JP2019121606A - Method for manufacturing positive electrode active substance material, method for manufacturing nonaqueous electrolyte secondary battery, positive electrode active substance material, positive electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery - Google Patents

Abstract

To provide a method for manufacturing a positive electrode active substance material of a high nickel rate, which is reduced in DC resistance, and a method for manufacturing a nonaqueous electrolyte secondary battery.SOLUTION: Provided is a method for manufacturing a positive electrode active substance material, which comprises: a first step of obtaining a dispersion liquid containing positive electrode active substance particles, dielectric particles and a dispersion medium; and a second step of removing the dispersion medium from the dispersion liquid. In the method, the positive electrode active substance particles have a composition represented by LiNiCoMO. The positive electrode active substance particles have an average particle diameter of 8 μm or more and 15 μm or less. The dielectric particles have an average particle diameter of 10 nm or more and 100 nm or less. The dispersion medium contains one or more selected from an ether group-containing solvent, a ketone group-containing solvent, a carbon hydride-based solvent and an ester group-containing solvent.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of manufacturing a positive electrode active material and a method of manufacturing a non-aqueous electrolyte secondary battery, a positive electrode active material, a positive electrode for a non-aqueous electrolyte secondary battery, and a non-aqueous electrolyte secondary battery.

  A lithium transition metal complex oxide mainly composed of nickel (Ni) is used in a non-aqueous electrolyte secondary battery as a positive electrode active material exhibiting a relatively high potential and a high capacity. When a nickel-based positive electrode using such a nickel-containing lithium transition metal composite oxide as such an active material, and a counter electrode (negative electrode) containing graphite are employed, the non-aqueous electrolyte secondary battery may be used as described in 4. Generally, it is charged at 2V.

  However, recently, higher capacity of non-aqueous electrolyte secondary batteries is required, and along with this, with the improvement of the nickel ratio in the positive electrode active material, a non-aqueous electrolyte secondary capable of charging at a higher voltage. A battery is required. Specifically, in the case where a counter electrode (negative electrode) containing graphite is employed, the amount of lithium ions removed and inserted is improved by setting the charge voltage to 4.3 V, and the nickel ratio is set to about 80%. Also, high capacity of 200 mAh / g or more can be achieved.

  Further, in the development of a non-aqueous electrolyte secondary battery, an improvement in discharge capacity, an improvement in capacity characteristics at high-speed charge and discharge rates, and an improvement in cycle characteristics are also required. Patent Document 1 proposes a method for obtaining a positive electrode material by mixing a solution of a dielectric material with a dispersion of lithium cobaltate and gelling it for the purpose of improving capacity characteristics at high-speed charge and discharge rates. ing.

JP, 2016-149270, A

  By the way, in the nonaqueous electrolyte secondary battery, in addition to the above-mentioned performance, reduction of direct current resistance (DCR) is also called for. However, reduction of direct current resistance in the case of using a positive electrode active material with a high nickel ratio has not been well studied.

An object of the present invention is to provide a method for producing a high nickel ratio positive electrode active material having a reduced direct current resistance and a method for producing a non-aqueous electrolyte secondary battery.
Another object of the present invention is to provide a high nickel ratio positive electrode active material having a reduced direct current resistance, and a positive electrode and a non-aqueous electrolyte secondary battery for a non-aqueous electrolyte secondary battery including the same.

In order to solve the above problems, according to one aspect of the present invention, there is provided a dispersion liquid comprising positive electrode active material particles, dielectric particles, and the positive electrode active material particles and a dispersion medium for dispersing the dielectric particles. 1 process,
And d) removing the dispersion medium from the dispersion liquid.
The positive electrode active material particles have a composition represented by the following formula (1),
The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less,
The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less,
The manufacturing method of the positive electrode active material material is provided, wherein the dispersion medium contains one or more selected from an ether group-containing solvent, a ketone group-containing solvent, a hydrocarbon solvent and an ester group-containing solvent.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.10 and x + y + z = 1.

  According to this aspect, it is possible to provide a method for producing a positive electrode active material material with a high nickel ratio, in which direct current resistance is reduced.

Here, in the second step, the dispersion medium may be removed by spray drying.
Spray drying is highly productive and excellent in operability.

In addition, the boiling point of the dispersion medium may be 130 ° C. or less.
Thereby, the dispersion medium can be easily removed from the dispersion.

Further, the dispersion may further contain one or more dispersants selected from nonionic surfactants and fatty acids having 4 to 24 carbon atoms.
Thereby, the dispersion stability of the positive electrode active material particles and the dielectric particles in the dispersion liquid is improved.

The dielectric particles may be made of TiBaO ₃ , BaSrTiO ₃ , Pb (Zr, Ti) O ₃ , (Pb, La) (Zr, Ti) O ₃ , Pb (Zr, Ti, Nb) O ₃ , SrBi ₂ Ta _It may contain one or more selected from the group consisting of ₂ O ₉ , (K, Na) NbO ₃ , KNbO ₃ , KTaO ₃ , (Na, Bi) TiO ₃ and BiFeO ₃ .
This further reduces the direct current resistance of the positive electrode active material.

The dielectric particles may also include one or more selected from the group consisting of TiBaO ₃ and BaSrTiO ₃ .
This further reduces the direct current resistance of the positive electrode active material.

According to another aspect of the present invention, there is provided a first step of obtaining a dispersion containing positive electrode active material particles, dielectric particles, and a dispersion medium for dispersing the positive electrode active material particles and the dielectric particles.
And d) removing the dispersion medium from the dispersion liquid.
The positive electrode active material particles have a composition represented by the following formula (1),
The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less,
The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less,
The manufacturing method of the nonaqueous electrolyte secondary battery is provided, wherein the dispersion medium contains one or more selected from an ether group-containing solvent, a ketone group-containing solvent, a hydrocarbon solvent and an ester group-containing solvent.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.20 and x + y + z = 1.
According to this aspect, it is possible to manufacture a non-aqueous electrolyte secondary battery with reduced direct current resistance.

