WO2007007581A1 - Positive electrode material for lithium secondary battery, process for production of the same, and lithium secondary material manufactured using the same - Google Patents

Positive electrode material for lithium secondary battery, process for production of the same, and lithium secondary material manufactured using the same Download PDF

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Publication number
WO2007007581A1
WO2007007581A1 PCT/JP2006/313259 JP2006313259W WO2007007581A1 WO 2007007581 A1 WO2007007581 A1 WO 2007007581A1 JP 2006313259 W JP2006313259 W JP 2006313259W WO 2007007581 A1 WO2007007581 A1 WO 2007007581A1
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Prior art keywords
lithium
positive electrode
secondary battery
lithium secondary
electrode material
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PCT/JP2006/313259
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French (fr)
Japanese (ja)
Inventor
Junji Akimoto
Junji Awaka
Yasuhiko Takahashi
Norihito Kijima
Mitsuharu Tabuchi
Kuniaki Tatsumi
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National Institute Of Advanced Industrial Science And Technology
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Priority to JP2007524578A priority Critical patent/JP5051770B2/en
Publication of WO2007007581A1 publication Critical patent/WO2007007581A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a positive electrode material for a lithium secondary battery, a method for producing the same, and a lithium secondary battery containing the material as a positive electrode active material.
  • lithium secondary batteries are mounted on portable electronic devices such as mobile phones and laptop computers.
  • lithium secondary batteries are expected to be put into practical use as large batteries for electric vehicles and power load leveling systems in the future, and their importance is increasing.
  • This lithium secondary battery can absorb and release lithium, such as a positive electrode using a lithium-containing transition metal composite oxide as an active material, and lithium metal, a lithium alloy, a metal oxide, or carbon.
  • the main components are a negative electrode using a possible material as an active material and a separator or solid electrolyte containing a non-aqueous electrolyte.
  • those considered as positive electrode active materials include layered rock salt type lithium cobalt oxide (LiCoO), layered rock salt type lithium nickel oxide (LiNiO),
  • the layered rock salt type lithium cobalt oxide LiCoO is a secondary battery using this as a positive electrode.
  • Battery performance such as the operating voltage of the battery (difference between the oxidation-reduction potential of the transition metal in the positive electrode and the oxidation-reduction potential of the negative electrode element), charge / discharge capacity (positive-electrode force desorption 'the amount of lithium that can be inserted), etc. Future demand is expected to increase further as a positive electrode constituent material for secondary batteries.
  • this compound contains cobalt, which is a rare metal, as a main component, it is one of the high cost factors of lithium secondary batteries. Furthermore, considering that about 20% of the world's global cobalt production is already used in the battery industry! /, It is possible to meet future demand growth with only LiCoO-capable cathode materials. Power is unknown It is.
  • the layered rock-salt type lithium nickel oxides using nickel cheaper than cobalt Li NiO is advantageous in terms of cost and capacity, and is a promising alternative to lithium cobalt oxides.
  • spinel type lithium manganese oxide LiMn O is more than cobalt and nickel.
  • Na MnO that has a one-dimensional tunnel structure is used as a starting point.
  • the compound has two types of tunnels with different sizes, so it is considered that ion diffusion is easy. For example, it is attracting attention as a positive electrode material with high output (capable of rapid charge / discharge). (See non-patent documents 1 and 2)
  • Patent Document 1 A. R. Armstrong, H. Huang, R. A. Jennings, P. G. Bruce, J. Mater. Chem., 8, 255-259 (1998)
  • Non-Patent Document 2 MM Doeff, A. Anapolsky, L. Edman, TJ Richardson, LC De Jonghe, J. Electrochem. Soc., 148, A230—A236 (2001) [0010] Therefore, it is a positive electrode material that can replace LiCoO in current lithium secondary batteries.
  • manganate-based positive electrode material that has a voltage flat part associated with trivalent and tetravalent oxidation-reduction reactions of manganese in the vicinity of 4 V, and that can be stably charged and discharged. Judgment criteria.
  • the present inventors can charge and discharge even in the 4V region and have a high capacity, a new lithium manganate, and a titanium substitution product (Li Mn Ti O (0.4 ⁇ x ⁇ 0.5, O ⁇ y ⁇ 0.56) was found and proposed earlier
  • the discharge capacity that can be realized with this material is about 60mAhZg in the initial discharge capacity and about 150mAhZg in the battery using the lithium negative electrode in the battery using the carbon negative electrode. In order to realize the theoretical capacity (193 mAhZg), further capacity improvement was necessary.
  • Patent Document 1 Japanese Patent Application No. 2004-065402
  • Patent Document 2 Japanese Patent Application No. 2004- 080970
  • Patent Document 3 Japanese Patent Application No. 2004 080971
  • a battery using lithium metal or a lithium alloy as a negative electrode material has been studied.
  • lithium metal or a lithium alloy as a negative electrode material
  • many studies have been conducted on “lithium polymer secondary batteries” using solid polymers as electrolytes.
  • a positive electrode material that can maximize its performance in the use of a lithium negative electrode, and the development of new materials with high voltage and high capacity is also being promoted.
  • the constituent elements of the positive electrode material oxide that can be used with various negative electrode materials are replaced with light elements with as low an atomic weight as possible for the purpose of reducing the weight of the battery itself. Development is also underway.
  • the above-mentioned spinel type lithium manganese oxide LiMn O is a battery using a lithium negative electrode.
  • the present invention solves the above-mentioned problems by using an inexpensive manganic acid raw material with less resource restrictions, and the above-described Li MnO type tunnel structure.
  • a new positive electrode material that can be charged and discharged stably with a high capacity in a working voltage range (about 4 V) equivalent to that of an existing practical positive electrode material, a manufacturing method thereof, and the positive electrode active material
  • the aim is to provide lithium secondary batteries using various negative electrode materials as substances.
  • the present invention provides a lithium manganese titanate positive electrode material, a production method thereof, and a lithium secondary battery using the same as shown in the following 1 to 6.
  • the chemical composition is expressed as Li Mn Ti O (0.5 ⁇ x ⁇ l, 0 ⁇ y ⁇ 0.56), and the crystal structure belongs to the orthorhombic system and has a tunnel structure occupied by lithium.
  • Lithium secondary battery positive electrode material that is also composed of lithium, mangan, titanium and oxygen power.
  • the lithium secondary battery according to 4 wherein a lithium or lithium alloy negative electrode is used as the negative electrode of the battery and can be stably charged and discharged in a voltage range of 4V.
  • an inexpensive raw material is used in a lithium secondary battery in a high operating voltage range (about 4V) equivalent to that of an existing lithium cobalt oxide-based positive electrode material.
  • a novel lithium manganese titanate positive electrode material can be obtained which can be charged and discharged stably and has a larger V and capacity than the existing positive electrode lithium manganate spinel.
  • the lithium secondary battery of the present invention using the above lithium manganese titanate positive electrode material has high voltage, high capacity, can exhibit excellent charge / discharge cycle characteristics, and is highly practical. Is.
  • FIG. 1 is a schematic diagram showing an example of a lithium secondary battery of the present invention.
  • FIG. 2 is an X-ray powder diffraction pattern of the positive electrode material of the present invention obtained in Examples 1 and 2.
  • FIG. 3 is a graph showing initial discharge characteristics of the batteries obtained in Example 1 and Comparative Example 1.
  • FIG. 4 is a graph showing initial discharge characteristics of the batteries obtained in Example 1 and Comparative Example 2.
  • FIG. 5 is a graph showing initial discharge characteristics of the batteries obtained in Example 3 and Comparative Examples 3 and 4.
  • FIG. 6 is a graph showing the discharge output characteristics of the battery obtained in Example 4.
  • Cathode material is the starting material Na Mn Ti l -y y 2 x l -y y
  • the ratio of titanium and titanium can be freely selected within the above composition range.
  • the Li Mn Ti O (0.5 ⁇ x ⁇ l, 0 ⁇ y ⁇ 0. 56) positive electrode material of the present invention is the above-mentioned prior application l -y y 2
  • the positive electrode material can be produced by subjecting the positive electrode material to a lithium insertion treatment.
  • the total amount of lithium in the positive electrode material can be 0.4 ⁇ x ⁇ l (however, X is larger than X in the starting material). It is preferable that 5 ⁇ x ⁇ l, especially 0.6 ⁇ x ⁇ l.
  • the positive electrode material of the present invention is capable of almost completely replacing sodium contained in the starting material with lithium by ion exchange treatment and lithium insertion treatment because of the crystal structure and the characteristics of the production process. It is characterized by that. However, it is generally known that such a method leaves significant or impure sodium. That is, the Li Mn Ti 2 O (0.5 ⁇ x ⁇ l, 0 ⁇ y ⁇ 0.56) positive electrode material of the present invention is
  • Impurity elements such as sodium may be contained within a range that does not impede the effect of the present invention, force S characterized by containing thium, manganese, titanium, and oxygen as main constituent elements.
  • the Li Mn Ti O (0.5 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.56) positive electrode material of the present invention includes manganese and titanium.
  • the amount of tongue can be freely selected within the range of 0 ⁇ y ⁇ 0.56. It has been confirmed in the prior application that replacing titanium has the effect of increasing the stability of the crystal structure and increasing the trivalent manganes that contribute to the charge / discharge reaction.
  • the amount of U and titanium is within the range of force 0 ⁇ y ⁇ 0.56, more preferably 0 ⁇ y ⁇ 0.4, which correlates with the amount of lithium in the structure.
  • the Li Mn Ti O (0.5 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.56) positive electrode material of the present invention is
  • the body has a Li MnO type tunnel structure, it hinders the effect of the present invention.
  • the Li Mn Ti O (0.5 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.56) positive electrode material of the present invention is the above-mentioned prior application.
  • lithium manganese titanium oxide Li Mn Ti O (0.40 ⁇ x ⁇ 0
  • Positive electrode material is sodium manganese titanium oxide Na Mn Ti O
  • the Na Mn Ti O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y ⁇ 0.56) compound is, for example, (1) sodium
  • the sodium raw material at least one of sodium (metallic sodium) and a sodium compound is used.
  • the sodium compound is not particularly limited as long as it contains sodium, for example, oxides such as Na 0 and Na O, salts such as Na CO and NaNO, NaO
  • manganese raw material at least one of manganese (metallic manganese) and a manganese compound is used.
  • Manganese compounds are not particularly limited as long as they contain manganese. For example, oxides such as MnO, MnO and MnO, salts such as MnCO and MnCl, M
  • hydroxides such as n (OH) and oxide hydroxides such as MnOOH.
  • n (OH) hydroxides
  • MnOOH oxide hydroxides
  • Mn 2 O, MnO and the like are preferable.
  • titanium raw material at least one of titanium (titanium metal) and a titanium compound is used.
  • the titanium compound is not particularly limited as long as it contains titanium, and examples thereof include oxides such as TiO, Ti 2 O, and TiO, and salts such as TiCl. Among these, special
  • TiO and the like are preferable.
  • the mixing ratio of the sodium raw material, the manganese raw material, and the titanium raw material is preferably such that the tunnel structure is formed. Specifically, Na Mn Ti O (0. 40 ⁇ x ⁇ 0. 50, 0 ⁇ y ⁇ 0.5.56)
  • the mixture may be such that the molar ratio of NaZ (Mn + Ti) is about 0.4 to 0.7, preferably 0.43 to 0.55.
  • the sodium contained in the product volatilizes and the amount of sodium in the product is often less than the charged composition. It is preferable to increase the amount charged.
  • the ratio of manganese and titanium can be selected arbitrarily within the range of (0 ⁇ y ⁇ 0.56).
  • the mixing method is not particularly limited as long as they can be mixed uniformly.
  • a known mixer such as a mixer may be used to mix them in a wet or dry manner.
  • the calcination temperature can be appropriately set according to the composition of the mixture, etc., but is usually about 600 to 1200 ° C., preferably 800 to 1050 ° C.
  • the firing atmosphere is not particularly limited, but usually it may be carried out in an acidic atmosphere or air.
  • the firing time can be appropriately changed according to the firing temperature and the like.
  • the cooling method is not particularly limited! Usually, natural cooling (cooling in the furnace) or slow cooling is sufficient! ,.
  • the fired product may be pulverized by a known method, if necessary, and the above firing step may be further performed. That is, in the method of the present invention, it is preferable that the mixture is repeatedly fired, gradually cooled and pulverized twice or more. The degree of grinding depends on the firing temperature. You can adjust it accordingly.
  • pulverized ⁇ ⁇ ⁇ ⁇ Ti O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y ⁇ 0.56) is dispersed in the molten salt containing the lithium-containing compound.
  • the molten salt a molten salt containing at least one of the salts that are melted at a low temperature such as lithium nitrate, lithium chloride, lithium bromide, and lithium iodide can be used.
  • a lithium compound and a powder of Na Mn Ti O fired product are mixed well.
  • the mixing ratio is usually 2 to 40, preferably 10 to 30 in terms of the molar ratio of Na in LiZNa Mn Ti 2 O in the molten salt.
  • the ion exchange temperature is 260 ° C to 330 ° C. If the ion exchange temperature is lower than 260 ° C, it is not completely exchanged for sodium potassium in Na Mn Ti O (0.40 x 0, 50, 0 ⁇ v ⁇ 0.56). A considerable amount of sodium remains in the product. On the other hand, when the ion exchange temperature is higher than 330 ° C, a part of the ion exchange temperature changes to a spinel structure, so that a uniform crystal structure cannot be obtained.
  • the treatment time is usually 2 to 20 hours, preferably 5 to 15 hours.
  • an ion exchange treatment method a treatment method in an organic solvent or an aqueous solution in which a lithium compound is dissolved is also suitable.
  • powdered Na Mn Ti O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y ⁇ 0.56) is put into an organic solvent in which a lithium-containing compound is dissolved, and the boiling point of the organic solvent Process at the following temperatures.
  • the treatment temperature is usually 30 ° C to 200 ° C, preferably 60 ° C to 180 ° C.
  • the treatment time is not particularly limited, but it is usually 5 to 50 hours, preferably 10 to 20 hours because a reaction time is required at a low temperature.
  • lithium-containing compound used in the present invention hydroxide, carbonate, acetate, nitrate, oxalate, halide, butyllithium and the like are preferable. Used in combination of two or more as required.
  • organic solvent used in the present invention higher alcohols such as hexanol and ethoxyethanol, ethers such as diethylene glycol monoethyl ether, or organic solvents having a boiling point of 140 ° C. or higher have good workability. It is preferable at this point. These may be used alone or in combination of two or more as required.
