JP2002326818A - Production method of slurry and production method of lithium transition metal compound oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a slurry excellent in stability suitable for manufacturing a lithium transition metal compound oxide without producing the problem of thickening and to provide a production method of the lithium transition metal compound oxide. SOLUTION: In the production of a lithium compound, a transition metal compound and an aluminum compound, the production method of the slurry is composed of producing the slurry containing the transition metal compound and either compound of the lithium compound or the aluminum compound, and adding the other lithium compound or aluminum. The production method of the lithium transition metal complex compound is composed of spray drying the slurry obtained by the production method and providing this to the baking process. The production method of the lithium transition metal complex compound is composed of being dried and baked after preparing the slurry, the production method of the lithium transition metal complex compound is that the time until starting the dryness from containing the lithium compound and the aluminum compound is within 500 hrs, when preparing the slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for preparing a slurry containing a lithium element, a transition metal element and an aluminum element. More specifically, the present invention relates to a method for producing a lithium transition metal composite oxide suitably used as a positive electrode active material of a lithium secondary battery, and a method for producing a slurry used therefor.

[0002]

2. Description of the Related Art As a positive electrode active material capable of providing a practically usable lithium secondary battery, a lithium transition metal composite oxide is expected to be promising. Among these lithium transition metal composite oxides, cobalt, nickel, and manganese are used as transition metals. When lithium cobalt composite oxide, lithium nickel composite oxide, and lithium manganese composite oxide are used as a positive electrode active material, a high-performance battery It is also known that properties can be obtained. Furthermore, in order to stabilize and increase the capacity of lithium transition metal composite oxides, improve safety, and improve battery characteristics at high temperatures, the lithium transition metal in which part of the transition metal site is replaced with another element such as aluminum element It is also known to use composite oxides. For example, as a lithium transition metal composite oxide, spinel type lithium manganese oxide L
In the case of iMn ₂ O ₄ , the Mn valence is 3.5 in form, and trivalent and tetravalent are mixed in a half-and-half manner.
By substituting a part of the Mn site with another transition metal having a valence less than this Mn valence, Mn trivalent with Jahn-Teller distortion is reduced to stabilize the crystal structure, and finally a battery having cycle characteristics and the like. The characteristics can be improved. The “lithium transition metal composite oxide” in the present invention represents a concept that also includes “lithium transition metal composite oxide in which a part of the transition metal site is substituted with another element such as aluminum element”.

[0003] As a method for producing a lithium transition metal composite oxide in which a part of the transition metal site is substituted by another element, for example, an aluminum element, a solid lithium compound, a transition metal compound, and an aluminum element which are raw materials are contained. A dry method of mixing and firing aluminum compounds, etc.,
Various methods can be used, such as a method in which a slurry in which the lithium compound, transition metal compound, aluminum compound, or the like is dispersed in a dispersion medium such as water is spray-dried and then subjected to a baking treatment. In these production methods, a method of performing a baking treatment after spray-drying a slurry containing the above-mentioned elemental component can granulate the lithium-transition metal composite oxide into a spherical form and increase the packing density (energy density per unit volume is increased). ) Can have the advantage. In other words, when the lithium transition metal composite oxide manufactured by the above method is used, when a battery of the same size is manufactured as compared with the case where the lithium transition metal composite oxide manufactured by the dry method is used, a high level is obtained. A battery having a capacity is obtained, and a battery having the same energy capacity has advantages such as downsizing.

[0004]

However, in the case of using a method of spray-drying the above slurry and then performing a baking treatment for the production of the lithium transition metal composite oxide, lithium compounds, transition metal compounds, aluminum compounds and the like are used. A slurry dispersed in a dispersion medium such as water is prepared, and the present inventors have found that the storage stability of the slurry may be deteriorated. That is, if the slurry is left to stand after the production, the particles in the slurry aggregate, and the viscosity of the slurry increases. Due to this increase in viscosity, the particle size after spray drying becomes unstable,
Ultimately, the slurry cannot be easily handled, for example, spray drying cannot be performed, and this hinders industrial operation. Further, in the industrial operation for carrying out the method for producing a lithium transition metal composite oxide as described above, the time and labor for preparing the slurry can be saved, and the required amount can be produced each time it is required according to the demand of the user. For this purpose, it is common practice to prepare a slurry in advance and store it for a long period of time, and to spray or dry a part or all of the slurry as necessary, and to perform a baking treatment. In this case, the storage stability of the slurry is required.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for producing a stable slurry without causing the problem of thickening, and as a result, have found that thickening is caused by the coexistence of a lithium compound and an aluminum compound. I got it. Then, to minimize the time during which the lithium compound and the aluminum compound coexist as much as possible, specifically, (1) After preparing a slurry of the lithium compound and the transition metal compound, add the aluminum compound thereto Alternatively, the above problem is solved by adding a lithium compound to a slurry of an aluminum compound and a transition metal compound, and (2) minimizing the time from the coexistence of the lithium compound and the aluminum compound to the next step such as drying. The inventors have found that the present invention can be solved and completed the present invention.

An object of the present invention is to provide a method for producing a slurry suitable for producing a lithium transition metal composite oxide. A first gist of the present invention is to provide a slurry containing a lithium compound, a transition metal compound and an aluminum compound. In the production, a slurry comprising a slurry containing either a lithium compound or an aluminum compound and a transition metal compound, and then adding the other lithium compound or aluminum compound is provided. Another aspect resides in a method for producing a lithium transition metal composite oxide, which comprises spray-drying a slurry obtained by the production method and subjecting the slurry to a baking treatment. After preparing a slurry containing a compound, a transition metal compound, and an aluminum compound, the slurry is dried and A method of manufacturing a lithium transition metal composite oxide consists in forming, from the contain a and the lithium compound and the aluminum compound in the preparation of the slurry, the time until the start of the drying 5
A method for producing a lithium transition metal composite oxide, wherein the time is within 00 hours.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The slurry produced by the method of the present invention contains a lithium compound, a transition metal compound and an aluminum compound. As the lithium compound used as a slurry preparation raw material, for example, lithium oxide, hydroxide,
In addition to oxyhydroxides, there may be mentioned inorganic acid salts such as carbonates, nitrates and sulfates, organic acid salts such as acetates, and halides such as chlorides. Among them, preferred are lithium hydroxide, lithium carbonate, lithium nitrate, lithium organic acid salts and lithium oxide, and more preferred are lithium hydroxide, lithium carbonate, lithium nitrate and lithium oxide. These hydrates can also be used. Most preferred are lithium hydroxide and lithium carbonate. A plurality of lithium compounds can be used in combination.