According to another aspect of the present invention, it has a composition represented by the following formula (1),
The average particle size is 8 μm to 15 μm,
There is provided a positive electrode active material containing positive electrode active material particles having an average particle diameter of 10 nm or more and 100 nm or less.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.10 and x + y + z = 1.
According to this aspect, it is possible to reduce the direct current resistance of the non-aqueous electrolyte secondary battery.

According to another aspect of the present invention, there is provided a positive electrode for a non-aqueous electrolyte secondary battery comprising the above-described positive electrode active material.
According to this aspect, it is possible to reduce the direct current resistance of the non-aqueous electrolyte secondary battery.

According to another aspect of the present invention, there is provided a non-aqueous electrolyte secondary battery including the above-described positive electrode for a non-aqueous electrolyte secondary battery.
According to this aspect, it is possible to reduce the direct current resistance of the non-aqueous electrolyte secondary battery.

As described above, according to the present invention, it is possible to provide a method for producing a positive electrode active material with a high nickel ratio and a reduced direct current resistance, and a method for producing a non-aqueous electrolyte secondary battery.
In addition, it is possible to provide a high nickel ratio positive electrode active material having a reduced direct current resistance, and a positive electrode for non-aqueous electrolyte secondary battery and a non-aqueous electrolyte secondary battery including the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows schematic structure of the non-aqueous electrolyte secondary battery which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<1. Examination of the present inventors>
First, prior to the description of the present invention, the examination of the present inventors until the present invention will be described. The present inventors recalled that a dielectric is supported on positive electrode active material particles for the purpose of reducing the direct current resistance (hereinafter also referred to as "DCR") of a high nickel ratio positive electrode active material. More specifically, by supporting dielectric particles on the surface of positive electrode active material particles, the possibility of promoting polarization in the positive electrode active material and facilitating the release and insertion of lithium ions was examined.

  However, in the method described in Patent Document 1, the positive electrode active material having a high nickel ratio is dissolved at the time of production, and a problem is encountered that the positive electrode active material can not be produced from the beginning. Therefore, as a result of intensive investigations, the present inventors prepare dielectric particles and positive electrode active material particles, disperse them in a predetermined dispersion medium in which they do not dissolve, and obtain a dispersion liquid. It has been found that it is possible to support dielectric particles on the surface of positive active material particles by removing. Furthermore, the present inventors have found the particle diameter of positive active material particles and dielectric particles that can support dielectric particles more reliably on the surface of positive active material particles and can reduce direct current resistance, resulting in the present invention.

<2. Method of manufacturing positive electrode active material>
First, a method of manufacturing a positive electrode active material will be described. The method for producing a positive electrode active material according to the present embodiment includes a first step of obtaining a dispersion including positive electrode active material particles, dielectric particles, and the positive electrode active material particles and a dispersion medium for dispersing the dielectric particles. And a second step of removing the dispersion medium from the dispersion,
The positive electrode active material particles have a composition represented by the following formula (1),
The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less,
The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less,
The manufacturing method of the positive electrode active material material in which the said dispersion medium contains 1 or more types selected from an ether group containing solvent, a ketone group containing solvent, a hydrocarbon type solvent, and an ester group containing solvent.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.20 and x + y + z = 1.
The details will be described below.

(Preparation of positive electrode active material particles)
First, prior to the first step, positive electrode active material particles are prepared. The positive electrode active material particles, as described above, have a composition represented by the following formula (1).
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.20 and x + y + z = 1.

  Such positive electrode active material particles have a relatively high nickel content and a large capacity density. Therefore, such positive electrode active material particles greatly contribute to the increase in capacity of the non-aqueous electrolyte secondary battery 10. On the other hand, when the dielectric is supported by the gel-mediated method as described in Patent Document 1, the positive electrode active material particles themselves are dissolved in the gel. However, the method according to the present embodiment prevents the positive electrode active material particles from being dissolved.

  The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less. As a result, aggregation of the positive electrode active material particles and deterioration of the dispersion stability can be prevented, and a contact area with the electrolytic solution is appropriately generated in the non-aqueous electrolyte secondary battery, and an appropriate amount of lithium ions can be released and inserted. It becomes. On the other hand, when the average particle diameter of the positive electrode active material particles exceeds 15 μm, the dispersion stability is lowered and the contact area with the electrolytic solution is decreased in the obtained non-aqueous electrolyte secondary battery. On the other hand, when the average particle diameter of the positive electrode active material particles is less than 8 μm, aggregation of the positive electrode active material particles is likely to occur. In addition, in the obtained non-aqueous electrolyte secondary battery, the resistance in the positive electrode active material layer is increased. Furthermore, as a result of the particle diameter of the positive electrode active material particles being too small, the specific surface area becomes too large, and a side reaction with the electrolytic solution tends to occur. The average particle diameter of the positive electrode active material particles is preferably 10 μm or more and 15 μm or less.

  In addition, the average particle diameter of the positive electrode active material particle | grains calculated | required the average particle diameter by the laser diffraction and the light-scattering method (the particle size distribution measurement by Microtrac). In the present specification, the “average particle diameter” refers to a particle diameter corresponding to 50% of cumulative particle size from the particle side in a volume-based particle size distribution measured by particle size distribution measurement based on a general laser diffraction / light scattering method (D50 Also referred to as the median diameter.

The method of synthesizing the positive electrode active material particles is not particularly limited, and for example, a coprecipitation method can be used. Specifically, first, positive electrode active material precursor particles are synthesized by coprecipitation method. A mixed powder is produced by mixing the obtained dry powder with a lithium source such as lithium carbonate (Li ₂ CO ₃ ). The obtained mixed powder can be fired, for example, at 800 ° C. to 1050 ° C. in an air atmosphere for 12 hours to synthesize positive electrode active material particles. Here, the molar ratio of Li to another element such as Ni, Co, or M is determined according to the composition of the positive electrode active material particles. A commercially available positive electrode active material particle may be obtained and used.

(First step)
Next, a dispersion containing positive electrode active material particles, dielectric particles and a dispersion medium is obtained. The dispersion liquid can be obtained by adding dielectric particles and positive electrode active material particles to a dispersion medium and dispersing the mixture by stirring or the like.

