JP5392036B2 - Manganese composite hydroxide particles for non-aqueous electrolyte secondary battery positive electrode active material and production method thereof, positive electrode active material for non-aqueous electrolyte secondary battery and production method thereof, and non-aqueous electrolyte secondary battery - Google Patents

Description

  The present invention relates to a manganese composite hydroxide particle for a non-aqueous electrolyte secondary battery positive electrode active material and a method for producing the same, a positive electrode active material for a non-aqueous electrolyte secondary battery and a method for producing the same, and a non-aqueous electrolyte secondary battery.

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 output secondary battery is strongly desired as a battery for electric vehicles including hybrid vehicles.
As a secondary battery satisfying such requirements, there is a lithium ion secondary battery. A lithium ion secondary battery includes a negative electrode, a positive electrode, an electrolyte, and the like, and a material capable of desorbing and inserting lithium is used as an active material for the negative electrode and the positive electrode.

  Research and development of lithium ion secondary batteries are currently being actively conducted. Among them, lithium ion secondary batteries using a layered or spinel type lithium metal composite oxide as a positive electrode material are of the 4V class. Since a high voltage can be obtained, practical use is progressing 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 Lithium composite oxides such as Mn _0.5 O ₂ ) have been proposed. Among them, lithium manganese composite oxide having a spinel structure excellent in thermal stability without using cobalt with a small reserve amount, and further replacing part of Mn of the lithium manganese composite oxide with Ni is 4.5V. In recent years, lithium manganese nickel composite oxide (LiMn _1.5 Ni _0.5 O ₄ ), which realizes the above operating voltage and has a high energy density, has attracted attention.

As a condition for obtaining good performance (high cycle characteristics, low resistance, high output) of the positive electrode in a lithium ion battery, the positive electrode material is required to be composed of particles having a uniform and appropriate particle size.
This is because if a material with a large particle size and a low specific surface area is used, a sufficient reaction area with the electrolyte or electrolyte cannot be secured, the reaction resistance increases, a high output battery cannot be obtained, and the particle size distribution is wide. This is because the use of materials causes problems such as a decrease in battery capacity and an increase in reaction resistance. The reason why the battery capacity is decreased is that the voltage applied to the particles in the electrode becomes non-uniform, and the particles are selectively deteriorated when charging and discharging are repeated.
In order to increase the output of the battery, it is effective to shorten the distance of movement of the lithium ion between the positive electrode and the negative electrode. Therefore, it is desired to manufacture the positive electrode plate thinly. Positive electrode active material particles having a particle size are useful.
Therefore, in order to improve the performance of the positive electrode material, it is necessary to manufacture the above-described lithium manganese composite oxide so that the particles have a small particle size and a uniform particle size.

Since the lithium manganese composite oxide is usually produced from a composite hydroxide, in order to make the lithium manganese composite oxide into particles having a small particle size and a uniform particle size, It is necessary to use a small particle size and a uniform particle size.
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, the composite hydroxide used as a raw material for the lithium manganese composite oxide forming the positive electrode material is small. It is necessary to use a composite hydroxide consisting of particles having a narrow particle size distribution.

  In Patent Document 1, in the particle size distribution curve, a particle size distribution having an average particle size D50 of 3 to 15 μm, a minimum particle size of 0.5 μm or more, and a maximum particle size of 50 μm or less, which means a particle size with a cumulative frequency of 50%. D10 / D50 is 0.60 to 0.90 and D10 / D90 is 0.30 to 0.70 in the relationship between D10 having a cumulative frequency of 10% and 90% D90. A lithium composite oxide is disclosed. This lithium composite oxide has high filling properties, is excellent in charge / discharge capacity characteristics and high output characteristics, and does not easily deteriorate even under conditions with a large charge / discharge load. For example, it is described that a lithium ion non-aqueous electrolyte secondary battery having excellent output characteristics and little deterioration in cycle characteristics can be obtained.

Various proposals have also been made on methods for producing a positive electrode active material for a non-aqueous electrolyte battery (for example, Patent Documents 2 and 3).
In Patent Document 2, in a method for producing a positive electrode active material for a nonaqueous electrolyte battery, an aqueous solution containing two or more transition metal salts or two or more aqueous solutions of different transition metal salts and an alkaline solution are simultaneously charged into a reaction vessel. In addition, a method of obtaining a precursor hydroxide or oxide by coprecipitation while coexisting with a reducing agent or by bubbling an inert gas has been proposed.

  In Patent Document 3, a manganese compound and a basic compound are reacted in a solution and oxidized to obtain a manganese oxide seed. In the solution containing the manganese oxide seed, A method is disclosed in which manganese oxide seeds are grown by oxidizing them while allowing them to react to produce manganese oxide. And it is said that the lithium manganate which used the manganese oxide obtained by this method as the raw material is excellent in crystallinity, has a large particle size, and has a uniform particle size distribution and particle shape.

  However, the lithium composite oxide disclosed in Patent Document 1 has a minimum particle size of 0.5 μm or more and a maximum particle size of 50 μm or less with respect to an average particle size of 3 to 15 μm. In the particle size distribution defined by D10 / D50 and D10 / D90, it cannot be said that the range of the particle size distribution is narrow. That is, it cannot be said that the lithium composite oxide of Patent Document 1 is a particle having a high particle size uniformity, and even if such a lithium composite oxide is employed, improvement in the performance of the positive electrode material cannot be expected, and the lithium composite oxide has sufficient performance. It is difficult to obtain a lithium ion non-aqueous electrolyte secondary battery.

On the other hand, with respect to the method of producing a composite oxide, the technique of Patent Document 2 is to collect the produced crystals while classifying them. Therefore, in order to obtain a product having a uniform particle size, the production conditions are strictly set. Therefore, industrial scale production is difficult. Moreover, even if crystal particles with a large particle size can be obtained, it is difficult to obtain particles with a small particle size.
Moreover, in patent document 3, particle | grain control is performed by the setting of the manganese ion density | concentration which remains in a solution, and seed production | generation and growth are not fully isolate | separated. In addition, since the concentration of manganese ions remaining in the desired medium for obtaining a uniform product with a uniform shape and particle size distribution is 10 to 40 g / l, a large amount of manganese ions are contained in the waste liquid, resulting in a decrease in production efficiency. At the same time, it is expected that the cost of waste liquid treatment and the environmental load will increase.

  As described above, a composite hydroxide that can sufficiently improve the performance of a lithium secondary battery has not been developed, and various methods for producing a composite hydroxide or a composite oxide have been studied. However, a method capable of producing a positive electrode active material capable of sufficiently improving the performance of a lithium secondary battery has not been developed on an industrial scale. In other words, a composite hydroxide having a small particle size and high particle size uniformity, and a method for producing a positive electrode active material have not been developed. Development is required.

JP 2008-147068 A JP 2003-86182 A Japanese Patent Laid-Open No. 2001-240417

In view of the problems involved, the present invention provides a manganese composite hydroxide particle for a non-aqueous electrolyte secondary battery positive electrode active material having a small particle size and high particle size uniformity, and a manganese composite water for such a non-aqueous electrolyte secondary battery positive electrode active material. It aims at providing the manufacturing method which can manufacture an oxide particle.
Moreover, it aims at providing the positive electrode active material for non-aqueous secondary batteries which can reduce the value of the positive electrode resistance measured when it uses for a battery, and its manufacturing method.
It is another object of the present invention to provide a non-aqueous electrolyte secondary battery having a high capacity, good cycle characteristics, and high output.

(Method for producing manganese composite hydroxide particles for positive electrode active material of non-aqueous electrolyte secondary battery)
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to the first invention has a general formula Mn _1-xy Ni _x M _y (OH) _{2 + α} (0 ≦ x ≦) by crystallization reaction. 0.27, 0 ≦ y ≦ 0.05, 0 ≦ α ≦ 0.5, M is an additive element, selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W A nucleation aqueous solution containing at least a manganese-containing metal compound and an ammonium ion supplier, at a liquid temperature of 25 A nucleation step in which nucleation is performed such that the pH value measured on the basis of ° C is 12.0 to 14.0, and an aqueous solution for particle growth containing nuclei formed in the nucleation step, PH value measured on the basis of a liquid temperature of 25 ° C. is 10.5 to It comprises a particle growth step for growing the nuclei by controlling to 12.0, and the pH in the particle growth step is controlled to be lower than the pH in the nucleation step.
In the method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material of the second invention, the range of x in the general formula is 0.23 ≦ x ≦ 0.27 in the first invention. It is characterized by that.
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to a third aspect of the invention is the first or second aspect, wherein the aqueous solution for particle growth is the nucleation after the nucleation step has been completed. The aqueous solution is formed by adjusting the pH value of the aqueous solution.
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to a fourth aspect of the present invention is the first or second aspect of the invention, wherein the aqueous solution for particle growth comprises the nuclei formed in the nucleation step. The aqueous solution is added to an aqueous solution different from the aqueous solution for nucleation forming the nuclei.
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to a fifth aspect of the present invention is the liquid part of the aqueous solution for particle growth after the nucleation step in any one of the first to fourth aspects. The particle growth step is performed after part of the material is discharged.
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to a sixth aspect of the present invention is the method according to any one of the first to fifth aspects, wherein the nucleation step and the particle growth step The temperature is maintained at 20 ° C. or higher.
The method for producing manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to a seventh aspect of the present invention is the method according to any one of the first to sixth aspects, wherein in the nucleation step and the particle growth step, The ammonia concentration is maintained in the range of 3 to 25 g / L.
The method for producing manganese composite hydroxide particles for a positive electrode active material for a non-aqueous electrolyte secondary battery according to an eighth aspect of the present invention is the manganese composite hydroxide obtained in the particle growth step according to any one of the first to seventh aspects of the invention. It is characterized in that a compound containing one or more kinds of the additional elements is coated.
(Manganese composite hydroxide particles for positive electrode active materials for non-aqueous electrolyte secondary batteries)
Non-aqueous electrolyte secondary battery cathode active material for manganese composite hydroxide particles of the ninth invention, the formula _{Mn 1-x-y Ni x} M y (OH) 2 + α (0 ≦ x ≦ 0.27,0 ≦ y ≦ 0.05, 0 ≦ α ≦ 0.5, M is an additive element, and one or more elements selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, and W ), Which is a spherical secondary particle formed by agglomerating a plurality of plate-like primary particles, and the secondary particles have an average particle size of 3 to 7 μm and are indicators of the spread of the particle size distribution. [(D90-d10) / average particle diameter] is 0.55 or less.
The manganese composite hydroxide particles for a positive electrode active material for a nonaqueous electrolyte secondary battery according to a tenth aspect of the invention are characterized in that, in the ninth aspect, the range of x in the general formula is 0.23 ≦ x ≦ 0.27. And
The manganese composite hydroxide particles for a positive electrode active material for a non-aqueous electrolyte secondary battery according to an eleventh aspect of the invention are the ninth or tenth aspect, wherein the secondary particles are uniformly mixed with one or more additional elements therein. The distribution and / or the surface thereof is uniformly coated.
The manganese composite hydroxide particles for a positive electrode active material for a non-aqueous electrolyte secondary battery according to a twelfth aspect of the present invention are those produced by any one of the ninth to eleventh aspects according to the manufacturing method of any of the first to eighth aspects of the invention. It is characterized by being.
(Method for producing positive electrode active material for non-aqueous electrolyte secondary battery)
Manufacturing method of the 13 positive electrode active material for non-aqueous electrolyte secondary battery of the invention have the general _{formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4 (-0.05 ≦ t ≦ 0.1, 0 ≦ x ≦ 0.55, 0 ≦ y ≦ 0.1, M is an additive element, and is selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, and W A method for producing a positive electrode active material comprising a lithium manganese composite oxide having a cubic crystal structure having a spinel structure, wherein the manganese composite water of any of the ninth to twelfth inventions The step of heat-treating the oxide particles, the mixing step of mixing the lithium compound with the particles after the heat treatment to form a mixture, and the mixture formed in the mixing step at a temperature of 600 ° C. to 850 ° C. And a firing step of firing.
According to a fourteenth aspect of the present invention, there is provided a method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery. In the thirteenth aspect, the range of x in the general formula is represented by 0.45 ≦ x ≦ 0.55, A method for producing a positive electrode active material comprising a cubic lithium manganese composite oxide, wherein the manganese composite hydroxide particles are heat treated at a temperature of 700 ° C. to 1000 ° C., and lithium is applied to the particles after the heat treatment. It has a mixing process which mixes a compound and forms a mixture, and the baking process which bakes the said mixture formed at this mixing process at the temperature of 600 to 850 degreeC.
The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to a fifteenth aspect of the present invention is the method according to the thirteenth or fourteenth aspect, wherein the mixture comprises the sum of the number of atoms of metals other than lithium and the number of lithium atoms contained in the mixture. The ratio is adjusted to be 2: 0.95 to 1.10.
(Positive electrode active material for non-aqueous electrolyte secondary battery)
The positive electrode active material for a non-aqueous electrolyte secondary battery of the sixteenth invention, the general _{formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4 (-0.05 ≦ t ≦ 0.1,0 ≦ x ≦ 0.55, 0 ≦ y ≦ 0.1, M is an additive element, and one or more elements selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, and W ), A positive electrode active material made of a cubic lithium manganese composite oxide having a spinel structure, having an average particle diameter of 2 to 8 μm and an index indicating the spread of the particle size distribution [(d90-d10 ) / Average particle size] is 0.60 or less.
The positive electrode active material for a non-aqueous electrolyte secondary battery according to a seventeenth aspect of the present invention is characterized in that, in the sixteenth aspect, the range of x in the general formula is 0.45 ≦ x ≦ 0.55.
A positive electrode active material for a non-aqueous electrolyte secondary battery according to an eighteenth aspect of the invention is characterized in that it is produced by any one of the thirteenth to fifteenth manufacturing methods in any of the sixteenth and seventeenth aspects. .
(Non-aqueous electrolyte secondary battery)
A nonaqueous electrolyte secondary battery according to a nineteenth aspect is characterized in that the positive electrode is formed of the positive electrode active material for a nonaqueous electrolyte secondary battery according to any of the sixteenth to eighteenth aspects.

