Pb overlap, the intensity Ib is set to zero.
　単斜晶構造を有するチタン含有酸化物は、Ｘ線回折による結晶子サイズが５～１００ｎｍの範囲内であることが好ましい。この範囲にあることで、固体内のリチウムイオンの拡散距離が短くなるため、固体内のリチウムイオンの拡散性が向上する。また、結晶子サイズを１０～３０ｎｍの範囲にすることが好ましい。これにより、結晶中のＨ２Ｏ分子の含有率を適切な範囲に保つことが可能となる。 The titanium-containing oxide having a monoclinic structure preferably has a crystallite size in the range of 5 to 100 nm by X-ray diffraction. By being in this range, since the diffusion distance of lithium ions in the solid is shortened, the diffusibility of lithium ions in the solid is improved. The crystallite size is preferably in the range of 10 to 30 nm. Thereby, it becomes possible to keep the content of H 2 O molecules in the crystal in an appropriate range.
　単斜晶構造を有するチタン含有酸化物を含む負極活物質の一次粒子の平均粒子径は、０．０５～１μｍが好ましい。サイクル寿命性能と電極密度を高めるため球状に造粒して二次粒子とすることが好ましい。二次粒子の平均粒子径は１～２０μｍが好ましい。負極活物質粒子のＮ２吸着のＢＥＴ比表面積は、５～５０ｍ２／ｇが好ましい。 The average particle diameter of the primary particles of the negative electrode active material containing a titanium-containing oxide having a monoclinic structure is preferably 0.05 to 1 μm. In order to increase the cycle life performance and the electrode density, it is preferable to granulate to form secondary particles. The average particle diameter of the secondary particles is preferably 1 to 20 μm. BET specific surface area of the N 2 adsorption of the anode active material particles is preferably 5 ~ 50m 2 / g.
　３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出し、単斜晶構造を有するチタン含有酸化物は、以下の合成方法で作製することができる。この製造方法は、チタン酸アルカリ化合物を得る工程と、チタン酸アルカリ化合物に酸を反応させてアルカリカチオンをプロトン交換することによりプロトン交換体としてチタン酸プロトン化合物を得る工程と、プロトン交換体（チタン酸プロトン化合物）を加圧雰囲気で２５０～５００℃の温度範囲で加熱処理する工程とを含む。結晶中にＨ２Ｏを０．０１～０．５重量％含有する単斜晶構造の二酸化チタンを得るためには、プロトン交換体（チタン酸プロトン化合物）を１．１気圧以上３気圧以下の範囲の加圧雰囲気で２００～３５０℃の低温度範囲で長時間加熱処理（例えば５時間以上）することが好ましい。あるいは１．２気圧以上５気圧以下の範囲の加圧雰囲気で４００～５００℃の高温で短時間の加熱処理（例えば１時間以下）を、アナターゼ型のＴｉＯ２が生成しない範囲で行うことが好ましい。焼成温度を５００℃以下にすることにより、アナターゼ型のＴｉＯ２の生成を抑制することが可能である。 A titanium-containing oxide having a monoclinic structure releasing 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C. can be produced by the following synthesis method. This manufacturing method includes a step of obtaining an alkali titanate compound, a step of reacting an acid with the alkali titanate compound to proton exchange an alkali cation to obtain a titanate proton compound as a proton exchanger, and a proton exchanger (titanium Heat treating the acid proton compound) in a temperature range of 250 to 500 ° C. in a pressurized atmosphere. In order to obtain a monoclinic structure titanium dioxide containing 0.01 to 0.5% by weight of H 2 O in the crystal, a proton exchanger (a titanate proton compound) is added at 1.1 to 3 atm. It is preferable to perform heat treatment for a long time (for example, 5 hours or more) in a low temperature range of 200 to 350 ° C. in a pressurized atmosphere in the range. Alternatively, it is preferable to perform the heat treatment for a short time (for example, 1 hour or less) at a high temperature of 400 to 500 ° C. in a pressurized atmosphere in the range of 1.2 atmospheres to 5 atmospheres in a range in which anatase TiO 2 is not generated. . By setting the firing temperature to 500 ° C. or lower, it is possible to suppress the production of anatase TiO 2 .
　チタン酸アルカリ化合物の例には、Ｋ２Ｔｉ２Ｏ５、Ｎａ２Ｔ３Ｏ７、Ｋ２Ｔｉ４Ｏ９及びＣｓ２Ｔｉ５Ｏ１２が含まれる。また、酸の例には、塩酸、硝酸、硫酸が含まれる。酸水溶液の濃度は０．５～２Ｍの範囲にすることが望ましい。 Examples of alkali titanate compounds include K 2 Ti 2 O 5 , Na 2 T 3 O 7 , K 2 Ti 4 O 9 and Cs 2 Ti 5 O 12 . Examples of the acid include hydrochloric acid, nitric acid, and sulfuric acid. The concentration of the aqueous acid solution is preferably in the range of 0.5 to 2M.
　以下、負極、正極及び非水電解質について説明する。 Hereinafter, the negative electrode, the positive electrode, and the nonaqueous electrolyte will be described.
　（１）負極
　この負極は、負極集電体と、集電体の片面もしくは両面に担持され、活物質、導電剤および結着剤を含む負極活物質含有層（負極材料層）とを有する。 (1) Negative electrode This negative electrode has a negative electrode current collector and a negative electrode active material-containing layer (negative electrode material layer) supported on one or both sides of the current collector and containing an active material, a conductive agent, and a binder.
　負極活物質には、単斜晶構造のチタン含有酸化物のみを使用しても良いが、これ以外の負極活物質を含有させても良い。他の負極活物質の例には、スピネル構造のリチウムチタン酸化物（例えば、一般式Ｌｉ４／３＋ｘＴｉ５／３Ｏ４（０≦ｘ≦１．１））、ラムスデライト構造のリチウムチタン酸化物（例えば、Ｌｉ２＋ｘＴｉ３Ｏ７（－１≦ｘ≦３））、Ｌｉ１＋ｘＴｉ２Ｏ４（０≦ｘ≦１）、Ｌｉ１．１＋ｘＴｉ１．８Ｏ４（０≦ｘ≦１）、Ｌｉ１．０７＋ｘＴｉ１．８６Ｏ４（０≦ｘ≦１）、ニオブチタン酸化物などが含まれる。負極活物質全体に対する他の負極活物質の割合は、５０重量％以下にすることが望ましい。 As the negative electrode active material, only a monoclinic structure titanium-containing oxide may be used, but other negative electrode active materials may be included. Examples of other negative electrode active materials include spinel-type lithium titanium oxide (for example, general formula Li 4/3 + x Ti 5/3 O 4 (0 ≦ x ≦ 1.1)), ramsdellite-type lithium titanium oxide Product (for example, Li 2 + x Ti 3 O 7 (−1 ≦ x ≦ 3)), Li 1 + x Ti 2 O 4 (0 ≦ x ≦ 1), Li 1.1 + x Ti 1.8 O 4 (0 ≦ x ≦ 1) ), Li 1.07 + x Ti 1.86 O 4 (0 ≦ x ≦ 1), niobium titanium oxide, and the like. The ratio of the other negative electrode active material to the whole negative electrode active material is desirably 50% by weight or less.
　ニオブチタン酸化物の例には、ＬｉａＴｉＭｂＮｂ２±βＯ７±σ（０≦ａ≦５、０≦ｂ≦０．３、０≦β≦０．３、０≦σ≦０．３、ＭはＦｅ，Ｖ，Ｍｏ及びＴａよりなる群から選択される１種以上の元素）で表されるものが含まれる。 Examples of niobium titanium oxide include Li a TiM b Nb 2 ± β O 7 ± σ (0 ≦ a ≦ 5, 0 ≦ b ≦ 0.3, 0 ≦ β ≦ 0.3, 0 ≦ σ ≦ 0.3). , M includes one represented by one or more elements selected from the group consisting of Fe, V, Mo, and Ta.
　導電剤としては、例えば、アセチレンブラック、カーボンブラック、コークス、炭素繊維、黒鉛、Ｌｉ４Ｔｉ５Ｏ１２、金属化合物粉末、金属粉末等を挙げることができる。導電剤の種類は１種もしくは２種以上にすることができる。好ましい導電剤の例には、熱処理温度が８００℃～２０００℃の平均粒子径１０μｍ以下のコークス、黒鉛、アセチレンブラック、金属化合物粉末（例えば、ＴｉＯ、ＴｉＣ、ＴｉＮの粉末）、金属粉末（例えば、Ａｌ，Ｎｉ，Ｃｕ、Ｆｅの粉末）が含まれる。さらに好ましい例には、黒鉛、繊維径１μｍ以下の炭素繊維、アセチレンブラック、コークス、Ｌｉ４Ｔｉ５Ｏ１２が含まれる。これらから選択される１種以上によると、電極抵抗の低減とサイクル寿命性能の向上が図れる。また、繊維径１μｍ以下の炭素繊維及び／またはＬｉ４Ｔｉ５Ｏ１２を導電剤として用いることにより、電極抵抗の低減とサイクル寿命性能の向上が図れる。 Examples of the conductive agent include acetylene black, carbon black, coke, carbon fiber, graphite, Li 4 Ti 5 O 12 , metal compound powder, and metal powder. The type of the conductive agent can be one type or two or more types. Examples of preferable conductive agents include coke having a heat treatment temperature of 800 ° C. to 2000 ° C. and an average particle size of 10 μm or less, graphite, acetylene black, metal compound powder (eg, TiO, TiC, TiN powder), metal powder (eg, Al, Ni, Cu, Fe powder). Further preferable examples include graphite, carbon fiber having a fiber diameter of 1 μm or less, acetylene black, coke, and Li 4 Ti 5 O 12 . According to one or more selected from these, electrode resistance can be reduced and cycle life performance can be improved. Further, by using carbon fibers having a fiber diameter of 1 μm or less and / or Li 4 Ti 5 O 12 as a conductive agent, it is possible to reduce electrode resistance and improve cycle life performance.
　結着剤としては、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、アクリル系ゴム、スチレンブタジェンゴム、コアシェルバインダー、ポリイミドなどが挙げられる。結着剤の種類は１種もしくは２種以上にすることができる。 Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, acrylic rubber, styrene butadiene rubber, core shell binder, and polyimide. The kind of binder can be made into 1 type, or 2 or more types.
　負極の活物質、導電剤及び結着剤の配合比は、負極活物質８０～９５重量％、導電剤１～１８重量％、結着剤２～７重量％の範囲にすることが好ましい。 The compounding ratio of the negative electrode active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the negative electrode active material, 1 to 18% by weight of the conductive agent, and 2 to 7% by weight of the binder.
　負極の比表面積は１～２０ｍ2／ｇの範囲が好ましい。この範囲であると高温環境下での非水電解質の還元分解が抑制されてサイクル寿命が向上される。ここで、負極の比表面積は、負極活物質含有層（集電体重量を除く）１ｇ当りの表面積を意味する。なお、負極活物質含有層とは、集電体上に担持された負極活物質、導電剤及び結着剤を含む多孔質の層である。 The specific surface area of the negative electrode is preferably in the range of 1 to 20 m 2 / g. Within this range, reductive decomposition of the nonaqueous electrolyte in a high temperature environment is suppressed, and the cycle life is improved. Here, the specific surface area of the negative electrode means a surface area per 1 g of the negative electrode active material-containing layer (excluding the weight of the current collector). Note that the negative electrode active material-containing layer is a porous layer containing a negative electrode active material, a conductive agent, and a binder carried on a current collector.
　負極の多孔度（集電体を除く）は、２０～５０％の範囲にすることが望ましい。これにより、負極と非水電解質との親和性に優れ、かつ高密度な負極を得ることができる。多孔度のさらに好ましい範囲は、２５～４０％である。 The porosity of the negative electrode (excluding the current collector) is preferably in the range of 20 to 50%. Thereby, it is possible to obtain a negative electrode having excellent affinity between the negative electrode and the non-aqueous electrolyte and a high density. A more preferable range of the porosity is 25 to 40%.
　負極集電体は、アルミニウム箔またはアルミニウム合金箔であることが望ましい。アルミニウム箔およびアルミニウム合金箔の厚さは、２０μｍ以下、より好ましくは１５μｍ以下である。アルミニウム箔の純度は９９．９９重量％以上が好ましい。アルミニウム合金としては、マグネシウム、亜鉛及びケイ素よりなる群から選択される少なくとも１種の元素を含むアルミニウム合金が好ましい。一方、鉄、銅、ニッケル、クロムなどの遷移金属は１００重量ｐｐｍ以下にすることが好ましい。 The negative electrode current collector is preferably an aluminum foil or an aluminum alloy foil. The thickness of the aluminum foil and the aluminum alloy foil is 20 μm or less, more preferably 15 μm or less. The purity of the aluminum foil is preferably 99.99% by weight or more. As the aluminum alloy, an aluminum alloy containing at least one element selected from the group consisting of magnesium, zinc and silicon is preferable. On the other hand, transition metals such as iron, copper, nickel, and chromium are preferably 100 ppm by weight or less.
　負極は、例えば、負極活物質の粒子、導電剤及び結着剤を適当な溶媒に懸濁させ、この懸濁物を集電体に塗布し、乾燥し、プレス（例えば加温プレス）を施すことにより作製される。 For the negative electrode, for example, the negative electrode active material particles, the conductive agent and the binder are suspended in an appropriate solvent, and the suspension is applied to a current collector, dried, and subjected to a press (for example, a warming press). It is produced by this.