  • the concentration of the lithium-containing compound in the organic solvent or aqueous solution is usually 3 to 10 mol%, preferably 5 to 8 mol%.
  • the dispersion concentration of Na Mn Ti O in the organic solvent or aqueous solution is not particularly limited, but is 1 to 20 weight from the viewpoint of operability and economy.
  • the obtained product is washed thoroughly with distilled water, washed with methanol and ethanol, and then dried to obtain the target Li Mn Ti O (0.40 x
  • the washing method and drying method are not particularly limited, and a normal method may be used, or natural drying in a desiccator may be used.
  • Li Mn Ti O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y) produced by ion exchange treatment
  • ⁇ 0. 56 is further subjected to ion insertion treatment in a molten salt containing a lithium compound, or in an organic solvent or an aqueous solution, so that it has a Li MnO type crystal structure and has a chemical composition formula Li Mn Ti A compound represented by O (0. 5 ⁇ x ⁇ l, 0 ⁇ y ⁇ 0. 56) is obtained.
  • Li Mn Ti 2 O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y ⁇ 0.56) prepared in advance is dispersed in the molten salt containing the lithium-containing compound. It is preferable to apply a lithium insertion treatment.
  • the molten salt lithium nitrate is used, and as additives, lithium hydroxide, lithium iodide, lithium bromide, lithium oxide, lithium peroxide, lithium carbonate, lithium chloride, etc. I ’m going to give you this.
  • the additive and Li Mn Ti O powder are mixed well.
  • the mixing ratio is usually 0.01 to 10, preferably 0.1 to 3, in terms of the molar ratio of the additive ZLi Mn Ti 2 O in the molten salt.
  • the temperature of the lithium insertion treatment is 260 ° C to 330 ° C.
  • the processing temperature is higher than 330 ° C, a part of the processing temperature changes to a spinel structure, so that a uniform crystal structure cannot be obtained.
  • the treatment time is usually 2 to 20 hours, preferably 5 to 15 hours. Insert process several times, It is more effective to repeat 2 to 3 times.
  • a method for lithium insertion treatment a method of treating in an organic solvent or an aqueous solution in which a lithium compound is dissolved is also suitable.
  • Li Mn Ti O (0.40 ⁇ x ⁇ 0.50, 0 ⁇ y) previously ion-exchanged in an organic solvent in which a lithium-containing compound is dissolved.
  • the treatment temperature is usually 30 ° C to 200 ° C, preferably 60 ° C to 180 ° C.
  • the treatment time is not particularly limited, but is usually 5 to 50 hours, preferably 10 to 20 hours, because the reaction time is required at low temperatures.
  • the lithium-containing compound used in the present invention is preferably a hydroxide, oxide, peroxide, carbonate, acetate, nitrate, oxalate, halide, butyllithium, or the like. These are used alone or in combination of two or more as required.
  • organic solvent used in the present invention higher alcohols such as hexanol and ethoxyethanol, ethers such as diethylene alcohol monoethyl ether, or organic solvents having a boiling point of 140 ° C. or higher have workability. It is preferable at the point which is favorable. These may be used alone or in combination of two or more as required.
  • the concentration of the lithium-containing compound in the organic solvent or aqueous solution is usually 3 to 10 mol%, preferably 5 to 8 mol%. Also, Li Mn Ti in organic solvent or aqueous solution
  • the dispersion concentration of O is not particularly limited, but is 1 to 20 weight from the viewpoint of operability and economy.
  • the obtained product is washed thoroughly with distilled water, washed with methanol and ethanol, and then dried to obtain the target Li Mn Ti O (0.5 ⁇ x
  • the washing method and the drying method are not particularly limited, and a normal method may be used, or natural drying in a desiccator may be used.
  • the lithium secondary battery of the present invention uses the positive electrode material for a lithium secondary battery. That is, the battery element of a known lithium secondary battery (coin type, button type, cylindrical type, etc.) is used as it is, except that the lithium manganese titanate of the present invention is used as the positive electrode material. Can be adopted.
  • FIG. 1 is a schematic view showing an example in which the lithium secondary battery of the present invention is applied to a button type battery.
  • the button-type battery 1 includes a negative electrode terminal 2, a negative electrode 3, (separator + electrolyte) 4, insulating knocking 5, a positive electrode 6, and a positive electrode can 7.
  • a positive electrode mixture is prepared by blending the above-described lithium manganese titanate salt of the present invention with a conductive agent, a binder or the like as necessary, and this is used as a current collector.
  • the positive electrode can be produced by pressure bonding.
  • a stainless mesh, aluminum foil or the like can be preferably used.
  • acetylene black, ketjen black or the like can be preferably used.
  • the binder tetrafluoroethylene, polyvinylidene fluoride, or the like can be preferably used.
  • the composition of the lithium manganese titanate, the conductive agent, the binder, etc. in the positive electrode mixture is not particularly limited, but usually the conductive agent is about 1 to 30% by weight (preferably 5 to 25% by weight). ), About 0 to 30% by weight (preferably 3 to: LO% by weight) of the binder, and the remainder being lithium manganese titanate.
  • examples of the counter electrode with respect to the positive electrode include carbon-based materials such as black lead and MCMB (mesocarbon microbeads), alloy-based materials such as tin-based materials, lithium metal, and lithium alloys.
  • carbon-based materials such as black lead and MCMB (mesocarbon microbeads)
  • alloy-based materials such as tin-based materials, lithium metal, and lithium alloys.
  • a known material capable of occluding lithium can be used.
  • electrolytes can be used.
  • an electrolyte such as lithium perchlorate or lithium hexafluorophosphate was dissolved in a solvent such as ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), or jetyl carbonate (DEC).
  • EC ethylene carbonate
  • DMC dimethyl carbonate
  • PC propylene carbonate
  • DEC jetyl carbonate
  • An ion exchange treatment was performed for a treatment time of 10 hours, and the obtained solid was washed with distilled water, methanol, ethanol, etc. and dried to obtain a sample.
  • the amount of sodium remaining in the chemical formula is appropriate in the chemical formula of 22), and the molar ratio of NaZLi was 0.005.
  • the Li MnO-type orthorhombic tunnel was investigated by X-ray powder diffraction.
  • each lg shown in Table 1 was mixed well with 22 g of lithium nitrate and lg of lithium hydroxide, and then heated in air at 300 ° C for 10 hours to perform lithium insertion treatment. .
  • the obtained solid was washed with distilled water, methanol, ethanol or the like and dried to obtain a sample.
  • the amount of lithium X was about 0.59 ⁇ x ⁇ 0.72, confirming the insertion reaction.
  • the remaining sodium content is below the ICP detection limit (0.01 wt%), and the lithium insertion treatment further reduces the residual sodium content. It was confirmed that it is also effective in reducing this.
  • Sara Miko of the prepared samples, Li MnO
  • Table 2 shows the calculated lattice constants assuming 2 0. 44 2 structure. The change of lattice constant became clear due to the lithium insertion process compared to the original Li Mn Ti O (0.43 ⁇ x ⁇ 0.44).
  • a positive electrode was prepared by mixing 20 mg of a sample with 5 mg of acetylene black as a conductive agent and 0.5 mg of tetrafluoroethylene as a binder, lithium metal as the negative electrode material, and lithium hexafluorophosphate as ethylene carbonate (EC ) And jetyl carbonate (DEC) in a mixed solvent (volume ratio 1: 1) to produce a lithium secondary battery (coin-type cell) having the structure shown in FIG. The charge / discharge characteristics were measured.
  • the battery was produced according to a known cell configuration method.
  • the obtained lithium secondary battery was subjected to a charge / discharge test under a temperature condition of 30 ° C with a current density of 30mAZg (equivalent to 0.2C at C rate) and a cutoff potential of 4.8V-2.5V.
  • a current density of 30mAZg equivalent to 0.2C at C rate
  • a cutoff potential of 4.8V-2.5V As a result, it was found that an average discharge voltage of 3.55-3.64 V and an initial discharge capacity of 173 to 184 mAhZg can be stably charged and discharged.
  • the C rate is the discharge rate, that is, the magnitude of the discharge current
  • 1C is the amount of current that can be discharged in one hour, and is called the one-hour rate.
  • 1Ah 1C means 1A.
  • Fig. 3 (a) and (b) The initial discharge characteristics are shown in Fig. 3 (a) and (b).
  • Fig. 3 (c) the battery shown in Fig. 3 (c), which uses Li MnO before Li insertion as the positive electrode material, was similarly manufactured.
  • a positive electrode was produced in the same manner as in Example 1.
  • a lithium secondary battery was produced in the same manner as in Example 1 and a charge / discharge test was conducted.
  • the average discharge voltage was 3.54-3.60 V, the initial discharge capacity. It was confirmed that charging and discharging can be stably performed at 168 to 176 mAhZg.
  • Table 5 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample.
  • the sample was used as it is as a positive electrode material without being subjected to lithium insertion treatment, and a lithium secondary battery was produced and charged / discharged in the same manner as in Example 1. Both samples had an average discharge voltage of 3.48 to 3.54 V. The initial discharge capacity was about 141 to 156 mAhZg. For comparison, the initial discharge curve for Li MnO is shown in Fig. 3 (c).
  • the existing positive electrode lithium manganese spinel Li A lithium secondary battery was prepared in the same manner as in Example 1 using MnO as the positive electrode material.
  • the battery using this positive electrode material showed a large two-stage discharge curve characteristic of the spinel type.
  • the battery using Li MnO of the present invention obtained in Example 1 of the present invention as the positive electrode material has a voltage 'capacitance, as shown in Fig. 4 (a).
  • the superiority to the spinel material was confirmed from the viewpoint of energy density.
  • a positive electrode was prepared in the same manner as in Example 1, carbon (MCMB) as the negative electrode material, lithium hexafluorophosphate as ethylene carbonate (EC) and jetyl carbonate (D EC).
  • MCMB carbon
  • EC ethylene carbonate
  • D EC jetyl carbonate
  • a lithium ion secondary battery (coin-type cell) having the structure shown in FIG. 1 was prepared using a 1M solution dissolved in the above mixed solvent (volume ratio 1: 1) as an electrolytic solution, and its charge / discharge characteristics were measured.
  • the battery was produced according to a known cell configuration'assembly method.
  • the current density was 30mAZg under the temperature condition of 30 ° C.
  • Table 6 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample. The initial discharge characteristics of Li MnO
  • a positive electrode was prepared, and a lithium secondary battery was prepared and charged and discharged in the same manner as in Example 3. All of these batteries were stable at an average discharge voltage of 3.7 to 3.8 V and an initial discharge capacity of 100 to 119 mAhZg. It was confirmed that charging / discharging was possible. Table 7 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample.
  • the sample was used as it is as a positive electrode material without being subjected to lithium insertion treatment, and a lithium secondary battery was produced and charged / discharged in the same manner as in Example 3. Both samples had an average discharge voltage of 3.8 to 3.9 V. The initial discharge capacity was about 50-60mAhZg. For comparison, the initial discharge curve for Li MnO is shown in FIG. 5 (b).
  • Example 3 In order to clarify the characteristics of the lithium secondary battery using the novel lithium manganese titanate according to the present invention as the positive electrode material, the same as in Example 3 using the existing positive electrode lithium manganese spinel Li Mn O as the positive electrode material A lithium secondary battery was fabricated in the same conditions.
  • a positive electrode component similar to that in Example 1 was diluted with N-methyl 2-pyrrolidone (NMP) to form a slurry, and a coated electrode was produced according to a conventional method.
  • Table 8 shows the electrode physical properties of the produced positive electrode.
  • the positive electrode thus obtained MCMB as the negative electrode, polyethylene microporous membrane as the separator, and lithium secondary battery using lithium hexafluorophosphate electrolyte as in Example 1 (single layer aluminum laminate cell)
  • the output characteristics were measured.
  • the battery was produced according to a known cell configuration method.
  • the obtained lithium secondary battery was charged to 4.8 V at a constant current of 30 mAZg (equivalent to 0.2 C at C rate) at 25 ° C, and discharged at 30 mAZg and 60 mA / g, respectively.
  • 150 mAZg, 300 mAZg, 450 mA / g, 750 mA / g, 900 mA / g, and 1050 mA / g were used at constant currents up to 2.5 V to evaluate the output characteristics of each sample.
  • Figure 6 compares the capacity retention at each rate for Li MnO and Li MnO.
  • the capacity retention rate was about 40% at 1050mAZg equivalent to 7C.
  • Li MnO was found to have a high capacity retention of over 70%. From this

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  • Inorganic Compounds Of Heavy Metals (AREA)

Abstract

Disclosed is a novel positive electrode material which can be produced using an inexpensive manganese oxide raw material without little constraint on resource, has a Li0.44MnO2-type tunnel structure, and can be charged/discharged stably at a high capacity in the operating voltage range equivalent to that of a already existing practical positive electrode material (around 4 V). Also disclosed is a process for producing the positive electrode material. Further disclosed is a lithium secondary battery comprising the material as the positive electrode active material and any one of various negative electrode materials. A positive electrode material for use in a lithium secondary battery, which is composed of lithium, manganese, titanium and oxygen and represented by the following chemical composition: LixMn1-yTiyO2 (0.5 ≤ x ≤ 1, 0 ≤ y ≤ 0.56), which has an orthorhombic crystal structure, and which has a tunnel structure occupied by lithium. The material can be used to construct a lithium secondary battery.

Description

明 細 書  Specification
リチウム二次電池用正極材料及びその製造方法、ならびにそれを用いた リチウム二次電池  Positive electrode material for lithium secondary battery, method for producing the same, and lithium secondary battery using the same
技術分野  Technical field
[0001] 本発明は、リチウム二次電池用正極材料及びその製造方法、ならびにその材料を 正極活物質として含むリチウム二次電池に関する。  TECHNICAL FIELD [0001] The present invention relates to a positive electrode material for a lithium secondary battery, a method for producing the same, and a lithium secondary battery containing the material as a positive electrode active material.
背景技術  Background art
[0002] 現在我が国においては、携帯電話、ノートパソコンなどの携帯型電子機器に搭載さ れている二次電池のほとんどは、リチウム二次電池である。また、リチウム二次電池は 、今後電気自動車、電力負荷平準化システムなどの大型電池としても実用化されるも のと予測されており、その重要性はますます高まっている。  [0002] Currently, in Japan, most of the secondary batteries mounted on portable electronic devices such as mobile phones and laptop computers are lithium secondary batteries. In addition, lithium secondary batteries are expected to be put into practical use as large batteries for electric vehicles and power load leveling systems in the future, and their importance is increasing.