(Method for producing manganese composite hydroxide particles for positive electrode active material of non-aqueous electrolyte secondary battery)
According to the first invention, in the nucleation step, the growth of nuclei can be suppressed by causing the pH value of the aqueous solution for nucleation to be 12.0 to 14.0, and almost only nucleation can be caused. Further, in the particle growth step, by setting the pH value of the aqueous solution for particle growth to 10.5 to 12.0, only nucleus growth can be preferentially caused and formation of new nuclei can be suppressed. As a result, the nuclei can be grown homogeneously, so that homogeneous manganese composite hydroxide particles having a narrow particle size distribution range can be obtained.
According to the second invention, since the positive electrode active material of the battery formed using the manufactured manganese composite hydroxide particles as a raw material, a part of Mn of the lithium manganese composite oxide is substituted with Ni. When used, an operating voltage of 4.5 V or more can be realized, and a material having a high energy density can be obtained.
According to the third aspect of the invention, the pH value of the aqueous solution for nucleation after completion of the nucleation step is adjusted to obtain an aqueous solution for particle growth, so that the transition to the particle growth step can be performed quickly.
According to the fourth aspect, since nucleation and particle growth can be more clearly separated, the state of the liquid in each step can be set to an optimum condition for each step. Therefore, the produced manganese composite hydroxide particles can have a narrower range of particle size distribution and be uniform.
According to the fifth aspect of the invention, the concentration of manganese composite hydroxide particles in the aqueous solution for nucleation can be increased, so that the particles can be grown in a state where the particle concentration is high. Therefore, the particle size distribution of the particles can be further narrowed, and the density within the particles can also be increased.
According to the sixth aspect of the invention, since the control of nucleation becomes easy, nuclei suitable for the production of homogeneous manganese composite hydroxide particles having a narrow particle size distribution range can be formed.
According to the seventh invention, the solubility of metal ions can be adjusted within a predetermined range, so that particles having a uniform shape and particle size can be formed, and the particle size distribution can be narrowed.
According to the eighth aspect of the present invention, when the positive electrode active material of the battery formed using the manganese composite hydroxide particles produced by this method as a raw material is used for the battery, it is possible to improve the durability characteristics and output characteristics of the battery. .
(Manganese composite hydroxide particles for positive electrode active materials for non-aqueous electrolyte secondary batteries)
According to the ninth aspect of the present invention, when manganese composite hydroxide particles are mixed with a lithium compound and fired, lithium is sufficiently diffused into the particles to obtain a positive electrode active material having a uniform lithium distribution. Can do. Further, if a positive electrode active material is produced using manganese composite hydroxide particles as a raw material, this positive electrode active material can also be made into homogeneous particles with a narrow particle size distribution range. Then, when a battery having a positive electrode made of this positive electrode active material is formed, the voltage applied to the particles in the electrode can be made uniform, and the deterioration of the electrode can be suppressed even if charging and discharging are repeated.
According to the tenth invention, when a positive electrode active material is produced using manganese composite hydroxide particles as a raw material, a part of Mn of the lithium manganese composite oxide is replaced with Ni. An operating voltage of 5 V or more can be realized, and a material having a high energy density can be obtained.
According to the eleventh aspect of the invention, when the positive electrode active material of a battery formed using the manganese composite hydroxide particles of the present invention as a raw material is used for the battery, the battery durability characteristics and output characteristics can be improved.
According to the twelfth aspect of the invention, since the particle size distribution range can be narrow and homogeneous manganese composite hydroxide particles, if a positive electrode active material is produced using this particle as a raw material, the positive electrode active material also has a particle size distribution range. Can be made into narrow and homogeneous particles. Then, when a battery having a positive electrode made of this positive electrode active material is formed, the voltage applied to the particles in the electrode can be made uniform, and the deterioration of the electrode can be suppressed even if charging and discharging are repeated.
(Method for producing positive electrode active material for non-aqueous electrolyte secondary battery)
According to the thirteenth invention, a lithium manganese composite oxide having high crystallinity can be produced by firing at a temperature of 600 ° C. to 850 ° C. Therefore, when a battery having a positive electrode formed by the manufactured positive electrode active material is manufactured, a battery having a high operating voltage and excellent charge / discharge characteristics can be obtained.
According to the fourteenth aspect of the present invention, manganese composite hydroxide particles can be made into manganese composite oxide particles in which manganese and nickel are sufficiently dissolved by heat treatment at a temperature of 700 ° C. to 1000 ° C., and lithium manganese composite oxide having high crystallinity. Can be manufactured. Therefore, when a battery having a positive electrode formed by the manufactured positive electrode active material is manufactured, a battery having a high operating voltage and excellent charge / discharge characteristics can be obtained.
According to the fifteenth aspect, when the positive electrode is formed using the obtained positive electrode active material, the reaction resistance at the positive electrode can be reduced and the initial discharge capacity can be prevented from decreasing.
(Positive electrode active material for non-aqueous electrolyte secondary battery)
According to the sixteenth aspect, when used in a battery, high battery output characteristics and high capacity can be realized.
According to the seventeenth aspect, when used in a battery, a high capacity can be realized. Furthermore, an operating voltage of 4.5 V or more can be realized, the energy density can be increased, and a high capacity can be realized.
According to the eighteenth aspect of the invention, since the positive electrode active material becomes a uniform particle with a narrow particle size distribution range, when a battery having a positive electrode made of this positive electrode active material is formed, the electrode resistance can be reduced and charge and discharge are repeated. However, electrode deterioration can be suppressed.
(Non-aqueous electrolyte secondary battery)
According to the nineteenth aspect of the invention, a battery having an initial discharge capacity of 110 mAh / g or more and a low positive electrode resistance can be obtained, and the thermal stability and safety can be increased.

It is a schematic flowchart of the process of manufacturing the manganese composite hydroxide of this invention. It is a schematic flowchart of the other process which manufactures the manganese composite hydroxide of this invention. It is a schematic flowchart of the process of manufacturing lithium manganese complex oxide from the manganese complex hydroxide of this invention. It is a schematic flowchart until it manufactures the non-aqueous electrolyte secondary battery after manufacturing the manganese composite hydroxide of this invention. It is the table | surface which showed the result of the Example and the comparative example. It is a SEM photograph (observation magnification 1,000 times) of the manganese compound hydroxide of the present invention. It is a schematic sectional drawing of the coin-type battery 1 used for battery evaluation. It is a schematic explanatory drawing of the measurement example of impedance evaluation, and the equivalent circuit used for analysis.

  Next, the present invention provides (1) a nonaqueous electrolyte secondary battery, (2) (1) a positive electrode active material for a nonaqueous electrolyte secondary battery used for a positive electrode of a nonaqueous electrolyte secondary battery, and a method for producing the same ( 3) It relates to manganese composite hydroxide particles as a raw material for the positive electrode active material for non-aqueous electrolyte secondary batteries of (2) and a method for producing the same.

  (1) In order to improve the performance of the non-aqueous electrolyte secondary battery, it is necessary to use an electrode that employs (2) a positive electrode active material for a non-aqueous electrolyte secondary battery that is excellent in battery characteristics. (2) In order to obtain a positive electrode active material for a non-aqueous electrolyte secondary battery having excellent battery characteristics, its particle size and particle size distribution are important factors, and it has a desired particle size and a desired particle size distribution. A positive electrode active material adjusted to be preferred. In order to obtain such a positive electrode active material, it is necessary to use (3) manganese composite hydroxide particles as a raw material having a desired particle size and a desired particle size distribution.

The present invention, as described above, (1) affects the performance of the non-aqueous electrolyte secondary battery, which is the final product. (3) Manganese composite hydroxide particles are produced as homogeneous particles with a narrow particle size distribution range. And (3) manganese composite hydroxide particles produced by this method.
Also, the range of particle size distribution produced by the above method is narrow and homogeneous (3) Manganese composite hydroxide particles are used as raw materials and have a desired particle size and are adjusted to the desired particle size distribution (2) A method for producing a positive electrode active material for an aqueous electrolyte secondary battery and a positive electrode active material for a non-aqueous electrolyte secondary battery produced by this method are also objects of the present invention.
And it has the positive electrode using the positive electrode active material for the non-aqueous electrolyte secondary battery manufactured by the method of the present invention and having a desired particle size and adjusted to a desired particle size distribution (1) non An aqueous electrolyte secondary battery is also an object of the present invention.

  Hereinafter, the inventions (1) to (3) will be described in detail. The most important feature of the present invention is (3) a method for producing manganese composite hydroxide particles and (3) manganese composite hydroxide particles. Before describing (1), the final product is (1) a non-aqueous electrolyte secondary battery, and (3) a manganese composite hydroxide particle is used as a raw material, and (2) a non-aqueous electrolyte secondary battery positive electrode active material is manufactured. And (2) a positive electrode active material for a non-aqueous electrolyte secondary battery will be described.

(1) Non-aqueous electrolyte secondary battery As shown in FIG. 4, the non-aqueous electrolyte secondary battery of the present invention employs a positive electrode using the positive electrode active material for non-aqueous electrolyte secondary battery described later (2). Is.
Since such a positive electrode is adopted, the battery has an initial discharge capacity of 110 mAh / g or more and a low positive electrode resistance, and the effect of improving the thermal stability and safety can be achieved.

First, the structure of the nonaqueous electrolyte secondary battery of the present invention will be described.
The non-aqueous electrolyte secondary battery of the present invention (hereinafter simply referred to as the secondary battery of the present invention) is a positive electrode material for the non-aqueous electrolyte secondary battery of the present invention (hereinafter simply referred to as the positive electrode active material of the present invention). The structure is substantially the same as that of a general non-aqueous electrolyte secondary battery.

Specifically, the secondary battery of the present invention has a structure including a case, and a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator accommodated in the case. More specifically, a positive electrode and a negative electrode are laminated via a separator to form an electrode body, and the obtained electrode body is impregnated with a non-aqueous electrolyte, and a positive electrode current collector of the positive electrode and a positive electrode terminal connected to the outside are provided. The secondary battery of the present invention is formed by connecting the negative electrode current collector of the negative electrode and the negative electrode terminal communicating with the outside using a current collecting lead or the like, and sealing the case to the case. It is.
In addition, it cannot be overemphasized that the structure of the secondary battery of this invention is not limited to the said example, Moreover, the external shape can employ | adopt various shapes, such as a cylinder shape and a laminated form.

(Structure of each part)
Next, each part constituting the secondary battery of the present invention will be described.

