JP6428105B2 - Nickel cobalt manganese compound and method for producing the same - Google Patents

Description

  The present invention relates to a nickel cobalt manganese compound having a small particle size, high particle size uniformity, and high density (tap density), in particular, a nickel cobalt manganese compound used as a precursor of a positive electrode active material of a lithium ion secondary battery, and It relates to the manufacturing method.

  In recent years, with the widespread use of portable electronic devices such as mobile phones and laptop computers, development of small and lightweight non-aqueous electrolyte secondary batteries having high energy density is strongly desired. In addition, development of a high-power secondary battery is strongly desired as a large battery such as a motor drive power source.

  As a secondary battery that satisfies these requirements, there is a lithium ion secondary battery. A lithium ion secondary battery includes a negative electrode, a positive electrode, an electrolytic solution, and the like, and a material capable of desorbing and inserting lithium is used as the negative electrode active material and the positive electrode active material.

  The lithium ion secondary battery is currently under active research and development. Among them, a lithium ion secondary battery using a layered or spinel type lithium metal composite oxide as a positive electrode material is 4V. Since a high voltage can be obtained, it has been put to practical use as a battery having a high energy density.

As a positive electrode material of such a lithium ion secondary battery, currently, lithium cobalt composite oxide (LiCoO ₂ ), which is relatively easy to synthesize, lithium nickel composite oxide (LiNiO ₂ ) using nickel cheaper than cobalt, lithium Nickel cobalt manganese composite oxide (LiNi _1/3 Co _1/3 Mn _1/3 O ₂ ), lithium manganese composite oxide (LiMn ₂ O ₄ ) using manganese, lithium nickel manganese composite oxide (LiNi _0.5 Mn _0.5 O _2), lithium-rich nickel-cobalt-manganese composite oxide _{(Li 2 MnO 3 -LiNi x Mn} y Co z O 2) lithium composite oxide or the like is proposed.

  Among these positive electrode active materials, in recent years, lithium-excess nickel cobalt manganese composite oxides with high capacity and excellent thermal stability have attracted attention. This composite oxide is a layered compound like lithium cobalt composite oxide, lithium nickel composite oxide, and the like (see, for example, Non-Patent Document 1).

  By the way, as a condition for obtaining good performance (high cycle characteristics, low resistance, high output) of the lithium ion secondary battery, the positive electrode material is required to be composed of particles having a uniform and appropriate particle size. Has been.

  In other words, in producing a high-performance lithium ion secondary battery as the final product by improving the performance of the positive electrode material, small particles are used as a compound as a raw material for the lithium nickel cobalt manganese composite oxide forming the positive electrode material. It is necessary to use a compound composed of particles having a large particle size uniformity and a high density (tap density).

  Examples of the precursor of the nickel cobalt manganese composite oxide used as the raw material for the positive electrode active material include the nickel cobalt manganese composite hydroxide described in Patent Document 1 and Patent Document 2. In these documents, a sulfuric acid ammonia aqueous solution containing nickel sulfate, cobalt sulfate and manganese sulfate is continuously dropped while stirring with a stirrer, and a sodium hydroxide aqueous solution is dropped into a reaction vessel, A method of obtaining a nickel cobalt manganese composite oxide powder by filtering the obtained slurry, washing with water and drying is disclosed.

  However, in order to obtain a high-performance lithium ion secondary battery, further improvement in the performance of the positive electrode material is required.

JP 2011-105588 A JP 2012-252964 A

“High performance lithium-ion batteries: solid solution cathode materials”, FB Technical News, No. 66, January 2011, pages 3-10

  Therefore, in view of such problems, the present invention provides a nickel cobalt manganese compound having a small particle size, high particle size uniformity, and a high density (tap density) compared to the conventional one and a method for producing the same. Objective.

  This inventor repeated earnest examination about the nickel cobalt manganese compound for manufacturing the lithium excess nickel cobalt manganese complex oxide of the positive electrode material of a lithium ion secondary battery. As a result, the inventor of the present invention includes a nickel cobalt manganese compound hydroxide partially carbonated in the nickel cobalt manganese compound, thereby reducing the primary particle size of the compound, The knowledge that the particle size uniformity is high and the density is high (tap density) was obtained. The present invention has been completed based on these findings.

That is, the method for producing a nickel cobalt manganese compound according to the present invention for achieving the above object is a method for producing a nickel cobalt manganese compound for producing a nickel cobalt manganese compound from nickel cobalt manganese compound particles obtained by a crystallization reaction. Te, nickel-cobalt-manganese compounds have the general formula _{1: Ni x Co y Mn z} M t (OH) and nickel-cobalt-manganese composite hydroxide represented by _{2 + a,} formula _{2: Ni x Co y Mn z} M t CO Composite with nickel cobalt manganese composite carbonate represented by _{3 + a} (wherein x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5, M is Mg, Ca, Al, Ti, V, Cr, a mixed aqueous solution containing a metal compound containing nickel, a metal compound containing cobalt, and a metal compound containing manganese, and one or more additional elements selected from r, Nb, Mo, and W. A nucleation step in which nucleation is performed while blowing carbon dioxide into a nucleation reaction aqueous solution containing an aqueous alkali solution and / or a pre-reaction aqueous solution containing an ammonium ion supplier, and a nucleation reaction aqueous solution after nucleation is performed at a liquid temperature. A particle growth step of obtaining nickel cobalt manganese compound particles by performing nucleus growth while blowing carbon dioxide gas into a particle growth reaction aqueous solution controlled so that the pH value at 25 ° C. standard is 6.5 to 10.5. It is characterized by.

  In the method for producing the nickel cobalt manganese compound, the amount of carbon dioxide blown is preferably 1 to 5 times the total molar amount of the added metal. In the nucleation step, the ammonium ion concentration in the nucleation reaction aqueous solution is set to 0 g. In the particle growth step, it is preferable to maintain the ammonium ion concentration in the particle growth reaction aqueous solution in the range of 0 g / L to 20 g / L. The aqueous nucleation reaction solution is preferably used in the particle growth step after aging for 5 minutes to 300 minutes.

  In the particle growth step, a solution obtained by adding a nucleation reaction aqueous solution containing nuclei formed in the nucleation step to an aqueous solution different from the nucleation reaction aqueous solution containing nuclei may be used as the particle growth reaction aqueous solution. It is also possible to discharge a part of the liquid component of the aqueous solution for particle growth reaction either before the start of the nucleus growth reaction or during the nucleus growth reaction.

  In the nucleation step and the particle growth step, the temperature of the nucleation reaction aqueous solution and the particle growth reaction aqueous solution is preferably maintained at 30 ° C. or higher.