[0003] このリチウム二次電池は、リチウム含有遷移金属複合酸化物を活物質とする正極と 、リチウム金属、リチウム合金、金属酸ィ匕物あるいはカーボンのような、リチウムを吸蔵 •放出することが可能な材料を活物質とする負極と、非水系電解液を含むセパレータ または固体電解質を主要構成要素とする。  [0003] This lithium secondary battery can absorb and release lithium, such as a positive electrode using a lithium-containing transition metal composite oxide as an active material, and lithium metal, a lithium alloy, a metal oxide, or carbon. The main components are a negative electrode using a possible material as an active material and a separator or solid electrolyte containing a non-aqueous electrolyte.
[0004] これらの構成要素のうち、正極活物質として検討されているものには、層状岩塩型リ チウムコバルト酸化物（LiCoO )、層状岩塩型リチウムニッケル酸化物（LiNiO )、ス  [0004] Among these components, those considered as positive electrode active materials include layered rock salt type lithium cobalt oxide (LiCoO), layered rock salt type lithium nickel oxide (LiNiO),
2 2 ピネル型リチウムマンガン酸ィ匕物（LiMn O )等が挙げられる。  2 2 Pinel type lithium manganate (LiMn 2 O 3) and the like.
2 4  twenty four
[0005] 特に、層状岩塩型リチウムコバルト酸化物 LiCoOは、これを正極に用いた二次電  [0005] In particular, the layered rock salt type lithium cobalt oxide LiCoO is a secondary battery using this as a positive electrode.
2  2
池の作動電圧（正極中の遷移金属の酸化還元電位と負極元素の酸化還元電位との 差)、充放電容量 (正極力 脱離 '挿入可能なリチウム量)などの電池性能に優れ、リ チウムニ次電池の正極構成材料として今後の需要が一層増大するものと予測されて いる。  Battery performance such as the operating voltage of the battery (difference between the oxidation-reduction potential of the transition metal in the positive electrode and the oxidation-reduction potential of the negative electrode element), charge / discharge capacity (positive-electrode force desorption 'the amount of lithium that can be inserted), etc. Future demand is expected to increase further as a positive electrode constituent material for secondary batteries.
し力しながら、この化合物は、稀少金属であるコバルトを主成分として含むために、 リチウム二次電池の高コストの要因の一つとなっている。さらに、現在すでに全世界 のコバルト生産量の約 20%が電池産業にお!、て用いられて!/、ることを考慮すれば、 LiCoO力もなる正極材料のみでは、今後の需要拡大に対応可能力どうかは、不明 である。 However, since this compound contains cobalt, which is a rare metal, as a main component, it is one of the high cost factors of lithium secondary batteries. Furthermore, considering that about 20% of the world's global cobalt production is already used in the battery industry! /, It is possible to meet future demand growth with only LiCoO-capable cathode materials. Power is unknown It is.
[0006] また、コバルトよりも安価なニッケルを用いた層状岩塩型リチウムニッケル酸ィ匕物 Li NiOは、コスト的にも容量的にも有利であり、リチウムコバルト酸ィ匕物の有力な代替 [0006] In addition, the layered rock-salt type lithium nickel oxides using nickel cheaper than cobalt Li NiO is advantageous in terms of cost and capacity, and is a promising alternative to lithium cobalt oxides.
2 2
材料として開発が進められている。し力しながら、このリチウムニッケル酸ィ匕物を正極 活物質に用いたリチウム二次電池は、充電状態での正極活物質の不安定性から、高 温に保持すると分解、発熱、発火などの危険性を有しており、安全性に関して解決し なければならない問題が多く残って!/ヽる。  Development is progressing as a material. However, a lithium secondary battery using this lithium nickel oxide as a positive electrode active material is not stable due to the instability of the positive electrode active material in the charged state. Many problems remain to be solved regarding safety!
[0007] また、前記コバルト系酸ィ匕物代替の材料と!/、う観点からは、資源的な制約が少なく かつ安価なマンガン酸ィ匕物を原料として使用し、さらに、 Mn3+と Mn4+の酸化還元 反応に伴うマンガンと酸素の化学結合の変化に耐えるようなマンガン系正極材料力 有望な材料である。 [0007] In addition, from the viewpoint of the above-mentioned cobalt-based oxide substitute material! /, It is possible to use a low-cost and low-cost manganate oxide as a raw material, and further, Mn 3+ Mn 4+ oxidation-reduction Manganese positive electrode material strength that can withstand changes in the chemical bond between manganese and oxygen associated with the reaction.
[0008] このうち、スピネル型リチウムマンガン酸化物 LiMn O は、コバルトやニッケルよりも  [0008] Among these, spinel type lithium manganese oxide LiMn O is more than cobalt and nickel.
2 4  twenty four
さらに安価なマンガンを用いており、かつ充電状態での安全性にも優れていることか ら、一部は LiCoOに代替して実用化されている。しかしながら、 LiCoOや LiNiOと  In addition, because it uses inexpensive manganese and has excellent safety in the charged state, some of them have been put into practical use instead of LiCoO. However, with LiCoO and LiNiO
2 2 2 比べて容量が小さいことが問題となっている。また、 50°C以上におけるマンガンの電 解液への溶解に起因する顕著な特性劣化と 、う問題点も有して 、るので、この材料 による LiCoOの代替は、予期された程には進展していない。  The problem is that the capacity is small compared to 2 2 2. In addition, there is a significant deterioration in properties due to the dissolution of manganese in electrolytes at temperatures above 50 ° C, so there is a problem with the substitution of LiCoO by this material as much as expected. Not done.
2  2
[0009] 一方、結晶構造の特徴として、一次元のトンネル構造をとる Na MnOを出発原  [0009] On the other hand, as a feature of the crystal structure, Na MnO that has a one-dimensional tunnel structure is used as a starting point.
0. 44 2 料として、イオン交換法によって Li MnOを合成する研究も行われている。この化  Research on the synthesis of Li MnO by an ion exchange method is also being conducted as a 0.44 material. This
0. 44 2  0. 44 2
合物は、 2種類のサイズの異なるトンネルを有することからイオン拡散が容易と考えら れ、例えば高出力（急速な充放電が可能）の正極材料として注目されて 、る。（非特 許文献 1, 2参照）  The compound has two types of tunnels with different sizes, so it is considered that ion diffusion is easy. For example, it is attracting attention as a positive electrode material with high output (capable of rapid charge / discharge). (See non-patent documents 1 and 2)
し力しながら、これまで報告されていた電池電圧は約 3V程度であり、電池容量も 10 OmAhZg程度であることから、実用的なレベルには達していな力つた。  However, since the battery voltage reported so far is about 3V and the battery capacity is about 10 OmAhZg, it has not reached the practical level.
特許文献 1 :A. R. Armstrong, H. Huang, R. A. Jennings, P. G. Bruce, J. Mater. Chem. , 8, 255— 259 (1998)  Patent Document 1: A. R. Armstrong, H. Huang, R. A. Jennings, P. G. Bruce, J. Mater. Chem., 8, 255-259 (1998)
非特許文献 2 : M. M. Doeff, A. Anapolsky, L. Edman, T. J. Richardson, L. C. De Jonghe, J. Electrochem. Soc. , 148, A230— A236 (2001) [0010] したがって、現行のリチウム二次電池において、 LiCoOに代替しうる正極材料であ Non-Patent Document 2: MM Doeff, A. Anapolsky, L. Edman, TJ Richardson, LC De Jonghe, J. Electrochem. Soc., 148, A230—A236 (2001) [0010] Therefore, it is a positive electrode material that can replace LiCoO in current lithium secondary batteries.
2  2
るか否かは、 4V付近にマンガンの 3価 4価の酸化還元反応に伴う電圧平坦部を有 し、安定に充放電可能なマンガン酸ィ匕物系正極材料である力否かが、その判断基準 となる。  Whether or not it is a manganate-based positive electrode material that has a voltage flat part associated with trivalent and tetravalent oxidation-reduction reactions of manganese in the vicinity of 4 V, and that can be stably charged and discharged. Judgment criteria.
本発明者らは、前記のイオン交換処理の温度を上昇させることで、 4V領域におい ても充放電可能で、かつ高容量である新規リチウムマンガン酸ィヒ物、およびそのチタ ン置換体（Li Mn Ti O (0. 4<x< 0. 5、 O≤y< 0. 56)を見出し、先に提案した  By increasing the temperature of the ion exchange treatment, the present inventors can charge and discharge even in the 4V region and have a high capacity, a new lithium manganate, and a titanium substitution product (Li Mn Ti O (0.4 <x <0.5, O≤y <0.56) was found and proposed earlier
l-y y 2  l-y y 2
。（特許文献 1〜3参照）  . (See Patent Documents 1 to 3)
し力しながら、この材料で実現できている放電容量は、炭素負極を使用した電池で 4V領域の充放電容量は、初期放電容量において約 60mAhZg程度、リチウム負極 を使用した電池で 150mAhZg程度であり、理論容量（193mAhZg)の実現のため には、さらに容量の改善が必要であった。  However, the discharge capacity that can be realized with this material is about 60mAhZg in the initial discharge capacity and about 150mAhZg in the battery using the lithium negative electrode in the battery using the carbon negative electrode. In order to realize the theoretical capacity (193 mAhZg), further capacity improvement was necessary.
特許文献 1：特願 2004— 065402号  Patent Document 1: Japanese Patent Application No. 2004-065402
特許文献 2：特願 2004— 080970号  Patent Document 2: Japanese Patent Application No. 2004- 080970
特許文献 3 :特願 2004 080971号  Patent Document 3: Japanese Patent Application No. 2004 080971
[0011] 一方、電池の更なるエネルギー密度向上の観点から、負極材料にリチウム金属、或 いはリチウム合金を使用した電池の検討が行われている。例えば、電池の安全性を 確保するために、電解質として固体高分子を使用した「リチウムポリマー二次電池」に 関する検討などが多くなされている。この目的のために、リチウム負極の使用におい て、最大限、性能が発揮されるような正極材料が求められており、高電圧かつ高容量 の新規材料開発も合わせて進められて ヽる。  [0011] On the other hand, from the viewpoint of further improving the energy density of a battery, a battery using lithium metal or a lithium alloy as a negative electrode material has been studied. For example, in order to ensure the safety of batteries, many studies have been conducted on “lithium polymer secondary batteries” using solid polymers as electrolytes. For this purpose, there is a demand for a positive electrode material that can maximize its performance in the use of a lithium negative electrode, and the development of new materials with high voltage and high capacity is also being promoted.
また、携帯電子機器等の電源として用いるために、電池自体の軽量ィ匕を目的として 、各種の負極材料と共に使用可能な正極材料酸ィ匕物の構成元素をできるだけ原子 量の小さい軽元素に置き換える開発も、合わせて進められている。  In addition, for use as a power source for portable electronic devices, the constituent elements of the positive electrode material oxide that can be used with various negative electrode materials are replaced with light elements with as low an atomic weight as possible for the purpose of reducing the weight of the battery itself. Development is also underway.
[0012] 前述のスピネル型リチウムマンガン酸化物 LiMn Oは、リチウム負極を使用した電  [0012] The above-mentioned spinel type lithium manganese oxide LiMn O is a battery using a lithium negative electrode.
2 4  twenty four
池においては、 Li Mn Oの化学組成までリチウム挿入が可能である力 挿入反応  In the pond, a force insertion reaction that allows lithium insertion up to the chemical composition of Li Mn O
2 2 4  2 2 4
が構造変化を伴うために、急速に容量劣化を引き起こすことが知られており、上記の 目的には合致しない。 発明の開示 Is known to cause rapid capacity degradation due to structural changes, and does not meet the above objectives. Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0013] したがって、本発明は、資源的な制約が少なくかつ安価なマンガン酸ィ匕物原料を 使用して、上記のような現状の課題を解決し、上述のような Li MnO型のトンネル 構造を有し、かつ、既存の実用正極材料と同等の作動電圧領域 (約 4V)において、 高容量で安定に充放電させることができる新規な正極材料、その製造方法、及びこ の材料を正極活物質として含み、各種負極材料を用いたリチウム二次電池を提供す ることにめる。  [0013] Therefore, the present invention solves the above-mentioned problems by using an inexpensive manganic acid raw material with less resource restrictions, and the above-described Li MnO type tunnel structure. In addition, a new positive electrode material that can be charged and discharged stably with a high capacity in a working voltage range (about 4 V) equivalent to that of an existing practical positive electrode material, a manufacturing method thereof, and the positive electrode active material The aim is to provide lithium secondary batteries using various negative electrode materials as substances.
課題を解決するための手段  Means for solving the problem
[0014] 本発明者は、上記特許文献 1〜3に記載された先願発明（以下、これらをまとめて 単に「先願発明」 t ヽぅ）を含む上記従来技術の問題に鑑みて鋭意検討を重ねてきた 。その結果、上記先願発明に係わるリチウムマンガンチタン酸ィ匕物 Li Mn Ti O ([0014] The present inventor has intensively studied in view of the problems of the prior arts including the prior inventions described in the above-mentioned Patent Documents 1 to 3 (hereinafter simply referred to as “prior invention inventions”). Has been repeated. As a result, the lithium manganese titanate Li Mn Ti O (
0. 4<x< 0. 5、 0≤y< 0. 56)を原料として、リチウム挿人処理を施すことによって、 元の結晶構造を維持したままで、酸ィ匕物中のリチウム量を増大させ、ほぼ理論容量 に近い値まで、 4V領域における容量を大幅に増カロさせることを見出し、本発明を完 成するに至った。 (4 <x <0.5, 0≤y <0.56) as a raw material, and lithium intercalation treatment, the amount of lithium in the oxide is reduced while maintaining the original crystal structure. It was found that the capacity in the 4V region was significantly increased to a value almost close to the theoretical capacity, and the present invention was completed.
[0015] すなわち、本発明は、下記 1〜6に示すリチウムマンガンチタン酸ィ匕物正極材料、そ の製造方法、およびそれを用いたリチウム二次電池を提供する。  That is, the present invention provides a lithium manganese titanate positive electrode material, a production method thereof, and a lithium secondary battery using the same as shown in the following 1 to 6.
1.化学組成式として Li Mn Ti O (0. 5≤x≤l, 0≤y< 0. 56)で表記され、結 晶構造として斜方晶系に属し、リチウムが占有するトンネル構造を有するリチウム、マ ンガン、チタン、酸素力も構成されるリチウム二次電池正極材料。  1. The chemical composition is expressed as Li Mn Ti O (0.5 ≤ x ≤ l, 0 ≤ y <0.56), and the crystal structure belongs to the orthorhombic system and has a tunnel structure occupied by lithium. Lithium secondary battery positive electrode material that is also composed of lithium, mangan, titanium and oxygen power.
