JP2014156397A - Nickel-containing hydroxide, nickel-containing oxide and methods of producing them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide nickel-containing hydroxide and nickel-containing oxide which is a monodisperse primary particle used for producing lithium composite nickel oxide which is a monodisperse primary particle having an average particle diameter of 3 μm or less used for a cathode active material for a lithium ion secondary battery, and to provide methods of producing the nickel-containing hydroxide and nickel-containing oxide.SOLUTION: There is provided the nickel-containing hydroxide which is a monodisperse primary particle represented by the general formula (1):NiM(OH)( M represents at least one or more elements of Co and Al in the formula), and has an average particle diameter measured by a dynamic light scattering method of 3 μm or less. There is also provided the nickel-containing oxide which is obtained by roasting the nickel-containing hydroxide at 300 to 900°C and is a monodispersed primary particle represented by the general formula (2):NiMO ( M represents at least one or more element of Co and Al in the formula), and has an average particle diameter measured by a dynamic light scattering method of 3 μm or less.

Description

  The present invention relates to a nickel-containing primary particle which is monodispersed used for producing a lithium composite nickel oxide which is a monodispersed primary particle having an average particle size of 3 μm or less used for a positive electrode active material for a lithium ion secondary battery. The present invention relates to the provision of hydroxides, nickel-containing oxides, and methods for producing them.

Lithium ion secondary batteries are mainly made of lithium cobalt oxide, and their market has been greatly expanded. However, in recent years, lithium cobalt oxide has reached an area that is almost as close as the capacity limit of the product itself, and it is difficult to use it for higher power electronic devices that will be required for future video, music, communication, etc. A new high-capacity lithium ion secondary battery in which the positive electrode active material is switched from the conventional lithium cobalt oxide to the lithium composite nickel oxide has been put on the market. However, since this new high-capacity lithium-ion secondary battery is not a mature material like the conventional lithium cobalt oxide, the powder shape currently on the market is a spherical shape that is an aggregate of sub-micron primary particles. Or it is an elliptical secondary particle and is not suitable for the battery which requires the high rate represented by HEV. Therefore, a material having a completely different shape has been required as a further improvement in the high rate characteristics that cannot be obtained with the conventional spherical lithium composite nickel oxide.
As a material that has been studied as such a material, there is a lithium composite nickel oxide prepared using nickel hydroxide in which primary particles having an average particle diameter of several μm are aggregated to form secondary particles.

  However, nickel hydroxide usually obtained by hydrolysis of a nickel salt solution is gel-like and has a high water content, making it difficult to dehydrate in a cleaning step when removing impurities mixed in during manufacture. Moreover, it strongly aggregates at the time of drying and takes a glassy form, and as it is, it cannot be obtained as fine particles. Therefore, in general, in order to obtain nickel hydroxide powder, nickel hydroxide in a glassy form must be pulverized using a pulverizer, and the production of nickel hydroxide having an average particle diameter of several μm is It has become very difficult. In addition, the lithium composite nickel oxide obtained by firing with the nickel hydroxide obtained in this way becomes extremely hard agglomerates. The lump does not collapse so much, and a lithium composite nickel oxide having an average particle diameter of several μm cannot be obtained efficiently.

  Under these circumstances, primary particles having an average particle diameter of 1 to 5 μm are closely connected to synthesize nickel hydroxide constituting almost spherical secondary particles under specific conditions, and using this, lithium composite nickel oxidation There is a proposal in Patent Document 1 for obtaining a product. In Patent Document 1, a nickel hydroxide having such a structure is mixed with a lithium compound and then fired at a predetermined temperature to obtain a lithium composite nickel oxide aggregate having voids therein, which is used as a positive electrode active material. If so, the specific capacity as the positive electrode active material is high, the electrode pressability is excellent, and the positive electrode active material layer can be filled with high density, which can greatly contribute to the increase in capacity and output of the battery. Yes.