  In the nucleation step, after adding an aqueous solution in which a salt containing one or more additional elements is dissolved in a mixed aqueous solution, or simultaneously with an aqueous solution in which a mixed aqueous solution and a salt containing one or more additional elements are dissolved, A nucleation reaction aqueous solution can be added to a pre-reaction aqueous solution containing at least an ammonium ion supplier, and the nickel cobalt manganese compound particles obtained in the particle growth step can be coated with one or more additional elements. preferable.

  In the manufacturing method of the nickel cobalt manganese compound, the coating method of the additive element is that an aqueous solution containing one or more additive elements is added to a liquid in which nickel cobalt manganese compound particles controlled to have a predetermined pH are suspended. A method of depositing one or more additional elements on the surface of the nickel cobalt manganese compound particles, a method of spray drying a slurry in which nickel cobalt manganese compound particles and a salt containing one or more additional elements are suspended, nickel There is a method of mixing cobalt manganese compound particles and a salt containing one or more additive elements by a solid phase method.

Nickel-cobalt-manganese compounds, one general formula _{1: Ni x Co y Mn z} M t (OH) and nickel-cobalt-manganese composite hydroxide represented by _{2 + a,} Formula _{2: Ni x Co y Mn z} M t CO 3 + a A composite of nickel cobalt manganese composite carbonate represented by the formula (wherein x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5 is satisfied, and M is selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W It is composed of substantially spherical secondary particles formed by aggregation of a plurality of primary particles, and the primary particles have an average particle size of 10 nm to 100 nm. The secondary particles have an average particle size of 3 μm to 10 μm, [(D90−d10) / average particle diameter] which is an index indicating the spread of the distribution is 0.55 or less.

  In the nickel-cobalt-manganese compound, it is preferable that one or more additive elements are uniformly distributed and / or uniformly coated on the surface of the secondary particles.

  According to the present invention, it is possible to obtain a nickel cobalt manganese compound having a small primary particle size, high secondary particle size uniformity, and high density (tap density).

It is a figure which shows the one part process of the manufacturing method of the nickel cobalt manganese compound concerning this invention. 2 is a diagram showing an electron microscope observation image (3000 times) of particles obtained in the nucleation step of Example 1. FIG. 2 is a diagram showing an electron microscope observation image (1000 times) of particles obtained in the particle growth step of Example 1. FIG. It is a figure which shows the electron microscope observation image (5000 times) of the particle | grains obtained at the particle growth process of Example 1. FIG. It is a figure which shows the electron microscope observation image (1000 times) of the particle | grains obtained at the particle growth process of Example 4. FIG. It is a figure which shows the electron microscope observation image (5000 times) of the particle | grains obtained at the particle growth process of Example 4. FIG. It is a figure which shows the electron microscope observation image (1000 times) of the particle | grains obtained at the particle growth process of the comparative example 1. It is a figure which shows the electron microscope observation image (5000 times) of the particle | grains obtained at the particle growth process of the comparative example 1.

  A specific embodiment to which the present invention is applied (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings in the following order. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

1. 1. Nickel cobalt manganese compound 1-1. Composition 1-2. Average particle diameter 1-3. Particle size distribution 2. Manufacturing method of nickel cobalt manganese compound 2-1. Nucleation process 2-2. Particle growth step 2-3. Cleaning step 2-4. Drying process

[1. Nickel cobalt manganese compound]
The nickel-cobalt-manganese compound according to the present embodiment is a composite of nickel-cobalt-manganese composite hydroxide and nickel-cobalt-manganese composite carbonate, and is a substantially spherical secondary formed by agglomeration of fine primary particles. Consists of particles. Since the nickel cobalt manganese compound has a small particle size, a high particle size uniformity, and a high density (tap density), it can be used as a raw material (precursor) of a positive electrode active material for a non-aqueous electrolyte secondary battery.

<1-1. Composition>
The nickel-cobalt-manganese compound has the general formula 1: Ni _x Co _y Mn _z M _t (OH) _{2 + a} (where x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0 .45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5, and M is Mg, Ca, Al, Ti, V, Cr, Zr, Nb, A nickel cobalt manganese composite hydroxide represented by Mo and W, and a general formula 2: Ni _x Co _y Mn _z M _t CO _{3 + a} (wherein X + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5 And M is one selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, W A added element above.) Is a composite of nickel-cobalt-manganese composite carbonate represented by.

(Additive elements)
The nickel-cobalt-manganese compound is composed of one or more additional elements selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W within a predetermined atomic ratio t. It is preferable that the particles are uniformly distributed and / or the surfaces of the secondary particles are uniformly coated.

  One or more nickel-cobalt-manganese compounds are added to improve battery characteristics such as cycle characteristics and output characteristics when nickel-cobalt-manganese compounds are used as a precursor of a positive electrode active material of a non-aqueous electrolyte secondary battery. An element is added. In the nickel-cobalt-manganese compound, when the atomic ratio t of the additive elements exceeds 0.1, the metal elements contributing to the oxidation-reduction reaction (Redox reaction) are reduced, and the battery capacity is lowered. Therefore, the additive element is adjusted so that the atomic ratio t falls within the range of 0 ≦ t ≦ 0.1.

  In the nickel cobalt manganese compound, within the range of the atomic ratio t described above, one or more additional elements are uniformly distributed inside and / or uniformly coated on the surface, thereby improving the battery characteristics of the entire compound. An effect can be obtained. For this reason, in the nickel cobalt manganese compound, even if the addition amount of one or more additional elements is small, the effect of improving the battery characteristics can be obtained and the decrease in the battery capacity can be suppressed. Furthermore, in the nickel cobalt manganese compound, in order to obtain the effect of improving battery characteristics with a smaller addition amount of one or more additional elements, the concentration of the one or more additional elements on the compound surface can be increased from the inside of the compound. preferable.

<1-2. Average particle size>
The primary particles of the nickel cobalt manganese compound have an average particle size of 10 nm to 100 nm. In the nickel-cobalt-manganese compound, by setting the primary particles of the nickel-cobalt-manganese compound to 10 nm to 100 nm, substantially spherical secondary particles having a predetermined average particle diameter can be formed.

  If the primary particle of the nickel cobalt manganese compound is less than 10 nm, the surface energy increases rapidly with an increase in specific surface area, which is not preferable because it is necessary to take measures to suppress aggregation in the formation of substantially spherical secondary particles. . On the other hand, when the primary particle of the nickel cobalt manganese compound exceeds 100 nm, it is difficult to form substantially spherical secondary particles due to a decrease in surface energy, which is not preferable.

  The secondary particles of the nickel cobalt manganese compound have an average particle size of 2 μm to 10 μm. In the nickel cobalt manganese compound, by adjusting the average particle size of the secondary particles to 2 μm to 10 μm, for example, the positive electrode active material obtained by using the nickel cobalt manganese compound as a raw material is adjusted to a predetermined average particle size. Can do.

