WO2012118117A1 - スピネル型リチウムマンガン系複合酸化物 - Google Patents
スピネル型リチウムマンガン系複合酸化物 Download PDFInfo
- Publication number
- WO2012118117A1 WO2012118117A1 PCT/JP2012/055069 JP2012055069W WO2012118117A1 WO 2012118117 A1 WO2012118117 A1 WO 2012118117A1 JP 2012055069 W JP2012055069 W JP 2012055069W WO 2012118117 A1 WO2012118117 A1 WO 2012118117A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- spinel
- composite oxide
- lmo
- lithium manganese
- lithium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G45/00—Compounds of manganese
- C01G45/12—Complex oxides containing manganese and at least one other metal element
- C01G45/1207—Permanganates ([MnO4)-] or manganates ([MnO4)2-]
- C01G45/1214—Permanganates ([MnO4)-] or manganates ([MnO4)2-] containing alkali metals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G45/00—Compounds of manganese
- C01G45/12—Complex oxides containing manganese and at least one other metal element
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G45/00—Compounds of manganese
- C01G45/12—Complex oxides containing manganese and at least one other metal element
- C01G45/1221—Manganates or manganites with trivalent manganese, tetravalent manganese or mixtures thereof
- C01G45/1242—Manganates or manganites with trivalent manganese, tetravalent manganese or mixtures thereof of the type (Mn2O4)-, e.g. LiMn2O4 or Li(MxMn2-x)O4
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/30—Three-dimensional structures
- C01P2002/32—Three-dimensional structures spinel-type (AB2O4)
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/76—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by a space-group or by other symmetry indications
-
- 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 can be used as a positive electrode active material for a lithium battery, and is particularly suitable as a positive electrode active material for a large battery mounted on an electric vehicle (EV) or a hybrid electric vehicle (HEV).
- EV electric vehicle
- HEV hybrid electric vehicle
- the present invention relates to a lithium manganese complex oxide (also referred to as “spinel type lithium manganese complex oxide” or “LMO” in the present invention) having a spinel structure (space group Fd-3m) that can be used.
- Lithium batteries especially lithium secondary batteries, have features such as high energy density and long life, so they can be used in home appliances such as video cameras, portable electronic devices such as notebook computers and mobile phones. It is widely used as a power source, and recently, it is expected to be applied to a large battery mounted on an electric vehicle (EV), a hybrid electric vehicle (HEV), or the like.
- EV electric vehicle
- HEV hybrid electric vehicle
- a lithium secondary battery is a secondary battery with a structure in which lithium is melted as ions from the positive electrode during charging, moves to the negative electrode and is stored, and reversely, lithium ions return from the negative electrode to the positive electrode during discharging. It is known that it is mainly caused by the potential of the positive electrode material.
- Examples of the positive electrode active material of the lithium secondary battery include lithium transition metal oxides such as LiCoO 2 , LiNiO 2 , and LiMnO 2 having a layer structure, and lithium manganese-based composite oxides such as LiMnO 4 and LiNi 0.5 Mn 0.5 O 4 .
- LMO lithium manganese complex oxide
- EV electric vehicles
- HEV hybrid electric vehicles
- excellent output characteristics are particularly required for batteries for EVs and HEVs.
- insertion and desorption of Li ions are three-dimensionally compared with lithium transition metal oxides such as LiCoO 2 having a layer structure.
- a possible spinel type lithium manganese complex oxide (LMO) has excellent output characteristics.
- Patent Document 1 a positive electrode active material having low internal resistance, high output, high capacity, and excellent charge / discharge cycle characteristics even under high temperature conditions.
- a positive electrode active material Containing 0.001 to 0.05 (molar ratio) of vanadium (V) and / or boron (B), the primary particle diameter is 1 ⁇ m or more, the crystallite size is 450 mm or more, and the lattice strain is 0.05% or less
- V vanadium
- B boron
- Patent Document 2 the ratio of the median diameter D50 of the positive electrode active material obtained by laser diffraction in the case where the positive electrode active material is dispersed in ethanol and ultrasonic wave is applied to the case where it is not applied (D50 (no ultrasonic wave) ) / D50 (with ultrasonic wave)) is disclosed as a positive electrode active material for a lithium secondary battery.
- Patent Document 3 discloses a general formula Li 1 + x M 2-x O 4 as a new positive electrode active material for a lithium battery that can increase the packing density (tap density) and at the same time improve the output characteristics.
- - [delta] (.
- M in the formula is, Mn, a transition metal containing Al and Mg, x is a .0 ⁇ [delta] 0.01 to 0.08) spinel represented by (space group Fd-3m) Lithium transition metal oxide, Li-O interatomic distance measured by the Rietveld method using the fundamental method is 1.971 ⁇ to 2.006 ⁇ , and the crystallite size is 500 nm to 2000 nm.
- a positive electrode active material for a lithium battery containing a spinel-type lithium transition metal oxide and a boron compound is disclosed.
- Patent Document 4 discloses a general formula Li 1 + x M 2-x as a new spinel-type lithium transition metal oxide (LMO) that has excellent output characteristics and preferably has both output characteristics and high-temperature cycle life characteristics.
- LMO lithium transition metal oxide represented by O 4
- M is a transition metal containing Mn, Al and Mg, and x is 0.01 to 0.08
- Patent Document 5 can manufacture a lithium secondary battery with improved high temperature cycle characteristics and excellent rate characteristics, and includes lithium and manganese as constituent elements as a positive electrode active material with good coatability. It is made of lithium manganate having a spinel structure, has an average primary particle diameter of 1 ⁇ m or more and less than 5 ⁇ m, a crystallite diameter in a powder X-ray diffraction pattern of 500 to 1500 nm, and a lattice strain ( ⁇ ) value of 0.05 ⁇ 10 -3 to 0.9 ⁇ 10 ⁇ 3 , a ratio D50 of the median diameter D50 ( ⁇ m) and the DBET ( ⁇ m) calculated from the BET specific surface area using the general formula (1)
- a positive electrode active material having / DBET of 1 to 4 is disclosed.
- the present invention is to provide a new spinel type lithium manganese composite oxide capable of maintaining the discharge capacity even after repeated charge and discharge at high temperature.
- the present invention has a specific surface area increase rate when a crystallite size is 250 nm to 350 nm, a strain is 0.085 or less, and ultrasonic dispersion is performed for 600 seconds at an ultrasonic intensity of 40 W in water at 25 ° C. and pH 7.
- a spinel type (space group Fd-3m) lithium-manganese complex oxide is proposed, characterized in that is less than 10.0%.
- the present inventor As a cause of gradually decreasing the output characteristics with repeated charge and discharge at high temperatures, the present inventor has agglomerated positive electrode active material particles or weak sintering, and does not collapse during positive electrode formation. However, with repeated charging and discharging at high temperatures, these aggregated parts and weakly sintered parts are separated and the particles collapse, so that the conductive network between the positive electrode active material particles breaks, resulting in a decrease in output characteristics. I expected to do it. Therefore, when the specific surface area increase rate was adjusted to 10.0% or less when ultrasonically dispersed for 600 seconds at an ultrasonic intensity of 40 W in water of 25 ° C.
- the spinel type lithium manganese composite oxide of the present invention can be used as a positive electrode active material of a lithium ion battery, the discharge capacity can be maintained even after repeated charge and discharge at a high temperature.
- it can be used as a positive electrode active material for so-called consumer batteries such as notebook computers, mobile phones, cordless phones, video movies, LCD TVs, electric shavers, portable radios, headphone stereos, backup power supplies, pacemakers, hearing aids, etc.
- it can be suitably used as a positive electrode active material for large batteries mounted on EVs, HEVs and the like.
- the spinel type (space group Fd-3m) lithium manganese composite oxide (hereinafter also referred to as “present LMO”) according to an embodiment of the present invention has a crystallite size of 250 nm to 350 nm and a strain of 0.085 or less.
- crystallite size In the present LMO, it is important that the crystallite size measured by the Rietveld method using the fundamental method is 250 nm to 350 nm. If the crystallite size is 250 nm to 350 nm, the particle size is sufficiently large, so that the ionic conductivity can be increased and the output can be increased. Moreover, since the specific surface area in contact with the electrolytic solution is reduced, it is possible to suppress the discharge capacity from gradually decreasing with repeated charging and discharging at high temperatures. From this viewpoint, the crystallite size of the present LMO is more preferably 280 nm or more, and more preferably 300 nm or more.
- crystallite means the largest group that can be regarded as a single crystal, and can be obtained by XRD measurement and Rietveld analysis.
- the firing temperature is set to 800 to 950 ° C., the shape of the firing container at the time of firing, the open area (open area) of the firing container It is preferable to adjust the ratio of the filling amount of the firing raw material with respect to.