  As a specific method for obtaining nickel hydroxide constituting the substantially spherical secondary particles by densely connecting the primary particles having an average particle diameter of 1 to 5 μm, the electrical conductivity is 80 mS / A nickel solution at 30 to 50 ° C., which is cm to 150 mS / cm, is prepared, and using a reaction tank with an axial flow type inclined paddle two-stage blade, the rotation speed of the stirring blade is 100 rpm to 150 rpm, sodium hydroxide, water It has been proposed to add potassium oxide or the like so that the pH of the reaction system is 11.1-11.5 (see paragraphs 25-30 of Patent Document 1).

  More specifically, it includes a reactor equipped with a stirrer, an axial-flow type inclined paddle two-stage blade and a pH meter, an alkaline agent supply pump, a tank equipped with a filtration device, a washing machine, and a dryer. This is performed using a manufacturing apparatus. In the reaction vessel, nickel hydroxide is synthesized based on the above conditions. For example, an aqueous nickel salt solution and an aqueous salt solution containing a metal element other than nickel are continuously supplied to the reaction vessel. Nickel hydroxide generated in the reaction tank overflows with water and is supplied to a tank equipped with a filtration device. The alkaline agent supply pump supplies the alkaline agent into the reaction vessel according to the measurement result by the pH meter. A tank equipped with a filtration device separates liquid containing nickel hydroxide by solid-liquid separation by filtration. The washing machine washes the nickel hydroxide separated in a tank equipped with a filtration device. The dryer is supposed to dry the nickel hydroxide.

However, the above-described method has a problem that it requires extremely limited apparatuses and conditions as compared with a method for producing ordinary nickel hydroxide.
As described above, lithium composite nickel oxides having completely different shapes have not yet been provided as a further improvement in the high rate characteristics that cannot be obtained with conventional spherical lithium composite nickel oxides.

JP 2008-174444 A

  The present invention has been made in view of the above-mentioned problems of the prior art, and aims to provide a positive electrode active material for a lithium ion secondary battery having a completely different structure from that of the prior art, specifically, a lithium ion secondary battery. A nickel-containing hydroxide and a nickel-containing oxide which are monodispersed primary particles used for producing a lithium composite nickel oxide which is a monodispersed primary particle having an average particle size of 3 μm or less used for a positive electrode active material for an automobile, An object of the present invention is to provide these production methods.

  In order to achieve the above object, the present inventor has conducted extensive research on lithium composite nickel oxides for positive electrode active materials for lithium ion secondary batteries. It is possible to obtain nickel-containing hydroxide primary particles having an average particle size of 3 μm or less in a monodispersed state by suspending in a metal hydroxide aqueous solution, heating, and maintaining the molten state as a molten state for a predetermined time. . When this is mixed with a lithium compound and fired, primary particles of lithium composite nickel oxide having an average particle diameter of 3 μm or less are obtained in a monodispersed state, and this is a lithium ion secondary battery with high output and excellent high-rate characteristics. As a result, the present invention was completed.

  That is, the first invention of the present invention is represented by the following general formula (1), is a monodispersed primary particle, and has an average particle size of 3 μm or less by dynamic light scattering measurement. A nickel-containing hydroxide is provided.

General formula (1): NiM (OH) ₂
(In the formula, M represents at least one element of Co and Al.)

  The second invention of the present invention is obtained by roasting the nickel-containing hydroxide in the first invention at 300 to 900 ° C., and is represented by the following general formula (2) and is simple. There is provided a nickel-containing oxide which is a primary particle of dispersion and has an average particle size of 3 μm or less as measured by a dynamic light scattering method.

General formula (2): NiMO
(In the formula, M represents at least one element of Co and Al.)

  The third invention of the present invention is a suspension of a conventional nickel-containing hydroxide having the composition represented by the general formula (1) in the first invention in an aqueous alkali metal hydroxide solution, while stirring. Nickel characterized in that it is heated and held at 90 to 180 ° C. for 30 minutes or more and 2 hours or less, then cooled and contacted with water to dissolve the alkali metal hydroxide to separate and recover the nickel-containing hydroxide. A method for producing the containing hydroxide is provided.

  Further, the fourth invention of the present invention is such that the amount of the alkali metal hydroxide in the alkali metal hydroxide aqueous solution in the third invention is 1 mol of the nickel-containing hydroxide added to the alkali metal hydroxide aqueous solution. There is provided a method for producing a nickel-containing hydroxide, characterized in that the amount of alkali metal hydroxide is 1 mol or more.