The transition metal compound used as a slurry preparation raw material includes various transition metal oxides, hydroxides, oxyhydroxides, inorganic salts such as carbonates, nitrates and sulfates, and organic salts such as acetates. And halides such as acid salts and chlorides. Examples of the transition metal species include manganese, nickel, cobalt, iron, chromium, vanadium, titanium, and copper. Among them, preferably,
Manganese, nickel and cobalt, more preferably manganese and nickel, most preferably manganese. A plurality of these transition metal elements or transition metal compounds can be used in combination. When a manganese compound is used as a raw material, specific manganese compounds include, for example, manganese oxides such as MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , MnO, manganese hydroxide, manganese carbonate, and manganese nitrate And manganese inorganic acid salts such as manganese sulfate, manganese oxyhydroxides such as MnOOH, and manganese organic acid salts such as manganese acetate. Preferably, manganese oxide, manganese hydroxide,
Organic acid salts of manganese oxyhydroxide, manganese nitrate, manganese sulfate and manganese, more preferably MnO
₂ , Mn ₂ O ₃ and Mn ₃ O ₄ . A plurality of these manganese compounds can be used in combination.

Examples of the aluminum compound include aluminum oxides, hydroxides, oxyhydroxides, inorganic acid salts such as organic acid salts, chlorides, nitrates and sulfates, and hydrates thereof. Specifically, Al ₂ O ₃ , AlO
OH, Al (OH) ₃ , Al (CH ₃ COO) ₃ , AlCl ₃ ,
Al (NO ₃ ) .9H ₂ O, Al ₂ (SO ₄ ) ₃ , etc. are preferable, and Al ₂ O ₃ , AlOOH and Al (OH) ₃ are preferable.

In the method of the present invention, when preparing a slurry,
It is necessary to avoid strong stirring in the coexistence of the lithium compound and the aluminum compound in the above-mentioned raw materials. For this purpose, first, a slurry containing the lithium compound and the transition metal compound is prepared, and the aluminum compound is added to the slurry ( Less than,
This may be referred to as a first embodiment) or by adding a lithium compound to a slurry containing an aluminum compound and a transition metal compound (hereinafter, also referred to as a second embodiment). In the method of the first embodiment, first, the lithium compound and the transition metal compound are mixed to form a slurry. The mixing ratio of the lithium compound and the transition metal compound may be appropriately selected according to the desired composition ratio of the lithium transition metal composite oxide. For example, when synthesizing a lithium manganese composite oxide having a layered structure, the molar ratio of Li / Mn is preferably 0.8 to 1.2, and more preferably 0.9 to 1.2. When synthesizing a lithium manganese composite oxide having a spinel structure, L
The i / Mn molar ratio is preferably from 0.4 to 0.6, and more preferably from 0.45 to 0.55.

The method for preparing the slurry containing the lithium compound and the transition metal compound is as follows. 1) A component of the lithium compound or the transition metal compound which is soluble in the dispersion medium is charged into a stirring dispersion medium (eg, water). And dissolve.
Next, a method of preparing a slurry by charging and dispersing a component of the lithium compound or the transition metal compound which is dispersed in the dispersion medium, 2) mixing the lithium compound and the transition metal compound in a powder state, adding the dispersion medium, and slurrying. Preparation method is mentioned. An aqueous medium such as water is usually used as the dispersion medium, but other organic solvents and the like can also be used. Further, the lithium compound and the transition metal compound may or may not be dissolved in this medium.

In preparing the slurry, improve the uniformity,
In addition, it is preferable that the slurry is sufficiently mixed and stirred in order to maintain the stability of the slurry in the next step after the addition of the aluminum compound. In that case, as long as the mixing and stirring are sufficiently performed, the stirring means is not particularly limited. For example, as a type of the stirrer, for example, a simple motor stirring may be used, for example, a planetary mixer, a three-axis planetary mixer, a two-axis butterfly mixer, Use of a concentric twin-screw mixer, dissolver, homomixer, kneader, or the like can be considered. In preparing the slurry, it is more preferable to pulverize the solid content in the slurry at the same time as stirring, that is, to carry out strong stirring. As a stirrer for this purpose, it is preferable to use a stirrer capable of strong stirring accompanied by pulverization of solids in the slurry, for example, a medium stirring type wet pulverizer. The medium stirring type wet pulverizer is generally called a bead mill, and is a wet pulverizer using beads such as glass, ceramics, and steel as a pulverizing medium. 70-90 as grinding media in vessel
% Of beads, the agitator disk and pins are rotated at a peripheral speed of 5 to 15 m / sec to give motion to the beads, and the slurry (object to be crushed) is pumped into the beads, and the slurry is finely moved by shearing force between the beads. It is a device that crushes and disperses. Therefore, the characteristics required for beads include high breaking strength, abrasion resistance, component content, stability, etc.In addition, when selecting beads, materials should be considered in consideration of contamination with slurry, corrosiveness, etc. You need to choose The pulverization conditions vary depending on the kind of the intended lithium-transition metal composite oxide and the like. However, in order for the oxide to have a desired secondary particle size, the average particle size of the solid particles in the slurry after strong stirring is required. The diameter is preferably as small as possible, usually 2 μm or less, preferably 1 μm or less, more preferably 0.5 μm
The following is assumed. However, since it is difficult to obtain a particle having an extremely small particle size, it is usually 0.01 μm or more, preferably 0.05 μm
m or more, more preferably 0.1 μm or more.

The solid content of the slurry obtained by the above method may be a lithium compound, a transition metal compound, or both. In other words, (1) a state in which the lithium compound is dissolved and the transition metal compound is dispersed in the slurry, (2)
Any of a state in which the lithium compound is dispersed and the transition metal compound is dissolved, and a state (3) in which both the lithium compound and the transition metal compound are dispersed may be used. is there. The solid content concentration in the slurry varies depending on the type of the raw material compound, but is usually 0.1 to 60% by weight, preferably 0.1 to 50% by weight, and most preferably 5 to 40% by weight. If the slurry concentration is too low, the productivity tends to decrease, while if it is too high, it becomes difficult to ensure uniformity of the slurry composition.