  Thereby, in the non-aqueous electrolyte secondary battery using the above-mentioned positive electrode active material, the packing density of the positive electrode is high, and the battery capacity and output characteristics can be improved. Thus, since the average particle diameter of the secondary particles of the nickel cobalt manganese compound correlates with the particle diameter of the obtained positive electrode active material, it affects the characteristics of a battery using this positive electrode active material as the positive electrode material. .

  When the average particle diameter of the secondary particles of the nickel cobalt manganese compound is less than 2 μm, the average particle diameter of the obtained positive electrode active material is also reduced, the packing density of the positive electrode is lowered, and the battery capacity per volume is lowered. Conversely, when the average particle size of the secondary particles of the nickel cobalt manganese compound exceeds 10 μm, the specific surface area of the obtained positive electrode active material is reduced, and the interface with the electrolyte is reduced, thereby increasing the resistance of the positive electrode. As a result, the output characteristics of the battery deteriorate.

<1-3. Particle size distribution>
The nickel-cobalt-manganese compound has an index ((d90-d10) / average particle size) indicating the spread of the particle size distribution of 0.55 or less.

  Since the particle size distribution of the positive electrode active material is strongly influenced by the raw material nickel cobalt manganese compound, if fine particles and / or coarse particles (large particle) are mixed in the compound, the same applies to the positive electrode active material. Particles will be present. That is, in the nickel cobalt manganese compound, when [(d90-d10) / average particle size] exceeds 0.55 and the range of particle size distribution is wide, fine particles and / or coarse particles are also present in the positive electrode active material. Will come to do.

  When a positive electrode is formed using a positive electrode active material containing a large amount of fine particles in a nickel cobalt manganese compound, heat may be generated due to local reaction of the fine particles, and the safety of the battery is reduced. At the same time, since the fine particles are selectively deteriorated, the cycle characteristics of the battery are deteriorated. In addition, when a positive electrode is formed using a positive electrode active material having a large amount of coarse particles in a nickel cobalt manganese compound, a sufficient reaction area between the electrolyte and the positive electrode active material cannot be obtained, resulting in an increase in reaction resistance. Battery output decreases.

  Therefore, in the nickel cobalt manganese compound, by setting [(d90-d10) / average particle size] to 0.55 or less, the positive electrode active material obtained using this as a precursor also has a narrow particle size distribution range. The particle size can be made uniform.

  In the index [(d90−d10) / average particle size] indicating the spread of the particle size distribution, d10 is the number of particles in each particle size accumulated from the smaller particle size side, and the accumulated volume is the total volume of all particles. Means a particle size of 10%. D90 means a particle size in which the number of particles is accumulated as in d10, and the accumulated volume is 90% of the total volume of all particles.

  Here, the method for obtaining the average particle diameter, d10 and d90 is not particularly limited, but for example, it can be obtained from the volume integrated value measured with a laser light diffraction / scattering particle size analyzer. Further, d50 is used as the average particle diameter, and a particle diameter in which the cumulative volume is 50% of the total particle volume may be used as in d90.

  The nickel-cobalt-manganese compound as described above is a composite of nickel-cobalt-manganese composite hydroxide and nickel-cobalt-manganese composite carbonate, and is formed from substantially spherical secondary particles formed by aggregation of fine primary particles. It has a small particle size, high particle uniformity, and high density (tap density). Accordingly, such a nickel cobalt manganese compound is particularly suitable as a raw material for the positive electrode active material of a non-aqueous electrolyte secondary battery, has excellent safety, and can be reduced in size and increased in output.

[2. Method for producing nickel cobalt manganese compound]
In the method for producing a nickel cobalt manganese compound according to the present embodiment (hereinafter sometimes simply referred to as “compound production method”), after obtaining nickel cobalt manganese compound particles by crystallization reaction, the compound particles are obtained. The nickel cobalt manganese compound is produced by washing and drying. More specifically, as shown in FIG. 1, the method for producing a compound nucleates nickel cobalt manganese compound particles (A) nucleation step, and grows nuclei generated in the nucleation step (B). A grain growth step.

  In the conventional continuous crystallization method, since the nucleation reaction and the particle growth reaction proceed simultaneously in the same reaction tank, the particle size distribution of the obtained compound particles has become wide. On the other hand, the method for producing compound particles clearly separates both the steps by mainly separating the time at which the nucleation reaction occurs (nucleation step) and the time at which the particle growth reaction mainly occurs (particle growth step). Even if it is carried out in the same reaction tank, it is characterized in that compound particles having a narrow particle size distribution can be obtained. In addition, the method for producing compound particles can control the crystal size of the resulting compound particles by blowing carbon dioxide gas during the crystallization reaction, and further reduce the ammonium ion concentration during the crystallization reaction. There is a feature in what can be done.

<2-1. Nucleation process>
First, the nucleation process will be described with reference to FIG. As shown in FIG. 1, in the nucleation step, a pre-reaction aqueous solution and a mixed aqueous solution are prepared in a reaction tank, the mixed aqueous solution is supplied into the reaction tank in which the pre-reaction aqueous solution is prepared, and carbon dioxide gas is blown into the reaction tank. Then, a nucleation reaction aqueous solution is generated to carry out a nucleation reaction. In the nucleation step, if necessary, the pre-reaction aqueous solution may be supplied into the reaction tank in which the mixed aqueous solution is prepared, and carbon dioxide gas is blown to produce the nucleation reaction aqueous solution.

  In the nucleation step, nucleation of new nickel cobalt manganese compound particles is continued in the nucleation reaction aqueous solution by supplying the mixed aqueous solution into the reaction tank in which the pre-reaction aqueous solution is prepared. In the nucleation step, the nucleation reaction is terminated when a predetermined amount of nuclei is generated in the aqueous nucleation reaction solution. In the nucleation step, whether or not a predetermined amount of nuclei has been generated in the nucleation reaction aqueous solution is determined by the amount of the metal salt contained in the mixed aqueous solution.

  In the nucleation step, in order to complete the nucleation reaction and stabilize the components in the nucleation reaction solution, it is preferable to stop the supply of the mixed aqueous solution and perform aging. The aging time is preferably about 5 to 300 minutes, more preferably about 10 to 60 minutes.

(Pre-reaction aqueous solution)
In the nucleation step, an alkaline aqueous solution and / or an ammonium ion supplier and water are supplied to the reaction tank, and these are mixed to produce a pre-reaction aqueous solution.

  The aqueous alkali solution is not particularly limited as long as it can be used to produce a pre-reaction aqueous solution and the pH value of the aqueous nucleation reaction solution can be adjusted. For example, an alkali metal such as sodium hydroxide or potassium hydroxide can be used. An aqueous solution of hydroxide can be used. In the nucleation step, an alkali metal hydroxide may be directly supplied into the reaction vessel to produce an aqueous nucleation reaction solution. However, the reaction vessel is used as an aqueous solution because of the ease of controlling the pH value of the nucleation reaction aqueous solution. It is preferable to prepare a nucleation reaction aqueous solution by supplying it inside.