The dielectric particles promote desorption and insertion of lithium ions in the vicinity of the surface of the positive electrode active material particles by covering the surface of the positive electrode active material particles. The dielectric particles are not particularly limited, but TiBaO ₃ , BaSrTiO ₃ , Pb (Zr, Ti) O ₃ , (Pb, La) (Zr, Ti) O ₃ , Pb (Zr, Ti, Nb) O ₃ , SrBi It may include one or more selected from the group consisting of ₂ Ta ₂ O ₉ , (K, Na) NbO ₃ , KNbO ₃ , KTaO ₃ , (Na, Bi) TiO ₃ and BiFeO ₃ . These dielectric particles are excellent in the dispersibility in the dispersion liquid, and contribute to the reduction of the direct current resistance of the positive electrode active material in the non-aqueous electrolyte secondary battery obtained from the relatively high dielectric constant. In particular, the dielectric particles preferably include one or more selected from the group consisting of TiBaO ₃ and BaSrTiO ₃ because they can be synthesized and manufactured at low cost as a manufacturing process.

  The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less. As a result, the surface of the positive electrode active material particles can be appropriately coated, and the effect of promoting the desorption and insertion of lithium ions by the dielectric particles can be obtained. On the other hand, when the average particle diameter of the dielectric particles is less than 10 nm, the surface of the positive electrode active material particles is covered too densely, so that the direct current resistance of the positive electrode active material particles is rather increased. In addition, since the particle diameter is excessively small, the particles are aggregated in the dispersion. On the other hand, when the average particle diameter of the dielectric particles exceeds 100 nm, the dielectric particles are less likely to be supported on the surface of the positive electrode active material particles, and the insulating effect is stronger than the dielectric effect. The effect of promoting lithium ion desorption / insertion due to The average particle size of the dielectric particles is preferably 10 nm or more and 80 nm or less.

  The average particle diameter of the dielectric particles was determined by the laser diffraction / light scattering method (particle size distribution measurement). In the present specification, the “average particle diameter” refers to a particle diameter corresponding to 50% of cumulative particle size from the particle side in a volume-based particle size distribution measured by particle size distribution measurement based on a general laser diffraction / light scattering method (D50 Also referred to as the median diameter. Further, since the average particle diameter of the dielectric particles is extremely small before and after the adhesion of the positive electrode active material particles, the average particle diameter of the dielectric particles of the dielectric particles before the adhesion may be used.

  The content of the dielectric particles in the dispersion is not particularly limited, but is, for example, 0.001 mol% or more and 3 mol% or less, preferably 0.01 mol% or more and 2 mol% or less with respect to the positive electrode active material particles. Thereby, while preventing excessive coating of the positive electrode active material particles by the dielectric particles, it is possible to sufficiently obtain the lithium ion detachment / insertion promoting effect by the dielectric particles.

  The dispersion medium contains one or more selected from an ether group-containing solvent, a ketone group-containing solvent, a hydrocarbon solvent and an ester group-containing solvent. These solvents can stably disperse the positive electrode active material particles and the dielectric particles while preventing the dissolution of the positive electrode active material particles and the dielectric particles.

  Examples of the ether group-containing solvent include glycol ether solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and diethylene glycol dimethyl ether (diglyme), and alkoxy alcohols such as 1-methoxypropanol. Examples of the ketone group-containing solvent include methyl ethyl ketone, acetyl acetone, acetone and the like. Examples of hydrocarbon solvents include linear or cyclic hydrocarbon solvents such as n-heptane, cyclohexane and hexane. Moreover, as ester group containing solvent, fatty-acid ester type | system | group solvent, such as ethyl acetate and methyl acetate, is mentioned.

  Among the above, from the viewpoint of the dispersion stability of the positive electrode active material particles and the dielectric particles and the ease of removal of the solvent, ester group-containing solvents and ketone group-containing solvents are preferable, and ketone group-containing solvents are more preferable.

  The boiling point of the dispersion medium is preferably 130 ° C. or less at atmospheric pressure (1 atm), and more preferably 80 ° C. or more and 120 ° C. or less. This enables easy removal of the solvent. When the dispersion medium contains a plurality of solvents, it is preferable that each solvent have a boiling point within the above range or an azeotropic point be within the above range.

  Also, the dispersion medium may contain other solvents in addition to the above-mentioned solvents. Examples of such solvents include alcohol solvents such as 2-propanol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, pentyl alcohol, isopentyl alcohol, and glycols such as propylene glycol Examples thereof include system solvents and polyhydric alcohol solvents such as glycerol and thioglycerol.

  However, the total content of the ether group-containing solvent, the ketone group-containing solvent, the hydrocarbon solvent and the ester group-containing solvent in the dispersion medium is preferably 60% by mass or more, and more preferably 70% by mass or more.

  The dispersion may also contain a dispersant. The dispersant contributes to the improvement of the dispersion stability of the dielectric particles and / or the positive electrode active material particles. The dispersant is preferably at least one selected from nonionic surfactants and fatty acids having 4 to 24 carbon atoms. These can suitably improve the dispersion stability of the dielectric particles and the positive electrode active material particles.

  Examples of the fatty acid having 4 to 24 carbon atoms include butanoic acid, tetradecanoic acid, stearic acid, leinic acid, arachidic acid and the like. Examples of ionic surfactants include fatty acid ester surfactants such as sorbitan fatty acid ester (for example Ionet S, Sanyo Chemical Industries), polyoxyethylene sorbitan fatty acid monoester (for example Ionet T, Sanyo Chemical Industries), SN sparse, SN dispersant (San Nopco) etc. are mentioned.

  The content of the dispersant in the dispersion liquid is not particularly limited, and can be set according to the required dispersion stability of the dielectric particles and the positive electrode active material particles.

  A dispersion liquid can be obtained by mixing the above-mentioned constituent materials. Stirring may be appropriately performed in order to ensure dispersion of the dielectric particles and the positive electrode active material particles.

  The temperature of the dispersion at the time of mixing is not particularly limited, and may be, for example, 20 ° C. or more and 40 ° C. or less, more specifically, room temperature.

(Second step)
Next, the dispersion medium is removed from the dispersion. Thereby, dielectric particles are supported on the surface of the positive electrode active material particles.
The removal of the dispersion medium can be performed, for example, by spray drying (spray drying) or reduced pressure drying (evaporator). Among these, spray drying is preferable from the viewpoint of operability and productivity.