Next, the aluminum compound is added to the slurry containing the lithium compound and the transition metal compound prepared as described above, and it is preferable that the slurry is sufficiently mixed and stirred in advance. When an aluminum compound is introduced, a state in which the lithium compound and the aluminum compound coexist in the slurry is obtained. Therefore, if excessive stirring is performed in this state, a problem of thickening may occur.
Therefore, it is preferable to add an aluminum compound which can be easily dissolved or dispersed in a slurry. Such an aluminum compound is obtained by dissolving or dispersing the above-mentioned aluminum compound raw material in a liquid medium. However, among these, alumina sol is most suitable, and the viscosity increase of the slurry prepared thereby can be more effectively suppressed.

The alumina sol is preferably a dispersion slurry in which alumina is dispersed in a dispersion medium such as water. Water is usually used as a dispersion medium for the sol. In the case of a basic sol,
Ammonia, KOH, NaOH, LiOH, diethanolamine,
An aqueous solution in which triethanolamine or the like is dissolved can be used as a dispersion medium. In the case of an acidic sol, an aqueous solution in which a monovalent acid such as nitric acid, hydrochloric acid, formic acid, or acetic acid is used is used. be able to. If necessary, dimethylformamide can be used as a non-aqueous system (organic solvent). In order to secure the stability of the sol, it is preferable to add a surfactant. The most preferred alumina sol is a basic sol obtained by dispersing alumina in an aqueous solution comprising water, ammonia and a surfactant.

The solid content of the alumina sol is usually 80% by weight or less, preferably 60% by weight or less, more preferably 30% by weight or less. If the solid content is too high, the dispersibility may deteriorate, and in some cases, the viscosity of the sol may increase, and the dispersibility at the time of being introduced into the slurry may decrease. On the other hand, an excessively low concentration is disadvantageous because productivity is reduced. The impurities contained in the dispersoid alumina are not problematic as long as the produced lithium transition metal composite oxide does not adversely affect the battery performance.

In a slurry containing a lithium compound and a transition metal compound to which an aluminum compound is added, when lithium hydroxide or a hydrate thereof is used as the lithium compound, the dispersibility in the slurry is improved. The dispersion of the aluminum compound to be added is preferably a basic one, and is more preferably one having a pH of about 7 to 14, preferably about 8 to 13, and particularly about 9 to 11.

The amount of the aluminum compound to be added is appropriately selected according to the composition ratio of the lithium transition metal composite oxide to be produced. The aluminum element usually replaces a part of the transition metal site of the composite oxide. , Which is used to improve battery characteristics such as cycle characteristics and rate characteristics, so that aluminum atoms are usually 0.1 to 30 atomic%, preferably 1 to 25 atomic%, as a percentage of the total of aluminum atoms and transition metal atoms. Atomic%, more preferably 4
-20 atomic%, most preferably about 4-15 atomic%. If the amount of the aluminum compound is too small, the effect of containing the aluminum element such as cycle characteristics may not be sufficiently exhibited. Also, if too much,
A large effect of improving characteristics cannot be seen, and the capacity tends to decrease.

The addition of the aluminum compound to the slurry is performed, for example, by weighing the slurry in a container with a lid,
After weighing a predetermined amount of aluminum compound in sol form,
It is also possible to put the mixture in the container and shake the container vigorously to mix uniformly, but usually, while stirring the slurry,
A method of gradually adding an aluminum compound is preferred because it is simple. After the aluminum compound is charged into the slurry, it is preferable to perform stirring with relatively weak stirring intensity (weak stirring) in order to further effectively suppress the viscosity increase of the slurry. The term "weak stirring" as used herein refers to stirring in which solid components in the slurry do not settle and uniform dispersion is maintained, and as a stirrer for performing such stirring, stirring such that the slurry does not settle. Any type is possible as long as it can be dispersed, and in general, a type in which a turbine type impeller is rotated at a high speed is preferable.

The viscosity of the slurry after the addition of the aluminum compound in the present invention is usually from 1 to 10,000 mPa · s.
If the viscosity of the slurry is too low, the storage stability of the slurry is poor, and in the spray drying step in the production of lithium transition metal composite oxide, if the viscosity is too low, it is difficult to obtain clean granulated particles. May occur. On the other hand, if the viscosity of the slurry is too high, smooth transfer does not proceed, causing problems in handling, and problems such as difficulty in obtaining fine particles in spray drying may occur.
The viscosity of the slurry is preferably from 1 to 5000 mPa · s, more preferably from 1 to 1800 mPa · s, and particularly preferably from 100 to 1000 mPa · s. The viscosity of the slurry in the present invention can be measured using a known BM type viscometer. The BM type viscometer is a measurement method that employs a method of rotating a predetermined metal rotor in the air at room temperature.
The viscosity of the slurry is calculated from the resistance (twisting force) applied to the rotation axis by rotating the rotor with the rotor immersed in the slurry. However, the room temperature is 1 in the atmosphere
It means an environment of 0 ° C. to 35 ° C. and a relative humidity of 20% RH to 80% RH.

Next, a second embodiment in which a lithium compound is added to a slurry in which an aluminum compound and a transition metal compound coexist will be described, except that the order of addition of the aluminum compound and the lithium compound is different.
Operations such as stirring are basically the same as in the first embodiment. Second
In the method according to the embodiment, first, a mixed slurry is formed from the aluminum compound and the transition metal compound. The mixing ratio of the aluminum compound and the transition metal compound is appropriately selected according to the desired composition ratio of the lithium transition metal composite oxide. As described above, since the addition of the aluminum compound is for replacing a part of the transition metal site of the lithium transition metal composite oxide to improve the battery characteristics, the addition ratio of the aluminum compound and the transition metal atom is The ratio to the total is selected in the same range as described above.
The aluminum compound raw material is not particularly limited as long as it can be dissolved or dispersed in a medium. Inorganic acid salts such as aluminum oxides, hydroxides, oxyhydroxides, organic acid salts, chlorides, nitrates, and sulfates Alternatively, the compound can be appropriately selected from the above exemplified compounds such as hydrates thereof and used. Water is usually used as a dispersion medium of the slurry, but an organic solvent can be used in some cases.