  In the nucleation step, at least one of an alkaline aqueous solution and an ammonium ion supplier may be supplied into the reaction tank to form a pre-reaction aqueous solution, which will produce nuclei of nickel cobalt manganese compound particles. be able to. Examples of the ammonium ion supplier include an aqueous ammonia solution.

  The method for supplying the alkaline aqueous solution and / or the ammonium ion supplier into the reaction vessel is not particularly limited. For example, a pump capable of controlling the flow rate such as a metering pump while sufficiently stirring the nucleation reaction aqueous solution. Thus, the nucleation reaction aqueous solution may be added so that the pH value is maintained within a predetermined range.

(Mixed aqueous solution)
In the nucleation step, a plurality of metal compounds are respectively dissolved in water at a predetermined ratio in a reaction tank different from the reaction tank for the pre-reaction aqueous solution to generate a mixed aqueous solution.

  In the nucleation step, it is preferable to use a water-soluble metal compound as the metal compound containing the metal necessary for the production of the target nickel cobalt manganese compound particles. Examples of the water-soluble metal compound include nitrate, sulfate, hydrochloric acid Examples thereof include nickel sulfate, cobalt sulfate, manganese sulfate and the like.

  The composition ratio of each metal in the nickel cobalt manganese compound particles is the same as the composition ratio of each metal in the mixed aqueous solution. Therefore, in the nucleation step, the ratio of each metal compound dissolved in water is adjusted so that the composition ratio of each metal in the mixed aqueous solution is the same as the composition ratio of each metal in the nickel cobalt manganese compound particles. Thus, a mixed aqueous solution is generated.

  The composition ratio of each metal in the nickel-cobalt-manganese compound particles is as follows: the atomic ratio of nickel is x, the atomic ratio of cobalt is y, the atomic ratio of manganese is z, and the atomic ratio of one or more additional elements described later is used. t = x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ Satisfies a ≦ 0.5.

  In the nucleation step, a mixed aqueous solution can be generated by mixing a compound containing one or more additional elements at a predetermined ratio, if necessary. In the nucleation step, it is preferable to use a water-soluble compound containing one or more additive elements selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W. For example, titanium sulfate Use ammonium peroxotitanate, potassium potassium oxalate, vanadium sulfate, ammonium vanadate, chromium sulfate, potassium chromate, zirconium sulfate, zirconium nitrate, niobium oxalate, ammonium molybdate, sodium tungstate, ammonium tungstate, etc. Can do.

  The one or more additive elements are preferably uniformly distributed and / or uniformly coated on the surfaces of the secondary particles in the nickel cobalt manganese compound particles. In order to uniformly disperse one or more kinds of additive elements inside the nickel cobalt manganese compound particles, a compound containing one or more kinds of additive elements described above may be added to the mixed aqueous solution. Thereby, in a nucleation process, it can co-precipitate in the state where one or more sorts of addition elements were uniformly dispersed inside nickel cobalt manganese compound particles.

  On the other hand, in order to coat the surface of the nickel cobalt manganese compound particles with one or more additive elements, for example, the nickel cobalt manganese compound particles are slurried with an aqueous solution containing one or more additive elements to generate the slurry. In the reaction tank, an aqueous solution containing one or more additional elements is added while controlling to a predetermined pH described later, and one or more additional elements are converted into a nickel cobalt manganese compound by a crystallization reaction. Precipitate on the surface of the particles.

  Thereby, in the nucleation step, the surface of the nickel cobalt manganese compound particles can be uniformly coated with one or more additional elements. In the nucleation step, an alkoxide solution containing one or more additive elements may be used instead of the aqueous solution containing one or more additive elements.

  Further, in the nucleation step, the surface of the nickel cobalt manganese compound particles is also sprayed on the nickel cobalt manganese compound particles by spraying and drying an aqueous solution or slurry containing one or more additive elements. It can be coated with additional elements.

  Further, in the nucleation step, a method in which nickel cobalt manganese compound particles and a slurry in which a salt containing one or more additional elements is suspended is spray-dried, or nickel cobalt manganese compound particles and one or more additional elements are added. The surface of the nickel cobalt manganese compound particles can be coated with one or more additional elements by a method of mixing the contained salt with a solid phase method or the like.

  When the surface of the nickel cobalt manganese compound particles is coated with one or more additive elements, the atomic ratio of the one or more additive element ions present in the mixed aqueous solution is reduced by an amount covering the nickel cobalt manganese compound particles. Thus, the atomic ratio of the metal ions of the obtained nickel cobalt manganese compound particles can be matched. Moreover, you may perform the process of coat | covering the surface of nickel cobalt manganese compound particle | grains with 1 or more types of additional elements with respect to the nickel cobalt manganese compound particle | grains after heating.

  The concentration of the mixed aqueous solution is 1 mol / L to 2.6 mol / L in total of the metal compounds, and preferably 1.5 mol / L to 2.2 mol / L. When the concentration of the mixed aqueous solution is less than 1 mol / L, the amount of crystallized material per reaction tank is decreased, which is not preferable because productivity is lowered. On the other hand, when the concentration of the mixed aqueous solution exceeds 2.6 mol / L, the saturated concentration at room temperature is exceeded, so there is a risk that crystals re-deposit and clog the equipment piping.

  In the nucleation step, the metal compound is not necessarily supplied to the reaction vessel as a mixed aqueous solution. For example, by mixing a plurality of metal compounds, when specific metal compounds react with each other to generate an unnecessary compound, the total concentration of the aqueous solution containing all the metal compounds is the concentration of the mixed aqueous solution described above. Alternatively, an aqueous solution containing a metal compound may be prepared individually so as to fall within the range of the above, and the prepared aqueous solution containing each metal compound may be simultaneously supplied into the reaction vessel at a predetermined ratio.

(carbon dioxide gas)
In the nucleation step, carbonic acid gas is blown into the reaction vessel supplied with the pre-reaction aqueous solution and the mixed aqueous solution to produce a nucleation reaction aqueous solution. Thereby, in a nucleation process, a part of nickel cobalt manganese compound hydroxide can be carbonated, and a complex of nickel cobalt manganese compound hydroxide and nickel cobalt manganese compound carbonate can be obtained.

  In the nucleation process, by supplying carbon dioxide during the nucleation reaction, dense secondary particles are obtained compared to the plate-like nickel cobalt manganese composite hydroxide particles obtained by the conventional method, and the tap density is improved. Contribute. That is, in the nucleation step, fine primary particles are obtained in the obtained composite, and the density of the substantially spherical secondary particles formed by aggregation of the primary particles can be increased (tap density).