2.あら力じめ作製された Li Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)を出発 原料として、リチウム挿入処理によって製造することを特徴とする 1に記載のリチウム 二次電池正極材料の製造方法。  2. It is produced by lithium insertion treatment using Li Mn Ti O (0. 40 <x <0.50, 0 ≤ y <0.56) prepared by force. The manufacturing method of the lithium secondary battery positive electrode material of description.
3.前記リチウム挿入処理を、リチウム化合物を含有する溶融塩中、或いはリチウム化 合物を溶解した有機溶剤または水溶液中にぉ ヽて行うことを特徴とする 2に記載の 正極材料の製造方法。  3. The method for producing a positive electrode material according to 2, wherein the lithium insertion treatment is performed in a molten salt containing a lithium compound, or in an organic solvent or an aqueous solution in which a lithium compound is dissolved.
4.正極、負極及び電解質物質を有するリチウム二次電池の正極を 1に記載の正極 材料により構成したことを特徴とするリチウム二次電池。 4. The positive electrode according to 1, wherein the positive electrode of the lithium secondary battery having a positive electrode, a negative electrode, and an electrolyte substance A lithium secondary battery comprising a material.
5.電池の負極としてリチウム又はリチウム合金負極を使用し、 4Vの電圧範囲で安定 に充放電できることを特徴とする 4に記載のリチウム二次電池。  5. The lithium secondary battery according to 4, wherein a lithium or lithium alloy negative electrode is used as the negative electrode of the battery and can be stably charged and discharged in a voltage range of 4V.
6.電池の負極として炭素負極を使用し、 4Vの電圧範囲で安定に充放電できること を特徴とする 4に記載のリチウム二次電池。  6. The lithium secondary battery according to 4, wherein a carbon negative electrode is used as a negative electrode of the battery and can be stably charged and discharged in a voltage range of 4V.
発明の効果  The invention's effect
[0016] 本発明によれば、安価な原料を使用して、リチウム二次電池において、既存のリチ ゥムコバルト酸ィ匕物系正極材料と同等の高 、作動電圧領域 (約 4V)にお 、て安定に 充放電させることができると共に、既存正極リチウムマンガン酸ィ匕物スピネルより大き V、容量を有する、新規なリチウムマンガンチタン酸ィ匕物正極材料を得ることができる。 また、上記リチウムマンガンチタン酸ィ匕物正極材料を使用する本発明のリチウム二 次電池は、高電圧かつ高容量で、優れた充放電サイクル特性をも発揮することがで き、実用性の高いものである。  [0016] According to the present invention, an inexpensive raw material is used in a lithium secondary battery in a high operating voltage range (about 4V) equivalent to that of an existing lithium cobalt oxide-based positive electrode material. A novel lithium manganese titanate positive electrode material can be obtained which can be charged and discharged stably and has a larger V and capacity than the existing positive electrode lithium manganate spinel. In addition, the lithium secondary battery of the present invention using the above lithium manganese titanate positive electrode material has high voltage, high capacity, can exhibit excellent charge / discharge cycle characteristics, and is highly practical. Is.
図面の簡単な説明  Brief Description of Drawings
[0017] [図 1]本発明のリチウム二次電池の 1例を示す模式図である。 FIG. 1 is a schematic diagram showing an example of a lithium secondary battery of the present invention.
[図 2]実施例 1及び 2で得られた本発明の正極材料の X線粉末回折図形である。  FIG. 2 is an X-ray powder diffraction pattern of the positive electrode material of the present invention obtained in Examples 1 and 2.
[図 3]実施例 1及び比較例 1で得られた電池の初期放電特性を示す図である。  FIG. 3 is a graph showing initial discharge characteristics of the batteries obtained in Example 1 and Comparative Example 1.
[図 4]実施例 1及び比較例 2で得られた電池の初期放電特性を示す図である。  FIG. 4 is a graph showing initial discharge characteristics of the batteries obtained in Example 1 and Comparative Example 2.
[図 5]実施例 3及び比較例 3、 4で得られた電池の初期放電特性を示す図である。  FIG. 5 is a graph showing initial discharge characteristics of the batteries obtained in Example 3 and Comparative Examples 3 and 4.
[図 6]実施例 4で得られた電池の放電出力特性を示す図である。  FIG. 6 is a graph showing the discharge output characteristics of the battery obtained in Example 4.
符号の説明  Explanation of symbols
[0018] 1 ボタン型リチウム二次電池 [0018] 1-button lithium secondary battery
2 負極端子  2 Negative terminal
3 負極  3 Negative electrode
4 セパレータ +電解液  4 Separator + electrolyte
5 絶縁パッキング 発明を実施するための最良の形態 5 Insulating packing BEST MODE FOR CARRYING OUT THE INVENTION
[0019] (リチウム二次電池用正極材料及びその製造方法）  [0019] (Positive electrode material for lithium secondary battery and method for producing the same)
本発明の基礎となった上記先願発明に係わるリチウムマンガンチタン酸ィ匕物 Li M n Ti O (0. 40く xく 0. 50、 0≤y< 0. 56)正極材料および本発明による Li Mn l -y y 2 χ Lithium manganese titanate oxide Li M n Ti O (0.40 x x 0.50, 0≤y <0.56) positive electrode material according to the invention of the prior application on which the present invention is based and the present invention Li Mn l -yy 2 χ
Ti O (0. 5≤x≤l, 0≤y< 0. 56)正極材料は、出発原料である Na Mn Ti l -y y 2 x l -y yTi O (0. 5≤x≤l, 0≤y <0. 56) Cathode material is the starting material Na Mn Ti l -y y 2 x l -y y
O (0. 40<x< 0. 50、 0≤y< 0. 56)ィ匕合物と同様の卜ンネノレ構造を有し、マンガO (0. 40 <x <0.50, 0≤y <0. 56)
2 2
ンとチタンの割合を上記の組成範囲内で自由に選択できることを特徴とする。  The ratio of titanium and titanium can be freely selected within the above composition range.
[0020] ナトリウム化合物の場合、構造中のナトリウムイオンの静電エネルギーによる反発が 原因で、 0. 40<x< 0. 50程度しかナトリウムを吸蔵できず、そのことが原因で、ナト リウムをリチウムにイオン交換した先願発明の正極材料においては、必然的にリチウ ム量は、ナトリウム量とほぼ同じ値であった。し力しながら、ナトリウムと比べて、イオン 半径の小さいリチウムの場合、より密にリチウムを吸蔵することが可能となるため、結 晶学的に予想される最大リチウム吸蔵量 (理論容量）は、 x=0. 66である。 [0020] In the case of sodium compounds, sodium can be occluded only by about 0.40 <x <0.50 due to the repulsion due to the electrostatic energy of sodium ions in the structure. In the positive electrode material of the invention of the prior application which was ion-exchanged, the amount of lithium was inevitably the same value as the amount of sodium. However, compared to sodium, lithium with a smaller ion radius can store lithium more densely, so the maximum lithium storage capacity (theoretical capacity) predicted crystallographically is x = 0.66.
[0021] また、リチウム挿入処理を施した場合、結晶学的に予測されるリチウム席に比して、 より多くのリチウムが吸蔵されることが、インターカレーシヨンィ匕学においては、よく知ら れており、そのようなリチウムも電池反応に寄与することができれば、電池容量の増大 が可能となる。 [0021] In addition, it is well known in intercalation theory that when lithium insertion treatment is performed, more lithium is occluded than the lithium site predicted crystallographically. If such lithium can also contribute to the battery reaction, the battery capacity can be increased.
[0022] 本発明の Li Mn Ti O (0. 5≤x≤l, 0≤y< 0. 56)正極材料は、上記先願発 l -y y 2  [0022] The Li Mn Ti O (0.5 ≤ x ≤ l, 0 ≤ y <0. 56) positive electrode material of the present invention is the above-mentioned prior application l -y y 2
明に係わるリチウムマンガンチタン酸化物 Li Mn Ti O (0. 40<x< 0. 50、 0≤y l -y y 2  Lithium Manganese Titanium Oxide Li Mn Ti O (0. 40 <x <0. 50, 0≤y l -y y 2
< 0. 56)正極材料にリチウム挿入処理を施すことにより、作製可能である。このリチウ ム揷入処理により、正極材料中の全リチウム量は 0. 4<x≤lとすることができるが（た だし、 Xは出発原料中の Xよりは大きな値となる）、 0. 5≤x≤l、特に 0. 6< x≤lとす ることが好ましい。  <0.56) It can be produced by subjecting the positive electrode material to a lithium insertion treatment. By this lithium insertion treatment, the total amount of lithium in the positive electrode material can be 0.4 <x≤l (however, X is larger than X in the starting material). It is preferable that 5≤x≤l, especially 0.6 <x≤l.
[0023] 本発明の正極材料は、結晶構造および製造工程の特徴から、出発原料中に含有 するナトリウムを、イオン交換処理およびリチウム挿入処理によって、ほぼ完全にリチ ゥムに置き換えることが可能であることを特徴とする。但し、通常このような方法では、 有意、或 、は不純物程度のナトリウムが残留してしまうことが知られて 、る。 [0024] すなわち、本発明の Li Mn Ti O (0. 5≤x≤l, 0≤y< 0. 56)正極材料は、リ[0023] The positive electrode material of the present invention is capable of almost completely replacing sodium contained in the starting material with lithium by ion exchange treatment and lithium insertion treatment because of the crystal structure and the characteristics of the production process. It is characterized by that. However, it is generally known that such a method leaves significant or impure sodium. That is, the Li Mn Ti 2 O (0.5≤x≤l, 0≤y <0.56) positive electrode material of the present invention is
-y y 2  -y y 2
チウム、マンガン、チタン、及び酸素を主要構成元素として含有することを特徴とする 力 S、本発明の効果を妨げない範囲内でナトリウム等の不純物元素を含有していてもよ い。  Impurity elements such as sodium may be contained within a range that does not impede the effect of the present invention, force S characterized by containing thium, manganese, titanium, and oxygen as main constituent elements.
[0025] 本発明の Li Mn Ti O (0. 5≤x≤ 1、 0≤y< 0. 56)正極材料は、マンガンとチ [0025] The Li Mn Ti O (0.5 ≤ x ≤ 1, 0 ≤ y <0.56) positive electrode material of the present invention includes manganese and titanium.
-y y 2  -y y 2
タンの量を 0≤y< 0. 56の範囲内で自由に選択できることを特徴とする。チタンを置 換することは、結晶構造の安定性を高めると共に、充放電反応に寄与する 3価のマン ガンを増大させる効果があることが先願発明にお 、て確認されて 、る。好ま U、チタ ン量は、構造中のリチウム量と相関がある力 0≤y< 0. 56、より好ましくは 0≤y< 0 . 4の範囲内にある。  The amount of tongue can be freely selected within the range of 0≤y <0.56. It has been confirmed in the prior application that replacing titanium has the effect of increasing the stability of the crystal structure and increasing the trivalent manganes that contribute to the charge / discharge reaction. Preferably, the amount of U and titanium is within the range of force 0≤y <0.56, more preferably 0≤y <0.4, which correlates with the amount of lithium in the structure.
[0026] また、本発明の Li Mn Ti O (0. 5≤x≤ 1、 0≤y< 0. 56)正極材料は、その全 [0026] The Li Mn Ti O (0.5 ≤ x ≤ 1, 0 ≤ y <0.56) positive electrode material of the present invention is
-y y 2  -y y 2
体が Li MnO型のトンネル構造を有することが望ましいが、本発明の効果を妨げ Although it is desirable that the body has a Li MnO type tunnel structure, it hinders the effect of the present invention.
0. 44 2 0. 44 2
な 、範囲内で他の結晶構造が一部含まれて 、ても良 、。  In addition, some other crystal structures may be included within the range.
[0027] つぎに、本発明の製造方法をさらに詳しく説明する。 [0027] Next, the production method of the present invention will be described in more detail.
本発明の Li Mn Ti O (0. 5≤x≤l, 0≤y< 0. 56)正極材料は、上記先願発 The Li Mn Ti O (0.5 ≤ x ≤ 1, 0 ≤ y <0.56) positive electrode material of the present invention is the above-mentioned prior application.
-y y 2  -y y 2
明に係わるリチウムマンガンチタン酸化物 Li Mn Ti O (0. 40<x< 0. 50、 0≤y Lithium Manganese Titanium Oxide Li Mn Ti O (0. 40 <x <0. 50, 0≤y
-y y 2  -y y 2
< 0. 56)正極材料を出発原料として作製される。  <0. 56) Prepared using a positive electrode material as a starting material.
また、出発原料となるリチウムマンガンチタン酸化物 Li Mn Ti O (0. 40<x< 0 In addition, lithium manganese titanium oxide Li Mn Ti O (0.40 <x <0
-y y 2  -y y 2
. 50、 0≤y< 0. 56)正極材料は、ナトリウムマンガンチタン酸化物 Na Mn Ti O 50, 0≤y <0. 56) Positive electrode material is sodium manganese titanium oxide Na Mn Ti O
-y y 2 -y y 2
(0. 40<x< 0. 50, 0≤y< 0. 56)を原料として作製される。 (0.40 <x <0.50, 0≤y <0.56).
[0028] Na Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)化合物は、例えば（1)ナトリウ[0028] The Na Mn Ti O (0.40 <x <0.50, 0≤y <0.56) compound is, for example, (1) sodium
-y y 2  -y y 2
ム及びナトリウム化合物の少なくとも 1種、（2)マンガン及びマンガンィ匕合物の少なくと も 1種、（3)チタン及びチタンィ匕合物の少なくとも 1種を含有する混合物を焼成するこ とによって製造することができる。  Manufactured by firing a mixture containing at least one of sodium and sodium compounds, (2) at least one of manganese and manganese compounds, and (3) at least one of titanium and titanium compounds be able to.