Next, a lithium compound is added to the slurry containing the aluminum compound and the transition metal compound which is prepared as described above, mixed and stirred sufficiently. When the lithium compound is introduced, the slurry is in a state in which the lithium compound and the aluminum compound coexist. Therefore, if the stirring is performed too strongly in this state, the viscosity is easily increased, and the stirring is preferably performed weakly. Therefore, it is preferable to add a lithium compound that can be easily dissolved or dispersed in the slurry. As such a lithium compound, a lithium salt, particularly lithium hydroxide, or a hydrate thereof is preferable. The amount of the lithium compound to be added is appropriately determined according to the composition ratio of the target lithium transition metal composite oxide in the same manner as described above.

When producing the lithium transition metal composite oxide of the present invention, the prepared slurry is subjected to spray drying. Spray drying can be appropriately carried out by a commonly used known technique of this type. In general, air (including CO ₂ -free air) is used as a drying gas used for spray drying, but an inert gas such as nitrogen can also be used. The drying temperature is usually about 50 to 300 ° C. The slurry prepared as described above by the method of the present invention comprises:
Viscosity rise is suppressed, and dispersion stability is maintained and stored for a long period of time. However, in order to more effectively prevent thickening of the slurry during spray drying, it is preferable to perform spray drying within as short a period as possible after preparing the slurry. Specifically, the time from mixing the lithium compound and the aluminum compound to spray drying is 5 minutes.
It is preferably within 00 hours, particularly within 350 hours, and more preferably within 200 hours. If the time until spray drying is kept within the above range, the slurry can be kept under a certain degree of vigorous stirring, and spray drying can be performed within a range that does not cause a problem in actual operation even if slight thickening occurs. It is possible to do. For example, in a state where a lithium compound, an aluminum compound, and a transition metal compound coexist, in some cases, the lithium compound, the aluminum compound, and the transition metal compound are simultaneously added to a vessel and mixed, and even if this is vigorously stirred, If spray drying is performed within the time, there is practically no problem. However, if the above time is too short, the preparation of the slurry and the spray drying must be carried out quickly in an extremely short time, which may make industrial implementation difficult. The spray drying process is performed by a known device such as a two-fluid spray type spray dryer, and is granulated into spherical dry particles of, for example, 1 to 100 μm.

The spray-dried dry particles are then subjected to a baking treatment. The firing temperature is usually 500 ° C. or higher, preferably 550 ° C. or higher, and is generally 1000 ° C. or lower, preferably 950 ° C. or lower. If the firing temperature is too low, a long reaction time is required to obtain a lithium transition metal composite oxide having good crystallinity, and the effect of improving the packing density may be reduced. If the firing temperature is too high, a phase other than the intended lithium transition metal composite oxide is generated,
Alternatively, a lithium transition metal composite oxide having many defects may be generated. When the temperature is raised from room temperature to the above reaction temperature, the temperature is gradually raised at a temperature of, for example, 5 ° C. or less per minute in order to perform the reaction more uniformly, or the temperature is temporarily stopped on the way, A holding time at a constant temperature may be added.

The firing time is from 1 hour to 100 hours, preferably from 2 hours to 50 hours. If the time is shorter than the above range, it is difficult to obtain a lithium transition metal composite oxide having good crystallinity, and a reaction time that is too long beyond this range is not practical. The calcination can be usually performed in an air atmosphere, but can be also optionally performed in an inert gas atmosphere selected from nitrogen, argon, helium, or the like, or in a mixed gas atmosphere of these gases and an oxygen-containing gas. .

In order to obtain a lithium-transition metal composite oxide having few crystal defects, it is preferable to cool slowly to a certain temperature after the above-mentioned calcination, and to cool at 800 ° C., preferably up to 600 ° C., at 5 ° C./min. It is preferable to gradually cool at the following cooling rate. The heating device used for firing is not particularly limited as long as the above-described temperature and atmosphere can be achieved, and for example, a box furnace, a tubular furnace, a tunnel furnace, a rotary kiln, and the like can be used.

The lithium transition metal composite oxide produced in this manner is formed from secondary particles in which fine primary particles are aggregated. The size of the primary particles can be controlled by the degree of pulverization of the raw material, the sintering temperature, the sintering time, and the like.
It can be controlled by spray drying conditions, furthermore, pulverization and classification conditions after firing. In order to use the lithium transition metal composite oxide as a positive electrode active material of a lithium secondary battery, it is necessary to form secondary particles having a particle diameter of 1 to 100 μm in which primary particles having a particle diameter of 0.1 to 10 μm are aggregated, and Those having a specific surface area of 0.1 to ⁵ m ² / g by adsorption are preferred.

A lithium secondary battery can be manufactured using the lithium transition metal composite oxide produced by the above method of the present invention as a positive electrode active material. Examples of the lithium transition metal composite oxide include lithium manganese composite oxides such as LiMn ₂ O ₄ and LiMnO ₂ , lithium nickel composite oxides such as LiNiO ₂ , lithium cobalt composite oxides such as LiCoO ₂ , and lithium iron composite oxides such as LiFeO ₂ Oxides,
Lichromium composite oxide such as LiCrO ₂ , Li _{1 + x} V
Lithium vanadium composite oxides such as ₃ O ₈ and LiV ₂ O ₄ ,
Lithium titanium composite oxide such as LiTi ₂ O ₄ , Li ₂ C
Examples thereof include lithium copper composite oxides such as uO ₂ and LiCuO ₂ . As described above, some of the transition metal sites of these lithium transition metal composite oxides may be replaced by other metals in addition to aluminum. In addition, oxygen may have a small amount of oxygen deficiency or non-stoichiometry. From the point that the effect of improving the packing density is large, the general formula LiMn ₂ O ₄ ,
Is preferred.

A lithium secondary battery usually has a positive electrode, a negative electrode and an electrolyte layer. As an example of a lithium secondary battery,
A secondary battery including a positive electrode, a negative electrode, an electrolytic solution, and a separator is exemplified. In this case, an electrolyte exists between the positive electrode and the negative electrode, and the separator is disposed between the positive electrode and the negative electrode so that the negative electrode does not contact with the electrolyte. The positive electrode contains the lithium transition metal composite oxide and a binder. Also, usually
The positive electrode is obtained by forming a positive electrode layer containing the positive electrode material and a binder on a current collector. Such a positive electrode layer can be manufactured by applying a slurry of a lithium transition metal composite oxide, a binder, and, if necessary, a conductive agent or the like with a solvent to a positive electrode current collector and drying the slurry.