(Positive electrode)
First, the positive electrode that is a feature of the secondary battery of the present invention will be described.
The positive electrode is a sheet-like member, and is formed by applying and drying a positive electrode mixture paste containing the positive electrode active material of the present invention, for example, on the surface of a current collector made of aluminum foil.

  In addition, a positive electrode is suitably processed according to the battery to be used. For example, a cutting process for forming an appropriate size according to a target battery, a pressure compression process using a roll press or the like to increase the electrode density, and the like are performed.

(Positive electrode paste)
The positive electrode mixture paste is formed by adding a solvent to the positive electrode mixture and kneading.

The positive electrode mixture is formed by mixing the positive electrode active material of the present invention in a powder form, a conductive material, and a binder.
The conductive material is added to give an appropriate conductivity to the electrode. The conductive material is not particularly limited. For example, graphite (natural graphite, artificial graphite, expanded graphite, and the like), and carbon black materials such as acetylene black and ketjen black can be used.
The binder plays a role of tethering the positive electrode active material particles. The binder used in this positive electrode mixture is not particularly limited. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), fluorine rubber, ethylene propylene diene rubber, styrene butadiene, cellulose resin, and poly Acrylic acid can be used.
In addition, activated carbon etc. may be added to a positive electrode compound material, and the electric double layer capacity | capacitance of a positive electrode can be increased by adding activated carbon etc.

  The solvent dissolves the binder and disperses the positive electrode active material, the conductive material, activated carbon, and the like in the binder. The solvent is not particularly limited, and for example, an organic solvent such as N-methyl-2-pyrrolidone can be used.

  Moreover, the mixing ratio of each substance in the positive electrode mixture paste is not particularly limited. For example, when the solid content of the positive electrode mixture excluding the solvent is 100 parts by mass, the content of the positive electrode active material is 60 to 95 parts by mass, the content of the conductive material is the same as the positive electrode of a general non-aqueous electrolyte secondary battery. The amount can be 1 to 20 parts by mass, and the content of the binder can be 1 to 20 parts by mass.

(Negative electrode)
The negative electrode is a sheet-like member formed by applying a negative electrode mixture paste to the surface of a metal foil current collector such as copper and drying it. The negative electrode is formed by substantially the same method as the positive electrode, although the components constituting the negative electrode mixture paste, the composition thereof, and the current collector material are different. Is done.

The negative electrode mixture paste is a paste obtained by adding an appropriate solvent to a negative electrode mixture in which a negative electrode active material and a binder are mixed.
As the negative electrode active material, for example, a material containing lithium, such as metallic lithium or a lithium alloy, or an occlusion material that can occlude and desorb lithium ions can be employed.
The occlusion material is not particularly limited, and for example, a fired organic compound such as natural graphite, artificial graphite and phenol resin, and a powdery material of carbon material such as coke can be used. When such an occlusion material is used for the negative electrode active material, a fluorine-containing resin such as PVDF can be used as the binder, as with the positive electrode, and as a solvent for dispersing the negative electrode active material in the binder, An organic solvent such as N-methyl-2-pyrrolidone can be used.

(Separator)
The separator is disposed so as to be sandwiched between the positive electrode and the negative electrode, and has a function of separating the positive electrode and the negative electrode and holding the electrolyte. As such a separator, for example, a thin film such as polyethylene or polypropylene and a film having a large number of fine pores can be used. However, the separator is not particularly limited as long as it has the above function.

(Non-aqueous electrolyte)
The nonaqueous electrolytic solution is obtained by dissolving a lithium salt as a supporting salt in an organic solvent.
Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate and trifluoropropylene carbonate, chain carbonates such as diethyl carbonate, dimethyl carbonate, ethylmethyl carbonate and dipropyl carbonate, tetrahydrofuran, 2- One kind selected from ether compounds such as methyltetrahydrofuran and dimethoxyethane, sulfur compounds such as ethylmethylsulfone and butanesultone, and phosphorus compounds such as triethyl phosphate and trioctyl phosphate are used alone or in admixture of two or more. be able to.
As the supporting salt, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiN (CF ₃ SO ₂ ) ₂ , and complex salts thereof can be used.
In addition, the non-aqueous electrolyte solution may contain a radical scavenger, a surfactant, a flame retardant, and the like for improving battery characteristics.

(Characteristics of the secondary battery of the present invention)
The secondary battery of the present invention has the above-described configuration and uses the positive electrode as described above. Therefore, an initial discharge capacity of 110 mAh / g or more and a low positive electrode resistance are obtained, and a high capacity and a high output are obtained. . In particular, as the positive electrode active material, the Ni content, that is, 4.5 V or more when the range of x in the general formula (see paragraph 0038) of the positive electrode active material described later is 0.45 ≦ x ≦ 0.55 High operating voltage can be obtained.
Moreover, it can be said that the thermal stability is high and the safety is also excellent in comparison with the positive electrode active material of a conventional lithium cobalt oxide.

(Use of the secondary battery of the present invention)
Since the secondary battery of the present invention has the properties as described above, it is suitable for the power source of small portable electronic devices (such as notebook personal computers and mobile phone terminals) that always require high capacity.
The secondary battery of the present invention is also suitable for an electric vehicle battery that requires high output. When a battery for an electric vehicle is enlarged, it is difficult to ensure safety and an expensive protection circuit is indispensable. However, the secondary battery of the present invention has excellent safety without increasing the size of the battery. Therefore, not only is it easy to ensure safety, but also an expensive protection circuit can be simplified and the cost can be further reduced. And since it can be reduced in size and increased in output, it is suitable as a power source for electric vehicles subject to restrictions on the mounting space.
The secondary battery of the present invention can be used not only as a power source for an electric vehicle driven purely by electric energy but also as a power source for a so-called hybrid vehicle used in combination with a combustion engine such as a gasoline engine or a diesel engine. .

(2) Positive electrode active material for non-aqueous electrolyte secondary battery The positive electrode active material for non-aqueous electrolyte secondary battery of the present invention (hereinafter referred to as positive electrode active material of the present invention) is a non-aqueous electrolyte secondary battery as described above. It is suitable as a positive electrode material.
The positive electrode active material of the present invention have the general _{formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4 (-0.05 ≦ t ≦ 0.1,0 ≦ x ≦ 0.55,0 ≦ y ≦ 0.1, M is an additive element, and is a lithium manganese composite represented by Mg, Ca, Ba, Sr, Ti, V, one or more elements selected from Cr, Zr, Nb, Mo, and W) The oxide particles have a cubic crystal structure having a spinel structure, and [(d90−d10) / average particle diameter], which is an index indicating the spread of the particle size distribution, is 0.60 or less. And it was adjusted so that an average particle diameter might be set to 2-8 micrometers.

(Particle size distribution)
The positive electrode active material of the present invention is adjusted so that [(d90-d10) / average particle size], which is an index indicating the spread of the particle size distribution, is 0.6 or less.
When the particle size distribution is wide, the positive electrode active material has many particles with a very small particle size relative to the average particle size and particles with a very large particle size (large particle) with respect to the average particle size. Will exist. When a positive electrode is formed using a positive electrode active material in which a large amount of fine particles are present, heat may be generated due to a local reaction of the fine particles, safety is reduced, and fine particles are selectively deteriorated. Cycle characteristics will deteriorate. On the other hand, when a positive electrode is formed using a positive electrode active material in which a large number of large particles are present, a sufficient reaction area between the electrolytic solution and the positive electrode active material cannot be obtained, resulting in a decrease in battery output due to an increase in reaction resistance.
Therefore, if the particle size distribution of the positive electrode active material is adjusted so that the index [(d90-d10) / average particle size] is 0.6 or less, the ratio of fine particles and large particles is small. A battery using a positive electrode active material for the positive electrode is excellent in safety, and good cycle characteristics and battery output can be obtained.

In addition, in the index [(d90−d10) / average particle diameter] indicating the spread of the particle size distribution, d10 indicates that when the particles in each particle diameter are accumulated from the smaller particle diameter, the accumulated volume is 10 of the total volume. % Means the particle size. Further, d90 means a particle size at which the cumulative volume becomes 90% of the total volume when the particles at each particle size are accumulated from the smallest particle size.
The method for obtaining the average particle diameter and d90 and d10 is not particularly limited, and for example, it can be obtained from the volume integrated value measured with a laser light diffraction / scattering particle size analyzer.

(Average particle size)
The positive electrode active material of the present invention preferably has the above-described particle size distribution and an average particle size adjusted to 2 to 8 μm. The reason for this is that when the average particle diameter is less than 2 μm, the packing density of the particles decreases when the positive electrode is formed, and the battery capacity per volume of the positive electrode decreases, while the average particle diameter exceeds 8 μm, This is because when the specific surface area of the positive electrode active material decreases and the interface with the battery electrolyte decreases, the resistance of the positive electrode increases and the output characteristics of the battery decrease.
Therefore, if the positive electrode active material of the present invention is adjusted so that the particle size distribution described above and the average particle size thereof are 2 to 8 μm, preferably 3 to 8 μm, more preferably 3 to 6 μm, In the battery used for the positive electrode, the battery capacity per volume can be increased, and excellent battery characteristics such as high safety and high output can be obtained.

(Composition of particles)
The positive electrode active material of the present invention is lithium manganese composite oxide particles, and the composition thereof is adjusted so as to be represented by the following general formula.
_{Formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4
(−0.05 ≦ t ≦ 0.1, 0 ≦ x ≦ 0.55, 0 ≦ y ≦ 0.1,
M: one or more elements selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W

  In the positive electrode active material of the present invention, the proportion of lithium is preferably in the above range. This is because when the proportion of lithium is less than the above range, the reaction resistance of the positive electrode in the non-aqueous electrolyte secondary battery using the obtained positive electrode active material increases, so the output of the battery decreases, This is because, when the ratio is larger than the above range, the initial discharge capacity of the positive electrode active material decreases and the reaction resistance of the positive electrode also increases.

Moreover, as represented by the above general formula, it is more preferable that the positive electrode active material of the present invention is adjusted so as to contain an additive element in the lithium manganese composite oxide particles. This is because when the additive elements as described above are added, the durability characteristics and output characteristics of the battery can be improved when used as the positive electrode active material of the battery.
In particular, if the additive element is adjusted so as to be uniformly distributed on the surface or inside of the particle, the above effect can be obtained with the whole particle, and the effect can be obtained with a small amount of addition and the decrease in capacity can be suppressed. There is.
And in order to acquire an effect with a smaller addition amount, it is preferable to raise the density | concentration of the addition element in the particle | grain surface from the inside of a particle | grain.

In particular, the range of x in the above general formula is preferably 0 ≦ x ≦ 0.1 or 0.45 ≦ x ≦ 0.55.
If the range of x is 0.45 ≦ x ≦ 0.55, a secondary battery having a positive electrode using this positive electrode active material can obtain a high operating voltage of 4.5 V or more.
Further, if the range of x is 0 ≦ x ≦ 0.1, the durability characteristics and output characteristics of the battery can be improved when used as the positive electrode active material of the battery.

  Note that when the atomic ratio y of the additive element M with respect to all atoms exceeds 0.1, the metal element contributing to the Redox reaction decreases, and the battery capacity decreases. Therefore, it is preferable to adjust so that it may become the said range.

(Method for producing positive electrode active material for non-aqueous electrolyte secondary battery)
The method for producing the positive electrode active material of the present invention is not particularly limited as long as the positive electrode active material can be produced so as to have the above crystal structure, average particle size, particle size distribution and composition, but if the following method is adopted, Since the positive electrode active material of this invention can be manufactured more reliably, it is preferable.

As shown in FIG. 3, the method for producing the positive electrode active material of the present invention comprises: a) a step of heat-treating manganese composite hydroxide particles as a raw material of the positive electrode active material of the present invention; and b) A mixing step of mixing a lithium compound to form a mixture, and c) a baking step of baking the mixture formed in the mixing step. Oxide particles, that is, the positive electrode active material of the present invention can be obtained.
Note that pulverization means mechanical energy is applied to an aggregate composed of a plurality of secondary particles generated by sintering necking between secondary particles at the time of firing, and the secondary particles are hardly destroyed. This is an operation of separating the particles and loosening the aggregates.
Hereinafter, each process will be described.

a) Heat treatment step The heat treatment step is a step of heating and heat treating manganese composite hydroxide particles (hereinafter simply referred to as composite hydroxide particles), and removing moisture contained in the hydroxide particles. . By performing this heat treatment step, moisture existing up to the firing step can be reduced. In other words, since the hydroxide particles can be converted to oxide particles, it is possible to prevent the ratio of the number of metal atoms and the number of lithium atoms in the produced positive electrode active material from being varied. Further, when an additive element is added, oxide particles in which the additive element is sufficiently dissolved can be obtained. By performing this heat treatment step, a lithium manganese composite oxide with high crystallinity can be produced.