　（２）正極
　この正極は、正極集電体と、前記集電体の片面もしくは両面に担持され、正極活物質、導電剤および結着剤を含む正極活物質含有層（正極材料層）とを有する。 (2) Positive electrode This positive electrode comprises a positive electrode current collector and a positive electrode active material-containing layer (positive electrode material layer) that is carried on one or both surfaces of the current collector and contains a positive electrode active material, a conductive agent, and a binder. Have.
　正極活物質には、リチウムイオンまたはナトリウムイオンを吸蔵放出可能なものが使用され得る。正極活物質の例には、リチウムマンガン複合酸化物、リチウムニッケル複合酸化物、リチウムコバルトアルミニウム複合酸化物、リチウムニッケルコバルトマンガン複合酸化物、スピネル型リチウムマンガンニッケル複合酸化物、リチウムマンガンコバルト複合酸化物、リチウム鉄酸化物、リチウムフッ素化硫酸鉄、オリビン結晶構造のリン酸化合物（例えば、ＬｉｘＦｅＰＯ４（０≦ｘ≦１）、ＬｉｘＭｎＰＯ４（０≦ｘ≦１））などが含まれる。また、リチウムイオンをナトリムイオンに置き換えたナトリウム金属酸化物等を用いることができる。オリビン結晶構造のリン酸化合物は、熱安定性に優れている。 As the positive electrode active material, a material capable of occluding and releasing lithium ions or sodium ions can be used. Examples of positive electrode active materials include lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt aluminum composite oxide, lithium nickel cobalt manganese composite oxide, spinel type lithium manganese nickel composite oxide, lithium manganese cobalt composite oxide , Lithium iron oxide, lithium fluorinated iron sulfate, phosphate compounds having an olivine crystal structure (for example, Li x FePO 4 (0 ≦ x ≦ 1), Li x MnPO 4 (0 ≦ x ≦ 1)), etc. . In addition, sodium metal oxide in which lithium ions are replaced with sodium ions can be used. The phosphate compound having an olivine crystal structure is excellent in thermal stability.
　正極活物質に、ＬｉｘＭｎ２－ａＮｉａＯ４（０≦ｘ≦１．１，０．１≦ａ≦０．６）で表されるスピネル構造のマンガンニッケル含有酸化物、ＬｉｘＦｅ１－ｗＭｎｗＳＯ４Ｆ（０≦ｘ≦１．１，０≦ｗ≦０．２）で表されるフッ素化硫酸化合物、ＬｉｘＦｅ１－ｙ―ｚＭｎｙＭｚＰＯ４（ＭはＭｇ、Ａｌ、Ｔｉ及びＺｒよりなる群から選択される少なくとも１種の元素、０≦ｘ≦１．１，０≦ｙ≦１、０≦ｚ≦０．２）で表せるオリビン構造のリン酸化合物よりなる群から選ばれる少なくとも一種の正極活物質を用いることが望ましい。このような正極活物質を含む正極を負極に組み合わせることにより、熱安定が高くなり、高温環境下でのサイクル寿命性能が大幅に改善されようになる。 As the positive electrode active material, a manganese nickel-containing oxide having a spinel structure represented by Li x Mn 2-a Ni a O 4 (0 ≦ x ≦ 1.1, 0.1 ≦ a ≦ 0.6), Li x Fe Fluorinated sulfuric acid compound represented by 1-w Mn w SO 4 F (0 ≦ x ≦ 1.1, 0 ≦ w ≦ 0.2), Li x Fe 1-yz Mn y M z PO 4 (M Is at least one element selected from the group consisting of Mg, Al, Ti and Zr, 0 ≦ x ≦ 1.1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 0.2) It is desirable to use at least one positive electrode active material selected from the group consisting of compounds. By combining the positive electrode containing such a positive electrode active material with the negative electrode, the thermal stability is increased, and the cycle life performance under a high temperature environment is greatly improved.
　ＬｉｘＭｎ２－ａＮｉａＯ４（０≦ｘ≦１．１，０．１≦ａ≦０．６）で表されるスピネル構造のマンガンニッケル含有酸化物については、ＬｉＭｎ１．５Ｎｉ０．５Ｏ４が好ましい。ＬｉＭｎ１．５Ｎｉ０．５Ｏ４を含む正極の電位は、４．７（Ｖ　ｖｓ．Ｌｉ／Ｌｉ＋）と高電位を得られる。ＬｉＭｎ１．５Ｎｉ０．５Ｏ４を含む正極を負極に組み合わせることで、電池の中間電圧（セル中間電圧）が３．１Ｖという高電圧を得られるために好ましい。また、高温下でもガス発生を抑制でき、サイクル寿命が大幅に向上することができる。 For a manganese nickel-containing oxide having a spinel structure represented by Li x Mn 2-a Ni a O 4 (0 ≦ x ≦ 1.1, 0.1 ≦ a ≦ 0.6), LiMn 1.5 Ni 0 .5 O 4 is preferred. The potential of the positive electrode containing LiMn 1.5 Ni 0.5 O 4 can be as high as 4.7 (V vs. Li / Li + ). By combining a positive electrode containing LiMn 1.5 Ni 0.5 O 4 with a negative electrode, it is preferable because a high voltage of 3.1 V can be obtained as the intermediate voltage of the battery (cell intermediate voltage). Further, gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
　ＬｉｘＦｅ１－ｗＭｎｗＳＯ４Ｆ（０≦ｘ≦１．１，０≦ｗ≦０．２）で表されるフッ素化硫酸化合物については、タボライト構造又はトリプライト構造のＬｉＦｅＳＯ４Ｆ，タボライト構造又はトリプライト構造のＬｉＦｅ０．９Ｍｎ０．１ＳＯ４Ｆが好ましい。また、低抵抗化と寿命性能改善のため、フッ素化硫酸化合物の粒子表面の少なくとも一部を炭素材料層で被覆することが好ましい。これにより、活物質粒子のＢＥＴ比表面積を５ｍ２／ｇ以上にすることができる。 With respect to the fluorinated sulfuric acid compound represented by Li x Fe 1-w Mn w SO 4 F (0 ≦ x ≦ 1.1, 0 ≦ w ≦ 0.2), LiFeSO 4 F having a tabolite structure or a triplite structure, LiFe 0.9 Mn 0.1 SO 4 F having a tabolite structure or a triplite structure is preferable. In order to reduce resistance and improve life performance, it is preferable to coat at least a part of the particle surface of the fluorinated sulfuric acid compound with a carbon material layer. Thereby, the BET specific surface area of an active material particle can be 5 m < 2 > / g or more.
　タボライト構造のＬｉＦｅＳＯ４Ｆを含む正極を負極に組み合わせることにより、電池の中間電圧（セル中間電圧）を１．９５Ｖにすることができる。また、トリプライト構造のＬｉＦｅ０．９Ｍｎ０．１ＳＯ４Ｆを含む正極を負極に組み合わせることにより、電池の中間電圧（セル中間電圧）を２．３Ｖにすることができる。また、実施形態に係る負極活物質を含む負極を用いることで、タボライト構造のＬｉＦｅＳＯ４Ｆまたはトリプライト構造のＬｉＦｅ０．９Ｍｎ０．１ＳＯ４Ｆの比表面積を５ｍ２／ｇ以上にしても、高温下でもガス発生を抑制できてサイクル寿命が大幅に向上することができる。 By combining a positive electrode containing LiFeSO 4 F having a tabolite structure with a negative electrode, the intermediate voltage (cell intermediate voltage) of the battery can be set to 1.95V. Further, by combining a positive electrode containing triplite-structured LiFe 0.9 Mn 0.1 SO 4 F with the negative electrode, the intermediate voltage of the battery (cell intermediate voltage) can be set to 2.3V. In addition, by using the negative electrode including the negative electrode active material according to the embodiment, the specific surface area of the LiboSO 4 F of the tabolite structure or LiFe 0.9 Mn 0.1 SO 4 F of the triplite structure is set to 5 m 2 / g or more. However, gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
　ＬｉｘＦｅ１－ｙ―ｚＭｎｙＭｚＰＯ４で表せるオリビン構造のリン酸化合物については、ＬｉＭｎ０．８５Ｆｅ０．１Ｍｇ０．０５ＰＯ４、ＬｉＦｅＰＯ４が好ましい。また、低抵抗化と寿命性能改善のため、オリビン構造のリチウムリン酸化合物の粒子表面の少なくとも一部を炭素材料層で被覆することが好ましい。これにより、活物質粒子のＢＥＴ比表面積を８ｍ２／ｇ以上にすることができる。 As for the phosphate compound having an olivine structure represented by Li x Fe 1-yz Mn y M z PO 4 , LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 and LiFePO 4 are preferable. In order to reduce the resistance and improve the life performance, it is preferable to coat at least a part of the particle surface of the lithium phosphate compound having an olivine structure with a carbon material layer. Thereby, the BET specific surface area of an active material particle can be 8 m < 2 > / g or more.
　ＬｉｘＦｅ１－ｙ―ｚＭｎｙＭｚＰＯ４において、ｙは０．５以上１以下が好ましく、より好ましくは０．７以上０．９以下である。この範囲であることにより、正極電圧が高くなりエネルギー密度向上と電子伝導性が高くなり大電流性能が向上される。また、ＭがＭｇ、Ａｌ、Ｔｉ及びＺｒよりなる群から選択される少なくとも１種の元素が０以上０．１以下、より好ましくは０．０１以上０．０８以下であることにより、高温サイクル（例えば４５℃以上）でのＭｎ、Ｆｅの溶解が抑制されて高温サイクル性能が大幅に向上する。 In Li x Fe 1-yz Mn y M z PO 4 , y is preferably 0.5 or more and 1 or less, more preferably 0.7 or more and 0.9 or less. By being in this range, the positive electrode voltage is increased, the energy density is improved, the electron conductivity is increased, and the large current performance is improved. Further, when at least one element selected from the group consisting of Mg, Al, Ti and Zr is 0 or more and 0.1 or less, more preferably 0.01 or more and 0.08 or less, a high temperature cycle ( For example, dissolution of Mn and Fe at 45 ° C. or higher is suppressed, and the high-temperature cycle performance is greatly improved.
　実施形態に係る負極活物質を含む負極にＬｉＭｎ０．８５Ｆｅ０．１Ｍｇ０．０５ＰＯ４を含む正極を組み合わせることにより、電池の中間電圧（セル中間電圧）を２．５Ｖにすることができる。また、ＬｉＦｅＰＯ４を含む正極と組み合わせると、電池の中間電圧（セル中間電圧）を１．８Ｖにすることができる。また、実施形態に係る負極活物質を含む負極を用いることで、ＬｉｘＦｅ１－ｙ―ｚＭｎｙＭｚＰＯ４で表せるオリビン構造のリン酸化合物の比表面積を８ｍ２／ｇ以上にしても、高温下でもガス発生を抑制できてサイクル寿命が大幅に向上することができる。 By combining the positive electrode containing LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 in the negative electrode containing a negative electrode active material according to the embodiment, it is an intermediate voltage of the battery (cell intermediate voltage) to 2.5V it can. Moreover, when combined with a positive electrode containing LiFePO 4 , the battery intermediate voltage (cell intermediate voltage) can be 1.8V. In addition, by using the negative electrode including the negative electrode active material according to the embodiment, the specific surface area of the phosphate compound having an olivine structure represented by Li x Fe 1-yz Mn y M z PO 4 is set to 8 m 2 / g or more. However, gas generation can be suppressed even at high temperatures, and the cycle life can be greatly improved.
　オリビン構造のリン酸化合物及び／またはフッ素化硫酸化合物を含む正極は、コバルト、ニッケル及びマンガンよるなる群から選択される少なくとも１種の金属の酸化物を含有していても良い。金属酸化物のより好ましい例には、ＬｉｘＣｏＯ２（０≦ｘ≦１）、ＬｉＮｉ１－ｅＣｏｅＭｎｆＯ２（０≦ｅ≦１，０≦ｆ≦１）、ＬｉｘＭｎ２Ｏ４（０≦ｘ≦１）などが含まれる。正極活物質含有層に対する金属酸化物の添加量を３０重量％以下にすることで、電極密度が高くなり電極の体積比容量が向上する。 The positive electrode containing a phosphate compound and / or a fluorinated sulfuric acid compound having an olivine structure may contain an oxide of at least one metal selected from the group consisting of cobalt, nickel and manganese. More preferable examples of the metal oxide include Li x CoO 2 (0 ≦ x ≦ 1), LiNi 1-e Co e Mn f O 2 (0 ≦ e ≦ 1, 0 ≦ f ≦ 1), Li x Mn 2 O 4 (0 ≦ x ≦ 1) and the like are included. By making the addition amount of the metal oxide to the positive electrode active material-containing layer 30% by weight or less, the electrode density is increased and the volume specific capacity of the electrode is improved.
　正極活物質の一次粒子の平均粒子径（直径）は１μｍ以下、より好ましくは０．０５～０．５μｍである。正極活物質の粒子表面の少なくとも一部が炭素材料で被覆されていることが好ましい。炭素材料は、層構造、粒子構造、あるいは粒子の集合体の形態をとり得る。 The average particle diameter (diameter) of the primary particles of the positive electrode active material is 1 μm or less, more preferably 0.05 to 0.5 μm. It is preferable that at least a part of the particle surface of the positive electrode active material is coated with a carbon material. The carbon material may take the form of a layer structure, a particle structure, or an aggregate of particles.