The positive electrode layer may further contain an active material capable of inserting and extracting lithium ions other than the lithium transition metal composite oxide, such as LiFePO ₄ . The ratio of the active material in the positive electrode layer is usually 10% by weight or more,
It is preferably at least 30% by weight, more preferably at least 50% by weight, usually at most 99.9% by weight, preferably at most 9% by weight.
9% by weight or less. If the amount is too large, the mechanical strength of the electrode tends to be inferior. If the amount is too small, the battery performance such as capacity tends to be inferior.

As the binder used for the positive electrode, for example, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, EPDM
(Ethylene-propylene-diene terpolymer), SBR
(Styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), fluorine rubber, polyvinyl acetate,
Examples include polymethyl methacrylate, polyethylene, nitrocellulose, and the like. The proportion of the binder in the positive electrode layer is usually 0.1% by weight or more, preferably 1% by weight or more,
More preferably, it is 5% by weight or more, and usually 80% by weight.
Or less, preferably 60% by weight or less, more preferably 4% by weight or less.
It is at most 0% by weight, most preferably at most 10% by weight.
If the ratio of the binder is too low, the active material cannot be sufficiently retained, and the mechanical strength of the positive electrode becomes insufficient, which may deteriorate battery performance such as cycle characteristics. May be lowered.

The positive electrode layer usually contains a conductive agent to increase conductivity. Examples of the conductive agent include carbon materials such as graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, and amorphous carbon such as needle coke. The proportion of the conductive agent in the positive electrode is usually 0.01% by weight or more, preferably 0.1% by weight or more, more preferably 1% by weight or more, and usually 50% by weight or less, preferably 30% by weight or less. It is preferably at most 15% by weight. If the proportion of the conductive agent is too low, the conductivity may be insufficient, while if it is too high, the battery capacity may be reduced.

The slurry solvent is not particularly limited as long as it dissolves or disperses the binder, but usually an organic solvent is used. For example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N, N
-Dimethylaminopropylamine, ethylene oxide,
Tetrahydrofuran and the like can be mentioned. In addition, the active material can be slurried with a latex such as SBR by adding a dispersant, a thickener and the like to water.

The thickness of the positive electrode layer is usually 1 to 1000 μm,
Preferably it is about 10 to 200 μm. If it is too thick, the conductivity tends to decrease, and if it is too thin, the capacity tends to decrease. As a material of the current collector used for the positive electrode, aluminum, stainless steel, nickel-plated steel, or the like is used, and aluminum is preferable. The thickness of the current collector is usually 1 to 1000 μm, preferably 5 to 500 μm
It is about. If the thickness is too large, the capacity of the lithium secondary battery as a whole decreases, and if it is too small, the mechanical strength may be insufficient. The positive electrode layer obtained by coating and drying is preferably compacted by a roller press or the like in order to increase the packing density of the active material.

Active material of negative electrode used for negative electrode of secondary battery
As lithium or lithium aluminum alloy
Although it may be a titanium alloy, it is more secure and
Carbon materials capable of occluding and releasing chromium are preferable. Carbon material
Although not particularly limited, graphite and coal-based coke, stone
Oil-based coke, coal-based pitch carbide, petroleum-based pitch
Charcoal or charcoal obtained by oxidizing these pitches
Compound, needle coke, pitch coke, phenol
Resin, carbides such as crystalline cellulose, etc.
Leaded carbon material, furnace black, acetylene bra
And pitch-based carbon fibers. In addition, the negative electrode
The substance is SnO, SnO_Two, Sn_1-xM_xO (M = H
g, P, B, Si, Ge or Sb, provided that 0 ≦ x <
1), Sn_ThreeO_Two(OH)_Two, Sn_3-xM _xO_Two(M = Mg,
P, B, Si, Ge, Sb or Mn, provided that 0 ≦ x <
3), LiSiO_Two, SiO_TwoOr LiSnO_TwoEtc.
Can be In addition, two or more selected from these
May be used as the negative electrode active material. The negative electrode is
As in the case of the normal positive electrode, the negative electrode layer must not be formed on the current collector.
You. The binder used at this time, and if necessary,
Used as a conductive agent and slurry solvent for the positive electrode
Similar ones can be used. Also, the negative electrode
Current collectors include copper, nickel, stainless steel, nickel
Kel-plated steel is used, and preferably copper is used.
You.

When a separator is used between the positive electrode and the negative electrode, a microporous polymer film is usually used, and polytetrafluoroethylene, polyester, nylon,
Those composed of polyolefin polymers such as cellulose acetate, nitrocellulose, polysulfone, polyacrylonitrile, polyvinylidene fluoride, polypropylene, polyethylene, and polybutene are used. Further, a nonwoven fabric filter such as a glass fiber or a nonwoven fabric filter of a glass fiber and a polymer fiber can also be used. The chemical and electrochemical stability of the separator is an important factor.
In this respect, a polyolefin-based polymer is preferable, and it is preferable that the battery is made of polyethylene from the viewpoint of the self-closing temperature, which is one of the purposes of the battery separator. In the case of a polyethylene separator, it is preferable to use ultra-high molecular weight polyethylene from the viewpoint of high-temperature shape retention, and the lower limit of the molecular weight is
Preferably it is 500,000, more preferably 1,000,000, and most preferably 1.5 million. On the other hand, the upper limit of the molecular weight is preferably 5,000,000, more preferably 4,000,000, and most preferably 3,000,000. If the molecular weight is too small, the blocking property becomes too high and there is a problem in use at a high temperature. If the molecular weight is too large, the fluidity is too low and the pores of the separator may not be blocked when heated.

As the electrolyte forming the electrolyte layer in the lithium secondary battery, for example, known organic electrolytes, solid polymer electrolytes, gel electrolytes, inorganic solid electrolytes and the like can be used. Is preferred. The organic electrolyte is composed of an organic solvent and a solute. The organic solvent is not particularly limited, for example, carbonates, ethers, ketones, sulfolane compounds,
Lactones, nitriles, chlorinated hydrocarbons, ethers, amines, esters, amides, phosphate compounds and the like can be used. Specific examples of these representatives include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, Methyl-2-pentanone, 1,2-dimethoxyethane, 1,2-diethoxyethane, γ-butyrolactone, 1,3-dioxolan, 4-methyl-1,3-dioxolan, diethyl ether, sulfolane, methylsulfolane, acetonitrile , Propionitrile, benzonitrile, butyronitrile, valeronitrile, 1,2-dichloroethane, dimethylformamide, dimethylsulfoxide, trimethyl phosphate, triethyl phosphate and the like. Rukoto is possible, these alone or two or more kinds of mixed solvents can be used.