  According to a fifth aspect of the present invention, the alkali metal hydroxide according to the third and fourth aspects is at least one of sodium hydroxide, potassium hydroxide, and lithium hydroxide. A method for producing hydroxide is provided.

  The sixth invention of the present invention provides the method for producing a nickel-containing oxide according to the second invention, characterized in that the nickel-containing hydroxide according to the first invention is roasted at 300 to 900 ° C. The

  Further, according to a seventh aspect of the present invention, when the nickel-containing oxide is obtained by roasting in the sixth aspect, at least one of the nickel-containing hydroxide, a desired amount of aluminum hydroxide, and aluminum oxide. There is provided a method for producing a nickel-containing oxide, characterized by mixing and baking.

  According to the method of the present invention, nickel-containing hydroxide primary particles having an average particle diameter of 3 μm or less can be easily obtained in a monodispersed state, and using this, the average particle diameter of 3 μm or less in a monodispersed state can be used. Lithium composite nickel oxide primary particles can be easily obtained. In this monodispersed state, when lithium composite nickel oxide primary particles having an average particle diameter of 3 μm or less are used as a positive electrode active material for a lithium ion secondary battery, a high output lithium secondary battery having excellent high rate characteristics can be obtained. In particular, it is suitable as a chargeable / dischargeable secondary battery used in the automobile field. Therefore, the industrial value of the present invention is extremely large.

Hereinafter, the present invention will be described in detail.
(1) Nickel-containing hydroxide primary particles in a monodispersed state having an average particle size of 3 μm or less and a production method thereof The nickel-containing hydroxide of the present invention is represented by the general formula (1): NiM (OH) ₂ , M in the formula represents at least one element of Co and Al, and is a monodispersed primary particle having an average particle diameter measured by dynamic light scattering method of 3 μm or less, preferably 1 μm or more and 2 μm or less. It is. The reason why the particle size of the nickel-containing hydroxide of the present invention is 3 μm or less is that the particle size of the lithium composite nickel oxide obtained by using this is 3 μm or less.

Even if the nickel-containing hydroxide of the present invention is baked at 300 to 900 ° C. to obtain a nickel-containing oxide, there is almost no grain growth and no secondary particles are formed by aggregation. By simply crushing the fired product, it is possible to easily obtain monodispersed nickel-containing primary oxide particles having an average particle size of 3 μm or less.
The reason why the surface state of the nickel-containing hydroxide of the present invention is so stable is not clear, but it is presumed that the following production method is related to the formation of a special surface state.

  In order to obtain the nickel-containing hydroxide of the present invention, a conventional nickel-containing hydroxide obtained by a usual method, for example, a hydrolysis method (hereinafter simply referred to as “nickel-containing hydroxide raw material”) is alkali. Suspended in an aqueous metal hydroxide solution, heated and stirred, maintained at 100-180 ° C. for 30 minutes to 2 hours, then cooled and contacted with water to dissolve the alkali metal hydroxide. The monodispersed nickel-containing hydroxide primary particles having an average particle diameter of 3 μm or less are separated and recovered.

  The nickel-containing hydroxide raw material that can be used is not limited to the particle shape as long as the composition conforms to the general formula (1). For example, the gelled nickel hydroxide obtained by hydrolysis of the nickel salt solution shown in the background art may be dried, and the obtained glassy aggregate may be pulverized.

  In the method of the present invention, a nickel-containing hydroxide raw material is put into an aqueous solution of an alkali metal hydroxide, heated, the water in the liquid is volatilized, and dissolved in an alkali metal hydroxide bath. This is because the alkali metal hydroxide is infiltrated into the inside of the containing hydroxide raw material, and is then melted to completely melt the nickel containing hydroxide raw material. The solid alkali metal hydroxide and the nickel-containing hydroxide raw material may be mixed and melted, but in this case, the nickel-containing hydroxide raw material often does not melt completely, and the method of the present invention. ineffective.