- this LMO has a specific surface area increase rate of 10.0% or less when it is placed in water at 25 ° C. and pH 7 and ultrasonically dispersed at an ultrasonic intensity of 40 W for 600 seconds. If the specific surface area increase rate is 10.0% or less, the positive electrode active material particles are agglomerated or weakly sintered, and these agglomerated portions and weakness are associated with repeated charge and discharge at high temperatures. Since it is possible to eliminate the dissociation of the sintered parts and the collapse of the particles, output characteristics due to repeated charge and discharge can be suppressed. From this point of view, the specific surface area increase rate of the present LMO is more preferably 6.5% or less, and even more preferably 4.5% or less.
- a high-speed rotary pulverizer (referred to as “airflow generation high-speed rotary pulverizer”) that generates an air flow after firing or heat treatment in the composition range of the present LMO. It is preferable to adjust the rotation speed while crushing. By crushing at a preferred rotational speed using such a pulverizer, it is possible to crush the part where the particles are aggregated or the sintering is weak, and the specific surface area increase rate can be reduced. it can.
- the present LMO preferably has a specific surface area after ultrasonic dispersion / a specific surface area before ultrasonic dispersion of 1.00 to 1.13, particularly 1.00 to 1.10. More preferably, it is 0.001 to 1.07.
- the sample circulator for laser diffraction particle size distribution measuring machine was used, and the present LMO, that is, lithium manganese composite oxide powder was put into water, and ultrasonic dispersion was performed.
- the particle size distribution before and after the measurement is measured using a laser diffraction particle size distribution analyzer, and the specific surface area before and after ultrasonic dispersion is measured from the obtained volume-based particle size distribution chart to calculate the increase rate of the specific surface area.
- the degree of aggregation may vary depending on the storage period and storage state of the lithium manganese composite oxide powder, and as a result, the rate of increase in specific surface area (CS) varies and measurement errors increase.
- the lithium manganese composite oxide powder is put into the circulating water in the sample circulator for laser diffraction particle size distribution analyzer, and then circulated for 2 minutes.
- the method of starting the measurement of a specific surface area (CS) increase rate after that can be mentioned.
- this LMO has a distortion of 0.085 or less. If the strain is as small as this, the skeleton of the spinel-type lithium manganese composite oxide is sufficiently strong, and when used as the positive electrode active material of a lithium secondary battery, the output characteristics (rate characteristics) and high-temperature cycle life characteristics And can improve the quick charge characteristics. Therefore, from such a viewpoint, the distortion of the present LMO is 0.080 or less, and more preferably 0.075 or less.
- the composition is pulverized by a high-speed rotary pulverizer (referred to as an “airflow generation high-speed rotary pulverizer”) that generates airflow after firing or heat treatment in the composition range of the present LMO.
- a high-speed rotary pulverizer referred to as an “airflow generation high-speed rotary pulverizer”
- the average particle size (D50) determined by the LMO laser diffraction / scattering particle size distribution measurement method is preferably 1 ⁇ m to 25 ⁇ m, more preferably 5 ⁇ m or more and 15 ⁇ m or less, and particularly preferably 10 ⁇ m or more or 15 ⁇ m or less.
- the 10% cumulative diameter (D10) determined by the LMO laser diffraction / scattering particle size distribution measurement method is preferably 0.1 ⁇ m to 20 ⁇ m, particularly 1 ⁇ m or more and 10 ⁇ m or less, especially 2 ⁇ m or more or 8 ⁇ m or less. Is preferred.
- the 90% cumulative diameter (D90) determined by the laser diffraction / scattering particle size distribution measurement method of the present LMO is preferably 5 ⁇ m to 50 ⁇ m, particularly 10 ⁇ m or more and 40 ⁇ m or less, especially 15 ⁇ m or more or 35 ⁇ m or less. preferable.
- the maximum particle size (Dmax) obtained by the laser diffraction scattering type particle size distribution measurement method of the present LMO is preferably 30 ⁇ m to 120 ⁇ m, more preferably 30 ⁇ m or more and 110 ⁇ m or less, and particularly preferably 30 ⁇ m or more or 100 ⁇ m or less. .
- the specific surface area (CS) determined by the laser diffraction / scattering particle size distribution measurement method of the present LMO is preferably 0.2 m 2 / cc to 5 m 2 / cc, particularly 0.2 m 2 / cc or more or It is preferably 3 m 2 / cc or less, particularly 0.3 m 2 / cc or more or 1.0 m 2 / cc or less.
- the present LMO can contain other metal elements in addition to Li and Mn.
- the present LMO has the general formula (1).
- ⁇ Li 1 + x M 2 ⁇ x O 4 (where M in the formula contains Mn and Mg, Al, Ti, Ni, Co, Mo, W , Nb, Ta, Re, and Fe, including one or more of them.
- X is 0.01 to 0.08)
- space group Fd-3m Lithium manganese complex oxide is preferable.
- the general formula (2) ⁇ Li (Li x Mg y Al z Mn 2-xyz) O 4 ( where, 0.01 ⁇ x ⁇ 0.08,0.02 ⁇ y ⁇ 0.07,0.
- a lithium manganese composite oxide represented by 06 ⁇ z ⁇ 0.14) is preferable.
- “x” is preferably 0.01 to 0.08, more preferably 0.01 to 0.05, and particularly preferably 0.01 to 0.03.
- “Y” is preferably 0.02 to 0.07, more preferably 0.02 to 0.06, and particularly preferably 0.02 to 0.04.
- “Z” is preferably 0.06 to 0.14, more preferably 0.07 to 0.13, and particularly preferably 0.11 to 0.13. Since the spinel structure generally contains oxygen vacancies, the atomic ratio “4” of oxygen in the above general formula (2) includes some non-stoichiometry (for example, 4- ⁇ (0 ⁇ ⁇ )). And a part of oxygen may be substituted with fluorine.
- the firing temperature is set to 800 to 950 ° C.
- the shape of the firing container at the time of firing the ratio of the filling amount of the firing raw material to the open area (open area) of the firing container
- raw materials such as a lithium raw material, a manganese raw material, other magnesium raw materials, and an aluminum raw material are mixed, granulated and dried as necessary, fired, classified as necessary, and further required. Accordingly, after heat treatment, the powder may be crushed and classified by an airflow generating high-speed rotary pulverizer as described above.
- a boron compound may be added to the raw material, mixed, wet pulverized, granulated and dried, and fired.
- a boron compound is added and fired to promote the sintering of fine particles in which spinel-type lithium manganese composite oxide (LMO) crystal particles are aggregated. Since agglomerated fine particles (secondary particles) can be formed, the packing density (tap density) can be increased.
- the generation and growth of spinel-type lithium manganese composite oxide (LMO) crystals can be promoted, so that the crystallite size of the spinel-type lithium manganese composite oxide can be increased and the number of interfaces in the primary particles can be increased. And the discharge capacity at high load discharge (3C) can be increased.
- the lithium raw material is not particularly limited, and for example, lithium hydroxide (LiOH), lithium carbonate (Li 2 CO 3 ), lithium nitrate (LiNO 3 ), LiOH ⁇ H 2 O, lithium oxide (Li 2 O) ) And other fatty acid lithium and lithium halide.
- lithium hydroxide salts, carbonates and nitrates are preferred.
- the magnesium raw material is not particularly limited, and examples thereof include magnesium oxide (MgO), magnesium hydroxide (Mg (OH) 2 ), magnesium fluoride (MgF 2 ), and magnesium nitrate (Mg (NO 3 ) 2 ). Among them, magnesium oxide is preferable.
- manganese raw material it is preferable to use metal manganese and manganese dioxide purified by electrolysis, especially electrolytic manganese dioxide obtained by electrolysis from the viewpoint of reactivity. Since electrolytic manganese dioxide has good electrochemical reactivity, it is considered preferable because it can further enjoy the effects of the present invention.
- the aluminum raw material is not particularly limited.
- aluminum hydroxide (Al (OH) 3 ), aluminum fluoride (AlF 3 ), or the like can be used, and among these, aluminum hydroxide is preferable.
- lithium borate examples include lithium metaborate (LiBO 2 ), lithium tetraborate (Li 2 B 4 O 7 ), lithium pentaborate (LiB 5 O 8 ), and lithium perborate (Li 2 B 2 O 5 ). Although various forms can be used, lithium tetraborate (Li 2 B 4 O 7 ) is particularly preferable. Boron does not dissolve in the spinel, but has a function of promoting the sintering of the spinel in the firing process.
- the added amount of the boron compound is more than 0% by mass and not more than 0.3% by mass of the spinel type lithium manganese composite oxide as boron (B) element, particularly 0.0001 to 0.2% by mass, especially 0.01%. It is preferable to adjust in the range of 0.1 to 0.18% by mass, of which 0.01 to 0.16% by mass.