  The drying temperature at the time of spray drying can be appropriately set according to the boiling point of the dispersion medium, and can be, for example, 90 ° C. or more and 120 ° C. or less.

(Third step (heat treatment))
Finally, heat treatment (baking) is performed to fix (neck) the dielectric particles on the surface of the positive electrode active material particles. Thereby, a positive electrode active material can be obtained.

The temperature of the heat treatment is not particularly limited, and is, for example, 400 ° C. or more and 800 ° C. or less, preferably 500 ° C. or more and 700 ° C. or less. However, the temperature is preferably such that the crystal structure of the positive electrode active material particles and the dielectric particles does not change. For example, when the dielectric particles contain TiBaO ₃ , the temperature is preferably 700 ° C. or less.

The heat treatment time is not particularly limited, and is, for example, 4 hours or more and 24 hours or less, preferably 4 hours or more and 12 hours or less.
The atmosphere during the heat treatment can be an oxygen-containing atmosphere, such as an air atmosphere.
In the case where the dielectric particles can adhere to the surface of the positive electrode active material particles even without heat treatment, this step can be omitted.

Thus, the positive electrode active material can be obtained. In such a positive electrode active material, dielectric particles are supported on the surface of the positive electrode active material particle, and the release and insertion of lithium ions are promoted. Therefore, the direct current resistance of the non-aqueous electrolyte secondary battery using the positive electrode active material is reduced.
Further, as described above, in one aspect of the present invention, the present invention also relates to a positive electrode active material produced by the above production method.

<3. Configuration of Nonaqueous Electrolyte Secondary Battery>
Hereinafter, the specific configuration of the non-aqueous electrolyte secondary battery 10 according to the above-described embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory view illustrating the configuration of a non-aqueous electrolyte secondary battery according to an embodiment of the present invention.

  As shown in FIG. 1, the non-aqueous electrolyte secondary battery 10 includes a positive electrode 20, a negative electrode 30, and a separator layer 40. The form of the non-aqueous electrolyte secondary battery 10 is not particularly limited. For example, the non-aqueous electrolyte secondary battery 10 may be cylindrical, square, laminate, button or the like.

  The positive electrode 20 includes a positive electrode current collector 21 and a positive electrode active material layer 22. The positive electrode current collector 21 is made of, for example, aluminum or the like.

  Further, the positive electrode active material layer 22 contains at least the above-described positive electrode active material. The positive electrode active material layer 22 may further contain other additives such as a conductive aid and / or a binder. In addition, the positive electrode active material layer 22 may contain a solid electrolyte.

  Examples of the conductive aid include carbon blacks such as ketjen black, acetylene black, and furnace black. Among these, any one or more carbon black may be contained. Among these carbon blacks, a preferred example is acetylene black. Acetylene black has fewer defects than other carbon blacks. Defective portions of carbon black may react with the electrolyte when the non-aqueous electrolyte secondary battery 10 is charged and discharged under high voltage. When the reaction occurs, gas is generated, and expansion or the like of the non-aqueous electrolyte secondary battery 10 may occur. From such a point of view, the carbon black is preferably acetylene black.

  The binder includes, for example, polyvinylidene fluoride, ethylene-propylene-diene terpolymer, styrene-butadiene rubber, acrylonitrile-butadiene rubber (acrylonitrile-butadiene rubber). ), Fluoroelastomer, polyvinyl acetate, polymethyl methacrylate, polyethylene, nitrocellulose and the like. The binder is not particularly limited as long as it can bind the positive electrode active material and the conductive auxiliary onto the positive electrode current collector 21. The content of the binder is not particularly limited, and may be any content as long as it is applied to the positive electrode active material layer of the non-aqueous electrolyte secondary battery.

  For example, the positive electrode active material layer 22 is obtained by dispersing a positive electrode active material, a conductive aid, and a binder in a suitable organic solvent (for example, N-methyl-2-pyrrolidone). The slurry (slurry) is coated on the positive electrode current collector 21, dried and rolled.

  The negative electrode 30 includes a negative electrode current collector 31 and a negative electrode active material layer 32. The negative electrode current collector 31 is made of, for example, copper (cupper), nickel or the like.

The negative electrode active material layer 32 may be anything as long as it is used as a negative electrode active material layer of a non-aqueous electrolyte secondary battery. For example, the negative electrode active material layer 32 may contain a negative electrode active material and may further contain a binder. In addition, the negative electrode active material layer 32 may contain a solid electrolyte. The negative electrode active material is, for example, a graphite active material (artificial graphite, natural graphite, a mixture of artificial graphite and natural graphite, natural graphite coated with artificial graphite, etc.), silicon (Si) or tin (Sn) or oxides thereof Mixtures of particles of graphite and a graphite active material, particles of silicon or tin, alloys based on silicon or tin, and titanium oxide (TiO _x ) compounds such as Li ₄ Ti ₅ O ₁₂ can be used. . The oxide of silicon is represented by SiO _x (0 ≦ x ≦ 2). Moreover, as a negative electrode active material, metal lithium etc. can be used other than these, for example.

  Further, as the binder, for example, styrene butadiene rubber (SBR) or the like is used. The mass ratio of the negative electrode active material to the binder is not particularly limited, and the mass ratio adopted in the conventional non-aqueous electrolyte secondary battery is also applicable to the present invention.

The separator layer 40 includes a separator and an electrolytic solution.
The separator contained in the separator layer 40 is not particularly limited. Any separator may be used in the separator layer 40 as long as it can be used as a separator of a non-aqueous electrolyte secondary battery. For example, as the separator, it is preferable to use, alone or in combination, a porous film, a non-woven fabric, or the like exhibiting excellent high-rate discharge performance. As a material which comprises a separator, it is represented by the polyolefin resin represented by polyethylene (polyethylene), a polypropylene (polypropylene) etc., a polyethylene terephthalate (polyethylene terephthalate), a polybutylene terephthalate (polybutylene terephthalate) etc., for example Polyester (polyester) resin, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-perfluorovinyl ether co-polymer Combination, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-fluoroethylene copolymer, vinylidene fluoride-hexafluoroacetone (Hexafluoroacetone) copolymer, vinylidene fluoride-ethylene (ethylene) copolymer, vinylidene fluoride-propylene copolymer, vinylidene fluoride-trifluoropropylene copolymer, vinylidene fluoride-tetraethylene fluoride Fluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-ethylene-tetra It can be used Ruoroechiren copolymer. In addition, the porosity in particular of a separator is not restrict | limited, either, The porosity which the separator of a nonaqueous electrolyte secondary battery has is applicable arbitrarily.