　導電剤の例には、アセチレンブラック、カーボンブラック、黒鉛、炭素繊維等が含まれる。繊維径が１μｍ以下の炭素繊維、特に、繊維径が１μｍ以下の気相成長の炭素繊維が好ましい。繊維径１μｍ以下の炭素繊維を含むことにより、正極の電子伝導抵抗の大きい問題を繊維径の細い炭素繊維のネットワークにより改善できて正極抵抗を効果的に低減することができる。このため、正極の出力性能を大幅に向上することができる。 Examples of the conductive agent include acetylene black, carbon black, graphite, carbon fiber and the like. Carbon fibers having a fiber diameter of 1 μm or less, particularly vapor-grown carbon fibers having a fiber diameter of 1 μm or less are preferred. By including a carbon fiber having a fiber diameter of 1 μm or less, the problem of large electron conduction resistance of the positive electrode can be improved by a network of carbon fibers having a small fiber diameter, and the positive electrode resistance can be effectively reduced. For this reason, the output performance of a positive electrode can be improved significantly.
　正極は、コバルト、ニッケル及びマンガンよるなる群から選択される少なくとも１種の金属の酸化物を含有していても良い。金属酸化物のより好ましい例には、ＬｉｘＣｏＯ２（０≦ｘ≦１）、ＬｉＮｉ１－ｅＣｏｅＭｎｆＯ２（０≦ｅ≦１，０≦ｆ≦１）、ＬｉｘＭｎ２Ｏ４（０≦ｘ≦１）などが含まれる。正極活物質含有層に対する金属酸化物の添加量を３０重量％以下にすることで、電極密度が高くなり電極の体積比容量が向上する。 The positive electrode may contain an oxide of at least one metal selected from the group consisting of cobalt, nickel and manganese. More preferable examples of the metal oxide include Li x CoO 2 (0 ≦ x ≦ 1), LiNi 1-e Co e Mn f O 2 (0 ≦ e ≦ 1, 0 ≦ f ≦ 1), Li x Mn 2 O 4 (0 ≦ x ≦ 1) and the like are included. By making the addition amount of the metal oxide to the positive electrode active material-containing layer 30% by weight or less, the electrode density is increased and the volume specific capacity of the electrode is improved.
　結着剤の例には、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、アクリル酸などが挙げられる。結着剤の種類は１種もしくは２種以上にすることができる。 Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine-based rubber, acrylic acid, and the like. The kind of binder can be made into 1 type, or 2 or more types.
　正極活物質、導電剤及び結着剤の配合比は、正極活物質８０～９５重量％、導電剤３～１９重量％、結着剤１～７重量％の範囲にすることが好ましい。 The compounding ratio of the positive electrode active material, the conductive agent and the binder is preferably in the range of 80 to 95% by weight of the positive electrode active material, 3 to 19% by weight of the conductive agent, and 1 to 7% by weight of the binder.
　集電体は、アルミニウム箔またはアルミニウム合金箔が好ましく、厚さは２０μｍ以下、より好ましくは１５μｍ以下であることが望ましい。 The current collector is preferably an aluminum foil or an aluminum alloy foil, and the thickness is desirably 20 μm or less, more preferably 15 μm or less.
　正極は、例えば、正極活物質、導電剤及び結着剤を適当な溶媒に懸濁し、この懸濁物を集電体に塗布し、乾燥し、プレスを施すことにより作製される。 The positive electrode is produced, for example, by suspending a positive electrode active material, a conductive agent, and a binder in a suitable solvent, applying the suspension to a current collector, drying, and pressing.
　正極活物質含有層のＢＥＴ法による比表面積は、０．１～１０ｍ２／ｇの範囲であることが好ましい。 The specific surface area by the BET method of the positive electrode active material-containing layer is preferably in the range of 0.1 to 10 m 2 / g.
　（３）非水電解質
　非水電解質は、リチウムイオン伝導性有する液状、ゲル状、固体の電解質で、リチウム塩を含む有機電解液、イオン液体、高分子固体電解質、無機固体電解質を含有することが好ましい。また、ナトリウムイオン伝導性有する液状、ゲル状、固体の電解質で、ナトリウム塩を含む有機電解液、イオン液体、高分子固体電解質、無機固体電解質を含有しても良い。 (3) Non-aqueous electrolyte The non-aqueous electrolyte is a liquid, gel-like, solid electrolyte having lithium ion conductivity, and may contain an organic electrolyte containing a lithium salt, an ionic liquid, a polymer solid electrolyte, and an inorganic solid electrolyte. preferable. Further, it is a liquid, gel, or solid electrolyte having sodium ion conductivity, and may contain an organic electrolyte containing sodium salt, an ionic liquid, a polymer solid electrolyte, or an inorganic solid electrolyte.
　非水電解質の例には、電解質を有機溶媒に溶解することにより調製される液状の有機電解質、液状の有機溶媒と高分子材料を複合化したゲル状の有機電解質、リチウム金属酸化物、リチウム金属硫化物またはリチウム塩電解質と高分子材料を複合化した固体非水電解質が挙げられる。また、リチウムイオンを含有した常温溶融塩（イオン性融体）を非水電解質として使用してもよい。高分子材料としては、例えば、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリアクリロニトリル（ＰＡＮ）、ポリエチレンオキサイド（ＰＥＯ）等を挙げることができる。 Examples of non-aqueous electrolytes include a liquid organic electrolyte prepared by dissolving an electrolyte in an organic solvent, a gel organic electrolyte obtained by combining a liquid organic solvent and a polymer material, lithium metal oxide, lithium metal Examples thereof include solid nonaqueous electrolytes in which a sulfide or lithium salt electrolyte and a polymer material are combined. Moreover, you may use the normal temperature molten salt (ionic melt) containing lithium ion as a non-aqueous electrolyte. Examples of the polymer material include polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO), and the like.
　液状の非水電解質は、リチウム塩電解質を０．５～２．５ｍｏｌ／Ｌの濃度で有機溶媒に溶解することにより、調製される。 A liquid non-aqueous electrolyte is prepared by dissolving a lithium salt electrolyte in an organic solvent at a concentration of 0.5 to 2.5 mol / L.
　リチウム塩電解質の例には、ＬｉＢＦ4、ＬｉＰＦ6、ＬｉＡｓＦ6、ＬｉＣｌＯ4、ＬｉＣＦ3ＳＯ3、ＬｉＮ（ＦＳＯ2）2、ＬｉＮ（ＣＦ3ＳＯ2）2、ＬｉＮ（Ｃ2Ｆ5ＳＯ2）2、Ｌｉ（ＣＦ3ＳＯ2）3Ｃ、ＬｉＢ［（ＯＣＯ）2］2などが挙げられる。使用する電解質の種類は、１種類または２種類以上にすることができる。中でも、ＬｉＰＦ６、ＬｉＢＦ4、ＬｉＮ（ＦＳＯ２）２よりなる群から選択される１種以上を含むことが好ましい。これにより、有機溶媒の化学的安定性が高まり、負極上の皮膜抵抗を小さくすることができ、低温性能とサイクル寿命性能を大幅に向上することができる。また、リチウムイオンをナトリウムイオンに置き換えたナトリウム塩電解質を用いることができる。 Examples of lithium salt electrolytes include LiBF 4 , LiPF 6 , LiAsF 6 , LiClO 4 , LiCF 3 SO 3 , LiN (FSO 2 ) 2 , LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ). 2 , Li (CF 3 SO 2 ) 3 C, LiB [(OCO) 2 ] 2 and the like. The type of electrolyte used can be one type or two or more types. Among them, LiPF 6, LiBF 4, LiN (FSO 2) preferably comprises one or more selected from the group consisting of 2. Thereby, the chemical stability of the organic solvent is increased, the film resistance on the negative electrode can be reduced, and the low temperature performance and cycle life performance can be greatly improved. A sodium salt electrolyte in which lithium ions are replaced with sodium ions can be used.
　有機溶媒としては、例えば、プロピレンカーボネート（ＰＣ）やエチレンカーボネート（ＥＣ）などの環状カーボネート、ジエチルカーボネート（ＤＥＣ）やジメチルカーボネート（ＤＭＣ）あるいはメチルエチルカーボネート（ＭＥＣ）などの鎖状カーボネート、ジメトキシエタン（ＤＭＥ）やジエトキシエタン（ＤＥＥ）などの鎖状エーテル、テトラヒドロフラン（ＴＨＦ）やジオキソラン（ＤＯＸ）などの環状エーテル、γ－ブチロラクトン（ＧＢＬ）、２－メチル－γ－ブチロラクトン（ＭＢＬ）、アセトニトリル（ＡＮ）、３－メトキシプロピオンニトリル（ＭＯＰＮ）、スルホラン（ＳＬ）などを挙げることができる。これらの有機溶媒は、単独または２種以上の混合物の形態で用いることができる。特に、プロピレンカーボネート（ＰＣ）、エチレンカーボネート（ＥＣ）及びγ―ブチロラクトン（ＧＢＬ）よりなる群から選択される１種以上を主体とすることにより、沸点が２００℃以上となり熱安定性が高くなり好ましい。特に、γ―ブチロラクトン（ＧＢＬ）、２－メチル－γ－ブチロラクトン（ＭＢＬ）及び３－メトキシプロピオンニトリル（ＭＯＰＮ）よりなる群から選択される１種以上を含むことにより、高沸点、高引火点及び低蒸気圧の非水溶媒となるために高温環境下での安定性が高くなり、且つ低温環境下での出力性能も高くなり好ましい。また、高濃度のリチウム塩を溶解して使用することが可能となる。リチウム塩またはナトリム塩は、有機溶媒に対して１．５～３ｍｏｌ／Ｌの範囲で溶解させることが好ましい。これにより、低温環境下においても高出力を取り出すことができる。この範囲より小さいと、大電流で放電中に正極と非水電解質界面のリチウムイオン濃度が急激に低下し、大幅に出力が低下する恐れがある。一方、濃度が３ｍｏｌ／Ｌを超えると、非水電解質の粘度が高くなり、リチウムイオンの移動速度が低下して大幅な出力低下となる恐れがある。 Examples of the organic solvent include cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC), chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC), dimethoxyethane ( DME) and chain ethers such as diethoxyethane (DEE), cyclic ethers such as tetrahydrofuran (THF) and dioxolane (DOX), γ-butyrolactone (GBL), 2-methyl-γ-butyrolactone (MBL), acetonitrile (AN) ), 3-methoxypropiononitrile (MOPN), sulfolane (SL), and the like. These organic solvents can be used alone or in the form of a mixture of two or more. In particular, it is preferable that the main component is one or more selected from the group consisting of propylene carbonate (PC), ethylene carbonate (EC), and γ-butyrolactone (GBL), and the boiling point becomes 200 ° C. or higher, resulting in high thermal stability. . In particular, by including one or more selected from the group consisting of γ-butyrolactone (GBL), 2-methyl-γ-butyrolactone (MBL) and 3-methoxypropiononitrile (MOPN), a high boiling point, a high flash point and Since it becomes a non-aqueous solvent having a low vapor pressure, stability under a high temperature environment is increased, and output performance under a low temperature environment is also increased, which is preferable. Moreover, it becomes possible to dissolve and use a high concentration lithium salt. The lithium salt or sodium salt is preferably dissolved in the range of 1.5 to 3 mol / L with respect to the organic solvent. Thereby, a high output can be taken out even in a low temperature environment. If it is smaller than this range, the lithium ion concentration at the interface between the positive electrode and the non-aqueous electrolyte is rapidly reduced during discharge with a large current, and the output may be significantly reduced. On the other hand, when the concentration exceeds 3 mol / L, the viscosity of the non-aqueous electrolyte increases, and the migration rate of lithium ions may decrease, resulting in a significant decrease in output.
　常温溶融塩（イオン性融体）は、リチウムイオン又はナトリウムイオンと、有機物カチオンと、有機物アニオンとから構成されることが好ましい。また、常温溶融塩は、室温以下で液体状であることが望ましい。以下、常温溶融塩を含む電解質について説明する。 The room temperature molten salt (ionic melt) is preferably composed of lithium ions or sodium ions, an organic cation, and an organic anion. The room temperature molten salt is preferably liquid at room temperature or lower. Hereinafter, an electrolyte containing a room temperature molten salt will be described.
　常温溶融塩とは、常温において少なくとも一部が液状を呈する塩をいい、常温とは電源が通常作動すると想定される温度範囲をいう。電源が通常作動すると想定される温度範囲とは、上限が１２０℃程度、場合によっては６０℃程度であり、下限は－４０℃程度、場合によっては－２０℃程度である。中でも、－２０℃以上、６０℃以下の範囲が適している。 “Room temperature molten salt” refers to a salt that is at least partially liquid at room temperature, and “room temperature” refers to a temperature range in which the power supply is assumed to normally operate. The temperature range in which the power supply is assumed to operate normally has an upper limit of about 120 ° C., in some cases about 60 ° C., and a lower limit of about −40 ° C., in some cases about −20 ° C. In particular, a range of −20 ° C. or more and 60 ° C. or less is suitable.
　リチウムイオンを含有した常温溶融塩には、リチウムイオンと有機物カチオンとアニオンから構成されるイオン性融体を使用することが望ましい。また、このイオン性融体は、室温以下でも液状であることが好ましい。 For room temperature molten salts containing lithium ions, it is desirable to use an ionic melt composed of lithium ions, organic cations and anions. The ionic melt is preferably in a liquid state even at room temperature or lower.