  The heating temperature may be a temperature at which the alkali metal hydroxide and the nickel-containing hydroxide form a uniform melt. When sodium hydroxide is used as the alkali metal hydroxide, the heating temperature is 90 to 180 ° C. Preferably, the temperature is 140 to 180 ° C. Below 90 ° C, the nickel-containing hydroxide raw material secondary particles by alkali metal hydroxide can be disintegrated or dissolved into primary particles, but crystal growth occurs when the primary particles are grown in a monodispersed state. The speed is slow, and it takes a very long time to grow a crystal of a desired size, and productivity is lacking. On the other hand, when the temperature exceeds 180 ° C., crystal growth rapidly advances, particle size control becomes difficult, and oxidation is likely to occur and the valence stability is impaired.

  In the present invention, after obtaining a uniform melt, the melt is held at that temperature for 30 minutes to 2 hours. This promotes grain growth of nickel-containing hydroxide in the melt. If it is less than 30 minutes, the grain growth is not sufficient, and monodispersed fine primary particles cannot be obtained. Moreover, since it will become large particle | grains and an average particle diameter will exceed 3 micrometers when it hold | maintains for 2 hours or more, it is not preferable.

The amount of alkali hydroxide added to the nickel-containing hydroxide raw material is 1 mol or more, preferably 2.5 mol or more per mol of the nickel-containing hydroxide raw material. This is for complete melting.
As the alkali hydroxide that can be used, sodium hydroxide, potassium hydroxide, lithium hydroxide, or the like can be used alone or in combination, but sodium hydroxide is preferred because it is easy to handle and inexpensive.

(2) Monodispersed primary nickel-containing oxide particles having an average particle size of 3 μm or less and a method for producing the same The nickel-containing oxide of the present invention is represented by the general formula (2): NiMO, where M is Co , Represents at least one element of Al, and is a monodispersed primary particle having an average particle diameter of 3 μm or less, preferably 1 μm or more and 2 μm or less, measured by dynamic light scattering. The reason why the particle size of the nickel-containing hydroxide of the present invention is 3 μm or less is that the particle size of the lithium composite nickel oxide obtained by using this is 3 μm or less.

In obtaining the nickel-containing oxide of the present invention, the monodispersed nickel-containing hydroxide primary particles of the present invention are roasted at 300 to 900 ° C.
When the roasting temperature is less than 300 ° C., the nickel valence of nickel oxide is not stable and its composition is not stable. Therefore, it is difficult to synthesize lithium nickel composite oxide aiming at a specific composition ratio. This is because the crystallinity of nickel oxide becomes too high, and when it is synthesized into a lithium nickel composite oxide, a different phase may be generated or a product with low crystallinity may be obtained.

  Also, for example, when preparing monodispersed nickel-containing hydroxide primary particles, lithium nickel aluminum is added by adding Al in a subsequent process in order to ensure safety even though aluminum is not added. When obtaining a composite oxide or increasing the aluminum content, a desired amount of finely pulverized aluminum hydroxide or aluminum oxide is added to the monodispersed nickel-containing hydroxide primary particles of the present invention to obtain a mixed powder. These and a lithium compound may be mixed and roasted.

  At this time, after suspending the nickel-containing hydroxide in water, sodium aluminate is added to a desired composition and dissolved by stirring, and the slurry is further neutralized by adding sulfuric acid to the nickel-containing hydroxide. Aluminum hydroxide may be deposited and adhered to the surface, or aluminum hydroxide or aluminum oxide may be mechanically adhered to the nickel-containing hydroxide surface using a vibration mill or the like.

  Now, as described above, the fired product obtained by roasting is in the form of a lump at the end of firing. Since this lump is obtained by lightly sintering monodispersed primary particles, it can be easily crushed to primary particles of 3 μm or less using a mechanical pulverizer such as a pin mill or a hammer mill. In addition, when there are inclusions such as dust, it is preferable to remove the inclusions such as dust using an ultrasonic vibration sieve.