In particular, when the nickel content is high, that is, when the range of x in the general formula is 0.45 ≦ x ≦ 0.55, the heating temperature is preferably 700 ° C. to 1000 ° C.
This is because when the heating temperature is less than 700 ° C., composite oxide particles in which manganese and nickel are sufficiently dissolved may not be obtained. On the other hand, when the temperature exceeds 1000 ° C., the particles are sintered and have a uniform particle size. This is because the composite oxide particles may not be obtained.
And if it heats and heat-processes at this temperature, since it can be set as the complex oxide particle which manganese and nickel fully dissolved, lithium manganese complex oxide with higher crystallinity can be manufactured.

  When the nickel content is low or nickel is not contained, that is, when the range of x in the general formula is 0 ≦ x ≦ 0.2, the heating temperature is preferably 100 ° C. to 900 ° C. . This is because when the heating temperature is less than 100 ° C., the removal of moisture is insufficient, whereas when it exceeds 900 ° C., the particle size becomes coarse due to sintering of the particles.

The atmosphere in which the heat treatment is performed is not particularly limited, and is preferably performed in an air stream that can be easily performed.
Further, the heat treatment time is not particularly limited, but if it is less than 5 hours, sufficient water removal or solid solution may not be performed, so at least 5 hours is preferable, and 5 to 20 hours is more preferable.
The equipment used for the heat treatment is not particularly limited as long as the composite hydroxide particles can be heated in an air stream, and an electric furnace that does not generate gas can be suitably used.

b) Mixing step The mixing step is a step in which particles that have been heat-treated in the heat treatment step (hereinafter referred to as heat-treated particles) and a substance containing lithium, for example, a lithium compound are mixed to obtain a lithium mixture.
The heat-treated particles are manganese composite hydroxide particles from which residual moisture has been removed in the heat treatment step, manganese composite oxide particles converted into oxides in the heat treatment step, or mixed particles thereof.

  The heat-treated particles and the lithium-containing substance are composed of the number of atoms of metals other than lithium (ie, the sum of the number of atoms of manganese and additive elements (Me)) and the number of lithium atoms (Me). Li) is mixed so that the ratio (Li / Me) is 0.475 to 0.55 (2: 0.95 to 1.1). That is, it mixes so that Li / Me in a lithium mixture may become the same as Li / Me in the positive electrode active material of this invention. This is because Li / Me does not change before and after the firing step, and Li / Me mixed in this mixing step becomes Li / Me in the positive electrode active material.

  The lithium-containing material used to form the lithium mixture is not particularly limited, but any lithium compound, for example, lithium hydroxide, lithium nitrate or lithium carbonate, or a mixture thereof is readily available. It is preferable in that it is. In particular, lithium hydroxide is more preferably used in consideration of ease of handling and stability of quality.

The lithium mixture is preferably mixed well before firing. If the mixing is not sufficient, Li / Me varies among individual particles, which may cause problems such as insufficient battery characteristics.
Moreover, a general mixer can be used for mixing, for example, a shaker mixer, a Laedige mixer, a Julia mixer, a V blender, etc. can be used, and the shape such as composite oxide particles is not destroyed. Therefore, the composite oxide particles and the substance containing lithium may be sufficiently mixed.

c) Firing step The firing step is a step of firing the lithium mixture obtained in the mixing step to form a lithium manganese composite oxide. When the lithium mixture is fired in the firing step, lithium in the lithium-containing substance diffuses into the composite oxide particles, so that a lithium manganese composite oxide is formed.

(Baking temperature)
Firing of the lithium mixture is performed at 600 to 850 ° C.
When the firing temperature is less than 600 ° C., the diffusion of lithium into the composite oxide particles is not sufficiently performed, and excess lithium and unreacted particles remain or the crystal structure is not sufficiently arranged. This causes a problem that the battery characteristics cannot be obtained.
On the other hand, when the firing temperature exceeds 850 ° C., intense sintering occurs between the composite oxide particles, and abnormal grain growth may occur. Then, there is a possibility that the particles after firing become coarse and the particle form (form of spherical secondary particles described later) cannot be maintained, and when the positive electrode active material is formed, the specific surface area decreases and the positive electrode A problem arises in that the resistance increases and the battery capacity decreases. Further, the battery capacity by the _Li 2 MnO ₃ as a different phase to produce is reduced.
Therefore, it is preferable to perform the baking of the lithium mixture at 600 to 850 ° C., particularly when the nickel content is high, that is, when the range of x in the general formula is 0.45 ≦ x ≦ 0.55, When the firing temperature is higher than 800 ° C., the particles are easily sintered.

(Baking time)
The firing time is preferably at least 10 hours or more, more preferably 15 to 20 hours. This is because if it is less than 10 hours, the lithium manganese composite oxide may not be sufficiently produced.

Further, as described above, when the concentration of the additive element M on the surface of the lithium manganese composite oxide particles is increased, the heat treatment particles as the raw material may be those whose particle surfaces are uniformly coated with the additive element. . By baking the lithium mixture containing the heat-treated particles under appropriate conditions, the concentration of the additive element on the surface of the composite oxide particles can be increased. Specifically, if a lithium mixture containing heat-treated particles coated with an additive element is fired at a low firing temperature and a short firing time, the lithium manganese composite with an increased concentration of the additive element M on the particle surface Oxide particles can be obtained.
Even when the lithium mixture containing the heat-treated particles coated with the additive element is fired, the lithium manganese composite oxide particles in which the additive element is uniformly distributed in the particles when the firing temperature is increased and the firing time is lengthened. Can be obtained. That is, the target lithium manganese composite oxide particles can be obtained by adjusting the heat-treated particles as raw materials and the firing conditions.

(Baking atmosphere)
The atmosphere during firing is preferably an oxidizing atmosphere, and more preferably an oxygen concentration of 18 to 100% by volume. That is, firing is preferably performed in the air or in an oxygen stream. This is because if the oxygen concentration is less than 18% by volume, the lithium manganese composite oxide may have insufficient crystallinity.

  The furnace used for firing is not particularly limited as long as the lithium mixture can be heated in the atmosphere or an oxygen stream, but an electric furnace that does not generate gas is preferable, and a batch type or a continuous type may be used. Any furnace can be used.

(3) Manganese composite hydroxide particles The manganese composite hydroxide particles of the present invention (hereinafter simply referred to as the composite hydroxide particles of the present invention) have the general formula Mn _1-xy Ni _x M _y (OH) _{2 + α} (0 ≦ x ≦ 0.27, 0 ≦ y ≦ 0.05, 0 ≦ α ≦ 0.5, M is an additive element, Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, One or more elements selected from Mo and W), which are spherical secondary particles formed by agglomerating a plurality of plate-like primary particles, and the secondary particles have an average particle size of 3 to 3. It is 7 μm, and is adjusted so that [(d90−d10) / average particle size], which is an index indicating the spread of the particle size distribution, is 0.55 or less.
Since the composite hydroxide particles of the present invention are particularly suitable as the raw material for the positive electrode active material of the present invention described above, the following description is based on the assumption that they are used as the raw material for the positive electrode active material of the present invention. To do.

(Particle structure)
The composite hydroxide particles of the present invention are adjusted to be spherical particles, specifically, spherical secondary particles formed by aggregation of a plurality of plate-like primary particles, and have such a structure. Accordingly, in the sintering step for forming the positive electrode active material of the present invention described above, lithium is sufficiently diffused into the particles, so that a positive electrode active material having a uniform lithium distribution can be obtained.

  And it is more preferable if the plate-like primary particles are aggregated in a random direction to form secondary particles. The plate-like primary particles agglomerate in random directions, so that almost uniform voids are formed between the primary particles. When mixed with the lithium compound and fired, the molten lithium compound spreads into the secondary particles and diffuses lithium. It is because it is performed sufficiently.

(Particle size distribution)
The composite hydroxide particles of the present invention are adjusted so that [(d90-d10) / average particle size], which is an index indicating the spread of the particle size distribution, is 0.55 or less.
The particle size distribution of the positive electrode active material is strongly influenced by the composite hydroxide particles as the raw material. Therefore, if fine particles or coarse particles are mixed in the composite hydroxide particles, the same particles are also present in the positive electrode active material. To come. That is, when [(d90−d10) / average particle size] exceeds 0.55 and the particle size distribution is wide, fine particles or coarse particles also exist in the positive electrode active material.
If the composite hydroxide particles of the present invention are adjusted so that [(d90-d10) / average particle size] is 0.55 or less, the positive electrode obtained using the composite hydroxide particles of the present invention as a raw material The active material also has a narrow particle size distribution range, and the particle size can be made uniform. That is, in the particle size distribution of the positive electrode active material obtained, the index [(d90−d10) / average particle size] can be 0.6 or less. Then, a battery having an electrode formed of a positive electrode active material formed using the composite hydroxide particles of the present invention as a raw material can have good cycle characteristics and output.

(Average particle size)
The composite hydroxide particles of the present invention have an average particle size adjusted to 3 to 7 μm. The reason is that by setting the average particle size to 3 to 7 μm, the positive electrode active material obtained using the composite hydroxide particles of the present invention as a raw material can be adjusted to a predetermined average particle size (2 to 8 μm). It is. That is, the above-described positive electrode active material of the present invention can be formed using the composite hydroxide particles of the present invention as a raw material.
When the average particle size of the composite hydroxide particles of the present invention is less than 3 μm, the average particle size of the positive electrode active material also decreases, the positive electrode packing density decreases, and the battery capacity per volume decreases. On the contrary, when the average particle size of the composite hydroxide particles of the present invention exceeds 7 μm, the specific surface area of the positive electrode active material is reduced and the interface with the electrolyte is decreased, thereby increasing the resistance of the positive electrode and the battery. This is because the output characteristics of the are deteriorated.
Therefore, the average particle diameter of the composite hydroxide particles of the present invention is adjusted to 3 to 7 μm, and the positive electrode active material of the present invention can be obtained using the composite hydroxide particles of the present invention as a raw material. When a positive electrode using a positive electrode active material is used for a battery, excellent battery characteristics can be obtained.

(Composition of particles)
The composite hydroxide particles of the present invention are manganese composite hydroxide particles, and the composition thereof is adjusted so as to be represented by the following general formula. With such a composition, it is possible to form a manganese double if hydroxides suitable material for manufacturing the lithium-manganese composite oxide as a cathode active material. Then, if a lithium manganese composite oxide is produced using the manganese composite hydroxide particles as a raw material, when an electrode using the lithium manganese composite oxide as a positive electrode active material is used in a battery, the measured value of the positive electrode resistance is The output characteristics of the battery can be improved.
The general _{formula: Mn 1-x-y Ni} x M y (OH) 2 + α
0 ≦ x ≦ 0.27, 0 ≦ y ≦ 0.05, 0 ≦ α ≦ 0.5
M: Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W

  In particular, in producing the positive electrode active material (0 ≦ x ≦ 0.2 or 0.45 ≦ x ≦ 0.55) described above using the composite hydroxide particles of the present invention as a raw material, x in the above general formula The range is preferably 0 ≦ x ≦ 0.1 or 0.23 ≦ x ≦ 0.27.

Further, when the positive electrode active material is obtained according to the above-described production method, the composition ratio (Mn: Ni: M) of the composite hydroxide particles of the present invention is also maintained in the positive electrode active material.
Therefore, the composition ratio of the composite hydroxide particles of the present invention is adjusted to be the same as that of the positive electrode active material to be obtained.

(Manufacturing method of manganese composite hydroxide particles)
The method for producing the composite hydroxide particles of the present invention having the above-described characteristics can be produced by the following method.