　前記有機物カチオンとしては以下の化１に示す骨格を有するアルキルイミダゾリウムイオン、四級アンモニウムイオンが挙げられる。 Examples of the organic cation include alkyl imidazolium ions and quaternary ammonium ions having a skeleton shown in Chemical Formula 1 below.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　アルキルイミダソリウムイオンとしては、ジアルキルイミダゾリウムイオン、トリアルキルイミダゾリウムイオン、テトラアルキルイミダゾリウムイオンなどが好ましい。ジアルキルイミダゾリウムとしては、１－メチル－３－エチルイミダゾリウムイオン（ＭＥＩ+）などが好ましい。トリアルキルイミダゾリウムイオンとしては、１，２－ジエチル－３－プロピルイミダゾリウムイオン（ＤＭＰＩ+）などが好ましい。テトラアルキルイミダゾリウムイオンとして、１，２－ジエチル－３，４（５）－ジメチルイミダゾリウムイオンなどが好ましい。 As the alkyl imidazolium ion, a dialkyl imidazolium ion, a trialkyl imidazolium ion, a tetraalkyl imidazolium ion and the like are preferable. As the dialkylimidazolium, 1-methyl-3-ethylimidazolium ion (MEI + ) and the like are preferable. As the trialkylimidazolium ion, 1,2-diethyl-3-propylimidazolium ion (DMPI + ) and the like are preferable. As the tetraalkylimidazolium ion, 1,2-diethyl-3,4 (5) -dimethylimidazolium ion and the like are preferable.
　四級アンモニムイオンとしては、テトラアルキルアンモニウムイオン、環状アンモニウムイオンなどが好ましい。テトラアルキルアモニウムイオンとしては、ジメチルエチルメトキシエチルアンモニウムイオン、ジメチルエチルメトキシメチルアンモニウムイオン、ジメチルエチルエトキシエチルアンモニウムイオン、トリメチルプロピルアンモニウムイオンが好ましい。 As the quaternary ammonium ions, tetraalkylammonium ions, cyclic ammonium ions and the like are preferable. As the tetraalkylammonium ion, dimethylethylmethoxyethylammonium ion, dimethylethylmethoxymethylammonium ion, dimethylethylethoxyethylammonium ion, and trimethylpropylammonium ion are preferable.
　上記アルキルイミダゾリウムイオンまたは四級アンモニウムイオン（特にテトラアルキルアンモニウムイオン）を用いることにより、融点を１００℃以下、より好ましくは２０℃以下にすることができる。さらに負極との反応性を低くすることができる。 By using the above alkylimidazolium ion or quaternary ammonium ion (particularly tetraalkylammonium ion), the melting point can be made 100 ° C. or lower, more preferably 20 ° C. or lower. Furthermore, the reactivity with the negative electrode can be lowered.
　リチウムイオンの濃度は、２０ｍｏｌ％以下であることが好ましい。より好ましい範囲は、１～１０ｍｏｌ％の範囲である。前記範囲にすることにより、２０℃以下の低温においても液状の常温溶融塩を容易に形成できる。また常温以下でも粘度を低くすることができ、イオン伝導度を高くすることができる。 The concentration of lithium ions is preferably 20 mol% or less. A more preferred range is from 1 to 10 mol%. By setting it within the above range, a liquid room temperature molten salt can be easily formed even at a low temperature of 20 ° C. or lower. Further, the viscosity can be lowered even at room temperature or lower, and the ionic conductivity can be increased.
　アニオンとしては、ＢＦ4 -、ＰＦ6 -、ＡｓＦ6 -、ＣｌＯ4 -、ＣＦ3ＳＯ3 -、ＣＦ3ＣＯＯ-、ＣＨ3ＣＯＯ-、ＣＯ3 2-、（ＦＳＯ２）２Ｎ－、Ｎ（ＣＦ3ＳＯ2）2 -、Ｎ（Ｃ2Ｆ5ＳＯ2）2 -、（ＣＦ3ＳＯ2）3Ｃ-などから選ばれる一種以上のアニオンを共存させることが好ましい。複数のアニオンを共存させることにより、融点が２０℃以下の常温溶融塩を容易に形成できる。より好ましいアニオンとしては、ＢＦ4 -、（ＦＳＯ２）２Ｎ－、ＣＦ3ＳＯ3 -、ＣＦ3ＣＯＯ-、ＣＨ3ＣＯＯ-、ＣＯ3 2-、Ｎ（ＣＦ3ＳＯ2）2 -、Ｎ（Ｃ2Ｆ5ＳＯ2）2 -、（ＣＦ3ＳＯ2）3Ｃ-が挙げられる。これらアニオンによって０℃以下の常温溶融塩の形成がより容易になる。 As anions, BF 4 − , PF 6 − , AsF 6 − , ClO 4 − , CF 3 SO 3 − , CF 3 COO − , CH 3 COO − , CO 3 2− , (FSO 2 ) 2 N − , N It is preferable that at least one anion selected from (CF 3 SO 2 ) 2 − , N (C 2 F 5 SO 2 ) 2 − , (CF 3 SO 2 ) 3 C − and the like coexists. By allowing a plurality of anions to coexist, a room temperature molten salt having a melting point of 20 ° C. or lower can be easily formed. More preferred anions include BF 4 − , (FSO 2 ) 2 N − , CF 3 SO 3 − , CF 3 COO − , CH 3 COO − , CO 3 2− , N (CF 3 SO 2 ) 2 − , N (C 2 F 5 SO 2 ) 2 − and (CF 3 SO 2 ) 3 C − . These anions make it easier to form a room temperature molten salt at 0 ° C. or lower.
　非水電解質電池は、正極、負極及び非水電解質に加え、セパレータ及び外装部材を備えていても良い。以下、セパレータ、外装部材について説明する。 The nonaqueous electrolyte battery may include a separator and an exterior member in addition to the positive electrode, the negative electrode, and the nonaqueous electrolyte. Hereinafter, the separator and the exterior member will be described.
　（４）セパレータ
　正極と負極の間にはセパレータを配置することができる。セパレータの例には、合成樹脂製不織布、多孔質フィルム、セルロース製不織布などを挙げることができる。多孔質フィルムは、例えば、ポリエチレン、ポリプロピレンなどのポリオレフィンから形成することができる。 (4) Separator A separator can be disposed between the positive electrode and the negative electrode. Examples of the separator include a synthetic resin nonwoven fabric, a porous film, and a cellulose nonwoven fabric. A porous film can be formed from polyolefin, such as polyethylene and a polypropylene, for example.
　セパレータは、厚さ３０μｍ以下で、多孔度５０％以上の、セルロース及び／またはポリオレフィンを含む、不織布あるいは多孔質膜が好ましい。気孔率６０％以上のセルロース繊維製セパレータを用いることが好ましい。繊維径は１０μｍ以下が好ましい。セパレータの形態には、不織布、フィルム、紙などを挙げることができる。気孔率６０％以上のセルロース繊維製セパレータは、非水電解質の含浸性が良く、低温から高温まで高い出力性能を出すことができる。気孔率のより好ましい範囲は６２％～８０％である。また、実施形態の負極活物質を含む負極は、長期充電保存、フロート充電あるいは過充電においても、気孔率６０％以上のセルロース繊維製セパレータと反応せず、また、リチウム金属のデンドライド析出による負極と正極との短絡が発生しない。さらに、繊維径を１０μｍ以下にすることで、セパレータと非水電解質との親和性が向上して電池抵抗を小さくすることができる。より好ましい繊維径の範囲は３μｍ以下である。 The separator is preferably a non-woven fabric or a porous membrane containing cellulose and / or polyolefin having a thickness of 30 μm or less and a porosity of 50% or more. It is preferable to use a cellulose fiber separator having a porosity of 60% or more. The fiber diameter is preferably 10 μm or less. Examples of the separator include non-woven fabric, film, and paper. Cellulose fiber separators with a porosity of 60% or more have good nonaqueous electrolyte impregnation properties, and can provide high output performance from low to high temperatures. A more preferable range of the porosity is 62% to 80%. In addition, the negative electrode containing the negative electrode active material of the embodiment does not react with a separator made of cellulose fiber having a porosity of 60% or more even during long-term charge storage, float charge or overcharge, and the negative electrode formed by lithium metal dendride precipitation No short circuit with the positive electrode occurs. Furthermore, by making the fiber diameter 10 μm or less, the affinity between the separator and the non-aqueous electrolyte is improved, and the battery resistance can be reduced. A more preferable fiber diameter range is 3 μm or less.
　セパレータは、厚さが２０～１００μｍ、密度が０．２～０．９ｇ／ｃｍ３であることが好ましい。この範囲であると、機械的強度と電池抵抗低減とのバランスを取ることができ、高出力で内部短絡しにくい電池を提供することができる。また、高温環境下での熱収縮が少なく良好な高温貯蔵性能を出すことが出来る。 The separator preferably has a thickness of 20 to 100 μm and a density of 0.2 to 0.9 g / cm 3 . Within this range, it is possible to balance the mechanical strength and the battery resistance reduction, and it is possible to provide a battery that is high in output and hardly shorts internally. Moreover, there is little heat shrinkage in a high temperature environment, and good high temperature storage performance can be obtained.
　（５）外装部材
　外装部材としては、ラミネートフィルム製容器や、金属製容器などが挙げられる。容器の形状は非水電解質電池の形態に応じたものにする。非水電解質電池の形態としては、扁平型、角型、円筒型、コイン型、ボタン型、シート型、積層型、電気自動車等に積載される大型電池等が挙げられる。 (5) Exterior member Examples of the exterior member include a laminate film container and a metal container. The shape of the container depends on the form of the nonaqueous electrolyte battery. Examples of the nonaqueous electrolyte battery include a flat battery, a square battery, a cylindrical battery, a coin battery, a button battery, a sheet battery, a stacked battery, a large battery mounted on an electric vehicle, and the like.
　ラミネートフィルムの厚さの好ましい範囲は、０．５ｍｍ以下である。より好ましい範囲は０．２ｍｍ以下である。また、ラミネートフィルムの厚さの下限値は、０．０１ｍｍにすることが望ましい。 The preferable range of the thickness of the laminate film is 0.5 mm or less. A more preferable range is 0.2 mm or less. Moreover, it is desirable that the lower limit value of the thickness of the laminate film be 0.01 mm.
　一方、金属製容器の板厚のより好ましい範囲は、０．５ｍｍ以下である。また、金属製容器の板厚の下限値は、０．０５ｍｍにすることが望ましい。 On the other hand, the more preferable range of the plate thickness of the metal container is 0.5 mm or less. Further, the lower limit value of the plate thickness of the metal container is desirably 0.05 mm.
　ラミネートフィルムとしては、例えば、金属層と金属層を被覆する樹脂層とを含む多層フィルムを挙げることができる。軽量化のために、金属層はアルミニウム箔もしくはアルミニウム合金箔であることが好ましい。樹脂層は、金属層を補強するためのものであり、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）などの高分子から形成することができる。 Examples of the laminate film include a multilayer film including a metal layer and a resin layer covering the metal layer. In order to reduce the weight, the metal layer is preferably an aluminum foil or an aluminum alloy foil. The resin layer is for reinforcing the metal layer, and can be formed of a polymer such as polypropylene (PP), polyethylene (PE), nylon, polyethylene terephthalate (PET).
　ラミネートフィルム製容器は、例えば、ラミネートフィルムを熱融着により貼り合わせることで得られる。 A laminate film container can be obtained, for example, by laminating a laminate film by heat fusion.
　金属製容器は、アルミニウムまたはアルミニウム合金から形成されていることが望ましい。アルミニウム合金からなる金属製容器で強度が増大し、容器の肉厚を薄くしても十分な機械的強度を確保することができる。これにより、容器の放熱性を向上させることができるため、電池温度の上昇を抑制することができる。また、エネルギー密度の向上により電池の軽量化および小型化も可能となる。これらの特徴は、高温条件、高エネルギー密度等が求められる電池、例えば、車載用二次電池に好適である。アルミニウム合金としては、マグネシウム、亜鉛及びケイ素よりなる群から選択される少なくとも１種類の元素を含む合金が好ましい。一方、アルミニウム及びアルミニウム合金は、それぞれ、鉄、銅、ニッケル、クロムなどの遷移金属の含有量を１００ｐｐｍ以下にすることが好ましい。 The metal container is preferably formed from aluminum or an aluminum alloy. The strength is increased by a metal container made of an aluminum alloy, and sufficient mechanical strength can be ensured even if the thickness of the container is reduced. Thereby, since the heat dissipation of a container can be improved, the raise of battery temperature can be suppressed. Further, the energy density can be improved to reduce the weight and size of the battery. These features are suitable for batteries that require high temperature conditions, high energy density, etc., for example, in-vehicle secondary batteries. As the aluminum alloy, an alloy containing at least one element selected from the group consisting of magnesium, zinc and silicon is preferable. On the other hand, it is preferable that the content of transition metals such as iron, copper, nickel, and chromium in aluminum and aluminum alloy is 100 ppm or less.
　金属製容器の封口は、レーザーにより行うことができる。このため、ラミネートフィルム製容器に比べて封止部の体積を少なくすることができ、エネルギー密度を向上することができる。 The metal container can be sealed with a laser. For this reason, the volume of a sealing part can be decreased compared with the container made from a laminate film, and an energy density can be improved.
　実施形態の非水電解質電池は、角形、円筒形、扁平型、薄型、コイン型等の様々な形態の非水電解質電池に適用することが可能であり、また、具体的な形態には、金属製の外装部材を用いた角形電池又は円筒形電池、ラミネートフィルム製の外装部材を用いた薄形電池が含まれる。非水電解質電池の一例を図１～図５を参照して説明する。 The non-aqueous electrolyte battery of the embodiment can be applied to various forms of non-aqueous electrolyte batteries such as a square, cylindrical, flat, thin, coin type, etc. Examples include a rectangular battery or a cylindrical battery using a manufactured exterior member, and a thin battery using a laminated film exterior member. An example of the nonaqueous electrolyte battery will be described with reference to FIGS.
　図１及び図２に、ラミネートフィルム製外装部材を用いた非水電解質電池の一例を示す。 FIG. 1 and FIG. 2 show an example of a nonaqueous electrolyte battery using a laminate film exterior member.