  In the nucleation step, the amount of carbon dioxide supplied during the nucleation reaction is preferably 1 to 5 times the total molar amount of the metal added to the mixed aqueous solution. When the supply amount of carbon dioxide gas is less than 1 times the total molar amount of metals added to the mixed aqueous solution, it is not preferable because it is insufficient to carbonate a part of the nickel cobalt manganese composite hydroxide. . On the other hand, if the supply amount of carbon dioxide exceeds 5 times the total molar amount of metals added to the mixed aqueous solution, it does not contribute to the reaction and is only released as carbon dioxide, and the liquid is acidified. Therefore, a large amount of alkaline solution for pH adjustment is required, resulting in high cost. Further, when caustic soda (sodium hydroxide) is used as the alkaline solution, it is not preferable because it is added in a large amount and the residual amount of sodium as an impurity may increase.

  That is, in the nucleation step, when the supply amount of carbon dioxide gas deviates from the above-described range, fine primary particles having a predetermined particle diameter cannot be obtained in the obtained composite, and the primary particles are It becomes difficult to increase the density of the secondary particles formed by aggregation. Therefore, when such nickel cobalt manganese compound particles are used as a precursor of the positive electrode active material of a non-aqueous electrolyte secondary battery, it is insufficient to improve battery characteristics such as cycle characteristics and output characteristics.

  In the nucleation step, carbon dioxide gas is blown in by a normal method until the nucleation reaction is completed. When carbon dioxide gas is blown in, for example, a fine foam or the like is not preferable because piping is clogged.

(Nucleation reaction aqueous solution)
In the nucleation step, carbonic acid gas is blown into the reaction vessel supplied with the pre-reaction aqueous solution and the mixed aqueous solution to produce a nucleation reaction aqueous solution.

  The ammonium ion concentration in the aqueous nucleation reaction solution is preferably maintained at a constant value within a range of 0 g / L to 15 g / L. When the ammonium ion concentration exceeds 15 g / L, the solubility of metal ions becomes too high due to the formation of ammonia complexes, the amount of metal ions remaining in the aqueous nucleation reaction solution increases, and the composition of the nickel cobalt manganese compound particles increases. Misalignment may occur.

  The nickel cobalt manganese compound particles obtained after the nucleation reaction tend to have a higher tap density as the ammonium ion concentration is lower, but the particle size distribution tends to be wider. Therefore, the optimum ammonium ion concentration is determined in consideration of the tap density and the spread of the particle size distribution.

  In the nucleation step, when the ammonium ion concentration varies, the solubility of metal ions varies and uniform nickel cobalt manganese compound particles are not formed. Therefore, it is preferable to maintain a constant value. For example, the ammonium ion concentration is preferably maintained at a desired concentration by setting the upper and lower limits to about 5 g / L. Therefore, the ammonium ion concentration in the aqueous nucleation reaction solution is preferably adjusted to be 0 g / L to 15 g / L by adjusting the supply amount of the ammonium ion supplier.

  When an alkaline aqueous solution is used instead of the ammonium ion supplier for the formation of the aqueous solution before the reaction, the ammonium ion concentration in the nucleation reaction aqueous solution is 0 g / L. It is used as an index for nucleation of nickel cobalt manganese compound particles. In this case, the pH value of the aqueous solution for nucleation reaction at a liquid temperature of 25 ° C. is controlled to be 6.5 to 10.5, preferably 6.8 to 9.5, depending on the supply amount of the alkaline aqueous solution.

  In the nucleation step, the pH value and ammonium ion concentration in the nucleation reaction aqueous solution can be measured by a general pH meter and ion meter, respectively.

  The temperature of the aqueous nucleation reaction solution is preferably adjusted to 30 ° C or higher, more preferably 40 ° C to 60 ° C. When the temperature of the aqueous solution of nucleation reaction is less than 30 ° C., the solubility is low, so that nucleation easily occurs and control becomes difficult. On the other hand, when the temperature of the nucleation reaction aqueous solution exceeds 60 ° C., carbon dioxide gas does not dissolve in the nucleation reaction aqueous solution, so that the carbonation reaction of the nickel cobalt manganese composite hydroxide is significantly inhibited. Therefore, it is preferable to adjust the temperature of the nucleation reaction aqueous solution to be 30 ° C to 60 ° C.

  In the nucleation step, the concentration of the crystallized product at the time when the crystallization reaction is completed (after the particle growth step described later) is approximately 30 g / L to 200 g / L, preferably 80 g / L to 150 g / L. In addition, it is desirable to supply a metal compound, a compound containing one or more additive elements, and the like. When the concentration of the crystallized product is less than 30 g / L, the aggregation of the primary particles in the nickel cobalt manganese compound particles becomes insufficient. On the other hand, when the concentration of the crystallized substance exceeds 200 g / L, the mixed aqueous solution to be added is not sufficiently diffused in the reaction tank, and the growth of the nickel cobalt manganese compound particles may be biased.

  In the nucleation step, the amount of nuclei of the nickel cobalt manganese compound particles to be generated is not particularly limited, but in order to obtain nickel cobalt manganese compound particles having a good particle size distribution, the total amount, that is, nickel cobalt The total metal salt supplied to obtain manganese compound particles is preferably 0.1% to 10%, more preferably 5% or less.

<2-2. Particle growth process>
Next, the particle growth process will be described with reference to FIG. As shown in FIG. 1, in the particle growth step, the pH value of the nucleation reaction aqueous solution obtained in the nucleation step is adjusted to be within a predetermined range, and further, carbon dioxide gas is blown into the reaction vessel to thereby form particles. A growth reaction aqueous solution is generated and a particle growth reaction is performed to obtain nickel cobalt manganese compound particles.

  In the particle growth step, the pH value of the aqueous nucleation reaction solution is controlled by adjusting the supply amount of the alkaline aqueous solution. In addition, the alkaline aqueous solution used here can utilize the aqueous solution of an alkali metal hydroxide similarly to the nucleation process.

  In the particle growth process, the pH value and ammonium ion concentration of the particle growth reaction aqueous solution change with the growth of the nickel cobalt manganese compound particles by supplying the alkaline aqueous solution into the reaction vessel. Need to return. Therefore, in the particle growth step, the mixed solution, alkaline solution, or ammonium ion supplier is supplied to the particle growth reaction aqueous solution as necessary, so that the pH value and ammonium ion concentration of the particle growth reaction aqueous solution are predetermined. Control to maintain range.

  Thereafter, in the particle growth step, the particle growth reaction is terminated when the nickel cobalt manganese compound particles have grown to a predetermined particle size. In the particle growth step, the relationship between the amount of metal salt added to each reaction aqueous solution in each step of the nucleation step and particle growth step and the particle size of the obtained nickel cobalt manganese compound particles is determined by preliminary tests. In this case, the end time of the particle growth reaction can be easily determined from the amount of the metal salt added in each step.