The method for producing composite hydroxide particles of the present invention is a method for producing manganese composite hydroxide particles by a crystallization reaction, and is produced in a) a nucleation step for performing nucleation, and b) a nucleation step. And a particle growth process for growing nuclei.
That is, in the method for producing composite hydroxide particles of the present invention, the nucleation reaction and the particle growth reaction proceed at the same time in the same tank as in the conventional continuous crystallization method (see Patent Documents 2 and 3). Rather, it is characterized by clearly separating mainly the time at which the nucleation reaction (nucleation process) occurs and the time at which the particle growth reaction (particle growth process) mainly occurs.

  First, an outline of the method for producing composite hydroxide particles of the present invention will be described with reference to FIG. In FIGS. 1 and 2, (A) corresponds to the nucleation step and (B) corresponds to the particle growth step.

(Nucleation process)
First, a plurality of metal compounds such as a plurality of metal compounds containing manganese and a metal compound containing other metals are dissolved in water at a predetermined ratio to prepare a mixed aqueous solution. In the method for producing composite hydroxide particles of the present invention, the composition ratio of each metal in the obtained composite hydroxide particles is the same as the composition ratio of each metal in the mixed aqueous solution.
Therefore, the ratio of the 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 composite hydroxide particles of the present invention. A mixed aqueous solution is prepared.

  On the other hand, an alkaline aqueous solution such as a sodium hydroxide aqueous solution, an ammonia aqueous solution containing an ammonium ion supplier, and water are supplied to the reaction tank and mixed to form an aqueous solution. This aqueous solution (hereinafter referred to as pre-reaction aqueous solution) is adjusted to the supply amount of the alkaline aqueous solution, and the pH value is a pH value of 12.0 to 14.0 when measured on the basis of the liquid temperature of 25 ° C. Adjusted to be in range. In addition, the concentration of ammonium ions in the aqueous solution before reaction is adjusted to 3 to 25 g / L. The temperature of the aqueous solution before reaction is adjusted to 20 to 60 ° C. The pH of the liquid in the reaction tank and the concentration of ammonium ions can be measured with a general pH meter and ion meter, respectively.

And if the temperature and pH value of aqueous solution before reaction are adjusted, mixed aqueous solution will be supplied in a reaction tank, stirring the aqueous solution in reaction tank. Then, in the reaction tank, an aqueous solution (hereinafter referred to as reaction aqueous solution) in which the pre-reaction aqueous solution and the mixed aqueous solution are mixed is formed, so that fine nuclei of the composite hydroxide of the present invention are generated in the reaction aqueous solution. be able to. At this time, since the pH value of the reaction aqueous solution is in the above range, the produced nuclei hardly grow and the production of the nuclei takes place preferentially.
In addition, since the pH value and ammonium ion of the reaction aqueous solution change with the nucleation, the alkaline aqueous solution and the ammonia aqueous solution are supplied to the reaction aqueous solution together with the mixed aqueous solution. Is controlled to maintain a predetermined value.

  By continuously supplying the mixed aqueous solution, the alkaline aqueous solution and the aqueous ammonia solution to the reaction aqueous solution, the generation of new nuclei is continued. Then, when a predetermined amount of nuclei is generated in the reaction aqueous solution, the nucleation step is finished. The formation of a predetermined amount of nuclei is judged by the amount of metal salt added to the reaction aqueous solution.

  The reaction aqueous solution described above, that is, a mixed aqueous solution, an aqueous solution containing an alkaline aqueous solution and an aqueous ammonia solution, which is adjusted to have a pH in the range of 12.0 to 14.0, is nucleated as defined in the claims. Aqueous solution.

(Particle growth process)
When the nucleation step is completed, the pH value of the aqueous reaction solution is adjusted to be pH 10.5 to 12.0 as the pH value when measured based on the liquid temperature of 25 ° C. Specifically, the pH value of the aqueous reaction solution is controlled by adjusting the supply amount of the aqueous alkaline solution.
When the pH value of the reaction aqueous solution is 12.0 or less, the composite hydroxide particles of the present invention having a predetermined particle diameter are formed in the reaction aqueous solution. At this time, since the pH value of the aqueous solution is in the above range, the nucleus growth reaction takes precedence over the nucleus generation reaction, so that almost no new nuclei are generated in the aqueous solution.
Then, when a predetermined amount of composite hydroxide particles having a predetermined particle size are generated, the particle growth step is terminated. The amount of composite hydroxide particles having a predetermined particle size is determined by the amount of metal salt added to the reaction aqueous solution.

  The above-mentioned reaction aqueous solution, that is, a mixed aqueous solution, an aqueous solution in which an aqueous alkaline solution and an aqueous ammonia solution are mixed and adjusted to have a pH in the range of 10.5 to 12.0 is the particle growth referred to in the claims. Aqueous solution.

  As described above, in the above-described method for producing composite hydroxide particles, nucleation is preferentially performed in the nucleation step, and almost no nucleation is generated. Is not generated. 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 composite hydroxide particles, uniform manganese composite hydroxide particles having a narrow particle size distribution range can be obtained.

In the case of the above method, in both steps, the metal ions are crystallized as nuclei or composite hydroxide particles, so that the ratio of the liquid component to the metal component in the aqueous reaction solution increases. Then, apparently, the concentration of the mixed aqueous solution to be supplied is lowered, and there is a possibility that the composite hydroxide particles are not sufficiently grown in the particle growth step.
Therefore, a part of the reaction aqueous solution is discharged out of the reaction tank after completion of the nucleation step or during the particle growth step. Specifically, the supply and stirring of the mixed aqueous solution and the like to the reaction aqueous solution are stopped, the nucleus and the composite hydroxide particles are settled, and the supernatant of the reaction aqueous solution is discharged. Then, the relative concentration of the mixed aqueous solution in the reaction aqueous solution can be increased. Since the composite hydroxide particles can be grown in a state where the relative concentration of the mixed aqueous solution is high, the particle size distribution of the composite hydroxide particles can be narrowed, and the secondary particles of the composite hydroxide particles The internal density can also be increased.

In the above embodiment, since the particle growth step is performed by adjusting the pH value of the aqueous solution for nucleation after the nucleation step is completed, the transition to the particle growth step is performed quickly. There is an advantage that can be done.
However, as shown in FIG. 2, separately from the aqueous solution for nucleation, a component adjusted aqueous solution adjusted to a pH value and ammonium ion concentration suitable for the nucleation step is formed, An aqueous solution containing nuclei subjected to the nucleation step in the reaction vessel may be added to form a reaction aqueous solution, and the particle growth step may be performed in this reaction aqueous solution (that is, an aqueous solution for particle growth).
In this case, since the nucleation step and the particle growth step can be more reliably separated, the state of the reaction aqueous solution in each step can be set to the optimum condition for each step. In particular, the pH value of the aqueous reaction solution can be set to the optimum condition from the beginning of the start of the particle growth process. As a result, the manganese composite hydroxide particles formed in the particle growth step can have a narrower range of particle size distribution and be uniform.

  Furthermore, in the case of the method of the present invention, the particle growth step can be carried out following the nucleation step if the aqueous solution for particle growth is formed by adjusting the pH value of the aqueous solution for nucleation as described above. Then, the transition from the nucleation step to the particle growth step can be performed only by adjusting the pH value of the reaction aqueous solution, and the pH adjustment can be easily performed by temporarily stopping the supply of the alkaline aqueous solution. There are advantages. The pH value of the aqueous reaction solution can also be adjusted by adding an inorganic acid of the same type as the acid constituting the metal compound, for example, sulfuric acid to the reaction aqueous solution in the case of a sulfate.

  Next, substances, solutions and reaction conditions used in each step will be described in detail.

(PH value)
(Nucleation process)
As described above, in the nucleation step, the pH value of the reaction aqueous solution is 12.0 to 14.0, preferably 12.0 to 13 as the pH value when measured based on the liquid temperature of 25 ° C. .4 has been adjusted.
When the pH value is higher than 14.0, the generated nuclei become too fine, and there is a problem that the reaction aqueous solution gels. When the pH value is less than 12.0, a nucleus growth reaction occurs with nucleation. The range of the particle size distribution of the formed nuclei becomes wide and becomes inhomogeneous.
Therefore, the pH value of the reaction aqueous solution in the particle growth step needs to be 12.0 to 14.0. If it is within such a range, the nucleation step suppresses the growth of nuclei and substantially only nucleation. The nuclei formed can be homogeneous and have a narrow particle size distribution range.

(Particle growth process)
As described above, in the particle growth step, the pH value of the reaction aqueous solution is adjusted so that the pH value is 10.5 to 12.0 as a pH value when measured with a liquid temperature of 25 ° C. as a reference. Yes.
If the pH value is higher than 12.0, hydroxide particles with many newly generated nuclei and good particle size distribution cannot be obtained. If the pH value is less than 10.5, the solubility by ammonia ions is high and the particles are precipitated. This is not preferable because the metal ions remaining in the liquid increase.
Therefore, the pH value of the reaction aqueous solution in the particle growth process needs to be 10.5 to 12.0, and within such a range, only the growth of nuclei generated in the nucleation process is preferentially caused, Since new nucleation can be suppressed, the formed manganese composite hydroxide particles can be made homogeneous and have a narrow particle size distribution range.

When the pH value is 12, it is a boundary condition between nucleation and nucleation, and therefore, it can be set as either a nucleation process or a particle growth process depending on the presence or absence of nuclei present in the reaction aqueous solution. .
That is, if the pH value in the nucleation step is higher than 12 and a large amount of nuclei are produced, and if the pH value is set to 12 in the particle growth step, a large amount of nuclei are present in the reaction aqueous solution, so the growth of nuclei takes priority. Thus, the hydroxide particles having a narrow particle size distribution and a relatively large particle size can be obtained.
On the other hand, when no nuclei exist in the reaction aqueous solution, that is, when the pH value is set to 12 in the nucleation step, since no nuclei grow, nucleation occurs preferentially, and the pH value of the particle growth step is set to 12. By making it smaller, the produced | generated nucleus grows and the said hydroxide particle | grains favorable are obtained.
In any case, the pH value of the particle growth process may be controlled to a value lower than the pH value of the nucleation process.

(Nucleation amount)
The amount of nuclei generated in the nucleation step is not particularly limited, but in order to obtain composite hydroxide particles having a good particle size distribution, the total amount, that is, supplied to obtain composite hydroxide particles. The total metal salt content is preferably 0.1% to 2%, more preferably 1.5% or less.

(Controlling the particle size of composite hydroxide particles)
Since the particle size of the composite hydroxide particles can be controlled by the time of the particle growth step, if the particle growth step is continued until it grows to the desired particle size, composite hydroxide particles having the desired particle size can be obtained. it can.
Further, the particle size of the composite hydroxide particles can be controlled not only by the particle growth step but also by the pH value of the nucleation step and the amount of raw material charged for nucleation.
That is, by increasing the pH value at the time of nucleation to the high pH value side or by increasing the nucleation time, the amount of raw material to be added is increased, and the number of nuclei to be generated is increased. Then, even when the particle growth step is performed under the same conditions, the particle size of the composite hydroxide particles can be reduced.
On the other hand, if the nucleation number is controlled to be small, the particle size of the obtained composite hydroxide particles can be increased.

(Description of other conditions)
Hereinafter, the conditions such as the metal compound, the ammonia concentration in the reaction aqueous solution, the reaction temperature, and the atmosphere will be described. The difference between the nucleation step and the particle growth step is only in the range in which the pH value of the reaction aqueous solution is controlled. Conditions such as the compound, the ammonia concentration in the reaction solution, the reaction temperature, and the atmosphere are substantially the same in both steps.

(Metal compound)
As the metal compound, a compound containing the target metal is used. As the compound to be used, a water-soluble compound is preferably used, and examples thereof include nitrates, sulfates and hydrochlorides. For example, manganese sulfate and nickel sulfate are preferably used.
When forming the mixed aqueous solution, each metal compound is adjusted so that the atomic ratio of the metal ions present in the mixed aqueous solution matches the atomic ratio of the metal ions in the target composite hydroxide. .

(Additive elements)
As the additive element (one or more elements selected from Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, and W), a water-soluble compound is preferably used. For example, magnesium sulfate, Calcium nitrate, barium nitrate, strontium nitrate, titanium sulfate, 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, or the like can be used.

  When such an additive element is uniformly dispersed inside the composite hydroxide particles, an additive containing the additive element may be added to the mixed aqueous solution. Then, it can be coprecipitated in a state where the additive element is uniformly dispersed inside the composite hydroxide particles.