　積層型電極群１は、２枚の樹脂フィルムの間に金属層を介在したラミネートフィルムからなる袋状容器２内に収納されている。積層型電極群１は、図２に示すように正極３と負極４とをその間にセパレータ５を介在させながら交互に積層した構造を有する。正極３は複数枚存在し、それぞれが集電体３ａと、集電体３ａの両面に形成された正極活物質含有層３ｂとを備える。負極４は複数枚存在し、それぞれが集電体４ａと、集電体４ａの両面に形成された負極活物質含有層４ｂとを備える。各負極４の集電体４ａは、一辺が正極３から突出している。突出した集電体４ａは、帯状の負極端子６に電気的に接続されている。帯状の負極端子６の先端は、容器２から外部に引き出されている。また、図示しないが、正極３の集電体３ａは、集電体４ａの突出辺と反対側に位置する辺が負極４から突出している。負極４から突出した集電体３ａは、帯状の正極端子７に電気的に接続されている。帯状の正極端子７の先端は、負極端子６とは反対側に位置し、容器２の辺から外部に引き出されている。 The laminated electrode group 1 is housed in a bag-like container 2 made of a laminate film in which a metal layer is interposed between two resin films. As shown in FIG. 2, the stacked electrode group 1 has a structure in which positive electrodes 3 and negative electrodes 4 are alternately stacked with separators 5 interposed therebetween. There are a plurality of positive electrodes 3, each of which includes a current collector 3 a and a positive electrode active material-containing layer 3 b formed on both surfaces of the current collector 3 a. A plurality of negative electrodes 4 are present, each including a current collector 4a and a negative electrode active material-containing layer 4b formed on both surfaces of the current collector 4a. One side of the current collector 4 a of each negative electrode 4 protrudes from the positive electrode 3. The protruding current collector 4 a is electrically connected to the strip-shaped negative electrode terminal 6. The tip of the strip-like negative electrode terminal 6 is drawn out from the container 2 to the outside. Although not shown, the current collector 3a of the positive electrode 3 has a side protruding from the negative electrode 4 on the side opposite to the protruding side of the current collector 4a. The current collector 3 a protruding from the negative electrode 4 is electrically connected to the belt-like positive electrode terminal 7. The tip of the strip-like positive electrode terminal 7 is located on the opposite side to the negative electrode terminal 6 and is drawn out from the side of the container 2 to the outside.
　図３及び図４に、金属製容器を用いた非水電解質電池の一例を示す。 3 and 4 show an example of a nonaqueous electrolyte battery using a metal container.
　電極群１１は、矩形筒状の金属製容器１２内に収納されている。電極群１１は、正極１３及び負極１４をその間にセパレータ１５を介在させて偏平形状となるように渦巻き状に捲回した構造を有する。非水電解質（図示しない）は、電極群１１に保持されている。図４に示すように、電極群１の端面に位置する正極１３の端部の複数個所それぞれに帯状の正極リード１６が電気的に接続されている。また、この端面に位置する負極１４の端部の複数個所それぞれに帯状の負極リード１７が電気的に接続されている。この複数ある正極リード１６は、一つに束ねられた状態で正極導電タブ１８と電気的に接続されている。正極リード１６と正極導電タブ１８から正極端子が構成されている。また、負極リード１７は、一つに束ねられた状態で負極導電タブ１９と接続されている。負極リード１７と負極導電タブ１９から負極端子が構成されている。金属製の封口板２０は、金属製容器１２の開口部に溶接等により固定されている。正極導電タブ１８及び負極導電タブ１９は、それぞれ、封口板２０に設けられた取出穴から外部に引き出されている。封口板２０の各取出穴の内周面は、正極導電タブ１８及び負極導電タブ１９との接触による短絡を回避するために、絶縁部材２１で被覆されている。 The electrode group 11 is housed in a rectangular cylindrical metal container 12. The electrode group 11 has a structure in which a positive electrode 13 and a negative electrode 14 are wound in a spiral shape so that a flat shape is formed with a separator 15 interposed therebetween. A nonaqueous electrolyte (not shown) is held by the electrode group 11. As shown in FIG. 4, a strip-like positive electrode lead 16 is electrically connected to each of a plurality of locations at the end of the positive electrode 13 located on the end face of the electrode group 1. In addition, a strip-like negative electrode lead 17 is electrically connected to each of a plurality of locations at the end of the negative electrode 14 located on this end face. The plurality of positive electrode leads 16 are electrically connected to the positive electrode conductive tab 18 in a bundled state. A positive electrode terminal is constituted by the positive electrode lead 16 and the positive electrode conductive tab 18. The negative electrode lead 17 is connected to the negative electrode conductive tab 19 in a bundled state. The negative electrode lead 17 and the negative electrode conductive tab 19 constitute a negative electrode terminal. The metal sealing plate 20 is fixed to the opening of the metal container 12 by welding or the like. The positive electrode conductive tab 18 and the negative electrode conductive tab 19 are each drawn out from an extraction hole provided in the sealing plate 20. The inner peripheral surface of each extraction hole of the sealing plate 20 is covered with an insulating member 21 in order to avoid a short circuit due to contact with the positive electrode conductive tab 18 and the negative electrode conductive tab 19.
　図５に、金属製容器を用いた非水電解質電池の別の例を示す。 FIG. 5 shows another example of a nonaqueous electrolyte battery using a metal container.
　図５に示す、扁平型もしくは薄型の非水電解質電池は、直方体形状のアルミニウム合金製容器２２と、容器２２内に収納された電極群２３と、容器２２内に収納され、電極群２３に保持された非水電解質（図示しない）とを含む。電極群２３は、正極２４及び負極２５をその間にセパレータ２６を介在させて偏平形状となるように渦巻き状に捲回した構造を有する。電極群２３は、例えば、正極２４及び負極２５をその間にセパレータ２６を介在させて偏平形状となるように渦巻き状に捲回した後、加熱プレスを施すことにより作製される。帯状の正極リード２７は、正極２４に電気的に接続されている。一方、帯状の負極リード２８は、負極２５に電気的に接続されている。正極リード２７は容器２２と電気的に接続され、負極リード２８は容器２２と絶縁された負極端子２９と電気的に接続されている。 The flat or thin nonaqueous electrolyte battery shown in FIG. 5 is a rectangular parallelepiped aluminum alloy container 22, an electrode group 23 housed in the container 22, and housed in the container 22 and held by the electrode group 23. Non-aqueous electrolyte (not shown). The electrode group 23 has a structure in which a positive electrode 24 and a negative electrode 25 are wound in a spiral shape so that a flat shape is formed with a separator 26 interposed therebetween. The electrode group 23 is produced, for example, by winding a positive electrode 24 and a negative electrode 25 in a spiral shape with a separator 26 interposed therebetween, and then applying a heat press. The strip-like positive electrode lead 27 is electrically connected to the positive electrode 24. On the other hand, the strip-shaped negative electrode lead 28 is electrically connected to the negative electrode 25. The positive electrode lead 27 is electrically connected to the container 22, and the negative electrode lead 28 is electrically connected to a negative electrode terminal 29 that is insulated from the container 22.
　以上説明した第１の実施形態の非水電解質電池によれば、３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出する単斜晶構造のチタン含有酸化物を含有する負極活物質を含むため、非水電解質電池の高温環境下での電池の膨れを抑制すると共にサイクル寿命性能を大幅に改善することができる。
（第２の実施形態）
　第２の実施形態によれば、非水電解質電池を単位セルとする組電池と、該組電池を含む電池パックとを提供することができる。非水電解質電池には、第１の実施形態の非水電解質を用いることができる。 According to the nonaqueous electrolyte battery of the first embodiment described above, the monoclinic structure titanium-containing oxide that releases 0.01 to 0.5 wt% of H 2 O in the temperature range of 300 to 600 ° C. Since the negative electrode active material to be contained is included, it is possible to suppress the swelling of the battery in a high temperature environment of the nonaqueous electrolyte battery and to greatly improve the cycle life performance.
(Second Embodiment)
According to 2nd Embodiment, the assembled battery which uses a nonaqueous electrolyte battery as a unit cell, and the battery pack containing this assembled battery can be provided. The nonaqueous electrolyte of the first embodiment can be used for the nonaqueous electrolyte battery.
　組電池の例には、電気的に直列又は並列に接続された複数の単位セルを構成単位として含むもの、電気的に直列接続された複数の単位セルからなるユニットまたは電気的に並列接続された複数の単位セルからなるユニットを含むもの等を挙げることができる。 Examples of the assembled battery include a plurality of unit cells electrically connected in series or in parallel as a constituent unit, a unit composed of a plurality of unit cells electrically connected in series, or electrically connected in parallel Examples include a unit including a unit composed of a plurality of unit cells.
　非水電解質電池の複数個を電気的に直列又は並列接続する形態の例には、それぞれが外装部材を備えた複数の電池を電気的に直列又は並列接続するもの、共通の筐体内に収容された複数の電極群を電気的に直列又は並列接続するものが含まれる。前者の具体例は、複数個の非水電解質電池の正極端子と負極端子を金属製のバスバー（例えば、アルミニウム、ニッケル、銅）で接続するものである。後者の具体例は、１個の筐体内に複数個の電極群を隔壁により電気化学的に絶縁した状態で収容し、これら電極群を電気的に直列接続するものである。電気的に直列接続する電池個数を５～７の範囲にすることにより、鉛蓄電池との電圧互換性が良好になる。鉛蓄電池との電圧互換性をより高くするには、単位セルを５個または６個直列接続した構成が好ましい。 Examples of a form in which a plurality of non-aqueous electrolyte batteries are electrically connected in series or in parallel include those in which a plurality of batteries each having an exterior member are electrically connected in series or in parallel, and are accommodated in a common housing. In addition, a plurality of electrode groups electrically connected in series or in parallel are included. In the former specific example, the positive terminals and the negative terminals of a plurality of nonaqueous electrolyte batteries are connected by a metal bus bar (for example, aluminum, nickel, copper). In the latter specific example, a plurality of electrode groups are accommodated in a single casing in an electrochemically insulated state by partition walls, and these electrode groups are electrically connected in series. By setting the number of electrically connected batteries in the range of 5 to 7, the voltage compatibility with the lead storage battery is improved. In order to further increase the voltage compatibility with the lead storage battery, a configuration in which five or six unit cells are connected in series is preferable.
　組電池が収納される筐体には、アルミニウム合金、鉄、ステンレスなどからなる金属缶、プラスチック容器等が使用できる。また、容器の板厚は、０．５ｍｍ以上にすることが望ましい。 For the case in which the assembled battery is stored, a metal can made of aluminum alloy, iron, stainless steel, a plastic container, or the like can be used. Further, the plate thickness of the container is desirably 0.5 mm or more.
　組電池の一例を図６を参照して説明する。図６に示す組電池３１は、第１の実施形態に係る角型の非水電解質電池（例えば図３，図４）３２１～３２５を単位セルとして複数備える。電池３２１の正極導電タブ１８と、その隣に位置する電池３２２の負極導電タブ１９とが、リード３３によって電気的に接続されている。さらに、この電池３２２の正極導電タブ１８とその隣に位置する電池３２３の負極導電タブ１９とが、リード３３によって電気的に接続されている。このように電池３２１～３２５間が直列に接続されている。 An example of the assembled battery will be described with reference to FIG. Assembled battery 31 shown in FIG. 6 includes a plurality non-aqueous electrolyte battery of the square according to the first embodiment (e.g. FIG. 3, FIG. 4) 32 1 to 32 5 as a unit cell. A battery 32 1 of the positive electrode conductive tab 18, a negative electrode conductive tab 19 of the battery 32 2 located next to it, are electrically connected by a lead 33. Further, a negative electrode conductive tab 19 of the battery 32 3 positioned positive electrode conductive tab 18 of the battery 32 2 next to it, are electrically connected by a lead 33. In this way, the batteries 32 1 to 32 5 are connected in series.
　また、電池パックの例を図７を参照して説明する。電池パック４０は、図１，２に示す非水電解質電池からなる組電池を備える。電池パック４０は、筐体４１と、筐体４１内に収容された組電池４２とを含む。組電池４２は、複数（例えば５個）の非水電解質電池４３１～４３５が電気的に直列に接続されたものである。非水電解質電池４３１～４３５は、厚さ方向に積層されている。筐体４１は、上部及び４つの側面それぞれに開口部４４を有している。非水電解質電池４３１～４３５の正負極端子６，７が突出している側面が、筐体４１の開口部４４に露出している。組電池４２の出力用正極端子４５は、帯状をなし、一端が非水電解質電池４３１～４３５のいずれかの正極端子６と電気的に接続され、かつ他端が筐体４１の開口部４４から突出して筐体４１の上部から突き出ている。一方、組電池４２の出力用負極端子４６は、帯状をなし、一端が非水電解質電池４３１～４３５のいずれかの負極端子７と電気的に接続され、かつ他端が筐体４１の開口部４４から突出して筐体４１の上部から突き出ている。 An example of the battery pack will be described with reference to FIG. The battery pack 40 includes an assembled battery composed of the nonaqueous electrolyte battery shown in FIGS. The battery pack 40 includes a housing 41 and an assembled battery 42 accommodated in the housing 41. Battery pack 42 is to nonaqueous electrolyte battery 43 1-43 5 a plurality (e.g. five) are electrically connected in series. A nonaqueous electrolyte battery 43 1-43 5 are stacked in the thickness direction. The housing 41 has an opening 44 on each of the upper part and the four side surfaces. Side nonaqueous electrolyte battery 43 1-43 5 of the positive and negative electrode terminals 6 and 7 are protruded is exposed to the opening 44 of the housing 41. Output positive terminal of the assembled battery 42 45 form a strip, one end is electrically connected to the 6 one of the positive terminal of the nonaqueous electrolyte battery 43 1-43 5, and the other end of the housing 41 opening 44 protrudes from the upper portion of the housing 41. On the other hand, the output negative terminal 46 of the assembled battery 42, without a band, one end of which is connected one of the negative electrode terminal 7 and electrically non-aqueous electrolyte battery 43 1-43 5, and the other end of the housing 41 It protrudes from the opening 44 and protrudes from the upper part of the housing 41.