(PH value)
In the particle growth step, it is necessary to control the pH value of the particle growth reaction aqueous solution to be in the range of 6.5 to 10.5, preferably 6.8 to 9.5, based on the liquid temperature of 25 ° C. When the pH value of the particle growth reaction aqueous solution exceeds 10.5, impurity cations are likely to remain, such being undesirable. Moreover, when the pH value of the particle growth reaction aqueous solution is less than 6.5, impurity anions tend to remain, which is not preferable.

  That is, in the particle growth step, nickel cobalt manganese compound particles with a small amount of remaining impurities can be obtained by controlling the pH value of the particle growth reaction aqueous solution within the above range. The fluctuation range of the pH value is preferably within 0.2 above and below the set value. When the fluctuation range of the pH value of the particle growth reaction aqueous solution is large, the growth of nickel cobalt manganese compound particles is not constant, and uniform compound particles with a narrow particle size distribution range may not be obtained.

(Ammonium ion concentration)
The ammonium ion concentration in the aqueous particle growth reaction solution is preferably maintained at a constant value within the range of 0 g / L to 20 g / L. If the ammonium ion concentration exceeds 20 g / L, the nuclei of nickel cobalt manganese compound particles may not be able to grow uniformly. In addition, when the ammonium ion concentration varies, the solubility of metal ions varies, and the growth of uniform nuclei of compound particles is inhibited. Therefore, it is preferable to maintain a constant value. The lower limit value of the ammonium ion concentration can be appropriately adjusted as necessary, and is not particularly limited. Therefore, the ammonium ion concentration in the reaction aqueous solution is preferably adjusted to be 0 g / L to 20 g / L by adjusting the supply amount of the ammonium ion supplier.

  In the particle growth process, as described above, the pH value of the particle growth reaction aqueous solution and the ammonium ion concentration in the particle growth reaction aqueous solution have been described. However, the amount of carbon dioxide added, the concentration of the mixed aqueous solution, Since conditions such as temperature are substantially the same as those in the nucleation step, description thereof is omitted here.

(Particle size control)
The particle diameter of the nickel cobalt manganese compound particles can be controlled by the time of the particle growth reaction. That is, in the particle growth step, nickel cobalt manganese compound particles having a desired particle size can be obtained by continuing the particle growth reaction until the particle grows to a desired particle size.

  Further, the particle diameter of the nickel cobalt manganese compound particles can be controlled not only by the particle growth process but also by controlling the pH value of the nucleation process and the amount of raw material supplied for nucleation. That is, in the nucleation process, the supply of raw materials to be added by shifting the pH value of the aqueous solution of nucleation reaction at the time of nucleation of nickel cobalt manganese compound particles to the high pH value side or extending the nucleation time By increasing the amount, the number of nuclei of the nickel cobalt manganese compound particles to be generated is increased.

  Thereby, even when a particle growth process is made into the same conditions, the particle diameter can be made small by controlling so that the nucleation number of nickel cobalt manganese compound particle | grains may be increased. On the other hand, in the method for producing a compound, the particle diameter of the nickel cobalt manganese compound particles can be increased by controlling the number of nucleation of the nickel cobalt manganese compound particles to be reduced.

(production equipment)
In the method for producing a compound, an apparatus is used that does not collect nickel cobalt manganese compound particles as a product until the reaction in the particle growth step is completed. Such an apparatus is, for example, a normally used batch reaction tank equipped with a stirrer. When such an apparatus is used in a compound production method, there is no problem that the growing particles are recovered simultaneously with the overflow liquid unlike a continuous crystallization apparatus that recovers a product by a general overflow. Particles with a narrow distribution and uniform particle size can be obtained.

  Further, in the method for producing a compound, since it is necessary to control the reaction atmosphere, an apparatus capable of controlling the atmosphere, such as a sealed apparatus, is used. In the compound production method, by using such an apparatus, the nickel cobalt manganese compound particles can have the structure as described above, and the nucleation reaction and the particle growth reaction can be advanced almost uniformly. Therefore, particles having excellent particle size distribution, that is, particles having a narrow particle size distribution range can be obtained.

  As described above, in the nucleation step in the compound production method, nucleation occurs preferentially and almost no nucleation occurs. Conversely, in the particle growth step, only nucleation occurs and almost new nuclei are generated. Not. For this reason, in the nucleation step, homogeneous nuclei with a narrow particle size distribution range can be formed, and in the particle growth step, nuclei can be grown homogeneously. Therefore, in the method for producing a compound, the range of the particle size distribution is narrow, and uniform nickel cobalt manganese compound particles can be obtained.

  In the method for producing a compound, in both steps, metal ions are crystallized as nuclei or composite particles, so that the ratio of the liquid component to the metal component in each reaction aqueous solution increases. In this case, apparently, the concentration of the mixed aqueous solution to be supplied is lowered, and there is a possibility that the nickel cobalt manganese compound particles are not sufficiently grown particularly in the particle growth step.

  For this reason, in the method for producing a compound, in order to suppress an increase in the liquid component in each reaction aqueous solution in both steps, the liquid in the particle growth reaction aqueous solution is somewhere between the start of the particle growth step and midway. It is preferable to discharge some of the components out of the reaction vessel. For example, in the method for producing the compound, the supply of the mixed aqueous solution, the alkaline aqueous solution, and the ammonium ion supplier to the particle growth reaction aqueous solution is stopped and the core and nickel cobalt manganese compound particles are allowed to settle, and the supernatant of the particle growth reaction aqueous solution is obtained. Drain the liquid.

  Thereby, in the manufacturing method of a nickel cobalt manganese compound, the relative density | concentration of the mixed aqueous solution in particle growth reaction aqueous solution can be raised. Since the nickel cobalt manganese compound particles can be grown in a state where the relative concentration of the mixed aqueous solution is high, the particle size distribution of the nickel cobalt manganese compound particles can be further narrowed, and the secondary particles of the nickel cobalt manganese compound particles can be narrowed. The density of the entire particle can also be increased.

  In the method for producing a compound, the pH of the nucleation reaction aqueous solution after the nucleation step is adjusted to form a particle growth reaction aqueous solution, and the particle growth step is subsequently performed from the nucleation step. There is an advantage that the transition to the process can be performed quickly. In addition, the pH value of each reaction aqueous solution can also be adjusted by adding sulfuric acid to each reaction aqueous solution in the case of the inorganic acid of the same kind as the acid which comprises a metal compound, for example, a sulfate.

  In the compound production method, the nucleation step and the particle growth step can be more reliably separated, so that the state of each reaction aqueous solution in each step can be set to the optimum condition for each step. In particular, the pH of the aqueous solution for particle growth can be adjusted to the optimum condition from the start of the particle growth process. The nickel cobalt manganese compound particles formed in the particle growth step can have a narrower particle size distribution range and be uniform.