(3) Lithium composite nickel oxide primary particles in a monodispersed state having an average particle diameter of 3 μm or less and a method for producing the same Lithium composite nickel oxide is represented by a general formula: LiNiMO _2, where M is Co or Al At least one element is shown. And it is a monodispersed primary particle whose average particle diameter by a dynamic light-scattering method measurement is 3 micrometers or less. When this is used for a lithium ion secondary battery, it will be filled with monodispersed primary particles, the packing density can be higher than when filling secondary particles with gaps, and there is a gap between the primary particles. Therefore, the movement of lithium ions is not hindered, the high-rate characteristics are improved, and a battery with excellent output characteristics can be obtained.
The average particle size is 3 μm or less, preferably 1 to 2 μm. When the average particle size is 3 μm or more, when a lithium ion secondary battery is used, the particles are too large and the diffusion resistance in the solid phase becomes high, resulting in a high rate. This is because the expected output cannot be obtained under the conditions.

  In order to obtain a lithium composite nickel oxide, the above-described monodispersed nickel-containing hydroxide primary particles having an average particle diameter of 3 μm or less, or a monodispersed nickel-containing oxide having an average particle diameter of 3 μm or less. Use primary particles. When other than this is used, it is difficult to obtain lithium composite nickel oxide as primary particles having an average particle size of 3 μm or less in a monodispersed state.

  The monodispersed nickel-containing hydroxide primary particles or nickel-containing oxide primary particles of the present invention and a lithium compound are mixed, the obtained mixture is roasted at 680 to 800 ° C., and the obtained fired product is crushed. Thus, the lithium composite oxide of the present invention is obtained. In this case, the lithium compound used is preferably any one of hydroxide, oxide, chloride, carbonate, and nitrate, but more preferably during synthesis. In addition, a hydroxide or an oxide that does not damage the furnace or mortar used in firing and has a low environmental load is desirable.

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples of the present invention, but the present invention is not limited to these examples. In addition, about the fine lithium composite nickel oxide produced by the Example and the comparative example, it shows about the average particle diameter, the analysis of a contained metal element, and a high-rate discharge characteristic.
The average particle size was measured using a nanotrack particle size distribution measuring device “model UPA-EX150” manufactured by Nikkiso Co., Ltd., and whether or not it was monodispersed was confirmed by comparing this value with the SEM observation result.
The high-rate discharge characteristics are defined as a discharge capacity value when 0.1C charge and 2C discharge are performed using a coin cell manufactured by the following battery production, and a value (2C battery capacity) measured in each example is described later. As a relative value, the value of the conventional example is set to 100.

[Battery creation]
90 wt% of the active material powder was mixed with 5 wt% of acetylene black and 5 wt% of PVDF (polyvinylidene fluoride), and NMP (n-methylpyrrolidone) was added to form a paste. This was applied to a 20 μm thick aluminum foil so that the weight of the active material after drying was 0.05 g / cm ² , vacuum-dried at 120 ° C., and punched into a disk shape having a diameter of 1 cm to obtain a positive electrode. Lithium metal was used as the negative electrode, and an equivalent mixed solution of ethylene carbonate (EC) and diethyl carbonate (DEC) using 1 mol of LiClO ₄ as a supporting salt was used as the electrolyte. A separator made of polyethylene was impregnated with an electrolytic solution, and a 2032 type coin battery was produced in a glove box in an Ar atmosphere in which the dew point was controlled at −80 ° C. The prepared battery was allowed to stand for about 24 hours, and after the OCV was stabilized, a charge / discharge test was performed at a cut-off voltage of 4.3 to 3.0V.

Using 1 mol of powder obtained by pulverizing a nickel-containing hydroxide raw material having a composition of massive Ni _0.82 Co _0.15 Al _0.03 (OH) ₂ as a raw material, this was used as an aqueous sodium hydroxide solution in the reaction vessel (2.5 mol / 200 cc) after suspension and sufficient stirring, the temperature of the reaction vessel is kept at 140 ° C. and held for 30 minutes after the bath temperature reaches the same temperature, and then cooled to cool the nickel-containing hydroxide. A powder was obtained. The obtained powder was monodispersed with an average particle size of 1.6 μm. The composition was the same as that of the nickel-containing hydroxide raw material.
Next, the obtained powder was mixed with lithium hydroxide monohydrate and a Spartan reuser so that the Li / (Ni + Co + Al) molar ratio = 1.02, and passed through a carbon dioxide adsorption facility and a drying facility at 760 ° C. The calcination was carried out in an industrial oxygen stream for 24 hours. The obtained fired product was crushed and classified with an ultrasonic sieve having a mesh of 50 μm to remove coarse dust, and the sieve was vacuum dried to produce a lithium composite nickel oxide product.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.818 Co _0.149 Al _0.033 O ₂ , the average particle size was 1.5 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.