　電池パックの別の例を図８および図９を参照して詳細に説明する。扁平型の非水電解質電池から構成される複数の単位セル５１は、外部に延出した負極端子５２および正極端子５３が同じ向きに揃えられるように積層され、粘着テープ５４で締結することにより組電池５５を構成している。これらの単位セル５１は、図９に示すように互いに電気的に直列に接続されている。 Another example of the battery pack will be described in detail with reference to FIG. 8 and FIG. A plurality of unit cells 51 composed of a flat type non-aqueous electrolyte battery are stacked so that the negative electrode terminal 52 and the positive electrode terminal 53 extending to the outside are aligned in the same direction, and are assembled by fastening with an adhesive tape 54. A battery 55 is configured. These unit cells 51 are electrically connected to each other in series as shown in FIG.
　プリント配線基板５６は、負極端子５２および正極端子５３が延出する単位セル５１側面と対向して配置されている。プリント配線基板５６には、図９に示すようにサーミスタ５７、保護回路５８及び外部機器への通電用端子５９が搭載されている。なお、組電池５５と対向するプリント配線基板５６の面には組電池５５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 56 is disposed to face the side surface of the unit cell 51 from which the negative electrode terminal 52 and the positive electrode terminal 53 extend. As shown in FIG. 9, a thermistor 57, a protection circuit 58, and a terminal 59 for energizing an external device are mounted on the printed wiring board 56. An insulating plate (not shown) is attached to the surface of the printed wiring board 56 facing the assembled battery 55 in order to avoid unnecessary connection with the wiring of the assembled battery 55.
　正極リード６０は、組電池５５の最下層に位置する正極端子５３に接続され、その先端はプリント配線基板５６の正極コネクタ６１に挿入されて電気的に接続されている。負極リード６２は、組電池５５の最上層に位置する負極端子５２に接続され、その先端はプリント配線基板５６の負極側コネクタ６３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６１，６３は、プリント配線基板５６に形成された配線６４，６５を通して保護回路５８に接続されている。 The positive electrode lead 60 is connected to the positive electrode terminal 53 located at the lowermost layer of the assembled battery 55, and the tip thereof is inserted into the positive electrode connector 61 of the printed wiring board 56 and electrically connected thereto. The negative electrode lead 62 is connected to the negative electrode terminal 52 located on the uppermost layer of the assembled battery 55, and the tip thereof is inserted into and electrically connected to the negative electrode side connector 63 of the printed wiring board 56. These connectors 61 and 63 are connected to the protection circuit 58 through wirings 64 and 65 formed on the printed wiring board 56.
　サーミスタ５７は、単位セル５１の温度を検出し、その検出信号は保護回路５８に送信される。保護回路５８は、所定の条件で保護回路５８と外部機器への通電用端子５９との間のプラス配線６６ａおよびマイナス配線６６ｂを遮断できる。所定の条件とは、例えばサーミスタ５７の検出温度が所定温度以上になったときである。また、所定の条件とは単位セル５１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、個々の単位セル５１もしくは組電池５５について行われる。個々の単位セル５１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、個々の単位セル５１中に参照極として用いるリチウム電極が挿入される。図８および図９の場合、単位セル５１それぞれに電圧検出のための配線６７を接続し、これら配線６７を通して検出信号が保護回路５８に送信される。 The thermistor 57 detects the temperature of the unit cell 51, and the detection signal is transmitted to the protection circuit 58. The protection circuit 58 can cut off the plus wiring 66a and the minus wiring 66b between the protection circuit 58 and the energization terminal 59 to the external device under a predetermined condition. The predetermined condition is, for example, when the temperature detected by the thermistor 57 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 51 is detected. This detection of overcharge or the like is performed for each unit cell 51 or the assembled battery 55. When detecting each unit cell 51, 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 51. 8 and 9, a voltage detection wiring 67 is connected to each unit cell 51, and a detection signal is transmitted to the protection circuit 58 through the wiring 67.
　正極端子５３および負極端子５２が突出する側面を除く組電池５５の三側面には、ゴムもしくは樹脂からなる保護シート６８がそれぞれ配置されている。 Protective sheets 68 made of rubber or resin are arranged on the three side surfaces of the assembled battery 55 excluding the side surfaces from which the positive electrode terminal 53 and the negative electrode terminal 52 protrude.
　組電池５５は、各保護シート６８およびプリント配線基板５６と共に収納容器６９内に収納される。すなわち、収納容器６９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６８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５６が配置される。組電池５５は、保護シート６８およびプリント配線基板５６で囲まれた空間内に位置する。蓋７０は、収納容器６９の上面に取り付けられている。 The assembled battery 55 is stored in a storage container 69 together with each protective sheet 68 and the printed wiring board 56. That is, the protective sheet 68 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 69, and the printed wiring board 56 is disposed on the inner side surface on the opposite side in the short side direction. The assembled battery 55 is located in a space surrounded by the protective sheet 68 and the printed wiring board 56. The lid 70 is attached to the upper surface of the storage container 69.
　なお、組電池５５の固定には粘着テープ５４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。 It should be noted that a heat shrink tape may be used in place of the adhesive tape 54 for fixing the assembled battery 55. 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８、図９では単位セル５１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よい。組み上がった電池パックを直列、並列に接続することもできる。 8 and 9 show a configuration in which the unit cells 51 are connected in series, but they may be connected in parallel to increase the battery capacity. The assembled battery packs can be connected in series or in parallel.
　また、電池パックの態様は用途により適宜変更される。電池パックの用途としては、大電流での充放電が望まれるものが好ましい。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、車載用が好適である。 In addition, the mode of the battery pack is appropriately changed depending on the application. As a use of the battery pack, one in which charging / discharging with a large current is desired is preferable. 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, the vehicle-mounted one is suitable.
　以上説明した第２の実施形態によれば、第１の実施形態の非水電解質電池を用いるため、高温環境下での電池膨れが抑制されて充放電サイクル寿命性能が向上された組電池及び電池パックを提供することができる。このため、車両用スタータ電源として使用されている鉛電池の代替電源として、あるいはハイブリッド車に搭載する車載用二次電池として好適な組電池及び電池パックを提供することが可能になる。
［実施例］
　以下、本発明の実施例を図面を参照して詳細に説明するが、本発明は以下に掲載される実施例に限定されるものでない。
（実施例１）
　オリビン構造のＬｉＭｎ０．８５Ｆｅ０．１Ｍｇ０．０５ＰＯ４粒子を用意した。この粒子は、二次粒子を含むもので、一次粒子の平均粒子径が５０ｎｍであった。ＢＥＴ比表面積は２５ｍ２／ｇであった。ＬｉＭｎ０．８５Ｆｅ０．１Ｍｇ０．０５ＰＯ４粒子の表面に平均粒子径５ｎｍの炭素微粒子が付着していた。ＬｉＭｎ０．８５Ｆｅ０．１Ｍｇ０．０５ＰＯ４粒子に対する炭素微粒子の付着量は０．１重量％であった。 According to the second embodiment described above, since the nonaqueous electrolyte battery according to the first embodiment is used, the assembled battery and the battery in which the battery swelling under a high temperature environment is suppressed and the charge / discharge cycle life performance is improved. Pack can be offered. For this reason, it becomes possible to provide an assembled battery and a battery pack suitable as an alternative power source for a lead battery used as a starter power source for a vehicle or as an in-vehicle secondary battery mounted on a hybrid vehicle.
[Example]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below.
Example 1
LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles having an olivine structure were prepared. These particles contain secondary particles, and the average particle size of the primary particles was 50 nm. The BET specific surface area was 25 m 2 / g. Carbon fine particles having an average particle diameter of 5 nm were attached to the surface of LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles. The amount of carbon fine particles attached to the LiMn 0.85 Fe 0.1 Mg 0.05 PO 4 particles was 0.1% by weight.
　こうして得られた正極活物質に対し、導電剤として正極全体に対して繊維径０．１μｍの気相成長の炭素繊維を３重量％、黒鉛粉末を５重量％、結着剤として正極全体に対して５重量％のＰＶｄＦをそれぞれ配合してｎ－メチルピロリドン（ＮＭＰ）溶媒に分散してスラリーを調製した。得られたスラリーを厚さ１５μｍのアルミニウム合金箔（純度９９重量％）の両面に塗布し、乾燥し、プレス工程を経て、片面の正極活物質含有層の厚さが４３μｍ、電極密度２．２ｇ／ｃｍ3の正極を作製した。正極活物質含有層の比表面積は、８ｍ２／ｇであった。正極作成後、９０℃真空乾燥を２４時間行った。 For the positive electrode active material thus obtained, 3% by weight of vapor-grown carbon fiber having a fiber diameter of 0.1 μm as a conductive agent, 5% by weight of graphite powder, and 5% by weight of graphite powder as a conductive agent. 5% by weight of PVdF was mixed and dispersed in an n-methylpyrrolidone (NMP) solvent to prepare a slurry. The obtained slurry was applied to both sides of a 15 μm thick aluminum alloy foil (purity 99% by weight), dried, and subjected to a pressing process. The thickness of the positive electrode active material-containing layer on one side was 43 μm, and the electrode density was 2.2 g. A positive electrode of / cm 3 was produced. The specific surface area of the positive electrode active material-containing layer was 8 m 2 / g. After producing the positive electrode, vacuum drying at 90 ° C. was performed for 24 hours.
　負極活物質を以下の方法で作製した。平均粒子径１０μｍの球状二次粒子のチタン酸カリウム（Ｋ２Ｔｉ２Ｏ５）をスプレードライ法で得た。チタン酸カリウム粒子を１Ｍの硫酸溶液中に加え２５℃で２週間撹拌することにより、プロトン交換を行った。得られたプロトン交換体は、Ｈ２Ｔｉ４Ｏ９である。プロトン交換体の粉末は、純水で洗浄後、洗浄液のｐＨが６～７の範囲になるまで洗浄した。 A negative electrode active material was produced by the following method. Spherical secondary particles of potassium titanate (K 2 Ti 2 O 5 ) having an average particle size of 10 μm were obtained by spray drying. Proton exchange was performed by adding potassium titanate particles in 1 M sulfuric acid solution and stirring at 25 ° C. for 2 weeks. The resulting proton exchanger is H 2 Ti 4 O 9 . The proton exchanger powder was washed with pure water and then washed until the pH of the washing solution was in the range of 6-7.
　次に、プロトン交換体（Ｈ２Ｔｉ４Ｏ９）を電気炉にて３２０℃の温度で６時間焼成した。電気炉内の雰囲気は、水蒸気圧を高めることにより加圧雰囲気にした。雰囲気の圧力を表１に示す。加熱後は速やかに電気炉から出し、大気中で急冷した。この焼成物を１００℃真空中に保管することにより吸着水を除去して乾燥することで、二酸化チタン化合物の試料を得た。この試料にＣｕ－Ｋα線を線源とする粉末Ｘ線回折測定を行い、得られた回折線から空間群Ｃ２／ｍに属する単斜晶構造の二酸化チタンであることを確認した。さらに、強度比（Ｉｂ／Ｉａ）が０．４３であった。ここで、強度Ｉａは、Ｃｕ－Ｋα線源とする粉末Ｘ線回折法における回折角（２θ）が２７ｄｅｇ～２９ｄｅｇ現れる（００２）面のピークトップ（Ｐａ）の強度で、強度Ｉｂは回折角（２θ）が２９ｄｅｇ～３２ｄｅｇで現れるピークトップ（Ｐｂ）の強度である。上記Ｘ線回折による結晶子サイズは１００ｎｍであった。 Next, the proton exchanger (H 2 Ti 4 O 9 ) was baked in an electric furnace at a temperature of 320 ° C. for 6 hours. The atmosphere in the electric furnace was changed to a pressurized atmosphere by increasing the water vapor pressure. Table 1 shows the atmospheric pressure. After heating, it was quickly removed from the electric furnace and rapidly cooled in the atmosphere. The fired product was stored in a vacuum at 100 ° C. to remove adsorbed water and dried to obtain a sample of a titanium dioxide compound. This sample was subjected to powder X-ray diffraction measurement using Cu—Kα rays as a radiation source, and it was confirmed from the obtained diffraction rays that the titanium dioxide had a monoclinic structure belonging to the space group C2 / m. Further, the intensity ratio (Ib / Ia) was 0.43. Here, the intensity Ia is the intensity of the peak top (Pa) of the (002) plane where the diffraction angle (2θ) in the powder X-ray diffraction method using a Cu—Kα ray source appears as 27 deg to 29 deg, and the intensity Ib is the diffraction angle ( 2θ) is the intensity of the peak top (Pb) appearing at 29 deg to 32 deg. The crystallite size by X-ray diffraction was 100 nm.