The above organic solvent preferably contains a high dielectric constant solvent for dissociating the electrolyte. Here, the solvent having a high dielectric constant has a relative dielectric constant of 20 at 25 ° C.
The above compounds are meant. It is preferable that ethylene carbonate, propylene carbonate, and a compound in which a hydrogen atom thereof is replaced with another element such as halogen, an alkyl group, or the like in the high dielectric constant solvent be contained in the electrolytic solution. The proportion of the high dielectric constant compound in the electrolyte is preferably 20
% By weight, more preferably 30% by weight or more, most preferably 40% by weight or more. If the content of the compound is small, desired battery characteristics may not be obtained in some cases.

The solute to be dissolved in this solvent is not particularly limited, but any of the conventionally known ones can be used, and LiClO ₄ , LiAsF ₆ , LiPF ₆ , LiPF
BF ₄ , LiB (C ₆ H ₅ ) ₄ , LiCl, LiBr, CH
₃ SO ₃ Li, CF ₃ SO ₃ Li, LiN (SO ₂ CF ₃ ) ₂ ,
LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) _{3 and the} like can be mentioned, and at least one of them can be used. Further, an additive such as CO ₂ , N ₂ O, CO, SO ₂ or an additive such as polysulfide S _x ²⁻ which can form a good film capable of efficiently charging and discharging lithium ions on the surface of the negative electrode is added at an arbitrary ratio. You may add to the said single or mixed solvent. Even when a polymer solid electrolyte is used, a known polymer can be used as the polymer. In particular, it is preferable to use a polymer having high ion conductivity with respect to lithium ions. For example, polyethylene oxide, polypropylene oxide, polyethylene imine, and the like are preferably used. It is also possible to add the above-mentioned solvent to the polymer together with the above-mentioned solute and use it as a gel electrolyte.

When an inorganic solid electrolyte is used,
Use of known crystalline and amorphous solid electrolytes for inorganic substances
Can be. Examples of the crystalline solid electrolyte include Li
I, Li_ThreeN, Li_{1 + x}M_xTi_2-x(PO_Four)_Three(However, M
= A small number selected from the group consisting of Al, Sc, Y and La
At least), Li_0.5-3xRE_{0.5 + x}TiO_Three(However, R
E = selected from the group consisting of La, Pr, Nd and Sm
At least one) and the like, and an amorphous solid electrolyte and
For example, 4.9LiI-34.1Li_TwoO-61B _TwoO_Five,
33.3Li_TwoO-66.7SiO_TwoOxide glass such as 0.45Li
I-0.37Li_TwoS-0.26B_TwoS_Three, 0.30LiI-0.42Li_Two
S-0.28SiS_TwoAnd the like. This
It is possible to use at least one of them.
Wear.

[0041]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In addition, the viscosity of the slurry in the examples was measured with a BM type viscometer (manufactured by Tokimec). The measurement is performed in the air at room temperature, a specific metal rotor is fixed to the rotating shaft of the apparatus main body, the rotor is immersed in a slurry liquid, the rotor is rotated, and the scale after 3 minutes is read, using a conversion table, The slurry viscosity was calculated from the rotor and the number of rotations.

Example 1 LiOH.H ₂ O and Mn ₂
O ₃ is the composition in the final spinel-type lithium manganese composite oxide, and Li: Mn: Al = 1.04:
1.88: 0.12 (molar ratio) was weighed, and pure water was added thereto to prepare a slurry having a solid concentration of 30% by weight. While stirring this slurry, pulverize it using a circulating medium stirring type wet pulverizer (Shinmaru Enterprises Co., Ltd .: Dynomill KDL-A type) until the average particle diameter of the solid content in the slurry becomes 0.29 μm. did.

Using a 300 ml pot, the mixture was ground for 6 hours. The viscosity of the obtained slurry was measured with a BM type viscometer (manufactured by Tokimec). As a result, the slurry viscosity was 7
It was 40 mPa · s. The viscosity of this slurry after storage for 27 days (room temperature, under air) was 880 mPa · s, and the rate of increase in viscosity was 19%. Thereby, it was confirmed that the slurry viscosity can be sufficiently stably stored for about 4 weeks. Next, a predetermined amount of alumina sol based on the composition ratio of the lithium-manganese composite oxide was added to the slurry, and the slurry was uniformly stirred and dispersed uniformly in the slurry. When the viscosity of the slurry thus prepared was measured,
The viscosity was 40 mPa · s, which was not different from the viscosity of the slurry before the addition of the alumina sol. The slurry was stored at room temperature for 4 weeks, and the viscosity of the slurry was measured.
-It was s. The viscosity increase rate of the slurry was 6.8%, indicating that the slurry could be stored very stably.

Next, the slurry was spray-dried using a two-fluid nozzle type spray dryer (LT-8 type spray dryer manufactured by Okawara Kakoki Co., Ltd.). At this time, air was used as the drying gas, and the dry gas introduction amount was 50 L / min.
The dry gas inlet temperature was 90 ° C. Then, the granulated particles obtained by spray drying were calcined at 900 ° C. for 5 hours to obtain an aluminum-substituted lithium manganese composite oxide having a molar ratio composition almost as charged.

The particle diameter of the obtained lithium manganese composite oxide was measured using a laser diffraction / scattering type particle size distribution analyzer (LA-910 type particle size distribution analyzer manufactured by Horiba, Ltd.). The particles had a substantially spherical shape with a diameter of 10.7 μm and a maximum particle size of 26 μm. or,
The crystallinity of the obtained lithium manganese composite oxide was changed to powder X
X-ray diffractometer (Philips X-ray diffractometer PW371)
As a result of measurement using a 0-type tube (Cu tube, 40 kV, 30 mA), it was confirmed that it had a cubic spinel-type lithium manganese composite oxide structure. 10 g of this lithium manganese composite oxide powder was placed in a 25 ml glass measuring cylinder, and the powder packing density (tap density) after tapping 200 times was measured. As a result, 1.7 g / cc was obtained.
Met.