- the method of mixing raw materials is not particularly limited as long as it can be uniformly mixed.
- the respective raw materials may be added simultaneously or in an appropriate order using a known mixer such as a mixer, and mixed by stirring in a wet or dry manner.
- a liquid medium such as water or a dispersant
- wet mixing it is preferable to add a liquid medium such as water or a dispersant to wet mix to form a slurry, and the obtained slurry is pulverized with a wet pulverizer.
- the raw materials mixed as described above may be fired as they are, but may be granulated to a predetermined size and fired.
- the granulation method may be either wet or dry as long as the various raw materials pulverized in the previous step are dispersed in the granulated particles without being separated, extrusion granulation method, rolling granulation method, fluidized granulation method, A mixed granulation method, a spray drying granulation method, a pressure molding granulation method, or a flake granulation method using a roll or the like may be used. However, when wet granulation is performed, it is necessary to sufficiently dry before firing.
- a drying method it may be dried by a known drying method such as a spray heat drying method, a hot air drying method, a vacuum drying method, a freeze drying method, etc.
- the spray heat drying method is preferable.
- the spray heat drying method is preferably performed using a heat spray dryer (spray dryer).
- a thermal spray dryer spray dryer
- the particle size distribution be sharper, but it can also be prepared to contain agglomerated particles (secondary particles) that are agglomerated roundly. it can.
- Firing is performed in a firing furnace in an air atmosphere, an oxygen gas atmosphere, an atmosphere in which the oxygen partial pressure is adjusted, a carbon dioxide gas atmosphere, or other atmosphere, at a temperature rising rate of 50 to 200 ° C./hr. It is preferable to perform firing at a temperature of 800 to 950 ° C. (which means a temperature when a thermocouple is brought into contact with a fired product in a firing furnace) for 0.5 to 30 hours. .
- a temperature range lower than the above-mentioned baking temperature is not specifically limited. For example, it can be fired using a rotary kiln, a stationary furnace, or other firing furnace.
- the ratio of an atmosphere contact area and a lithium manganate raw material filling volume at the time of baking is preferable to adjust suitably the ratio of an atmosphere contact area and a lithium manganate raw material filling volume at the time of baking.
- the atmosphere contact area and the ratio of the lithium manganate raw material filling volume can be adjusted.
- the crystallite size can be changed by adjusting the shape of the firing container, the ratio of the amount of firing raw material to the opening area (open area) of the firing container, etc., so that it falls within a predetermined range. It is preferable to adjust these.
- the powder may be washed by contacting with a polar solvent such as water, and then dried by heating to 300 to 700 ° C. in an air atmosphere. Impurities contained in the powder can be released by contacting with a polar solvent.
- a polar solvent such as water
- the LMO powder and a polar solvent may be mixed and stirred to form a slurry, and the resulting slurry may be solid-liquid separated by filtration or the like to remove impurities.
- Slurry means a state in which the present LMO powder is dispersed in a polar solvent.
- the liquid temperature at the time of washing with water is preferably 5 to 70 ° C., more preferably 10 ° C. or more and 60 ° C. or less, and particularly preferably 20 ° C.
- the amount of the polar solvent brought into contact with the present LMO powder is preferably adjusted so that the mass ratio of the present LMO powder to the polar solvent (also referred to as “slurry concentration”) is 10 to 70 wt%.
- the magnetic separation method may be either a dry magnetic separation method in which the dried LMO powder is brought into contact with a magnet or a wet magnetic separation method in which a slurry of the present LMO powder is brought into contact with a magnet.
- the wet magnetic separation method is preferred in that the present LMO powder in a more dispersed state, in other words, not agglomerated can be brought into contact with the magnet.
- the LMO powder and a polar solvent are mixed and stirred in the water washing step to form a slurry, and the slurry obtained in the magnetic separation step is put into a wet magnetic separator, followed by magnetic separation.
- the impurities separated in the water washing step and the magnetic separation step can be collectively separated and removed from the present LMO powder.
- the structure of the wet magnetic separator is arbitrary. For example, a magnetic separator having a configuration in which a filter or a fin-like magnet is disposed in a pipe can be exemplified.
- the LMO powder and polar solvent are mixed and stirred to form a slurry, and when the slurry obtained in the magnetic separation step is put into a wet magnetic separator and magnetically selected, the supply speed of the slurry used for magnetic separation increases the magnetic separation efficiency.
- it is preferably 0.2 to 3.0 m / sec, particularly 0.3 m / sec or more or 2.0 m / sec or less, and more preferably 0.5 m / sec or more or 1.5 m / sec or less. Is preferred.
- the magnetic force of the magnet used for magnetic separation is preferably 8000 G to 17000 G (Gauss), more preferably 10000 G or more or 17000 G or less, especially 12000 G or more. More preferably, it is 17000 G or less. If the magnetic force of the magnet is too weak, it is difficult to obtain a magnetic separation effect. On the other hand, if the magnetic force of the magnet is too strong, necessary items are also removed and the recovery rate is lowered.
- the heat treatment is not necessarily performed.
- the heat treatment may be performed at a low temperature not exceeding 400 ° C., for example, in an air atmosphere or an oxygen partial pressure higher than the air. From the viewpoint of removing moisture, the heat treatment is performed at a low temperature of about 200 to 300 ° C. Is preferred.
- the temperature of the heat treatment means the product temperature of the processed material measured by bringing a thermocouple into contact with the processed material in the furnace.
- the pulverization after firing or heat treatment is preferably performed using an airflow generating high-speed rotary pulverizer as described above. If pulverization is performed by an air flow generation high-speed rotary pulverizer, the portion where the particles are aggregated or the sintering is weak can be pulverized, and the distortion of the particles can be suppressed.
- the crushing means is not limited to a high-speed rotary crusher that generates airflow, as an example, a pin mill known as a rotary disk crusher makes a negative pressure inside by rotating a rotating disc with a pin.
- the rotation speed of the pin mill is preferably 4000 rpm or more, particularly 5000 to 8000 rpm.
- the classification has the technical significance of adjusting the particle size distribution of the agglomerated powder and removing foreign substances, and it is preferable to classify the particles into an average particle size (D50) in the range of 1 to 75 ⁇ m.
- the present LMO can be effectively used as a positive electrode active material for a lithium battery.
- the positive electrode mixture can be manufactured by mixing the present LMO, a conductive material made of carbon black or the like, and a binder made of Teflon (registered trademark) binder or the like.
- a positive electrode mixture is used for the positive electrode, for example, a material capable of inserting and extracting lithium such as lithium or carbon is used for the negative electrode, and lithium such as lithium hexafluorophosphate (LiPF 6 ) is used for the non-aqueous electrolyte.
- a lithium secondary battery can be constituted by using a salt dissolved in a mixed solvent such as ethylene carbonate-dimethyl carbonate.
- the present invention is not limited to the battery having such a configuration.
- ⁇ Measurement of crystallite size and strain> For the measurement of the X-ray diffraction pattern, an X-ray diffraction apparatus (D8 ADVANCE manufactured by Bruker AXS Co., Ltd.) using Cu-K ⁇ rays was used.
- the Rietveld method using the fundamental method is a method for refining the crystal structure parameters from the diffraction intensity obtained by powder X-ray diffraction or the like. This method assumes a crystal structure model, and refines various parameters of the crystal structure so that the X-ray diffraction pattern derived from the structure and the measured X-ray diffraction pattern match as much as possible.
- the crystal structure is attributed to the cubic crystal of the space group Fd-3m (Origin Choice 2), Li is present at the 8a site, Mn and Mn substitution elements (eg, Mg, Mn, Al, Ti, Ni, Co, Mo, W, Nb, Ta, Re and Fe, any one or more), and an excess Li component x exists, O occupies the 32e site. Assuming that the parameter Beq.
- the crystal structure was identified by the Rietveld method using the fundamental method so that Rwp ⁇ 10.0 and GOF ⁇ 2, and then the lattice constant, crystal Child size and distortion were measured.
- Detector PSD Detector Type: VANTEC-1 High Voltage: 5585V Discr. Lower Level: 0.35V Discr. Window Width: 0.15V Grid Lower Level: 0.075V Grid Window Width: 0.524V Flood Field Correction: Disabled Primary radius: 250mm Secondary radius: 250mm Receiving slit width: 0.1436626mm Divergence angle: 0.3 ° Filament Length: 12mm Sample Length: 25mm Receiving Slit Length: 12mm Primary Sollers: 2.623 ° Secondary Sollers: 2.623 ° Lorentzian, 1 / Cos: 0.004933548Th
- ⁇ Particle size distribution> The particle size distribution of the sample (powder) was measured as follows. Using a sample circulator for laser diffraction particle size distribution measuring instrument (“Microtorac ASVR” manufactured by Nikkiso Co., Ltd.), a sample (powder) was put into water and irradiated with ultrasonic waves of 40 watts for 6 minutes at a flow rate of 40 mL / sec. Thereafter, the particle size distribution was measured using a laser diffraction particle size distribution measuring instrument “HRA (X100)” manufactured by Nikkiso Co., Ltd., and D50, D10, D90, Dmax and CS (specific surface area) from the obtained volume-based particle size distribution chart. Asked.