The amount of sodium hydroxide was 1 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, and the temperature of the reaction vessel was 100 ° C. A hydroxide was obtained.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle diameter was 0.6 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 126.

The amount of sodium hydroxide was 5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, and the temperature of the reaction vessel was 180 ° C. A hydroxide was obtained.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle diameter was 2.9 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 115.

The average particle size of 1. is the same as in Example 1 except that the amount of sodium hydroxide is 1 mol per 1 mol of the nickel-containing hydroxide raw material powder, the temperature of the reaction vessel is 100 ° C., and the holding time is 120 minutes. A monodispersed nickel-containing hydroxide at 3 μm was obtained.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle diameter was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was 122.

The average particle size was the same as in Example 1 except that the amount of sodium hydroxide was 1.5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, the reaction vessel temperature was 140 ° C., and the holding time was 60 minutes. A monodispersed nickel-containing hydroxide at 1.7 μm was obtained.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle size was 1.7 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.

The average particle size was set to 0. 5 as in Example 1 except that the amount of sodium hydroxide was 5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, the reaction vessel temperature was 90 ° C., and the holding time was 120 minutes. A monodispersed nickel-containing hydroxide was obtained at 9 μm.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle size was 0.9 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was 125.

(Comparative Example 1)
This example corresponds to a comparative example when the reaction temperature is high.
The average particle size was the same as in Example 1 except that the amount of sodium hydroxide was 2.5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, the reaction vessel temperature was 220 ° C., and the holding time was 60 minutes. A monodispersed nickel-containing hydroxide at 5.2 μm was obtained.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.820 Co _0.151 Al _0.029 O ₂ , the average particle size was 5.1 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was as low as 98.

(Comparative Example 2)
This example corresponds to a comparative example when the holding time is short.
The same procedure as in Example 1 was performed except that the amount of sodium hydroxide was 2.5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, the reaction vessel temperature was 140 ° C., and the holding time was 20 minutes. A nickel-containing hydroxide was obtained in which a large amount of raw material agglomerates remained without being monodispersed.

(Comparative Example 3)
This example corresponds to a comparative example when the holding time is long.
The amount of sodium hydroxide was 2.5 mol with respect to 1 mol of the nickel-containing hydroxide raw material powder, the reaction vessel temperature was 140 ° C., and the holding time was 150 minutes. A monodispersed plate-like nickel-containing hydroxide was obtained.

The nickel hydroxide containing raw _material, Ni _{0.845 Co} 0.155 _(OH) monodisperse containing nickel hydroxide was changed to the _second composition those in the same manner as in Example 1 with an average particle diameter of 1.7μm I got a thing.
Next, using this, a lithium composite nickel oxide was produced in the same manner as in Example 1. The resulting chemical composition of the lithium nickel composite oxide be _{Li 1.02 Ni 0.845 Co 0.155 O 2} , the average particle size was monodisperse with 1.6 [mu] m.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 128.

The nickel-containing hydroxide obtained in Example 1 is once suspended in pure water so as to have a slurry concentration of 300 g / L, and this has a composition of Ni _0.82 : Co _0.15 : Al _0.03. Al (OH) ₃ obtained by dissolving sodium aluminate and neutralizing with sulfuric acid was converted to nickel-containing hydroxide attached to the particle surface and mixed with lithium hydroxide monohydrate. A lithium composite nickel oxide was produced in the same manner as in Example 7. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.822 Co _0.149 Al _0.029 O ₂ , the average particle size was 1.6 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.

The nickel-containing hydroxide obtained by attaching Al ₂ O ₃ to the particle surface by mechanofusion so that the nickel-containing hydroxide obtained in Example 1 has a composition of Ni _0.82 : Co _0.15 : Al _0.03. A lithium composite nickel oxide was produced in the same manner as in Example 7 except that the mixture was mixed with lithium hydroxide monohydrate. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle diameter was 1.5 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was 121.