　また、得られた二酸化チタンの粒子は、３００℃～６００℃の温度範囲で発生したＨ２Ｏの重量％が０．１５重量％で、Ｎ２吸着によるＢＥＴ法による比表面積は２０ｍ２／ｇであった。一次粒子の平均粒子径は０．３μｍで、二次粒子の平均粒子径は１０μｍであった。Ｈ２Ｏの重量％測定の方法を説明する。二酸化チタンの粒子２０ｍｇについて、室温から６００℃まで昇温（昇温速度：５℃／ｍｉｎ）する条件でＴＧ測定及びＭＳ測定を行った。ＭＳ測定では、キャリアガスにＨｅを使用した。ＭＳ測定により、３００℃～６００℃の温度範囲で発生したガスがＨ２Ｏであることが判明した。また、ＴＧ測定から、Ｈ２Ｏ放出による二酸化チタンの重量減少は、０．１５重量％であることがわかった。この値を３００℃～６００℃の温度範囲で発生したＨ２Ｏの重量％とした。 The obtained titanium dioxide particles have a 0.15 wt% H 2 O generated in the temperature range of 300 ° C. to 600 ° C. and a specific surface area of 20 m 2 / g by the BET method by N 2 adsorption. Met. The average particle diameter of the primary particles was 0.3 μm, and the average particle diameter of the secondary particles was 10 μm. A method for measuring the weight percentage of H 2 O will be described. With respect to 20 mg of titanium dioxide particles, TG measurement and MS measurement were performed under the condition of increasing the temperature from room temperature to 600 ° C. (temperature increase rate: 5 ° C./min). In MS measurement, He was used as a carrier gas. MS measurement revealed that the gas generated in the temperature range of 300 ° C. to 600 ° C. was H 2 O. Further, from the TG measurement, it was found that the weight loss of titanium dioxide due to H 2 O release was 0.15% by weight. This value was defined as the weight percentage of H 2 O generated in the temperature range of 300 ° C. to 600 ° C.
　二酸化チタン化合物の粒子と、導電剤としてアセチレンブラック粉末と、平均粒子径６μｍの黒鉛粉末と、結着剤としてＰＶｄＦとを重量比で８５：６：５：４となるように配合してｎ－メチルピロリドン（ＮＭＰ）溶媒に分散させ、ボールミルを用いて回転数１０００ｒｐｍで、かつ攪拌時間が２時間の条件で攪拌を用い、スラリーを調製した。得られたスラリーを厚さ１５μｍのアルミニウム合金箔（純度９９．３重量％）に塗布し、乾燥し、加熱プレス工程を経ることにより、片面の負極活物質含有層の厚さが５９μｍ、電極密度が２．８ｇ／ｃｍ3の負極を作製した。負極作成後、９０℃真空乾燥を２４時間行った。負極活物質含有層のＢＥＴ比表面積（負極活物質含有層１ｇ当りの表面積）は８ｍ2／ｇであった。負極の集電体を除いた部分での多孔度は４０％であった。 Particles of titanium dioxide compound, acetylene black powder as a conductive agent, graphite powder having an average particle diameter of 6 μm, and PVdF as a binder are blended in a weight ratio of 85: 6: 5: 4, and n− A slurry was prepared by dispersing in a methylpyrrolidone (NMP) solvent and using a ball mill with stirring at a rotational speed of 1000 rpm and a stirring time of 2 hours. The obtained slurry was applied to an aluminum alloy foil (purity: 99.3% by weight) having a thickness of 15 μm, dried, and subjected to a heat press process, whereby the thickness of the negative electrode active material-containing layer on one side was 59 μm, and the electrode density Produced a negative electrode of 2.8 g / cm 3 . After producing the negative electrode, vacuum drying at 90 ° C. was performed for 24 hours. The BET specific surface area of the negative electrode active material-containing layer (surface area per 1 g of the negative electrode active material-containing layer) was 8 m 2 / g. The porosity of the negative electrode excluding the current collector was 40%.
　次いで、複数の正極と複数の負極をその間に厚さ１２μｍのポリエチレン製多孔質フィルムからなるセパレータを挟んで積層し、電極群を作製した。複数の正極それぞれのアルミニウム箔集電体に帯状の正極端子を電気的に接続すると共に、複数の負極それぞれのアルミニウム箔集電体に帯状の負極端子を電気的に接続した。この電極群を、厚さ６ｍｍ、幅７０ｍｍ、高さ１１０ｍｍのラミネートフィルム製容器（外装部材）に収納した。 Next, a plurality of positive electrodes and a plurality of negative electrodes were laminated with a separator made of a polyethylene porous film having a thickness of 12 μm interposed therebetween, to produce an electrode group. A strip-shaped positive electrode terminal was electrically connected to the aluminum foil current collector of each of the plurality of positive electrodes, and a strip-shaped negative electrode terminal was electrically connected to the aluminum foil current collector of each of the plurality of negative electrodes. This electrode group was accommodated in a laminate film container (exterior member) having a thickness of 6 mm, a width of 70 mm, and a height of 110 mm.
　プロピレンカーボネート（ＰＣ）からなる有機溶媒に、ＬｉＰＦ6からなるリチウム塩を１．５ｍｏｌ／Ｌ溶解させ、液状の非水電解質を調製した。 A liquid nonaqueous electrolyte was prepared by dissolving 1.5 mol / L of a lithium salt made of LiPF 6 in an organic solvent made of propylene carbonate (PC).
　得られた非水電解質を容器内に注液し、前述した図１に示す構造を有する薄型の非水電解質二次電池を作製した。 The obtained nonaqueous electrolyte was poured into a container to produce a thin nonaqueous electrolyte secondary battery having the structure shown in FIG.
　負極活物質の粒子の測定方法を以下に示す。 The method for measuring the particles of the negative electrode active material is shown below.
　負極活物質の粒子測定は、レーザー回折式分布測定装置（島津ＳＡＬＤ－３００）を用い、まず、ビーカーに試料を約０．１ｇと界面活性剤と１～２ｍＬの蒸留水を添加して十分に攪拌した後、攪拌水槽に注入し、２秒間隔で６４回光度分布を測定し、粒度分布データを解析するという方法にて測定した。 To measure the particles of the negative electrode active material, use a laser diffraction distribution measuring device (Shimadzu SALD-300). First, add about 0.1 g of the sample, a surfactant, and 1 to 2 mL of distilled water to a beaker. After stirring, the mixture was poured into a stirred water tank, and the light intensity distribution was measured 64 times at intervals of 2 seconds, and the particle size distribution data was analyzed.
　負極活物質及び負極のＮ２吸着によるＢＥＴ比表面積は、以下の条件で測定した。 Electrode active material, and a BET specific surface area by N 2 adsorption of the negative electrode was measured under the following conditions.
　粉末の負極活物質１ｇまたは２ｘ２ｃｍ2の負極を２枚切り取り、これをサンプルとした。ＢＥＴ比表面積測定装置はユアサ　アイオニクス社製を使用し、窒素ガスを吸着ガスとした。正極活物質含有層の比表面積は、負極のＮ2吸着によるＢＥＴ比表面積と同様な方法で測定された。 Two pieces of 1 g of powdered negative electrode active material or 2 × 2 cm 2 negative electrodes were cut out and used as samples. A BET specific surface area measuring apparatus manufactured by Yuasa Ionics was used, and nitrogen gas was used as an adsorption gas. The specific surface area of the positive electrode active material-containing layer was measured by the same method as the BET specific surface area by N 2 adsorption of the negative electrode.
　なお、負極の多孔度は、負極活物質含有層の体積を、多孔度が０％の時の負極活物質含有層体積と比較し、多孔度が０％の時の負極活物質含有層体積からの増加分を空孔体積とみなして算出したものである。なお、負極活物質含有層の体積は、集電体の両面に負極活物質含有層が形成されている場合、両面の負極活物質含有層の体積を合計したものとする。
（実施例２～１５および比較例１～２，５）
　正極活物質の種類、正極活物質含有層の比表面積（ｍ２／ｇ）、負極活物質の種類、負極活物質製造における加熱処理雰囲気の圧力、３００～６００℃で負極活物質から放出されたＨ２Ｏ量（重量％）を下記表１に示すように設定した以外は、前述した実施例１で説明したのと同様にして非水電解質二次電池を作製した。
（比較例３）
　以下の方法で作製した負極活物質を用いること以外は、実施例１で説明したのと同様にして非水電解質二次電池を作製した。 The porosity of the negative electrode is determined by comparing the volume of the negative electrode active material-containing layer with the volume of the negative electrode active material-containing layer when the porosity is 0%, and the volume of the negative electrode active material-containing layer when the porosity is 0%. This is calculated by regarding the increase in the volume as the pore volume. The volume of the negative electrode active material-containing layer is the sum of the volumes of the negative electrode active material-containing layers on both sides when the negative electrode active material-containing layer is formed on both sides of the current collector.
(Examples 2 to 15 and Comparative Examples 1 to 2 and 5)
The type of positive electrode active material, the specific surface area of the positive electrode active material-containing layer (m 2 / g), the type of negative electrode active material, the pressure of the heat treatment atmosphere in the production of the negative electrode active material, released from the negative electrode active material at 300 to 600 ° C. A nonaqueous electrolyte secondary battery was fabricated in the same manner as described in Example 1 except that the H 2 O amount (% by weight) was set as shown in Table 1 below.
(Comparative Example 3)
A nonaqueous electrolyte secondary battery was produced in the same manner as described in Example 1 except that the negative electrode active material produced by the following method was used.
　Ｌｉ２ＣＯ３とアナターゼ型ＴｉＯ２を原子比Ｌｉ：Ｔｉ＝４：５となるように粉体混合し、８５０℃で空気中で１２時間焼成し、Ｌｉ４／３Ｔｉ５／３Ｏ４を得た。Ｘ線回折像よりスピネル構造であることを確認した。 Li 2 CO 3 and anatase TiO 2 are mixed in powder so that the atomic ratio Li: Ti = 4: 5, and calcined in air at 850 ° C. for 12 hours. Li 4/3 Ti 5/3 O 4 Obtained. From the X-ray diffraction image, it was confirmed that the structure was a spinel structure.
　得られたチタン酸リチウム（Ｌｉ４／３Ｔｉ５／３Ｏ４）の粒子は、３００℃～６００℃の温度範囲で発生したＨ２Ｏの重量％が０重量％で、Ｎ２吸着によるＢＥＴ法による比表面積は８ｍ２／ｇであった。一次粒子の平均粒子径は０．３μｍで、二次粒子の平均粒子径は５μｍであった。
（比較例４）
　以下に記載の負極活物質を用いること以外は、実施例１で説明したのと同様にして非水電解質二次電池を作製した。 The particles of the obtained lithium titanate (Li 4/3 Ti 5/3 O 4) is, 300 ℃ ~ H 2 O wt% of which occurred in the temperature range of 600 ° C. is 0 wt%, BET by N 2 adsorption The specific surface area determined by the method was 8 m 2 / g. The average particle diameter of the primary particles was 0.3 μm, and the average particle diameter of the secondary particles was 5 μm.
(Comparative Example 4)
A nonaqueous electrolyte secondary battery was produced in the same manner as described in Example 1 except that the negative electrode active material described below was used.
　市販のアナターゼ二酸化チタン（ＴｉＯ２）の粒子を負極活物質に用いた。アナターゼ二酸化チタン（ＴｉＯ２）の粒子は、３００℃～６００℃の温度範囲で発生したＨ２Ｏの重量％が０重量％で、Ｎ２吸着によるＢＥＴ法による比表面積は５ｍ２／ｇであった。一次粒子の平均粒子径は０．３μｍで、二次粒子の平均粒子径は５μｍであった。
（比較例６）
　正極活物質の種類、正極活物質含有層の比表面積（ｍ２／ｇ）を下記表１に示すように設定した以外は、比較例３で説明したのと同様にして非水電解質二次電池を作製した。
（比較例７）
　正極活物質の種類、正極活物質含有層の比表面積（ｍ２／ｇ）を下記表１に示すように設定した以外は、比較例４で説明したのと同様にして非水電解質二次電池を作製した。 Commercially available particles of anatase titanium dioxide (TiO 2 ) were used as the negative electrode active material. The particles of anatase titanium dioxide (TiO 2 ) had 0% by weight of H 2 O generated in the temperature range of 300 ° C. to 600 ° C., and the specific surface area by the BET method by N 2 adsorption was 5 m 2 / g. It was. The average particle diameter of the primary particles was 0.3 μm, and the average particle diameter of the secondary particles was 5 μm.
(Comparative Example 6)
The nonaqueous electrolyte secondary battery is the same as described in Comparative Example 3 except that the type of the positive electrode active material and the specific surface area (m 2 / g) of the positive electrode active material-containing layer are set as shown in Table 1 below. Was made.
(Comparative Example 7)
The nonaqueous electrolyte secondary battery is the same as described in Comparative Example 4 except that the type of the positive electrode active material and the specific surface area (m 2 / g) of the positive electrode active material-containing layer are set as shown in Table 1 below. Was made.
　得られた実施例１～１５及び比較例１～７の非水電解質二次電池のうち、実施例１～５と比較例１～４は、２５℃で１Ｃ（１時間率）の定電流で３Ｖまで９０分で充電した後、１．５Ｖまで１Ｃで放電した時の放電容量（Ａｈ）と、放電率５０％の開回路電圧（Ｖ）を測定した。５０℃高温サイクル試験は、５０℃環境下で３Ｃの定電流で３Ｖまで充電した後、１．５Ｖまで３Ｃで放電するサイクルを繰り返し、初期容量の８０％容量に達した時のサイクル数と電池厚さ変化を測定した。 Among the obtained non-aqueous electrolyte secondary batteries of Examples 1 to 15 and Comparative Examples 1 to 7, Examples 1 to 5 and Comparative Examples 1 to 4 were at a constant current of 1 C (1 hour rate) at 25 ° C. After charging to 3 V in 90 minutes, the discharge capacity (Ah) when discharged at 1 C to 1.5 V and the open circuit voltage (V) with a discharge rate of 50% were measured. The 50 ° C high-temperature cycle test repeats the cycle of charging to 3V at a constant current of 3C in a 50 ° C environment, and then discharging at 3C to 1.5V, and the number of cycles and battery when the capacity reaches 80% of the initial capacity. The thickness change was measured.