- HRA X100
- the water-soluble solvent used in the measurement was water that passed through a 60 ⁇ m filter, the solvent refractive index was 1.33, the particle permeability was reflected, the measurement range was 0.122 to 704.0 ⁇ m, and the measurement time was The average value measured twice for 30 seconds was used as the measured value.
- CS Specific surface area
- a sample circulator for laser diffraction particle size distribution analyzer (“Microtorac ASVR” manufactured by Nikkiso Co., Ltd.)
- the sample (powder) is put into water (25 ° C., pH 7), and ultrasonic intensity is obtained at a flow rate of 40 mL / sec. Obtained by measuring the particle size distribution before and after ultrasonic dispersion of 40 W ultrasonic waves for 600 seconds (10 minutes) using a laser diffraction particle size distribution measuring instrument “HRA (X100)” manufactured by Nikkiso Co., Ltd.
- HRA (X100) manufactured by Nikkiso Co., Ltd.
- the specific surface area before and after ultrasonic dispersion was measured from the volume-based particle size distribution chart, and the specific surface area increase rate was calculated.
- the water-soluble solvent used in the measurement was water that passed through a 60 ⁇ m filter, the solvent refractive index was 1.33, the particle permeability was reflected, the measurement range was 0.122 to 704.0 ⁇ m, and the measurement time was The average value measured twice for 30 seconds was used as the measured value.
- Li battery evaluation was performed by the following method.
- the average value of the weight of ⁇ 16 mm aluminum foil is obtained in advance
- the weight of the positive electrode mixture is obtained by subtracting the weight of the aluminum foil from the weight of the positive electrode
- the mixture of the positive electrode active material, acetylene black and PVDF The content of the positive electrode active material was determined from the ratio.
- the negative electrode was made of metal Li having a diameter of 20 mm and a thickness of 1.0 mm, and an electrochemical evaluation cell TOMCELL (registered trademark) was produced using these materials.
- the positive electrode 3 made of the positive electrode mixture was disposed in the center of the inside of the lower body 1 made of organic electrolyte resistant stainless steel.
- a separator 4 made of a microporous polypropylene resin impregnated with an electrolytic solution was disposed, and the separator was fixed with a Teflon spacer 5.
- a negative electrode 6 made of metal Li was disposed below, a spacer 7 also serving as a negative electrode terminal was disposed, and the upper body 2 was placed thereon and tightened with screws to seal the battery.
- the electrolytic solution used was a mixture of EC and DMC in a volume of 3: 7, and a solvent in which LiPF 6 was dissolved in 1 mol / L as a solute.
- the percentage (%) of the numerical value obtained by dividing the discharge capacity at the 40th cycle by the discharge capacity at the second cycle was calculated as the high temperature capacity retention rate (0.1 C). Moreover, the same cycle conditions were performed by changing 0.1 C to 1.0 C, and the high temperature capacity retention rate (1.0 C) was obtained. All are shown in Table 1 as relative values when the value of Comparative Example 1 is 100.
- the temperature was decreased at a rate of temperature decrease of 20 ° C./hr until it was naturally cooled to room temperature.
- the temperature variation within the holding time was controlled within the range of 903 ° C to 923 ° C.
- the fired mass obtained by firing in this way is put in a mortar and crushed with a pestle, and the sieved product sieved with a sieve opening of 5 mm is crushed with a commercially available pin mill (manufactured by Hadano Sangyo Co., Ltd.) ( (Crushing condition: rotational speed 5000 rpm) and classification with a sieve having an opening of 50 ⁇ m, and the powder under the sieve was recovered as a spinel type lithium manganese complex oxide powder (sample).
- Example 2 A spinel type lithium manganese composite oxide powder (sample) was obtained in the same manner as in Example 1 except that the rotational speed of the pin mill was changed to 7000 rpm.
- Example 3 The calcination mass obtained by calcination was carried out in the same manner as in Example 1 and put into a mortar, crushed with a pestle, and sieved with a sieve opening of 5 mm, a commercially available pin mill (Hagano Sangyo Co., Ltd.) (Crushed condition: 7000 rpm), classified with a sieve having an opening of 50 ⁇ m, and the powder under the sieve was recovered as a spinel type lithium manganese composite oxide powder.
- a commercially available pin mill Hagano Sangyo Co., Ltd.
- Example 1 A spinel type lithium manganese composite oxide powder (sample) was obtained in the same manner as in Example 1 except that the rotation speed of the pin mill was changed to 11000 rpm.
- Example 1-3 has the general formula Li 1 + x M 2-x O 4 (wherein M is Mn, Mg and Al, and x is 0.01 to 0.08). It is confirmed that the same effect can be obtained for the sample in which the amount of Mg and Al is changed. It is considered that the same effect as the above embodiment can be obtained. Therefore, M in the above formula includes Mn, and any one or more of the group consisting of Mg, Al, Ti, Ni, Co, Mo, W, Nb, Ta, Re, and Fe Even if it exists, it is thought that the same effect can be acquired.
- the water-soluble solvent used in the measurement was water that passed through a 60 ⁇ m filter, the solvent refractive index was 1.33, the particle permeability was reflected, the measurement range was 0.122 to 704.0 ⁇ m, and the measurement time was The average value measured twice for 30 seconds was used as the measured value.
- CS specific surface area
- a sample circulator (“Microtrac SDC” manufactured by Nikkiso Co., Ltd.) for laser diffraction particle size distribution analyzer is used, and the sample (powder) is put into water (25 ° C, pH 7).
- a laser diffraction particle size distribution measuring instrument “MT3300EXII” manufactured by Nikkiso Co., Ltd. for the particle size distribution before and after ultrasonic dispersion for 60 seconds (10 minutes) with 90 W ultrasonic wave at a flow rate of 90%.
- the specific surface area before and after ultrasonic dispersion was measured from the volume-based particle size distribution chart obtained by HRA mode analysis, and the specific surface area increase rate was calculated.
- the water-soluble solvent used in the measurement was water that passed through a 60 ⁇ m filter, the solvent refractive index was 1.33, the particle permeability was reflected, the measurement range was 0.122 to 704.0 ⁇ m, and the measurement time was The average value measured twice for 30 seconds was used as the measured value.