[0029] ナトリウム原料としては、ナトリウム (金属ナトリウム）およびナトリウム化合物の少なく とも 1種を用いる。ナトリウム化合物としては、ナトリウムを含有するものであれば特に 制限されず、例えば Na 0、 Na O等の酸化物、 Na CO、 NaNO等の塩類、 NaO  [0029] As the sodium raw material, at least one of sodium (metallic sodium) and a sodium compound is used. The sodium compound is not particularly limited as long as it contains sodium, for example, oxides such as Na 0 and Na O, salts such as Na CO and NaNO, NaO
2 2 2 2 3 3  2 2 2 2 3 3
Hなどの水酸ィ匕物等が挙げられる。これらの中でも、特に Na CO等が好ましい。 [0030] マンガン原料としては、マンガン（金属マンガン）及びマンガン化合物の少なくとも 1 種を用いる。マンガンィ匕合物としては、マンガンを含有するものであれば特に制限さ れず、例えば Mn O、 Mn O、 MnO等の酸化物、 MnCO、 MnCl等の塩類、 M Examples thereof include hydroxides such as H. Of these, Na 2 CO 3 is particularly preferable. [0030] As the manganese raw material, at least one of manganese (metallic manganese) and a manganese compound is used. Manganese compounds are not particularly limited as long as they contain manganese. For example, oxides such as MnO, MnO and MnO, salts such as MnCO and MnCl, M
3 4 2 3 2 3 2  3 4 2 3 2 3 2
n (OH)等の水酸化物、 MnOOH等の酸化水酸化物等が挙げられる。これらの中で  Examples thereof include hydroxides such as n (OH) and oxide hydroxides such as MnOOH. Among these
2  2
も、特に Mn O、 MnO等が好ましい。  In particular, Mn 2 O, MnO and the like are preferable.
2 3 2  2 3 2
[0031] チタン原料としては、チタン (金属チタン)及びチタンィ匕合物の少なくとも 1種を用い る。チタンィ匕合物としては、チタンを含有するものであれば特に制限されず、例えば T iO、 Ti O、 TiO等の酸化物、 TiCl等の塩類等が挙げられる。これらの中でも、特  [0031] As the titanium raw material, at least one of titanium (titanium metal) and a titanium compound is used. The titanium compound is not particularly limited as long as it contains titanium, and examples thereof include oxides such as TiO, Ti 2 O, and TiO, and salts such as TiCl. Among these, special
2 3 2 4  2 3 2 4
に TiO等が好ましい。  Of these, TiO and the like are preferable.
2  2
[0032] はじめに、これらを含む混合物を調整する。ナトリウム原料とマンガン原料及びチタ ン原料の混合割合は、前記トンネル構造が生成するような割合で混合することが好ま しい。具体的には、 Na Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)のィ匕学糸且  [0032] First, a mixture containing these is prepared. The mixing ratio of the sodium raw material, the manganese raw material, and the titanium raw material is preferably such that the tunnel structure is formed. Specifically, Na Mn Ti O (0. 40 <x <0. 50, 0≤y <0.5.56)
l-y y 2  l-y y 2
成式となるようにすれば良い。例えば、モル比で NaZ (Mn+Ti)が 0. 4〜0. 7程度 、好ましくは 0. 43-0. 55となるように混合すればよい。通常、高温で焼成を行った 場合、含有するナトリウムが揮発しやすぐ生成物中のナトリウム量が仕込み組成より も少なくなる場合が多いことから、モル％で数％〜10数％程度、ナトリウムの仕込み 量を増やした方が好ましい。また、マンガンとチタンの割合は、（0≤y< 0. 56)の範 囲で任意に選択すればょ 、。  The formula should be used. For example, the mixture may be such that the molar ratio of NaZ (Mn + Ti) is about 0.4 to 0.7, preferably 0.43 to 0.55. Usually, when firing at a high temperature, the sodium contained in the product volatilizes and the amount of sodium in the product is often less than the charged composition. It is preferable to increase the amount charged. Also, the ratio of manganese and titanium can be selected arbitrarily within the range of (0≤y <0.56).
[0033] また、混合方法は、これらを均一に混合できる限り特に限定されず、例えばミキサー 等の公知の混合機を用いて、湿式又は乾式で混合すれば良!、。  [0033] The mixing method is not particularly limited as long as they can be mixed uniformly. For example, a known mixer such as a mixer may be used to mix them in a wet or dry manner.
[0034] 次 、で、混合物を焼成する。焼成温度は、混合物の組成等に応じて適宜設定する ことができるが、通常は 600〜1200°C程度、好ましくは 800〜1050°Cとすればよい 。また、焼成雰囲気も特に限定的ではないが、通常は酸ィ匕性雰囲気又は大気中で 実施すれば良い。焼成時間は、焼成温度等に応じて適宜変更することができる。冷 却方法は特に限定されな!、が、通常は自然放冷 (炉内放冷)又は徐冷すれば良！、。  [0034] Next, the mixture is fired. The calcination temperature can be appropriately set according to the composition of the mixture, etc., but is usually about 600 to 1200 ° C., preferably 800 to 1050 ° C. Also, the firing atmosphere is not particularly limited, but usually it may be carried out in an acidic atmosphere or air. The firing time can be appropriately changed according to the firing temperature and the like. The cooling method is not particularly limited! Usually, natural cooling (cooling in the furnace) or slow cooling is sufficient! ,.
[0035] 焼成後は、必要に応じて焼成物を公知の方法で粉砕し、さらに上記の焼成工程を 実施しても良い。すなわち、本発明方法では、上記混合物の焼成、徐冷及び粉砕を 2回以上繰り返して実施することが好ましい。なお、粉砕の程度は、焼成温度などに 応じて適宜調節すれば良!、。 [0035] After firing, the fired product may be pulverized by a known method, if necessary, and the above firing step may be further performed. That is, in the method of the present invention, it is preferable that the mixture is repeatedly fired, gradually cooled and pulverized twice or more. The degree of grinding depends on the firing temperature. You can adjust it accordingly.
[0036] 次いで、焼成された Na Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)に、リチ ゥム化合物を含む溶融塩中、或 、は有機溶剤または水溶液中でイオン交換処理を 施すことにより、 Li MnO型の結晶構造を有し、化学組成式 Li Mn Ti O (0. [0036] Next, the calcined Na 2 Mn Ti 2 O (0.40 <x <0.50, 0≤y <0.56) in a molten salt containing a lithium compound, or an organic solvent or an aqueous solution It has a Li MnO type crystal structure and is given the chemical composition formula Li Mn Ti O (0.
40<x< 0. 50, 0≤y< 0. 56)で表されるィ匕合物力 ^得られる。 40 <x <0. 50, 0≤y <0. 56).
[0037] この場合に、リチウム含有ィ匕合物を含む溶融塩中において、粉砕された Ν^Μη^ Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)を分散させな力ら、イオン交換処理を施す ことが好適である。溶融塩としては、硝酸リチウム、塩化リチウム、臭化リチウム、ヨウ化 リチウム等の低温で溶融する塩類のうちで、 、ずれか 1種以上を含む溶融塩を用いる ことができる。好ましい方法としては、リチウム化合物と Na Mn Ti O焼成物の粉 末をよく混合しておく。混合比は、通常、溶融塩中の LiZNa Mn Ti O中の Naの モル比で 2〜40、好ましくは 10〜30である。 [0037] In this case, pulverized Ν ^ Μη ^ Ti O (0.40 <x <0.50, 0≤y <0.56) is dispersed in the molten salt containing the lithium-containing compound. However, it is preferable to perform ion exchange treatment. As the molten salt, a molten salt containing at least one of the salts that are melted at a low temperature such as lithium nitrate, lithium chloride, lithium bromide, and lithium iodide can be used. As a preferred method, a lithium compound and a powder of Na Mn Ti O fired product are mixed well. The mixing ratio is usually 2 to 40, preferably 10 to 30 in terms of the molar ratio of Na in LiZNa Mn Ti 2 O in the molten salt.
[0038] イオン交換の温度は、 260°C〜330°Cである。イオン交換の温度が 260°Cよりも低 ヽ場合 ίま、 Na Mn Ti O (0. 40く xく 0. 50、 0≤v< 0. 56)中のナトリウムカリ チウムに完全に交換されず、相当量のナトリウムが生成物中に残存する。一方、ィォ ン交換温度が 330°Cよりも高い場合は、一部がスピネル構造に変化するため、均一 な結晶構造を得ることができない。処理時間は、通常 2〜20時間、好ましくは 5〜15 時間である。 [0038] The ion exchange temperature is 260 ° C to 330 ° C. If the ion exchange temperature is lower than 260 ° C, it is not completely exchanged for sodium potassium in Na Mn Ti O (0.40 x 0, 50, 0≤v <0.56). A considerable amount of sodium remains in the product. On the other hand, when the ion exchange temperature is higher than 330 ° C, a part of the ion exchange temperature changes to a spinel structure, so that a uniform crystal structure cannot be obtained. The treatment time is usually 2 to 20 hours, preferably 5 to 15 hours.
[0039] さらに、イオン交換処理の方法として、リチウム化合物を溶解した有機溶剤または水 溶液中で処理する方法も適する。この場合、リチウム含有化合物を溶解させた有機 溶剤中に、粉碎された Na Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)を投入 し、その有機溶剤の沸点以下の温度で処理する。イオン交換速度を高めるため、水 または有機溶剤の沸点付近で、溶媒を還流させながら、イオン交換することが好まし い。処理温度は通常 30°C〜200°C、好ましくは 60°C〜180°Cで処理される。また、 処理時間は、特に制限されないが、低温であると反応時間が必要であることから、通 常 5〜50時間、好ましくは 10〜20時間である。  [0039] Further, as an ion exchange treatment method, a treatment method in an organic solvent or an aqueous solution in which a lithium compound is dissolved is also suitable. In this case, powdered Na Mn Ti O (0.40 <x <0.50, 0≤y <0.56) is put into an organic solvent in which a lithium-containing compound is dissolved, and the boiling point of the organic solvent Process at the following temperatures. In order to increase the ion exchange rate, it is preferable to perform ion exchange while refluxing the solvent near the boiling point of water or an organic solvent. The treatment temperature is usually 30 ° C to 200 ° C, preferably 60 ° C to 180 ° C. Further, the treatment time is not particularly limited, but it is usually 5 to 50 hours, preferably 10 to 20 hours because a reaction time is required at a low temperature.
[0040] 本発明に用いられるリチウム含有化合物としては、水酸化物、炭酸塩、酢酸塩、硝 酸塩、シユウ酸塩、ハロゲン化物、ブチルリチウム等が好ましぐこれらは単独または 必要に応じて 2種以上を組み合わせて用いられる。また、本発明に用いられる有機溶 剤としては、へキサノール、エトキシエタノール等の高級アルコール、ジエチレングル コールモノェチルエーテル等のエーテル、もしくは沸点が 140°C以上の有機溶剤が 、作業性が良好である点で好ましい。これらは単独または必要に応じて 2種以上組み 合わせて用いられる。 [0040] As the lithium-containing compound used in the present invention, hydroxide, carbonate, acetate, nitrate, oxalate, halide, butyllithium and the like are preferable. Used in combination of two or more as required. In addition, as the organic solvent used in the present invention, higher alcohols such as hexanol and ethoxyethanol, ethers such as diethylene glycol monoethyl ether, or organic solvents having a boiling point of 140 ° C. or higher have good workability. It is preferable at this point. These may be used alone or in combination of two or more as required.
[0041] 有機溶剤または水溶液中におけるリチウム含有ィ匕合物の濃度は、通常 3〜10モル %、好ましくは 5〜8モル％である。また、有機溶剤または水溶液中での Na Mn Ti Oの分散濃度は、特に制限されないが、操作性及び経済性の観点から 1〜20重量 [0041] The concentration of the lithium-containing compound in the organic solvent or aqueous solution is usually 3 to 10 mol%, preferably 5 to 8 mol%. The dispersion concentration of Na Mn Ti O in the organic solvent or aqueous solution is not particularly limited, but is 1 to 20 weight from the viewpoint of operability and economy.
%が好ましい。 % Is preferred.
[0042] イオン交換処理の後、得られた生成物を、蒸留水でよく洗浄した後、メタノール、ェ タノールで洗浄後、乾燥させることによって、目的とする Li Mn Ti O (0. 40く x [0042] After the ion exchange treatment, the obtained product is washed thoroughly with distilled water, washed with methanol and ethanol, and then dried to obtain the target Li Mn Ti O (0.40 x
< 0. 50、 0≤y< 0. 56)が得られる。洗浄方法、乾燥方法については、特に制限さ れず、通常の方法が用いられる他、デシケーター内における自然乾燥でも良い。 <0. 50, 0 ≤ y <0. 56). The washing method and drying method are not particularly limited, and a normal method may be used, or natural drying in a desiccator may be used.
[0043] 次いで、イオン交換処理で作製された Li Mn Ti O (0. 40<x< 0. 50、 0≤y[0043] Next, Li Mn Ti O (0.40 <x <0.50, 0≤y) produced by ion exchange treatment
< 0. 56)に、さらに、リチウム化合物を含む溶融塩中、或いは有機溶剤または水溶 液中でイオン挿入処理を施すことにより、 Li MnO型の結晶構造を有し、化学組 成式 Li Mn Ti O (0. 5≤x≤l, 0≤y< 0. 56)で表される化合物が得られる。 <0. 56) is further subjected to ion insertion treatment in a molten salt containing a lithium compound, or in an organic solvent or an aqueous solution, so that it has a Li MnO type crystal structure and has a chemical composition formula Li Mn Ti A compound represented by O (0. 5≤x≤l, 0≤y <0. 56) is obtained.
[0044] この場合に、リチウム含有ィ匕合物を含む溶融塩中において、あらかじめ作製された Li Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)を分散させな力 ^ら、リチウム挿入 処理を施すことが好適である。溶融塩としては、硝酸リチウムを使用し、さらに添加剤 として水酸化リチウム、ヨウ化リチウム、臭化リチウム、酸化リチウム、過酸化リチウム、 炭酸リチウム、塩化リチウム等の塩類のうちで、いずれ力 1種以上をカ卩える。好ましい 方法としては、添加剤と Li Mn Ti O粉末をよく混合しておく。混合比は、通常、 溶融塩中の添加剤 ZLi Mn Ti Oのモル比で 0. 01〜10、好ましくは 0. 1〜3で ある。  In this case, Li Mn Ti 2 O (0.40 <x <0.50, 0≤y <0.56) prepared in advance is dispersed in the molten salt containing the lithium-containing compound. It is preferable to apply a lithium insertion treatment. As the molten salt, lithium nitrate is used, and as additives, lithium hydroxide, lithium iodide, lithium bromide, lithium oxide, lithium peroxide, lithium carbonate, lithium chloride, etc. I ’m going to give you this. As a preferred method, the additive and Li Mn Ti O powder are mixed well. The mixing ratio is usually 0.01 to 10, preferably 0.1 to 3, in terms of the molar ratio of the additive ZLi Mn Ti 2 O in the molten salt.