When the surface of the composite hydroxide particle is coated with an additive element, for example, the composite hydroxide particle is slurried with an aqueous solution containing the additive element, and the additive element is separated from the surface of the composite hydroxide particle by a crystallization reaction. If deposited on the surface, the surface can be coated with an additive element. In this case, an alkoxide solution of the additive element may be used instead of the aqueous solution containing the additive element. Furthermore, the surface of the composite hydroxide particles can be coated with the additive element by spraying an aqueous solution or slurry containing the additive element on the composite hydroxide particle and drying it. This coating step may be performed on the composite oxide particles.
When the surface is coated with an additive element, the atomic ratio of the additive element ions present in the mixed aqueous solution is reduced by the amount to be coated, so that the atomic ratio of the metal ions of the resulting composite hydroxide particles is reduced. Can be matched.

(Concentration of mixed aqueous solution)
The concentration of the mixed aqueous solution is preferably 1 to 2.2 mol / L in total of the metal compounds. When the concentration of the mixed aqueous solution is less than 1 mol / L, the amount of crystallized product per reaction tank is decreased, and thus the productivity is not preferable.
On the other hand, if the salt concentration of the mixed aqueous solution exceeds 2.2 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 addition, the metal compound does not necessarily have to be supplied to the reaction vessel as a mixed aqueous solution, and is reacted at a predetermined ratio as an aqueous solution of individual metal compounds so that the total concentration of the metal compounds in the aqueous reaction solution falls within the above range. You may supply in a tank.
Further, it is desirable that the amount of the mixed aqueous solution or the aqueous solution of each metal compound supplied to the reaction tank is such that the crystallized substance concentration is approximately 30 to 200 g / L when the crystallization reaction is completed. This is because when the crystallized substance concentration is less than 30 g / L, the aggregation of primary particles may be insufficient, and when it exceeds 200 g / L, diffusion of the mixed aqueous solution to be added in the reaction vessel is sufficient. This is because the grain growth may be biased.

(Ammonia concentration)
In the reaction vessel, the ammonia concentration in the aqueous reaction solution is preferably maintained at a constant value within the range of 3 to 25 g / L in order not to cause the following problems.
First, ammonia acts as a complexing agent, and if the ammonia concentration is less than 3 g / L, the solubility of metal ions cannot be kept constant. Since particles are not formed and gel-like nuclei are easily generated, the particle size distribution is also likely to be widened.
On the other hand, when the ammonia concentration exceeds 25 g / L, the solubility of metal ions becomes too high, and the amount of metal ions remaining in the reaction aqueous solution increases, resulting in compositional deviation and the like.
Further, when the ammonia concentration varies, the solubility of metal ions varies, and uniform hydroxide particles are not formed. Therefore, it is preferable to maintain a constant value. That is, the ammonia concentration is preferably maintained at a desired concentration with an upper limit and a lower limit of about 5 g / L.
In addition, although an ammonium ion supply body is not specifically limited, For example, ammonia, ammonium sulfate, ammonium chloride, ammonium carbonate, ammonium fluoride etc. can be used.

(Reaction temperature)
In the reaction vessel, the temperature of the reaction solution is preferably set to 20 ° C or higher, more preferably 20 to 60 ° C. When the temperature of the reaction solution is less than 20 ° C, the temperature is low, so that nucleation is likely to occur and control becomes difficult. On the other hand, when the temperature exceeds 60 ° C, the volatilization of ammonia is promoted, so This is because an ammonium ion donor must be added.

(Alkaline aqueous solution)
The aqueous alkali solution for adjusting the pH in the reaction vessel is not particularly limited, and for example, an aqueous alkali metal hydroxide solution such as sodium hydroxide or potassium hydroxide can be used. In the case of such an alkali metal hydroxide, it may be added directly to the mixed aqueous solution before being supplied to the reaction vessel, but from the ease of pH value control of the aqueous reaction solution in the reaction vessel, the reaction in the reaction vessel as an aqueous solution. It is preferable to add to an aqueous solution.
Further, the method of adding the alkaline aqueous solution to the reaction vessel is not particularly limited, and the pH value of the aqueous solution in the reaction vessel is predetermined by a pump capable of controlling the flow rate such as a metering pump while sufficiently stirring the mixed aqueous solution. It may be added so that it is maintained in the range of.

(Reaction atmosphere)
The atmosphere during the reaction is not particularly limited, but an excessively oxidizing atmosphere is not preferable for stable production. For example, by performing the crystallization reaction by controlling the oxygen concentration in the reaction vessel space to 10% or less, unnecessary oxidation of the particles can be suppressed, and particles having a uniform particle size can be obtained. As a means for maintaining the space in the reaction tank in such a state, an inert gas such as nitrogen is always circulated into the tank.

(production equipment)
In the method for producing composite hydroxide particles of the present invention, an apparatus that does not recover the product until the reaction is completed is used. For example, it is a normally used batch reactor equipped with a stirrer. When such an apparatus is used, there is no problem that the growing particles are recovered simultaneously with the overflow liquid unlike the continuous crystallization apparatus that recovers the product by the overflow, so that the particle size distribution is narrow and the particle size is uniform. Particles can be obtained.
Moreover, when controlling reaction atmosphere, it is preferable that it is an apparatus which can control atmosphere, such as a sealed apparatus. If such an apparatus is used, the nucleation reaction and the particle growth reaction proceed almost uniformly, so that particles having an excellent particle size distribution (that is, particles having a narrow particle size distribution range) can be obtained.

The average particle diameter and particle size distribution of the composite hydroxide produced by the method of the present invention and the positive electrode active material produced by the method of the present invention using this composite hydroxide as a raw material were confirmed.
Moreover, about the secondary battery which has the positive electrode manufactured using the positive electrode active material manufactured by the method of this invention, the performance (initial discharge capacity, cycle capacity maintenance factor, positive electrode resistance) was confirmed.
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Measurement of average particle size and particle size distribution)
The average particle size and particle size distribution ([(d90-d10) / average particle size] value) of the composite hydroxide and the positive electrode active material are measured using a laser diffraction scattering type particle size distribution measuring device (manufactured by Nikkiso Co., Ltd., Microtrac HRA). It is calculated from the volume integrated value measured by using.
In addition, the crystal structure was confirmed by X-ray diffraction measurement (X'Pert PRO, manufactured by Panalytic Co.), and the composition of the obtained composite hydroxide and positive electrode active material was determined by ICP emission spectroscopy after dissolving the sample. confirmed.

(Manufacture of secondary batteries)
For the evaluation, a 2032 type coin battery (hereinafter referred to as coin type battery 1) shown in FIG. 7 was used.
As shown in FIG. 7, the coin-type battery 1 includes a case 2 and an electrode 3 accommodated in the case 2.
The case 2 has a positive electrode can 2a that is hollow and open at one end, and a negative electrode can 2b that is disposed in the opening of the positive electrode can 2a. When the negative electrode can 2b is disposed in the opening of the positive electrode can 2a, A space for accommodating the electrode 3 is formed between the negative electrode can 2b and the positive electrode can 2a.
The electrode 3 includes a positive electrode 3a, a separator 3c, and a negative electrode 3b, which are stacked in this order. The positive electrode 3a contacts the inner surface of the positive electrode can 2a, and the negative electrode 3b contacts the inner surface of the negative electrode can 2b. As shown in FIG.
The case 2 includes a gasket 2c, and relative movement is fixed by the gasket 2c so as to maintain a non-contact state between the positive electrode can 2a and the negative electrode can 2b. Further, the gasket 2c also has a function of sealing a gap between the positive electrode can 2a and the negative electrode can 2b to block the inside and outside of the case 2 in an airtight and liquid tight manner.

The coin type battery 1 as described above was manufactured as follows.
First, 52.5 mg of a positive electrode active material for a non-aqueous electrolyte secondary battery, 15 mg of acetylene black, and 7.5 mg of polytetrafluoroethylene resin (PTFE) are mixed, and press molded to a diameter of 11 mm and a thickness of 100 μm at a pressure of 100 MPa. A positive electrode 3a was produced. The produced positive electrode 3a was dried at 120 ° C. for 12 hours in a vacuum dryer.
Using the positive electrode 3a, the negative electrode 3b, the separator 3c, and the electrolytic solution, the coin-type battery 1 described above was produced in a glove box in an Ar atmosphere in which the dew point was controlled at −80 ° C.
As the negative electrode (2), a negative electrode sheet in which graphite powder having an average particle diameter of about 20 μm punched into a disk shape with a diameter of 14 mm and polyvinylidene fluoride were applied to a copper foil was used. The separator (3) was a 25 μm thick polyethylene porous film. As the electrolytic solution, an equivalent mixed solution (manufactured by Toyama Pharmaceutical Co., Ltd.) of ethylene carbonate (EC) and diethyl carbonate (DEC) using 1M LiClO4 as a supporting electrolyte was used.

The initial discharge capacity, cycle capacity maintenance rate, and positive electrode resistance for evaluating the performance of the manufactured coin-type battery 1 were defined as follows.
The initial discharge capacity is left for about 24 hours after the coin-type battery 1 is manufactured, and after the open circuit voltage OCV (open circuit voltage) is stabilized, the current density with respect to the positive electrode is set to 0.1 mA / cm 2 and the cut-off voltage 4. The capacity when the battery was charged to 3 V, discharged after 1 hour of rest, and discharged to a cutoff voltage of 3.0 V was defined as the initial discharge capacity. In the general formula representing the positive electrode active material, x was in the range of 0.45 ≦ x ≦ 0.55, and charged to a cutoff voltage of 4.9V.
The cycle capacity retention rate is a discharge capacity after repeating charge and discharge 100 times after repeating a cycle of charging to 4.2 V and discharging to 3.0 V with a current density of 2 mA / cm 2 with respect to the positive electrode. The ratio was calculated as the capacity retention rate.
A multi-channel voltage / current generator (manufactured by Advantest Corporation, R6741A) was used for the measurement of the charge / discharge capacity.
Further, the positive resistance is obtained by charging the coin-type battery 1 at a charging potential of 4.1 V and measuring it by an AC impedance method using a frequency response analyzer and a potentiogalvanostat (manufactured by Solartron, 1255B), as shown in FIG. A plot is obtained. Since this Nyquist plot is expressed as the sum of the characteristic curve indicating the solution resistance, the negative electrode resistance and its capacity, and the positive electrode resistance and its capacity, fitting calculation is performed using an equivalent circuit based on this Nyquist plot, and the positive resistance The value of was calculated. In the general formula representing the positive electrode active material, x in the range of 0.45 ≦ x ≦ 0.55 was charged at a charging potential of 4.7V.

  Note that, in this example, Wako Pure Chemical Industries, Ltd. reagent grade samples were used for the production of composite hydroxide, the production of the positive electrode active material, and the secondary battery.

Example 1
(Composite hydroxide production process)
The composite hydroxide was prepared as follows using the method of the present invention.
First, the temperature in the tank was set to 40 ° C. while stirring by putting half the amount of water in the reaction tank (34L), and a nitrogen atmosphere was passed through the reaction tank to form a nitrogen atmosphere. At this time, the oxygen concentration in the reaction vessel space was 2.0%.

  Appropriate amounts of 25% aqueous sodium hydroxide and 25% aqueous ammonia are added to the water in the reaction tank, and the pH value of the reaction liquid in the tank is 13.0 as a pH value measured based on a liquid temperature of 25 ° C. Adjusted. The ammonia concentration in the reaction solution was adjusted to 15 g / L.

(Nucleation process)
Next, manganese sulfate and nickel sulfate were dissolved in water to form a 1.8 mol / L mixed aqueous solution. In this mixed aqueous solution, the element molar ratio of each metal was adjusted to be Mn: Ni = 1.5: 0.5.
The mixed aqueous solution was added to the reaction solution in the reaction vessel at 88 ml / min. At the same time, 25% aqueous ammonia and 25% aqueous sodium hydroxide solution were also added to the reaction solution in the reaction tank at a constant rate, and the pH value was adjusted to 13.0 (with the ammonia concentration in the reaction solution kept at the above value). Crystallization was carried out for 2 minutes and 30 seconds while controlling the nucleation pH value) to carry out nucleation.