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
中でも、リチウムマンガン系複合酸化物(LMO)は、原料価格が安く、毒性がなく安全であるため、電気自動車(EV)やハイブリッド電気自動車(HEV)などの大型電池用の正極活物質として着目されている。また、EVやHEV用電池には優れた出力特性が特に求められるが、この点、層構造をもつLiCoO2などのリチウム遷移金属酸化物に比べ、3次元的にLiイオンの挿入・脱離が可能なスピネル型リチウムマンガン系複合酸化物(LMO)は出力特性に優れている。
そこで本発明は、高温下で充放電を繰り返しても放電容量を維持することができる新たなスピネル型リチウムマンガン系複合酸化物を提供せんとするものである。
また、結晶子サイズを大きくすることにより、電解液に接する比表面積を小さくして電解液中に金属を溶出し難くするという方法が知られている。粒子サイズを大きくすることによって、イオン導電性が高くなり、出力を高めることもできる。しかし、結晶子サイズを大きくするために、単に高温条件下で焼成すると、結晶子サイズは大きくなるものの、スピネル型リチウムマンガン系複合酸化物(LMO)の粒子同士が強固に焼結する結果、電池用材料として所望の粒子の大きさにした場合に電池特性が低下するという問題があった。これに対し、本発明では、結晶子サイズと共に、さらに歪みと比表面積増加率を同時に規定することで、高温時における充放電の繰り返しによる放電容量の低下を抑えることができるようになった。
本発明の実施形態に係るスピネル型(空間群Fd-3m)リチウムマンガン系複合酸化物(以下「本LMO」とも称する)は、結晶子サイズが250nm~350nmであり、歪みが0.085以下であり、25℃、pH7の水に入れて超音波強度40Wで600秒間超音波分散させた場合の比表面積増加率が10.0%以下であることを特徴とするスピネル型(空間群Fd-3m)リチウムマンガン系複合酸化物である。
本LMOにおいては、ファンダメンタル法を用いたリートベルト法で測定される結晶子サイズが250nm~350nmであることが重要である。
結晶子サイズが250nm~350nmであれば、粒子サイズが十分に大きいから、イオン導電性を高めることができ、出力を高めることができる。また、電解液に接する比表面積が小さくなるから、高温時における充放電の繰り返しに伴って徐々に放電容量が低下するのを抑制することができる。
かかる観点から、本LMOの結晶子サイズは、中でも280nm以上であるのがさらに好ましく、その中でも300nm以上であるのがより一層好ましい。
ここで、「結晶子」とは、単結晶とみなせる最大の集まりを意味し、XRD測定しリートベルト解析を行なうことにより求めることができる。
本LMOは、25℃、pH7の水に入れて超音波強度40Wで600秒間超音波分散させた場合の比表面積増加率が10.0%以下であることが重要である。
かかる比表面積増加率が10.0%以下であれば、正極活物質粒子どうしが凝集していたり、焼結が弱かったりして、高温時における充放電の繰り返しに伴ってこれらの凝集部分や弱い焼結部分が乖離して粒子が崩壊するのを無くすことができるから、充放電の繰り返しによる出力特性を抑えることができる。
かかる観点から、本LMOの比表面積増加率は6.5%以下であるのがさらに好ましく、中でも4.5%以下であるのがより一層好ましい。
この際、リチウムマンガン系複合酸化物粉末の保管期間や保管状態などによって凝集度合が変化することがあり、そうすると比表面積(CS)の増加率がばらつき、測定誤差が大きくなってしまう。そこで、上記の超音波分散に先立って、次のような予備処理をすることにより比表面積(CS)増加率の測定誤差を少なくするようにするのが好ましい。
比表面積(CS)増加率の測定に先立って行う予備処理として、リチウムマンガン系複合酸化物粉末をレーザー回折粒度分布測定機用試料循環器中の循環水に投入した後、循環を2分間行い、その後に比表面積(CS)増加率の測定を開始する方法を挙げることができる。
本LMOは、歪みが0.085以下であることが重要である。
この程度に歪みが小さければ、スピネル型リチウムマンガン系複合酸化物の骨格が充分に強固であり、リチウム二次電池の正極活物質として使用した場合に、出力特性(レート特性)、高温サイクル寿命特性および急速充電特性を高めることができる。
よって、このような観点から、本LMOの歪みは、0.080以下、その中でも0.075以下であるのがさらに好ましい。
本LMOのレーザー回折散乱式粒度分布測定法により求められる平均粒径(D50)は1μm~25μmであるのが好ましく、特に5μm以上或いは15μm以下、中でも特に10μm以上或いは15μm以下であるのが好ましい。
本LMOのレーザー回折散乱式粒度分布測定法により求められる10%積算径(D10)は、0.1μm~20μmであるのが好ましく、特に1μm以上或いは10μm以下、中でも特に2μm以上或いは8μm以下であるのが好ましい。
本LMOのレーザー回折散乱式粒度分布測定法により求められる90%積算径(D90)は、5μm~50μmであるのが好ましく、特に10μm以上或いは40μm以下、中でも特に15μm以上或いは35μm以下であるのが好ましい。
本LMOのレーザー回折散乱式粒度分布測定法により求められる最大粒径(Dmax)は、30μm~120μmであるのが好ましく、特に30μm以上或いは110μm以下、中でも特に30μm以上或いは100μm以下であるのが好ましい。
さらにまた、本LMOのレーザー回折散乱式粒度分布測定法により求められる比表面積(CS)は、0.2m2/cc~5m2/ccであるのが好ましく、特に0.2m2/cc以上或いは3m2/cc以下、中でも特に0.3m2/cc以上或いは1.0m2/cc以下であるのが好ましい。かかる範囲に調整することにより、高温サイクル特性を良好にすることができる。
本LMOは、Li及びMnのほかに、他の金属元素を含むことができる。
中でも、本LMOは、一般式(1)・・Li1+xM2-xO4(但し、式中のMは、Mnを含み、かつMg、Al、Ti、Ni、Co、Mo、W、Nb、Ta、Re及びFeからなる群のうちの何れか1種類又は2種類以上を含む。xは0.01~0.08である。)で表わされるスピネル型(空間群Fd-3m)リチウムマンガン系複合酸化物であるのが好ましい。
また、「y」は、0.02~0.07であるのが好ましく、中でも0.02~0.06、特に0.02~0.04であるのがより好ましい。
また、「z」は、0.06~0.14であるのが好ましく、中でも0.07~0.13、特に0.11~0.13であるのがより好ましい。
なお、スピネル構造のものは一般的に酸素欠損を含むため、上記一般式(2)において酸素の原子比「4」は多少の不定比性(例えば4-δ(0≦δ))を含むことを許容する意であり、酸素の一部がフッ素で置換されていてもよい。
次に、本LMOの製造方法について説明する。
但し、この製造方法に限定するものではない。
ホウ素化合物の添加量は、ホウ素(B)元素としてスピネル型リチウムマンガン系複合酸化物の0質量%より多く且つ0.3質量%以下、特に0.0001~0.2質量%、中でも0.01~0.18質量%、その中でも0.01~0.16質量%の範囲で調整するのが好ましい。
造粒方法は、前工程で粉砕された各種原料が分離せずに造粒粒子内で分散していれば湿式でも乾式でもよく、押し出し造粒法、転動造粒法、流動造粒法、混合造粒法、噴霧乾燥造粒法、加圧成型造粒法、或いはロール等を用いたフレーク造粒法でもよい。但し、湿式造粒した場合には、焼成前に充分に乾燥させることが必要である。乾燥方法としては、噴霧熱乾燥法、熱風乾燥法、真空乾燥法、フリーズドライ法などの公知の乾燥方法によって乾燥させればよく、中でも噴霧熱乾燥法が好ましい。噴霧熱乾燥法は、熱噴霧乾燥機(スプレードライヤー)を用いて行なうのが好ましい。熱噴霧乾燥機(スプレードライヤー)を用いて造粒することにより、粒度分布をよりシャープにすることができるばかりか、丸く凝集してなる凝集粒子(2次粒子)を含むように調製することができる。
焼成炉の種類は特に限定するものではない。例えばロータリーキルン、静置炉、その他の焼成炉を用いて焼成することができる。
このように、焼成容器の形状、焼成容器の開口面積(開放面積)に対する焼成原料の充填量の割合などを調節することで、結晶子サイズを変化させることができるため、所定範囲に入るようにこれらを調整するのが好ましい。
極性溶媒と接触させて、粉末中に含まれる不純物を離脱させることができる。例えば本LMO粉末と極性溶媒とを混合し攪拌してスラリーとし、得られたスラリーをろ過などによって固液分離して不純物を除去するようにすればよい。スラリーとは、極性溶媒中に本LMO粉末が分散した状態を意味する。
水洗時の液温に関しては、5~70℃であるのが好ましく、中でも10℃以上或いは60℃以下であるのがより一層好ましく、その中でも特に20℃以上或いは45℃以下であるのがより一層好ましい。水洗時の液温は高いほど、より一層の洗浄効果を得ることができるが、液温が70℃を超えると電池特性が悪化することが確認されている。この理由は、液温が高過ぎると、リチウム遷移金属酸化物中のリチウムがイオン交換水のプロトンとイオン交換してリチウムが抜けて高温特性が悪くなるためであると推定できる。
本LMO粉末と接触させる極性溶媒の量については、極性溶媒に対する本LMO粉末の質量比(「スラリー濃度」とも称する)が10~70wt%となるように調整するのが好ましく、中でも20wt%以上或いは60wt%以下、その中でも30wt%以上或いは50wt%以下となるように調整するのがより一層好ましい。極性溶媒の量が少なすぎると、SO4などの不純物を溶出させることが困難となり、逆に多過ぎてもそれに見合った洗浄効果を得ることができないため不経済である。
水洗後の乾燥は、酸素を含有する雰囲気下で300~700℃に加熱して乾燥させるのが好ましい。
このような磁選は、本製造方法のいずれのタイミングで行ってもよい。例えば水洗工程後や、最後の解砕乃至粉砕後に行うのが好ましい。最後の解砕乃至粉砕後に行うことで、解砕機や粉砕機が破損して混入する鉄なども最終的に除去することができる。
磁選方法としては、乾燥した状態の本LMO粉末を磁石と接触させる乾式磁選法、本LMO粉末のスラリーを磁石と接触させる湿式磁選法のいずれでもよい。
磁選効率の観点からは、より分散した状態、言い換えれば凝集してない状態の本LMO粉末を磁石と接触させることができる点で、湿式磁選法の方が好ましい。
なお、水洗後に磁選を行う場合は、水洗工程と組み合わせることができる点で、湿式磁選法を選択するのが好ましい。逆に、最後の解砕乃至粉砕後に行う場合は、その後に乾燥させる必要がない点で、乾式磁選法を採用するのが好ましい。
湿式磁選器の構造は任意である。例えばパイプ内にフィルター或いはフィン状の磁石を配設してなる構成を備えたような磁選器を例示することができる。