  In the method for producing a compound, a particle growth reaction aqueous solution obtained by adding a nucleation reaction aqueous solution containing nuclei formed in the nucleation step to an aqueous solution different from the nucleation reaction aqueous solution can be used. For example, in the compound production method, a component adjusted aqueous solution adjusted to a pH value and ammonium ion concentration suitable for the particle growth step is formed separately from the nucleation reaction aqueous solution, and another reaction solution is added to this component adjusted aqueous solution. A nucleation reaction aqueous solution containing nuclei generated by performing a nucleation reaction in a tank may be added to form a particle growth reaction aqueous solution, and the particle growth reaction may be performed in this particle growth reaction aqueous solution.

  In this case, in the compound production method, the nucleation step and the particle growth step can be more reliably separated, so that the state of the reaction aqueous solution in each step can be set to an optimum condition for each step. In particular, in the method for producing a compound, the pH value of the aqueous solution for particle growth can be set to the optimum condition from the beginning of starting the particle growth process.

<2-3. Cleaning process>
In the washing step, the slurry containing the nickel cobalt manganese compound particles obtained in the particle growth step as described above is washed. First, in the washing step, the slurry containing nickel cobalt manganese compound particles is filtered, washed with water, and filtered again. Filtration may be performed by a commonly used method. For example, a centrifuge or a suction filter is used.

  Washing with water may be performed by a usual method as long as it can remove excess salt contained in the nickel cobalt manganese compound particles. The water used in the water washing is preferably water having as little impurity content as possible, and more preferably pure water, in order to prevent contamination of impurities.

<2-4. Drying process>
In the drying step, the nickel cobalt manganese compound particles washed in the washing step are dried. First, in the drying step, for example, the washed nickel cobalt manganese compound particles are dried at a drying temperature of 100 ° C. to 230 ° C. When this drying is finished, a nickel cobalt manganese compound can be obtained in the drying step.

  In the method for producing a compound described above, both steps are the same by clearly separating mainly the time at which the nucleation reaction occurs (nucleation step) and the time at which the particle growth reaction mainly occurs (particle growth step). Even when carried out in the reaction vessel, nickel cobalt manganese compound particles having a narrow particle size distribution can be obtained. In addition, in the method for producing a nickel cobalt manganese compound, by blowing carbon dioxide during the crystallization reaction, the crystal size of the resulting compound particles can be controlled, and the ammonium ion concentration during the crystallization reaction is further reduced. be able to.

  Therefore, in the method for producing a nickel cobalt manganese compound, it is possible to obtain a nickel cobalt manganese compound having a small primary particle size, high secondary particle size uniformity, and high density (tap density).

  In the method for producing a compound, the nucleation step and the particle growth step can be performed separately in one reaction tank by simply controlling the reaction atmosphere and adjusting the pH of the reaction solution. Therefore, the manufacturing method of the nickel cobalt manganese compound is easy and suitable for large-scale production, so that it can be said that its industrial value is extremely large.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited to these Examples and a comparative example. Note that, through all the examples and comparative examples, commercially available reagent products were used for the production of nickel cobalt manganese compound particles.

(Example 1)
In Example 1, nickel cobalt manganese compound particles were produced as follows.

<Nucleation process>
First, in the nucleation step, the temperature in the tank was set to 40 ° C. while stirring the water up to about 1 L in the reaction tank (5 L). The inside of the reaction tank at this time was an air atmosphere (oxygen concentration: 21% by volume). In the nucleation step, an appropriate amount of 25% by mass ammonia water was added to the water in the reaction tank, and the ammonium ion concentration in the reaction solution was adjusted to 15 g / L to obtain a pre-reaction aqueous solution.

  Next, in the nucleation step, nickel sulfate, cobalt sulfate and manganese sulfate were dissolved in water to prepare a 2.0 mol / L mixed aqueous solution. In the nucleation step, the element molar ratio of each metal in the mixed aqueous solution was adjusted to be Ni: Co: Mn = 0.167: 0.167: 0.666.

  In the nucleation step, this mixed aqueous solution was added to the pre-reaction aqueous solution in the reaction vessel at 10 mL / min. At the same time, 40 mL of carbon dioxide was added at a rate of 1.4 L / min. And then nucleated by stirring (aging) for about 30 minutes. At this time, in the nucleation step, when observed with an electron microscope at a magnification of 3000, fine particles serving as nuclei as shown in FIG. 2 were obtained.

<Particle growth process>
In the particle growth step, after completion of nucleation in the nucleation step, sulfuric acid is gradually added and adjusted so that the pH value of the reaction aqueous solution becomes 9.0 based on the liquid temperature of 25 ° C., and then 25 mass% sodium hydroxide. Start supplying aqueous solution, add aqueous ammonia solution, maintain ammonium ion concentration at 15 g / L, and continue crystallization for 3 hours while controlling pH value to 9.0 based on liquid temperature of 25 ° C. And the stirring was stopped to complete the crystallization. In the particle growth step, the product obtained by crystallization was washed with water, filtered and dried to obtain a compound.

  In the crystallization in the particle growth process, the pH is controlled by adjusting the supply flow rate of the 25% by mass sodium hydroxide aqueous solution by the pH controller, and the fluctuation range is within the range of 0.2 above and below the set value. It was.

  In the particle growth process, in order to measure the tap density, the obtained compound was heat-treated at 500 ° C. and then crushed to measure the tap density and the particle size distribution. The results are shown in Table 1. Further, in the particle growth step, the shape of the obtained compound was observed at 1000 times and 5000 times with an electron microscope, and as a result, dense spherical particles were formed as shown in FIGS.

(Example 2)
In Example 2, except that the ammonium ion concentration in the nucleation step and the particle growth step was set to 10 g / L, a compound was obtained and the tap density and the particle size distribution were measured in the same manner as in Example 1, and the results are shown in Table 2. It was shown in 1.

Example 3
In Example 3, except that the ammonium ion concentration in the nucleation step and the particle growth step was changed to 5 g / L, a compound was obtained and the tap density and the particle size distribution were measured in the same manner as in Example 1. It was shown in 1.

(Example 4)
In Example 4, in the nucleation step, the pH value was set to 8.5 based on the liquid temperature of 25 ° C. with a 25% by mass aqueous sodium hydroxide solution instead of 25% by mass ammonia water. The compound was obtained and the tap density and particle size distribution were measured in the same manner as in Example 1 except that was not added. The results are shown in Table 1. Furthermore, in Example 4, when the shape of the obtained compound was observed with an electron microscope at 1000 times and 5000 times, as shown in FIG. 5 and FIG. 6, the particles obtained in Example 1 were more dense. It formed spherical particles.