Moreover, the separator may have a coating layer containing an inorganic filler. Specifically, the coating layer may contain at least one of Mg (OH) ₂ or Al ₂ O ₃ as an inorganic filler. According to this configuration, the coating layer containing the inorganic filler prevents direct contact between the positive electrode and the separator, thereby preventing oxidation and decomposition of the electrolytic solution generated on the surface of the positive electrode during high temperature storage, and decomposition and formation of the electrolytic solution It is possible to suppress the generation of gas which is a substance.

  Here, the coating layer containing the inorganic filler may be formed on both sides of the separator, or may be formed only on one side of the separator on the positive electrode side. If the coating layer containing the inorganic filler is formed at least on the positive electrode side, direct contact between the positive electrode and the electrolytic solution can be prevented.

Furthermore, the present invention is not limited to the above-described examples. For example, the coating layer containing the inorganic filler may be formed on the positive electrode, not on the separator. In such a case, the coating layer containing the inorganic filler can prevent direct contact between the positive electrode and the separator by being formed on both sides of the positive electrode. Needless to say, the coating layer containing the inorganic filler may be formed on both the positive electrode and the separator. Also, instead of the separator layer 40, a solid electrolyte may be used. As a solid electrolyte replacing the separator layer 40, for example, a sulfide-based solid electrolyte material is used. As the sulfide-based solid electrolyte material, for example, Li ₂ S-P ₂ S ₅ , Li ₂ S-P ₂ S ₅ -LiX (X is a halogen element such as I, Cl), Li ₂ S-P ₂ S _{5 -Li 2 O, Li 2 S-} P 2 S 5 -Li 2 O-LiI, Li 2 S-SiS 2, Li2 S -SiS 2 -LiI, Li 2 S-SiS 2 -LiBr, Li 2 S-SiS 2 _{-LiCl, Li 2 S-SiS 2} -B 2 S 3 -LiI, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 S-B 2 S 3, Li 2 S-P 2 S 5 -Z _m S _{n (m, n} is any positive number, Z is Ge, and Zn, or _{Ga), Li 2 S-GeS} 2, Li 2 S-SiS 2 -Li 3 PO 4, Li 2 S-SiS 2 - Li _p MO _{q (p, q} is a positive number, M is P, Si, Ge B, Al, either Ga or In), and the like. Here, the sulfide-based solid electrolyte material is produced by treating a starting material (for example, Li ₂ S, P ₂ S ₅ or the like) by a melt-quenching method, a mechanical milling method, or the like. Further, heat treatment may be further performed after these treatments. The solid electrolyte may be amorphous or crystalline, or may be in a mixed state.
Further, as the solid electrolyte, among the above sulfide solid electrolyte material, sulfur (S) as at least an element, it is preferable to use a material containing phosphorus (P) and lithium (Li), in particular Li _{2 S-P} 2 it is more preferable to use those containing S _5.
Here, in the case of using a material containing Li ₂ S—P ₂ S ₅ as a sulfide-based solid electrolyte material forming a solid electrolyte, the mixing molar ratio of Li ₂ S and P ₂ S ₅ is, for example, Li ₂ S It may be selected in the range of P ₂ S ₅ = 50: 50 to 90:10.

  As the electrolyte solution, the same non-aqueous electrolyte solution conventionally used for lithium secondary batteries can be used without particular limitation. Here, the electrolytic solution has a composition in which a non-aqueous solvent contains an electrolyte salt. As the non-aqueous solvent, for example, cyclic carbonates such as propylene carbonate, ethylene carbonate, buthylene carbonate, chloroethylene carbonate, vinylene carbonate, etc. ; Cyclic esters such as γ-butyrolactone and γ-valerolactone; Dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate linear carbonates such as ethyl carbonate); linear esters such as methyl formate, methyl acetate, methyl butylate; tetrahydrofuran (tetrahydrofuran) or derivatives thereof; 1, 3-dioxane (1,3-dioxane), 1,4-dioxane (1,4-dioxane), 1,2-dimethoxyethane (1,2-dimethoxyethane), 1,4-dibutoxyethane (1,4-dibutoxyane) Ethers such as dibutyloxyne, methyl diglyme, etc .; acetonitrile (acetonitril), benzonitrile (benz) nitriles such as Nitril), dioxolanes or derivatives thereof; ethylene sulfide, sulfolanes, sultones, sultones or derivatives thereof alone or in combination of two or more thereof Although it can be used, it is not limited to these.

In addition, as electrolyte salts, for example, LiClO ₄ , LiBF ₄ , LiAsF ₆ , LiPF ₆ , LiSCN, LiBr, LiI, Li ₂ SO ₄ , Li ₂ B ₁₀ Cl ₁₀ , NaClO ₄ , NaI, NaSCN, NaBr, KClO ₄ , Inorganic ion salts containing one of lithium (Li) such as KSCN, sodium (Na) or potassium (K), LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) _{2, LiN (CF 3 SO 2} ) (C 4 F 9 SO 2), LiC (CF 3 SO 2) 3, LiC (C 2 F 5 SO 2) 3, (CH 3) 4 NBF 4, (CH 3) _{4 NBr, (C 2 H 5} ) 4 NClO 4, (C 2 H 5) 4 NI, (C 3 H 7) 4 NBr, (n-C 4 H 9) 4 NC lO ₄ , (nC ₄ H ₉ ) ₄ NI, (C ₂ H ₅ ) ₄ N-maleate, (C ₂ H ₅ ) ₄ N-benzoate, (C ₂ H ₅ ) ₄ N-phtalate, stearyl sulfonic acid Organic ionic salts such as lithium (lithium stearyl sulfate), lithium octyl sulfonate, lithium dodecylbenzene sulfonate and the like can be used. In addition, it is possible to use these ionic compounds individually or in mixture of 2 or more types. The concentration of the electrolyte salt may be the same as that of the non-aqueous electrolyte used in the conventional lithium secondary battery, and is not particularly limited. In the present invention, an electrolytic solution containing a suitable lithium compound (electrolyte salt) at a concentration of about 0.5 mol / L to 2.0 mol / L can be used.