水洗工程において本LMO粉末と極性溶媒とを混合攪拌してスラリーとし、磁選工程で得られたスラリーを湿式磁選器に投入して磁選する場合、磁選に供するスラリーの供給速度は、磁選効率を高める観点から、0.2~3.0m/secであるのが好ましく、中でも0.3m/sec以上或いは2.0m/sec以下、その中でも0.5m/sec以上或いは1.5m/sec以下とするのが好ましい。
熱処理は、大気雰囲気下若しくは大気よりも酸素分圧の高い雰囲気下において、例えば400℃を超えない低温で実施すればよく、水分除去の観点からすると200~300℃程度の低温での熱処理をするのが好ましい。
熱処理の温度とは、炉内の処理物に熱電対を接触させて測定される処理物の品温を意味する。
解砕手段を気流発生高速回転粉砕機に限定する訳ではないが、一例として、円盤回転型粉砕機として知られるピンミルは、ピンの付いた回転盤が回転することで、内部を負圧にして原料供給口より粉を吸い込む方式の解砕器であるため、微粉は比表面積が大きくて気流に乗りやすいためピンミルを通過する一方、粗大粒子はピンミルによってしっかり解砕されるため、粒子間の凝集や弱い焼結部分をしっかりと解し、かつ粒子内に歪みが入るのを防止することができる。
ピンミルの回転数は4000rpm以上、特に5000~8000rpmにするのが好ましい。
また、分級は、凝集粉の粒度分布調整とともに異物除去という技術的意義があり、平均粒径(D50)1μm~75μmの範囲に分級するのが好ましい。
本LMOは、リチウム電池の正極活物質として有効に利用することができる。
例えば、本LMOと、カーボンブラック等からなる導電材と、テフロン(登録商標)バインダー等からなる結着剤とを混合して正極合剤を製造することができる。そしてそのような正極合剤を正極に用い、例えば負極にはリチウムまたはカーボン等のリチウムを吸蔵・脱蔵できる材料を用い、非水系電解質には六フッ化リン酸リチウム(LiPF6)等のリチウム塩をエチレンカーボネート-ジメチルカーボネート等の混合溶媒に溶解したものを用いてリチウム2次電池を構成することができる。但し、このような構成の電池に限定する意味ではない。
本明細書において「X~Y」(X,Yは任意の数字)と表現する場合、特にことわらない限り「X以上Y以下」の意と共に、「好ましくはXより大きい」或いは「好ましくYより小さい」の意も包含する。
また、「X以上」(Xは任意の数字)と表現する場合、特にことわらない限り「好ましくはXより大きい」の意を包含し、「Y以下」(Yは任意の数字)と表現する場合、特にことわらない限り「好ましくYより小さい」の意を包含する。
X線回折パターンの測定には、Cu‐Kα線を用いたX線回折装置(ブルカー・エイエックスエス株式会社製D8 ADVANCE)を使用した。ファンダメンタル法を用いたリートベルト法は、粉末X線回折等により得られた回折強度から、結晶の構造パラメータを精密化する方法である。結晶構造モデルを仮定し、その構造から計算により導かれるX線回折パターンと、実測されたX線回折パターンとができるだけ一致するように、その結晶構造の各種パラメータを精密化する手法である。
回折角2θ=10~120°の範囲より得られたX線回折パターンのピークについて解析用ソフトウエア(製品名「Topas Version3」)を用いて解析することにより格子定数、結晶子サイズ及び歪みを求めた。
なお、結晶構造は、空間群Fd-3m(Origin Choice2)の立方晶に帰属として、その8aサイトにLiが存在し、16dサイトにMn、Mnの置換元素(例えばMg、Mn、Al、Ti、Ni、Co、Mo、W、Nb、Ta、Re及びFeからなる群のうちの何れか1種類又は2種類以上)、さらには過剰なLi分xが存在し、32eサイトをOが占有していると仮定し、パラメータBeq.を1と固定し、酸素の分率座標を変数として、表に示す通り観測強度と計算強度の一致の程度を表す指標Rwp<10.0、GOF<2.0を目安に収束するまで繰り返し計算を行った。なお、結晶子サイズ及び歪みはガウス関数を用い、解析を行った。
Detector:PSD
Detector Type:VANTEC-1
High Voltage:5585V
Discr. Lower Level:0.35V
Discr. Window Width:0.15V
Grid Lower Level:0.075V
Grid Window Width:0.524V
Flood Field Correction:Disabled
Primary radius:250mm
Secondary radius:250mm
Receiving slit width:0.1436626mm
Divergence angle:0.3°
Filament Length:12mm
Sample Length:25mm
Receiving Slit Length:12mm
Primary Sollers:2.623°
Secondary Sollers:2.623°
Lorentzian,1/Cos:0.004933548Th
サンプル(粉体)の粒度分布を次のようにして測定した。
レーザー回折粒度分布測定機用試料循環器(日機装株式会社製「Microtorac ASVR」)を用い、サンプル(粉体)を水に投入し、40mL/secの流速中、40wattsの超音波を6分間照射した後、日機装株式会社製レーザー回折粒度分布測定機「HRA(X100)」を用いて粒度分布を測定し、得られた体積基準粒度分布のチャートからD50、D10、D90、Dmax及びCS(比表面積)を求めた。
なお、測定の際の水溶性溶媒には60μmのフィルターを通した水を用い、溶媒屈折率を1.33、粒子透過性条件を反射、測定レンジを0.122~704.0μm、測定時間を30秒とし、2回測定した平均値を測定値として用いた。
レーザー回折粒度分布測定機用試料循環器(日機装株式会社製「Microtorac ASVR」)を用い、サンプル(粉体)を水(25℃、pH7)に投入し、40mL/secの流速中、超音波強度40Wの超音波を600秒(10分)間照射して超音波分散させた前後の粒度分布を、日機装株式会社製レーザー回折粒度分布測定機「HRA(X100)」を用いて測定し、得られた体積基準粒度分布のチャートから、超音波分散前後の比表面積を測定し、比表面積増加率を算出した。
なお、測定の際の水溶性溶媒には60μmのフィルターを通した水を用い、溶媒屈折率を1.33、粒子透過性条件を反射、測定レンジを0.122~704.0μm、測定時間を30秒とし、2回測定した平均値を測定値として用いた。
(電池の作製)
Li電池評価は以下の方法で行った。
負極はφ20mm×厚み1.0mmの金属Liとし、これらの材料を使用して電気化学評価用セルTOMCELL(登録商標)を作製した。
電解液は、ECとDMCを3:7体積混合したものを溶媒とし、これに溶質としてLiPF6を1moL/L溶解させたものを用いた。
上記のようにして準備した電気化学用セルを用いて下記に記述する方法で充放電試験し、高温サイクル寿命特性を求めた。
電池充放電する環境温度を45℃となるようにセットした環境試験機内にセルを入れ、充放電できるように準備し、セル温度が環境温度になるように4時間静置後、充放電範囲を3.0V~4.3Vとし、0.1Cで2サイクル充放電行った後、充放電範囲3.0V~4.3Vで、1Cにて充放電サイクルを39回行い、40サイクル目は容量確認の為、充放電範囲3.0V~4.3Vで0.1Cにて充放電を行った。
40サイクル目の放電容量を、2サイクル目の放電容量で割り算して求めた数値の百分率(%)を、高温容量維持率(0.1C)として算出した。また、0.1Cを1.0Cに変更して同様なサイクル条件を行い、高温容量維持率(1.0C)を求めた。いずれも、比較例1の値を100とした時の相対値として表1に示した。
炭酸リチウム20.16g、電解二酸化マンガン(200℃-400℃加熱時のTG減量:3.0%)84.46g、酸化マグネシウム0.66gおよび水酸化アルミニウム4.76gを混合して混合原料を得た。
得られた混合原料を、焼成容器(アルミナ製のルツボ大きさ=たて*よこ*たかさ=10*10*5(cm))内に、開放面積と充填高さの比(開放面積cm2/充填高さcm)が100となるように充填した。この際の原料見掛密度は1.1g/cm3であった。
そして、静置式電気炉を用いて、常温から焼成設定温度まで昇温速度=150℃/hrで昇温し、焼成温度(保持温度)913℃で20時間保持し、その後、保持温度から600℃まで降温速度=20℃/hrで降温させ、その後は常温まで自然冷却させた。なお、保持時間内の温度ばらつきは903℃~923℃の範囲内で制御した。
このように焼成して得られた焼成塊を、乳鉢に入れて乳棒で解砕し、篩目開き5mmで篩分けした篩下品を市販のピンミル(槙野産業(株)製)で解砕し(解砕条件:回転数5000rpm)、目開き50μmの篩で分級し、篩下の粉末をスピネル型リチウムマンガン系複合酸化物粉末(サンプル)として回収した。
ピンミルの回転数を7000rpmに変更した以外は実施例1と同様にスピネル型リチウムマンガン系複合酸化物粉末(サンプル)を得た。
実施例1と同様に焼成まで行い、焼成して得られた焼成塊を、乳鉢に入れて乳棒で解砕し、篩目開き5mmで篩分けした篩下品を市販のピンミル(槙野産業(株)製)で解砕し(解砕条件7000rpm)、目開き50μmの篩で分級し、篩下の粉末をスピネル型リチウムマンガン系複合酸化物粉末として回収した。
次に、得られたスピネル型リチウムマンガン系複合酸化物粉末35gとイオン交換水(pH5.8)1Lとを混合し、10分間攪拌してスピネル型リチウムマンガン系複合酸化物粉末のスラリーとした(スラリー濃度35質量%)。この時の液温は25℃であった。このスラリーを湿式磁選器(スラリーが接触する箇所の磁石の磁力:17000G)内に1.0m/secの速度で流通させた後、減圧ろ過した。
続いて、濾別したスピネル型リチウムマンガン系複合酸化物粉末を大気中で350℃(品温)に加熱して5時間、水蒸気排出速度1.0g/secで乾燥させた後、分級機によって分級を行い、325メッシュアンダーのスピネル型リチウムマンガン系複合酸化物粉末(サンプル)を得た。
ピンミルの回転数を11000rpmに変更した以外は、実施例1と同様にスピネル型リチウムマンガン系複合酸化物粉末(サンプル)を得た。
これらの結果、結晶子サイズが250nm~350nmであり、歪みが0.085以下であって、しかも比表面積増加率が10.0%以下であれば、高温時における充放電の繰り返しに伴う出力の低下を防ぐことができることが分かった。
粒度分布の測定に関しては、レーザー回折粒度分布測定機用試料循環器(日機装株式会社製「Microtrac SDC」)を用い、サンプル(粉体)を水(25℃、pH7)に投入し、90%の流速中、超音波強度40Wの超音波を6分間照射した後、日機装株式会社製レーザー回折粒度分布測定機「MT3300EXII」を用いて粒度分布を測定し、得られた体積基準粒度分布のチャートからD50、D10、D90、Dmax及びCS(比表面積)を求めた。この場合も、上記と同様の結果が得られることを確認した。