(Particle growth process)
Thereafter, only the supply of the 25% aqueous sodium hydroxide solution was temporarily stopped until the pH value of the reaction solution reached 11.6 (particle growth pH value) as a pH value measured with a liquid temperature of 25 ° C. as a reference.
After the pH value of the reaction solution reached 11.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference, the supply of 25% sodium hydroxide aqueous solution was resumed and the pH value was controlled to 11.6. The crystallization was continued for 2 hours and particle growth was performed.

  Crystallization was stopped when the reaction tank was full, and stirring was stopped and the mixture was allowed to stand to promote precipitation of the product. Then, after extracting half amount of the supernatant from the reaction tank, crystallization was resumed, and after crystallization for 2 hours (4 hours in total), crystallization was terminated. The product was washed with water, filtered, and dried to obtain particles.

When the obtained composite hydroxide was chemically analyzed, the composition was Mn _0.75 Ni _0.25 (OH) _{2 + α} (0 ≦ α ≦ 0.5). As shown in FIG. 5, when the particle size distribution of the composite hydroxide particles was measured, the average particle size was 3.5 μm, and the [(d90−d10) / average particle size] value was 0.49. .
From the SEM photograph (FIG. 6) which is the SEM (scanning electron microscope S-4700 manufactured by Hitachi High-Technologies Corporation) observation result of the obtained composite hydroxide particles, the obtained composite hydroxide particles are substantially spherical. It was confirmed that the particle diameters were almost uniform.

(Cathode active material manufacturing process)
The composite hydroxide particles were heat-treated at a temperature of 900 ° C. for 15 hours in an air stream (oxygen: 21% by volume) to recover the composite oxide particles.
Lithium hydroxide was weighed so that Li / Me = 0.50 and mixed with the recovered composite oxide particles to form a mixture. Mixing was performed using a shaker mixer apparatus (TURBULA Type T2C manufactured by Willy et Bacofen (WAB)).
The obtained mixture was baked in an oxygen stream at 700 ° C. for 20 hours, cooled, and crushed to obtain a positive electrode active material.

As shown in FIG. 5, when the particle size distribution of the obtained positive electrode active material was measured, the average particle size was 3.7 μm, and the [(d90−d10) / average particle size] value was 0.52. .
Moreover, when SEM observation of the positive electrode active material was performed in the same manner as the composite hydroxide particles, it was confirmed from the SEM photograph that the obtained positive electrode active material was substantially spherical and had a uniform particle size. It was done.
Moreover, when the obtained positive electrode active material was analyzed by the powder X-ray diffraction by Cu-K (alpha) ray, it was confirmed that it is a cubic lithium manganese nickel complex oxide single phase which has a spinel structure.
The positive electrode active material has a composition of Li 3.9 mass%, Ni 16.3 mass%, and Mn 46.1 mass% according to chemical analysis, and Li _1.003 Ni _0.5 Mn _1.5 It was confirmed to be O ₄ .

(Battery evaluation)
When a charge / discharge test was performed on the coin-type battery 1 having the positive electrode formed using the positive electrode active material, as shown in FIG. 5, the initial discharge of the coin-type battery 1 at 3.0 to 4.9 V was performed. The capacity was 125.5 mAh / g. The positive electrode resistance value was 18.3Ω.

  Hereinafter, about Examples 2-7 and Comparative Examples 1-5, only the substance and conditions changed from the said Example 1 are shown. Moreover, the result of each evaluation of Examples 2-7 and Comparative Examples 1-5 was shown in FIG.

(Example 2)
A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 1 except that the firing temperature was 750 ° C. by mixing so that Li / Me = 0.55.

(Example 3)
In the same manner as in Example 1 except that nucleation was performed with a crystallization time of 30 seconds as a pH value measured with a liquid temperature of 25 ° C. as a reference in the composite hydroxide production process, A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated.

Example 4
In the composite hydroxide production process, in addition to manganese sulfate and nickel sulfate, sodium tungstate was dissolved in water to form a 1.8 mol / L mixed aqueous solution. In this mixed aqueous solution, the element molar ratio of each metal was adjusted to be Mn: Ni: W = 0.75: 0.25: 0.005. Other than that was carried out similarly to Example 1, and obtained and evaluated the positive electrode active material for nonaqueous electrolyte secondary batteries.

(Example 5)
In the composite hydroxide production process, zirconium sulfate was dissolved in water in addition to manganese sulfate and nickel sulfate to form a 1.8 mol / L mixed aqueous solution. In this mixed aqueous solution, the element molar ratio of each metal was adjusted to be Mn: Ni: Zr = 0.75: 0.25: 0.005. Other than that was carried out similarly to Example 1, and obtained and evaluated the positive electrode active material for nonaqueous electrolyte secondary batteries.

(Example 6)
A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 1 except that mixing was performed so that Li / Me = 0.48.

(Example 7)
In the composite hydroxide production process, the temperature in the tank is 50 ° C., the ammonia concentration is 20 g / l, the pH of the solution is 13.4 as the pH value measured on the basis of the solution temperature 25 ° C., the crystallization time is 30 seconds, and the nucleus A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 1 except that the generation was performed.

(Comparative Example 1)
Using a reaction tank for continuous crystallization provided with an overflow pipe at the top, while maintaining the pH of the liquid at a constant value of 11.0 as a pH value measured on the basis of a liquid temperature of 25 ° C., the same as in Example 1 The metal salt solution, the aqueous ammonia solution and the neutralizing solution were continuously added at a constant flow rate, and crystallization was performed by a general method for continuously recovering the overflowing slurry. The non-aqueous electrolyte was the same as in Example 1 except that the average residence time in the tank was 10 hours and the slurry was recovered after the equilibrium in the continuous tank and solid-liquid separation was performed to obtain a crystallized product. A positive electrode active material for a secondary battery was obtained and evaluated.

(Comparative Example 2)
The positive electrode active for a non-aqueous electrolyte secondary battery is the same as in Example 1 except that the pH during nucleation and growth is maintained at a constant value of 11.6 as a pH value measured with a liquid temperature of 25 ° C. The material was obtained and evaluated.

(Comparative Example 3)
Manganese nickel composite hydroxide was obtained in the same manner as in Example 1 except that the pH value during nucleation and growth was maintained at a constant value of 12.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference. .
Since new nuclei were formed during the entire crystallization reaction, the particles were indefinitely shaped with a wide particle size distribution and containing gel-like precipitates, so that solid-liquid separation was difficult and the treatment was stopped.

(Comparative Example 4)
A positive electrode active material for a nonaqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 1 except that the firing temperature was 900 ° C. From the result of X-ray diffraction measurement, the peak of Li2MnO3, which is a different phase, was strongly recognized, and the performance as a positive electrode active material was not expected, so the battery evaluation was not performed.

(Comparative Example 5)
A positive electrode active material for a nonaqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 1 except that the firing temperature was 500 ° C.

(Example 8)
(Hydroxide production process)
The hydroxide was prepared as follows using the method of the present invention.
First, the temperature in the tank was set to 40 ° C. while stirring by putting half the amount of water in the reaction tank (34L), and a nitrogen atmosphere was passed through the reaction tank to form a nitrogen atmosphere. At this time, the oxygen concentration in the reaction vessel space was 2.0%.

  Appropriate amounts of 25% aqueous sodium hydroxide and 25% aqueous ammonia are added to the water in the reaction tank, and the pH of the reaction liquid in the tank is 12.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference. Adjusted. The ammonia concentration in the reaction solution was adjusted to 15 g / L.

(Nucleation process)
Next, manganese sulfate was dissolved in water to form a 1.8 mol / L aqueous solution. The aqueous solution was added to the reaction solution in the reaction vessel at 88 ml / min. Simultaneously, 25% aqueous ammonia and 25% aqueous sodium hydroxide solution were also added to the reaction solution in the reaction tank at a constant rate, and the pH value was adjusted to 12.6 (with the ammonia concentration in the reaction solution kept at the above value). Crystallization was carried out for 2 minutes and 30 seconds while controlling the nucleation pH value) to carry out nucleation.

(Particle growth process)
Thereafter, only the supply of the 25% aqueous sodium hydroxide solution was temporarily stopped until the pH value of the reaction solution reached 11.6 (particle growth pH value) as a pH value measured with a liquid temperature of 25 ° C. as a reference.
After the pH value of the reaction solution reached 11.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference, the supply of 25% sodium hydroxide aqueous solution was resumed and the pH value was controlled to 11.6. The crystallization was continued for 2 hours and particle growth was performed.

  Crystallization was stopped when the reaction tank was full, and stirring was stopped and the mixture was allowed to stand to promote precipitation of the product. Then, after extracting half amount of the supernatant from the reaction tank, crystallization was resumed, and after crystallization for 2 hours (4 hours in total), crystallization was terminated. The product was washed with water, filtered, and dried to obtain particles.

As shown in FIG. 5, when the particle size distribution of the hydroxide particles was measured, the average particle size was 4.1 μm, and the [(d90−d10) / average particle size] value was 0.48.
From the SEM photograph which is the SEM (Hitachi High-Technologies scanning electron microscope S-4700) observation result of the obtained hydroxide particle, the obtained hydroxide particle is substantially spherical, and the particle size is almost the same. It was confirmed that they were evenly aligned.

(Cathode active material manufacturing process)
The hydroxide particles were heat-treated at a temperature of 150 ° C. for 15 hours in an air (oxygen: 21% by volume) air stream to recover the oxide particles.
Lithium hydroxide was weighed so that Li / Me = 0.50 and mixed with the collected oxide particles to form a mixture. Mixing was performed using a shaker mixer apparatus (TURBULA Type T2C manufactured by Willy et Bacofen (WAB)).
The obtained mixture was baked in an oxygen stream at 800 ° C. for 20 hours, cooled, and crushed to obtain a positive electrode active material.

As shown in FIG. 5, when the particle size distribution of the obtained positive electrode active material was measured, the average particle size was 4.4 μm, and the [(d90−d10) / average particle size] value was 0.53. .
Further, when SEM observation of the positive electrode active material was performed by the same method as that of the hydroxide particles, it was confirmed from the SEM photograph that the obtained positive electrode active material was substantially spherical and had a uniform particle size. It was.
Moreover, when the obtained positive electrode active material was analyzed by the powder X-ray diffraction by Cu-K (alpha) ray, it was confirmed that it is a cubic lithium manganese complex oxide single phase which has a spinel structure.
Then, the positive electrode active material, by chemical _analysis, it was confirmed that the Li _{1.00 Mn} 2.0 _{O 4.}

(Battery evaluation)
When a charge / discharge test was performed on the coin-type battery 1 having the positive electrode formed using the positive electrode active material, as shown in FIG. 5, the initial discharge of the coin-type battery 1 at 3.0 to 4.3 V was performed. The capacity was 130.2 mAh / g. The capacity retention rate after 100 cycles was 91%. The positive electrode resistance value was 22.1Ω.

  Hereinafter, about Examples 9-14 and Comparative Examples 6-10, only the substance and conditions changed from the said Example 8 are shown. Moreover, the result of each evaluation of Examples 9-14 and Comparative Examples 6-10 is shown in FIG.

Example 9
A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that the firing temperature was 750 ° C. by mixing so that Li / Me = 0.55.

(Example 10)
A positive electrode active material for a nonaqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that nucleation was performed with a crystallization time of 30 seconds in the hydroxide production process.

(Example 11)
In the hydroxide production process, in addition to manganese sulfate, sodium tungstate was dissolved in water to form a 1.8 mol / L mixed aqueous solution. In this mixed aqueous solution, the element molar ratio of each metal was adjusted to be Mn: W = 1.0: 0.005. Other than that was carried out similarly to Example 8, and obtained and evaluated the positive electrode active material for nonaqueous electrolyte secondary batteries.

(Example 12)
In the hydroxide production process, zirconium sulfate was dissolved in water in addition to manganese sulfate to form a 1.8 mol / L mixed aqueous solution. In this mixed aqueous solution, the element molar ratio of each metal was adjusted to be Mn: Zr = 1.0: 0.005. Other than that was carried out similarly to Example 8, and obtained and evaluated the positive electrode active material for nonaqueous electrolyte secondary batteries.

(Example 13)
A positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that mixing was performed so that Li / Me = 0.48.

(Example 14)
In the hydroxide production process, a positive electrode active material for a non-aqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that the bath temperature was 50 ° C. and the ammonia concentration was 20 g / l.