<4. Method of Manufacturing Nonaqueous Electrolyte Secondary Battery>
Subsequently, an example of a method of manufacturing the non-aqueous electrolyte secondary battery 10 will be described. The manufacturing method described below is merely an example, and it is needless to say that the nonaqueous electrolyte secondary battery 10 can be manufactured by other methods.

  First, the method of manufacturing a non-aqueous electrolyte secondary battery according to this embodiment includes at least a process for manufacturing a positive electrode active material, that is, the first process and the second process.

  Next, the positive electrode 20 is manufactured as follows. First, a slurry is formed by dispersing the material (for example, positive electrode active material, conductive additive and binder) constituting the positive electrode active material layer 22 in an organic solvent (for example, N-methyl-2-pyrrolidone). .

  Next, the obtained mixture is subjected to solid-mixing, and further, the positive electrode active material is added to perform solid-mixing. Finally, an organic solvent is added to adjust the viscosity to obtain a slurry.

  Next, the slurry is applied onto the positive electrode current collector 21 and dried to form the positive electrode active material layer 22. Furthermore, the positive electrode active material layer 22 is compressed to a desired thickness by a compressor. Thereby, the positive electrode 20 is manufactured. Here, the thickness of the positive electrode active material layer 22 is not particularly limited as long as it is the thickness of the positive electrode active material layer of the non-aqueous electrolyte secondary battery. The step of applying the positive electrode active material to the current collector may be performed in a dry environment.

  In the negative electrode 30, first, a mixture of a negative electrode active material, carboxymethyl cellulose (CMC) and a conductive auxiliary agent in a desired ratio is added with a predetermined amount of ion-exchanged water, and mixed and mixed. Thereafter, ion exchange water is further added to adjust the viscosity, and a styrene butadiene rubber (SBR) binder is added to form a negative electrode slurry. Next, the slurry is applied onto the negative electrode current collector 31 and dried to form the negative electrode active material layer 32. Furthermore, the negative electrode active material layer 32 is compressed to a desired thickness by a compressor. Thereby, the negative electrode 30 is manufactured. Here, the thickness of the negative electrode active material layer 32 is not particularly limited, as long as it is the thickness of the negative electrode active material layer of the non-aqueous electrolyte secondary battery. When metal lithium is used as the negative electrode active material layer 32, a metal lithium foil may be stacked on the negative electrode current collector 31.

  Subsequently, the separator is sandwiched between the positive electrode 20 and the negative electrode 30 to manufacture an electrode structure. Next, the electrode structure is processed into a desired form (for example, cylindrical, square, laminate, button, etc.) and inserted into the container of the form. Furthermore, the pores in the separator are impregnated with the electrolytic solution by injecting an electrolytic solution of a desired composition into the container. Thereby, the non-aqueous electrolyte secondary battery 10 is manufactured.

  Below, the Example which concerns on this embodiment is demonstrated concretely. In addition, the Example shown below is an example of this invention, Comprising: This invention is not limited to the following example.

<1. Cell production>
Example 1
(Production of positive electrode active material)
The positive electrode active material particles having a composition formula of Li _1.00 Ni _0.85 Co _0.10 Al _0.05 O ₂ were synthesized by the following method. First, positive electrode active material precursor particles having a composition represented by a composition formula Ni _0.85 Co _0.10 Al _0.05 (OH) ₂ were synthesized by coprecipitation method. A dry powder obtained, by mixing the lithium carbonate (Li 2 _{CO 3),} to produce a mixed powder. The obtained powder was fired at 800 ° C. to 1050 ° C. for 24 hours in an oxygen atmosphere to synthesize positive electrode active material particles. Here, the molar ratio of Li to Ni + Co + M (= Me) is determined according to the composition of the lithium-nickel-cobalt composite oxide, so Li _1.00 Ni _0.85 Co _0.10 Al _0.05 O ₂ The molar ratio of Li to Me, Li: Me, is 1.00: 1.00. The Li: Me ratio of the obtained lithium nickel cobalt composite oxide is confirmed by ICP-OES (for example, HORIBA ULTIMA2), and the Li: Me ratio after firing is 1.00: 1.00, The preparation was carried out by adjusting the amount of lithium carbonate in advance. For example, the molar ratio of Li to Me is adjusted to be between 1.03: 1.00 and 1.07: 1.00, and the ratio of Li: Me after firing is 1.00: 1.00. I made it.

  The average particle diameter (arithmetic average value of equivalent sphere diameter) of the positive electrode active material particles was calculated by analyzing the SEM image. That is, the sphere equivalent diameters of the plurality of positive electrode active material particles were calculated based on the SEM image, and the arithmetic average value of these was used as the average particle diameter. As a result, the average particle size was 12 μm.

Next, the obtained positive electrode active material particles, TiBaO ₃ particles (average particle diameter 10 nm) as dielectric particles, and ionet as a dispersing agent are added to acetone as a dispersion medium, and the dispersion liquid is stirred. (Slurry) was obtained (first step). The addition amount of the positive electrode active material particles and the TiBaO ₃ particles was adjusted so that the supported TiBaO ₃ particles became 1.0 mol% with respect to the positive electrode active material particles. Also, the mixing was performed at room temperature conditions.

  Next, the dispersion was spray-dried at a drying temperature of 100 ° C. to obtain a powder.

The obtained powder was fired at 700 ° C. in an oxygen atmosphere for 12 hours to fix TiBaO ₃ particles on the surface of the positive electrode active material particles, to obtain a positive electrode active material according to Example 1.

(Production of coin full cell)
The coin half cell was produced by the following processing. First, positive electrode active material, acetylene black and polyvinylidene fluoride were mixed at a mass ratio of 96: 2: 2. This mixture (positive electrode mixture) was dispersed in N-methyl-2-pyrrolidone to form a slurry.