なお、測定の際の水溶性溶媒には60μmのフィルターを通した水を用い、溶媒屈折率を1.33、粒子透過性条件を反射、測定レンジを0.122~704.0μm、測定時間を30秒とし、2回測定した平均値を測定値として用いた。
なお、測定の際の水溶性溶媒には60μmのフィルターを通した水を用い、溶媒屈折率を1.33、粒子透過性条件を反射、測定レンジを0.122~704.0μm、測定時間を30秒とし、2回測定した平均値を測定値として用いた。
Claims (6)
- 結晶子サイズが250nm~350nmであり、歪みが0.085以下であり、
25℃、pH7の水に入れて超音波強度40Wで600秒間超音波分散させた場合の比表面積増加率が10.0%以下であることを特徴とするスピネル型(空間群Fd-3m)リチウムマンガン系複合酸化物。 - 超音波分散後比表面積/超音波分散前比表面積が1.00~1.13であることを特徴とする請求項1記載のスピネル型(空間群Fd-3m)リチウムマンガン系複合酸化物。
- 一般式Li1+xM2-xO4(但し、式中のMは、Mnを含み、かつMg、Al、Ti、Ni、Co、Mo、W、Nb、Ta、Re及びFeからなる群のうちの何れか1種類又は2種類以上を含む。xは0.01~0.08である。)で表わされる請求項1又は2に記載のスピネル型リチウムマンガン系複合酸化物。
- 電解マンガンをマンガン原料として用いて作製されたものであることを特徴とする請求項1~3の何れかに記載のスピネル型リチウムマンガン系複合酸化物。
- 電解二酸化マンガンをマンガン原料として用いて作製されたものであることを特徴とする請求項1~3の何れかに記載のスピネル型リチウムマンガン系複合酸化物。
- 850℃以上で焼成して得られたものであることを特徴とする請求項1~5の何れかに記載のスピネル型リチウムマンガン系複合酸化物。
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1315431.5A GB2503138B (en) | 2011-03-02 | 2012-02-29 | Spinel-type lithium manganese-based composite oxide |
| US14/002,524 US9437873B2 (en) | 2011-03-02 | 2012-02-29 | Spinel-type lithium manganese-based composite oxide |
| KR1020137017517A KR101463880B1 (ko) | 2011-03-02 | 2012-02-29 | 스피넬형 리튬망간계 복합 산화물 |
| JP2012554124A JP5308581B2 (ja) | 2011-03-02 | 2012-02-29 | スピネル型リチウムマンガン系複合酸化物 |
| CN201280007149.1A CN103339062B (zh) | 2011-03-02 | 2012-02-29 | 尖晶石型锂锰系复合氧化物 |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011044936 | 2011-03-02 | ||
| JP2011-044936 | 2011-03-02 | ||
| JP2011-203385 | 2011-09-16 | ||
| JP2011203385 | 2011-09-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2012118117A1 true WO2012118117A1 (ja) | 2012-09-07 |
Family
ID=46758047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2012/055069 Ceased WO2012118117A1 (ja) | 2011-03-02 | 2012-02-29 | スピネル型リチウムマンガン系複合酸化物 |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US9437873B2 (ja) |
| JP (1) | JP5308581B2 (ja) |
| KR (1) | KR101463880B1 (ja) |
| CN (1) | CN103339062B (ja) |
| GB (1) | GB2503138B (ja) |
| WO (1) | WO2012118117A1 (ja) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014050812A1 (ja) * | 2012-09-25 | 2014-04-03 | 三井金属鉱業株式会社 | スピネル型リチウムマンガン含有複合酸化物 |
| WO2015083788A1 (ja) * | 2013-12-04 | 2015-06-11 | 三井金属鉱業株式会社 | スピネル型リチウムコバルトマンガン含有複合酸化物 |
| JP2015140292A (ja) * | 2014-01-29 | 2015-08-03 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質、および、非水系電解質二次電池 |
| JP2016017017A (ja) * | 2014-07-09 | 2016-02-01 | 旭硝子株式会社 | リチウム含有複合酸化物の製造方法、リチウムイオン二次電池用正極およびリチウムイオン二次電池 |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6649369B2 (ja) * | 2015-04-30 | 2020-02-19 | 三井金属鉱業株式会社 | 5v級スピネル型リチウムマンガン含有複合酸化物の製造方法 |
| US20180241072A1 (en) | 2015-08-24 | 2018-08-23 | Sumitomo Metal Mining Co., Ltd. | Nonaqueous electrolyte secondary battery positive electrode active material and method for manufacturing same, and nonaqueous electrolyte secondary battery |
| US10744885B2 (en) | 2016-11-21 | 2020-08-18 | Ford Global Technologies, Llc | Battery pre-heating prior to fast charge |
| CN108455675B (zh) * | 2018-03-08 | 2020-09-25 | 蒋央芳 | 一种锰酸锂的制备方法 |
| CN108649209B (zh) * | 2018-05-23 | 2021-02-19 | 陕西海恩新材料有限责任公司 | 一种混合正极材料及其制备方法 |
| JP7403946B2 (ja) * | 2018-08-20 | 2023-12-25 | 株式会社田中化学研究所 | 精製リチウム化合物の製造方法及びリチウム遷移金属複合酸化物の製造方法 |
| KR102233337B1 (ko) | 2018-12-06 | 2021-03-29 | 삼화콘덴서공업 주식회사 | 이차전지 |
| KR102151074B1 (ko) | 2018-12-06 | 2020-09-02 | 삼화콘덴서공업 주식회사 | 이차전지 |
| CN110233259B (zh) | 2018-12-29 | 2021-02-09 | 宁德时代新能源科技股份有限公司 | 正极活性材料、正极极片及电化学储能装置 |
| CN109830655A (zh) * | 2019-01-07 | 2019-05-31 | 新乡市中天新能源科技股份有限公司 | 一种离子共掺杂制备尖晶石型锰酸锂正极材料的方法 |
| KR20200137393A (ko) | 2019-05-30 | 2020-12-09 | 삼성에스디에스 주식회사 | 데이터 보호 방법 및 그 시스템 |
| CN110247035B (zh) | 2019-06-06 | 2021-06-04 | 山东省科学院能源研究所 | 一种高镍正极材料改性方法 |
| CN110148737B (zh) | 2019-06-06 | 2021-04-27 | 山东省科学院能源研究所 | 一种富锂锰基电极材料及其制备方法 |
| WO2022039088A1 (ja) * | 2020-08-19 | 2022-02-24 | 住友化学株式会社 | リチウム金属複合酸化物の製造方法 |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0722020A (ja) * | 1993-06-29 | 1995-01-24 | Tosoh Corp | リチウムマンガン複合酸化物の製造方法及びその用途 |
| JP2010033786A (ja) * | 2008-07-25 | 2010-02-12 | Mitsui Mining & Smelting Co Ltd | リチウム二次電池用正極活物質の評価方法及び製造方法 |
| JP2010219065A (ja) * | 2010-06-21 | 2010-09-30 | Ngk Insulators Ltd | 正極活物質及びリチウム二次電池 |
| WO2011002074A1 (ja) * | 2009-07-03 | 2011-01-06 | 三井金属鉱業株式会社 | リチウム遷移金属酸化物の製造方法 |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1207800C (zh) * | 2001-07-17 | 2005-06-22 | 成都市雷雳高科技发展有限公司 | 一种锂锰氧化物正极材料的合成方法 |
| JP2004253169A (ja) | 2003-02-18 | 2004-09-09 | Ngk Insulators Ltd | リチウム二次電池及びそれに用いる正極活物質の製造方法 |
| JP4168402B2 (ja) | 2003-10-24 | 2008-10-22 | 日立金属株式会社 | リチウム二次電池用正極活物質とその製造方法並びに非水系リチウム二次電池 |
| EP2214232B1 (en) | 2007-10-23 | 2012-02-08 | Mitsui Mining & Smelting Co., Ltd | Spinel type lithium-transition metal oxide |