[0045] リチウム挿入処理の温度は、 260°C〜330°Cである。処理温度が 330°Cよりも高い 場合は、一部がスピネル構造に変化するため、均一な結晶構造を得ることができない 。処理時間は、通常 2〜20時間、好ましくは 5〜15時間である。挿入処理は、数回、 好ましくは 2〜3回繰り返した方が効果的である。 [0045] The temperature of the lithium insertion treatment is 260 ° C to 330 ° C. When the processing temperature is higher than 330 ° C, a part of the processing temperature changes to a spinel structure, so that a uniform crystal structure cannot be obtained. The treatment time is usually 2 to 20 hours, preferably 5 to 15 hours. Insert process several times, It is more effective to repeat 2 to 3 times.
[0046] さらに、リチウム挿入処理の方法として、リチウム化合物を溶解した有機溶剤または 水溶液中で処理する方法も適する。この場合、リチウム含有化合物を溶解させた有 機溶剤中に、あらかじめイオン交換された Li Mn Ti O (0. 40<x< 0. 50、 0≤y [0046] Further, as a method for lithium insertion treatment, a method of treating in an organic solvent or an aqueous solution in which a lithium compound is dissolved is also suitable. In this case, Li Mn Ti O (0.40 <x <0.50, 0≤y) previously ion-exchanged in an organic solvent in which a lithium-containing compound is dissolved.
l -y y 2  l -y y 2
< 0. 56)を投入し、その有機溶剤の沸点以下の温度で処理する。リチウム挿入速度 を高めるため、有機溶剤の沸点付近で、溶媒を還流させながら、挿入処理することが 好ましい。処理温度は通常 30°C〜200°C、好ましくは 60°C〜180°Cで処理される。 また、処理時間は、特に制限されないが、低温であると反応時間が必要であることか ら、通常 5〜50時間、好ましくは 10〜20時間である。  <0. 56) is added and treated at a temperature below the boiling point of the organic solvent. In order to increase the lithium insertion rate, it is preferable to perform the insertion treatment while refluxing the solvent near the boiling point of the organic solvent. The treatment temperature is usually 30 ° C to 200 ° C, preferably 60 ° C to 180 ° C. Further, the treatment time is not particularly limited, but is usually 5 to 50 hours, preferably 10 to 20 hours, because the reaction time is required at low temperatures.
[0047] 本発明に用いられるリチウム含有ィ匕合物としては、水酸化物、酸化物、過酸化物、 炭酸塩、酢酸塩、硝酸塩、シユウ酸塩、ハロゲンィ匕物、ブチルリチウム等が好ましぐ これらは単独または必要に応じて 2種以上を組み合わせて用いられる。また、本発明 に用いられる有機溶剤としては、へキサノール、エトキシエタノール等の高級アルコ ール、ジエチレンダルコールモノェチルエーテル等のエーテル、もしくは沸点が 140 °C以上の有機溶剤が、作業性が良好である点で好ましい。これらは単独または必要 に応じて 2種以上組み合わせて用いられる。  [0047] The lithium-containing compound used in the present invention is preferably a hydroxide, oxide, peroxide, carbonate, acetate, nitrate, oxalate, halide, butyllithium, or the like. These are used alone or in combination of two or more as required. In addition, as the organic solvent used in the present invention, higher alcohols such as hexanol and ethoxyethanol, ethers such as diethylene alcohol monoethyl ether, or organic solvents having a boiling point of 140 ° C. or higher have workability. It is preferable at the point which is favorable. These may be used alone or in combination of two or more as required.
[0048] 有機溶剤または水溶液中におけるリチウム含有ィ匕合物の濃度は、通常 3〜10モル %、好ましくは 5〜8モル％である。また、有機溶剤または水溶液中での Li Mn Ti  [0048] The concentration of the lithium-containing compound in the organic solvent or aqueous solution is usually 3 to 10 mol%, preferably 5 to 8 mol%. Also, Li Mn Ti in organic solvent or aqueous solution
x 丄— y y x 丄 — y y
Oの分散濃度は、特に制限されないが、操作性及び経済性の観点から 1〜20重量The dispersion concentration of O is not particularly limited, but is 1 to 20 weight from the viewpoint of operability and economy.
2 2
%が好ましい。  % Is preferred.
[0049] リチウム挿入処理の後、得られた生成物を、蒸留水でよく洗浄した後、メタノール、 エタノールで洗浄後、乾燥させることによって、目的とする Li Mn Ti O (0. 5≤x  [0049] After the lithium insertion treatment, the obtained product is washed thoroughly with distilled water, washed with methanol and ethanol, and then dried to obtain the target Li Mn Ti O (0.5 ≤ x
l -y y 2  l -y y 2
≤1、 0≤y< 0. 56)が得られる。洗浄方法、乾燥方法については、特に制限されず 、通常の方法が用いられる他、デシケーター内における自然乾燥でも良い。  ≤1, 0≤y <0.56) is obtained. The washing method and the drying method are not particularly limited, and a normal method may be used, or natural drying in a desiccator may be used.
[0050] (リチウム二次電池） [0050] (Lithium secondary battery)
本発明のリチウム二次電池は、前記リチウム二次電池用正極材料を用いるものであ る。すなわち、正極材料として本発明のリチウムマンガンチタン酸ィ匕物を用いる以外 は、公知のリチウム二次電池 (コイン型、ボタン型、円筒型等）の電池要素をそのまま 採用することができる。 The lithium secondary battery of the present invention uses the positive electrode material for a lithium secondary battery. That is, the battery element of a known lithium secondary battery (coin type, button type, cylindrical type, etc.) is used as it is, except that the lithium manganese titanate of the present invention is used as the positive electrode material. Can be adopted.
図 1は、本発明のリチウム二次電池を、ボタン型電池に適用した 1例を示す模式図 である。このボタン型電池 1は、負極端子 2、負極 3、（セパレータ +電解液) 4、絶縁 ノ ッキング 5、正極 6及び正極缶 7により構成される。  FIG. 1 is a schematic view showing an example in which the lithium secondary battery of the present invention is applied to a button type battery. The button-type battery 1 includes a negative electrode terminal 2, a negative electrode 3, (separator + electrolyte) 4, insulating knocking 5, a positive electrode 6, and a positive electrode can 7.
[0051] 本発明では、上記した本発明のリチウムマンガンチタン酸ィ匕物に、必要に応じて導 電剤、結着剤等を配合して正極合材を調製し、これを集電体に圧着することにより正 極を作製できる。集電体としては、好ましくはステンレスメッシュ、アルミ箔等を用いる ことができる。導電剤としては、好ましくはアセチレンブラック、ケッチェンブラック等を 用いることができる。結着剤としては、好ましくはテトラフルォロエチレン、ポリフッ化ビ ユリデン等を用いることができる。  [0051] In the present invention, a positive electrode mixture is prepared by blending the above-described lithium manganese titanate salt of the present invention with a conductive agent, a binder or the like as necessary, and this is used as a current collector. The positive electrode can be produced by pressure bonding. As the current collector, a stainless mesh, aluminum foil or the like can be preferably used. As the conductive agent, acetylene black, ketjen black or the like can be preferably used. As the binder, tetrafluoroethylene, polyvinylidene fluoride, or the like can be preferably used.
[0052] 正極合材におけるリチウムマンガンチタン酸ィ匕物、導電剤、結着剤等の配合も特に 限定的でないが、通常は導電剤が 1〜30重量％程度 (好ましくは 5〜25重量％)、結 着剤が 0〜30重量％程度 (好ましくは 3〜： LO重量％)とし、残部をリチウムマンガンチ タン酸ィ匕物となるようにすれば良 、。  [0052] The composition of the lithium manganese titanate, the conductive agent, the binder, etc. in the positive electrode mixture is not particularly limited, but usually the conductive agent is about 1 to 30% by weight (preferably 5 to 25% by weight). ), About 0 to 30% by weight (preferably 3 to: LO% by weight) of the binder, and the remainder being lithium manganese titanate.
[0053] 本発明のリチウム二次電池において、上記正極に対する対極としては、例えば黒 鉛、 MCMB (メソカーボンマイクロビーズ)等の炭素系材料、スズ系材料等の合金系 材料、リチウム金属、リチウム合金などのリチウムを吸蔵可能な公知のものを採用する ことができる。また、セパレータ、電池容器等も公知の電池要素を採用すれば良い。  [0053] In the lithium secondary battery of the present invention, examples of the counter electrode with respect to the positive electrode include carbon-based materials such as black lead and MCMB (mesocarbon microbeads), alloy-based materials such as tin-based materials, lithium metal, and lithium alloys. A known material capable of occluding lithium can be used. Moreover, a well-known battery element should just be employ | adopted for a separator, a battery container, etc.
[0054] また、電解液としても公知のものが適用できる。例えば、過塩素酸リチウム、 6フッ化 リン酸リチウム等の電解質を、エチレンカーボネート (EC)、ジメチルカーボネート（D MC)、プロピレンカーボネート（PC) ,ジェチルカーボネート（DEC)等の溶媒に溶解 させたものを電解液として使用できる。  [0054] Also, known electrolytes can be used. For example, an electrolyte such as lithium perchlorate or lithium hexafluorophosphate was dissolved in a solvent such as ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), or jetyl carbonate (DEC). Can be used as the electrolyte.
実施例  Example
[0055] 次に、実施例により本発明の特徴とするところをさらに説明する力 以下の具体例 は本発明を限定するものではない  Next, the ability to further explain the features of the present invention by way of examples The following specific examples are not intended to limit the present invention.
[0056] (実施例 1) [Example 1]
[正極材料の製造]  [Manufacture of cathode materials]
炭酸ナトリウム（Na CO )、酸化マンガン（Mn O )、酸化チタン (TiO )をモル比で Na Mn Ti O (x=0. 5 ;y=0、 0. 055、 0. 11、 0. 22)の各組成割合で均一に l-y y 2 Sodium carbonate (Na 2 CO 3), manganese oxide (Mn 2 O 3), titanium oxide (TiO 2) in molar ratio Uniformly at each composition ratio of Na Mn Ti O (x = 0.5; y = 0, 0.055, 0.11, 0.22) ly y 2
混合した。混合物を空気中 900°C〜1000°Cで 12時間焼成した後、炉内で徐冷した 。得られた焼成体を粉砕するという一連の操作 (焼成、徐冷及び粉砕)を再度繰り返 し、ほぼ単一相の目的とする Li MnO型の結晶構造を有する出発原料 Na M  Mixed. The mixture was calcined in air at 900 ° C. to 1000 ° C. for 12 hours and then gradually cooled in a furnace. A series of operations (calcination, slow cooling and pulverization) of pulverizing the obtained fired body is repeated again, and the starting material Na M having a target Li MnO type crystal structure of almost single phase
0. 44 2 0. 44 n Ti Oを得た。  0.44 2 0.44 n Ti 2 O was obtained.
l-y y 2  l-y y 2
[0057] 次に、これらの試料を、硝酸リチウムと塩化リチウムを 88： 12のモル比で混合した溶 融塩中でイオン交換処理を行った。 Na Mn Ti Oの溶融塩中における量は、  [0057] Next, these samples were subjected to ion exchange treatment in a molten salt in which lithium nitrate and lithium chloride were mixed at a molar ratio of 88:12. The amount of Na Mn Ti O in the molten salt is
0. 44 l-y y 2  0.44 l-y y 2
モル比で、溶融塩中の Li:試料中の Na = 20 : 1とし、溶融塩の温度は 300°Cとした。 処理時間 10時間で、イオン交換処理を行い、得られた固体を蒸留水、メタノール、ェ タノール等で洗浄、乾燥して試料を得た。この試料を ICP発光分析法により、化学組 成を分析した結果、 Li Mn Ti O (0. 43≤x≤0. 44 ;y=0, 0. 055, 0. 11、 0.  In the molar ratio, Li in the molten salt: Na in the sample = 20: 1, and the temperature of the molten salt was 300 ° C. An ion exchange treatment was performed for a treatment time of 10 hours, and the obtained solid was washed with distilled water, methanol, ethanol, etc. and dried to obtain a sample. As a result of analyzing the chemical composition of this sample by ICP emission spectrometry, Li Mn Ti O (0.43≤x≤0.44; y = 0, 0. 055, 0.11, 0.
l-y y 2  l-y y 2
22)の化学式で妥当であり、残存して含有するナトリウム量は、 NaZLiのモル比で 0 . 005であった。さらに、 X線粉末回折法により、 Li MnO型の斜方晶系のトンネ  The amount of sodium remaining in the chemical formula is appropriate in the chemical formula of 22), and the molar ratio of NaZLi was 0.005. In addition, the Li MnO-type orthorhombic tunnel was investigated by X-ray powder diffraction.
0. 44 2  0. 44 2
ル構造を有するほぼ単一相であることが明ら力となり、各試料の格子定数は表 1のと おりであった。また、作製された試料のうち、 Li MnO (y=0)の X線粉末回折図  Clearly, it was clear that the sample had almost a single phase with a rutile structure, and the lattice constant of each sample was as shown in Table 1. In addition, among the prepared samples, X-ray powder diffraction pattern of Li MnO (y = 0)
0. 44 2  0. 44 2
形を図 2 (a)に示す。  The shape is shown in Fig. 2 (a).
[0058] [表 1] [0058] [Table 1]
Figure imgf000015_0001
Figure imgf000015_0001
[0059] 次に、表 1に記載された各試料各 lgを、硝酸リチウム 22gと水酸化リチウム lgとよく 混合した後、空気中、 300°Cで 10時間加熱し、リチウム挿入処理を行った。得られた 固体を蒸留水、メタノール、エタノール等で洗浄、乾燥して試料を得た。この試料を I CP発光分析法により、化学組成を分析した結果、リチウム量 Xは 0. 59≤x≤0. 72 程度となり、挿入反応を確認した。また、残存して含有するナトリウム量は、 ICPの検 出限界 (0. 01wt%)以下であり、リチウム挿入処理は、残存するナトリウム量のさらな る低減にも有効であることが確認された。さら〖こ、作製された試料のうち、 Li MnO [0059] Next, each lg shown in Table 1 was mixed well with 22 g of lithium nitrate and lg of lithium hydroxide, and then heated in air at 300 ° C for 10 hours to perform lithium insertion treatment. . The obtained solid was washed with distilled water, methanol, ethanol or the like and dried to obtain a sample. As a result of analyzing the chemical composition of this sample by ICP emission spectrometry, the amount of lithium X was about 0.59≤x≤0.72, confirming the insertion reaction. The remaining sodium content is below the ICP detection limit (0.01 wt%), and the lithium insertion treatment further reduces the residual sodium content. It was confirmed that it is also effective in reducing this. Sara Miko, of the prepared samples, Li MnO
0. 63 0. 63
(y=0)の X線粉末回折図形を図 2 (b)に示す。出発原料とした Li MnOと同構The X-ray powder diffraction pattern of (y = 0) is shown in Fig. 2 (b). Same structure as Li MnO as starting material
2 0. 44 2 造であると仮定して、計算された格子定数を表 2に示す。リチウム挿入処理により、元 の Li Mn Ti O (0. 43≤x≤0. 44)と比べて、格子定数の変化が明ら力となった Table 2 shows the calculated lattice constants assuming 2 0. 44 2 structure. The change of lattice constant became clear due to the lithium insertion process compared to the original Li Mn Ti O (0.43≤x≤0.44).