The slurry was applied onto the positive electrode current collector 21 and dried to form a positive electrode active material layer 22. The positive electrode 20 was manufactured by rolling so that the thickness of the positive electrode active material layer 22 was 50 μm. The volume density of the positive electrode active material layer 22 was 3.7 g / cc, and the area density was 20 mg / cm ² .

  The negative electrode 30 was produced by coating and drying a negative electrode slurry in which graphite is dispersed in ion-exchanged water, on a copper foil which is the negative electrode current collector 31. Then, a 12 μm thick porous polypropylene film (having magnesium hydroxide coated on both sides, manufactured by Teijin Ltd.) is prepared as a separator, and the separator is disposed between the positive electrode 20 and the negative electrode 30 to obtain an electrode. The structure was manufactured. Next, the electrode structure was processed into a coin full cell size and stored in a coin full cell container.

  Then, an electrolyte solution was produced by dissolving lithium hexafluorophosphate at a concentration of 1.3 M in a non-aqueous solvent in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 3: 7. Subsequently, the coin full cell according to Example 1 was manufactured by injecting the electrolytic solution into the coin full cell and impregnating the electrolytic solution into the separator.

(Production of coin half cell)
An electrode structure was manufactured in the same manner as the coin full cell. Then, the electrode structure was processed to the size of a coin half cell and stored in a coin half cell container.

  Then, an electrolyte solution was produced by dissolving lithium hexafluorophosphate at a concentration of 1.3 M in a non-aqueous solvent in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 3: 7. Subsequently, the coin half cell according to Example 1 was manufactured by injecting the electrolytic solution into the coin half cell and impregnating the electrolytic solution into the separator.

(Examples 2 to 6)
A positive electrode active material as in Example 1, except that the particle size of the positive electrode active material particles, the type and diameter of the dielectric particles, and the type of dispersion medium and dispersant used are changed as shown in Table 1; I created coin full cell and coin half cell.

(Comparative example 1)
A positive electrode active material, a coin full cell and a coin half cell were produced in the same manner as in Example 1 except that the dielectric particles were not supported on the positive electrode active material particles.

(Comparative Example 2, Comparative Example 3)
A positive electrode active material, coin full cell and coin half cell were prepared in the same manner as in Example 1 except that the type and particle size of dielectric particles and the type of dispersion medium and dispersant used were changed as shown in Table 1. did.

  Table 1 summarizes the manufacturing conditions in each of the above Examples and Comparative Examples.

<2. Evaluation>
(Initial capacity)
Next, the initial capacity was evaluated using the coin half cell obtained in each Example and each comparative example. Charge and discharge were performed at a charge and discharge rate (rate) and a cut off voltage (unit: V) shown in Table 2 below. The temperature during charging and discharging was room temperature (25 ° C.). CC-CV means constant current constant voltage, CC means constant current. Then, the discharge capacity at the first cycle was measured, and this value was obtained as an initial capacity. With respect to the initial capacity obtained in each Example and each Comparative Example, the ratio of the initial capacity obtained in each Example and each Comparative Example was evaluated when the initial capacity obtained in Comparative Example 1 was 1.

(DC resistance (DCR))
Next, the direct current resistance of the positive electrode was evaluated using the coin full cell obtained in each Example and each comparative example.
Specifically, for the coin full cells obtained in each example and each comparative example, charge and discharge are performed at the charge and discharge rate (rate) and the cut off voltage (unit: V) shown in Table 3 I went cycle. The temperature during charge and discharge was room temperature (25 ° C.). CC-CV means constant current constant voltage, CC means constant current.

  In the third cycle of charging, charging was stopped and the coin full cell was disassembled when the SOC (ratio of the amount of charge to the electric capacity) was 50%. The positive electrode obtained by disassembling was made to mutually oppose, and the symmetrical model cell was produced. The other configurations of the separator, the electrolytic solution, and the symmetric model cell were the same as those of the coin full cell.

Next, using a charge / discharge evaluation system (Toyo System, TOSCAT), adjust the battery to the SOC 50% state for each measurement under the condition of 25 ° C, and from the state of open circuit 0.2ItA, 0.5ItA, 1ItA The battery voltage was discharged at 10 seconds, the voltage drop at each discharge from the open circuit voltage was plotted against each current, and the slope of the least squares linearized graph was plotted at 10 seconds. The discharge DC resistance (DCR) value was used. With respect to the resistance obtained in each Example and each Comparative Example, the ratio (%) of the resistance obtained in each Example and each Comparative Example was evaluated when the resistance obtained in Comparative Example 1 was 100.
The results are shown in Table 4.

<3. Contrast>
Comparing Examples 1 to 6 with Comparative Example 1, in Examples 1 to 6, dielectric particles exist in the positive electrode active material, and the ratio of the positive electrode active material particles in the positive electrode active material layer In spite of the decrease, the initial capacity equal to or higher than that of Comparative Example 1 was obtained. In Examples 1 to 6, DC resistance was reduced.

  On the other hand, in Comparative Example 2 and Comparative Example 3, as compared with Comparative Example 1, the initial capacity decreased and the DC resistance also increased. In particular, in Comparative Example 2, it is conceivable that isopropyl alcohol used as the dispersion medium dissolves a part of lithium component of the positive electrode active material particles.