Al (OH) ₃ and Ni _0.82 : Co _0.15 : Al ₀ finely ground to submicron before mixing the nickel-containing hydroxide powder obtained in Example 1 with lithium hydroxide monohydrate _A lithium composite nickel oxide was produced in the same manner as in Example 7, except that the nickel-containing hydroxide _having a composition of _0.03 was mixed with lithium hydroxide monohydrate.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.150 Al _0.029 O ₂ , the average particle diameter was 1.5 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 119.

The nickel-containing hydroxide obtained in Example 1 was the same as in Example 1 except that the nickel-containing hydroxide was roasted once in an air atmosphere at 400 ° C. and mixed with the nickel-containing oxide before mixing with lithium hydroxide monohydrate. The lithium nickel composite oxide was manufactured by the method. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.820 Co _0.150 Al _0.030 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 119.

The nickel-containing hydroxide obtained in Example 1 was the same as Example 1 except that the nickel-containing hydroxide was roasted once in the atmosphere at 900 ° C. and changed to the nickel-containing oxide before mixing with lithium hydroxide monohydrate. The lithium nickel composite oxide was manufactured by the method. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.151 Al _0.028 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.

The nickel-containing hydroxide obtained in Example 1 was the same as Example 1 except that the nickel-containing hydroxide was roasted once at 650 ° C. in the atmosphere before being mixed with lithium hydroxide monohydrate and changed to the nickel-containing oxide. The lithium nickel composite oxide was manufactured by the method. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.821 Co _0.151 Al _0.028 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.

Lithium was obtained in the same manner as in Example 1 except that the nickel-containing hydroxide thus obtained was once baked in an air atmosphere at 300 ° C. and changed to a nickel-containing oxide before mixing with lithium hydroxide monohydrate. Nickel composite oxide was produced.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.03 Ni _0.821 Co _0.151 Al _0.028 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 120.
However, it is very difficult to control the composition in the synthesis of this embodiment.

(Comparative Example 4)
The obtained nickel-containing hydroxide was the same as in Example 1 except that the nickel-containing hydroxide was once baked at 1000 ° C. in the atmosphere before being mixed with lithium hydroxide monohydrate and changed to a nickel-containing oxide. A lithium nickel composite oxide was produced.
As for the chemical composition of the obtained lithium composite nickel oxide, a heterogeneous phase could be confirmed with Li _1.02 Ni _0.819 Co _0.149 Al _0.032 O ₂ and it could not be used as a battery material.

Using Ni _0.845 Co _{0.155 (OH)} nickel hydroxide containing raw material comprising a _second composition, except that the resulting nickel hydroxide containing an average particle diameter became 1.7μm Example 1 Similarly, lithium composite nickel oxide was produced. The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.844 Co _0.156 O ₂ , the average particle size was 1.7 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was 129.

The nickel-containing hydroxide obtained in Example 15 is once suspended in pure water so as to have a slurry concentration of 300 g / L, and this has a composition of Ni _0.82 : Co _0.15 : Al _0.03. A nickel-containing hydroxide in which Al (OH) ₃ obtained by dissolving sodium aluminate and neutralizing with sulfuric acid was adhered to the surface of the particles was used in the same manner as in Example 15 except that this was used. A composite nickel oxide was produced.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.819 Co _0.149 Al _0.032 O ₂ , the average particle size was 1.5 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide and the battery capacity was determined. The 2C battery capacity (relative ratio) was 121.

The obtained nickel-containing hydroxide is made into a nickel-containing hydroxide in which Al ₂ O ₃ is adhered to the particle surface by mechanofusion so as to have a composition of Ni _0.82 : Co _0.15 : Al _0.03 . A lithium composite nickel oxide was produced in the same manner as in Example 16 except that this was used.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.820 Co _0.150 Al _0.030 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 119.

The resulting nickel-containing hydroxide powder is comminuted to submicron before mixing with lithium hydroxide monohydrate and has a composition of Ni _0.82 : Co _0.15 : Al _0.03. A lithium composite nickel oxide was produced in the same manner as in Example 16 except for mixing.
The chemical composition of the obtained lithium composite nickel oxide was Li _1.02 Ni _0.818 Co _0.151 Al _0.031 O ₂ , the average particle size was 1.4 μm, and it was in a monodispersed state.
A battery was prepared using this lithium composite nickel oxide, and the battery capacity was determined. The 2C battery capacity (relative ratio) was 118.