<Example 2> Mn ₂ O ₃ and AlOOH were each composed of the final spinel-type lithium manganese composite oxide, and Li: Mn: Al = 1.04: 1.88:
It was weighed so as to be 0.12 (molar ratio), and pure water was added thereto to prepare a slurry having a solid concentration of 40% by weight. While stirring this slurry, a circulating medium stirring type wet pulverizer (Shinmaru Enterprises: Dino Mill K)
(DL-A type), and pulverized until the average particle diameter of the solid content in the slurry became 0.3 μm. Grinding was performed for 6 hours using a 300 ml pot. The viscosity of this slurry is B
It was measured by an M-type viscometer (manufactured by Tokimec). As a result, the slurry viscosity was 1160 mPa · s.

Next, a predetermined amount of LiOH.H ₂ based on the composition ratio of the lithium manganese composite oxide is added to the slurry.
O was added in the form of an aqueous solution, and the mixture was weakly stirred to be uniformly dispersed in the slurry. The solid content concentration in the slurry thus prepared was 27% by weight. The viscosity of this slurry was measured with a BM type viscometer (manufactured by Tokimec Co.), and was 305 mPa · s. The reduction rate of the viscosity was 74% as compared with the viscosity of the slurry before adding the LiOH · H ₂₀ aqueous solution. And fell sharply. This is represented by L shown in Reference Example 1 below.
The viscosity is clearly lower than that of a slurry prepared by wet pulverizing the raw material components i, Mn and Al all at once (simultaneously). The reason for the high slurry viscosity in Reference Example 1 is presumed to be that when LiOH.H ₂ O and AlOOH are pulverized at the same time, lithium aluminate is formed, which increases the slurry viscosity. In order to confirm the change with time of the slurry viscosity, the obtained slurry was stored at room temperature for 4 weeks, and the viscosity was measured.
It was 0 mPa · s. The viscosity increase rate of the slurry is 47.
Although it is 5%, the absolute value of the viscosity of this slurry is small, indicating stability without any problem in the operation process.

Reference Example 1 LiOH.H ₂ O, Mn
Each of ₂ O ₃ and AlOOH is a composition in the final spinel type lithium manganese composite oxide, and is represented by Li: Mn: Al.
= 1.04: 1.88: 0.12 (molar ratio), and pure water was added thereto to prepare a slurry having a solid concentration of 30% by weight. While stirring this slurry, pulverize it using a circulating medium stirring type wet pulverizer (Shinmaru Enterprises Co., Ltd .: Dynomill KDL-A type) until the average particle diameter of the solid content in the slurry becomes 0.30 μm. did. Grinding was performed for 6 hours using a 300 ml pot. The viscosity of this slurry was measured using the same apparatus as in the example immediately after pulverization, and as a result, it was 1195 mPa · s.
After storage for 2 weeks (336 hours) from the preparation of the slurry,
The slurry viscosity was measured by the same viscometer as described above.
As a result, the viscosity of the slurry was 1600 mPa · s, and the increase rate of the viscosity of the slurry was 33.9%, which showed stability without any problem in the operation process. The slurry after storage is further added at room temperature for 2 weeks (total 672 hours)
After storage, the slurry viscosity was measured with the same viscometer as above. As a result, the slurry viscosity was 2000 mPa
s and thickened. The rate of increase in viscosity was 67.4%. From this, it can be seen that there is no practical problem if spray drying is performed as short as possible after preparation of the slurry.

Next, the slurry after storage for 2 weeks is sprayed with a two-fluid nozzle type spray dryer (LT-Okawara Kakoki Co., Ltd.).
Spray drying was performed using an 8 type spray drier.
At this time, air was used as a dry gas, the dry gas introduction rate was 50 L / min, and the dry gas inlet temperature was 90 ° C. Then, the granulated particles obtained by spray drying are
By firing at 5 ° C. for 5 hours, an aluminum-substituted lithium manganese composite oxide having a molar ratio composition almost as charged was obtained. As a result of measuring the particle size of the obtained lithium manganese composite oxide using a laser diffraction / scattering type particle size distribution analyzer (manufactured by Horiba, Ltd .: LA-910 type particle size distribution analyzer), the average secondary particle size was 11.1. The particles had a substantially spherical shape with a size of 5 μm and a maximum particle size of 26 μm. The crystallinity of the obtained lithium manganese composite oxide was measured using a powder X-ray diffractometer (X-ray diffractometer PW3710 manufactured by Philips).
(Cu mold, Cu bulb, 40 kV, 30 mA), and as a result, it was confirmed to have a cubic spinel-type lithium manganese composite oxide structure. 10 g of the obtained lithium manganese composite oxide powder was placed in a 25 ml glass measuring cylinder, and the powder packing density (tap density) after tapping 200 times was measured. As a result, 1.7 g / c was obtained.
c.

<Battery Evaluation Test Example> The battery evaluation of the lithium manganese composite oxide obtained in the examples of the present invention and the comparative examples was performed by the following method. A. Preparation of Positive Electrode, Confirmation of Capacity and Rate Test 75% by weight of each lithium manganese composite oxide obtained in Example 1 and Reference Example 1, acetylene black 2
A mixture weighed at a ratio of 0% by weight and a polytetrafluoroethylene powder at a ratio of 5% by weight is sufficiently kneaded in a mortar, and a thin sheet is punched out using a 9 mmφ or 12 mmφ punch to produce a disc-shaped positive electrode mixture sheet. did. At this time, the total weight of the positive electrode mixture sheet was about 8 mg and about 18 mg, respectively.
mg. This was pressed against an Al expanded metal to form a 9 mmφ positive electrode. A coin cell was assembled using the positive electrode as a test electrode and Li metal as a counter electrode.
This coin cell is charged at a constant current of 0.5 mA / cm ² ,
That is, a reaction for releasing lithium ions from the positive electrode is performed at an upper limit of 4.35 V, and then a constant current discharge of 0.5 mA / cm ² , that is, a reaction for storing lithium ions in the positive electrode is performed at a lower limit of 3.2 V. The initial charge capacity per unit weight of the active material was Qs (C) mAh / g, and the initial discharge capacity was Qs (D) mAh / g.