<4. Production of cell (all solid secondary battery)>
(Example 7)
First, after weighing the reagents Li ₂ S, Na ₂ S, P ₂ S ₅ , and LiCl so that the target composition is Li ₆ PS ₅ Cl, mechanical milling is performed by mixing with a planetary ball for 20 hours. went. The mechanical milling was performed at a rotational speed of 380 rpm, at room temperature (25 ° C.) in an argon atmosphere for 20 hours.
By pressing 800 mg of a powder sample of Li ₆ PS ₅ Cl composition obtained by the above mechanical milling process (pressure 400 MPa / cm ² ), a pellet having a diameter of 13 mm and a thickness of about 0.8 mm was obtained. The obtained pellet was coated with a gold foil, and further, the gold foil coated pellet was placed in a carbon crucible to prepare a sample for heat treatment. The obtained sample for heat treatment is vacuum sealed using a quartz glass tube, and then heated from room temperature (25 ° C.) to 550 ° C. at 1.0 ° C./min using an electric furnace, and then to 550 ° C. Heat-treated for 6 hours, and then cooled to room temperature (25.degree. C.) at 1.0.degree. C./minute to obtain a sample. The collected sample was pulverized using an agate mortar, and then X-ray crystal diffraction was performed to confirm that the target Argyrodite crystal was formed, and this material was used as a solid electrolyte.
What mixed the positive electrode active material material of Example 1, the solid electrolyte, and the carbon nanofiber (CNF) which is a conductive agent by a mass ratio of 60:30:10 was made into positive mix.
Moreover, as a negative electrode, metal lithium foil with a thickness of 30 micrometers was used.
10 mg of a positive electrode mixture, 150 mg of a solid electrolyte, and a metal lithium foil (negative electrode) were laminated, and pressed at a pressure of 294 MPa to prepare a test cell according to Example 7.

(Examples 8 to 12 and Comparative Examples 4 to 6)
Example 8 to Example 12 and Comparative Example 4 to Comparative Example 6 are the same as Example 7 except that the positive electrode active material of Example 2 to Example 6 and Comparative Example 1 to Comparative Example 3 is used. The test cell according to

<5. Evaluation>
Next, using the test cells obtained in Example 7 to Example 12 and Comparative Example 4 to Comparative Example 6, cycle characteristics at high-speed charge and discharge rates were evaluated.
Specifically, the test cells obtained in each example and each comparative example are charged at a constant current of 0.05 C at 5 ° C. to an upper limit voltage of 4.0 V, and a discharge end voltage of 0 to 2.5 V The charge and discharge cycle of .05C discharge was repeated 50 cycles. Then, the ratio of the discharge capacity at the 50th cycle to the discharge capacity at the first cycle was taken as the maintenance rate of the discharge capacity. The results are shown in Table 5.

<6. Contrast>
Comparing Example 7 to Example 12 with Comparative Example 4 to Comparative Example 6, the test cells according to Example 7 to Example 12 are faster in charging speed than the test cells according to Comparative Example 4 to Comparative Example 6. The cycle characteristics at the discharge rate were excellent.

  Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention belongs can conceive of various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also fall within the technical scope of the present invention.

10 non-aqueous electrolyte secondary battery 20 positive electrode 21 positive electrode current collector 22 positive electrode active material layer 30 negative electrode 31 negative electrode current collector 32 negative electrode active material layer 40 separator layer

Claims (10)

A first step of obtaining a dispersion containing positive electrode active material particles, dielectric particles, and the positive electrode active material particles and a dispersion medium for dispersing the dielectric particles;
And d) removing the dispersion medium from the dispersion liquid.
The positive electrode active material particles have a composition represented by the following formula (1),
The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less,
The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less,
The manufacturing method of the positive electrode active material material in which the said dispersion medium contains 1 or more types selected from an ether group containing solvent, a ketone group containing solvent, a hydrocarbon type solvent, and an ester group containing solvent.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.10 and x + y + z = 1.   The method for producing a positive electrode active material according to claim 1, wherein the dispersion medium is removed by spray drying in the second step.   The manufacturing method of the positive electrode active material material of Claim 1 or 2 whose boiling point of the said dispersion medium is 130 degrees C or less.   The positive electrode active according to any one of claims 1 to 3, wherein the dispersion further contains at least one dispersant selected from nonionic surfactants and fatty acids having 4 to 24 carbon atoms. Method of manufacturing material The dielectric particles may be TiBaO ₃ , BaSrTiO ₃ , Pb (Zr, Ti) O ₃ , (Pb, La) (Zr, Ti) O ₃ , Pb (Zr, Ti, Nb) O ₃ , SrBi ₂ Ta ₂ O _9. One or more selected from the group consisting of (K, Na) NbO ₃ , KNbO ₃ , KTaO ₃ , (Na, Bi) TiO ₃ and BiFeO _{3 according} to any one of claims 1 to 4. The manufacturing method of the positive electrode active material material of description. It said dielectric particles, TiBaO _3, and BaSrTiO comprises one or more _{of 3} is selected from the group consisting of, process for producing a positive electrode active material according to any one of claims 1-5. A first step of obtaining a dispersion containing positive electrode active material particles, dielectric particles, and the positive electrode active material particles and a dispersion medium for dispersing the dielectric particles;
And d) removing the dispersion medium from the dispersion liquid.
The positive electrode active material particles have a composition represented by the following formula (1),
The average particle diameter of the positive electrode active material particles is 8 μm or more and 15 μm or less,
The average particle diameter of the dielectric particles is 10 nm or more and 100 nm or less,
The manufacturing method of the non-aqueous electrolyte secondary battery in which the said dispersion medium contains 1 or more types selected from an ether group containing solvent, a ketone group containing solvent, a hydrocarbon type solvent, and an ester group containing solvent.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.20 and x + y + z = 1. It has a composition represented by the following formula (1),
The average particle size is 8 μm to 15 μm,
A positive electrode active material comprising a positive electrode active material particle having an average particle diameter of 10 nm or more and 100 nm or less.
Li _a Ni _x Co _y M _z O ₂ (1)
In the above formula (1), M is aluminum (Al), manganese (Mn), chromium (Cr), iron (Fe), vanadium (V), magnesium (Mg), titanium (Ti), zirconium (Zr), From niobium (Nb), molybdenum (Mo), tungsten (W), copper (Cu), zinc (Zn), gallium (Ga), indium (In), tin (Sn), lanthanum (La), cerium (Ce) And at least one metal element selected from the group consisting of a, x, y and z is such that 0.20 ≦ a ≦ 1.20, 0.70 ≦ x <1.00, 0 <y ≦ 0. It is a value within the range of 20, 0 <z ≦ 0.10 and x + y + z = 1.   The positive electrode for nonaqueous electrolyte secondary batteries containing the positive electrode active material material of Claim 8.   A non-aqueous electrolyte secondary battery comprising the positive electrode for a non-aqueous electrolyte secondary battery according to claim 9.

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