(Conventional example)
Ni _0.82 Co _0.15 Al _0.03 (OH) ₂ mixed aqueous solution of nickel sulfate and cobalt sulfate, sodium aluminate aqueous solution, ammonia water to form ammine complex salt, caustic soda for pH adjustment, etc. Were simultaneously dropped into the reaction vessel to obtain a nickel-containing hydroxide by a conventional crystallization method for obtaining a nickel-containing hydroxide. The reaction temperature was 50 ° C., the pH was 11, and the residence time was 8 hours. The composition of the obtained nickel-containing hydroxide is Ni _0.82 Co _0.15 Al _0.03 (OH) ₂ , and the spherical nickel-containing hydroxide in which the primary particles aggregate to form secondary particles It was a thing.
A lithium nickel composite oxide was produced in the same manner as in Example 1 except that this was used.
The obtained lithium composite nickel oxide has a chemical composition of Li _1.02 Ni _0.821 Co _0.149 Al _0.030 O ₂ , and primary particles aggregate to form secondary particles. The average particle size of the secondary particles was 11.1 μm.
A battery was prepared using this lithium composite nickel oxide, the battery capacity was determined, and this value was taken as 100, which was used as a quality criterion for other examples.

  As apparent from the above, according to the method of the present invention, nickel-containing hydroxide primary particles having an average particle diameter of 3 μm or less can be easily obtained in a monodispersed state, and this can be used in a monodispersed state. Lithium composite nickel oxide primary particles having an average particle diameter of 3 μm or less can be easily obtained. In this monodispersed state, lithium composite nickel oxide primary particles having an average particle diameter of 3 μm or less by dynamic light scattering measurement are obtained. When used as a positive electrode active material for a lithium ion secondary battery, it is possible to obtain a high-power lithium secondary battery excellent in high rate characteristics, and a chargeable / dischargeable secondary battery, particularly a secondary battery used in the automotive field. It is suitable as.

Claims (7)

A nickel-containing hydroxide represented by the following general formula (1), monodispersed primary particles, and having an average particle size of 3 μm or less as measured by a dynamic light scattering method.
General formula (1): NiM (OH) ₂
(In the formula, M represents at least one element of Co and Al.) It is obtained by roasting the nickel-containing hydroxide according to claim 1 at 300 to 900 ° C., which is represented by the following general formula (2) and is a monodispersed primary particle, and dynamic light scattering Nickel-containing oxide characterized by having an average particle size of 3 μm or less by method measurement.
General formula (2): NiMO
(In the formula, M represents at least one element of Co and Al.)   A nickel-containing hydroxide obtained by hydrolysis of a nickel salt solution having the composition represented by the general formula (1) is suspended in an aqueous alkali metal hydroxide solution and heated to 90 to 180 ° C. while stirring. The nickel-containing hydroxide according to claim 1, wherein the nickel-containing hydroxide is separated and recovered by holding the mixture for at least 2 minutes and not more than 2 minutes, then cooling and contacting with water to dissolve the alkali metal hydroxide. Manufacturing method.   The amount of the alkali metal hydroxide in the alkali metal hydroxide aqueous solution is 1 mol or more of alkali metal hydroxide per 1 mol of nickel-containing hydroxide added to the alkali metal hydroxide aqueous solution. Item 4. A method for producing a nickel-containing hydroxide according to Item 3.   The method for producing a nickel-containing hydroxide according to claim 3 or 4, wherein the alkali metal hydroxide is at least one of sodium hydroxide, potassium hydroxide, and lithium hydroxide.   The method for producing a nickel-containing oxide according to claim 2, wherein the nickel-containing hydroxide according to claim 1 is roasted at 300 to 900 ° C.   The nickel-containing hydroxide and the desired amount of aluminum hydroxide and aluminum oxide are mixed and roasted when the nickel-containing oxide is obtained by the roasting. 6. A method for producing a nickel-containing oxide according to 6.