[0060] [表 2] [0060] [Table 2]
Figure imgf000016_0001
Figure imgf000016_0001
[0061] [リチウム二次電池] [0061] [Lithium secondary battery]
得られた Li Mn Ti O (0. 59≤x≤0. 72 ;y=0、 0. 055、 0. 11、 0. 22)の各 l-y y 2  Each of the obtained Li Mn Ti O (0. 59 ≤ x ≤ 0.72; y = 0, 0. 055, 0.11, 0.22) l-y y 2
試料 20mgに導電剤としてアセチレンブラック 5mg、結着剤としてテトラフルォロェチ レン 0. 5mgを配合して正極を作製し、リチウム金属を負極材料、 6フッ化リン酸リチウ ムをエチレンカーボネート (EC)とジェチルカーボネート (DEC)との混合溶媒 (体積 比 1： 1)に溶解させた 1M溶液を電解液とする、図 1に示す構造のリチウム二次電池（ コイン型セル)を作製し、その充放電特性を測定した。電池の作製は、公知のセルの 構成'組み立て方法に従って行った。  A positive electrode was prepared by mixing 20 mg of a sample with 5 mg of acetylene black as a conductive agent and 0.5 mg of tetrafluoroethylene as a binder, lithium metal as the negative electrode material, and lithium hexafluorophosphate as ethylene carbonate (EC ) And jetyl carbonate (DEC) in a mixed solvent (volume ratio 1: 1) to produce a lithium secondary battery (coin-type cell) having the structure shown in FIG. The charge / discharge characteristics were measured. The battery was produced according to a known cell configuration method.
[0062] 得られたリチウム二次電池について、 30°Cの温度条件下で、電流密度 30mAZg ( Cレートで 0. 2C相当）、 4. 8V- 2. 5Vのカットオフ電位で充放電試験を行ったとこ ろ、平均放電電圧 3. 55-3. 64V、初期放電容量 173〜184mAhZgで安定に充 放電可能なことが判明した。（ここで、 Cレートは放電レート、すなわち放電電流の大 きさのことであり、 1Cは 1時間で放電しきることができる電流量を指し、 1時間率という 。例えば、容量が lAhの電池の 1Cは 1Aということになる。 ) [0062] The obtained lithium secondary battery was subjected to a charge / discharge test under a temperature condition of 30 ° C with a current density of 30mAZg (equivalent to 0.2C at C rate) and a cutoff potential of 4.8V-2.5V. As a result, it was found that an average discharge voltage of 3.55-3.64 V and an initial discharge capacity of 173 to 184 mAhZg can be stably charged and discharged. (Here, the C rate is the discharge rate, that is, the magnitude of the discharge current, and 1C is the amount of current that can be discharged in one hour, and is called the one-hour rate. For example, for a battery with a capacity of lAh 1C means 1A.)
Li Mn Ti O  Li Mn Ti O
0. 69 0. 89 0. 11 2の場合、 10サイクル後の放電容量も 168mAhZg程度を維 持しており、サイクル特性も良好であった。各電池の初期充電容量、初期放電容量、 平均初期放電電圧を表 3に示す。 [0063] [表 3] In the case of 0. 69 0. 89 0. 11 2, the discharge capacity after 10 cycles maintained about 168 mAhZg, and the cycle characteristics were also good. Table 3 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each battery. [0063] [Table 3]
Figure imgf000017_0001
Figure imgf000017_0001
[0064] また、 Li MnOおよび Li Mn Ti Oを正極材料として作製した電池の  [0064] Further, a battery manufactured using Li MnO and Li Mn Ti O as a positive electrode material was used.
0. 63 2 0. 72 0. 78 0. 22 2  0. 63 2 0. 72 0. 78 0. 22 2
初期放電特性を、図 3 (a)、（b)に示す。比較のために図 3 (c)に記載した、 Li挿入前 の Li MnOを正極材料として同様に作製した電池に対して、 Li MnOは、 4V The initial discharge characteristics are shown in Fig. 3 (a) and (b). For comparison, the battery shown in Fig. 3 (c), which uses Li MnO before Li insertion as the positive electrode material, was similarly manufactured.
0. 44 2 0. 63 2 領域の放電容量が大幅に増大していることがわかる。さらに、（b)にみられるように、 Mnの一部をチタンで置換することによって、放電曲線がなだらかになることが確認さ れた。 It can be seen that the discharge capacity in the 0. 44 2 0. 63 2 region has increased significantly. Furthermore, as shown in (b), it was confirmed that the discharge curve becomes smooth by substituting a part of Mn with titanium.
[0065] (実施例 2) [Example 2]
[正極材料の製造]  [Manufacture of cathode materials]
上記、実施例 1で得られた表 1に記載の各試料各 lgを、硝酸リチウム 22gとヨウ化リ チウム lgとよく混合した後、空気中、 300°Cで 10時間加熱し、リチウム挿入処理を行 つた。得られた固体を蒸留水、メタノール、エタノール等で洗浄、乾燥して試料を得た 。これらの試料を ICP発光分析法により、化学組成を分析した結果、リチウム量 Xは表 4に示すように、 0. 67≤x≤0. 76程度であり、挿入処理の有効性を確認した。また、 残存して含有するナトリウム量は、 ICPの検出限界 (0. 01wt%)以下であり、挿入処 理は、残存するナトリウム量のさらなる低減にも有効であった。さらに、作製された試 料のうち、 Li MnO (y =0)の X線粉末回折図形を図 2 (c)に示す。  Each sample lg shown in Table 1 obtained in Example 1 above was mixed well with 22 g of lithium nitrate and lg of lithium iodide, and then heated in air at 300 ° C. for 10 hours for lithium insertion treatment. I did. The obtained solid was washed with distilled water, methanol, ethanol or the like and dried to obtain a sample. As a result of analyzing the chemical composition of these samples by ICP emission spectrometry, the amount of lithium X was about 0.67≤x≤0.76 as shown in Table 4, and the effectiveness of the insertion treatment was confirmed. In addition, the amount of sodium remaining was below the ICP detection limit (0.01 wt%), and the insertion process was effective in further reducing the amount of sodium remaining. Furthermore, of the prepared samples, the X-ray powder diffraction pattern of Li MnO (y = 0) is shown in Fig. 2 (c).
0. 76 2  0. 76 2
出発原料とした Li MnOと同構造であると仮定して、計算された格子定数を表 4  Assuming that it has the same structure as Li MnO as the starting material, the calculated lattice constant is shown in Table 4.
0. 44 2  0. 44 2
に示す。リチウム挿入処理により、元の Li Mn Ti O (0. 43≤x≤0. 44)と比べて l-y y 2  Shown in L-y y 2 compared to the original Li Mn Ti O (0. 43 ≤ x ≤ 0.44) due to the lithium insertion process
、格子定数の変化が明ら力となった。また、ヨウ化リチウムの添加によるイオン挿入処 理カ 水酸化リチウムを添加した実施例 1の場合と、ほぼ同等の効果があることが確 f*i¾ れ 。 [0066] [表 4] The change in the lattice constant clearly became a force. Further, it was confirmed that the effect of ion insertion treatment by addition of lithium iodide was almost the same as that of Example 1 in which lithium hydroxide was added. [0066] [Table 4]
Figure imgf000018_0001
Figure imgf000018_0001
[0067] [リチウム二次電池]  [0067] [Lithium secondary battery]
このようにして得られた Li Mn Ti O (0. 67≤x≤0. 76)の各試料を用いて実  Using each sample of Li Mn Ti O (0.67≤x≤0.76) obtained in this way,
l-y y 2  l-y y 2
施例 1と同様にして正極を作製し、実施例 1と同様にリチウム二次電池を作製し充放 電試験を行ったところ、いずれも平均放電電圧 3. 54-3. 60V、初期放電容量 168 〜176mAhZgで安定に充放電可能であることが確認された。各試料の初期充電容 量、初期放電容量、平均初期放電電圧を表 5に示す。  A positive electrode was produced in the same manner as in Example 1. A lithium secondary battery was produced in the same manner as in Example 1 and a charge / discharge test was conducted. In each case, the average discharge voltage was 3.54-3.60 V, the initial discharge capacity. It was confirmed that charging and discharging can be stably performed at 168 to 176 mAhZg. Table 5 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample.
[0068] [表 5] [0068] [Table 5]
Figure imgf000018_0002
Figure imgf000018_0002
[0069] (比較例 1)  [0069] (Comparative Example 1)
上記、実施例 1で得られた表 1に記載の Li Mn Ti O (0. 43≤x≤0. 44)の各  Each of Li Mn Ti O (0.43≤x≤0.44) listed in Table 1 obtained in Example 1 above.
l-y y 2  l-y y 2
試料について、リチウム挿入処理を施さずにそのまま正極材料として使用し、実施例 1と同様にリチウム二次電池を作製し充放電試験を行ったところ、いずれも平均放電 電圧 3. 48〜3. 54V、初期放電容量は 141〜156mAhZg程度であった。比較の ために、 Li MnOの場合の初期放電曲線を図 3 (c)に記載した。  The sample was used as it is as a positive electrode material without being subjected to lithium insertion treatment, and a lithium secondary battery was produced and charged / discharged in the same manner as in Example 1. Both samples had an average discharge voltage of 3.48 to 3.54 V. The initial discharge capacity was about 141 to 156 mAhZg. For comparison, the initial discharge curve for Li MnO is shown in Fig. 3 (c).
0. 44 2  0. 44 2
[0070] (比較例 2)  [0070] (Comparative Example 2)
本発明による新規リチウムマンガンチタン酸ィ匕物を正極材料として使用したリチウム 二次電池の特性を明確にするために、既存正極であるリチウムマンガンスピネル Li Mn Oを正極材料として、実施例 1と同様にリチウム二次電池を作製し、同条件でIn order to clarify the characteristics of a lithium secondary battery using the novel lithium manganese titanate according to the present invention as a positive electrode material, the existing positive electrode lithium manganese spinel Li A lithium secondary battery was prepared in the same manner as in Example 1 using MnO as the positive electrode material.
1 1. 9 4 1 1. 9 4
充放電試験を行ったところ、平均放電電圧 3. 67V、初期放電容量は 152mAhZg であった。  When a charge / discharge test was conducted, the average discharge voltage was 3.67 V, and the initial discharge capacity was 152 mAhZg.
また、図 4 (b)に示すように、この正極材料を使用した電池は、スピネル型に特徴的 な大きな 2段の放電曲線を示した。これに対して、本発明の実施例 1で得られた本発 明の Li MnOを正極材料とする電池は、図 4 (a)にみられるように、電圧'容量、 As shown in Fig. 4 (b), the battery using this positive electrode material showed a large two-stage discharge curve characteristic of the spinel type. On the other hand, the battery using Li MnO of the present invention obtained in Example 1 of the present invention as the positive electrode material has a voltage 'capacitance, as shown in Fig. 4 (a).
0. 63 2 0. 63 2
すなわちエネルギー密度の観点で、スピネル材料に対する優位性が確認された。  That is, the superiority to the spinel material was confirmed from the viewpoint of energy density.
[0071] (実施例 3)  [Example 3]
実施例 1で得られた Li Mn Ti O (0. 59≤x≤0. 72、 y=0、 0. 055、 0. 11、 0 l -y y 2  Li Mn Ti O obtained in Example 1 (0.59≤x≤0.72, y = 0, 0.055, 0.11, 0 l -y y 2
. 22)の各試料を用いて実施例 1と同様にして正極を作製し、炭素（MCMB)を負極 材料、 6フッ化リン酸リチウムをエチレンカーボネート（EC)とジェチルカーボネート (D EC)との混合溶媒 (体積比 1： 1)に溶解させた 1M溶液を電解液として、図 1に示す 構造のリチウムイオン二次電池 (コイン型セル)を作製し、その充放電特性を測定した 。電池の作製は、公知のセルの構成'組み立て方法に従って行った。  22) Using each sample, a positive electrode was prepared in the same manner as in Example 1, carbon (MCMB) as the negative electrode material, lithium hexafluorophosphate as ethylene carbonate (EC) and jetyl carbonate (D EC). A lithium ion secondary battery (coin-type cell) having the structure shown in FIG. 1 was prepared using a 1M solution dissolved in the above mixed solvent (volume ratio 1: 1) as an electrolytic solution, and its charge / discharge characteristics were measured. The battery was produced according to a known cell configuration'assembly method.
[0072] このリチウムイオン二次電池について、 30°Cの温度条件下で、電流密度 30mAZg [0072] About this lithium ion secondary battery, the current density was 30mAZg under the temperature condition of 30 ° C.
(Cレートで 0. 2C相当）、 4. 8V- 2. 5Vのカットオフ電位で充放電試験を行ったとこ ろ、平均放電電圧 3. 7〜3. 8V、初期放電容量 114〜120mAhZgで安定に充放 電可能なことが判明した。 Li MnO  (Equivalent to 0.2C at the C rate), 4.8V-2.5V The cut-off potential of 8V-2.5V shows a stable average discharge voltage of 3.7 to 3.8V and initial discharge capacity of 114 to 120mAhZg. It was found that the battery can be charged and discharged. Li MnO
0. 63 2の場合、 10サイクル後の放電容量も 79mAh In the case of 0. 63 2, the discharge capacity after 10 cycles is also 79mAh
Zg程度を維持しており、サイクル特性も良好であった。各試料の初期充電容量、初 期放電容量、平均初期放電電圧を表 6に示す。また、 Li MnOの初期放電特性 The Zg level was maintained and the cycle characteristics were good. Table 6 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample. The initial discharge characteristics of Li MnO
0. 63 2  0. 63 2
を図 5 (a)に示す。  Is shown in Fig. 5 (a).