| JP2010073370A (ja) | 2008-09-16 | 2010-04-02 | Mitsui Mining & Smelting Co Ltd | リチウム電池用正極活物質材料 |
-
2012
- 2012-02-29 WO PCT/JP2012/055069 patent/WO2012118117A1/ja not_active Ceased
- 2012-02-29 JP JP2012554124A patent/JP5308581B2/ja active Active
- 2012-02-29 KR KR1020137017517A patent/KR101463880B1/ko active Active
- 2012-02-29 GB GB1315431.5A patent/GB2503138B/en active Active
- 2012-02-29 US US14/002,524 patent/US9437873B2/en active Active
- 2012-02-29 CN CN201280007149.1A patent/CN103339062B/zh active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0722020A (ja) * | 1993-06-29 | 1995-01-24 | Tosoh Corp | リチウムマンガン複合酸化物の製造方法及びその用途 |
| JP2010033786A (ja) * | 2008-07-25 | 2010-02-12 | Mitsui Mining & Smelting Co Ltd | リチウム二次電池用正極活物質の評価方法及び製造方法 |
| WO2011002074A1 (ja) * | 2009-07-03 | 2011-01-06 | 三井金属鉱業株式会社 | リチウム遷移金属酸化物の製造方法 |
| JP2010219065A (ja) * | 2010-06-21 | 2010-09-30 | Ngk Insulators Ltd | 正極活物質及びリチウム二次電池 |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2522134B (en) * | 2012-09-25 | 2015-12-30 | Mitsui Mining & Smelting Co | Spinel-type lithium-manganese composite oxide |
| KR101529951B1 (ko) * | 2012-09-25 | 2015-06-18 | 미쓰이금속광업주식회사 | 스피넬형 리튬망간 함유 복합 산화물 |
| GB2522134A (en) * | 2012-09-25 | 2015-07-15 | Mitsui Mining & Smelting Co | Spinel-type lithium-manganese composite oxide |
| JPWO2014050812A1 (ja) * | 2012-09-25 | 2016-08-22 | 三井金属鉱業株式会社 | スピネル型リチウムマンガン含有複合酸化物 |
| WO2014050812A1 (ja) * | 2012-09-25 | 2014-04-03 | 三井金属鉱業株式会社 | スピネル型リチウムマンガン含有複合酸化物 |
| US9337486B2 (en) | 2012-09-25 | 2016-05-10 | Mitsui Mining & Smelting Co., Ltd. | Spinel-type lithium-manganese composite oxide |
| GB2549666A (en) * | 2013-12-04 | 2017-10-25 | Mitsui Mining & Smelting Co | Spinel-type lithium cobalt manganese-containing complex oxide |
| KR101613861B1 (ko) | 2013-12-04 | 2016-04-20 | 미쓰이금속광업주식회사 | 스피넬형 리튬코발트망간 함유 복합 산화물 |
| JP5813277B1 (ja) * | 2013-12-04 | 2015-11-17 | 三井金属鉱業株式会社 | スピネル型リチウムコバルトマンガン含有複合酸化物 |
| WO2015083788A1 (ja) * | 2013-12-04 | 2015-06-11 | 三井金属鉱業株式会社 | スピネル型リチウムコバルトマンガン含有複合酸化物 |
| GB2536166B (en) * | 2013-12-04 | 2018-03-07 | Mitsui Mining & Smelting Co | Spinel-type lithium cobalt manganese-containing complex oxide |
| GB2536166A (en) * | 2013-12-04 | 2016-09-07 | Mitsui Mining & Smelting Co | Spinel-type lithium cobalt manganese-containing complex oxide |
| US9786914B2 (en) | 2013-12-04 | 2017-10-10 | Mitsui Mining & Smelting Co., Ltd. | Spinel-type lithium cobalt manganese-containing complex oxide |
| JP2015140292A (ja) * | 2014-01-29 | 2015-08-03 | 住友金属鉱山株式会社 | 非水系電解質二次電池用正極活物質、および、非水系電解質二次電池 |
| JP2016017017A (ja) * | 2014-07-09 | 2016-02-01 | 旭硝子株式会社 | リチウム含有複合酸化物の製造方法、リチウムイオン二次電池用正極およびリチウムイオン二次電池 |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20130091357A (ko) | 2013-08-16 |
| GB201315431D0 (en) | 2013-10-16 |
| US20130337330A1 (en) | 2013-12-19 |
| GB2503138A (en) | 2013-12-18 |
| JP5308581B2 (ja) | 2013-10-09 |
| CN103339062A (zh) | 2013-10-02 |
| JPWO2012118117A1 (ja) | 2014-07-07 |
| CN103339062B (zh) | 2015-07-08 |
| US9437873B2 (en) | 2016-09-06 |
| KR101463880B1 (ko) | 2014-11-20 |
| GB2503138B (en) | 2019-05-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5308581B2 (ja) | スピネル型リチウムマンガン系複合酸化物 | |
| JP5756625B2 (ja) | リチウム電池用正極活物質材料の製造方法 | |
| JP4987063B2 (ja) | スピネル型リチウム遷移金属酸化物 | |
| JP5523637B2 (ja) | マンガン系スピネル型リチウム遷移金属酸化物 | |
| JP5813277B1 (ja) | スピネル型リチウムコバルトマンガン含有複合酸化物 | |
| JP4939670B2 (ja) | スピネル型リチウム遷移金属酸化物及びリチウム電池用正極活物質材料 | |
| JP5828989B2 (ja) | リチウム二次電池用正極活物質 | |
| JP2016188168A (ja) | スピネル型リチウム金属複合酸化物 | |
| WO2012090749A1 (ja) | リチウム二次電池用正極活物質の製造方法 | |
| JP5898373B2 (ja) | リチウム二次電池用正極活物質 | |
| JP4673451B2 (ja) | リチウム遷移金属酸化物の製造方法 | |
| JP6649369B2 (ja) | 5v級スピネル型リチウムマンガン含有複合酸化物の製造方法 | |
| JP2010073370A (ja) | リチウム電池用正極活物質材料 | |
| JP6120493B2 (ja) | リチウム・マンガン複合酸化物の製造方法、その製造方法によって得られるリチウム・マンガン複合酸化物を含む二次電池用正極の製造方法、およびそれを正極として用いるリチウムイオン二次電池の製造方法 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12752155 Country of ref document: EP Kind code of ref document: A1 |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 2012554124 Country of ref document: JP |
|
| ENP | Entry into the national phase |
Ref document number: 20137017517 Country of ref document: KR Kind code of ref document: A |
|
| ENP | Entry into the national phase |
Ref document number: 1315431 Country of ref document: GB Kind code of ref document: A Free format text: PCT FILING DATE = 20120229 |
|
| WWE | Wipo information: entry into national phase |
Ref document number: 14002524 Country of ref document: US Ref document number: 1315431.5 Country of ref document: GB |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 12752155 Country of ref document: EP Kind code of ref document: A1 |