B. Preparation of Negative Electrode and Confirmation of Capacity A graphite powder having an average particle size of about 8.10 μm (d002 = 3.35 °) as the negative electrode active material and polyvinylidene fluoride as the binder in a weight ratio of 92.5: 7.5. And mixed in an N-methylpyrrolidone solution to obtain a negative electrode mixture slurry. 20 μm of this slurry
Was coated on one side of a copper foil having a thickness of 5 mm, dried and evaporated, and then punched into 12 mmφ and pressed at 0.5 ton / cm ² to obtain a negative electrode. The negative electrode was used as a test electrode, and a battery cell was assembled using Li metal as a counter electrode.
The initial storage capacity per unit weight of the negative electrode active material when a test for storing Li ions in the negative electrode at a constant current of 0.2 mA / cm ² was performed at a lower limit of 0 V was defined as QfmAh / g.

C. Assembling of coin type cell Using the coin type cell (CR2032), the battery performance was evaluated. That is, the positive electrode was placed on the positive electrode can, a 25 μm-thick porous polyethylene film was placed as a separator on the positive electrode can, pressed with a polypropylene gasket, the negative electrode was placed, and a spacer for thickness adjustment was placed.
As a non-aqueous electrolyte solution, a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) having a volume fraction of 3: 7 in which 1 mol / L lithium hexafluorophosphate (LiPF ₆ ) is dissolved is used as an electrolyte. This was used and added to the inside of the battery to be sufficiently impregnated. Then, a negative electrode can was placed and the battery was sealed. Note that, at this time, the positive electrode and the negative electrode were of the same composition as those prepared for checking the capacity, and the balance between the weight of the positive electrode active material and the weight of the negative electrode active material was set to be approximately the following equation.

## EQU1 ## Weight of positive electrode active material [g] / weight of negative electrode active material [g] =
(Qf / 1.2) / Qs (C)

D. In order to compare the high-temperature characteristics of the coin-type cells obtained in the cycle test , the 1-hour rate current value of the battery, that is, 1C, was used.

## EQU2 ## The following test was conducted by setting 1 C [mA] = Qs (D) × weight of positive electrode active material [g]. First, a constant current of 0.1 at room temperature.
Two cycles of 2C charge / discharge and one cycle of constant current 1C charge / discharge were performed, and then a test was performed at a high temperature of 50 ° C. at a constant current of 0.2C charge / discharge, followed by a constant current 1C charge / discharge of 100 cycles. Note that the upper limit of charge is 4.2 V and the lower limit voltage is 3.0.
V. At this time, with respect to the discharge capacity Qh (1) in the first cycle of the 100-cycle 1C charge / discharge test at 50 ° C.
The ratio of the discharge capacity Qh (50) at the 50th cycle is defined as a high-temperature cycle capacity maintenance ratio P, that is,

[Mathematical formula-see original document] P [%] = {Qh (50) / Qh (1)} × 100, and the high-temperature characteristics of the batteries were compared using this value.

Table 1 shows the initial discharge capacity, initial efficiency, and high-temperature cycle capacity retention of the batteries using the cathode materials obtained in the above Examples and Reference Example 1 in a 50 ° C. cycle test. And the average particle size and the tap density (bulk density) of the secondary particles of the lithium manganese composite oxide are shown. Note that the initial efficiency (%) = [Qs (C) / Q
s (D)] × 100.

[0055]

[Table 1]

[0056]

According to the method of the present invention, when manufacturing a lithium transition metal composite oxide used for a positive electrode of a lithium secondary battery, a slurry of a raw material compound having excellent long-term stability and easy handling can be obtained. The lithium transition metal composite oxide which can be produced and prepared from the slurry obtained by the method of the present invention has the same or equivalent battery characteristics and properties as conventional batteries. Therefore, the method of the present invention is extremely useful as an industrial production method.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 10/40 H01M 10/40 Z F term (Reference) 4G048 AA04 AB02 AB05 AC06 AE05 AE08 5H029 AJ03 AK03 AK18 AL02 AL06 AL07 AL12 AL18 AM02 AM03 AM04 AM05 AM07 AM11 AM16 CJ02 CJ08 CJ28 DJ16 DJ17 HJ13 5H050 AA08 BA15 CA07 CA08 CA09 CA29 CB02 CB03 CB07 CB08 CB12 CB29 FA17 FA19 GA02 GA10 GA27 HA13 HA20

Claims (12)

[Claims] In producing a slurry containing a lithium compound, a transition metal compound and an aluminum compound, a slurry containing either a lithium compound or an aluminum compound and a transition metal compound is formed, and then the other lithium is prepared. A method for producing a slurry, comprising adding a compound or an aluminum compound. 2. The method according to claim 1, wherein the other lithium compound or aluminum compound is dissolved or dispersed in a liquid medium and added. 3. The method according to claim 1, wherein one of the lithium compound and the aluminum compound is a lithium compound, and the other aluminum compound is an alumina sol. 4. The method according to claim 1, wherein one of the lithium compound and the aluminum compound is lithium hydroxide or a hydrate thereof, and the solution or dispersion of the other aluminum compound is basic. The method for producing a slurry according to any one of claims 1 to 3. 5. The method according to claim 1, wherein one of the lithium compound and the aluminum compound is an aluminum compound, and the other lithium compound is a lithium hydroxide solution. . 6. A slurry in which either one of a lithium compound and an aluminum compound and a transition metal compound are vigorously stirred in a liquid medium to form a slurry, and then the other lithium compound or aluminum compound is added and weakly stirred. The method for producing a slurry according to any one of claims 1 to 5, wherein: 7. The slurry production according to claim 1, wherein one of the lithium compound and the aluminum compound and the transition metal compound are pulverized in a liquid medium. Method. 8. The method for producing a slurry according to claim 1, wherein the transition metal compound is a compound containing at least one element selected from manganese, nickel and cobalt. 9. The method for producing a slurry according to claim 1, wherein the transition metal compound is a manganese compound. 10. The manganese compound according to claim 9, wherein the manganese compound is selected from the group consisting of manganese oxide, manganese hydroxide, manganese oxyhydroxide, manganese nitrate, manganese sulfate and an organic acid salt of manganese. Method for producing slurry. 11. A method for producing a lithium transition metal composite oxide, comprising spray-drying a slurry obtained by the method according to claim 1 and subjecting the slurry to a baking treatment. . 12. After preparing a slurry containing a lithium compound, a transition metal compound, and an aluminum compound,
A method for producing a lithium transition metal composite oxide, comprising drying and calcining the slurry, wherein the time from when the lithium compound and the aluminum compound are contained during the preparation of the slurry until the drying is started. Is within 500 hours.