[0073] [表 6] [0073] [Table 6]
Figure imgf000019_0001
[0074] (実施例 4)
Figure imgf000019_0001
[Example 4]
実施例 2で得られた Li Mn Ti O (0. 67≤x≤0. 76)の各試料を用いて同様に Using each sample of Li Mn Ti O (0.67≤x≤0.76) obtained in Example 2 in the same manner
-y y 2  -y y 2
して正極を作製し、実施例 3と同様にリチウム二次電池を作製し充放電試験を行った ところ、いずれも平均放電電圧 3. 7〜3. 8V、初期放電容量 100〜119mAhZgで 安定に充放電可能であることが確認された。各試料の初期充電容量、初期放電容量 、平均初期放電電圧を表 7に示す。  A positive electrode was prepared, and a lithium secondary battery was prepared and charged and discharged in the same manner as in Example 3. All of these batteries were stable at an average discharge voltage of 3.7 to 3.8 V and an initial discharge capacity of 100 to 119 mAhZg. It was confirmed that charging / discharging was possible. Table 7 shows the initial charge capacity, initial discharge capacity, and average initial discharge voltage of each sample.
[0075] [表 7] [0075] [Table 7]
Figure imgf000020_0002
Figure imgf000020_0002
Figure imgf000020_0001
Figure imgf000020_0001
[0076] (比較例 3)  [0076] (Comparative Example 3)
上記、実施例 1で得られた表 1に記載の Li Mn Ti O (0. 43≤x≤0. 44)の各 Each of Li Mn Ti O (0.43≤x≤0.44) listed in Table 1 obtained in Example 1 above.
-y y 2  -y y 2
試料について、リチウム挿入処理を施さずにそのまま正極材料として使用し、実施例 3と同様にリチウム二次電池を作製し充放電試験を行ったところ、いずれも平均放電 電圧 3. 8〜3. 9V、初期放電容量は 50〜60mAhZg程度であった。比較のために 、 Li MnOの場合の初期放電曲線を図 5 (b)に記載した。  The sample was used as it is as a positive electrode material without being subjected to lithium insertion treatment, and a lithium secondary battery was produced and charged / discharged in the same manner as in Example 3. Both samples had an average discharge voltage of 3.8 to 3.9 V. The initial discharge capacity was about 50-60mAhZg. For comparison, the initial discharge curve for Li MnO is shown in FIG. 5 (b).
0. 44 2  0. 44 2
[0077] (比較例 4)  [0077] (Comparative Example 4)
本発明による新規リチウムマンガンチタン酸ィ匕物を正極材料として使用したリチウム 二次電池の特性を明確にするために、既存正極であるリチウムマンガンスピネル Li Mn Oを正極材料として、実施例 3と同様にリチウム二次電池を作製し、同条件で In order to clarify the characteristics of the lithium secondary battery using the novel lithium manganese titanate according to the present invention as the positive electrode material, the same as in Example 3 using the existing positive electrode lithium manganese spinel Li Mn O as the positive electrode material A lithium secondary battery was fabricated in the same conditions.
1 1. 9 4 1 1. 9 4
充放電試験を行ったところ、平均放電電圧 3. 84V、初期放電容量は 94mAhZgで あった。また、この電池における 10サイクル後の放電容量は 52mAhZg程度であり、 本発明による正極材料の特性 (平均放電電圧 3. 8V、初期放電容量 120mAhZg、 10サイクル後の放電容量 79mAh,g)の優位性が確認された。この例で得られた電 池の初期放電曲線を図 5 (c)に記載し、図 5 (a)の本発明の電池と比較した。 [0078] (実施例 5) As a result of the charge / discharge test, the average discharge voltage was 3.84 V, and the initial discharge capacity was 94 mAhZg. In addition, the discharge capacity after 10 cycles in this battery is about 52 mAhZg. Was confirmed. The initial discharge curve of the battery obtained in this example is shown in FIG. 5 (c) and compared with the battery of the present invention in FIG. 5 (a). [0078] (Example 5)
実施例 1で得られた Li Mn Ti O (x=0. 44および 0. 63、 y=0)について、実施  For Li Mn Ti O obtained in Example 1 (x = 0.44 and 0.63, y = 0)
l-y y 2  l-y y 2
例 1と同様の正極構成部材を N メチル 2—ピロリドン (NMP)で希釈して、スラリ 一とし、定法に従い、塗布電極を作製した。混合割合は、酸化物活物質:導電剤:結 着剤 = 89. 5 :4. 5 : 6. 0 (wt%)とした。作製された正極の電極物性を、表 8に示す。  A positive electrode component similar to that in Example 1 was diluted with N-methyl 2-pyrrolidone (NMP) to form a slurry, and a coated electrode was produced according to a conventional method. The mixing ratio was set as follows: oxide active material: conductive agent: binder = 89.5: 4.5: 6.0 (wt%). Table 8 shows the electrode physical properties of the produced positive electrode.
[0079] [表 8] [0079] [Table 8]
Figure imgf000021_0001
Figure imgf000021_0001
[0080] [リチウム二次電池] [0080] [Lithium secondary battery]
このようにして得られた正極、 MCMBを負極、セパレータとしてポリエチレン製微孔 膜、実施例 1と同様に 6フッ化リン酸リチウム系電解液を用いてリチウム二次電池 (単 層アルミラミネートセル)を作製し、その出力特性を測定した。電池の作製は、公知の セルの構成 '組み立て方法に従って行った。  The positive electrode thus obtained, MCMB as the negative electrode, polyethylene microporous membrane as the separator, and lithium secondary battery using lithium hexafluorophosphate electrolyte as in Example 1 (single layer aluminum laminate cell) The output characteristics were measured. The battery was produced according to a known cell configuration method.
[0081] 得られたリチウム二次電池について、 25°Cの温度条件下で、 30mAZg (Cレートで 0. 2C相当）の定電流で 4. 8Vまで充電し、放電をそれぞれ 30mAZg、 60mA/g, 150mAZg、 300mAZg、 450mA/g, 750mA/g, 900mA/g, 1050mA/g の定電流で 2. 5Vまで行うことにより、各試料の出力特性を評価した。各レートでの容 量保持率を Li MnOおよび Li MnOの場合について、図 6で比較した。 Li  [0081] The obtained lithium secondary battery was charged to 4.8 V at a constant current of 30 mAZg (equivalent to 0.2 C at C rate) at 25 ° C, and discharged at 30 mAZg and 60 mA / g, respectively. , 150 mAZg, 300 mAZg, 450 mA / g, 750 mA / g, 900 mA / g, and 1050 mA / g were used at constant currents up to 2.5 V to evaluate the output characteristics of each sample. Figure 6 compares the capacity retention at each rate for Li MnO and Li MnO. Li
0. 44 2 0. 63 2 0. 44 0. 44 2 0. 63 2 0. 44
MnOの場合、 7C相当の 1050mAZgで 40%程度の容量保持率であったものが、 In the case of MnO, the capacity retention rate was about 40% at 1050mAZg equivalent to 7C.
2  2
Li MnOでは、 70%を超える高い容量保持率であることが判明した。このことから Li MnO was found to have a high capacity retention of over 70%. From this
0. 63 2 0. 63 2
、リチウム挿入処理によって、高容量化できるばかりでなぐ高出力化が可能であるこ とが確認された。  As a result of the lithium insertion process, it was confirmed that not only high capacity but also high output could be achieved.

Claims

請求の範囲 The scope of the claims
[1] 化学組成式として Li Mn Ti O (0. 5≤x≤l、 0≤y< 0. 56)で表記され、結晶構 造として斜方晶系に属し、リチウムが占有するトンネル構造を有するリチウム、マンガ ン、チタン、酸素力も構成されるリチウム二次電池正極材料。  [1] The chemical composition is expressed as Li Mn Ti O (0.5 ≤ x ≤ l, 0 ≤ y <0.56), and the crystal structure belongs to the orthorhombic system and the tunnel structure occupied by lithium Lithium secondary battery positive electrode material that also has lithium, manganese, titanium, and oxygen power.
[2] あら力じめ作製された Li Mn Ti O (0. 40<x< 0. 50、 0≤y< 0. 56)を出発原 料として、リチウム挿入処理によって製造することを特徴とする請求項 1に記載のリチ ゥム二次電池正極材料の製造方法。  [2] It is characterized in that Li Mn Ti O (0. 40 <x <0. 50, 0≤y <0.56) prepared by force is used as a starting material and manufactured by lithium insertion treatment. The method for producing a lithium secondary battery positive electrode material according to claim 1.
[3] 前記リチウム挿入処理を、リチウム化合物を含有する溶融塩中、或いはリチウム化合 物を溶解した有機溶剤または水溶液中にぉ ヽて行うことを特徴とする請求項 2に記 載の正極材料の製造方法。  [3] The positive electrode material according to claim 2, wherein the lithium insertion treatment is performed in a molten salt containing a lithium compound, or in an organic solvent or an aqueous solution in which a lithium compound is dissolved. Production method.
[4] 正極、負極及び電解質物質を有するリチウム二次電池の正極を請求項 1に記載の正 極材料により構成したことを特徴とするリチウム二次電池。 [4] A lithium secondary battery comprising the positive electrode material according to claim 1, wherein the positive electrode of the lithium secondary battery having a positive electrode, a negative electrode, and an electrolyte substance.
[5] 電池の負極としてリチウム又はリチウム合金負極を使用し、 4Vの電圧範囲で安定に 充放電できることを特徴とする請求項 4に記載のリチウム二次電池。 5. The lithium secondary battery according to claim 4, wherein a lithium or lithium alloy negative electrode is used as the negative electrode of the battery and can be stably charged and discharged in a voltage range of 4V.
[6] 電池の負極として炭素負極を使用し、 4Vの電圧範囲で安定に充放電できることを特 徴とする請求項 4に記載のリチウム二次電池。 6. The lithium secondary battery according to claim 4, wherein a carbon negative electrode is used as the negative electrode of the battery and can be stably charged and discharged in a voltage range of 4V.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1837937A1 (en) * 2006-03-20 2007-09-26 National Institute of Advanced Industrial Science and Technology Lithium manganese-based composite oxide and method and method forpreparing the same
WO2009066639A1 (en) * 2007-11-22 2009-05-28 Sumitomo Chemical Company, Limited Sodium-manganese complex metal oxide, method for producing the same, and sodium secondary battery
JP2009227505A (en) * 2008-03-21 2009-10-08 National Institute Of Advanced Industrial & Technology Manganese oxide, electrode active material for battery, those producing methods and secondary battery using electrode active material for battery
JP2009227506A (en) * 2008-03-21 2009-10-08 National Institute Of Advanced Industrial & Technology Manganese oxide, electrode active material for secondary battery, those producing methods and lithium secondary battery using electrode active material for secondary battery
JP2009242121A (en) * 2008-03-28 2009-10-22 National Institute Of Advanced Industrial & Technology Lithium manganese oxide powder particle and production method of the same, and lithium secondary battery using the same as positive active material

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0831408A (en) * 1994-05-13 1996-02-02 Matsushita Electric Ind Co Ltd Positive electrode for non-aqueous electrolyte lithium secondary battery and manufacture thereof
JP2870741B2 (en) * 1997-04-14 1999-03-17 堺化学工業株式会社 Lithium manganate particulate composition, method for producing the same, and lithium ion secondary battery
JPH11130438A (en) * 1997-08-18 1999-05-18 Agency Of Ind Science & Technol Production of lithium manganese double oxide particulate composition and utilization of the same for lithium ion secondary battery
JP2003086179A (en) * 2001-09-10 2003-03-20 Nippon Telegr & Teleph Corp <Ntt> Electrode material, its method of manufacture, and battery using the same
JP2003157832A (en) * 2001-11-22 2003-05-30 Japan Storage Battery Co Ltd Nonaqueous electrolyte secondary battery
JP2005259362A (en) * 2004-03-09 2005-09-22 National Institute Of Advanced Industrial & Technology Positive electrode material for lithium secondary battery, manufacturing method of the same, and lithium secondary battery using the material
JP2005268127A (en) * 2004-03-19 2005-09-29 National Institute Of Advanced Industrial & Technology Positive electrode material for lithium secondary battery, its manufacturing method and lithium secondary battery using it

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0831408A (en) * 1994-05-13 1996-02-02 Matsushita Electric Ind Co Ltd Positive electrode for non-aqueous electrolyte lithium secondary battery and manufacture thereof
JP2870741B2 (en) * 1997-04-14 1999-03-17 堺化学工業株式会社 Lithium manganate particulate composition, method for producing the same, and lithium ion secondary battery
JPH11130438A (en) * 1997-08-18 1999-05-18 Agency Of Ind Science & Technol Production of lithium manganese double oxide particulate composition and utilization of the same for lithium ion secondary battery
JP2003086179A (en) * 2001-09-10 2003-03-20 Nippon Telegr & Teleph Corp <Ntt> Electrode material, its method of manufacture, and battery using the same
JP2003157832A (en) * 2001-11-22 2003-05-30 Japan Storage Battery Co Ltd Nonaqueous electrolyte secondary battery
JP2005259362A (en) * 2004-03-09 2005-09-22 National Institute Of Advanced Industrial & Technology Positive electrode material for lithium secondary battery, manufacturing method of the same, and lithium secondary battery using the material
JP2005268127A (en) * 2004-03-19 2005-09-29 National Institute Of Advanced Industrial & Technology Positive electrode material for lithium secondary battery, its manufacturing method and lithium secondary battery using it

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1837937A1 (en) * 2006-03-20 2007-09-26 National Institute of Advanced Industrial Science and Technology Lithium manganese-based composite oxide and method and method forpreparing the same
US8021783B2 (en) 2006-03-20 2011-09-20 National Institute Of Advanced Industrial Science And Technology Lithium manganese-based composite oxide and method for preparing the same
WO2009066639A1 (en) * 2007-11-22 2009-05-28 Sumitomo Chemical Company, Limited Sodium-manganese complex metal oxide, method for producing the same, and sodium secondary battery
JP2009129702A (en) * 2007-11-22 2009-06-11 Sumitomo Chemical Co Ltd Sodium-manganese composite metal oxide, manufacturing method thereof, and sodium secondary battery
JP2009227505A (en) * 2008-03-21 2009-10-08 National Institute Of Advanced Industrial & Technology Manganese oxide, electrode active material for battery, those producing methods and secondary battery using electrode active material for battery
JP2009227506A (en) * 2008-03-21 2009-10-08 National Institute Of Advanced Industrial & Technology Manganese oxide, electrode active material for secondary battery, those producing methods and lithium secondary battery using electrode active material for secondary battery
JP2009242121A (en) * 2008-03-28 2009-10-22 National Institute Of Advanced Industrial & Technology Lithium manganese oxide powder particle and production method of the same, and lithium secondary battery using the same as positive active material

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