　実施例６～１１と比較例５は、２５℃で１Ｃ（１時間率）の定電流で２．８Ｖまで９０分で充電した後、１．２Ｖまで１Ｃで放電した時の放電容量（Ａｈ）と、放電率５０％の開回路電圧（Ｖ）を測定した。５０℃高温サイクル試験は、５０℃環境下で３Ｃの定電流で２．８Ｖまで充電した後、１．２Ｖまで３Ｃで放電するサイクルを繰り返し、初期容量の８０％容量に達した時のサイクル数と電池厚さ変化を測定した。 In Examples 6 to 11 and Comparative Example 5, discharge capacity (Ah) when charging at a constant current of 1 C (1 hour rate) at 25 ° C. to 2.8 V in 90 minutes and then discharging to 1.2 V at 1 C Then, an open circuit voltage (V) with a discharge rate of 50% was measured. The 50 ° C high-temperature cycle test repeats a cycle of charging to 2.8V at a constant current of 3C in a 50 ° C environment and then discharging at 3C to 1.2V, and the number of cycles when the capacity reaches 80% of the initial capacity. The battery thickness change was measured.
　実施例１２～１５と比較例６～７は、２５℃で１Ｃ（１時間率）の定電流で３．７Ｖまで９０分で充電した後、２．５Ｖまで１Ｃで放電した時の放電容量（Ａｈ）と、放電率５０％の開回路電圧（Ｖ）を測定した。５０℃高温サイクル試験は、５０℃環境下で３Ｃの定電流で３．７Ｖまで充電した後、２．５Ｖまで３Ｃで放電するサイクルを繰り返し、初期容量の８０％容量に達した時のサイクル数と電池厚さ変化を測定した。 In Examples 12 to 15 and Comparative Examples 6 to 7, the discharge capacity when charging at a constant current of 1 C (1 hour rate) at 25 ° C. to 3.7 V in 90 minutes and then discharging to 2.5 V at 1 C ( Ah) and an open circuit voltage (V) with a discharge rate of 50%. The 50 ° C high-temperature cycle test repeats a cycle of charging to 3.7V at a constant current of 3C in a 50 ° C environment and then discharging at 3C to 2.5V, and the number of cycles when the capacity reaches 80% of the initial capacity. The battery thickness change was measured.
　これらの測定結果を下記表２に示す These measurement results are shown in Table 2 below.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１及び表２から明らかなように、実施例１～１５の非水電解質二次電池は、比較例１～７に比べ、電池容量、５０℃高温サイクル寿命性能及び電池膨れのバランスに優れる。 As is clear from Tables 1 and 2, the nonaqueous electrolyte secondary batteries of Examples 1 to 15 are superior to Comparative Examples 1 to 7 in the balance of battery capacity, 50 ° C. high-temperature cycle life performance, and battery swelling.
　正極活物質の種類が同じである実施例１～５で比較すると、Ｈ２Ｏ放出量が０．０２～０．３重量％の範囲内の実施例１，２，４の５０℃高温サイクル寿命性能が、実施例３，５に比して優れている。 Compared with Examples 1 to 5 where the type of the positive electrode active material is the same, the 50 ° C. high-temperature cycle life of Examples 1, 2, and 4 in which the H 2 O release amount is in the range of 0.02 to 0.3 wt% The performance is superior to Examples 3 and 5.
　また、正極活物質の種類が同じである実施例８～１１で比較すると、Ｈ２Ｏ放出量が０．０２～０．３重量％の範囲内の実施例８，９が、実施例１０，１１に比して電池容量、５０℃高温サイクル寿命性能及び電池膨れのバランスに優れている。 Further, when compared with Examples 8 to 11 in which the kind of the positive electrode active material is the same, Examples 8 and 9 having a H 2 O release amount of 0.02 to 0.3% by weight are compared with Example 10, Compared to 11, the battery capacity, 50 ° C high-temperature cycle life performance, and battery swelling are excellent.
　さらに、正極活物質の種類が同じである実施例１２～１５で比較すると、Ｈ２Ｏ放出量が０．０２～０．３重量％の範囲内の実施例１２，１３が、実施例１４，１５に比して電池容量、５０℃高温サイクル寿命性能及び電池膨れのバランスに優れている。 Furthermore, when compared with Examples 12 to 15 in which the type of the positive electrode active material is the same, Examples 12 and 13 having a H 2 O release amount of 0.02 to 0.3% by weight are compared with Examples 14 and 13, respectively. Compared to 15, the battery capacity, 50 ° C. high-temperature cycle life performance and battery swelling are excellent.
　Ｈ２Ｏ放出量が同じである実施例１，６，７，８，１２で比較すると、正極活物質にＬｉＦｅＰＯ４を用いる実施例６が、電池容量、５０℃高温サイクル寿命性能及び電池膨れのバランスが優れている。 When compared with Examples 1, 6, 7, 8, and 12 in which the amount of H 2 O released is the same, Example 6 using LiFePO 4 as the positive electrode active material has a battery capacity, 50 ° C. high-temperature cycle life performance, and battery swelling. The balance is excellent.
　実施例３及び比較例１の負極活物質のＴＧ測定における負極活物質の重量減少率の温度変化を、図１０に示す。図１０から明らかなように、実施例３の負極活物質では、３００℃までの重量減少率が比較例１よりも小さく、３００～６００℃の温度範囲になると、重量減少率が増加し、６００℃を超えると重量減少率にほとんど変化が見られない。一方、比較例１では、３００℃までの重量減少率が実施例３よりも大きく、６００℃を超えた温度範囲で若干の重量減少が見られる。３００℃までの重量減少は、ＴｉＯ２粒子の吸着水又は結晶水であると考えられる。 FIG. 10 shows the temperature change of the weight reduction rate of the negative electrode active material in the TG measurement of the negative electrode active material of Example 3 and Comparative Example 1. As is apparent from FIG. 10, in the negative electrode active material of Example 3, the weight reduction rate up to 300 ° C. is smaller than that in Comparative Example 1, and the weight reduction rate increases when the temperature range is 300 to 600 ° C. If the temperature exceeds ℃, there is almost no change in the weight loss rate. On the other hand, in Comparative Example 1, the weight reduction rate up to 300 ° C. is larger than that in Example 3, and a slight weight reduction is observed in the temperature range exceeding 600 ° C. The weight loss up to 300 ° C. is considered to be adsorbed water or crystal water of TiO 2 particles.
　実施例３及び比較例１の負極活物質のＭＳ測定の結果を図１１に示す。 FIG. 11 shows the results of MS measurement of the negative electrode active materials of Example 3 and Comparative Example 1.
　これらの少なくとも一つの実施形態又は実施例によれば、３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出する単斜晶構造のチタン含有酸化物を含有する負極活物質を含むため、高温環境下での膨れが抑制され、サイクル寿命性能が改善された非水電解質電池を提供することができる。 According to at least one embodiment or example of the present invention, a negative electrode containing a monoclinic structure titanium-containing oxide that releases 0.01 to 0.5 wt% of H 2 O in a temperature range of 300 to 600 ° C. Since it contains an active material, it is possible to provide a nonaqueous electrolyte battery in which swelling under a high temperature environment is suppressed and cycle life performance is improved.
　なお、本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。 In addition, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.
　１，１１，２３…電極群、２…外装部材、３，１３，２４…正極、３ａ…正極集電体、３ｂ…正極活物質含有層、４，１４，２５…負極、４ａ…負極集電体、４ｂ…負極活物質含有層、５，１５，２６…セパレータ、６…負極端子、７…正極端子、１２…金属製容器、１６，２７…正極リード、１７，２８…負極リード、１８…正極導電タブ、１９…負極導電タブ、２０…封口板、２１…絶縁部材、３１…組電池、３２１～３２５、４３１～４３５…非水電解質電池、３３…リード、４０…電池パック、４１…筐体、４２…組電池、４４…開口部、４５…出力用正極端子、４６…出力用負極端子、５１…単位セル、５５…組電池、５６…プリント配線基板、５７…サーミスタ、５８…保護回路、５９…外部機器への通電用端子。 DESCRIPTION OF SYMBOLS 1,11,23 ... Electrode group, 2 ... Exterior member, 3, 13, 24 ... Positive electrode, 3a ... Positive electrode collector, 3b ... Positive electrode active material containing layer, 4, 14, 25 ... Negative electrode, 4a ... Negative electrode current collector Body, 4b ... negative electrode active material containing layer, 5, 15, 26 ... separator, 6 ... negative electrode terminal, 7 ... positive electrode terminal, 12 ... metal container, 16, 27 ... positive electrode lead, 17, 28 ... negative electrode lead, 18 ... Positive electrode conductive tab, 19 ... Negative electrode conductive tab, 20 ... Sealing plate, 21 ... Insulating member, 31 ... Battery assembly, 32 1 to 32 5 , 43 1 to 43 5 ... Nonaqueous electrolyte battery, 33 ... Lead, 40 ... Battery pack , 41 ... housing, 42 ... assembled battery, 44 ... opening, 45 ... output positive terminal, 46 ... output negative terminal, 51 ... unit cell, 55 ... assembled battery, 56 ... printed wiring board, 57 ... thermistor, 58 .. protection circuit, 59... Terminal for energizing external equipment.

Claims (4)

  1. 　正極と、
    　３００～６００℃の温度範囲でＨ２Ｏを０．０１～０．５重量％放出し、かつ単斜晶構造を有するチタン含有酸化物を含有する負極活物質を含む負極と、
    　非水電解質と
    を含む非水電解質電池。     A positive electrode;
    A negative electrode including a negative electrode active material containing a titanium-containing oxide having a monoclinic structure and releasing 0.01 to 0.5% by weight of H 2 O in a temperature range of 300 to 600 ° C .;
    A non-aqueous electrolyte battery comprising a non-aqueous electrolyte.
  2. 　前記正極は、ＬｉｘＭｎ２－ａＮｉａＯ４（０≦ｘ≦１．１，０．１≦ａ≦０．６）で表されるスピネル構造のマンガンニッケル含有酸化物、ＬｉｘＦｅ１－ｗＭｎｗＳＯ４Ｆ（０≦ｘ≦１．１，０≦ｗ≦０．２）で表されるフッ素化硫酸化合物、及び、ＬｉｘＦｅ１－ｙ―ｚＭｎｙＭｚＰＯ４（ＭはＭｇ、Ａｌ、Ｔｉ及びＺｒよりなる群から選択される少なくとも１種類の元素、０≦ｘ≦１．１，０≦ｙ≦１、０≦ｚ≦０．２）で表されるオリビン構造のリン酸化合物よりなる群から選ばれる少なくとも一種類の正極活物質を含む、請求項１に記載の非水電解質電池。 The positive electrode, Li x Mn 2-a Ni a O 4 (0 ≦ x ≦ 1.1,0.1 ≦ a ≦ 0.6) manganese-nickel-containing oxide having a spinel structure represented by, Li x Fe 1 -w Mn w SO 4 F (0 ≦ x ≦ 1.1,0 ≦ w ≦ 0.2) fluorinated acid compound represented by, and, Li x Fe 1-y- z Mn y M z PO 4 ( M is an olivine structure represented by at least one element selected from the group consisting of Mg, Al, Ti and Zr, 0 ≦ x ≦ 1.1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 0.2) The nonaqueous electrolyte battery according to claim 1, comprising at least one positive electrode active material selected from the group consisting of the phosphoric acid compounds.
  3. 　前記チタン含有酸化物は、ＬｉｘＴｉＯ２（０≦ｘ≦１）で表される、請求項１または２に記載の非水電解質電池。 The non-aqueous electrolyte battery according to claim 1, wherein the titanium-containing oxide is represented by Li x TiO 2 (0 ≦ x ≦ 1).
  4. 　請求項１～３のいずれか１項に記載の非水電解質電池を含む電池パック。 A battery pack comprising the nonaqueous electrolyte battery according to any one of claims 1 to 3.
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Publication number Priority date Publication date Assignee Title
WO2010110035A1 (en) * 2009-03-25 2010-09-30 株式会社 東芝 Anode active material for use in non-aqueous electrolyte battery, production method thereof, non-aqueous electrolyte battery, and battery pack
WO2010131364A1 (en) * 2009-05-15 2010-11-18 株式会社 東芝 Battery with nonaqueous electrolyte, negative electrode active material for use in the battery, and battery pack
WO2011013254A1 (en) * 2009-07-31 2011-02-03 株式会社 東芝 Nonaqueous electrolyte battery, active material used therein, method for producing same, method for producing alkali titanate compound, and battery pack
JP2012059467A (en) * 2010-09-07 2012-03-22 Toshiba Corp Electrode for battery and manufacturing method thereof, nonaqueous electrolyte battery, battery pack and active material
JP2013249223A (en) * 2012-05-31 2013-12-12 Titan Kogyo Kk Titanium oxide for electrode and method for manufacturing the same

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010110035A1 (en) * 2009-03-25 2010-09-30 株式会社 東芝 Anode active material for use in non-aqueous electrolyte battery, production method thereof, non-aqueous electrolyte battery, and battery pack
WO2010131364A1 (en) * 2009-05-15 2010-11-18 株式会社 東芝 Battery with nonaqueous electrolyte, negative electrode active material for use in the battery, and battery pack
WO2011013254A1 (en) * 2009-07-31 2011-02-03 株式会社 東芝 Nonaqueous electrolyte battery, active material used therein, method for producing same, method for producing alkali titanate compound, and battery pack
JP2012059467A (en) * 2010-09-07 2012-03-22 Toshiba Corp Electrode for battery and manufacturing method thereof, nonaqueous electrolyte battery, battery pack and active material
JP2013249223A (en) * 2012-05-31 2013-12-12 Titan Kogyo Kk Titanium oxide for electrode and method for manufacturing the same

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