(Comparative Example 1)
In Comparative Example 1, except that carbon dioxide gas was not blown in the nucleation step and the particle growth step, the ammonium ion concentration was 13 g / L, and the pH value was 11.0 based on the liquid temperature of 25 ° C. Was the same as in Example 1 to obtain a compound and measure the tap density and particle size distribution. The results are shown in Table 1. Further, in Comparative Example 1, when the shape of the obtained compound was observed with an electron microscope at 1000 times and 5000 times, aggregated particles of coarse plate crystals were formed as shown in FIGS.

(Evaluation)
As shown in Table 1, the nickel cobalt manganese compound obtained in Examples 1 to 4 is an index indicating the average particle size and the spread of the particle size distribution [(d90-d10) / average particle size] Was in the preferred range.

  Further, as shown in Table 1, these compounds were particles having a good particle size distribution and substantially uniform particle sizes, and the tap density was improved and the compounds were high in density. In particular, in Example 4, a nickel cobalt manganese compound having a higher tap density was obtained as shown in Table 1 by not adding ammonia.

  On the other hand, as shown in Table 1, the nickel cobalt manganese compound obtained in Comparative Example 1 had both an average particle size and a value of [(d90-d10) / average particle size] within a preferable range. However, in Comparative Example 1, as shown in Table 1, compared with Examples 1 to 4, a high-density nickel cobalt manganese compound with improved tap density was not obtained.

  When the nickel cobalt manganese compound according to the present invention is applied as a positive electrode active material to a non-aqueous electrolyte secondary battery, the secondary battery is a small portable electronic device (a notebook personal computer or a mobile phone) that always requires a high capacity. It can be suitably used as a power source for a terminal or the like.

  In addition, the non-aqueous electrolyte secondary battery in which the nickel cobalt manganese compound according to the present invention is applied as a positive electrode active material has excellent safety, and can be reduced in size and output. It can be suitably used as a power source for transportation equipment that receives the power.

Claims (12)

A nickel cobalt manganese compound production method for producing a nickel cobalt manganese compound from nickel cobalt manganese compound particles obtained by a crystallization reaction,
The nickel cobalt manganese compound includes a general formula 1: nickel cobalt manganese composite hydroxide represented by Ni _x Co _y Mn _z M _t (OH) _{2 + a} and a general formula 2: Ni _x Co _y Mn _z M _t CO _{3 + a.} A composite of nickel cobalt manganese composite carbonate represented by the formula (wherein x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5 is satisfied, and M is selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W It is an additive element more than seeds.)
In a nucleation reaction aqueous solution comprising a mixed aqueous solution containing a metal compound containing nickel, a metal compound containing cobalt and a metal compound containing manganese, and a pre-reaction aqueous solution containing an alkaline aqueous solution and / or an ammonium ion supplier, A nucleation step for nucleation while blowing carbon dioxide gas;
The nucleation aqueous solution after the nucleation is subjected to nucleation while blowing carbon dioxide into a particle growth reaction aqueous solution controlled so that the pH value at a liquid temperature of 25 ° C. is 6.5 to 10.5, A method for producing a nickel cobalt manganese compound, comprising a particle growth step of obtaining nickel cobalt manganese compound particles.   2. The method for producing a nickel cobalt manganese compound according to claim 1, wherein the blowing amount of the carbon dioxide gas is 1 to 5 times the total molar amount of the added metal.   In the nucleation step, the ammonium ion concentration in the nucleation reaction aqueous solution is maintained within a range of 0 g / L to 15 g / L. In the particle growth step, the ammonium ion concentration in the particle growth reaction aqueous solution is It maintains within the range of 0g / L-20g / L, The manufacturing method of the nickel cobalt manganese compound of Claim 1 or Claim 2 characterized by the above-mentioned.   4. The nickel cobalt manganese compound according to claim 1, wherein the nucleation reaction aqueous solution after the nucleation is aged for 5 to 300 minutes and used in the particle growth step. 5. Manufacturing method.   In the particle growth step, as the particle growth reaction aqueous solution, the nucleation reaction aqueous solution containing the nuclei formed in the nucleation step is added to an aqueous solution different from the nucleation reaction aqueous solution containing the nuclei. The method for producing a nickel cobalt manganese compound according to any one of claims 1 to 4, wherein a material is used.   6. The particle growth step, wherein a part of the liquid component of the particle growth reaction aqueous solution is discharged either before the nucleus growth reaction is started or during the nucleus growth reaction. The manufacturing method of the nickel cobalt manganese compound of any one.   The temperature in the said nucleation reaction aqueous solution and the said particle growth reaction aqueous solution is maintained at 30 degreeC or more in the said nucleation process and the said particle growth process, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. The manufacturing method of the nickel cobalt manganese compound of description.   In the nucleation step, after adding an aqueous solution in which the salt containing the one or more additional elements is dissolved in the mixed aqueous solution, or after dissolving the salt containing the mixed aqueous solution and the one or more additional elements. The nickel cobalt according to any one of claims 1 to 7, wherein an aqueous solution is simultaneously added to a pre-reaction aqueous solution containing at least the ammonium ion supplier to form the nucleation reaction aqueous solution. A method for producing a manganese compound.   The nickel cobalt manganese compound particles according to any one of claims 1 to 8, wherein the nickel cobalt manganese compound particles obtained in the particle growth step are coated with the one or more additional elements. Manufacturing method. The coating method of the additive element is:
An aqueous solution containing the one or more additional elements is added to a liquid in which the nickel cobalt manganese compound particles controlled to have a predetermined pH are suspended, and the surface of the nickel cobalt manganese compound particles is added with the 1 A method of precipitating additional elements of seeds or more,
A method of spray drying a slurry in which the nickel cobalt manganese compound particles and the salt containing one or more additional elements are suspended;
The method for producing a nickel cobalt manganese compound according to claim 9, wherein the nickel cobalt manganese compound particles and the salt containing one or more additional elements are mixed by a solid phase method. One general formula _{1: Ni x Co y Mn z} M t (OH) and nickel-cobalt-manganese composite hydroxide represented by _{2 + a,} Formula _{2: Ni x Co y Mn z} M t CO nickel cobalt represented by _{3 + a} Compound with manganese complex carbonate (wherein x + y + z + t = 1, 0.05 ≦ x ≦ 0.45, 0.05 ≦ y ≦ 0.45, 0.6 ≦ z ≦ 0.9, 0 ≦ t ≦ 0.1, 0 ≦ a ≦ 0.5, M is one or more additive elements selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W And is composed of substantially spherical secondary particles formed by aggregation of a plurality of primary particles,
The primary particles have an average particle size of 10 nm to 100 nm, and the secondary particles have an average particle size of 3 μm to 10 μm, which is an index indicating the spread of the particle size distribution [(d90−d10) / average particle size]. Is a nickel cobalt manganese compound, characterized in that it is 0.55 or less.   The nickel-cobalt-manganese compound according to claim 11, wherein the one or more additive elements are uniformly distributed in the secondary particles and / or uniformly cover the surfaces of the secondary particles. .