(Comparative Example 6)
Using a reaction tank for continuous crystallization provided with an overflow pipe at the top, while maintaining the pH of the liquid at a constant value of 11.0 as a pH value measured on the basis of a liquid temperature of 25 ° C., the same as in Example 8. The metal salt solution, the aqueous ammonia solution and the neutralizing solution were continuously added at a constant flow rate, and crystallization was performed by a general method for continuously recovering the overflowing slurry. The non-aqueous electrolyte was the same as in Example 8, except that the average residence time in the tank was 10 hours, and the slurry was collected after the equilibrium in the continuous tank and solid-liquid separation was performed to obtain a crystallized product. A positive electrode active material for a secondary battery was obtained and evaluated.

(Comparative Example 7)
The positive electrode active for a non-aqueous electrolyte secondary battery was carried out in the same manner as in Example 8 except that the pH during nucleation and growth was maintained at a constant value of 11.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference. The material was obtained and evaluated.

(Comparative Example 8)
Manganese hydroxide was obtained in the same manner as in Example 8, except that the pH value during nucleation and growth was maintained at a constant value of 12.6 as a pH value measured with a liquid temperature of 25 ° C. as a reference.
Since new nuclei were formed during the entire crystallization reaction, it became an aggregate of irregular particles containing fine particles with a wide particle size distribution, and solid-liquid separation was difficult and the treatment was stopped.

(Comparative Example 9)
A positive electrode active material for a nonaqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that the firing temperature was 900 ° C. From the result of X-ray diffraction measurement, the peak of Li2MnO3, which is a different phase, was strongly recognized, and the performance as a positive electrode active material was not expected, so the battery evaluation was not performed.

(Comparative Example 10)
A positive electrode active material for a nonaqueous electrolyte secondary battery was obtained and evaluated in the same manner as in Example 8 except that the firing temperature was 500 ° C.

(Evaluation)
Since the composite hydroxide particles and the positive electrode active materials of Examples 1 to 14 were produced according to the present invention, the average particle size and the distribution of the particle size distribution are [(d90-d10) / average particle size] values. All of them are in a preferable range, and are particles having a good particle size distribution and a substantially uniform particle size. The coin-type battery 1 using these positive electrode active materials has a high initial discharge capacity, excellent cycle characteristics, low positive electrode resistance, and has excellent characteristics.

In Comparative Example 1, since the continuous crystallization method is used, nucleation and particle growth cannot be separated, and the particle growth time is not constant, so that the particle size distribution is wide. For this reason, the coin-type battery 1 has a high initial discharge capacity, but has a poor positive electrode resistance.
In Comparative Example 2, since the pH values at the time of nucleus growth and particle growth were both set to pH 12 or less, the amount of nucleation was insufficient, and both the composite hydroxide particles and the positive electrode active material had large particle sizes. For this reason, the coin-type battery 1 using this positive electrode active material has a high positive electrode resistance due to insufficient reaction surface area.
In Comparative Example 3, since the pH value at the time of nucleation growth and particle growth was set to pH 12 or more, new nuclei were generated throughout the crystallization reaction, and the particles were refined and aggregated, so that the particle size distribution was widened. Further, it has become difficult to produce a positive electrode active material.

  In Comparative Examples 4 and 5, since the manufacturing process of the positive electrode active material did not comply with the present invention, in Comparative Example 4, a heterogeneous phase was generated and performance as a positive electrode active material could not be expected. Moreover, in the comparative example 5, the coin-type battery 1 using this positive electrode active material has a large positive electrode resistance, and the initial discharge capacity is also deteriorated.

In Comparative Example 6, since the continuous crystallization method was used, nucleation and particle growth could not be separated, and the particle growth time was not constant, so the particle size distribution was wide. For this reason, although the coin-type battery 1 has a high initial discharge capacity, the cycle characteristics are poor and the positive electrode resistance is also poor.
In Comparative Example 7, since the pH value at the time of nucleation growth and particle growth was set to pH 12 or less, the amount of nucleation was insufficient, and both the hydroxide particles and the positive electrode active material had a large particle size. For this reason, the coin-type battery 1 using the positive electrode active material has a high positive electrode resistance due to a lack of a reaction surface area, and also has deteriorated cycle characteristics.
In Comparative Example 8, since the pH value at the time of nucleus growth and particle growth was set to pH 12 or more, new nuclei were generated during the entire crystallization reaction, and the particles were refined and aggregated. Further, it has become difficult to produce a positive electrode active material.

  In Comparative Examples 9 and 10, since the manufacturing process of the positive electrode active material did not comply with the present invention, in Comparative Example 9, a heterogeneous phase was generated and performance as a positive electrode active material could not be expected. Therefore, battery evaluation was not performed. Moreover, in the comparative example 10, the coin-type battery 1 using this positive electrode active material has a high positive electrode resistance, and the initial discharge capacity is also deteriorated.

From the above results, if the manganese composite hydroxide particles and the positive electrode active material are produced using the production method of the present invention, the nonaqueous electrolyte secondary battery using this positive electrode active material has a high initial discharge capacity, It can be confirmed that the cycle characteristics are good and the positive electrode resistance is low, and the battery has excellent characteristics.

The non-aqueous electrolyte secondary battery of the present invention is suitable for a power source of a small portable electronic device (such as a notebook personal computer or a mobile phone terminal) that always requires a high capacity, and an electric vehicle battery that requires a high output. Also suitable.
In addition, the nonaqueous electrolyte secondary battery of the present invention has excellent safety, and can be downsized and increased in output, and thus is suitable as a power source for an electric vehicle subject to restrictions on mounting space.
The present invention can be used not only as a power source for an electric vehicle driven purely by electric energy but also as a power source for a so-called hybrid vehicle used in combination with a combustion engine such as a gasoline engine or a diesel engine.

DESCRIPTION OF SYMBOLS 1 Coin type battery 2 Case 3 Electrode 3a Positive electrode 3b Negative electrode 3a Separator

Claims (19)

Formula _{Mn 1-x-y Ni x} M y (OH) 2 + α (0 ≦ x ≦ 0.27,0 ≦ y ≦ 0.05,0 ≦ α ≦ 0.5 by crystallization reaction, M is the additional element And a manufacturing method for manufacturing a manganese composite hydroxide represented by Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W). ,
Nucleation is controlled by controlling an aqueous solution for nucleation containing a metal compound containing at least manganese and an ammonium ion supplier so that the pH value measured based on a liquid temperature of 25 ° C. is 12.0 to 14.0. A nucleation process to be performed;
Particles for growing the nuclei by controlling the aqueous solution for particle growth containing nuclei formed in the nucleation step so that the pH value measured on the basis of a liquid temperature of 25 ° C. is 10.5 to 12.0. A growth process,
A method for producing manganese composite hydroxide particles for a positive electrode active material for a non-aqueous electrolyte secondary battery, wherein the pH in the particle growth step is controlled to be lower than the pH in the nucleation step. The range of x in the said general formula is 0.23 <= x <= 0.27, The manufacturing method of the manganese composite hydroxide particle for nonaqueous electrolyte secondary battery positive electrode active materials of Claim 1 characterized by the above-mentioned. The aqueous solution for particle growth is
3. The manganese composite water for a positive electrode active material of a non-aqueous electrolyte secondary battery according to claim 1, wherein the nucleation step is performed by adjusting a pH value of the nucleation aqueous solution. A method for producing oxide particles. The aqueous solution for particle growth is
The non-aqueous system according to claim 1 or 2, wherein the aqueous solution containing nuclei formed in the nucleation step is added to an aqueous solution different from the aqueous solution for nucleation forming the nuclei. The manufacturing method of the manganese composite hydroxide particle for electrolyte secondary battery positive electrode active materials. The non-aqueous electrolyte secondary battery according to any one of claims 1 to 4, wherein after the nucleation step, a part of the liquid part of the aqueous solution for particle growth is discharged and then the particle growth step is performed. A method for producing manganese composite hydroxide particles for a positive electrode active material. 6. The manganese for a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the temperature of each aqueous solution is maintained at 20 ° C. or higher in the nucleation step and the particle growth step. A method for producing composite hydroxide particles. The nonaqueous electrolyte secondary according to any one of claims 1 to 6, wherein the ammonia concentration of each aqueous solution is maintained within a range of 3 to 25 g / L in the nucleation step and the particle growth step. A method for producing manganese composite hydroxide particles for battery positive electrode active materials. The non-aqueous electrolyte secondary battery according to claim 1, wherein the manganese composite hydroxide obtained in the particle growth step is coated with a compound containing one or more kinds of the additive elements. A method for producing manganese composite hydroxide particles for a positive electrode active material. Formula _{Mn 1-x-y Ni x} M y (OH) 2 + α (0 ≦ x ≦ 0.27,0 ≦ y ≦ 0.05,0 ≦ α ≦ 0.5, M is additive element, Mg, A spherical secondary formed by agglomeration of a plurality of plate-like primary particles expressed by one or more elements selected from Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, and W) Particles,
The secondary particles are
Non-aqueous electrolyte secondary battery positive electrode active, characterized in that the average particle diameter is 3 to 7 μm and [(d90-d10) / average particle diameter], which is an index indicating the spread of the particle size distribution, is 0.55 or less Manganese composite hydroxide particles for substances. The range of x in the said general formula is 0.23 <= x <= 0.27, The manganese composite hydroxide particle for nonaqueous electrolyte secondary battery positive electrode active materials of Claim 9 characterized by the above-mentioned. The secondary particles are
The manganese for a non-aqueous electrolyte secondary battery positive electrode active material according to claim 9 or 10, wherein the one or more additive elements are uniformly distributed and / or uniformly coated on the surface thereof. Composite hydroxide particles. The manganese composite hydroxide particles for a non-aqueous electrolyte secondary battery positive electrode active material according to any one of claims 9 to 11, wherein the manganese composite hydroxide particles are produced by the production method according to any one of claims 1 to 8. . _{Formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4 (-0.05 ≦ t ≦ 0.1,0 ≦ x ≦ 0.55,0 ≦ y ≦ 0.1, M is added Cubic lithium-manganese composite oxide having a spinel structure represented by Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W) A method for producing a positive electrode active material comprising:
Heat treating the manganese composite hydroxide particles of any one of claims 9 to 12,
A mixing step of mixing the lithium compound with the particles after the heat treatment to form a mixture;
The manufacturing method of the positive electrode active material for nonaqueous electrolyte secondary batteries characterized by having the baking process which bakes the said mixture formed at this mixing process at the temperature of 600 to 850 degreeC. The range of x in the general formula is represented by 0.45 ≦ x ≦ 0.55, and is a method for producing a positive electrode active material comprising a cubic lithium manganese composite oxide having a spinel structure,
Heat treating the manganese composite hydroxide particles at a temperature of 700 ° C. to 1000 ° C .;
A mixing step of mixing the lithium compound with the particles after the heat treatment to form a mixture;
The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 13, further comprising a firing step of firing the mixture formed in the mixing step at a temperature of 600 ° C. to 850 ° C. The mixture is
The ratio of the sum of the number of atoms of metals other than lithium contained in the mixture to the number of atoms of lithium is adjusted to be 2: 0.95 to 1.10. The manufacturing method of the positive electrode active material for non-aqueous electrolyte secondary batteries of description. _{Formula: Li 1 + t Mn 2-} x-y-t Ni x M y O 4 (-0.05 ≦ t ≦ 0.1,0 ≦ x ≦ 0.55,0 ≦ y ≦ 0.1, M is added Cubic lithium-manganese composite oxide having a spinel structure represented by Mg, Ca, Ba, Sr, Ti, V, Cr, Zr, Nb, Mo, W) A positive electrode active material comprising a material,
A positive electrode for a non-aqueous electrolyte secondary battery having an average particle diameter of 2 to 8 μm and an index ((d90-d10) / average particle diameter) indicating a spread of particle size distribution of 0.60 or less Active material. The range of x in the said general formula is 0.45 <= x <= 0.55, The positive electrode active material for nonaqueous electrolyte secondary batteries of Claim 16 characterized by the above-mentioned. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 16 or 17, wherein the positive electrode active material is produced by the production method according to any one of claims 13 to 15. The positive electrode
A non-aqueous electrolyte secondary battery characterized by being formed of the positive electrode active material for a non-aqueous electrolyte secondary battery according to any one of claims 16 to 18.